Influence of posture on relationships between pelvic parameters and lumbar lordosis: Comparison of the standing, seated, and supine positions. A preliminary study

BACKGROUND

Pelvic incidence (PI) is an anatomical parameter that is considered invariable in a given individual. Although changes in posture influence the mobile lumbar spine, lumbar lordosis (LL) and the pelvis are typically evaluated only in the standing position. Thus, whether other positions commonly used during daily activities influence the relationship between LL and PI is unknown. The objective of this study was to determine whether LL and sacral slope (SS) correlated with PI, using two standardised positions, seated and supine, different from the standing position that is generally used.

HYPOTHESIS

We are supposing that lumbar lordosis and sacral sloop are correlated to pelvic incidence whatever the posture. The goal of this study was to confirm or deny this hypothesis, using two standardize positions (sitting and lying) different that the usual standing position. LL and SS correlate with PI in the standing, seated, and supine positions.

METHOD

Lumbar and pelvic parameters were measured on radiographs obtained in the standing, seated, and supine positions in 15 asymptomatic adult volunteers younger than 50years of age. Mean values with their standard deviations were computed and compared across the three positions using ANOVA. Spearman's test was applied to assess correlations.

RESULTS

PI had the same value in all three positions. The L1-S1 LL angle was 54.8±9.8° in the standing position, 15.9±14.6° in the seated position, and 50.2±9.6° in the supine position. Pelvic tilt (PT) in the same three positions was 12.1±6.3°, 37.7±10.4°, and 9.5±5.1°, respectively; and SS was 37.1±6.3°, 11.3±10.8°, and 41±7.2°, respectively. Correlations were strongest in the supine position between PI and LL (r=0.72), LL and SS (r=0.9), and PI and SS (r=0.84).

CONCLUSION

Whereas PI remains unchanged in a given individual, lumbar lordosis and sacral orientation show significant changes across positions used in daily life, with the greatest changes seen in the seated position. During spinal fusion surgery, adjusting LL based on IP is crucial even in patients who have limited physical activity.

LEVEL OF EVIDENCE

IV.

Risk factors for anterior bone loss in cervical disc arthroplasty

OBJECTIVE The objective of this study was to identify the risk factors of anterior bone loss (ABL) in cervical disc arthroplasty (CDA) and the subsequent effect of this phenomenon. METHODS The authors performed a retrospective radiological review of 185 patients with a minimum 5-year follow-up after CDA (using Bryan, Discocerv, Mobi-C, or Baguera C). Postoperative radiographs were examined and compared to the initial postoperative films to determine the percentage of ABL. The relationship of ABL to potential risk factors was analyzed. RESULTS Complete radiological assessment was available in 145 patients with 193 CDRs and 383 endplates (average age 45 years, range 25-65 years, 54% women). ABL was identified in 63.7% of CDRs (48.7% mild, 11.9% moderate, 3.1% severe). Age (p = 0.770), sex (p = 0.200), postoperative alignment (p = 0.330), midflexion point (p = 0.509), maximal flexion (p = 0.080), and extension (p = 0.717) did not relate to ABL. There was no significant difference in the rate of severe ABL between implants. Multilevel surgery conferred an increased risk of any and severe ABL (p = 0.013 for both). The upper endplate, defined as superior to the CDA, was more commonly involved (p = 0.008), but there was no significant difference whether the endplate was between or not between implants (p = 0.226). The development of ABL did not affect the long-term range of movement (ROM) of the CDA, but did increase the overall risk of autofusion. ABL was not associated with pain or functional deficits. No patients required a reoperation or revision of their implant during the course of this study, and there were no cases of progressive ABL beyond the first year. CONCLUSIONS ABL is common in all implant types assessed, although most is mild. Age, sex, postoperative alignment, ROM, and midflexion point do not relate to this phenomenon. However, the greater the number of levels operated, the higher the risk of developing ABL. The development of ABL has no long-term effect on the mechanical functioning of the disc or necessity for revision surgery, although it may increase the rate of autofusion.

Decision-making factors in the treatment of adult spinal deformity

PURPOSE

We aimed to elucidate the factors for the decision-making process in the treatment of adult spinal deformity (ASD), including sagittal parameters, that impact health-related quality of life (HRQOL).

METHODS

A multicenter prospective ASD database was retrospectively reviewed. The demographic data, HRQOL, and radiographic measures were analyzed using multivariate analyses in younger (≤ 50 years) and older (> 50 years) age groups.

