Researchers investigate incidence of new position-related nerve deficit in spine surgery

Winner of the Sanford J. Larson, MD, PhD, Award, Gurpreet Surinder Gandhoke, MD, presented his research, Incidence of Position Related Neuropraxia in 4,489 Consecutive Patients Undergoing Spine Surgery. Role of SSEP Monitoring? during the 2016 American Association of Neurological Surgeons (AANS) Annual Scientific Meeting.

The authors reviewed records of 4,489 consecutive patients undergoing spine surgery at a university hospital. Within this group, there were reported incidence of peripheral nerve injury from positioning. IOM changes related to arm and leg positioning and their sensitivity and specificity predicting the development of a new position-related peripheral nerve injury was calculated. Impact of length of surgery and other variables, including age, sex, BMI, DM, HTN, CAD, CVD and a history of smoking, on the development of a new peripheral nerve injury were defined.

The positions were as follows: arms abducted and flexed at the elbow, 64.7 percent; arms tucked at the side, 35 percent; and the lateral position, 0.3 percent. 13 out of 4,489 patients developed a new positioning-related peripheral nerve deficit. 54 percent developed meralgia paresthetica, and 46 percent developed ulnar neuropathy. 72 (1.6 percent) patients developed IOM changes from positioning, and all of these patients underwent a repositioning maneuver. One of these 72 (1.3 percent) developed a new position-related nerve deficit. Of the 98.4 percent of patients who did not develop position-related IOM changes, 0.3 percent developed a new position-related nerve deficit.

Sensitivity of IOM to detect a new position-related nerve deficit was 7.69 percent, and the specificity was 98.41 percent. Neither the length of surgery or any analyzed patient-related variable had a statistically significant impact on the development of a new neuropraxia.

The incidence of a new position-related nerve deficit in spine surgery was less than 0.3 percent. IOM has high specificity and poor sensitivity in detecting a positioning related nerve deficit.