Patellar tendon reconstruction using an Achilles tendon-bone block allograft for periprosthetic joint infection accompanied by patellar tendon disruption after total knee arthroplasty: a case report.

Background: As a complication of total knee arthroplasty (TKA), patella tendon disruption has been scarcely reported. Moreover, combined periprosthetic joint infection with patellar tendon disruption is even rare. This is a case report on successful treatment of a recurred periprosthetic joint infection accompanying the patellar tendon disruption after revision of TKA.

Case Description: A 63-year-old woman presented with pain and exudate in the right knee. she had a history of two-stage revision TKA at another hospital for periprosthetic joint infection of right knee. With repeated incision and debridement, Achromobacter xylosoxidan was identified in samples collected from deep tissue. Therefore, two-stage revision TKA was performed. Intra-operatively, a complete defect of the patellar tendon was observed. Re-revision TKA was performed as a routine of two-stage revision of TKA for periprosthetic joint infection. Reconstruction of the patellar tendon defect was performed using an Achilles tendon-bone block allograft. Stability of allograft was confirmed at 30 degrees of flexion, and excellent implant placement was confirmed by postoperative radiographs. At the final follow-up 3 years after surgery, evidence of infectious sign was absent, and the range of flexion up to 120 degrees was recovered without extension lag. Normal locomotive gait was restored, and recreational activities previously performed were possible without discomfort.

Conclusions: Proper reconstruction of extensor mechanism was achieved by patellar wrapping technique using an Achilles tendon-bone block allograft.