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Study Design: Narrative review. Objectives: To discuss the current understanding of the natural history of degenerative cervical myelopathy (DCM). Methods: Literature review summarizing current evidence pertaining to the natural history and risk factors of DCM. Results: DCM is a common condition in which progressive arthritic disease of the cervical spine leads to spinal cord compression resulting in a constellation of neurological symptoms, in particular upper extremity dysfunction and gait impairment. Anatomical factors including cord-canal mismatch, congenitally fused vertebrae and genetic factors may increase individuals’ risk for DCM development. Non-myelopathic spinal cord compression (NMSCC) is a common phenomenon with a prevalence of 24.2% in the healthy population, and 35.3% among individuals >60 years of age. Clinical radiculopathy and/or electrophysiological signs of cervical cord dysfunction appear to be risk factors for myelopathy development. Radiological progression of incidental Ossification of the Posterior Longitudinal Ligament (OPLL) is estimated at 18.3% over 81-months and development of myelopathy ranges between 0-61.5% (follow-up ranging from 40 to 124 months between studies) among studies. In patients with symptomatic DCM undergoing non-operative treatment, 20-62% will experience neurological deterioration within 3-6 years. Conclusion: Current estimates surrounding the natural history of DCM, particularly those individuals with mild or minimal impairment, lack precision. Clear predictors of clinical deterioration for those treated with non-operative care are yet to be identified. Future studies are needed on this topic to help improve treatment counseling and clinical prognostication.

Kitchen elbow sign (KE-Sign) is a skin abnormality on the extensor side of the elbow and forearm that is often observed in patients with adult spinal deformity (ASD). The significance of KE-Sign in surgical cases was investigated. Overall, 114 patients with ASD treated with long spinal fusion were reviewed and divided into KE-Sign positive and negative groups. The preoperative and 1-year follow-up evaluations included radiographic parameters [C7 sagittal vertical axis (SVA), pelvic incidence (PI) and lumbar lordosis (LL)], the Oswestry Disability Index (ODI), visual analogue scales (VASs) for low back pain, leg pain, and satisfaction, and Short Form 36 questionnaire (SF-36). Multi-regression analysis was performed to identify patient satisfaction predictors and improvement in the ODI as dependent variables and preoperative background factors as independent variables. Preoperative characteristics showed no significant difference between both groups. Improvement in the ODI and VAS for satisfaction were significantly superior in the KE-Sign positive group. In multiple regression analysis, KE-Sign and preoperative ODI were significantly associated with improvement in the ODI; age, KE-Sign, preoperative low back pain VAS, and leg pain VAS were significantly associated with satisfaction. KE-Sign can be a predictor of better surgical outcomes in ASD patients.

Increased signal intensity (ISI) is usually recognized at the disc level of the responsible lesion in the patients with cervical myelopathy. However, it is occasionally seen at the vertebral body level, below the level of compression. We aimed to investigate the clinical significance and the radiographic characteristics of ISI at the vertebral body level.This retrospective study included 135 patients with cervical spondylotic myelopathy who underwent surgery and with local ISI. We measured the local and C2-7 angle at flexion, neutral, and extension. We also evaluated the local range of motion (ROM) and C2-7 ROM. The patients were classified into group D (ISI at disc level) and group B (ISI at vertebral body level).The prevalence was 80.7% (109/135) and 19.3% (26/135) for groups D and B, respectively. Local angle at flexion and neutral were more kyphotic in group B than in group D. The local ROM was larger in group B than in group D. Moreover, C2-7 angle at flexion, neutral and extension were more kyphotic in group B than in group D. Two years later, local angle at flexion, neutral, and extension were also kyphotic in group B than group D; however, local and C2-7 ROM was not significantly different between the two groups. There was no significant difference of clinical outcomes 2 years postoperatively between both groups.Group B was associated with the kyphotic alignment and local greater ROM, compared to group D. As the spinal cord is withdrawn in flexion, the ISI lesion at vertebral body might be displaced towards the disc level, which impacted by the anterior components of the vertebrae. ISI at the vertebral body level might be related to cord compression or stretching at flexion position. This should be different from the conventionally held pincer-mechanism concept.

Recently, the number of adult spinal deformity surgeries including sacroiliac joint fixation (SIJF) by using an S2 alar iliac screw or iliac screw has increased to avoid the distal junctional failure. However, we occasionally experienced patients who suffered from hip pain after a long instrumented spinal fusion. We hypothesized that long spinal fusion surgery including SIJF influenced the hip joint as an adjacent joint. The aim of this paper was to evaluate the association between spinal deformity surgery including SIJF and radiographic progression of hip osteoarthritis (OA). This study was retrospective cohort study. In total, 118 patients who underwent spinal fusion surgery at single center from January 2013 to August 2018 were included. We measured joint space width (JSW) at central space of the hip joint. We defined reduction of more than 0.5 mm/year in JSW as hip OA progression. The patients were divided into two groups depending on either a progression of hip osteoarthritis (Group P), or no progression (Group N). The number of patients in Group P and Group N was 47 and 71, respectively. Factor that was statistically significant for hip OA was SIJF (p = 0.0065, odds ratio = 7.1, 95% confidence interval = 1.6–31.6). There were no other significant differences by the multiple logistic regression analysis. This study identified spinal fixation surgery that includes SIJF as a predictor for radiographic progression of hip OA over 12 months. We should pay attention to hip joint lesions after adult spinal deformity surgery, including SIJF.

