Segmental Kyphosis Research Articles

Traumatic vertebra and endplate fractures promote adjacent disc degeneration: evidence from a clinical MR follow-up study.

The integrity of endplate is important for maintaining the health of adjacent disc and trabeculae. Yet, pathological impacts of traumatic vertebra and endplate fractures were less studied using clinical approaches. This study aims to investigate their effects on the development of adjacent disc degeneration, segmental kyphosis, Modic changes (MCs), and high-intensity zones (HIZs). Magnetic resonance (MR) images of patients with acute traumatic vertebral compression fractures (T11-L5) were studied. On MR images, endplate fractures were evaluated as present or absent. Disc signal, height, bulging area, sagittal Cobb angle, MCs, and HIZs were measured on baseline and follow-up MR images to study the changes of the disc in relation to vertebra fractures and endplate fractures. Ninety-seven patients were followed up for 15.4 ± 14.0months. There were 123 fractured vertebrae, including 79 (64.2%) with endplate fractures and 44 (35.8%) without. Both the adjacent and control discs decreased in signal and height over time (p < 0.001), and the disc adjacent to vertebral fractures had greater signal and height loss than the control disc (p < 0.05). In the presence of endplate fractures, the adjacent discs had greater signal decrease in follow-up (p < 0.05), as compared to those without endplate fractures. Sagittal Cobb angle significantly increased in segments with endplate fractures (p < 0.05). Vertebra fractures were associated with new occurrence of MCs in the fractured vertebra (p < 0.001) but not HIZs in the adjacent disc. Traumatic vertebral fractures were associated with accelerated adjacent disc degeneration, which appears to be further promoted by concomitant endplate fractures. Endplate fractures were associated with progression of segmental kyphosis.

Percutaneous instrumentation with cement augmentation for traumatic hyperextension thoracic and lumbar fractures in ankylosing spondylitis: a single-institution experience.

The typical traumatic thoracolumbar (TL) fracture in patients with ankylosing spondylitis (AS) is a hyperextension injury involving all three spinal columns, which is associated with unfavorable outcomes. Although a consensus on the management of these highly unstable injuries is missing, minimally invasive surgery (MIS) has been progressively accepted as a treatment option, since it is related to lower morbidity and mortality rates. This study aimed to evaluate clinical and radiological outcomes after percutaneous instrumentation with cement augmentation for hyperextension TL fractures in patients with AS at a single institution. This cohort study was completed retrospectively. Back pain was assessed at preoperative, postoperative, and final follow-up visits using the visual analog scale (VAS). Patient-reported outcomes via the Oswestry Disability Index (ODI) and the new mobility score (NMS) were obtained to assess disability and mobility during follow-up. Radiological outcomes included the Cobb angle, sagittal index (SI), union rate, and implant failure. Intra- and postoperative complications were recorded. A total of 22 patients met inclusion criteria. The mean patient age was 74.2 ± 7.3 years with a mean follow-up of 39.2 ± 17.4 months. The VAS score for back pain significantly improved over the follow-up period (from 8.4 ± 1.1 to 2.8 ± 0.8, p < 0.001). At the last follow-up, all patients had minor disability (mean ODI score 24.4 ± 6.1, p = 0.003) and self-sufficiency of mobility (mean NMS 7.5 ± 1.6, p = 0.02). The Cobb angle (5.2° ± 2.9° preoperatively to 4.4° ± 3.3° at follow-up) and SI (7.9° ± 4.2° to 8.8° ± 5.1°) were maintained at follow-up, showing no loss of segmental kyphosis. Bone union was observed in all patients. The overall complication rate was 9.1%, while the reoperation rate for implant failure was 4.5%. Percutaneous instrumentation with cement augmentation for traumatic hyperextension TL fractures in AS demonstrated good clinical and radiological outcomes, along with a high bone union level and low reoperation rate. Accordingly, MIS reduced the complication rate in the management of these injuries of the ankylosed spine.

Outcomes of Posterior Lumbar Hemivertebra Resection and Short Fusion in Patients With Severe Sacral Tilt.

ObjectiveTo introduce surgical strategies to restore coronal balance during limited fusion for early lumbar hemivertebra resection in patients with severe sacral tilt. MethodsSacral tilt was defined as a sacral tilt angle ≥ 5, and severe sacral tilt was defined as a sacral tilt angle > 10. From July 2004 to December 2017, 73 consecutive patients treated with posterior hemivertebra resection and short fusion in our institution were evaluated. Severe sacral tilt was noted in 26 patients (14 boys and 12 girls), and all were enrolled in this study. Undercorrection of the primary lumbar curve as compensation for the sacral tilt and short fusion was performed in these patients. The medical charts and imaging data of the patients were retrospectively reviewed to evaluate the outcomes. ResultsAll patients were followed for at least 2 years. The mean age at the time of surgery was 3.7 (2–9) years old, with a total of 31 lumbar hemivertebra excised. On average, 2.8 (2–5) segments were fused for each patient. Sacral tilt minimally improved from 14.5° preoperatively to 13.6° postoperatively (p=0.15) and remained stable at the follow-up. The overall lumbar curve was 41.9° preoperatively, 11.7° immediately postoperatively, and 14.6° at the final follow-up. The segmental scoliosis curve was 39.1° preoperatively, 9.7° immediately postoperatively, and 11.2° at the final follow-up. Segmental kyphosis was corrected from 27.2° to 6.5° after the surgery and was 7.1° at the latest follow-up. ConclusionSacral tilt is seen in patients with congenital scoliosis in lumbar hemivertebra. Undercorrection of the lumbar curve and segmental scoliosis to compensate for sacral tilt and short fusion after hemivertebra resection may be helpful to restore coronal balance and preserve mobility in segments in patients with pronounced severe sacral tilt.

