OBJECTIVE: The purpose of the present study was to investigate the association between quantitatively assessed trunk extensor strength and gait-induced back pain (GIBP) in patients with adult spinal deformity (ASD).
METHODS: Ninety-five patients with ASD aged ≥ 50 years who were admitted to our hospital between April 2018 and March 2023 were included in the study. GIBP was evaluated through a 6-minute walking test (6MWT), with GIBP being defined as the occurrence of back pain during the evaluation and inability to complete the test. The patients were divided into three groups: difficulty completing the 6MWT (Group 1), ability to complete the 6MWT with breaks (Group 2), and ability to complete the 6MWT without taking a break (Group 3). The main independent variable was trunk extensor strength, which was measured using a hand-held dynamometer. Ordered logistic regression analysis was conducted to assess the association between GIBP and trunk extensor strength while adjusting for basic characteristics and radiographic parameters as covariates.
RESULTS: The numbers of patients with ASD included in each group were; 27 in Group 1 (28.4%), 31 in Group 2 (32.6%), and 37 in Group 3 (39.0%). An ordered logistic regression analysis adjusted for basic characteristics and radiographic parameters, trunk extensor strength was significantly associated with GIBP (odds ratios, 1.128; 95% confidence intervals, 1.025-1.242).
CONCLUSIONS: The results of the present study strongly indicate that trunk extensor strength is a valuable factor associated with GIBP in patients with ASD.

BACKGROUND: The surgical treatment of severe and complex adult spinal deformity (ASD) commonly required three-column osteotomy (3-CO), which was technically demanding with high risk of neurological deficit. Personalized three dimensional (3D)-printed guide template based on preoperative planning has been gradually applied in 3-CO procedure. The purpose of this study was to compare the efficacy, safety, and precision of 3D-printed osteotomy guide template and free-hand technique in the treatment of severe and complex ASD patients requiring 3-CO.
METHODS: This was a single-centre retrospective comparative cohort study of patients with severe and complex ASD (Cobb angle of scoliosis > 80° with flexibility < 25% or focal kyphosis > 90°) who underwent posterior spinal fusion and 3-CO between January 2020 to January 2023, with a minimum 12 months follow-up. Personalized computer-assisted three-dimensional osteotomy simulation was performed for all recruited patients, who were further divided into template and non-template groups based on the application of 3D-printed osteotomy guide template according to the surgical planning. Patients in the two groups were age- and gender- propensity-matched. The radiographic parameters, postoperative neurological deficit, and precision of osteotomy execution were compared between groups.
RESULTS: A total of 40 patients (age 36.53 ± 11.98 years) were retrospectively recruited, with 20 patients in each group. The preoperative focal kyphosis (FK) was 92.72° ± 36.77° in the template group and 93.47° ± 33.91° in the non-template group, with a main curve Cobb angle of 63.35° (15.00°, 92.25°) and 64.00° (20.25°, 99.20°), respectively. Following the correction surgery, there were no significant differences in postoperative FK, postoperative main curve Cobb angle, correction rate of FK (54.20% vs. 51.94%, P = 0.738), and correction rate of main curve Cobb angle (72.41% vs. 61.33%, P = 0.101) between the groups. However, the match ratio of execution to simulation osteotomy angle was significantly greater in the template group than the non-template group (coronal: 89.90% vs. 74.50%, P < 0.001; sagittal: 90.45% vs. 80.35%, P < 0.001). The operating time (ORT) was significantly shorter (359.25 ± 57.79 min vs. 398.90 ± 59.48 min, P = 0.039) and the incidence of postoperative neurological deficit (5.0% vs. 35.0%, P = 0.018) was significantly lower in the template group than the non-template group.
CONCLUSIONS: Performing 3-CO with the assistance of personalized 3D-printed guide template could increase the precision of execution, decrease the risk of postoperative neurological deficit, and shorten the ORT in the correction surgery for severe and complex ASD. The personalized osteotomy guide had the advantages of 3D insight of the case-specific anatomy, identification of osteotomy location, and translation of the surgical planning or simulation to the real surgical site.

