Postoperative early weight-bearing using double plating for periprosthetic, interprosthetic, and interimplant distal femur fractures following total knee arthroplasty: A report of three cases.

Background: Distal femur fractures (DFFs) following total knee arthroplasty (TKA) in older patients often require prolonged non-weight-bearing, thereby decreasing their activities of daily living (ADL) and increasing mortality. This report clarifies early weight-bearing safety and utility by using double-plate fixation on medial and lateral sides (LM180 double-plate fixation) for DFFs following TKA. Case presentation: Three cases of Su Type III periprosthetic, interprosthetic, and interimplant DFFs following TKA, where bone stock was limited, were treated with LM180 double-plate fixation using locking plates through medial and lateral incisions on the distal femur. In interprosthetic and interimplant DFF cases, the proximal section was secured by overlapping the lateral plate +/- medial plate with the proximal femur stem of the intramedullary nail by using monocortical screws and cerclage wires. Early postoperative partial weight-bearing was recommended, and full weight-bearing was allowed 4-5 weeks postoperation. All cases regained independent walking without hardware failure. Average ADL scores, namely, Barthel index (BI) and functional independence measure (FIM), were recovered to 85/100 and 114.7/126, respectively, approaching near-normal values. Conclusion: LM180 double-plate fixation for DFFs such as Su Type III periprosthetic, Vancouver type C interprosthetic, and interimplant DFFs following TKA with limited bone stock can be used to achieve early weight-bearing without fixation failure and help maintain ADL.

Diagnostic performance of advanced tomosynthesis in patients with metal devices in the affected knee: a case report.

Simple radiography is the most frequently and widely available technology to examine bone pathologies. Computed tomography (CT) can evaluate pathologies more accurately in multiple planes and three dimensions; however, radiation exposure is much higher than with simple radiography. In addition, diagnostic ability is decreased for both technologies when metal devices are present. Tomosynthesis is a radiographic technology used to evaluate tissues quasi-three-dimensionally with less radiation exposure. Tomosynthesis technology was recently upgraded to reduce the effects of metal artifacts. This case report compares examination time, medical expense, image resolution, and radiation exposure for upgraded tomosynthesis, simple radiography, CT, and standard tomosynthesis in three patients with metal devices in the affected knees. Examination times were similar for the imaging technologies. Diagnostic performance was better for upgraded tomosynthesis than for simple radiography and standard tomosynthesis, and similar to that for CT. Moreover, radiation exposure and expense were higher for tomosynthesis than for simple radiography but lower than for CT. These findings suggest that upgraded tomosynthesis is the best method for evaluating bone pathology when metal devices are present and radiation exposure must be limited.

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.

Treatment Outcomes of Lower Urinary Tract Symptoms due to Fragility Sacral Fractures: A Review of Eight Patients and Literature.

BACKGROUND: Sacral fractures can cause lower urinary tract symptoms (LUTS) due to damage to the cauda equina. While several studies have reported on sacral fractures due to high-energy trauma, those due to fragility fractures have only been reported in case reports and their clinical differences are not well known. This study aimed to investigate the clinical characteristics of LUTS caused by fragility sacral fractures and propose a novel treatment strategy. METHODS: This study is retrospective, uncontrolled, clinical case series. The inclusion criteria were sole sacral fractures due to low-energy trauma and appearance of LUTS after injury. Patients with additional spinal fractures or combined abdominal or pelvic organ injuries that could cause LUTS were excluded. Improvement in LUTS, period from onset to improvement, and imaging findings were recorded. RESULTS: Eight patients met the inclusion criteria (4 surgical and 4 conservative treatment cases). Six patients showed improvement in LUTS. In surgical cases, the mean period from onset of LUTS to surgery and from onset of LUTS to improvement was 14.5 and 21.5 days, respectively. Intraoperative rupture or laceration of the dural sac was not observed. In 2 conservatively improved cases, the period from onset to improvement of LUTS was 14 and 17 days. CONCLUSIONS: LUTS can improve even with conservative treatment and should be utilized as the primary choice. LUTS caused by severe sacral canal deformity and stenosis can be reversible, and the decision to perform surgical treatment is still timely if LUTS do not improve with conservative treatment for several weeks.