The impact of segmental spinal alignment on the development of proximal junctional kyphosis after instrumented posterior spinal fusions for idiopathic scoliosis.

To assess if the preservation of preoperative kyphosis within the cephalad two motion segments of instrumented posterior spinal fusions (PSF), for idiopathic scoliosis (IS), would be associated with lower frequency of proximal junctional kyphosis (PJK) at 2years postoperatively. Previous studies on PJK in IS have reported conflicting findings; none has evaluated the relationship between segmental kyphosis within the cephalad instrumented construct and PJK. One hundred consecutive patients undergoing PSF for IS by a single surgeon with minimum 2-year follow-up were evaluated. Radiographic evaluation focused on sagittal alignment of the upper instrumented vertebrae (UIV), the 1 and 2 vertebrae cephalad (UIV + 1, UIV + 2) and caudal (UIV - 1, UIV - 2). This was measured between the inferior endplate of the UIV and the superior endplate of the UIV + 1 and UIV + 2 or between the superior endplate of the UIV and the inferior endplate of the UIV - 1 and UIV - 2. PJK was defined as present if the final UIV + 2 ≥ 10° and final UIV + 2-preop UIV + 2 ≥ 10°. There were 78 females and 22 males whose mean age was 14.6 (± 2.1) years at surgery; mean follow-up was 3.9 (2-9.3) years. The overall frequency of PJK was 25% (25/100) at final follow-up. Preoperative mean coronal curve measured 63° (40°-107°) with a mean 66% correction at final follow-up. UIV was T2 (n = 15), T3 (n = 47) or T4 (n = 38). More caudal UIVs were associated with PJK development (p = 0.04): T2 (13%), T3 (21%) and T4 (34%). Greater preoperative T5-T12 thoracic kyphosis and UIV - 2, and lower major curve apex (below T12) were more likely to develop PJK (p = 0.019, p = 0.004 and p = 0.007, respectively). Post-operatively, larger values for UIV - 1 (p ≤ 0.001) and UIV - 2 (p = 0.002) were associated with PJK at final follow-up. Longer fusion lengths (10-13 vs. 6-9 segments, p = 0.02) and the presence of thoracolumbar/lumbar structural curves (Lenke 3-6 vs. 1-2, p = 0.032) had higher rates of PJK (32% vs 10% and 37% vs 18%, respectively). Changes in UIV - 1 and UIV - 2 (preoperatively to immediately post-op) did not influence the development of PJK. At final follow-up, no patient required revision surgery for symptomatic proximal junctional kyphosis. In this study, changes in UIV - 1 and UIV - 2 at surgery were not related to PJK. Greater preoperative T5-T12 thoracic kyphosis and UIV - 2, lower major curve apex (T12 and below), and greater post-operative UIV - 1 and UIV - 2 were associated with higher frequencies of PJK. Higher UIV (T2 vs. T4) and LIV levels had a protective effect against PJK. Based on this study, the preservation of segmental kyphosis within the instrumented cephalad two levels of the PSF did not minimize the occurrence of radiographic PJK. Level IV.

Comparing porous tantalum fusion implants and iliac crest bone grafts for spondylodesis of thoracolumbar burst fractures: Prospectice Cohort study

The aim of this study was to compare two different techniques of performing one-level spondylodesis for thoracolumbar burst fractures using either an autologous iliac crest bone graft (ICBG) or a porous tantalum fusion implant (PTFI). In a prospective nonrandomized study, 44 patients (20 women, 24 men; average age 43.1 ± 13.2 years) suffering from severe thoracolumbar burst fractures were treated with combined anterior–posterior stabilization. An ICBG was used in 21 cases, and a PTFI was used in the other 23 cases. A two-year clinical and radiographic follow-up was carried out. There were no statistically significant differences in age, sex, localization/classification of the fracture, or visual analog scale (VAS) before injury between the two groups. All 44 patients were followed up for an average period of 533 days (range 173–1567). The sagittal spinal profile was restored by an average of 11.1° (ICBG) vs. 14.3° (PTFI) (monosegmental Cobb angle). Loss of correction until the last follow-up tended to be higher in the patients treated with ICBG than in those treated with PTFI (mean: 2.8° vs. 1.6°). Furthermore, significantly better restoration of the sagittal profile was obtained with the PTFI than with the iliac bone graft at the long-term follow-up (mean: ICBG 7.8°, PTFI 12.3°; p < 0.005). Short-segment posterior instrumentation combined with anterior one-level spondylodesis using either an ICBG or a PTFI resulted in sufficient correction of posttraumatic segmental kyphosis. PTFI might be a good alternative for autologous bone grafting and prevent donor site morbidities.

