Utility of Fusion Surgery in Patients with Degenerative Lumbar Spondylolisthesis and their Outcome

Abstract

IntroductionDegenerative 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, etc. But once patient suffers from severe neurological symptoms like intermittent claudication or vesico-rectal disorder due to 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 & that fusion provides better outcome than decompression alone which also results a safety profile. Material and MethodsA 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 & BSOH, Dhaka. We selected the patients for surgery depending on two major criteria: (1) The patient has clinically important & significant pain or neurological symptoms; (2) The patient has not shown sufficient clinical improvement despite conservative care at least for 3 months. But we tried to manage those having significant osteoporosis & infection through conservative treatment despite fulfilling the above criteria. Our choice of surgery was TLIF for each patient. The steps included laminectomy, insertion of cage in the disc space, interbody chips bone graft surrounding the cage & posterolateral bone grafting with fixation of spine by transpedicular screws & rods. Total follow up time was 11 years & the minimum follow up time was 6 months. Evaluation of the patients was done comparing their pre & post-operative states which included clinical evaluation, X-ray showing gradual fusion with special investigation including CT scan & MRI Results82 patients (Female- 51 & male-31) with average age of 59 years (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 & minimum 6 months. The potential side effects included bleeding, post-operative infection, nonunion, residual deformity with spinal stenosis & malposition of screws & rods. The mean anterior slip was 26.1% (0–50%) prior to surgery & 24.8% at the final follow up. The longer was the duration of pre-operative insult to the spinal cord or nerve root, 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%) & poor result in 4 (5%) cases. Nonunion after surgery was observed in 3 patients. The Oswestry Disability Index Scores averages 11.1% (Range 0–62). ConclusionThough 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. Inspite successful fusion is achieved, better outcome will be ensured if any kind of activity that may overload the back is avoided.