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.

Hyoid position as a novel predictive marker for postoperative dysphagia and dysphonia after anterior cervical discectomy and fusion.

PURPOSE: The purpose of this study is to investigate the predictive value of the hyoid horizontal positional change on the severity of dysphagia and dysphonia (PDD) after anterior cervical discectomy and fusion (ACDF) comparing pre-vertebral soft-tissue thickness (PVST). METHODS: This is a retrospective observational study with prospectively collected data at a single academic institution. ACDF patients between 2015 to 2018 who had complete self-reported PDD surveys and pre- and postoperative lateral cervical radiographs were included in the analysis. PDD was assessed utilizing the Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI). The hyoid-vertebral distance (HVD) and PVST (the averages of C2 to C7 levels (PVSTC2-7) and all operating levels (PVSTOP)) were assessed preoperatively and upon discharge. The associations among postoperative changes of HVD, PVSTs, and the 4-week HSS-DDI score were evaluated. RESULTS: Of the 268 patients with a HSS-DDI score assessment, 209 patients had complete data. In univariate analyses, HVD and PVSTC2-7 changes demonstrated significant correlations with HSS-DDI, whereas PVSTOP showed no significant association. After adjusting with sex and operating level, the changes in HVD (p = 0.019) and PVSTC2-7 (p = 0.009) showed significant associations with the HSS-DDI score and PVSTOP showed no significant association. PVSTC2-7 could not be evaluated in 12% of patients due to measurement difficulties of PVST at lower levels. CONCLUSION: We introduce a novel potential predictive marker for PDD after ACDF. Our results suggest that HVD can be utilized for the risk assessment of PDD, especially in PVST unmeasurable cases, which accounts for over 10% of ACDF patients.

Minimum Clinically Important Differences of the Hospital for Special Surgery Dysphagia and Dysphonia Inventory and Other Dysphagia Measurements in Patients Undergoing ACDF.

BACKGROUND: Postoperative dysphagia is a common complication after anterior cervical surgery, and it can be measured using patient-reported outcome measures (PROMs). The Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI) is a condition-specific PROM to evaluate dysphagia and dysphonia after anterior cervical discectomy and fusion (ACDF). The minimum clinically important difference (MCID) of the HSS-DDI has not, to our knowledge, been established. Other PROMs have been used to assess dysphagia (SWAL-QOL and MD Anderson Dysphagia Inventory [MDADI]) in ACDF. Currently, few studies have addressed the MCIDs of these PROMs. QUESTIONS/PURPOSES: To determine (1) the minimum detectable changes (MDC) of the HSS-DDI, SWAL-QOL, and MDADI using a distribution-based approach, and (2) the MCID of the HSS-DDI, SWAL-QOL, and MDADI, using an anchor-based approach. METHODS: We used a longitudinally maintained database that was originally established for the HSS-DDI development and validation study. In all, 323 patients who underwent elective ACDF were assessed for enrollment eligibility; 83% (268 of 323) met the inclusion criteria and completed the HSS-DDI Week 4 survey. We set six outcomes: distribution-based MDCs for the (1) HSS-DDI, (2) SWAL-QOL, (3) MDADI, in addition to anchor-based MCIDs for the (4) HSS-DDI, (5) SWAL-QOL, and (6) MDADI. The HSS-DDI consists of 31 questions and ranges 0 (worst) to 100 (normal). We used the focused SWAL-QOL, which consists of 14 selected items from the original SWAL-QOL and ranges from 0 (worst) to 100 (normal). The MDADI is a 20-item survey and ranges from 20 (worst) to 100 (normal). A distribution-based approach is used to calculate values defined as the smallest difference above the measurement error. An anchor-based approach is used to determine the MCIDs based on an external scale, called an anchor, which indicates the minimal symptom change that is considered clinically important. All 268 patients were used for the distribution-based (0.5 SD) HSS-DDI MDC analysis. The first 16% (44 of 268) of patients completed retesting of the HSS-DDI via a telephone interview and were used for another distribution-based (standard error of measurement: SEM) MDC analysis. The number of patients for the test-retest group was determined based on the previously reported minimum required sample size of reliability studies. The first 63% (169 of 268, SWAL-QOL and 168 of 268, MDADI) of patients completed two other surveys for the external validation of the HSS-DDI, and were used for the SWAL-QOL and MDADI 0.5 SD analyses. Among the patients, 86% (230 of 268) completed the Week 8 HSS-DDI survey that was used for the anchor-based HSS-DDI MCID analysis, and 56% (SWAL-QOL, 150 of 268 and MDADI, 151 of 268) of patients completed the Week 8 surveys that were used for the SWAL-QOL and MDADI MCID analyses. Subjective improvement grades from the previous assessment were used as the anchor. The MCIDs were calculated as the mean score changes among those who reported little better or greater in the improvement assessment and receiver operating characteristic (ROC) curve analyses. We adopted the higher value of these two as the MCID for each PROM. RESULTS: The distribution-based MDCs for the HSS-DDI total score, SWAL-QOL, and MDADI were 11 of 100, 9 of 100, and 8 of 80 points, respectively, using the 0.5 SD method. Using the SEM-based method, the MDC for the HSS-DDI total score was 9 of 100 points. Regarding the anchor-based MCIDs, the values calculated with the mean score change method were consistently higher than those of ROC analysis and were adopted as the MCIDs. The MCIDs were 10 for the total HSS-DDI total score, 8 for the SWAL-QOL, and 6 for the MDADI. CONCLUSIONS: Improvements of less than 10 points for the HSS-DDI score, 9 points for the SWAL-QOL, and 6 points for the MDADI are unlikely to be perceived by patients to be clinically important. Future studies on dysphagia after anterior cervical surgery should report between-group differences in light of this, rather than focusing on p values and statistical significance. LEVEL OF EVIDENCE: Level III, therapeutic study.

