The relationship between quantitative anatomic parameters in MRI and patient-reported outcomes (PROs) before and after surgery in degenerative lumbar foraminal stenosis remains unknown. We included 58 patients who underwent transforaminal lumbar interbody fusion (TLIF) for single-level degenerative disc disease with foraminal stenosis between February 2013 and June 2020. PROs were evaluated using the visual analog scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and EuroQol-5D (EQ-5D). The foraminal parameters assessed using preoperative MRI included foraminal height, posterior intervertebral disc height, superior and inferior foraminal width, and foraminal area. The correlation between foraminal parameters and PROs before operation, at 1 year follow-up, and change from baseline were assessed. The associations between the aforementioned parameters were examined using linear regression analysis. The analysis revealed that among these parameters, superior foraminal width was found to be significantly correlated with ODI and EQ-5D at the 1 year follow-up and with change in ODI and EQ-5D from baseline. The associations remained significant after adjustment for confounding factors including age, sex, body mass index, and duration of hospital stay. The results indicated that in degenerative lumbar foraminal stenosis, decreased superior foraminal width was associated with better improvement in disability and quality of life after TLIF.

Background Recent research has proposed a classification of spinopelvic stiffness according to pelvic spatial orientation for risk stratification in patients who undergo total hip arthroplasty (THA). However, the influence of global alignment was not investigated, and this study evaluated the effect of global balance (sagittal vertical axis [SVA]) on spinopelvic motion. Methods We conducted a retrospective review of consecutive primary THA patients. We measured SVA, spinopelvic parameters (pelvic tilt [PT], pelvic incidence, and sacral slope), thoracic kyphosis (TK), lumbar lordosis (LL), proximal femur angle (PFA), and cup version using functional radiographs of patients in the standing and upright sitting positions. Linear regression was performed to identify parameters related to global trunk alignment change (∆SVA). Spinopelvic stiffness was defined as PT position change < 10°, and a subset of patients with PT change < 0° was categorized into a paradoxical spinopelvic motion group. Results One hundred twenty-four patients were analyzed (mean age: 65 years, 61% female). In univariate regression analysis, ∆TK, ∆LL, and ∆PFA were correlated to ∆SVA. In multivariate regression analysis, ΔLL (p < 0.001) and ΔPFA (p < 0.001) were found to be correlated to ΔSVA (ΔSVA = − 11.97 + 0.05ΔTK – 0.23ΔLL – 0.17ΔPFA; adjusted R2 = 0.558). Spinopelvic stiffness was observed in 40 patients (32%), including five (4%) with paradoxical motion (∆PT = − 3° ± 1°, p < 0.001) with characteristics of balanced standing global trunk alignment (standing SVA = − 1.0 ± 5.1 cm), similar stiffness of the lumbosacral spine (∆LL = − 7° ± 5°), higher hip motion (∆PFA = − 78° ± 6°, p = 0.017), and higher anterior trunk shift (∆SVA = 6.2 ± 2.0 cm, p = 0.003) from standing to sitting as compared to the stiffness group. Two of these five patients experienced dislocation events after THA. Conclusions The lumbosacral and hip motions were the major contributors to global alignment postural change. Paradoxical motion is a rare but dangerous clinical condition in THA that might be related to a disproportionally large trunk shift in the stiff lumbosacral spine causing excessive hip motion. In paradoxical motion, diminishing functional acetabular clearance during position change might pose the prosthesis at higher risk of impingement and instability than spinopelvic stiffness.

Background Reduction of lumbar spondylolisthesis during spinal fusion surgery is important for improving the fusion rate and restoring the sagittal alignment. Despite the variety of reduction methods, the fundamental mechanics of lumbar spondylolisthesis reduction remain unclear. This study aimed to investigate the biomechanical behavior while performing spondylolisthesis reduction with the anterior and posterior lever reduction method. Methods We developed an L4–L5 spondylolisthesis model using sawbones. Two spine surgeons performed the simulated reduction with a customized Cobb elevator. The following data were collected: the torque and angular motion of Cobb, displacement of vertebral bodies, change of lordotic angle between L4 and L5, total axial force and torque applied on the model, and force received by adjacent disc. Results Less torque value (116 N-cm vs. 155 N-cm) and greater angular motion (53o vs. 38o) of Cobb elevator were observed in anterior lever reduction. Moreover, the total axial force received by the entire model was greater in the posterior lever method than that in the anterior lever method (40.8 N vs. 16.38 N). Besides, the displacement of both vertebral bodies was greater in the anterior lever method. Conclusions The anterior lever reduction is a more effort-saving method than the posterior lever reduction method. The existing evidence supports the biomechanical advantage of the anterior reduction method, which might be one of the contributing factors to successfully treating high-grade lumbar spondylolisthesis with short-segment instrumentation.

We aimed to investigate the association between preoperative body mass index (BMI) and postoperative long-term mortality in patients who underwent a vertebroplasty. We retrospectively enrolled patients with a vertebral compression fracture who underwent a vertebroplasty between May 2013 and June 2020 in a medical center in Taiwan. The survival status of the study sample was confirmed by the end of March 2021. Cox-proportional hazard models were conducted to examine the effects of being overweight/obese (≥25 kg/m2 vs. <25 kg/m2) and BMI (as a continuous variable) on all-cause mortality after adjusting for age, sex, history of smoking, diabetes, hypertension, chronic kidney disease, and osteoporosis. A total of 164 patients were analyzed (mean age 75.8 ± 9.3 years, male 25.6%, mean BMI 24.0 ± 4.1 kg/m2) after a median follow-up of 785 days. Compared with a BMI < 25 kg/m2, a BMI ≥ 25 kg/m2 was associated with a significantly lower risk of all-cause mortality (HR 0.297, 95% CI 0.101 to 0.878, p = 0.028). These findings were consistent when BMI was examined as a continuous variable (HR 0.874, 95% CI 0.773 to 0.988, p = 0.031). A low BMI (<22 kg/m2) should be considered as a risk factor for postoperative long-term mortality in this ageing population.

PurposeWe investigated the association between pre-operative anemia and long-term all-cause mortality in patients with vertebral fracture who underwent a vertebroplasty.Materials and methodsWe retrospectively selected patients who were admitted for vertebroplasty for vertebral compression fracture between 2013 and 2020. Patients who had pathologic fractures or had no assessment of bone mineral density were excluded. Relevant information was collected from electronic medical records. Patients’ survival status was confirmed at the end of March 2021. Cox-proportional hazard models were conducted to examine the effects of anemia (&lt;12 g/dL vs. ≥12 g/dL) and pre-operative hemoglobin levels (as a continuous variable) on all-cause mortality with multivariate adjustments.ResultsA total of 167 patients were analyzed (mean age 75.8 ± 9.3 years, male 25.7%). After a median follow-up duration of 2.1 years, pre-operative anemia (hemoglobin &lt;12 g/dL vs. ≥12 g/dL) was independently associated with a higher risk of all-cause mortality (hazard ratio 2.762, 95% CI 1.184 to 6.442, p = 0.019). An increase in pre-operative hemoglobin was associated with a lower risk of all-cause mortality after multivariate adjustment (hazard ratio 0.775, 95% CI 0.606 to 0.991, p = 0.042).ConclusionPre-operative anemia (&lt;12 g/dL) was independently associated with survival outcome among patients with vertebral compression fractures who underwent vertebroplasty. Our findings highlight anemia as a risk factor of long-term mortality in this elderly surgical population.