Sardar, Zeeshan M.

Study Design: A national prospective cervical spine surgery registry was developed to archive radiographic studies, patient-reported outcome measures (PROMs), and surgical implant data to assess long-term safety. Objective: To describe the design, development, funding, and implementation of a cervical spine data registry for 1000 patients with myelopathy and radiculopathy. Summary of Background Data: While surgery for cervical radiculopathy and myelopathy is safe and effective, there is significant practice variation among spine surgeons. While randomized clinical trials (RCTs) can provide high-quality comparative effectiveness data, RCTs lack the ability to evaluate the safety and effectiveness of various surgical procedures and implants among heterogenous real-world patient populations. The CSRS Registry was designed to collect patient demographics, outcomes, radiographic imaging, surgical approach, and implant data for the purpose of conducting high-quality research. Methods: Patients with cervical myelopathy or radiculopathy were enrolled in the CSRS National Registry. De-identified patient data, validated PROMs, radiographic data, and implant data were collected from multiple clinical sites across the United States. Results: One thousand patients [mean age, 58 y; 456 (46%) women] were enrolled, with 31% follow-up at 1 year. Five hundred ninety-two patients were diagnosed with radiculopathy, 252 with myelopathy, and 156 with radiculopathy and myelopathy. Patients had significant improvements in their PROMs after surgery. At 1 year, the mean NDI score improved from 37.2 to 20.9 ( P <0.001). The mean self-reported P-mJOA score at baseline was 14.2 and improved to 15.2 by 1 year ( P <0.001). Baseline CSDI score was 23.6 and improved with a 1-year decrease to an average score of 13.6 ( P <0.001). There was significant improvement in PROMIS-10 Physical Health score from 41.0 to 45.9 (n=311; P <0.001) at 1-year follow-up. Conclusions: The CSRS Registry has successfully collected clinical outcomes data that is being leveraged for comparative effectiveness research and evaluations of the long-term safety and effectiveness of spinal implants.

Study Design: Single-center retrospective cohort study. Objective: To determine if the 4-rod construct (4RC) is protective against the occurrence of rod fractures when compared with the 3-rod construct (3RC) in adult spinal deformity (ASD) patients with long fusions to the sacrum. Summary of Background Data: Past studies have explored the different outcomes in subjects with dual-rod versus multirod constructs. There is a lack of literature distinguishing the ramifications of 3RC versus 4RC, particularly in the prevalence of rod fractures and rod fractures requiring subsequent revision surgery as a result of pseudarthrosis. Methods: ASD patients undergoing long instrumented fusions to the sacrum were dichotomized between the 3RC and 4RC cohorts. Outcomes of interest include the occurrence of rod fractures (RFs) and RFs requiring revision (RFR). Two-tailed independent-sample t test with Welch's correction and χ 2 /Fisher exact test were used for continuous and categorical variables, respectively. Multivariable logistic regression analysis was performed to assess whether the 4RC is protective against rod fractures when compared with the 3RC. Results: One hundred forty-five patients with a minimum 2-year follow-up were included (3RC=57, 4RC=88). Four RC had a greater body mass index (BMI) ( P =0.002), longer operating room (OR) time ( P =0.002), greater estimated blood loss (EBL) ( P =0.002), total instrumented levels (TIL) ( P =0.028), and more 3-column osteotomies (3COs) performed ( P =0.028). Four RC had greater baseline coronal vertical axis (CVA) (28.2±24.9 vs. 18.5±16.9 mm, P =0.006) and sagittal vertical axis (SVA) (55.1±64.8 vs. 30.4±41.8 mm, P =0.006). Three RC had a greater rate of RF (28.1% vs. 14.8%, P =0.0506) and RFR (14.9% vs. 10.2%, P =0.486) when compared with 4RC, but these findings were not statistically significant. After controlling for BMI, the use of 3-column osteotomies, total instrumented levels, change in coronal alignment (∆CVA), change in sagittal alignment (∆SVA), use of bone morphogenetic protein, and number of interbody fusions, 3RC was associated with 4.93× greater odds of experiencing RFs ( P =0.0078). However, significance fell short when adjusting for the occurrence of RFR [OR=2.58 (0.60–11.19), P =0.2067]. Conclusion: ASD patients having long fusions to the sacrum with 4RC across the lumbosacral junction are shown to be at lesser risk of developing rod fractures but not revision surgery as compared with 3RC at 2-year follow-up.