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.

Recurrent fifth metatarsal stress fractures in a professional soccer player with hypoparathyroidism: a case report.

BACKGROUND: Hypoparathyroidism is characterized by low or inappropriately normal levels of parathyroid hormone leading to hypocalcemia. In this report, a case of recurrent fifth metatarsal stress fractures in a professional soccer player with hypoparathyroidism is presented. CASE PRESENTATION: A 23-year-old male professional soccer player developed left foot pain. He had no specific medical or family history. He was diagnosed with a fifth metatarsal stress fracture and underwent osteosynthesis with a cannulated cancellous screw 3 days after the injury. After three and a half months, the X-ray showed bone union, and he returned to full sports activity. However, he felt pain in his left foot again, and a re-fracture was found on X-ray a week later. Osteosynthesis was performed again. Two months after re-operation, the cause of re-fracture was investigated. Laboratory results showed abnormally low levels of serum calcium (8.4 mg/dL) and intact parathyroid hormone (i-PTH: 19.0 pg/mL). However, other laboratory examinations were normal. Therefore, he was diagnosed with primary hypoparathyroidism according to the diagnostic criteria. Medical treatment was started with alfacalcidol 1.0 µg/day. One month after starting medication, the serum calcium improved to 9.4 mg/dL. Four months after the re-operation, the X-ray showed bone union, and he was therefore allowed to play soccer. While he played professional soccer, there were no new subjective complaints. CONCLUSIONS: Hypoparathyroidism may be one of the risk factors for stress fractures. We believe that serum calcium levels should be checked in patients with stress fractures, and if the serum calcium is low, hypoparathyroidism should be considered.

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.

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.

Comparison of vitamin D sufficiency between indoor and outdoor elite male collegiate athletes.

This study compared vitamin D sufficiency between indoor and outdoor elite athletes. We also evaluated the association between vitamin D level, body composition, and stress fractures incidence. 27 outdoor elite male collegiate athletes (field hockey players) and 21 indoor elite male collegiate athletes (fencing players) were enrolled. Participants' demographic information including past fractures were recorded. Furthermore, all the athletes' body compositions including percentage of body fat were measured. Blood samples were collected to test serum calcium, phosphorus, and 25(OH)D. levels. Participants were classified into three groups: vitamin D sufficiency (serum 25(OH)D levels of ≥30 ng/ml), vitamin D insufficiency (serum 25(OH)D levels of <30 ng/ml), and vitamin D deficiency (serum 25(OH)D levels of <20 ng/ml). The indoor athletes showed significantly higher mean percentage of body fat than outdoor athletes, 12.2 ± 3.2% and 9.7 ± 3.7%, respectively. The serum 25(OH)D levels of indoor athletes were significantly lower than those of outdoor athletes, 15.3 ± 3.3 ng/mL and 24.9 ± 4.5 ng/ml, respectively (P < 0.001). Furthermore, the indoor athletes showed a significantly higher rate of vitamin D deficiency than the outdoor athletes, 19 of 21 (90.5%) and 5 of 27 (18.5%), respectively (P < 0.001). The cohort of outdoor athletes with stress fractures' history had significantly lower serum 25(OH)D levels than those without history of any fractures, 21.1 ± 4.3 ng/ml and 26.4 ± 3.0 ng/ml, respectively (P < 0.05). In conclusion, a majority of the indoor elite athletes were vitamin D-deficient. The serum 25(OH)D levels were significantly higher in outdoor elite athletes. However, lower serum 25(OH)D levels might be associated with stress fractures among outdoor athletes.