Motion Capture-based 3-dimensional Measurement of Range of Motion in Patients Undergoing Cervical Laminoplasty.

STUDY DESIGN: A prospective study. OBJECTIVE: To measure 3-dimensional cervical range of motion (ROM) by noninvasive optical tracking-based motion-capture technology in patients undergoing laminoplasty, and to elucidate the postoperative effects of laminoplasty on cervical mobility. SUMMARY OF BACKGROUND DATA: Cervical laminoplasty is a motion-sparing decompression surgery for degenerative cervical myelopathy. Unlike cervical laminectomy and fusion, the true postoperative impact of laminoplasty on neck motion has not been well studied. METHODS: Participants comprised 25 patients undergoing double-door cervical laminoplasty for degenerative cervical myelopathy in a single center. Maximum flexion/extension, left/right rotation, and left/right side bending were recorded using the motion-capture device preoperatively and 3 months postoperatively. ROMs in 3 orthogonal axes were calculated. Preoperative differences in C2-7 Cobb angles on lateral flexion/extension x-rays were also measured as the radiologic ROM to assess reliability. Preoperative and 1-year postoperative Japanese Orthopaedic Association score, Neck Disability Index [NDI], and Euro-QOL were recorded, and correlations with ROMs were assessed. RESULTS: Preoperative mean (±SD) ROMs for flexion/extension, rotation, and side bending were 90±17, 107±16, and 53±17 degrees, respectively. Although radiologic sagittal ROM measurement showed a smaller range than motion capture, averaging 36±13 degrees, a moderate to strong correlation between radiologic and motion capture values was observed (R=0.57, P=0.003). Preoperative NDI showed a negative correlation with coronal ROM (rho=-0.547, P=0.02). Postoperative ROM showed a significant reduction in rotation (95±16 degrees, P=0.002) but not in flexion/extension or side bending. CONCLUSIONS: Three-dimensional motion-capture analysis allowed reliable measurement of cervical ROM. Rotational ROM was significantly reduced after laminoplasty, showing that cervical kinematics are still significantly altered.

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.

Impact of malnutrition on mortality and neurological recovery of older patients with spinal cord injury.

This retrospective cohort study established malnutrition's impact on mortality and neurological recovery of older patients with cervical spinal cord injury (SCI). It included patients aged ≥ 65 years with traumatic cervical SCI treated conservatively or surgically. The Geriatric Nutritional Risk Index was calculated to assess nutritional-related risk. Overall, 789 patients (mean follow-up: 20.1 months) were examined and 47 had major nutritional-related risks on admission. One-year mortality rate, median survival time, neurological recovery, and activities of daily living (ADL) at 1 year post-injury were compared between patients with major nutrition-related risk and matched controls selected using 1:2 propensity score matching to adjust for age, pre-traumatic neurological impairment, and activity. In the Kaplan-Meier analysis, the median survival times were 44.9 and 76.5 months for patients with major nutrition-related risk and matched controls, respectively (p = 0.015). Matched controls had more individuals with a neurological improvement of American Spinal Injury Association Impairment Scale ≥ 1 grade (p = 0.039) and independence in ADL at 1 year post-injury than patients with major nutrition-related risk (p < 0.05). In conclusion, 6% of older patients with cervical SCI had major nutrition-related risks; they showed a significantly higher 1 year mortality rate, shorter survival time, poorer neurological improvement, and lower ADL at 1 year post-injury than matched controls.

Large-Scale Comparative Study Between Microendoscopic Laminectomy and Full-Endoscopic Laminectomy for the Treatment of Single-Level Lumbar Spinal Canal Stenosis.

