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Noonan, Timothy, Michael Pinzur, Odysseas Paxinos, Robert Havey, and Avinash Patwardhin. "Tibiotalocalcaneal Arthrodesis With a Retrograde Intramedullary Nail: A Biomechanical Analysis of the Effect of Nail Length." Foot & Ankle International 26, no. 4 (2005): 304–8. http://dx.doi.org/10.1177/107110070502600406.
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Background: Fatigue fractures of the tibia have been observed at the level of the proximal end of the nail after successful tibiocalcaneal arthrodesis with a retrograde intramedullary device. Materials: To study the effect of nail length, five matched pairs of cadaver tibiae were instrumented with strain gauges and potted in methyl-methacrylate from a level 3 cm proximal to the distal medial malleolus to simulate a successful tibiocalcaneal arthrodesis. A standard length (15 cm) ankle arthrodesis nail and an identical longer device terminating in the proximal tibial metaphysis were inserted in each paired tibia using appropriate technique. The strain of the posterior cortex of the tibia was recorded under bending moments of up to 50 Nm for each intact specimen after nail insertion and after proximal locking of the nail. The nails were then exchanged between the specimens of the same pairs and the experiment was repeated to insure uniformity. Results: The standard length locked nail increased the principal strain of the posterior cortex of the tibia at the level of the proximal screw holes 5.3 times more than the locked long nail (353 and 67 microstrains), respectively. This stress concentration was not observed when the proximal extent of the nail terminated within the proximal tibial metaphysis. Conclusion: A successful tibiocalcaneal arthrodesis with a standard length locked intramedullary nail creates stress concentration around the proximal screw holes that may be responsible for the fractures observed clinically. This study supports the use of a “long” retrograde locked intramedullary nail for tibiocalcaneal arthrodesis in patients with systemic or localized osteopenia.
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T, Sreenivas. "Congenital Distal Tibiofibular Synostosis - A Case Report." International Journal of Health Sciences and Research 11, no. 9 (2021): 178–80. http://dx.doi.org/10.52403/ijhsr.20210927.
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Congenital tibiofibular synostosis is the fusion of tibia and fibula since birth. So far there are many reports of congenital proximal tibio fibular synostosis in English literature, but congenital distal tibio fibular synostosis is very rarely described. Imaging studies by means of X rays, CT and MRI are required to rule out osteochondromas arising from distal tibia, fibula and other conditions. If the patient is symptomatic by means of deformity surgical intervention in the form of corrective osteotomy may be considered to prevent alternation of joint biomechanics. We report a rare case of congenital distal tibiofibular synostosis in a 21 year old female presented with complaints of deformity and pain on and off in left lower leg since childhood. Key words: Congenital; Synostosis; Deformity; Osteochondroma.
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Watson, David, and Roy Sanders. "Locking Plates: Biology, Biomechanics, and Application to the Proximal Tibia." Techniques in Orthopaedics 22, no. 4 (2007): 197–202. http://dx.doi.org/10.1097/bto.0b013e31814b2450.
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Yoganandan, N., F. A. Pintar, S. Kumaresan, and M. Boynton. "Axial Impact Biomechanics of the Human Foot-Ankle Complex." Journal of Biomechanical Engineering 119, no. 4 (1997): 433–37. http://dx.doi.org/10.1115/1.2798290.
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Recent epidemiological, clinical, and biomechanical studies have implicated axial impact to the plantar surface of the foot to be a cause of lower extremity trauma in vehicular crashes. The present study was conducted to evaluate the biomechanics of the human foot–ankle complex under axial impact. Nine tests were conducted on human cadaver below knee–foot–ankle complexes. All specimens were oriented in a consistent anatomical position on a mini-sled and the impact load was delivered using a pendulum. Specimens underwent radiography and gross dissection following the test. The pathology included intra-articular fractures of the calcaneus and/or the distal tibia complex with extensions into the anatomic joints. Impactor load cell forces consistently exceeded the tibial loads for all tests. The mean dynamic forces at the plantar surface of the foot were 7.7 kN (SD = 4.3) and 15.1 kN (SD = 2.7) for the nonfracture and fracture tests, respectively. In contrast, the mean dynamic forces at the proximal tibial end of the preparation were 5.2 kN (SD = 3.1) in the nonfracture group, and 10.2 kN (SD = 1.5) in the fracture group. The foot and tibial end forces were statistically significantly different between these two groups (p < 0.01). The present investigation provides fundamental data to the understanding of the biomechanics of human foot–ankle trauma. Quantifying the effects of other factors such as gender and bone quality on the injury thresholds is necessary to understand foot–ankle tolerance fully.
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Kang, KwanSu, Young Woong Jang, Oui Sik Yoo, et al. "Biomechanical Characteristics of Three Baseplate Rotational Arrangement Techniques in Total Knee Arthroplasty." BioMed Research International 2018 (June 6, 2018): 1–11. http://dx.doi.org/10.1155/2018/9641417.
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Introduction. Several ongoing studies aim to improve the survival rate following total knee arthroplasty (TKA), which is an effective orthopedic surgical approach for patients with severely painful knee joint diseases. Among the studied strategies, baseplate rotational arrangement techniques for TKA components have been suggested but have been the subject of only simple reliability evaluations. Therefore, this study sought to evaluate comparatively three different baseplate rotational arrangement techniques that are commonly used in a clinical context. Materials and Methods. Three-dimensional (3D) finite element (FE) models of the proximal tibia with TKA were developed and analyzed considering three baseplate rotational arrangement techniques (anterior cortex line, tibial tuberosity one-third line, and tibial tuberosity end line) for six activities of daily life (ADLs) among patients undergoing TKA. Mechanical tests based on the ASTM F1800 standard to validate the FE models were then performed using a universal testing machine. To evaluate differences in biomechanical characteristics according to baseplate rotational arrangement technique, the strain and peak von Mises stresses (PVMSs) were assessed. Results. The accuracy of the FE models used in this study was high (94.7 ± 5.6%). For the tibial tuberosity one-third line rotational arrangement technique, strains ≤ 50 µstrain (the critical bone damage strain, which may affect bone remodeling) accounted for approximately 2.2%–11.3% and PVMSs within the bone cement ranged from 19.4 to 29.2 MPa, in ADLs with high loading conditions. For the tibial tuberosity end line rotational arrangement, strains ≤ 50 µstrain accounted for approximately 2.3%–13.3% and PVMSs within the bone cement ranged from 13.5 to 26.7 MPa. For anterior cortex line rotational arrangement techniques, strains ≤50 µstrain accounted for approximately 10.6%–16.6% and PVMSs within the bone cement ranged from 11.6 to 21.7 MPa. Conclusion. The results show that the most recently developed frontal cortex line rotational alignment technique is the same or better than the other two rotational alignment techniques in terms of biomechanics. This finding can be, however, dependent on the contact characteristics between the baseplate and the proximal tibia. That is, it is indicated that the optimum baseplate rotational arrangement technique in terms of reducing the incidence of TKA mechanical failure can be achieved by adjusting the characteristics of contact between the baseplate and the proximal tibia.
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Kraeutler, Matthew J., K. Linnea Welton, Jorge Chahla, Robert F. LaPrade, and Eric C. McCarty. "Current Concepts of the Anterolateral Ligament of the Knee: Anatomy, Biomechanics, and Reconstruction." American Journal of Sports Medicine 46, no. 5 (2017): 1235–42. http://dx.doi.org/10.1177/0363546517701920.
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In 1879, Paul Segond described an avulsion fracture (now known as a Segond fracture) at the anterolateral proximal tibia with the presence of a fibrous band at the location of this fracture. Although references to this ligament were occasionally made in the anatomy literature after Segond’s discovery, it was not until 2012 that Vincent et al named this ligament what we know it as today, the anterolateral ligament (ALL) of the knee. The ALL originates near the lateral epicondyle of the distal femur and inserts on the proximal tibia near Gerdy’s tubercle. The ALL exists as a ligamentous structure that comes under tension during internal rotation at 30°. In the majority of specimens, the ALL can be visualized as a ligamentous structure, whereas in some cases it may only be palpated as bundles of more tense capsular tissue when internal rotation is applied. Biomechanical studies have shown that the ALL functions as a secondary stabilizer to the anterior cruciate ligament (ACL) in resisting anterior tibial translation and internal tibial rotation. These biomechanical studies indicate that concurrent reconstruction of the ACL and ALL results in significantly reduced internal rotation and axial plane tibial translation compared with isolated ACL reconstruction (ACLR) in the presence of ALL deficiency. Clinically, a variety of techniques are available for ALL reconstruction (ALLR). Current graft options include the iliotibial (IT) band, gracilis tendon autograft or allograft, and semitendinosus tendon autograft or allograft. Fixation angle also varies between studies from full knee extension to 60° to 90° of flexion. To date, only 1 modern study has described the clinical outcomes of concomitant ALLR and ACLR: a case series of 92 patients with a minimum 2-year follow-up. Further studies are necessary to define the ideal graft type, location of fixation, and fixation angle for ALLR. Future studies also must be designed in a prospective comparative manner to compare the clinical outcomes of patients undergoing ACLR with ALL reconstruction versus without ALL reconstruction. By discovering the true effect of the ALL, investigators can elucidate the importance of ALLR in the setting of an ACL tear.
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Cristescu, Ioan, Cristi Angheluta, Florin Safta, et al. "The Outcome of Tricalcium Phosphate Wedges Used in Opening High Tibial Osteotomy." Key Engineering Materials 695 (May 2016): 139–43. http://dx.doi.org/10.4028/www.scientific.net/kem.695.139.
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In the case of patients suffering from medial compartment osteoarthritis of the knee, a high tibial osteotomy is the preferred treatment for preserving the knee articulation and correcting the knee biomechanical axis. Nowadays, the open wedge high tibial osteotomy is the preferred surgical technique for treating patient with varus knee angulation. The procedure consists in creating a medial gap in the proximal tibial metaphysis that is filled with autologus bone graft or bone substitutes. Synthetic bone substitutes made by bioceramics like hydroxyapatite or tricalcium phosphate are becoming more popular. Tricalcium phosphate (TCP) used as a bone substitute has shown to have osteoconductive properties and it is resorbable. We describe our experience in Orthopaedics III Department of the Clinical Emergency Hospital Bucharest, where we treated a total of 26 patients suffering from medial compartment osteoarthritis of the knee with high tibial open wedge osteotomy, between 2011 and 2015. TCP wedge implants were successfully used as bone substitutes for the tibial medial osteotomy in conjunction with a proximal tibia plate and screws. Open wedge high tibia osteotomy used for correcting the biomechanical axis of the lower limb is a safe surgical procedure that preserves the anatomical knee joint.
