Total bilateral ruptures of the knee extensor apparatus☆

Objective Bilateral extensor tendon ruptures of the knee are rare and have only been published in the form of case reports or small series. Methods Seven patients corresponding to 14 extensor tendon ruptures of the knee were evaluated by the same examiner after a minimum one year post-surgery. Clinical and radiographic evaluations were performed; for statistical analysis, the level of significance was set at 0.05. Results The most common injury was patellar tendon rupture (n = 9; 64.29%) followed by quadriceps tendon rupture (n = 5, 35.71%). The intrasubstance was the most affected location (57.15%), followed by the myotendinous junction (21.43%) and the patellar bone insertions (21.43%). Quadriceps tendon ruptures were more prevalent in patients older than 50 years, while patellar tendon ruptures tended to occur in younger individuals. All but one patient had recognized risk factors for tendinous degeneration and rupture: 75% of the cases suffered from diseases, 50% had history of drug use and/or abuse, and 37.5% had both disease and drug use history. Mean attained values for flexion ROM were 124.64° ± 9.43 (110-140°) and 89.57 ± 6.02 (78-94) for Kujala score. More than half of the patients complained of residual pain and quadriceps muscular weakness. Mean age was younger in the individuals who complained of residual pain. Conclusion Bilateral tendon ruptures of the knee extensor apparatus ruptures are rare and serious injuries, mostly associated with risk factors. Early surgical repair and intensive rehabilitation program for bilateral extensor tendon ruptures of the knee may warrant satisfactory functional outcomes in the medium to long term, despite non-negligible levels of residual pain, quadriceps muscle weakness, and atrophy.