Aim: Posterior epidural migration of a sequestered lumbar intervertebral disc fragment (PEMSLIDF) is an extremely rare condition published so far only as case reports or small case series (ranging between 2 to 8 cases). Diagnosing this condition is often challenging and the diagnosis is usually made intraoperatively. The affected patients usually suffer cauda equina syndrome (CES). In the present study, we aimed to discuss the clinical and radiological findings, types and features of surgical therapies, and outcomes of 9 patients with PEMSLIDF.
Material and methods: This study included 9 (0.36%) patients with PEMSLIDF among 2470 patients who underwent lumbar disc hernia surgery between August 2002 and September 2012. The preoperative clinical and radiological properties of the patients were evaluated. The postoperative outcomes were assessed using neurological examination, radiological imaging, visual analog scale (VAS) and modified Odom criteria.
Results: As far as we know, this study is the largest case series examining the characteristics of PEMSLIDF. Seven (77.8%) of our patients were male and 2 (22.2%) were female and they had a mean age of 49.5 years (range 28-70 years). The mean duration from symptom onset to hospital admission was 7.4 days. Seven patients had CES. All patients underwent sequestrectomy and discectomy via posterior microsurgery. The patient outcomes were evaluated by the Modified Odom criteria and the outcome was excellent in two (22.2%) patients, good in 4 (44.5%), fair in 2 (22.2%), and poor in 1 (11.1%).
Conclusion: The entire free fragment can usually be excised via the posterior microsurgery technique. Early surgical treatment is of great importance to prevent more serious neurological deficits.