Bone union-promoting effect of romosozumab in an ovariectomized rat posterolateral lumbar fusion model.

Spinal fixation surgery has been increasingly performed in patients with osteoporosis. Romosozumab, a drug that was introduced in Japan recently, is known to possibly promote bone healing. However, few studies have reported the therapeutic effects of romosozumab in clinical practice in Japan. Therefore, here, we investigated the effects of romosozumab dosage on bone fusion promotion using an ovariectomized rat spinal fusion model. Eight-week-old female Sprague-Dawley rats were matched by body weight and divided into three groups: 1.0 romosozumab (R) group (Evenity®, 25 mg/kg), 1/10R group (Evenity®, 2.5 mg/kg), and control (C) group (saline). Subcutaneous injections were administered twice a week for 8 weeks postoperatively. Computed tomography scans were performed every 2 weeks from the time of surgery till 8 weeks postoperatively. The mean fusion rates in terms of volume were significantly higher in the R groups [1/10R, 1.0R] than in the C group from 4 weeks postoperatively. The rate of increase was significantly higher in the 1.0R group from 4 weeks postoperatively and in the 1/10R group from 6 weeks postoperatively, than in the C group. The proportion of trabecular bone area was approximately 1.5 times higher in the R groups than in the C group. No significant differences were observed between the R groups. Our results suggest that romosozumab stimulates bone growth at the graft site, and similar effects were achieved at 1/10 of the standard dosage.

Short-Term Clinical and Radiographic Evaluation of Patients Treated With Expandable and Static Interbody Spacers Following Lumbar Lateral Interbody Fusion.

OBJECTIVE: The goal of this study was to evaluate, using computed tomography (CT) and magnetic resonance imaging (MRI), patients who underwent oblique lateral interbody fusion (OLIF) using either expandable or static interbody spacers. METHODS: Thirty-five patients with degenerative disc disease were surgically treated with one-level OLIF and were followed up for more than 6 months. The Static group consisted of 22 patients, and 13 patients were in the Expandable group. Intraoperative findings included operative time (min), blood loss (ml), and cage size. Low back pain, leg pain, and leg numbness were measured using the Japanese Orthopedic Association score, visual analogue score, and the Roland-Morris Disability Questionnaire. Radiologic evaluation using computed tomography (CT) and magnetic resonance imaging (MRI) allowed measurement of cage subsidence, cross-sectional area (CSA) of the dural sac, disc height, segmental lordosis, foraminal height, and foraminal CSA preoperatively and 6 months postoperatively. RESULTS: The Expandable group had significantly larger cage height and lordosis than the Static group (P < 0.05). The Expandable group also had greater dural sac area expansion and enlargement of the intervertebral foramen, as well as better correction of vertebral body slip (P < 0.05). Cage subsidence was significantly lower in the Expandable group (P < 0.05). JOA and VAS scores for leg numbness were significantly better in the Expandable group (P < 0.05). CONCLUSIONS: Compared with static spacers, expandable spacers significantly enlarged the dural sac area, corrected vertebral body slippage, expanded the intervertebral foramen, and achieved good indirect decompression while reducing cage subsidence, resulting in improvement in clinical symptoms.

Association between Osteoporosis and Skeletal Muscle Mass in Men.

STUDY DESIGN: Cross-sectional study. PURPOSE: This cross-sectional study aimed to investigate the risk factors for osteoporosis in men by assessing bone mineral density (BMD), skeletal muscle mass, body fat mass, grip strength, and advanced glycation end products (AGEs). OVERVIEW OF LITERATURE: Fewer studies have reported the correlation between BMD and skeletal muscle mass in women. Moreover, a few studies have examined the relationship between osteoporosis and skeletal muscle mass. METHODS: This study included 99 men (mean age, 74.9 years; range, 28-93 years) who visited Qiball Clinic for BMD and body composition examinations. The osteoporosis group consisted of 24 patients (mean age, 72.5 years; range, 44-92 years), and the control group consisted of 75 individuals (mean age, 74.9 years; range, 28-93 years). Whole-body skeletal muscle mass was measured using a bioelectrical impedance analyzer. BMD was measured by dual X-ray absorptiometry. Skin autofluorescence (SAF), a marker of dermal AGE accumulation, was measured using a spectroscope. Osteoporosis was defined as a bone density T score of -2.5 or less. Physical findings, skeletal muscle mass, BMD, grip strength, and SAF were compared between the osteoporosis and control groups. RESULTS: The osteoporosis group had significantly lower trunk muscle mass (23.1 kg vs. 24.9 kg), lower leg muscle mass (14.4 kg vs. 13.0 kg), and skeletal mass index (7.1 kg/m2 vs. 6.7 kg/m2) than the control group (all p<0.05). Lower limb muscle mass was identified as a risk factor for osteoporosis in men (odds ratio, 0.64; p=0.03). CONCLUSIONS: Conservative treatment of osteoporosis in men will require an effective approach that facilitates the maintenance or strengthening of skeletal muscle mass, including exercise therapy with a focus on lower extremities and nutritional supplementation.

