Trapeziometacarpal Prosthesis vs. Resection-Interposition Arthroplasty

Trapeziometacarpal Prosthesis vs. Resection-Interposition Arthroplasty A Randomized Controlled Trial

Rhizarthrosis is a frequently occurring pathology leading to severe limitations in daily life due to pain and loss of function. Good clinical results have been reported for some carpometacarpal (CMC) joint prosthesis designs, but high failure rates due to loosening and dislocation must be considered. The study aim was to investigate a new, double mobility CMC-prosthesis design with special focus on (1) the functional outcome and (2) patient quality of life (QOL)

The Epping resection-suspension arthroplasty procedure was described in 1983 to address the proximal migration of the first ray while providing pain free grip strength without any implants. It has shown rather good functional outcome and pain relief. A reduction in thumb opposition strength of 27% compared to the contralateral side and intermittent pain in physical activity is reported, however. Further, studies comparing trapeziectomy and trapeziectomy with tendon interposition recommend trapeziectomy due to the simple technique and comparable outcome.

Endoprosthesis of the first carpometacarpal (CMC) joint represents a different treatment strategy aiming at an exact reconstruction of the joint geometry. Some studies report excellent functional outcome and pain relief. However, there are some prosthesis designs (cemented and uncemented) with high rates of loosening, luxation and poor subjective results. To address these issues, a prosthesis was designed combining a cylindric, double mobility cup and a hydroxyapatite covered stem and cup available in different sizes. The aim of this study was to compare this new prosthesis design to the Epping arthroplasty as the current standard in the investigator's institution regarding (1) the functional outcome with special focus on mobility and strength and (2) patient quality of life (QOL) and pain relief.

Note: The registration of this trial on Clinicaltrials.gov was carried out retrospectively after primary completion of the study.

Inclusion Criteria:

• symptomatic rhizarthrosis grade 2 and 3 according to Eaton's classification,
• failed conservative treatment prior to surgery,
• written informed consent to the study.

Exclusion Criteria:

• scaphotrapezotrapezoidal (STT) arthrosis,
• former CMC joint surgery,
• patients under custodianship.