Nassr, Ahmad

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: C5 palsy is a known complication following decompressive cervical spine surgery, most often attributed to factors such as foraminal stenosis, cord drift, or traction. While its incidence after cervical procedures is well-documented, C5 palsy occurring after thoracolumbar deformity surgery has not been previously described. Case: A 70-year-old woman with a prior C2-T4 posterior cervical spinal fusion underwent thoracolumbar deformity correction with T4-pelvis fusion. Two months postoperatively, she developed sudden right deltoid and biceps weakness. Laboratory and imaging workups ruled out other pathological causes, and electromyography confirmed a new C5 palsy. She was treated with physical therapy and electrical stimulation and achieved complete recovery by 6 months post-thoracolumbar surgery. Conclusion: This case describes isolated delayed C5 palsy following thoracolumbar deformity surgery in a patient with prior cervical spine fusion 2 years earlier. Potential contributing factors include global alignment changes, altered neural tension, and intrinsic anatomic fragility of the C5 nerve root. This presentation expands the clinical context of postoperative C5 palsy and highlights the importance of monitoring for cervical neurologic deficits, even in the absence of cervical intervention. Level of Evidence: 5 – Case Report

OBJECTIVE The optimal surgical treatment for lumbar spinal stenosis (LSS) with degenerative spondylolisthesis (DS) remains controversial. Posterior lumbar facet arthroplasty preserves motion after decompression and may address some of the limitations of fusion techniques. The Total Posterior Spine System (TOPS) investigational device exemption trial compared decompression with facet arthroplasty to decompression plus fusion (open with interbody). This study reports the 3-year outcomes from this trial. METHODS This randomized, controlled, multicenter trial enrolled 321 patients with LSS and grade I DS across 37 sites (2:1 randomization of arthroplasty to fusion). Eligible patients were 35–80 years old, had failed ≥ 6 months of nonsurgical treatment, and met thresholds for disability and leg pain. The primary endpoint was a composite clinical success score at 36 months, defined by four criteria: 1) no reoperation or lumbar injection, 2) no major device adverse events, 3) ≥ 15-point improvement in the Oswestry Disability Index (ODI), and 4) no new/progressive neurological deficit. Secondary outcomes included the ODI score, visual analog scale (VAS) scores for back and leg pain, the Zurich Claudication Questionnaire (ZCQ), device-related adverse events, and reoperations. RESULTS One hundred seventy-nine patients in the arthroplasty (TOPS) group and 74 in the fusion group were eligible for the 36-month analysis. The composite clinical success achievement rate was significantly higher in the arthroplasty group (76.0%) than in the fusion group (56.8%; p = 0.0038). The rate of reoperation or lumbar injection was significantly lower for the arthroplasty group (14.0%) compared to the fusion group (25.3%; p = 0.0222). Arthroplasty was associated with a significantly higher minimal clinically important difference (MCID) achievement rate for VAS back pain score compared with fusion (85.2% vs 72.2%; p = 0.041). Although there was no significant difference in ODI score, VAS leg pain score, or ZCQ component scores between groups, the arthroplasty group trended toward higher MCID achievement rates across all patient-reported outcome measures. There was no significant difference in reoperation failure rates between groups (5.8% for arthroplasty vs 9.5% for fusion; p = 0.329). CONCLUSIONS Decompression and dynamic stabilization with lumbar facet arthroplasty was associated with statistically significantly superior clinical outcomes and lower rates of secondary invasive procedures, including reoperations and injections, compared with decompression and fusion. Long-term follow-up is critical in defining the role of lumbar facet arthroplasty for the treatment of DS.

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.

Study Design: Retrospective cohort. Objective: This study aims to assess the effects of CT-based subsidence on lumbar sagittal alignment and patient-reported outcome measures (PROMs) after transforaminal lumbar interbody fusion (TLIF), and to determine if subsidence and cage properties are independent predictors of postoperative changes in regional lordosis. Summary of Background Data: Subsidence is a well-known complication following interbody fusion and has previously been associated with recurrence of preoperative symptoms and higher reoperation rates. There is incomplete evidence to characterize the effects of subsidence on lumbar alignment and PROMs following TLIF. Methods: All adult patients who underwent 1- or 2-level TLIF at a multi-institutional academic center between 2017 and 2019 were retrospectively identified. Interbody subsidence at the superior and inferior endplate of each TLIF level was directly measured on both coronal and sagittal CT scans obtained between 6 months and 1 year postoperatively. Patients were grouped based on the maximum subsidence at each operative level: mild-moderate (<4 mm) or severe (≥4 mm). Preoperative, immediate (<3 mo), and intermediate (>6 mo) postoperative radiographic outcomes (local and global lumbar alignment) and PROMs (VAS Back, Oswestry Disability Index, PROMIS Physical Function and Mood) were collected. Univariate and multivariate analysis compared patient demographics, surgical factors, and changes in radiographic measures and PROMs across subsidence groups. Multiple linear regression analyzed independent effects of subsidence and cage characteristics on alignment. Results: Sixty-seven patients with 85 unique fusion levels were included (55 with mild-moderate subsidence, 30 with severe subsidence). Levels with severe subsidence demonstrated significantly less regional lordosis at final follow-up than nonseverely subsided levels (6.4 vs. 9.1 degrees, P =0.032). No PROM significantly differed between severe and nonsevere subsidence subgroups. Linear regression analysis revealed that severe subsidence was a strong independent predictor of regional lordosis ( P =0.029) at final follow-up. Conclusions: Severe subsidence negates perioperative improvements in regional lordosis following TLIF, while changes in regional alignment are maintained in the absence of severe subsidence. Level of Evidence: Level III.

