Independent Risk Factors of Proximal Junctional Kyphosis with Vertebral Fracture After Spinal Long Fusion: Survivorship Analysis of Adult Spinal Deformity Surgery Patients.

OBJECTIVE: This study aimed to identify risk factors for postoperative proximal junctional kyphosis (PJK) with vertebral fracture in adult spinal deformity (ASD) patients. We performed a survival analysis considering various factors, including osteoporosis. METHODS: This single-center retrospective study included 101 ASD patients (mean age: 67.2 years, mean follow-up: 8.1 years). We included patients aged ≥50 years with abnormal radiographic variables undergoing corrective long spinal fusion. The main outcome measure was PJK with vertebral fracture, analyzed based on patient data, radiographic measurements, sagittal parameters, bone mineral density, and osteoporosis medication. RESULTS: PJK occurred in 37.6% of patients, with vertebral fracture type 2 accounting for 65% of these cases. Kaplan-Meier analysis indicated a median PJK-free survival time of 60.7 months. Existing vertebral fracture (grade 1 or higher or grade 2 or higher) was a significant risk factor for PJK with vertebral fracture, with hazard ratios of 4.58 and 5.61, respectively. The onset time of PJK with vertebral fracture was 1.5 months postoperatively, with 44% of these cases occurring within 1 month and 64% within 2 months. CONCLUSIONS: PJK with vertebral fracture affected 25% of ASD patients, emphasizing the importance of osteoporosis evaluation. Existing vertebral fracture emerged as a significant independent risk factor, surpassing bone mineral density. This study provides valuable insights for spine surgeons, highlighting the need to provide osteoporosis treatment and emphasize potential postoperative complications during discussions with patients.

[Analysis of imaging characteristics and effectiveness of cervical spondylotic myelopathy with cervical kyphosis].

Objective: To investigate the imaging characteristics of cervical kyphosis and spinal cord compression in cervical spondylotic myelopathy (CSM) with cervical kyphosis and the influence on effectiveness. Methods: The clinical data of 36 patients with single-segment CSM with cervical kyphosis who were admitted between January 2020 and December 2022 and met the selection criteria were retrospectively analyzed. The patients were divided into 3 groups according to the positional relationship between the kyphosis focal on cervical spine X-ray film and the spinal cord compression point on MRI: the same group (group A, 20 cases, both points were in the same position), the adjacent group (group B, 10 cases, both points were located adjacent to each other), and the separated group (group C, 6 cases, both points were located >1 vertebra away from each other). There was no significant difference between groups ( P>0.05) in baseline data such as gender, age, body mass index, lesion segment, disease duration, and preoperative C 2-7 angle, C 2-7 sagittal vertical axis (C 2-7 SVA), C 7 slope (C 7S), kyphotic Cobb angle, fusion segment height, and Japanese Orthopedic Association (JOA) score. The patients underwent single-segment anterior cervical discectomy with fusion (ACDF). The occurrence of postoperative complications was recorded; preoperatively and at last follow-up, the patients' neurological function was evaluated using the JOA score, and the sagittal parameters (C 2-7 angle, C 2-7 SVA, C 7S, kyphotic Cobb angle, and height of the fused segments) were measured on cervical spine X-ray films and MRI and the correction rate of the cervical kyphosis was calculated; the correlation between changes in cervical sagittal parameters before and after operation and the JOA score improvement rate was analyzed using Pearson correlation analysis. Results: In 36 patients, only 1 case of dysphagia occurred in group A, and the dysphagia symptoms disappeared at 3 days after operation, and the remaining patients had no surgery-related complications during the hospitalization. All patients were followed up 12-42 months, with a mean of 20.1 months; the difference in follow-up time between the groups was not significant ( P>0.05). At last follow-up, all the imaging indicators and JOA scores of patients in the 3 groups were significantly improved when compared with preoperative ones ( P<0.05). The correction rate of cervical kyphosis in group A was significantly better than that in group C, and the improvement rate of JOA score was significantly better than that in groups B and C, all showing significant differences ( P<0.05), and there was no significant difference between the other groups ( P>0.05). The correlation analysis showed that the improvement rate of JOA score was negatively correlated with C 2-7 angle and kyphotic Cobb angle at last follow-up ( r=-0.424, P=0.010; r=-0.573, P<0.001), and positively correlated with the C 7S and correction rate of cervical kyphosis at last follow-up ( r=0.336, P=0.045; r=0.587, P<0.001), and no correlation with the remaining indicators ( P>0.05). Conclusion: There are three main positional relationships between the cervical kyphosis focal and the spinal cord compression point on imaging, and they have different impacts on the effectiveness and sagittal parameters after ACDF, and those with the same position cervical kyphosis focal and spinal cord compression point have the best improvement in effectiveness and sagittal parameters.

