Impact of pathogenic FBN1 variant types on the development of severe scoliosis in patients with Marfan syndrome.

BACKGROUND: Among the several musculoskeletal manifestations in patients with Marfan syndrome, spinal deformity causes pain and respiratory impairment and is a great hindrance to patients' daily activities. The present study elucidates the genetic risk factors for the development of severe scoliosis in patients with Marfan syndrome. METHODS: We retrospectively evaluated 278 patients with pathogenic or likely pathogenic FBN1 variants. The patients were divided into those with (n=57) or without (n=221) severe scoliosis. Severe scoliosis was defined as (1) patients undergoing surgery before 50 years of age or (2) patients with a Cobb angle exceeding 50° before 50 years of age. The variants were classified as protein-truncating variants (PTVs), which included variants creating premature termination codons and inframe exon-skipping, or non-PTVs, based on their location and predicted amino acid alterations, and the effect of the FBN1 genotype on the development of severe scoliosis was examined. The impact of location of FBN1 variants on the development of severe scoliosis was also investigated. RESULTS: Univariate and multivariate analyses revealed that female sex, PTVs of FBN1 and variants in the neonatal region (exons 25-33) were all independent significant predictive factors for the development of severe scoliosis. Furthermore, these factors were identified as predictors of progression of existing scoliosis into severe state. CONCLUSIONS: We elucidated the genetic risk factors for the development of severe scoliosis in patients with Marfan syndrome. Patients harbouring pathogenic FBN1 variants with these genetic risk factors should be monitored carefully for scoliosis progression.

Patients with a large ossification of the posterior longitudinal ligament have a higher incidence of arteriosclerosis in the carotid artery.

PURPOSE: This study aimed to investigate the impact of the severity of cervical ossification of the posterior longitudinal ligament (OPLL) on the incidence of arteriosclerosis in the carotid artery. METHODS: Patients with OPLL-induced cervical myelopathy were prospectively enrolled. The study involved analyzing patient characteristics, blood samples, computed tomography scans of the spine, and intima-media thickness (IMT) measurements of the common carotid artery. Patients were divided into two groups based on the size of the cervical OPLL to compare demographic data, comorbidities, and the presence of thickening of the carotid intima-media (max IMT ≥ 1.1 mm). RESULTS: The study included 96 patients (mean age: 63.5 years; mean body mass index: 26.9 kg/m2; 71.8% male; 35.4% with diabetes mellitus). The mean maximum anteroposterior (AP) diameter of the OPLL was 4.9 mm, with a mean occupancy ratio of 43%. The mean maximum IMT was 1.23 mm. Arteriosclerosis of the carotid artery was diagnosed in 62.5% of the patients. On comparing the two groups based on OPLL size, the group with larger OPLL (≥ 5 mm) had a higher BMI and a greater prevalence of carotid intima-media thickening. This significant difference in the prevalence of carotid intima-media thickening persisted even after adjusting for patient backgrounds using propensity score matching. CONCLUSIONS: Patients with a larger cervical OPLL showed a higher frequency of intima-media thickening in the carotid artery.

Post-operative shift in pain profile following fusion surgery for adult spinal deformity: a cluster analysis.

PURPOSE: Adult spinal deformity (ASD) is associated with a combination of back and leg pain of various intensities. The objective of the present study was to investigate the diverse reaction of pain profiles following ASD surgery as well as post-operative patient satisfaction. METHODS: Multicenter surveillance collected data for patients ≥ 19 years old who underwent primary thoracolumbar fusion surgery at > 5 spinal levels for ASD. Two-step cluster analysis was performed utilizing pre-operative numeric rating scale (NRS) for back and leg pain. Radiologic parameters and patient-reported outcome (PRO) scores were also obtained. One-year post-operative outcomes and satisfaction rates were compared among clusters, and influencing factors were analyzed. RESULTS: Based on cluster analysis, 191 ASD patients were categorized into three groups: ClusterNP, mild pain only (n = 55); ClusterBP, back pain only (n = 68); and ClusterBLP, significant back and leg pain (n = 68). ClusterBLP (mean NRSback 7.6, mean NRSleg 6.9) was the oldest 73.4 years (p < 0.001) and underwent interbody fusion (88%, p < 0.001) and sacral/pelvic fixation (69%, p = 0.001) more commonly than the other groups, for the worst pelvis incidence-lumbar lordosis mismatch (mean 43.7°, p = 0.03) and the greatest sagittal vertical axis (mean 123 mm, p = 0.002). While NRSback, NRSleg and PRO scores were all improved postoperatively in ClustersBP and BLP, ClusterBLP showed the lowest satisfaction rate (80% vs. 80% vs. 63%, p = 0.11), which correlated with post-operative NRSback (rho = -0.357). CONCLUSIONS: Cluster analysis revealed three clusters of ASD patients, and the cluster with the worst pain back and leg pain had the most advanced disease and showed the lowest satisfaction rate, affected by postoperative back pain.

