Aims. To report the development of the technique for minimally invasive lumbar decompression using robotic-assisted navigation. Methods. Robotic planning software was used to map out bone removal for a laminar decompression after registration of CT scan images of one cadaveric specimen. A specialized acorn-shaped bone removal robotic drill was used to complete a robotic lumbar laminectomy. Post-procedure advanced imaging was obtained to compare actual bony decompression to the surgical plan. After confirming accuracy of the technique, a minimally invasive robotic-assisted laminectomy was performed on one 72-year-old female patient with lumbar spinal stenosis. Postoperative advanced imaging was obtained to confirm the decompression. Results. A workflow for robotic-assisted lumbar laminectomy was successfully developed in a human cadaveric specimen, as excellent decompression was confirmed by postoperative CT imaging. Subsequently, the workflow was applied clinically in a patient with severe spinal stenosis. Excellent decompression was achieved intraoperatively and preservation of the dorsal midline structures was confirmed on postoperative MRI. The patient experienced improvement in symptoms postoperatively and was discharged within 24 hours. Conclusion. Minimally invasive robotic-assisted lumbar decompression utilizing a specialized robotic bone removal instrument was shown to be accurate and effective both in vitro and in vivo. The robotic bone removal technique has the potential for less invasive removal of laminar bone for spinal decompression, all the while preserving the spinous process and the posterior ligamentous complex. Spinal robotic surgery has previously been limited to the insertion of screws and, more recently, cages; however, recent innovations have expanded robotic capabilities to decompression of neurological structures. Cite this article: Bone Jt Open 2024;5(9):809–817

We assigned 67 patients with central lumbar stenosis alternately to either multiple laminotomy or total laminectomy. The protocol, however, allowed multiple laminotomy to be changed to total laminectomy if it was thought that the former procedure might not give adequate neural decompression. There were therefore three treatment groups: group I consisting of 26 patients submitted to multiple laminotomy; group II, 9 patients scheduled for laminotomy but submitted to laminectomy; and group III, 32 patients scheduled for, and submitted to, laminectomy. The mean follow-up was 3.7 years. Bilateral laminotomy at two or three levels required a longer mean operating time than total laminectomy at an equal number of levels. The mean blood loss at surgery and the clinical results did not differ in the three groups. The mean subjective improvement score for low back pain was higher in group I but there was also a higher incidence of neural complications in this group. No patient in group I had postoperative vertebral instability, whereas this occurred in three patients in groups II and III, who had lumbar scoliosis or degenerative spondylolisthesis preoperatively. Multiple laminotomy is recommended for all patients with developmental stenosis and for those with mild to moderate degenerative stenosis or degenerative spondylolisthesis. Total laminectomy is to be preferred for patients with severe degenerative stenosis or marked degenerative spondylolisthesis

Study design. A retrospective study design. Objective. To comprehensively compare the 2-year clinical outcome of lumbar laminectomy alone versus lumbar laminetomy supplemented with dynamic stabilization (Dynesys system) in degenerative lumbar stenosis in elderly patients. Material and Methods. A total of 60 elderly patients with an average age of 65.1 years (range, 50 to 78 yrs) affected by lumbar stenosis that underwent lumbar laminectomy alone (30 cases) or lumbar laminectomy with supplementary Dynesys system (30 cases) at our Department were sorted and matched according to three criteria : similar patient age, similar degenerative lumbar desease, and identical operative methods (i.e. levels of laminectomy). Patients were compared according to Oswestry Disability Index (ODI), Roland Morris, SF-36 and VAS outcomes scores. Results. The two cohorts were well matched at 2-years follow-up. Patients treated with lumbar laminectomy alone presented reduced operative time and intraoperative blood loss and reduced postoperative complications, with better clinical outcome compared with patients that received laminectomy with supplementary Dynesys system, for ODI score (28.9 vs 31), Roland Morris (8.25 vs 9.1) and VAS scores (leg pain 36 vs 44.3; back pain 31 vs 38.7), while SF-36 scores resulted similar in both groups of patients. Conclusions. In degenerative lumbar stenosis, supplementary dynamic stabilization in addition to decompressive laminectomy did not presented significant advantages, with respect to functional outcome, in comparison to lumbar laminectomy alone

