The influence of spinopelvic morphologies on sagittal spinal alignment: an analysis of incidence angle of inflection points.

PURPOSE: To elucidate whether specific spinopelvic morphologies affect the subsequent spinal sagittal alignments and determine the alignment patterns. METHODS: Whole-spine standing radiographs of 244 patients were analyzed. Sagittal alignment parameters were compared according to the three types of pelvic version: anteverted pelvis (AP), neutral pelvis, and retroverted pelvis (RP), grouped per the amount of pelvic tilt (PT) and the ratio of sacral slope to pelvic incidence (PI). Incidence angles of inflection points (IAIPs) were defined as the angle between a line from the center of the femoral heads through the midpoint of the sacral superior endplate and a line perpendicular to each L1, T1 superior endplate, C2 inferior endplate, and the C1 ring, respectively. RESULTS: C1 incidence equaled to the geometrical sum from the pelvis to the C1 vertebra; it also equaled the sum of the C1 slope and PT (p < 0.001). Moving from the AP group to the RP group, there were progressive increases in PT, PI, and IAIPs and decreases in LL, and SS/PI (p < 0.001). Negative correlation was observed between the pelvic anteversion and the IAIPs, and a significant positive correlation was observed between the pelvic retroversion and the IAIPs. CONCLUSION: IAIPs are novel PI-relevant radiographic parameters reflecting the relationship between the pelvis and the spinal alignment. An anteverted pelvis requires more lumbar lordosis than pelvic incidence and aligns with low IAIPs, and a retroverted pelvis requires less lumbar lordosis than pelvic incidence and aligns with high IAIPs. These slides can be retrieved under Electronic Supplementary Material.

Incidence of acute spinal cord injury and associated complications of methylprednisolone therapy: a national population-based study in South Korea.

STUDY DESIGN: Retrospective population-based cohort study OBJECTIVES: To evaluate the incidence of acute spinal cord injury (SCI) in South Korea, and the prescription rates and complications related to high dose methylprednisolone therapy. SETTING: Health Insurance Review and Assessment Service (HIRA) data METHODS: National database of the Korean HIRA between 2007 and 2017 was reviewed. To identify patients with acute SCI and the use of high dose methylprednisolone, International Classification of Disease revision codes, medical behavior codes and examination codes were used. Patients were grouped according to whether or not they received methylprednisolone therapy (MP group vs non-MP group). RESULTS: The average age-adjusted incidence of acute SCI per 1,000,000 persons was 26.4 and the peak incidence was in the 50s overall. The methylprednisolone prescription rate was highest in 2012 (76%) and continued to decrease thereafter, being lowest in 2017 (41%). The MP group showed higher complication rates in terms of pneumonia (OR 1.8, 95% CI, 1.62-2.0), GI bleeding (OR 1.2, 95% CI, 1.05-1.38), and UTI (OR 1.68, 95% CI, 1.53-1.84). The average length of hospitalization was longer in patients who received methylprednisolone (26.5 days vs. 24.4 days, p < 0.05). CONCLUSIONS: The average age-adjusted incidence of acute SCI for 11 years was 26.4 per 1,000,000 persons and highest in 50s. Strategies should be established, and national health resources should be allocated to prevent acute SCI from occurring in older people. The prescription rate of high dose methylprednisolone for acute SCI is decreasing in South Korea but it is still high.

Outcome of balloon kyphoplasty for the treatment of osteoporotic vertebral compression fracture in patients with rheumatoid arthritis.

