Direct Internal Fixation for Unstable Atlas Fractures

Purpose@#To investigate the radiologic and clinical outcomes of direct internal fixation for unstable atlas fractures. @*Materials and Methods@#This retrospective study included 12 patients with unstable atlas fractures surgically treated using C1 lateral mass screws, rods, and transverse connector constructs. Nine lateral mass fractures with transverse atlantal ligament (TAL) avulsion injury and three 4-part fractures with TAL injury (two avulsion injuries, one TAL substance tear) were treated. Radiologic outcomes included the anterior atlantodental interval (AADI) in flexion and extension cervical spine lateral radiographs at 6 months and 1 year after treatment. CT was also performed to visualize bony healing of the atlas at 6 months and 1 year. Visual Analog Scale (VAS) scores for neck pain, Neck Disability Index (NDI) values, and cervical range of motion (flexion, extension, and rotation) were recorded at 6 months after surgery. @*Results@#The mean postoperative extension and flexion AADIs were 3.79±1.56 (mean±SD) and 3.13±1.01 mm, respectively. Then mean AADI was 3.42±1.34 and 3.33±1.24 mm at 6 months and 1 year after surgery, respectively. At 1 year after surgery, 11 patients showed bony healing of the atlas on CT images. Only one patient underwent revision surgery 8 months after primary surgery due to nonunion and instability findings. The mean VAS score for neck pain was 0.92±0.99, and the mean NDI value was 8.08±5.70. @*Conclusion@#C1 motion-preserving direct internal fixation technique results in good reduction and stabilization of unstable atlas fractures. This technique allows for the preservation of craniocervical and atlantoaxial motion.

Lumbar Spinal Stenosis: Pathophysiology and Treatment Principle: A Narrative Review

Patients with lumbar spinal stenosis may exhibit symptoms such as back pain, radiating pain, and neurogenic claudication. Although long-term outcome of treatments manifests similar results for both nonsurgical and surgical treatments, positive effects such as short-term improvement in symptoms and decreased fall risk may be expected with surgery. Surgical treatment is basically decompression, and a combination of treatments can be added depending on the degree of decompression and the accompanying instability. Recently, minimally invasive surgery has been found to result in excellent outcomes in the treatment of lumbar spinal stenosis. Therefore, better treatment effects can be anticipated with an approach aimed at understanding the overall pathophysiology and treatment methods of lumbar spinal stenosis.

A Case of Intraoperative Anaphylaxis Caused by Bovine-Derived Thrombin

Intraoperative bovine-derived topical thrombin is still widely used for hemostasis during surgery. A 38-year-old woman with chronic spontaneous urticaria was referred to the orthopedic surgery department for herniated disk and myelopathy. During the first stage of operation, bovine-derived thrombin powder soaked in Gelfoam was used as a hemostatic aid. After 30 minutes, the patient developed anaphylactic shock with systemic skin rash and angioedema. Repeated intravenous bolus and infusion of vasopressor were carried out, and her blood pressure normalized. Skin test and specific immunoglobulin E test showed positive results for bovine thrombin and beef, respectively. During the second stage of operation (After 10 days from first stage of operation), bovine-derived thrombin powder was excluded and the operation was successful without any unexpected events. Therefore, bovine thrombin should be used with caution because it might cause anaphylaxis.

Results of Magnetically Controlled Growing Rods for Early Onset Scoliosis / 대한정형외과학회잡지