Greater cervical kyphosis during flexion increases the risk of kyphotic deformity after laminoplasty in patients with cervical spondylotic myelopathy.

Kyphotic deformity following the loss of cervical lordosis can lead to unfavourable neurological recovery after cervical laminoplasty (CLP); therefore, it is essential to identify its risk factors. Recent studies have demonstrated that the dynamic parameters of the cervical spine, based on baseline flexion/extension radiographs, are highly useful to estimate the loss of cervical lordosis after CLP. However, it remains unclear whether such dynamic parameters can predict kyphotic deformity development after CLP. Hence, the present study aimed to investigate whether the dynamic parameters could predict kyphotic deformity in patients with cervical spondylotic myelopathy (CSM) after CLP. This retrospective study included 165 patients, consisting of 10 and 155 patients with and without cervical kyphosis of C2-C7 angle ≤ -10° at the final follow-up period, respectively. Among the static and dynamic parameters of the cervical spine, greater cervical kyphosis during flexion (fC2-C7 angle) demonstrated the best discrimination between these two cohorts, with an optimal cutoff value of -27.5°. Meanwhile, greater gap range of motion (gROM = flexion ROM - extension ROM ) had the highest ability to predict a loss of ≥ 10° in C2-C7 angle after CLP, with an optimal cutoff value of 28.5°. This study suggests that in patients with CSM, fC2-C7 angle ≤ -25° on baseline radiographs is a potential risk for kyphotic deformity after CLP. In clinical practice, the patients with this criterion (fC2-C7 angle ≤ -25°) along with gROM ≥ 30° are at high risk of developing significant kyphotic deformity after CLP.

Preoperative low Hounsfield units in the lumbar spine are associated with postoperative mechanical complications in adult spinal deformity.

PURPOSE: To determine the most valid bone health parameter to predict mechanical complications (MCs) following surgery for adult spinal deformity (ASD). METHODS: This multicenter study retrospectively examined the records of patients who had undergone fusion of three or more motion segments, including the pelvis, with a minimum two-year follow-up period. Patients with moderate and severe global alignment and proportion scores were included in the study and divided into two groups: those who developed MCs and those who did not. Bone mineral density (BMD) of the lumbar spine and femoral neck was measured using dual-energy X-ray absorptiometry, and Hounsfield units (HUs) were measured in the lumbar spine on computed tomography. Radiographic parameters were evaluated preoperatively, immediately after surgery, and at final follow-up. RESULTS: Of 108 patients, 30 (27.8%) developed MCs, including 26 cases of proximal junctional kyphosis/failure, 2 of distal junctional failure, 6 of rod fracture, and 11 reoperations. HUs were significantly lower in patients who experienced MCs (113.7 ± 41.1) than in those who did not (137.0 ± 46.8; P = 0.02). BMD did not differ significantly between the two groups. The preoperative and two-year postoperative global tilt, as well as the immediately postoperative sagittal vertical axis, were significantly greater in patients who developed MCs than in those who did not (P = 0.02, P < 0.01, and P = 0.01, respectively). CONCLUSION: Patients who experienced MCs following surgery for ASD had lower HUs than those who did not. HUs may therefore be more useful than BMD for predicting MCs following surgery for ASD.