Abstract Background Native vertebral osteomyelitis (NVO) is a life-threatening spinal infection with rising incidence and significant morbidity. Despite its growing burden, long-term data on clinical characteristics, management trends, and outcomes remain limited. Methods We conducted a 26-year multicenter retrospective cohort study of adults (≥18 years) diagnosed with NVO at Mayo Clinic sites between 1999 and 2024. Demographic, microbiologic, treatment, and outcome data were analyzed across five time periods. Predictors of treatment failure were assessed using a multivariable competing risk model. Results Among 1255 patients (median age 67; 66% male), lumbosacral involvement was most common (65%), and 21% had multilevel involvement. Pathogens were identified in 77%, most commonly Staphylococcus aureus (49%; Methicillin-susceptible S. aureus 37%, methicillin-resistant S. aureus 13%). Over time from 1999–2004 to 2020–2024, Gram-negative bacilli increased from 6% to 14% (P = .048). Comorbidities including chronic kidney disease (10% to 21%), active chemotherapy (6% to 11%), and immunosuppression (8% to 17%) increased significantly. Additionally, 1-year treatment failure declined (16% to 10%). In multivariable analysis, diabetes mellitus (subdistribution hazard ratio [sHR] 1.92, 95% CI 1.18–3.13) and multilevel involvement (sHR 1.67, 95% CI 1.17–2.38) were associated with increased incidence of treatment failure, while concurrent infections (sHR 0.57, 95% CI 0.37–0.87) and higher Charlson Comorbidity Index (sHR 0.62, 95% CI 0.43–0.90) were associated with lower failure. Conclusions This large multicenter cohort highlights increasing host complexity, shifting microbiology, and predictors of failure, emphasizing the importance of early risk stratification and tailored strategies, such as multidisciplinary evaluation and close follow-up of high-risk patients to improve outcomes.

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.

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.

Study Design Retrospective cohort study of a national database. Objectives This study investigates the association between preoperative antidepressant use and postoperative opioid utilization as well as overall outcomes following primary anterior cervical fusion (ACF) and posterior cervical fusion (PCF). Methods We conducted parallel retrospective cohort analyses utilizing TriNetX for patients aged ≥18 years old with ≥2-year follow-up undergoing primary ACF and PCF between December 31, 2006, and December 31, 2022. Cohorts were thoroughly matched resulting in 4575 ACF and 3497 PCF pairs. Medical outcomes, opioid abuse, healthcare utilization, mechanical and surgical outcomes were assessed through risk ratios (RR), risk differences, P -values, and Kaplan-Meier analysis. Results Antidepressant use was associated with increased new opioid prescriptions from 2 weeks to 2 years (ACF RR 1.090-1.130, P < 0.001; PCF RR 1.060-1.078, P < 0.001), higher hospital readmissions (RR 1.484, P < 0.001), prolonged inpatient stays (RR 1.329, P < 0.001), and ED visits from 6 weeks to 2 years (ACF RR 1.150-1.184, P < 0.001; PCF RR 1.092-1.144, P ≤ 0.034). Postoperative infections were elevated at 2 years (ACF RR 1.679-2.060, P ≤ 0.008; PCF RR 1.375-1.677, P ≤ 0.020). Opioid abuse was higher at 2 years (ACF RR 2.8000, P = 0.003; PCF RR 2.667, P = 0.001), and pulmonary embolism increased in ACF at 2 years (RR 1.633, P = 0.032). Reoperations were elevated at 1 and 2 years (RR 1.238-1.371, P ≤ 0.045), with reduced 2-year reoperation-free survival in ACF ( P = 0.001) and PCF ( P = 0.045). Conclusion Preoperative antidepressant use is associated with significantly increased risks of postoperative opioid utilization and both medical and surgical complications, including sepsis, infections, adjacent segment disease, and reoperations, up to 2 years after primary anterior or posterior cervical fusion.