Osteochondral autograft transplantation for isolated patellofemoral osteoarthritis

The purpose of this retrospective study was to evaluate clinical outcomes of osteochondral autograft transplantation (OAT) for isolated patellofemoral (PF) osteoarthritis (OA).

OAT was performed in seven patients (six men, one woman; mean age, 61.1 years) with isolated PF OA. The mean duration of follow up was 46.9 months (range, 24–84 months). Clinical outcomes were evaluated preoperatively and postoperatively according to the International Knee Documentation Committee (IKDC) objective score and the knee scoring system of the Japanese Orthopaedic Association (JOA) score. The International Cartilage Repair Society (ICRS) score was recorded in three cases that underwent second-look arthroscopies postoperatively. For morphological evaluation, the Kellgren and Lawrence (KL) classification and the modified magnetic resonance observation of cartilage repair tissue (MOCART) score were used.

The mean IKDC and JOA scores were both significantly improved. The percentage of normal and nearly normal on the IKDC score was increased from 28.6% (2/7) to 85.7% (6/7) (P = 0.05). The mean JOA score was improved from 80.0 (range, 65.0–85.0) to 95.0 (range, 90.0–100) (P = 0.0008). The mean ICRS scores were 10.3 (nearly normal) in the three cases that underwent second-look arthroscopies postoperatively. Regarding KL classification, the grade was unchanged in five cases (two cases in grade 1, three cases in grade 2) and improved in two cases (from grade 3 to 2, from grade 4 to 3). The mean modified MOCART score was 67.9 (range, 60.0–75) at 12-month follow up. There were no complications, and satisfaction was obtained in all cases. The study design was case series: level IV.

All clinical scores improved significantly postoperatively. Osteochondral plugs were transplanted perpendicular to the articular surface to obtain good congruity of the repaired articular surface. In this way, OAT is an effective procedure to prevent progression of isolated PF OA.