Predictive role of FRAX© for postoperative proximal junctional kyphosis with vertebral fracture after adult spinal deformity surgery.

PURPOSE: To identify risk factors, including FRAX (a tool for assessing osteoporosis) scores, for development of proximal junctional kyphosis (PJK), defined as Type 2 in the Yagi-Boachie classification (bone failure), with vertebral fracture (VF) after surgery for symptomatic adult spinal deformity. METHODS: This was a retrospective, single institution study of 127 adults who had undergone corrective long spinal fusion of six or more spinal segments for spinal deformity and been followed up for at least 2 years. The main outcome was postoperative development of PJK with VF. Possible predictors of this outcome studied included age at surgery, BMI, selected radiographic measurements, bone mineral density, and 10-year probability of major osteoporotic fracture (MOF) as determined by FRAX. We also analyzed use of medications for osteoporosis. Associations between the selected variables and PJK with VF were assessed by the Mann-Whitney, Fishers exact, and Wilcoxon signed-rank tests, and Kaplan-Meier analysis, as indicated. RESULTS: Forty patients (31.5%) developed PJK with VF postoperatively,73% of them within 6 months of surgery. Statistical analysis of the selected variables found that only a preoperative estimate by FRAX of a > 15% risk of MOF within 10 years, pelvic tilt > 30° at first standing postoperatively and lower instrumented level (fusion terminating at the pelvis) were significantly associated with development of PJK with VF. CONCLUSION: Preoperative assessment of severity of osteoporosis using FRAX provides an accurate estimate of risk of postoperative PJK with VF after surgery for adult spinal deformity.

Post-tubercular Lumbosacral Kyphotic Deformity in a 11-Year-Old Child: A Case Report.

CASE: An 11-year-old girl with intact neurology presented with a lumbosacral kyphotic deformity due to healed tuberculosis. Radiological imaging showed sagittal balanced spine with compensatory thoracic lordosis and cervical kyphosis. She underwent L4 and L5 posterior vertebral column resection (PVCR) with posterior instrumentation from L2 to pelvis. The patient demonstrated immediate correction of compensatory curves postoperatively. At 3-year follow-up, she returned to her activities of daily living with Oswestry Disability Index and Scoliosis Research Society scores of 12 and 4.8% respectively. CONCLUSION: Pediatric post-tubercular deformities in the lumbosacral region are rare. They can cause secondary changes in other regions, such as the loss of thoracic kyphosis or cervical lordosis. These deformities should be addressed at an early age to prevent structural changes in compensatory curves.

Non-traumatic complete cervical spine dislocation with severe fixed kyphosis: successful multidisciplinary approach to a challenging case.

BACKGROUND: To our knowledge, there is no previous report in the literature of non-traumatic neglected complete cervical spine dislocation characterized by anterior spondyloptosis of C4, extreme head drop, and irreducible cervicothoracic kyphosis. CASE PRESENTATION: We report the case of a 33-year-old Caucasian man with a 17-year history of severe immune polymyositis and regular physiotherapy who presented with severe non-reducible kyphosis of the cervicothoracic junction and progressive tetraparesia for several weeks after a physiotherapy session. Radiographs, computed tomography, and magnetic resonance imaging revealed a complete dislocation at the C4-C5 level, with C4 spondyloptosis, kyphotic angulation, spinal cord compression, and severe myelopathy. Due to recent worsening of neurological symptoms, an invasive treatment strategy was indicated. The patient's neurological status and spinal deformity greatly complicated the anesthetic and surgical management, which was planned after extensive multidisciplinary discussion and relied on close collaboration between the orthopedic surgeon and the anesthetist. Regarding anesthesia, difficult airway access was expected due to severe cervical angulation, limited mouth opening, and thyromental distance, with high risk of difficult ventilation and intubation. Patient management was further complicated by a theoretical risk of neurogenic shock, motor and sensory deterioration, instability due to position changes during surgery, and postoperative respiratory failure. Regarding surgery, a multistage approach was carefully planned. After a failed attempt at closed reduction, a three-stage surgical procedure was performed to reduce displacement and stabilize the spine, resulting in correct spinal realignment and fixation. Progressive complete neurological recovery was observed. CONCLUSION: This case illustrates the successful management of a critical situation based on a multidisciplinary collaboration involving radiologists, anesthesiologists, and spine surgeons.

