Psychopathological profile and sagittal alignment in low-back pain.

INTRODUCTION: Low-back pain requires comprehensive care using a biopsychosocial model. The psychologic dimension plays an important role, but the link between sagittal alignment and a given psychopathological profile is little studied. The aim of this study was to analyze the psychopathological profiles and sagittal parameters of a population with low-back pain and to assess the link. MATERIAL AND METHODS: 205 patients, with a mean age of 49.6 years (range, 18-70 years), presenting chronic common low-back pain without radicular involvement, were included prospectively. Mood scores comprised: the self-administered "Hospital Anxiety and Depression Scale" (HAD), Hamilton Anxiety Scale (HAM-A), Hamilton Depression Scale (HAM-D) and Young Mania Rating Scale (YMRS). Radiological parameters, measured on lateral full-spine radiographs, included: L1-S1 lordosis, T1-T12 kyphosis, pelvic incidence, pelvic tilt, sacral slope, sagittal vertical axis (SVA), T1 slope, and Roussouly type. RESULTS: Mean HAM-A score was 16.1; 54% of patients had scores ≥14, indicating anxiety disorder. Mean HAM-D score was 10.8; 55% of patients had scores ≥10, indicating depressive disorder. Mean YMRS score was 2.6; only 1 patient had a score ≥20, indicating manic disorder. The 112 patients with HAM-A score >14 showed mean 51.6° L1-S1 lordosis (p=0.356), 48.3° T1-T12 kyphosis (p=0.590), -4.3mm C7 SVA (p=0.900), and 29.3° T1 slope (p=0.451). In case of HAM-A <14, there were no significant differences. The 113 patients with HAM-D score >10 showed significant differences in T1-T12 kyphosis (mean 49.0°; p<0.05) and T1 slope (30.2°; p<0.05); mean L1-S1 lordosis was 50.5° (p=0.861) and C7 SVA 1.6mm (p=0.462). In case of HAM-D <10, T1-T12 kyphosis was 45.5° (p<0.05) and T1 slope 26.2° (p<0.05); mean lordosis was 50.9° (p=0.861) and mean C7 SVA -7.1mm (p=0.259). Multivariate analysis found no significant link between Roussouly type and psychiatric scores: HAD (p=0.715), HAM-A (p=0.652), and HAM-D (p=0.902). CONCLUSION: More than 50% of patients with common low-back pain presented a mood disorder. Depressive disorder was associated with greater T1-T12 kyphosis and T1 slope. There was no relationship between psychiatric scores and overall sagittal alignment. LEVEL OF EVIDENCE: II.

Accuracy and technical limits of percutaneous pedicle screw placement in the thoracolumbar spine.

PURPOSE: The two-dimensional fluoroscopic method of percutaneous pedicle screw instrumentation has been clinically described as reliable method in the caudal thoracic and lumbosacral spine. Its accuracy has not been clearly reported in the cranial thoracic spine. The aim of this in vitro study was to investigate percutaneous pedicle screw placement accuracy according to pedicle dimensions and vertebral levels. METHODS: Six fresh-frozen human specimens were instrumented with 216 screws from T1 to S1. Pedicle isthmus widths, heights, transversal pedicles and screws were measured on computed tomography. Pedicle cortex violation ≥ 2 mm was defined as screw malposition. RESULTS: The narrowest pedicles were at T3-T5. A large variability between transversal pedicle axes and percutaneous pedicle screw was present, depending on the spinal level. Screw malposition rates were 36.1% in the cranial thoracic spine (T1-T6), 16.7% in the caudal thoracic spine (T7-T12), and 6.9% in the lumbosacral spine (L1-S1). The risk for screw malposition was significantly higher at cranial thoracic levels compared to caudal thoracic (p = 0.006) and lumbosacral (p < 0.0001) levels. Cortex violation ≥ 2 mm was constantly present if the pedicle width was < 4.8 mm. CONCLUSION: Percutaneous pedicle screw placement appears safe in the caudal thoracic and lumbosacral spine. The two-dimensional fluoroscopic method has a limited reliability above T7 because of smaller pedicle dimensions, difficulties in visualizing radiographic pedicle landmarks and kyphosis.

Lower lumbar vertebra size and anatomic variation: An Anatomo-Radiologic Study.

