Impact of trapeziectomy on wrist stability

Abstract

Objective To examine the radiographic and clinical changes of trapezietomy,and determine the effect of this procedure on carpal instability.Methods From January 2008 to January 2011,19 patients (21 thumbs) with thumb carpometacarpal arthritis were treated with trapeziectomy and ligament reconstruction tendon interposition arthroplasty with flexor carpi radialis (FCR).Pre-and post-operative radiographic and clinical parameters were compared.Radiographic measurements included radioscaphoid angle,radiolunate angle,scapholunate angle,lunate capitate angle and carpal height ratio.Clinical evaluations included grip strength,pinch strength,and pain level quantified by visual analogue scale (VAS).The existence of dorsal intercalated segment instability (DISI) deformity was also evaluated radiographically.Results All the patients were followup for 6 to 37 months,with an average of 14.7 months.The mean radioscaphoid angle was 44°preoperatively and 40°postoperatively; radiolunate angle was 8°preoperatively and 10° postoperatively; scapholuante angle was 51° preoperatively and 48° postoperatively; lunocapitate angle was 14° preoperatively and 12° postoperatively.There were no significant changes except the scapholunate angle which was significantly reduced after the surgery.Grip strength improved from 18.6 to 20.5 kg,and pinch strength increased from 4.4 to 4.5 kg after the surgery.Patient pain levels (VAS) were significantly reduced from 6.6 to 0.5.DISI deformity was present in 28.6 ％ (6/ 21) of the patients preoperatively and 33.3 ％ (7/21) after the surgery.In the DISI cases,the procedure did not change the radioscaphoid angle,radiolunate angle,scapholunate angle and carpal height ratio.The lunate capitate angle however was significantly reduced.Conclusion Both radiographic and clinical parameters showed that trapeziectomy does not significantly affect carpal stability.DISI deformity is not worsened by trapeziectomy either. Key words: Carpal joints; Trapezium bone; Thumb carpometacarpal arthritis