Bilateral Spontaneous Midsubstance Patellar Tendon Rupture after Bilateral Total Knee Arthroplasty

INTRODUCTION Patellar tendon rupture can occur due to multiple causes ranging from inflammatory pathologies to episodes of trauma. Extensor mechanism rupture is a rare complication of total knee arthroplasty (TKA). In most of these cases, the failure occurs as avulsion of patellar tendon from tibial tuberosity. We report a rare case with bilateral mid-substance patellar tendon rupture one month after bilateral total knee arthroplasty. CASE PRESENTATION A 69-year-old male was operated for bilateral grade 4 osteoarthritis. On day 30 post-operative, he sustained bilateral patellar tendon rupture while getting up from toilet. He had a history of multiple steroid injections in the knee, which could have affected the tendon. The other etiologies could be inherent weakness of tendon due to diabetes and old age and micro-trauma/stretch associated with sudden correction of previous deformity by TKA. The management in our case was done by primary repair along with augmentation by autologous semitendinosus graft and suture anchor. CONCLUSION The operating surgeon must be aware of the possibility of patellar tendon rupture following total knee arthroplasty. This will help the surgeon in early recognition and preparedness to handle such complications, should they arise. Surgeons may consider advising caution to both patient and rehabilitation team in cases with old age, chronic diabetes mellitus, and with a history of steroid injections.