Classification of unilateral cervical locked facet with or without lateral mass-facet fractures and a retrospective observational study of 55 cases

This study describes a morphology-based unilateral cervical facet interlocking classification in an attempt to clarify the injury mechanism, instability, neurological deficits, radiological features, and determine optimum management strategies for these injuries. A total of 55 patients with unilateral cervical locked facet (UCLF) involving C3 to C7 were identified between January 1, 2012 and December 1, 2019. The injuries were classified into three types, and they were further divided into six subtypes using three-dimensional computed tomography. The injury mechanism, clinical features, neurological deficits, and imaging characteristics were analyzed, and the appropriate treatment strategies for UCLF were discussed. UCLFs were divided into the following six subtypes: UCLF without lateral mass-facet fracture (type I) in nine cases, with superior articular process fracture (type II A) in 22, with inferior articular process fracture (type II B) in seven, both superior and inferior articular process fractures (type II C) in four, with lateral mass splitting fracture (type III A) in three, and with lateral mass comminution fractures (type III B) in ten. A total of 22 (40.0%) of the 55 patients presented with radiculopathy, and 23 patients (41.8%) had spinal cord injuries. The subtype analyses showed high rates of radiculopathy in types II A (68.2%) and II C (75.0%), as well as significant spinal cord injury in types I (77.8%) and III (61.5%). Destruction of the facet capsule was observed in all patients, but the injury of disc, ligamentous complex, and vertebra had a significant difference among the types or subtypes. The instability parameters of the axial rotation angle, segmental kyphosis, and sagittal displacement showed significant differences in various types of UCLF. Closed reduction by preoperative and intraoperative general anesthesia traction was achieved in 27 patients (49.1%), and successful rate of closed reduction in type I (22.2%) was significantly lower than that in type II (51.5%) and type III (61.5%). A total of 35 of 55 patients underwent a single anterior fixation and fusion, 10 patients were treated with posterior pedicle and (or) lateral mass fixation, and combined surgery was performed in ten patients. Ten patients (18.2%) with a poor outcome were observed after first surgery. Among them, 3 patients treated with a single anterior surgery had persistent or aggravated radiculopathy and posterior approach surgery with ipsilateral facet resection, foramen enlargement, and pedicle and (or) lateral mass screw fixation was performed immediately, 5 patients treated with a short-segment posterior surgery showed mild late kyphosis deformity, and 2 patients with vertebral malalignment were encountered after anterior single-level fusion during the follow-up. This retrospective study indicated that UCLF is a rotationally unstable cervical spine injury. The classification proposed in this study will contribute to understanding the injury mechanism, radiological characteristics, and neurological deficits in various types of UCLF, which will help the surgeons to evaluate the preoperative closed reduction and guide the selection of surgical approach and fusion segment.

32. DJK and revision rates in multilevel posterior cervical fusions terminating at the cervicothoracic junction

<h3>BACKGROUND CONTEXT</h3> Despite the consensus that posterior cervical fusion can be used to treat multiple cervical pathologies, questions remain as to if crossing the cervicothoracic junction (CTJ) influences the rate of revision and how radiographic outcomes may differ. Even less is known about how crossing the CTJ may predict the development of adjacent segment disease. A retrospective review of 91 posterior cervical fusion patients was performed comparing long constructs (≥3 levels) terminating at C7 vs T1-3. Revision and DJK rates were compared between the two groups. Mean change in cervical lordosis, T1 slope, cervical SVA, and T1 slope-cervical lordosis mismatch (T1S-CL) were also compared. Distal segment kyphosis at final follow up was significantly greater in the thoracic group, but no other statistically significant differences were identified. <h3>PURPOSE</h3> Compare revision rates and radiographic outcomes in patients receiving posterior cervical fusion of ≥3 levels that terminate at C7 vs T1, 2 or 3. Our hypothesis is patients with multilevel posterior cervical fusion constructs terminating at C7 will have similar rates of revision, DJK and cervicothoracic radiographic outcomes compared to patients whose constructs crossed the CTJ to T1, T2, or T3. <h3>STUDY DESIGN/SETTING</h3> Single center retrospective analysis. <h3>PATIENT SAMPLE</h3> Consecutive posterior cervical fusion patients with greater than or equal to 3 levels fused from January 2010 until December 31, 2019 at a single institution. <h3>OUTCOME MEASURES</h3> Primary outcome: 1. Need for revision. Secondary outcomes: 2. Distal junctional kyphosis; 3. Mean change in cervical lordosis (CL); 4. Mean change in T1 slope (T1S); 5. T1S - CL mismatch; 6. cervical SVA. <h3>METHODS</h3> A retrospective review of medical records identified posterior cervical fusion cases with at least one year of radiographic follow-up and fusion greater than or equal to 3 segments. Identified cases were divided into 2 groups based on location of lowest instrumented vertebra. Group 1 included fusions terminating at C7 and group 2 included fusions terminating at T1, 2, or 3. At multiple intervals, cervical lordosis (CL), T1 slope, cervical sagittal vertical axis (cSVA), distal segment kyphosis, and T1 slope-cervical lordosis mismatch (T1S-CL) were measured. Any need for revision surgery was also documented. <h3>RESULTS</h3> A total of 91 patients were included, 53 in Group 1 (mean age 58.9 years, 56.6% women) and 38 in Group 2 (mean age 64.4 yrs, 55% women). Revision rate did not reveal statistical difference between the two groups (Group 1: 9.4% vs Group 2: 2.6% P=0.39). There was no statistical difference in patients meeting criteria for DJK at final follow up (Group 1: 5.6% vs Group 2: 5.2% P=0.9). However, within each group, a statistically significant increase in mean distal segment kyphosis at final follow-up was identified in Group 2 (Group 1: 0.82°, P=0.31 vs Group 2: 2.5°, P=0.0001). Mean change in CL, T1 Slope, cSVA and T1S-CL mismatch were not statistically different between the groups at final follow up. <h3>CONCLUSIONS</h3> Our study demonstrated that revision rates, cervicothoracic radiographic parameters, and DJK were not significantly different when comparing multilevel posterior cervical fusions terminating at C7 vs the upper thoracic spine. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Is Sacral Dysmorphism Protective Against Spinopelvic Dissociation? Multicenter Case Series.

