Byung-Wan Choi

Cross-cultural adaptation and validation of the Korean version of the neck disability index.

Study Design. Validation of a translated, culturally adapted questionnaire. Objective. The purpose of this study is to translate and culturally adapt the Neck Disability Index (NDI) and to validate the use of the derived version in Korean patient. Summary of Background Data. Although several valid measures exist for measurement of neck pain and functional impairment, these measures have yet been validated in Korean version. Methods. The NDI was linguistically translated into Korean, and prefinal version was assessed and modified by a pilot study. The reliability and validity of the derived Korean version was examined in 78 patients with degenerative cervical spine disease. Test-retest reliability, internal consistency, and construct validity were investigated by comparing Visual Analogue Scale (VAS) and Short Form Health Survey (SF-36) scores. Results. Factor analysis of Korean NDI extracted 2 factors with eigenvalues >1. The intraclass-correlation coefficient of test-retest reliability was 0.93. Reliability, estimated by internal consistency, had a Cronbach alpha value of 0.82. The correlation between NDI and VAS scores was r = 0.49, and the correlation between NDI and SF-36 scores was r = −0.44. The physical health component score of SF-36 was highly correlated with NDI, and the correlation between VAS scores and the mental health component scores of SF-36 was high. Conclusion. The derived Korean version of the NDI was found to be a reliable and valid instrument for measuring disability in Korean patients with cervical problems. The authors recommend its use in future Korean clinical studies.

Clinical usefulness of CT-myelogram comparing with the MRI in degenerative cervical spinal disorders: is CTM still useful for primary diagnostic tool?

Study Design A radiographic review of 50 patients (29 radiculopathy and 21 myelopathy) who had undergone the anterior cervical discectomy and fusion was performed by 3 observers retrospectively. Objective To compare the accuracy between magnetic resonance imaging (MRI) and postmyelographic computed tomography (CTM) in degenerative cervical spine disease by assessing the degree of interobserver and intraobserver agreement. Summary of Background Data The assessment of degenerative cervical spinal disease is still demanding. Now MRI is accepted as a primary diagnostic tool for degenerative cervical spine disease. Compared with MRI, usage of CTM has diminished, but it is usually reserved for the patients for whom MRI results were ambiguous or technically suboptimal. Methods We retrospectively reviewed MRIs and CTMs of 50 patients (29 radiculopathy and 21 myelopathy) who had undergone the anterior cervical discectomy and fusion procedure. Using an assessment scale, 3 observers examined 5 parameters: spinal canal narrowing, foraminal stenosis, bony abnormality, intervertebral disk herniation, and nerve root compression. The degree of severity was graded using a 4-point scale for each item. Intraobserver, interobserver agreement, and the accentuation of each image were analyzed. Results Intraclass correlation coefficiency statistical analysis showed moderate intraobserver agreement (Cronbachs α=0.63) and interobserver agreement (0.52). There was no significant difference in intraobserver, interobserver agreement between MRI (0.58) and CTM (0.57). Compared between MRI and CTM, disc abnormality and nerve root compression on MRI and foraminal stenosis and bony lesion on CTM showed better agreement. Conclusions CTM was still useful in diagnosis of the foraminal stenosis and bony lesion comparing with MRI but showed limitation in disc abnormality and nerve root compression. So even though CTM may provide valuable additional information in difficult or ambiguous cases, it also requires universal standards and sound experience for constant and objective information.

Risk factors for the development of adjacent segment disease following anterior cervical arthrodesis for degenerative cervical disease: Comparison between fusion methods

This study aimed to determine the risk factors for developing adjacent segment disease (ASDz) after anterior cervical arthrodesis for the treatment of degenerative cervical disease by analyzing patients treated with various fusion methods. We enrolled 242 patients who had undergone anterior cervical fusion for degenerative cervical disease, and had at least 5years of follow-up. We evaluated the development of ASDz and the rate of revision surgery. To identify the risk factors for ASDz, the sagittal alignment, spinal canal diameter, range of motion of the cervical spine, number of fusion segments, and fusion methods were evaluated. The patients were divided into three groups according to the fusion method: Group A contained patients who had received autogenous bone graft only (53 patients), Group B contained patients who received autogenous bone graft and plate augmentation (62 patients), and Group C contained patients who underwent cage and plate augmentation (127 patients). ASDz occurred in 33 patients, of whom 19 required additional surgery. The risk of developing ASDz was significantly higher in male patients (p=0.043), patients whose range of motion of the cervical spine was >30° (p=0.027), and patients with spinal canal stenosis (p=0.010). The rate of development of ASDz was not different depending on the number of fusion segments. The rate of development of ASDz was 41.5% in Group A, 9.6% in Group B, and 5.51% in Group C (p=0.03). In patients who underwent anterior cervical arthrodesis for degenerative disease, the occurrence of ASDz was related to age, the cervical spine range of motion, and spinal canal stenosis. Additional plate augmentation for anterior cervical arthrodesis surgery can lower the rate of ASDz development.

