Which clinical and radiological variables could predict clinical outcomes of percutaneous endoscopic lumbar discectomy for treatment of patients with lumbosacral disc herniation?

Background context: Percutaneous endoscopic lumbar discectomy (PELD) is one of minimally invasive techniques to treat patients with low back and radiating pain resulting from lumbosacral disc herniation (LDH). Purpose: The purpose of this study is to evaluate the clinical efficacy of PELD to treat patients with low back and radicular pain due to LDH and to investigate which clinical and radiological variables have the ability to predict clinical outcome after PELD. Study design/setting: This is a retrospective study design carried out at a spine hospital. Patient sample: The sample comprised 75 patients who had undergone PELD for treatment of low back and radiating leg pain resulting from LDH and who could be followed up for at least 12 months. Outcomes measures: Clinical outcomes were assessed using numeric rating scale for back and radiating leg pain (NRS back and leg), Oswestry Disability Index (ODI), and modified MacNab criteria at 1 month (short-term follow-up) and at least 12 months (long-term follow-up) after PELD.

Methods: The patients were divided into successful and unsuccessful outcome groups according to improvement of NRS back, NRS leg, and ODI (%) at long-term follow-up period. We compared the various clinical and radiological variables between the two groups to identify which variables could be the prognostic factors of clinical outcomes of PELD. This analysis was performed in terms of whole population, the subgroup of dominant back pain, and the subgroup of dominant leg pain, respectively.

Results: Significant improvements were observed in NRS back, NRS leg, ODI (%), and modified MacNab criteria at short-term and long-term follow-up after PELD. Positive straight leg raising (SLR) was significantly related to successful outcome as to NRS leg and ODI (%), and longer pain duration also showed significant relationship with unsuccessful outcomes as to NRS leg in whole population. Positive SLR had significant relationship with successful NRS leg as well as successful ODI (%) in the subgroup of dominant leg pain.

Conclusions: PELD was an effective treatment in patients with back and leg pain due to LDH. Positive SLR had the predictive ability to successful reduction of radiating leg pain and successful functional improvement. Longer pain duration was also related to unsuccessful reduction of radiating leg pain.