BACKGROUND: We previously compared the operative outcomes of microendoscopic laminectomy (MEL) and full-endoscopic laminectomy (FEL) for single-level lumbar spinal canal stenosis (LSCS). In this initial report, the operative outcomes of FEL were not inferior to those of MEL. OBJECTIVE: The purpose of this study is to compare the outcomes of MEL and FEL for single-level LSCS on a large scale using widely used multiple evaluation methods. METHODS: MEL was performed using a 16 mm tubular retractor and an endoscope, while FEL was performed using a 6.4 mm working channel endoscope. A retrospective study was performed on patients with LSCS treated with MEL (n = 355) or FEL (n = 154). Patient background and operative data were also collected. The Oswestry Disability Index (ODI), European Quality of Life-5 Dimensions (EQ-5D), and 36-item Short Form Survey (SF-36) scores were recorded preoperatively and 1-year postoperatively. RESULTS: Background data of the two groups and the mean operation time (MEL, 72.1 m; FEL, 74.2 m) were not significant (p>0.2). The mean volumes of intraoperative bleeding (MEL, 25.2 ml; FEL, 10.3 ml) were significantly different (p<0.001). The mean postoperative hospital stays (MEL, 3.9 days; FEL, 2.1 days) were significantly different (p<0.001). Fifteen dural tears (MEL, 11; FEL, 4) and 1 surgical site infection (MEL, 1; FEL, 0) were observed but not significant (p>0.5). Reoperation was required for postoperative hematoma in five patients (MEL, 3; FEL, 2). Although the ODI, EQ-5D, and SF-36 scores improved significantly at one year postoperatively in the MEL and FEL groups (p<0.001), there were no significant differences between the two groups (p>0.1). CONCLUSION: The operative outcomes and minimal invasiveness were no statistical difference between the MEL and FEL groups. Further development of the operative techniques and the instruments of FEL are required to shorten the operation time.

Neurological recovery rate and predictive factors of incomplete AIS grade C spinal cord injury in the older aged population.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To define the prognosis and predictive factors for neurological improvement in older patients with incomplete spinal cord injury (SCI) of American Spinal Injury Association Impairment Scale grade C (AIS-C). SETTINGS: Multi-institutions in Japan. METHODS: We included patients aged ≥65 years with traumatic SCI of AIS-C who were treated conservatively or surgically with >3 follow-up months. To identify factors related to neurological improvement, patients were divided into three groups according to their neurological status at the final follow-up, with univariate among-group comparisons of demographics, radiographic, and therapeutic factors. Significant variables were included in the multivariate logistic regression analysis. RESULTS: Overall, 296 older patients with SCI of AIS-C on admission were identified (average age: 75.2 years, average follow-up: 18.7 months). Among them, 190 (64.2%) patients improved to AIS-D and 21 (7.1%) patients improved to AIS-E at final follow-up. There were significant among-group differences in age (p = 0.026), body mass index (p = 0.007), status of pre-traumatic activities of daily living (ADL) (p = 0.037), and serum albumin concentrations (p = 0.011). Logistic regression analysis showed no significant differences in variables in the stratified group of patients who improved to AIS-D. Meanwhile, serum albumin was a significant variable in patients who improved to AIS-E (p = 0.026; OR: 6.20, pre-traumatic ADL was omitted due to data skewness). CONCLUSIONS: Most older patients with incomplete AIS-C SCI demonstrated at least 1 grade of neurological improvement. However, <10% of patients achieved complete recovery. Key predictors of complete recovery were high serum albumin levels on admission and independent pre-traumatic ADL. SPONSORSHIP: No funding was received for this study.

Diurnal Variation of Brain Activity in the Human Suprachiasmatic Nucleus.

The suprachiasmatic nucleus (SCN) is the central clock for circadian rhythms. Animal studies have revealed daily rhythms in the neuronal activity in the SCN. However, the circadian activity of the human SCN has remained elusive. In this study, to reveal the diurnal variation of the SCN activity in humans, we localized the SCN by employing an areal boundary mapping technique to resting-state functional images and investigated the SCN activity using perfusion imaging. In the first experiment (n = 27, including both sexes), we scanned each participant four times a day, every 6 h. Higher activity was observed at noon, while lower activity was recorded in the early morning. In the second experiment (n = 20, including both sexes), the SCN activity was measured every 30 min for 6 h from midnight to dawn. The results showed that the SCN activity gradually decreased and was not associated with the electroencephalography. Furthermore, the SCN activity was compatible with the rodent SCN activity after switching off the lights. These results suggest that the diurnal variation of the human SCN follows the zeitgeber cycles of nocturnal and diurnal mammals and is modulated by physical lights rather than the local time.

