Methylprednisolone injections for the treatment of Morton neuroma: a patient-blinded randomized trial.

Abstract

Morton neuroma is a common cause of neuralgia affecting the web spaces of the toes. Corticosteroid injections are commonly administered as a first-line therapy, but the evidence for their effectiveness is weak. Our primary research aim was to determine whether corticosteroid injection is an effective treatment for Morton neuroma compared with an anesthetic injection as a placebo control. We performed a pragmatic, patient-blinded randomized trial set within hospital orthopaedic outpatient clinics in Edinburgh, United Kingdom. One hundred and thirty-one participants with Morton neuroma (mean age, fifty-three years; 111 [85%] female) were randomized to receive either corticosteroid and anesthetic (1 mL methylprednisolone [40 mg] and 1 mL 2% lignocaine) or anesthetic alone (2 mL 1% lignocaine). An ultrasonographic image was obtained before treatment, and injections were performed with the needle placed under ultrasonographic guidance. The primary outcome was the difference in patient global assessment of foot health between the two groups at three months after injection. This was measured with use of a 100-unit visual analog scale (VAS) anchored by best imaginable health state and worst imaginable health state. Compared with the control group, global assessment of foot health in the corticosteroid group was significantly better at three months (mean difference, 14.1 scale points [95% confidence interval, 5.5 to 22.8 points]; p = 0.002). The difference between the groups was also significant at one month. Significant and nonsignificant improvements associated with the corticosteroid injection were observed for measures of pain, function, and patient global assessment of general health at one and three months after injection. The size of the neuroma as determined by ultrasonography did not significantly influence the treatment effect. Corticosteroid injections for Morton neuroma can be of symptomatic benefit for at least three months.