Quantitative evaluation of the lumbar ligamentum flavum using MRI T2-mapping: Efficacy of its clinical application in patients with lumbar spinal stenosis.

OBEJECTIVE: To perform a magnetic resonance imaging T2-mapping of the ligamentum flavum in healthy individuals and patients with lumbar spinal stenosis scheduled for surgery and compare the T2 relaxation times. SUBJECTS AND METHODS: The T2 relaxation time of the ligamentum flavum was compared among 3 groups, healthy young individuals (H group (age< 50)), healthy middle-aged and older individuals (H group (age≥50)), and patients with lumbar spinal stenosis (L group). Additionally, the thickness of the ligament was measured in the axial image plane, and the occupied area ratio of each fiber was measured by staining the surgically obtained ligament, and each was correlated with the T2 relaxation time. We also evaluated the adhesion of the ligamentum flavum with the dura mater during the surgery. RESULTS: The T2 relaxation times were significantly prolonged in H group (age ≥50) and L group (P < 0.001) compared to H group (age<50). The relationship between collagen fiber and T2 relaxation times was significantly positive (r = 0.720, P < 0.001). Moreover, the relaxation times were significantly prolonged in those with adhesion of the ligamentum flavum with the dura mater (P < 0.05). The cut-off for the relaxation time was 50 ms (sensitivity: 62.50%, false positive rate: 10.8%). CONCLUSION: Healthy middle-aged and older individuals and patients with lumbar spinal stenosis and adhesion of the ligamentum flavum with the dura mater have prolonged T2 relaxation times. Hence, the adhesion between the ligamentum flavum and dura mater should be considered in cases with a relaxation time ≥50 ms.

Does vacuum phenomenon at non-fused discs affect the postoperative course after transforaminal lumbar interbody fusion in patients showing a positive value of difference in lumbar lordosis?

INTRODUCTION: Preoperative difference in lumbar lordosis (DiLL) was associated with surgical outcomes after single-level transforaminal lumbar interbody fusion (TLIF). Patients with DiLL>0 (DiLL (+)) tended to show worse clinical outcomes and postoperative greater restoration of lumbar lordosis (LL). However, some patients with DiLL (+) showed relatively good outcomes and no postoperative LL restration. This study aimed to elucidate whether the lumbar intervertebral disc vacuum phenomenon (VP) influences clinical course after single-level TLIF in patients with DiLL (+) and DiLL (-). METHODS: Patients with lumbar spinal stenosis and degenerative spondylolisthesis treated with single-level TLIF were included. Pre- and postoperative LL were measured, and postoperative LL improvement was calculated. Preoperative DiLL was calculated as preoperative supine LL minus standing LL. Severity of VP at the non-fused discs (SVP (non-FS)) was evaluated using preoperative reconstructed computed tomography imaging. Clinical outcomes were assessed using the Oswestry disability index, visual analogue scale (VAS; low back pain (LBP), lower-extremity pain, numbness, and the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire. Patients were stratified by the median preoperative SVP (non-FS) score into severe and mild VP groups in patients with DiLL (+) or DiLL (-), and their surgical outcomes were compared. RESULTS: Overall, 89 patients were included. In patients with DiLL (+) (n = 37), patients with severe VP showed worse clinical outcomes, particulary for LBP and DiLL (+) patients with mild VP showed greater LL improvement (6.5° ± 10.0°). In patients with DiLL(-) (n = 52), patients with severe VP showed worse clinical outcomes, particularly for LBP and no differences in preoperative, postoperative, and improvement of LL were observed between two groups. CONCLUSION: Patients with DiLL (+) and DiLL (-) showed different clinical courses depending on VP severity at the non-fused discs after single-level TLIF.

