Minimum 10-Year Outcome Of Discectomy For Lumbar Disc Herniation

Lumbar disc herniation is a kind of common and frequent lumbar disease and it's also a grave menace to human health and daily public work and life. Lumbar discectomy including partial lamina resection and nucleus pulposus extraction in posterior approach is most popular used operation at home and abroad nowadays. These operative skills had been used for more than 50 years and proved with excellent effects in short-term effects. But it's still a dispute about the outcome of long-term follow-up for this therapeutic option. More and more new method and technique was adopted to deal with lumbar disc herniation in rencent 20 years, but each of them has it's respective arguments and limitations. The question is:Is the lumbar discectomy an obsolescent option for lumbar disc herniation? What about the precise assessment of long-term outcome for standard discectomy procedures? In order to reveal the long-term outcome of lumbar discectomy, the date of 143 cases who were performed the one level discectomy in our orthopaedic department and followed up more than 10 years were analyzed retrospectively and systematicly in the study. We hope the results might provide helpful reference for the choice of clinical strategy in paitients with lumbar disc herniation. Our work was divided into 2 parts:Part one:clinical assessment of minimum 10 years outcome of mono-level lumbar discectomyObjective:To investigate retrospectively the clinical effects and recurrence rate of 143 cases who were performed the one level discectomy in our orthopaedic department and followed up more than 10 years. To evaluate the outcome of patients in groups of different operating age and extents of disc herniation, and analyse whether difference exists in each group. Methods:One hundred and forty-three post-operative patients who received one level discectomy and followed-up more than 10 years were divied into 3 groups depends on operating age:<30 years old,30～50 years old and >50 years old; 87 cases who's pre-operative CT scan could be collected were divided into 3 groups depends on extents of disc herniation:Ⅰ°,Ⅱ°andⅢ°. To evaluate each group and the holistic clincal outcome with JOA scores and ODI scores, and then judge whether there are differece between every groups.Results:1,significant differences were found in scores between pre-operative group and post-operative group, The overall satisfactory rate was 83.2% with recurrence rate of 6.3% at a mean follow-up of 12.7 years; 2,obvious differece was found in JOA scores in group who's age at operation less than 30 years old compared with other 2 groups at follow-up time, and no significant differece was found in ODI scores all the three groups; 3,at follow-up time, significant differece was found in JOA and ODI scores in group withⅢ°lambur disc heriation before operation compared with other 2 groups, and no statistical differece was found in clincal scores at follow-up time in other 2 groups.Conclusions:1,Long-term follow-up of 143 cases proved mono-level lumbar discectomy was an option for disc herniation with good curative effect and lower recurrent rate, the technique should be the prior selection in dealing with patients with lumbar disc herniation.2,The long-term clincal effects in group of patients under 30 years old was worse than those older than 30 years, some patients(51%) endure persistent low back pain.3,The long-term clincal effects in patients with severe disc protrution who were performed lumbar discectomy was worse than those patients with mild lumbar disc herniation. 4,Trunk muscle exercise post-operative was an important factor to keep excellant long-term outcome.Part two:Radiological findings in patients who accepted minimum 10-year follow-up after lumbar discectomy and correlation study compared with clinical symptomsObjective:To study the pre-opreative and post-opreative radiological findings from 61 cases who had complete data, analyse it's characteristics and the correlation between the radiological findings and clinical symptoms.Methods:To measure the disc height ratio pre-opreative and followed-up then compare the correlation with clinical symptoms; the cases were divided into 2 defferent groups depend on operating age and extents of disc herniation, to analyse the correlation between those factors and clinical symptoms; to measure the disc instability of those followed-up cases and assess the correlation with clincal findings; to observe the characteristics of radiological outcome of CT scan and MR image in follow-up cases.Results:1,Loss of disc height was found in all 61 cases at different degree, but there was no obvious correlation between height decrease and clincal scores; 2,disc height ratio is 79.37±5.34%, the value has no correlation with patient's operating age, but the more severe the pre-operative disc protrution, the more disc height lost found during follow-up peroid; 3,no obvious vertebral space instability was detected in any case, the angle of disc instability was 4.71°averagely, and the angle of disc instability in 44% patients≤2; 4,hyperplasia in lumbar facet joints, accumulation of scars in canal and reossification at primary discestomy region was found in CT scan images during follow-up peroid, no characteristic changes was found in MR images.Conclusions:1,Loss of disc height was found in all 61 cases who accepted long-term followed-up at different degree. The extend of disc height decrease was associated with the degree of disc heriation, but had no correlation with the operating age. There was no direct correlation between disc height decrease and clincal features.2,The angle of disc instability in operated level decreased obviously, spontaneous fusion was observed in some patients,but those findings had nothing to do with clincal symptoms;3,We can found the evidence of spontaneous adaptation and reconstruction locally from CT scan and MR images when followed-up, but the surgery would not cause extensively degeneration in lumbar spine.