RESULTS

This study included 414 patients (134 surgical and 280 nonsurgical; mean age 30.7 years) in the younger age group and 575 patients (323 surgical and 252 nonsurgical; mean age 65.8 years) in the older age group. Worse HRQOL measures drove surgical treatment, both in younger and older patients. The SRS-22 self-image score was the most differentiating domain, both in the younger and older age groups, and an additional significant factor in the older age group was pain and disability. Coronal deformity drove surgical treatment for the younger age group; however, older surgical patients were less likely to have coronal malalignment. Sagittal parameters were associated with the decision-making process. Greater pelvic incidence minus lumbar lordosis mismatch in the younger age group and smaller lumbar lordosis index in the older age group were most correlated with the decision to undergo surgery.

CONCLUSIONS

Aside from the HRQOL measures and coronal deformity, sagittal parameters were identified as significant factors for the decision-making process in the ASD population, and the lack of lumbar lordosis in relation to pelvic incidence was a strong driver to pursue surgical treatment. These slides can be retrieved under Electronic Supplementary Material.

L5 pedicle subtraction osteotomy: indication, surgical technique and specificities

PURPOSE

To evaluate the radiographic, functional outcomes, complications and surgical specificities of L5 pedicle subtraction osteotomy for fixed sagittal and coronal malalignment.

METHODS

A retrospective cohort of consecutive patients with prospectively collected data. Ten patients who underwent PSO at L5 were eligible for a 2-year minimum follow-up (average, 4.0 years). Patients were evaluated by standardized upright radiographs. Preoperative and postoperative radiographies, surgical data and complications were collected.

RESULTS

All surgeries were revision surgeries. The mean lumbar lordosis before surgery was - 22.5° (range, 8° to - 33°) and improved to - 58.5° (range, - 40° to - 79°). The sagittal vertical axis demonstrated a preoperative mean sagittal malalignment of 13.7 cm (range 3.5 to 20 cm), with correction to 4.6 cm postoperatively. Three patients required additional surgery at the latest follow-up for rod breakage.

CONCLUSIONS

PSO of L5 can be a safe and effective technique to treat and correct fixed sagittal imbalance and provide biomechanical stability. The high complication rate mandates a careful assessment of the risk/benefit ratio of such a major surgery. Most patients are satisfied, particularly when sagittal balance is achieved.

Improvement of dyspnea after bariatric surgery is associated with increased Expiratory Reserve Volume: A prospective follow-up study of 45 patients

Objectives

To assess the effects of bariatric surgery in patients with obesity on dyspnea and to analyze the relationships between improvement of dyspnea after bariatric surgery and changes in pulmonary function, especially Expiratory Reserve Volume (ERV) which is the lung volume abnormality most frequently associated with obesity.

Methods

Forty-five patients (5 males/40 females, mean Body Mass Index = 46.2 ± 6.8 kg/m²) were evaluated before and 6 to 12 months after bariatric surgery. Dyspnea was assessed by the modified Medical Research Council (mMRC) scale. Pulmonary function tests, arterial blood gases and six-minute walk test were performed. Laboratory parameters including C-Reactive Protein (CRP) were analyzed.

Results

Ninety percent of patients were dyspneic before surgery (mMRC scale ≥ 1) versus 59% after surgery (p<0.001). Mean mMRC score improved after bariatric surgery (1.5 ± 0.9 vs 0.7 ± 0.7, p<0.0001). Among patients with dyspnea before surgery (n = 38), a more marked increase in ERV after surgery was observed in patients with improvement of dyspnea compared to patients with no improvement of dyspnea (+0.17 ± 0.32 L vs +0.49 ± 0.35 L, p = 0.01). Multivariate analysis including age, variation of BMI, variation of CRP, variation of Total Lung Capacity and variation of ERV demonstraded that ERV was the only variable associated with improvement of the mMRc score after bariatric surgery (p = 0.04).

Conclusion

Weight loss associated with bariatric surgery improves dyspnea in daily living. This improvement could be partly related to increased ERV.

THE GLOBAL TILT: EVALUATION OF A PARAMETER CONSIDERING THE GLOBAL SPINOPELVIC ALIGNMENT

PURPOSE

Regarding the close interaction between the spinal balance and the pelvis orientation no parameter is routinely used to describe and to evaluate the global spinopelvic balance, taking into account simultaneously the spinal part and the pelvic part of the global alignment. The global tilt was described to analyze malalignment, considering spinal and pelvic imbalance together. From a geometrical point of view, the global tilt is the sum of the C7 vertical tilt and the pelvic tilt. The aim of this study is to evaluate the global tilt by analyzing its correlation with spinal malalignment.

