Factors influencing complications after 3-columns spinal osteotomies for fixed sagittal imbalance from multiple etiologies: a multicentric cohort study about 286 cases in 273 patients.

PURPOSE: Spinal osteotomies performed to treat fixed spinal deformities are technically demanding and associated with a high complications rate. The main purpose of this study was to analyze complications and their risk factors in spinal osteotomies performed for fixed sagittal imbalance from multiple etiologies. METHODS: The study consisted of a blinded retrospective analysis of prospectively collected data from a large multicenter cohort of patients who underwent 3-columns (3C) spinal osteotomy, between January 2010 and January 2017. Clinical and radiological data were compared pre- and post-operatively. Complications and their risk factors were analyzed. RESULTS: Two hundred eighty-six 3C osteotomies were performed in 273 patients. At 1 year follow-up, both clinical (VAS pain, ODI and SRS-22 scores) and radiological (SVA, SSA, loss of lordosis and pelvic version) parameters were significantly improved (p < 0.001). A total of 164 patients (59.2%) experienced at least 1 complication (277 complications). Complications-free survival rates were only 30% at 5 years. Most of those were mechanical (35.2%), followed by general (17.6%), surgical site infection (17.2%) and neurological (10.9%). Pre-operative neurological status [RR = 2.3 (1.32-4.00)], operative time (+ 19% of risk each additional hour) and combined surgery [RR = 1.76 (1.08-2.04)] were assessed as risk factors for overall complication (p < 0.05). The use of patient-specific rods appeared to be significantly associated with less overall complications [RR = 0.5 (0.29-0.89)] (p = 0.02). CONCLUSION: Spinal 3C osteotomies were efficient to improve both clinical and radiological parameters despite high rates of complication. Efforts should be made to reduce operative time which appears to be the strongest predictive risk factor for complication.

Revision after spinal stenosis surgery.

PURPOSE: To make a literature review on spinal stenosis recurrence after a first surgery and edit rules to avoid this complication. METHODS: We conducted two separate PUBMED searches to evaluate the revision post-stenosis and degenerative scoliosis surgery using the terms: lumbar vertebrae/surgery, spinal stenosis, spine, scoliosis and reoperation. The resulting papers were categorized into three groups: (1) those that evaluated reoperation post-simple decompression; (2) those that evaluated spinal decompression and fusion for short (3 levels or less) or long (more than 3 levels) segment spinal fusion; and (3) those diagnosing the stenosis during the surgery. RESULTS: (1) We found 11 relevant papers that only looked at revision spine surgery post-laminectomy for spinal stenosis. (2) We found 20 papers looked at reoperation post-laminectomy and fusion amongst which there were two papers specifically comparing long-segment (> 3 level) and short-segment (3 or less levels) fusions. (3) In the unspecified group, we found only one article. Fifteen articles were excluded as they were not specifically looking at our objective criteria for revision surgery. In regard to revision post-adult deformity surgery, we found 18 relevant articles. CONCLUSIONS: After this literature review and analysis of post-operative stenosis, it seems important to provide some advice to avoid revision surgeries more or less induced by the surgery. It looks interesting when performing simple decompression without fusion in the lumbar spine to analyse the risk of instability induced by the decompression and facet resection but also by a global balance analysis. Regarding pre-operative stenosis in a previously operated area, different causes may be evocated, like screw or cage malpositionning but also insufficient decompression which is a common cause. Intraoperatively, the use of neuromonitoring and intraoperative CT scan with navigation are useful tool in complex cases to avoid persisting stenosis. Pre-op analysis and planning are key parameters to decrease post-op problems. These slides can be retrieved under Electronic Supplementary Material.

Sagittal classification in adolescent idiopathic scoliosis: original description and therapeutic implications.

