Postoperative Complications of Surgery for Cervical Spondylotic Myelopathy with and Without Athetoid Cerebral Palsy.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: With the aging of the Japanese population, patients with athetoid cerebral palsy (ACP) are getting older, and the rate of surgery for CSM is increasing in ACP patients. However, postoperative complications of such surgery among adult patients with ACP have not been reported yet. We investigated postoperative complications of surgery for CSM with ACP and compared them with those of surgery for CSM without ACP using a national inpatient database of Japan. METHODS: Using the Diagnosis Procedure Combination database, we identified 61382 patients who underwent surgery for CSM from July 2010 to March 2018. We examined patient backgrounds, surgical procedures, and type of hospital, and a 4:1 propensity score matching was performed to compare the outcomes between the non-ACP and ACP groups. RESULTS: There were 60 847 patients without ACP and 535 patients with ACP. The mean age was 68.5 years in the non-ACP group and 55 years in the ACP group. The percentages of patients who underwent fusion surgery were 21.6% and 68.8% in the non-ACP and ACP groups, respectively. The 4:1 propensity score matching selected 1858 in the non-ACP group and 465 in the ACP group. The ACP group was more likely to have postoperative urinary tract infection (.4% vs 2.8%, P < .001), postoperative pneumonia (.4% vs 2.4%, P < .001), and 90-day readmission for reoperation (1.9% vs 4.3%, P = .003). CONCLUSIONS: We found that ACP patients were more vulnerable to postoperative complications and reoperation after CSM than non-ACP patients.

A new surgical method to treat intracanal lumbar disc herniation using the unilateral biportal endoscopic transforaminal approach: patient series.

BACKGROUND: Unilateral biportal endoscopic lumbar discectomy (UBELD) is a new minimally invasive spine surgery. The purpose of this study is to describe a new surgical method to treat intracanal lumbar disc herniation (LDH) using the unilateral biportal endoscopic transforaminal approach (UBE-TFA). The first 15 patients who had undergone UBELD for single-level LDH were included in this study. Operative time, intraoperative blood loss, postoperative stay, and intraoperative complications were recorded. The Oswestry Disability Index (ODI), numeric rating scale (NRS) score for leg pain, and modified MacNab criteria were assessed at 3 months postoperatively. OBSERVATIONS: The mean operative time was 52.0 ± 13.8 minutes. The mean intraoperative blood loss was 10.5 ± 10.2 mL. The mean postoperative stay was 1.1 ± 0.3 days. There were no complications. The postoperative mean ODI was significantly improved from 44.9 ± 14.4 to 7.7 ± 11.2 at the final follow-up (p < 0.001). There was a significant decrease in the postoperative mean NRS score for leg pain, from 6.1 ± 1.9 to 0.8 ± 1.3 at the final follow-up (p < 0.001). Based on the modified MacNab criteria, good to excellent results were obtained in 86.7% of the patients. LESSONS: We considered UBELD-TFA as not only one of the promising surgical methods for UBELD, but also a new surgical implementation of the TFA.

Bone Turnover Markers in Patients With Ossification of the Posterior Longitudinal Ligament in the Thoracic Spine.

STUDY DESIGN: A prospective, single-center, observational study. OBJECTIVE: To explore the association between serum levels of bone turnover markers and ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine. SUMMARY OF BACKGROUND DATA: The relationship between bone turnover markers, such as N-terminal propeptide of type I procollagen (PINP) or tartrate-resistant acid phosphate 5b (TRACP-5b), and OPLL has previously been examined. However, the correlation between these markers and thoracic OPLL, which is more severe than cervical-only OPLL, remains unclear. METHODS: This prospective study included 212 patients from a single institution with compressive spinal myelopathy and divided them into those without OPLL (Non-OPLL group, 73 patients) and those with OPLL (OPLL group, 139 patients). The OPLL group was further subdivided into cervical OPLL (C-OPLL, 92 patients) and thoracic OPLL (T-OPLL, 47 patients) groups. Patients' characteristics and biomarkers related to bone metabolism, such as calcium, inorganic phosphate (Pi), 25-hydroxyvitamin D, 1α,25 dihydroxyvitamin D, PINP, and TRACP-5b, were compared between the Non-OPLL and OPLL groups, as well as the C-OPLL and T-OPLL groups. Bone metabolism biomarkers were also compared after adjusting for age, sex, body mass index, and the presence of renal impairment using propensity score-matched analysis. RESULTS: The OPLL group had significantly lower serum levels of Pi and higher levels of PINP versus the Non-OPLL group as determined by propensity score-matched analysis. The comparison results between the C-OPLL and T-OPLL groups using a propensity score-matched analysis showed that T-OPLL patients had significantly higher concentrations of bone turnover markers, such as PINP and TRACP-5b, compared with C-OPLL patients. CONCLUSIONS: Increased systemic bone turnover may be associated with the presence of OPLL in the thoracic spine, and bone turnover markers such as PINP and TRACP-5b can help screen for thoracic OPLL.

