Artificial ligament reconstruction for chronic bilateral knee extensor mechanism ruptures involving unilateral quadriceps tendon rupture and contralateral patellar tendon rupture in a patient with uremia: a case report and literature review

Patients with uremia undergoing long-term hemodialysis are susceptible to tendon degeneration and impaired tendon–bone interface integrity, which may predispose them to spontaneous or low-energy rupture of the knee extensor mechanism. However, these injuries are rare and often lead to delayed diagnosis due to the absence of a definite trauma history and atypical clinical presentations. We report a case of chronic bilateral knee extensor mechanism rupture in a 43-year-old male with end-stage renal disease on regular hemodialysis for over 8 years. The patient presented with bilateral knee pain for more than 4 months. Physical examination revealed complete loss of active knee extension, with palpable depressions below the left patella and above the right patella. Radiographs showed patella alta on the left and patella baja on the right, while MRI confirmed a left patellar tendon rupture and a right quadriceps tendon rupture. The patient underwent bilateral reconstruction using LARS artificial ligaments, followed by a staged rehabilitation program and brace protection. At the 2-year follow-up, knee range of motion approached normal, and Lysholm, Tegner, and IKDC scores showed significant improvement compared with preoperative values. Uremia and long-term hemodialysis substantially increase the risk of spontaneous or low-energy knee extensor mechanism ruptures. Sudden knee pain, impaired ambulation, or loss of active extension in these patients should prompt consideration of extensor mechanism rupture, with early confirmation via radiographs and MRI. In chronic ruptures with severe tendon degeneration or compromised autograft quality, artificial ligament reconstruction offers an effective surgical alternative.