Long-Term Outcomes Of Lumbar Discectomy By Fenestration

[Objective]To investigate the long-term outcomes and influencing factor of discectomy for single segment lumbar disc herniation.[Methods]Sixty patients who underwent discectomy by inter-laminar fenestration were followed for an average of 214 months (range 183 to 249 months, 15 to 21 years). The long-term follow-up results were evaluated by using the Oswestry disability index and the Stauffer-Coventry's evaluating criteria. Radiography also was used in twenty-four patients who agreed to visit the hospital. The disc height, the ratio of the disc height to upper-lever vertebral body and disc stability were calculated by measurement on the plain radiograms. Several variables were examined to assess their influence to the outcome.[Results]Excellent to good results were achieved in 73.4% of the cases, Overall 90% patients were satisfied with their clinical results. The mean Oswestry disability score was 11.2. The reoperation rate was 10 %( 6 patients). The disc heights of the operation site narrow differently after surgery in twenty four patients who agreed to visit the hospital. The average disc height was 6.82mm. The average ratio of the disc height to upper-lever vertebral body was 0.269.There were 16.7% (4 patients) in who postoperative disc instability developed at the level of discectomy. The ODI for disc-height≥7mm of Group was significantly lower than disc-height<7mm of Group (P<0.05), The ODI have inverse correlation with the disc height of the level of discectomy (P<0.05). Factors that were related to outcome included physical labor intensity, smoking and the period of symptom increased (P<0.05)[Conclusion]Overall the long-term outcome of lumbar discectomy by fenestration in this series was favorable. Oswestry disability index can quantify subjective symptoms. It is important to evaluate curative effect after lumbar discectomy. The Disc space narrowing can correlate with the symptom of back-leg pain. Heavy manual work, smoking and the persistence of symptom increased were negative predictors of a good outcome.