The effect of ultrasound guided steroid injection on progression to surgery in thumb CMC arthritis.

Thumb carpometacarpal joint (CMCJ) osteoarthritis is a common complaint that produces pain and disability within the hand. This study aims to ascertain whether joint injection with local anaesthetic and steroid is of predicative value in disease progression in thumb carpometacarpal osteoarthritis. Forty-three patients were assessed at an average follow up of 24 months following ultrasound-guided injection. Fourteen patients (32%) progressed to surgery, at a mean interval of 8.6 months (range 4-14 months). There was a statistically significant correlation between those patients who had on-going pain following injection at one week and progression to surgery (p = 0.025) with an odds ratio of 3.14 and positive likelihood ratio of 2.1. Patients with thumb CMCJ osteoarthritis that does not respond favourably to injection at one week are likely to progress to surgery in the first year after the injection. This work offers a useful tool in predicting disease progression and patient counseling.