BACKGROUND: Osteoporosis and osteoporotic fractures are widely known as complications of rheumatoid arthritis. Kyphoplasty (KP) is known as an effective treatment modality for reducing pain and correcting kyphotic deformity in osteoporotic vertebral compression fracture (OVCF). However, cutcomes of KP in rheumatoid patients are not well known. The purpose of the study was to investigate the clinical and radiological outcomes of balloon KP on OVCF in patients with rheumatoid arthritis. METHODS: A total of 23 patients (31 vertebral bodies) with rheumatoid arthritis who received KP for OVCF and could be followed up for at least 1 year were examined. For clinical outcomes, visual analogue scale (VAS) and the Korean version of the Oswestry disability index (KODI) were evaluated. For radiological outcomes, changes in anterior vertebral height and local kyphotic angle were measured, alongside cement leakage, adjacent fracture, and the recollapse of cemented vertebra. RESULTS: The anterior vertebral height was significantly restored after surgery compared with prior to surgery (p < 0.001). Cement leakage was found in 14 cases (45.1 %), and disc space leakage was prevalent (50 %), while vascular cement leakage was found in one case. Adjacent fracture was found in 3 patients (11.5 %). VAS for lumbago showed a significant decrease (p < 0.001) after surgery (VAS = 2.4) compared with that before (VAS = 8.1); it was somewhat increased after the 1-year follow-up (VAS = 2.8; p = 0.223). KODI also decreased (48.8 %) after surgery compared with before (84.6 %). However, it increased somewhat (49.9 %) after the 1-year follow-up. CONCLUSION: KP on rheumatoid arthritis patients for OVCF was effective for reducing pain in the early stage and restoring vertebral body height. Recollapse of the treated vertebral body was found relatively frequently alongside the correction loss of local kyphotic angle.

Long-term outcomes of long level posterolateral fusion in lumbar degenerative disease: comparison of long level fusion versus short level fusion: a case control study.

BACKGROUND: We sought to evaluate the long-term outcomes of long-level instrumented posterolateral fusion (PLF) directly compared to those with short level instrumented PLF for degenerative spinal stenosis. METHODS: From 1987-2002, patients who underwent instrumented PLF with wide decompression for degenerative spinal stenosis were reviewed. A total of 295 patients were available for follow-up over 10 years (mean, 14 years). These patients were divided into Group 1 (fusion of 1 or 2 levels) and Group 2 (fusion of three or more levels). Clinical and radiological outcomes were evaluated. RESULTS: On clinical outcomes, Group 1 showed better results than Group 2 based on the Katz's Activities Daily Living index (p = 0.024), Kirkaldy-Willis criteria (p = 0.001) and the Korean version of the Oswestry disability index (p = 0.01). However, excellent and good outcome was noted in more than 64.5 % in Group 2. For radiological outcomes, overall fusion rate was higher in Group 1 compared with Group 2, but not significantly different (p = 0.35). However, the metal problems and surgical complications were more developed in Group 2 (p < 0.001). Although the radiologic changes on adjacent segments increased in accordance with the follow-up period, particularly in Group 2 (p < 0.001), no correlation with clinical symptoms was found. CONCLUSIONS: The long-level fusion group maintained acceptable clinical and radiological outcomes compared to the short-level fusion group at minimum of 10 years of follow-up.

Ultrasonographic evaluation of the first extensor compartment of the wrist in de Quervain's disease.

BACKGROUND: This prospective cohort study was undertaken to explore the hypothesis that the retinaculum is thicker in de Quervain's disease and to identify another landmark for the presence of the intracompartmental septum. METHODS: A case group (60 wrists) comprised of Korean female patients with unilateral de Quervain's disease and a healthy control group (60 wrists) were evaluated by ultrasonography. The case group underwent surgery for extensor retinacular release, and surgical findings were used as the reference standard. The mean extensor retinacular thickness in the case and control groups was compared using a Wilcoxon rank-sum test. A receiver operation characteristic curve was constructed for the parameter. RESULTS: The mean thickness of the extensor retinaculum was 0.94 mm (SD 0.37) in the case group and 0.35 mm (SD 0.07) in the control group, and this difference was significant. The cutoff value of the extensor retinaculum for diagnosing de Quervain's disease was 0.45 mm (sensitivity 96.3%, specificity 93.3%). Bony crests were found in all cases of presence of the intracompartmental septum and could be classified into three types according to shape. CONCLUSIONS: We concluded that the extensor retinaculum is thicker in de Quervain's disease. And the bony crest on the radial styloid can be considered a new landmark for determining the presence of an intracompartmental septum. TYPE OF STUDY AND LEVEL OF EVIDENCE: Diagnostic, level II.