Comparative Analysis of Microendoscopic and Open Laminectomy for Single-Level Lumbar Spinal Stenosis at L1-L2 or L2-L3.

BACKGROUND: Several reports have highlighted comparable surgical outcomes between microendoscopic laminectomy (MEL) and open laminectomy (open) for lumbar spinal stenosis. However, the unilateral approach in MEL may present challenges for the upper lumbar levels, where facet joints are located deeper inside. Our objective was to compare surgical outcomes and radiographic evaluations for single-level decompression cases at L1-L2 or L2-L3 between MEL and open laminectomy. METHODS: We analyzed patients who underwent single-level decompression for upper lumbar spinal stenosis at 12 distinguished spine centers from April 2017 to September 2021. Baseline demographics, preoperative, and 1-year postoperative patient-reported outcomes, along with imaging parameters, were compared between the MEL and open groups. To account for potential confounding, patients' backgrounds were adjusted using the inverse probability weighting method based on propensity scores. RESULTS: Among the 2487 patients undergoing decompression surgery, 118 patients (4.7%) underwent single-level decompression at L1-L2 or L2-L3. Finally, 80 patients (51 in the MEL group, 29 in the open group) with postoperative data were deemed eligible for analysis. The MEL group exhibited significantly improved postoperative EuroQol 5-Dimension values compared to the open group. Additionally, the MEL group showed a lower facet preservation rate according to computed tomography examination, whereas the open group had a higher incidence of retrolisthesis. CONCLUSIONS: Although overall surgical outcomes were similar, the MEL group demonstrated potential advantages in enhancing EuroQol 5-Dimension scores. The MEL group's lower facet preservation rate did not translate into a higher postoperative instability rate.

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.

Reduced volume and altered composition of paraspinal muscles in Marfan syndrome: A retrospective cohort study.

Retrospective cohort study. Spinal deformities in patients with Marfan syndrome (MFS) are distinct from those in patients with idiopathic scoliosis (IS). It is more prone to progression and more likely to present with sagittal malalignment than IS. However, the etiology of this characteristic spinal deformity in MFS remains unclear. This study aimed to determine the spinal musculature characteristics in patients with MFS on the hypothesis that the paraspinal muscles of patients with MFS would be qualitatively or quantitatively different from those of patients with IS. Seventeen consecutive patients with MFS aged 25 years or younger undergoing surgery for scoliosis in our hospital were compared with age- and sex-matched patients with IS undergoing surgery for scoliosis. The body size-adjusted relative cross-sectional area (rCSA), fatty infiltration ratio (FI%), and relative functional cross-sectional area (rFCSA) of the psoas muscles (PM) and paravertebral muscles (PVM) at L3/4 and L4/5 were measured using preoperative T2-weighted magnetic resonance imaging. Functional CSA was defined as total CSA minus the fatty infiltration area of each muscle and rFCSA was calculated as the body size-adjusted functional CSA. The rCSA of the PM at L3/4 and L4/5 was significantly smaller in the MFS group than in the IS group (L3/4, P = .021; L4/5, P = .002). The FI% of the PM at L4/5 was significantly higher in the MFS group (P = .044). Consequently, the rFCSA of the PM at L3/4 and L4/5 and the rFCSA of the PVM at L3/4 in the MFS group were significantly smaller than those in the IS group (PM at L3/4, P = .021; PM at L4/5, P = .001; PVM at L3/4, P = .025). Compared with patients with IS, patients with MFS exhibited significantly decreased body-size-adjusted CSA of the PM and reduced body-size-adjusted functional CSA of the PVM and PM. These findings may partially explain the characteristics of distinctive spinal deformities in patients with MFS.