INTRODUCTION: In routine practice, it is often necessary to use shorter screws in L5 than L4. The present study measured L5 versus L4 vertebral pedicles, to guide surgical strategy. MATERIAL AND METHOD: CT or MRI scans for 95 patients were analyzed. Radiographic measurements (anteroposterior diameter (APD), pedicle length (PL) and pedicle width (PW)) were taken by a spine surgeon. Statistical analysis used R 3.4.3 software. RESULTS: Ninety-five patients were included: 48 female (50.53%), 47 male (49.47%); mean age, 57 years (range, 19-85 years). Univariate analysis found a strong correlation between right and left PL values in L4 and L5. Right and left values were pooled, obtaining a mean L4 PL of 55.34mm (range, 54.23-56.45mm) and L5 PL of 51.80mm (44.81-58.80) and L4 PW of 10.48mm (10.06-10.91) and L5 PW of 9.90mm (7.43-12.39). Multivariate analysis disclosed significant effects of age and gender, with greater age and male gender associated with greater anteroposterior vertebral diameter. Mean anteroposterior vertebral length was significantly shorter in L5 than L4 by 3.57mm (range, 4.08-3.06mm). DISCUSSION: Anteroposterior pedicle length was shorter in L5 than L4, in line with the literature. This answers the surgeon's question: "Should pedicle screws be shorter in L5 than L4?". From these results, it seems logical to use an L5 screw that is 5mm shorter than in L4, to secure good intra-body screw fixation.

Hangman's fracture: Management strategy and healing rate in a prospective multi-centre observational study of 34 patients.

BACKGROUND: Hangman's fractures account for 15% to 20% of all cervical spine fractures. The grading system developed by Effendi and modified by Levine and Edwards is generally used as the basis for management decisions. Nonetheless, the optimal management remains controversial. The objective of this study was to describe the treatments used in France in patients with hangman's fractures. The complications and healing rates were analysed according to the fracture type and treatment used. HYPOTHESIS: Among patients with hangman's fracture, those with disc damage must be treated surgically. MATERIAL AND METHODS: A prospective, multi-centre, observational study was conducted under the aegis of the French Society for Spine Surgery (SociétéFrançaisedeChirurgieRachidienne, SFCR). Patients were included if they had computed tomography (CT) evidence of hangman's fracture. Follow-up data were collected prospectively. Fracture healing was assessed on CT scans obtained 3 and 12 months after the injury. The type of treatment and complications were recorded routinely. RESULTS: We included 34 patients. The fracture type according to Effendi modified by Levine and Edwards was I in 68% of patients, II in 29% of patients, and III in a single patient (3%). The treatment was non-operative in 21 (62%) patients and surgical in 11 (32%). All 28 patients re-evaluated after 1 year had evidence of fracture healing. The remaining 6 patients were lost to follow-up. CONCLUSION: Hangman's fracture is associated with low rates of mortality and neurological complications. Non-operative treatment is appropriate in Type I hangman's fracture, with a 100% healing rate in our study. Types II and III are characterised by damage to the ligaments and discs requiring either anterior C2-C3 fusion or posterior C1-C3 screw fixation. LEVEL OF EVIDENCE: III.

Osteoarthritis and spontaneous fusion of facet joints after percutaneous instrumentation in thoracolumbar fractures.

PURPOSE: This retrospective study determined the rate of osteoarthritis and spontaneous facet joint fusion and analyzed risk factors related to patient characteristics, fracture type or surgical technique on pre- and postoperative CT after percutaneous instrumentation in thoracolumbar fractures. METHODS: 1050 facet joints adjacent to screws in 148 patients (15-85 years) with thoracolumbar fractures were analyzed with an average time between CTs of 12.3 months. Screw diameters, lengths and cement augmentation were recorded. Facet joint violation by screw trajectory and by insertion depth was classified in three grades. Pre- and postoperative osteoarthritis was graded as absent, minor or severe and postoperative facet joint fusion as absent, partial or complete. RESULTS: The facet violation rate was moderate in 15.4% and severe in 0.6% according to screw trajectory, and 11.0 and 0.6%, respectively, according to insertion depth. Osteoarthritis was preoperatively rated moderate in 9.6% and severe in 1.2%. A progression was evidenced in 79 facet joints (7.5%). Screw cement augmentation was the main predictive factor (p < 0.0001). Partial fusion was evidenced in 2.6% and complete fusion in 1% of facet joints. Risk factors were: BMI (p = 0.0002), age (p = 0.0013), preoperative osteoarthritis (p = 0.0005), time between 2 CTs (p = 0.0001), B-type fractures (p = 0.0005), concomitant anterior fusion (p = 0.0034). CONCLUSIONS: Occurrence or worsening of osteoarthritis was mainly observed in elderly patients with cement-augmented screws and spontaneous facet fusion in elderly patients with high BMI and preoperative osteoarthritis, or in anteriorly fused B-type injuries. Thus, percutaneous instrumentation can safely be removed after fracture consolidation in younger patients while preserving facet joints.