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Kim, Joong Il, Bo Hyun Kim, Hyuk Soo Han, and Myung Chul Lee. "Rotational Changes in the Tibia After High Tibial Valgus Osteotomy: A Comparative Study of Lateral Closing Versus Medial Opening Wedge Osteotomy." American Journal of Sports Medicine 48, no. 14 (2020): 3549–56. http://dx.doi.org/10.1177/0363546520960114.
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Background: After high tibial valgus osteotomy (HTO), rotational changes in the tibia may occur, which can affect the biomechanics of the patellofemoral joint and may lead to anterior knee pain. Purpose: To compare the rotational changes in the tibia between closing wedge HTO (CWHTO) and opening wedge HTO (OWHTO). Study Design: Cohort study; Level of evidence, 3. Methods: Among the patients who underwent HTO between May 2012 and August 2015, 53 (28 CWHTO and 25 OWHTO) who had computed tomography scans before and at 1 year after the HTO were included. The following parameters were compared between CWHTO and OWHTO: (1) tibial torsion angle, (2) knee rotation angle, and (3) tibial tuberosity–trochlear groove (TT-TG) distance. During the last follow-up, patients were asked to rate their anterior knee pain when climbing the stairs, using the visual analog scale. Results: The tibial torsion angle significantly decreased (internal rotation of the distal fragment) after CWHTO (mean ± SD, –2.1°± 4.1°; P = .019) and OWHTO (–1.8°± 3.3°; P = .029). The knee rotation angle significantly decreased (external rotation of the proximal fragment) after OWHTO (–1.8°± 3.4°; P = .039) but was not changed after CWHTO (0.1°± 3.1°; P = .859). The mean TT-TG distance significantly decreased after CWHTO (–3.1 ± 3.0 mm; P < .001) but increased after OWHTO (2.0 ± 4.3 mm; P = .012). At the final follow-up (minimum, 4 years), the visual analog scale pain score during stair climbing was significantly higher after OWHTO than after CWHTO (3.1 ± 1.4 vs 2.2 ± 1.3, P = .024). Conclusion: Internal rotation of the distal fragment occurred after both CWHTO and OWHTO. However, external rotation of the proximal fragment and increased TT-TG distance occurred after OWHTO. Because such rotational changes could affect anterior knee pain, further studies are warranted to investigate the definite relationship between tibial rotational changes and anterior knee pain after HTO.
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HARMAN, MELINDA K., SCOTT A. BANKS, BENJAMIN J. FREGLY, W. GREGORY SAWYER, and W. ANDREW HODGE. "BIOMECHANICAL MECHANISMS FOR DAMAGE: RETRIEVAL ANALYSIS AND COMPUTATIONAL WEAR PREDICTIONS IN TOTAL KNEE REPLACEMENTS." Journal of Mechanics in Medicine and Biology 05, no. 03 (2005): 469–75. http://dx.doi.org/10.1142/s0219519405001588.
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Damage patterns on the articular surface of the proximal tibia, including cartilage degeneration in osteoarthritic knees and damage of polyethylene knee prostheses after total knee replacement, provide information related to knee joint biomechanics and damage mechanisms at the articular surface. This study reports articular damage patterns and knee kinematics assessed in the knees of older subjects, before and after total knee replacement. The damage patterns are used to evaluate computational dynamic contact and tribological models that predict polyethylene damage in a patient-specific total knee replacement model.
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Bhat, S. A., P. Kinjavdekar, M. M. S. Zama, et al. "An in vitro biomechanical investigation of an interlocking nail system developed for buffalo tibia." Veterinary and Comparative Orthopaedics and Traumatology 27, no. 01 (2014): 36–44. http://dx.doi.org/10.3415/vcot-12-12-0149.
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SummaryObjectives: The objectives of the study were to determine the mechanical properties of a customized buffalo interlocking nail (BIN), intact buffalo tibia, and ostectomized tibia stabilized with BIN in different configurations, as well as to assess the convenience of interlocking nailing in buffalo tibia.Methods: The BIN (316L stainless steel, 12 mm diameter, 250 mm long, nine-hole solid nails with 10° proximal bend) alone was loaded in compression and three-point bending (n = 4 each); intact tibiae and ostectomized tibiae (of buffaloes aged 5–8 years, weighing 300–350 kg) stabilized with BIN using 4.9 mm standard or modified locking bolts (4 or 8) in different configurations were subjected to axial compression, cranio-caudal three-point bending and torsion (n = 4 each) using a universal testing machine. Mechanical parameters were determined from load-displacement curves and compared using Kruskal-Wallis test (p <0.05).Results: Intact tibiae were significantly stronger than BIN and bone-BIN constructs in all testing modes. The strength of fixation constructs with eight locking bolts was significantly more than with four bolts. Overall strength of fixation with modified locking bolts was better than standard bolts. Based on technical ease and biomechanical properties, cranio-caudal insertion of bolts into the bone was found better than medio-lateral insertion.Clinical significance: The eight bolt BINbone constructs could be useful to treat tibial fractures in large ruminants, especially buffaloes.
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Galanis, Dimitrios, Konstantinos Soultanis, Pavlos Lelovas, et al. "Protective effect ofGlycyrrhiza glabraroots extract on bone mineral density of ovariectomized rats." BioMedicine 9, no. 2 (2019): 8. http://dx.doi.org/10.1051/bmdcn/2019090208.
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Objective: The aim of this study was to evaluate the potential effect of the methanolic extract of plantGlycyrrhiza glabraroots on bone mineral density and femoral bone strength of ovariectomized rats.Methods: Thirty 10-month-old Wistar rats were randomly separated into three groups of ten, Control, Ovariectomy and Ovariectomy-plus-Glycyrrhiza in their drinking water. Total and proximal tibial bone mineral density was measured in all groups before ovariectomy (baseline) and after 3 and 6 months post ovariectomy. Three-point-bending of the femurs and uterine weight and histology were examined at the end of the study.Results: No significant difference was noted in bone density percentage change of total tibia from baseline to 3 months between Control and Ovariectomy-plus-Glycyrrhiza groups (+5.31% ± 4.75 and +3.30% ± 6.31 respectively,P = non significant), and of proximal tibia accordingly (+5.58% ± 6.92 and +2.61% ± 13.62,P = non significant) demonstrating a strong osteoprotective effect. There was notable difference in percentage change of total tibia from baseline to 6 months between groups Ovariectomy and Ovariectomy-plus-Glycyrrhiza (−13.03% ± 5.11 and −0.84% ± 7.63 respectively,P < 0.005), and of proximal tibia accordingly (−27.9% ± 3.69 and −0.81% ± 14.85 respectively,P < 0.001), confirming the protective effect ofGlycyrrhiza glabraextract in preserving bone density of the Ovariectomy-plus-Glycyrrhiza group. Three-point-bending did not reveal any statistically significant difference between Ovariectomy and Ovariectomy-plus-Glycyrrhiza groups. Uterine weights of the Ovariectomy-plus-Glycyrrhiza group ranged between the other two groups with no statistically significant difference to each.Conclusions:Glycyrrhiza glabraroot extract notably protected tibial bone mineral density loss in Ovariectomy-plus-Glycyrrhiza rats in comparison with ovariectomized rats, but did not improve biomechanical strength.
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Ting, Arthur J., Richard R. Tarr, Augusto Sarmiento, Ken Wagner, and Charles Resnick. "The Role of Subtalar Motion and Ankle Contact Pressure Changes from Angular Deformities of the Tibia." Foot & Ankle 7, no. 5 (1987): 290–99. http://dx.doi.org/10.1177/107110078700700505.
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It is a well known entity that fractures of the tibia heal with some component of angular deformity. Ankle and subtalar joints may compensate for small degrees of angular deformities, but the exact amount of malunion that can be accepted without development of late sequalae has yet to be determined. Two recent studies from this institution have concluded that (1) contact changes at the tibiotalar joint tend to be greater with distal third tibial fracture deformities compared to proximal and middle with the ankle in neutral, 5° dorsiflexion, and 20° of plantar flexion. (2) Anterior and posterior bow deformities produced a greater change in contact area of the tibiotalar joint than with valgus or varus deformities. This phenomena may be possibly explained by the subtalar motion in the horizontal plane which averages 23°. Thus, it was the primary purpose of this paper to determine the exact role, if any, in subtalar motion on tibiotalar contact in angular deformities of the tibia. To achieve this objective the subtalar joint was transfixed thereby eliminating its perceived compensatory movement. Six cadaveric lower extremities were disarticulated at the knee joint and stripped of soft tissue preserving capsular and ligamentous structures. A custom universal joint was used to create various angulatory deformities at proximal, middle, and distal third levels of the tibia. Contact pressure across the tibiotalar joint was recorded using pressure-sensitive film and analyzed quantitatively in terms of contact area as well as pattern. The same combinations of angular deformities were then run with the subtalar joint transfixed in neutral. The results indicated that as in the two previous studies distal third deformities resulted in the greatest amount of change in ankle contact pressure area. The data also demonstrated that when subtalar motion was restricted ankle contact area decreased significantly in all planes of angulatory deformity. (1) The data collected agree with the results of two previous studies which showed that there was a decreased in total ankle contact area consistently at the distal third level with posterior angulatory deformities of the tibia. (2) By defining the resultant fracture angle and the foot axis angle a geometric explanation can be given to demonstrate a distal level fracture of the tibia has a greater effect on the ankle articulation than one more proximal. (3) The ankle joint has been shown by others to be less congruent as it moves away from its neutral position. This was found to affect and therefore cause a decrease in ankle contact area with tibial angulatory deformities. (4) The ankle joint is more adapted for weightbearing in neutral and in dorsiflexion. The anterior portion of the talar dome is probably more adapted to weightbearing than the posterior portion. This accounted for greater changes in ankle contact area during plantarflexion than in dorsiflexion. (5) The subtalar joint was found to play a very significant role in maintaining the talus in its normal relationship to the tibia. Restriction of the subtalar joint affected all deformities of the tibia as the resultant fracture angle increased. (6) The data supports Inman's concept of the subtalar joint acting as a torque transmitter and compensates for tibial varus and valgus deformities. (7) Subtalar joint restriction affected varus deformities more than valgus deformities probably due to shifting of the talar dome therefore significantly altering its normal biomechanics.
