Autologous chondrocyte transplantation in the treatment of thumb CMC joint osteoarthritis.

Degenerative thumb carpometacarpal (CMC) joint osteoarthritis is a common disease in women starting at 40-50 years of age. Nevertheless, synovitis and initial cartilage damage start earlier, and then degenerative arthritis develops leading to joint narrowing with progressive exposure of subchondral bone, subluxation, osteophyte formation and joint deformity that can impact the surrounding joints. The aim of this study was to evaluate the outcome of patients treated with autologous chondrocyte transplantation at the thumb CMC joint at early stages. A prospective study on 10 cases of thumb CMC osteoarthritis in 8 patients was done. The thumbs were stage Eaton II (2 cases) and III (8 cases) and were treated by CMC arthroplasty with the implant of autologous chondrocytes by an open or arthroscopic technique. Two patients were treated bilaterally. Preoperatively all patients had persistent pain resistant to various kinds of nonoperative treatments for at least 1 year. Mean preoperative pinch strength was 3.7 Kg pain on VAS was 8, DASH was 55. All patients had limited abduction and flexion at the end range. Ethics committee approval was obtained for this study. Fragments of 3-4 mm of cartilage were harvested by arthroscopy or by an open technique from the wrist or elbow joint. Cartilage cells were sent to the laboratory to be grown on a collagenous biphasic matrix (MACI/Novocart®). After 3 weeks, the chondrocyte augmented scaffold was ready to be implanted in the thumb CMC joint, or frozen for a second operation later. All patients were females aged 42-67 years (mean 52 years). The dominant hand was treated in 6 cases. In 7 cases, the patients were operated with an open technique and in three cases by arthroscopy. Partial trapezium resection and dorsoradial ligament reconstruction was added to stabilize the CMC joint in most cases. Patients were seen in person at 1, 3, and 6, months, 1 year, 2 years, and 5 years after the initial surgery. Patients (nine thumbs) were then reviewed at a mean follow up 8 years (range 4.4-11 years); pain on VAS, Mayo, DASH and PRWE scores were evaluated at follow-up. One patient was lost to follow-up after 2 years. Of those nine hands, seven had an excellent result according to Mayo score, one had a good result. One thumb CMC joint was still painful and was reoperated and converted to arthroplasty after 4.4 years. All patients regained full range of motion. Mean pinch strength increased to 6.25 ± 1.3 Kg, mean DASH score was 7.3 ± 6.7; pain on VAS was 1.0 ± 1.5; these data were statistically significant compared to preoperative values (p < 0.01). Grip strength also increased in all cases, but this was not statistically significant. PRWE was 7.7 ± 6.4. No complications occurred postoperatively. The results obtained are encouraging since the implanted cartilage has lasted a mean of 8 years and up to 11 years. Biological tissue engineering techniques are being developed and could be a new solution to restore normal cartilage in young patients to postpone more aggressive surgical procedures until an older age. In cases of CMC joint instability, a ligament stabilization procedure was added to avoid subsequent damage to the implanted neocartilage. A longer follow-up and a greater number of cases are necessary to definitively establish the usefulness of this procedure, which has the advantage of being completely biological but the disadvantage of being costly.