The Relationship between Spinal Stenosis and Neurological Outcome in Traumatic Cervical Spine Injury: An Analysis using Pavlov's Ratio, Spinal Cord Area, and Spinal Canal Area

Background This study examined the relationship between four radiological parameters (Pavlovs ratio, sagittal diameter, spinal cord area, and spinal canal area) in patients with a traumatic cervical spine injury, as well as the correlation between these parameters and the neurological outcome. Methods A total of 212 cervical spinal levels in 53 patients with a distractive-extension injury were examined. The following four parameters were measured: Pavlovs ratio on the plain lateral radiographs, the sagittal diameter, the spinal cord area, and the spinal canal area on the MRI scans. The Pearson correlation coefficients between the parameters at each level and between the levels of each parameter were evaluated. The correlation between the radiological parameters and the spinal cord injury status classified into four categories, A (complete), B (incomplete), C (radiculopathy), and D (normal) was assessed. Results The mean Pavlovs ratio, sagittal diameter, spinal cord area and spinal canal area was 0.84, 12.9 mm, 82.8 mm2 and 236.8 mm2, respectively. An examination of the correlation between the radiological spinal stenosis and clinical spinal cord injury revealed an increase in the values of the four radiological parameters from cohorts A to D. Pavlovs ratio was the only parameter showing statistically significant correlation with the clinical status (p = 0.006). Conclusions There was a correlation between the underlying spinal stenosis and the development of neurological impairment after a traumatic cervical spine injury. In addition, it is believed that Pavlovs ratio can be used to help determine and predict the neurological outcome.

Efficacy of Postoperative Radiograph for Evaluating the Prevertebral Soft Tissue Swelling after Anterior Cervical Discectomy and Fusion

Background After surgery for degenerative spinal disease by the anterior approach, the degree of soft tissue swelling can be assessed simply using plain radiographs. However, there are little studies according to the surgical methods or extent of surgery, and no study had addressed the clinical meaning of swelling determined by plain radiography. The purpose of this study was to evaluate the clinical significance of prevertebral soft tissue swelling (PSTS) after anterior cervical fusion with plate fixation for the treatment of degenerative cervical spinal disorders. Methods One hundred and thirty-five patients that underwent anterior cervical fusion with plate augmentation for degenerative cervical spondylosis were included in this study. PSTS differences were analyzed with respect to numbers of fusion segments and location of fusion. Cases were divided into two groups based on the amount of PSTS, and incidences of dyspnea, dysphagia, dysphonia were evaluated. Results PSTS increments were significantly greater in patients that had undergone multi-level or high-level fusion. Complications of dyspnea, dysphagia and dysphonia were found more frequently in patients with marked PSTS group. Conclusions Increments of PSTS after anterior cervical fusion for degenerative spinal disorders are greater and incidences of complications are higher in patients that undergo multi-level or high-level fusion. Thus, measurement of PSTS using consecutive cervical lateral radiographs after anterior cervical surgery is clinically meaningful procedure.

Usefulness of polyetheretherketone (PEEK) cage with plate augmentation for anterior arthrodesis in traumatic cervical spine injury.