C1 fracture: Analysis of consolidation and complications rates in a prospective multicenter series.

INTRODUCTION: Three types of C1 fracture have been described, according to location: type 1 (anterior or posterior arc), type 2 (Jefferson: anterior and posterior arc), and type 3 (lateral mass). Stability depends on transverse ligament integrity. The main aim of the present study was to analyze complications and consolidation rates according to fracture type, age and treatment. MATERIAL AND METHODS: The French Society of Spinal Surgery (SFCR) performed a multicenter prospective study on C1-C2 trauma. All patients with recent fracture diagnosed on CT were included. Consolidation on CT was studied at 3 months and 1 year. Medical, neurologic, infectious and mechanical complications were inventoried using the KEOPS data-base. RESULTS: Sixty-three of the 417 patients (15.1%) had C1 fracture: type 1 (33.3%), type 2 (38.1%), or type 3 (28.6%). The transverse ligament was intact in 53.9% of cases. Treatment was non-operative in 63.5% of cases, surgical in 27.0%, and surgical after failure of non-operative treatment in 9.5%. There were 8 medical complications, more frequently in patients aged >70 years, following surgery (p<0.0001). The consolidation rate was 84.2% with non-operative treatment, 100% for primary surgery, and 33.3% for secondary surgery (p=0.002). There were 10 cases of non-union, in 4.8% of type 1, 13.6% of type 2 and 33.3% of type 3 fractures (p=0.001). CONCLUSION: Medical complications showed association with age and with type of treatment. Non-operative treatment was suited to types 1, 2 and 3 with minimal displacement and intact transverse ligament. C1-C2 fusion was suited to displaced unstable type 2 fracture. Displaced type 3 fracture incurred risk of non-union. Early surgery may be recommended. LEVEL OF EVIDENCE: III.

Open versus percutaneous instrumentation in thoracolumbar fractures: magnetic resonance imaging comparison of paravertebral muscles after implant removal.

OBJECTIVE Percutaneous instrumentation in thoracolumbar fractures is intended to decrease paravertebral muscle damage by avoiding dissection. The aim of this study was to compare muscles at instrumented levels in patients who were treated by open or percutaneous surgery. METHODS Twenty-seven patients underwent open instrumentation, and 65 were treated percutaneously. A standardized MRI protocol using axial T1-weighted sequences was performed at a minimum 1-year follow-up after implant removal. Two independent observers measured cross-sectional areas (CSAs, in cm2) and region of interest (ROI) signal intensity (in pixels) of paravertebral muscles by using OsiriX at the fracture level, and at cranial and caudal instrumented pedicle levels. An interobserver comparison was made using the Bland-Altman method. Reference ROI muscle was assessed in the psoas and ROI fat subcutaneously. The ratio ROI-CSA/ROI-fat was compared for patients treated with open versus percutaneous procedures by using a linear mixed model. A linear regression analyzed additional factors: age, sex, body mass index (BMI), Pfirrmann grade of adjacent discs, and duration of instrumentation in situ. RESULTS The interobserver agreement was good for all CSAs. The average CSA for the entire spine was 15.7 cm2 in the open surgery group and 18.5 cm2 in the percutaneous group (p = 0.0234). The average ROI-fat and ROI-muscle signal intensities were comparable: 497.1 versus 483.9 pixels for ROI-fat and 120.4 versus 111.7 pixels for ROI-muscle in open versus percutaneous groups. The ROI-CSA varied between 154 and 226 for open, and between 154 and 195 for percutaneous procedures, depending on instrumented levels. A significant difference of the ROI-CSA/ROI-fat ratio (0.4 vs 0.3) was present at fracture levels T12-L1 (p = 0.0329) and at adjacent cranial (p = 0.0139) and caudal (p = 0.0100) instrumented levels. Differences were not significant at thoracic levels. When adjusting based on age, BMI, and Pfirrmann grade, a significant difference between open and percutaneous procedures regarding the ROI-CSA/ROI-fat ratio was present in the lumbar spine (p < 0.01). Sex and duration of instrumentation had no significant influence. CONCLUSIONS Percutaneous instrumentation decreased muscle atrophy compared with open surgery. The MRI signal differences for T-12 and L-1 fractures indicated less fat infiltration within CSAs in patients who received percutaneous treatment. Differences were not evidenced at thoracic levels, where CSAs were smaller. Fat infiltration was not significantly different at lumbar levels with either procedure in elderly patients with associated discopathy and higher BMI. In younger patients, there was less fat infiltration of lumbar paravertebral muscles with percutaneous procedures.