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Branch, Eric A., Dustin Loveland, Sohale Sadeghpour, and Adam W. Anz. "A Biomechanical Assessment of Biceps Femoris Repair Techniques." Orthopaedic Journal of Sports Medicine 6, no. 1 (2018): 232596711774889. http://dx.doi.org/10.1177/2325967117748891.
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Background: Knee injuries encountered in clinical practice can involve avulsions of the biceps femoris from the fibula and proximal tibia. Advances in tendon repair methods now allow for repairs with increased surface areas using modern suture anchor techniques. Despite descriptions of repair techniques, there are no biomechanical studies on the biceps femoris for comparison. Purpose/Hypothesis: The objective of this controlled laboratory study was to determine the failure load of the native biceps femoris distal insertion and to evaluate modern repair techniques. Our hypothesis was 2-fold: (1) Suture repairs to the tibia and fibula would perform better on tensile testing than repairs to the fibula alone, and (2) complex bridge repairs, similar to those frequently used in rotator cuff surgery, would perform better on tensile testing than simple repairs. Study Design: Controlled laboratory study. Methods: A total of 40 paired, fresh-frozen cadaveric specimens were dissected, identifying the biceps femoris and its insertion on the proximal tibia and fibula. The native biceps femoris footprint was left intact in 8 specimens and tested to failure on a uniaxial materials testing machine evaluating tensile properties, while in the other 32 specimens, the biceps femoris insertion was dissected using a No. 15 scalpel blade, underwent repair, and was then tested to failure on a uniaxial materials testing machine evaluating tensile properties. Four repair constructs were evaluated, with 8 specimens allocated for each: construct 1 involved a simple repair (ie, passing suture through tissue in a running Krackow fashion and tying at the anchor site) to the fibula with 2 suture anchors, construct 2 involved a simple repair to the fibula and tibia with 3 suture anchors, construct 3 was a fibular repair with a tibial suture bridge involving the fibula and tibia and 3 suture anchors, construct 4 involved a transosseous repair through the fibula and 1 suture anchor on the tibia. Analysis of variance was used to evaluate for significance of the mean failure load and stiffness between groups. Results: The mean (±95% CI) failure loads were the following: native biceps femoris, 1280 ± 247.0 N; simple fibular repair, 173 ± 84.6 N; simple fibular and tibial repair, 176 ± 48.1 N; fibular repair with tibial suture bridge, 191 ± 78.5 N; and transosseous repair, 327 ± 66.3 N. The mean stiffness values were the following: native, 46 ± 13.0 N/mm; simple fibular repair, 16 ± 5.1 N/mm; simple fibular and tibial repair, 14 ± 5.4 N/mm; fibular repair with tibial suture bridge, 13 ± 2.8 N/mm; and transosseous repair, 15 ± 2.5 N/mm. Interconstruct comparison of failure loads revealed no statistical difference between constructs utilizing anchors alone. The transosseous repair showed a significant difference for the failure load when compared with each anchor repair construct ( P = .02, .02, and .04 for constructs 1, 2, and 3, respectively). Interconstruct comparison of stiffness revealed no statistical difference between all constructs ( P > .86). None of the repair techniques re-created the failure load or stiffness of the native biceps femoris tendon ( P = .02). Conclusion: In this biomechanical study, no difference was found between the mean failure loads of different biceps femoris repair constructs involving suture anchors alone and No. 2 braided polyester and ultra–high-molecular-weight polyethylene suture. A technique involving transosseous fibular tunnels and 2-mm suture tape illustrated a greater mean failure load than repairs relying on suture anchors for fixation. Clinical Relevance: Understanding the tensile performance of biceps femoris repair constructs aids clinicians with preoperative and intraoperative decisions. Current biceps femoris repair techniques do not approximate the native strength of the tendon. A transosseous style of repair offers the highest failure load.
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Completo, A., F. Fonseca, and J. A. Simões. "Finite Element and Experimental Cortex Strains of the Intact and Implanted Tibia." Journal of Biomechanical Engineering 129, no. 5 (2007): 791–97. http://dx.doi.org/10.1115/1.2768382.
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Finite Element (FE) models for the simulation of intact and implanted bone find their main purpose in accurately reproducing the associated mechanical behavior. FE models can be used for preclinical testing of joint replacement implants, where some biomechanical aspects are difficult, if not possible, to simulate and investigate in vitro. To predict mechanical failure or damage, the models should accurately predict stresses and strains. Commercially available synthetic femur models have been extensively used to validate finite element models, but despite the vast literature available on the characteristics of synthetic tibia, numerical and experimental validation of the intact and implant assemblies of tibia are very limited or lacking. In the current study, four FE models of synthetic tibia, intact and reconstructed, were compared against experimental bone strain data, and an overall agreement within 10% between experimental and FE strains was obtained. Finite element and experimental (strain gauge) models of intact and implanted synthetic tibia were validated based on the comparison of cortex bone strains. The study also includes the analysis carried out on standard tibial components with cemented and noncemented stems of the P.F.C Sigma Modular Knee System. The overall agreement within 10% previously established was achieved, indicating that FE models could be successfully validated. The obtained results include a statistical analysis where the root-mean-square-error values were always <10%. FE models can successfully reproduce bone strains under most relevant acting loads upon the condylar surface of the tibia. Moreover, FE models, once properly validated, can be used for preclinical testing of tibial knee replacement, including misalignment of the implants in the proximal tibia after surgery, simulation of long-term failure according to the damage accumulation failure scenario, and other related biomechanical aspects.
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Garcia, T. C., M. G. Serdy, K. Hayashi, B. A. Nir, S. M. Stover, and D. Demner. "Biomechanical comparison of mono- and bicortical screws in an experimentally induced gap fracture." Veterinary and Comparative Orthopaedics and Traumatology 27, no. 06 (2014): 422–29. http://dx.doi.org/10.3415/vcot-14-03-0040.
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SummaryObjectives: To compare the bending and torsional mechanical properties of mono- and bicortical locking screws in a canine cadaveric tibial gap ostectomy bridged by a locking compression plate (LCP).Methods: A 10-hole 3.5 mm LCP was applied medially to the tibia with a gap ostectomy using locking screws in the two proximal and distal plate holes. One tibia of each pair was randomly assigned monocortical screws and the other bicortical screws. Constructs were tested non-destructively in mediolateral and caudocranial four-point bending and torsion, and then to failure in four-point bending. Stiffness, yield and failure variables were compared between screw lengths and load conditions using analysis of variance.Results: Caudocranial and mediolateral fourpoint bending stiffnesses were not different between screw constructs. Torsional stiffness was greater and neutral zone smaller for bicortical constructs. Constructs were stiffer and stronger in caudocranial bending than in mediolateral bending. In caudocranial bending, bicortical constructs failed by bone fracture and monocortical constructs by screw loosening.Conclusion: Bicortical constructs were stiffer than monocortical constructs in torsion but not bending. Bicortical screw constructs failed by bone fracture under the applied loads whereas monocortical screw constructs failed at the bone-screw interface.Clinical relevance: Bicortical screw placement may be a safer clinical alternative than monocortical screw placement for minimally invasive percutaneous osteosynthesis LCPplated canine tibiae with comminuted diaphyseal fractures.
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Kaplan, Jonathan T., John W. Ramsay, Sarah E. Cameron, et al. "Association Between Knee Anatomic Metrics and Biomechanics for Male Soldiers Landing With Load." American Journal of Sports Medicine 48, no. 6 (2020): 1389–97. http://dx.doi.org/10.1177/0363546520911608.
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Background: Anterior cruciate ligament (ACL) injury is a military occupational hazard that may be attributed to an individual’s knee biomechanics and joint anatomy. This study sought to determine if greater flexion when landing with load resulted in knee biomechanics thought to decrease ACL injury risk and whether knee biomechanics during landing relate to knee anatomic metrics. Hypothesis: Anatomic metrics regarding the slope and concavity of the tibial plateau will exhibit a significant relation to the increased anterior shear force on the knee and decreased knee flexion posture during landing with body-borne load. Study Design: Descriptive laboratory study. Methods: Twenty male military personnel completed a drop landing task with 3 load conditions: light (~6 kg), medium (15% body weight), and heavy (30% body weight). Participants were divided into groups based on knee flexion exhibited when landing with the heavy load (high- and low-Δflexion). Tibial slopes and depth were measured on weightbearing volumetric images of the knee obtained with a prototype cone beam computed tomography system. Knee biomechanics were submitted to a linear mixed model to evaluate the effect of landing group and load, with the anatomic metrics considered covariates. Results: Load increased peak proximal anterior tibial shear force ( P = .034), knee flexion angle ( P = .024), and moment ( P = .001) during landing. Only the high flexion group increased knee flexion ( P < .001) during weighted landings with medium and heavy loads. The low flexion group used greater knee abduction angle ( P = .030) and peak proximal anterior tibial shear force ( P = .034) when landing with load. Anatomic metrics did not differ between groups, but ratio of medial-to-lateral tibial slope and medial tibial depth predicted peak proximal anterior tibial shear force ( P = .009) and knee flexion ( P = .034) during landing, respectively. Conclusion: Increasing knee flexion is an attainable strategy to mitigate risk of ACL injury, but certain individuals may be predisposed to knee forces and biomechanics that load the ACL during weighted landings. Clinical Relevance: The ability to screen individuals for anatomic metrics that predict knee flexion may identify soldiers and athletes who require additional training to mitigate the risk of lower extremity injury.
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Anchustegui, Nicolas G., Audrey Rustad, Cooper Shea, et al. "MEDIAL AND LATERAL POSTERIOR TIBIAL SLOPE IN THE SKELETALLY IMMATURE: A HUMAN CADAVERIC STUDY." Orthopaedic Journal of Sports Medicine 7, no. 3_suppl (2019): 2325967119S0013. http://dx.doi.org/10.1177/2325967119s00130.