Investigate the incidence of sacral dysmorphism (SD) in patients with spinopelvic dissociation (SPD). Retrospective case series. Two academic level 1 trauma centers. One thousand eight hundred fifty adult patients with sacral and pelvic fractures (OTA/AO 61-A, B, C). Plain pelvic radiographs and CT scans. Incidence of SD in patients with SPD. Secondary radiographic evaluation of fracture classification and deformity on sagittal imaging. Eighty-two patients with SPD were identified, and 12.2% displayed features of SD, significantly less than reported in the literature. The S2 sacral body was the most common horizontal fracture location in patients with SD and nondysmorphic sacra (ND). Roy-Camille type I patterns were more common in ND (35%), versus type II in SD patients (40%). SD patients had lower body mass indexes (19.7 vs. 25.2, P = 0.001). Segmental kyphosis (22.5 degrees ND vs. 23.8 degrees SD, P = 0.838) and sacral kyphosis (26 degrees ND vs. 31 degrees SD, P = 0.605) were similar between groups. Percutaneous fixation was the most common surgical technique. We report a significantly lower prevalence of SD in patients with SPD than previously reported in the literature. This suggests that variations in sacral osseous anatomy alter force transmission across the sacrum during traumatic loading, which may be protective against certain high-energy fracture patterns. Preoperative evaluation of sacral anatomy is critical, not only in determining the size and orientation of sacral segment safe zones for screw placement, but also to better understand the pathomechanics involved in sacral trauma. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Survival analysis and risk factors of new vertebral fracture after vertebroplasty for osteoporotic vertebral compression fracture

BACKGROUND CONTEXTAlthough risk factors of new adjacent vertebral fracture (AVF) and remote vertebral fracture (RVF) after vertebroplasty may differ, research on this topic is lacking. PURPOSETo determine the natural course of new vertebral fractures after vertebroplasty for osteoporotic vertebral compression fracture (OVCF) and to analyze each risk factor for understanding the incidence of AVF and RVF. STUDY DESIGNRetrospective cohort study. PATIENT SAMPLEThe study subjects included 205 patients who received vertebroplasty for OVCF and were followed-up for at least 1-year. OUTCOME MEASURESData on factors that could affect the occurrence of vertebral fractures, such as age, body mass index, and bone density, were collected from the patients’ medical records. Fracture pattern, fracture location, sagittal imbalance, degree of segmental kyphosis after vertebroplasty, cement distribution, and cement leakage were radiologically examined. METHODSxDuring the follow-up period, any newly developed vertebral fractures were identified. We analyzed whether the time of occurrence differed between AVF and RVF by performing a survival analysis and each risk factor separately. RESULTSNew vertebral fractures occurred in 47 patients (22.9%) after vertebroplasty, AVF occurred in 21 patients (10.2%), and RVF occurred in 26 patients (12.7%). The onset time of AVF was 6.2±1.8 months after vertebroplasty, showing a significant difference from that of RVF, which was 15.2±1.8 months (p<.001). In the univariate analysis, the risk factors of AVF included severe osteoporosis (T-score<−3.0), vertebroplasty in the thoracolumbar junction, sagittal imbalance, and segmental kyphosis angle >15° (p=0.029, p=0.033, p=0.001, and p=0.021, respectively). The risk factors of RVF included severe osteoporosis (T-score <−3.0) and sagittal imbalance (p=0.013 and p=0.004). In the multivariate analysis, the risk factors of AVF included vertebroplasty in the thoracolumbar junction and sagittal imbalance (hazard ratio=3.34, p=0.032 and hazard ratio=4.05, p=0.008), and those of RVF included only sagittal imbalance (hazard ratio=2.66, p=0.024). CONCLUSONAfter vertebroplasty for OVCF, a significant difference in the meantime of occurrence was found; it took 6 months for AVF and 15 months for RVF to develop. Vertebroplasty in the thoracolumbar junction was identified as a risk factor for AVF, whereas sagittal imbalance was a risk factor of both AVF and RVF.