The impact of instrumented lumbar fusion surgery on psychiatric problems in elderly patients with degenerative spinal stenosis: The observational study.

This is a prospective cohort study to investigate the effects of instrumented lumbar fusion surgery on psychiatric problems, including anxiety, insomnia, and depression, in patients with degenerative spinal stenosis, as well as on pain and the activities of daily living. Surgery was performed in the patients with Schizas grade C or D spinal stenosis with; if a patient's quality of life was impaired for at least 3 months or if patient had neurologic deficits. Finally, 69 patients were reviewed. Beck anxiety inventory, insomnia severity index, geriatric depression scale short form-Korean, visual analog scale for back pain, visual analog scale for leg pain, and Oswestry disability index was measured on the day surgery was decided on (T1), the day before surgery (T2), the day before discharge (T3), and 6 months after surgery (T4). The patients had mild degrees of anxiety, insomnia, and depression at T1, and Beck anxiety inventory, insomnia severity index, visual analog scale for back pain, visual analog scale for leg pain, and Oswestry disability index improved significantly by T4. In elderly patients with degenerative spinal stenosis, instrumented lumbar fusion surgery improves not only pain and activities of daily living, but also anxiety and insomnia. However, there was no improvement in depression over the 6-month follow-up period.

Arachnoid ossificans of thoracolumbosacral spine in the advanced ankylosing spondylitis: a case report.

Arachnoid ossificans is a rare type of chronic arachnoiditis characterised by the presence of calcification or ossification of the dura and arachnoid. There are a few reports of these findings in relation to various disease entities, but only one case has been reported in relation to ankylosing spondylitis. We describe a 76-year-old man of ankylosing spondylitis with arachnoiditis ossificans, who has suffered from low back pain and neuropathic leg pain.

Anterior operation for unstable thoracolumbar and lumbar burst fractures: tricortical autogenous iliac bone versus titanium mesh cage.

STUDY DESIGN: We retrospectively compared 25 cases that used the autogenous iliac bone grafting with 18 cases that used a titanium mesh cage for reconstruction of the vertebral body. OBJECTIVE: To analyze clinical and radiographic results of the autogenous iliac bone and a titanium mesh cage used to reconstruct the vertebral body. SUMMARY OF BACKGROUND DATA: Grafting of the autogenous iliac bone as a strut bone has been traditionally applied for reconstruction of the spine using anterior approach. Although grafting the autogenous iliac bone as a strut bone achieves a high bone fusion rate, it has reported complications in the donor site. For this reason, bone fusion with a mesh cage has been introduced. METHODS: Between March 2000 and December 2010, 43 cases that underwent decompression and instrumented fusion for unstable burst fractures using the anterior approach were enrolled. Levels of injury were T12 in 8 cases, L1 in 19 cases, L2 in 11 cases, and L3 in 5 cases. The mean follow-up period was 64.5 months (range, 14-129 mo). RESULTS: The local kyphotic angle in the group that used the tricortical autogenous iliac bone (group A) was measured 24.81±2.27 degrees preoperatively and 4.95±0.61 degrees at the last follow-up. The angle in the group that used a titanium mesh cage (group B) was 25.21±1.55 degrees preoperatively and 3.9±0.43 degrees at the last follow-up. Both groups obtained bone fusion of grade I and II by Bridwell fusion criteria. The operation site visual analog scale and Korean Oswestry disability index did not differ significantly between 2 groups. Donor site visual analog scale and the operation time was significantly in favor of group B (P<0.05). CONCLUSIONS: Titanium mesh cage filled with the autogenous cancellous bone shortened operation time and reduced the risk of complications in the donor site compared with the group that used the tricortical iliac bone.

Update of the Natural History, Pathophysiology, and Treatment Strategies of Degenerative Cervical Myelopathy: A Narrative Review.

