Journal of neurosurgery. Spine最新文献

Objective: Although minimally invasive techniques are established in thoracolumbar spine surgery, their benefit and applicability in cervical spine surgery still require further validation. This study aimed to investigate feasibility and screw accuracy, as well as paraspinal muscle atrophy, in the authors' initial patient cohort of subaxial percutaneous navigated cervical screw-rod instrumentation through a retrospective matched-patient analysis.

Methods: The patients of the percutaneous group (PG) (n = 20) were matched with the patients of the conventional group (CG) who underwent the midline approach (n = 20) on the basis of total instrumented segments, level of instrumentation, age, and sex. Pedicle screw accuracy was assessed using the Bredow classification and cross-sectional muscle areas were compared preoperatively and at a minimum follow-up of 60 days.

Results: Surgical indications were primarily degenerative in the CG (70%) and more diverse in the PG (40% degenerative, 35% oncological, and 20% traumatic). The percutaneous system was more frequently used in combined anterior-posterior approaches (50% PG vs 35% CG). Skin incision to navigation time was significantly shorter in the PG (mean ± SD 14 ± 15 minutes vs 44 ± 23 minutes in the CG), while screw placement time and clinically acceptable postoperative screw accuracy (88% PG vs 95% CG) were comparable. After a median follow-up of 140 days, muscle area change was without relevant differences (99.1% PG vs 93.7% CG), and no neurovascular injuries occurred in either group.

Conclusions: Percutaneous cervical screw-rod instrumentation using navigated pedicle screws is a versatile tool offering comparable accuracy. Besides the advantages of shorter preparation time and applicability in combined approaches, the real benefits of muscle preservation need to be proven in larger prospective patient cohorts.

Objective: The objective of this study was to develop and test the ability of a novel multivariate model to predict outcomes following minimally invasive transforaminal lumbar interbody fusion (TLIF) for degenerative spondylolisthesis at the L4-5 segment, and conduct internal validation of the proposed models for preoperative patient selection and to improve postoperative outcomes.

Methods: The authors conducted a retrospective analysis of a prospectively collected database. One hundred ninety-one consecutive patients undergoing TLIF on the L4-5 segment for symptomatic degenerative spondylolisthesis were prospectively enrolled and followed for 1 year. A comprehensive patient clinical and radiological assessment was performed at baseline and 12 months postoperatively. Regression mathematical modeling of preoperative variables was used to create the prognostic model of clinical outcomes (Oswestry Disability Index [ODI] and 36-Item Short-Form Health Survey [SF-36]). To predict the clinical outcome, 3 models were identified: 1) y0, based on the postoperative ODI score; 2) y1, based on the postoperative SF-36 Physical Component Summary (PCS) score; and 3) y2, based on the SF-36 Mental Component Summary (MCS) score. The following criteria were chosen as independent variables: age, BMI, duration of symptoms, presence of motor deficit, preoperative SF-36 PCS, preoperative SF-36 MCS, preoperative ODI score, preoperative back pain, preoperative leg pain, preoperative lumbar lordosis, preoperative interbody space height, preoperative sagittal angle, preoperative linear translation, intervertebral disc degeneration, facet joint degeneration, value of the apparent diffusion coefficient, and facet angle on the operative side.

Results: All patient-reported outcomes improved postoperatively (median, baseline vs 12 months): ODI score from 72% to 20% (p = 0.01), visual analog scale (VAS) back pain score from 78 to 24 mm (p = 0.02), VAS leg pain score from 92 to 14 mm (p = 0.01), SF-36 PCS score from 26.13 to 41.24 (p = 0.03), and SF-36 MCS score from 22.46 to 46.27 (p = 0.01). Reoperations occurred in 6 patients (3.1%), 9 (4.7%) were readmitted within 30 days of surgery, 168 (88.0%) returned to work, and 24 (12.6%) experienced an unplanned outcome (back pain and/or lower extremity pain > 20 mm according to the VAS, > 20 points on the ODI, a reoperation, or a readmission). These results suggest that the independent preoperative variables determined by radiography and MRI allow the prediction of the clinical outcome, but they have differing roles and dominance depending on the developed predictive model.

Conclusions: The predictive regression models that were developed in this study using these data can improve preoperative risk counseling and patient selection for minimally invasive TLIF surgery at the L4-5 segment.