Coexisting Lower Back Pain in Patients With Cervical Myelopathy.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim of the present study is to investigate the coexisting lower back pain (LBP) in patients with cervical myelopathy and to evaluate changes in LBP after cervical spine surgery. SUMMARY OF BACKGROUND DATA: Only a few studies with a small number of participants have evaluated the association between cervical myelopathy surgery and postoperative improvement in LBP. METHODS: Patients who underwent primary cervical decompression surgery with or without fusion for myelopathy and completed preoperative and 1-year postoperative questionnaires were reviewed using a prospectively collected database involving 9 tertiary referral hospitals. The questionnaires included the patient-reported Japanese Orthopaedic Association (PRO-JOA) score and Numerical Rating Scales (NRS). The minimum clinically important difference (MCID) for NRS-LBP was defined as >30% improvement from baseline. Patient demographics, characteristics, and PRO-JOA score were compared between patients with and without concurrent LBP, and the contributor to achieving the MCID for LBP was analyzed using logistic regression analysis. RESULTS: A total of 786 consecutive patients with cervical myelopathy were included, of which 525 (67%) presented with concurrent LBP. LBP was associated with a higher body mass index ( P <0.001) and worse preoperative PRO-JOA score ( P <0.001). Among the 525 patients with concurrent LBP, the mean postoperative NRS-LBP significantly improved from 4.5±2.4 to 3.4±2.7 ( P <0.01) postoperatively, with 248 (47%) patients reaching the MCID cutoff. Patients with a PRO-JOA recovery rate >50% were more likely to achieve MCID compared with those with a recovery rate <0% (adjusted odd ratio 4.02, P <0.001). CONCLUSIONS: More than 50% of patients with myelopathy reported improvement in LBP after cervical spine surgery, and 47% achieved the MCID for LBP, which was positively correlated with a better PRO-JOA recovery rate. Treating cervical myelopathy in patients with concomitant LBP may be sufficient to mitigate concomitant LBP. LEVEL OF EVIDENCE: Level III.

Early Versus Delayed Surgery for Elderly Traumatic Cervical Spinal Injury: A Nationwide Multicenter Study in Japan.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: The effectiveness of early surgery for cervical spinal injury (CSI) has been demonstrated. However, whether early surgery improves outcomes in the elderly remains unclear. This study investigated whether early surgery for CSI in elderly affects complication rates and neurological outcomes. METHODS: This retrospective multicenter study included 462 patients. We included patients with traumatic acute cervical spinal cord injury aged ≥65 years who were treated surgically, whereas patients with American Spinal Injury Association (ASIA) Impairment Scale E, those with unknown operative procedures, and those waiting for surgery for >1 month were excluded. The minimum follow-up period was 6 months. Sixty-five patients (early group, 14.1%) underwent surgical treatment within 24 hours, whereas the remaining 397 patients (85.9%) underwent surgery on a standby basis (delayed group). The propensity score-matched cohorts of 63 cases were compared. RESULTS: Patients in the early group were significantly younger, had significantly more subaxial dislocations (and fractures), tetraplegia, significantly lower ASIA motor scores, and ambulatory abilities 6 months after injury. However, no significant differences in the rate of complications, ambulatory abilities, or ASIA Impairment Scale scores 6 months after injury were observed between the matched cohorts. At 6 months after injury, 61% of the patients in the early group (25% unsupported and 36% supported) and 53% of the patients in the delayed group (34% unsupported and 19% supported) were ambulatory. CONCLUSIONS: Early surgery is possible for CSI in elderly patients as the matched cohort reveals no significant difference in complication rates and neurological or ambulatory recovery between the early and delayed surgery groups.

Clinical role of crosslink augmentation during short-segment posterior lumbar interbody fusion with total facetectomy: A propensity score-matched analysis.