Analysis of the relationship between spinal alignment and retrocrural space area in adult spinal deformity surgery: Potential risk factors for acute celiac artery compression syndrome.

PURPOSE: This study was designed to reveal the association between spinal parameters and RCS area in patients with adult spinal deformities treated with spinal correction surgery. We hypothesized that reduction of the retrocrural space (RCS) area is related to thoracolumbar alignment, which may cause acute celiac artery compression syndrome (ACACS). METHODS: Eighty-nine patients (age: 68.4 ± 7.6 years; sex: 7 male/82 female) with ASD treated by spinal correction surgery were enrolled. Preoperative and postoperative spinal parameters were measured, and the differences between these parameters were calculated. Postoperative T12 translation was measured and RCS area was evaluated using reconstructed computed tomography. The change of RCS area after surgery was defined as ΔRCS. Patients were divided into increased and decreased RCS groups by the ΔRCS value, and spinal parameters were compared between groups. The correlation between spinal parameters and ΔRCS was calculated. RESULTS: The patients in the decreased RCS group had greater anterior T12 translation than those in the increased RCS group (p < 0.001). T12 translation was significantly correlated with ΔRCS (ß = -0.31, p = 0.017). There were no correlations between ΔRCS and other spinal parameters. CONCLUSION: Thoracolumbar alignment was associated with RCS area. Consistent with the hypothesis, overcorrection of the thoracolumbar junction was associated with reduced RCS area and might be one risk factor for ACACS.

Objective Assessment of Sleep Disorders in Patients with Lumbar Spinal Stenosis Using Wearable Trackers.

Introduction: Low-back pain causes sleep disorders, which impairs the quality of life (QOL) of patients. Sleep disorders are associated with lumbar spinal stenosis (LSS); however, the postoperative effects of LSS surgery on sleep disorders are unknown. This study aimed to assess sleep disorders in patients with LSS using wearable activity trackers and determine whether surgery improves sleep quality. Methods: A total of 39 patients scheduled for LSS surgery (mean age 71.1±8.7 years; 22 men and 17 women) were studied. Sleep disorders in the participants were objectively evaluated using a wearable Motionlogger Micro system. Sleep efficiency (SEf), mean active count (MAC), and wake after sleep onset (WASO) were measured before and 6 months following surgery. Furthermore, the patient-based outcomes of pain and QOL-related scores were measured and compared with those of healthy participants. The group with improved SEf following surgery was designated as "nonpoor sleepers," whereas the group that did not exhibit improvements was designated as "poor sleepers." The two groups were compared based on patient factors, patient-based questionnaires, and sleep disorder measurements. Results: The SEf and WASO were significantly worse in patients with LSS compared with healthy participants (P<0.05). Furthermore, the SEf in patients with LSS was associated with the Oswestry Disability Index scores. No improvement was observed in the SEf, MAC, and WASO before and after surgery. Evaluation of each case revealed 21 and 12 cases of nonpoor and poor sleepers, respectively. Preoperative low-back pain was significantly associated with improvement in postoperative sleep quality. Conclusions: Sleep disorders in patients with LSS were evaluated, and improvement in sleep disorders following surgery was associated with the intensity of preoperative low-back pain. Sleep disorders are associated with QOL disorders, suggesting that focusing on the treatment of sleep disorders is important in the management of patients with LSS.

Combined effect of DBM, PRP, and bone marrow fluid on bone union in a rat posterolateral fusion model.

Platelet-rich plasma (PRP) promotes bone union through osteoinduction. We investigated whether adding demineralized bone matrix (DBM), derived naturally from biomaterial and with various growth factors, for osteoconductivity and bone marrow fluid for osteogenesis results in different bone unions. Eight-week-old male Sprague-Dawley rats were divided into four groups of five based on transplantation material: sham control (C group); DBM alone (D group); DBM + PRP (DP group); and DBM + PRP + bone marrow fluid (DPB group). After posterolateral fusion at L3-5, postoperative weekly CT imaging determined average number of bone union in facet joints (4 joints × 5 animals = 20 joints) and bone formation. Pathological evaluation and bone strength were assessed using 3-point bending two weeks postoperatively. Facet joint bone union at four weeks postoperatively was 4/20 (20%, DP group) and 8/20 (40%, DPB group) joints. Six weeks postoperatively, it was 7/20 (35%, D group), 12/20 (60%, DP group), and 16/20 (80%, DPB group). Eight weeks postoperatively, it was 13/20 (65%, D group), 17/20 (85%, DP group), and 20/20 (100%, DPB group), suggesting that DPB > DP > D > C. Bone formation and bone strength showed a similar DPB > DP > D > C group trend. Adding PRP and bone marrow fluid to DBM promotes bone union and strength.