OBJECTIVEVarious surgical treatments have been reported for vertebral pseudarthrosis after osteoporotic vertebral fracture (OVF). However, the outcomes are not always good. The authors now have some experience with combined anterior-posterior short-segment spinal fusion (1 level above and 1 level below the fracture) using a wide-foot-plate expandable cage. Here, they report their surgical outcomes with this procedure.METHODSBetween June 2016 and August 2018, 16 consecutive patients (4 male and 12 female; mean age 75.1 years) underwent short-segment spinal fusion for vertebral pseudarthrosis or delayed collapse after OVF. The mean observation period was 20.1 months. The level of the fractured vertebra was T12 in 4 patients, L1 in 3, L2 in 4, L3 in 3, and L4 in 2. Clinical outcomes were assessed using the lumbar Japanese Orthopaedic Association (JOA) scale and 100-mm visual analog scale for low-back pain. Local kyphotic angle, intervertebral height, bone union rate, and instrumentation-related adverse events were investigated as imaging outcomes. The data were analyzed using the Wilcoxon signed-rank test.RESULTSThe mean operating time was 334.3 minutes (range 256–517 minutes), and the mean blood loss was 424.9 ml (range 30–1320 ml). The only perioperative complication was a superficial infection of the posterior wound that was cured by irrigation. The lumbar JOA score and visual analog scale value improved from 11.2 and 58.8 mm preoperatively to 20.6 and 18.6 mm postoperatively, respectively. The mean local kyphotic angle and mean intervertebral height were 22.6° and 28.0 mm, respectively, before surgery, −1.5° and 40.5 mm immediately after surgery, and 7.0° and 37.1 mm at the final observation. Significant improvement was observed in both parameters immediately after surgery and at the final observation when compared with the preoperative values. Intraoperative endplate injury occurred in 8 cases, and progression of cage subsidence of 5 mm or more was observed in 2 of these cases. Proximal junctional kyphosis was observed in 2 cases. There were no cases of screw loosening. No cases required reoperation due to instrument-related adverse events. Bone union was observed in all 14 cases that had CT evaluation.CONCLUSIONSThis short-segment fusion procedure is relatively minimally invasive, and local reconstruction and bone fusion have been achieved. This procedure is considered to be attempted for the surgical treatment of osteoporotic vertebral pseudarthrosis after OVF.

OBJECTIVEPersistent lumbar foraminal stenosis (LFS) is one of the most common reasons for poor postoperative outcomes and is a major contributor to “failed back surgery syndrome.” The authors describe a new surgical strategy for LFS based on anatomical considerations using 3D image fusion with MRI/CT analysis.METHODSA retrospective review was conducted on 78 consecutive patients surgically treated for LFS at the lumbosacral junction (2013–2017). The location and extent of stenosis, including the narrowest site and associated pathology (bone or soft tissue), were measured using 3D image fusion with MRI/CT. Stenosis was defined as medial intervertebral foraminal (MF; inner edge to pedicle center), lateral intervertebral foraminal (LF; pedicle center to outer edge), or extraforaminal (EF; outside the pedicle). Lumbar (low-back pain, leg pain) and patient satisfaction visual analog scale (VAS) scores and Japanese Orthopaedic Association (JOA) scores were evaluated. Surgical outcome was evaluated 2 years postoperatively.RESULTSMost instances of stenosis existed outside the pedicle’s center (94%), including LF (58%), EF (36%), and MF (6%). In all MF cases, stenosis resulted from soft-tissue structures. The narrowest stenosis sites were localized around the pedicle’s outer border. The areas for sufficient nerve decompression were extended in MF+LF (10%), MF+LF+EF (14%), LF+EF (39%), LF (11%), and EF (26%). No iatrogenic pars interarticularis damage occurred. The JOA score was 14.9 ± 2.6 points preoperatively and 22.4 ± 3.5 points at 2 years postoperatively. The JOA recovery rate was 56.0% ± 18.6%. The VAS score (low-back and leg pain) was significantly improved 2 years postoperatively (p < 0.01). According to patients’ self-assessment of the minimally invasive surgery, 62 (79.5%) chose “surgery met my expectations” at follow-up. Nine patients (11.5%) selected “I did not improve as much as I had hoped but I would undergo the same surgery for the same outcome.”CONCLUSIONSMost LFS existed outside the pedicle’s center and was rarely noted in the pars region. The main regions of stenosis were localized to the pedicle’s outer edge. Considering this anatomical distribution of LFS, the authors recommend that lateral fenestration should be the first priority for foraminal decompression. Other surgical options including foraminotomy, total facetectomy, and hemilaminectomy likely require more bone resections than LFS treatment. The microendoscopic surgery results were very good, indicating that this minimally invasive surgery was suitable for treating this disease.

Adult spinal fusion surgery improves lumbar alignment and patient satisfaction. Adult spinal deformity surgery improves saggital balance not only lumbar lesion, but also at hip joint coverage. It was expected that hip joint coverage rate was improved and joint stress decreased. However, it was reported that adjacent joint disease at hip joint was induced by adult spinal fusion surgery including sacroiliac joint fixation on an X-ray study. The mechanism is still unclear. We aimed to investigate the association between lumbosacral fusion including sacroiliac joint fixation and contact stress of the hip joint.A 40-year-old woman with intact lumbar vertebrae underwent computed tomography. A three-dimensional nonlinear finite element model was constructed from the L4 vertebra to the femoral bone with triangular shell elements (thickness, 2 mm; size, 3 mm) for the cortical bone's outer surface and 2-mm (lumbar spine) or 3-mm (femoral bone) tetrahedral solid elements for the remaining bone. We constructed the following four models: a non-fusion model (NF), a L4-5 fusion model (L5F), a L4-S1 fusion model (S1F), and a L4-S2 alar iliac screw fixation model (S2F). A compressive load of 400 N was applied vertically to the L4 vertebra and a 10-Nm bending moment was additionally applied to the L4 vertebra to stimulate flexion, extension, left lateral bending, and axial rotation. Each model's hip joint's von Mises stress and angular motion were analyzed.The hip joint's angular motion in NF, L5F, S1F, and S2F gradually increased; the S2F model presented the greatest angular motion.The average and maximum contact stress of the hip joint was the highest in the S2F model. Thus, lumbosacral fusion surgery with sacroiliac joint fixation placed added stress on the hip joint. We propose that this was a consequence of adjacent joint spinopelvic fixation. Lumbar-to-pelvic fixation increases the angular motion and stress at the hip joint.

BACKGROUND The authors report an extremely rare presentation of a patient with an intraforaminal cervical gas cyst with radiculopathy. The patient’s condition was refractory to conservative treatment, and he was treated by anterior cervical discectomy and fusion (ACDF). Several intraspinal gas cysts with lumbar disc herniation have been treated surgically. However, no cases of intraforaminal cervical gas requiring ACDF have been reported. OBSERVATIONS A 70-year-old male patient presented with right-sided neck and shoulder pain, aggravating in the supine position. Cervical radiography showed vacuum disc phenomenon at C4–5, and multiplanar computed tomography showed intraforaminal gas along the right C5 nerve root. The patient experienced severe pain with impaired sleep and daytime fatigue. After confirming C5 radiculopathy using an echo-guided technique using ultrasonography guidance, the authors performed C4–5 ACDF. Postoperatively, the patient’s neck and shoulder pain disappeared immediately. There was no recurrence at the 2-year follow-up. LESSONS This is the first case report of an intraspinal cervical gas cyst with radiculopathy treated by ACDF surgery. The vacuum disc had been implicated as the genesis of the intraforaminal cervical gas cyst, leading to radiculopathy. ACDF surgery provides favorable outcomes in cases of intraspinal gas refractory to conservative therapy.