Aims. Surgical approaches to cervical ossification of the posterior longitudinal ligament (OPLL) remain controversial. The purpose of the present study was to analyze and compare the long-term neurological recovery following anterior decompression with fusion (ADF) and posterior laminectomy and fusion with bone graft and internal fixation (PLF) based on > ten-year follow-up outcomes in a single centre. Methods. Included in this retrospective cohort study were 48 patients (12 females; mean age 55.79 years (SD 8.94)) who were diagnosed with cervical OPLL, received treatment in our centre, and were followed up for 10.22 to 15.25 years. Of them, 24 patients (six females; mean age 52.88 years (SD 8.79)) received ADF, and the other 24 patients (five females; mean age 56.25 years (SD 9.44)) received PLF. Clinical data including age, sex, and the OPLL canal-occupying ratio were analyzed and compared. The primary outcome was Japanese Orthopaedic Association (JOA) score, and the secondary outcome was visual analogue scale neck pain. Results. Compared with the baseline, neurological function improved significantly after surgery in all patients of both groups (p < 0.001). The JOA recovery rate in the ADF group was significantly higher than that in the PLF group (p < 0.001). There was no significant difference in postoperative cervical pain between the two groups (p = 0.387). The operating time was longer and intraoperative blood loss was greater in the PLF group than the ADF group. More complications were observed in the ADF group than in the PLF group, although the difference was not statistically significant. Conclusion. Long-term neurological function improved significantly after surgery in both groups, with the improvement more pronounced in the ADF group. There was no significant difference in postoperative neck pain between the two groups. The operating time was shorter and intraoperative blood loss was lower in the ADF group; however, the incidence of perioperative complications was higher. Cite this article: Bone Jt Open 2024;5(9):768–775

1 . Standard lumbar laminectomy was performed at multiple levels in thirty dogs, and manipulations were carried out in the spinal canal to observe their effects on periradicular adhesion formation. The canal was scarified, packed with Gelfoam, or treated with three varieties of Silastic membranes. The results were serially assessed from three days to twelve weeks by gross observation, nerve conduction studies, histological examination of transverse sections of the spine, myelin study of lumbar roots and micropaque study of the arterial supply to the roots. 2. The results were consistent biologically. The principal source of scar is dorsally in the fibrous tissue elements of the erector spinae muscle mass. This scar, the laminectomy membrane, covers the laminectomy defect and extends into the canal bilaterally to adhere to the dura and nerve roots. 3. Gelfoam does not contribute to scar formation, but instead acts as an effective interposing membrane. Silastic membranes are capable of providing protection against nerve root adhesions without interfering with the anatomical or physiological integrity of the nerves. 4. Certain clinical implications of the study are discussed

We have developed criteria to determine the appropriate indications for lumbar laminectomy, using the standard procedure developed at the RAND corporation and the University of California at Los Angeles (RAND-UCLA). A panel of five surgeons and four physicians individually assessed 1000 hypothetical cases of sciatica, back pain only, symptoms of spinal stenosis, spondylolisthesis, miscellaneous indications or the need for repeat laminectomy. For the first round each member of the panel used a scale ranging from 1 (extremely inappropriate) to 9 (extremely appropriate). After discussion and condensation of the results into three categories laminectomy was considered appropriate in 11% of the 1000 theoretical scenarios, equivocal in 26% and inappropriate in 63%. There was some variation between the six categories of malalignment, but full agreement in 64% of the hypothetical cases. We applied these criteria retrospectively to the records of 196 patients who had had surgical treatment for herniated discs in one Swiss University hospital. We found that 48% of the operations were for appropriate indications, 29% for equivocal reasons and that 23% were inappropriate. The RAND-UCLA method is a feasible, useful and coherent approach to the study of the indications for laminectomy and related procedures, providing a number of important insights. Our conclusions now require validation by carefully designed prospective clinical trials, such as those which are used for new medical techniques

Aims. The optimal procedure for the treatment of ossification of the posterior longitudinal ligament (OPLL) remains controversial. The aim of this study was to compare the outcome of anterior cervical ossified posterior longitudinal ligament en bloc resection (ACOE) with posterior laminectomy and fusion with bone graft and internal fixation (PTLF) for the surgical management of patients with this condition. Methods. Between July 2017 and July 2019, 40 patients with cervical OPLL were equally randomized to undergo surgery with an ACOE or a PTLF. The clinical and radiological results were compared between the two groups. Results. The Japanese Orthopaedic Association (JOA) score and recovery rate in the ACOE group were significantly higher than those in the PTLF group during two years postoperatively, provided that the canal occupying ratio (COR) was > 50%, or the K-line was negative. There was no significant difference in JOA scores and rate of recovery between the two groups in those in whom the COR was < 50%, or the K-line was positive. There was no significant difference in the Cobb angle between C2 and C7, sagittal vertical axis, cervical range of motion (ROM), and complications between the two groups. Conclusion. Compared with PTLF, ACOE is a preferred surgical approach for the surgical management of patients with cervical OPLL in that it offers a better therapeutic outcome when the COR is > 50%, or the K-line is negative, and it also preserves better cervical curvature and sagittal balance. The prognosis of ACOE is similar to that of PTLE when the COR is < 50%, or the K-line is positive. Cite this article: Bone Joint J 2023;105-B(4):412–421