Cervical myelopathy is a clinical syndrome resulting in symptoms of neurologic deficits due to prolonged spinal cord compression or ischemia in the cervical spine. Spinal cord compression can be caused by ossification of the posterior longitudinal ligament and hypertrophy of ligamentun flavum in addition to degenerative cervical spondylosis, degenerative disc disease, and progressive cervical kyphosis. Degenerative cervical myelopathy (DCM) is a series of disease entities caused by spinal cord compression by various nontraumatic and non-infectious causes. The pathophysiology of DCM includes spinal cord structure and function abnormalities caused by both static and dynamic factors. Surgical decompression for patients with moderate to severe cervical myelopathy not only inhibits the progression of neurological deterioration, but also improves functional status, pain, and quality of life. However, the role of nonsurgical treatment in patients with mild spinal cord compression is controversial. In general, patients with cervical myelopathies who do not undergo surgery have a poor prognosis. Appropriate surgical treatment is recommended when spinal cord compression is confirmed on image study in patients with reasonable symptoms of cervical myelopathy. The patient's overall health, degree of compression, presence of concurrent cervical radiculopathy, and cervical spine alignment, in addition to lesion location and etiology, should be considered when determining an appropriate surgical procedure. This review covers the updated issues, including pathophysiology, clinical manifestations, differential diagnosis, and available treatments for DCM.

Incidence and treatment trends of infectious spondylodiscitis in South Korea: A nationwide population-based study.

The incidence of infectious spondylodiscitis (IS) has increased in recent years due to an increase in the numbers of older patients with chronic diseases, as well as patients with immunocompromise, steroid use, drug abuse, invasive spinal procedures, and spinal surgeries. However, research focusing on IS in the general population is lacking. This study investigated the incidence and treatment trends of IS in South Korea using data obtained from the Health Insurance Review and Assessment Service. A total of 169,244 patients (mean age: 58.0 years) diagnosed from 2010 to 2019 were included in the study. A total of 10,991 cases were reported in 2010 and 18,533 cases in 2019. Hence, there was a 1.5-fold increase in incidence rate per 100,000 people from 22.90 in 2010 to 35.79 in 2019 (P < 0.05). The incidence rate of pyogenic spondylodiscitis per 100,000 people increased from 15.35 in 2010 to 33.75 in 2019, and that of tuberculous spondylodiscitis decreased from 7.55 in 2010 to 2.04 in 2019 (P < 0.05, respectively). Elderly individuals ≥ 60 years of age accounted for 47.6% (80,578 patients) of all cases of IS. The proportion of patients who received conservative treatment increased from 82.4% in 2010 to 85.8% in 2019, while that of patients receiving surgical treatment decreased from 17.6% to 14.2% (P < 0.05, respectively). Among surgical treatments, the proportions of corpectomy and anterior fusion declined, while proportion of incision and drainage increased (P < 0.05, respectively). The total healthcare costs increased 2.9-fold from $29,821,391.65 in 2010 to $86,815,775.81 in 2019 with a significant increase in the ratio to gross domestic product. Hence, this population-based cohort study demonstrated that the incidence rate of IS has increased in South Korea. The conservative treatment has increased, while the surgical treatment has decreased. The socioeconomic burden of IS has increased rapidly.

Cumulative Incidence and Factors Associated With Subsequent Vertebral Compression Fractures: A Nationwide Population-based Study.

OBJECTIVE: Patients who experience vertebral compression fractures are vulnerable to subsequent vertebral compression fractures (SVCFs). The purpose of this nationwide population-based study was to determine the age-specific cumulative incidence and factors associated with SVCFs in South Korea. METHODS: Diagnostic codes, medical costs, and comorbid diseases in patients who had a vertebral compression fracture in 2011 and 2012 were collected from the National Health Insurance Service database of South Korea from 2007 to 2018. Demographic data, mortality rate, medical cost, and frequency of vertebroplasty or kyphoplasty were compared between patients with an initial fracture (IF) and those with a subsequent fracture (SF). RESULTS: The cumulative incidence of SVCFs over 4 years was 24.4% and increased rapidly within a few months after the IF. In 2011, SVCFs occurred in 17,004 patients, and the incidence rate per 100,000 people was 113.6 (84.9 in men vs. 138.5 in women). The odds ratio (OR) of SVCFs in units of 10 years was the highest in women in their 60s, at 2.89. However, in men in their 70s, the OR was the highest, at 2.51. The rates of vertebroplasty or kyphoplasty, medical expenses, and mortality rate were significantly higher in the SF group than in the IF group (P < 0.01). CONCLUSIONS: The age-specific cumulative incidence of SVCFs per 100,000 people was 113.6. SVCFs were more frequent among women, the elderly, and patients who underwent vertebroplasty or kyphoplasty. Women in their 60s or above and men in their 70s or above were at highest risk.