Long-term clinical outcomes of microendoscopic laminotomy (MEL) for patients with multilevel radiographic lumbar spinal canal stenosis (LSS) have not been widely explored. The clinical significance and natural progression of additional untreated levels (e.g., remaining radiographic (RR)-LSS not addressed by selective MEL) remain unknown. This retrospective study aimed to investigate the long-term clinical outcomes of selective MEL in LSS patients and compare outcomes between patients with and without remaining RR-LSS to determine the efficacy of this procedure.Forty-nine patients at a single center underwent posterior spinal microendoscopic decompression surgery for neurogenic claudication or radicular leg pain in moderate-to-severe spinal stenosis. The patients were categorized into the RR-LSS-positive and RR-LSS-negative cohorts based on unaddressed levels of stenosis. Pre-operative and 10-year follow-up evaluations, including the Japanese Orthopedic Association (JOA) score, visual analog scale (VAS) score for low back pain and leg pain, Oswestry Disability Index (ODI), and satisfaction, were compared between the groups. Additionally, the need for reoperation was determined.MEL significantly improved JOA scores, lumbar VAS, and ODI over the 10-year postoperative period. Pre-operative characteristics and postoperative outcomes were not significantly different between the cohorts. Overall, 18.4% (9/49) of patients required reoperation during the follow-up period. The reoperation rate in the RR-LSS-positive (13.8%; 4/29) group was similar to that in the RR-LL-negative (15.0%; 3/20) group.MEL is effective for lumbar stenosis, with improved clinical outcomes up to 10 years following surgery. Selective MEL, addressing only symptomatic levels in multilevel stenosis, with residual remaining lumbar stenosis, is similarly effective without increased reoperation rates. Surgeons may consider more limited selective decompression in patients with multilevel stenosis, avoiding the risk and invasiveness of extensive procedures.Level III.

This prospective study aimed to determine the association between radiographic lumbar spinal stenosis (LSS) and the quality of life (QOL) in the general Japanese population.The severity of radiographic LSS was qualitatively graded on axial magnetic resonance images as follows: no stenosis, mild stenosis with ≤1/3 narrowing, moderate stenosis with a narrowing between 1/3 and 2/3, and severe stenosis with2/3 narrowing. Patients less than 40 years of age and those who had undergone previous lumbar spine surgery were excluded from the study. The Oswestry Disability Index (ODI), which includes 10 sections, was used to assess the QOL. One-way analysis of variance was performed to determine the statistical relationship between radiographic LSS and ODI. Further, logistic regression analysis adjusted for gender, age, and body mass index was performed to detect the relationship.Complete data were available for 907 patients (300 men and 607 women; mean age, 67.3±12.4 years). The prevalence of severe, moderate, and non-mild/non-radiographic were 30%, 48%, and 22%, respectively. In addition, the mean values of ODI in each group were 12.9%, 13.1%, and 11.7%, respectively, and there was no statistically significant difference between the three groups in logistic analysis (P = 0.55). In addition, no significant differences in any section of the ODI were observed among the groups. However, severe radiographic LSS was associated with low back pain in the "severe" group as determined by logistic analysis adjusted for gender, age, and body mass index (odds ratio: 1.53, confidence interval: 1.13-2.07) compared with the non-severe group.In this general population study, severe radiographic LSS was associated with low back pain (LBP), but did not affect ODI.

Study design Prospective cohort imaging study. Purpose This study aimed to evaluate lumbar sagittal alignment and range of motion (ROM) using radiographs in a large asymptomatic cohort and identify sex-based differences and age-related changes in the subjects. Overview of literature Several researchers have tried to establish normal alignment and kinematic behavior of the lumbar spine, using plain radiographs. Few studies have employed a large and sex-and age-balanced cohort. Methods Total 627 healthy volunteers (at least 50 males and 50 females in each age decade, from the 3rd to the 8th decade) underwent whole spine radiography in the standing position; lumbar spine radiography was performed for all subjects in the recumbent position. Lumbar lordosis (LL, T12-S1) and ROM during flexion and extension were measured using a computer digitizer. Results The mean LL was 36.8°±13.2° in the recumbent position and 49.8°±11.2° in the standing position. The LL was greater in the standing position than in the recumbent position; further, LL was higher in females as compared to that in males. Local lordosis at each disk level increased incrementally with distal progression through the lumbar spine in both the positions. Local lordosis at L4- S1 was 29.8°±8.0° in the recumbent position and 34.2°±8.3° in the standing position and occupied 85.1% and 70.8% of the total LL, respectively. However, local lordosis in the standing position decreased with age at L2-3, L3-4, and L4-5 levels. Total lumbar ROM (T12-S1) decreased with age. The ROM in females was higher than that in males. Conclusions We established the standard value and age-related changes in the lumbar alignment and ROM in each age decade in asymptomatic subjects. These data will be useful and provide the normal values for comparison in clinical practice to identify sexbased differences and age-related changes.

