Dean Chou

BACKGROUND AND OBJECTIVES: Minimally clinically important difference (MCID) defines the smallest difference in patient-reported outcomes (PROs) required for a level of clinical improvement. The hypothesis of this study is that at least one of the MCID thresholds in this study will provide appropriate MCID thresholds for the PROs in grade 2 spondylolisthesis. METHODS: This study used the Grade 2 Spondylolisthesis module of the Quality Outcomes Database Spine CORe ^® Study Group, which included 328 patients from 14 institutions. PROs collected include Oswestry Disability Index (ODI), Numeric Rating Scale (NRS) for back pain and leg pain, and European Quality of Life-5 Dimensions (EQ-5D). Seven MCID thresholds were calculated with North American Spine Society satisfaction scale as the anchor. Each method was evaluated using area under the curve, reflecting the ability to predict satisfaction. RESULTS: There were 328 patients with ≥80% 5-year follow-up. The optimal percentage cutoff method generally demonstrated the highest predictive accuracy for defining MCID in ODI, NRS back pain, and NRS leg pain, whereas the optimal numeric cutoff method generally demonstrated the highest predictive accuracy for EQ-5D. For ODI, 2-year optimal percentage cutoff was 30.4% and 5-year optimal percentage cutoff was 38.1%. For NRS back pain, 2-year optimal percentage cutoff was 75.0% and 5-year optimal percentage cutoff was 42.9%. For NRS leg pain, 2-year optimal percentage cutoff was 62.5% and 5-year optimal percentage cutoff was 66.6%. For EQ-5D, the optimal numeric cutoffs were 0.293 at 2 years and 0.128 at 5 years. CONCLUSION: Using satisfaction as an anchor, this study identified the optimal percentage cutoff as the most appropriate method for determining MCID in ODI and NRS pain scores, while the optimal numeric cutoff was most appropriate for EQ-5D in grade 2 spondylolisthesis. These findings provide reference definitions for evaluating postoperative improvement in this patient population.

BACKGROUND AND OBJECTIVES: Postoperative thoracolumbar (TL) realignment in patients with adult spinal deformity (ASD) may induce cervical spine (CS) decompensation. This study identifies predictors of CS decompensation after TL surgery and defines a baseline CS-alignment threshold based on C2-pelvic angle (C2-PA) for CS inclusion in the TL construct. METHODS: Patients with ASD undergoing TL fusion to the sacrum with an upper instrumented vertebrae at T2 or below and available baseline radiographs and patient-reported outcome measures (PROMs) were included. CS decompensation was defined as CS surgery or >2 SD above the mean in C2-PA, cervical sagittal vertical axis (cSVA), or T1-slope cervical lordosis (TS-CL) at the studied postoperative time point. RESULTS: One thousand one hundred ninety patients were included; 166 (13.9%) had CS decompensation after TL surgery, including 24 (2.0%) requiring CS extension. CS decompensation was identified in 81 patients (6.8%) at 6 weeks (4 (0.3%) extensions), 13 (1.2%) at 6 months (2 (0.2%)), 43 (3.9%) at 1 year (7 (0.6%)), and 29 (2.8%) at 2 years (11 (0.9%)). Patients with CS decompensation at 6 months showed worse global and CS alignment at 6 weeks (lumbar lordosis: 53.6 vs 46.3; cSVA: 30.5 vs 38.5; P < .05). CS decompensation at 1 year was associated with worse PROMs (physical component score: 39.0 vs 35.4; Scoliosis research society score: 3.6 vs 3.3; P < .05). CS decompensation at 2 years was associated with worse CS alignment at 1 year (TS-CL: 20.8 vs 28.6; cSVA: 31.1 vs 37.8) and worse PROMs at 2 years. Higher baseline C2-PA was associated with shorter time to CS decompensation. Cox modeling identified baseline C2-PA (hazard ratio [HR] 1.05, 95% CI, 1.03-1.06), TS-CL (HR 1.05, 95% CI, 1.03-1.06), surgical invasiveness (HR 0.99, 95% CI, 0.98-0.99), and upper thoracic instrumentation (HR 2.9, 95% CI, 1.8-4.7) as predictors of CS decompensation, with a C2-PA threshold of 26.2°. CONCLUSION: Two years after TL ASD surgery, 13.9% had CS decompensation, with 14% requiring CS extension. Baseline CS alignment independently predicted CS decompensation. Patients with preoperative C2-PA >26.2° may benefit from CS inclusion in the TL construct after external validation of this threshold by future research.

