Patellar Tendon Reconstruction Following Septic Arthritis: A Case Report of an Autograft Technique With Quadriceps Tendon Reinforcement.

Loss of the patellar tendon or the entire extensor mechanism is a rare but devastating complication of post-traumatic septic arthritis. Although both autografts and allografts are used for reconstruction, the combination of hamstring tendon autografts with quadriceps tendon reinforcement offers a reliable biological option to restore knee extension. We report the case of a 35-year-old man who developed complete patellar tendon loss following septic arthritis secondary to a heavily contaminated penetrating knee injury from a motorcycle accident. After infection control with aggressive debridement, partial patellectomy, and 45 days of intravenous antibiotics, reconstruction was performed using semitendinosus and gracilis autografts passed through transosseous tunnels in the tibial tuberosity and patella, reinforced with a V-Y quadriceps tendon plasty. At the one-year follow-up, the patient achieved good functional outcomes: Lysholm score of 88, International Knee Documentation Committee (IKDC) score of 82, Kujala score of 86, and Tegner score of 5. He returned to heavy manual labor without limitations, despite not resuming competitive sports. This case demonstrates that biological reconstruction with hamstring autografts and quadriceps reinforcement can successfully restore extensor mechanism function after post-traumatic septic arthritis. In previously infected fields, autografts offer improved biological incorporation and a lower theoretical risk of reinfection, while providing a cost-effective alternative to allograft use.