Selective Denervation for the Thumb Carpometacarpal Joint: Clinical Outcome and Comparison Based on Eaton Stage.

Abstract

Various operative treatment options for advanced thumb carpometacarpal (CMC) joint arthritis have been presented without a definite surgical guideline. Selective denervation is a less invasive method for thumb CMC arthritis. However, it is unclear whether the clinical outcome varies with the stage of thumb CMC arthritis. This study aimed to evaluate the effectiveness of selective denervation on CMC arthritis for pain relief and functional outcome and to determine whether selective denervation depends on the stage of thumb CMC arthritis. We evaluated 29 thumbs of 28 patients with thumb CMC arthritis treated with selective denervation. The disease stage was determined with the classification system described by Eaton. The denervation was performed in the articular branches of the palmar cutaneous branch of the median nerve, lateral antebrachial cutaneous nerve, and superficial branch of radial nerve. The clinical outcomes were evaluated using the visual analog scale (VAS) and Disabilities of the Arm, Shoulder, and Hand (DASH) scores, along with evaluation of the improvement in both postoperative range of motion and strength recovery. The mean duration of follow-up was 24 months (range, 18-48 months). The average VAS and DASH scores decreased from 6.1 to 1.3 and from 54.3 to 24.1, respectively. The range of motion during palmar abduction and opposition of the metacarpophalangeal joint improved with an increase in mean value from 44.1 to 53.7 degrees, and the Kapandji score increased from 7.2 to 9.2, respectively. The grip and key pinch strengths increased from mean preoperative values of 14.3 and 3.1 kg to 27.1 and 6.2 kg, respectively, as measured at the 12-month follow-up. The rate of change in the VAS and DASH scores was significantly higher in stages I to III than in stage IV ( P = 0.01, P < 0.01, respectively). The selective denervation for thumb CMC arthritis was effective in pain relief and functional recovery with several advantages, including less invasive procedure, quick recovery time, and regaining of strength. The clinical outcomes were more effective in the early-stage group (Eaton stages I and II) compared with the advance-stage group (Eaton stages III and IV).