Evaluation of the efficacy and safety of Escherichia coli-derived recombinant human bone morphogenetic protein-2 in transforaminal lumbar interbody fusion to treat degenerative spinal disease: a protocol of prospective, randomized controlled, assessor-blinded, open-label, multicenter trial.

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been widely used as an alternative bone graft in spine fusion surgery. However, clinical outcome such as effects and complications has not yet been revealed for transforaminal lumbar interbody fusion (TLIF). Although previous studies have reported some results, the evidence is weak. Therefore, the purpose of this trial is to evaluate the effectiveness and safety of Escherichia coli-derived rhBMP-2 combined with hydroxyapatite (HA) in TLIF. METHODS: This trial is designed as a prospective, assessor-blinded, open-label, multicenter, randomized controlled study. Participants will be recruited from six tertiary teaching hospitals. All randomized participants will be undergoing one- or two-level TLIF with rhBMP-2 (77 participants) as the active experimental group or with an auto-iliac bone graft (77 participants) as the control group. The primary interbody fusion rate outcome will be evaluated using computed tomography (CT) 12 months after surgery. The secondary outcomes will be as follows: clinical outcomes (visual analog scale score, EuroQol-5-dimensions-5-level score, Oswestry Disability Index score, and some surgery-related variables) and adverse effects (radiculitis, heterotrophic ossification, endplate resorption, and osteolysis). Radiological outcomes will be evaluated using simple radiography or CT. All outcomes will be measured, collected, and evaluated before surgery and at 12, 24, and 52 weeks postoperatively. DISCUSSION: This study will be the primary of its kind to evaluate the effectiveness and safety of E. coli-derived rhBMP-2 with HA in one- or two-level TLIF. It is designed to evaluate the equivalence of the results between rhBMP-2 with HA and auto-iliac bone graft using an appropriate sample size, assessor-blinded analyses, and prospective registration to avoid bias. This study will set up clear conclusions for using E. coli-derived rhBMP-2 with HA in TLIF. TRIAL REGISTRATION: This study protocol was registered at Korea Clinical Research Information Service ( https://cris.nih.go.kr ; number identifier: KCT0005610) on 19 November 2020. And protocol version is v1.1, January 2022.

Efficacy and safety of Escherichia coli-derived recombinant human bone morphogenetic protein-2 in additional lumbar posterolateral fusion: minimum 1-year follow-up.

BACKGROUND CONTEXT: Recombinant human bone morphogenetic protein-2 (BMP-2) is the growth factor with the most striking osteoinductive performance in orthopedic operations; it is also able to induce heterotopic bone formation. However, there has been little clinical research on Escherichia coli-derived BMP-2 (E.BMP-2). PURPOSE: To confirm the efficacy and safety of E.BMP-2 with a hydroxyapatite carrier when applied to one-sided posterolateral fusion (PLF) in addition to lumbar interbody fusion (LIF), and to measure the lower dose of E.BMP-2 ever reported achieving solid fusion. STUDY DESIGN/SETTING: Retrospective case-control study PATIENT SAMPLE: A total of 121 patients who received surgery for one or two levels of fusion for lumbar degenerative spinal stenosis or spondylolisthesis from January 2009 to December 2019 were included. OUTCOME MEASURES: Clinical and functional outcomes were evaluated using preoperative and final follow-up visual analogue scales for back pain (VAS-BP) and leg pain (VAS-LP), and Korean Oswestry disability index (K-ODI) scores. Fusion rates were evaluated by computed tomography at six months and one year after surgery. In addition, a subgroup analysis of group E according to number of fusion levels was conducted, and the fusion rates in the one-level and two-level fusion groups were compared. METHODS: LIF and additional one-sided PLF was performed in all patients. They received autogenous iliac bone grafts (Group C, n=69) or 1mg of E.BMP-2 (Group E, n=52). RESULTS: There were no significant differences between preoperative and final VAS-BP, VAS-LP and K-ODI. The PLF rate was 79.7% for Group C and 82.7% for Group E at postoperative six months, and 94.2% for Group C and 100% for Group E at postoperative one year (p =.679, 0.134, respectively). The LIF rate was 71.0% in Group C and 71.2% in Group E at six months after surgery, and 97.1% in Group C and 100% in Group E at one year (p =.987, 0.506, respectively). In terms of numbers of fusion levels in Group E, PLF rates at six months (p =.486) and one year after surgery were similar in the two groups, as were LIF rates at six months (p =.822) and one year after surgery. There were no cases of malignancy or radiculopathy in Group E during one-year of follow-up. CONCLUSIONS: One milligram of E.BMP-2 is a safe and effective osteoinductive material in short-level lumbar PLF surgery.

