gms | German Medical Science

Objectives/Interrogation: Arthroscopic surgery has become a more popular for the treatment of osteoarthritis of the thumb carpometacarpal joints (CMC-OA), since introduction of interposition arthroplasty. However, it is difficult to indicate the arthroscopic interposition arthroplasty for the patients with radial instability in CMC-OA. We reported a new technique of arthroscopic suspension arthroplasty for CMC-OA along with a minimum of 2 years of results.

Methods: Twenty-nine thumbs with were treated by arthroscopic suspension arthroplasty. The procedure included partial trapeziectomy followed by ligamentoplasty using PL tendon similar to Thompson technique. Under arthroscopic visualization, the bone tunnel was made on base of 1st and 2nd metacarpal bone, and PL was passed through the bone tunnels in the order of dorsal diaphysis, articular surface of 1st metacarpal, base of 2nd metacarpal, dorsal capsule and APL tendon. Finally, the tendon was fixed to both metacarpals using interference screws and was tightly sutured to APL. We evaluated pain VAS; DASH; grip and pinch strength; thumb abduction range of motion, and radiographic examination including trapezial space and subluxation ratio preoperatively and every 3 months until 1 year after surgery, and every 6 months thereafter. Besides, these assessments were analyzed in the patients with greater than 1/3 subluxation of the 1st metacarpal base, referred to Menon's classification.

Results and Conclusions: The mean duration of the follow-up was 3.2 years. The mean preoperative pain VAS and DASH were 71 and 45.7, respectively, which were significantly reduced to 7 and 20.0 at the final. Also, strength of grip, tip, and key pinch significantly increased at 9, 9, and 12 months later after surgery, respectively. Abduction motion tended to decrease, although the differences were not significant. Although trapezial space ratio was significantly reduced, there were no significant differences in the results between each follow-up time and the final follow-up. Subluxation ratio was significantly improved and maintained until the final follow-up. Furthermore, the values of clinical and radiographic outcomes, except motion, were significantly improved in patients with greater than 1/3 subluxation of the 1st metacarpal base. In conclusion, the clinical outcomes of this technique were: satisfaction with pain relief, recovery of hand and thumb strength, insignificant decrease of abduction motion, and radiological reduction, even in the patients with radial instability in CMC-OA.