Objective: Achieving and maintaining adequate segmental lumbar lordosis through anterior lumbar interbody fusion (ALIF) has been associated with favorable clinical outcomes. However, preoperative and immediate postoperative factors predicting changes in segmental alignment have not been established for ALIF.

Methods: Adults who underwent L5-S1 ALIF surgery for degenerative disc disease at a single institution between 2017 and 2022 were included. Multivariate stepwise linear regression analyses were performed to identify modifiable demographic, surgical, and alignment parameters that were predictive of 6-week to 1-year postoperative L5-S1 segmental lordosis loss. Next, multivariate logistic regression analyses were performed to evaluate the association between segmental loss and postoperative mechanical complications. Finally, multivariate logistic regression and receiver operating characteristic (ROC) curve analyses were performed to establish lower and upper thresholds for 6-week postoperative L5-S1 segmental lordosis that mitigated the need for revision surgery and segmental lordosis loss, respectively. Similar thresholds were established for low (< 45°), average (45°-60°), and high (> 60°) pelvic incidence (PI) categories as well.

Results: Among 94 patients, the mean age was 50.2 years, 57% were female, and the mean Charlson Comorbidity Index score was 1.4. Radiographically, patients had 7.6° L5-S1 lordotic correction (p < 0.001) and 10.2-mm L5-S1 anterior disc height increase (p < 0.001) after their ALIF surgery, and these changes were maintained to 1 year postoperatively. Stepwise regression revealed that baseline obesity (coefficient = -2.2, p = 0.047), lack of posterior fixation (coefficient = -2.4, p = 0.045), and larger correction in L5-S1 lordosis (coefficient = -0.4, p < 0.001) were independently associated with postoperative L5-S1 segmental lordosis loss. Cage subsidence was associated with higher odds of postoperative segmental loss (OR 1.2, p = 0.017). ROC curve analyses identified a 6-week postoperative L5-S1 segmental lordosis range of 21.6° to 26.8° (low PI 19.0°-24.8°, average PI 21.0°-26.4°, and high PI 24.1°-28.7°) as that which minimized loss of lordotic correction and the need for revision surgery over a 1-year follow-up period.

Conclusions: ALIF offers powerful restoration of segmental alignment that is maintained after surgery. The extent of subsequent loss can be predicted by baseline obesity, the presence of posterior instrumentation, and the degree of achieved lordotic correction. Preoperative surgical planning should consider correcting L5-S1 segmental lordosis to between the thresholds defined in this study to mitigate the risk of postoperative mechanical complications.

Objective: With the advent of bundled payments in spine surgery, there is increasing emphasis on value-based care. Although there is substantial literature on economies of scale in total joint arthroplasty, there remains a paucity of literature in spine surgery. The purpose of this study was to assess the impact of hospital volume on cost, length of stay (LOS), and discharge destination after elective inpatient spine surgery procedures in a Medicare population.

Methods: The 2019 Medicare Provider Analysis and Review Limited Data Set and Centers for Medicare and Medicaid Services 2019 Impact File were used in this study. Diagnosis-related group codes were used to identify 5 spine surgery cohorts consisting of nonfusion surgery, cervical fusion, noncervical fusion, anterior-posterior fusion, and complex fusion. Elective non-Medicare Advantage patients were included (n = 142,617). Patients were grouped according to low (1-100 cases; n = 51,685 [36%]), medium (101-200 cases; n = 44,145 [31%]), and high (≥ 201 cases; n = 46,787 [33%]) hospital volume. Hospital costs were calculated using cost-to-charge ratios. Multivariate models were created to evaluate associations between hospital volume and total hospital cost, hospital LOS, and discharge destination, controlling for confounders (type of surgery, complications, demographics, comorbidities, surgical details, and hospital details).

Results: In the univariate analysis of primary outcomes, high-volume spine centers were associated with greater cost (p < 0.001) and longer LOS (p < 0.001), and medium-volume spine centers were associated with a lower incidence of nonhome discharge (p < 0.001), compared with low-volume hospitals. However, in the multivariate analysis, increasing hospital volume was associated with decreasing cost (medium volume -$882 vs high volume -$1764, p < 0.001), decreasing LOS (medium volume -0.066 days vs high volume -0.132 days, p < 0.001), and decreasing risk of nonhome discharge (adjusted OR 0.809 [95% CI 0.783-0.836], p < 0.001 for medium volume; 0.746 [95% CI 0.721-0.772], p < 0.001 for high volume).