Outcomes of lumbar spinal fusion in super-elderly patients aged 80 years and over: Comparison with patients aged 65 years and over, and under 80 years.

ABSTRACT: Despite the increasing prevalence of spinal surgery in super-elderly (SE) patients, the outcomes and complication rates have not been fully elucidated. The purpose of this study was to compare the outcomes and complications of lumbar spinal fusion for degenerative lumbar spinal stenosis (DLSS) in SE patients aged 80 years and over with those in patients aged 65 years and over, and under 80 years.This study analyzed 160 patients who underwent spinal fusion for DLSS between January 2011 and November 2019. Thirty patients in the SE group (group SE, ≥80 years) and 130 patients in the elderly group (group E, ≥65 years and <80 years) were enrolled. The performance status was evaluated by preoperative American society of anesthesiologists (ASA) score. Visual analog scales for back pain (VAS-BP) and leg pain (VAS-LP), and Korean Oswestry disability index (K-ODI) were used to assess clinical outcomes preoperatively and 1 year postoperatively. Percent changes of VAS-BP, VAS-LP and K-ODI were also analyzed. Fusion rates were evaluated by computed tomography 6 months and 1 year postoperatively. Furthermore, bone mineral density, operative time, estimated blood loss, blood transfusion, hospital days, hospitalization in intensive care unit and postoperative complications were compared.The average age of group SE was 82.0 years and that of group E was 71.6 years. There were no differences in preoperative ASA score, preoperative or postoperative VAS BP and VAS-LP, bone mineral density, operative time, estimated blood loss, blood transfusion, hospital days, hospitalization in intensive care unit and fusion rates between the groups. Preoperative and postoperative K-ODI were higher in group SE than group E (all P < .05). However, percent changes of VAS-BP, VAS-LP and K-ODI showed no significant differences. Overall early and late complications were not significantly different between the groups; however postoperative delirium was more common in group SE than group E (P = .027). SE status was the only risk factor for postoperative delirium with odds ratio of 3.4 (P = .018).Spinal fusion surgery is considerable treatment to improve the quality of life of SE patients with DLSS, however careful perioperative management is needed to prevent postoperative delirium.

Outcomes of the use of cement-augmented cannulated pedicle screws in lumbar spinal fusion.