Percutaneous kyphoplasty through unilateral puncture on the convex side for the treatment of painful osteoporotic vertebral compression fracture with scoliosis.

PURPOSE: To assess the clinical safety, accuracy, and efficacy of percutaneous kyphoplasty (PKP) surgery using an enhanced method of unilateral puncture on the convex side for the treatment of painful osteoporotic vertebral compression fractures (P-OVCF) with scoliosis. METHODS: Clinical and radiographic data of P-OVCF patients with scoliosis who underwent PKP via unilateral puncture on the convex side from January 2018 to December 2021 were retrospectively analyzed. This technique's detailed surgical steps and tips were described. The local kyphosis angle (LKA), scoliosis Cobb angle (SCA), and local scoliosis Cobb angle (LSCA) were measured using X-ray and compared at pre-operation, post-operation, and the last follow-up. The width of pedicle (POW), inner inclination angle (IIA), lateral distance (LD), and puncture course length (PCL) were measured on the axial computed tomography image and compared between two sides. Postoperative computed tomography was employed to evaluate the condition of cement distribution and puncture. Clinical outcomes were evaluated using the Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) for back pain (BP). RESULTS: Thirty-six patients, 23 women and 13 men, with an average age of 76.31 ± 6.28 years were monitored for 17.69 ± 4.70 months. The median surgical duration of single vertebrae was 35 min. The volume of bone cement for single vertebrae was 3.81 ± 0.87 ml and the proportion of sufficient cement distribution of the patients was 97.22. LKA was considerably improved from pre-operation to post-operation and sustained at the last follow-up. SCA and LSCA were not significantly modified between these three-time points. IIA, PCL, and LD were lower on the convex side than on the concave side. POW was considerably wider on the convex side. The ODI and VAS-BP scores were significantly improved after surgery and sustained during the follow-up. CONCLUSIONS: Combining with the proper assessment of the pre-injured life status of patients, PKP surgery using unilateral puncture on the convex side for the treatment of P-OVCF with scoliosis can achieve safe, excellent clinical, and radiographic outcomes.

Aggressive vertebral hemangiomas contain no adipose tissue resulting in thoracic spine kyphosis: A case report.

RATIONALE: Aggressive vertebral hemangiomas (AVHs) destroy continuous vertebral bodies and intervertebral discs and resulting in spinal kyphosis is extremely rare. The very aggressive behavior was attributable to its significant vascular component and contained no adipose tissue. PATIENT CONCERNS: We report a case of thoracic spine kyphosis of AVHs with multiple vertebral bodies and intervertebral disc destruction in a 45-year-old woman. DIAGNOSES: Based on the imaging studies, the patient underwent surgical removal of this lesion and spinal reconstruction. Histopathology consistent with vertebral hemangioma and contained no adipose. INTERVENTIONS: The patient underwent surgical removal of the lesion and spinal reconstruction. After subperiosteal dissection of the paraspinal muscles and exposure of the laminae, the laminae of the T5-7 vertebrae were removed and exposing the lesion. The lesion was soft and showed cystic changes, completely curetted and autogenous bone was implanted. Vertebroplasty was performed through T3-T9 pedicles bilaterally. Pedicle screw fixation was performed for segmental fixation and fusion. OUTCOMES: After 9 days of operation, the incision healed cleanly and free of pain. She was discharged in good general condition. The patient remained asymptomatic after follow-up 6 months of postoperative. LESSONS: AVHs destroy multiple vertebral bodies and intervertebral discs and resulting in spinal kyphosis is extremely rare.