Management of mild degenerative cervical myelopathy and asymptomatic spinal cord compression: an international survey.

STUDY DESIGN: Cross-sectional survey. OBJECTIVE: Currently there is limited evidence and guidance on the management of mild degenerative cervical myelopathy (DCM) and asymptomatic spinal cord compression (ASCC). Anecdotal evidence suggest variance in clinical practice. The objectives of this study were to assess current practice and to quantify the variability in clinical practice. METHODS: Spinal surgeons and some additional health professionals completed a web-based survey distributed by email to members of AO Spine and the Cervical Spine Research Society (CSRS) North American Society. Questions captured experience with DCM, frequency of DCM patient encounters, and standard of practice in the assessment of DCM. Further questions assessed the definition and management of mild DCM, and the management of ASCC. RESULTS: A total of 699 respondents, mostly surgeons, completed the survey. Every world region was represented in the responses. Half (50.1%, n = 359) had greater than 10 years of professional experience with DCM. For mild DCM, standardised follow-up for non-operative patients was reported by 488 respondents (69.5%). Follow-up included a heterogeneous mix of investigations, most often at 6-month intervals (32.9%, n = 158). There was some inconsistency regarding which clinical features would cause a surgeon to counsel a patient towards surgery. Practice for ASCC aligned closely with mild DCM. Finally, there were some contradictory definitions of mild DCM provided in the form of free text. CONCLUSIONS: Professionals typically offer outpatient follow up for patients with mild DCM and/or asymptomatic ASCC. However, what this constitutes varies widely. Further research is needed to define best practice and support patient care.

Predictors for hemostatic thrombin-gelatin matrix usage in spine surgery: a multicenter observational study.

STUDY DESIGN: A prospective cohort study. OBJECTIVES: Thrombin-gelatin matrix (TGM) is a rapid and potent hemostatic agent, but it has some limitations, including the cost and its preparation time. The purpose of this study was to investigate the current trend in the use of TGM and to identify the predictors for TGM usage in order to ensure its proper use and optimized resource allocation. METHODS: A total of 5520 patients who underwent spine surgery in a multicenter study group within a year were included in the study. The demographic factors and the surgical factors including spinal levels operated, emergency surgery, reoperation, approach, durotomy, instrumented fixation, interbody fusion, osteotomy, and microendoscopy-assistance were investigated. TGM usage and whether it was routine or unplanned use for uncontrolled bleeding were also checked. A multivariate logistic regression analysis was used to identify predictors for unplanned use of TGM. RESULTS: Intraoperative TGM was used in 1934 cases (35.0%), among which 714 were unplanned (12.9%). Predictors of unplanned TGM use were female gender (adjusted odds ratio [OR]: 1.21, 95% confidence interval [CI]: 1.02-1.43, p = 0.03), ASA grade ≥ 2 (OR: 1.34, 95% CI: 1.04-1.72, p = 0.02), cervical spine (OR: 1.55, 95% CI: 1.24-1.94, p < 0.001), tumor (OR: 2.02, 95% CI: 1.34-3.03, p < 0.001), posterior approach (OR: 1.66, 95% CI: 1.26-2.18, p < 0.001), durotomy (OR: 1.65, 95% CI: 1.24-2.20, p < 0.001), instrumentation (OR: 1.30, 1.03-1.63, p = 0.02), osteotomy (OR: 5.00, 2.76-9.05, p < 0.001), and microendoscopy (OR: 2.24, 1.84-2.73, p < 0.001). CONCLUSIONS: Many of the predictors for unplanned TGM use have been previously reported as risk factors for intraoperative massive hemorrhaging and blood transfusion. However, other newly revealed factors can be predictors of bleeding that is technically challenging to control. While routine usage of TGM in these cases will require further justification, these novel findings are valuable for implementing preoperative precautions and optimizing resource allocation.

Congenital atlanto-occipital dislocation in a patient with Down syndrome: a case report.

