Anterior cervical discectomy and fusion can restore cervical sagittal alignment in degenerative cervical disease.

OBJECTIVE: The purpose of this study was to evaluate its effect on the restoration and maintenance of cervical sagittal alignment in usual cervical degenerative diseases without preoperative sagittal malalignment. MATERIALS AND METHODS: We retrospectively evaluated 108 patients who were diagnosed with degenerative cervical disease and underwent ACDF (allograft and plating) with > 1-year follow-up. For radiographic evaluation, we analysed segmental and C2-7 cervical lordosis, disc height, C2-7 sagittal vertical axis (SVA), T1 slope, and T1 slope minus C2-7 lordosis (T1S - CL) in lateral X-ray. Clinical assessment was based on arm VAS, neck VAS, and NDI scores. Correlation analysis was performed across the pre-post-changes in radiological parameters. Correlations between the changes in radiological and clinical parameters at final follow-up were also analysed. RESULTS: C2-7 lordosis was 7.13° preoperatively and increased to 13.06° (p < 0.001) and maintained at 10.08° at final follow-up (p = 0.007). Segmental lordosis increased from 0.66° to 8.33° and maintained at 5.19° (p < 0.001). Segmental disc height was 4.67 mm preoperatively (increased to 7.13 mm postoperatively and decreased to 5.74 mm at final follow-up) (p < 0.001). SVA distance (31.53 mm to 30.02 mm) (p = 0.750) and T1 slope (30.03° to 31.37°) did not show meaningful change after surgery. Increase in segmental lordosis was correlated to an increase in C2-7 lordosis (p < 0.001). C2-7 SVA change correlated with both the T1 slope change (p < 0.001) and T1S - CL (p = 0.012). Change in SVA was correlated to a change in segmental lordosis and T1 slope (p = 0.003, p = 0.014). Clinical outcomes did not correlate with radiological findings. CONCLUSION: ACDF for the treatment of degenerative cervical disease without preoperative deformity was effective in restoring cervical sagittal alignment. Improvement of segmental lordosis related to an improvement in C2-7 lordosis and SVA. Radiological sagittal alignment did not show any relation with clinical outcomes in usual degenerative cases.

Selective laminectomy for cervical spondylotic myelopathy: a comparative analysis with laminoplasty technique.

INTRODUCTION: The purpose of this study was to evaluate the effectiveness of selective laminectomy compared with laminoplasty for patients with multilevel cervical spondylotic myelopathy (CSM) by evaluating the radiological and clinical outcomes. METHODS: We retrospectively reviewed 67 patients with who underwent posterior laminectomy (LN) or laminoplasty (LP). LN was performed in 32 cases and LP in 35 cases. Radiologically, we evaluated the neutral C2-7 Cobb angle and range of motion (ROM) preoperatively and at final follow-up. Preoperative spinal cord compression and expansion of the spinal cord area postoperatively was evaluated using MRI. Differences in operating time and intraoperative and postoperative bleeding were analyzed. The clinical outcome was analyzed using the neck disability index (NDI) and the visual analog scale (VAS) for neck pain. RESULTS: Surgery was performed on 2.04 segments in the LN group and 4.06 in the LP group. Cobb angle and ROM significantly decreased in the LN group at the final follow-up. No difference was found in the preoperative cord compression ratio or extent of expansion of the spinal cord postoperatively. The laminectomy group had a significantly shorter operation time and less intraoperative and postoperative bleeding. Both groups showed improved NDI, JOA score, and VAS for neck pain after surgery, with no significant differences. CONCLUSION: Selective posterior laminectomy for the treatment of multilevel CSM showed advantages of shorter operation time and less blood loss, without a significant difference in clinical outcome, when compared with laminoplasty. However, postoperative kyphosis and decreased range of motion were limitations of laminectomy.

Cervical radiculopathy combined with cervical myelopathy: prevalence and characteristics.

