Revision of failed trapeziometacarpal prothesis by CMI pyrocarbon implant: Retrospective study of 28 patients with a mean follow-up of 7.5 years

Abstract

IntroductionThere is no consensus on the best salvage option after a failed trapeziometacarpal prothesis. Conserving the trapezium and inserting a pyrocarbon hemiarthroplasty implant will prevent thumb shortening and preserve the thumb's motion. The aim of this study was to evaluate the clinical and radiological outcomes in the medium term of trapeziometacarpal prothesis revisions done using the CMI pyrocarbon implant. Patients and methodsThis was a retrospective study of 28 patients with a mean age of 63.5 years. The mean time to revision was 6.1 years after the initial arthroplasty. The dominant side was operated in 70% of patients. The surgery consisted of removing the existing prosthesis, reconstructing the trapezium with a bone graft, and inserting the CMI pyrocarbon implant. The review consisted of a functional assessment (visual analog scale for pain, QuickDASH score, patient satisfaction), physical assessment (Kapandji, grip strength, key pinch strength, tip pinch strength) and radiological assessment (complications, radiolucent lines, scaphometacarpal height, implant centering, bone remodeling). ResultsAt a mean follow-up of 7.5 years, no further surgical revisions were needed. The mean QuickDASH score was 1.1 and the mean QuickDASH was 13%. Twenty-five patients (89%) were satisfied with the outcome. The Kapandji score improved significantly from 7.5 to 9.5 on average. Grip strength improved significantly from 16.7kg to 21.5kg on average. The mean postoperative key pinch strength was 93% of the contralateral side. The mean postoperative tip pinch strength was 88% of the contralateral side. There were no fractures or dislocations visible on the radiographs. However, there was bone remodeling in the trapezium related to the pyrocarbon implant's indentation that was well tolerated by patients in the medium term. ConclusionFor revision of failed trapeziometacarpal prothesis, inserting the CMI pyrocarbon implant combined with trapezium reconstruction appears to be a good alternative to the more commonly used trapeziectomy procedure. Reconstructing the trapezium and inserting this hemiarthroplasty implant preserves the thumb's projection, length, and stability. The functional improvement experienced by patients makes this a relevant treatment option. Level of evidenceIV; retrospective study without control group.