BACKGROUND AND OBJECTIVES: Many spinal imaging reports are written above recommended health literacy levels, limiting patient comprehension at a time when rapid electronic access to radiology results is increasing. We aim to evaluate whether supplemental natural language processing (NLP)–modified radiology reports—within the context of usual patient portal access to the original report—are associated with improved patient-reported perceived understandability compared with standard reports among patients undergoing spine imaging. METHODS: This is a prospective randomized controlled study with limited participant blinding, conducted with 2 spine surgeons affiliated with a single academic medical center in New York City. Participants (18 years or older) undergoing spine imaging at initial surgical consultation were enrolled and were randomized to receive either their original radiology report or a supplemental NLP–modified version. Radiology reports were rewritten using a standardized natural language processing prompt (ChatGPT 4.0) and reviewed for accuracy by study investigators. The primary outcome was survey-based patient-reported perceived understandability. Secondary outcomes included objective readability scores (Flesch-Kincaid Grade Level, Flesch Reading Ease, Simple Measure of Gobbledygook, Gunning-Fog Index). RESULTS: Fifty-two adults were enrolled; 42 (81%) completed the postintervention survey. Among 52 randomized participants (26 women [50%]), NLP–modified reports demonstrated significantly improved objective readability across all indices compared with original reports (Flesch-Kincaid Grade Level, 5.9 ± 1.1 vs 11.0 ± 1.7; Reading Ease, 71.0 ± 10.3 vs 28.2 ± 12.5; Simple Measure of Gobbledygook, 20.1 ± 12.7 vs 23.5 ± 15.7; Gunning-Fog Index, 8.2 ± 1.1 vs 14.3 ± 1.8; all P < .01). Of 42 survey respondents, those receiving supplemental NLP-modified reports reported greater ease of understanding the report language (4.2 ± 1.2 vs 2.6 ± 1.5, mean-difference 95% CI: 0.75-2.53, P < .01, Bonferroni-corrected- P = .02), and less difficulty with medical terms (2.0 ± 1.5 vs 3.6 ± 1.4, mean-difference 95% CI: −2.51 to −0.60, P < .01, Bonferroni-corrected- P = .04). CONCLUSION: Supplemental NLP-modified radiology reports were associated with improved objective readability and higher patient-reported perceived ease of understanding in a spine surgery initial consultation setting. These findings support further investigation of NLP-generated supplemental explanations within supervised clinical workflows.

BACKGROUND AND OBJECTIVES: Circumferential minimally invasive surgery (cMIS) techniques in adult spinal deformity (ASD) surgery may reduce physiological burden compared with open technique, but their utility in octogenarians has not been previously assessed. METHODS: Operative ASD patients aged 80 years or older with complete baseline (BL) and 2-year postoperative radiographic and health-related quality of life data were assessed and compared by surgical technique: open vs cMIS. Propensity score matching aligned groups by BL Charlson Comorbidity Index (CCI), C7-S1 sagittal vertical axis, pelvic incidence minus lumbar lordosis mismatch, and C7 plumb line. BL and peri/postoperative factors were assessed using analysis of variance and Bonferroni-adjusted analysis of covariance while controlling for BL CCI and posterior fusion length. RESULTS: Thirty-four octogenarian ASD patients met inclusion criteria, of whom 29.4% underwent cMIS and 70.6% underwent open correction. cMIS patients were less likely to require surgical intensive care unit (10% vs 75%, P < .001) and had shorter hospital stays (4.6 vs 10.1 days, P = .013). Open patients reported higher Scoliosis Research Society-22 Appearance and Mental domain scores (both P < .005) and more frequently reached minimal clinically important difference in both domains by 2 years ( P = .025, .024). cMIS patients more often required reoperation for radiographic sagittal imbalance by 2 years when controlling for CCI and levels fused (20.0% vs 8.3%, P < .001). No deaths occurred in either group by 2 years. CONCLUSION: In octogenarians undergoing ASD surgery, cMIS reduced physiological burden but had higher reoperation rates, whereas open surgery showed greater durability.