BACKGROUND CONTEXT Even though many clinical reports about cages have been documented in patients with degenerative disorders, reports were scarce for traumatic injury cases, and those cases using metal cages were restricted to only one-level injury. PURPOSE To evaluate the usefulness of polyetheretherketone (PEEK) cage and plate construction in anterior interbody fusions (AIF) for traumatic cervical spine injuries by analyzing radiographic changes and clinical outcomes. STUDY DESIGN/SETTING Retrospective study. PATIENT SAMPLE Fifty-eight patients (91 levels) underwent cage and plate construction for treatment of traumatic cervical spine injury. OUTCOME MEASURES The fusion rate, fusion time, changes of Cobb angle, subsidence rate, and adjacent level changes were assessed as a radiographic outcome. Clinical analysis includes the recovery rate on the American Spinal Injury Association (ASIA) impairment scale and the presence of the complications. METHODS We evaluated 58 patients (91 levels) who underwent surgery and had at least 24 months in follow-up study. Radiographic evaluation included the assessment of interbody fusion rate, fusion time, changes of Cobb angle, subsidence rate, and adjacent level changes. Clinical assessment was done by analyzing recovery state of ASIA impairment scale from preoperative period to the last follow-up and by evaluating complications. RESULTS Fifty-four cases showed bony fusion within 3 months after the surgery. The mean Cobb angle between the vertebral bodies was 2.54 degrees before operation, 9.13 degrees after operation, and 8.39 degrees at the latest follow-up. The mean intervertebral disc height was increased by 3.01 mm after the operation, but the mean height was 2.17 mm shorter at the last follow-up than after postoperation. In terms of clinical results, five Grade A cases and one Grade B case as assessed by the ASIA impairment scale were unchanged until the last follow-up. Twenty-three cases of Grade C, 16 cases of Grade D, and 13 cases of Grade E improved to seven cases, 26 cases, and 19 cases, respectively. Three cases went through additional surgery, two posterior fusions for delayed union and posterior instability and one AIF for adjacent level disease. CONCLUSION The PEEK cage and additional plate fixation is a surgical procedure that decreases donor site morbidity, obtains high fusion rate with rigid fixation, and provides satisfactory clinical outcome for traumatic cervical spine injuries, regardless of the numbers of the involved levels.

Adjacent Segment Pathology Following Anterior Decompression and Fusion Using Cage and Plate for the Treatment of Degenerative Cervical Spinal Diseases

Study Design Retrospective study. Purpose To analyze the incidence and prevalence of clinical adjacent segment pathology (CASP) following anterior decompression and fusion with cage and plate augmentation for degenerative cervical diseases. Overview of Literature No long-term data on the use of cage and plate augmentation have been reported. Methods The study population consisted of 231 patients who underwent anterior cervical discectomy and fusion (ACDF) with cage and plate for degenerative cervical spinal disease. The incidence and prevalence of CASP was determined by using the Kaplan-Meier survival analysis. To analyze the factors that influence CASP, data on preoperative and postoperative sagittal alignment, spinal canal diameter, the distance between the plate and adjacent disc, extent of fusion level, and the presence or absence of adjacent segment degenerative changes by imaging studies were evaluated. Results CASP occurred in 15 of the cases, of which 9 required additional surgery. At 8-year follow-up, the average yearly incidence was 1.1%. The rate of disease-free survival based on Kaplan-Meier survival analysis was 93.6% at 5 years and 90.2% at 8 years. No statistically significant differences in CASP incidence based on radiological analysis were observed. Significantly high incidence of CASP was observed in the presence of increased adjacent segment degenerative changes (p<0.001). Conclusions ACDF with cage and plate for the treatment of degenerative cervical disease is associated with a lower incidence in CSAP by 1.1% per year, and the extent of preoperative adjacent segment degenerative changes has been shown as a risk factor for CASP.

Analysis of demographics, clinical, and radiographical findings of ossification of posterior longitudinal ligament of the cervical spine in 146 Korean patients.