METHODS

A cohort of patients who underwent a lumbar pedicle subtraction osteotomy (PSO) for major sagittal malalignment was realized. All patients had preoperative and postoperative full spine EOS radiographies to measure spinopelvic parameters. The lack of lordosis was calculated after prediction of theoretical lumbar lordosis. Correlation analysis between different spinopelvic parameters, including the global tilt, was performed for preoperative and postoperative values.

RESULTS

Thirty-one consecutive patients were included. All parameters were correlated with spinal malalignment but the global tilt was the most correlated parameter in preoperative (r = 0.71) and in postoperative (r = 0.78). When spinal and pelvic parameters were analyzed separately, 19% of patients presented mismatches between spine and pelvis.

CONCLUSION

This study highlights the interest of a global parameter evaluating the spinal balance and the pelvic balance together. The global tilt appeared to be the most correlated parameter in this study with spinal malalignment and could be used for the interpretation of clinical series in spine surgery.

Global tilt and lumbar lordosis index: two parameters correlating with health-related quality of life scores-but how do they truly impact disability?

BACKGROUND CONTEXT

Many radiological parameters have been reported to correlate with patient's disability including sagittal vertical axis (SVA), pelvic tilt (PT), and pelvic incidence minus lumbar lordosis (PI-LL). European literature reports other parameters such as lumbar lordosis index (LLI) and the global tilt (GT). If most parameters correlate with health-related quality of life scores (HRQLs), their impact on disability remains unclear.

PURPOSE

This study aimed to validate these parameters by investigating their correlation with HRQLs. It also aimed to evaluate the relationship between each of these sagittal parameters and HRQLs to fully understand the impact in adult spinal deformity management.

STUDY DESIGN

A retrospective review of a multicenter, prospective database was carried out.

PATIENT SAMPLE

The database inclusion criteria were adults (>18 years old) presenting any of the following radiographic parameters: scoliosis (Cobb ≥20°), SVA ≥5 cm, thoracic kyphosis ≥60° or PT ≥25°. All patients with complete data at baseline were included.

OUTCOME MEASURES

Health-related quality of life scores, demographic variables (DVs), and radiographic parameters were collected at baseline.

METHODS

Differences in HRQLs among groups of each DV were assessed with analyses of variance. Correlations between radiographic variables and HRQLs were assessed using the Spearman rank correlation. Multivariate linear regression models were fitted for each of the HRQLs (Oswestry Disability Index [ODI], Scoliosis Research Society-22 subtotal score, or physical component summaries) with sagittal parameters and covariants as independent variables. A p<.05 value was considered statistically significant.

RESULTS

Among a total of 755 included patients (mean age, 52.1 years), 431 were non-surgical candidates and 324 were surgical candidates. Global tilt and LLI significantly correlated with HRQLs (r=0.4 and -0.3, respectively) for univariate analysis. Demographic variables such as age, gender, body mass index, past surgery, and surgical or non-surgical candidate were significant predictors of ODI score. The likelihood ratio tests for the addition of the sagittal parameters showed that SVA, GT, T1 sagittal tilt, PI-LL, and LLI were statistically significant predictors for ODI score even adjusted for covariates. The differences of R² values from Model 1 were 1.5% at maximum, indicating that the addition of sagittal parameters to the reference model increased only 1.5% of the variance of ODI explained by the models.

CONCLUSION

GT and LLI appear to be independent radiographic parameters impacting ODI variance. If most of the parameters described in the literature are correlated with ODI, the impact of these radiographic parameters is less than 2% of ODI variance, whereas 40% are explained by DVs. The importance of radiographic parameters lies more on their purpose to describe and understand the malalignment mechanisms than their univariate correlation with HRQLs.

TWO ADJACENT LEVELS DISLOCATION OF THE CERVICAL SPINE MANAGED VIAAN ANTERIOR ONLY APPROACH. A Case Report

We report the rare case of a 52-year-old man who presented an incomplete tetraplegia after a hang gliding accident. Computed tomography revealed a complete bilateral facet fracture-dislocation at the C4C5 level, with a unilateral facet fracture-dislocation on the left side at the C3C4 level; there was also a sagittal fracture of the fifth cervical vertebra extending through the middle of its body with a second fracture through the posterior arch. The patient was taken urgently to the operating room and closed reduction maneuvers were performed under general anesthesia, followed by an anterior prevascular approach for C3 to C5 fusion with two iliac crest grafts and a plate. Patient’s muscle strength was 3/5 on all four limbs on discharge and between 4/5 and 5/5 at one year. He stopped self-catheterization nine months after the accident. At two years follow-up, X-rays and CT scan showed a stable construct with satisfactory fusion. This is the first paper, in the literature, to describe double level contiguous cervical dislocation with a sagittal split fracture, and managed via an anterior only approach.