Patients with cervical myelopathy may experience symptoms of radiculopathy, and it is not easy to determine whether these symptoms are caused by the myelopathy itself or by a radiculopathy accompanied by root compression. Therefore, we aimed to investigate the prevalence of radiculopathy combined with cervical myelopathy and to evaluate the characteristics of cervical myelopathy with or without radiculopathy. We enrolled 127 patients with cervical myelopathy in this retrospective study and reviewed their medical records and magnetic resonance imaging findings. They were divided into two groups according to the presence of cervical radiculopathy, and their age, sex, involved spinal segment, cord signal change, surgical method, clinical status were compared, and postsurgical recovery was compared using four clinical questionnaires. The incidence and level of radiculopathy combined with myelopathy were investigated. Combined cervical radiculopathy and myelopathy was diagnosed in 66 patients (51.9%, group 1), whereas 61 patients did not have radiculopathy (group 2). There was no difference in sex, age, cord signal change, preoperative Japanese Orthopedic Association score, neck disability index, and neck visual analogue scale (VAS) between the two groups, but group 1 showed higher preoperative arm VAS score (p = 0.001). Postoperative arm and neck VAS scores were significantly improved in group 1 (p = 0.001 and 0.009). Half of the patients had combined cervical myelopathy and radiculopathy. A high preoperative arm VAS score was a characteristic of radiculopathy combined with myelopathy.

Limitation of previous Allen classification and subaxial cervical spine injury classification (SLIC) system in distractive-extension injury of cervical spine: proposal of modified classification system.

PURPOSE: To verify the clinical applicability of a modified classification system in distractive-extension cervical spine injury that reflects the degrees of soft tissue damage and spinal cord injury while complementing previous Allen classification and subaxial cervical spine injury classification (SLIC) system. METHODS: A total of 195 patients with cervical spine distraction-extension (DE) injury were retrospectively classified. We added stages IIIA (with concomitant spinal cord injury without bony abnormalities) and IIIB (with concomitant additional soft tissue swelling) to the existing stages I and II of the Allen classification. We also supplemented the SLIC system by refining and assigning scores to bony morphology and soft tissue damage. The previous and proposed classification systems were compared by analyzing their scoring performances in terms of clinical features and prognosis. RESULTS: The Allen classification yielded 153 and 42 patients with stage 1 and 42 stage 2 injuries, respectively. Patients classified according to the proposed system were stratified as follows: stage I, 58; stage II, 27; stage IIIA, 33; and stage IIIB, 77. Regarding neurological symptoms and prognosis, stages IIIA and IIIB were poorer than stage I but significantly better than stage II (P < 0.05). On the SLIC system, 146 patients scored ≥5; and 37 and 12 patients scored 4 and ≤3 points, respectively, whereas the numbers of patients who scored ≥5, 4, and ≤3 points on the modified SLIC system were 170, 21, and 4, respectively. CONCLUSIONS: The proposed classification and scoring system to complement the Allen classification and SLIC system with respect to the degrees of soft tissue damage and spinal cord injury is considered effective for diagnosing and determining therapeutic directions and prognosis in cases of cervical spine extension injury.

Relationship between magnetic resonance imaging findings and spinal cord injury in extension injury of the cervical spine.

OBJECTIVE: The purpose of this study was to determine the relationship between magnetic resonance imaging (MRI) findings and neurologic symptoms in cervical spine extension injury and to analyze the MRI parameters associated with neurologic outcome. MATERIALS AND METHODS: This study included 102 patients with cervical spine extension injury, whose medical records and MRI scans at the time of injury were available. Quantitative MRI parameters such as maximum spinal canal compression (MSCC), maximum cord compromise (MCC), and lesion length showing intramedullary signal changes were measured. Furthermore, intramedullary hemorrhage, spinal cord edema, and soft tissue damage were evaluated. Fisher's exact test was used for a cross-analysis between the MRI findings and the three American Spinal Injury Association category groups depending on the severity level of neurologic injury: complete (category A), incomplete (categories B-D), and normal (category E). RESULTS: MSCC accounted for 23.05, 19.5, and 9.94 % for the complete, incomplete, and normal AIS categories, respectively, without showing statistically significant differences (P = 0.085). MCC was noted in 22.05, 15.32, and 9.2 %, respectively, with the complete-injury group (AIS category A) showing significantly higher. In particular, cases of complete injury had >15 % compression, accounting for 87.5 % (P < 0.001). The mean intramedullary lesion length was significantly higher in complete-injury patients than in incomplete-injury patients (24.22 vs. 8.24 mm). Intramedullary hemorrhage and spinal cord edema were significantly more frequently observed in complete-injury cases (P < 0.001). The incidence of complete injury was proportional to the severity of soft tissue damage. CONCLUSION: MCC, intramedullary lesion length, intramedullary hemorrhage, and spinal cord edema were MRI parameters associated with poor neurologic outcomes in patients with cervical spine extension injury.