Posterior vertebral column resection as a safe procedure leading to solid bone fusion in metastatic epidural spinal cord compression

Cancer is one of the leading causes of death and greatly decreases a patient's quality of life. Vertebral metastases often lead to epidural spinal cord compression (ESCC) requiring surgical therapy. It has previously been shown that in patients with metastatic ESCC (MESCC), a surgical intervention leads to an improved outcome. Although the treatment paradigms in spinal metastases have changed and separation surgery followed by stereotactic radiosurgery is considered the best strategy, there are still cases in which 360° decompression with stabilization is indicated. In these patients, a proper bone fusion should be the treatment goal to guarantee good clinical results in extended survival times through progressions in oncological therapies. The aim of this study was to examine the safety and feasibility of posterior vertebral column resection (pVCR) in everyday clinical practice, achievement of bone fusion, and midterm outcome in patients with MESCC. All patients treated with pVCR due to MESCC between 2013 and 2020 were enrolled in this observational single-center study. Demographics, outcome parameters, numeric rating scale (NRS) score, Frankel grade, and Karnofsky Performance Scale (KPS) score were evaluated. Radiological images routinely acquired during follow-up were reviewed and screened for the presence of bone fusion. Sixty-six patients were treated by eight surgeons. The mean follow-up period was 549 ± 739 days. At baseline, the average age was 64.4 ± 10.9 years. Reported NRS scores (preoperative 6.2 ± 1.7 vs postoperative 3.4 ± 1.6) and segmental kyphosis as measured on sagittal CT images (preoperative 13.5° ± 8.6° vs postoperative 3.8° ± 5.4°) decreased significantly (p < 0.001). In only 2 patients (3%), the Frankel grade worsened postoperatively, whereas in 12 patients (18.2%) an improvement was documented. The KPS score remained constant during the observation period (preoperative 73.2% ± 18.2% vs 78.3% ± 18% at last follow-up). Bone fusion was observed in 26 patients (86.7%) receiving CT more than 100 days after the index surgery. pVCR is a reliable surgical technique in daily clinical practice, which proves to be beneficial in terms of short- as well as midterm outcome, as judged by the KPS and NRS. The overall improvement in the Frankel grade shows patient safety. A bone fusion was observed regularly in oncological patients undergoing pVCR. The authors therefore conclude that pVCR is a safe, fast, and efficient strategy to achieve stability and pain relief by achievement of bone fusion in cancer patients.

One-stage posterior laminectomy with instrumented fusion and foraminotomy for cervical ossification of posterior longitudinal ligament with radiculopathy pain

ObjectiveTo explore the clinical efficacy of posterior LFF for cervical OPLL with radicular pain of upper limbsMethodsBetween January 2014 and January 2018, 48 OPLL patients with radicular pain symptoms of upper limbs who underwent a one-stage posterior laminectomy and instrumented fusion with/without foraminotomy were reviewed retrospectively and divided into two groups: LF group (laminectomy with instrumented fusion without foraminotomy) and LFF group (laminectomy with instrumented fusion and foraminotomy). Clinical data were assessed and compared between the two groups. The radicular pain of upper limbs and neck was measured using the visual analog scale (VAS). The neurological function was evaluated with the American Spinal Injury Association (ASIA) scale. Changes of sagittal alignment were investigated by postoperative plain x-ray or computed tomography (CT). Moreover, the decompression of the spinal cord was evaluated based on postoperative MRI.ResultsAll the 48 patients were followed up for 24–42 months with an average follow-up time of 31.1±5.3 months. A total of 56 cervical intervertebral foramens were enlarged in 48 patients, including 40 cases (83.3%) with 1 intervertebral foramen enlargement and 8 cases (16.7%) with 2 intervertebral foramen enlargements. There were no significant differences in intraoperative blood loss, postoperative drainage amount, Japanese Orthopaedic Association (JOA) scores, JOA recovery rates, VAS scores for neck pain, and ASIA grade between two groups. The mean operative time was shorter in the LF group compared with the LFF group. The VAS score for arm pain was significantly lower while the surgical duration was longer in group B. No statistical difference was observed between the two groups in terms of C2–C7 SVA, cervical lordosis, focal angulation at the foraminotomy segment, and local spinal cord angle. Compared with the LF group, there was no segmental kyphosis or instability where the additional posterior foraminotomy was performed in the LFF group.ConclusionsOne-stage posterior LFF can achieve satisfied clinical efficacy in improving neurological function and relieving the radicular pain of the upper limbs for OPLL patients with radiculopathy symptoms.

Surgery-related Factors Do Not Affect Short-term Adjacent Segment Kinematics After Anterior Cervical Arthrodesis.

Prospective cohort study. The aim of this study was to identify surgical factors that affect adjacent segment kinematics after anterior cervical discectomy and fusion (ACDF) as measured by biplane radiography. Previous studies investigated the effect of surgical factors on spine kinematics as a potential etiology for adjacent segment disease (ASD). Those studies used static flexion-extension radiographs to evaluate range of motion. However, measurements from static radiographs are known to be unreliable. Furthermore, those studies were unable to evaluate the effect of ACDF on adjacent segment axial rotation. Patients had continuous cervical spine flexion/exten- sion and axial rotation movements captured at 30 images per second in a dynamic biplane radiography system preoperatively and 1 year after ACDF. Digitally reconstructed radiographs generated from subject-specific CT scans were matched to biplane radiographs using a previously validated tracking process. Dynamic kinematics, postoperative segmental kyphosis, and disc distraction were calculated from this tracking process. Plate-to-disc distance was measured on postoperative radiographs. Graft type was collected from the medical record. Multivariate linear regression was performed to identify surgical factors associated with 1-year post-surgery changes in adjacent segment kinematics. A secondary analysis was also performed to compare adjacent segment kinematics between each of the surgical factors and previously defined thresholds believed to be associated with adjacent segment degeneration. Fifty-nine patients completed preoperative and postoperative testing. No association was found between any of the surgical factors and change in adjacent segment flexion/exten- sion or axial rotation range of motion (all P > 0.09). The secondary analysis also did not identify differences between adjacent segment kinematics and surgical factors (all P > 0.07). Following ACDF for cervical spondylosis, factors related to surgical technique were not associated with short-term changes in adjacent segment kinematics that reflect the hypermobility hypothesized to lead to the development of ASD.Level of Evidence: 2.