The diagnostic accuracy of MRI and nonenhanced CT for high-risk vertebral artery anatomy for subaxial anterior cervical spine surgery safety.

OBJECTIVE: Medial migration of the vertebral artery (VA) can be a risk factor for injury during anterior procedures. CT angiography (CTA) has been considered the gold standard for the evaluation of various areas of the arterial anatomy. MRI and nonenhanced CT are more commonly used as routine preoperative imaging studies, but it is unclear if these modalities can safely exclude the anomalous course of the VA. The aims of this cross-sectional observational study were to investigate risk factors for medially migrated VA on CTA and to evaluate the diagnostic accuracy of MRI and nonenhanced CT for high-risk VA anatomy in the subaxial cervical spine. METHODS: The records of 248 patients who underwent CTA for any reason at a single academic institution between 2007 and 2018 were reviewed. The authors included MRI and nonenhanced CT taken within 1 year before or after CTA. An axial VA position classification was used to grade VA anomalies in the subaxial cervical spine. The multivariable linear regression analysis with mixed models was performed to identify the risk factors for medialized VA. The sensitivity and specificity of MRI and nonenhanced CT for high-risk VA positions were calculated. RESULTS: A total of 175 CTA sequences met the inclusion criteria. The mean age was 63.8 years. Advanced age, disc and pedicle levels, lower cervical levels, and left side were independent risk factors for medially migrated VA. The sensitivities of MRI and nonenhanced CT for the detection of grade 1 or higher VA position were only fair, and the sensitivity of MRI was lower than that of nonenhanced CT (0.31 vs 0.37, p < 0.001), but the specificities were similarly high for both modalities (0.97 vs 0.97). With the combination of MRI and nonenhanced CT, the sensitivity significantly increased to 0.50 (p < 0.001 vs MRI and vs CT alone) with a minimal decrease in specificity. CONCLUSIONS: Axial images of MRI and nonenhanced CT demonstrated high specificities but only fair sensitivities. Nonenhanced CT demonstrated better diagnostic value than MRI. When combining both modalities the sensitivity improved, but a substantial proportion of medialized VAs could not be diagnosed.

Risk factors for postoperative dysphagia and dysphonia following anterior cervical spine surgery: a comprehensive study utilizing the hospital for special surgery dysphagia and dysphonia inventory (HSS-DDI).

BACKGROUND CONTEXT: Postoperative dysphagia and dysphonia (PDD) are prevalent complications after anterior cervical discectomy and fusion (ACDF). Identification of risk factors for these complications is necessary for effective prevention. Recently, patient reported outcome measures (PROM) have been used to determine PDD after ACDF. The Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI) is a validated PROM that specifically assesses dysphagia and dysphonia after anterior cervical spine surgery. PURPOSE: To identify the perioperative risk factors for PDD utilizing the HSS-DDI. STUDY DESIGN/SETTING: Observational study of prospectively collected data at a single academic institution. PATIENT SAMPLE: Patients undergoing anterior cervical discectomy and fusion from 2015 to 2019 who enrolled in the prospective data collection. OUTCOME MEASURE: The HSS-DDI administered 4 weeks, 8 weeks, and 4-6 months after surgery. METHODS: As potential risk factors, the data on demographic factors, analgesic medications, history of psychiatric illness, preoperative sagittal alignment, surgical factors, preoperative diagnoses, and preoperative Neck Disability Index (NDI) scores were collected. Bivariate and multivariable regression analyses utilizing the Tobit model were conducted. RESULTS: 291 patients were included in the final analysis. The median HSS-DDI at 4-weeks, 8 weeks, and 4-6 months postoperatively, were 80.7, 92.7, and 98.4, respectively. Multivariable analysis demonstrated that current smoking, previous cervical spine surgery, preoperative C2-7 angle, upper level surgery, multilevel surgery, opioid use, and a high preoperative NDI score, were independent contributing factors to a low HSS-DDI score at 4-weeks follow-up. Intraoperative topical steroid use was an independent protective factor for a low HSS-DDI score. Opioid use and high NDI score remained independent factors at 4-6 months. Sub-domain analysis demonstrated that prior cervical surgery, preoperative C2-7 angle, multilevel surgery, and intraoperative topical steroid use were significant for dysphagia only. Current smoking was significant for dysphonia only. CONCLUSIONS: Our results showed that preoperative opioid use and a high preoperative NDI score are novel independent risk factors for postoperative dysphagia and dysphonia in addition to other known factors.