Simplified S1 vertebral bone quality score independently predicts proximal junctional kyphosis after surgery for degenerative lumbar scoliosis.

OBJECTIVE: Our study aimed to assess the effectiveness of the simplified S1 vertebral bone quality (VBQ) score in predicting the incidence of proximal junctional kyphosis (PJK) after surgery for degenerative lumbar scoliosis (DLS). METHODS: We reviewed 122 patients with DLS who underwent posterior lumbar decompression and long-segment fusion surgery in our hospital from January 2016 to December 2020. The patients were classified into PJK group and non-PJK group. S1 VBQ scores are determined by signal intensity measurements taken from the mid-sagittal plane of T1-weighted non-contrast MRI. Logistic regression analysis was used to identify factors associated with PJK. Receiver-operating characteristic curve (ROC) analysis was used to evaluate the value of S1 VBQ score in predicting pedicle PJK after DLS. RESULTS: 122 DLS patients (90 females and 32 males) met the inclusion criteria. In addition, 27 patients (22.13%) had PJK at the time of last follow-up. VBQ was higher in PJK patients than non-PJK patients (3.58 ± 0.67 vs. 3.08 ± 0.54, p < 0.001). Preoperatively, patients in the PJK group had a greater TLK than those in the non-PJK group (20.00 ± 6.22 vs. 16.86 ± 5.38, p = 0.011). After surgery, patients in the PJK group had greater TLK (p < 0.001) and PJA (p < 0.001) compared with the non-PJK group. At final FU, patients in the PJK group had greater TK (p = 0.002), TLK (p < 0.001), SVA (p < 0.001), and PJA (p < 0.001) than patients in the non-PJK group (Table 4). In multivariate logistic regression analysis, higher VBQ score (OR 4.565, 95% CI 1.43-14.568, p = 0.010), advanced age (OR 1.119, 95% CI 1.021-1.227, p = 0.016), and larger TLK (OR 1.191, 95% CI 1.041-1.362, p = 0.011) were significant predictors of postoperative PJK in patients with DLS (Table 6). A statistically significant positive correlation existed between VBQ score and PJA change (r = 0.370, p < 0.001). We created ROC curves for VBQ scores as predictors of PJK with a diagnostic accuracy of 72.1% (95% CI 60.15-82.9%.The ideal limit for the VBQ score was 3.205 (sensitivity: 77.8%, specificity: 81.4%). CONCLUSION: To the best of our knowledge, this is the first study to evaluate the effectiveness of the S1 VBQ score in predicting postoperative PJK in DLS. Our study included major risk factors and found that S1 VBQ score was a significant predictor of PJK in patients undergoing DLS surgery. The higher the S1 VBQ score, the higher the probability of PJK.

Is the Child Opportunity Index a Factor in Surgical Outcomes for Adolescent Idiopathic Scoliosis?

