Symptomatic Lumbar Hypertrophy of Flavum Ligament Associated with Neurogenic Claudication

To investigate clinical improvements and histologic studies of patients with symptomatic lumbar hypertrophic of flavum ligament (HFL) associated with neurogenic claudication. There were 32 subjects (18 males and 14 females) included in the study with the mean age of 46 years old (range 32 to 64). Patient functionality was measured by Neurogenic Claudication Outcome Score (NCOS). All patients were treated previously in a rehabilitation unit for four weeks and indicated for surgery due to neurogenic claudication (excluding those without neurological deficit). Imaging modalities were taken preoperatively (plain spine x-ray, computed tomography (CT) scan, magnetic resonance imaging (MRI) and postoperatively (plain x-ray at day 3 and two months later, CT scan after eight weeks).Histological studies were also taken, as well as the NCOS for evaluating the claudication. A student’s t-test analysis was carried out on the NCOS pre- and postoperative to evaluate the improvement significance. The improvement of the NCOS score in male was 23.1±2.23 and female was 24.85±2.68 (p=0.023). Histologically, the flavum ligament was harder, stiffer, and calcified resulting in a decrease in the ratio of elastin to fibrous tissue, leading to the hypertrophic process. In the short term, surgical results improved in all patients with no surgical complication. Surgical decompression can yield a better outcome in the short term for treating symptomatic lumbar HFL associated with neurogenic claudication.This early pathological process in the flavum ligament results in an overall tissue thickening leading to narrowing of the lumbar canal.

Keywords: Hypertrophy of flavum ligament, neurogenic claudication, surgical decompression.