Conservative treatment for stable low-energy thoracolumbar vertebral fractures in nonfused segments among elderly patients with diffuse idiopathic skeletal hyperostosis: A matched case-control study.

Diffuse idiopathic skeletal hyperostosis (DISH) is the spontaneous osseous fusion of the spine with anterior bridging osteophytes. It is well-known that conservative treatment for vertebral fractures of fused segment among DISH spines is associated with worse clinical outcomes. However, the prognosis of conservatively treated stable vertebral fractures in neighboring nonfused segments among DISH spines is still unknown. The purpose of this study was to analyze the results of conservative treatment of stable low-energy thoracolumbar (TL) vertebral fracture in nonfused segments among patients with DISH lesions.A total of 390 consecutive patients who visited an emergency department by ambulance with spinal trauma between 2013 and 2017 were retrospectively reviewed. The diagnosis of DISH was determined based on fused spinal segments with bridging osteophytes in at least 3 adjacent vertebrae. For each case of stable TL vertebral fractures in nonfused segments of the DISH spine, we identified 2 age-, sex-, and fracture lesion-matched non-DISH controls who underwent conservative treatment for low-energy TL vertebral fractures during the same period.Of the 33 identified cases of TL fractures with DISH, 14 met our inclusion criteria. The bony union rates of the DISH group and control group were 57% and 75% at the 3-month follow-up examination (P = .38) and 69% and 100% at the 6-month follow-up examination (P = .02), respectively. Among the 13 patients with fractures below the TL junction, fused segments were not diagnosable based on the initial standard radiographs of the lumbar spine for 61.5% of patients.Although this study design was exploratory and the sample size was small, our results suggest that with conservative treatment, stable fractures in nonfused segments in the DISH spine might have a worse prognosis than ordinary osteoporotic vertebral fractures. The diagnosis of coexisting DISH lesions can be missed when only radiographs of the lumbar spine are used to determine the diagnosis.

Risk factors for spinal cord injury progression after anterior fusion for cervical spine trauma: a retrospective case-control study.

STUDY DESIGN: Single-center, retrospective case-control study. OBJECTIVES: This study aimed to determine the risk factors for progression of neurological symptoms after anterior fusion for cervical spine trauma with no or incomplete spinal cord injury. SETTING: Community-based hospital with an acute care center in Japan. METHODS: We retrospectively reviewed 54 consecutive unstable subaxial cervical spine fracture/dislocation cases that had undergone surgical treatment. A total of 20 patients with no or incomplete spinal cord injury who underwent anterior fusion were identified. Injury characteristics, bony spinal canal diameter (SCD) at the injured level on computed tomography (CT), diagnosis delay of more than 24 h, and other surgery-related parameters were documented as potential risk factors. RESULTS: The study population included 16 male and 4 female patients. The median age was 71.5 (range: 20-88) years. Two cases of SCI progression were identified (AIS E to C5-8 C and AIS D to C5-8 C). Both cases occurred in men who were older than the average age of all the patients. Only delayed diagnosis was significantly associated with the progression of SCI (p = 0.02). SCDs on CT demonstrated a tendency to be smaller than those of cases without progression, but this was not statistically significant (progression: median, 8.1 [7.2-8.9] mm; no progression: median, 10.1 [4.2-12.6] mm; p = 0.21). CONCLUSION: Our results suggested that a delay in diagnosis was associated with neurological progression after ACF. Furthermore, imposing ligamentous flavum might become a compression factor if the diagnosis is delayed.