Single Puncture Interosseous Nerve (SPIN) Block for Chronic Wrist Pain at the Mid-Pronator Quadratus Level

Chronic wrist pain can be profoundly debilitating.Although surgical denervation has been reported, the evidence on percutaneous nerve block is very scarce, there has been no anatomical study to date has validated any articular branch block or radiofrequency ablation at the wrist level.This study described three successful clinical cases of chronic wrist pain treated using a novel ultrasound-guided Single Puncture Interosseous Nerve (SPIN) Block and further evaluated the anatomical spread of this novel block using a minimal volume of methylene blue injected into seven wrists from four soft-embalmed cadavers.Subsequent dissections were conducted to assess the spread of the injectate.An average of 100% improvement in rest pain and 75% improvement in dynamic pain without adverse events were achieved in three patients with chronic wrist pain 3 months after the nerve blocks.The functional improvement of hand and wrist was improved by an average of 67% at 3 months.In cadaveric evaluations, successful staining to the anterior interosseous nerve and posterior interosseous nerve was observed in 71% and 57% of specimens respectively.We therefore concluded that the SPIN Block can successfully improve the pain control and function with chronic wrist pain, which is also supported by our cadaver findings.