Helgeson, Melvin D.

Study Design: Retrospective. Objective: To examine the long-term perioperative changes in lumbar bone quality, paraspinal muscle size and fat content, and facet degeneration after hemipelvectomy (HP) and hip disarticulation (HD). Summary of Background Data: Emerging evidence shows that transfemoral (TFA) and transtibial (TTA) amputations may accelerate lumbar modic changes and precipitate axial back pain. TFA and TTA amputation studies demonstrate that the severity of postamputation lower back pain is associated with the amputation type (TFA > TTA) and the degree of alteration in lumbopelvic kinematics. Methods: All patients who underwent HP or HD for malignancy or infection at an academic center between 2003 and 2022 were retrospectively identified. Preoperative to postoperative changes in multifidus, erector spinae, quadratus lumborum, and psoas cross-sectional area (CSA), and Hounsfield units (HU) were calculated on CT for the amputated and contralateral side at the level of the L3–4 disc space. Paired univariate analysis was utilized to compare preoperative and postoperative outcomes. Results: A total of 16 patients (8 HP, 8 HD) met the inclusion/exclusion criteria. The preoperative to postoperative changes in HUs in the L1, L3, and L5 vertebral bodies were −27.0 ( P =0.004), −51.5 ( P =0.002), and −48.1 ( P =0.001), respectively. The decrease in L1 HU was greater for prosthesis nonusers (user: −16.50, nonuser: −51.32, P =0.021). L5–S1 segment facet degeneration increased postoperatively ( P =0.030, n=7 progressed). There were significant preoperative to postoperative changes in psoas CSA (preop: 1063.4, postop: 586.5, P =0.005) and psoas HU (preop: 50.95, postop: 33.55, P <0.001) on the amputated but not the contralateral side. Conclusion: Hind-quarter amputations were associated with decreased lumbar bone quality, progression of facet degeneration, and loss of amputated side psoas muscle tone. Daily prosthesis use was moderately protective for lumbar bone quality following amputation. HP but not HD was associated with postoperative loss of amputated side quadratus lumborum tone. Level of Evidence: Level III.

OBJECTIVE Multisegmental pathological autofusion is a hallmark feature of ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH), creating a rigid, brittle spine highly susceptible to three-column fractures and devastating neurological injury. This study aimed to evaluate survival outcomes in this patient population and identify clinical and demographic predictors of mortality. METHODS Adults with DISH or AS who sustained a fracture and were admitted to a single tertiary care center for spinal fracture were retrospectively identified using ICD-10 diagnostic codes. Data were extracted on demographics, clinical presentation, fracture characteristics, and details of treatment. RESULTS A total of 383 patients (median age 78 years, 75.2% male) were included. Over a median follow-up of 17.3 months, overall mortality was 38.1%, in-hospital mortality was 5.2%, 30-day mortality was 5.7%, and 1-year mortality was 18.0%. Initial treatment consisted of external orthosis in 220 (57.4%) and surgery in 144 (37.6%), while 19 (5.0%) were left untreated. Patients who died were older (median 83 vs 74 years, p < 0.001), had a lower BMI (29.4 vs 32.3 kg/m 2 , p < 0.001), had higher frailty on the 5-item modified frailty index (mFI-5), and more commonly had congestive heart failure (CHF), cancer, functional dependency, and chronic kidney disease (CKD) (all p < 0.01). Mortality was not associated with fracture location, mechanism of injury, fracture number, or the presence of neurological deficits. Univariable time-to-event analysis showed that decreased survival was predicted by older age (HR 1.08, p < 0.0001), lower BMI (HR per kg/m 2 0.93, p < 0.0001), functional dependency (HR 2.05, p < 0.001), cancer (HR 1.55 p = 0.01), CKD (HR 1.48, p = 0.019), CHF (HR 2.18, p < 0.001), and higher mFI-5 score (HR per point 1.34, p < 0.001). On multivariable analysis, older age (HR 1.06 per year, p < 0.001), lower BMI (HR per kg/m 2 0.95, p < 0.001), and mFI-5 score (HR per patient 1.37, p < 0.001) remained significant independent predictors of mortality. Treatment modality did not predict mortality. CONCLUSIONS AS- or DISH-associated spinal fractures have a high associated mortality, regardless of mechanism or severity. Treatment modality did not affect odds of survival, suggesting that nonoperative management with an external orthosis may be an appropriate option, particularly in older and medically complex patients.