INTRODUCTION: Surgical treatment of AIS aims to correct the coronal and sagittal alignment of the spine. The global alignment of the spine may be normalized through reciprocal changes between the fused spine and adjacent segments. We propose a new classification system describing the specific sagittal patterns induced by AIS to define reproducible guidelines for the surgical strategy. METHODS: We analyzed 100 consecutive AIS patients aged between 12 and 18 years candidate for spinal fusion. The following parameters were measured and compared for each pattern: spino-pelvic parameters, magnitude and length of the lumbar sagittal angle, magnitude and length of the thoracic sagittal angles (T1T12 and T4T12 angles, TKmax), T10 L2 angle, C7 slope and C2C7 angle. RESULTS: Three parameters strongly differentiated the four patterns: thoracic sagittal angles (T1T12 and T4T12 angles, TKmax), T10 L2 angle and C7 slope. Less than half of the patients (44%) had a normal sagittal shape. Within, Type 2 characterized by thoracic hypokyphosis, Type 2a (thoracic hypokyphosis) were mostly Lenke type 1 or 2 curves, and type 2b (thoracic hypokyphosis with TL kyphosis) occurred specifically in double major or TL/L curves. Type 3 were two-curve sagittal shape with cervicothoracic kyphosis and TL lordosis (9%), mainly in Lenke 1 curves. DISCUSSION: This new classification summarizes all the pathological scenarios of the sagittal alignment of AIS into four patterns. A specific surgical planning can be extrapolated for each pattern. In type 1, the objective is to preserve the sagittal shape. In type 2, the objective is to restore thoracic kyphosis. In type 2b, TL junction should be straightened. In type 3, the objective is to reshape the lower arc of thoracic sagittal angle and straighten the TL junction. These slides can be retrieved under Electronic Supplementary Material.

Evolution and complications after surgery for spine deformation in patients with Parkinson's disease.

INTRODUCTION: Surgical treatment of spinal deformity is high risk in patients suffering from Parkinson's disease (PD). Several series have already reported a high rate of complications. However, none of these studies included more than 40 patients and none of the risk factors of complications were described. The aim of this study was to describe the rate and risk factors of revision surgery as well as the clinical outcome at the last visit in a large multicenter study of PD patients operated for spinal deformities. METHODS: A multicenter retrospective study included arthrodesis for spinal deformity in patients with PD. Clinical and surgical data including revision surgeries were collected. Assessment of functional outcomes at last follow-up was classified in 3 grades and spinal balance was assessed on anteroposterior and lateral plain X-rays of the entire spine. RESULTS: Forty-eight patients were included. Median age was 67 years old (range 41-80). Median follow-up was 27 months. The rate of surgical revision was 42%. Eighty per cent of revisions were performed for chronic mechanical complication. Global results were considered to be good in 17 patients (35%), doubtful in 17 patients (35%) and a failure in 14 patients (30%), for the whole series. CONCLUSIONS: The results of surgery for spinal deformities in patients with Parkinson disease vary with a high rate of complications and revisions. Nevertheless, these results should be seen in relation to the natural progression of these spinal deformities once spinal imbalance has developed. The association between preoperative clinical balance and final outcome suggests that early surgery can probably play a role in treatment. LEVEL OF EVIDENCE: Level IV (e.g. case series).

Surgical treatment of thoraco-lumbar kyphosis (TLK) associated with low pelvic incidence.

PURPOSE: Thoraco-lumbar kyphosis (TLK) is poorly described in the literature and its surgical treatment remains equivocal for patients with low pelvic incidence. The aim of the study was to identify which surgical correction would yield the best functional results as measured by the Oswestry score. MATERIALS AND METHODS: This is a retrospective study including patients described as a type 1 of Roussouly's classification with a thoraco-lumbar kyphosis. Fifty-six patients with degenerative spinal disease were included, 42 (75%) with scoliosis and 14 (25%) without. Patients had a median age of 56 years (49-63), and there were 6 (11%) men. The primary outcome was the functional Oswestry disability index (ODI). RESULTS: At last follow-up, the median ODI was 15 (Q1-Q3: 6-23). In the degenerative spinal disease group, the median ODI was 7 (3.5-20) at last follow-up. Ten (84%) patients were classified as Roussouly's type 1 after surgery. In the degenerative scoliosis group, the ODI was 17 (8-23) in patients classified as Roussouly's type 1 and 20 (7.5-25) in patients classified as Roussouly's type 2 with no significant difference between these groups (p = 1). There were two patients classified as Roussouly's type 3a and their ODI at last follow-up were of 60 and 50. CONCLUSION: It seems that keeping the physiological morphology is the treatment of choice. For patients with degenerative scoliosis, reducing the kyphosis could work. We do not recommend to increase the lordosis and obtain a type 3 morphology with an anteverted pelvis because of the risk of PJK and poor functional results.