This study was a retrospective subgroup analysis of prospective cohort data.The main objectives of this study were to develop a classification of degenerative spondylolisthesis (DS) and concurrent lumbar spinal stenosis (LSS) based on pathologic stage, and to determine how these subtypes of DS affect outcomes for minimally invasive (MIS) decompression SUMMARY OF BACKGROUND DATA:: DS with LSS is a common clinical scenario, yet there is no consensus on optimal treatment. Natural history of DS is described as early degenerative damage, followed by instability, and eventual restabilization via spondylotic changes. MIS decompression surgery has become increasingly popular, but the effect of DS subtypes on clinical outcomes after MIS decompression is unknown.From 2008 to 2013, all patients who underwent microendoscopic laminotomy for single-level LSS with DS were included. In total, 218 patients (91 male, 127 female individuals) were reviewed. DS pathologic staging was defined as early, advanced, or end stage, based on percent slippage (10% slippage), degree of dynamic instability (3 mm), and disc height. The following variables were evaluated preoperatively and2 years postoperatively and compared among groups: Japanese Orthopaedic Association (JOA) score, JOA recovery rate, and Visual Analog Scale low back pain.In total, 173 patients were included in final analysis. Final follow-up period was 2.3 years. Average JOA recovery rate was 63.8%. There were no significant differences in JOA recovery and Visual Analog Scale among 3 DS stages (P0.05). In total, 9.8% of patients required additional spine surgery, with 5% requiring subsequent fusion. All patients who required subsequent fusion were in the advanced stage DS group.Microendoscopic decompression is an effective treatment for patients with DS and concurrent LSS, with only 5% of patients requiring subsequent fusion at over 2-year follow-up, and another 5% requiring revision or adjacent segment decompression. The advanced stage DS group, indicating a10% anterolisthesis and/or3 mm of dynamic instability, was more likely to require additional surgery.

Background Lateral interbody release (LIR) via a transpsoas lateral approach is a surgical strategy to address degenerative lumbar scoliosis (DLS) patients with anterior autofusion of vertebral segments. This study aimed to characterize the clinical and radiographic outcomes of this lumbar reconstruction strategy using LIR to achieve anterior column correction. Methods Data for 21 fused vertebrae in 17 consecutive patients who underwent LIR between January 2014 and March 2020 were reviewed. Demographic and intraoperative data were recorded. Radiographic parameters were assessed preoperatively and at final follow-up, including segmental lordotic angle (SLA), segmental coronal angle (SCA), bone union rate, pelvic incidence (PI), lumbar lordosis (LL), pelvic tilt, sacral slope, PI-LL mismatch, sagittal vertical axis, Cobb angle, and deviation of the C7 plumb line from the central sacral vertical line. Clinical outcomes were evaluated using Oswestry Disability Index (ODI), visual analog scale (VAS) scores for low back and leg pain, and the short form 36 health survey questionnaire (SF-36) postoperatively and at final follow-up. Complications were also assessed. Results Mean patient age was 70.3 ± 4.8 years and all patients were female. Average follow-up period was 28.4 ± 15.3 months. Average procedural time to perform LIR was 21.3 ± 9.7 min and was not significantly different from traditional lateral interbody fusion at other levels. Blood loss per single segment during LIR was 38.7 ± 53.2 mL. Fusion rate was 100.0% in this cohort. SLA improved significantly from − 7.6 ± 9.2 degrees preoperatively to 7.0 ± 8.8 degrees at final observation and SCA improved significantly from 19.1 ± 7.8 degrees preoperatively to 8.7 ± 5.9 degrees at final observation (P Conclusions The LIR technique for anterior column realignment of fused vertebrae in the context of severe ASD may be an option of a safe and effective surgical strategy.

Background context : Microendoscopic spinal surgery has demonstrated efficacy and is increasingly utilized as a minimally invasive approach to neural decompression, but there is a theoretical concern that bleeding and postoperative epidural hematoma (PEH) may occur with increased frequency in a contained small surgical field. Hemostatic agents, such as topical gelatin-thrombin matrix sealant (TGTMS), are routinely used in spine surgery procedures, yet there has been no data on whether PEH is suppressed by these agents when administered in microendoscopic spine surgery. Purpose : The purpose of this study was to investigate the effect of TGTMS on bleeding and PEH formation in lumbar micoroendoscopic surgery. Study design : This is a randomized controlled trial (RCT) with additional prospective observational cohort. Patient sample : Patients were registered from July 2017 to September 2018 and a hundred and three patients undergoing microendoscopic laminectomy for lumbar spinal stenosis at a single institution were enrolled in this study. Outcome measures : The primary outcome was the drainage volume within 48 hours after surgery. Secondary outcomes were the numerical rating scale (NRS) of leg pain on the second (NRS2) and seventh day (NRS7) after surgery and the hematoma area ratio (HAR) in horizontal images on magnetic resonance image (MRI). Methods : In the RCT, 41 cases that received TGTMS (F group) were compared with 41 control group cases (C group) that did not receive TGTMS at the end of the procedure. Drainage volume, NRS2, NRS7, and HAR on MRI were evaluated. Nineteen cases were excluded from the RCT (I group) due to difficulty of hemostasis during surgery and the intentional use of TGTMS for hemostasis. I group was compared with C group in the drainage volume and NRS of leg pain as a prospective observational study. Results : The RCT demonstrated no statistically significant difference in drainage volume between those receiving TGTMS (117.0±71.7; mean±standard deviation) and controls (125.0±127.0) (p=0.345). The NRS2 and NRS7 was 3.5±2.6 and 2.8±2.5 in the F group, respectively, and 3.1±2.6 and 2.1±2.3 in the C group, respectively. The HAR on MRI was 0.19±0.19 in the F group and 0.17±0.13 in the C group. There was no significant difference in postoperative leg pain and HAR (p=0.644 for NRS2, p=0.129 for NRS7, and p=0.705 for HAR). In the secondary observational cohort, the drainage volume in the I group was 118.3±151.4, and NRS2 and NRS7 was 3.5±2.0 and 2.6±2.6, respectively. There were no statistically significant differences in drainage volume (p=0.386) or postoperative NRS of leg pain between these two groups (p=0.981 and 0.477 for NRS2 and NRS7, respectively). Conclusions : The prophylactic use of TGTMS in patients undergoing microendoscopic laminotomy for lumbar spinal stenosis did not demonstrate any difference in postoperative bleeding or PEH. Nonetheless, for patients that had active bleeding that required the use of TGTMS, there was no evidence of difference in postoperative clinical outcomes relative to controls.