Down syndrome, also known as trisomy 21, is associated with congenital cervical spine abnormalities, including atlantoaxial instability with or without os odontoideum, atlanto-occipital instability, and hypoplasia of the atlas. Herein, we report a case of Down syndrome complicated by congenital atlanto-occipital dislocation. The patient presented with severe cervical myelopathy at 13 years of age after a 10-year follow-up. Radiography and computed tomography revealed os odontoideum protruding into the foramen magnum and congenital anterior atlanto-occipital dislocation. Additionally, a bifurcated internal occipital crest with a thinned central portion of the occipital bone was noted. Magnetic resonance imaging revealed kyphotic alignment of the spinal cord with severe compression at the foramen magnum level. As the neurological impairment was partially improved by halo vest immobilization, we performed in situ O-C2 fusion with an iliac autograft and decompression of the foramen magnum and posterior arch of C1. An improvement was observed immediately after surgery. Two years after surgery, radiography and computed tomography showed solid O-C2 segment fusion. The accumulation of similar cases is essential for determining the prognosis or optimal treatment for this rare congenital condition.

Does surgical site infection affect patient-reported outcomes after spinal surgery? A multicenter cohort study.

BACKGROUND: Surgical site infections are common in spinal surgeries. It is uncertain whether outcomes in spine surgery patients with vs. without surgical site infection are equivalent. Therefore, we assessed the effects of surgical site infection on postoperative patient-reported outcomes. METHODS: We enrolled patients who underwent elective spine surgery at 12 hospitals between April 2017 and February 2020. We collected data regarding the patients' backgrounds, operative factors, and incidence of surgical site infection. Data for patient-reported outcomes, namely numerical rating scale, Neck Disability Index/Oswestry Disability Index, EuroQol Five-Dimensional questionnaire, and 12-Item Short-Form Health Survey scores, were obtained preoperatively and 1 year postoperatively. We divided the patients into with and without surgical site infection groups. Multivariate logistic regression analyses were performed to identify the risk factors for surgical site infection. Using propensity score matching, we obtained matched surgical site infection-negative and -positive groups. Student's t-test was used for comparisons of continuous variables, and Pearson's chi-square test was used to compare categorical variables between the two matched groups and two unmatched groups. RESULTS: We enrolled 8861 patients in this study; 74 (0.8 %) developed surgical site infections. Cervical spine surgery and American Society of Anesthesiologists physical status classification ≥3 were identified as risk factors; microendoscopy was identified as a protective factor. Using propensity score matching, we compared surgical site infection-positive and -negative groups (74 in each group). No significant difference was found in postoperative pain or dysesthesia of the lower back, buttock, leg, and plantar area between the groups. When comparing preoperative with postoperative pain and dysesthesia, statistically significant improvement was observed for both variables in both groups (p < 0.01 for all variables). No significant differences were observed in postoperative outcomes between the matched surgical site infection-positive and -negative groups. CONCLUSIONS: Patients with surgical site infections had comparable postoperative outcomes to those without surgical site infections.

Does T1 slope minus cervical lordosis mismatch affect surgical outcomes of cervical laminoplasty in the absence of preoperative severe kyphosis?

BACKGROUND: The impact of the T1 slope minus cervical lordosis (T1S-CL) on surgical outcomes in patients with degenerative cervical myelopathy undergoing laminoplasty (LP) remain uncertain. METHODS: One hundred patients who underwent cervical LP were retrospectively reviewed. Radiographic measurements included C2-C7 lordosis (CL), T1 slope (T1S), and C2-C7 sagittal vertical axis (SVA). Additionally, pain numeric rating scale, neck disability index (NDI), 12-Item Short-Form Health Survey, Euro QOL 5 dimensions (EQ5D), and Japanese Orthopedic Association score were investigated. According to past reports, T1S-CL > 20° was defined as mismatched. Then, based on T1S-CL mismatching, patients were divided into 2 groups. RESULTS: This research understudied 67 males and 33 females with a mean age of 67 y. Preoperatively, only eight patients showed a T1S-CL mismatch. While the C2-7 Cobb angles did not change significantly after surgery, the T1 slope (T1S) angle increased, increasing the T1S-CL as a result. As we compared the clinical outcomes based on the preoperative T1S-CL mismatching, there were no significant differences between the two groups. On the other hand, the number of patients in the mismatched group increased to 21 patients postoperatively. As we compared clinical outcomes based on the postoperative T1S-CL mismatching, the postoperative NDI score and preop/postop EQ5D score were significantly worse in the mismatch group. CONCLUSIONS: Although cervical LP showed inferior outcomes in patients with postoperative T1S-CL mismatch even in the absence of severe preoperative kyphosis (> 10°), preoperative T1S-CL mismatch was not adversely prognostic.

