Search

Primary amyloidosis is a rare systemic disorder often associated with multiple organ dysfunction. The most common form, light chain amyloidosis, has an estimated age-adjusted incidence of 5.1–12.8 cases per million person-years. Spine involvement is extremely uncommon. We present the case of a young Asian man with newly diagnosed amyloidosis involving the lumbar spine among multiple organs with a pathological vertebral fracture that required urgent spine surgery. We believe this is the first reported case to discuss the perianaesthetic challenges in the management of lumbar spine amyloidosis.

A 67-year-old man who had been pinned between a basket crane and a tree complained of severe pain in his lower back and a decreased appetite. Laparotomy after decompressing the gastrointestinal tract revealed incarceration of an ileal loop within a fractured third lumbar vertebra. The damaged bowel was resected, and an end-to-end anastomosis was performed. Once the patient’s condition had stabilised, posterior lumbar fixation was performed. There were no abdominal complications or lower limb neurological deficits during the follow-up period. Enhanced CT and MRI had been helpful in making the diagnoses. Histopathological examination revealed the aetiology of the traumatic incarceration: the intestine had been pinched as the disc space closed, and the body attempted to return to its original state by exerting countertraction.

Background Surgical treatment of severe thoracolumbar kyphosis (TLK) secondary to late osteoporotic vertebral compression fracture (OVCF) presents several challenges to spine surgeons. Proper selection of distal fusion level is an important issue in surgical planning to decrease the likelihood of distal mechanical complications. This study was designed to compare the clinical and radiographic outcomes in elderly patients suffering from severe TLK related with late OVCF between different distal fusion strategies and to recommend a superior distal fusion level for these patients. Methods A total of 57 consecutive subjects with a minimum follow-up of two years were retrospectively reviewed. TLK was defined as the hyperkyphosis with an apex below T10. Severe TLK was defined as the Cobb angle of kyphosis ≥60°. Patients fused to sagittal stable vertebra (SSV) were assigned to Group SSV, while those fused to the vertebra above and below SSV were assigned to Groups SSV- and SSV+, respectively. Bone cement was used to enhance pedicle screw fixation. Clinical and radiographic results were collected and compared between different groups. Results Deformity corrections and living quality improvements at the latest follow-up were superior in Group SSV than Group SSV- with shorter fusion levels, while to the equal extent with Group SSV+ with longer fusion levels. 7 cases of distal complications were observed in Group SSV-. Negatively balanced lowest instrumented vertebra was revealed to be the independent factor predicting distal complications. Patients’ satisfaction of their surgical management was greater in Group SSV than Group SSV- (83.2 ± 4.4% vs. 70.5 ± 10.9%, P = 0.024), while comparable with Groups SSV + SSV+ (84.8 ± 5.7%). Conclusions Fusion to SSV with cement-augmented pedicle screws could limit the development of distal junctional mechanical complications after surgical treatment for severe TLK secondary to late OVCF in elderly patients, while achieves satisfactory deformity correction with the preservation of necessary lumbar motility.

Background The anterior cage at L5-S1 segment is more vulnerable to anterior migration because of the sacral slope, the greater disc angle (DA), the higher shear force, and the weaker pedicle screw fixation at S1. We hypothesized that a supplemental screw (SS) fixation is effective for the prevention of anterior cage migration in oblique lateral interbody fusion (OLIF) at L5-S1. Methods This study involved 61 consecutive patients who underwent OLIF at L5-S1 and had more than 1-year regular follow-up. In the first 35 cases, the anterior cage was fixed with pedicle screws only (non-SS group). In the remaining 26 cases, the anterior cage was fixed with a SS and pedicle screws (SS group). Radiological parameters including anterior disc height (ADH), posterior disc height (PDH), DA, cage migration, cage subsidence, and fusion rate at L5-S1 were compared between the two groups. Result Of the total 61 patients, fifteen (24.6%) patients had an anterior cage migration of >2 mm and six (9.8%) patients had an anterior cage migration of >5 mm. Baseline demographic characteristics were similar between the two groups. The mean cage migration was 2.0 ± 3.1 mm in the non-SS group and 0.9 ± 0.9 mm in the SS group (P = 0.038). Thirteen (37.1%) patients had a cage migration of >2 mm in the non-SS group, while only two (7.7%) had a cage migration of >2 mm in the SS group (P = 0.002). There were no significant differences in the ADH, PDH, DA, cage subsidence, and fusion rate between the two groups (all P > 0.05). There was no SS-related complication in the SS group. Conclusions SS fixation in front of the anterior L5-S1 cage is simple, safe, and effective for the prevention of anterior cage migration in OLIF at L5-S1.

The risk of osteoporosis in patients with rheumatoid arthritis (RA) is frequently overlooked, and investigating a simple indicator in routine care may be beneficial to motivate osteoporosis examination. The aim of this retrospective, case-controlled study was to identify the correlation between serum albumin concentrations and the prevalence of osteoporosis in postmenopausal patients with RA.This study enrolled 197 patients who underwent dual-energy X-ray absorptiometry of lumbar spine (LS) and proximal femur without osteoporosis treatment [mean age, 67.5 years; disease duration, 12.8 years; Disease Activity Score assessing 28 joints with C-reactive protein, 2.0; prednisolone dose, 4.9 mg/day (usage, 42.6%); and LS T-score, -1.9]. Patients were classified into 2 groups: osteoporosis, defined as ≥ 1 part bone mineral density T-score ≤ -2.5 or history of fragility fracture of the vertebra or proximal femur (121 patients), and non-osteoporosis (76 patients). Groups were then matched by propensity score using clinical backgrounds affecting bone metabolism.In non-matched model, serum albumin concentration was significantly associated with osteoporosis-related factors such as aging, inflammation, physical disability, and glucocorticoid dose. Multivariate logistic regression revealed that serum albumin concentration was independently and significantly associated with osteoporosis risk (odds ratio = 0.22, 95% confidence interval = 0.08, 0.61, p = 0.0033). After propensity score matching, 57 patients for each group showed that in addition to the LS and femoral neck T-scores (p 0.001), serum albumin concentrations (p = 0.01) remained lower in the osteoporosis group compared to non-osteoporosis group. Receiver operating characteristic curve analysis in non-matched model revealed that when cut-off value of serum albumin concentration for indicating osteoporosis was set at 4.2 g/dl, the area under the curve was 0.69, sensitivity 0.74, and specificity 0.58.Low serum albumin concentration was significantly and independently associated with the prevalence of osteoporosis, which may be considered as one of the osteoporosis-related factors in postmenopausal patients with RA.

Background The surgical strategy of lumbar degenerative spondylolisthesis (LDS) is controversial, especially regarding whether or not fusion should be used. Although some reports have indicated that decompression combined with fusion may be better than decompression alone in the treatment of LDS, the effect of fusion status after uninstrumented posterolateral lumbar fusion (PLF) on the outcomes of patients with stable LDS remains unknown. This study aimed to evaluate the surgical outcomes of uninstrumented PLF for stable LDS and clarify whether radiographic fusion status could affect surgical outcomes. Methods A total of 93 consecutive patients who had undergone single-level uninstrumented PLF for Meyerding grade I LDS without preoperative dynamic instability with a minimum follow-up period of 5 years were retrospectively studied. Patients were divided into two groups: nonunion (52 patients) and union (41 patients). The primary outcomes were the 5-year percent recovery of postoperative Japanese Orthopaedic Association (JOA) scores, Oswestry Disability Index (ODI), Visual analog scale (VAS) scores, and reoperation rate. The outcome scores were compared between the groups using the inverse probability weighting method using propensity scores. Results The union and nonunion groups had comparable weighted means of the 5-year postoperative clinical score for the percent recovery of the JOA score (70.2% vs. 71.1%, P = 0.86), ODI (14.5 vs.14.6, P = 0.98), VAS of low back pain (20.3 vs. 18.7 mm, P = 0.72), and VAS of leg pain (24.0 vs. 19.4 mm, P = 0.43). The reoperation rate was 2.4% (one case of adjacent segment pathology) in the union group and 0% in the nonunion group (P = 0.44). Conclusion The fusion status following uninstrumented PLF had no significant effect on the 5-year postoperative clinical outcomes and reoperation rate in patients with Meyerding grade I LDS without dynamic instability.

Background Lateral lumbar interbody fusion (LLIF) is widely used in degenerative lumbar spine surgery. Previous studies of radiographic investigations after LLIF have assessed the anterior interbody fusion rate, the changes in the segmental lumbar lordosis, efficacy of indirect neural decompression, and remodeling of the ligamentum flavum hypertrophy and spinal canal dimension, and so on. The purpose of this study was to evaluate the radiological changes in the degenerated facet joints following LLIF with bilateral percutaneous pedicle screw (PPS) fixation, focusing on spontaneous fusion. Methods We retrospectively analyzed 31 patients (79 surgical levels) who underwent two- or three-level LLIF with PPS fixation without direct posterior decompression and bone grafting. We assessed the fusion rate and characteristics of the facet joints’ fusion process on the preoperative, immediately postoperative, 12-month, and at least 2-year computed tomography (CT) images. On average, the last follow-up CT was performed after 30.2 months. Multivariate logistic regression analysis investigated factors related to spontaneous facet joint fusion postoperatively. Results The fusion rates of the interbody and facet joints were 32.9% (26/79) and 19.0% (15/79) after 12-months and 79.7% (63/79) and 58.2% (46/79) at the final CT follow-up, respectively. Of the 46 cases with spontaneous facet fusion, three cases fused posteriorly only. Concomitant anterior interbody fusion was seen in 43/46 (93.5%) cases. Facet fusion started in a ring shape from the outermost joint edges, exposing subchondral bone without cartilage covering, and progressed to the central thicker cartilage regions. Multivariate analysis established that concomitant anterior interbody fusion (adjusted odds ratio [aOR]: 12.10, P = 0.0035) and preoperative facet joint osteoarthritis of Weishaupt Grade ≧ 1 (aOR: 4.770, P = 0.0068) were significant contributing factors to postoperative spontaneous facet fusion. Conclusions Our study shows that spontaneous facet fusion frequently occurs after LLIF and may be an indicator of the inherent structural stability of the LLIF construct.