Cervical spine alignment in the pediatric population: a radiographic normative study of 150 asymptomatic patients.

PURPOSE: To describe the normal cervical sagittal alignment of the pediatric spine in a normal population and to identify the changes during growth period. METHODS: We randomly selected in PACS database 150 full-spine standing views. Exclusion criteria were: age >18 years, spinal deformity and any disease affecting the spine (medical charts reviewing). For cervical alignment we measured: OC-angle according to Mc Gregor, C1C7 angle, upper cervical angle, inferior cervical angle and C7 tilt. Spino pelvic parameters were analyzed: T1 tilt, thoracic kyphosis, lumbar lordosis, pelvic incidence, sacral slope and pelvic tilt. We compared two age subgroups (juvenile and adolescent). Differences between age groups and gender were tested using Student's t test. Correlations between sagittal spinal parameters were evaluated using Pearson's test. RESULTS: Cervical spine shape was correlated to cranio cervical orientation to maintain horizontal gaze (r = 0.60) and to thoracic kyphosis (r = -0.46). Cervical spine alignment was significantly different between the two age groups except for the global C1C7 cervical lordosis, which remained stable. A significant gender difference was found for all the cervical sagittal angles (p < 0.01) whereas no differences were demonstrated for the spino pelvic parameters, except the lumbar lordosis (p = 0.047). CONCLUSIONS: This study is the first to report the cervical spinal alignment in a normal pediatric Caucasian population. Even though cervical lordosis is the common shape, our results showed variability in cervical sagittal alignment. Cervical spine is a junctional area that adjusts its alignment to the head position and to the underlying spinal alignment.

Surgery of lumbar and thoracolumbar scolioses in adults over 50. Morbidity and survival in a multicenter retrospective cohort of 180 patients with a mean follow-up of 4.5 years.

INTRODUCTION: The increasing life expectancy of the population and the improvement in surgical and medical management of elderly patients mean that the indication for surgical treatment of adult lumbar and thoracolumbar scolioses has been extended. However the benefit/risk ratio of these procedures is still under debate. MATERIALS AND METHODS: We reviewed 180 patients, mean age 63years old with a minimum follow-up of 1year in a retrospective, continuous, multicenter study. The incidence rate of complications from surgery and the factors influencing their frequency were evaluated by uni- and multivariate analysis. The risk of a second operation was studied by actuarial survival analysis. RESULTS: After a mean follow-up of 4.5years, 79 patients (44%) presented with at least one complication, including 32% with a serious complication. The most frequent complications were mechanical. The risk factors were medical co-morbidities, the extent of fusion and the extent of the preoperative sagittal imbalance. A second operation was necessary in 25% of patients at 1year and 50% of patients at 6years of follow-up. DISCUSSION: Studies in the literature show that functional results are better with surgical treatment than with medical treatment in the management of thoracic spine and thoracolumbar deformities in patients over 50years old. An objective assessment of this deformity and associated co-morbidity should make it possible to reduce the rate of complications for this type of surgery. LEVEL OF EVIDENCE: Level IV.

Age- and sex-related variations in sagittal sacropelvic morphology and balance in asymptomatic adults.

INTRODUCTION: Many studies suggest the importance of the sagittal sacropelvic balance and morphology in spinal and hip disorders. This study describes the normal age- and sex-related changes in sacropelvic morphology and balance in a prospective cohort of asymptomatic adults without spinal disorder. MATERIALS AND METHODS: A prospective cohort of 709 asymptomatic adults without spinal pathology was recruited. There were 354 males and 355 females aged 37.9 ± 14.7 and 35.7 ± 13.9 years, respectively. For each subjects, pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were measured from standing lateral radiographs. Ratios of SS to PI (SS/PI), PT to PI (PT/PI), and PT to SS (PT/SS) were also calculated. RESULTS: There was no significant difference in PI (pelvic incidence), SS (sacral slope), PT (pelvic tilt), PT/PI, SS/PI, or PT/SS between males and females. The mean ± 2 standard deviations (SD) range was 32°-74°, 0°-27°, and 24°-55° for PI, PT and SS, respectively. The mean ± 2 SD range was greater than 0.5 for SS/PI and less than 0.5 for PT/PI. PI was not related to age in either sex group. PT, SS, PT/PI, SS/PI, and PT/SS presented only weak correlation coefficients (r ≤ 0.21) with respect to age. CONCLUSION: The current study presents the largest cohort of asymptomatic adults in the literature dedicated to the evaluation of sagittal sacropelvic morphology and balance. The range of values corresponding to the mean ± 2 SD can provide invaluable information to clinicians about the normal range of values expected in 95% of the normal population.

