CMC (Carpometacarpal) OA (Osteoarthritis) Thumb Splint Study

Osteoarthritis (OA) of the thumb carpometacarpal (CMC) joint is a common condition that is seen regularly in outpatient occupational therapy and physiotherapy departments. Prevalence rates of symptomatic thumb OA have been found to be as high as 25%. The conservative treatment of choice consists of splinting. There are many different types of thumb splints available, but no specific guidelines as to which is preferred. There is limited evidence to support the benefits of splinting.

The purpose of this study is to compare the effectiveness of two different thumb splints: the Comfort Cool, a prefabricated neoprene splint and a custom made neoprene and thermoplastic thumb splint. These are two of the most commonly prescribed splints in local occupational therapy departments.

Thumb (CMC) osteoarthritis is treated conservatively with splinting. The objectives of splinting the CMC joint include stabilizing the joint, reducing pain symptoms as well as enhancing performance of everyday activities. There is limited evidence to support the effectiveness of splinting in reducing pain and very little evidence to support the effectiveness of thumb splints to enhance function.

This CMC splint comparison study is a cross-over community based study of the effect of two different types of CMC stabilizing splints on patients with thumb OA. The objectives include measuring clients' OA symptoms and function using the Australian Canadian Osteoarthritis Hand Index (AUSCAN-HI 3.1), grip strength, pinch strength and client's personal splint preference on 4 separate occasions in order to compare the two thumb splints. The two splints differ in material and design. One splint is softer and incorporates more of the hand. The evidence gathered will support the effectiveness of specific splint design. It will also provide best practice guidelines for splint selection in clients with CMC OA.

We are using a one group own control cross-over design where outcome measures will be taken at week 1, week 4, week 5 and week 9. Each client will wear both splints for a 4 week period separated by a 1 week wash out period.

Procedure:

First appointment: At the initial visit the client will be randomly assigned to splint order. The client will complete the AUSCAN-HI 3.1, and a grip and pinch strength measurement. The first CMC stabilizing splint will be fabricated and fitted as per normal splinting treatment for clients with CMC OA. The client will be instructed how to wear and care for their splint. General instructions will include wearing the splint for symptomatic use as well as heavy activities.

Second visit: The second visit will take place 4 weeks after the first unless the client needs to come in earlier for a splint adjustment. At this time the AUSCAN-HI 3.1 will be administered again. Grip and pinch strength will also be re-measured.

Third visit: After a one week wash-out period where the client does not wear any splint, they will attend the OT Outpatient department and complete the AUSCAN-HI 3.1, perform a grip and pinch strength measurement. They will be provided with the second CMC stabilizing splint and instructed in a wearing regime and the care of it.

Fourth visit: This will take place at approximately 9 weeks, 4 weeks after wearing the second splint. The AUSCAN-HI 3.1 will be completed for the last time as well as a grip and pinch strength measurement. The client will also be asked their personal splint preference at this time.

Data will be collected and input into the computer.

Note: The procedures for grip and pinch strength measurement will follow the guidelines set out in the ASHT Clinical Assessment Recommendations.

Data Analysis: Data will be analyzed using ANOVA, to determine if there is a significant difference between the 2 splints for OA pain, function, grip strength and personal preference.

Eligibility Criteria:
Inclusion Criteria:

* physician diagnosis of CMC OA
* 45 years or older
* able to read and write in English

Exclusion Criteria:

• previous thumb surgery