STUDY DESIGN This was a retrospective cohort study. OBJECTIVE The objective of this study was to characterize the long-term clinical and radiographic results of articular segmental decompression surgery using endoscopy [cervical microendoscopic laminotomy (CMEL)] for cervical spondylotic myelopathy (CSM) and to compare outcomes to conventional expansive laminoplasty (ELAP). SUMMARY OF BACKGROUND DATA The spinal cord compression in CSM consists of a pincer mechanism due to bulging disk and a hypertrophied ligamentum flavum. The long-term clinical benefits of segmental decompression surgery, which removes the dorsal compressive elements of articular segment in CSM patients, have not yet been elucidated. MATERIALS AND METHODS Consecutive patients with CSM who required surgical treatment were enrolled. All enrolled patients (n=81) underwent CMEL or ELAP. All patients were followed postoperatively for >5 years. The preoperative and 5-year follow-up evaluation included neurological assessment [Japanese Orthopaedic Association (JOA) score], JOA recovery rates, axial neck pain (visual analog scale), and cervical sagittal alignment (C2-C7 subaxial cervical angle). RESULTS Sixty-four patients (CMEL group: 33, ELAP group: 31) were included for analysis. The preoperative JOA score was 10.1 points in the CMEL group and 11.1 points in the ELAP group (P=0.15). The JOA recovery rates were similar, 58.6% in the CMEL group and 55.2% in the ELAP group (P=0.55). The axial neck pain in the CMEL group was significantly lower than that in the ELAP group (P

Degenerative cervical myelopathy (DCM) is a progressive degenerative spine disease and the most common cause of spinal cord impairment in adults worldwide. Few studies have reported on regional variations in demographics, clinical presentation, disease causation, and surgical effectiveness.The objective of this study was to evaluate differences in demographics, causative pathology, management strategies, surgical outcomes, length of hospital stay, and complications across four geographic regions.This is a multicenter international prospective cohort study.This study includes a total of 757 symptomatic patients with DCM undergoing surgical decompression of the cervical spine.The outcome measures are the Neck Disability Index (NDI), the Short Form 36 version 2 (SF-36v2), the modified Japanese Orthopaedic Association (mJOA) scale, and the Nurick grade.The baseline characteristics, disease causation, surgical approaches, and outcomes at 12 and 24 months were compared among four regions: Europe, Asia Pacific, Latin America, and North America.Patients from Europe and North America were, on average, older than those from Latin America and Asia Pacific (p=.0055). Patients from Latin America had a significantly longer duration of symptoms than those from the other three regions (p.0001). The most frequent causes of myelopathy were spondylosis and disc herniation. Ossification of the posterior longitudinal ligament was most prevalent in Asia Pacific (35.33%) and in Europe (31.75%), and hypertrophy of the ligamentum flavum was most prevalent in Latin America (61.25%). Surgical approaches varied by region; the majority of cases in Europe (71.43%), Asia Pacific (60.67%), and North America (59.10%) were managed anteriorly, whereas the posterior approach was more common in Latin America (66.25%). At the 24-month follow-up, patients from North America and Asia Pacific exhibited greater improvements in mJOA and Nurick scores than those from Europe and Latin America. Patients from Asia Pacific and Latin America demonstrated the most improvement on the NDI and SF-36v2 PCS. The longest duration of hospital stay was in Asia Pacific (14.16 days), and the highest rate of complications (34.9%) was reported in Europe.Regional differences in demographics, causation, and surgical approaches are significant for patients with DCM. Despite these variations, surgical decompression for DCM appears effective in all regions. Observed differences in the extent of postoperative improvements among the regions should encourage the standardization of care across centers and the development of international guidelines for the management of DCM.

This study aims to establish normative data for parameters of spino-pelvic and spinal sagittal alignment, gender related differences and age-related changes in asymptomatic subjects. A total of 626 asymptomatic volunteers from Japanese population were enrolled in this study, including 50 subjects at least for each gender and each decade from 3rd to 8th. Full length, free-standing spine radiographs were obtained. Cervical lordosis (CL; C3–7), thoracic kyphosis (TK; T1–12), lumbar lordosis (LL; T12–S1), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS) and sagittal vertical axis (SVA) were measured. The average values (degrees) are 4.1 ± 11.7 for CL, 36.0 ± 10.1 for TK, 49.7 ± 11.2 for LL, 53.7 ± 10.9 for PI, 14.5 ± 8.4 for PT, and 39.4 ± 8.0 for SS. Mean SVA is 3.1 ± 12.6 mm. Advancing age caused an increase in CL, PT and SVA, and a decrease in LL and SS. There was a significant gender difference in CL, TK, LL, PI, PT and SVA. From 7th decade to 8th decade, remarkable decrease of LL & TK and increase of PT were seen. A large increase of SVA was also seen between 60’ and 70’. Standard values of spino-pelvic sagittal alignment were established in each gender and each decade from 20’ to 70’. A remarkable change of spino-pelvic sagittal alignment was seen from 7th decade to 8th decade in asymptomatic subjects.

STUDY DESIGN A prospective imaging study to develop diagnostic criteria. OBJECTIVE The aim of this study was to investigate image findings on delayed magnetic resonance imaging (MRI) after the acute phase of spinal cord injury without radiographic abnormality (SCIWORA) and their relationship with symptom severity. SUMMARY OF BACKGROUND DATA MRI is used to diagnose acute neurological injury, with increased signal intensity (ISI) and prevertebral hyperintensity (PVH) often seen in patients with SCIWORA; however, changes after the acute phase are unclear. METHODS We included 68 patients diagnosed with SCIWORA within 48 hours of injury. We then compared their acute (within 2 days) and delayed (after 2 weeks) MRI images. ISI grade (0-3) and ISI and PVH ranges (relative to the C3 vertebral height) were measured. Neurological status at admission and 2 weeks after injury was assessed by the Japanese Orthopaedic Association scoring system for cervical myelopathy (JOA score) and the American Spinal Injury Association impairment scale. RESULTS For acute MRI, the rates of grade 0, 1, and 2 ISI were 4, 54, and 10 patients, respectively. For delayed MRI, the rates of grade 0, 1, and 2 ISI changed to 3, 31, and 34 patients, respectively. ISI ranges reduced in delayed MRI, but there was no significance. PVH ranges were 3.0 ± 1.7 in acute MRI, and reduced to 1.3 ± 0.9 with significant difference (P

STUDY DESIGN A prospective cohort study. OBJECTIVE The purpose of this study was to compare surgical outcomes between non-elderly and elderly patients with cervical spondylotic myelopathy (CSM) who underwent laminoplasty. SUMMARY OF BACKGROUND DATA Since age at the time of surgery influences the surgical outcome, we designed a large-scale cohort study to examine the surgical outcome for CSM from a single operative procedure used exclusively in elderly patients. METHODS A total of 505 consecutive patients with CSM (311 men; 194 women) were prospectively enrolled. The mean age was 66.6 years (range, 41-91), and the average postoperative follow-up period was 26.5 ± 12.5 months. Patients were divided into three groups according to age: non-elderly (