BACKGROUND: Low socioeconomic status (SES) has been previously associated with delays in orthopaedic care. However, it is unclear how SES impacts patients with adolescent idiopathic scoliosis (AIS), particularly regarding preoperative major coronal curve angle or surgical outcomes. Utilizing the Child Opportunity Index (COI)-an address-driven measure of pediatric education, health/environment, and SES-we investigated whether COI is associated with differences in preoperative scoliosis magnitude, age at surgery, and AIS surgical outcomes. METHODS: Consecutive patients with AIS surgically treated at a single center from 2011 to 2017 were reviewed. COI was calculated by inserting a patient's home address into the nationally available COI database to derive a COI value. COI is scored from 0.0 to 100.0 (0.0 is lowest, 100.0 is highest). Specifically, COI is categorized as very low (<20.0), low (20 to 39.9), moderate (40 to 59.9), high (60 to 79.9), and very high (≥80). Those without addresses were excluded. Patients without proper radiographs to assess curve correction were also excluded. A COI threshold of 60.0 was used to separate patients into a low (<60.0) or high COI ( ) group based on published COI guidelines. Outcomes, including preoperative curve magnitude, age at surgery, percentage curve correction, operative time (OT), intraoperative estimated blood loss per level fused, length of stay, and complications, were compared across groups. Pearson correlation analysis was used to assess correlations between COI and preoperative curve magnitude, as well as age. RESULTS: Four hundred four patients were included in the study, and 263 had 2-year follow-up data. Patients were an average age of 14.9 years old (range: 11.2 to 19.8), had a median COI of 76 (range: 4 to 100), and had a mean preoperative major curve angle of 59 degrees (range: 36 to 93). COI was significantly higher for white patients compared with non-white (80.0 vs 40.0, P < 0.001), and higher for non-Hispanic individuals (79.0 vs 15.0, P < 0.001). Patients with Low COI were associated with a lower OT per level fused ( P = 0.003) and decreased postoperative complication risk ( P = 0.02). COI was not associated with preoperative major coronal curve angle, age at surgery, or any other surgical outcomes. CONCLUSION: COI was significantly lower for non-white patients and those of Hispanic ethnicity. Patients from low COI backgrounds achieved similar surgical results as those from high COI addresses and had a decreased OT per level fused and complication incidence, though the clinical significance of these differences is unknown. Future prospective studies are needed to determine whether these findings are reproducible across other states and health systems. LEVEL OF EVIDENCE: Level III-prognostic study.

Spinal Manifestations of Skeletal Dysplasia: A Practical Guide for Clinical Diagnosis.

Skeletal dysplasias are a group of genetic conditions defined by atypical bone or cartilage growth and development. Skeletal abnormalities include short stature, limb deformity, joint contracture, and spinal deformity. Over 90% of disorders have a known genetic mutation that can definitively determine the diagnosis. As patients may present with a primary spinal concern, a careful clinical and radiographic evaluation can allow the physician to develop a working diagnosis to guide additional evaluation. Spinal manifestations include scoliosis and kyphoscoliosis, cervical instability, cervical kyphosis, thoracolumbar kyphosis, spinal stenosis, and atypical vertebral body morphology. An understanding of the affected conditions, prevalence, and natural history of these radiographic findings aids the orthopaedic surgeon in establishing a diagnosis and guides appropriate orthopaedic care.

Transpedicular injection of rhBMP-2 with ß-tricalcium phosphate to reduce the proximal junctional kyphosis after adult spinal deformity correction: preliminary study.

The aim of this preliminary study was to assess the impact of injecting recombinant human bone morphogenetic protein-2 (rhBMP-2) with ß-tricalcium phosphate (ß-TCP) carrier into the uppermost instrumented vertebra (UIV) during surgery to prevent the development of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF). The 25 patients from study group had received 0.5 mg rhBMP-2 mixed with 1.5 g ß-TCP paste injection into the UIV during surgery. The control group consisted of 75 patients who underwent surgery immediately before the start of the study. The incidences of PJK and PJF were analyzed as primary outcomes. Spinopelvic parameters and patient-reported outcomes were analyzed as secondary outcomes. Hounsfield unit (HU) measurements were performed to confirm the effect of rhBMP-2 with ß-TCP on bone formation at preoperative and postoperative at computed tomography. PJK and PJF was more occurred in control group than study group (p = 0.02, 0.29, respectively). The HU of the UIV significantly increased 6 months after surgery. And the increment at the UIV was also significantly greater than that at the UIV-1 6 months after surgery. Injection of rhBMP-2 with ß-TCP into the UIV reduced PJK and PJF rates 6 months after surgery with new bone formation.

Effect of high disease activity on spinal sagittal malalignment in patients with rheumatoid arthritis.