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Background: Recent research has identified posterior tibial slope as a risk factor for anterior cruciate ligament (ACL) injury, due to increased forces on the ACL with this tibial anatomy. Biomechanical studies suggest that altering a patient’s posterior tibial slope may lower the risk of ACL injury. Due to the presence of an open physis, guided growth may be used to reduce the posterior tibia slope in this high risk skeletally immature population. The primary purpose of this study was to quantify and measure the posterior tibial slope in pediatric knees. Methods: Forty-four pediatric knee CT scans were analyzed using OsiriX, an imaging software. Specimens analyzed were between the ages of 2 and 12 years of age. The proximal tibial slope for each specimen was measured on CT scan sagittal slices at 2 locations: 1) At the medial tibial plateau at the mid region of the medial femoral condyle, as determined on a coronal slice through the femoral condyle; 2) At the lateral tibial plateau at the mid region of the lateral femoral condyle, as determined on the coronal slice through the femoral condyle. The measurement of the posterior tibial slope was determined by placing two lines parallel to the diaphysis of the tibia, one located in the middle of the diaphysis and one located at the most posterior aspect of the diaphysis. The most proximal aspect of both the medial and lateral tibial plateau were then identified and angle measurements were taken in reference to the parallel lines. The angle measurements were plotted graphically by age in order to account for variability in development within age groups. The anterior medial and lateral tibia plateau widths were measured by identifying the mid region of the respective plateaus. From this point, the distance between the top of the tibial plate and the physis was measured. Results: The average posterior tibial slope angle for the medial and lateral tibial plateau were (5.53° ± 4.17°) and (5.95° ± 3.96°) respectively. Independent samples t-test and ANOVA indicate the difference between the posterior tibial slope angle of the medial and lateral tibial plateau were not statistically significant (p < 0.05). When plotted graphically by age, a slight negative trend between age and posterior tibial slope was identified. As age increases, the medial and lateral posterior tibial slope decreases. The mean anterior medial tibial plateau width and lateral tibial plateau width were .99 cm and 1.19 cm respectively. Discussion/Conclusion: ACL primary and secondary injury occur at very high rates in the skeletally immature, especially in females at age 11 and older, and in males at age 13 and older. This data set offers some preliminary values for posterior tibial slope in patients without a history of ACL injury, allowing for comparisons to patients with ACL Injury. Increased tibial slope is a risk factor for ACL injury. In the skeletally immature, one option to alter the tibial slope is the use of guided growth with implants to slow the anterior growth of the proximal tibia, reducing the posterior slope of the tibia, and possibly lower the risk of ACL injury in this high-risk population. [Figure: see text][Figure: see text][Figure: see text][Figure: see text][Figure: see text][Table: see text][Table: see text]
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Losito, James M., R. Clinton Laird, Monica R. Alexis, and Jessica Mora. "Tibial and Proximal Fibular Stress Fracture in a Rower." Journal of the American Podiatric Medical Association 93, no. 4 (2003): 340–43. http://dx.doi.org/10.7547/87507315-93-4-340.
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Proximal fibular stress fractures are rare injuries that usually result from jumping and running activities of military recruits and athletes. This article describes a female university athlete with proximal lateral leg pain diagnosed by means of a triphase bone scan as proximal fibular stress fracture and proximal to middle one-third tibial stress fracture. This case highlights the need to examine not only the sport but also the athlete’s training habits to identify possible factors contributing to the injury. Body type, biomechanics, and gender are also possible etiologic factors. (J Am Podiatr Med Assoc 93(4): 340-343, 2003)
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Weiner, Marsha, Timothy A. Damron, Francis R. Patterson, Frederick W. Werner, and Kenneth A. Mann. "Biomechanical Study of Pins in Cementing of Contained Proximal Tibia Defect." Clinical Orthopaedics and Related Research 419 (February 2004): 232–37. http://dx.doi.org/10.1097/00003086-200402000-00038.
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Monzem, Samuel, Rafael Y. Ballester, Behzad Javaheri, et al. "Long-term bisphosphonate treatment coupled with ovariectomy in mice provokes deleterious effects on femoral neck fracture pattern and modifies tibial shape." Bone & Joint Open 1, no. 9 (2020): 512–19. http://dx.doi.org/10.1302/2633-1462.19.bjo-2020-0117.r1.
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Aims The processes linking long-term bisphosphonate treatment to atypical fracture remain elusive. To establish a means of exploring this link, we have examined how long-term bisphosphonate treatment with prior ovariectomy modifies femur fracture behaviour and tibia mass and shape in murine bones. Methods Three groups (seven per group) of 12-week-old mice were: 1) ovariectomized and 20 weeks thereafter treated weekly for 24 weeks with 100 μm/kg subcutaneous ibandronate (OVX+IBN); 2) ovariectomized (OVX); or 3) sham-operated (SHAM). Quantitative fracture analysis generated biomechanical properties for the femoral neck. Tibiae were microCT scanned and trabecular (proximal metaphysis) and cortical parameters along almost its whole length measured. Results Fracture analyses revealed that OVX+IBN significantly reduced yield displacement (vs SHAM/OVX) and resilience, and increased stiffness (vs SHAM). OVX+IBN elevated tibial trabecular parameters and also increased cortical cross-sectional area and second moment of area around minor axis, and diminished ellipticity proximally. Conclusion These data indicate that combined ovariectomy and bisphosphonate generates cortical changes linked with greater bone brittleness and modified fracture characteristics, which may provide a basis in mice for interrogating the mechanisms and genetics of atypical fracture aetiology. Cite this article: Bone Joint Open 2020;1-9:512–519.
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Paley, D. "Congenital pseudarthrosis of the tibia: biological and biomechanical considerations to achieve union and prevent refracture." Journal of Children's Orthopaedics 13, no. 2 (2019): 120–33. http://dx.doi.org/10.1302/1863-2548.13.180147.
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Congenital pseudarthrosis of the tibia (CPT) is likely to be a primary periosteal disease and secondary bone disease. The primary goal of treatment is to obtain union, correct the diaphyseal deformity, correct any proximal fibular migration and prevent refracture. The pathobiology demonstrates increased osteoclasis by the surrounding fibrous hamartoma and reduced osteogenesis and bone morphogenic protein production by the bone. This leads to a loss of remodelling potential and gradual bowing and atrophy of the bone with eventual fracture of the tibia and or fibula. This recommends the synergistic use of bisphosphonates and bone morphogenic protein. The pathomechanics of CPT implicate the anterolateral bowing, narrow diameter of the atrophic bone ends and proximal fibular migration. These biomechanical factors can be addressed by means of straightening of the deformity, intramedullary support of both bones, stable fixation and reduction of proximal migration of the fibula. A summary of the literature on CPT shows that the mean probability of achieving primary union without refracture, by most treatments is 50% (12% to 80%). Two recent studies have shown a much higher success rate approaching 100%, by creating a cross-union between the tibia and fibula. The cross-union with intramedullary reinforcement of the bone makes refracture unlikely due to the cross-sectional area of union with its two-bar linkage. A new classification to guide such treatment is also proposed. Level of Evidence V – expert opinion
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Hansen, Matthias, Dorothea Mehler, Martin Henri Hessmann, Jochen Blum, and Pol Maria Rommens. "Intramedullary Stabilization of Extraarticular Proximal Tibial Fractures: A Biomechanical Comparison of Intramedullary and Extramedullary Implants Including a New Proximal Tibia Nail (PTN)." Journal of Orthopaedic Trauma 21, no. 10 (2007): 701–9. http://dx.doi.org/10.1097/bot.0b013e31815aba5e.
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Godin, Jonathan A., Jorge Chahla, Gilbert Moatshe, et al. "A Comprehensive Reanalysis of the Distal Iliotibial Band: Quantitative Anatomy, Radiographic Markers, and Biomechanical Properties." American Journal of Sports Medicine 45, no. 11 (2017): 2595–603. http://dx.doi.org/10.1177/0363546517707961.
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Background: The qualitative anatomy of the distal iliotibial band (ITB) has previously been described. However, a comprehensive characterization of the quantitative anatomic, radiographic, and biomechanical properties of the Kaplan fibers of the deep distal ITB has not yet been established. It is paramount to delineate these characteristics to fully understand the distal ITB’s contribution to rotational knee stability. Purpose/Hypothesis: There were 2 distinct purposes for this study: (1) to perform a quantitative anatomic and radiographic evaluation of the distal ITB’s attachment sites and their relationships to pertinent osseous and soft tissue landmarks, and (2) to quantify the biomechanical properties of the deep (Kaplan) fibers of the distal ITB. It was hypothesized that the distal ITB has definable parameters concerning its anatomic attachments and consistent relationships to surgically pertinent landmarks with correlating plain radiographic findings. In addition, it was hypothesized that the biomechanical properties of the Kaplan fibers would support their role as important restraints against internal rotation. Study Design: Descriptive laboratory study. Methods: Ten nonpaired, fresh-frozen human cadaveric knees (mean age, 61.1 years; range, 54-65 years) were dissected for anatomic and radiographic purposes. A coordinate measuring device quantified the attachment areas of the distal ITB to the distal femur, patella, and proximal tibia and their relationships to pertinent bony landmarks. A radiographic analysis was performed by inserting pins into the attachment sites of relevant anatomic structures to assess their location relative to pertinent bony landmarks with fluoroscopic guidance. A further biomechanical assessment of 10 cadaveric knees quantified the load to failure and stiffness of the Kaplan fibers’ insertion on the distal femur after a preconditioning protocol. Results: Two separate deep (Kaplan) fiber bundles were identified with attachments to 2 newly identified femoral bony prominences (ridges). The proximal and distal bundles inserted on the distal femur 53.6 mm (95% CI, 50.7-56.6 mm) and 31.4 mm (95% CI, 27.3-35.5 mm) proximal to the lateral epicondyle, respectively. The centers of the bundle insertions were 22.5 mm (95% CI, 19.1-25.9 mm) apart. The total insertion area of the distal ITB on the proximal tibia was 429.1 mm2 (95% CI, 349.2-509.1 mm2). A distinct capsulo-osseous layer of the distal ITB was also identified that was intimately related to the lateral knee capsule. Its origin was in close proximity to the lateral gastrocnemius tubercle, and it inserted on the proximal tibia at the lateral tibial tubercle between the fibular head and the Gerdy tubercle. Radiographic analysis supported the quantitative anatomic findings. The mean maximum load during pull-to-failure testing was 71.3 N (95% CI, 41.2-101.4 N) and 170.2 N (95% CI, 123.6-216.8 N) for the proximal and distal Kaplan bundles, respectively. Conclusion: The most important finding of this study was that 2 distinct deep bundles (Kaplan fibers) of the distal ITB were identified. Each bundle of the deep layer of the ITB was associated with a newly identified distinct bony ridge. Radiographic analysis confirmed the measurements previously recorded and established reproducible landmarks for the newly described structures. Biomechanical testing revealed that the Kaplan fibers had a strong attachment to the distal femur, thereby supporting a role in rotational knee stability. Clinical Relevance: The identification of 2 distinct deep fiber (Kaplan) attachments clarifies the function of the ITB more definitively. The results also support the role of the ITB in rotatory knee stability because of the fibers’ vectors and their identified maximum loads. These findings provide the anatomic and biomechanical foundation needed for the development of reconstruction or repair techniques to anatomically address these deficiencies in knee ligament injuries.
