gms | German Medical Science

Objectives/Interrogation: Thumb basal joint arthritis that affects up to 11% and 33% of men and women in 50s and 60s, respectively, is treated by several surgical techniques (Menon's interposition or LRTI arthroplasty, Mini TightRope CMC Technique). By using RegJoint spacer and avoiding resection of FCR or APL tendon, we simplify and shorten the surgery. We hypothesize that this new technique is a better alternative for rhizarthrosis operation, because it reduces post-OP pain and shortens the time until complete recovery.

Methods: In 92 pts (aged 43 - 81 years) with rhizarthrosis, dorsoradial longitudinal incision at the base of the thumb was performed. We created a capsular flap with a distal base over the TMC joint, following partial or complete resection of the trapezium. Thereafter, we inserted the RegJoint disk spacer and firmly sutured the capsule. In 23 pts we performed additional beak (volar) ligament reconstruction with APL or FCR tendon. Patients began with physiotherapy after 3 weeks of immobilization. Thereafter, we monitored their recovery for 1 year post-OP by performing QuickDASH score, VAS, Kapandji's 10-point functional score, Mayo wrist score and X-ray. The statistical significance of improvements were tested with 1W RM ANOVA (p < 0.05).

Results and Conclusions: All monitored parameters statistically significantly improved until the first month post-OP. Average measures of QuickDASH score reduced from 43.5 pre-OP to 34.5, 26.4 and 21.3 1m, 3m and 1y post-OP, respectively. Average VAS score, which was 7.1 pre-OP, also improved to 5.7, 3.1 and 1.9 1m, 3m and 1y post-OP, respectively. Kapandji's functional score improved from 4.7 point pre-OP to 5.9, 8.1 and 9.2 point 1m, 3m and 1 year post-OP, respectively. Mayo wrist score that was 45 preOP improved to 54, 69 and 76 1m, 3m and 1 year post-OP, respectively. Pre- and post-operatively X-ray controls were made to evaluate the distance between the base of first metacarpal bone and the remaining trapezium/distal pole of scaphoid. The average distance statistically significantly increased from 0.3 mm to 3.1 and 3 mm after 1 and 3 months, respectively. Until the 1st y post-OP the distance narrowed to 2.1 mm.

Using this novel and feasible technique of rhizarthrosis therapy, the final recovery outcomes are at least comparable to the other surgical techniques. Most importantly, we can perform earlier mobilization with significantly lower pain and stable (well-positioned) base of first metacarpal, which enables earlier return of patient to the workplace.