[Sagittal balance of the spine: a therapeutic revolution]. / Analyse de l'équilibre sagittal du rachis. Une révolution dans les approches thérapeutiques des pathologies dégénératives lombaires.

In humans, the erect position and bipedal walk is possible because of a balance between pelvic and spinal parameters. The most important pelvic parameter is the pelvic incidence which represents the base on which the spine lies. With aging, thoracic kyphosis increases, lumbar lordosis decreases, compromising the spino-pelvic balance. Compensatory phenomenons are possible, but rely mostly on the amplitude of pelvic incidence. Analysis of spino-pelvic parameters and detection of a compensated or uncompensated sagittal imbalance are mandatory before any therapeutic action is undertaken for a degenerative pathology of the spine.

A variability study of computerized sagittal spinopelvic radiologic measurements of trunk balance.

OBJECTIVE: The accurate measurement of spinal and pelvic alignment in the sagittal plane is of prime importance for various disorders. Pelvic incidence (PI) is a fundamental anatomic parameter that is specific and constant for each adult individual and is related to pelvic orientation as well as to the size of lumbar lordosis (LL). It is the summation of the sacral slope (SS) and pelvic tilt (PT), two position-dependent variables that determine pelvic orientation in the sagittal plane. The authors have proposed a computer software designed to measure PI, SS, PT, LL, and thoracic kyphosis (TK) on standardized standing lateral digitized x-rays of the spine and pelvis. The purpose of this study was to evaluate the inter- and intraobserver variability of measurements using this software, to determine if it can be used reliably in a clinical environment. METHODS: The standing lateral x-rays of 30 subjects were randomly selected from the database of two medical institutions. The normal population had standard radiographs on which the various pertinent landmarks were marked by one operator prior to digitization, whereas the scoliotic population had digital radiographs that obviated the need for prior marking of landmarks. Four individuals measured all variables on the 30 x-rays on two occasions, with a 15-day interval between the two sessions. Statistical analysis was done with intraclass correlation coefficients (ICCs). RESULTS: The ICC measured within observers was between 0.93 and 0.99, whereas the ICC between observers varied between 0.92 and 0.99. The variations observed were similar for normal and scoliotic subjects, and prior marking of the x-rays had no significant influence. CONCLUSION: We conclude that the variability of measurements with this method is lower than with similar radiologic measures done manually and that the use of this software can be recommended for future clinical and research studies of spinopelvic sagittal balance.

[Geometrical and mechanical analysis of lumbar lordosis in an asymptomatic population: proposed classification]. / Analyse géométrique et mécanique de la lordose lombaire dans une population de 160 adultes asymptomatiques: essai de classification.

PURPOSE OF THE STUDY: The main objective of this study was to describe the morphology and the mechanism underlying the organization of lumbar lordosis in terms of position and shape of the pelvis. A classification of lumbar lordosis was proposed based on the orientation of the sacral plane. MATERIAL AND METHODS: One hundred sixty asymptomatic young adult volunteers were x-rayed in a standardized standing position. A dedicated software was used for analysis of the spine and pelvis. The pelvic parameters were: pelvic incidence, sacral slope, pelvic tilt. The point separating thoracic kyphosis and lumbar lordosis was called the inflexion point. Lumbar lordosis was bounded by the sacral plate and the inflexion point. At the apex, the lumbar curve was divided into two tangent arcs of circle, quantified by an angle and the number of included vertebrae. The lower arc was geometrically equal to the sacral slope. Regarding the vertical line, a lordosis tilt angle was drawn between the inflexion point and the frontal limit of the sacral plate. RESULTS: The value of the lumbar lordosis was very variable. The best correlation was between lumbar lordosis and sacral slope, then between sacral slope and pelvic incidence. The upper arc of a circle remained constant while the lower arc changed with sacral slope. Good correlations were found between the sacral slope and the position of the apex and between sacral slope and lordosis tilt angle. DISCUSSION AND CONCLUSION: Regarding sacral slope, lumbar lordosis can be classified into four types. When the sacral slope is low, lumbar lordosis can either be both short and curved with a low apex and a backward tilt (type 1) or both long and flat with a higher position of the apex (type 2). When the sacral slope increases, lumbar lordosis increases in angle and number of vertebrae with an upper apex, with a progressively forward tilt (types 3 and 4). Depending on the shape and position of the pelvis, and because of the relation between sacral slope and pelvic tilt, the morphology of lumbar lordosis could be the main mechanical cause of degenerative diseases of the lumbar spine.