In currently used expansive laminoplasty (ELAP) for cervical spondylotic myelopathy (CSM), persistent axial pain, restriction of neck motion and loss of cervical l ordosis have been the significance postoperative problems. To prevent them, the author has developed skip laminectomy in which ordinary laminectomy at appropriate levels is combined with partial laminectomy of the cephalad half of laminae with preservation of the muscular attachments at adjacent levels. Since December 98, the author performed this procedure on 55 patients with CSM who required multilevel posterior decompressions. Twenty-one of these cases with follow-up period longer than 8 months, with an average of 12 months, were observed. In skip laminectomy, a consecutive four-level decompression between C3/4 and C6/7 as an example is accomplished by removing alternate laminae (C4 and C6), the cephalad half of the C5 and C7 lamina and the ligamentum flava at those four levels. The laminae to be removed were selected after analysis of the pre- and postoperative radiological findings. Intraoperative blood loss averaged 34 grams. The operation time averaged 128 minutes. The patients were allowed to sit up or walk on the first postoperative day without neck support of any kind. An average recovery rate according to the Japanese Orthopaedic Association score was 63%. None of these patients complained of residual axial pain. The postoperative ranges of neck motion on lateral X rays averaged 87% of the preoperative ranges. The spinal curvature index, according to Ishihara’s method, was reduced in only one of the 21 cases. Postoperative atrophy of the deep extensor muscles measured on T2 weighed axial MRI was minimal. Skip laminectomy is less damaging to the posterior extensor muscles and its use reduces the postoperative problems commonly seen after ELAP

AIM: To compare the outcomes between two different surgical techniques for cervical myelopathy (skip laminectomy vs laminoplasty). METHODS: Cervical skip laminectomy is a new technique described by Japanese surgeons in 2000. The advantage of this procedure over the other conventional techniques is it addresses multilevel problem in a least traumatic way without need for instrumentation. We are comparing the above two techniques with 25 patients in each group operated by 3 surgeons. The first group had conventional laminoplasty and the second group underwent the skip laminectomy. The groups were comparable in age, sex, pathology and clinical presentation. Both these group had clinical outcome measurements using SF 12 questionnaires, pre and postoperative clinical assessment with standard tools performed by independent surgeon and a specialist spinal physiotherapist. We also routinely performed pre and postoperative MRI scans to assess the adequacy of decompression. RESULTS & CONCLUSION: There was no significant difference in the outcome of these patients in terms of the operative technique, hospital stay, clinical and radiological outcome. However skip laminectomy is relatively a easier procedure to perform, while the laminoplasty does need instrumentation

Introduction & Aims: The X-stop interspinous process decompression system is being used as an alternative to laminectomy in the treatment of neurogenic claudication. To date the clinical outcomes are favourable, but the economic value has not been established within the NHS financial model. Objective: To compare the average hospital costs of performing an x-stop procedure (under general or local anaesthetic) to a laminectomy in patients with neurogenic claudication. Design: A retrospective analysis of average length of stay, anaesthetic and operative times, equipment and anaesthetic agent costs. Sources included theatre management systems, the British National Formulary and Leeds Teaching Hospitals Trust in-patient stay data. The study period was from April 2005 to October 2006. The number of patients in the two groups were 318 (laminectomy) and 75 (X-stop). Results: In comparison to laminectomy, patients under-going an X-stop procedure have a reduced average length of in-patient stay (3 versus 5 days), reduced anaesthetic time (25 versus 29 minutes) and operative duration (40 versus 128 minutes). The average cost for each procedure is £3346 for an X-stop under general anaesthetic (profit £119), £2835 for a laminectomy (profit £1177) and £2237 for an X-stop as a day case (profit £1228). Conclusions: Tariff reimbursement is an important consideration to ensure insertion of these devices is profitable for the hospital. Our results show that even with the additional cost of the implant device, an X-stop procedure under general anaesthetic remains profitable in comparison to a laminectomy, whilst a day-case X-stop procedure is more profitable. Additional savings are be made by reduced bed and theatre occupancy. Future studies will differentiate costs of 1- and 2-level X-stop procedures, complication rates and revision surgery