OBJECTIVE: The functional interaction between the hip and spine in patients undergoing total hip arthroplasty (THA) is clinically significant, as it impacts post-operative outcomes. Therefore, this study aimed to identify factors associated with the progression of sagittal spinal deformity and assess the association with patient-reported outcomes.
METHODS: This retrospective case-control study included 200 patients who underwent primary THA and completed a mean follow-up duration of 42.2 months (range, 24.0-78.0). We employed a multivariate logistic regression to identify variables predictive of a post-THA sagittal vertical axis (SVA) ≥ 50 mm, which was indicative of a spinal sagittal imbalance. Propensity score-matched cohorts for age, sex, body mass index, follow-up duration, hip flexion contracture, developmental dysplasia, pelvic incidence (PI), and SVA were created, and the outcomes were compared between the two groups.
RESULTS: PI (odds ratio 1.39; 95% confidence interval 1.04-1.86, p = 0.033) was associated with an SVA ≥ 50 mm. After successfully matching patients with (n = 50) and without (n = 50) an SVA ≥ 50 mm, the minimum clinically important difference showed significant differences between the 50 matched pairs (p = 0.016 for EuroQol-5D, p = 0.003 for Hip Disability and Osteoarthritis Outcome Score Joint Replacement, and p < 0.001 for low back pain).
CONCLUSIONS: PI is associated with the development of a positive sagittal spinal malalignment post-THA. This finding can assist surgeons in managing patient expectations and in optimising outcomes. Feasible strategies are warranted to minimise the risk of spinal deformity progression post-THA.

Adult spinal deformity (ASD) significantly impacts the quality of life due to three-dimensional spinal abnormalities. Patient-reported outcome measures, such as the Patient-Reported Outcomes Measurement Information System (PROMIS-29), play a crucial role in assessing postoperative outcomes. This study aims to investigate trends in PROMIS-29 scores over 36 months in patients undergoing long-segment thoracolumbar fusion for ASD and provide insights into its long-term utility.
A retrospective study including 163 ASD patients undergoing long-segment thoracolumbar fusion was conducted. PROMIS-29 scores were collected at baseline and at postoperative (0-), 3-, 6-, 12-, 18-, 24-, 30-, and 36-month follow-ups. Statistical analyses was performed to assess significant score changes from baseline and in consecutive recordings.
Significant improvements in all PROMIS-29 categories were observed at 36 months, with the greatest changes in pain intensity (-35.19%, P < 0.001), physical function (+29.13%, P < 0.001), and pain interference (-28.8%, P < 0.001). Between the 0 and 3 month mark, the greatest significant changes were recorded in pain intensity (-26.5%, P < 0.001), physical function (+24.3%, P < 0.001), and anxiety (-16.9%, P < 0.018). However, scores plateaued after the 3-month mark, with zero categories showing significant changes with subsequent consecutive recordings.
PROMIS-29 scores demonstrated notable improvements in ASD patients particularly in pain intensity, pain interference, and physical function. However, scores plateaued beyond the 3-month mark, suggesting PROMIS-29\'s limited sensitivity to nuanced changes in long-term patient recovery. Future investigations exploring optimal combinations of patient reported outcome measures for comprehensive short- and long-term outcome assessments in ASD surgery would be beneficial.

Proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) are challenging complications of long fusion constructs for the treatment of adult spinal deformity. The objective of this study is to understand the biomechanical stresses proximal to the upper instrumentation of a T10-pelvis fusion in a large patient cohort. The pre-fusion models were subject-specific thoracolumbar spine models that incorporate the height, weight, spine curvature, and muscle morphology of 250 individuals from the Framingham Heart Study Multidetector CT Study. To create post-fusion models, the subject-specific models were further modified to eliminate motion between the intervertebral joints from T10 to the pelvis. OpenSim analysis tools were used to calculate the medial lateral shear force, anterior posterior shear force, and compressive force on the T9 vertebra during the static postures. Differences between pre-fusion and post-fusion T9 biomechanics were consistent between increased segmental mobility and unchanged segmental mobility conditions. For all static postures, compression decreased (p < 0. 0005). Anterior-posterior shear force significantly increased (p < 0. 0005) during axial twist and significantly increased (p < 0. 0005) during trunk flexion. Medial lateral shear force significantly increased (p < 0. 0005) during axial twist. This computational study provided the first use of subject-specific models to investigate the biomechanics of long spinal fusions. Patients undergoing T10-Pelvis fusion were predicted to have increased shear forces and decreased compressive force at the T9 vertebra, independent of change in segmental mobility. The computational model shows potential for the investigation of spinal fusion biomechanics to reduce the risk of PJK or PJF.