Effect of Preoperative Severity and Location of Lumbar Intervertebral Disc Vacuum Phenomenon on Surgical Outcomes After Single-Level Transforaminal Lumbar Interbody Fusion.

OBJECTIVE: This study aimed to examine whether preoperative severity and location of lumbar intervertebral disc vacuum phenomenon (VP) influence surgical outcomes after single-level transforaminal lumbar interbody fusion. METHODS: We included 106 patients (age, 67.4 ± 10.4 years; 51 male/55 female) with lumbar degenerative diseases, who were treated with single-level transforaminal lumbar interbody fusion. Severity of VP (SVP) score was measured preoperatively. SVP score at fused disc was used as SVP (FS) score and at nonfused discs was used as SVP (non-FS) score. Surgical outcomes were assessed using the Oswestry Disability Index (ODI) and visual analog scale (VAS; low back pain (LBP), lower extremity pain, numbness, LBP in motion, in standing, and in sitting). The patients were divided into severe VP (FS or non-FS) and mild VP (FS or non-FS) groups, and surgical outcomes were compared between the 2 groups. Correlations between each SVP score and surgical outcomes were analyzed. RESULTS: There were no differences in surgical outcomes between the severe VP (FS) and mild VP (FS) groups. Postoperative ODI, VAS score for LBP, lower extremity pain, numbness, and LBP in standing were significantly worse in the severe VP (non-FS) group than in the mild VP (non-FS) group. SVP (non-FS) scores significantly correlated with postoperative ODI, VAS score for LBP, lower extremity pain, numbness, and LBP in standing; however, SVP (FS) scores did not correlate with any surgical outcomes. CONCLUSIONS: Preoperative SVP at fused disc is not associated with surgical outcomes; however, SVP at nonfused discs is correlated with clinical outcomes.

Medical Accidents Related to Ferromagnetic Objects Brought into the MRI Room: Analysis of the National Multicenter Database by Orthopedic Surgeons.

Introduction: Magnetic resonance imaging (MRI) is widely used in orthopedics, but orthopedic surgeons, including spine surgeons, do not have detailed knowledge of MRI-related accidents. We, as orthopedic surgeons, investigated the details of medical accidents related to ferromagnetic objects brought into the MRI room using a national multicenter database. Methods: We conducted an exploratory analysis of accidents involving MRI ferromagnets based on the Japanese database of adverse medical occurrences. From a total of 104,659 accident reports over nine years, 172 involving the presence of ferromagnetic objects in the MRI room were extracted and analyzed. Results: The accident reports frequently involved children and the elderly. Nurses filed the highest number of reports (44.8%) by occupation, which was more than twice as many as physicians (19.8%). The most common ferromagnetic devices brought into the MRI rooms were pacemakers (n = 22). There were also large magnetic objects such as oxygen cylinders (n = 12) and IV stands (n = 7). In the field of orthopedics, ankle weights (n = 4), pedometers (n = 3), and artificial limbs (n = 2) were brought in. "Failure to check" was the most common cause of accidents (69%). Actual harm to patients occurred in 9% of cases, with no fatalities. Conclusions: Manuals and checklists should be developed and continuous education provided to prevent accidents involving magnetic objects brought into the MR scanner room. As orthopedic surgeons, including spine surgeons, we should be cautious with emergency, geriatric, and pediatric patients because their information and medical history may not be accurate. We should not overlook equipment commonly found in orthopedic practice such as ankle weights and pedometers.

Clinical Efficacy of Neurotropin for Lumbar Spinal Stenosis with Low Back Pain.