PURPOSE: To evaluate the first results of surgical treatment using newly developed magnetically controlled growing rods (MCGR) for early onset scoliosis (EOS). MATERIALS AND METHODS: From January 2013 to January 2017, 5 patients, who underwent surgical treatment with MCGR for EOS and were followed for more than one year, were analyzed retrospectively. The demographic and radiology data, including age at surgery, diagnosis, number of lengthening, Cobb angle, T1–S1 length, T1–T12 length, and complications, were analyzed. RESULTS: The mean age of the patients was 6.0±2.7 years old. The subjects were 3 males and 2 females: 2 with neuromuscular scoliosis, 1 with syndromic scoliosis, 1 with idiopathic scoliosis, and 1 with congenital scoliosis. The mean number of lengthening was 9.8±2.9 times and the follow-up was 21.6±5.7 months. The Cobb angle improved from 82.0°±28.5° to 48.3°±28.8° at the last follow-up. The T1–S1 length increased from 283.1±72.7 mm to 342.6±86.3 mm at the last follow-up. The T1–T12 length increased from 163.1±50.5 mm to 202.3±65.5 mm at the last follow-up. One screw loosening complication was encountered and there were no neurological complications. CONCLUSION: The treatment using MCGR for EOS is effective and useful.

Effect of Sagittal Balance on Risk of Falling after Lateral Lumbar Interbody Fusion Surgery Combined with Posterior Surgery

PURPOSE: To demonstrate the impact of correcting sagittal balance (SB) on functional outcomes of surgical treatment for degenerative spinal disease and actual falls via utilization of new minimally invasive lumbar fusion techniques via a lateral approach. MATERIALS AND METHODS: From November 2011 to March 2015, we enrolled 56 patients who underwent minimally invasive lateral lumbar interbody fusion (LLIF) and matched 112 patients receiving decompression/postero-lateral fusion (PLF) surgery for lumbar spinal stenosis. According to SB status using C7-plumb line-distance (C7PL) and surgery type, patients were divided into three groups: SB PLF, sagittal imbalance (SI) PLF, and LLIF groups. We then compared their outcomes. RESULTS: The mean C7PL was 6.2±13.6 mm in the SB PLF group, 72.9±33.8 mm in the SI PLF group, and 74.8±38.2 mm in the LLIF group preoperatively. Postoperatively, C7PL in only the LLIF group improved significantly (p=0.000). Patients in the LLIF group showed greater improvement in fall-related functional test scores than the SI PLF group (p=0.007 for Alternate-Step test, p=0.032 for Sit-to-Stand test). The average number of postoperative falls was 0.4±0.7 in the SB PLF group, 1.1±1.4 in the SI PLF group, and 0.8±1.0 in the LLIF group (p=0.041). Oswestry Disability Index and the Euro-QoL 5 dimension visual analogue scale scores also showed greater improvements in the LLIF group than in the SI PLF group at postoperative 1 year (p=0.003, 0.016). CONCLUSION: Surgical correction of SI in patients with lumbar spinal stenosis using a combination of minimal invasive LLIF and posterior surgery achieved better surgical outcomes and a lower incidence of actual falls than PLF surgery.

Efficacy and Safety of Different Aceclofenac Treatments for Chronic Lower Back Pain: Prospective, Randomized, Single Center, Open-Label Clinical Trials

PURPOSE: Nonsteroidal anti-inflammatory drugs are a mainstay for medical treatment of chronic lower back pain (CLBP). Increased dose intervals for medication have been associated with increased patient adherence to prescriptions. The purpose of this clinical trial was to compare the efficacy and safety of a once daily dose of aceclofenac controlled release (CR) and a twice daily dose of aceclofenac for CLBP management. MATERIALS AND METHODS: A prospective, randomized, single center, open-label clinical trial was performed to compare the efficacy and safety of aceclofenac CR (200 mg once daily) to aceclofenac dose (100 mg twice daily). Fifty patients in each group were enrolled for the study. The primary end point was Visual Analogue Scale (VAS) change at baseline to that at 2 weeks after medication and safety profiles. Also, change in quality of life measured by EuroQoL 5D (EQ-5D) and Oswestry Disability Index (ODI) functional score for the lumbar spine were also assessed. RESULTS: Within groups at pre- and post-treatment, there were significant VAS reductions for aceclofenac CR and aceclofenac (p=0.028). EQ-5D increased significantly in both groups (p=0.037). ODI scores decreased significantly in both groups (p=0.012). However, there were no significant differences between aceclofenac CR and aceclofenac at pre- and post-treatment. Patients with aceclofenac CR showed significant increases in heartburn and indigestion and adverse gastrointestinal effects, compared to aceclofenac. CONCLUSION: In patients with CLBP, aceclofenac CR and aceclofenac demonstrated significant symptomatic pain relief, improvement in quality of life and functional scores. Aceclofenac CR slightly increased gastrointestinal adverse effects, such as heartburn and indigestion.