Postoperative outcomes after degenerative lumbar spine surgery in rheumatoid arthritis patients -a propensity score-matched analysis.

BACKGROUND: Although treatment options for rheumatoid arthritis (RA) have evolved significantly since the introduction of biologic agents, degenerative lumbar disease in RA patients remains a major challenge. Well-controlled comparisons between RA patients and their non-RA counterparts have not yet been reported. The objective of the present study was to compare postoperative outcomes of lumbar spine surgery between RA and non-RA patients by a retrospective propensity score-matched analysis. METHODS: Patients who underwent primary posterior spine surgery for degenerative lumbar disease in our prospective multicenter study group between 2017 and 2020 were enrolled. Demographic data including age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA) physical status classification, diabetes mellitus, smoking, steroid usage, number of spinal levels involved, and preoperative patient-reported outcome (PRO) scores (numerical rating scale [NRS] for back pain and leg pain, Short Form-12 physical component summary [PCS], EuroQOL 5-dimension [EQ-5D], and Oswestry Disability Index [ODI]) were used to calculate a propensity score for RA diagnosis. One-to-one matching was performed and 1-year postoperative outcomes were compared between groups. RESULTS: Among the 4567 patients included, 90 had RA (2.0%). RA patients in our cohort were more likely to be female, with lower BMI, higher ASA grade and lower current smoking rate than non-RA patients. Preoperative NRS scores for leg pain, PCS, EQ-5D, and ODI were worse in RA patients. Propensity score matching generated 61 pairs of RA and non-RA patients who underwent posterior lumbar surgery. After background adjustment, RA patients reported worse postoperative PCS (28.4 vs. 37.2, p = 0.008) and EQ-5D (0.640 vs. 0.738, p = 0.03), although these differences were not significant between RA and non-RA patients not on steroids. CONCLUSIONS: RA patients showed worse postoperative quality of life outcomes after posterior surgery for degenerative lumbar disease, while steroid-independent RA cases showed equivalent outcomes to non-RA patients.

Surgical outcomes between posterior decompression alone and posterior decompression with fusion surgery among patients with Meyerding grade 2 degenerative spondylolisthesis: a multicenter cohort study.

BACKGROUND: Whether lumbar decompression with fusion surgery is effective against Meyerding grade 2 degenerative spondylolisthesis (DS) is unknown. Therefore, the current study aimed to compare the surgical outcomes between posterior decompression alone and posterior decompression with fusion surgery among patients with grade 2 DS with central canal stenosis. METHODS: This retrospective cohort study included prospectively registered patients (n = 3863) who underwent surgery for degenerative lumbar spinal canal stenosis at nine high-volume spine centers from April 2017 to July 2019. Patients with grade 2 DS and central canal stenosis were included in the analysis. Patients with radiculopathy, including foraminal stenosis, degenerative scoliosis, and concomitant anterior spinal fusion, and those with a previous history of lumbar surgery were excluded. The participants were divided into the decompression alone group (group D) and decompression with fusion surgery group (group F). Data about patient-reported outcomes, including Numeric Rating Scale (low back pain, leg pain, leg numbness, and foot numbness), Oswestry Disability Index, EuroQol Five-Dimensional questionnaire, and 12-Item Short-Form Health Survey scores, were obtained preoperatively and 2 years postoperatively. RESULTS: In total, 2354 (61%) patients, including 42 (1.8%) with grade 2 DS (n = 18 in group D and n = 24 in group F), completed the 2-year follow-up. Group D had a higher proportion of female patients than group F. However, the two groups did not significantly differ in terms of other baseline demographic characteristics. Group D had a significantly shorter surgical time and lower volume of intraoperative blood loss than group F. Postoperative patient-reported outcomes did not significantly differ between the two groups, although the preoperative degree of low back pain was higher in group F than in group D. The slip degree of group D did not worsen during the follow-up period. CONCLUSION: The surgical outcomes were similar regardless of the addition of fusion surgery among patients with grade 2 DS. Decompression alone was superior to decompression with fusion surgery as it was associated with a lower volume of intraoperative blood loss and shorter surgical time.