BACKGROUND CONTEXT: There are few studies of the radio-clinical outcomes of cement-augmented cannulated pedicle screw (CPS) fixation in osteoporotic patients. PURPOSE: To compare the radiological and clinical outcomes between groups receiving cement-augmented CPS and solid pedicle screws (SPS) in lumbar fusion surgery. STUDY DESIGN/SETTING: Retrospective comparative study PATIENT SAMPLE: A total of 187 patients who underwent lumbar fusion surgery for degenerative spinal stenosis or spondylolisthesis from 2014 to 2019. OUTCOME MEASURES: Radiological evaluation included screw failure, cage failure, rod breakage, and fusion grade at postoperative 6 months and 1 year. Pre- and postoperative visual analog scales for back pain (VAS-BP), leg pain (VAS-LP), Korean Oswestry disability index (K-ODI), and postoperative complications were also compared. METHODS: Outcomes of patients with high risk factors for implant failure [old age, osteoporosis, autoimmune disease or chronic kidney disease (CKD)] who underwent open transforaminal lumbar interbody fusion with cement-augmented CPS fixation (Group C, n=55) or SPS fixation (Group S, n=132) were compared. RESULTS: 324 pedicle screws in Group C and 775 pedicle screws in Group S were analyzed. Group C had a significantly higher average age and lower T-score, and included more patients with autoimmune disease and CKD than group S (all p<.05). Clear zones, screw migration and loss of correction were significantly less frequent in Group C (all p<.05). Thirteen screw breakages were observed; they were only in Group C (4.0%) and all were in the proximal of the two holes. Interbody and posterolateral fusion rates were not significantly different. At last follow-up, all clinical parameters including VAS-BP, VAS-LP, and K-ODI scores had improved significantly in both groups. Postoperative complications were not significantly different in the two groups. CONCLUSION: In lumbar fusion surgery, using cement-augmented CPS in high-risk groups for implant failure could be a useful technical option for reducing acute radiological complications and obtaining clinical results comparable to those obtained using SPS in patients with low risk of implant failure. LEVEL OF EVIDENCE: Level 4.

Reproducibility and Accuracy of Pelvic Tilt in Predicting the Difference Between Pelvic Incidence and Lumbar Lordosis Value.

OBJECTIVE: We investigated the pelvic morphologic factors that determine the degree of pelvic incidence (PI)-lumbar lordosis (LL) mismatch. METHODS: Overall, 306 patients were included. The regional and global sagittal parameters were measured. Linear regression analyses were performed for 4 pelvic parameters and PI-LL mismatch. E1 and E2 were defined as linear regression equations between pelvic tilt (PT) and PI-LL mismatch and PI and PI-LL mismatch, respectively. The patients were categorized by cluster analysis using the hierarchal method for the 4 pelvic parameters. RESULTS: E1 and E2 showed statistical significance; however, the coefficient of determination of E1 was higher than that of E2 (R2 = 0.675 vs. 0.238; P < 0.01). Sex, LL, E1, and E2 showed significant differences in the regional parameters. The T1 pelvic angle (TPA), spinosacral angle (SSA), and incidence angle of inflection points (IAIPs) showed significant differences in global parameters (P < 0.01). The IAIPs and TPA were low in the anteverted pelvis group and high in the retroverted pelvis group (P < 0.001). The SSA was low in the small pelvis group and high in the large pelvis group (P < 0.001). The proportion of women in the large pelvis group (93%) was significantly higher than that in the other groups (P < 0.01). CONCLUSIONS: The individual differences between the PI and LL values can be more accurately determined using the individual PT, and the optimal PT amount will differ depending on the pelvis shape. The increase in the TPA and IAIPs corresponded to the PT, and the SSA increased in accordance with the pelvic size.

Degenerative Cervical Myelopathy: Pathophysiology and Current Treatment Strategies.

Chronic compression or ischemia of the spinal cord in the cervical spine causes a clinical syndrome known as cervical myelopathy. Recently, a new term "degenerative cervical myelopathy (DCM)" was introduced. DCM encompasses spondylosis, intervertebral disk herniation, facet arthrosis, ligamentous hypertrophy, calcification, and ossification. The pathophysiology of DCM includes structural and functional abnormalities of the spinal cord caused by static and dynamic factors. In nonoperative patients, cervical myelopathy has a poor prognosis. Surgical treatments, such as anterior or posterior decompression accompanying arthrodesis, arthroplasty, or laminoplasty, should be considered for patients with chronic progressive cervical myelopathy. Surgical decompression can prevent the progression of myelopathy and improve the neurologic status, functional outcomes, and quality of life, irrespective of differences in medical systems and sociocultural determinants of health. The anterior surgical approach to the cervical spine has the advantage of removing or floating the intervertebral disk, osteophytes, and ossification of the posterior longitudinal ligament that compress the spinal cord directly. The posterior surgical approach to the cervical spine is mainly used for multisegment spinal cord compression in patients with cervical lordosis. In this review article, we addressed the pathophysiology, clinical manifestations, differential diagnosis, and treatment options for DCM.