Dual Growing Rod Treatment for Progressive Pediatric Spinal Deformity

STUDY DESIGN: Retrospective study. OBJECTIVES: To evaluate the outcomes of dual growing rod treatment over a follow-up period of at least 2 years in patients with progressive pediatric spinal deformity. SUMMARY OF LITERATURE REVIEW: The dual growing rod treatment is safe and effective in curve correction and maintenance in patients with progressive pediatric spinal deformity. MATERIALS AND METHODS: Between 2009 to 2017, 14 patients who underwent dual growing rod treatment were followed up for more than 2 years. We analyzed their demographic and radiologic data, including age at surgery, sex, diagnosis, instrumented levels, number of total operations, number of lengthening procedures, interval of lengthening, Cobb angle, thoracic kyphosis angle, lumbar lordosis angle, T1-S1 length, and complications. RESULTS: The mean age of the patients was 11.0±2.9 years old. There were 10 male and 4 female patients, including 8 cases of neuromuscular scoliosis, 3 cases of idiopathic scoliosis, 2 cases of spondyloepiphyseal dysplasia, and 1 case of congenital scoliosis. The mean follow-up period was 42.4±14.0 months. The total number of operations was 6.6±2.6. The average number of lengthening procedures was 4.3±2.3 at an interval of 6.9±2.1 months. The Cobb angle improved from 60.4°±27.9° to 33.5°±19.7° after the initial treatment and 29.1°±16.4° after the last follow-up or final fusion. The T1-S1 length increased from 328.2±57.5 mm to 388.0±64.9 mm after the initial treatment and 424.9±64.4 mm after the last follow-up or final spinal fusion. The average growth rate was 11.5 mm/year. Six patients experienced 11 complications, of which 4 were Implant-related, and 7 were Infections. CONCLUSIONS: The dual growing rod technique is an effective and relatively safe treatment in patients with progressive pediatric spinal deformity.

Prevalence of Neuropathic Pain and Patient-Reported Outcomes in Korean Adults with Chronic Low Back Pain Resulting from Neuropathic Low Back Pain

STUDY DESIGN: A noninterventional, multicenter, cross-sectional study. PURPOSE: We investigated the prevalence of neuropathic pain (NP) and patient-reported outcomes (PROs) of the quality of life (QoL) and functional disability in Korean adults with chronic low back pain (CLBP). OVERVIEW OF LITERATURE: Among patients with CLBP, 20%–55% had NP. METHODS: Patients older than 20 years with CLBP lasting for longer than three months, with a visual analog scale (VAS) pain score higher than four, and with pain medications being used for at least four weeks before enrollment were recruited from 27 general hospitals between December 2014 and May 2015. Medical chart reviews were performed to collect demographic/clinical features and diagnosis of NP (douleur neuropathique 4, DN4). The QoL (EuroQoL 5-dimension, EQ-5D; EQ-VAS) and functional disability (Quebec Back Pain Disability Scale, QBPDS) were determined through patient surveys. Multiple linear regression analyses were performed to compare PROs between the NP (DN4≥4) and non-NP (DN4 < 4) groups. RESULTS: A total of 1,200 patients (females: 65.7%; mean age: 63.4±13.0 years) were enrolled. The mean scores of EQ-5D, EQ-VAS, and QBPDS were 0.5±0.3, 55.7±19.4, and 40.4±21.1, respectively. Among all patients, 492 (41.0%; 95% confidence interval, 38.2%–43.8%) suffered from NP. The prevalence of NP was higher in male patients (46.8%; p < 0.01), in patients who had pain based on radiological and neurological findings (59.0%; p < 0.01), and in patients who had severe pain (49.0%; p < 0.01). There were significant mean differences in EQ-5D (NP group vs. non-NP group: 0.4±0.3 vs. 0.5±0.3; p < 0.01) and QBPDS (NP group vs. non-NP group: 45.8±21.2 vs. 36.3±20.2; p < 0.01) scores. In the multiple linear regression, patients with NP showed lower EQ-5D (β=−0.1; p < 0.01) and higher QBPDS (β=7.0; p < 0.01) scores than those without NP. CONCLUSIONS: NP was highly prevalent in Korean patients with CLBP. Patients with CLBP having NP had a lower QoL and more severe dysfunction than those without NP. To enhance the QoL and functional status of patients with CLBP, this study highlights the importance of appropriately diagnosing and treating NP.

