ABSTRACT
Introduction: A case of neglected anterior dislocation of the knee leading to instablity with severe secondary osteoarthritis is very rare to come across, and there are not many reported articles to the best of our knowledge. Due to the rarity of the occurrence, there are no proper treatment guidelines laid out yet. Case Report: A 62-year-old hypertensive male with BMI 26.6 presents with an unstable lax right knee with severe osteoarthritis secondary to untreated chronic traumatic anterior dislocation of the knee that happened 12 years back. He was examined clinically and radiologically and further underwent total knee arthroplasty (TKA) for the same at our center. Discussion: Knee dislocation is a very rare injury and a case of neglected dislocation leading to unstable osteoarthritic knee is even more rare. These cases need thorough planning which should include an extensive clinical examination followed by imaging studies and Doppler scan to study the status of the vasculature. TKA for such a case is challenging and the use of hinged prosthesis or a constrained prosthesis is recommended when unstable.
ABSTRACT
BACKGROUND: The tibial cut referenced to the center of the intercondylar eminence often leads to varus malalignment in the presence of preexisting proximal tibia vara. The purpose of this study was to investigate the effect of lateralization of the lateral tibial plateau reference point (based on the amount of proximal tibia vara) on the postoperative coronal plane alignment. METHODS: In this prospective cohort study, 62 patients (95 knees) with osteoarthritis and proximal tibia vara underwent primary total knee arthroplasty using a lateral tibial plateau reference point for the extramedullary jig. The pre- and postoperative radiographs were obtained for measurement of mechanical axis deviation, degree of tibia vara, proximal lateral reference point of the tibial condyle, and coronal alignment of the femoral and tibial components. The distance between the tibial reference point and the center of the intercondylar eminence was measured intraoperatively. RESULTS: The mean tibia vara was 7.1° (standard deviation [SD], 2.3°). The mean lateral displacement of the reference point was 7 mm (SD, 2.2 mm). Postoperative tibiofemoral angle was 6° to 10° of valgus in 94% of cases. There was a strong correlation between the magnitude of tibia vara and the amount of lateralization of the tibial reference point (R2 = 0.79, p < 0.001). CONCLUSIONS: In total knee arthroplasty patients with proximal tibia vara, reasonable accuracy can be achieved with use of the extramedullary jig for tibial component alignment by lateralizing the proximal tibial reference point.
