A PROSPECTIVE OBSERVATIONAL STUDY OF THUMB FUNCTION FOLLOWING FIRST CARPOMETACARPAL JOINT ARTHRODESIS

Abstract

IntroductionDespite the rising popularity of 1st carpometacarpal joint (CMCJ) arthrodesis as one of the surgical options for basilar thumb arthritis, the available literature on this is poor. This study aims to investigate post-operative pinch and grip strength following 1st CMCJ arthrodesis, at a minimum of 1 year follow-up. Complication rates, range of motion and patient reported scores were also evaluated.MethodsA retrospective cohort (2012–2020) was used, which included patients who had arthrodesis performed by the Hands surgeons at Counties Manukau DHB. In a 15 minute visit, we took the measurements using our standard dynamometer and pinch gauge, and collected three questionnaires [QuickDASH, PRWHE, PEM]. For analysis, we compared our results to the preoperative measures, contralateral hand, and to a previous study on a similar cohort looking at thumb strength following trapeziectomy.Results42 arthrodesis were performed, and 24 were available for follow-up. The average follow-up time was 77 months and the average age was 51 years old. Overall, we found a statistically significant improvement in thumb strength following surgery. Mean preoperative grip strength was 21.4kg and 32.5kg postoperatively (= +11kg). Preoperative pinch strength was 5.5kg and 7kg postoperatively (= +1.5kg). These results were significantly higher compared to the trapeziectomy cohort. We also found an improvement in 1st CMCJ ROM post-operatively. 7 complications were reported (29.1%). 4 were metalware-related and 3 were non-union. QuickDASH score significantly improved from a median of 42.95 to 12.5 while PRWHE from 67.5 to 14.5. Overall patient satisfaction was 87.4%.Conclusion1st CMCJ arthrodesis leads to an improvement in thumb function, pain and range of movement and results in high patient satisfaction, and therefore should be recommended for younger patients who need a pain-free and strong thumb.