Study Design. Retrospective clinical data analysis. Objective. This study was conducted to analyze retrospectively the demographics, clinical presentation, and radiographical findings of ossification of posterior longitudinal ligament (OPLL) of the cervical spine in Korean patients, which could serve as a basis for further studies on and treatment of OPLL. Summary of Background Data. As the frequency of diagnosing the OPLL has been gradually increasing because of the increased importance and interest, it is important to understand the demographic characteristics of the disease. Methods. Of 222 patients with a diagnosis of OPLL of the cervical spine, 146 patients were evaluated. Demographic features such as age and sex, and clinical features related to symptoms and treatments, were analyzed, and radiological features observed on plain radiographs, computerized tomography for 3-dimensional reconstruction, and magnetic resonance images were investigated. Results. Of the 146 subjects, 106 were male patients and 40 were female patients, which showed a male to female ratio of 2.65:1. The mean age of the subjects was 53.3 years. Neurological symptoms such as radiculopathy or myelopathy were observed in 109 patients (74.7%). Diagnosis of OPLL by plain radiography could not be ascertained in 19.9% of the patients. Ossification of paraspinal ligaments also accompanied OPLL in 86.3% of the subjects. Intramedullary high-signal intensity on T2-weighted sagittal plane magnetic resonance images was shown in 62 patients (42.5%). Concurrent herniated intervertebral disc was observed in 37 patients (25.3%). Conclusion. The demographics, clinical presentation, and radiographical findings of OPLL of the cervical spine in Korean patients were analyzed, which could serve as a basis for further study on and treatment of OPLL. The classification method using plain radiographs has some limitation for disease treatment or prognosis. For the exact diagnosis and classification of the OPLL, computerized tomographic scan is more useful.

Change of radiological parameters after interspinous implantation (X-stop®) in degenerative spinal stenosis

ObjectThis study was intended to objectively demonstrate the effect of interspinous implantation through preoperative and postoperative radiological analyses in degenerative lumbar spinal stenosis.MethodsThis study included 20 segments of 14 cases that had been diagnosed as spinal stenosis through physical and radiological findings and had interspinous implantation (X‐stop®). On simple radiography, height and width of the intervertebral foramen, height of the anterior and posterior intervertebral disks, and interbody angle were measured. On magnetic resonance imaging (MRI), the intervertebral foramen and intradural areas were also measured. Changes in preoperative and postoperative measurements were compared, and correlation between radiological indicators was identified. Clinical evaluation was done using visual analog scale (VAS) and Oswestry disability index (ODI) scores. The relationship between the clinical outcomes and radiological changes was also evaluated.ResultsThe comparison of preoperative and postoperative radiological measurements showed significant changes in height and width of the intervertebral foramen, and interbody angle on simple radiography, and in height of the intervertebral foramen on MRI. Regarding correlation between radiological indicators, there was correlation between height of the intervertebral foramen on simple radiography and area of the intervertebral foramen on MRI, and between the intervertebral foramen and intradural areas on MRI. For correlation between the clinical improvement level and the changes in radiological parameters, VAS correlated with intervertebral foramen height on simple radiography and increased area of the intervertebral foramen on MRI. However, for ODI, there was no factor showing significant correlation.ConclusionsIn patients with degenerative spinal stenosis showing neurogenic claudication, interspinous implantation was more effective in increasing the height and area of the intervertebral foramen than in increasing intradural area, and the short‐term clinical results were promising.

The Relationship between Increased Intervertebral Disc Height and Development of Postoperative Axial Neck Pain after Anterior Cervical Fusion

Objective To evaluate the relationship between postoperative increase in intervertebral disc space height (IVH) and posterior axial neck in cases of degenerative cervical disease treated with anterior cervical discectomy and fusion (ACDF). Methods A total of 155 patients who underwent ACDF with more than 1 year follow up were included. Radiologically, IVH and interfacet distance (IFD) of the operated segment were measured preoperatively and postoperatively. We clinically evaluated neck and arm pains according to visual analogue scale (VAS) scores and assessed neck disability index (NDI) scores preoperatively, postoperatively, at 3 months, 6 months, and 1 year postoperatively. The relationship between radiological parameters, and clinical scores were analyzed using a regression analysis. Results The mean increase in IVH was 2.62 mm, and the mean increase in IFD was 0.67 mm. The VAS scores for neck pain preoperatively, postoperatively, and at 3 months, 6 months, 1 year postoperatively were 4.46, 2.11, 2.07, 1.95, and 1.29; those for arm pain were 5.89, 3.24, 3.20, 3.03, and 2.18. The NDI scores were improved from 18.52 to 7.47. No significant relationship was observed between the radiological evaluation results regarding the increase in intervertebral height or interfacet distance and clinical changes in VAS or NDI scores. Conclusion The increase in intervertebral space or interfacet distance by the insertion of a large graft material while performing ACDF for the treatment of degenerative cervical disease was not related with the change in VAS scores for neck and arm pains and NDI scores postoperatively and during the follow-up period.