Minimum clinically important change for outcome scores among patients aged 75 or over undergoing lumbar spine surgery.

PURPOSE: To elucidate the minimum clinically important change (MCIC) of the physical component summary (PCS) of the Short Form-12, Oswestry Disability Index (ODI), EuroQOL-5 dimensions (EQ-5D), and the Core Outcome Measures Index (COMI) in patients aged ≥ 75 years undergoing lumbar spine surgery. METHODS: We retrospectively reviewed patients aged ≥ 75 years with degenerative lumbar spine disease who underwent lumbar spine decompression or fusion surgery within three levels between April 2017 and June 2018. We also evaluated patients aged < 75 years in the same period as reference. We evaluated the baseline and postoperative PCS, ODI, EQ-5D, and COMI scores. Patients were asked to answer an anchor question regarding health transition for MCICs using the anchor-based method. RESULTS: A total of 247 patients aged ≥ 75 years and 398 patients aged < 75 years were included for analysis. Of patients aged ≥ 75 years, 83.4% showed at least "somewhat improved" outcomes, while 91.0% of patients aged < 75 years reported this outcome. PCS change score was not adequately correlated to health transition in patients aged ≥ 75 years. Receiver operating characteristic curve analyses revealed MCICs of 17.8 for ODI, 0.18 for EQ-5D, and 1.6 for COMI in patients aged ≥ 75 years, and 12.7 for ODI, 0.19 for EQ-5D, and 2.3 for COMI in patients aged < 75 years. CONCLUSION: In patients aged ≥ 75 years, PCS may not be feasible for evaluation of health transition. The MCIC value for ODI score was higher and that for EQ-5D/COMI score was lower in patients aged ≥ 75 years, compared with those in patients aged < 75 years.

Risk factors for worsening sexual function after lumbar spine surgery and characteristics of non-responders to the questionnaire of sex life.

PURPOSE: To precisely assess the Oswestry Disability Questionnaire (ODQ) and its total score (Oswestry Disability Index: ODI) and reveal characteristics of non-responders of the 8th item of ODQ (ODI-8) relating to sexual function. Furthermore, we evaluated risk factors for aggravation of postoperative sexual function. METHODS: We enrolled patients undergoing lumbar spine surgery at eight hospitals between April 2017 and November 2018. Patients' background data and operative factors were collected. We also assessed pain or dysesthesia (lower back, buttock, leg, and plantar area) on a numerical rating scale, EuroQol 5 Dimension, core outcome measures index back, and ODI before and 1 year after surgery. Factor analysis was conducted for the ODQ. Non-responders of the ODI-8 were compared with full-responders using propensity score matching. Risk factors for worsening ODI-8 were evaluated by multivariate logistic regression analysis. RESULTS: Of the 2,610 patients enrolled, 601 (23.0%) answered all but the ODI-8 item; these patients were likely to show better preoperative clinical symptoms than full-responders, even after adjusting for age and gender using propensity scores. Age, spinal deformity, and the American Society of Anesthesiologists physical status (ASA-PS) 3/4 were significant risk factors for postoperative aggravation of the ODI-8. Factor analysis revealed that the ODQ was composed of dynamic and static activities; the ODI-8 was considered a dynamic activity. CONCLUSION: Almost a fourth of the patients skipped the ODI-8. Age, the presence of spinal deformity, and worse ASA-PS were found to be risk factors for postoperative aggravation of sexual function. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Tracheal stenosis due to cervicothoracic hyperlordosis in patients with cerebral palsy treated with posterior spinal fusion: a report of the first two cases.