Agreement on the Level Selection in Laminoplasty among Experienced Surgeons: A Survey-Based Study

STUDY DESIGN: Survey based study. PURPOSE: To assess the degree of agreement in level selection of laminoplasty (LP) for the selected cervical myeloradiculopathy cases between experienced spine surgeons. OVERVIEW OF LITERATURE: Although, cervical LP is a widely used surgical technique for multi-level spinal cord compression, until now there is no consensus about how many segments or which segments should be opened to achieve a satisfactory decompression. METHODS: Thorough clinical and radiographic data (plain X-ray, computed tomography, and magnetic resonance imaging) of 30 patients who had cervical myelopathy were prepared. The data were provided to three independent spine surgeons with over 10 years experience in operation of their own practices. They were questioned about the most preferable surgical method and suitable decompression levels. The second survey was carried out after 6 months with the same cases. If the level difference between respondents was a half level or below, agreement was considered acceptable. The intraobserver and interobserver agreements in level selection were assessed by kappa statistics. RESULTS: Three respondents selected LP as an option for 6, 8, and 22 cases in the first survey and 10, 21, and 24 cases in the second survey. The reasons for selection of LP were levels of ossification of the posterior longitudinal ligament (p=0.004), segmental kyphotic deformity (p=0.036) and mean compression score (p=0.041). Intraobserver agreement showed variable results. Interobserver agreement was poor to fair by perfect matching (kappa=0.111–0.304) and fair to moderate by acceptable matching (kappa=0.308–0.625). CONCLUSIONS: The degree of agreement for level selection of LP was not high even though experienced surgeons would choose the opening segments on the basis of same criteria. These results suggest that more specific guidelines in determination of levels for LP should be required to decrease unnecessary wide decompression according to individual variance.

The Impact of Lumbar Lordosis on the Adjacent Segment Disease after Posterior Lumbar Interbody Fusion

STUDY DESIGN: A retrospective study. OBJECTIVES: We analyzed the risk factors and relevance of lumbar lordosis on the incidence of adjacent segment disease after posterior lumbar interbody fusion. SUMMARY OF LITERATURE REVIEW: Maintaining lumbar sagittal balance is important for decreasing the incidence of adjacent segment disease after posterior lumbar interbody fusion. MATERIALS AND METHODS: Among the patients who had undergone posterior lumbar interbody fusion of 1 or 2 levels between August 2001 and October 2008, we analyzed 153 patients who were available for at least three years of follow-up; among the subjects, 115 were males and 38 were females. Mean age among the patients at the time of initial surgery was 60.3 (range, 41-82) and mean followup period was 5.6 years (range, 3-11). The causative diseases were spinal stenosis in 78 cases, degenerative spondylolisthesis in 51 cases, isthmic spondylolisthesis in 23 cases, and degenerative disc disease in 1 case. At last follow-up, there were 52 cases (33.9%) of adjacent segment disease. Among them were found 21 cases (40.4%) of disc degeneration, 17 cases (32.7%) of instability, and 14 cases (26.9%) of simultaneous disc degeneration and instability. A total of 10 patients (6.5%) underwent a revision operation, and the mean period from initial to revision operation was 5.5 years (range, 3.1-10.3). We analyzed the correlation between risk factors of adjacent segment disease and the incidence of the disease depending on the gap between lumbar lordosis and pelvic incidence, and compared the clinical results of the 2 groups using modified Whitecloud classification. RESULTS: The incidence of adjacent segment disease was not statistically significant for patient age, sex, BMD, degree of obesity, causative disease, and the level of previous surgery. However, the incidence of adjacent segment disease was statistically higher in patients who had more than 9 degrees gap between lumbar lordosis and pelvic incidence (p=0.013). In our analysis of clinical results, 63.5% of the group of patients who developed adjacent segment disease and 80.2% of the group without adjacent segment disease had good or satisfactory results (p=0.031). CONCLUSIONS: Maintaining lumbar sagittal balance is important for decreasing the incidence of adjacent segment disease after posterior lumbar interbody fusion, and close observation is needed in patients with 9 or more degrees gap between lumbar lordosis and pelvic incidence.