Global tilt: a single parameter incorporating spinal and pelvic sagittal parameters and least affected by patient positioning

PURPOSE

Regarding the close interaction between the spinal alignment and the pelvis orientation, no parameter is routinely used to describe and to evaluate the global spinopelvic balance, taking into account simultaneously the spinal part and the pelvic part of the global alignment. We described the global tilt (GT) that could analyze malalignment considering the spine and the pelvis simultaneously. From a geometrical point of view, the global tilt is the sum of the pelvic tilt (PT) and the C7 vertical tilt (angular value of sagittal vertical axis). The aim of this study is to evaluate the global tilt with comparison to PT and sagittal vertical axis (SVA), with the hypothesis that GT would be the least sensitive to positional changes.

METHODS

A cohort of 22 patients with sagittal malalignment was identified from a multicentric database of adult spinal deformities (ASD). Inclusion criteria were age >30 years, SVA > 40 mm and/or PT > 20°. All patients had full spine EOS radiographs in positions 1 and 2 (P1 and P2), in which the patient was asked to stand and put his hands on his shoulders without any effort (P1), or to make an effort to be as straight as possible (P2). PT, SVA and GT were measured in both positions and changes between P1 and P2 were calculated and compared using Student's t test with significance level at p < 0.05.

RESULTS

No significant changes were observed for GT; SVA and PT were significantly influenced by patient positioning. SVA decreased and PT increased for all cases in P2 whereas the changes in GT were in either direction. The average increase in PT was 7.1° (±5.4) or 30.8 % (±24.9); decrease in SVA was 45.1 mm (±25.6) or 60.0 % (±44.2) while the change in GT was 4.4° (±3.3) or 12.6 % (±9.3).

DISCUSSION

GT appears to be less affected by the patient's position compared to SVA and PT. This seems logical because GT contains both spinal alignment and pelvic compensation; it is not affected by their changes in opposing directions.

CONCLUSION

GT appears to be the most reliable single sagittal plane parameter in ASD. It is the least affected by patient position and incorporates both the pelvic and the spinal alignment within one measure.

Early reintervention after anterior cervical spine surgery: Epidemiology and risk factors: A case-control study

INTRODUCTION

Anterior cervical spine surgery is a frequent and effective procedure; complications are rare, but potentially fatal. The objective of the present study was to assess epidemiology and risk factors for early reintervention in anterior cervical spine surgery.

METHODS

A retrospective case-control study recruited 2319 patients operated on in our department, with 7 years' follow-up. Incidence and prevalence of causes of early reintervention were analyzed. Each case was matched to 2 controls from the same source population. Risk factors were identified and odds ratios (OR) were calculated.

RESULTS

Thirteen patients (0.6%: 3 female, 10 male; mean age, 59±12 years) underwent surgical reintervention within 72hours. Causes comprised: retropharyngeal hematoma (0.2%), epidural hematoma (0.3%) and dural breach (0.04%). As risk factor for early reintervention, only ASA score≥3 proved significant (OR: 5.5; 95% confidence interval: 1.1-29.85). As risk factor for epidural hematoma, only smoking proved significant (OR: 14.67; 95% confidence interval: 1.16-185.29). No risk factors emerged for onset of retropharyngeal hematoma.

CONCLUSION

ASA score≥3 and smoking entail risk of epidural hematoma and early reintervention. Postoperative pain, neurologic deficit, dysphagia, dysphonia, dyspnea and agitation suggest onset of complications, requiring necessary measures to be taken. Implementation of drainage fails to prevent such complications.

