Prone Position-Related Meralgia Paresthetica after Lumbar Spinal Surgery : A Case Report and Review of the Literature

Lateral femoral cutaneous neuropathy occurring during spinal surgery is frequently related to iliac bone graft harvesting, but meralgia paresthetica (MP) can result from the patient being in the prone position. Prone position-related MP is not an uncommon complication after posterior spine surgery but there are only few reports in the literature on this subject. It is usually overlooked because of its mild symptoms and self-limiting course, or patients and physicians may misunderstand the persistence of lower extremity symptoms in the early postoperative period to be a reflection of poor surgical outcome. The authors report a case of prone position-related MP after posterior lumbar interbody fusion at the L3-4 and reviewed the literature with discussion on the incidence, pathogenesis, and possible risk factors related to this entity.     

Risk factor analysis for meralgia paresthetica: A hospital-based study in Taiwan

Recognizing the cause is essential for the management of meralgia paresthetica (MP), also known as lateral femoral cutaneous neuropathy. The aim of this study was to investigate the etiologies of MP and their influence on each other. This retrospective study enrolled referral patients with electromyographic studies who fulfilled the clinical and electrodiagnostic criteria of MP from January 2003 to December 2013. Data including age, gender, body weight, body height, occupation, and relevant medical history were collected. The etiological analysis was based on age and gender. A total of 50 patients (30 males and 20 females) were enrolled. The average age (±standard deviation) at diagnosis was 49.8 ± 12.8 years. Risk factors were identified in 29 cases (58.0%). More patients younger than 50 years of age were male (73.1%, p = 0.049). Peaks of age occurred between 41–50 years in men and 51–60 years in women. More males had a body mass index ≥ 24 kg/m² (69.2% vs. 31.6%, p = 0.012) and ≥27 kg/m² (34.6% vs. 0.0%, p = 0.006). Overweight and obese patients were more vulnerable to occupational factors (50.0% vs. 19.0%, p = 0.030). Only one case had diabetes mellitus (2%). Male middle-aged patients with a higher body mass index and certain occupations had an increased risk of MP. In contrast to the peak age distribution of the male patients, the frequency of developing MP was relatively even among the women at all ages. The cause was often obscure.     

Association between preoperative low muscle mass and psychological factors after surgery among patients with lumbar spinal stenosis: A longitudinal study

It remains controversial whether preoperative low muscle mass affects clinical outcomes after lumbar surgery. Previous studies evaluated outcomes such as pain, quality of life, and disability, but none investigated preoperative low muscle mass and psychological factors. The purpose of this study was to clarify the association between preoperative low muscle mass and postoperative psychological factors in lumbar spinal stenosis (LSS). A longitudinal analysis was performed in 85 consecutive preoperative patients with LSS. Demographic data, leg pain, low back pain, Japanese Orthopaedic Association score, Pain Catastrophizing Scale (PCS) score, Fear-Avoidance Beliefs Questionnaire on Physical Activity (FABQ-PA) score, Hospital Anxiety and Depression Scale (HADS) score, walking velocity, grip strength, and appendicular lean mass were assessed. Muscle mass was measured using bioelectrical impedance analysis. Patients were divided into two groups based on skeletal muscle mass index. These clinical outcomes were evaluated preoperatively and 1 year after surgery. In the 73 patients who were analyzed 1 year after surgery, the prevalence of preoperative low muscle mass was 21.9%. The normal muscle mass group showed significantly improved PCS, FABQ-PA, HADS-anxiety, and HADS-depression scores 1 year after surgery. The low muscle mass group did not demonstrate significantly improved PCS, FABQ-PA, or HADS-depression scores, and had a significantly smaller increase in the FABQ-PA score than the normal muscle mass group. Multivariate analysis showed that low muscle mass was significantly related to change in FABQ-PA score. Our results suggest that preoperative low muscle mass hinders improvement in fear-avoidance beliefs 1 year after surgery.