The Incidence and Management Trends of Metastatic Spinal Tumors in South Korea: A Nationwide Population-based Study.

STUDY DESIGN: Population-based study. From 2008 to 2017, data from the national database of the Korean Health Insurance Review & Assessment Service were analyzed. The national insurance system and all medical expense bill data of the entire population are included in the database. OBJECTIVE: The aim of this study was to elucidate the incidence and management trends of metastatic spinal tumors in South Korea. SUMMARY OF BACKGROUND DATA: The spine is the most common location of bone metastases. However, population-based studies in this topic are limited. METHODS: The International Classification of Disease, 10th revision, medical behavior, and examination codes were used to identify the incidence and management trends of metastatic spinal tumors. The Cochran-Armitage trend test was used in statistical analysis. RESULTS: Overall, 38,007 patients (average age, 61 years) diagnosed with metastatic spinal tumors were analyzed. Metastatic tumors were most common in patients in their 60s (25.7%). The 10-year incidence of spinal metastases in South Korea was 6.68 cases per 100,000 population. The age-adjusted incidence per 100,000 population decreased from 8.16 cases in 2008 to 6.18 in 2017 (P = 0.03). Sex-adjusted incidence rates in men increased from 8.60 per 100,000 persons in 2008 to 8.70 in 2017 (P < 0.001); those of women decreased from 8.20 per 100,000 persons in 2008 to 4.15 in 2017 (P < 0.05). The most common primary tumor site was the lung (26.9%), followed by the breast (16.9%), prostate (10.8%), and liver (8.1%). Radiation therapy was constant at about 3500 cases per annum (P = 0.62); surgical treatment increased from 1158 to 1382 cases (P < 0.001). Resection and instrumentation surgeries increased significantly (P < 0.001), whereas cementation decreased continuously. Total healthcare costs increased significantly from $19,925,296 in 2008 to $30,268,217 in 2017 (P < 0.001). CONCLUSION: The incidence of metastatic spinal tumors decreased in South Korea. Resection and instrumentation procedures increased, and total healthcare costs increased rapidly. LEVEL OF EVIDENCE: 3.

A New Surgical Strategy for Infective Spondylodiscitis: Comparison Between the Combined Antero-Posterior and Posterior-Only Approaches.

STUDY DESIGN: Retrospective comparative study. OBJECTIVE: To investigate the radiographic and clinical effectiveness of surgical treatment using a posterior-only approach, as compared with a combined antero-posterior approach, in patients with infective spondylodiscitis. SUMMARY OF BACKGROUND DATA: Spondylodiscitis is the most common infectious disease of the spine. There is currently no consensus over the surgical approach, use of bone graft, and type of instrumentation for optimal treatment of infective spondylodiscitis. METHODS: Seventy-nine patients who received surgical treatment for infective spondylodiscitis were divided into a combined antero-posterior (AP) group and a posterior-only (P) group. Significant differences in pre- and postoperative radiographic and clinical characteristics between the two groups were identified, and univariate and stepwise multivariate logistic regression analyses were used to determine the factors that affected the decision for treatment approach between the two groups. RESULTS: Preoperatively, initial height loss, wedge angle, and kyphotic angle were significantly higher in the AP group. However, estimated blood loss, operation time, and last visual analogue scale score for back pain were significantly lower in the P group. There was no difference in postoperative time to reach solid fusion. Postoperative corrected kyphotic angle was 12.8° in the AP group and 5.3° in the P group. The regional wedge angle was identified as a factor that influenced use of the combined antero-posterior approach, with a sensitivity of 60%, and specificity of 89.8% at the optimal cut-off value of 8.2°. CONCLUSION: Interbody fusion with long-level pedicle screws fixation through a posterior-only approach was shown to be as effective as a combined antero-posterior approach for the surgical treatment of infective spondylodiscitis. A posterior-only approach is recommended when the regional wedge angle of the collapsed vertebra is less than 8.2°. LEVEL OF EVIDENCE: 4.