Conclusions: Increased hospital volume was independently associated with lower costs, shorter LOS, and decreased risk of nonhome discharge after elective inpatient spine surgery. High-volume centers might benefit from economies of scale and lean methodology practices that should be studied to improve value on a national level. Small and medium hospitals could be disproportionately impacted by declining Medicare reimbursements. Further study is necessary to provide fair reimbursement adjustments as bundled payments for spine surgery are introduced.

Objective: This study aimed to determine minimum clinically important difference (MCID) values for dysphagia using the Eating Assessment Tool-10 (EAT-10) in patients undergoing anterior cervical surgery, focusing on early dissatisfaction and later satisfaction thresholds to guide clinical decisions.

Methods: Data were prospectively collected from patients undergoing anterior cervical surgery across three institutions from 2016 to 2024. Dysphagia severity was assessed preoperatively and at various postoperative stages up to 1 year using EAT-10. The inverse probability of treatment weighting was used to control for confounding variables. The retrospective study of patient data employed two analytical phases: the first phase examined the relationship between dissatisfaction at 3 months (indicated by a North American Spine Society satisfaction score > 2) and changes in EAT-10 scores from baseline to peak (i.e., worst) postoperative scores; the second phase focused on recovery, comparing changes in EAT-10 scores from peak postoperative scores to 12 months against satisfaction (score < 2) at 12 months.

Results: The mean ± SD baseline EAT-10 score for the 1463 patients included in the study was 1.5 ± 4.7 and the mean peak score was 5.2 ± 7.4. The patients underwent anterior cervical discectomy and fusion (90%), arthroplasty (6%), or corpectomy (4%); a hybrid procedure was used in 1%. The phase 1 analysis indicated that a 4-point increase in EAT-10 score was a threshold for significant postoperative dissatisfaction in those without baseline dysphagia, with much higher thresholds observed in patients with any baseline dysphagia. In phase 2, among patients with baseline EAT-10 scores < 3 who experienced an increase to EAT-10 score ≥ 8 postoperatively, a subsequent decrease of 9 points by 12 months was necessary to report satisfaction. For patients with baseline scores 3-8 whose postoperative scores rose to ≥ 8, a subsequent decrease of 15 points was necessary for satisfaction. Patients with initial scores of ≥ 8 who did not improve to < 3 immediately after surgery required further reductions of 2-11 points to reach satisfaction.

Conclusions: The MCID thresholds from this study provide crucial benchmarks for assessing dysphagia changes after anterior cervical surgery, allowing tailored interventions. Patients with baseline dysphagia are less likely to experience early dissatisfaction, and high peak scores negatively impact long-term satisfaction. These findings emphasize the importance of proactive dysphagia management to enhance patient outcomes.

Objective: The aim of this study was to determine the rate of postoperative new-onset sacroiliac joint pain (SIJP) following adult spinal deformity (ASD) surgery with pelvic fixation.

Methods: Patients undergoing ASD surgery with pelvic fixation, without baseline SIJP, and with a minimum 1-year follow-up were included. Patients were screened for SIJP by self-reported buttock/groin pain and/or posterior superior iliac spine (PSIS) pain scores ≥ 4. Patients with positive results on questionnaires were indicated for an SIJ examination consisting of 5 provocative maneuvers with ≥ 3 positive examination findings considered to be indicative of SIJP. Types of pelvic fixation were then compared for rates of postoperative SIJP.

Results: A total of 346 patients were identified, with mean age of 65 (SD 10) years and BMI of 28 (SD 5); 71% of patients were female. Thirteen patients (4%) underwent SIJ fusion at the index procedure. At the 1-year follow-up, 82 patients (24%) had positive screening responses for SIJP on the questionnaire; 63 underwent an SIJ examination and only 3 patients (1%) had a positive result. At the 2-year follow-up, 138 patients were administered the SIJP screening questionnaire; 31 (22%) had a positive questionnaire response for SIJP, 17 underwent an SIJ examination, and only 2 patients (1%) had a positive result. There was no difference in SIJP between patients with traditional iliac fixation (n = 162, 0% at 1 and 2 years) and S2-alar-iliac screws (n = 184), where 2% developed SIJP by 1 (p = 0.25) and 2 (p = 0.52) years, respectively. There was also no difference in SIJP between patients with 4 points of pelvic fixation (n = 85, 0% at 1 and 2 years) and patients with fewer than 4 points of pelvic fixation (n = 261), where 1% (p = 0.57) and 2% (p > 0.99) developed SIJP at 1 and 2 years, respectively. Of the 79 patients with iliac crest harvesting, none developed SIJP at the 1- or 2-year follow-up.