OBJECTIVE: Atlantoaxial subluxation is a well-known serious complication encountered in patients with rheumatoid arthritis (RA). However, it is unknown whether RA affects global spinal alignment. The aim of this study was to investigate whether high disease activity in patients with RA exacerbates spinal sagittal malalignment. METHODS: The authors included 197 patients with RA who were followed up for > 2 years; standing spinal radiographs were obtained in all patients. Patients were divided into persistent moderate disease activity/high disease activity (pMDA/HDA; n = 64) and non-pMDA/HDA (n = 133) groups based on the disease activity at follow-up visits. Radiographic parameters assessed included pelvic incidence, pelvic tilt (PT), lumbar lordosis (LL), thoracic kyphosis (TK), and C7 sagittal vertical axis (SVA). RESULTS: Over an average 5-year follow-up, increases in SVA, PT, and TK and a decrease in LL were observed. The pMDA/HDA group had a larger increase in PT and a higher incidence of vertebral fractures than the non-pMDA/HDA group. After adjusting variables using propensity score matching, the authors still found a higher rate of increase in PT (0.79°/year vs 0.01°/year, p = 0.001) in the pMDA/HDA group than in the non-pMDA/HDA group. This trend remained consistent even when patients who developed vertebral fractures were excluded. CONCLUSIONS: Spinal sagittal alignment deteriorates over time in patients with RA. High disease activity in RA exacerbates spinal deformity.

Distal Junctional Failures in Degenerative Thoracolumbar Hyperkyphosis.

OBJECTIVE: Degenerative thoracolumbar hyperkyphosis (DTH) is a disease that negatively affects individual health and requires surgical intervention, yet the ideal surgical approach and complications, especially distal junctional failures (DJF), remain poorly understood. This study aims to investigate DJF in DTH and to identify the risk factors for DJF so that we can improve surgical decision-making, and advance our knowledge in the field of spinal surgery to enhance patient outcomes. METHODS: This study retrospectively reviewed 78 cases (late osteoporotic vertebral compression fracture [OVCF], 51; Scheuermann's kyphosis [SK], 17; and degenerative disc diseases [DDD], 10) who underwent corrective surgery in our institute from 2008 to 2019. Clinical outcomes were assessed using health-related quality of life (HRQOL) measures, including the visual analogue scale (VAS) scores for back and leg pain, the Oswestry disability index (ODI), and the Japanese Orthopaedic Association (JOA) scoring system. Multiple radiographic parameters, such as global kyphosis (GK) and thoracolumbar kyphosis (TLK), were assessed to determine radiographic outcomes. Multivariate logistic regression analysis was employed to identify the risk factors associated with DJF. RESULTS: HRQOL improved, and GK, TLK decreased at the final follow-up, with a correction rate of 67.7% and 68.5%, respectively. DJF was found in 13 of 78 cases (16.7%), two cases had wedging in the disc (L3-4) below the instrumentation, one case had a fracture of the lowest instrumented vertebrae (LIV), one case had osteoporotic fracture below the fixation, nine cases had pull-out or loosening of the screws at the LIV and three cases (23.1%) required revision surgery. The DJF group had older age, lower computed tomography Hounsfield unit (CT HU), longer follow-up, more blood loss, greater preoperative sagittal vertical axis (SVA), and poorer postoperative JOA and VAS scores (back). The change in TLK level was larger in the non-DJF group. Post-sagittal stable vertebrae (SSV) moved cranially compared with pre-SSV. CONCLUSION: Age, CT HU, length of follow-up, estimated blood loss, and preoperative SVA were independent risk factors for DJF. We recommend fixation of the two vertebrae below the apex vertebrae for DTH to minimize surgical trauma.

T1 Pedicle Subtraction Osteotomy With Subaxial Cervical Pedicle Screw Fixation.

Patients suffering from ankylosing spondylitis are not only predisposed to the development of rigid cervicothoracic deformities but are also at an increased risk of cervical fractures. Deformity correction and stabilization are particularly challenging in this patient population due to the brittle bone quality and low bone mineral density. Thoracic pedicle subtraction osteotomy is a workhorse approach for the correction of focal severe kyphotic deformity with lower complication rates than 3-column osteotomy. Successful execution of an upper thoracic PSO requires careful presurgical planning as well as anticipation of the patient's postoperative needs. Here, we describe the use of a T1 PSO in the correction of a rigid cervicothoracic chin-on-chest deformity in a patient with AS. The risk of implant failure was reduced by the use of a multi-rod construct, navigated cervical pedicle screws, and dual-pitched thoracic pedicle screws.

