Effectiveness of Pulsed Radiofrequency Based on the Minimum Clinically Important Differences in Lumbar Spine-Related Pain in Patients without Recent Lumbar Surgery.

BACKGROUND: Pulsed radiofrequency (PRF) has been used for treatment of chronic pain in several body regions, including axial and radicular pain. However, a limited number of reports have specifically demonstrated the effectiveness of PRF for spine-related pain among nonsurgical patients. Therefore, we evaluated the effectiveness of PRF for lumbar spine-associated pain in patients without recent spine surgery, and identified the factors associated with clinically meaningful improvement in pain and quality of life. METHODS: Records of patients who underwent PRF for lumbar spine-related pain and were followed up over 6 months between 2019 and 2022 were retrospectively reviewed. Data on patient demographics, interventional factors, and patient-reported outcomes, such as the numerical rating scale (NRS) and EuroQol Group 5 Dimension 5-Level Quality of Life (EQ-5D-5 L), were collected. Patients were divided into 2 groups (responsive and nonresponsive) based on the NRS and EQ-5D-5 L scores using the previously reported minimal clinically important difference values of the NRS and EQ-5D-5 L as cutoffs, and baseline parameters were compared to identify contributing factors. RESULTS: Forty-three patients were included in the final analysis. The NRS and EQ-5D-5 L scores improved significantly at 3 and 6 months after PRF compared to baseline. The groups with NRS and EQ-5D-5 L improvement over the minimal clinically important difference had significantly higher baseline NRS and EQ-5D-5 L scores. CONCLUSIONS: Our results demonstrated that PRF improved pain and patient-reported outcomes for spine-related pain for at least 6 months in our patient cohort. PRF may be a good option for treating lumbar spine-related issues, even with severe pain and/or dysfunction.

Distal junctional failure after corrective surgery without pelvic fixation for thoracolumbar junctional kyphosis due to osteoporotic vertebral fracture.

BACKGROUND: Thoracolumbar junctional kyphosis (TLJK) due to osteoporotic vertebral fracture (OVF) negatively impacts patients' quality of life. The necessity of pelvic fixation in corrective surgery for TLJK due to OVF remains controversial. This study aimed to: 1) evaluate the surgical outcomes of major corrective surgery for thoracolumbar junctional kyphosis due to osteoporotic vertebral fracture, and 2) identify the risk factors for distal junctional failure to identify potential candidates for pelvic fixation. METHODS: Patients who underwent surgical correction (fixed TLJK>40°, OVF located at T11-L2, the lowermost instrumented vertebra at or above L5) were included. Sagittal vertical axis, pelvic tilt, pelvic incidence, thoracic kyphosis, lumbar lordosis (L1-S1), local kyphosis, and lower lumbar lordosis (L4-S1) were assessed. Proximal and distal junctional kyphosis (P/DJK) and failures (P/DJF) were evaluated. Pre/postoperative spinopelvic parameters were compared between DJF and non-DJF patients. RESULTS: Thirty-one patients (mean age: 72.3 ± 7.9 years) were included. PJK was observed in five patients (16.1%), while DJK in 11 (35.5%). Twelve cases (38.7%) were categorized as failure. Among the patients with PJK, there was only one patient (20%) categorized as PJF and required an additional surgery. Contrary, all of eleven patients with DJK were categorized as DJF, among whom six (54.5%) required additional surgery for pelvic fixation. In comparisons between DJF and non-DJF patients, there was no significant difference in pre/postoperative LK (pre/post, p = 0.725, p = 0.950). However, statistically significant differences were observed in the following preoperative alignment parameters: SVA (p = 0.014), LL (p = 0.001), LLL (p = 0.006), PT (p = 0.003), and PI-LL (p < 0.001). CONCLUSIONS: Spinopelvic parameters, which represent the compensatory function of lumbar hyperlordosis and pelvic retroversion, have notable impacts on surgical outcomes in correction surgery for TLJK due to OVF. Surgeons should consider each patient's compensatory function when choosing a surgical approach.