Tracheobronchial Involvement of Rosai-Dorfman Disease: Case Report and Review of the Literature

Rosai-Dorfman Disease (RDD) is a rare non-neoplastic entity, also known as sinus histiocytosis with massive lymphadenopathy (SHML), characterized by a benign proliferation of histiocytes in lymph nodes. Localized forms of RDD involving the tracheobronchial tree are very rare. There is no consensus regarding the management of central airway forms and recurrence is frequent. We report the case of an 81-year-old Caucasian woman admitted in 2014 for chronic cough. Her main medical past history included a diagnosis of sinonasal RDD in 1996 with recurrent obstructive rhinosinusitis requiring repeated sinonasal surgery, and a diagnosis of tracheal RDD in 2010 with 2 asymptomatic smooth lesions (5 and 7 mm) on the anterior tracheal wall. Physical examination was normal in 2014. Pulmonary function tests showed an obstructive pattern. Computed tomographic scan revealed a mass arising from the anterior wall of the trachea that projects into the tracheal lumen. Fiberoptic bronchoscopy showed a hypervascular multilobular lesion (2 cm) arising from the anterior tracheal wall and causing 50% obstruction of the tracheal lumen. Mechanical resection with electrocoagulation of the tracheal mass was performed by rigid bronchoscopy with no complication. Histological examination demonstrated tracheal RDD. One year after endotracheal resection, the patient presented no recurrence of cough and the obstructive pattern had resolved. Reports on tracheobronchial involvement are scarce. Symptomatic tracheobronchial obstruction requires mechanical resection by rigid bronchoscopy or surgery. Recurrence is frequent, justifying long-term follow-up.

Prospective study using anterior approach did not show association between Modic 1 changes and low grade infection in lumbar spine

INTRODUCTION

The modern literature is producing a rapidly growing number of articles which highlight the relationship between infection and lumbar disc degeneration. However, the means by which samples are collected is questionable. Posterior approach surgery is not free from skin contamination. The possibility of intraoperative contamination of disc biopsies cannot be excluded.

OBJECTIVE

The objective of this study was to determine if an association existed between lumbar disc degeneration and chronic infection of the intervertebral disc.

MATERIALS AND METHODS

313 patients (186/127, F/M) with chronic low back pain secondary to degenerative disc disease which was resistant to medical treatment were included in a single-centre prospective study. All underwent a lumbar anterior video-assisted minimally invasive fusion or disc prosthesis in L4-L5 and/or L5-S1 via an anterior retroperitoneal approach. The patients MRI scans demonstrated in Pfirrmann's classification grade IV or V disc degeneration; 385 disc drives were taken. In terms of Modic changes, 303 Modic 1, 58 Modic II and 24 absence of Modic change, respectively. All underwent intraoperative biopsy, performed according to a strict aseptic protocol. The biopsies were then cultured for 4 weeks with specialised enrichment cultures and subjected to histopathological analysis.

RESULTS

The mean age was 47 ± 8.6 years sterile cultures were obtained in 379 samples (98.4%) and 6 were positive (1.6%). The cultured bacteria were: Propionibacterium acnes (n:2), Staphylococcus epidermidis (n:2), Citrobacter freundii (n:1), and Saccharopolyspora hirsuta (n:1). Histopathological analysis did not demonstrate any evidence of a neutrophilia. There were no delayed or secondary infections.

DISCUSSION AND CONCLUSION

Unlike the posterior approach where contamination is common, the anterior video-assisted approach allows a biopsy without skin contact. This approach to the spine is the most effective way to eliminate the risk of contamination. Our results confirm the absence of any relationship between infection and disc degeneration. We suggest that the 6 positive samples in our study may be related to contamination. The absence of infection at 1-year followup is an additional argument in favour of our results. In conclusion, our study shows no association between infection and disc degeneration. The pathophysiology of disc degeneration is complex, but the current literature opens new perspectives.

Modified closing-opening wedge osteotomy for the treatment of sagittal malalignment in thoracolumbar fractures malunion

BACKGROUND CONTEXT

Many techniques have been described for the surgical treatment of rigid posttraumatic thoracolumbar kyphosis, but none is well adapted to the modified shape of the wedged vertebra.

PURPOSE

The study aimed to describe the modified closing-opening wedge osteotomy (MCOWO), a new osteotomy technique that adapts to the triangular shape of the wedged apical vertebra of the deformity.

STUDY DESIGN

A retrospective assessment of the degree of correction before and after the MCOWO was carried out.

PATIENT SAMPLE

Ten patients presenting rigid posttraumatic thoracolumbar kyphosis were enrolled in this study.

OUTCOME MEASURES

We used preoperative and postoperative whole spine radiographs to assess the sagittal plane parameters, and computed tomography scan for measurement of the vertebral segment height at the osteotomy level, spinal cord length, aorta length, and fusion rate.

METHODS

Ten patients underwent the MCOWO at T12 or L1. The procedure involves removing the postero-superior triangular corner of the wedged vertebra and transforming it to a shape similar to a trapezoid.