Prevalence, Features, and Predictive Factors of Spontaneous Spinal Arthrodesis in Posttraumatic Thoracolumbar Kyphosis.

OBJECTIVE: Spontaneous spinal arthrodesis (SSA) is a phenomenon of spontaneous fusion, and SSA is not rare in posttraumatic thoracolumbar kyphosis (PTK). However, few reports have focused on SSA in patients with PTK. The objective of this study was to investigate the prevalence, features, and predictive factors of SSA in patients with PTK. METHODS: In this retrospective study, 70 patients with PTK were included. Data on the clinical and radiologic parameters were obtained and evaluated. According to whether there was SSA or not, patients were divided into an SSA group (n = 45) or a non-SSA group (n = 25). A binary logistic regression analysis was used to identify the predictive factors for SSA. RESULTS: The incidence of SSA in PTK was 64%. Among 45 patients with PTK with SSA, SSA was present as a solid bridging anterior osteophyte along the vertebral bodies in 11 patients, posterior contiguous bony growth through the facet joints bilaterally in 13 patients, bony formation in both anterior and posterior elements in 18 patients, and direct contiguous bony formation from the injured vertebral body to the adjacent one in 3 patients. Patients with longer disease duration, larger local Cobb angle, and anterior wall height loss (AWHL) ratio of injured vertebral body, and less kyphosis flexibility index were significantly more likely to develop SSA. The parameter of AWHL remained significant in binary logistic regression analysis. CONCLUSIONS: SSA in PTK was common, and the SSA sign presented in various patterns, which might have implications for surgical decisions. AWHL was the independent predictor for SSA.

Morphological analysis of isolated hemivertebra: radiographic manifestations related to the severity of congenital scoliosis.

PURPOSE: The natural history of congenital scoliosis (CS) caused by hemivertebra varies greatly. This study aimed to explore the association between the morphology of hemivertebra and the severity of CS, since the diagnosis of the hemivertebra. METHODS: Patients with isolated (single fully segmented) hemivertebra were enrolled. The degree and progression of deformity were compared by three morphological parameters of hemivertebra, comprising whether the width of hemivertebra extends across the central vertical line of lower adjacent vertebra (midline); the lateral height ratio (LHR, lateral height of hemivertebra× 2/(lateral height of HV-1 plus HV + 1) with the cut-point being 0.9; and the sagittal position of hemivertebra that was divided into the lateral and posterolateral group. RESULTS: In total, 156 patients (mean age 9.7 ± 6.2 years, 81 males) were enrolled. The number of thoracic, thoracolumbar (T12/13-L1), and lumbar hemivertebrae were 63, 41, and 52, respectively. Hemivertebrae across the midline had larger scoliosis and kyphosis (58.3 ± 20.6° vs. 42.8 ± 15.0°, P <  0.001; 45.1 ± 32.5° vs. 29.5 ± 25.7°, P = 0.013, respectively). Hemivertebrae with LHR ≥0.9 was associated with larger scoliosis (55.7 ± 20.6° vs. 41.4 ± 13.3°, P <  0.001). Larger scoliosis and kyphosis were observed in posterolateral hemivertebrae (54.4 ± 21.0° vs. 44.4 ± 15.6°, P = 0.026; 51.4 ± 31.5° vs. 20.6 ± 17.1°, P <  0.001, respectively). Co-occurrence of more than one of the three positive parameters above indicated higher annual progression (5.0 ± 2.2° vs. 3.3 ± 1.3°, P <  0.001). CONCLUSION: Three positive parameters, width across the midline, LHR ≥0.9, and posterolateral position were associated with a more severe deformity in patients with isolated hemivertebra. Hemivertebrae with more than one positive parameter may cause progressive deformity, and thus need prompt surgery. LEVEL OF EVIDENCE: Prognostic, level IV.