Study Design: Retrospective analysis of patients from the prospective Quality Outcomes Database Spine CORe ^® Spondylolisthesis cohort to assess the prevalence of sleep dysfunction and factors associated with improved sleep after surgery. Objective: To characterize the prevalence of sleep disruption and identify factors associated with improved sleep among patients undergoing surgery for Meyerding grade I degenerative lumbar spondylolisthesis. Summary of Background Data: Improved sleep after surgery for lumbar spinal stenosis has been reported in several studies but not in patients with spondylolisthesis. Methods: A total of 608 patients from the prospective Quality Outcomes Database Spine CORe ^® Spondylolisthesis cohort were retrospectively analyzed. Patients were included in this study if they responded to the sleep subitem of the Oswestry Disability Index (ODI) at baseline and 24-month follow-up. The level of sleep dysfunction was assessed and compared at baseline and 24-month follow-up using univariable and multivariable statistics. Results: Overall, 526 of the 608 patients met the inclusion criteria. At baseline, 455 patients (86.5%) had sleep disruption. At 24 months or greater, 325 patients (71.4% of the 455 impaired) had improved sleep, with 184 patients (40.4%) reporting no disruption of sleep postoperatively. In multivariable analyses, improvement in sleep was predicted by a higher baseline ODI (OR=1.01, 95% CI: 1.001–1.01, P P =0.002) and higher ASA grade (OR=1.15, 95% CI: 1.02–1.30, P =0.03) in the 65 years or younger cohort, while minimally invasive techniques (OR=1.14, 95% CI: 1.01–1.30, P =0.04) were significant in the 65 years of age or older cohort. Conclusion: Most patients (86.5%) presenting for surgery for low-grade degenerative spondylolisthesis have impaired sleep. However, 24 months after surgery, over 70% of patients with baseline dysfunction reported improvements with 40.4% reporting no sleep dysfunction.

Study Design.: Retrospective review of the prospectively enrolled, multicenter ASD database. Objective.: We sought to compare clinical and economic outcomes for ASD patients with poor-bone-health versus those with normal-bone-health. Summary of Background Data.: Osteoporosis is a common comorbidity in the adult spinal deformity (ASD) population, with a reported prevalence of 14-29%. Methods.: Patients were categorized into five guideline-concordant cohorts: Confirmed-Osteoporosis (COP: patients with osteopenia or osteoporosis based on DEXA values or a formal preoperative diagnosis); Fracture Osteoporosis (Fx: patients with fragility fractures); Fracture-without-confirmed-Osteoporosis (FXNO: patients with fragility fractures but no osteopenia/osteoporosis diagnosis based on DEXA/formal documentation); Confirmed/fracture-osteoporosis (COP/FX: patients with fragility fractures and/or osteopenia/osteoporosis by DEXA/diagnosis); and the Normal cohort (Nm: patients with normal bone health and no fragility fractures). Cost analyses were performed using multivariate linear regression controlling for BMI, diabetes, baseline deformity (T1PA), and levels fused. Multivariate logistic regression assessed risk of reoperation/complications between groups while controlling for BMI, diabetes, baseline deformity (T1PA), and levels fused. Results.: Overall, 205 patients were included in the Fx-cohort, 136 patients in the COP-cohort, 115 patients in the FXNO-cohort, and 71 patients Nm-cohort. Compared with the Nm-cohort, osteoporotic-cohorts demonstrated significantly worse baseline spinopelvic alignment and higher comorbidity burden. Fx and FXNO cohorts had higher rates of PJF (Fx: 11.2% vs 1.4%, aOR 7.8; FXNO: 10.4% vs 1.4%, aOR 9.0) and revision surgery (Fx: 19.5% vs 7.0%, aOR 2.8; FXNO: 22.6% vs 7.0%, aOR 3.6). Osteoporotic cohorts demonstrated significantly higher short-term QALYs at 6 weeks ( P <0.05) with no difference in the long term. Revision surgery averaged $95,117 per case, translating into an estimated $4.0 million potential-cost-savings. Conclusion.: Our findings highlight the clinical and economic burden of untreated poor bone quality in the setting of ASD surgery. Proactive medical management is crucial to mitigate complications, reduce revisions, and significantly lower healthcare costs in ASD surgery.