RESULTS

The patients' mean age was 36.6±7.5 years, the mean time between the fracture and the surgery was 12.2±5.6 months, and the mean follow-up was 30.6±5 months. In all patients, statistically significant improvement was observed in the sagittal plane after surgery. The thoracolumbar angle improved from 52±6° preoperatively to 7.1±5.7° at the last follow-up. Mean osteotomy angle was 38.1±2.6°, mean spinal cord shortening was 1.2±0.2 cm, and mean aorta lengthening was 2.3±0.4 cm. All the patients showed complete fusion at 2 years, and none required revision surgery. Two patients presented a temporary unilateral weakness that recovered completely within 3 months after the surgery.

CONCLUSIONS

The MCOWO is an interesting procedure for patients with posttraumatic thoracolumbar kyphosis. The modified osteotomy is adapted to the modified shape of the compressed vertebra. Spinal cord shortening and aorta lengthening were well tolerated in all patients.

Change in acetabular version after lumbar pedicle subtraction osteotomy to correct post-operative flat back: EOS® measurements of 38 acetabula

BACKGROUND

Abnormalities in acetabular orientation can promote the development of hip osteoarthritis, femoro-acetabular impingement, or even acetabular cup malposition. The objective of the present study was to determine whether pedicle substraction osteotomy (PSO) to correct sagittal spinal imbalance affected acetabular orientation.

HYPOTHESIS

PSO performed to correct sagittal spinal imbalance affects acetabular orientation by changing the pelvic parameters.

MATERIALS AND METHODS

This was a descriptive study in which two observers measured the acetabular parameters on both sides in 19 patients (38 acetabula) before and after PSO for post-operative flat-back syndrome. Mean time from PSO to post-operative measurements was 19months. Measurements were taken twice at a 2-week interval, on standing images obtained using the EOS(®) imaging system and sterEOS(®) software to obtain 3D reconstructions of synchronised 2D images. Acetabular anteversion and inclination were measured relative to the vertical plane. Mean pre-PSO and post-PSO values were compared using the paired t-test, and P values lower than 0.05 were considered significant. To assess inter-observer and intra-observer reproducibility, we computed the intra-class correlation coefficients (ICCs).

RESULTS

The measurements showed significant acetabular retroversion after PSO, of 7.6° on the right and 6.5° on the left (P<0.001). Acetabular inclination diminished significantly, by 4.5° on the right and 2.5° on the left (P<0.01). Inclination of the anterior pelvic plane decreased by 8.4° (P<0.01). Pelvic incidence was unchanged, whereas sacral slope increased by 10.5° (P<0.001) and pelvic tilt decreased by 10.9° (P<0.001). The ICC was 0.98 for both inter-observer and intra-observer reproducibility.

CONCLUSION

Changing the sagittal spinal alignment modifies both the pelvic and the acetabular parameters. PSO significantly increases sacral slope, thus inducing anterior pelvic tilt with significant acetabular retroversion. The measurements obtained using sterEOS(®) showed good inter-observer and intra-observer reproducibility. To our knowledge, this is the first study of changes in acetabular version after PSO.

Conversion paralysis after cervical spine arthroplasty: a case report and literature review

We report a case of conversion paralysis after cervical spine arthroplasty performed in a 45-year-old woman to treat cervico-brachial neuralgia due to a left-sided C6-C7 disc herniation. Upon awakening from the anaesthesia, she had left hemiplegia sparing the face, with normal sensory function. Magnetic resonance imaging (MRI) of the brain ruled out a stroke. MRI of the spinal cord showed artefacts from the cobalt-chrome prosthesis that precluded confident elimination of mechanical spinal cord compression. Surgery performed on the same day to substitute a cage for the prosthesis ruled out spinal cord compression, while eliminating the source of MRI artefacts. Findings were normal from follow-up MRI scans 1 and 15days later, as well as from neurophysiological testing (electromyogram and motor evoked potentials). The deficit resolved fully within the next 4days. A psychological assessment revealed emotional distress related to an ongoing divorce. The most likely diagnosis was conversion paralysis. Surgeons should be aware that conversion disorder might develop after a procedure on the spine, although the risk of litigation requires re-operation. Familiarity with specific MRI sequences that minimise artefacts can be valuable. A preoperative psychological assessment might improve the detection of patients at high risk for conversion disorder.

One-stage posterior spinal shortening by L5 partial spondylectomy for spondyloptosis or L5-S1 high-grade spondylolisthesis management

STUDY DESIGN

A case series of seven consecutive patients with L5-S1 spondyloptosis (SPP) and Meyerding IV spondylolisthesis (HGSPL) treated consecutively by a new surgical technique with partial reduction and fixation after spinal shortening.