PURPOSE: We compared the clinical effects of Neurotropin, limaprost alfadex, and a combination of both drugs for lumbar spinal stenosis (LSS) with low back pain (LBP). METHODS: We conducted a multicenter, randomized, active-controlled, open-label trial from March 2021 to May 2022. Participants were patients diagnosed with LSS by MRI and were randomly assigned to three groups: Neurotropin/limaprost combination (NL group), Neurotropin (N group), and limaprost group (L group). Participants received the drugs administered orally for 12 weeks, and each examination and observation was performed before any drug administration and every 2 weeks thereafter. We recorded age, sex, height, weight, duration of symptoms, intermittent claudication distance, level of stenosis in MRI, and concomitant analgesics as examination items in the trial period. Items measured during the trial were visual analog scale (VAS) score (mm) for LBP, leg pain and numbness, walking activity (walking speed, stride length), standing balance (3 m Timed Up-and-Go (TUG) Test results, Five Times Sit-to-Stand Test (FTSST) results), LBP/Quality of Life (QOL)-related scores (Oswestry Disability Index (ODI), Euro QOL 5-Dimensions 5-Level (EQ-5D-5L), Roland-Morris Disability Questionnaire (RDQ)), psychological factors (Pain catastrophizing scale (PCS) and Pain Self-Efficacy Questionnaire (PSEQ) scores), and adverse events. Each item was evaluated using changes at each visit (weeks 2-12) from baseline value before drug administration (week 0), and changes were considered significant when p < 0.05. RESULTS: We included results from 64 patients in the present study; 24 were assigned to the NL group (mean age 71.2 years), 20 to the N group (mean age 76.2 years), and 20 to the L group (mean age 74.4 years). There were no significant differences between the three groups in patient characteristics, concomitant analgesics, or baseline VAS score, gait balance, or QOL-related scores (p ≥ 0.05). The VAS and leg pain scores were significantly improved in Group L, and LBP was improved significantly in Group N. QOL and ODI scores improved significantly in the NL and L groups, EQ-5D score improved significantly in the L group, and RDQ score improved significantly in all groups (p < 0.05). Psychological factor and PCS scores improved significantly in the NL and L groups (p < 0.05). Walking speed and stride length were improved significantly in the NL and N groups (p < 0.05). TUG/FTSST scores were improved significantly in all groups (p < 0.05). Leg pain VAS score was improved significantly (p < 0.05) in the L group compared with the NL group after 6 and 12 weeks of administration, and LBP VAS was improved significantly in the N group after 6 weeks compared with the NL group (p < 0.05). Walking speed was significantly improved in the NL group after 2 weeks compared with the N group and improved significantly in the NL group after 6 weeks (p < 0.05) compared with the L group. RDQ was decreased significantly in the L group compared with the NL group after 8 weeks (p < 0.05). CONCLUSIONS: Combined use of Neurotropin and limaprost showed an additional effect on walking speed compared with single drug administration. Neurotropin may contribute to the improvement of low back pain, walking speed/stride length, and standing balance. TRIAL REGISTRATION: Japan Registry of Clinical Trials (jRCTs031200282).

The impact of postoperative inclination of the joint line on clinical outcomes in total knee arthroplasty using a prosthesis with anatomical geometry.

The goal of this study was to investigate the impact of postoperative inclination of the joint line on clinical results after total knee arthroplasty (TKA) using a prosthesis with anatomical geometry. This study included 145 primary cruciate-retaining type of knee prosthesis with anatomical geometry. Three years postoperatively, clinical outcomes including the patient-reported outcomes (PROs) were recorded. Limb alignment was evaluated by the hip-knee-ankle (HKA) axis and inclination of the joint line was assessed by the joint line orientation angle (JLOA). Knees were divided into two groups according to the HKA: in-range (- 3 to 3°) and outlier group (< - 3° or > 3°) or the JLOA: in-range (2-4°) and outlier group (< 2° or > 4°), and clinical outcomes were compared between the groups. Postoperative Knee Society Function Score (KS-FS) was significantly higher in the HKA in-range group than the outlier group (p = 0.01). The Knee Society Knee Score and all subscales of the Knee injury Osteoarthritis Outcome Score were comparable between the groups. A multivariate analysis revealed a significant association between age at operation and postoperative KS-FS > of 80 points. Neither HKA in-range nor JLOA in-range were associated with the higher knee function. In conclusion, TKA-postoperative inclination of the joint line was not relevant to the short-term PROs. Treatment strategies that attempt to make joint line inclination in order to improve postoperative PROs should be avoided, and alignment goals such as kinematic alignment should be considered carefully.

Postoperative change in lumbopelvic alignment after short-segment transforaminal lumbar interbody fusion is related to preoperative postural difference in lumbar lordosis.