Atypical femoral fracture mimicking lumbar radiculopathy in two patients taking bisphosphonate long-term: A case report.

BACKGROUND: Atypical femoral fracture (AFF) is a rare complication in patients with osteoporosis undergoing long-term bisphosphonate therapy. The most common symptom of incomplete AFF is nonspecific thigh pain, which is often difficult to distinguish from other causes. CASE PRESENTATION: We present two cases of AFF misdiagnosed as lumbar radiculopathy. Both patients visited our hospital for thigh pain, and in both cases the findings of lumbar spine magnetic resonance imaging showed substantial nerve compression. These patients had been treated for lumbar radiculopathy, but localized symptoms became conspicuous and femoral radiographs revealed complete AFF. The initial radiographs were reviewed retrospectively and revealed slight lateral cortical thickening in the affected femur, denoting a missed incomplete AFF. Internal fixation with intramedullary nails was performed. CONCLUSIONS: AFF may mimic lumbar radiculopathy. Therefore, clinicians should consider AFF as a differential diagnosis in older patients with lumbar canal stenosis who are undergoing long-term bisphosphonate therapy and present with thigh pain.

Dropped Head Syndrome Caused by Thoracolumbar Deformity: A Report of 3 Cases.

CASE: We present 3 patients with dropped head syndrome (DHS) caused by thoracolumbar kyphotic deformity who were successfully treated with thoracolumbar corrective surgery only. After the surgery, their symptoms, neck pain, and horizontal gaze difficulty disappeared, and cervical kyphotic alignment was improved indirectly. At the final follow-up, the whole spinal alignment was maintained, and there was no recurrence of symptoms. CONCLUSION: Surgeons should consider thoracolumbar spine deformity as the possible primary cause of typical DHS symptoms and recognize that thoracolumbar corrective surgery is an effective method for treating DHS patients with thoracolumbar deformity.

Comparison of pedicle screw placement accuracy between two types of imaging support (Artis Zeego versus two-dimensional fluoroscopy): a cross-sectional observational study.

BACKGROUND: The pedicle screw system is widely used in spine surgery, and it provides rigid fixation and leads to successful subsequent deformity correction and bony fusion. The standard imaging technique for pedicle screw insertion is two-dimensional images obtained from C-arm-type X-ray fluoroscopy. Artis Zeego is an emerging intraoperative imaging technique that can provide conventional two-dimensional fluoroscopic images and rapid three-dimensional fluoroscopic computed tomography reconstruction imaging. The aim of this study is to compare the insertion accuracies of PS placement using Artis Zeego and conventional 2D X-ray fluoroscopy. METHODS: In this study, we retrospectively reviewed the postoperative images of thoracolumbar fusion patients who underwent surgery using pedicle screws between 2013 and 2018. Pedicle screw malplacement was assessed using a four-grade classification by Rao et al. Misplacement rates were compared between pedicle screws assisted with Artis Zeego and two-dimensional fluoroscopy. RESULTS: A total of 1107 pedicle screws in 153 patients were inserted using Artis Zeego, and 427 pedicle screws in 80 patients were inserted using fluoroscopy. The overall perforation rate was 4.2% (46 perforations of 1106 pedicle screws) in the Artis Zeego group and 7.7% (33 perforations of 427 pedicle screws) in the fluoroscopy group. In the Artis Zeego group, 43 (3.9%) screws were classified as grade 1, and three (0.3%) screws were classified as grade 2. In the fluoroscopy group, 21 (4.9%) screws were classified as grade 1, 10 (2.3%) screws were classified as grade 2, and 2 (0.5%) screws were classified as grade 3. The use of Artis Zeego was associated with a significantly lower screw malplacement rate than was the use of fluoroscopy (p < 0.001). CONCLUSIONS: Our results demonstrated that pedicle screw placement with Artis Zeego was associated with a lower malplacement rate than was conventional two-dimensional fluoroscopy. No severe malplacement was observed in the Artis Zeego group. Thus, Artis Zeego could be a good option for improving pedicle screw accuracy.