Background/Objectives: To identify predictors of successful fusion and adjacent segment disease (ASD) following ALIF. Methods: Records of patients undergoing one- or two-level ALIF were queried for baseline and postoperative radiographic data, demographics, operative notes, and implant characteristics. All had ≥1 year of follow-up with CT, and multivariable Cox regression was used to identify predictors of radiographic fusion through the interbody, ASD, and ASD requiring reoperation. Results: In total, 177 patients (median 59 yr; 52.5% male) were treated at 245 unique levels, of which 193 fused (81.3% with posterior fixation and 59.6% with standalone), 43 had ASD (17.6%), and 14 had ASD requiring reoperation (5.7%). Fusion was predicted by anterior cage placement (HR 0.94/mm; 95% CI [0.90, 0.98]; p = 0.003) and BMP use (HR 1.92; [1.15, 3.18]; p = 0.012). Radiographic ASD was predicted by older age (HR 1.08 per year; [1.03, 1.14]; p < 0.001), undergoing a revision [vs. index] fusion operation (HR 3.51; [1.44; 8.59]; p = 0.006), lower preoperative disc height (HR 0.83/mm; [0.74, 0.94]; p = 0.003), and preoperative facet vacuum phenomenon (HR 2.46; [1.18, 5.15]; p = 0.017). None of the extracted variables predicted reoperation for ASD. Conclusions: BMP use along with anterior cage placement and posterior fixation may improve the odds of fusion through the interbody following one- or two-level ALIF. Adjacent segment pathology is more common in patients with greater preoperative degenerative pathology (vacuum sign; more collapsed disc) and advanced age. Pelvic fixation did not improve fusion odds, but the data highlight the benefits of supplementary posterior fixation vs. standalone ALIF.

Background: Successful applications of artificial intelligence (AI) in healthcare have increased interest in how it could be integrated into orthopaedic surgery. However, orthopaedics surgeons’ current use of AI and attitudes toward its incorporation remain largely unexplored. The 2025 American British Canadian Travelling Fellowship Survey on AI in Orthopaedic Surgery aimed to assess AI use, knowledge, training, and attitudes among orthopaedic surgeons. Methods: The survey was administered from May 7 to September 4, 2025 to orthopaedic surgeons across Australia, New Zealand, the United Kingdom, and North America. Questions addressed demographics, AI training and use, and attitudes toward AI. Descriptive statistics summarized responses, chi-square tests compared AI use by geography and attitudes by career stage, and linear regression explored associations between demographics, AI behaviors, and outlook on AI. Results: Among 350 participants, most were trainees (45.1%) and from North America (42.9%). AI use exceeded training, and 79.9% rated their AI knowledge as average or poor. Trainees reported significantly more favorable attitudes toward AI than late-career respondents. Higher self-rated AI knowledge and AI use in clinical and research settings were associated with a more positive outlook on the future of AI in orthopaedics. Conclusions: These findings highlight the need for formal AI education, as use is widespread despite limited training, particularly among later-career surgeons. Future studies should reduce self-selection and career-stage imbalance and include additional demographic variables to improve generalizability. Level of Evidence: III . See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND AND OBJECTIVES: Anterior lumbar interbody fusion (ALIF) is a powerful procedure for sagittal correction and indirect decompression in the lumbar spine, though aggressive correction can cause stretch neuropraxia and implant subsidence. The aim of this study was to identify radiographic and clinical predictors of segmental correction, as well as to evaluate the degree to which segmental correction on supine intraoperative radiographs translates to postoperative upright alignment changes. METHODS: We identified patients treated with 1- or 2-level ALIF at a tertiary care center and extracted data on demographics, spinopelvic parameters, and surgical details. Patients treated with isolated ALIF and ALIF with supplementary posterior instrumentation were compared on pre- and postoperative intradiscal lordosis (IDL) and change in IDL. Multivariable linear regression was performed to identify independent predictors of postoperative IDL. RESULTS: We included 204 patients (median age 57 years, 55.4% male) treated at 258 levels, of whom 114 (55.9%) underwent supplementary posterior fixation and 150 (73.5%) underwent single-level implantation. Across all patients, postoperative IDL was significantly greater than preoperative segmental lordosis (25.4° vs 15.3°; P < .001). Standalone ALIF achieved less ΔIDL than circumferential fusion for L5/S1 procedures (7.4° vs 11.6°; P < .001), though ΔIDL for L3/4 and L4/5 was similar between the standalone and circumferential groups. Multivariable analysis showed postoperative IDL to be predicted by greater preoperative IDL (β = 0.26° per degree; [0.15, 0.36]; P < .001), L5/S1 [vs L4/5] implantation (β = 3.97°; [2.72, 5.21]; P < .001), use of supplementary posterior fixation (β = 1.80°; [0.70, 2.89]; P < .001), and greater implant lordosis (β = 0.62° per degree; [0.44, 0.79]; P < .001). CONCLUSION: Postoperative IDL after 1- or 2-level ALIF is best predicted by placement of larger interbody sizes, L5/S1 implantation, greater baseline IDL, and use of adjunct posterior fixation. Patients with higher preoperative lordosis experienced smaller postoperative increases in IDL, though this was likely influenced by a treatment bias.