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Anijs, Thomas, Ilse Kouwert, Nico Verdonschot, and Dennis Janssen. "Towards a Standard Approach to Assess Tibial Bone Loss Following Total Knee Arthroplasty." Clinical Reviews in Bone and Mineral Metabolism 18, no. 4 (2020): 72–86. http://dx.doi.org/10.1007/s12018-021-09276-9.
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AbstractLong-term implant failure in the form of aseptic loosening and periprosthetic fracture is the most common cause of revision procedures in total knee arthroplasty (TKA). While early loosening can often be attributed to failure of primary fixation, late implant failure could be associated with loss of fixation secondary to bone resorption, as a result of stress shielding in the proximal tibia. This current review study was performed to identify the clinical effects of different implant-, patient-, and surgery-related biomechanical factors on TKA-related tibial bone loss in clinical reality. Implant-related factors considered were the fixation method, and the implant type, geometry, and stiffness. In terms of patient characteristics, the effects of age, sex, knee alignment, bone density, body weight, and activity level were analyzed. The clinical literature on these topics mostly concerned longitudinal radiographic studies investigating the effect of a single factor on changes in the proximal tibia over time using bone densitometry. Implant stiffness, implant geometry and knee alignment were the only factors consistently found to affect regional bone density changes over time. Each clinical study used its own specific study design, with different definitions used for the baseline density, time points of baseline and follow-up measurements, and regions of interest. Due to the differences in study design, direct comparison between the clinical impact of different biomechanical factors was not possible. Based on the findings over the densitometry studies, a standardized guideline was proposed to allow reliable comparison between consistently reported outcome of future radiographic TKA studies.
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Pommer, A., A. Wieser, M. P. Hahn, A. Dávid, and G. Muhr. "Fixation of proximal tibia fractures by a retrograde nail: a biomechanical investigation." Archives of Orthopaedic and Trauma Surgery 120, no. 3-4 (2000): 212–14. http://dx.doi.org/10.1007/s004020050047.
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Lim, Chin Tat, David Q. K. Ng, Ken Jin Tan, Amit K. Ramruttun, Wilson Wang, and Desmond Y. R. Chong. "A biomechanical study of proximal tibia bone grafting through the lateral approach." Injury 47, no. 11 (2016): 2407–14. http://dx.doi.org/10.1016/j.injury.2016.09.017.
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Michel, Philipp A., J. Christoph Katthagen, Lukas F. Heilmann, Felix Dyrna, Benedikt Schliemann, and Michael J. Raschke. "Biomechanics of Upper Extremity Double Plating." Zeitschrift für Orthopädie und Unfallchirurgie 158, no. 02 (2019): 238–44. http://dx.doi.org/10.1055/a-0862-6334.
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AbstractDouble plating (DP) is an established treatment modality in traumatology. For certain indications, such as open reduction and internal fixation of bicondylar tibial plateau fractures and distal humeral fractures, DP is standard of care in the clinical routine. However, the principles of DP can be transferred to other anatomic regions and indications. In the past years, DP has been brought more and more into focus. For revision cases, such as the treatment of fracture non-unions, DP seems generally useful. In anatomical locations with high torsional stress and bending forces, but also in regions with traction forces by muscles and tendons DP provides multiplanar stability and therefore seems to have biomechanical advantages. Usually two smaller implants can replace one larger implant. Thus, the number of points of fixation can be increased, the stability can be improved and soft-tissue irritations by bulky implants can be minimized. Along with the established indication and application at the distal humerus, there is biomechanical evidence in the current literature for DP of clavicle fractures and humeral shaft fractures. Furthermore, DP provides mechanical advantages in the treatment of certain proximal humeral fractures and olecranon fractures. This review of the literature summarizes the published literature on biomechanics of upper extremity DP.
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Mitkovic, Milan, Sasa Milenkovic, Ivan Micic, et al. "Knee angular deformity correction using unicorticotomy and callus distraction by external fixation method and presentation of new external fixation device for varus correction of proximal tibia." Acta chirurgica Iugoslavica 60, no. 2 (2013): 103–8. http://dx.doi.org/10.2298/aci1302103m.
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The main goal of this paper is to present clinical results of surgical correction of angular (varus and valgus) deformities of knee area. Goal is also to present new external fixation device for surgical treatment of varus deformity of proximal tibia. As material it has been used series of 70 patients treated during the period of 6.5 years in University Orthopaedic and traumatology clinic. Biomechanical investigation of 80% cut bone model fixed by new external fixation device was performed in the measurement laboratory of Mechanical Faculty University of Nis. Clinical results of treatment of 58 high tibial surgeries (49 varus and 9 valgus) and 12 distal femur surgeries (2 varus and 10 valgus) showed that unicorticotomy and callus distraction by the use of Mitkovic external fixation device leaded to correction and bone union. Superficial pin tract infection happened in 9 patients and has been successfully treated without pins removal. Biomechanical investigation of new device showed that during axial loading of bone model by 690 N (70 kg) movement of medial distal end of bone model was 0.30 mm while posterior distal end of bone model was 0.26 mm. From results obtained in can be concluded that unicorticotomy and gradual callus distraction by the use of external fixation is one reliable method. Biomechanical testing of new external fixation device showed that it is more stable in control of varus and posterior position of proximal tibial fragment.
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McBryde, Angus, Brett Chiasson, Andrew Wilhelm, Frank Donovan, Tamara Ray, and Philip Bacilla. "Syndesmotic Screw Placement: A Biomechanical Analysis." Foot & Ankle International 18, no. 5 (1997): 262–66. http://dx.doi.org/10.1177/107110079701800503.
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At the present time, syndesmotic screw fixation is recommended when there is a tibiofibular diastasis, a Maisonneuve fracture, or syndesmotic instability after fixation of distal tibia-fibula fractures. The aim/purpose of this study was to demonstrate the optimal level of syndesmotic screw placement before creation of a Maisonneuve fracture. Legs of 17 embalmed cadavers underwent knee disarticulation. The legs were then dissected to expose the syndesmosis/interosseous membrane. The paired cadaver legs were tested in two groups. In group I (10 pairs), the left legs were tested without any syndesmotic fixation and the right legs were tested with the syndesmosis fixed at 2.0 cm above the tibiotalar joint. In group II (7 pairs), the syndesmosis in each left leg was fixed at 3.5 cm above the tibiotalar joint and the right leg syndesmosis was fixed at 2.0 cm above the tibiotalar joint. After ligament section and syndesmosis fixation, each leg was then jig mounted with transfixing wires through the proximal tibia and calcaneus. The ankle was placed in neutral with 15° of pronation and a load of 150 pounds and a strain gauge anchored medially and laterally. The proximal tibia was internally rotated while the ankle was held fixed until syndesmotic, bony, or hardware failure occurred. Torsional force, the degree of rotation and the amount of syndesmotic widening were quantitated. Two-tailed t-test comparing no fixation with fixation at 2.0 cm indicated less syndesmotic widening with screw placed at 2.0 cm ( P = 0.04). Two-tailed t-test comparing screw fixation at 2.0 cm and 3.5 cm indicated less syndesmotic widening with screw placed at 2.0 cm ( P = 0.07). It would seem reasonable to place a syndesmotic screw at 2.0 cm above tibiotalar joint.
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Carballo, Camila, Ian Hutchinson, Zoe Album, et al. "Biomechanics and Microstructural Analysis of the Mouse Knee and Ligaments." Journal of Knee Surgery 31, no. 06 (2017): 520–27. http://dx.doi.org/10.1055/s-0037-1604151.
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AbstractThe purpose of this study is to determine the feasibility of using murine models for translational study of knee ligament injury, repair, and reconstruction. To achieve this aim, we provide objective, quantitative data detailing the gross anatomy, biomechanical characteristics, and microscopic structure of knee ligaments of 44 male mice (C57BL6, 12 weeks of age). Biomechanical testing determined the load-to-failure force, stiffness, and the site of ligament failure for the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and the medial and lateral collateral ligaments (MCL and LCL). These data are complemented by histological characterization of each of the knee ligaments. In addition, the osseous morphology of the mouse knee was examined using high-resolution nanofocus computed tomography (CT), while standard micro-CT was employed to measure bone morphometrics of the distal femur and proximal tibia. Collectively, our findings suggest that the gross anatomy of the mouse knee is similar to the human knee despite some minor differences and features unique to the murine knee. The ACL had the highest load to failure (5.60 ± 0.75 N), the MCL (3.33 ± 1.45 N), and the PCL (3.45 ± 0.84 N) were similar, and the LCL (1.44 ± 0.37 N) had the lowest load to failure and stiffness. Murine models provide a unique opportunity to focus on biological processes that impact ligament pathology and healing due to the availability of transgenic strains. Our data support their use as a translational platform for the in vivo study of ligament injury, repair, and reconstruction.
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Voor, Michael, Valentin Antoci, Boon Kam, and Craig Roberts. "Hybrid External Fixation of Proximal Tibia Fractures: Biomechanical Analysis of Four Commercial Systems." Orthopedics 30, no. 12 (2007): 1033–38. http://dx.doi.org/10.3928/01477447-20071201-06.
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Jiang, Rui, Cong-Feng Luo, and Bing-Fang Zeng. "Biomechanical evaluation of different fixation methods for fracture dislocation involving the proximal tibia." Clinical Biomechanics 23, no. 8 (2008): 1059–64. http://dx.doi.org/10.1016/j.clinbiomech.2008.04.005.
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Wolinsky, Philip R., Douglas Dennis, Brett D. Crist, Shane Curtiss, and Scott J. Hazelwood. "The Biomechanics of Varied Proximal Locking Screw Configurations in a Synthetic Model of Proximal Third Tibial Fracture Fixation." Journal of Orthopaedic Trauma 25, no. 3 (2011): 175–79. http://dx.doi.org/10.1097/bot.0b013e3181e47d0f.