Long-term results after the one-stage posterior-only surgical correction of thoraco-lumbar kyphoscoliosis in congenital spine deformity caused by two ipsilateral hemi-vertebrae

BackgroundTwo ipsilateral hemivertebrae is less common and presents severe growth imbalance caused by the vertebral anomalies. However, there is a paucity of reports regarding to two ipsilateral thoracolumbar hemivertebrae. The purpose of present study is to evaluate the long-term outcomes of the posterior surgical correction of thoraco-lumbar spine deformity caused by two ipsilateral hemivertebrae.MethodsFrom 2006 to 2014, a total of 14 consecutive pediatric patients with congenital thoraco-lumbar hemivertebrae were treated by posterior excision of hemivertebrae with short segment fusion. The following parameters were measured: coronal major curvature, cranial and caudal compensatory curvature, segmental kyphosis, lumbar lordosis, trunk shift, apical vertebra translation and sagittal vertical axis. These results were compared and evaluated in preoperatively, immediately postoperatively and at the final follow-up. All patients had a minimum of 5 years follow-up.ResultsThe mean age at surgery was 11.1 ± 4.8 years (2yos to 17yos). The mean follow-up period was 80.2 ± 19.4 months (60mons to 117mons). There was a mean improvement of 74.2% in the coronal major curve from a mean angle of 64.1° before surgery to 15.8° at the final follow-up. The cranial and caudal curves improved of 69.8 and 69.0% from 25.6° to 7.7°, 26.9 to 8.2, respectively. The mean thoraco-lumbar kyphosis was 59.9° before and 13.6° after surgery, 20.8° at the final follow-up. Alignment in the coronal and sagittal plane was either maintained or improved within normal values in all patients.ConclusionsGood correction and spinal balance can be achieved by posterior-only hemivertebrectomy in patients with thoracolumbar kyphocsoliosis caused by two ipsilateral hemivertebra. The complication of neurological injury is low but a technically demanding procedure. More attention should be paid in residual curve progression after surgery.

Treatment of unstable fresh thoracolumbar burst fracture by over-bending rod reduction and fixation technique via posterior approach

To investigate the efficacy and safety of over-bending rod reduction and fixation technique via posterior approach in the treatment of unstable fresh thoracolumbar burst fracture. A clinical data of 27 patients with unstable fresh thoracolumbar burst fracture, who were met the inclusive criteria and admitted between January 2018 and October 2019, was retrospectively analyzed. There were 15 males and 12 females with an average age of 41.8 years (range, 26-64 years). The fractures were caused by falling from height in 14 cases, traffic accident in 8 cases, and crushing by a heavy objective in 5 cases. The interval between injury and operation was 1-7 days (mean, 3.2 days). The injured fracture was located at T 10 in 1 case, T 11 in 3 cases, T 12 in 6 cases, L 1 in 7 cases, L 2 in 7 cases, and L 3 in 3 cases. According to AO classification, there were 11 cases of type A3, 7 cases of type B, and 9 cases of type C. Neurological function was rated as grade A in 3 cases, grade B in 7 cases, grade C in 5 cases, and grade D in 12 cases according to the American Spinal Injury Association (ASIA) grading. All cases were treated by over-bending rod reduction and fixation technique via posterior approach, and 16 cases were combined with limited fenestration decompression. The evaluation indicators consisted of operation time, intraoperative blood loss, the compression ratio of the anterior vertebral height, the invasion rate of the injured vertebra into the spinal canal, the Cobb angle of segmental kyphosis, visual analogue scale (VAS) score, and Oswestry Disability Index (ODI). The operation time was 67-128 minutes (mean, 81.6 minutes), and the intraoperative blood loss was 105-295 mL (mean, 210 mL). All patients were followed up 12-23 months (mean, 17.2 months). A total of 178 pedicle screws were implanted during operation, and the accuracy of the implantation was 98.9% (176/178). The compression ratios of the anterior vertebral height at the early postoperatively and last follow-up were significantly increased when compared with preoperative one ( P<0.05), and the invasion rate of the injured vertebra into the spinal canal, Cobb angle, VAS score, and ODI were significantly lower than those preoperatively ( P<0.05). Except that the ODI at last follow-up was significantly lower than that of the early postoperative period ( P<0.05), there was no significant difference between the last follow-up and the early postoperative period for other indicators ( P>0.05). At last follow-up, the neurological function was rated as grade A in 1 case, grade B in 2 cases, grade C in 4 cases, grade D in 9 cases, and grade E in 11 cases according to the ASIA grading, showing significant difference when compared with that before operation ( Z=-3.446, P=0.001). Over-bending rod reduction and fixation technique can effectively restore vertebral height, reset the invaded vertebral block, and selectively perform limited decompression and posterolateral bone grafting to ensure the completeness of intravertebral decompression and stability, which is one of the effective methods to treat unstable fresh thoracolumbar burst vertebral fracture.