BACKGROUND: Postoperative changes in lumbar lordosis (LL) after transforaminal lumbar interbody fusion (TLIF) and the related factors are not well-understood. Recently, the preoperative difference in LL between standing and supine positions (DiLL) was proposed as a factor for predicting postoperative radiologic outcomes after short-segment TLIF. This study investigated the influence of DiLL on mid-term radiological outcomes after short-segment TLIF. METHODS: Sixty-six patients with lumbar degenerative disease treated with short-segment TLIF (1-2 levels) who underwent lumbar spine standing radiographs at 3 months, 6 months, 1 year, 2 years, 3 years, 4 years, and 5 years postoperatively were divided into DiLL (+) and DiLL (-) groups (preoperative DiLL ≥0° and <0°, respectively). Associations between the postoperative change in LL and DiLL and clinical outcomes (Oswestry disability index (ODI) and Nakai score) were evaluated. RESULTS: Temporary restoration of LL (+4.5°) until 1 year postoperatively and a subsequent decrease in LL from 1 to 5 years postoperatively (-5.3°) was observed in the DiLL (+) group. No postoperative change in LL was observed in the DiLL (-) group. Postoperative changes in LL were mainly observed in non-fused segments. The postoperative change in LL (ΔLL) until 1 year postoperatively had a significant positive association with DiLL (p = 0.00028), whereas ΔLL from 1 to 5 years postoperatively showed a significant negative association with DiLL (p = 0.010) and a positive association with Nakai score (p = 0.028). ΔLL until 5 years postoperatively showed a significant positive association with postoperative ODI improvement (p = 0.011). CONCLUSIONS: DiLL (+) patients showed a specific time course with temporary LL restoration until 1 year postoperatively and a subsequent decrease in LL from 1 to 5 years postoperatively. Patients with larger postoperative increase in LL until 5 years postoperatively and lesser decrease in LL from 1 to 5 years postoperatively tended to show better mid-term clinical outcomes.

Lateral shift of the femoral condyle after total knee arthroplasty: simulation using 2D-templates of the medial pivot design on knee radiographs of young Japanese patients.

BACKGROUND: Total knee arthroplasty (TKA) is an established surgical treatment for advanced knee osteoarthritis by which patients can expect improvement of knee pain and function. Although many surgeons have investigated limb alignment after TKA, changes in coronal positional relation between the femur and tibia are not known well. METHODS: Radiographs of 105 knees of young Japanese patients between 20 and 49 years-old (60 men and 45 women) without osteoarthritic changes who received arthroscopic surgeries at our hospital were used in this study. Using 2D-templates of the medial pivot design (the FINE total knee), we simulated TKA on a SYNAPSE-PACS software. First, the femoral component was placed in normal knee alignment and then was merged to the medial concave of the insert where the tibial component was placed in neutral alignment. The length of the mediolateral shift of the femoral component was measured as an estimate of lateral shift of the femoral condyle, of which association with radiographic parameters including the femorotibial angle (FTA), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA) was analyzed. Subjects were classified into three groups according to the femoral component size that was chosen in simulation of TKA, and the lateral shift of the femoral condyle was compared between groups. RESULTS: The estimated mean lateral shift of the femoral condyle was 5.99 ± 1.98 mm and was greater in males than females (p < 0.05). Also, it was most highly correlated with the medial proximal tibial angle (MPTA) (r = - 0.553, p < 0.01). A group receiving larger component sizes significantly shifted more laterally compared with a group receiving smaller component sizes (p < 0.01). CONCLUSIONS: These results suggest that the coronal positional relation between the femur and tibia is altered and subsequent ligament imbalance may occur after mechanically aligned TKA using the medial pivot design.

Comparison of pain and discomfort in supine and lateral positions after surgery for lumbar degenerative disease: A prospective randomized controlled study.

INTRODUCTION: To compare postoperative pain and discomfort between supine and lateral positions after lumbar surgery, a prospective randomized controlled study was performed. METHODS: Forty-three patients with lumbar degenerative disease, treated by decompression (n = 23) or fusion surgery (n = 20), were randomly assigned to be placed in either the supine (supine group: n = 21) or lateral (lateral group: n = 22) position postoperatively, and asked to maintain their position until a day after the surgery. Postoperative back pain and discomfort (visual analog scale [VAS], 0-100 mm) and the number of patients who could maintain their position were examined. RESULTS: The VAS scores for back pain (supine: 64.9 ± 22.0, lateral: 55.7 ± 21.4) showed no significant difference between the positions. However, the supine group showed significantly more severe discomfort (75.6 ± 15.7) than the lateral group (64.9 ± 15.7, p = 0.039). Significantly fewer patients maintained their position in the supine group (28.2%) than in the lateral group (68.2%; p = 0.022). Among patients who underwent fusion surgery, significantly fewer patients maintained their position in the supine group (10.0%) than those in the lateral group (60.0%, p = 0.029). CONCLUSION: Postoperative discomfort was significantly reduced in the lateral position than in the supine position; thus, the lateral position is more suitable after lumbar surgery in terms of postoperative discomfort.