Introduction: Spinous process osteotomy (SPO) and multiple laminotomy can be used for multi-level lumbar decompression. We conducted an experimental study to compare the effects of these two methods on spinal kinetics. Method: Ten fresh calf spines (L2- sacrum) were mounted in dental stone and segmental motion of L3 relative to L5 was assessed using an electromagnetic 3-D motion detection system (FASTRAK, Polhemus, Colchester, VT, USA). Pure moments of 0, 2.5, 5, 7, and 10 Nm were used in flexion/extension, right/left lateral bending, and right/left axial rotation. The moments were generated by applying two equal and opposite forces (weights) to the perimeter of a plastic circular disc, which was fixed to the superior end plate of L3 by three screws. In five spines decompression was performed at L3/4 and 4/5 using standard laminotomy technique. Decompression using SPO was done at L3–5 through a unilateral approach in the rest. Segmental mobility between the two methods was compared using the Mann-Whitney test. Results: Mean range of motion in the specimens before intervention was-lateral bending (32.70 ± 7.6 SD), rotation (13.10 ± 4.8 SD), flexion/extension (19.30 ± 7.1 SD). There was statistically significant difference between mean increase in lateral bending after SPO to that following laminotomy (4.00 ± 1.5 SD vs 0.60 ± 1.6 SD; p=0.008). Mean increase in flexion- extension after SPO was not significantly different from that after laminotomy (4.50 ± 1.1 SD vs 3.90 ± 3.8 SD; p= 0.75). There was no difference in the mean increase in axial rotation after SPO compared to that following laminotomy (7.90 ± 3.6 SD vs 6.80 ± 5.0 SD; p= 0.75). Conclusions: Both laminotomy and SPO produced increased range of motion in a calf spine model. SPO produced significant increase in lateral bending although its clinical significance is unknown. Ethics approval: none. Interest Statement: Local grant (Research Fund, Centre for Spinal Studies, Robert Jones and Agnes Hunt Hospital, UK

Introduction and aims: Surgical decompression for lumbar stenosis entails a risk of iatrogenic instability. Consequently, laminectomy has been largely superseded by the more conservative procedure of fenestration, but the decompression may be compromised. We describe an additional technique of undercutting laminectomy, which conserves stability while maximising decompression, and the results are presented. Method: Forty-nine patients with lumbar spinal stenosis were treated by fenestration, medial facetectomy and removal with curved osteotomes of the ventral aspect of the lamina superior to the involved facets together with the attached ligamentum flavum. The results were assessed at a mean follow-up period of three years and four months using walking distance and a pain analogue scale as outcome measures, and surgical complications were recorded. The radiological results were assessed in 25 patients by measurement on MRI scan of the spinal canal cross-sectional area pre- and post-operatively. Results: Ten patients had undercutting laminectomy at one level, 19 at two levels, 14 at three levels and four at four levels. Medical co-morbidity was present in most patients; 11 were ASA 1, 25 ASA2 and 11 ASA 3. Pre-operatively, all patients reported leg pain or numbness and 20 patients reported back pain. All but one had limited walking distance, the mean being 564 metres (range 5m–8000m). Post-operatively the mean pain score was 3.3 and the mean walking distance 762 metres. Forty-one patients said they felt the operation had been worthwhile and six said they did not. Surgical complications occurred in five patients, consisting of dural tear in four patients (repaired with no sequelae) and a wound haematoma requiring drainage in one patient. The mean spinal canal cross-sectional area at the level of maximal stenosis pre-operatively was 28mm. 2. and postoperatively was 75mm. 2. , giving a mean increase of 133%. No patients had any evidence of iatrogenic instability as judged by the development of degenerative spondylolisthesis or scoliosis. Conclusion: The technique described achieves excellent decompression of the stenotic lumbar canal as measured radiologically, while largely preserving the facet joints. In relation to published reports on fenestration and medial facetectomy alone, the clinical results are at least as good

