Title : Patellar tendon rupture following Total Knee Arthroplasty (TKA): A case report
Abstract:
Background: Patellar tendon rupture is an uncommon complication after Total Knee Arthroplasty (TKA). This complication leads to impairment of the extensor mechanism and leads to many challenges during surgical reconstruction.
Case Presentation: We present the case of a 60-year-old female who presented to the ED with right knee pain following a mechanical fall. On physical exam, she had full range of motion of the right lower extremity and was able to bear weight on the leg with assistance. She had a past surgical history of a right total knee arthroplasty about 1 month prior. She was discharged following radiographic confirmation that her knee hardware was intact. At a subsequent clinic visit, and with MRI confirmation, it was apparent she sustained a right patellar tendon rupture. The patient underwent surgical reconstruction using an Achilles tendon allograft. Through a standard anteromedial approach, extensive scar tissue and remnant tendon were exposed. A lateral retinacular release was performed to mobilize the extensor mechanism. A tibial trough measuring 2.5–3 cm × 2 cm was fashioned at the tibial tuberosity, into which the cortical-cancellous bone block of the Achilles allograft was secured with a 4 mm partially-threaded cancellous screw. The tendon was split into three branches: the central portion anchored to the distal pole of the patella with two suture anchors and further woven into the quadriceps tendon at the superior patellar pole, while the medial and lateral branches were tacked to their respective retinacula. The patellar tendon stump was incorporated into the graft construct, and stability was confirmed with knee flexion to 90°.
Standard layered closure was performed.
Outcome: The reconstruction restored patellar height and extensor continuity, with appropriate tension confirmed intraoperatively. The patient tolerated the procedure well without intraoperative complications.
Conclusion: Achilles tendon allograft is a viable option for reconstructing patellar tendon rupture following TKA, providing restoration of the extensor mechanism with secure fixation at both tibial and patellar sites. This case highlights key technical steps to achieve anatomic alignment and functional restoration in a challenging scenario.