Changes in lumbar lordosis and predicted minimum 5-year surgical outcomes after short-segment transforaminal lumbar interbody fusion.

Although most patients who undergo transforaminal lumbar interbody fusion (TLIF) show favorable surgical results, some still have unfavorable results for various reasons. This study aimed to investigate the influence of differences in lumbar lordosis (LL) between the standing and supine positions (DiLL: supine LL-standing LL) on minimum 5-year surgical outcomes after short-segment TLIF. Ninety-one patients with lumbar degenerative disease who underwent short-segment TLIF (1-2 levels) were categorized based on preoperative differences in LL as DiLL (+) and DiLL (-). Comparison and correlation analyses were performed. The incidence of adjacent segment disease (ASD) by radiology (R-ASD) and symptomatic ASD (S-ASD), bony fusion rates, and pre- and postoperative clinical scores (visual analog scale [VAS]; Japanese Orthopaedic Association [JOA] score; Oswestry disability index (ODI); and Nakai's score) were evaluated. Postoperatively, VAS for low back pain (LBP) in the sitting position, JOA scores for LBP, lower leg pain, intermittent claudication, ODI, and Nakai's score were significantly worse in the DiLL (+) group than in the DiLL (-) group. DiLL values were significantly correlated with VAS for LBP, ODI, and Nakai's score, postoperatively. Positive DiLL values were associated with poorer postoperative outcomes. DiLL is a simple and useful method for predicting mid-term outcomes after TLIF.

Unexpectedly rapid decrease in the size of a spinal epidural abscess after percutaneous posterior pedicle screw fixation without decompression surgery: a case report.

INTRODUCTION: Spondylodiscitis accompanying spinal epidural abscess is often treated with decompression surgery when there are neurological symptoms. We report a case of spondylodiscitis accompanying spinal epidural abscess with severe lower extremity pain that was successfully treated with percutaneous posterior pedicle screw fixation without decompression surgery. CASE PRESENTATION: A 53-year-old man was admitted to our hospital with severe low back pain (LBP), lower extremity pain and numbness, and fever. Lumbar magnetic resonance imaging (MRI) revealed spondylodiscitis at L2-L3 and a small epidural abscess located ventrally in the spinal canal. Initially, the patient was treated conservatively with empirical antibiotics. However, the lower extremity symptoms worsened and the epidural abscess expanded cranially to the T12 level. Percutaneous pedicle screw fixation without decompression was performed thirty-three days after admission. Postoperatively, the LBP and lower extremity pain dramatically improved. A postoperative MRI performed one week post-operatively showed an unexpectedly rapid decrease in the size of the epidural abscess, although no decompression surgery was performed. Two months after surgery, the epidural abscess completely disappeared. At the final follow-up (five years postoperatively), no recurrence of epidural abscess was observed, and the patient had no symptoms or disturbance of activities of daily living. DISCUSSION: This surgical strategy should be carefully selected for patients with spondylodiscitis with accompanying spinal epidural abscess who have lower extremity symptoms. The stabilising effect of pedicle screw fixation may be advantageous for controlling spinal infections. Percutaneous posterior pedicle screw fixation without decompression is an optional treatment for spondylodiscitis accompanying spinal epidural abscess.

Risk Factors for Lateral Translation in Residual Adolescent Idiopathic Scoliosis with a Thoracolumbar/Lumbar Curve.