Purpose: The goal of laminectomy is to relieve spinal stenosis and improve radiculopathy. Back pain related to poor trunk muscular conditioning may negatively affect post-operative outcomes. A better understanding of this relationship is important to improve the selection of appropriate surgical candidates. The purpose of this study was to assess the association between cross-sectional lumbar paraspinal muscle area as measured by CT or MRI and outcomes following laminectomy. Method: Prospective observational study of 23 patients undergoing primary elective lumbar laminectomy without fusion who were assessed with pre-operative CT scans. Clinical outcomes were measured with Numerical Pain Scale (NPS) for back and leg pain and the Oswestry Low Back Disability Index (ODI) at baseline and follow-up at a minimum of one year. Lumbar paraspinal muscle cross-sectional area was measured using digital imaging software and adjusted for percent fat infiltration; CT scans evaluations were blinded to clinical outcomes. Results: There were significant improvements in clinical outcomes following laminectomy. ODI decreased from 53.9±11.8 (mean±standard deviation) at baseline to 27.3±20.6 after a follow-up of 15.2±3.5 months. A strong correlation existed between cross-sectional lumbar paraspinal muscle area after adjusting for infiltrating fat content an improvement in ODI (r=0.51, p< 0.02) or back pain NPS (r=0.55, p< 0.02). These relationships remained statistically significant after adjusting for age and body mass index. No significant associations were identified for improvements in leg pain NPS. Conclusion: This study suggests a possible relationship between cross-sectional lumbar paraspinal muscle area and outcomes following laminectomy. This raises important questions regarding the role of trunk muscular conditioning in the etiology of back pain and success of surgery. Further research is required to refine this measurement as a tool to improve patient selection for surgery

1. One hundred and sixty cases of incomplete or complete paraplegia due to extradural malignant tumour have been reviewed. Between 1959 and 1969 laminectomy for decompression of the cord was performed in 154 of these cases as an urgent measure and the results in 129 cases with full records have been assessed. 2. Immediate laminectomy, a palliative procedure, gave worthwhile improvement in 35 percent of cases of incomplete paraplegia; such patients could walk and had satisfactory control of bladder function at least six months after operation. 3. There were no satisfactory results when the paraplegia was complete. 4. The relief of pain following decompression may be gratifying, even if the patient does not improve sufficiently to fulfil the criteria of a satisfactory result. 5. The results emphasise the importance of early diagnosis, myelography and decompression if a patient with incomplete paralysis is to be offered any chance of relief

Purpose: To measure outcome in patients undergoing decompression for lumbar canal stenosis (LCS) by lami-nectomy. Methods: 100 patients (57 men, 43 women) under one consultant surgeon presenting with neurogenic claudication and MRI confirmed LCS were studied . 23 patients had pre –existing spondylolisthesis (21 Grade 1, 2 Grade-2) and were managed by laminectomy without fixation. Patients completed a set of outcome measure questionnaires (SF-36, Visual analogue scores for back pain, leg pain, leg sensory symptoms and the Roland-Morris back disability score) pre-operatively, 3 months post surgery and at longer term follow up (median 2 years). Outcome scores were analysed and for SF-36 compared to age matched normative data. Statistical significance was calculated using Wilcoxon’s matched pairs and correlations using Spearman’s rank test. Statistical analysis was performed using the SPSS statistical package. Results: Average age 68 years (inter-quartile range 60 – 77). For the cohort visual analogue scores and Roland scores showed significant improvement (p < 0.01) at both 3 months and at long term follow up compared to pre-operative scores. For the physical functioning domain of SF-36, outcome scores improved significantly (p< 0.01) at short and long term follow up with 80% of patients having better long term scores compared to pre-operative scores. The physical functioning domain of SF-36 was significantly correlated with the changes seen in the visual analogue pain scores and the Roland back pain score (p < 0.01). Outcome for the spondylo-listhesis subgroup was similar to the outcome in patients without pre existing spondylolisthesis. Conclusions: Laminectomy for lumbar canal stenosis is an effective treatment resulting in significant health gains which are maintained in the longer term. Our data validates SF-36 as a measurement of disease severity and outcome in this condition

1. The usual methods of posterior arthrodesis of the lumbo-sacral joint are not satisfactory in cases in which laminectomy has been performed. 2. Estimation of fusion by mobility radiographs is unreliable and cannot distinguish between fibrous ankylosis and bony fusion. 3. Bone grafts inserted from behind between the vertebral bodies almost invariably fail to become incorporated. 4. Intertransverse arthrodesis has given promising results and is probably the best method available at present