Study design A cross-sectional study. Objective This study aims to investigate the correlation of the cervical canal and spinal cord size, and evaluate whether the size of the spinal cord relative to the spinal canal is a risk factor for development of cervical spinal cord compression (SCC). Summary of background data There is little knowledge regarding the relationship between cervical bony canal and spinal cord diameters. Although developmental canal stenosis has been recognized as a risk factor for SCC, the size of the spinal cord relative to the spinal canal has not been similarly discussed. Methods Cervical canal anteroposterior (AP) diameters on X-rays and AP diameters and cross-sectional areas of dural sacs and spinal cords on magnetic resonance imaging (MRI) were measured in 1211 healthy volunteers. Correlation between cervical canal diameter on X-rays and AP diameter and cross-sectional area of dural sacs and spinal cords on MRI were assessed. The ratio of the AP diameter of the spinal cord/dural sac was compared between subjects with and without SCC. Results Spinal canal diameters were not highly correlated with spinal cord AP diameters and cross-sectional areas, although spinal canal diameters were significantly correlated with dural sac AP diameters. The individual difference in the ratio of the AP diameter of the spinal cord/dural sac was large (35%-93%), and the ratio was significantly larger in the subjects with SCC. An AP diameter ratio more than 62% at the C2 to C3 disc level is a risk factor for developing SCC. Conclusion The spinal cord diameter was independent of the spinal canal diameter and the relative size of a spinal cord and spinal canal differed on an individual basis. In addition, the ratio of spinal cord/dural sac in subjects with SCC was significantly larger. Therefore, a relatively large spinal cord could be a risk factor for SCC.

Study design A prospective comparative study. Objective This study aimed to establish cervical spine morphometry, alignment, and range of motion (ROM) and to clarify the impact of these age-related and degenerative changes. Summary of background data There are no studies that have evaluated differences in the results of cervical spine radiographs between a large series of cervical spondylotic myelopathy (CSM) patients and healthy subjects. Methods We enrolled 1016 consecutive CSM patients who underwent laminoplasty. CSM patients were also divided based on each decade of life between the fourth and ninth decades. We also enrolled a total of 1230 healthy volunteers as asymptomatic subjects in this study. There were at least 100 men and 100 women in each decade of life between the third and eighth decades. Cervical sagittal alignment on neutral and flexion-extension views was measured by the Cobb method at C2-7. ROM was assessed by measuring the difference in alignment between flexion and extension. Results Cervical lordosis in the neutral position increased gradually with age in both groups. CSM patients showed significantly smaller lordotic angles compared with those shown by asymptomatic subjects within each decade. The total ROM decreased with increasing age in both groups. The total ROM of females was larger than males. The ROM of CSM patients was significantly smaller than asymptomatic subjects. The flexion ROM did not change with aging in either group. There was no significant difference in the flexion ROM between males and females in the two groups. However, the extension ROM decreased gradually in both groups. The extension ROM of CSM patients was significantly smaller than asymptomatic subjects. Conclusion Age-related and degenerative changes in the cervical spine, alignment, and ROM in each decade of life were established between CSM patients and asymptomatic subjects.

Decompressive surgery is the accepted treatment for the patients of cervical compressive myelopathy. Laminoplasty is an established procedure for the decompression of multisegmental stenosis in cervical spine. French-door laminoplasty is one of the most popular double-door laminoplasties, which was developed in 1980 by Kurokawa et al. French-door laminoplasty can be indicated to most of cases with compressive myelopathy in the cervical spine. This procedure is available at all levels between C2 and C7 and sometimes applied to upper thoracic levels. This procedure has acquired good surgical results with minimal invasiveness and lower rate of complications. However, there are some limitations for surgical indications. When the patients have local kyphosis >13°, K-line (−), or higher occupied ratio of OPLL (>50%), the surgical outcomes would be poor.

Cervical pedicle screw fixation is an effective procedure for stabilizing an unstable motion segments, as this procedure can offer the strongest stability among several instruments used in cervical spine. However, it has generally been considered too risky due to the potential for injury to neurovascular structures. So far it has not widely been used.

Osteoporotic vertebral body fractures (OVFs) represent a significant medical and socioeconomic burden. There is ongoing debate concerning the role of cement augmentation versus conservative management, but we are increasingly recognizing the longer-term effects of kyphotic vertebral alignment on functional outcomes, pain, and subsequent fracture rates. The purpose of this study was to determine the effect of timing of intervention with percutaneous balloon kyphoplasty (BKP) for OVF on clinical and radiographic outcomes.51 patients (mean age, 75.5 years) who underwent BKP for OVF were analyzed. Patients were divided into two groups based on timing of BKP: early (4 weeks) or late (4 weeks). Multiple factors were assessed preoperatively and throughout follow up and compared between groups using bivariate testing, including: focal kyphosis, subsequent vertebral fracture, and low back pain.This was a retrospective sub-group analysis. There were 32 patients in the early group and 19 patients in the late group. There was no significant difference in preoperative bone density between groups. Mean follow-up was 1.2 years. Local kyphosis at final follow-up was significantly greater in the late group (-28.4°) than in the early group (-9.5°; p 0.001). There was no significant difference in local kyphosis between preoperative measurement and final follow-up in the early (p = 0.741) or late cohort (p = 0.794). Patients treated with early BKP demonstrated significantly better LBP scores (p 0.05) and a lower rate of subsequent vertebral fracture (p 0.05).BKP is able to prevent progressive collapse and kyphosis after OVF, but not effectively restore alignment, and as a result, patients who undergo early BKP (4 weeks) demonstrate better alignment, better LBP scores, and reduced rates of subsequent fracture at an average of 1.2 years following treatment.