Prognostic factors in distractive extension injuries of the subaxial cervical spine.

BACKGROUND: The subaxial spine has high risk of fatal damage by trauma and thereby requires more accurate and aggressive treatment. For the proper treatment and predicting the prognosis, the evaluation to reveal the risk factors for the prognosis is important. We analyzed the various factors contributing to the prognosis in distractive extension injuries of the subaxial cervical spine. METHODS: The study included 103 patients who were diagnosed as distractive extension injury of subaxial cervical spine. We evaluate the patient age, sex, cause of injury, initial neurological impairment, number and portion of injured segment, spinal stenosis, extent of soft tissue damage, ossification of the posterior longitudinal ligament, and degenerative spondylosis as a prognostic factor. To analyze the factor related with prognosis, the subjects were divided into group A, in which patients had neurological recovery ≥grade 2 on the ASIA scale or showed normal in final follow-up and group B, in which patients have no neurological recovery. RESULTS: Prognosis was not associated with age, sex, and cause of injury (P = 0.677, 0.541, and 0.965, respectively). Prognosis was poor in cases with spinal stenosis (P = 0.009), soft tissue damage ≥grade 3 on magnetic resonance imaging (MRI) (P = 0.002), or severe neurological impairment (P ≤ 0.001). Logistic regression analysis also showed that prognosis was poor in cases with spinal stenosis (OR 5.03; 95% CI 1.20-16.93), soft tissue damage ≥grade 3 on MRI (OR 7.63; 95% CI 1.86-31.34), or severe neurological impairment (ASIA C, D, OR 0.59, 95% CI 0.14-2.41; ASIA A, B, OR 18.43, 95% CI 1.64-207.69). CONCLUSION: The prognosis of patients with distractive extension injury of the subaxial cervical spine was poor in cases with spinal stenosis, severe soft tissue damage in MRI findings or severe initial neurological impairment.

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

OBJECT: This study was intended to objectively demonstrate the effect of interspinous implantation through preoperative and postoperative radiological analyses in degenerative lumbar spinal stenosis. METHODS: This 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. RESULTS: The 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. CONCLUSIONS: In 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.

Adjacent segment degenerative disease: is it due to disease progression or a fusion-associated phenomenon? Comparison between segments adjacent to the fused and non-fused segments.

INTRODUCTION: The purpose of this study was to determine whether fusion causes adjacent segment degeneration or whether degeneration is due to disease progression. MATERIALS AND METHODS: Eighty-seven patients that had undergone single level anterior cervical decompression and fusions with at least 5 years of follow-up were enrolled in this retrospective study. Segments adjacent to fusion levels (above or below) were allocated to group A, and all others were allocated to group B. Radiographic evaluations of adjacent level changes included assessments of; disc degenerative changes, anterior ossification formation, and segmental instability. The developments of new clinical symptoms were also evaluated. RESULTS: In group A, adjacent segment degenerative change developed in 28 segments (16%) and two cases (2%) developed new clinical symptoms. In group B, adjacent segment degenerative change developed in 10 segments (3%), and two cases (0.7%) also developed new clinical symptoms. Additional operations were performed in one patient in each group. CONCLUSION: Although, fusion per se can accelerate the severity of adjacent level degeneration, no significant difference was observed between adjacent and non-adjacent segments in terms of the incidence of symptomatic disease. The authors conclude that adjacent segment disease is more a result of the natural history of cervical spondylosis than the presence of fusion.

Radiological Assessment of the Effects of Anterior Cervical Discectomy and Fusion on Distraction of the Posterior Ligamentum Flavum in Patients with Degenerative Cervical Spines.

