Accuracy of Carpal Tunnel Injection: A Prospective Evaluation of 756 Patients

Abstract

This is the largest study looking at accuracy of carpal tunnel injection using anatomic landmarks. Our injection accuracy (75.7%) is less than reported in previous studies, which note 82% to 100% accuracy using the same injection technique. This may indicate that carpal tunnel injection is less reliable than previously thought. Safety of carpal tunnel injection remains an important concern. The median nerve was penetrated in 8.7% of attempts.

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

“…Another study revealed that 75% of CS injections were accurately placed solely using landmarks, while 8.7% penetrated and damaged the median nerve [32]. US guidance to locate the flexor carpi ulnaris tendon and median nerve can reduce this adverse effect [33].…”

Normal variations in position and relations of the median nerve in the carpal tunnel: A cross‐sectional observational study using clinical magnetic resonance imaging

“…The third reason relates to complications of injection of corticosteroid into the carpal tunnel to treat mild to moderate degrees of CTS (Green ; McGrath ; Gonzalez and Bylak ; Graham et al ). In one large prospective series of surgically confirmed needle placements, the median nerve was penetrated in 8.7% of cases when needles were inserted on the ulnar border of palmaris longus (Green et al ). Our study suggests that the median nerve is most commonly positioned in the radial half of the carpal tunnel; the mean position is 57% along a line drawn between the hook of hamate and the tubercle of the trapezium (Figs.…”

“…The position of the median nerve may also influence the success and complication rates of interventions such as carpal tunnel release or injection. A recent study has reported an 8.7% incidence of surgically confirmed median nerve penetration after standardized needle placement for carpal tunnel injection (Green et al ).…”

Ultrasound Findings in Less Frequent Causes of Carpal Tunnel Syndrome

“…33,34 Ultrasound-guided CTS injections allow correct placement of the needle under a real-time examination and avoidance of local damage to the MN or adjacent structures. 35,36 Lipofibromatous Hamartoma Lipofibromatous hamartoma is a rare condition of unknown origin characterized by accumulation of fibrous tissue and fat inside a nerve. 37,38 It can be associated with macrodactyly.…”

“…Although most clinically guided injections are effective and well tolerated, they can be complicated by inadvertent intraneural injections (Figure 3), resulting in acute pain and inflammation due to neurotoxicity of steroid preparations 33,34 . Ultrasound‐guided CTS injections allow correct placement of the needle under a real‐time examination and avoidance of local damage to the MN or adjacent structures 35,36 …”