Relationship between Bone Mineral Density and Spinal Muscle Area in Magnetic Resonance Imaging

BACKGROUND: Bone mineral density (BMD) is known to have a positive correlation with lean body mass. Several studies have also reported the positive correlation between muscle power and BMD. From this point of view, we hypothesized BMD of lumbar spine to have a positive correlation with muscle mass. METHODS: Seventy-nine female patients aged between 60 and 75 years old and who underwent magnetic resonance imaging (MRI) and BMD studies were included. Muscle mass in spine MRI was defined by the sum of the average muscle area of three axial images for each disc level. Lumbosacral muscle is the sum of paraspinal muscle and psoas muscle. RESULTS: In correlation analysis, paraspinal muscle mass showed positive correlation with BMD of lumbar spine. Lumbosacral muscle mass showed positive correlation with BMD of trochanteric area of the femur. However, BMD of other area showed no significant correlation with muscle mass. CONCLUSIONS: Therefore, postmenopausal women older than 60 years with a well developed spine muscle mass, have a high BMD.

At Least One Cyclic Teriparatide Administration Can Be Helpful to Delay Initial Onset of a New Osteoporotic Vertebral Compression Fracture

PURPOSE: Teriparatide markedly increases bone formation and strength, while reducing the incidence of new-onset osteoporotic vertebral compression fractures (OVCFs). In some countries, expenses for teriparatide use are covered by medical insurance for up to 6 months; however, the national medical insurance of the authors' country does not cover these expenses. This retrospective cohort study compared the therapeutic effects of teriparatide on the initial onset of a new OVCF after treatment of osteoporosis and/or related OVCFs with regard to therapeutic durations of longer than 3 months (LT3M) or shorter than 3 months (ST3M). MATERIALS AND METHODS: From May 2007 to February 2012, 404 patients who were prescribed and administered teriparatide and who could be followed-up for longer than 12 months were enrolled. They were divided into two groups depending on teriparatide duration: LT3M (n=132) and ST3M (n=272). RESULTS: The group with the teriparatide duration of LT3M showed significantly less development of an initial OVCF within 1 year (p=0.004, chi-square). Duration of teriparatide use, body mass index, pre-teriparatide lowest spinal bone mineral density, and severity of osteoporosis significantly affected multiple regression analysis results (p<0.05). Survival analysis of first new-onset OVCFs demonstrated a significantly better survival rate for the LT3M group (log rank, p=0.005). Also, the ST3M group showed a higher odds ratio of 54.00 for development of an initial OVCF during follow-up than the LT3M group (Mantel-Haenzel common odds ratio, p=0.006). CONCLUSION: At least one cyclic teriparatide administration is recommended to provide a protective effect against the initial onset of a new OVCF for up to one year after therapy.