BACKGROUND: This study aimed to assess the effects of anterior cervical discectomy and fusion (ACDF) on distraction of the posterior ligamentum flavum (LF) by increasing the intervertebral disc height and positioning a graft in patients with degenerative cervical spine disease. METHODS: Sixty-eight patients with degenerative cervical diseases who underwent single-level ACDF were included in the analysis. The intervertebral disc height, Cobb angle, and transverse thickness of the LF were measured, and magnetic resonance imaging was performed both preoperatively and 6 weeks postoperatively on each patient. Correlation analyses were performed to evaluate the relationships between age, sex, change in intervertebral disc height, Cobb angle, and position of the intervertebral implant according to the postoperative change in LF thickness. The position of the intervertebral implant was categorized as anterior, middle, or posterior. We also evaluated radiological effects according to the implant position. RESULTS: The mean intervertebral disc height increased from 5.88 mm preoperatively to 7.49 mm postoperatively. The Cobb angle was 0.88° preoperatively and 1.43° postoperatively. Age (p = 0.551), sex (p = 0.348), position of cage (p = 0.312), pre- and postoperative intervertebral disc height (p = 0.850, p = 0.900), Cobb angle (p = 0.977, p = 0.460), and LF thickness (p = 0.060, p = 1.00) were not related to changes in postoperative LF thickness. Postoperative increase in disc height was related to Cobb angle (r = 0.351, p = 0.038). No other factors were significantly related. The position of the cage was not related with the change of Cobb angle (p = 0.91), LF thickness (p = 0.31), or disc height (p = 0.54). CONCLUSIONS: Change in the intervertebral disc height and the position of the intervertebral implant after ACDF did not affect the thickness of the LF after surgery in patients with degenerative cervical spine disease.

Prognosis of Hardware-Related Problems in Anterior Cervical Discectomy and Fusion with Cage and Plate Constructs.

OBJECTIVE: To analyze hardware-related problems and their prognoses after anterior cervical discectomy and fusion (ACDF) using cages and plates for degenerative and traumatic cervical disc diseases. METHODS: The study included 808 patients who underwent anterior cervical discectomy and fusion for degenerative and traumatic disc diseases with >1 year of follow-up. We investigated time of onset and progression of problems associated with instrumentation and cage usage. The mean follow-up time was 3.4 years. Type of plate, range and level of fusion, patient factors (age, sex, body mass index, and bone mineral density), and local kyphosis were evaluated. RESULTS: Complications were found in 132 cases (16.5%), including subsidence in 69 cases, plate loosening in 8 cases, screw loosening in 8 cases, screw breakage in 1 case, and multiple complications in 36 cases. In 3 cases, additional posterior cervical surgery was performed. One case needed hardware revision. There were no esophageal, tracheal, or neurovascular structural injuries secondary to metal failure. There were no significant differences in type of plate, level of surgery, or patient factors. The greater the number of fusion segments, the greater the incidence of complications (P = 0.001). The clinical outcomes improved regardless of the complications (P = 0.083). CONCLUSIONS: Most hardware-related complications are not symptomatic and can be treated conservatively. Only a few cases need revision surgery. Precise surgical techniques are needed in multilevel anterior cervical discectomy and fusion (>3 levels) because of the increased complication rate.

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 (Cronbach's alpha=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.

Etiology and Related Factors of Postoperative Delirium in Orthopedic Surgery.

BACKGROUND: Delirium is a serious complication for elderly patients after orthopedic surgery. The purpose of this study was to assess the etiology and related factors of delirium after orthopedic surgery in Korea. METHODS: We retrospectively reviewed the medical records of 3,611 patients over 50 years who had orthopedic surgery. The age of patients (50s, 60s, 70s, and > 80s), type of anesthesia (general, spinal, and local), operation time (more than 2 hours vs. less than 2 hours), surgical site (spine, hip, knee, or others), and etiology (trauma or disease) were compared to determine possible risk factors of delirium after orthopedic surgery. RESULTS: Of 3,611 patients, 172 (4.76%) were diagnosed with delirium after orthopedic surgery. Postoperative delirium occurred in 1.18% in their 50s, 3.86% in their 60s, 8.49% in their 70s, and 13.04% in > 80s (p < 0.001). According to anesthesia type, 6.50% of postoperative delirium occurred after general anesthesia, 0.77% after spinal anesthesia, and 0.47% after local anesthesia (p < 0.001). More than 2 hours of operation was associated with higher occurrence of delirium than less than 2 hours was (5.88% vs. 4.13%, p = 0.017). For the etiology, 8.17% were trauma cases and 3.02% were disease (p < 0.001). Postoperative delirium occurred in 22 of 493 patients (4.46%) after spine surgery, 18 of 355 patients (5.07%) after hip surgery, 17 of 394 patients (4.31%) after knee surgery, and 15 of 1,145 patients (1.31%) after surgery at other sites (p < 0.001). CONCLUSIONS: Postoperative delirium was more common in older patients who had surgery under general anesthesia, whose surgery took more than 2 hours, and who were hospitalized through the emergency room.