The future of space exploration will include a prolonged presence on the Moon, commercial low-orbit spaceflight, and long-range missions to Deep Space, including a prolonged Martian presence. Understanding the effects the space environment will have on astronauts’ musculoskeletal system is mission critical and include both microgravity and space radiation. In spaceflight, crewmembers are exposed to a vast mixture of radiation species and energies including cosmic rays (CR) from galactic cosmic radiation (GCR), solar ejections, and neutrons. Any trip beyond the protection of the Earth’s electromagnetic field will expose astronauts to the near-maximum levels of lifetime allowable radiation exposure. We have previously reviewed how microgravity induces pathophysiological adaptations in the spine and how countermeasure strategies can play a role in minimizing astronaut morbidity. Now, through the National Aeronautics and Space Administration’s (NASA) Human Research Roadmap (HRR), there is a renewed interest in characterizing and mitigating the effects of radiation as astronauts prepare for the Artemis missions and beyond. Thus, our aim in this critical narrative review is to focus on how the second greatest challenge to crewmembers’ health, radiation, and identify how potential countermeasures will affect the spine.

OBJECTIVE Glucagon-like peptide-1 (GLP-1) agonists are established therapeutics for weight loss that are increasingly used for BMI optimization prior to spine surgery. However, emerging evidence has suggested that GLP-1 agonists might reduce bone mineral density (BMD), increasing the risk of postoperative biomechanical complications. CT-based Hounsfield units (HUs) have gained popularity as a method for measuring spinal BMD. The aim of this study was to evaluate the effects of GLP-1 agonist–induced weight loss on spinal BMD as measured by opportunistic CT-based HUs. METHODS Patients who were treated with any GLP-1 agonist (2017–2022) for > 3 months were retrospectively identified. Patient body weight (BW), BMI, and HU measurements in the L1 vertebral body were measured before and after GLP-1 therapy. Patients were grouped according to the percentage of weight loss during GLP-1 therapy. One-way ANOVA was used to compare the mean changes in spinal HUs across the groups. RESULTS Among the 102 included patients, the mean ± standard error of the mean BW reduction was 14.5 ± 2.5 kg over 15.9 ± 1.2 months of GLP-1 agonist therapy. Of these, 7 patients (6.9%) lost > 20% BW (mean decrease of 31.9 ± 7.0 HU, p = 0.011), 14 (13.7%) lost 15%–20% BW (mean decrease of 19.1 ± 8.3 HU, p = 0.038), 14 (13.7%) lost 10%–15% BW (mean decrease of 12.2 ± 5.1 HU, p = 0.036), 24 (23.5%) lost 5%–10% BW (mean decrease of 15.7 ± 3.3 HU, p < 0.0001), 26 (25.5%) lost < 5% BW (mean decrease of 14.7 ± 6.0 HU, p = 0.022), and 17 (16.7%) gained BW during GLP-1 therapy (mean decrease of 6.3 ± 5.0 HU, p = 0.229). One-way ANOVA testing did not show a significant difference in HU reduction across the weight loss groups (F = 1.12, p = 0.355). In addition, there was a significant correlation between the decrease in L1 HUs and the duration of GLP-1 therapy (r = −0.38, p = 0.0001) but not the amount of weight loss (r = −0.18, p = 0.070). In the multivariate analysis, the duration of GLP-1 therapy (p = 0.032) was a significant independent predictor of vertebral HU reduction, but the amount of weight loss (p = 0.664) was not. CONCLUSIONS Despite similar pretreatment BW and HU measurements, all weight loss groups had significant decreases in vertebral HUs following GLP-1 agonist therapy, with a significant correlation observed between HU reduction and treatment duration. This suggests that long-term GLP-1 agonist therapy can significantly diminish spinal BMD regardless of the amount of weight loss achieved.