The purpose of this study was to evaluate whether epidural fibrosis formation around the spinal cord was affected by endogenous oestrogen deficient state after lumbar laminectomy in the rats. Thirty-six 12-month-old adult female Sprague-Dawley rats were used in this study. Bilaterally ooferectomy were done in 18 rats. Rats were divided into two groups: oophrectomised (oestrogen deficient) group and sham operated (oestrogen maintained) group. Three weeks after the ooferectomy each rat underwent complete bilaterally laminectomy at the L2 and L3 vertebral levels (two levels per rat). The rats were randomly divided into three equal groups (12 rats in each group). The rats were sacrificed at four, eight, and twelve weeks postoperatively and the lumbar spine excised en bloc, fixed and decalcified. Section stained with hematoxylin and eosin and Masson’s trichrome were used to evaluate epidural fibrosis, acute inflammatory cells, chronic inflammatory cells and vascular proliferation. Sections were analyzed by investigator blinded to the study and graded on a five-point grading system. Statistic were performed using Mann-Whitney U test when compare two variable and Kruskal-Wallis test when compare more than two variables. Compared with the oopherectomised group, the sham operated group showed decreased rate of epidural fibrosis and higher acute and chronic inflammatory cells response at four and eight weeks but this was no statistically significant (p> 0.05). The results of this study revealed that endogenous oestrogen may decrease epidural fibrosis formation after lumbar laminectomy in the rats

Aim: To compare the outcomes between two different surgical techniques for cervical myelopathy (skip laminectomy vs laminoplasty). Methods: Cervical skip laminectomy is a new technique described by Japanese surgeons in 2000. The advantage of this procedure over the other conventional techniques is it addresses multilevel problem in a least traumatic way without need for instrumentation. We are comparing the above two techniques with 25 patients in each group operated by 3 surgeons. The first group had conventional laminoplasty and the second group underwent the skip laminectomy. The groups were comparable in age, sex, pathology and clinical presentation. Both these group had clinical outcome measurements using SF 12 questionnaires, pre and postoperative clinical assessment with standard tools performed by independent surgeon and a specialist spinal physiotherapist. We also routinely performed pre and postoperative MRI scans to assess the adequacy of decompression. Results and Conclusion: here was no significant difference in the outcome of these patients in terms of the operative technique, hospital stay, clinical and radiological outcome. However skip laminectomy is relatively a easier procedure to perform, while the laminoplasty does need instrumentation

Postoperative radiculopathy is a complication of posterior cervical decompression associated with tethering of the nerve root. We reviewed retrospectively 287 consecutive patients with cervical compression myelopathy who had been treated by multilevel cervical laminectomy and identified 37 (12.9%) with postoperative radiculopathy. There were 27 men and ten women with a mean age of 56 years at the time of operation. The diagnosis was either cervical spondylosis (25 patients) or ossification of the posterior longitudinal ligament (12 patients). Radiculopathy was observed from four hours to six days after surgery. The most frequent pattern of paralysis was involvement of the C5 and C6 roots of the motor-dominant type. The mean time for recovery was 5.4 months (two weeks to three years). The results at follow-up showed that the rate of motor recovery was negatively related to the duration of complete recovery of postoperative radiculopathy (γ = −0.832, p < 0.01) and that patients with spondylotic myelopathy had a significantly better rate of clinical recovery than those with ossification of the posterior longitudinal ligament (t = 2.960, p < 0.01). Postoperative radiculopathy may be prevented by carrying out an anterior decompression in conjunction with spinal fusion, which will achieve stabilisation and directly remove compression of the cord at multiple levels

1. The results of wide laminectomy of the fifth lumbar vertebra and disc excision in 132 patients are reviewed and compared with some published results of the interlaminar operation. 2. There was no significant difference in either the immediate or the long-term results of the two operations suggesting that post-operative morbidity was not related to operative technique. 3. The incidence of post-operative back pain was found to increase with age at operation, duration of pre-operative symptoms and length of follow-up, and supported the impression that backache is predominantly a feature of the underlying degenerative process rather than the incidental operation. 4. The significance of recurrent disc lesions is discussed. Recurrence usually occurred at the previously cleared disc space and was thought to indicate incomplete degeneration of the disc at the time of the original operation. 5. The place of fusion combined with disc excision is discussed. No reliable indications for coincident fusion were found in this series. 6. The value of radiography is discussed. Plain radiographs were essential before operation to exclude other causes of backache and sciatica; otherwise they were of little value. Motion radiographs were no more helpful and myelography was used only when the level of the lesion was in doubt. 7. The risk of an acute cauda equina lesion following manipulation of a prolapsed lumbar disc is noted and the danger of manipulation, unless facilities for emergency surgery are available, is stressed