Influence of Atlantoaxial Fusion on Sagittal Alignment of the Occipitocervical and Subaxial spines in Os Odontoideum with Atlantoaxial Instability.

Study Design: Retrospective case analysis. Purpose: We hypothesized that larger the C1-C2 fusion angle, greater the severity of the sagittal malalignment of C0-C1 and C2- C7. Overview of Literature: In our experience, instances of sagittal malalignment occur at C0-C1 and C2-C7 following atlantoaxial fusion in patients with Os odontoideum (OO). Methods: We assessed 21 patients who achieved solid atlantoaxial fusion for reducible atlantoaxial instability secondary to OO. The mean patient age at the time of the operation was 42.8 years, and the mean follow-up duration was 4.9 years. Radiographic parameters were preoperatively measured and at the final follow-up. The patients were divided into two groups (A and B) depending on the C1-C2 fusion angle. In group A (n=11), the C1-C2 fusion angle was ≥22°, whereas in group B, it was <22°. The differences in the radiographic parameters of the two groups were evaluated. Results: At the final follow-up, the C1-C2 angle was increased. However, this increase was not statistically significant (18° vs. 22°, p=0.924). The C0-C1 angle (10° vs. 5°, p<0.05) and C2-C7 angle (22° vs. 13°, p<0.05) significantly decreased. The final C1-C2 angle was negatively correlated with the final C0-C1 and C2-C7 angles. The final C0-C1 angle (4° vs. 6°, p<0.05) and C2-C7 angle (8° vs. 20°, p<0.05) were smaller in group A than in group B. After atlantoaxial fusion, the C0-C1 range of motion (ROM; 17° vs. 9°, p<0.05) and the C2-C7 ROM (39° vs. 31°, p<0.05) were significantly decreased. Conclusions: We found a negative association between the sagittal alignment of C0-C1 and C2-C7 after atlantoaxial fusion and the C1-C2 fusion angle along with decreased ROM. Therefore, overcorrection of C1-C2 kyphosis should be avoided to maintain good physiologic cervical sagittal alignment.

Posterior Sublaminar Wiring and/or Transarticular Screw Fixation for Reducible Atlantoaxial Instability Secondary to Symptomatic Os Odontoideum: A Neglected Technique?

STUDY DESIGN: Retrospective case analysis. PURPOSE: We retrospectively evaluated the clinical and radiological outcomes of posterior sublaminar wiring (PSLW) and/or transarticular screw fixation (TASF) for reducible atlantoaxial instability (AAI) secondary to os odontoideum. OVERVIEW OF LITERATURE: Limited information is available about the surgical outcomes of symptomatic os odontoideum with AAI. METHODS: We examined 23 patients (12 women and 11 men) with os odontoideum and reducible AAI. The average age of the patients at the time of the operation was 44.2 years. The average follow-up duration was 4.5 years. Thirteen patients with anterior AAI underwent PSLW alone, while 10 patients with combined (anterior+posterior) AAI underwent PSLW and TASF. An autogenous iliac bone graft was used for all patients. Nine patients complained of neck or suboccipital pain, and 14 complained of myelopathy. RESULTS: Angulational instability (preoperative 18.7°±8.9° vs. postoperative 2.1°±4.6°, p<0.001), translational instability (16.3±4.9 mm vs. 1.8±2.2 mm, p<0.001), and segmental angle of the C1-C2 joint (23.7°±7.2° vs. 28.4°±3.8°, p<0.05) showed significant improvement postoperatively. Neck Visual Analog Scale score (6.2±2.4 vs. 2.5±1.8, p<0.05) and the modified Japanese Orthopedic Association (9.1±3.1 vs. 13.2±2.6, p<0.05) score also improved, with a recovery rate of 51.8%. Among the three patients who developed nonunion and/or wire breakage, one underwent revision surgery with repeat PSLW and was finally able to achieve fusion. The final fusion rate was 91.3%. CONCLUSIONS: PSLW and/or TASF provided satisfactory clinical and radiological outcomes in reducible AAI secondary to os odontoideum without significant neurological complications. Our results suggest that PSLW and/or TASF can be considered a viable surgical option over segmental fixation in highly selected cases of os odontoideum with reducible AAI.

