New treatment of patellar instability after total knee arthroplasty: A case report and review of literature.

Background: Patellar instability is an uncommon complication after total knee arthroplasty (TKA). Partial lateral patella facetectomy (LPF) with lateral retinaculum release treatment of patellar instability is rarely reported.

Case Summary: We present a case of patellar instability 8 mo after primary TKA. Treatment of this complication was adapted to address the cause of the dislocation. To eliminate patellar instability, we restored the vastus medialis and performed LPF with lateral retinaculum release. We achieved normal patellar tracking. Clinical and radiographic evaluations at the 1-year postoperative follow-up were satisfactory.

Conclusion: LPF with lateral retinaculum release represents a promising option to restore central patellar tracking in patients with patellar instability after TKA in cases without component malposition.