Sagittal morphology and equilibrium of pelvis and spine.

A prospective analysis of the sagittal profile of 100 healthy young adult volunteers was carried out in order to evaluate the relationship between the shape of the pelvis and lumbar lordosis and to create a databank of the morphologic and positional parameters of the pelvis and spine in a normal healthy population. Inclusion criteria were as follows: no previous spinal surgery, no low back pain, no lower limb length inequality, no scoliotic deviation. For each subject, a 30 x 90-cm sagittal radiograph including spine, pelvis and proximal femurs in standing position on a force plate was performed. The global axis of gravity was determined with the force plate. Each radiograph was digitized using dedicated software. The spinal parameters registered were values for thoracic kyphosis and lumbar lordosis. The pelvic angles measured were: pelvic incidence, sacral slope and pelvic tilt. The global axis of gravity was on average 9 mm anterior of the center of the femoral heads. The anatomic parameter of pelvic incidence angle varied from 33 degrees to 85 degrees (mean: 51.7 degrees, SD: 11 degrees). The average lumbar lordosis was 46.5 degrees. The average thoracic kyphosis was 47 degrees. We found a statistical correlation between incidence angle and lumbar lordosis (r=0.69, P<0.001) and between sacral slope angle and lumbar lordosis (r=0.75, P<0.001). Spine and pelvis balance around the hip axis in order to position the gravity line over the femoral heads. We propose a scheme of sagittal balance of the standing human body.

Investigation of glycosylation processes in mitochondria and microsomal membranes from human skeletal muscle.

Glycoconjugates are directly involved in major skeletal muscle functions. As little is known about glycosylation processes in muscle, we investigated glycoconjugate synthesis in subcellular fractions from human skeletal muscle tissue. Mitochondria and microsomal membranes were prepared from muscle biopsies by thorough mechanical disruption and differential centrifugations. This procedure resulted in the isolation of intact mitochondria (1 mg protein/g muscle) and of a microsomal fraction (1.5 mg protein/g muscle). Glycosyltransferases were studied in both subcellular fractions using either dolichylmonophosphate as a polyprenic acceptor or chemically modified fetuin as a glycoprotein substrate. Our results provide evidence for high rates of glycosylation in muscle. The highest activities were obtained with GDP-mannose: dilichylmonophosphate mannosyltransferase, a key enzyme in glycosylation process (220 pmol/mg per h in mitochondria and 1,550 pmol/mg per h in microsomal membranes). Substantial individual variations were observed for dolichol pathway glycosyltransferases but low individual variations were found for glycosyltransferases involved in maturation of glycoproteins. The role which glycosylation defects may play in muscle dysfunction has yet to be defined.

[Spinal osteoblastoma. Report of 8 cases]. / L'ostéoblastome rachidien. A propos de huit observations.

The authors studied the special features of the vertebral location of this benign tumour of osteoblastic origin in eight cases of spinal osteoblastoma. Clinically, neurological complications are frequently present and scolioses may arise and persist after treatment; radiologically, new imaging techniques enable the limits of the tumour to be assessed with greater accuracy with respect to the neighbouring bone and their relationship to the components of the vertebral canal; surgically, there are difficulties specific to this location raised by the proximity of nervous components, and also by the vertebral destabilization entailed by the considerable bone involvement. Anatomicopathological diagnosis remains difficult, particularly in the case of osteoid osteoma.