Study Design: Single-center retrospective analysis. Objective: To establish an empirically derived threshold to define both coronal and sagittal malalignment (CM & SM) based on preoperative patient-reported outcomes (PROs). Summary of Background Data: Currently, no radiographic alignment threshold defines preoperative CM in adult spinal deformity (ASD) patients based on disability. In a cohort of ASD patients undergoing corrective surgery, we sought to establish a threshold to define both CM and SM based on PRO and assess the clinical impact of CM and combined with SM. Methods: ASD patients with ≥6 level fusions were included. CVA and SVA were measured. PROs included preoperative ODI and SRS-22r scores. CVA and SVA thresholds were derived to accurately differentiate patients with ODI >40 and SRS-pain+function <5. Patients were then separated into 4 groups: (1) neutral alignment (NA); (2) CM; (3) SM; and (4) combined coronal and sagittal malalignment (CCSM). Results: Totally, 368 patients were included. Thresholds to distinguish patients with ODI ≥40 and SRS-pain/function <5 were: (1) CVA=3.96 cm (ODI) and 3.17 cm (SRS); (2) SVA=4.97 cm (ODI) and 7.52 cm (SRS). The lower numbers were chosen to define each threshold: CVA=3 cm and SVA=5 cm. Alignment breakdown was: NA=179 (48.6%), CM=66 (17.9%), SM=65 (17.7%), and CCSM=58 (15.8%). Both SM=( P =0.006) and CCSM ( P <0.001) patients had significantly worse ODI scores than NA patients, and CCSM patients were significantly worse than SM alone ( P =0.010). On the basis of preoperative total SRS-22r scores, only CCSM ( P =0.003) patients were significantly worse than the NA group. CVA significantly correlated with 4/7 (57.1%) preoperative PROs (ODI/SRS-total/function/image), while SVA correlated with 5/7 (71.4%) preoperative PROs (ODI/SRS-total/function/image/pain). A linear relationship was seen between increasing CVA and worsening ODI (β=0.92, 95% CI: 0.37–1.48, P =0.001). A significant and slightly stronger relationship was seen between increasing SVA and worsening ODI (β=1.28, 95% CI: 1.00–1.56, P <0.001). Conclusions: CM and SM thresholds that accurately distinguished ASD patients with severe pain and disability preoperatively were 3 cm for CVA and 5 cm for SVA, respectively. Preoperative CM was significantly associated with worse ODI, SRS-22r total/function/image scores. CCSM led to more disability than SM alone.