BACKGROUND: Spinal measurements play an integral role in surgical planning for a variety of spine procedures. Full-length imaging eliminates distortions that can occur with stitched images. However, these images take radiologists significantly longer to read than conventional radiographs. Artificial intelligence (AI) image analysis software that can make such measurements quickly and reliably would be advantageous to surgeons, radiologists, and the entire health system.
METHODS: Institutional Review Board approval was obtained for this study. Preoperative full-length standing anterior-posterior and lateral radiographs of patients that were previously measured by fellowship-trained spine surgeons at our institution were obtained. The measurements included lumbar lordosis (LL), greatest coronal Cobb angle (GCC), pelvic incidence (PI), coronal balance (CB), and T1-pelvic angle (T1PA). Inter-rater intra-class correlation (ICC) values were calculated based on an overlapping sample of 10 patients measured by surgeons. Full-length standing radiographs of an additional 100 patients were provided for AI software training. The AI algorithm then measured the radiographs and ICC values were calculated.
RESULTS: ICC values for inter-rater reliability between surgeons were excellent and calculated to 0.97 for LL (95% CI 0.88-0.99), 0.78 (0.33-0.94) for GCC, 0.86 (0.55-0.96) for PI, 0.99 for CB (0.93-0.99), and 0.95 for T1PA (0.82-0.99). The algorithm computed the five selected parameters with ICC values between 0.70 and 0.94, indicating excellent reliability. Exemplary for the comparison of AI and surgeons, the ICC for LL was 0.88 (95% CI 0.83-0.92) and 0.93 for CB (0.90-0.95). GCC, PI, and T1PA could be determined with ICC values of 0.81 (0.69-0.87), 0.70 (0.60-0.78), and 0.94 (0.91-0.96) respectively.
CONCLUSIONS: The AI algorithm presented here demonstrates excellent reliability for most of the parameters and good reliability for PI, with ICC values corresponding to measurements conducted by experienced surgeons. In future, it may facilitate the analysis of large data sets and aid physicians in diagnostics, pre-operative planning, and post-operative quality control.

OBJECTIVE: To assess the characteristics and risk factors for decisional regret following corrective adult spinal deformity (ASD) surgery at our hospital.
METHODS: This is a retrospective cohort study of a single-surgeon ASD database. Adult patients (> 40 years) who underwent ASD surgery from May 2016 to December 2020 with minimum 2-year follow-up were included (posterior-only, ≥ 4 levels fused to the pelvis) (n = 120). Ottawa decision regret questionnaires, a validated and reliable 5-item Likert scale, were sent to patients postoperatively. Regret scores were defined as (1) low regret: 0-39 (2) medium to high regret: 40-100. Risk factors for medium or high decisional regret were identified using multivariate models.
RESULTS: Ninety patients were successfully contacted and 77 patients consented to participate. Nonparticipants were older, had a higher incidence of anxiety, and higher ASA class. There were 7 patients that reported medium or high decisional regret (9%). Ninety percentage of patients believed that surgery was the right decision, 86% believed that surgery was a wise choice, and 87% would do it again. 8% of patients regretted the surgery and 14% believed that surgery did them harm. 88% of patients felt better after surgery. On multivariate analysis, revision fusion surgery was independently associated with an increased risk of medium or high decisional regret (adjusted odds ratio: 6.000, 95% confidence interval: 1.074-33.534, p = 0.041).
CONCLUSIONS: At our institution, we found a 9% incidence of decisional regret. Revision fusion was associated with increased decisional regret. Estimates for decisional regret should be based on single-institution experiences given differences in patient populations.