BACKGROUND: Spinal deformity is frequently identified in patients with cerebral palsy (CP). As it progresses, tracheal stenosis often develops due to compression between the innominate artery and anteriorly deviated vertebrae at the apex of the cervicothoracic hyperlordosis. However, the treatment strategy for tracheal stenosis complicated by spinal deformity in patients with CP remains unknown. CASE PRESENTATION: This study reports two cases: a 19-year-old girl (case 1) and a 17-year-old girl (case 2), both with CP at Gross Motor Function Classification System V. Both patients experienced acute oxygen desaturation twice within the past year of their first visit to our department. X-ray and computed tomography revealed severe scoliosis and cervicothoracic hyperlordosis causing tracheal stenosis at T2 in case 1 and at T3-T4 in case 2, suggesting that their acute oxygen desaturation had been caused by impaired airway clearance due to tracheal stenosis. After preoperative halo traction for three weeks, both patients underwent posterior spinal fusion from C7 to L5 with Ponte osteotomy and sublaminar taping at the proximal thoracic region to correct cervicothoracic hyperlordosis and thoracolumbar scoliosis simultaneously. Postoperative X-ray and computed tomography revealed that the tracheal stenosis improved in parallel with the correction of cervicothoracic hyperlordosis. Case 1 did not develop respiratory failure 1.5 years after surgery. Case 2 required gastrostomy postoperatively due to severe aspiration pneumonia. However, she developed no respiratory failure related to impaired airway clearance at one-year follow-up. CONCLUSIONS: We present the first two cases of CP that developed tracheal stenosis caused by cervicothoracic hyperlordosis concomitant with progressive scoliosis and were successfully treated by posterior spinal fusion from C7 to L5. This enabled us to relieve tracheal stenosis and correct the spinal deformity at the same time. Surgeons must be aware of the possibility of coexisting tracheal stenosis in treating spinal deformity in patients with neurological impairment because the surgical strategy can vary in the presence of tracheal stenosis. This study demonstrated that some patients with CP with acquired tracheal stenosis can be treated with spinal surgery.

Associations between curve severity and revised Scoliosis Research Society-22 and scoliosis Japanese Questionnaire-27 scores in female patients with adolescent idiopathic scoliosis: a multicenter, cross-sectional study.

BACKGROUND: Patient-reported outcome measures are widely utilized to assess health-related quality of life (HRQOL) in patients with adolescent idiopathic scoliosis (AIS). However, the association between HRQOL and curve severity is mostly unknown. The aim of this study is to clarify the association between HRQOL and curve severity, and to determine the optimal cutoff values of patient-reported outcomes for major curve severity in female patients with AIS. METHODS: Female patients with AIS treated conservatively were recruited. The patients' HRQOL outcomes were examined using the revised Scoliosis Research Society-22 (SRS-22r) and the Scoliosis Japanese Questionnaire-27 (SJ-27). The correlations of the SRS-22r and SJ-27 scores with the major Cobb angle were assessed using Spearman's correlation coefficient analysis. The association between HRQOL issues in the SJ-27 and the major Cobb angle was evaluated by calculating Akaike's Information Criterion (AIC). Furthermore, the optimal cutoff values of the SRS-22r and SJ-27 scores for the major Cobb angle were determined by AIC analysis. RESULTS: The study cohort comprised 306 female patients with AIS. The SRS-22r and SJ-27 scores were significantly correlated with the major Cobb angle. Questions in the SJ-27 regarding discomfort when wearing clothes showed a lower AIC value in patients with severe scoliosis. The optimal cutoff values were a SRS-22r score of 3.2 for the discrimination of severe scoliosis (Cobb angle ≥48°), and a SJ-27 score of 32 for the discrimination of moderate scoliosis (Cobb angle ≥33°). CONCLUSION: Discomfort when wearing clothes was the most important HRQOL problem caused by severe scoliosis. The SRS-22r and SJ-27 scores are useful for the discrimination of clinical status in female patients with severe scoliosis or moderate scoliosis.

Comparison between microendoscopic laminectomy and open posterior decompression surgery for single-level lumbar spinal stenosis: a multicenter retrospective cohort study.

BACKGROUND: Microendoscopic laminectomy (MEL), in which a 16-mm tubular retractor with an internal scope is used, has shown excellent surgical results for patients with lumbar spinal canal stenosis. However, no reports have directly compared MEL with open laminectomy. This study aimed to elucidate patient-reported outcomes (PROs) and perioperative complications in patients undergoing MEL versus open laminectomy. METHODS: This is a multicenter retrospective cohort study of prospectively registered patients who underwent lumbar spinal surgery at one of the six high-volume spine centers between April 2017 and September 2018. A total of 258 patients who underwent single posterior lumbar decompression at L4/L5 were enrolled in the study. With regard to demographic data, we prospectively used chart sheets to evaluate the diagnosis, operative procedure, operation time, estimated blood loss, and complications. The follow-up period was 1-year. PROs included a numerical rating scale (NRS) for lower back pain and leg pain, the Oswestry Disability Index (ODI), EuroQol 5 Dimension (EQ-5D), and patient satisfaction with the treatment. RESULTS: Of the 258 patients enrolled, 252 (97%) completed the 1-year follow-up. Of the 252, 130 underwent MEL (MEL group) and 122 underwent open decompression (open group). The MEL group required a significantly shorter operating time and sustained lesser intraoperative blood loss compared with the open group. The MEL group showed shorter length of postoperative hospitalization than the open group. The overall complication rate was similar (8.2% in the MEL group versus 7.7% in the open group), and the revision rate did not significantly differ. As for PROs, both preoperative and postoperative values did not significantly differ between the two groups. However, the satisfaction rate was higher in the MEL group (74%) than in the open group (53%) (p = 0.02). CONCLUSIONS: MEL required a significantly shorter operating time and resulted in lesser intraoperative blood loss compared with laminectomy. Postoperative PROs and complication rates were not significantly different between the procedures, although MEL demonstrated a better satisfaction rate.