Effect of Early Postoperative Resolution of MRI Signal Intensity Changes on the Outcomes of Degenerative Cervical Myelopathy.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: To investigate whether the timing of postoperative resolution of increased signal intensity (ISI) in the spinal cord is associated with surgical outcomes. SUMMARY OF BACKGROUND DATA: It remains unclear whether changes in ISI in the early postoperative period influence surgical outcomes. METHODS: This retrospective cohort study evaluated consecutive patients undergoing surgery for degenerative cervical myelopathy at a single academic hospital between January 2012 and September 2019. These patients underwent magnetic resonance imaging (MRI) preoperatively, within two weeks postoperatively (early MRI) and after six months postoperatively (late MRI). ISI was classified as follows: grade 0, none; grade 1, light (obscure); and grade 2, intense (bright). Patients were categorized into the following three groups: those with postoperative ISI resolution at early MRI (group E) or only at the late MRI (group L) stage and those whose ISI was persistent (group P). The surgical outcomes were compared between these three groups. RESULTS: We included 204 patients with complete data eligible for the analysis, and 163 of them had preoperative ISI. Postoperative ISI regression was observed in 49 (30.1%) patients. Of these 49 patients, 25 showed ISI resolution at early MRI (group E) and 24 only at late MRI (group L). All 49 were grade 1 on preoperative MRI, and this was not found to significantly impact surgical outcomes. In comparing surgical outcomes between the groups, group E had better postoperative Japanese Orthopedic Association scores and Japanese Orthopedic Association recovery rates than groups L and P. No significant differences were observed between groups L and P. CONCLUSIONS: Early resolution of preoperative grade 1 ISI on postoperative T2-weighted MRI may be associated with better surgical outcomes in patients with degenerative cervical myelopathy undergoing cervical spinal surgery.

Noninvasive Skin Autofluorescence of Advanced Glycation End Products for Detecting Ossification of the Posterior Longitudinal Ligament in the Thoracic Spine.

STUDY DESIGN: A single-center prospective observational study. OBJECTIVE: The aim was to clarify the usefulness of assessing advanced glycation end products (AGEs) by noninvasive skin autofluorescence in patients with ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: AGE accumulation is associated with various systemic disorders, including aging, diabetes mellitus, and obesity. AGEs have also been associated with OPLL, but their assessment by noninvasive skin autofluorescence has not been yet studied in these patients. MATERIALS AND METHODS: We enrolled patients with degenerative spinal spondylosis and divided them into non-OPLL and OPLL groups. The OPLL group was further subdivided into cervical OPLL (C-OPLL) and thoracic OPLL (T-OPLL) groups. We compared patients' characteristics, serum laboratory data (i.e. hemoglobin A1c, total cholesterol, creatinine, and estimated glomerular filtration rate), and the skin autofluorescence intensity of AGEs (the AGE score) between the non-OPLL and OPLL groups and among the non-OPLL, C-OPLL, T-OPLL groups. Finally, the association of the AGE score with the presence of C-OPLL or T-OPLL was assessed by multinomial logistic regression. RESULTS: Among the 240 eligible patients, 102 were in the non-OPLL group and 138 were in the OPLL group (92 with C-OPLL and 46 with T-OPLL). We observed no significant difference in the AGE score between the non-OPLL and OPLL groups, but when comparing the score among the non-OPLL, C-OPLL, and T-OPLL groups, we found that the T-OPLL group had a significantly higher AGE score. The results of multinomial regression analysis showed that a higher AGE score was significantly associated with T-OPLL (odds ratio: 1.46; 95% CI: 1.01-2.11; P=0.044). CONCLUSION: The AGE score determined by noninvasive skin autofluorescence could help to screen for OPLL in the thoracic spine.

Does Surgical Treatment Affect the Degree of Anxiety or Depression in Patients With Degenerative Cervical Myelopathy?