Temporary Percutaneous Instrumentation and Selective Anterior Fusion for Thoracolumbar Fractures.

STUDY DESIGN: Prospective clinical trial in thoracolumbar trauma with 5-year follow-up. OBJECTIVE: To analyze clinical and radiographic outcomes of minimal invasive surgery, and the rational of circumferential fracture treatment with regard to age, degenerative changes, bone mineral density, and global sagittal balance. SUMMARY OF BACKGROUND DATA: Non-neurologic fractures with anterior column defect can be treated by posterior percutaneous instrumentation and selective anterior fusion. After consolidation, instrumentation can be removed at 1 year to provide mobility in non-fused segments. METHODS: Fifty-one patients, 47 (18-75) years, were operated for A2, A3, or B-type fractures. Visual analog scale (VAS) for back pain and Oswestry Disability Index (ODI) were assessed. Radiographic measurements were: sagittal index, regional kyphosis, T4-T12 kyphosis, L1-S1 lordosis, pelvic incidence, pelvic tilt, sacral slope, and T9 tilt. Anterior fusion and facet joints were analyzed on computed tomography (CT) at 1 year. RESULTS: The ODI was 8.8 before accident, 35.4 at 3 months, 17.8 at 2 years, 14.4 at 5 years. The VAS was 2.0 at 3 months and 1.0 at 5 years. The sagittal index was 18.0° preoperatively and 1.0° at 3 months (P < 0.0001). A loss of reduction of 1.1° occurred after implant removal (P = 0.009). Global sagittal balance remained unchanged. Ten patients with osteopenia or osteoporosis had a worse ODI: 24.7 versus 11.9 (P = 0.016), and a greater loss of correction: 4.9° versus 1.3° (P = 0.007). Cages filled with cancellous bone from the fractured vertebra fused regularly. Spontaneous facet joint fusions were observed in two patients at the fracture level in B-type injuries. CONCLUSION: Percutaneous instrumentation and selective anterior fusion using autologous bone and mesh cages lead to high fusion rates, which provided good long-term clinical results in younger patients with thoracolumbar fractures. Sagittal alignment was maintained after instrumentation removal without damaging paravertebral muscles. Outcomes were worse in elderly patients presenting osteopenia or osteoporosis. LEVEL OF EVIDENCE: 3.

Fusion Rates of Different Anterior Grafts in Thoracolumbar Fractures.