Study Design: A retrospective study.Purpose: This study aimed to investigate the rate and associated factors of facet violation (FV) in percutaneous pedicle screws (PPS) from the thoracic to the lumbar spine and the effect of FV on facet osteoarthritis (OA) progression.Overview of Literature: Some reports claim PPS has a higher FV rate than conventional open surgery. However, previous reports of FV in PPS were limited to the lumbar spine; only a few reports included the thoracic spine.Methods: The present study includes 1,028 PPS inserted from T4 to S1 in 218 patients. The rate of FV and facet OA progression after FV were assessed using computed tomography (CT) scans conducted postoperatively at 1 week and 6 months or more. To identify factors associated with FV or facet OA progression after FV, a multivariate logistic regression analysis was conducted. To investigate whether FV caused facet OA progression, we compared OA progression between patients with FV and matched controls.Results: FV was observed in 68 (6.6%) of the 1,028 facets, and the thoracic spine was identified as an independent factor associated with FV. OA progression was detected in 48.2% of the cases with FV via CT scans conducted postoperatively at a mean duration of 22.6 months. The time between CT scans was identified as an independent factor for facet OA progression after FV. The rate of OA progression in patients with FV was significantly greater than that of the controls.Conclusions: FV was observed in 6.6% of the patients, and the thoracic spine was identified as an independent factor associated with FV. OA progression of a violated facet occurs over time. FV is considered a complication leading to facet OA progression.

Bones are the third most common location for solid tumor metastasis affecting up to 10% of patients with solid tumors. When the spine is involved, thoracic and lumbar vertebrae are frequently affected. Access to spinal lesions can be through minimally invasive surgery (MIS) or traditional open surgery (OS). This study aims to determine which method provides an advantage. Following the PRISMA (Preferred Inventory for Systematic Reviews and Meta-Analysis) guidelines, a systematic review was conducted to identify studies that compare MIS with OS in patients with spinal metastatic disease. Data were analyzed using Review Manager ver. 5.3 (RevMan; Cochrane, London, UK). Ten studies were included. Operative time was similar among groups at -35.23 minutes (95% confidence interval [CI], -73.36 to 2.91 minutes; p=0.07). Intraoperative bleeding was lower in MIS at -562.59 mL (95% CI, -776.97 to -348.20 mL; ppp=0.89). We observed a decreased need for postoperative bed rest at -1.60 days (95% CI, -2.46 to -0.74 days; p=0.0003), a shorter length of stay at -3.08 days (95% CI, -4.50 to -1.66 days; p=0.001), and decreased odds of complications at 0.60 (95% CI, 0.37 to 0.96; p=0.03) in the MIS group. Both approaches revealed similar reintervention rates at 0.65 (95% CI, 0.15 to 2.84; p=0.57), effective rates of reducing metastasis-related pain at -0.74 (95% CI, -2.41 to 0.94; p=0.39), and comparable scores of the Tokuhashi scale at -0.52 (95% CI, -2.08 to 1.05; p=0.41), Frankel scale at 1.00 (95% CI, 0.60 to 1.68; p=1.0), and American Spinal Injury Association Scale at 0.53 (95% CI, 0.21 to 1.37; p=0.19). MIS appears to provide advantages over OS. Larger and prospective studies should fully detail the role of MIS as a treatment for spine metastasis.

Background Condoliase-induced chemonucleolysis is a less-invasive alternative treatment for lumbar disc herniation (LDH); however, its long-term clinical outcome is still unclear. This study aimed to investigate 1-year clinical outcomes and assess radiographs after chemonucleolysis with condoliase. Methods We enrolled patients with LDH who received condoliase injection with a follow-up period of >1 year. Sixty patients (37 men, 23 women; mean age, 44.5 ± 18.9 years; mean follow-up period, 22.0 ± 6.0 months) were analyzed. Changes in disc height and degeneration were evaluated using magnetic resonance imaging. Visual analog scale (VAS) scores for leg and back pain and the Oswestry disability index (ODI) were obtained. All data were assessed at baseline, 1-month, 3-month, and 1-year follow-up. Results Surgical treatment was subsequently required in 8 patients (12.5%) after condoliase therapy. Their ODI and VAS scores for leg pain and back pain significantly improved at 1 year, as in those who received condoliase therapy only. On MRI, progression of Pfirrmann grade was observed in 23 patients (44.2%) at 3 months; however, 8 patients recovered to baseline at 1 year. The mean disc height decreased at 3 months; however, it recovered at 1 year. Disc height recovery (disc recovery rate >50%) was observed in 30.8% of the patients. Patients with disc height recovery were significantly younger than those without. Patients with longer symptom duration (≥1 year) showed significantly lower rates of effectiveness compared with those with shorter symptom durations ( Conclusions Chemonucleolysis with condoliase is a safe and minimally invasive treatment. Disc degeneration induced by chemonucleolysis could be recovered, particularly in younger patients. Prolonged symptom duration had adverse effects on outcome; thus, therapeutic intervention at the optimal time is needed.

Collagen peptides (CPs) have been shown to potentially have a role as a treatment option in osteopenia. In the present randomized prospective study, we examined the effect of calcium, vitamin D with and without CPs supplementation on changes in volumetric bone mineral density (vBMD) and bone geometry assessed by peripheral quantitative computed tomography at the tibia, areal bone mineral density (aBMD) assessed by dual-energy X-ray absorptiometry at the lumbar spine and the hip and bone turnover markers over 12-mo. Fifty-one postmenopausal women with osteopenia were allocated to Group A who received orally 5 g CPs, 500 mg calcium and 400 IU vitamin D3 and Group B who received the same dose of calcium and vitamin D3 per day. The primary endpoint was the change of trabecular bone mineral content (BMC) and vBMD after 12-mo supplementation in Groups A and B. At the trabecular site (4% of the tibia length), Group A had a significant increase of total BMC by 1.96 ± 2.41% and cross-sectional area by 2.58 ± 3.91%, trabecular BMC by 5.24 ± 6.48%, cross-sectional area by 2.58 ± 3.91% and vBMD by 2.54 ± 3.43% and a higher % change of these parameters at 12 mo in comparison to Group B (p0.01, p = 0.04, p0.01, p = 0.04, p = 0.02, respectively). At the cortical site (38% of the tibia length), total and cortical vBMD increased by 1.01 ± 2.57% and 0.67 ± 1.71%. Furthermore, the mean aBMD at the spine was higher (p = 0.01), while bone markers decreased in Group A compared to Group B. The present study shows improvement of trabecular and cortical parameters as assessed by peripheral quantitative computed tomography at the tibia, prevention of aBMD decline and decrease of bone turnover after 12-mo supplementation with calcium, vitamin D with CPs.

To examine the association of low back pain (LBP) and lumbar kyphosis with functional disabilities and knee symptoms in patients with knee osteoarthritis (OA).We analyzed 586 participants (80.1% female; mean ± SD age 68.8 ± 5.2 years) from the Nagahama Study who were age ≥60 years and had radiographically confirmed knee OA. The Knee Society Knee Scoring System (KSS) was used to assess functional disabilities and knee symptoms. LBP was defined as the presence of any persistent back pain for more than 3 months. Lumbar kyphosis was determined by skin-surface methods using a computer-aided electronic device called the Spinal Mouse. Multiple linear regression analysis was used for assessing the association of LBP and lumbar kyphosis with the KSS scores. Subgroup analyses based on sex were also performed.LBP and lumbar kyphosis were independently associated with a lower KSS function score after adjustment for covariates (mean difference -4.96 [95% confidence interval (95% CI) -7.56, -2.36] points for LBP alone, mean difference -4.47 [95% CI -8.51, -0.43] points for lumbar kyphosis alone, and mean difference -13.86 [95% CI -18.86, -8.86] points for the coexistence of LBP and lumbar kyphosis, respectively). The coexistence of LBP and lumbar kyphosis in women was associated with a lower KSS symptom score (mean difference -4.49 [95% CI -6.42, -2.55] points).These findings suggest that both LBP and lumbar kyphosis are useful clinical signals indicating functional disability and knee symptoms in patients with knee OA.

To determine the incidence and worsening of lumbar spine structure and low back pain (LBP) and whether they are predicted by demographic characteristics or clinical characteristics or appendicular joint osteoarthritis (OA).Paired baseline (2003-2004) and follow-up (2006-2010) lumbar spine radiographs from the Johnston County Osteoarthritis Project were graded for osteophytes (OST), disc space narrowing (DSN), spondylolisthesis, and presence of facet joint OA (FOA). Spine OA was defined as at least mild OST and mild DSN at the same level for any level of the lumbar spine. LBP, comorbidities, and back injury were self-reported. Weibull models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) of spine phenotypes accounting for potential predictors including demographic characteristics, clinical characteristics, comorbidities, obesity, and appendicular OA.Obesity was a consistent and strong predictor of incidence of DSN (HR 1.80 [95% CI 1.09-2.98]), spine OA (HR 1.56 [95% CI 1.01-2.41]), FOA (HR 4.99 [95% CI 1.46-17.10]), spondylolisthesis (HR 1.87 [95% CI 1.02-3.43]), and LBP (HR 1.75 [95% CI 1.19-2.56]), and worsening of DSN (HR 1.51 [95% CI 1.09-2.09]) and LBP (HR 1.51 [95% CI 1.12-2.06]). Knee OA was a predictor of incident FOA (HR 4.18 [95% CI 1.44-12.2]). Spine OA (HR 1.80 [95% CI 1.24-2.63]) and OST (HR 1.85 [95% CI 1.02-3.36]) were predictors of incidence of LBP. Hip OA (HR 1.39 [95% CI 1.04-1.85]) and OST (HR 1.58 [95% CI 1.00-2.49]) were predictors of LBP worsening.Among the multiple predictors of spine phenotypes, obesity was a common predictor for both incidence and worsening of lumbar spine degeneration and LBP.

BACKGROUND: Exercise training after lumbar fusion surgery (LFS) is important for regaining the strength in the spinal muscles, pain management, and minimizing dysfunction. It may be prudent to evaluate technologies such as web-based chat and social media apps for increasing the efficacy of post-surgery interventions in LFS patients. OBJECTIVE: To explore the effectiveness of a WeChat-based individualized post-discharge rehabilitation program in patients with LFS. METHODS: Seventy-two eligible discharged LFS patients were enrolled from October 2018 to February 2019. The experimental group (36 cases) received a 10-week WeChat-based individualized rehabilitation program, while the control group (36 cases) received routine follow-up guidance. The outcomes were measured using the Exercise Compliance Questionnaire, Numerical Rating Scale, Oswestry Disability Index and Chinese version of the self-efficacy for exercise scale. RESULTS: The analysis using generalized estimation equations method shows significant differences in the interaction effect of group*time in exercise compliance (Wald c2= 7.459, P< 0.05), group effect in pain (Wald c2= 5.811, P< 0.05) and self-efficacy (Wald c2= 16.383, P< 0.05). However, there was no significant difference between the experimental and control groups in the group effect in dysfunction improvement (Wald c2= 2.289, P> 0.05). CONCLUSIONS: The WeChat-based rehabilitation intervention can improve exercise compliance and self-efficacy, and help achieve greater pain relief compared to the routine intervention. However, the WeChat-based intervention did not offer better improvement in the self-dysfunction in the post-discharge LFS patients.