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Teitz, Carol C., and Richard M. Harrington. "A Biomechanical Analysis of the Squeeze Test for Sprains of the Syndesmotic Ligaments of the Ankle." Foot & Ankle International 19, no. 7 (1998): 489–92. http://dx.doi.org/10.1177/107110079801900713.
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The “squeeze test” is a clinical test for detecting “stable” syndesmosis injuries. The test is positive when proximal compression of the calf produces pain in the area of the distal tibiofibular and interosseous ligaments. The purpose of this study was to examine what fibular movement, if any, occurs at the level of the ankle mortise when compression is applied proximally. A differential variable reluctance transducer was inserted into the origin and insertion of the anterior tibiofibular ligaments of fresh cadaver human lower limbs which had been prepared to simulate the clinical conditions of the squeeze test. Compression was applied both manually and with a specially designed clamp. Squeezing the calf caused separation of the distal fibula and tibia.
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KIM, JAY-JUNG, and CHEOL-WOONG KIM. "POSTERIOR CRUCIATE LIGAMENT (PCL) RECONSTRUCTION BY TRANSTIBIAL TUNNEL: SUGGESTIONS OF LENGTHENING AND SLIPPAGE RATIO." International Journal of Modern Physics B 24, no. 15n16 (2010): 2579–84. http://dx.doi.org/10.1142/s0217979210065295.
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This paper examined the biomechanical fatigue behavior of Achilles tendon autograft after posterior cruciate ligament (PLC) reconstructions. It experimented with various fixation devices and locations on the degree of initial lengthening and slippage to investigate the relationship between lengthening and slippage ratios among calcaneal and soft tissue fixation methods. Eight specimens of proximal tibia and Achilles tendon grafts were harvested from cadavers and classified into four groups according to the type of transtibial fixation technique. A cyclic load ranging from 50N to 250N was applied to each graft when fixed to the proximal tibia at 55 degrees. The soft tissue fixation method, which uses an interference screw, demonstrated a 56.4% ratio of slippage to total elongation. The use of a double cross-pin with the same method demonstrated a 45.4% slippage ratio. The former was associated with approximately 2 mm less total elongation and 13% more slippage than lengthening compared to the latter. This result was predominantly due to the poor standard of fixation compared to the same method using a double cross-pin.
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Niu, W. X., L. J. Wang, T. N. Feng, C. H. Jiang, Y. B. Fan, and M. Zhang. "Effects of Bone Young’s Modulus on Finite Element Analysis in the Lateral Ankle Biomechanics." Applied Bionics and Biomechanics 10, no. 4 (2013): 189–95. http://dx.doi.org/10.1155/2013/818414.
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Finite element analysis (FEA) is a powerful tool in biomechanics. The mechanical properties of biological tissue used in FEA modeling are mainly from experimental data, which vary greatly and are sometimes uncertain. The purpose of this study was to research how Young’s modulus affects the computations of a foot-ankle FEA model. A computer simulation and an in-vitro experiment were carried out to investigate the effects of incremental Young’s modulus of bone on the stress and strain outcomes in the computational simulation. A precise 3-dimensional finite element model was constructed based on an in-vitro specimen of human foot and ankle. Young’s moduli were assigned as four levels of 7.3, 14.6, 21.9 and 29.2 GPa respectively. The proximal tibia and fibula were completely limited to six degrees of freedom, and the ankle was loaded to inversion 10° and 20° through the calcaneus. Six cadaveric foot-ankle specimens were loaded as same as the finite element model, and strain was measured at two positions of the distal fibula. The bone stress was less affected by assignment of Young’s modulus. With increasing of Young’s modulus, the bone strain decreased linearly. Young’s modulus of 29.2 GPa was advisable to get the satisfactory surface strain results. In the future study, more ideal model should be constructed to represent the nonlinearity, anisotropy and inhomogeneity, as the same time to provide reasonable outputs of the interested parameters.
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Moatshe, Gilbert, Jorge Chahla, Alex Brady, et al. "The Influence of Graft Tensioning Sequence on Tibiofemoral Orientation during Bicruciate and Posterolateral Corner Knee Ligament Reconstruction: A Biomechanical Study." Orthopaedic Journal of Sports Medicine 6, no. 7_suppl4 (2018): 2325967118S0006. http://dx.doi.org/10.1177/2325967118s00066.
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Objectives: During a multiple knee ligament reconstruction, the graft tensioning order may influence the final tibiofemoral orientation and corresponding knee kinematics. Therefore, the objective of this study was to biomechanically evaluate the effect of different graft tensioning sequences on knee tibiofemoral orientation following multiple knee ligament reconstruction in a bicruciate ligament (anterior cruciate ligament [ACL] and posterior cruciate ligament [PCL]) with posterolateral corner [PLC] injured knee. Methods: Ten non-paired, fresh-frozen human cadaveric knees were utilized for this study. Following reconstruction of both cruciate and posterolateral corner ligaments and proximal graft fixation, each knee was randomly assigned to each of four graft tensioning order groups: (1) PCL → ACL → PLC, (2) PCL → PLC → ACL, (3) PLC → ACL → PCL and (4) ACL → PCL → PLC. The tibiofemoral orientation after graft tensioning was measured and compared to the intact states. Results: Tensioning the ACL first (tensioning order 4) resulted in posterior displacement of the tibia at 0° by 1.7 ± 1.3 mm compared to the intact state (p=0.002) (Figure 1). All tensioning orders resulted in significantly increased anterior tibial translation compared to the intact state at higher flexion angles ranging from 2.7 mm to 3.2 mm at 60° and 3.1 mm to 3.4 mm at 90° for tensioning orders 1 and 2 respectively (all p<0.001). There was no significant difference in tibiofemoral orientation in the sagittal plane between the tensioning orders at higher flexion angles. All tensioning orders resulted in increased internal tibial rotation (all p<0.001). Tensioning and fixing the PLC first (tensioning order 3) resulted in the most increases in internal rotation of the tibia; 2.4° ± 1.9°, 2.7° ± 1.8° and 2.0° ± 2.0° at 0°, 30° and 60° respectively (Table 1). Conclusion: None of the tensioning orders restored intact knee tibiofemoral orientation. Tensioning the posterolateral corner first should be avoided in bicruciate knee ligament reconstruction with a concurrent posterolateral corner reconstruction because it significantly increased tibial internal rotation. We recommend that the PCL be tensioned first, followed by the ACL to avoid posterior translation of the tibia in extension where the knee is primarily loaded with most activities and finally the PLC. [Figure: see text][Table: see text]
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Uchiyama, Eiichi, Daisuke Suzuki, Hideji Kura, Toshihiko Yamashita, and Gen Murakami. "Distal Fibular Length Needed for Ankle Stability." Foot & Ankle International 27, no. 3 (2006): 185–89. http://dx.doi.org/10.1177/107110070602700306.
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Background: The fibula is commonly used for bone grafts. Previous clinical and biomechanical studies have suggested that the length of the residual portion of the distal part of the fibula has an important effect on the long-term stability of the ankle joint. However, we cannot find clear-cut guidelines for the amount of bone that can be harvested safely. Methods: Using six normal fresh-frozen cadaver legs, motions of the tibia, talus and calcaneus were measured. The fibula was cut sequentially 3 cm from the proximal tip of the fibula and distally 10 cm, 6 cm, and 4 cm from the distal tip of the lateral malleolus. The angular motion of each bone was measured while a medial and lateral traction force of 19.6 N was applied to the proximal tibia. Angles of the tibia, talus, and calcaneus were measured. Results: Sequential resection of the fibula increased the inversion angles of the ankle joint. The proximal 3-cm cut increased the inversion angle from 42.1 ± 6.2 degrees to 49.6 ± 3.6 degrees, and the distal 4-cm cut increased the angle from 57.6 ± 6.6 degrees to 67.4 ± 5.9 degrees. The rotational angles were almost constant with sequential resections of the fibula; however, the distal 4-cm cut increased the rotational angle from 11.3 ± 25.1 degrees to 78.7 ± 37.5 degrees. Conclusions: The whole fibula including the head is essential for the stability of the ankle joint complex, and the distal fibula is responsible for stabilizing the ankle mortise during external rotation and inversion. We recommend fixation of the syndesmosis or bracing to prevent ankle joint instability with rotation of the talus in the mortise, especially when the distal fibula is shortened 6 cm or more.
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Liu, Hsia-Wei, Chih-Hwa Chen, Ching-Lin Tsai, Chung-Ming Yu, I.-Hsuan Lin, and Ging-Ho Hsiue. "ENCAPSULATION OF PERIOSTEAL STEM CELLS IN INJECTABLE PHOTOPOLYMERIZED HYDROGEL ENHANCES TENDON GRAFT OSTEOINTEGRATION." Journal of Musculoskeletal Research 10, no. 03 (2006): 109–20. http://dx.doi.org/10.1142/s0218957706001820.
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Photopolymerized hydrogel based on poly(ethylene glycol) diacrylate (PEGDA) was applied to periosteum-derived periosteal stem cell (PSC) encapsulation and orthopedic tissue engineering. To provide support for cell adhesion, hyaluronic acid (HA) was incorporated into the PEGDA solution prior to photopolymerization. HA can be utilized to mimic the extracellular matrix composition as well as control cell growth and differentiation. In vitro studies have demonstrated its ability to encapsulate PSCs to form bone-like tissue in a photopolymerized hydrogel. Osteointegration of a tendon graft within the bone tunnel is a primary concern when employing tendon grafts for ligament reconstruction. This study presents a novel technique for fabricating injectable hydrogel–photoencapsulated PSCs in a bone tunnel to enhance tendon–bone healing. A total of 21 adult New Zealand white rabbits were used. The long extensor digitorum tendon was transplanted into a bone tunnel of the proximal tibia. The tendon was pulled through a drill hole in the proximal tibia and attached to the medial aspect of the tibia. Hydrogel suspension containing PSCs at a concentration of 20 million/mL was injected into the bone tunnel. Histological examination of the tendon–bone interface and biomechanical testing for maximal pull-out load were evaluated at postoperative weeks 3 and 6. Histological analysis of the tendon–bone interface showed an interface fibrous layer formed by the photoencapsulation of PSCs between the tendon and the bone. This layer became progressive integrated with the tendon–bone surface during the healing process. Biomechanical testing revealed higher maximal pull-out strength in experimental groups with a statistically significant difference at 3 and 6 weeks. These results suggest that photopolymerizable PEGDA and HA hydrogels are promising for tissue-engineered stem cell therapy to enhance tendon–bone healing.