Anatomical study of cervical intervertebral foramen in patients with cervical spondylotic radiculopathy.

PURPOSE: To determine the underlying anatomical characteristics in patients with cervical spondylotic radiculopathy (CSR) by comparing those of surgically treated CSR patients with those of healthy subjects. METHODS: Computed tomography (CT) scans of the cervical spine in 42 patients who underwent decompression surgery for CSR were investigated. As a control group, 42 age- and sex-matched healthy subjects were randomly selected from the 1272 subjects who underwent CT examinations of the entire spine as their routine medical check-up. Image measurements included C2-7 sagittal Cobb angle, spinal canal diameters, and angles of the nerve root groove at each level from C3 to C7, and the size of the intervertebral foramen and the size of osteophytes at each level from C3/4 to C7/T1. As for the frequency of osteophytes at the surgical level, we compared the operated and nonoperated intervertebral foramina among the CSR patients, and all other parameters were compared with the corresponding segments in the control group. RESULTS: Forty-eight intervertebral segments were surgically treated in the CSR group. There was a higher incidence of osteophytes in the operated foramen (70.8%) than in the nonoperated foramen (28.2%, p < 0.01) in the patients with CSR. The anteroposterior diameter (width) of the foramen was significantly smaller at all levels in the CSR patients, whereas the height of the foramen did not significantly differ between the two groups. CONCLUSION: It can be speculated that the width of the intervertebral foramen (developmental factor) and the formation of osteophytes (spondylotic factor) were related to the onset of the CSR.

Partial Resection of Spinous Process for the Elderly Patients with Thoraco-Lumbar Kyphosis: Technical Report.

Background and objectives: Global sagittal imbalance with lumbar hypo-lordosis can cause low back pain (LBP) during standing and/or walking. This condition has recently been well-known as one of the major causes of reduced health-related quality of life (HRQOL) in elderly populations. Decrease in disc space of anterior elements and an increase in the spinous process height of posterior elements may both contribute to the decrease in lordosis of the lumbar spine. To correct the sagittal imbalance, the mainstream option is still a highly invasive surgery, such as long-segment fusion with posterior wedge osteotomy. Therefore, we developed a treatment that is partial resection of several spinous processes of thoraco-lumbar spine (PRSP) and lumbar extension exercise to improve the flexibility of the spine as postoperative rehabilitation. Materials and Methods: Consecutively, seven patients with over 60 mm of sagittal vertical axis (SVA) underwent PRSP. The operation was performed with several small midline skin incisions under general anesthesia. After splitting the supraspinous ligaments, the cranial or caudal tip of the spinous process of several thoraco-lumbar spines was removed, and postoperative rehabilitation was followed to improve extension flexibility. Results: The average follow-up period was 13.0 months. The average blood loss and operation time were 11.4 mL and 47.4 min, respectively. The mean SVA improved from 119 to 93 mm but deteriorated in one case. The mean numerical rating scale of low back pain improved from 6.6 to 3.7 without any exacerbations. The mean Oswestry Disability Index score was improved from 32.4% to 19.1% in six cases, with one worsened case. Conclusions: We performed PRSP and lumbar extension exercise for the patients with LBP due to lumbar kyphosis. This minimally invasive treatment was considered to be effective in improving the symptoms of low back pain and HRQOL, especially of elderly patients with lumbar kyphosis.

Effect of Spinal Alignment Changes on Lower Back Pain in Patients Treated with Total Hip Arthroplasty for Hip Osteoarthritis.