BACKGROUND: Treating osteoporosis in patients with a distal radius fracture (DRF) became paramount at the Fracture Liaison Service. Spinal sagittal imbalance emerged as a risk factor for subsequent fractures. Therefore, here we investigated the spinal profile of patients with DRF to investigate its association with a history of falls and prevalent vertebral fractures.
METHODS: We reviewed the cases of 162 women presenting with DRF and 162 age-matched women without fracture who underwent an osteoporosis evaluation including bone mineral density (BMD) and lateral spine imaging. We compared the incidence of prevalent vertebral fracture and sagittal vertical axis (SVA) to measure spinal sagittal imbalance. We also performed a regression analysis of the risks of prevalent vertebral fracture, such as age, body mass index (BMI), BMD, and SVA.
RESULTS: The SVA was significantly smaller (indicating more stable sagittal balance) in patients with a DRF versus controls (16 mm vs. 34 mm, respectively; p<0.001). The incidence of a prevalent vertebral fracture was similar between groups (12% vs. 15%, respectively; p=0.332). In both groups, the SVA was significantly greater in those with versus without a vertebral fracture. The vertebral fracture was significantly associated with age and SVA but not BMI or spinal BMD.
CONCLUSIONS: Spinal sagittal balance was superior in DRF patients, yet the frequency of prevalent vertebral fractures was similar. The identification of this unique spinal profile in patients with DRF may increase our understanding of osteoporotic fractures.

Neck pain (NP) is a common musculoskeletal disorder among fighter pilots and has become a rising concern due to its detrimental impact on military combat effectiveness. The occurrence of NP is influenced by a variety of factors, but less attention has been paid to the association of NP with demographic, occupational, and cervical sagittal characteristics in this group. This study aimed to investigate the prevalence and risk factors of NP in Chinese male fighter pilots using a questionnaire and cervical sagittal measurements.
Demographic and flight-related data, as well as musculoskeletal pain information, were gathered from Chinese male fighter pilots via a self-report questionnaire. Cervical sagittal parameters were measured and subtypes were classified using standardized lateral cervical radiographs. Differences in various factors between the case and control groups were analyzed using t-tests or chi-square tests. Binary logistic regressions were conducted to explore potential risk factors contributing to NP. Predictors were presented as crude odds ratios (CORs) and adjusted odds ratios (AORs), along with their respective 95% confidence intervals (CIs).
A total of 185 male fighter pilots were included in this cross-sectional study. Among them, 96 (51.9%) reported experiencing NP within the previous 12 months. The multivariate regression analysis revealed that continuous flight training (AOR: 4.695, 95% CI: 2.226-9.901, p < 0.001), shoulder pain (AOR: 11.891, 95% CI: 4.671-30.268, p < 0.001), and low back pain (AOR: 3.452, 95% CI: 1.600-7.446, p = 0.002) were significantly associated with NP.
The high 12-month prevalence of NP among Chinese male fighter pilots confirms the existence of this growing problem. Continuous flight training, shoulder pain, and low back pain have significant negative effects on pilots\' neck health. Effective strategies are necessary to establish appropriate training schedules to reduce NP, and a more holistic perspective on musculoskeletal protection is needed. Given that spinal integrated balance and compensatory mechanisms may maintain individuals in a subclinical state, predicting the incidence of NP in fighter pilots based solely on sagittal characteristics in the cervical region may be inadequate.

Increasing body anthropometry brings substantial spinal stress, which influences the spinal curvatures; this in turn may affect the foot plantar pressure distribution.
This study investigated the impact of body anthropometry on static plantar pressure distribution and their relationship among handball players and non-athletes subjects.
Thirty handball players aged from 21 to 26 years, and thirty age-matched non-athletes subjects aged from 21 to 28 years participated in this study. The spinal lordosis and kyphosis angles, trunk length, pelvic tilting, and pelvic rotation were evaluated using Formetric 4-dimensions and the Pedoscan device was used to assess the plantar pressure distribution.
The handball players were significantly taller, heavier, and have a long trunk length than non-athletes group (p < 0.05), and a significantly increased thoracic kyphosis, forefeet pressure distribution compared to non-athletes group (p < 0.05). The handball players had a significantly increased forefeet pressure distribution compared to the rearfeet pressure distribution (p < 0.05), a high positive correlation between body height, and both trunk length and kyphosis angle (r = 0.932, 0.665 respectively), and the body height showed a high positive correlation with the forefeet pressure distribution (r = 0.665). There was a high positive correlation between the handball players\' thoracic kyphosis and forefeet pressure distribution (r = 0.751).
Increasing the handball players\' body height was related to increased thoracic kyphosis and forefeet pressure distribution compared to non-athletes subjects. Additionally, the kyphotic posture of handball players is associated with increasing the total forefeet pressure distribution compared to the total rearfeet pressure distribution.