STUDY DESIGN: Retrospective CT analysis of anterior fusion in thoracolumbar trauma. OBJECTIVE: The aim of this study was to compare fusion rates of different bone grafts and to analyze risk factors for pseudarthrosis. SUMMARY OF BACKGROUND DATA: Interbody fusion is indicated in anterior column defects. Different grafts are used: autologous iliac crest, titanium mesh cages filled with cancellous bone, and autologous ribs. It is not clear which graft offers the most reliable fusion. MATERIAL AND METHODS: Radiologic data of 116 patients (71 men, 45 women) operated for type A2, A3, B, or C fractures were analyzed. The average age was 44.6 years (range, 16-75 y) and follow-up was 2.7 years (range, 1-9 y). All patients were treated by posterior instrumentation followed by an anterior graft: 53 cases with iliac crest, 43 cases with mesh cages, and 20 with rib grafts. Fusion was evaluated on CT and classified into complete fusion, partial fusion, unipolar pseudarthrosis, and bipolar pseudarthrosis. RESULTS: Iliac crest fused in 66%, cages in 98%, and rib grafts in 90%. The fusion rate of cages filled with bone was significantly higher as the iliac graft fusion rate (P=0.002). The same was applied to rib grafts compared with iliac crest (P=0.041). Additional bone formation around the main graft, bridging both vertebral bodies, was observed in 31 of the 53 iliac crests grafts. Pseudarthrosis occurred more often in smokers (P=0.042). A relationship between fracture or instrumentation types, sex, age, BMI, and fusion could not be determined. CONCLUSIONS: Tricortical iliac crest grafts showed an unexpected high pseudarthrosis rate in thoracolumbar injuries. Their cortical bone is dense and their fusion surface is small. Rib grafts led to a better fusion when used in combination with the cancellous bone from the fractured vertebral body. Titanium mesh cages filled with cancellous bone led to the highest fusion rate and built a complete bony bridge between vertebral bodies. Smoking seemed to influence fusion. LEVEL OF EVIDENCE: Case control study, Level III.

Thoracolumbar fracture reduction by percutaneous in situ contouring.

PURPOSE: Percutaneous in situ contouring is based on bilateral bending of rods on the spine, thus increasing lordosis at the fracture. It was analyzed if this technique would provide a better reduction than prone positioning and how sagittal alignment would behave. METHODS: Twenty-nine patients were operated using in situ contouring and selective anterior fusion for non-neurologic A2, A3 or B2 fractures. Clinical results were assessed prospectively using visual analog scale (VAS) and Oswestry Disability Index (ODI). The radiographic deformity correction was measured by sagittal index and regional kyphosis. Sagittal balance was assessed using kyphosis, lordosis, T9 tilt, pelvic incidence, pelvic tilt and sacral slope. Posterior wall fragment reduction was evaluated by computed tomography. RESULTS: After 2 years, VAS and ODI were comparable to the status prior to the accident. The sagittal index was 19.7° preoperatively, 5.3° after prone positioning and -1.1° after in situ contouring (p < 0.001). The loss of correction was 2.4°, mainly during the first 3 months. Similar observations were made for regional kyphosis. The sagittal spino-pelvic alignment was stable postoperatively. A preoperative canal obstruction ≥50 % was observed in 16 patients, and the fragments migrated anteriorly in all patients. CONCLUSIONS: Percutaneous instrumentation and anterior fusion provides good clinical results. In situ contouring increases lordosis obtained by prone positioning. Anterior column lengthening and ligamentotaxis reduce posterior wall fragments, which decompress the canal without laminectomy. The fusion of anterior defects prevents the loss of correction and provides a stable sagittal profile. The instrumentation may be removed without damaging the paravertebral muscles and loss of correction.

Sagittal balance correction of idiopathic scoliosis using the in situ contouring technique.

PURPOSE: Idiopathic scoliosis can lead to sagittal imbalance. The relationship between thoracic hyper- and hypo-kyphotic segments, vertebral rotation and coronal curve was determined. The effect of segmental sagittal correction by in situ contouring was analyzed. METHODS: Pre- and post-operative radiographs of 54 scoliosis patients (Lenke 1 and 3) were analyzed at 8 years follow-up. Cobb angles and vertebral rotation were determined. Sagittal measurements were: kyphosis T4-T12, T4-T8 and T9-T12, lordosis L1-S1, T12-L2 and L3-S1, pelvic incidence, pelvic tilt, sacral slope, T1 and T9 tilt. RESULTS: Thoracic and lumbar curves were significantly reduced (p = 0.0001). Spino-pelvic parameters, T1 and T9 tilt were not modified. The global T4-T12 kyphosis decreased by 2.1° on average (p = 0.066). Segmental analysis evidenced a significant decrease of T4-T8 hyperkyphosis by 6.6° (p = 0.0001) and an increase of segmental hypokyphosis T9-T12 by 5.0° (p = 0.0001). Maximal vertebral rotation was located at T7, T8 or T9 and correlated (r = 0.422) with the cranial level of the hypokyphotic zone (p = 0.003). This vertebra or its adjacent levels corresponded to the coronal apex in 79.6 % of thoracic curves. CONCLUSIONS: Lenke 1 and 3 curves can show normal global kyphosis, divided in cranial hyperkyphosis and caudal hypokyphosis. The cranial end of hypokyphosis corresponds to maximal rotation. These vertebrae have most migrated anteriorly and laterally. The sagittal apex between segmental hypo- and hyper-kyphosis corresponds to the coronal thoracic apex. A segmental sagittal imbalance correction is achieved by in situ contouring. The concept of segmental imbalance is useful when determining the levels on which surgical detorsion may be focused.

