Purpose of the study: Although the iliac autograft is the gold standard for single-level intervertebral fusion, complications and morbidity related to autologous graft harvesting from the iliac crest remain a point of concern. Bone morphogenic protein (BMP) has proven advantages for fusion of the intersomatic and posterolateral graft. This study compared the efficacy and tolerance of OP-1 compared with an autologous graft in patients with symptomatic spondylolisthesis. This study reports the preliminary results of a prospective randomised controlled trial comparing OP-1 with an iliac autologous graft for instrumented single-level posterolateral fusion for arthrodesis of grade 1 spondylolisthesis.

Material and methods: Lamino-arthrectomy associated with a posteriolateral instrumented arthrodesis with an iliac autologous graft or a mixture of OP-1 and local autologous graft material was performed in 27 patients with spondylolisthesis leading to lumboradiculalgia or neurogenic claudication. The final outcome was time to fusion at one year on the scanner and plain x-rays. The Oswestry score and pain at the harvesting site as well as side effects were also noted.

Results: The cohort included 27 patients. Three were excluded from the analysis, leaving 24 patients assessed at one year. The demographic data were comparable for the two groups regarding mean age (64 years versus 69 years for the OP-1 group). At one year, ten radiographically certain fusions were noted in the control group and eight in the OP-1 group. Two nonunions and one doubtful fusion were noted in the control group compared with three doubtful fusions in the OP-1 group. The mean Oswestry score was comparable in the two groups. The mean score in the control group improved from 49.5 to 28.5 compared with 45.9 to 29.7 in the OP-1 group. There was no secondary effect attributable to use of OP-1. There were no cases of systemic toxicity, nor heterotopic calcification or restenosis for the 11 patients in the OP-1 group.

Conclusion: A fusion rate of 73% without secondary effects attributable to OP-1 was observed in this preliminary study. This study allows the conclusion that this technique is reliable, safe and, in terms of fusion, a valid alternative to autologous iliac crest graft. The main advantage resulting from the use of OP-1 is to avoid the morbidity linked with harvesting the iliac graft.

Purpose of the study: Conventional treatment for recurrent lumbar disc herniation is repeated discectomy. Other methods such as fusion, ligamentoplasty or implantation of a discal prosthesis are sometimes proposed but all increase morbidity. The purpose of this work was to ascertain the efficacy of isolated repeated radicular release for the treatment of recurrent discal herniation.

Material and methods: Thirty-four patients underwent surgery for recurrent discal herniation. Repeated radicular release was used in all patients included in this analysis who completed a self-administered questionnaire at last follow-up to assess the final functional outcome.

Results: The cohort included 13 women and 21 men, mean age at surgery 45 years. Mean time from first discectomy to revision surgery for recurrence was 55 months. At the time of the review, four patients had died, all four from cancer. None of these patients had undergone a revision procedure on the lumbar spine. One patient was lost to follow-up so 85% of the cohort was analyzed with 60 months average follow-up. A dural tear occurred during the proscedure in six patients (17%. Five patients (14.7%) required revision surgery, one for deep infection, four for recurrent or persistent lumboradiculalgia (recurrent discal herniation, isthmic fracture, lateral stenosis associated with inflammatory discopathy). The rate of revision for painful failure was 11.4%. The final outcome could be assessed for 25 patients and was satisfactory for 22/25 (88%). The self-administered questionnaire revealed 65% average improvement with more than half of the patients reported better than 80% improvement. Ten patients (40%) complained of lumbar pain and a third had residual, generally intermittent, radiculalgia. Eighteen of 25 patients resumed their work at a comparable level after six months on average; 84% of the patient would accept the same operation again.

Discussion: In terms of morbidity and rate of revision, the results are comparable to reports in the literature. Repeated release does not increase the risk of a new recurrence.

Conclusion: This work enabled us to demonstrate that in the large majority of patients repeated discectomy provides satisfactory functional outcome with little morbidity.

Purpose of the study: Experimentally, posterolateral fusion only allows incomplete control of flexion/extension, rotation and lateral inclination. This defect of posterolateral fusion is most marked with there is a wide anterior gap. For certain authors, this situation justifies use of intersomatic arthrodesis. The purpose of this work was to evaluate, within a spinal segment immobilized by posterolateral fusion, the changes observed in disc height and the possible clinical and radiographic impact of a change in disc height.

Material and methods: This was a retrospective analysis of a consecutive series of patients who underwent posterolateral fusion from January 1999 through December 2003 performed in addition to radicular release for degenerative spondylolisthesis were included. Functional symptoms were noted using: VAS, Beaujon function scale, Beaujon self-administered questionnaire, satisfaction scale, GHA28 anxiety/depression scale, and SF36 quality of life questionnaire. Spineview® was applied at the olisthesic level (disc height, listhesis, anglulation), at adjacent levels, for pelvic parameters, sagittal tilt, and vertebral motion on stress views. We searched for a correlation between the consequences of changes in these variables was and the functional outcome as well as the quality of the fusion. The effect of variations in the following preoperative variables was studied with multivariate analysis: disc height, intervetebral angulaion, listhesis, vertebral motion, sagittal balance, use of osteosynthesis or not.

Results: Forty patients were reviewed with a mean follow-up of 38 months (range 15–70 months). Decreased disc height at the olithesic level was associated with local kyphosis. The level above tended towards lordosis while the level below towards kyphosis. These variations had no effect on the final functional outcome.

