Treatment of nocturnal leg cramps by blockade of the medial branch of the deep peroneal nerve after lumbar spine surgery

INTRODUCTION Patients with lumbar spine disease sometimes complain of nocturnal leg cramps. We sought to investigate the effectiveness of blocking the medial branch of the deep peroneal nerve as treatment for nocturnal leg cramps after spinal surgery for lumbar spine disease. METHODS We evaluated 66 postoperative patients in this prospective comparative study of a group of patients with a nerve block (n = 41) and a control group without (n = 25). In the block group, the medial branch of the deep peroneal nerve was blocked at the distal two-thirds of the interspace between the first and second metatarsals using 5.0 mL of 1.0% lidocaine. RESULTS Two weeks after the block, the frequency of nocturnal leg cramps was reduced to less than a quarter of pretreatment baseline frequency in 61.0% of patients (n = 25) and less than half in 80.5% (n = 33). In the control group, the frequency of the leg cramps was reduced from baseline in 32.0% of patients (n = 8), and was unchanged or increased in 68.0% (n = 17) at 2 weeks. Cramp frequency was reduced to less than a quarter or less than half of baseline frequency in a significantly (P < 0.05 and P < 0.01, respectively) larger percentage of patients in the block group. The severity of each cramp was less in about two-thirds of patients (63.4%; n = 26) in the block group and was unchanged in one-third (31.7%; n = 13). CONCLUSIONS Blocking the medial branch of the peroneal nerve can be an effective, long-lasting, and simple treatment with low risk for nocturnal cramps sustained after lumbar spine surgery.