BACKGROUND: Patients with adjacent segment degeneration after previous lumbar fusion often present with flat back posture. However, it is sometimes unclear if the flat back results from stenosis above the fusion or from structural spinal deformity. The authors illustrate the case of a patient who refused further fusion and asked for decompression only coupled with posterior arthroplasty. They demonstrate his change in sagittal alignment despite absence of a three-column osteotomy. OBSERVATIONS: A 72-year-old man with a previous lumbar fusion presented with 1 year of progressive neurogenic claudication and radiculopathy. Imaging revealed flat back syndrome with positive sagittal balance and adjacent segment disease with severe stenosis at L2–3. The patient was recommended to undergo a three-column osteotomy, but he refused another fusion surgery. He requested decompression and posterior arthroplasty at L2–3, with the understanding that his flat back syndrome would not be treated. Following surgery, the patient’s preoperative symptoms improved, and, surprisingly, postoperative radiographs revealed a 6.7-cm improvement in sagittal balance. LESSONS: Alleviation of lumbar stenosis not only provided symptomatic relief but also improved this patient’s sagittal imbalance, illustrating the contribution of lumbar stenosis to sagittal imbalance. Laminectomy with total factectomies was facilitated by the posterior arthroplasty device, which prevented pathological motion despite the destabilizing decompressive procedure. https://thejns.org/doi/10.3171/CASE25565

Augmented reality (AR) is being increasingly integrated into spine surgery. However, most existing reviews predominantly focus on its use in instrumentation-based procedures. The broader role of AR in of non-instrumentation minimally invasive spine surgery (MISS), including decompression, endoscopic, and tubular techniques, has not been fully synthesized. This narrative review aims to bring together the current evidence on AR applications across the full range of MISS, with a particular focus on visualization- and workflow-critical non-instrumentation procedures, an area that has been underrepresented in prior reviews. A comprehensive literature search was conducted in PubMed, Embase, and the Cochrane Library for articles published between 2010 and 2025. Search terms included Medical Subject Headings (MeSH) and free-text keywords related to augmented reality, minimally invasive spine surgery, decompression, and navigation. Only peer-reviewed English-language articles were included. Study selection was performed independently by three reviewers, with discrepancies resolved by consensus. The review synthesizes AR applications across percutaneous procedures, tubular surgery, endoscopic spine surgery (ESS), microscopic surgery, and lateral approaches. The literature indicates that AR can enhance intraoperative visualization through in-situ image overlays, reduce visual attention shifts and cognitive workload, improve workflow efficiency, and lower radiation exposure. However, current evidence is largely derived from small-sample, single-center feasibility studies (levels IV–V evidence). Comparative analyses suggest AR is most valuable as a complementary visualization layer within multimodal navigation ecosystems rather than a standalone replacement. AR represents a promising adjunct in MISS, particularly for non-instrumentation procedures in which visualization is limited. To define its definitive clinical value, future research must prioritize workflow standardization, validation of performance metrics, and adequately powered multicenter trials that assess clinically meaningful outcomes. Integration with artificial intelligence (AI) and robotic platforms may further enhance surgical precision and efficiency, shaping the next phase of MISS.

BACKGROUND AND OBJECTIVES: The Patient-Generated Subjective Global Assessment (PG-SGA) is a standardized tool for assessing malnutrition in patients with cancer. The primary aim of this study was to assess the impact of preoperative nutritional status as measured by PG-SGA on survival in patients requiring surgical intervention and/or radiotherapy for spinal metastases. METHODS: Patients with spinal metastases who underwent surgery and/or radiation therapy for symptomatic spinal metastases were enrolled in the AO Spine Metastatic Tumor Research and Outcomes Network, a prospective international multicenter research registry, between September 2017 and August 2022. Using the PG-SGA, nutritional status was classified into 3 categories: A, well nourished; B, moderately malnourished; and C, severely malnourished. RESULTS: A total of 589 patients met the inclusion criteria; 362 were classified as well nourished (61%), 159 were moderately malnourished (27%), and 68 were severely malnourished (12%). The median survival was 491 days, 328 days, and 117 days for well-nourished, moderately malnourished, and severely malnourished patients, respectively. In the multivariate analyses, severe malnourishment (HR 2.5 95% CI 1.4-4.3, P < .01) and an ECOG performance status of 3 or 4 (HR 2.7 95% CI 1.2-6.0) remained associated with significantly worse survival. CONCLUSION: Malnutrition as measured by the PG-SGA demonstrated to be significantly and independently associated with postoperative survival. The PG-SGA is a simple and useful tool to identify spinal metastases patients at risk of early postoperative mortality, and inclusion in the preoperative evaluation of these patients should be considered.