Suspension arthroplasty versus interposition arthroplasty in the treatment of trapeziometacarpal osteoarthritis. a clinical and magnetic resonance imaging study

Introduction: Biological arthroplasties are the most used surgical techniques, for the treatment of trapeziometacarpal osteoarthritis; all of them provide the reconstruction of trapeziometacarpal joint by a tendon graft. The aim of the study is to compare two surgical techniques: interposition arthroplasty and suspension arthroplasty at 12-month follow-up in order to evaluate the clinical and radiographic results. Methods: Sixty-seven patients surgically treated for basal thumb osteoarthritis were divided into two groups: 36 patients, (8 M; 27 F) (39 hands), treated with interposition arthroplasty are included in group A and 31 patients, (6 M; 25 F) (34 hands), treated with suspension are included in group B. Both groups were radiographically evaluated with X-ray and MRI at 12 months and clinically evaluated with DASH score, VAS, Grind test, hand grip tests, Kapandji test and ROM before surgery and at final follow-up. Results: At final follow-up about Kapandji test, in group A, 31 hands (79.4%) presented Kapandji score of 10 and eight hands (20.6%), a Kapandji score of 8. In group B, six hands (17.6%) reported a Kapandji score of 8 and 28 patients (82.4%), a Kapandji score of 10 (p < 0.05). Regarding the radial abduction, patients of group A recovered on average 79.5° of abduction and in group B recovered on average 78°. About DASH score and VAS score, group B shows better results. Mean decalage was 2.3 mm in group A and 0 mm in group B. Jamar dynamometer shows statistically better results for group B in all tests (hand grip test, pulp pinch and key pinch test). Conclusions: Suspension arthroplasty seems to guarantee better outcomes in terms of pain reduction, clinical score and recovery of grip strength. Moreover, it seem to be associated with better results at MRI like absence of I ray decalage and minor scaphoid subchondral oedema at final follow-up.