Radiological features of cervical spine in dropped head syndrome: a matched case-control study.

PURPOSE: Dropped head syndrome (DHS) is presumably caused by focal myopathy in the cervical posterior muscles; however, distinguishable radiological features of the cervical spine in DHS remain unidentified. This study investigated the radiological features of the cervical spine in dropped head syndrome. METHODS: The records of DHS patients and age- and sex-matched cervical spondylotic myelopathy (CSM) patients were reviewed. Cervical spinal parameters (C2-7, C2-4, and C5-7 angles) were assessed on lateral cervical spine radiographs. Quantitative radiographic evaluation of cervical spine degeneration was performed using the cervical degenerative index (CDI), which consists of four elements: disk space narrowing (DSN), endplate sclerosis, osteophyte formation, and listhesis. RESULTS: Forty-one DHS patients were included. Statistically significant differences were noted between the upper and lower cervical spine in the sagittal angle parameters on the neutral, flexion, and extension radiographs in DHS group, whereas no significant differences were observed in CSM group. CDI comparison showed significantly higher scores of DSN in C3/4, C4/5, C5/6, and C6/7; sclerosis in C5/6 and C6/7; and osteophyte formation in C4/5, C5/6, and C6/7 in DHS group than in CSM group. Comparison of listhesis scores revealed significant differences in the upper levels of the cervical spine (C2/3, C3/4, and C4/5) between two groups. CONCLUSION: Our results demonstrated that the characteristic radiological features in the cervical spine of DHS include lower-level dominant severe degenerative change and upper-level dominant spondylolisthesis. These findings suggest that degenerative changes in the cervical spine may also play a role in the onset and progression of DHS.

Unexpected Complications after Corrective Spinal Fusion Surgery for Adult Spinal Deformity with Severe Hip Contracture.

INTRODUCTION: In cases with markedly decreased hip function, patients predominantly utilize spine movement while standing up to compensate for the hip malfunction. However, spinal fusion surgeries might lead to the disruption of this compensatory mechanism, resulting in difficulties in walking and standing up as well as proximal junctional failure (PJF) due to the excessive stress on the spine caused by the pendulum-like motion needed for standing up. Hence, in patients with severe hip pathology, surgeons should be cautious about the indication for spinal fusion, which inevitably affects spinal mobility. This is the first report presenting a case that supports the aforementioned theory. CASE REPORT: In this study, we report the case of a 76-year-old Japanese woman who underwent corrective spinal fusion surgery for spinal scoliosis secondary to hip contracture. The patient exhibited post-operative complications, such as unexpected difficulty in walking and standing up and PJF. The patient underwent a revision spinal surgery with an extension of spinal fusion for PJF and muscle release around the hip for hip contracture which resulted in improved walking and standing movements with no reports of pain. CONCLUSION: Spinal fusion surgeries performed on patients with severe hip pathology could cause early PJFs and unexpected decline in activities of daily living. Patients with such risks often do not complain of hip symptoms before spinal correction surgery. Surgeons should routinely evaluate hip joints and be cautious about the indication for spinal fusion which inevitably affects spinal mobility.

Analysis of the subsequent treatment of osteoporosis by transitioning from bisphosphonates to denosumab, using quantitative computed tomography: A prospective cohort study.

