Postoperative outcomes of arthroscopic hemi-trapeziectomy and Suture-Button-Suspensionplasty for thumb carpometacarpal joint arthritis and changes in the sinking of the thumb metacarpal bone

The goal of treating thumb carpometacarpal (CM) joint arthritis is to eliminate pain and maximize the functionality of the thumb. we perform Suture-Button Suspensionplasty (SBS) combined with arthroscopic hemi-trapeziectomy for thumb CM joint arthritis. By preserving the trapezium, it enables the secure preservation of the strong ligaments and joint capsule that form the CM joint, which we believe is crucial for maintaining long-term stability of the joint. Furthermore, performing this procedure arthroscopically allows for the treatment of intra-articular loose bodies and synovitis, which is expected to reduce pain associated with intra-articular pathologies. In this study, we evaluated the short-term outcomes of this procedure performed in our clinic, as well as assessed the progression of sinking of the metacarpal bone, which is essential for maintaining the functionality of the thumb CM joint.

The surgery involved arthroscopic hemi-trapeziectomy with 3mm of trapezium excision and SBS. Evaluation was conducted on 15 cases with preoperative and 3-month postoperative CT scans. Clinical assessment included Visual Analog Scale (VAS), pinch strength, grip strength, and Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH) score. Image evaluation involved CT scans preoperatively and at 3 months postoperatively to measure the sinking of the metacarpal bone from the furthest point of the trapezium to the nearest point of the metacarpal bone.

VAS improved significantly from 6.6 to 0.5, pinch strength increased from 2.7kg to 4.0kg, grip strength increased from 15.3kg to 21.2kg, and DASH score improved significantly from 29 to 6.6. The distance from the furthest point of the trapezium to the nearest point of the metacarpal bone was 11.3mm preoperatively and 11.0mm at 3 months postoperatively in the coronal view, and 11.6mm preoperatively and 11.2mm at 3 months postoperatively in the sagittal view, with no sinking progression of the metacarpal bone observed at 3 months postoperatively.

SBS combined with arthroscopic hemi-trapeziectomy yielded excellent short-term outcomes. Unlike reports involving complete trapezium excision, sinking of the metacarpal bone was suppressed, leading to favorable joint remodeling. Arthroscopic hemi-trapeziectomy, preserving the original ligamentous structure, is believed to enable long-term maintenance and improvement of the original functionality of the CM joint, making it a valuable and useful technique.

Keywords: Thumb CM osteoarthritis, Suture-Button-Suspensionplasty, Arthroscopic hemi-trapeziectomy