Acute Myocardial Infarction and Postpharyngeal Hematoma after Anterior Cervical Spine Surgery on a Coronary Artery Disease Patient: A Case Report

STUDY DESIGN: Case report. OBJECTIVES: To report a case of preventive intubation to coronary artery disease patient who underwent percutaneous coronary intervention following an anterior cervical spine surgery. SUMMARY OF LITERATURE REVIEW: Postpharyngeal hematoma occurs more to a patient who underwent percutaneous coronary intervention for myocardial infarction following an anterior cervical spine surgery. And postoperative airway obstruction due to it is one of the most serious adverse events associated with anterior cervical spine surgery. Preventive intubation was tried and it was useful for treatment. MATERIALS AND METHODS: A 61-year-old man suffered from neck pain and radiating pain on left upper extremity was performed an anterior cervical spine surgery. After operation, he complained acute myocardial infarction symptoms and Emergency percutaneous coronary intervention was performed. After that, postpharyngeal hematoma appeared and compressed the airway. Intubation was performed to prevent airway obstruction. RESULT: Airway obstruction was prevented through early intubation. Hematoma evacuation and insertion of Hemovac performed and the patient discharged without any complications such as neurologic or cardiac problems. CONCLUSION: Preventive intubation to coronary artery disease patient who underwent percutaneous coronary intervention following an anterior cervical spine surgery is useful for treatment of airway obstruction due to postpharyngeal hematoma.

Gastrointestinal Risk Assessment in the Patients Taking Nonsteroidal Anti-inflammarory Drugs for Lumbar Spinal Disease

STUDY DESIGN: A cross-section observational study. OBJECTIVES: To evaluate the current prescription patterns of non-steroidal anti-inflammatory drugs (NSAIDs) and gastrointestinal (GI) risk assessment in patients with lumbar spine disease. SUMMARY OF LITERATURE REVIEW: NSAIDs are commonly prescribed medications for lumbar spine disease patients. Since the rate of GI complication varies for each patient, identification of individual GI risks is a prerequisite to prevent such a complication. There are few reports about the GI risks in patients with lumbar spine disease who take NSAIDs. MATERIALS AND METHODS: 2264 patients with lumbar degenerative spondylopathy who were taking NSAIDs were enrolled from May 2010 to September 2010. The Standardized Calculator of Risk for Event (SCORE) was used to measure patients' GI risk factors. NSAID prescription patterns and GI protective agents were also investigated. RESULTS: Being aged over 65 (1098 patients; 48.5%) and the presence of GI side-effects from NSAIDs (896 patients; 39.6%) were the most common risk factors. 31.9% and 5.8% percent of patients belonged to each of the high risk and the very high risk groups in GI risk factor analysis. The total prescription rate of gastroprotectants was 91.7% for all patients. However, the prescription rate of selective COX-2 inhibitors in the high risk group was low, and in 54.8% of patients who took COX-2 inhibitors there was GI discomfort. CONCLUSIONS: The prescription pattern of GI protective agents was not correlated with GI symptoms. Therefore, physicians should consider NSAID prescription based on the GI risk factors of individual patients.

Comparative Study of the Clinical Outcomes of Unilateral Transforaminal Lumbar Interbody Fusion(TLIF) with Bilateral TLIF using Wiltse Approach and Conventional Approach

STUDY DESIGN: Comparative study. OBJECTIVES: To compare the outcomes of unilateral TLIF, bilateral TLIF using Wiltse approach and bilateral TLIF using conventional midline approach. SUMMARY OF LITERATURE REVIEW: There are many studies about outcomes of Unilateral TLIF, but few have compared the 3 different fusion procedures. MATERIALS AND METHODS: 60 patients were divided into 3 groups. Each group has enrolled 20 patients (Study group: unilateral TLIF, Control group 1: bilateral TLIF using Wiltse approach, Control group 2: bilateral TLIF using conventional midline approach). For clinical outcomes, we compared operative time, blood loss, time for ambulation and discharge, VAS for back pain and leg pain and ODI among three groups. For radiologic evaluation, disc height and segmental lordosis were examined. RESULTS: The mean operative time was 147 minutes in study group(SG), 172 minutes in control group 1(CG1), 167 minutes in control group 2(CG2). The mean total blood loss was 466ml in SG, 569ml in CG1, 1140ml in CG2 respectively. VAS for back pain at the third postoperative day significantly decreased in SG and CG1 compared with CG2. There was no significant difference in ODI, disc height and segmental lordosis among the groups. CONCLUSION: Using Wiltse approach, there were several advantages in decreasing blood loss, immediate postoperative back pain, hospital stay and early ambulation. Clinical and radiological results of unilateral TLIF were comparable with bilateral TLIF.