Introduction: Although lateral vertebral translation is associated with inducing curve progression and pain, no study has analyzed risk factors for lateral slip in patients with residual adolescent idiopathic scoliosis (AIS). This study aimed to investigate risk factors for lateral slip in patients with residual AIS. Methods: We included 42 preoperative patients with residual AIS with a thoracolumbar/lumbar (TL/L) curve (3 male, 39 female; age 41.9±18.2 years, TL/L Cobb angle 55.5±10.0°). All patients were >20 years and had been diagnosed with AIS during their adolescence. Lateral slip was defined as more than a 6-mm slip on coronal CT images. Results: Patients were divided into slip (n=22) and nonslip (n=20) groups. Significant differences were observed in age, TL/L Cobb angle, TL/L curve flexibility, lumbar lordosis, thoracolumbar kyphosis, apical vertebral rotation, apical vertebral translation, and L3 and L4 tilt between the groups. Multivariate analyses and receiver operating characteristic curves found that only older age was a significant risk factor for lateral slip (odds ratio: 1.214; 95% confidence interval: 1.047-1.407; P=0.010), with a cutoff value of 37 years old. Conclusions: Older age, especially >37 years, is a risk factor for lateral slip in patients with residual AIS. These findings suggest that surgery for residual AIS should be considered before patients are in their mid-30s to avoid lateral translation.

Evaluation of Spinal Alignment and Clinical Findings for the Efficacy of One-Stage Surgery in Tandem Spinal Stenosis.

Introduction We compared preoperative skeletal muscle, pre-and post-operative spinal alignment or clinical symptoms between tandem spinal stenosis (TSS) patients who underwent simultaneous cervical and lumbar decompression and lumbar spinal stenosis (LSS) patients who underwent only lumbar decompression and the efficacy of one-stage surgery was examined. Methods This study included 82 patients, identifying 13 patients for the TSS group (mean age 77.2 years) and 69 patients for the LSS group (mean age 72.2 years). One-stage decompression surgery was performed on both groups. The spinal alignments were evaluated using Lumbar scoliosis (LS), Sagittal vertical axis (SVA), Lumbar lordosis (LL), Pelvic tilt (PT), Pelvic incidence (PI), and Sacral slope (SS). The clinical symptoms were evaluated using the visual analogue scale (VAS) score for low back pain (LBP), the Japanese Orthopedic Association scoring system (JOA score), the Roland-Morris Disability Questionnaire (RDQ), the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and Oswestry Disability Index (ODI). Results The amount of bleeding was not significantly different between the two groups (p > .05). SVA, LL, PT, and SS were significantly improved in the LSS group (p < 0.05). In the TSS group, SVA, LL, PT, and SS tended to improve, but without significant differences. The proportion of JOABPEQ gait dysfunction that was difficult to climb stairs was 83% in the TSS group, and social life disturbance that was difficult to engage in ordinary activities was 67% in the TSS group, which was significantly higher than that in the LSS group (p < .05). Although clinical symptoms improved by surgery in both groups (p < .05), there was no significant difference in the degree of clinical symptom improvement before and after surgery (p > .05). Conclusions One-stage surgery for TSS is effective because it has the same intraoperative bleeding volume as LSS alone and is minimally invasive. It also improves forward-leaning posture and clinical symptoms equivalent to LSS alone.

Postoperative loss of correction after combined posterior and anterior spinal fusion surgeries in a lumbar burst fracture patient with Class II obesity.

Background: When treating thoracolumbar fractures with severe cranial endplate injury but no or slight caudal endplate injury, it is debatable whether anterior fusion should be performed only for the injured cranial level, or for both cranial and caudal levels. We report an unexpected postoperative correction loss after combined multilevel posterior and single-level anterior fusion surgery in a patient with obesity. Case Description: A 28-year-old male with Class II obesity was brought to the emergency room with an L1 burst fracture with spinal canal involvement. Cranial endplate injury was severe, whereas caudal endplate injury was mild. The first surgery with 1-above 1-below posterior fixation failed to achieve sufficient stability; thus, additional surgeries (3-above 3-below posterior fixation and single-level T12-L1 anterior fusion) were performed. Postoperatively, the local kyphosis angle (LKA) between T12 and L2 was 22° in the lateral lying position and 29° in the standing position. Twenty-one-month post surgery, bony fusion between T12 and L1 was observed, and the LKA was 28° in both the lateral lying and standing positions. After posterior implants were removed 24 months after the surgery, significant correction loss both at the T12-L1 segment (6°) and L1-L2 segment (6°) occurred, and LKA was 40° at the final follow-up. Conclusion: In this patient, an intense axial load due to excessive body weight was at least one of the causes of postoperative correction loss. Postural differences in LKA may be useful to evaluate the stability of thoracolumbar fractures after fusion surgery and to predict postoperative correction loss.