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Preoperative mental state has been reported as one of the factors affecting the surgical outcomes of spine surgery, but few studies have examined in detail how patients' mental state is affected by spine surgery. The purpose of this study was to investigate using the Hospital Anxiety and Depression Scale (HADS) whether surgery improves preoperative depression and anxiety in patients with degenerative cervical myelopathy. METHODS: We investigated patient-reported outcomes (Mental Component Summary, Physical Component Summary of SF-12 Health Survey, and EQ-5D, Neck Disability Index, JOACMEQ, satisfaction with treatment) and HADS one year after surgery, comparing them before and after surgery between April 2017 and February 2020. Among the cases diagnosed as preoperative anxiety and depression, we additionally compared the patient-reported outcomes based on the presence or absence of postoperative improvement in mental state, having also investigated the correlation between patient-reported outcomes and HADS for sub-analysis. RESULTS: Among the 99 patients eligible for inclusion in the present study, we found that patient-reported outcomes and the HADS scores improved significantly after surgery. There was a moderate correlation between the amount of change in HADS-D score before and after surgery and the amount of change in NDI (moderate, r = .41), NRS of neck (moderate, r = .46), and JOACMEQ (cervical spine function; moderate, r = .43, upper extremity function; moderate, r = .41, QOL; moderate, r = .41). CONCLUSIONS: We found that surgical treatment for patients with degenerative cervical myelopathy may improve postoperative anxiety and depression as well as other patient-reported outcomes.

Association Between Deep Posterior Cervical Paraspinal Muscle Morphology and Clinical Features in Patients With Cervical Ossification of the Posterior Longitudinal Ligament.

STUDY DESIGN: A retrospective observational study. OBJECTIVE: To clarify the association of the paraspinal muscle area and composition with clinical features in patients with cervical ossification of the posterior longitudinal ligament (OPLL). METHODS: Consecutive patients with cervical OPLL who underwent cervical magnetic resonance imaging (MRI) before surgery were reviewed. The cross-sectional area (CSA) and fatty infiltration ratio (FI%) of deep posterior cervical paraspinal muscles (multifidus [MF] and semispinalis cervicis [SCer]) were examined. We assessed the association of paraspinal muscle measurements with the clinical characteristics and clinical outcomes, such as Neck Disability Index (NDI) score. Moreover, we divided the patients into 2 groups according to the extent of the ossified lesion (segmental and localized [OPLL-SL] and continuous and mixed [OPLL-CM] groups) and compared these variables between the 2 groups. RESULTS: 49 patients with cervical OPLL were enrolled in this study. The FI% of the paraspinal muscles was significantly associated with the number of vertebrae (ρ = 0.283, p = 0.049) or maximum occupancy ratio of OPLL (ρ = 0.397, p = 0.005). The comparative study results indicated that the NDI score was significantly worse (OPLL-SL, 22.9 ± 13.7 vs. OPLL-CM, 34.4 ± 13.7) and FI% of SCer higher (OPLL-SL, 9.1 ± 1.7% vs. OPLL-CM, 11.1 ± 3.7%) in the OPLL-CM group than those in the OPLL-SL group. CONCLUSIONS: Our results suggest that OPLL severity may be associated with fatty infiltration of deep posterior cervical paraspinal muscles, which could affect neck disability in patients with cervical OPLL.

Runx2 and Runx3 differentially regulate articular chondrocytes during surgically induced osteoarthritis development.

The Runt-related transcription factor (Runx) family plays various roles in the homeostasis of cartilage. Here, we examined the role of Runx2 and Runx3 for osteoarthritis development in vivo and in vitro. Runx3-knockout mice exhibited accelerated osteoarthritis following surgical induction, accompanied by decreased expression of lubricin and aggrecan. Meanwhile, Runx2 conditional knockout mice showed biphasic phenotypes: heterozygous knockout inhibited osteoarthritis and decreased matrix metallopeptidase 13 (Mmp13) expression, while homozygous knockout of Runx2 accelerated osteoarthritis and reduced type II collagen (Col2a1) expression. Comprehensive transcriptional analyses revealed lubricin and aggrecan as transcriptional target genes of Runx3, and indicated that Runx2 sustained Col2a1 expression through an intron 6 enhancer when Sox9 was decreased. Intra-articular administration of Runx3 adenovirus ameliorated development of surgically induced osteoarthritis. Runx3 protects adult articular cartilage through extracellular matrix protein production under normal conditions, while Runx2 exerts both catabolic and anabolic effects under the inflammatory condition.

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.

RSPO2 defines a distinct undifferentiated progenitor in the tendon/ligament and suppresses ectopic ossification.