Aims The aim of this study was to investigate the clinical and radiographic outcomes of microendoscopic laminotomy in patients with lumbar stenosis and concurrent degenerative spondylolisthesis (DS), and to determine the effect of this procedure on spinal stability. Patients and Methods A total of 304 consecutive patients with single-level lumbar DS with concomitant stenosis underwent microendoscopic laminotomy without fusion between January 2004 and December 2010. Patients were divided into two groups, those with and without advanced DS based on the degree of spondylolisthesis and dynamic instability. A total of 242 patients met the inclusion criteria. There were 101 men and 141 women. Their mean age was 68.1 years (46 to 85). Outcome was assessed using the Japanese Orthopaedic Association and Roland Morris Disability Questionnaire scores, a visual analogue score for pain and the Short Form Health-36 score. The radiographic outcome was assessed by measuring the slip and the disc height. The clinical and radiographic parameters were evaluated at a mean follow-up of 4.6 years (3 to 7.5). Results There were no significant differences in the preoperative measurements between the group and no significant differences between the clinical parameters at the final follow-up. The mean percentage slip was 17.1% preoperatively and 17.7% at the final follow-up (p = 0.35). Progressive instability was noted in 13 patients (8.2%) with DS and 6 patients (7.0%) with advanced DS, respectively (p = 0.81). There was radiological evidence of restabilization of the spine in 30 patients (35%) with preoperative instability. The success rate of microendoscopic laminotomy was good/excellent in 166 (69%), fair in 49 (20%) and poor in 27 patients (11%) in both groups. Conclusion Microendoscopic laminotomy is an effective form of surgical treatment for patients with DS and stenosis. Preservation of the stabilizing structures using this technique prevents postoperative instability. Cite this article: Bone Joint J 2018;100-B:499–506.

Study Design Retrospective multicenter study. Objective Although untethering surgery has been a standard treatment in patients with adult tethered cord syndrome (TCS), spine-shortening osteotomy (SSO) has recently been performed as an alternative technique. The purpose of this study was to compare the clinical outcomes of the two procedures for TCS in adults. Methods Fourteen patients (37.7 ± 12.5 years) with TCS were enrolled at 6 hospitals. Their clinical charts, operative records, and follow-up data were reviewed. The categories of tethering lesions were tight terminal filum in 1 patient, lipoma in 5 patients, and lipomyelomeningocele in 8 patients. Eleven patients underwent untethering surgery, and 3 patients underwent SSO surgery. Results There were no significant differences in age, sex, types of preoperative symptoms, or duration of follow-up between the two groups. The preoperative duration of symptoms was significantly longer (25 ± 12.4 years) and the percentage of those with prior surgery was higher in the SSO group (66.7%). The preoperative pathology was lipomeningocele in all SSO group and lipoma or tight terminal filum in the untethering group. Cerebrospinal fluid leakage and urinary infection occurred in 1 patient each among those with untethering, and massive intraoperative bleeding occurred in 1 patient with SSO. SSO provided better clinical improvement than untethering surgery ( p = 0.003). Conclusions Based on this small retrospective case series, SSO appears to provide clinical improvement at least comparable to the untethering procedure, especially in more challenging cases.

Study design Cross-sectional study. Objective The purposes of this study were (1) to investigate the frequency and degree of cervical disc degeneration and protrusion on cervical spine magnetic resonance (MR) images and (2) to analyze the correlation between the severity of disc degeneration and disc protrusion. Summary of background data Cervical disc degenerative changes or protrusion is commonly observed on MR images in healthy subjects. However, there are few large-scale studies, and the frequency and range of these findings in healthy subjects have not been clarified. Moreover, there are no reports regarding the correlation between cervical disc degeneration and disc protrusion. Methods Cervical disc degeneration and protrusion were prospectively measured using magnetic resonance imaging in 1211 relatively healthy volunteers. These included at least 100 males and 100 females in each decade of life between the 20s and the 70s. Cervical disc degeneration was defined according to the modified Pfirrmann classification system, and the amount of disc protrusion was evaluated using the anteroposterior diameter of disc protrusion on sagittal MR image. Results Mild disc degeneration was very common, including 98.0% of both sexes in their 20s. The severity of cervical disc degeneration significantly increased with age in both sexes at every level. The disc degeneration predominantly occurred at C5-C6 and C6-C7. The difference between sexes was not significant except for individuals in their 50s. The average anteroposterior diameter of disc protrusion increased with aging, especially from the 20s to the 40s. The anteroposterior diameter of disc protrusion increased with a progression in the disc degeneration grade. Conclusion Cervical disc degeneration and protrusion were frequently observed in healthy subjects even in their 20s and deteriorated with age. Cervical disc protrusion was significantly correlated with cervical disc degeneration, and spatial cervical disc protrusion was affected by biochemical degenerative changes as observed on MR images. Level of evidence 2.

Study design Cross-sectional study. Objective The purpose of this study was to determine the prevalence and distribution of abnormal findings on cervical spine magnetic resonance image (MRI). Summary of background data Neurological symptoms and abnormal findings on MR images are keys to diagnose the spinal diseases. To determine the significance of MRI abnormalities, we must take into account the (1) frequency and (2) spectrum of structural abnormalities, which may be asymptomatic. However, no large-scale study has documented abnormal findings of the cervical spine on MR image in asymptomatic subjects. Methods MR images were analyzed for the anteroposterior spinal cord diameter, disc bulging diameter, and axial cross-sectional area of the spinal cord in 1211 healthy volunteers. The age of healthy volunteers prospectively enrolled in this study ranged from 20 to 70 years, with approximately 100 individuals per decade, per sex. These data were used to determine the spectrum and degree of disc bulging, spinal cord compression (SCC), and increased signal intensity changes in the spinal cord. Results Most subjects presented with disc bulging (87.6%), which significantly increased with age in terms of frequency, severity, and number of levels. Even most subjects in their 20s had bulging discs, with 73.3% and 78.0% of males and females, respectively. In contrast, few asymptomatic subjects were diagnosed with SCC (5.3%) or increased signal intensity (2.3%). These numbers increased with age, particularly after age 50 years. SCC mainly involved 1 level (58%) or 2 levels (38%), and predominantly occurred at C5-C6 (41%) and C6-C7 (27%). Conclusion Disc bulging was frequently observed in asymptomatic subjects, even including those in their 20s. The number of patients with minor disc bulging increased from age 20 to 50 years. In contrast, the frequency of SCC and increased signal intensity increased after age 50 years, and this was accompanied by increased severity of disc bulging. Level of evidence 2.