Background context Recently, the number of patients with lumbar spinal stenosis (LSS) who present with a coexisting spinal deformity such as degenerative spondylolisthesis (DS) and scoliosis (DLS) has been increasing. Lumbar decompression without fusion can lead to a reactive improvement in the lumbar and sagittal spinopelvic alignment, even if a sagittal imbalance exists preoperatively. However, the mid- to long-term impact of the coexistence of DS and DLS on the change in sagittal spinopelvic alignment and clinical outcomes after decompression surgery remains unknown. Purpose This study aimed to investigate whether the coexistence of DS or DLS in patients with LSS is associated with differences in radiological and clinical outcomes after minimally invasive lumbar decompression surgery. Study design/setting A retrospective analysis of prospectively collected data. Patient sample A total of 169 patients who underwent minimally invasive lumbar decompression surgery and follow-up >5 years postoperatively. Outcome measures Self-report measures: Low back pain (LBP)/leg pain/leg numbness visual analog scale (VAS) scores and the Japanese Orthopedic Association scores Physiologic measures: Standing sagittal spinopelvic alignment METHODS: In total, 81 patients with LSS, 50 patients with LSS and DS (≥3 mm anterior slippage), and 38 patients with LSS and DLS (≥15° coronal Cobb angle) were included in the current study. Clinical and radiological outcome results before surgery and at 2 and 5 years after surgery were compared among the groups. Results In patients with LSS with coexisting DS, the clinical outcomes at 2 and 5 years after surgery were similar to those of patients with only LSS. In patients with LSS with coexisting DLS, the VAS LBP and leg pain at 2 years after surgery was significantly higher (34.7 vs 27.8, P=0.014; 27.8 vs 14.7, P=0.028) and the achievement rate of the minimal clinically important difference in VAS LBP and leg pain was significantly lower than that of the LSS group (36.1% vs 54.2%, P=0.036; 58.3% vs 69.9%, P=0.10). The clinical outcomes except VAS leg numbness at 5 years after surgery were similar to those of patients with only LSS. The reoperation rate of the DS group was significantly lower than that of the LSS group (4.0% vs 14.8%; P=0.01); however, the reoperation rate of the DLS group was comparable to that of the LSS group (15.8% vs 14.8%; P=0.493). Lumbar lordosis (LL), sacral slope, pelvic tilt, and pelvic incidence-LL had significantly improved and been maintained for 5 years after the surgery in both the DS and the DLS groups. The sagittal vertical axis had improved at 2-year follow-up; however, no significant difference was observed at the 5-year follow-up in both the DS and the DLS groups. Conclusion Mid-term clinical outcomes in patients with LSS with and without deformity were comparable. Lumbar decompression without fusion can result in a reactive improvement in the lumbar and sagittal spinopelvic alignment, even with coexisting DS or DLS. Minimally invasive surgery could be considered for most patients with LSS.

Introduction and objectives Most of the studies evaluating the effect of cross links on spinal stability are performed in vitro on porcine or human spine segments and there is limited data regarding clinical benefits of cross link augmentation in traumatic injuries. In this study we aimed to evaluate the effects of cross-links insertion between rods on the fusion rates and post-surgical patients’ satisfaction among patients with traumatic thoracolumbar fractures who underwent posterior spinal fixation with pedicle screws. Materials and methods This study was conducted as a randomized clinical trial on 60 patients suffering from traumatic thoracolumbar vertebrae fractures. Patients were randomized into three groups: A (without any cross-link), B (One cross-link insertion) and C (two cross-links insertion). Six months after surgery outcomes were evaluated: fusion rates (plain X-ray and CT scan), Back pain (Visual Analog Scale) and patient satisfaction (fair, good, excellent). Results In group A 13 (65%) patients had structured bone fusion, but in 7 (35%) patients bone fusion was not observed. In both groups B and C, 19 patients (95%) had bone fusion, but only in 1 patient (5%) fusion failed (p = 0.009). In group A, fair satisfaction has the highest rate (8 patients (40%)) compared to the other groups. The highest reported severity of back pain was observed in group A while the lowest reported intensity of back pain was related to group B (p = 0.001). Conclusions Adding cross link to posterior spinal fixations of patients with traumatic thoracolumbar fractures can be associated with better final fusion results and patients’ satisfaction. However it is necessary to design studies with greater sample sizes to confirm this theory. Trial registration number: IRCT20120527009878N3.

Introduction Accounting for an estimated 1.10-1.76% of all lumbar herniations, lumbar intradural disc herniation (IDH) occurs primarily in males during the fourth to fifth decades of life. While not validated, congenital lumbar spinal stenosis (CLSS) is implicated as one precipitating factor for IDH. Case report We report 28-year-old Hispanic female with CLSS, severe obesity, and degenerative disk disease, with a history of minimally invasive surgical (MIS) decompression for a large paracentral L4-5 disc herniation at 25. After three years, the patient developed sudden burning dysesthesias in the L4-5 dermatomes bilaterally and temporary leg weakness. Lumbar magnetic resonance imaging exhibited severe L4-5 spinal stenosis, and the patient underwent repeat MIS decompression, which again provided her with adequate symptom resolution. However, 20 days postoperatively she developed cauda equina syndrome with anal dysfunction, and bilateral leg and foot weakness. Upon open surgical exploration we discovered a tense L4-5 dural protrusion. After a dorsal durotomy, a large IDH with a ventral dural tear was identified. Subsequent to adequate debulking of the IDH, the ventral tear was repaired, and an expansile duraplasty was performed. Overall, the patient's bladder and bowel function, pain, hypoesthesia, and motor strength all improved. Two weeks after surgery she presented with a lumbar pseudomeningocele that was managed conservatively. Conclusion This report not only highlights an atypical presentation of IDH and is the first case of CLSS linked with IDH, lending support to the hypothesis that CLSS can lead to IDH, but also provides a comprehensive review of IDHs.

OBJECTIVE Previous studies have demonstrated the short-term radiographic and clinical benefits of circumferential minimally invasive surgery (cMIS) and hybrid (i.e., minimally invasive anterior or lateral interbody fusion with an open posterior approach) techniques to correct adult spinal deformity (ASD). However, it is not known if these benefits are maintained over longer periods of time. This study evaluated the 2- and 3-year outcomes of cMIS and hybrid correction of ASD. METHODS A multicenter database was retrospectively reviewed for patients undergoing cMIS or hybrid surgery for ASD. Patients were ≥ 18 years of age and had one of the following: maximum coronal Cobb angle (CC) ≥ 20°, sagittal vertical axis (SVA) > 5 cm, pelvic incidence–lumbar lordosis mismatch (PI-LL) ≥ 10°, or pelvic tilt (PT) > 20°. Radiographic parameters were evaluated at the latest follow-up. Clinical outcomes were compared at 2- and 3-year time points and adjusted for age, preoperative CC, levels operated, levels with interbody fusion, presence of L5–S1 anterior lumbar interbody fusion, and upper and lower instrumented vertebral level. RESULTS Overall, 197 (108 cMIS, 89 hybrid) patients were included with 187 (99 cMIS, 88 hybrid) and 111 (60 cMIS, 51 hybrid) patients evaluated at 2 and 3 years, respectively. The mean (± SD) follow-up duration for cMIS (39.0 ± 13.3 months, range 22–74 months) and hybrid correction (39.9 ± 16.8 months, range 22–94 months) were similar for both cohorts. Hybrid procedures corrected the CC greater than the cMIS technique (adjusted p = 0.022). There were no significant differences in postoperative SVA, PI-LL, PT, and sacral slope (SS). At 2 years, cMIS had lower Oswestry Disability Index (ODI) scores (adjusted p < 0.001), greater ODI change as a percentage of baseline (adjusted p = 0.006), less visual analog scale (VAS) back pain (adjusted p = 0.006), and greater VAS back pain change as a percentage of baseline (adjusted p = 0.001) compared to hybrid techniques. These differences were no longer significant at 3 years. At 3 years, but not 2 years, VAS leg pain was lower for cMIS compared to hybrid techniques (adjusted p = 0.032). Those undergoing cMIS had fewer overall complications compared to hybrid techniques (adjusted p = 0.006), but a higher odds of pseudarthrosis (adjusted p = 0.039). CONCLUSIONS In this review of a multicenter database for patients undergoing cMIS and hybrid surgery for ASD, hybrid procedures were associated with a greater CC improvement compared to cMIS techniques. cMIS was associated with superior ODI and back pain at 2 years, but this difference was no longer evident at 3 years. However, cMIS was associated with superior leg pain at 3 years. There were fewer complications following cMIS, with the exception of pseudarthrosis.

Background context The minimal clinically important difference (MCID) represents the smallest change in an outcome measure recognized as clinically meaningful to a patient after receiving a clinical intervention. Most studies that discussed the MCIDs for lumbar spinal stenosis (LSS) included mixed pathologies or procedures despite that the MCID value should be different depending on the intervention. Moreover, despite the efficacy of adopting percentage-change improvement for the MCID threshold, there are limited reports and discussions in the field of lumbar surgery. Purpose The aim of the present study was to elucidate the MCIDs for the Oswestry Disability Index (ODI), EuroQOL 5-dimension 3-level (EQ-5D-3L), physical component summary (PCS) of the Short Form of the Medical Outcomes Study, and Numeric Rating Scale (NRS) in patients with degenerative LSS treated with decompression surgery without fusion. Study design/setting A multicenter retrospective cohort study was performed. Patient sample A total of 422 patients who underwent decompression surgery for LSS and answered a complete set of questionnaires were included in the study. Patients who underwent endoscopic or revision surgery were excluded. Outcome measures Preoperative and 1-year postoperative scores of each health-related quality of life questionnaires (HRQOLs) and patient satisfaction questionnaire response Methods: The patient satisfaction question was used as an anchor, and the cutoff values were estimated based on absolute point improvement from baseline using a receiver-operating characteristic (ROC) curve analysis and the "mean change" method for MCIDs. The MCID values for percentage-change in HRQOLs were also calculated using ROC curve analysis. The three cutoff values for each HRQOL were validated using the Youden index for determining the most robust MCIDs. Results Of the patients, 356 (84.4%) were at least "somewhat satisfied" with the treatment results. The two cutoff values of absolute point-change in each HRQOL, which were estimated by two different anchor-based methods, were similar. The area under the curve of the ROC curve for percentage-change tended to be higher than that for absolute point-change. Moreover, the Youden index of the percentage-change in each HRQOL was higher than that of the absolute point-change calculated by either the "mean change" method or the ROC curve analysis. Based on these results, it was proposed that MCID was 42.4% for percentage-change in ODI, 22.0% for EQ-5D-3L, 13.7% for PCS, 25.0% for NRS (low back pain), 55.6% for NRS (leg pain), 22.2% for NRS (leg numbness). Conclusions The MCIDs of HRQOLs were calculated in patients with LSS treated with decompression surgery without concomitant fusion procedure. The MCID cutoffs based on percentage-change from baseline were more effective than those of absolute point-change.

