Utility of Fusion Surgery in Patients with Degenerative Lumbar Spondylolisthesis and their Outcomes
Authors: Alam Shah , Karim Rezaul , Zonayed Sharif Ahmed , Khalid Hasan , Chakraborty Shubhendu , Alam Tashfique , Islam Sieful 
Published: May 2015

Introduction

Degenerative spondylolisthesis refers to slip of one vertebral body over the one below as a result of degenerative changes in the spine. Mild-to-moderate symptoms are initially treated by conservative means such as NSAIDs, epidural injections, physiotherapy, and so on. But once patient suffers from severe neurological symptoms such as intermittent claudication or vesicorectal disorder because of the spinal stenosis, it leads the patients to experience surgical procedures. There is no uniform agreement among surgeons about the optimal treatment. But our experience along with several high-quality studies indicate that surgery provides better clinical outcome for degenerative spondylolisthesis and that fusion provides better outcome than decompression alone.

Patients and Methods

A prospective study was designed over 82 patients who had degenerative lumbar spondylolisthesis with severe neurological symptoms. The study time was from January 2003 to July 2014 in NITOR and BSOH, Dhaka. We selected the patients for surgery depending on two major following criteria: (1) The patient has clinically important and significant pain or neurological symptoms. (2) The patient has not shown sufficient clinical improvement despite conservative care at least for 3 months. We tried to manage those having significant osteoporosis and infection through conservative treatment despite fulfilling the aforementioned criteria. Our choice of surgery was TLIF for each patient. The steps included laminectomy, insertion of cage in the disc space, interbody strut bone graft surrounding the cage, and posterolateral bone grafting with fixation of spine by transpedicular screws and rods. Total follow-up time was 11 years and the minimum time was 6 months. Evaluation was done comparing their pre- and postoperative states which included clinical evaluation, X-ray showing gradual fusion with special investigation including CT scan and MRI.

Results

A total of 82 patients (51 females and 31 males) with an average age of 59 years (range, 41–76 years.) having degenerative lumbar spondylolisthesis with severe neurological symptoms met the inclusion criteria. Among the patients, 57 had osteoarthritis. Total follow-up time was 11 years and minimum 6 months. The potential side effects included bleeding, postoperative infection, nonunion, residual deformity with spinal stenosis, and malposition of screws and rods. The mean anterior slip was 26.1% (range, 0–50%) before surgery and 24.8% at the final follow-up. The longer was the duration of preoperative insult to the spinal cord, the slower was the rate of recovery. According to these, the excellent outcome was seen in 69 patients (84% of cases), fair result was seen in 4 (5%), good in 5 (6%), and poor result in 4 (5%) cases. Nonunion after surgery was observed in three patients. Neurological symptoms improved in 1 month to 1 year. The Oswestry Disability Index Scores averages 11.1% (range, 0–62%) in at least 6 months' follow-up time.

Conclusion

Although surgical procedures cannot confirm lifelong recovery of the patients with symptoms, but does ensure a better and comfortable lifestyle with potential improvement of leg symptoms in case of degenerative spondylolisthesis. In spite successful fusion is achieved, better outcome will be ensured if any kind of activity that may overload the back is avoided.