Challenges in postoperative rehabilitation of chronic patellar tendon rupture following delayed surgical reconstruction: a case report

BACKGROUND: Chronic patellar tendon rupture (CPTR) represents a rare but disabling injury that presents major surgical and rehabilitative challenges, especially when diagnosis and repair are delayed. CASE PRESENTATION: This case describes a 33-year-old male who sustained a right knee injury during recreational sport that remained untreated for 12 months. Magnetic resonance imaging (MRI) confirmed CPTR with marked retraction and patella alta. Surgical reconstruction using a semitendinosus-gracilis autograft was followed by a six-month, phase-based rehabilitation program emphasizing protected mobility, progressive strengthening, and neuromuscular control. Throughout supervised sessions, the patient achieved clinically meaningful but partial functional improvement: pain decreased from VAS 6 to zero, and KOOS subscales improved relative to baseline values. Although postoperative MRI revealed partial graft rupture, residual laxity, and persistent patellar elevation, the patient regained independent ambulation, reported high satisfaction, and demonstrated a residual extension lag of 5-10°. CONCLUSION: This case underscores the complex relationship between structural imaging findings and functional recovery following delayed CPTR reconstruction, illustrating that partial functional improvement may coexist with persistent structural abnormalities. Additionally, socioeconomic barriers that delayed access to specialized care significantly shaped the recovery trajectory, reinforcing the importance of early diagnosis and integrated rehabilitation strategies in complex extensor-mechanism injuries.