Background context Hypertrophy of the ligamentum flavum (LF) is a major contributor to the development of lumbar spinal canal stenosis (LSS). Although previous studies have identified some factors related to hypertrophy of the LF, the etiology remains unclear. It is well known that myofibroblasts have a key role in the pathology of fibrosis in other tissues, including the skin, liver, kidney, and lung. We hypothesized that myofibroblasts were also important players in the pathology of fibrosis in the LF. Purpose To elucidate the distribution and role of myofibroblasts in the hypertrophic LF. Study design A histological, immunohistochemical, and gene expression analysis of the LF in the human lumbar spine. Patient sample Hypertrophic LF tissue samples were collected from patients with LSS. Outcome Measures Histology, immunohistochemistry, microarray, reverse transcription-quantitative polymerase chain reaction, western blotting and enzyme-linked immunosorbent assay. Methods The degree of fibrosis in the dural and dorsal layers of the LF was evaluated by Masson's trichrome tissue staining. Collagen gene expression was evaluated by quantitative reverse transcription polymerase chain reaction. Immunostaining of αSMA was performed to evaluate localization of myofibroblasts in LF tissue. The association between gene expression of alpha-smooth muscle actin (αSMA) and that of several types of collagen was investigated. The signal activated on the dorsal side of LF was examined by gene set enrichment analysis using microarray data. Expression levels of αSMA and several types of collagen in LF fibroblasts were investigated under hypoxic conditions. Results In the histological study using Masson's trichrome staining, the fibrosis score was significantly higher in the dorsal layer than in the dural layer. Gene expression levels for several types of collagen (COL1A1, COL1A2, COL3A1, COL5A1, COL6A1, and COL11A1) and heat shock protein 47 (a collagen-specific chaperone) were significantly higher in the dorsal layer. Furthermore, immunohistochemistry revealed a significantly greater number of αSMA-stained cells in the dorsal layer. There was a strong correlation of αSMA mRNA expression with COL1A-1 in LF fibroblasts. Gene set enrichment analysis showed that the set of fibrosis-related gene signals, including those for epithelial-mesenchymal transition, hypoxia, and inflammation, were significantly upregulated in the dorsal layer compared with the dural layer. Under hypoxic stimulation, expression of αSMA and several types of collagen was increased in LF fibroblasts. Conclusions This study is the first to reveal that myofibroblast expression levels are higher in the dorsal layer of the LF than in the dural layer. We confirmed that hypertrophy of the LF in LSS is associated with increased expression of myofibroblasts in the dorsal layer. Hypoxia could be a cause of expression of myofibroblasts leading to fibrosis and finally to hypertrophy of the LF. Clinical significance The results of this study partially elucidate the molecular mechanisms of LF hypertrophy and suggest that myofibroblasts may be involved in age-related degeneration of the LF.

The aim of the study was to determine the effect of pregabalin as monotherapy on biochemical markers and bone mineral density. 40 patients diagnosed with neuropathic pain or fibromyalgia syndrome who were using pregabalin for at least 6 months and age and sex matched 40 healthy individuals were recruited for this cross-sectional study. Bone mineral density of both groups were measured by dual energy x ray absorbsiometry(DXA), bone biochemical markers, serum calcium, and vitamin D levels were investigated. Association between pregabalin use and bone biochemical markers, serum calcium, vitamin D levels were evaluated. The mean age of 40 patients (27 females, 13 males) was 40.6 ± 7.1 years and the mean age of 40 healthy individuals (27 females, 13 males) was 40.4 ± 7.3 years. The other demographic data were similar. There were no significant differences in lumbar and femur neck BMD scores between 2 groups. Also, there were no associations neither between pregabalin use and biochemical markers including serum calcium levels nor between pregabalin use and vitamin D levels. However, the patients who had been used pregabalin less than 24 months had low lumbar t and z scores than patients who had been used pregabalin more than 24 months. This effect was more prominent in male patients. Although no negative effect of pregabalin was found on bone metabolism in these group of patients, we have suggested that further prospective controlled studies with large sample size in different age groups could provide new data about the effects of pregabalin on bone metabolism. We suggest to investigate the bone metabolism especially in male patients on pregabalin treatment who had been used pregabalin treatment less than 24 months.

BACKGROUND CONTEXT Patients undergoing minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) frequently present with lower extremity neurologic symptoms with or without associated lower back pain. While symptomatic improvement of leg and back pain has been reported, the resolution of back pain when it is a predominant presenting symptom remains underreported following MI-TLIF. PURPOSE The purpose of this study was to compare clinical outcomes at 1 year of patients undergoing MI-TLIF with lower extremity neurologic symptoms with and without a significant component of back pain. STUDY DESIGN A retrospective review of prospectively collected data from a single surgeon surgical database from 2017 to 2019 was performed. PATIENT SAMPLE Fifty one patients undergoing MI-TLIF. OUTCOME MEASURES Self-reported measures included the Oswestry Disability Index (ODI), Visual analog scale back pain (VAS-back), and VAS leg pain (VAS-leg). METHODS Patients were divided into two groups: Leg Pain Predominant (patients reported greater than 50% leg pain upon presentation) and Back Pain Predominant (patients reported 50% or greater back pain). Multivariate analysis was performed to determine differences between groups based upon any significantly baseline characteristics. RESULTS Preoperative demographic and radiographic outcomes were similar between the two groups. Both groups demonstrated significant improvement in ODI, VAS-Back and VAS-leg at 1-year postoperatively. On multivariate analysis, there were differences in ODI at 1-year, 1-year back pain, and 1-year leg pain between groups with those who initially presented with leg pain having a lower ODI, VAS Back, and VAS leg. Patients who presented with predominantly leg pain were more likely to meet minimal clinically important difference (MCID) criteria for ODI and VAS-back compared to those with predominantly back pain. CONCLUSION Following MI-TLIF, patients with lower extremity neurologic symptoms with and without a significant component of back pain have improvements in back pain, leg pain, and ODI regardless of their primary presenting pain complaint; however, patients who presented with predominantly leg pain were more likely to meet MCID criteria for improvement in their back pain and ODI score.

BACKGROUND: Patients with lumbar disc herniation (LDH) may experience low back pain (LBP) and radiating pain (RP). Currently, there is no substantial clinical benefit (SCB) of assessing both LBP and RP due to LDH. OBJECTIVE: To determine enhanced SCB values by simultaneously assessing LBP and RP. METHODS: We retrospectively evaluated hospitalized LDH patients with concomitant LBP and RP between June 1, 2012, and May 31, 2013, and determined the numeric rating scale (NRS) and Oswestry Disability Index (ODI) scores at admission and discharge. Furthermore, the area under the receiver operating characteristic curve (AUC) was computed to assess diagnostic accuracy. RESULTS: SCB as per NRS for both LBP and RP was -2.50 in the 186 enrolled patients (AUC: 0.699 and 0.704, respectively). SCB as per ODI was -18.78 (AUC: 0.771). SCB for the mean of the two NRS scores for LBP and RP was -2.75 (AUC: 0.757). SCB for NRS score with a larger change in LBP and RP was -3.50 (AUC: 0.767). CONCLUSIONS: SCB may be determined by comprehensively considering LBP and RP and choosing the mean NRS or NRS score with a large change.

BACKGROUND: The enhanced recovery after surgery (ERAS) protocol is a multidisciplinary, multimodal approach which has been shown to facilitate recovery of physiological function, and reduce postoperative pain, complication rates, and length of stay without adversely affecting readmission rates. Design and implementation of ERAS protocols in the recent spine surgery literature has primarily focused on patients undergoing minimally invasive lumbar surgery. However, conventional open transforaminal lumbar interbody fusion (TLIF) remains a common procedure and to date there are no studies assessing an ERAS protocol in this patient population. PURPOSE: This study presents a single surgeon experience implementing an ERAS protocol in patients undergoing 1- or 2-level open TLIF. STUDY DESIGN/SETTING: Retrospective consecutive patient cohort with controls propensity-matched for age, body mass index, sex, and smoking status. PATIENT SAMPLE: Consecutive patients that underwent 1- or 2-level open TLIF for degenerative disease from 12/2018 – 02/2021 and controls from 12/2011–12/2017 by a single surgeon. ERAS was implemented in December 2018. OUTCOME MEASURES: Primary: length of stay; Secondary: first day to ambulate, first day to bowel movement, first day to void, daily average and maximum pain scores, opioid use, discharge disposition, 30-day readmission rate, and re-operations. METHODS: Demographic, perioperative, clinical, radiographic data were collected. Multivariate mixed-linear regression models were developed for length of stay, physiological function, pain scales, and opiate use. RESULTS: There were 114 patients included with 57 in each cohort. After propensity matching, patient characteristics were similar between groups. Operative time decreased significantly after institution of ERAS (170±44 vs. 141±37 minutes, p

To retrospectively evaluate the clinical efficacy and safety of percutaneous kyphoplasty (PKP) for the management of osteoblastic-related metastatic vertebral lesions.A total of 31 patients with 58 osteoblastic-related metastatic vertebral lesions underwent PKP were reviewed. The clinical efficacy was assessed based on parameters including visual analogue scale, Oswestry Disability Index, vertebral body height variation and quality of life. Major and minor complications were systematically evaluated to assess the safety of the procedure.Average follow-up period was 22.5 ± 11.1 months(range, 3 to 46 months). The procedure duration time ranged from 50 to 180 minutes (average 96.8 ± 36.9 minutes). Mean visual analogue scale scores decreased significantly from 6.1 ± 1.8 pre-operatively to 2.7 ± 1.5 at 3 days after PKP (p0.001), and remained largely immutable at 1 month (2.0 ± 0.7; 31 patients; p0.001), 3 months (2.4 ± 1.2; 30 patients; p0.001) and 1 year (3.0 ± 1.0; 27 patients; p0.001). Oswestry Disability Index scores and vertebral body height variation also changed after the procedure, with significant differences between pre-operative scores and at each follow-up examination (p0.001). Mean quality of life scores were 90.8 ± 12.9 pre-operatively and improved to 99.5 ± 12.1(27 patients, p0.001) at 1 year after PKP. The only minor encountered complication was bone cement leakage, which was seen in 6.5%(2 of 31) of patients. None of the patients experienced major complications.PKP is a safe and effective treatment strategy for osteoblastic-related metastatic vertebral lesions from a variety of tumor etiologies.

