Modified Partial Lateral Facetectomy of the Patella for Stage III Patellofemoral Osteoarthritis with 5-Year Follow-Up.

The main aim of this article was to examine the therapeutic evaluation of our modified partial lateral facetectomy of the patella for stage III lateral patellofemoral osteoarthritis (PFOA), which includes (1) partial lateral patella articular facet that was resected; (2) coronal Z-shaped incision to lengthen lateral retinaculum; (3) patellar perimeter electrocoagulation to denervate. Between December 2008 and January 2013, 36 knees of 32 patients with severe patellofemoral (PF) osteoarthritis (OA) were treated with our modified partial patellar lateral facetectomy. All patients were stage III according to the Iwano scale, and their patellas were all Wiberg type III or Baumgartl type IV in shape. The study group included 6 males and 26 females with an average age of 54.03 years and an average disease course of 8.67 years. The modified Kujala scores were used to evaluate PF function, and the congruence angle was used to evaluate the patellar position. Knee Society Scores (KSS) were used to evaluate overall knee function. Six knees of five cases were lost to follow-up. Thirty knees of 27 cases were followed up for 5 years, with an average follow-up time of 60 ± 3.2 months. The average preoperative modified Kujala score was 15.93, and the average score at last follow-up was 32.03; The satisfactory PF function was achieved in 28 knees (93.33%). The congruence angle improved from preoperative +23. 07 degrees to 11. 91 degrees at the last follow-up. The average preoperative KSS were 110.40 points, which increased to 156.77 points at the last postoperative follow-up. Pain was significantly relieved, and the ability to climb stairs was significantly improved. All scores showed statistically significant improvements after surgery ( p  < 0.05). No complications were reported. Our modified partial lateral facetectomy of the patella for stage III lateral PFOA can relieve pain and partially improve function. This modified procedure is relatively simple, safe, and an effective treatment method for middle-aged and elderly patients with PFOA. Furthermore, this surgery can be used as an alternative or prephase to total knee arthroplasty. This is a Level IV, therapeutic study.