PURPOSE: Denosumab reduces bone resorption and improves bone mineral density (BMD). Studies have analyzed subsequent treatment transitioning from bisphosphonates to denosumab based on dual-energy X-ray absorptiometry scanning (DXA). Quantitative computed tomography (QCT) can help assess cortical and trabecular bones separately in three dimensions without the interference of the surrounding osteophytes. In the present study, we analyzed the subsequent treatment transition from bisphosphonates to denosumab using QCT. METHODS: Thirty-two patients with postmenopausal osteoporosis to be treated with denosumab were recruited. The patients were divided into two groups (15 prior bisphosphonate and 17 naïve) based on their previous treatment. BMD of the lumbar spine and hip were evaluated by DXA and QCT at baseline and 12 months following denosumab treatment. RESULTS: The percentage change in volumetric BMD assessed by QCT at 12 months significantly improved in the naïve group compared with that in the prior bisphosphonate group. The region-specific assessment of femur at 12 months revealed that denosumab treatment was effective in both cortical and trabecular bones except the trabecular region of the prior bisphosphonate group. CONCLUSION: Our study suggests that although denosumab treatment was useful in both treatment groups, BMD increase was significantly higher in the naïve group than in the prior-bisphosphonate group. Interestingly, in the prior-bisphosphonate group, denosumab treatment was more effective in the cortical region than the trabecular region. Our study offers insights into the subsequent treatment and permits greater confidence when switching to denosumab from bisphosphonates.

The effect of denosumab on pedicle screw fixation: a prospective 2-year longitudinal study using finite element analysis.

BACKGROUND: Pedicle screw loosening is a major complication following spinal fixation associated with osteoporosis in elderly. However, denosumab is a promising treatment in patients with osteoporosis. The effect of denosumab on pedicle screw fixation is unknown. Therefore, we investigated whether denosumab treatment improves pedicle screw fixation in elderly patients with osteoporosis. METHODS: This was a 2-year prospective open-label study. From February 2015 to January 2016, we included 21 patients with postmenopausal osteoporosis who received initial denosumab treatment. At baseline, 12 months, and 24 months, we measured volumetric bone mineral density (BMD) using quantitative computed tomography (QCT) and performed CT-based finite element analysis (FEA). Finite element models of L4 vertebrae were created to analyze the bone strength and screw fixation. RESULTS: BMD increased with denosumab treatment. FEA revealed that both pullout strength of pedicle screws and compression force of the vertebra increased significantly at 12 and 24 months following denosumab treatment. Notably, pullout strength showed a stronger correlation with three-dimensional volumetric BMD around pedicle screw placement assessed by QCT (r = 0.83, at 24 months) than with two-dimensional areal BMD assessed by dual energy X-ray absorptiometry (r = 0.35, at 24 months). CONCLUSION: To our knowledge, this is the first study to reveal that denosumab treatment achieved strong pedicle screw fixation with an increase in BMD around the screw assessed by QCT and FEA; therefore, denosumab could be useful for osteoporosis treatment during spinal surgery in elderly patients with osteoporosis.

Relationship Between Muscle Mass of the Lower Limbs and Falls Caused by Spinal Misalignment in Women Aged 70 Years: A Retrospective Study.

STUDY DESIGN: This retrospective study was conducted from 2015 to 2016 at the osteoporosis outpatient clinic of Showa University School of Medicine. OBJECTIVE: This study aimed to investigate the association between lower-limb muscle mass and spinal misalignment-related falls in elderly women. SUMMARY OF BACKGROUND DATA: Poor spinal alignment affects gait and balance, reducing the quality of life. Negative correlations between age-associated skeletal muscle loss and spinal sagittal alignment have been reported. MATERIALS AND METHODS: This study included 127 women with osteoporosis aged more than 70 years. The correlation between lower-limb skeletal muscle index (SMI) and sagittal vertical axis (SVA) was calculated using radiographic measurements. Spinopelvic parameters, including SVA, sacral slope, pelvic tilt (PT), pelvic incidence, and lumbar lordosis, were measured. Lower-limb SMI was measured using whole-body dual-energy x-ray absorptiometry and calculated as SMI=nonfat mass/height2. The balance function was evaluated using the single-leg stance test. Data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests; significance level was set at P<0.05. Bivariate and multivariate logistic regression analyses were used to determine correlations. RESULTS: Participants were classified into the balance and mismatch groups on the basis of a threshold SVA value of 50 mm. The groups did not differ significantly in age, height, weight, pelvic incidence, or sacral slope. Lumbar lordosis significantly decreased and PT and lower-limb SMI significantly increased in the mismatch group compared with the balance group. Lower-limb SMI was significantly correlated with increased SVA in bivariate and multivariate regression analyses. Patients with PT ≥20 degrees and SVA ≥50 mm had significantly increased lower-limb SMI. CONCLUSIONS: Increased SVA is associated with increased lower-limb SMI, which negatively affects standing balance. An increased lower-limb SMI may represent a novel compensatory mechanism for poor spinal alignment in elderly women with osteoporosis. LEVEL OF EVIDENCE: Level III.