Clinical and Radiological Characteristics of Ossification of the Posterior Longitudinal Ligament of the Cervical Spine in Patients without Myelopathy: Results of a 1-year Pilot Study.

AIM: We analyzed the demographics, clinical and radiological characteristics of non-myelopathic cervical ossification of the posterior longitudinal ligament (OPLL) patients. MATERIAL AND METHODS: This study included 115 patients with cervical OPLL but without myelopathy. Demographic features of age, sex, and the nature of the patient"s symptoms were evaluated. Clinically, visual analog scale (VAS) scores for the neck and arm, and Japanese Orthopaedic Association (JOA) scores were evaluated. Radiologically, the number of involved segments, type of OPLL, and the maximal compression ratio were analyzed using a computed tomography (CT) scan. The relationship between clinical scores and radiological parameters was analyzed. RESULTS: At the time of diagnosis, there was absence of symptoms in 23, axial neck pain in 44, radiculopathy in 40, and tingling sensation of fingers in 8. VAS score for the neck was 4.42 and that for the arm was 3.64. The mean JOA score was 16.13. Radiologically, the mean number of involved segments was 3.55. The type of OPLL mass was continuous, mixed, segmental, and local in 10, 43, 42, and 20 cases, respectively. The maximal compression ratio was 0.38. There was a significant relationship between the maximal compression ratio and the number of involved segments (p < 0.001). No relationship was found between clinical symptoms, clinical scores, and radiological findings. CONCLUSION: Some non-myelopathic cervical OPLL patients showed no symptoms, some presented axial neck pain and radiculopathy. Radiologically, a significant relationship between the maximal compression ratio and the number of involved segments was found. However, there was no relationship between clinical symptoms and radiological findings in neurologically intact patients.

Are There Differences in the Progression of Ossification of the Posterior Longitudinal Ligament Following Laminoplasty Versus Fusion?: A Meta-Analysis.

STUDY DESIGN: Systematic review and meta-analysis of studies for the treatment of cervical myelopathy with ossification of the posterior longitudinal ligament (OPLL) treated with laminoplasty or fusion. OBJECTIVE: To delineate whether OPLL continues to progress after laminoplasty compared with fusion and to clarify the relationship between radiological progression of OPLL and neurological decline. SUMMARY OF BACKGROUND DATA: Laminoplasty is usually performed in patients with multilevel OPLL due to the surgical morbidity of anterior surgery. However, the disadvantage of laminoplasty is that the remaining OPLL can progress after the surgery. METHODS: A literature search of PubMed, Embase, Web of Science, and the Cochrane library was performed to identify investigations concerning the progression of OPLL after laminoplasty or fusion. The pooled results were analyzed by calculating the effect size based on the event rate and the logit event rate. RESULTS: We included data from 11 studies involving 530 patients, of whom 429 underwent laminoplasty and 101 underwent fusion surgery. The prevalence of radiological OPLL progression was 62.5% (95% confidence interval [CI] 55.3%-69.3%) for the laminoplasty group and 7.6% (95% CI 3.4%-15.9%) for the fusion group. The laminoplasty displayed substantially high prevalence of the progression of OPLL compared with the fusion group. In the laminoplasty group, the prevalence of OPLL progression increased with time and reached 60% at about 10-year follow-up. The prevalence for neurological decline was similar for about 2 years, 8.3% (95% CI 3.7%-17.9%) for the laminoplasty group and 3.8% (95% CI 1.3%-10.2%) for the fusion group. CONCLUSION: Laminoplasty frequently induces progression of OPLL compared with fusion surgery, but does not make significant clinical deterioration. However, laminoplasty may not be recommended for OPLL patient because it can be getting worse with time. LEVEL OF EVIDENCE: 1.