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Saul, D., M. Ninkovic, M. Komrakova, et al. "Effect of zileuton on osteoporotic bone and its healing, expression of bone, and brain genes in rats." Journal of Applied Physiology 124, no. 1 (2018): 118–30. http://dx.doi.org/10.1152/japplphysiol.01126.2016.
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Estrogen deficiency and aging are associated with osteoporosis, impaired bone healing, and lower cognitive performance. Close functional and physical connections occur between bone and the central nervous system. An anti-inflammatory drug, zileuton (which is an inhibitor of arachidonate 5-lipoxygenase), is known to have a positive effect on bone tissue repair and brain ischemia. We studied the effect of zileuton on osteopenic bone and its healing and on the genes considered to be crucial for the cross talks between bone and brain. Three-month-old Sprague-Dawley rats were ovariectomized or left untreated. After 8 wk, bilateral metaphyseal tibia osteotomy with plate osteosynthesis was performed in all rats. Ovariectomized rats were fed with food containing zileuton (1, 10, or 100 mg/kg body wt) for 5 wk. In tibiae, bone volume, callus and cortical volume, and gene expression of osteocalcin and alkaline phosphatase were enhanced by zileuton (10 or 100 mg); biomechanical properties and bone density were not changed. In femur, zileuton enlarged cortical volume distal and trabecular volume proximal, decreasing their density. The expression level of brain Sema3a, known to regulate bone mass positively, was downregulated after ovariectomy. In contrast, bone Sema4d, a negative regulator of bone mass, was upregulated in the tibia callus after ovariectomy, whereas zileuton treatment (10 or 100 mg) resulted in reverse effects. Here, we describe for the first time the expression of Rbbp4 mRNA and its increase in tibia after ovariectomy. Zileuton caused downregulation of Rbbp4 in the hippocampus and had an effect on bone healing, changed the expression of genes involved in cross talk between bones and brain, and may be a potent drug for further examination in estrogen deficiency-related dysfunction(s). NEW & NOTEWORTHY Zileuton, a 5-lipoxygenase inhibitor, increased bone volume, callus and cortical volume in osteotomized tibia, and trabecular and cortical volume in femur. Although the expression of Sema3a (positively regulating bone mass) in brain was downregulated and Sema4d (negatively regulating bone mass) was upregulated in tibia callus after ovariectomy, zileuton could counteract these effects. Rbbp4 (involved in age-related memory loss) was increased in tibia callus after ovariectomy.
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Ramlee, Muhammad Hanif Hanif, Nur Amalina Zainudin, Hadafi Fitri Mohd Latip, Gan Hong Seng, Evelyn Garcia-Nieto, and Mohammed Rafiq Abdul Kadir. "Biomechanical evaluation of pin placement of external fixator in treating tranverse tibia fracture: Analysis on first and second cortex of cortical bone." Malaysian Journal of Fundamental and Applied Sciences 15, no. 1 (2019): 75–79. http://dx.doi.org/10.11113/mjfas.v15n2019.1263.
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Biomechanical perspective of external fixator is one of the greatest factor to consider in successfully treating bone fracture. This is due to the fact that mechanical behavior of the structure can be analyzed and optimized in order to avoid mechanical failure, increase bone fracture healing rate and prevent pre-term screw loosening. There are three significant factors that affect the stability of external fixator which are the placement of pin at the bone, configuration and components of external fixator. These factors lead to one question: what is the optimum pin placement in which exerts optimum stability? To date, literature on above mentioned factors is limited. Therefore, we conducted a study to evaluate the uniplanar-unilateral external fixator for two different pin placement techniques in treating transverse tibia fracture via finite element method. The study was started off with the development of transverse tibia fracture using Mimics software. Computed tomography (CT) data image was utilized to develop three dimensional tibia bone followed by crafting fracture on the bone. Meanwhile, the external fixator was developed using SolidWork software. Both tibia bone and external fixator were meshed in 3-matic software with triangular mesh element. Simulation of this configuration was took place in a finite element software, Marc.Mentat software. A load of 400 N was applied to the proximal tibia bone in order to simulate stance phase of a gait cycle. From the findings, the pin placement at the second cortex of bone provided optimum stability in terms of stress distribution and displacement, which should be considered for better treatment for transverse tibia fracture. On the other hand, the pin placement at first cortex should be avoided to prevent many complications.
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Mabuchi, Akiyoshi, Hiroshi Kitoh, Masato Inoue, Mitsuhiko Hayashi, Naoki Ishiguro, and Nobuharu Suzuki. "The Biomechanical Effect of the Sensomotor Insole on a Pediatric Intoeing Gait." ISRN Orthopedics 2012 (November 1, 2012): 1–5. http://dx.doi.org/10.5402/2012/396718.
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Background. The sensomotor insole (SMI) has clinically been shown to be successful in treating an intoeing gait. We investigated the biomechanical effect of SMI on a pediatric intoeing gait by using three-dimensional gait analysis. Methods. Six patients with congenital clubfeet and four patients with idiopathic intoeing gait were included. There were five boys and five girls with the average age at testing of 5.6 years. The torsional profile of the lower limb was assessed clinically. Three-dimensional gait analysis was performed in the same shoes with and without SMI. Results. All clubfeet patients exhibited metatarsal adductus, while excessive femoral anteversion and/or internal tibial torsion was found in patients with idiopathic intoeing gait. SMI showed significant decreased internal rotation of the proximal femur in terminal swing phase and loading response phase. The internal rotation of the tibia was significantly smaller in mid stance phase and terminal stance phase by SMI. In addition, SMI significantly increased the walking speed and the step length. Conclusions. SMI improved abnormal gait patterns of pediatric intoeing gait by decreasing femoral internal rotation through the end of the swing phase and the beginning of the stance phase and by decreasing tibial internal rotation during the stance phase.
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Guth, Jared, Sam Akhavan, Patrick Schimoler, Mark Miller, and Jon Hammarstedt. "Biomechanical analysis of ideal knee flexion angle for ACL graft tensioning utilizing multiple femoral and tibial tunnel locations." Orthopaedic Journal of Sports Medicine 9, no. 7_suppl4 (2021): 2325967121S0022. http://dx.doi.org/10.1177/2325967121s00225.
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Objectives: Despite more anatomic reconstruction of the ACL, graft failure rate has been reported to be greater than 5% at 5 years. There is concern that anatomic reconstructions may not result in an isometric graft and may predispose the graft to stretching. The current biomechanical study evaluated excursion of the ACL with different drill points for both femoral and tibial tunnels. The purpose was to evaluate the excursion of the ACL with both anatomic and non-anatomic tunnel combinations and determine the optimal flexion angle to tension the ACL to minimize stretching of the graft during motion. Methods: Ten cadaveric knee specimens, mid-femur to mid-tibia, were dissected of skin and subcutaneous tissue. The ACL was sectioned and the femoral and tibial attachments were marked prior to excision. A 1/16 inch drill was used to create a tunnel in the center of the ACL footprint on the tibia and femur and additional tunnels were made 5mm from the original tunnel (Figure 1). A suture was passed through each tunnel combination (Femur A-F; Tibia A-E) and was attached to a string potentiometer. The knee was ranged from full extension to 120 degrees of flexion for 10 cycles while mounted in a custom fixture that measured angle of flexion in the sagittal plane. The change in length (excursion) of the suture during movement was recorded for each combination of femoral and tibial tunnels. Results: Anatomic reconstruction of the ACL with tunnel placement in the center of the femoral (femoral tunnel A) and tibial (tibial tunnel A) footprint did not result in an isometric graft, with excursion of the ACL during knee motion of 7.46mm (SD 2.7mm). The tunnel combination that resulted in the least amount of excursion during knee motion was a reconstruction with a femoral footprint 5mm anterior to the femoral (femoral tunnel D) and 5mm posterior to the tibial footprint (tibial tunnel D) (4.2mm, SD 1.37mm). The tunnel combination that resulted in the most amount of excursion during knee motion was utilized femoral footprint 5mm proximal to the femoral (femoral tunnel F) and 5mm posterior to the tibial footprint (tibial tunnel D) (9.81mm, SD 2.68mm). In an anatomic tunnel placement, we found the angle with the most excursion of the ACL to occur at 2.84 degrees of flexion (SD 4.22). Conclusions: Anatomic ACL reconstruction results in significant excursion of the ACL during range of motion. If not tensioned properly, the ACL can stretch during range of motion, potentially leading to re-rupture. In order to prevent stretching of the graft, the current biomechanical study recommends tensioning an anatomic ACL reconstruction at its point of maximal exertion, or about 10 degrees of flexion. We also determined optimal flexion angles for tensioning the ACL for tunnel combinations that may be non-anatomic. [Table: see text][Table: see text][Table: see text]
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Moatshe, Gilbert, Jorge Chahla, Alex W. Brady, et al. "The Influence of Graft Tensioning Sequence on Tibiofemoral Orientation During Bicruciate and Posterolateral Corner Knee Ligament Reconstruction: A Biomechanical Study." American Journal of Sports Medicine 46, no. 8 (2018): 1863–69. http://dx.doi.org/10.1177/0363546517751917.