Biomechanical Changes of the Lumbar Segment after Total Disc Replacement : Charite(R), Prodisc(R) and Maverick(R) Using Finite Element Model Study

OBJECTIVE: The purpose of this study was to analyze the biomechanical effects of three different constrained types of an artificial disc on the implanted and adjacent segments in the lumbar spine using a finite element model (FEM). METHODS: The created intact model was validated by comparing the flexion-extension response without pre-load with the corresponding results obtained from the published experimental studies. The validated intact lumbar model was tested after implantation of three artificial discs at L4-5. Each implanted model was subjected to a combination of 400 N follower load and 5 Nm of flexion/extension moments. ABAQUStrade mark version 6.5 (ABAQUS Inc., Providence, RI, USA) and FEMAP version 8.20 (Electronic Data Systems Corp., Plano, TX, USA) were used for meshing and analysis of geometry of the intact and implanted models. RESULTS: Under the flexion load, the intersegmental rotation angles of all the implanted models were similar to that of the intact model, but under the extension load, the values were greater than that of the intact model. The facet contact loads of three implanted models were greater than the loads observed with the intact model. CONCLUSION: Under the flexion load, three types of the implanted model at the L4-5 level showed the intersegmental rotation angle similar to the one measured with the intact model. Under the extension load, all of the artificial disc implanted models demonstrated an increased extension rotational angle at the operated level (L4-5), resulting in an increase under the facet contact load when compared with the adjacent segments. The increased facet load may lead to facet degeneration.

Reevaluation of the Pavlov Ratio in Patients with Cervical Myelopathy

BACKGROUND: This study was designed to reevaluate the effectiveness of the Pavlov ratio in patients with cervical myelopathy. METHODS: We studied 107 patients who underwent open door laminoplasty for the treatment of cervical myelopathy between the C3 to C7 levels. We determined the Pavlov ratio on preoperative and postoperative cervical spine lateral radiographs, the vertebral body-to-canal ratio on sagittal reconstruction CT scans, and the vertebral body-to-cerebrospinal fluid (CSF) column ratio on T2-weighted sagittal MR images from C3 to C6. The severity of myelopathy was determined using the JOA score on both preoperative and postoperative images. The recovery rate was also calculated. The Pavlov ratio in plain radiographs from patients with myelopathy was compared with the ratio of the vertebral body to the spinal canal on CT and MRI. RESULTS: The average Pavlov ratio between C3 and C6 ranged from 0.71 to 0.76. On CT scan, the average vertebral body-to-canal ratio between C3 and C6 ranged from 0.62 to 0.66. On MRI, the vertebral body-to-CSF column ratio between C3 and C6 ranged between 0.53 and 0.57. A positive correlation was noted between the Pavlov ratio and the vertebral body-to-canal ratio on sagittal-reconstruction CT (correlation coefficient = 0.497-0.627, p = 0.000) and between the Pavlov ratio and the vertebral body-to-CSF column ratio on MRI (correlation coefficient = 0.511-0.649, p = 0.000). CONCLUSIONS: We demonstrated a good correlation between the Pavlov ratio and both the vertebral body-to-canal ratio on CT and the vertebral body-to-CSF column ratio on MRI. Therefore, the Pavlov ratio can be relied upon to predict narrowing of the cervical spinal canal in the sagittal plane.