Acute airway obstruction due to postoperative retropharyngeal hematoma after anterior cervical fusion: a retrospective analysis.

BACKGROUND: Acute airway obstruction (AAO) after anterior cervical fusion (ACF) can be caused by postoperative retropharyngeal hematoma, which requires urgent recognition and treatment. However, the causes, evaluation, and appropriate treatment of this complication are not clearly defined. The purpose of this retrospective review of a prospective database was to investigate etiologic factors related to the development of AAO due to postoperative hematoma after ACF and formulate appropriate prevention and treatment guidelines. METHODS: Cervical spinal cases treated at our academic institutions from 1998 to 2013 were evaluated. Demographic data, including factors related to hemorrhagic tendency, and operative data were analyzed. Patients who developed a hematoma were compared with those who did not to identify risk factors. Cases complicated by hematoma were reviewed, and times until development of hematoma and surgical evacuation were determined. Degrees of airway compromise and patient behavior were classified and evaluated. Treatment was selected according to the patient's status. RESULTS: Among 785 ACF procedures performed, there were nine cases (1.15%) of AAO. None of these nine patients had preoperative risk factors. In six patients (67%), the hematoma occurred within 24 h, whereas three patients (33%) presented with hematoma at a median of 72 h postoperatively. Four of the nine patients with AAO underwent evacuation of the hematoma. Two patients with inspiratory stridor, anterior neck swelling, and facial edema progressed to respiratory distress and their hematomas were removed by surgery, during which, sustained superficial venous bleeding was confirmed. Intubation was attempted several times in one patient with cyanosis, but is unsuccessful; cricothyroidotomy was performed in this patient and pumping in the small muscular arterial branches was confirmed in the operating room. All of the patients recovered without any complications. CONCLUSIONS: With rapid recognition and appropriate treatment, there were no long-term complications caused by postoperative hematoma. There were no specific preoperative risk factors for hematoma. Systematic evaluation and appropriate management can be helpful for preventing serious complications after development of a postoperative hematoma.

Significance of Intramedullary High Signal Intensity on Magnetic Resonance Imaging in Patients with Cervical Ossification of the Posterior Longitudinal Ligament.

BACKGROUND: The purpose of this study was to analyze the relation between intramedullary high signal intensity (IMHS) on magnetic resonance imaging (MRI), radiographic parameters, and clinical symptoms in cervical ossification of the posterior longitudinal ligament (OPLL) patients. METHODS: Two hundred forty-one patients, who underwent simple radiography, computed tomography (CT), and MRI were included in the present study. As radiographic parameters, the OPLL occupying ratio and occupying area were measured on CT images. Dynamic factors were assessed by measuring cervical range of motion (ROM) on simple radiographs. Visual analog scale (VAS) for neck and arm pain, and Japanese Orthopaedic Association (JOA) scores were evaluated for clinical analysis. The differences in radiographic and clinical findings were assessed between patients with IMHS on T2-weighted MRI findings (group A) and patients without IMHS (group B). RESULTS: Eighty-one patients were assigned to group A and 160 patients to group B. The occupying ratios were found to be higher in group A than in group B on both sagittal and axial views (p < 0.01). Group A also showed a higher area occupying ratio (p < 0.01). The length and area of underlying spinal canal on the sagittal and cross-sectional planes were lower in group A than in group B (p < 0.01). No significant difference in ROM was observed (p = 0.63). On the clinical findings, group A had a lower JOA score (p < 0.001), and no intergroup differences in VAS scores were observed. CONCLUSIONS: In cervical OPLL cases, IMHS on MRI was associated with manifestation of myelopathic symptom. Occupying ratio was associated with high signal intensity on MRI, whereas no association was found with ROM. Occurrence of high signal intensity increased inversely with the length and area of underlying spinal canal.