Reducing Lateral Femoral Cutaneous Nerve Palsy in Obese Patients in the Beach Chair Position: Effect of a Standardized Positioning and Padding Protocol.

INTRODUCTION: To report on the effectiveness of a standardized patient positioning and padding protocol in reducing lateral femoral cutaneous nerve (LFCN) palsy in obese patients who have undergone shoulder surgery in the beach chair position.

METHODS: We retrospectively reviewed the medical records of 400 consecutive patients with a body mass index (BMI) of ≥30 kg/m who underwent either open or arthroscopic shoulder surgery in the beach chair position by a single surgeon. Before June 2013, all patients were placed in standard beach chair positioning with no extra padding. After June 2013, patients had foam padding placed over their thighs underneath a wide safety strap and underneath the abdominal pannus. Flexion at the waist was minimized, and reverse Trendelenburg was used to position the shoulder appropriately. Patient demographic and surgical data, including age, sex, weight, BMI, presence of diabetes, procedure duration, American Society of Anesthesiologists (ASA) grade, and anesthesia type (general, regional, regional/general) were recorded. Symptoms of LFCN palsy were specifically elicited postoperatively in a prospective fashion and identified clinically by focal pain, numbness, and/or tingling over the anterolateral thigh.

RESULTS: The median age was 58.0 years, and the study consisted of 142 male (36%) and 258 female (64%) subjects. Five cases (3.6%) of LFCN palsy occurred with conventional beach chair positioning, and a single case (0.4%) occurred with the standardized positioning and padding technique (P = 0.02). Median age, sex, presence of diabetes, median BMI, surgery type, and surgical time were not significantly different between the patients who did and did not develop LFCN palsy. All cases resolved completely within 6 months.

DISCUSSION: The occurrence of LFCN palsy following shoulder surgery in the beach chair position remains uncommon, even among obese patients. Use of a standardized positioning and padding protocol for obese patients in the beach chair position reduced the prevalence of LFCN palsy.

LEVEL OF EVIDENCE: Level III (prognostic).