Discussion: No formal argument could be found in the literature favoring the use of intersomatic arthrodesis to complete posterolateral fusion for the treatment of degenerative spondylisthesis. Disc height is lost after isolated posterolateral fusion with a risk of local kyphosis and persistent intervertebral motion, but these effects do not appear to influence the functional outcome nor the rate of fusion. More than disc height, it would appear that sagittal balance should be preserved to improve functional outcome.

Conclusion: This study enabled us to observe, as is reported in the literature, decreased disc height after posterolateral fusion for degenerative spondylolisthesis. However, there appears to be no correlation between this decreased disc height and the functional outcome. More than disc height, sagittal balance appears to be the determining factor.

Purpose of the study: We present a review of the two-year outcome of a new clinical sacroiliac fixation technique used in our first seven patients.

Material and methods: Between May 2002 and March 2003, seven patients with a Tile C fracture of the pelvic girdle were stabilized with a new operative technique. This technique used two sacral screws linked to two iliac expansive screws via a 5.5 mm rod. Three of the patients presented preoperative neurological injuries attributed to the trauma (L5 or S1 paralysis). All presented associated lesions: lower limb (n=3 patients), spine (n=2), acetabulum (n=2). Mean patient age was 36.3 years. We present a retrospective clinical and radiological review of these seven cases. The Majeed score, the radiological index of lower limb length, and the combined index of vertical displacement and sacroiliac CT results were noted.

Results: The mean Majeed score was 93. Reduction of the combined vertical displacement was considered excellent or good (< 10 mm) in all patients; The reduction in the leg length discrepancy was considered good for all patients. There was no loss of reduction at last follow-up. There were no septic or skin complications and no complications related to implanted material. The implants were removed in one patient. The sacroiliac CT revealed formation of ossification bridges in all patients.

Discussion: The results of our small series are encouraging, particularly for vertical stability over time. There was no case of lysis around the screws and the clinical results were satisfactory.

Conclusion: For us, this technique is the optimal method for the treatment of Tile C injury to the pelvic girdle. This technique enables vertical stabilization while maintaining a certain degree of horizontal mobility facilitating reduction and fixation of the associated anterior injuries. This technique has its limitations since it is not particularly adapted for posterior lesions with fracture of the sacrum in Denis zone 2. These early encouraging results will require further long-term assessment in a larger group of patients.

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: It is widely agreed that fusion of a spinal segment modifies the mechanical behaviour of sub-jacent vertebrae. The mean centre of rotation (MCR) is defined to study changes in the mechanical behaviour at junctions. This parameter describes the relative movement of an object moving from one position to another. The purpose of this study was to describe changes in the position of the MCR after posterolateral lumbar spine fusion and to determine factors influencing these changes.

Material and methods: Fifty-one patients with posterolateral fusion with or without instrumentation of the lumbar spine limited to one or two levels were reviewed. Preoperative and last follow-up stress x-rays of the lumber spine were studied. The following parameters were determined with Spinview, a devoted software, at the level of fusion, at the three suprajacent levels, and when appropriate, at subjacent levels: disc height, intervetebral angular mobility, position of the MCR. Pre and postoperative positions of the MCR were compared with the Wilcoxon test for paired variables. Univariate and multivariate analyses were performed to search for factors influencing changes in the position of the MCR. Variables studied were: age, follow-up, extent of the fusion and its anatomic position, instrumentation, preoperative mobility of the zone to be fused, and quality of the arthrodesis at last follow-up.

Results: There were no significant changes in the position of the MCR of the first suprajacent level. Two variables exhibited significant correlation with these changes: pre and postoperative angular mobility of the future zone of fusion, and use of instrumentation. Instrumentation significantly increased variability in the position of the MCR. Postoperative mobility of the zone of fusion minimised this variability.

Discussion: Studying variations in the position of the MCR appears to reflect well changes in the mechanical behaviour of levels adjacent to the spinal fusion. Use of appropriate software should be helpful for routine applications. In our series, changes in the position of the MCR correlated well with significant increase in angular and anteroposterior mobility and also with decreased disc height at the first suprajacent level. These observations explain early degradation of junction zones observed after arthrodesis.

Purpose: Pelvic girdle fractures with vertical and horizontal instability (Tile classification class C) are classical indications for surgical stabilisation of the posterior and anterior lesions. There is general agreement concerning the anterior fixation, but several methods have been described for the posterior fixation: open or percutaneous sacroiliac screwing using fluoroscopic or computed tomographic guidance, sacral compression bar applied laterally on the posterior iliac masses, sacral screw for sacroiliac fixation using the Galveston technique, among others.

Material and methods: We propose a new sacroiliac fixation technique for fractures of the pelvic girdle associating vertical and horizontal instability (Tile classification class C). This fixation technique controls vertical displacement while authorising, if needed, a certain degree of mobility in the horizontal plane allowing easier reduction of the anterior fracture. This technique uses two sacral screws, one in S1 and the other in S2, and two iliac screws. The iliac screws are inserted in the posterior iliac crest passing through two sacroiliac connectors placed on a rod connecting the two sacral screws. Vertical displacement is controlled by blocking the two connectors on the screw heads. If needed, the connectors can be left unblocked allowing a certain degree of freedom for moving the half-pelvis in the horizontal plane.

Results: This technique was used in four cases. Anatomic reduction was achieved. There was no secondary movement of the osteosynthesis material and no secondary displacement. Because of the quality of the fixation, the sitting position was allowed rapidly as was full-weight bearing and walking. This type of fixation is reserved for type C12 fractures of the Tile classification.

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: 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.