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Background: During multiple knee ligament reconstructions, the graft tensioning order may influence the final tibiofemoral orientation and corresponding knee kinematics. Nonanatomic tibiofemoral orientation may result in residual knee instability, altered joint loading, and an increased propensity for graft failure. Purpose: To biomechanically evaluate the effect of different graft tensioning sequences on knee tibiofemoral orientation after multiple knee ligament reconstructions in a bicruciate ligament (anterior cruciate ligament [ACL] and posterior cruciate ligament [PCL]) with a posterolateral corner (PLC)–injured knee. Study Design: Controlled laboratory study. Methods: Ten nonpaired, fresh-frozen human cadaveric knees were utilized for this study. After reconstruction of both cruciate ligaments and the PLC and proximal graft fixation, each knee was randomly assigned to each of 4 graft tensioning order groups: (1) PCL → ACL → PLC, (2) PCL → PLC → ACL, (3) PLC → ACL → PCL, and (4) ACL → PCL → PLC. Tibiofemoral orientation after graft tensioning was measured and compared with the intact state. Results: Tensioning the ACL first (tensioning order 4) resulted in posterior displacement of the tibia at 0° by 1.7 ± 1.3 mm compared with the intact state ( P = .002). All tensioning orders resulted in significantly increased tibial anterior translation compared with the intact state at higher flexion angles ranging from 2.7 mm to 3.2 mm at 60° and from 3.1 mm to 3.4 mm at 90° for tensioning orders 1 and 2, respectively (all P < .001). There was no significant difference in tibiofemoral orientation in the sagittal plane between the tensioning orders at higher flexion angles. All tensioning orders resulted in increased tibial internal rotation (all P < .001). Tensioning and fixing the PLC first (tensioning order 3) resulted in the most increases in internal rotation of the tibia: 2.4° ± 1.9°, 2.7° ± 1.8°, and 2.0° ± 2.0° at 0°, 30°, and 60°, respectively. Conclusion: None of the tensioning orders restored intact knee tibiofemoral orientation. Tensioning the PLC first should be avoided in bicruciate knee ligament reconstruction with concurrent PLC reconstruction because it significantly increased tibial internal rotation. We recommend that the PCL be tensioned first, followed by the ACL, to avoid posterior translation of the tibia in extension where the knee is primarily loaded during most activities. The PLC should be tensioned last. Clinical Relevance: This study will help guide surgeons in decision making for the graft tensioning order during multiple knee ligament reconstructions.
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Ding, Jing, Jin He, Zhi-qiang Zhang, Zhen-kai Wu, and Fang-chun Jin. "Effect of Hemiepiphysiodesis on the Growth Plate: The Histopathological Changes and Mechanism Exploration of Recurrence in Mini Pig Model." BioMed Research International 2018 (December 30, 2018): 1–10. http://dx.doi.org/10.1155/2018/6348171.
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Purpose. Hemiepiphysiodesis has been widely used to correct angular deformity of long bone in immature patients. However, there is a limited knowledge about the biomechanical effect of this technique on the histopathological changes of the growth plate and the mechanism of recurrence of malformation after implant removal. We aimed to evaluate the biomechanical effect of hemiepiphysiodesis on the histopathological changes of the growth plate and the mechanism of recurrence of malformation after implant removal in Bama miniature pigs, and to explore the role of asymmetric stress during this procedure. Methods. Eight 3-month-old male Bama miniature pigs sustained surgeries on the bilateral medial hind leg proximal tibia as the intervention group (n=16), and four pigs sustained bilateral sham surgeries as the control (n=8). In the 18th week after surgeries, hardware was removed in the unilateral leg of each animal in the intervention group. In the 24th week of the study, all animals were euthanized. A total of 24 samples were obtained and stained with H&E, TUNEL, and immunohistochemistry. Sixteen samples in the intervention group were divided into two subgroups. The tibias without an implant were included in the implant removal group (IR group), while the tibias with an implant were included in the implant persist group (IP group). The proximal tibia specimens were divided into 3 equidistant parts from medial to lateral, named as area A, area B, and area C, respectively. The change of thickness of growth plates, chondral apoptosis index, and the expression of Caspase-3, Caspase-9, CHOP, and P65 were compared. Results. H&E staining showed the thickness of growth plate to be varied in different areas. In the IP group, the thickness of growth plate in areas A and B was statistically significantly thinner than that in area C (p<0.05). In the IR group, the thickness of growth plate in areas A and B was statistically significantly thicker than that in area C (p<0.05). TUNEL staining showed that the apoptosis rate increased significantly after hemiepiphysiodesis and declined after implant removal (p<0.05). Immunohistochemical staining suggested that the expression of Caspase-3, Caspase-9, P65, and CHOP protein was upregulated in the experimental group and downregulated after implant removal. Conclusion. The thickness parameter of the growth plate changes with asymmetric pressure. When the pressure is relieved, the recurrence of malformation is related to the thickening of the growth plate.
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Bischoff, Jeffrey E., Lew Schon, and Charles Saltzman. "Influence of Geometry and Depth of Resections on Bone Support for Total Ankle Replacement." Foot & Ankle International 38, no. 9 (2017): 1026–34. http://dx.doi.org/10.1177/1071100717712508.
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Background: Aseptic component loosening is a leading cause of revision for total ankle replacement. Different operative approaches for resecting the tibia and talus impact the bony support for the prostheses due to variations in both bone density and resection area, and may therefore impact loosening performance. Methods: Computed tomography data from 116 subjects were obtained, and solid models of the talus and tibia were generated. Bone density, resection area, and bony support were measured on a series of flat resections for each subject, at multiple resection depths. Similar measurements were performed using a series of subject-specific, anatomic radius–based resections (“round resections”) at multiple depths. Results were compared to assess the impact of both resection type (flat vs round) and resection depth (6-16 mm for the tibia, 2-6 mm for the talus) on bony support. Results: Statistically significant decreases in bony support for both the talus and the tibia were obtained for flat resections as compared to round resections. A decrease of 8% to 19% for the tibia was seen for all resection depths; a decrease of 8% to 46% for the talus was seen, with greater decreases seen for shallower flat-cut resections. Conclusion: Bony support in total ankle arthroplasty may be decreased using flat resections compared to round resections at comparable resection depths. Estimated differences are resection-level dependent and different for the distal tibia vs the proximal talus. Clinical Relevance: Biomechanical characteristics of total ankle replacement impacted by bony support of the prostheses, including implant stability and resistance to subsidence, may be improved with round resections as compared to flat-cut resections.
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Weiler, Andreas, Jörg Dickschas, and Clemens Gwinner. "Anterior Open-Wedge Osteotomy in Posterior Cruciate Ligament Deficient Knees: From a Historical Perspective to First Clinical Results." Journal of Knee Surgery 34, no. 06 (2021): 592–98. http://dx.doi.org/10.1055/s-0041-1723983.
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AbstractRecently, the bony anatomy of the proximal tibia has gained strong interest, particularly in the cruciate ligament deficient knee. Regarding the anterior cruciate ligament (ACL), several studies outlined that a steep tibial slope (≥12 degrees) contributes to early failures after ACL reconstruction. As a consequence, the first clinical reports are available on slope reducing osteotomies in revision ACL surgery. Vice versa, biomechanical as well as clinical reports suggest that a flat slope increases the load on the posterior cruciate ligament (PCL) and might contribute to a poor result after PCL reconstruction. Since many decades, slope increasing anterior open wedge osteotomies are used to treat a symptomatic genu recurvatum. The aim of the current report is to describe different surgical techniques and report our first clinical experience of an anterior open wedge osteotomy as a sole procedure in chronic PCL deficient knees with a flat tibial slope. In six cases, a mean preoperative slope of 3.7 degrees (range = 2–5 degrees) was increased to a mean of 11.5 degrees (range = 9–13 degrees). There was one case with a delayed bone healing, which was successfully treated without loss of correction by revision internal fixation and bone grafting.
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PASSALI, C., A. PATSAKI, P. LELOVAS, et al. "Red wine polyphenols modulate bone loss in the ovariectomized rat model of postmenopausal osteoporosis." Journal of the Hellenic Veterinary Medical Society 70, no. 2 (2019): 1541. http://dx.doi.org/10.12681/jhvms.20860.
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The aim of this study was to examine the effect of Red Wine Polyphenols (RWPs) extract on bone mineral density (BMD) in the ovariectomized (OVX) rat model. Thirty-five 10-month-old Wistar rats were separated into controls (CTRL), OVX and OVX plus RWPs in their drinking water (dose, 50 mg/kg body weight per day), starting immediately after OVX for 6 months. Βody and uterine weight, BMD of the tibia at baseline, 3 and 6 months post-OVX, and 3-pointing bending of the femur, were examined. Statistical comparison of the total tibia BMD within groups during the study period showed a significant reduction in the OVX and OVX+RWPs groups both from baseline to 3 and 6 months and from 3 to 6 months, whereas in the CTRL group, there was no significant change. For the proximal tibial metaphysis, comparison of BMD percentage changes from baseline to 3 months and 6 months and from 3 to 6 months revealed highly statistical differences between OVX and OVX+RWPs groups (P = 0.000). OVX induced a significant reduction of biomechanical parameters as expected; the 3-point bending test showed that the maximum force before fracture, energy absorption and fracture stress significantly increased in the OVX group treated with RWPs compared with the nontreated OVX rats (P = 0.048, P = 0.002 and P = 0.003, respectively). Dietary intake of RWPs for 6 months significantly prevented trabecular bone loss and improved bone strength in estrogen-deficient ovariectomized rats.
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Perrien, Daniel S., Nisreen S. Akel, Paul K. Edwards, et al. "Inhibin A Is an Endocrine Stimulator of Bone Mass and Strength." Endocrinology 148, no. 4 (2007): 1654–65. http://dx.doi.org/10.1210/en.2006-0848.
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Gonadal function plays a major role in bone homeostasis. It is widely held that the skeletal consequences of hypogonadism are solely due to a loss of sex steroids; however, increases in bone turnover begin during perimenopause before decreases in serum estradiol levels. These data and our demonstration that inhibins acutely regulate bone cell differentiation in vitro led us to test whether inhibin A (InhA) regulates bone mass in vivo. Using a transgenic model of inducible human InhA expression, InhA increased total body bone mineral density, increased bone volume, and improved biomechanical properties at the proximal tibia in intact mice and also prevented the loss of BMD and bone volume and strength associated with gonadectomy at both the spine and proximal tibia. In addition, InhA increased mineral apposition rate, double-labeled surface, and serum osteocalcin levels in vivo and osteoblastogenesis ex vivo without affecting osteoclast number or activity. Together these results demonstrate novel stimulatory effects of InhA on the skeleton in vivo. These studies provide in vivo evidence demonstrating that gonadal factors other than sex steroids play an important role in regulating bone mass and strength and, combined with our previous clinical data, suggest that gonadal InhA may be a component of the normal endocrine repertoire that regulates bone quality in both the axial and appendicular skeleton.
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Lee, Seong-Man, Chang-Wug Oh, Jong-Keon Oh, et al. "Biomechanical Analysis of Operative Methods in the Treatment of Extra-Articular Fracture of the Proximal Tibia." Clinics in Orthopedic Surgery 6, no. 3 (2014): 312. http://dx.doi.org/10.4055/cios.2014.6.3.312.
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