Ectopic endochondral ossification in the tendon/ligament is caused by repetitive mechanical overload or inflammation. Tendon stem/progenitor cells (TSPCs) contribute to tissue repair, and some express lubricin [proteoglycan 4 (PRG4)]. However, the mechanisms of ectopic ossification and association of TSPCs are not yet known. Here, we investigated the characteristics of Prg4-positive (+) cells and identified that R-spondin 2 (RSPO2), a WNT activator, is specifically expressed in a distinct Prg4+ TSPC cluster. The Rspo2+ cluster was characterized as mostly undifferentiated, and RSPO2 overexpression suppressed ectopic ossification in a mouse Achilles tendon puncture model via chondrogenic differentiation suppression. RSPO2 expression levels in patients with ossification of the posterior longitudinal ligament were lower than those in spondylosis patients, and RSPO2 protein suppressed chondrogenic differentiation of human ligament cells. RSPO2 was induced by inflammatory stimulation and mechanical loading via nuclear factor κB. Rspo2+ cells may contribute to tendon/ligament homeostasis under pathogenic conditions.

Association Between Preoperative Neuropathic Pain and Patient Reported Outcome Measures After Cervical Spinal Cord Decompression Surgery.

STUDY DESIGN: A prospective observational study. OBJECTIVE: To evaluate the impact on surgical outcomes of preoperative neuropathic pain (NeP) assessed by the painDETECT questionnaire (PDQ) administered to participants undergoing cervical decompression surgery for degenerative cervical myelopathy (DCM). METHODS: Participating patients were separated into the Non-NeP group (preoperative PDQ score ≤ 12), and NeP group (score ≥ 13). They were asked to complete a booklet questionnaire, including NRS for pain, the Short Form-12 for PCS and MCS, EQ-5D, NDI, and COMI-Neck, at baseline and 1 year after surgery. The JOA score for DCM and radiological changes were also evaluated. Propensity scores were used for the generalized linear model to adjust the patients' backgrounds. RESULTS: Of the 116 patients recruited, 105 completed the one-year follow-up. In this study, 31 (29.5%) and 74 (70.5%) patients in the NeP and non-NeP groups, respectively, were compared. Except for the higher female ratio in the NeP group (64.6% vs 33.2%, P = .009), preoperative demographic data and surgical factors were not significantly different between both groups. The NeP group showed greater neck/arm/hand NRS scores and worse pre- and postoperative NDI/EQ-5D/COMI-Neck scores at baseline and 1 year after surgery, but this was not significant in the MCS/PCS and JOA scores. Change scores of neck/arm/hand NRS scores and MCS/PCS/NDI/EQ-5D/COMI-Neck scores were not significant between both groups. CONCLUSIONS: The preoperative NeP, assessed by PDQ, was observed in approximately 30% of patients with DCM who underwent decompression surgery. The presence of NeP was associated with worse pre- and postoperative NDI/EQ-5D/COMI-Neck scores.

Effect of diabetes on patient-reported outcome measures at one year after laminoplasty for cervical spondylotic myelopathy.

Although patients with diabetes reportedly have more peripheral neuropathy, the impacts of diabetes on postoperative recovery in pain and patient-reported outcome measures (PROMs) after laminoplasty for cervical spondylotic myelopathy (CSM) is not well characterized. The authors aimed to elucidate the effects of diabetes on neck/arm/hand/leg/foot pain and PROMs after laminoplasty CSM. The authors retrospectively reviewed 339 patients (82 with diabetes and 257 without) who underwent laminoplasty between C3 and C7 in 11 hospitals during April 2017 -October 2019. Preoperative Numerical Rating Scale (NRS) scores in all five areas, the Short Form-12 Mental Component Summary, Euro quality of life 5-dimension, Neck Disability Index, and the Core Outcome Measures Index-Neck) were comparable between the groups. The between-group differences were also not significant in NRS scores and PROMs one year after surgery. The change score of NRS hand pain was larger in the diabetic group than the nondiabetic group. The diabetic group showed worse preoperative score but greater improvement in the Short Form-12 Physical Component Summary than the nondiabetic group, following comparable score one year after surgery. These data indicated that the preoperative presence of diabetes, at least, did not adversely affect pain or PROMs one year after laminoplasty for CSM.

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.

Evaluation of bone strength using finite-element analysis in patients with ossification of the posterior longitudinal ligament.