Posterior thoracolumbar hemivertebra resection and short-segment fusion in congenital scoliosis: surgical outcomes and complications with more than 5-year follow-up

BackgroundTreatment of congenital hemivertebra is challenging and data on long-term follow-up (≥ 5 years) are lacking. This study evaluated the surgical outcomes of posterior thoracolumbar hemivertebra resection and short-segment fusion with pedicle screw fixation for treatment of congenital scoliosis with over 5-year follow-up.MethodsThis study evaluated 27 consecutive patients with congenital scoliosis who underwent posterior thoracolumbar hemivertebra resection and short-segment fusion from January 2007 to January 2015. Segmental scoliosis, total main scoliosis, compensatory cranial curve, compensatory caudal curve, trunk shift, shoulder balance, segmental kyphosis, and sagittal balance were measured on radiographs. Radiographic outcomes and all intraoperative and postoperative complications were recorded.ResultsThe segmental main curve was 40.35° preoperatively, 11.94° postoperatively, and 13.24° at final follow-up, with an average correction of 65.9%. The total main curve was 43.39° preoperatively, 14.13° postoperatively, and 16.06° at final follow-up, with an average correction of 60.2%. The caudal and cranial compensatory curves were corrected from 15.78° and 13.21° to 3.57° and 6.83° postoperatively and 4.38° and 7.65° at final follow-up, with an average correction of 69.2% and 30.3%, respectively. The segmental kyphosis was corrected from 34.30° to 15.88° postoperatively and 15.12° at final follow-up, with an average correction of 61.9%. A significant correction (p < 0.001) in segmental scoliosis, total main curve, caudal compensatory curves and segmental kyphosis was observed from preoperative to the final follow-up. The correction in the compensatory cranial curve was significant between preoperative and postoperative and 2-year follow-up (p < 0.001), but a statistically significant difference was not observed between the preoperative and final follow-up (p > 0.001). There were two implant migrations, two postoperative curve progressions, five cases of proximal junctional kyphosis, and four cases of adding-on phenomena.ConclusionPosterior thoracolumbar hemivertebra resection after short-segment fusion with pedicle screw fixation in congenital scoliosis is a safe and effective method for treatment and can achieve rigid fixation and deformity correction.

Thoracic Kyphosis and Lumbar Lordosis Distribution After Idiopathic Scoliosis Correction Using Posterior Hybrid Versus Screw Instrumentation.

This was a retrospective observational study. The aim of this study was to evaluate kyphosis and lordosis distribution, inflexion points, and the relationship with proximal junctional kyphosis (PJK) comparing hybrid instrumentation (in situ contouring, derotation) versus screw instrumentation (thoracic cantilever reduction, lumbar in situ contouring, and derotation). The combination of reduction techniques aims at restoring the levels of lumbar apex and thoracolumbar inflexion point according to Roussouly alignment types. This approach could minimize the PJK risk after adolescent idiopathic scoliosis (AIS) surgery. The study assessed coronal curve correction, thoracolumbar and spinopelvic sagittal parameters in 86 skeletally mature adolescents and young adults 2.2 years after AIS correction, comparing a hybrid group (HG, n=34) to a screw group (SG, n=52). Segmental kyphosis and lordosis distribution, number of vertebrae included in curves, thoracic and lumbar apex, thoracolumbar inflexion point and Roussouly types were modeled using KEOPS software. Global coronal and sagittal correction were similar in both groups. In the SG, lumbar lordosis (LL) decreased from 61.1 to 53.9 degrees (P<0.0001) and matched with pelvic incidence (r=0.69), whereas LL did not change in the HG. Postoperatively, the thoracolumbar inflexion point migrated cranially, resulting in a longer LL in both groups. Postoperative thoracolumbar inflexion point (P<0.0001) and the lumbar apex (P=0.0274) were more caudal in the SG compared with the HG. The PJK rate was 14.7% in the HG and 7.7% in the SG. In patients with PJK, lumbar apex and thoracolumbar inflexion point shifted cranially and were too high according to the Roussouly type. Hybrid and screw instrumentation led to similar global AIS correction, but the use of cantilever reduction in the SG allowed setting the thoracolumbar inflexion point and the lumbar apex lower than in the HG. Cranial migration of these points was identified as PJK risk factor. Level III.

IMPORTANCE OF RADIOGRAPHY IN ORTHOSTATISM IN THE CONDUCT OF THORACOLOMBAR TRANSITION FRACTURES

ABSTRACT Objective: To evaluate the importance of radiography in the orthostatic position in the initial assessment of patients with thoracolumbar transition fractures and whether this image changes the surgical indication. Methods: Medical records and imaging tests of patients treated for thoracolumbar transition fractures from June 2018 to June 2019 were evaluated. Trauma patients between 18 and 60 years of age with fractures of T10 to L3 who had been indicated for conservative treatment were included. Cases of fractures considered unstable were excluded. Radiographs were taken with the patient in the supine position (supine X-ray), computed tomography (CT), and orthostatic radiography (orthostatic X-ray). Segmental kyphosis and degree of wedging were evaluated. The measurements were compared using the Wilcoxon test. The McNemar test was used to assess changes in conduct according to the criteria for surgical indication (kyphosis ≥ 25 ° and wedging ≥ 50%). Results: Fifty patients were evaluated, nine of whom (18%) were indicated for a change of conduct according to the orthostatic examinations and were submitted to surgical treatment. Vertebral kyphosis increased by 40.6% (p &lt;0.001). The wedging increased by 25.62% (p &lt;0.0001). Conclusion: Eighteen percent of the total number of patients who did not present instability criteria in radiographs in the supine position satisfied at least one of these criteria when the orthostatic X-ray was performed. Level of evidence 3B; Retrospective case series study.