BACKGROUND CONTEXT Recently, a single position lumbar fusion has been described in which both the anterior or lateral interbody fusion as well as posterior percutaneous pedicle screw fixation are performed in a single position. PURPOSE The purpose of this study was to present and analyze the current evidence for single position lumbar fusion. STUDY DESIGN/SETTING This is a systematic review and meta-analysis. PATIENT SAMPLE Prospective or retrospective studies published in English that assessed outcomes of single position lumbar fusion surgery for patients with lumbar degenerative disease, spondylolisthesis, or radiculopathy were included. OUTCOME MEASURES Outcome measures included operative time, estimated blood loss, hospital length of stay, X-Ray exposure time, and postoperative outcomes including leg numbness or pain, leg weakness, lumbar lordosis, and segmental lordosis. METHODS This systematic review was performed in accordance with PRISMA guidelines. Two separate meta-analyses were performed. The first compared single position (SP) surgery, both lateral and prone, to dual position or flipped (F) surgery. The second meta-analysis compared lateral single position (LSP) surgery to prone single position (PSP) surgery. Variables were included if (1) they were a mean with a reported standard deviation or (2) if they were a categorical variable. For calculating standard error of the mean, we used sample size, mean, and standard deviation. A random effects model was used. The heterogeneity among studies was assessed with a significance level of

Lateral decubitus single position anterior-posterior (AP) fusion utilizing anterior lumbar interbody fusion and percutaneous posterior fixation is a novel, minimally invasive surgical technique. Single position lumbar surgery (SPLS) with anterior lumbar interbody fusion (ALIF) or lateral lumbar interbody fusion (LLIF) has been shown to be a safe, effective technique. This study directly compares perioperative outcomes of SPLS with lateral ALIF vs. traditional supine ALIF with repositioning (FLIP) for degenerative pathologies.To determine if SPLS with lateral ALIF improves perioperative outcomes compared to FLIP with supine ALIF.Multicenter retrospective cohort study.Patients undergoing primary AP fusions with ALIF at 5 institutions from 2015 to 2020.Levels fused, inclusion of L4-L5, L5-S1, radiation dosage, operative time, estimated blood loss (EBL), length of stay (LOS), perioperative complications. Radiographic analysis included lumbar lordosis (LL), pelvic incidence (PI), and PI-LL mismatch.Retrospective analysis of primary ALIFs with bilateral percutaneous pedicle screw fixation between L4-S1 over 5 years at 5 institutions. Patients were grouped as FLIP or SPLS. Demographic, procedural, perioperative, and radiographic outcome measures were compared using independent samples t-tests and chi-squared analyses with significance set at p.05. Cohorts were propensity-matched for demographic or procedural differences.A total of 321 patients were included; 124 SPS and 197 Flip patients. Propensity-matching yielded 248 patients: 124 SPLS and 124 FLIP. The SPLS cohort demonstrated significantly reduced operative time (132.95±77.45 vs. 261.79±91.65 min; p0.001), EBL (120.44±217.08 vs. 224.29±243.99 mL; p.001), LOS (2.07±1.26 vs. 3.47±1.40 days; p.001), and rate of perioperative ileus (0.00% vs. 6.45%; p =.005). Radiation dose (39.79±31.66 vs. 37.54±35.85 mGy; p =.719) and perioperative complications including vascular injury (1.61% vs. 1.61%; p =.000), retrograde ejaculation (0.00% vs. 0.81%, p =.328), abdominal wall (0.81% vs. 2.42%; p =.338), neuropraxia (1.61% vs. 0.81%; p =.532), persistent motor deficit (0.00% vs. 1.61%; p =.166), wound complications (1.61% vs. 1.61%; p =.000), or VTE (0.81% vs. 0.81%; p =.972) were similar. No difference was seen in 90-day return to OR. Similar results were noted in sub-analyses of single-level L4-L5 or L5-S1 fusions. On radiographic analysis, the SPLS cohort had greater changes in LL (4.23±11.14 vs. 0.43±8.07 deg; p =.005) and PI-LL mismatch (-4.78±8.77 vs. -0.39±7.51 deg; p =.002).Single position lateral ALIF with percutaneous posterior fixation improves operative time, EBL, LOS, rate of ileus, and maintains safety compared to supine ALIF with prone percutaneous pedicle screws between L4-S1.

We sought to introduce technical notes of full endoscopic lumbar interbody fusion (FE-LIF) with an anterior expandable cylindrical fusion cage.This study retrospectively reviewed patients who underwent FE-LIF with an anterior expandable cylindrical fusion cage through transforaminal or interlaminar approaches from August 2018 to April 2019. Patient demographics and operation-related complications were recorded. Clinical and radiologic outcomes were evaluated at 1 year after surgery.A total of 32 patients (34 segments) were included in this study. Among them, 14 received full endoscopic transforaminal lumbar interbody fusion and 18 received full endoscopic interlaminar lumbar interbody fusion. There were significant differences in interbody fusion indications between the 2 groups (P0.05). All operations were successfully completed without complications. Postoperative lumbar magnetic resonance imaging showed that nerve decompression was sufficient in all patients, and the visual analog scale scores of low back pain and leg pain, the Oswestry Disability Index scores, and sensory and muscle strength were significantly improved after surgery (P0.01). The MacNab score included 9 excellent ratings, 4 good ratings, and 1 fair rating in the full endoscopic transforaminal lumbar interbody fusion group and included 10 excellent ratings and 8 good ratings in the full endoscopic interlaminar lumbar interbody fusion group; the scores were not significantly different between the 2 groups at 1 year after surgery (P0.05). Complete interbody fusion was achieved in both groups according to computed tomography at 1 year after surgery.FE-LIF is a safe and effective minimally invasive lumbar surgery with an anterior expandable cylindrical fusion cage.

Background Context For chronic low back pain, the causal mechanisms between pathological features from imaging and patient symptoms are unclear. For instance, disc herniations can often be present without symptoms. There remains a need for improved knowledge of the pathophysiological mechanisms that explore spinal tissue damage and clinical manifestations of pain and disability. Spaceflight and astronaut health provides a rare opportunity to study potential low back pain mechanisms longitudinally. Spaceflight disrupts diurnal loading on the spine and several lines of evidence indicate that astronauts are at a heightened risk for low back pain and disc herniation following spaceflight. Purpose To examine the relationship between prolonged exposure to microgravity and the elevated incidence of postflight disc herniation, we conducted a longitudinal study to track the spinal health of twelve NASA astronauts before and after approximately 6-months in space. We hypothesize that the incidence of postflight disc herniation and low back complaints associates with spaceflight-included muscle atrophy and pre-existing spinal pathology. Study Design This is a prospective longitudinal study. Patient Sample Our sample included a cohort of twelve astronaut crewmembers. Outcome Measures From 3T MRI, we quantified disc water content (ms), disc degeneration (Pfirrmann grade), vertebral end plate irregularities, facet arthropathy and/ fluid, high intensity zones, disc herniation, multifidus total cross-sectional area (cm2), multifidus lean muscle cross-sectional area (cm2), and muscle quality/composition (%). From quantitative fluoroscopy we quantified, maximum flexion-extension ROM (°), maximum lateral bending ROM (°), and maximum translation (%). Lastly, patient outcomes and clinical notes were used for identifying postflight symptoms associated with disc herniations from 3T MRI. Methods Advanced imaging data from 3T MRI were collected at three separate time points in relation to spending 6-months in space: (1) within a year before launch (“pre-flight”), (2) within a week after return to Earth (“post-flight”), and (3) between 1- and 2-months after return to Earth (“recovery”). Fluoroscopy of segmental kinematics was collected at preflight and postflight timepoints. We assessed the effect of spaceflight and postflight recovery on longitudinal changes in spinal structure and function, as well as differences between crew members who did and did not present a symptomatic disc herniation following spaceflight. Results Half of our astronauts (n=6) experienced new symptoms associated with a new or previously asymptomatic lumbar disc protrusion or extrusion following spaceflight. We observed decreased multifidus muscle quality following spaceflight in the lower lumbar spine, with a reduced percentage of lean muscle at L4L5(-6.2%, p=.009) and L5S1 (-7.0%, p=.006) associated with the incidence of new disc herniation. Additionally, we observed reduced lumbar segment flexion-extension ROM for L2L3 (-17.2%, p=.006) and L3L4 (-20.5%, p=.02) following spaceflight, and furthermore that reduced ROM among the upper three lumbar segments (-24.1%, p=.01) associated with the incidence of disc herniation. Existing end plate pathology was most prevalent in the upper lumbar spine and associated with reduced segmental ROM (-20.5%, p=.02). Conclusions In conclusion from a 10-year study investigating the effects of spaceflight on the lumbar spine and risk for disc herniation, we found the incidence of lumbar disc herniation following spaceflight associates with compromised multifidus muscle quality and spinal segment kinematics, as well as pre-existing spinal end plate irregularities. These findings suggest differential effects of spinal stiffness and muscle loss in the upper versus lower lumbar spine regions that may specifically provoke risk for symptomatic disc herniation in the lower lumbar spine following spaceflight. Results from this study provide a unique longitudinal assessment of mechanisms and possible risk factors for developing disc herniations and related low back pain. Furthermore, these findings will help inform physiologic countermeasures to maintain spinal health in astronauts during long-duration missions in space.

We sought to assess differences in patient-reported outcome measures (PROMs) between patients who do and do not follow up for 2 years after lumbar fusion.Primary, elective, single-level anterior lumbar interbody fusion, lateral lumbar interbody fusion, or transforaminal lumbar interbody fusion procedures were identified. Patients were grouped by 2-year PROM follow-up completion. Mean and delta PROM scores for visual analog scale (VAS) back and leg, Oswestry Disability Index (ODI), short-form (SF)-12 Physical Composite Score (PCS), and Mental Composite Score (MCS) were computed for both groups preoperatively and postoperatively. Minimum clinically important difference (MCID) achievement was determined for PROM scores using established threshold values. Linear and logistic regression assessed mean and ΔPROM scores as predictors of 2-year follow-up completion and compared MCID achievement between groups, respectively.We included 316 lumbar fusion patients. PROM scores were more favorable for complete follow-up patients for 6-month VAS back (P = 0.003), 6-month and 1-year ODI (P ≤ 0.027, both), and 6-week and 6-month SF-12 PCS (P ≤ 0.015, both). Six-month VAS back (P = 0.007); 6-month and 1-year ODI (P ≤ 0.028, both); 6-week, 6-month, and 1-year SF-12 PCS (P ≤ 0.041, all); and 6-week SF-12 MCS (P ≤ 0.028, both) significantly predicted 2-year follow-up. ΔPROMs significantly differed between groups at 1 year for ΔVAS leg (P = 0.029), ΔODI (P = 0.013), and ΔSF-12 MCS (P = 0.004). One-year ΔVAS leg (P = 0.035), ΔODI (P = 0.011), and ΔSF-12 MCS (P = 0.003) significantly predicted follow-up. MCID achievement for ΔPROMs significantly differed between groups for 6-week VAS leg (P = 0.035), overall ODI (P = 0.034), and SF-12 PCS from 12 weeks through 1 year (P ≤ 0.011, all) and overall (P0.001).Patients with full follow-up demonstrated significantly more favorable outcome scores and improvement in pain, disability, and physical function at several postoperative time points.

