Sagittal balance and fatty infiltration of paraspinal muscle are important factors in patients with lumbar spinal stenosis (LSS) that may affect patients’ quality of life. Sagittal spinopelvic parameters and fatty infiltration may be associated with the severity of LSS. The purpose of this study was to test the hypothesis that severity of fatty infiltration correlates with severity of LSS and with sagittal pelvic alignment independent of age. Age and body mass index (BMI) were extracted. Fatty infiltration was rated according to Goutallier classification and the severity of LSS was graded according to Schizas at five intervertebral disc levels. Overall fatty infiltration was computed as average fatty infiltration (aFI) and severity of LSS was defined as the highest severity of LSS of all segments. The sagittal spinopelvic parameters pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL) and PI-LL were measured. Associations among parameters were assessed using Spearman correlation coefficients adjusted for age (α = 0.05). 165 LSS patients with a median age of 69 years were included. All parameters correlated with age (R>0.162, P<0.05) except BMI and LL (R0.05). aFI correlated with PI, PT and PI-LL before (R>0.371, P0.180, P0.187, P<0.05) but not after (R0.05) adjusting for age. aFI correlated with severity of LSS before (R=0.349, P0.05) after adjusting for age. The correlation of aFI with sagittal spinopelvic parameters indicates that there might be a relationship between muscle characteristics and the sagittal alignment. Sagittal spinopelvic parameters and fatty infiltration of paraspinal muscles are not associated with radiological severity of LSS. Whether they are associated with clinical manifestation of LSS remains to be investigated.

Study Design: Retrospective observational study. Objectives: We aim to evaluate whether age is a risk factor for cage subsidence, and whether other patient characteristics, preoperative radiological or imaging parameters are associated with cage subsidence and the need for revision surgery in patients undergoing transforaminal lumbar interbody fusion (TLIF). Methods: Patient demographics and surgery-related information were extracted. Cage subsidence was evaluated using upright standing sagittal plane X-rays and defined as more than 2 mm migration of the cage into the adjacent vertebral body. Patients who received revision surgery within 1 year for any reason were recorded. Radiographic parameters were measured. Univariable logistic regression models were used to evaluate the risk factors for cage subsidence and need for revision surgery. Results: At 3-month and 1-year follow-up, cage subsidence was observed in 28 patients (16.5%) and 58 patients (34.1%), respectively. Twenty-seven patients received revision surgery within the first year after TLIF. Age (odds ratio (OR): 1.07 per year) and male sex (OR: 2.76) had a significantly increased odds ratio for cage subsidence 3 months after TLIF. Male sex (OR: 2.55) but not age was a significant risk factor for cage subsidence 1 year after TLIF. Of all assessed risk factors, only BMI (OR: 1.11 per kg/m ² ) had a significantly increased risk for the need of revision surgery. Conclusions: Age was associated with cage subsidence 3 months but not 1 year after TLIF suggesting that age is only a risk factor for early cage subsidence and not in a longer follow-up.

A proper restoration of sagittal alignment is essential in AIS patients, but few studies provided a formula to predict an optimal surgical thoracic kyphosis (TK) gain in adolescent idiopathic scoliosis (AIS) patients. A formula was recently proposed (LL = (PI+TK)/2 + 10) to predict the optimal lumbar lordosis (LL) in adult spinal deformity patients, which has not been validated in adolescents. The aim of this study is to establish a formula with TK and pelvic parameters in normal adolescents and predict an optimal TK with this formula pre- and post-operatively in Lenke 1 AIS patients. A total of 60 asymptomatic adolescents were used to validate the proposed formula. The subject was considered to match with the formula, if the difference between the virtual TK and the theoretical TK was less than 10°. Then regression analysis was performed to establish a new formula to predict TK in adolescents. The predictive efficiency of the new formula was also validated in 40 Lenke 1 AIS patients. Of the 60 asymptomatic adolescents, only 26 (43.33%) asymptomatic adolescents matched with the adjusted formula: TK = 2 × (LL-10)-PI. The paired t test revealed a significantly different theoretical TK (tTK) compared to the virtual TK (41.23 ± 18.29° vs. 24.80 ± 8.75°, P < 0.001). Multiple linear regression showed that TK had a relationship with LL, SS and age (R2 = 0.331): TK = − 0.785 × LL-0.843 × SS + 0.858 × age + 3.754. There were 27 (67.50%), 32 (80.00%) and 35 (87.50%) Lenke 1 AIS patients matched this formula preoperatively, postoperatively and at the last follow-up. Our results revealed that the predictive formula for sagittal alignment for adults was not applicable in adolescents. This study established a new predictive formula for TK based on asymptomatic adolescents. In Lenke 1 AIS patients, post-op TK in 87.5% of patients matched the predictive value, indicating that the new formula can be considered as a reference when making a surgery strategy.

Background: The accurate assessment and staging of lymphedema are critical for effective management. This study sought to compare the International Society of Lymphology (ISL) staging system with the Taiwan Lymphoscintigraphy Staging (TLS) system, and to evaluate the reliability of both lymphedema staging systems. Methods: A retrospective study of patients with primary or secondary extremity lymphedema was conducted. Lymphedema was staged using both the ISL staging system and the TLS system. The correlation between the systems was analyzed using the Spearman’s rank correlation coefficient, and the inter- and intra-observer reliability of the TLS system was assessed using the intraclass correlation coefficient (ICC). A severity index based on limb circumference differences adjusted for body mass index (BMI) was also developed, and its correlation with both staging systems was verified by a one-way analysis of variance (ANOVA) analysis. Results: In total, 50 patients (mean age: 56.1±12.9 years, BMI: 24.7±3.6 kg/m²) were included in the study. A statistically significant correlation was found between the ISL staging system and the TLS system (r=0.49, P<0.05). The severity index was also significantly correlated with the ISL staging system (r=0.56, P<0.05) and the TLS system (r=0.37, P0.90). The ANOVA results revealed significant differences in the severity index among the different ISL staging system stages and TLS system grades (P<0.05), highlighting the utility of the severity index in distinguishing varying levels of lymphedema severity. Conclusions: The ISL staging system and the TLS system showed strong agreement and reliability. The TLS system, with its quantitative imaging approach, is particularly suited for research, while the ISL staging system remains useful for routine clinical practice. The severity index offers an effective quantitative measure for assessing lymphedema severity.