Sagittal spinopelvic alignment and body mass index in patients with degenerative spondylolisthesis.

The sagittal orientation and osteoarthritis of facet joints, paravertebral muscular dystrophy and loss of ligament strength represent mechanical factors leading to degenerative spondylolisthesis. The importance of sagittal spinopelvic imbalance has been described for the developmental spondylolisthesis with isthmic lysis. However, it remains unclear if these mechanisms play a role in the pathogenesis of degenerative spondylolisthesis. The purpose of this study was to analyze the sagittal spinopelvic alignment, the body mass index (BMI) and facet joint degeneration in degenerative spondylolisthesis. A group of 49 patients with L4-L5 degenerative spondylolisthesis (12 males, 37 females, average age 65.9 years) was compared to a reference group of 77 patients with low back pain without spondylolisthesis (41 males, 36 females, average age 65.5 years). The patient's height and weight were assessed to calculate the BMI. The following parameters were measured on lateral lumbar radiographs in standing position: L1-S1 lordosis, segmental lordosis from L1-L2 to L5-S1, pelvic tilt, pelvic incidence and sacral slope. The sagittal orientation and the presence of osteoarthritis of the facet joints were determined from transversal plane computed tomography (CT). The average BMI was significantly higher (P=0.030) in the spondylolisthesis group compared to the reference group (28.2 vs. 24.8) and 71.4% of the spondylolisthesis patients had a BMI>25. The radiographic analysis showed a significant increase of the following parameters in spondylolisthesis: pelvic tilt (25.6° vs. 21.0°; P=0.046), sacral slope (42.3° vs. 33.4°; P=0.002), pelvic incidence (66.2° vs. 54.2°; P=0.001), L1-S1 lordosis (57.2° vs. 49.6°; P=0.045). The segmental lumbar lordosis was significantly higher (P<0.05) at L1-L2 and L2-L3 in spondylolisthesis. The CT analysis of L4-L5 facet joints showed a sagittal orientation in the spondylolisthesis group (36.5° vs. 44.4°; P=0.001). The anatomic orientation of the pelvis with a high incidence and sacral slope seems to represent a predisposing factor for degenerative spondylolisthesis. Although the L1-S1 lordosis keeps comparable to the reference group, the increase of pelvic tilt suggests a posterior tilt of the pelvis as a compensation mechanism in patients with high pelvic incidence. The detailed analysis of segmental lordosis revealed that the lordosis increased at the levels above the spondylolisthesis, which might subsequently increase posterior stress on facet joints. The association of overweight and a relatively vertical inclination of the S1 endplate is predisposing for an anterior translation of L4 on L5. Furthermore, the sagittally oriented facet joints do not retain this anterior vertebral displacement.

Could an osteoinductor result in degeneration of a neurofibroma in NF1?

We report a case of fatal evolution of neurofibromatosis in a young boy. A laminectomy was performed when he was 9 years old. A secondary hyperkyphosis led to many surgeries resulting in recurrent malunions. When he was 23 years old, a breakage of his rods was treated by a new instrumentation and a T12-L1 interbody cage fitted with rh-BMP. Five months later, he developed a huge posterior tumour on his back. The biopsy diagnosed a neurofibrosarcoma. The growth of the tumour was extremely rapid. He died after several months from a septic shock. NF1 is characterised by neurofibromas that have a possibility of malign degeneration and conversion to a sarcoma. However, the chronology, rapidity of evolution and the exceptional volume of the tumour made us wonder whether the BMP had a part of responsibility as osteoinductor in the malignant degeneration, in this particular case, of neurofibromatosis. It seemed important to point out this case to the medical community.