Extracorporeal Shockwave Therapy for Popliteal Tendon Impingement Post-total Knee Replacement: A Case Report of Successful Nonsurgical Management

Popliteal tendon impingement (PTI) is a rare and often overlooked cause of persistent pain and functional limitations after total knee replacement (TKR). Conventional treatments provide limited relief. A 78-year-old male previously underwent cruciate-retaining TKR with restricted kinematic alignment to treat Grade 3 knee osteoarthritis. Despite appropriate intra- and postoperative care, he developed persistent posterolateral knee pain and effusion 3 months postoperatively. Dynamic ultrasonography revealed effusion around the popliteal tendon without bony spurs or cementophytes. After 6 months of unsuccessful conservative management, the patient received five sessions of weekly focused extracorporeal shockwave therapy (ESWT) targeting the posterolateral knee. Three months later, the patient demonstrated improvements in the Visual Analog Scale score (from 5 to 1), knee range of motion (0°–122° to 0°–130°), Western Ontario and McMaster Universities Osteoarthritis Index score (16 to 8), and Oxford Knee Score (27 to 37). This case demonstrates the potential efficacy of focused ESWT as a noninvasive alternative for managing PTI following TKR.