Treatment for complex knee osteoarthritis with total knee arthroplasty via lateral parapatellar approach-four case reports.

RATIONALE: It was previously believed that lateral parapatellar approach was only considered in the presence of valgus deformity, with much technical difficulties and complications. However, this approach may serve as an optional alternative for carefully selected complex knee cases when performing total knee arthroplasty (TKA) under certain clinical conditions. PATIENT CONCERNS: All 4 patients suffered from knee joints pain and limited mobility range from 1 to 10 years. There was no history of unusual diseases, infectious diseases or hereditary disorders. DIAGNOSES: Primary or secondary knee osteoarthritis. INTERVENTIONS: All 4 patients underwent TKA under general anesthesia. The lateral approach was used in 3 cases, and the remaining case chosen the medial approach. OUTCOMES: Patients successfully received TKA with satisfactory restoration of lower limb alignment postoperatively. Three cases achieved good outcomes, demonstrating significant improvement in knee range of motion without complications. One case treated with the medial approach developed poor wound healing with subsequent infection. LESSONS: The lateral parapatellar approach can be regarded as a feasible surgical choice for specific complex knee scenarios during TKA.