Background and objectives: The influence of changes in spinal alignment after total hip arthroplasty (THA) on improvement in lower back pain (LBP) remains controversial. To evaluate how changes in spinal malalignment correlate with improvement in preoperative LBP in patients who underwent THA for hip osteoarthritis. Materials and Methods: From November 2015 to January 2017, 104 consecutive patients who underwent unilateral THA were prospectively registered. Whole spine X-rays and patient-reported outcomes (PROs) were obtained preoperatively and 12 months postoperatively. The PROs used were the Numerical Rating Scale (NRS) for back pain, EuroQol 5 Dimension, and Short Form-12. Results: Seventy-four (71%) patients with complete data were eligible for the analysis. The sagittal parameters changed slightly but significantly. Coronal alignment significantly improved. Twenty-six (37%) patients had LBP preoperatively. These patients had smaller lumbar lordosis (LL), larger PT, and larger PI minus LL than the patients without LBP. Fourteen (54%) of the 26 patients with preoperative LBP showed pain improvement, but there were no significant differences in the radiographic parameters. Conclusions: Although preoperative LBP was likely to be resolved after THA, there were no significant correlations between alignment changes and LBP improvement. The cause of LBP in patients with hip osteoarthritis (OA) patients might be multifactorial.

Associated factors for and progression rate of sacroiliac joint degeneration in subjects undergoing comprehensive medical checkups.

PURPOSE: Associated factors for and the natural course of sacroiliac (SI) joint degeneration in the normal population are unknown. The purpose of this study was to determine associated factors for and the progression rate of SI joint degeneration. METHODS: We enrolled 553 healthy middle-aged subjects who underwent the first and second comprehensive health screening at an interval of 5.9 years (range 3.0-10.7 years). The medical checkup included blood tests and whole-body computed tomography. We investigated associated factors of SI joint degeneration, the relationship of the laterality of degeneration between the SI and L4/5 facet joint, L5/S facet joint, and the natural course of SI joint degeneration over time. RESULTS: At the first checkup, 70 subjects (12.7%) showed substantial degeneration (type 2 or 3) of the SI joints. Multivariate analysis revealed that female sex; pubic symphysis degeneration, L4/5, and L5/S facet joint degeneration; high body mass index; and several blood parameters were associated factors for SI joint degeneration. Laterality of SI joint degeneration was significantly more frequent than that of L4/5 or L5/S facet joint degeneration. Kaplan-Meier survival analysis revealed that the progression rates of SI joint degeneration from type 0 (no degeneration) or type 1 (slight degeneration) to substantial degeneration amounted to 3.4% and 35.5% after 10 years, respectively. CONCLUSION: We found substantial SI joint degeneration in 12.7% of healthy middle-aged subjects and considered it to be part of the normal aging process. There may be individual factors associated with its occurrence. These slides can be retrieved under Electronic Supplementary Material.

A sliding scale to predict postoperative complications undergoing posterior spine surgery.

BACKGROUND: There is a lack of consensus of operative time (OT) and estimated blood loss (EBL) for elderly patients based on the predicted risk of complications after posterior spine surgery. The purpose of this study was to evaluate the effect of age, OT, and EBL on the postoperative complication risk and to develop a simple sliding scale. METHODS: We explored prospectively collected data of consecutive patients who underwent posterior spine surgery in seven tertiary referral hospitals from November 2013 to May 2016. Age (<70, 70-74, 75-79, 80-84, ≥85 years), OT (<2, 2-<3, 3-<4, 4-<5, ≥5 h), and EBL (<500, 500-<1000, 1000-<1500, 1500-<2000, ≥2000 ml) were categorized ranging from 1 (lowest) to 5 (highest). The association between the crude cumulative categories' number and the incidence of complications was analyzed. We further evaluated the association by re-categorizing the cumulative number into three groups (3-4, 5-10, ≥11). RESULTS: Total of 2416 patients (median age: 70 years old) were enrolled and major complications were observed in 75 (3.1%) patients. Age, OT, and EBL showed similar odds ratio (1.18-1.19) as each category increased. The cumulative categories' number fitted the estimate complication risk (Hosmer-Lemeshow P = 0.87), and statistically significant trend was observed between predicted and actual complication rates (Cochran-Armitage test, P < 0.001). When cumulative categories' numbers were stratified into three groups, significant increasing trend of risk were observed (Mantel-Haenszel P < 0.001). Based on the categorical numbers, we proposed a simple sliding scale. CONCLUSION: Our data indicated that the risk of postoperative complication was associated with cumulative score based on increased age, OT, and EBL. A simple sliding scale was developed based on these factors, which may be useful to predict complication risk after posterior spine surgery.