Importance of ST arthroplasty in the treatment of STT osteoarthritis and concomitant basal thumb osteoarthritis

Abstract

Basal thumb osteoarthritis is one of the most prevalent forms of osteoarthritis worldwide and is frequently associated with osteoarthritis of the STT joint. The surgical gold standard comprises various modifications of arthroplasty resection. A retrospective study compared the postoperative results of Lundborg's resection-suspension-arthroplasty, modified by Wulle, with and without additional ST arthroplasty. In this study, 50 patients with symptomatic basal thumb osteoarthritis (stages III and IV) were examined. Twenty-one of them were treated with conventional resection-suspension-arthroplasty (RSA) and 29 patients were treated with the same technique and additional ST arthroplasty (RSA-plus). The analysis included an assessment of the Thumb Disability Examination (TDX) score, the Kapandji Thumb Opposition score, the Visual Analogue Scale (VAS) pain score as well as grip force, key pinch force, two-point and three-point pinch force. In both groups, the duration of the operation was comparable. The overall TDX score was 15.9 ± 19.5 in the RSA-plus group and 20.8 ± 24.3 in the RSA group (p > 0.05). A marginally significant difference was noted for the Kapandji score, which was 9.5 ± 1.1 in the RSA-plus group and 8.9 ± 1.6 in the RSA group (p = 0.08). There was no significant difference between both groups for grip strength (RSA-plus: 48.3 ± 21 kPa, RSA: 55.2 ± 24.9 kPa (p > 0.05)), key pinch force (RSA-plus: 32.6 ± 15 kPa, RSA: 37.3 ± 15.4 kPa (p > 0.05)), two-point pinch force (RSA-plus: 30.6 ± 12.9 kPa, RSA: 34.8 ± 12.4 kPa (p > 0.05)) and three-point pinch force (RSA-plus: 36.2 ± 14.2 kPa, RSA: 42 ± 13.6 kPa (p > 0.05)). Both groups demonstrated insignificant differences in pain intensity at rest (RSA-plus: 0.4 ± 1.3, RSA: 1 ± 2.1 (p > 0.05)), during movement (RSA-plus: 0.7 ± 1.8, RSA: 1.6 ± 2.7 (p > 0.05)) and under stress (RSA-plus: 1.6 ± 2.5, RSA: 2.9 ± 3.4 (p > 0.05)). The followed-up patient groups demonstrated no significant differences in the examined variables. This leads us to the conclusion that there are no disadvantages associated with performing ST arthroplasty in addition to conventional RSA. In fact, based on the collected data, we suggest that ST arthroplasty should be more widely indicated in the context of RSA.