Trapeziometacarpal Prosthesis vs. Resection-Interposition Arthroplasty

Study Overview
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Brief Summary
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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)

Detailed Description
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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.

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

Conditions
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Arthropathy of Hand

Intervention / Treatment
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* Procedure: Epping resection arthroplasty
* Procedure: CMC I prosthesis


Participation Criteria
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Eligibility Criteria
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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.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Epping resection arthroplasty<br>During the Epping resection-suspension arthroplasty the trapeziectomy is performed, the flexor carpi radialis tendon is divided into two parts and one of these is stripped and cut proximally. To prevent shortening of the first ray with following loss of strength, this tendon strip is pulled through a drill hole in the base of the 1st metacarpal from ulnar palmar to radial dorsal. The rest of the tendon strip is sutured to a roll replacing the os trapezium. | Procedure: Epping resection arthroplasty<br>* Follwing the described epping resection arthroplasty, The first ray was immobilized using an orthosis for four weeks postoperatively in both study groups followed by eight weeks of physical therapy.<br>|
| Active Comparator: CMC I prosthesis group<br>During implantation of the prosthesis the CMC joint is opened and 3 mm of the metacarpal base as well as osteophytes are resected. Following the release of the trapezium the first metacarpal and the trapezium are prepared for the prosthesis by broaching and drilling. After the test-implants have shown satisfying joint tension and anatomic conditions, the HA coated stem and cup are pressfit inserted in the appropriate size followed by the modular head. | Procedure: CMC I prosthesis<br>* Follwing the described CMC I prosthesis procedure, The first ray was immobilized using an orthosis for four weeks postoperatively in both study groups followed by eight weeks of physical therapy.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Functional outcome- Thumb opposition | Measurement of thumb opposition (scale from 1 to 10) range according to Kapandji. A score of 0 indicates no opposition, a score of 10 indicates maximal opposition. | twelve months postoperative | 
| Functional outcome - Thumb retropulsion | Measurement of thumb retropulsion (scale from 1 to 3) range according to Kapandji | twelve months postoperative | 
| Functional outcome - maximal palmar abduction | measurement of the maximal palmar abduction using a goniometer. | twelve months postoperative | 
| Functional outcome - maximal radial abduction | measurement of the maximal radial abduction using a goniometer. | twelve months postoperative | 
| Functional outcome - tip-to-tip force | The tip-to-tip force (between thumb and index finger) was measured in Newton (N) using a handheld dynamometer (Cit Technics, Haren, Netherlands). | twelve months postoperative |