BACKGROUND CONTEXT: Patients with ossification of the posterior longitudinal ligament (OPLL) are often reported to have increased bone mineral density (BMD). The bone strength of the proximal femur measured by quantitative computed tomography-based finite element analysis (QCT/FEA) is reportedly comparable between healthy subjects with and without OPLL. However, the bone strength in symptomatic OPLL patients remains unknown. PURPOSE: To investigate bone strength measured by QCT/FEA in symptomatic patients with OPLL. STUDY DESIGN/SETTING: A single-center prospective observational study. PATIENT SAMPLE: A total of 157 patients with cervical or thoracic compressive myelopathy were included in the study. OUTCOME MEASURES: We analyzed patients' characteristics, Japanese Orthopedic Association (JOA) score, serum laboratory tests including calcium (Ca), inorganic phosphate (Pi), and bone turnover markers, BMD of the proximal femur and lumbar spine measured using dual-energy X-ray absorptiometry, and predicted bone strength (PBS) of the proximal femur and lumbar spine measured using QCT/FEA. METHODS: Eligible patients were divided into the non-OPLL and OPLL groups. We compared the patients' characteristics, JOA scores, laboratory data, BMD, and PBS of the proximal femur and lumbar spine between the non-OPLL and OPLL groups among total, male, and female patients by performing Fisher's exact test for categorical variables and the unpaired t test for continuous variables. Then, we used the inverse probability weighted logistic regression model after calculating propensity scores to compare the bone metabolism-associated markers, BMD, and PBS measurements between the groups. RESULTS: Among the eligible 157 patients, 68 were in the non-OPLL group and 89 were in the OPLL group. Compared with the non-OPLL group, the OPLL group had a significantly younger age and higher BMI in the total, male, and female patients. The JOA scores in the total and female patients were significantly higher in the OPLL group than in the non-OPLL group. The OPLL group showed significantly lower Ca levels in the female patients and significantly lower Pi levels in the total or male patients compared with the non-OPLL group in the inverse probability weighting method. The BMD of the proximal femur and lumbar spine and the PBS of the proximal femur were significantly higher in the OPLL group than in the non-OPLL group. There were no significant differences in the PBS and BMD between the male subgroups. However, the BMD and PBS of the proximal femur and lumbar spine were significantly higher in the OPLL females than in the non-OPLL females. CONCLUSIONS: Hyperostosis of the posterior longitudinal ligament in OPLL was associated with higher bone strength by QCT/FEA, especially in female OPLL patients.

Influence of Perioperative Antithrombic Agent Discontinuation in Elective Posterior Spinal Surgery: A Propensity-Score-Matched Analysis.

OBJECTIVE: To investigate the influence of perioperative antithrombotic agent (antiplatelet agents and anticoagulants) discontinuation in elective posterior spinal surgery in terms of bleeding complications, such as epidural hematoma and postoperative thromboembolism. METHODS: We enrolled patients undergoing elective posterior spinal surgery at 9 hospitals between April 2017 and August 2020. We collected data regarding patient baseline characteristics, surgical details, intraoperative estimated blood loss, and postoperative complication rates, including epidural hematoma and thromboembolism. We divided the patients into a discontinuation group, in which antithrombic agents were discontinued perioperatively, and a control group without antithrombic agents. Propensity scores for taking any antithrombic agents were calculated, with 1-to-1 matching based on the estimated propensity scores to adjust for patient baseline characteristics and surgical details. Intraoperative estimated blood loss and 30-day postoperative complication rates were compared between the groups. RESULTS: We enrolled 9853 patients, including 1123 patients (11.4%) who discontinued antithrombic agents perioperatively. One-to-one propensity score matching yielded 1111 pairs with and without antithrombic agents. Intraoperative estimated blood loss per 10 minutes (8.2 mL vs. 8.9 mL) and the incidence of epidural hematoma requiring revision (0.97% vs. 0.72%) were similar between the groups. Although postoperative cardiac events and stroke were observed only in the discontinuation group (0.27% and 0.09%, respectively), these incidences were not significantly different between the groups. CONCLUSIONS: Perioperative antithrombic agent discontinuation in elective posterior spinal surgery normalized the intraoperative bleeding tendency and the incidence of postoperative epidural hematoma and did not influence in a significative way the incidence of postoperative thromboembolism.

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.

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.