Thoracic Reciprocal Change Can Be Predicted Before Surgery in Adult Spinal Deformity.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Analysis of postoperative sagittal alignment of the unfused spine is lacking in patients with adult spinal deformity (ASD). The present study aims to evaluate the efficacy of the whole spine full-flexion lateral radiograph to predict the reciprocal change of the unfused spine after correction surgery. We hypothesized that the novel parameter (T1-UIV angle: angle between the upper vertebral endplate of the T1 and the upper vertebral endplate of the upper instrumented vertebra) of the preoperative whole spine full-flexion lateral radiograph is similar to that of the postoperative lateral radiograph if the patient has the ideal sagittal alignment. METHODS: Twenty-six ASD patients who underwent correction surgery with a minimum 2-year follow-up were enrolled and separated into the Ideal and Non-Ideal groups according to the Scoliosis Research Society (SRS)-Schwab classification of the final follow-up radiograph. Radiographic parameters, including T1-UIV of the preoperative whole spine full-flexion lateral radiograph, were obtained. RESULTS: Thirteen patients were included in the Ideal group and 13 were in Non-Ideal group. Preoperative T1-UIV of the whole spine full-flexion lateral radiograph exhibited significant correlations with the T1-UIV angles of the postoperative and final follow-up radiographs (r = 0.64, P < .01, y = 0.800x + 8.012, and r = 0.69, P < .01, y = 0.857x + 2.960, respectively). Interestingly, this correlation was stronger for the Ideal group (r = 0.77, P < .01, y = 1.207x - 1.517, and r = 0.89, P < .01, y = 0.986x + 0.694, respectively). CONCLUSION: A novel radiographic strategy (T1-UIV of preoperative the whole spine full-flexion lateral radiograph) could estimate the postoperative alignment of the unfused spine correctly.

Age-Related Progression of Degenerative Lumbar Kyphoscoliosis: A Retrospective Study.

INTRODUCTION: Degenerative lumbar kyphoscoliosis is a serious clinical condition that affects activities of daily living. This study aimed to investigate the age-related progression of nonoperative degenerative lumbar kyphoscoliosis, to clarify its final state in elderly people, and to identify factors associated with its progression. METHODS: This retrospective longitudinal study included 115 nonoperative cases (mean age at first consultation, 70.9 years; range, 50-89 years). All were followed up for >6 years. The analysis included changes between initial and latest measurements in the coronal parameters (Cobb angle, L4 tilt angle, intervertebral angle, lateral spondylolisthesis, and C7-central sacral vertical line) and sagittal parameters (thoracic kyphosis, lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope, sagittal vertical axis, and vertebral wedging rate). Factors in scoliosis progression were investigated by analyzing the correlations between the initial parameter values and the increase in Cobb angle. RESULTS: Changes in the coronal parameters increased with age from 50s to 70s but decreased significantly in those aged 80s. Sagittal parameters increased by the age group, accelerating in those aged 80s, with the progression of vertebral wedging. In patients aged 50s-70s, the increase in Cobb angle correlated significantly with the initial Cobb angle, L4 tilt angle, and L4/L5 intervertebral angle. However, in the cases without initial scoliosis, the increase in Cobb angle correlated significantly only with the L4 tilt angle. There were no significant differences in any parameter according to the use of a trunk brace or medication for osteoporosis. CONCLUSIONS: L4 tilt angle is an important factor in the progression of degenerative scoliosis. The progression of scoliosis gradually ends after the age of 80 years with the decreasing variation of L4 tilt angle, whereas kyphosis accelerates with aging, especially in those aged >80 years, with the progression of vertebral wedging.