Proximal junctional kyphosis after pediatric angular kyphotic deformity correction: Are we missing something?

Purpose:Corrective maneuvers in an angular kyphotic deformity have its own problems including early complications such as neurological deficit and late complications such as proximal junctional kyphosis (PJK) and proximal junctional failure (PJF). This article discusses the probable mechanisms, leading to PJK in pediatric severe angular kyphotic deformities and preventive strategies for the same. We will also assess natural course of untreated PJK and its devastating consequences.Materials and Methods:Three patients, two 13-year males presented with progressive, painless thoracolumbar kyphoscoliotic deformity, with segmental kyphosis 100° and 140° and scoliosis of 33° and 78°, respectively, and one 14-year-old female presented with angular kyphotic deformity of 60° with apex at D11-12 level.Results:Posterior vertebral column resection with segmental deformity correction with good coronal and sagittal balance was done. In the follow-up, PJF was seen. Second surgery was done with the extension of instrumentation to D4 along with deformity correction in both the male patients. The female patient did not opt for a revision surgery, and we are following the natural history of this case.Conclusion:In severe thoracolumbar angular kyphotic deformities with normal or negative sagittal balance, it might be a safer option to select the sagittal stable vertebra as upper instrumented vertebra based on the C2 plumb line on the preoperative standing lateral radiographs. However, a study with a larger sample size is needed to validate our hypothesis.

Clinical Outcomes of Minimally Invasive Posterior Decompression for Lumbar Spinal Stenosis with Degenerative Spondylolisthesis.

Retrospective cohort study. To compare the clinical outcomes 5 years after minimally invasive posterior decompression for lumber spinal stenosis (LSS) between patients with and without degenerative spondylolisthesis (DS). Indications for surgical procedures for patients with LSS and DS are still under investigation. Since minimally invasive surgery does not affect most anatomical structures, preoperative DS may not negatively affect the clinical outcomes of minimally invasive posterior decompression. Overall, 198 patients with LSS who underwent microendoscopic or microscopic decompression and were followed up for more than 5 years postoperatively were included in the present study. Patients who showed a segmental kyphosis >5° at the surgical level during flexion were treated with fusion surgery. However, other patients, including those with DS, were treated with posterior decompression. The patients were divided into two groups: the DS group included 82 patients with >3-mm slip and the non-DS group included 112 patients with ≤3-mm slip or without slip. A mixed-effects model adjusted for age and sex was used to compare the improvements in the visual analog scale score for low-back pain and the Japanese Orthopaedic Association score of the two groups. For subgroup analysis (n = 53), the changes in the preoperative physical component summary and the mental component summary of Short Form-36 of the two groups at 5 years after surgery were evaluated. There was no significant difference in the improvement of preoperative low-back pain visual analog scale score and Japanese Orthopaedic Association score 5 years after surgery between the two groups. Subgroup analysis showed no significant difference between the two groups in the improvement of preoperative physical component summary and mental component summary 5 years after surgery. After carefully eliminating patients with segmental instability, DS did not affect the clinical outcomes of minimally invasive decompression surgery.Level of Evidence: 3.

Surgical Planning for Adult Spinal Deformity: Anticipated Sagittal Alignment Corrections According to the Surgical Level.

Study Design:Retrospective cohort study.Objectives:Establish simultaneous focal and regional corrective guidelines accounting for reciprocal global and pelvic compensation.Methods:433 ASD patients (mean age 62.9 yrs, 81.3% F) who underwent corrective realignment (minimum L1-pelvis) were included. Sagittal parameters, and segmental and regional Cobb angles were assessed pre and post-op. Virtual postoperative alignment was generated by combining post-op alignment of the fused spine with the pre-op alignment on the unfused thoracic kyphosis and the pre-op pelvic retroversion. Regression models were then generated to predict the relative impact of segmental (L4-L5) and regional (L1-L4) corrections on PT, SVA (virtual), and TPA.Results:Baseline analysis revealed distal (L4-S1) lordosis of 33 ± 15°, flat proximal (L1-L4) lordosis (1.7 ± 17°), and segmental kyphosis from L2-L3 to T10-T11. Post-op, there was no mean change in distal lordosis (L5-S1 decreased by 2°, and L4-L5 increased by 2°), while the more proximal lordosis increased by 18 ± 16°. Regression formulas revealed that Δ10° in distal lordosis resulted in Δ10° in TPA, associated with Δ100 mm in SVA or Δ3° in PT; Δ10° in proximal lordosis yielded Δ5° in TPA associated with Δ50 mm in SVA; and finally Δ10° in thoraco-lumbar junction yielded Δ2.5° in TPA associated with Δ25 mm in SVA and no impact on PT correction.Conclusions:Overall impact of lumbar lordosis restoration is critically determined by location of correction. Distal correction leads to a greater impact on global alignment and pelvic retroversion. More specifically, it can be assumed that 1° L4-S1 lordosis correction produces 1° change in TPA / 10 mm change in SVA and 0.5° in PT.