OBJECTIVE The objective of this study was to compare a multiple pelvic screw fixation strategy (dual bilateral 4 pelvic screw fixation [4PvS]) with the use of single bilateral 2 pelvic screw fixation (2PvS), with the aim of addressing lumbosacral junction stability. METHODS This analysis is a single-center, retrospective review of ASD patients treated between 2015 and 2021. All patients had a minimum 2-year follow-up and spinal fusion to the sacrum without sacroiliac fusion and met at least one radiographic and procedural criterion: pelvic incidence–lumbar lordosis ≥ 20°, T1 pelvic angle ≥ 20°, sagittal vertical axis ≥ 7.5 cm, scoliosis ≥ 50°, three-column osteotomy, or spinal fusion of ≥ 8 levels. Two sacropelvic fixation methods were compared: 4PvS versus 2PvS. Primary outcomes included spinal implant-related reoperation and screw breakage, while secondary outcomes included reoperation for symptomatic pelvic screws, screw loosening or bending, L5–S1 pseudarthrosis, and patient-reported outcomes. Propensity score matching and inverse probability of treatment weighting (IPTW) were used to minimize selection bias and estimate causal treatment effects. Clinical outcomes were assessed using conditional multivariable logistic regression. RESULTS In this study of 406 patients (67.98% female, mean age 64.48 years), 349 patients (85.96%) received 2PvS and 57 (14.04%) received 4PvS. Age (OR 1.081, 95% CI 1.027–1.145) and total number of osteotomies (OR 1.180, 95% CI 1.048–1.355) emerged as independent predictors of receiving the 4PvS technique. In unmatched cohorts (n = 406), 2-year implant-related reoperation rates (p = 0.1896) and pelvic screw breakage rates (p = 0.2498) were not significantly different between groups. However, in the 4:1 propensity score–matched cohort, the 2-year reoperation rate (10.53% for 2PvS vs 3.51% for 4PvS; OR 3.27, 95% CI 1.10–9.74 [p = 0.0312]) and the pelvic screw breakage rate (9.21% for 2PvS vs 3.51% for 4PvS; OR 2.87, 95% CI 1.08–7.63 [p = 0.0349]) were significantly higher among the 2PvS groups. The IPTW analysis confirmed these findings, with reoperation rates of 10.45% for 2PvS and 1.18% for 4PvS (p = 0.0244) and pelvic screw breakage rates of 8.72% and 1.18%, respectively (p = 0.0477). A safety assessment revealed comparable operative times and intra- and perioperative complications between the two techniques. CONCLUSIONS Patients who underwent 4PvS demonstrated significantly lower 2-year implant-related reoperation and pelvic screw breakage rates compared with 2PvS, with no differences in intraoperative or perioperative complications.

OBJECTIVE The American Spine Registry (ASR) is a collaborative effort between the American Academy of Orthopaedic Surgeons and the American Association of Neurological Surgeons. The goal of this study was to evaluate how representative the ASR is of the national practice with spinal procedures, as recorded in the National Inpatient Sample (NIS). METHODS The authors queried the NIS and the ASR for cervical and lumbar arthrodesis cases performed during 2017–2019. International Classification of Diseases, 10th Revision and Current Procedural Terminology codes were used to identify patients undergoing cervical and lumbar procedures. The two groups were compared for the overall proportion of cervical and lumbar procedures, age distribution, sex, surgical approach features, race, and hospital volume. Outcomes available in the ASR, such as patient-reported outcomes and reoperations, were not analyzed due to nonavailability in the NIS. The representativeness of the ASR compared to the NIS was assessed via Cohen’s d effect sizes, and absolute standardized mean differences (SMDs) of < 0.2 were considered trivial, whereas > 0.5 were considered moderately large. RESULTS A total of 24,800 arthrodesis procedures were identified in the ASR for the period between January 1, 2017, and December 31, 2019. During the same time period, 1,305,360 cases were recorded in the NIS. Cervical fusions comprised 35.9% of the ASR cohort (8911 cases) and 36.0% of the NIS cohort (469,287 cases). The two databases presented trivial differences in terms of patient age and sex for all years of interest across both cervical and lumbar arthrodeses (SMD < 0.2). Trivial differences were also noted in the distribution of open versus percutaneous procedures of the cervical and lumbar spine (SMD < 0.2). Among lumbar cases, anterior approaches were more common in the ASR than in the NIS (32.1% vs 22.3%, SMD = 0.22), but the discrepancy among cervical cases in the two databases was trivial (SMD = 0.03). Small differences were illustrated in terms of race, with SMDs < 0.5, and a more significant discrepancy was identified in the geographic distribution of participating sites (SMDs of 0.7 and 0.74 for cervical and lumbar cases, respectively). For both of these measures, SMDs in 2019 were smaller than those in 2018 and 2017. CONCLUSIONS The ASR and NIS databases presented a very high similarity in proportions of cervical and lumbar spine surgeries, as well as similar distributions of age and sex, and distribution of open versus endoscopic approach. Slight discrepancies in anterior versus posterior approach among lumbar cases and patient race, and more significant discrepancies in geographic representation were also identified, yet decreasing trends in differences suggested the improving representativeness of the ASR over the course of time and its progressive growth. These conclusions are important to underline the external validity of quality investigations and research conclusions to be drawn from analyses in which the ASR is used.