Abstract
Introduction
There are conflicting reports about the efficacy of injection to the thumb carpometacarpal joint (CMCJ) for osteoarthritis (OA). The accuracy of joint injection without radiological control is unclear. We investigated the accuracy of blind injection and recorded their immediate and short term efficacy.
Materials/Methods
We injected 25 consecutive patients between March 2010-January 2011. The CMCJ was palpated, manually distracted and a 23 gauze needle introduced blindly. Image intensifier was then used to visualize and redirect needle if necessary. Radio-opaque dye was injected to confirm intra-articular placement. We recorded patient demographics, number of attempts required for correct needle placement, pre and 10 minutes post-injection visual analogue scale (VAS) pain score, and Nelson Score (NS)before and six weeks after injection. NS is a validated thumb CMCJ specific patient administered questionnaire.
Results
Mean age was 60 (range 46–90). M:F ratio was 23:2. CMC J OA ranged from grade 2–4.1st attempt was successful in 6 cases. Mean attempts required for accurate injection was 3 (range 0–4). Mean pain pre- injection VAS was 7 (range 4–10), 10 minutes following injection 0.5 (range 0–4) and at 6 weeks 5 (range 3–10). Mean pre-operative NS was 29.6 (range 14–65) and at 6 weeks 32.4 (range 14–55). The difference was not statistically significant (paired t test, p=0.24).
Conclusion
Our results suggest that blind injection of thumb CMCJ may not be accurate. Accuracy can be improved by X-ray guided injection. The procedure afforded excellent immediate pain relief but was not effective over six weeks follow up.