Background: Scoliosis has various etiologies, ranging from idiopathic, congenital, to those with spinal cord abnormalities. Advanced imaging is not always feasible and limited by cost, low-yield, and anesthesia risks in children. Given artificial intelligence's potential, we hypothesize that a deep learning (DL)–based image classifier will demonstrate superior performance in radiographic classification of scoliosis etiology compared witht experienced spine surgeons based on spine radiographs. Methods: One thousand thirty-six pediatric patients from single institution with scoliosis diagnosis and paired anterior-posterior - lateral images were included. Patients were manually classified based on their scoliosis etiology from chart review, including previous spine imaging studies when available. Categories included idiopathic, congenital, and spinal cord pathology. Images were randomized and assigned for training, validation, and testing. A DL-classifier using EfficientNet B4 architecture was trained on the radiographs. Accuracy and positive predictive value as defined by precision, recall, and F1-score were calculated to assess final performance metrics. Results: The trained classifier performed well at identifying correct etiologies, with F1-Score (harmonic mean of precision-recall) of 0.97. Model precision was 0.99 for adolescent idiopathic scoliosis, 0.89 for congenital, and 0.78 for spinal cord pathology. Performance was higher on more common classes, with lower performance observed in class with fewer images. The algorithm has highest overall precision (0.96), recall (0.96), and F1 (0.96), while Surgeons 1 and 2 have lower accuracies (precision 0.80, recall 0.79, and F1 0.79 and precision 0.76, recall 0.67, and F10.71, respectively). There was no clear pattern identified regarding the surgeons' errors and poor agreement on which X-rays corresponded to underlying spinal cord pathology. Conclusion: A DL-convolutional-neural-network classifier has been trained to high degree of accuracy to distinguish between 3 scoliosis etiologies on pediatric spine radiographs. This model could provide a novel tool to clinicians to decide when to refer for axial imaging. It had superior diagnostic performance compared with experienced spine surgeons. After further validation and refinement, a clinician could put a patient's X-rays into the predictive tool for analysis and use the results to discuss with the family the risk of finding spinal cord pathology, helping them determine together the best timing for an MRI. Level of Evidence: Level III . See Instructions for Authors for a complete description of levels of evidence.

Introduction: Bone health optimization is a key component of the preoperative management of spine surgery patients, as poor bone quality increases the odds of mechanical complications. The present study aimed to achieve the following: (1) compare the relative efficacy of current osteoporosis medications in improving bone quality; (2) identify factors influencing treatment response in preoperative spine surgery patients. Methods: Patients treated at a single, multisite institution who received osteoporosis treatment were identified. Data were gathered on pre- and post-treatment lumbar spine Hounsfield Unit (HU) measurements, patient demographics, frailty scores (modified Frailty Index/mFI, risk analysis index/RAI), and pharmacologic treatment details. The primary outcome was a ≥7 point improvement in lumbar HU, and baseline and logistic regression models were utilized to identify factors associated with this improvement. Medications were grouped as anabolic (teriparatide, romosozumab) and antiresorptive (denosumab, alendronate) therapies. Results: A total of 267 patients were included (median age: 74 years; IQR [66–81]; 67.3% female), with 127 (47.6%) improving by ≥7 HU. The treatment agents used were alendronate (95), denosumab (113), romosozumab (31), and teriparatide (28). Univariable comparisons revealed significant differences across medication groups in age (p < 0.001), sex (p < 0.001), mFI (p < 0.001), RAI (p = 0.004), BMI (p < 0.001), pre-treatment HU (p = 0.022), and treatment duration (p < 0.001). The highest HU improvement rates (ΔHU ≥ 7) were observed in patients receiving the anabolic medications romosozumab (67.7%) and teriparatide (60.7%). Univariable logistic regression identified male sex (OR 0.54, p = 0.019), higher pre-treatment HU (OR 0.99, p = 0.006), and longer treatment duration (OR 0.97, p = 0.003) as factors associated with lower odds of HU improvement. Only romosozumab was associated with significantly higher odds of HU improvement relative to alendronate (OR 3.02, p = 0.012). In our multivariable analysis, male sex (OR 0.53, p = 0.028) and higher pre-treatment HU (OR 0.99, p = 0.002) remained significant predictors of HU improvement. However, medication type was not significant in the multivariable analysis. Conclusions: Our study highlights that male sex and higher pre-treatment HU were independently associated with lower odds of HU improvement, while medication type was not a significant predictor. Additionally, anabolic agents offered superior improvement relative to antiresorptive therapies.

BACKGROUND Degenerative cervical myelopathy (DCM) is the most common cause of adult spinal cord dysfunction. Tourette syndrome (TS) represents a rare cause of DCM that is incompletely characterized in the literature. Patients with TS might develop repetitive involuntary cervical movements that can accelerate spondylotic changes. Therefore, patients with myelopathy secondary to TS or other tic disorders might exhibit DCM symptoms at younger ages. The present study examines the surgical management of DCM secondary to TS in the literature and describes the outcomes of 3 patients who were treated for DCM secondary to TS. OBSERVATIONS In these 3 described cases, fractures led to DCM in 2 patients, while cervical spondylosis led to DCM in 1 patient, all associated with TS. Treating motor tics with medications or deep brain stimulation (DBS) provided effective tic management. All 3 patients experienced improvements in their neurological symptoms following surgery, consistent with other reports in the literature. LESSONS When treating patients with cervical myelopathy secondary to TS, the authors recommend prioritizing motor tic management prior to considering secondary interventions such as surgery. According to the authors, treating motor tics with medications or DBS provides effective tic management. This approach allows for an uncomplicated postoperative course and satisfactory relief of cervical myelopathy. https://thejns.org/doi/10.3171/CASE24751