We investigated the clinical role of crosslink augmentation during PLIF with total facetectomy. We retrospectively reviewed 376 patients who underwent one- or two-segment PLIF with unilateral or bilateral total facetectomy between January 2017 and March 2022. The patients were categorized into two groups based on whether a crosslink was instrumented or not. Radiological outcome measurements included fusion status and implant failure rates on 12-month postoperative computed tomography. Patient-reported outcome measures included the Numerical Rating Scale for lower back pain, Oswestry Disability Index, and Short Form-12 Physical Component Summary scores, which were assessed preoperatively and at 12 months postoperatively. Surgery-related complications included surgical site infection, symptomatic implant failure, and epidural hematoma. Propensity score matching was performed to compare both groups after adjusting for confounding factors, including baseline and surgical procedural characteristics. A total of 200 cases were included in the propensity score calculation, and one-to-one matching was performed, resulting in 56 pairs with and without a crosslink. The fusion status (88.7 % vs. 85.5 %), screw loosening (14.3 % vs. 14.3 %), cage subsidence (17.9 % vs. 16.1 %), and cage dislodgement (5.4 % vs. 0 %) showed no significant difference between those with and without a crosslink, respectively. No significant differences were observed in the patient-reported outcomes or surgery-related complication rates between the groups. Crosslink augmentation during PLIF with total facetectomy is not recommended because it does not provide any radiological or clinical benefit and is associated with avoidable expenses.

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.

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.

Impact of the COVID-19 pandemic on surgical volume and outcomes in spine surgery: a multicentre retrospective study in Tokyo.

OBJECTIVES: To investigate the effect of the COVID-19 pandemic on surgical volume and outcomes in spine surgery. DESIGN: A retrospective cohort study using prospectively collected data. SETTING AND PARTICIPANTS: A total of 9935 patients who underwent spine surgery between January 2019 and December 2021 at eight high-volume spine centres in the Greater Tokyo metropolitan area were included. OUTCOME MEASURES: The primary outcome measures were the number of surgical cases, perioperative complications and patient-reported outcomes, including numerical rating scales for each body part, Euro quality of life 5-dimension (EQ5D), Neck Disability Index and Oswestry Disability Index (ODI). RESULTS: The total number of surgeries in 2020 and 2021 remained lower than that of 2019, with respective percentages of 93.1% and 95.7% compared with the prepandemic period, with a marked reduction observed in May 2020 compared with the same period in 2019 (56.1% decrease). There were no significant differences between the prepandemic and postpandemic groups in the incidence of perioperative complications, although the frequency of reoperation tended to be higher in the postpandemic group (3.04% vs 3.76%, p=0.05). Subgroup analysis focusing on cervical spine surgery revealed significantly worse preoperative EQ5D scores in the postpandemic group (0.57 vs 0.54, p=0.004). Similarly, in lumbar spine surgery, the postpandemic group showed higher levels of leg pain (5.7 vs 6.1 to 0.002) and worse ODI scores (46.2 vs 47.7 to 0.02). However, postoperative outcomes were not different between pre and post-pandemic groups. CONCLUSIONS: The COVID-19 pandemic has significantly impacted spinal surgeries in Japan, leading to a decrease in surgical volumes and changes in patient characteristics and surgical procedures. However, surgical outcomes remained comparable between the pre and postpandemic periods, indicating the resilience and adaptability of healthcare systems.

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 gray matter volume in the default-mode network associated with insulin resistance.

Insulin resistance may lead to structural and functional abnormalities of the human brain. However, the mechanism by which insulin resistance impairs the brain remains elusive. In this study, we used two large neuroimaging databases to investigate the brain regions where insulin resistance was associated with the gray matter volume and to examine the resting-state functional connectivity between these brain regions and each hypothalamic nucleus. Insulin resistance was associated with reduced gray matter volume in the regions of the default-mode and limbic networks in the cerebral cortex in older adults. Resting-state functional connectivity was prominent between these networks and the paraventricular nucleus of the hypothalamus, a hypothalamic interface connecting functionally with the cerebral cortex. Furthermore, we found a significant correlation in these networks between insulin resistance-related gray matter volume reduction and network paraventricular nucleus of the hypothalamus resting-state functional connectivity. These results suggest that insulin resistance-related gray matter volume reduction in the default-mode and limbic networks emerged through metabolic homeostasis mechanisms in the hypothalamus.