Background context Dynamic changes in the spinal cord cross-sectional area due to cervical ossification of the posterior longitudinal ligament (C-OPLL) are unknown, but dynamic multidetector-row computed tomography (MDCT) may be a useful tool. Purpose The purpose of this study was to evaluate the influence of dynamic factors on the spinal cord in patients with C-OPLL using MDCT during flexion and extension after myelography. Study design/setting This was a prospective cohort study. Patient sample Participants included 107 prospectively enrolled consecutive patients with C-OPLL and myelopathy. Outcome measure The outcome measure was the extension/flexion ratio at the spinal cord cross-sectional area at the most stenotic cervical level (SCASL). Methods Dynamic MDCT was performed, and the SCASL was measured. Patients were divided into the kyphosis group or lordosis group according to C2–C7 alignment. They were divided further into the K-line (−) group or K-line (+) group. The Japanese Orthopedic Association (JOA) score was used to determine myelopathy severity. Results All patients with C-OPLL had myelopathy, with a mean JOA score of 10.7 and mean disease duration of 16.7 months. The average extension/flexion ratio at all disc levels was less than 100%, suggesting that the spinal cord was compressed more during extension. In the kyphosis group, the spinal cord was compressed slightly more during flexion than during extension. In the K-line (−) group, the spinal cord was compressed more during flexion, although C2–C7 alignment was slightly lordotic on average. Large changes in the spinal cord cross-sectional area during extension-flexion and disease duration significantly influenced the severity of myelopathy. Conclusions Dynamic MDCT was useful for evaluating dynamic changes in the spinal cord. At the most stenotic level, the spinal cord became narrower during extension at all disc levels. In the kyphosis group and K-line (−) group, it became narrower during flexion. Cervical flexion may induce greater spinal cord compression in patients with kyphosis and K-line (−).

STUDY DESIGN Retrospective comparative study. OBJECTIVE To compare the surgical results of anterior and posterior combined surgery (AP) and posterior fixation with vertebroplasty (VP) for treating osteoporotic delayed vertebral collapse. SUMMARY OF BACKGROUND DATA The optimal treatment of osteoporotic delayed vertebral collapse has been controversial. Because of aged patients' numerous comorbid medical complications and frequent instrumentation failure secondary to osteoporosis, it is challenging for surgeons to manage osteoporotic delayed vertebral collapse. In spite of this, there have been few reports comparing the surgical results. METHODS A total of 93 patients with osteoporotic delayed vertebral fracture who underwent spinal surgery were enrolled at 6 hospitals. Sixty-five patients underwent AP surgery in 3 hospitals, and 28 patients underwent VP surgery in the other 3 hospitals. We restricted the spinal-fracture level to thoracolumbar lesion (T10-L2) and excluded patients followed up more than 2 years after surgery. The final numbers of patients included in this study were 24 in the AP group and 21 in the VP group. There were no significant differences between the 2 groups in terms of age, sex, disease duration, or duration of follow-up. RESULTS Operative time was significantly longer and intraoperative blood loss significantly greater in the AP group. No significant difference between the 2 groups was observed in neurological improvement or the angle of kyphosis correction. However, the loss of correction was significantly greater in the VP group. There were no significant differences in perioperative respiratory or other complications. Implant-related complications and pseudarthrosis were more often observed in the VP group. One patient in the VP group underwent additional surgery for progression kyphosis. CONCLUSION AP surgery provides stable spinal fixation and reduces implant failure particularly at the thoracolumbar junction because of load bearing of anterior spinal elements. Surgery-related complications in AP surgery were as few in number as with the VP group, and AP surgery is useful for osteoporotic delayed vertebral fracture.

Nonunion is a major complication of anterior cervical fusion that causes poor outcomes and occasionally requires additional operative intervention. The purpose of this study is to evaluate the accuracy of functional computed tomography (CT) scanning for determining fusion status after anterior cervical fusion by comparing with functional radiographs.The fusion status in 59 patients treated by anterior cervical fusion was assessed by functional radiography and functional CT scanning at 6 and 12 months after surgery. Fusion rates and clinical symptoms were evaluated. Fusion on functional radiography was defined as less than 2 mm of motion between adjacent spinous processes and a particular bony trabeculation on functional CT; fusion was defined as nonexistence of a clear zone or a gas pattern and a particular bone connection on reconstructed sagittal-view images.Functional radiographs demonstrated solid fusion in 83.9% at 6 months and 91.1% at 12 months postoperatively; functional CT showed solid fusion in 55.3 and 78.6%, respectively. The fusion rate detected on functional CT images was significantly lower than that on functional radiographs at each period. At 6 months postoperatively, patients with incomplete union on functional CT were more likely to have neck pain than those who had complete union on functional CT. (46.2 vs 13.3%, P0.05) CONCLUSION: Functional CT can detect nonunion more clearly than functional radiography. At 6 months postoperatively, patients with incomplete union on functional CT images were likely to have more neck pain. Functional CT may allow accurate detection of symptomatic nonunion after anterior cervical fusion.

Object Cervical spondylosis that causes upper-extremity muscle atrophy without gait disturbance is called cervical spondylotic amyotrophy (CSA). The distal type of CSA is characterized by weakness of the hand muscles. In this retrospective analysis, the authors describe the clinical features of the distal type of CSA and evaluate the results of surgical treatment. Methods The authors performed a retrospective review of 17 consecutive cases involving 16 men and 1 woman (mean age 56.3 years) who underwent surgical treatment for the distal type of CSA. The condition was diagnosed on the basis of cervical spondylosis in the presence of muscle impairment of the upper extremity (intrinsic muscle and/or finger extension muscles) without gait disturbance, and the presence of a compressive lesion involving the anterior horn of the spinal cord, the nerve root at the foramen, or both sites as seen on axial and sagittal views of MRI or CT myelography. The authors assessed spinal cord or nerve root impingement by MRI or CT myelography and evaluated surgical outcomes. Results The preoperative duration of symptoms averaged 11.8 months. There were 14 patients with impingement of the anterior horn of the spinal cord and 3 patients with both anterior horn and nerve root impingement. Twelve patients were treated with laminoplasty (plus foraminotomy in 1 case), 3 patients were treated with anterior cervical discectomy and fusion, and 2 patients were treated with posterior spinal fixation. The mean manual muscle testing grade was 2.4 (range 1–4) preoperatively and 3.4 (range 1–5) postoperatively. The surgical results were excellent in 7 patients, good in 2, and fair in 8. Conclusions Most of the patients in this series of cases of the distal type of CSA suffered from impingement of the anterior horn of the spinal cord, and surgical outcome was fair in about half of the cases.