Injection Techniques for Common Chronic Pain Conditions of the Hand: A Comprehensive Review.

Introduction: This compilation presents a comprehensive review of the literature on common chronic pain conditions of the hand. It briefly presents these common conditions with their biological background, diagnosis, and common management options. It then presents and compares the latest literature available for injection techniques to treat these diagnoses and compares the available evidence.

Methods: A comprehensive literature review was performed in MEDLINE, PubMed, and Cochrane databases from 1996 to 2019 using the terms "hand pain", "injection techniques", "steroid injection", "chronic pain", "osteoarthritis", "rheumatoid arthritis", "carpal tunnel syndrome", "De Quervain's tenosynovitis", "ganglion cyst", "gout", "Raynaud's", and "stenosing tenosynovitis".

Results: Hand pain is a common condition with 9.7% prevalence in men and 21.6% in women and can cause significant morbidity and disability. It also carries a significant cost to the individuals and the healthcare system, totaling in $4 billion dollars in 2003. Injection therapy is an alternative when conservative treatment fails. Osteoarthritis is the most common chronic hand pain syndrome and affects about 16% of the population. Its mechanism is largely mechanic, and as such, there is controversy if steroid injections are of benefit. Hyaluronic acid (HA) appears to provide substantial relief of pain and may increase functionality. More studies of HA are required to make a definite judgment on its efficacy. Similarly, steroid ganglion cyst injection may confer little benefit. Carpal tunnel syndrome is a compressive neuropathy, and only temporarily relieved with injection therapy. US-guidance provides significant improvement and, while severe cases may still require surgery, can provide a valuable bridge therapy to surgery when conservative treatment fails. Similar bridging treatments and increased efficacy under US-guidance are effective for stenosing tenosynovitis ("trigger finger"), though, interestingly, inflammatory background is associated with decreased effect in this case. When the etiology of the pain is inflammatory, such as in RA, corticosteroid (CS) injections provide significant pain relief and increased functionality. They do not, however, change the course of disease (unlike DMARDs). Another such example is De-Quervain tenosynovitis that sees good benefit from CS injections, and an increased efficacy with US-guidance, and similarly are CS injections for gout. For Raynaud's phenomenon, Botox injections have encouraging results, but more studies are needed to determine safety and efficacy, as well as the possible difference in effect between primary and secondary Raynaud's.

Conclusions: Chronic hand pain is a prevalent and serious condition and can cause significant morbidity and disability and interferes with independence and activities of daily living. Conservative treatment remains the first line of treatment; however, when first-line treatments fail, steroid injections can usually provide benefit. In some cases, HA or Botox may also be beneficial. US-guidance is increasing in hand injection and almost ubiquitously provides safer, more effective injections. Hand surgery remains the alternative for refractory pain.