We evaluated the effects of using a navigation technique with anterior approach surgery for thoracolumbar burst fractures on vertebral body screw placement and discussed its effects on the long-term prognosis of patients.We performed a prospective study of patients who had undergone anterior approach thoracolumbar surgery from May 2018 to August 2019. The 40 patients were randomly divided into the navigation group (NG) and control group (CG). In the NG, vertebral body screw placement was performed with 2-dimensional navigation guidance. For the CG, no navigation guidance was used. The clinical and radiological evaluations of the 2 groups were compared preoperatively, immediately after surgery, and at the final follow-up. Paired t tests and the χNo differences were found in the hospital stay, operation time, autologous blood recovery, postoperative drainage volume, Cobb angle of the preoperative coronal plane and sagittal plane, postoperative sagittal plane, postoperative Cobb angle of the coronal and sagittal planes measured on radiographs and computed tomography scans between the 2 groups (P0.05). The correction of the kyphosis deformity of the fracture segment was better in both groups (P0.001). The intraoperative blood loss and Cobb angle of the postoperative coronal plane in the NG was less than that in the CG (P0.05). Also, the 4 vertebral body screws in the NG were more parallel to the endplate than were those in the CG.We found that the use of navigation can improve the accuracy of screw placement in anterior approach surgery for thoracolumbar burst fractures and improve patients' long-term prognosis.

Both lower extremities and lower back are common sources of injury for cyclists. For providers to optimize care within this area of sports medicine, they need to understand the most common sources of injury in this population. Cycling presents a unique challenge: treating both the athlete and the complex relationship between rider and bicycle. Physicians should not replace the role of a professional bike fitter and should view these individuals as integral members of the team to alleviate current and prevent future injury. This article explores common lower extremity and lumbar back overuse injuries in cyclists and their medical management.

Background Anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF) are commonly performed in separate stages with a change in patient positioning to provide arthrodesis in the lumbar spine. Interest has recently emerged in performing these approaches as a single-stage surgery with the patient in the lateral decubitus position. The objective of this study was to evaluate the technical feasibility of performing minimally invasive anterolateral fixation in a single supine position. Methods Two fresh-frozen cadavers were used and placed supine. Standard minimally invasive anterior access was obtained by the approach surgeon. An ALIF was performed at L5-S1 using standard techniques. A lateral incision was marked over the L4-5 disc space using fluoroscopy. Direct palpation and bimanual dissection were achieved through the same anterior incision, allowing access to the retroperitoneal space. Dilator and retractor docking was performed under fluoroscopic guidance. Direct visualization of the docking hardware through the anterior incision was used to ensure the safety of peritoneal contents and vasculature. The LLIF was then performed using standard techniques at L4-5. Results Plain radiographs confirmed acceptable positioning of both the ALIF and LLIF grafts. No injury to the cadaveric peritoneum, vasculature, or lumbar plexus was observed. A slightly enlarged anterior incision also permitted retroperitoneal access and visualization of the L3-4 disc space. Conclusion This cadaver feasibility study demonstrates that combined minimally invasive ALIF and LLIF procedures may be performed as a single-stage with the patient in the supine position. Clinical consideration and study of this approach are warranted.

BACKGROUND CONTEXT The transpsoas lateral lumbar interbody fusion (LLIF) technique is an effective alternative to traditional anterior and posterior approaches to the lumbar spine; however, nerve injuries are the most reported postoperative complication. Commonly used strategies to avoid nerve injury (eg, limiting retraction duration) have not been effective in detecting or preventing femoral nerve injuries. PURPOSE To evaluate the efficacy of emerging intraoperative femoral nerve monitoring techniques and the importance of employing prompt surgical countermeasures when degraded femoral nerve function is detected. STUDY DESIGN/SETTING We present the results from a retrospective analysis of a multi-center study conducted over the course of 3 years. PATIENT SAMPLE One hundred and seventy-two lateral lumbar interbody fusion procedures were reviewed. OUTCOME MEASURES Intraoperative femoral nerve monitoring data was correlated to immediate postoperative neurologic examinations. METHODS Femoral nerve evoked potentials (FNEP) including saphenous nerve somatosensory evoked potentials (snSSEP) and motor evoked potentials with quadriceps recordings were used to detect evidence of degraded femoral nerve function during the time of surgical retraction. RESULTS In 89% (n=153) of the surgeries, there were no surgeon alerts as the FNEP response amplitudes remained relatively unchanged throughout the surgery (negative group). The positive group included 11% of the cases (n=19) where the surgeon was alerted to a deterioration of the FNEP amplitudes during surgical retraction. Prompt surgical countermeasures to an FNEP alert included loosening, adjusting, or removing surgical retraction, and/or requesting an increase in blood pressure from the anesthesiologist. All the cases where prompt surgical countermeasures were employed resulted in recovery of the degraded FNEP amplitudes and no postoperative femoral nerve injuries. In two cases, the surgeons were given verbal alerts of degraded FNEPs but did not employ prompt surgical countermeasures. In both cases, the degraded FNEP amplitudes did not recover by the time of surgical closure, and both patients exhibited postoperative signs of sensorimotor femoral nerve injury including anterior thigh numbness and weakened knee extension. CONCLUSIONS Multimodal femoral nerve monitoring can provide surgeons with a timely alert to hyperacute femoral nerve conduction failure, enabling prompt surgical countermeasures to be employed that can mitigate or avoid femoral nerve injury. Our data also suggests that the common strategy of limiting retraction duration may not be effective in preventing iatrogenic femoral nerve injuries.

Objectives Considering sagittal balance is particularly important in ASD patients because they frequently show hypolordotic prior fusion. Therefore, the purpose of this study was to identify risk factors for aggravation of sagittal imbalance after posterior lumbar fusion in ASD patients. Methods Fifty-nine patients who underwent revision posterior surgery for ASD between 2014 and 2018 were included. Patients were divided into two groups according to postoperative sagittal balance status determined by the pelvic incidence minus lumbar lordosis (PI-LL) value, based on the age-adjusted Schwab classification (group A: ideal correction, N = 20; group B: undercorrection, N = 39). Several radiographic parameters were measured in plain radiographs. Clinical results were analysed using the visual analog scale, Oswestry Disability Index, and EuroQol 5-domain. Results Better preoperative PI-LL (p = 0.001), slippage of the vertebral body (p = 0.022), higher disc height (p = 0.048), and absence of L4-5-S1 fusion (p = 0.041) in the index surgery were significantly correlated with better postoperative sagittal balance in multivariate analysis. The PI-LL improved postoperatively from 19.4 to 12.5 in group A (p = 0.019) and remained unchanged (from 38.6 to 38.6, p = 1.000) in group B. Although clinical outcomes improved postoperatively in both groups, no inter-group differences were observed. Conclusions Preoperative sagittal imbalance, rigid affected segments, and previously fused lower lumbar segment (L4-5-S1) are independent risk factors for aggravation of sagittal imbalance in ASD patients. Surgeons should strive to restore sagittal balance after ASD surgery under the above-mentioned conditions.

BACKGROUND CONTEXT Excessive use of postoperative imaging after lumbar surgery has been documented, becoming a target for cutting costs. This must be balanced with the patient's need for information and allay their postoperative concerns. PURPOSE To determine the incidence and associated costs of patient interactions with the healthcare system, outside the standard follow up routine, in the first postoperative year. STUDY DESIGN Retrospective longitudinal cohort. PATIENT SAMPLE Consecutive series of 200 patients who underwent lumbar fusions from 2018 to 2019 from a multi-surgeon single tertiary spine center. OUTCOME MEASURES All healthcare encounters: phone calls, office and emergency department visits, and additional testing METHODS A consecutive series of 200 patients who underwent lumbar fusions from 2018 to 2019 were identified. All non-routine healthcare encounters: phone calls, office and emergency department visits, and additional testing were collected. Direct costs for all healthcare services were determined using the Medicare Allowable rates. Indirect costs were determined using local, median income, length of office visits, and distance from the clinic to the patient's home. RESULTS Of 200 patients, 14 with thoracic fusion were excluded. The mean age of the 186 included patients was 58.26 years and 85 (46%) were male. Forty-seven percent (87/186) had only routine postoperative visits and 24 had revision surgery. Seventy-five patients made a total of 102 phone calls, 55 office visits, leading to 38 diagnostic studies none of which led to an additional intervention. Using Medicare Allowable rates, the mean direct cost was $776 per patient and the using a median income of $16/h the mean indirect cost was $124 per patient. There were no differences in the baseline characteristics among the patients who only had routine post-op encounters, had non-routine encounters or had a repeat surgery. CONCLUSIONS Forty percent of the patients undergoing lumbar surgery had a healthcare encounter outside their routine follow up that did not result in additional intervention after their index operation. These potentially unnecessary encounters create additional cost and inconvenience to both the patient and healthcare system. Providing patient reassurance is important and providers should identify ways to reduce associated costs through patient education, virtual visits, or new technologies to monitor patient's postoperative progress.

OBJECTIVE To compare the results of interbody fusion in patients undergoing minimally invasive lateral lumbar interbody fusion (LLIF) using demineralized bone matrix (DBM) alone versus DBM+recombinant human bone morphogenetic protein-2 (rhBMP2). METHODS This retrospective case-controlled study was conducted in patients undergoing minimally invasive LLIF (n = 54) for lumbar interbody fusion; they were divided into 2 groups: DBM-only group and DMB+rhBMP2 group. The improvements of segmental and lumbar lordosis and restoration of disc height were measured, and the interbody fusion rates were determined using a modified Bridwell grading system. Clinical outcomes after surgery, such as visual analog scale scores of back pain and leg pain, and Oswestry disability index were compared. RESULTS There were no significant differences in disc height, lumbar and segmental lordosis, or interbody fusion rate between the 2 groups. However, the proportion of Bridwell grade 1 as complete interbody bridging was higher in the DBM+rhBMP2 group than in the DBM-only group at both 6 and 12 months (P < 0.001). Clinical parameters showed equally significant improvement during follow-up in both groups, with no significant differences between the groups. CONCLUSION In minimally invasive LLIF, adding Escherichia coli-derived rhBMP2 to DBM did not affect clinical outcomes or radiation parameters, but increased the speed of fusion and interbody bony bridging rate.