Myovascular Preserving Open-Door Laminoplasty for Cervical Spondylotic Myelopathy With Miniplate Fixation.

OBJECTIVE: Laminoplasty is an effective procedure for treating cervical spondylotic myelopathy. We conduct myovascular preserving open-door laminoplasty (MPLP) in combination with a laminoplasty plate to improve the stability of the enlarged lamina. We compare the details of the MPLP technique with conventional open-door laminoplasty. METHODS: We compared 25 cases of MPLP (mean age = 70.5, mean follow-up period = 19 months) with 15 controls who received conventional open-door laminoplasty using hydroxyapatite spacers (mean age = 74, mean follow-up period = 53 months). Regarding surgical outcomes, blood loss, operative time, Japanese Orthopaedic Association score, and postoperative visual analog score for neck pain were measured. Regarding image analysis, preoperative and postoperative range of motion (ROM), C2-7 angle, implant back out, hinge bone fusion time, presence or absence of hinge bone union failure, and posterior neck fat infiltration rate were evaluated. RESULTS: Operative time was significantly shorter for MPLP, and postoperative neck pain was significantly decreased. In image evaluation, %ROM was significantly increased in MPLP, but no difference in C2-7 angle existed between the 2 groups. Implant back out was not recognized in either group. In MPLP, the hinge union period was significantly shortened, and the postoperative fat infiltration rate was significantly decreased. CONCLUSIONS: We were able to reduce neck pain after surgery by an approach entailing longitudinal splitting of the spinous processes. We were able to ensure shorter operation times due to cervical plates and better hinge bone fusion times due to initial stability. LEVEL OF EVIDENCE: 4.

Lateral lumbar interbody fusion in revision surgery for restenosis after posterior decompression.

OBJECTIVE: The purpose of this study was to compare the clinical results of revision interbody fusion surgery between lateral lumbar interbody fusion (LLIF) and posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF) with propensity score (PS) adjustments and to investigate the efficacy of indirect decompression with LLIF in previously decompressed segments on the basis of radiological assessment. METHODS: A retrospective study of patients who underwent revision surgery for recurrence of neurological symptoms after posterior decompression surgery was performed. Postoperative complications and operative factors were evaluated and compared between LLIF and PLIF/TLIF. Moreover, postoperative improvement in cross-sectional areas (CSAs) in the spinal canal and intervertebral foramen was evaluated in LLIF cases. RESULTS: A total of 56 patients (21 and 35 cases of LLIF and PLIF/TLIF, respectively) were included. In the univariate analysis, the LLIF group had significantly more endplate injuries (p = 0.03) and neurological deficits (p = 0.042), whereas the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), surgical site infections (SSIs) (p = 0.02), and estimated blood loss (EBL) (p < 0.001). After PS adjustments, the LLIF group still showed significantly more endplate injuries (p = 0.03), and the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), EBL (p < 0.001), and operating time (p = 0.04). The PLIF/TLIF group showed a trend toward a higher incidence of SSI (p = 0.10). There was no statistically significant difference regarding improvement in the Japanese Orthopaedic Association scores between the 2 surgical procedures (p = 0.77). The CSAs in the spinal canal and foramen were both significantly improved (p < 0.001). CONCLUSIONS: LLIF is a safe, effective, and less invasive procedure with acceptable complication rates for revision surgery for previously decompressed segments. Therefore, LLIF can be an alternative to PLIF/TLIF for restenosis after posterior decompression surgery.

Risk factors predicting osteosarcopenia in postmenopausal women with osteoporosis: A retrospective study.

