Purpose: The quality of the functional result for surgical treatment of lumbar stenosis has been the subject of much debate. The objectives of this retrospective review were to assess functional outcome ten years after surgical treatment of lumbar stenosis and determine the rate of revision in order to identify factors influencing outcome at last follow-up.

Material and methods: One hundred forty-one patients underwent surgery for lumbar stenosis between January 1990 and December 1992. Mean follow-up was ten years. Functional outcome at last follow-up was assessed with a specific questionnaire with items for lumbar and radicular pain and signs of radicular ischemia and with a self-administered satisfaction questionnaire as well as two visual analogue scales (VAS) for lumbar and radicular pain. Other data noted were: epidemiological and morphological features, comorbidity, presence or not of objective signs of neurological involvement, the SF-36, and a self-assessed anxiety-depression score (GHQ28). Two types of analysis were performed. A descriptive analysis to determine the severity of functional signs observed at last follow-up, patient satisfaction and incidence and reasons for surgical revision. Multivariate analysis was designed to search for factors affecting the self-administered senosis score.

Results: During the study period, fifteen patients underwent a revision procedure involving the lumbar spine. At last follow-up the overall satisfaction index was 71%. The best results were obtained for radiculalgia and intermittent neurogenic claudication. Residual lumbalgia was the main complaint at last follow-up. The patient’s psychological profile was the predominant factor affecting functional outcome. Other factors influencing functional outcome were revision surgery, persistent objective neurological disorders, and comorbidity.

Conclusion: Surgical treatment of lumbar stenosis allows satisfactory long-term results in the majority of patients. At ten years, the risk of revision surgery was 10%. A review of the literature shows that these results are better than those obtained with medical treatment and that these surgical interventions enable quality-of-life similar to that observed in an age-matched population.

Purpose: Analysis of the sagittal balance of the spine is a fundamental step in understanding spinal disease and proposing appropriate treatment. The objectives of this prospective study were to establish the physiological values of pelvic and spinal parameters of sagittal spinal balance and to study their interrelations.

Material and methods: Two hundred fifty lateral views of the spine taken in the standing position and including the head, the spine and the pelvis were studied. The following variables were noted: lumbar lordosis, thoracic kyphosis, sagittal tilt at 9, sacral slope, pelvic incidence, pelvic version, intervertebral angle, and the vertebral wedge angle from T9 to S1. These measures were taken after digitalising the x-rays. Two types of analysis were performed. A descriptive univariate analysis was used to characterise angular parameters and a multivariate analysis (correlation, principal component analysis) was used to compare interrelations between the variables and determine how economic balance is achieved.

Results and discussion: Mean angular values were: maximal lumbar lordosis 61±12.7°, maximal thoracic kyphosis 41.4±9.2°, sacral slope 42±8.5°, pelvic version 13±6°, pelvic incidence 55±11.2°, sagittal tilt at T9 10.5±3.1°. There was a strong correlation between sacral slope and pelvic incidence (r=0.8), lumbar lordosis and sacral slope (r=0.86), pelvic version and pelvic incidence (r=0.66), lumbar lordosis pelvic incidence pelvic version and thoracic kyphosis (r=0.9), and finally between pelvic incidence and sagittal tilt at T9, sacral slope, pelvic version, lumbar lordosis, and thoracic kyphosis (r=0.98). Multivariate analysis demonstrated three independent parameters influencing sagittal tilt at T9, reflecting the lateral balance of the spine. The first was a linear combination of the pelvic incidence, lumbar lordosis and sacral slope. The second was pelvic version and the third thoracic kyphosis.

Conclusion: This work provides an aid for analysis and comprehension of anteroposterior imbalance observed in spinal disease and also to calculate with the linear regression equations describing the corrections to be obtained with treatment.

Purpose of the study: Little is known about the impact of posterolateral arthrodesis on adjacent levels. In order to examine this question, we analyzed the radiological evolution of the lumbar spine in patients treated for lumbar stenosis, comparing cases where posterolateral arthrodesis was used with the other cases. Our aim was to determine whether the long-term radiographical modifications were affected by the arthrodesis.

Material and methods: Among our series of patients presenting with lumbar stenosis between 1984 and 1992, we retained two groups: patients in group 1 (n = 46) who underwent single-level decompressions at L4–L5 or L4–L5 and L5–S1 level; and patients in group II (n = 81) who underwent decompressions on the same levels associated with posterolateral arthrodesis extending from L4 to the sacrum with or without instrumentation. We compared the course of the two levels above the decompression (L2–L3 and L3–L4) between the two groups. We compared three radiological parameters: disc height, intervertabral slipping, and intersegmental mobility. We also examined the correlations between radiological modifications and functional outcome. Mean follow-up for these 127 patients was 9 years.

Results: The two groups were comparable for age, gender, follow-up, and presurgical functional score, disc height and intervertebral slipping at equivalent levels. At last follow-up, disc narrowing was observed at L2–L3 and L3–L4; it was significantly greater in the group with complementary arthrodesis. At L3–L4, intervertebral slipping also worsened more in the arthrodesis patients. Use of osteosynthesis significantly increased the risk of developing such radiological lesions. These lesions were associated, solely in the arthrodesis group, with poorer functional outcome.

Conclusion: Our findings allow the conclusion that, despite the effect of physiological aging, the observed long-term degenerative lesions in patients undergoing treatment of lumbar stenosis are related to the associated arthrodesis which increases their frequency and severity, deteriorating the functional outcome.

