Total Knee Arthroplasty in Patients With Excessive External Tibial Torsion > 45° and Patella Instability – Surgical Technique and Follow Up

Patients presenting with advanced knee osteoarthritis (OA), excessive external tibial torsion (EETT) and chronic patella subluxation pose significant surgical challenges. A combination of TKA, tibial derotation osteotomy, and tibial tuberosity transfer was performed in ten patients (twelve knees) with OA secondary to EETT and patellar instability. Six weeks of non weight-bearing and flexion limited to 45° was mandated after surgery. The mean follow-up and patient age was 81 months (range, 14 to 159) and 56 years (range, 49 to 62). The mean pre-operative external tibial torsion was 62°, with an average rotational correction of 30°. Significant improvement was found in the Knee Society Score, SF-12 and all WOMAC questionnaire score subscales (p < 0.0001); 5 patients had complications, but no loosening or nonunion was seen.