The Surgical Treatment of the Cervical Myelopathy with Laminectomy and Posterior Fusion by using Lateral Mass Screw Fixation / 대한정형외과학회잡지

PURPOSE: This prospective study was designed to investigate the outcomes of laminectomy and fusion with using lateral mass screw (LMS) fixation for the treatment of cervical myeolpathy. MATERIALS AND METHODS: We studied a series of 26 consecutive patients with cervical myelopathy and who were planned to undergo laminectomy and fusion with using LMS fixation. MRI was done to investigate the high signal intensity lesion (HSIL) in the cord on the T2 weighted sagittal images. The JOA score, the grip and release test, the finger escape sign, and Hoffman's sign were checked. We analyzed the clinical outcomes depending on the high signal intensity lesion in the cord, the preoperative kyphosis, and the preoperative instability. RESULTS: The indications for lateral mass screw fixation was kyphotic deformity, segmental instability or ossification of the ligament flavum (OLF). Patients with HSIL on the T2-weighted sagittal MRI was found in 17 patients. The JOA score, the grip and release test, and the finger escape sign were significantly improved after the operation and at the 2 year follow up. The patients with HSIL on the T2-weighted sagittal MRI or segmental instability had a significantly lower preoperative JOA score and a poor postoperative recovery as assessed by the JOA score. CONCLUSION: Laminectomy and fusion using lateral mass screw fixation for the surgical treatment of cervical myelopathy, which is associated with kyphotic deformity, instability or OLF, is considered a safe and effective treatment option to prevent postoperative kyphosis.

Outcome Analysis of Single Level Anterior Cervical Fusion using Interbody PEEK Cage with Autologous Iliac Bone Graft / 대한정형외과학회잡지

PURPOSE: Anterior cervical fusion with a tricortical iliac bone graft is a well established procedure for treating degenerative cervical spine disease. An interbody cage has been used to prevent donor site morbidity but there are few reports on the clinical and radiological outcome. MATERIALS AND METHODS: Thirty eight patients, who underwent single level ACDF with PEEK interbody Solis(R)cage (Stryker spine, South Allendale, NJ, USA), were enrolled in this study. This study evaluated Odom's criteria and visual analogue scale (VAS) for the neck, arm and donor site pain, and the radiological findings, including the disk height, cage subsidence, and sagittal alignment of cervical spine. RESULTS: The mean disk height loss was 1.1 mm during the follow up period. Case subsidence >2 mm developed in 17 cases (44.7%). The mean subsidence of this group was 3.09 mm. The bone union rate was 95% at 12 weeks. There was no significant change in the sagittal alignment of the cervical spine. The VAS for neck, arm, and donor site pain improved all cases. Only 9 patients complained of mild discomfort at the donor site CONCLUSION: Single-level ACDF using PEEK interbody cage has a lack of donor site morbidity, excellent clinical outcomes and bone union. However, more study of the factors related to postoperative cage subsidence will be needed.

Loss of Sagittal Balance and Clinical Outcomes following Corrective Osteotomy for Lumbar Degenerative Kyphosis / 대한정형외과학회잡지

PURPOSE: To report the loss of correction of a sagittal imbalance and the clinical outcomes after a corrective osteotomy for lumbar degenerative kyphosis. MATERIALS AND METHODS: This study analyzed the radiological parameters, surgical techniques, and clinical outcomes of 23 patients, who underwent corrective osteotomy for lumbar degenerative kyphosis. The patients were divided into groups I (>5 cm loss of correction of sagittal imblance, 12 patients) and II (3.5 out of 5, 11 patients) was compared with group B (low satisfaction score group <3.5 out of 5, 12 patients). RESULTS: The sagittal imbalance was corrected by performing a Smith-Petersen osteotomy (SPO) in 11 cases and Pedicle subtraction osteotomy (PSO) in 12. The mean preoperative sagittal imbalance was improved from 26.4 cm to 4.05 cm, postoperatively, and 11.2 cm at the last follow up. The mean loss of correction was 11.2 cm in group I and 2.3 cm in group II. The mean satisfaction score was 4.56 in group A and 2.18 in group B. The presence of an old compression fracture was found to be related to the loss of correction, and the preoperative symptomatic spinal stenosis was related to poor clinical outcomes. CONCLUSION: After mean 45 month follow up, the mean loss of sagittal correction was 38.3%, which mainly occurred at the proximal unfused segment. The clinical success rate was 45.5%, regardless of the loss of sagittal balance correction.