Purpose of the study: The principal objective of this prospective continuous observation study was to determine the incidence of perioperative and early postoperative complications secondary to surgical treatment of lumbar stenosis. Secondary objectives were to describe these complications and try to identify favouring factors.

Material and methods: All patients without major spinal deviation who underwent surgery for lumbar spine stenosis in our unit from January 1998 to January 2000 were included in the study. Minimal follow-up had to be six months. The series thus included 306 patients. Three categories of preoperative parameters were recorded: comorbid fractures, type of stenosis operated, type of surgery (simple release, release plus fusion, etc). In order to obtain an exhaustive data set, all complications were recorded on observation charts during hospitalisation and at follow-up visits at three, six and twelve months postoperatively. Complications were divided into four major categories: major complications, early or late infections, early or late mechanical disorders, neurological complications including meningeal disease and neurological disorders secondary to surgery. Data were explored with univariate analysis to determine the overall incidence of complications and the specific incidence for each category of complications and multivariate analysis with logistic regression to determine factor favouring development of complications.

Results: Overall incidence of complications secondary to surgery was 26.5%. Incidence of general, infectious, neurological and mechanical complications were 13, 4.5, 2.6, and 2% respectively. Incidence of complications considered to be serious and/or requiring reoperation was 12%. Factors influencing the development of complications were comorbidity, body mass index, duration of the operation, and reoperation.

Discussion and conclusion: The rate of complications reported in the literature have been very variable and have been established from retrospective reviews making comparison with our findings rather difficult. Our work pointed out the role of certain favouring factors which could be usefully examined in a larger series.

Purpose of the study: The principal aim of this prospective multicentric observational study was to validate an self-administered questionnaire for evaluation of functional outcome after surgical treatment of lumbar stenosis. The questionnaire was associated with an index of neurological impairment in order to account for objective neurological injury and an index exploring patient satisfaction after treatment for lumbalgia, radiculalgia and gait disorders.

Material and methods: The structure of the questionnaire was examined to determine whether the three dimensions of the evaluation scale were pertinent, to establish reproducibility (intra-observer variability), to study sensitivity to change, and finally to examine the items in the questionnaire and their capacity for effective measurement using the Cronbach alpha coefficient and principal components analysis. Reproducibility was tested on 49 patients who filled out the self-administered questionnaire twice, 15 days apart. The intra-class coefficients of correlation were calculated. Sensitivity was tested by correlating the variations of the scores obtained pre- and postoperatively with the index of satisfaction and by calculating mean standardised responses. The questionnaire items were validated by correlating the scores obtained using the questionnaire with scores obtained with three other self-administered questionnaires: SF36, EIFFEL2 and GHQ28.

Results: One hundred four patients were included in this study, 96 were seen at follow-up visits six and twelve months after surgery. Principal component analysis demonstrated the pertinence of the three dimensions in the evaluation scale. The overall Cronback alpha was 0.86. The overall intra-class coefficient of correlation was 0.95, varying from 0.86 to 0.97 for the dimensions studied. There was a good correlation (0.82) between the scores obtained and index of satisfaction. All mean standardised responses were greater than A1, indicating good sensitivity to change. There was a good correlation between the evaluated score and the EIFFEL2 self-administered questionnaire and the following dimensions of the SF36: physical activity, physical pain, vitality and limitation due to physical pain.

Discussion and conclusion: Using a simple self-administered questionnaire (eight questions), an index of satisfaction (four questions) and an objective score of neurological disorders allowed reliable, sensitive and reproducible assessment of the changes in the functional impairment caused by lumbar stenosis before and after surgical treatment.

Purpose of the study: Discal herniation is an exceptional cause of lumbar canal stenosis. When surgery for this disorder was first performed in the sixties, discectomy was not exceptional because discal protrusions were frequent. It was rather rapidly observed however that these protrusions were actually osteoarthitic discal rims that do not cause root compression. Discectomy was thus almost completely abandoned for lumbar stenosis surgery. Consequently, the development of true discal herniation after surgery for lumbar canal stenosis is highly exceptional. To our knowledge, this situation has not been reported in the literature. Among several hundred procedures for decompression of the lumbar canal practised in our unit over the last thirty years, we have observed seven cases.

Material and methods: The patients were aged 43 to 74 years at the time of reoperation (mean 61 years). The stenosis was at the L4-L5 level in all patients and extended to L3-L4 in three and to L5-S1 in two and was bilateral in one patient. The L4-L5 disk had been removed at the prior surgery in three patients. Delay to recurrent pain was variable, from six months to eleven years. The sciatic pain was associated with motor disorders in one patient. Discal herniation was observed at the L4-L5 level in all patients and was often voluminous, excluded in three patients. Reossification was present in one patient but did not have a compressive effect. Treatment after recurrence was chemonucleolysis in three patients, with two successes and one failure. Surgical treatment by discal excision was used in four cases associated with instrumented fusion in one patient.

Results: The patients were reviewed at one to ten years after the second operation. Nucleolysis was successful in two and a failure in one. The patient with failure of nucleolysis was treated by a new decompression with fusion and achieved an excellent result at ten years. Pain relief was achieved after surgery in all patients though only partial in one.

Discussion and conclusion: Discal herniation is rare in elderly subjects and can cause problems late after surgical decompression of lumbar canal stenosis. It is important to search for discal herniation which is not always easy to confirm radiologically due to postoperative remodeling. Chemonucleolysis is an effective and economical solution when the disk has not been resected during the first procedure. When an operation is necessary, spinal fusion is not useful except in case of associated instability.