OBJECTIVE

To report clinical and radiological outcomes of a spinal shortening procedure by a single posterior approach in seven patients with HGSPL and SPP.

BACKGROUND DATA

The surgical treatment of L5-S1 SPP and HGSPL remains challenging, and numbers of surgical treatment options have been described with several principles. We reported a new surgical technique achieving partial reduction and fixation of L5-S1 SPP and HGSPL and highlighted its clinical and radiological outcomes.

METHODS

Seven patients with Meyerding Grade IV (2), and Grade V (5) were operated consecutively between 2004 and 2011 for HGSPL and SPP. Surgery time, blood loss and complications were collected for all patients. The slip angle or Dubousset lumbo-sacral Angle (Dub-LSA), L5 slip percentage (%slip), pelvic tilt (PT), lumbar lordosis (LL), thoracic kyphosis (TK) and C7-tilt were measured pre and postoperatively. All patients underwent posterior one-stage decompression with sacral dome osteotomy, L5 vertebrectomy with L5-S1 discectomy, and partial reduction and instrumented fusion in a single posterior approach.

RESULTS

The mean age and follow-up were, respectively, 20 years and 65 months. The mean preoperative %slip was 115 %, which improved to 63 % postoperatively. The mean preoperative Dub-LSA, PT, LL, TK, and C7-tilt were 37°, 31°, -74°, 30°, and 6°, respectively, which improved to 94°, 25°, -44°, 42° and -0.14° postoperatively. No implant failure or pseudarthrosis were reported at last follow-up.

CONCLUSION

This novel and efficient one-stage shortening technique offers the possibility to manage lumbosacral kyphosis and spinal local malalignment in L5-S1 SPP.

Post-trauma scoliosis after conservative treatment of thoracolumbar spinal fracture in children and adolescents: results in 48 patients

PURPOSE

Authors examined a case series of patients younger than 18 years old who had sustained a traumatic thoracolumbar spine fracture to evaluate radiological and clinical findings of coronal spinal balance, after conservative treatment.

METHODS

From 1996 to 2014, a tricentric cohort of 48 patients with an average age of 12 years was radiographically reviewed at 50 months. Cobb angle of fractured vertebra and regional Cobb angle were measured both at baseline and follow-up. Analyses were done according to initial Risser grade, number of fractures and level of injury.

RESULTS

There was a total of 11 scoliosis. In group with Risser grade 3 or above, with a single vertebral fracture and lumbar fracture, final regional Cobb angle was statistically higher than initial regional Cobb angle.

CONCLUSIONS

The prevalence of scoliosis in our population is higher than those of idiopathic scoliosis; Risser grade 3 or above, lumbar fracture and a single fracture seem to account for more severe coronal deformation.

Osteotomies through a fusion mass in the lumbar spine

INTRODUCTION

Flat-back syndrome is one of the main causes of surgical failure after lumbar fusion and can lead to a revision surgery to correct it. Three-column pedicle subtraction osteotomy is an efficient technique to restore lumbar lordosis (LL) for fixed sagittal malalignment. The fusion mass stemming from the past surgeries makes the procedure demanding as most anatomical landmarks are missing.

MATERIAL AND METHODS

This review article will focus on the correction of this lack of LL through the fusion mass. We will successively review the preoperative management, the surgical specificities, and various types of clinical cases that can be encountered in flat-back syndromes.

CONCLUSION

PSO in the fixed fusion mass is technically demanding. Preoperative CT-scan and preoperative navigation allow us to push the limits when anatomical landmarks disappear. Bleeding and neurologic are the two major complications feared by the surgeon. The best way to avoid these revision surgeries is to restore a proper lumbar lordosis at the time of initial surgery by considering lumbo-pelvic indexes.

Osteotomy of the spine for multifocal deformities

INTRODUCTION

When a deformity involves more than one area of the spine, it becomes a multifocal deformity; such a deformity could either be extending on two adjacent segments, or be two separated deformities on two non-adjacent segments.

MATERIALS AND METHODS

The surgical management of multifocal spinal deformities is challenging and must be done through a thorough preoperative planning where spinal and pelvic parameters should accurately be determined. Different strategies should be applied depending on the type of the multifocal deformity, the area involved, the angulation and stiffness of the spine in that area, and the presence of either a pure sagittal malalignment or a combined coronal and sagittal malalignment. This paper discusses these strategies and gives guidelines regarding the use of the different osteotomy techniques depending on each different situation that the deformity spine surgeon may encounter. For instance, where is the ideal level to perform a pedicle subtraction osteotomy (PSO) in a multifocal deformity? How does one take advantage of the remaining high discs to increase the correction without the need for a second PSO? When and where does one perform an asymmetrical PSO? When and where does one perform two PSOs? How does navigation help the spine surgeon to push the surgical limits further in these complex cases?