There is growing interest in "osteosarcopenia" as the coexistence of osteoporosis and sarcopenia exacerbates negative outcomes. However, limited information is available regarding the risk factors of osteosarcopenia development in patients with osteoporosis. Therefore, we retrospectively reviewed 276 consecutive patients with postmenopausal osteoporosis who regularly visited Showa University Hospital. Patients were eligible for the study if they were ≥65 years of age and underwent dual-energy X-ray absorptiometry, blood sampling, and physical performance assessment. Patients were divided into the osteosarcopenia and osteoporosis alone groups according to the diagnostic criteria of the Asian Working Group for Sarcopenia. Of the 276 patients with osteoporosis, 54 patients (19.6%) had osteosarcopenia. Patients in the osteosarcopenia group had a greater risk of frailty than did those in the osteoporosis alone group (odds ratio 2.33; 95% confidence interval, 1.13-4.80, P = 0.028). Low body mass index seemed to be the strongest factor related to the development of osteosarcopenia, and none of the patients in the osteosarcopenia group were obese (BMI ≥27.5 kg/m2). Multiple logistic analyses revealed that patients aged 65-74 years who had comorbidities such as kidney dysfunction and high levels of HbA1c were at risk of developing osteosarcopenia. Thus, we strongly recommend the assessment of the key components of the diagnosis of osteosarcopenia in an osteoporosis clinic for patients with low body mass index. Furthermore, appropriate assessments, including comorbidities, will help in identifying patients at greater risk of developing osteosarcopenia.

Impact of Spinopelvic sagittal alignment on the surgical outcomes of dropped head syndrome: a multi-center study.

BACKGROUND: Most of the previous studies about the surgical treatment of dropped head syndrome (DHS) are small case series, and their primary outcome measures were cervical alignment parameters. Therefore, little is known about the associations between pre- and postoperative global sagittal alignment in the whole spine and the clinical outcomes of the surgical treatment of DHS. In this study, we investigated the surgical outcomes of DHS, including correction of cervical and global spinal sagittal alignment. METHODS: This study was a retrospective observational study. Fifteen patients with DHS who had undergone correction surgery were enrolled. Surgical outcomes, including complications and implant failures, were investigated. We assessed cervical alignment parameters as well as spinopelvic global alignment parameters, including pelvic incidence (PI), lumbar lordosis (LL), and C7-sacral sagittal vertical axis (SVA). We examined the changes in these parameters using pre- and posoperative whole spine lateral radiographs. The parameters were compared between the failure and nonfailure groups. RESULTS: Recurrence of sagittal imbalance and horizontal gaze difficulty was observed in 6 cases (40%). In all, 3 cases (20%) exhibited a distal junctional failure and required multiple surgeries with extension of fusion. Of all the radiographic parameters compared between the failure and nonfailure groups, significant differences were only observed in pre and postoperative SVA and PI-LL. CONCLUSIONS: Our results suggest that the global sagittal alignment parameters, including PI-LL and SVA, were different between the patients with failure and non failure, and these parameters might have notable impacts on surgical outcomes. Surgeons should consider PI-LL and SVA while determining the surgical course for patients with DHS.

Chronic dysphagia caused by Laryngo-vertebral Synostosis after anterior fusion for cervical spine trauma: a case report.

BACKGROUND: Anterior cervical spine surgery is often associated with postoperative dysphagia, but chronic dysphagia caused by laryngo-vertebral synostosis is extremely rare. We report a case of chronic dysphagia caused by synostosis between the cricoid cartilage and cervical spine after anterior surgery for cervical spine trauma. CASE PRESENTATIONS: We present a case of a 39-year-old man who had sustained complex spine trauma at C5-6 associated with complete spinal cord injury at the age of 22; the patient presented with a 5-year history of chronic dysphagia. Computed tomography demonstrated posterior shift of the esophagus as well as calcification of the cricoid cartilage and its fusion to the right anterior tubercle of the C5 vertebra. A barium swallow study demonstrated significant barium aspiration into the airway and no laryngeal elevation. The patient underwent resection of the bony bridge and omohyoid muscle flap insertion. His symptoms ameliorated after surgery. CONCLUSION: Synostosis between the cricoid cartilage and cervical spine may occur associated with cervical spine trauma and causes chronic dysphagia. Resection of the fused part can improve dysphagia caused by this rare condition and omohyoid muscle flap might be a good option to prevent recurrence.