Comparative functional analysis between pyrolytic carbon prostheses and ligamentous suspension/reconstruction in the treatment of rhizarthrosis.

OBJECTIVE: To evaluate midterm functional outcome after pyrolytic carbon prosthesis (PyroDisk) implantation in the treatment of rhizarthrosis of the thumb, comparing outcomes with those of ligamentous resection/suspension/reconstruction.

MATERIAL AND METHODS: A cross-sectional study retrospectively comparing 2patient groups aged between 40 and 65 years with rhizarthrosis of the thumb. Thirty-two patients operated between 2009 and 2013 were distributed between group i (interposition arthroplasy with PyroDisk implant) and group ii (ligamentous resection/suspension/reconstruction arthroplasty). Data on pain, functionality (Quick-Dash questionnaire) and articular movement were collected in 2015. In addition, a radiological study was undertaken using radiographs and CT.

RESULTS: Thirty-two patients, 16 in each group with mean follow-up of 35 months (23-47). Pain at the end of follow-up was greater in the group with the pyrolytic carbon prosthesis (p=0.000). According to the QuickDash questionnaire, the patients in group i achieved a mean functionality of 31.14 (0-70) points compared to 15.81 (8-24) points for group ii (p=0.027). No differences were found in degree of mobility at the end of follow-up (p=0.46). The prosthesis had to be removed in 6 cases.

DISCUSSION: The pyrolytic carbon prosthesis has been presented as an alternative treatment for rhizarthrosis of the thumb. The papers pubslished to date highlight the discrepancies in midterm functional outcomes.

CONCLUSIONS: Pyrolitic carbon prostheses have shown inferior functional outcomes, compared with resection/suspension/reconstruction arthroplasties.