Abstract:

Background: Decompression surgery in patients with degenerative lumbar spine stenosis is considered when symptoms causing pain and disability to the patient are resistant to non-operative treatment. In well selected patients for decompression surgery, it is an effective treatment modality. Familiarity of the associated factors for good outcome may help surgeons in prognosis evaluation when they consider lumbar spine decompression surgery in these patients.

Aim/purpose: of the study: The study aimed at determining the short-term functional outcomes and their associated factors for posterior lumbar spine decompression in patients with degenerative lumbar spine stenosis attended at BMC.

Methodology: A prospective cohort study was conducted in the orthopedics and trauma wards, neuro surgery wards and surgical outpatient clinic. Diagnosis for degenerative lumbar spine stenosis was made based on patient’s clinical presentation and confirmed with Magnetic Resonance Imaging (MRI) results documented by a radiologist. Patients who met the inclusion criteria were enrolled in the study after signing a written consent form. Pain status and the level of disability was evaluated before decompression surgery, and after 6 weeks post-surgery using Visual Analog Scale (VAS) Oswestry Disability Index (ODI) and respectively. Data were collected using a structured questionnaire then entered in Epi Info version 7 cleaned and the exported to Stata version 16 where analysis was done.

Results: 29 patients with degenerative lumbar spine stenosis who underwent posterior lumbar spine decompression surgery were enrolled into this study. 22 patients were female and 7 patients were male with the mean age of 54. The patient mean pre-operative low back pain and leg pain VAS score was 9.14 ± 1.16 while the mean preoperative level of disability ODI score was 66.65 ± 9.41. The commonly affected and decompressed level was L4/L5. Postoperative functional outcome evaluated at 6 weeks showed the mean score for pain measured by VAS was 4.82 ± 1.67 and disability measured by ODI was 43.10 ± 18.98 respectively. Age was associated with post-operative level of pain improvement whereas anatomical level of the lumbar spine stenosis was associated with improvement in post-operative level of disability.

Conclusion: Decompression surgery provides improvement in functional outcome in patients with degenerative lumbar spine stenosis. Age is associated with pain improvement post-surgery whereas the level of stenosis is an important factor associated with post-operative improvement in level of disability.

Recommendations: When decompression surgery is planned for patients with degenerative lumbar spine stenosis, age and the level of stenosis should be put into consideration as they are factors associated with improvement in post-operative functional status. Further studies can be done that include large sample size and long period of duration for follow up to establish clear association and long-term outcomes of these patients. Also, future studies that include stabilization/fusion may be done to evaluate pain and instability in these patients.