CONCLUSION

All these questions about the management of multifocal deformities will be discussed and answered with technical details and concrete examples of the different situations that may be encountered.

Lumbo-pelvic related indexes: impact on adult spinal deformity surgery

PURPOSE

Lumbo-pelvic indexes appeared recently in the literature taking advantage from the relationship between pelvic incidence (PI) and lumbar lordosis (LL). Schwab proposed to subtract LL from PI (PI-LL) as Boissière proposed the lumbar lordosis index (LLI), which is the ratio between LL and PI (LL/PI). Both indexes have been described to weight LL by a constant parameter not affected by degenerative processes, the PI. The aim of this study is to evaluate these parameters in adult spinal deformity (ASD) by analyzing their relationship with spinal malalignment and vertebral osteotomies.

METHODS

Two groups of patients with an ASD were realized; an adult scoliosis group (n = 78) and a postoperative flat-back syndrome group (n = 20). In the adult scoliosis group, 28 patients underwent an osteotomy [pedicle subtraction osteotomy (PSO) or Smith Petersen osteotomy] and 50 patients were corrected by posterior fusion without osteotomy. In the postoperative flat-back syndrome group all patients underwent a PSO. All patients had preoperative and postoperative full spine EOS radiographies to measure spino-pelvic parameters. The lack of lordosis was calculated, after prediction of theoretical LL from Legaye's formula, by subtracting measured LL to theoretical LL. Correlation analysis between the different parameters was performed.

RESULTS

Both lumbo-pelvic parameters highly correlated with spinal malalignment (r = 0.97 for PI-LL and r = -0.97 for LLI for total patients) and were highly predictive of a spinal osteotomy performance (r = 0.88 for PI-LL >28° and r = 0.94 for LLI <0.5). Sagittal vertical axis (r = 0.67) and pelvic tilt (r = 0.64) correlated moderately with spinal malalignment for total patients. The LLI was more correlated with spinal osteotomies in the adult scoliosis group (r = 0.86 for PI-LL >28° and r = 0.94 for LLI <0.5), as Schwab's index was more precise to predict osteotomies in the postoperative flat-back syndrome group (Youden index = 0.95 for PI-LL >28° vs 0.90 for LLI <0.5).

CONCLUSIONS

This study highlights the necessity to considerer spinal malalignment with lumbo-pelvic indexes as they appear to be highly correlated with lack of LL. They can be used as mathematical tools to detect spinal malalignment in ASD and guide the surgeon's decision of realizing a vertebral osteotomy for ASD sagittal correction. They can be used as well for the interpretation of clinical series in ASD.

Complex osteotomies vertebral column resection and decancellation

Pedicle subtraction osteotomy (PSO) is nowadays widely used to treat sagittal imbalance. Some complex malalignment cases cannot be treated by a PSO, whereas the imbalance is coronal or mixed or the sagittal imbalance is major and cannot be treated by a single PSO. The aim of this article was to review these complex situations--coronal imbalance, mixed imbalance, two-level PSO, vertebral column resection, and vertebral column decancellation, and to focus on their specificities. It wills also to evoke the utility of navigation in these complex cases.

Total disc replacement

Total disc replacement (TDR) (partial disc replacement will not be described) has been used in the lumbar spine since the 1980s, and more recently in the cervical spine. Although the biomechanical concepts are the same and both are inserted through an anterior approach, lumbar TDR is conventionally indicated for chronic low back pain, whereas cervical TDR is used for soft discal hernia resulting in cervicobrachial neuralgia. The insertion technique must be rigorous, with precise centering in the disc space, taking account of vascular anatomy, which is more complex in the lumbar region, particularly proximally to L5-S1. All of the numerous studies, including prospective randomized comparative trials, have demonstrated non-inferiority to fusion, or even short-term superiority regarding speed of improvement. The main implant-related complication is bridging heterotopic ossification with resulting loss of range of motion and increased rates of adjacent segment degeneration, although with an incidence lower than after arthrodesis. A sufficiently long follow-up, which has not yet been reached, will be necessary to establish definitively an advantage for TDR, particularly in the cervical spine.