BACKGROUND: Enhanced recovery after surgery (ERAS) has been demonstrated to improve early postoperative outcomes and is becoming a crucial component of any perioperative management paradigm. OBJECTIVE: To investigate the effect of an ERAS protocol on lumbar disk herniation (LDH) patients undergoing dynamic stabilization and discectomy. METHODS: A total of 119 lumbar disk herniation (LDH) patients undergoing Dynesys dynamic stabilization and discectomy were divided into the ERAS (n1 = 56) and control group (n2 = 63). ERAS group received an enhanced recovery after surgery (ERAS) protocol, and control group received a traditional care protocol. RESULTS: Both the ERAS and control groups had significantly decreased visual analog scale (VAS) score and Oswestry Disability Index (ODI) and increased Japanese Orthopaedic Association (JOA) score at postoperative 1 week, 1 month and 3 months compared with preoperative scores. Moreover, the ERAS group had lower postoperative VAS score and ODI and higher postoperative JOA score and rate of improved JOA score compared with the control group. Intraoperative blood loss, operation time, ambulation time and length of stay were all lower in the ERAS group than in the control group. CONCLUSIONS: The ERAS protocol designed was feasible for LDH patients undergoing dynamic stabilization and discectomy with significantly improved perioperative outcomes.

Tumor-induced osteomalacia TIO is a rare paraneoplastic syndrome caused by excessive production of fibroblast growth factor 23 FGF23 by a tumor. Previous studies have revealed generalized mineralization defects and low areal bone mineral density aBMD in TIO. However, data on the bone microarchitecture in TIO are limited. In this study, we evaluated the microarchitecture in the peripheral distal radius and tibia and axial lumbar spine skeleton using high-resolution peripheral quantitative computed tomography HR-pQCT and trabecular bone score TBS and investigated related factors in a large cohort of Chinese patients with TIO. A total of 186 patients with TIO who had undergone dual-energy X-ray absorptiometry DXA or HR-pQCT scans were enrolled. Compared with age-, sex- and BMI-matched healthy controls, TIO patients n=113 had lower vBMD, damaged microstructure and reduced bone strength in the peripheral skeleton, especially at the tibia. The average TBS obtained from 173 patients was 1.15 ± 0.16. The proportion of patients with abnormal TBS

Objectives As in-vivo knowledge of training-induced remodeling of intervertebral discs (IVD) is scarce, this study assessed how lumbar IVDs change as a function of long-term training in elite athletes and age-matched controls using compositional Magnetic Resonance Imaging (MRI). Design Prospective case-control study. Methods Prospectively, lumbar spines of 17 elite rowers (ERs) of the German national rowing team (mean age: 23.9 ± 3.3 years) were imaged on a clinical 3.0 T MRI scanner. ERs were imaged twice during the annual training cycle, i.e., at training intensive preseason preparations (t0) and 6 months later during post-competition recovery (t1). Controls (n = 22, mean age: 26.3 ± 1.9 years) were imaged once at corresponding time points (t0: n = 11; t1: n = 11). Segment-wise, the glycosaminoglycan (GAG) content of lumbar IVDs (n = 195) was determined using glycosaminoglycan chemical exchange saturation transfer (gagCEST). Linear mixed models were set up to assess the influence of cohort and other variables on GAG content. Results During preseason, IVD GAG values of ERs were significantly higher than those of controls (ERs(t0): 2.58 ± 0.27% (mean ± standard deviations); controls(t0): 1.43 ± 0.36%; p ≤ 0.001), while during post-competition recovery, such differences were not present anymore (ERs(t1): 2.11 ± 0.18%; controls(t1): 1.89 ± 0.24%; p = 0.362). Conclusions Professional elite-level rowing is transiently associated with significantly higher gagCEST values, which indicate increased lumbar IVD-GAG content and strong remodeling effects in response to training. Beyond professional rowing, core-strengthening full-body exercise may help to enhance the resilience of the lumbar spine as a potential therapeutic target in treating back pain.

Aim: Endoscopic discectomies provide several advantages over other techniques such as traditional open lumbar discectomy (OLD) including possibly decreased complications, shorter hospital stay and an earlier return to work. Methods: An electronic database search including MEDLINE/PubMed, EMBASE, Scopus, Cochrane Database of Systematic Reviews and Cochrane Controlled trials (CENTRAL) were reviewed for randomized controlled trials (RCTs) only. Results: A total of nine RCTs met inclusion criteria. Three showed benefit of endoscopic discectomy over the comparator with regards to pain relief, with the remaining six studies showing no difference in pain relief or function. Conclusion: Based on review of the nine included studies, we can conclude that endoscopic discectomy is as effective as other surgical techniques, and has additional benefits of lower complication rate and superior perioperative parameters.

Introduction Fibrous dysplasia (FD) is a rare genetic disease characterized by development of dysplastic bone tissue leading to pain, deformities and compressive complications. Spinal involvement is rare particularly for the polyostotic form. Case report Herein, we present a case of 52-year-old man presented with isolated low back pain who received non-steroidal anti-inflammatory drugs (NSAIDs) with partial pain relief. On examination, the thoracic and lumbar spines were tender. Lumbar spine movements, attested by Shober’s test and finger-to-floor test, were limited. There was no radicular pain and neurological examination was normal. The erythrocyte sedimentation rate was 20 mm/1st hour, C- reactive protein 2 mg/l and white blood cell count, serum calcium, phosphorus, alkaline phosphatase and parathormone were normal. Plain x-ray lumbar and thoracic spine and hips were normal. X-ray cervical spine and peripheral bone showed no lesions. Computed tomography (CT) and magnetic resonance imaging showed multiple osteolytic lesions with ground-glass opacity and sclerotic rims of thoracic and lumbar (L1 and L2) spine. Investigations to rule out malignancy or infections were negative. CT guided biopsy of a lumbar vertebra was performed and showed the presence of abnormal fibrous matrix surrounding an irregular shaped immature bone. The diagnosis of polyostotic FD of the spine was made. Zoledronic acid infusion was introduced and the patient felt better thereafter with no additional osteolytic lesions or new pain localization reported for 2 years on follow up. Conclusion Thoracic and lumbar spine FD is a rare localization that should be considered in the differential diagnosis of back pain.

OBJECTIVE To investigate influences of spinopelvic parameters, such as lumbar lordosis (LL) angles, pelvic incidence, sacral slope, pelvic tilt, and sagittal vertical axis, on development of the proximal junctional failure fracture type after posterior instrumentation. METHODS This retrospective 1:3 matched case-control cohort study included 24 patients who developed proximal instrumented fracture in the study group and 72 patients without proximal junctional failure in the control group. Weighted Charlson Comorbidity Index and bone mineral density with T-score were recorded. In addition to spinopelvic parameters, proximal local kyphosis (PLK), which refers to a kyphosis angle between the upper end plate of upper instrumented vertebra plus 1 level and the lower end plate of upper instrumented vertebra; pelvic incidence-LL mismatch; and spinopelvic realignment score were calculated. RESULTS More comorbidities (Charlson Comorbidity Index, P = 0.002) and poorer bone density (T-score, P = 0.001) were noted in the study group. Before surgery, the study group had significantly lower LL (P = 0.046) and sacral slope (P = 0.043) and significantly higher PLK (P < 0.001) and pelvic tilt (P = 0.044) than the control group. Postoperatively, the study group had significantly higher PLK (P < 0.001) and lower LL (P = 0.031) than the control group; the degree of pelvic incidence-LL mismatch (P = 0.007) remained significantly higher in the study group. Preoperative (P = 0.026) and postoperative (P = 0.045) spinopelvic realignment scores was worse in the study group. Multivariate analysis revealed that postoperative PLK was the most significant radiographic factor to predict proximal instrumented fracture (P = 0.002, odds ratio 1.140, 95% confidence interval). CONCLUSIONS In our experience, appropriate LL and lower PLK should be obtained at surgery to prevent development of instrumented fracture.

OBJECTIVE Lumbosacral fractional curves in adult spinal deformity (ASD) patients often have sharp coronal curves resulting in significant pain and imbalance. Postoperative stretch neuropraxia after fractional curve correction can lead to discomfort and unsatisfactory outcomes. The goal of this study was to use radiographic measures to increase understanding of the relationship between postoperative stretch neuropraxia and fractional curve correction. METHODS In 62 ASD patients treated from 2015 to 2018, radiographic review was performed, including measurement of the distance between the lower lumbar neural foramen (L4 and L5) in the concavity and convexity of the lumbosacral fractional curve and the ipsilateral femoral heads (FHs; L4–FH and L5–FH) in pre- and postoperative anteroposterior spine radiographs. The largest absolute preoperative to postoperative change in distance between the lower lumbar neural foramen and the ipsilateral FH (ΔL4/L5–FH) was used for analysis. Chi-square analyses, independent and paired t-tests, and logistic regression were performed to study the relationship between L4/L5–FH and stretch neuropraxia for categorical and continuous variables, respectively. RESULTS Of the 62 patients, 13 (21.0%) had postoperative stretch neuropraxia. Patients without postoperative stretch neuropraxia had an average ΔL4–FH distance of 16.2 mm compared to patients with stretch neuropraxia, who had an average ΔL4–FH distance of 31.5 mm (p < 0.01). Patients without postoperative neuropraxia had an average ΔL5–FH distance of 11.1 mm compared to those with stretch neuropraxia, who had an average ΔL5–FH distance of 23.0 mm (p < 0.01). Chi-square analysis showed that patients had a 4.78-fold risk of developing stretch neuropraxia with ΔL4–FH > 20 mm (95% CI 1.3–17.3) and a 5.17-fold risk of developing stretch neuropraxia with ΔL5–FH > 15 mm (95% CI 1.4–18.7). Logistic regression analysis indicated that the odds of developing stretch neuropraxia were 15:1 with a ΔL4–FH > 20 mm (95% CI 3–78) and 21:1 with a ΔL5–FH > 15 mm (95% CI 4–113). CONCLUSIONS The novel ΔL4/L5–FH distances are strongly associated with postoperative stretch neuropraxia in ASD patients. A ΔL4–FH > 20 mm and ΔL5–FH > 15 mm significantly increase the odds for patients to develop postoperative stretch neuropraxia.

BACKGROUND CONTEXT Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is the workhorse minimally invasive treatment for patients with degenerative lumbar stenosis and spondylolisthesis refractory to nonoperative care. While the basic tenets of surgical treatment do not differ between minimally invasive and open techniques, surgeons performing MI-TLIF are more likely to attempt reduction of spondylolisthesis in order to optimize restoration of canal dimensions due to a greater reliance on indirect decompression, which has been shown to be effective. While intraoperative reduction is often successful, postoperative loss of reduction and slip recurrence can be seen. PURPOSE To determine the rate and clinical impact of slip recurrence after MI-TLIF with expandable cage technology. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE Patients undergoing MI-TLIF for degenerative spondylolisthesis using an articulating, expandable cage OUTCOME MEASURES Patient-reported outcome measures (PROMs), including the Oswestry Disability Index (ODI), visual analog scale (VAS) for back/leg pain, Short Form-12 (SF-12) and PROMIS Physical Function (PF) METHODS Patients undergoing MI-TLIF for degenerative spondylolisthesis using articulating, expandable cages from 2017-2019 were retrospectively studied. Lateral radiographs were reviewed and evaluated for the presence or absence of spondylolisthesis preoperatively, intraoperatively, and at follow-up times including 2 weeks, 6 weeks, 12 weeks, 6 months and 1-year postoperatively. Spondylolisthesis was measured from the posterior inferior corner of the cephalad vertebra to the posterior superior corner of the caudal vertebral, with any measurement >1mm classified as spondylolisthesis, and Meyerding grade was noted. Intraoperative reduction was measured and loss of reduction was defined as >1mm increase in spondylolisthesis comparing follow-up imaging to intraoperative films. PROMs were recorded at the preoperative and follow-up time points. Fusion was assessed 1-year postoperatively via CT. RESULTS A total of 63 patients and 70 levels were included, with mean age 59.8 years (SD,13.8). Nineteen levels (27.1%) had complete reduction intraoperatively, 40 (57.1%) had partial reduction and 11 (15.7%) had no reduction. Of the 30 levels with loss of reduction (50.8%), 20 (66.7%) occurred by 2 weeks postoperatively and 28 (93.3%) occurred by 12 weeks postoperatively. At 6 months, there were significant differences between those who had loss of reduction and those who did not in VAS back pain (3.0 vs 0.9, p=0.017) and SF-12 PCS (41.5 vs 50.0, p=0.035), but no differences were found between the groups for any instruments at any other time points. The overall fusion rate was 89.5% (34/38) at 1 year postoperatively. There was no significant difference in fusion rate between the loss of reduction (16/18) and no loss of reduction (18/20) groups. Patients with loss of reduction had no difference in reoperation rate (1/28) compared to those without loss of reduction (2/24). CONCLUSIONS While a majority of patients demonstrated reduction intraoperatively, 51% had loss of reduction, most commonly in the acute postoperative period. There were few differences in PROMs between patients who had loss of reduction and those who did not, suggesting that radiographic loss of reduction after MI-TLIF in the setting of degenerative spondylolisthesis may not be clinically meaningful. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Background Spinal disorders and low back pain (LBP) have been associated with worse clinical outcomes of total hip arthroplasty (THA). It is essential to identify spinal factors associated with post-THA LBP improvement. Therefore, we aimed to determine the proportion of patients with improved LBP after THA and to identify the preoperative spinal factors associated with LBP improvement. Methods We included 151 patients who underwent primary THA between December 2015 and December 2019 and had a preoperative visual analog scale score for LBP of ≥2. The patients were classified into the LBP improved or LBP continued group based on a visual analog scale score for LBP at 1 year after THA. Preoperative spinal parameters were compared between the 2 groups. Results Ninety-five patients (62.9%) were classified into the LBP improved group. Among the coronal spinal parameters, the Cobb angle was significantly lower in the LBP improved group. Among the sagittal spinal parameters, the LBP continued group showed a significantly more posteriorly titled pelvis, lower lumbar lordosis, greater sagittal vertical axis, and greater pelvic incidence minus lumbar lordosis mismatch, indicating a sagittal spinal imbalance. Logistic regression analysis found that preoperative factors associated with LBP improvement after THA had a low Cobb angle and high anterior pelvic plane angle (anteriorly tilted pelvis). Conclusion Among patients with LBP before THA, 62.9% had improved LBP. Sagittal spinal imbalance and high Cobb angle were the key spinal factors associated with persistent LBP. Our findings suggest that hip surgeons should evaluate spinal alignment before THA in patients with LBP.

Background Identifying altered motor control patterns during functional movements in patients with chronic non-specific low back pain (LBP) has important clinical implications for reducing the risk of recurrence. While prior research has shown that magnitudes of lumbar and hip motion are not altered in patients with chronic non-specific LBP, it is possible that outcomes which describe coordination could provide greater discriminatory information between pathological and healthy movement. Research question Determine the effect of biological sex and chronic non-specific LBP on coordination between hip and lumbar motion during cyclic and discrete reaching. Methods Twenty participants with chronic non-specific LBP (11 male/9 female, 23.5 ± 4.9 years old) and 21 control participants (12 male/9 female, 22.9 ± 6.1 years old) completed discrete and cyclic reaching tasks to a target in the mid-sagittal plane, while whole-body kinematics were collected using a three-dimensional motion capture system. Movement time, lumbar motion, hip motion, and the ratio between lumbar and hip motion were compared between participants with and without chronic non-specific LBP and between men and women using two-way mixed ANOVAs. Results Participants with chronic non-specific LBP had reduced lumbar-hip ratios relative to control participants during both the cyclic (F = 4.779, p = 0.035, η2 = 0.114) and discrete tasks (F = 4.743, p = 0.036, η2 = 0.119), however group differences were not observed for hip or lumbar excursion during either task (p > 0.05). Participants with chronic non-specific LBP had slower reaching times relative to controls during the discrete reaching task (F = 4.795, p = 0.035, η2 = 0.115). No significant effects of sex, and no interactions between group and sex were observed for any outcome. Significance Reduced lumbar-hip ratios during reaching likely reflect a compensatory movement strategy that could play an important role in the development and progression of LBP.

OBJECTIVE This report describes a minimally invasive lumbar foraminotomy technique that can be applied in patients who underwent complex spine decompression procedures or in patients with severe foraminal stenosis. METHODS Awake, endoscopic decompression surgery was performed in 538 patients over a 5-year period between 2014 and 2019. Transforaminal endoscopic foraminal decompression surgery using a high-speed endoscopic drill was performed in 34 patients who had previously undergone fusions at the treated level. RESULTS At 2-year follow-up, the mean (± SD) preoperative visual analog scale score for leg pain and the Oswestry Disability Index improved from 7.1 (± 1.5) and 40.1% (± 12.1%) to 2.1 (± 1.9) and 13.6% (± 11.1%). CONCLUSIONS A minimally invasive, awake procedure is presented for the treatment of severe lumbar foraminal stenosis in patients with lumbar radiculopathy after lumbar fusion.

OBJECTIVE Postoperative urinary retention (POUR) is a common complication after spine surgery and is associated with prolongation of hospital stay, increased hospital cost, increased rate of urinary tract infection, bladder overdistention, and autonomic dysregulation. POUR incidence following spine surgery ranges between 5.6% and 38%; no reliable prediction tool to identify those at higher risk is available, and that constitutes an important gap in the literature. The objective of this study was to develop and validate a preoperative risk model to predict the occurrence of POUR following routine elective spine surgery. METHODS The authors conducted a retrospective chart review of consecutive adults who underwent lumbar spine surgery between June 1, 2017, and June 1, 2019. Patient characteristics, preexisting ICD-10 codes, preoperative pain and opioid use, preoperative alpha-1 blocker use, details of surgical planning, development of POUR, and management strategies were abstracted from electronic medical records. A binomial logistic model and a multilayer perceptron (MLP) were optimized using training and validation sets. The models’ performance was then evaluated on model-naïve patients (not a part of either cohort). The models were then stacked to take advantage of each model’s strengths and to avoid their weaknesses. Four additional models were developed from previously published models adjusted to include only relevant factors (i.e., factors known preoperatively and applied to the lumbar spine). RESULTS Overall, 891 patients were included in the cohort, with a mean of 59.6 ± 15.5 years of age, 52.7% male, BMI 30.4 ± 6.4, American Society of Anesthesiologists class 2.8 ± 0.6, and a mean of 5.6 ± 5.7 comorbidities. The rate of POUR was found to be 25.9%. The two models were comparable, with an area under the curve (AUC) of 0.737 for the regression model and 0.735 for the neural network. By combining the two models, an AUC of 0.753 was achieved. With a regression model probability cutoff of 0.24 and a neural network cutoff of 0.23, maximal sensitivity and specificity were achieved, with specificity 68.2%, sensitivity 72.9%, negative predictive value 88.2%, and positive predictive value 43.4%. Both models individually outperformed previously published models (AUC 0.516–0.645) when applied to the current data set. CONCLUSIONS This predictive model can be a powerful preoperative tool in predicting patients who will be likely to develop POUR. By using a combination of regression and neural network modeling, good sensitivity, specificity, and NPV are achieved.

Background The objective of this study was to identify the predictors of the conservative management outcomes in patients with lumbar herniated nucleus pulposus (HNP). Methods A prospective study was conducted between June 2010 and April 2012 in Banda Aceh, Indonesia. Clinical and baseline neurologic examinations such as passive straight leg raising test (SLRT), cross SLRT, and patellar and Achilles reflexes were assessed prior to the conservative management. The patients were evaluated at 2nd, 4th, 8th, 12th and 24th week following commencement of the conservative management. Results We recruited and followed 171 HNP patients of which 35.7% of them had good outcome. At univariate analysis, patients with more than 12 months duration of complaint, those with dominant radicular pain, severe pain intensity (visual analogue scale 7–10), positive SLRT, positive cross SLRT, and reduced motor power of knee extensors (muscle strength grade 1–4), were associated with poor outcome. Multivariate analysis suggested that patients with dominant radicular type of pain were likely to had poor outcome compared to those with dominant back pain (odd ratio (OR) 10.57 with 95% confidence interval (CI) 1.15–96.93). Patients with reduced motor power of knee extensors also had a higher chance to have poor outcome compared to those who were normal (OR: 10.57; 95% CI: 1.15–96.93). Conclusion Type of pain and the strength of lower extremities could be able to predict the failure of conservative management in patients with lumbar disc herniation. However, further studies with the bigger sample size are warrant to validate our results.