Conclusions: Based on examination, the incidence of de novo SIJP following ASD surgery with pelvic fixation is low: only 1% at the 1- and 2-year follow-ups. The large discrepancy between at least moderate regional reported pain but a negative provocative examination warrants further investigation as to the source of substantial pain in nearly one-quarter of ASD patients postoperatively.

Objective: The objective was to compare incomplete (A3) versus complete (A4) thoracolumbar burst fractures managed nonoperatively or operatively with respect to reaching minimal clinically important difference (MCID) in Oswestry Disability Index (ODI) score.

Methods: A prospective observational international multicenter cohort study was conducted. After stratification using the AO Spine Thoracolumbar Injury Classification System, A3 and A4 outcomes were analyzed separately within nonoperative and operative management groups. Outcomes included absolute and relative improvement in ODI scores between discharge and 12-month follow-up. Kaplan-Meier curves were generated and compared with the log-rank test. Multivariable Cox regression models were constructed. The Cox regression models were adjusted using the key covariates of age, sex, thoracolumbar injury classification and severity (TLICS) score, and the interaction between fracture type and treatment type. Additional adjustment was performed for discharge ODI scores to compare relative improvement.

Results: In total, 198 neurologically intact patients were identified, with incomplete fractures (58.6%) being more common than complete burst fractures (41.4%). The rate of nonoperative management was significantly higher among A3 than A4 fractures (48.3% vs 24.4%, p < 0.01). A4 fractures demonstrated a higher mean TLICS score than A3 fractures (2.8 vs 2.4, p = 0.04). There were no significant functional differences in MCID in ODI scores, defined as an improvement in 12.8 points within 1 year after treatment (HR 1.21, 95% CI 0.86-1.70, p = 0.28). Examination of only the surgically treated cohort of patients also revealed no significant difference in achieving relative ODI score improvement within 1 year after treatment between those with A4 and those with A3 fractures (HR 1.19, 95% CI 0.78-1.82, p = 0.43). A similar finding was demonstrated for the nonoperative cohort, with no difference between the incomplete or complete burst fracture morphologies (HR 1.24, 95% CI 0.68-2.27, p = 0.48). Odds of achieving an absolute ODI score of 20 or less were also similar between patients with A4 and A3 fractures, regardless of whether operative (HR 0.81, 95% CI 0.52-1.25, p = 0.34) or nonoperative (HR 0.72, 95% CI 0.38-1.35, p = 0.30) management was pursued.

Conclusions: Patients with A3 and A4 fractures had similar odds to reach MCID in ODI score at 1 year. Even when exclusively considering the nonoperative cohort of patients who sustained A4 fractures with perceived increased biomechanical stability, there was no difference in functional improvement compared to patients with A3 fractures. Further large prospective multicenter studies are required to specifically assess radiographic outcomes and compare surgical approaches in the management of A3 and A4 fractures.

Objective: Posterior cervical foraminotomy (PCF) is an established motion-preserving alternative to anterior cervical discectomy and fusion (ACDF) for cervical radiculopathy. However, concerns remain regarding the efficacy of PCF in patients with vertically narrow foramina, where decompression in the craniocaudal direction is limited. This study was conducted to evaluate the impact of narrow foraminal height (FH; < 6 mm) on clinical and radiographic outcomes following PCF.

Methods: This retrospective cohort study reviewed the records of 82 patients who underwent PCF with ≥ 2 years of follow-up. Patients were categorized into narrow FH (n = 30) and high FH (n = 52) groups. Clinical outcomes included visual analog scale (VAS) scores for neck and arm pain, the Neck Disability Index (NDI), and the achievement of the minimal clinically important difference (MCID). Radiographic parameters and revision surgery rates were also assessed.

Results: The narrow FH group had a significantly higher rate of revision surgeries (13.3% vs 0%, p = 0.016). Although both groups experienced significant pain reduction, only the high FH group showed significant improvement in NDI scores at 3 months. The proportion of patients achieving MCID for arm pain was significantly lower in the narrow FH group (p = 0.021). Postoperative cervical range of motion was also more restricted in the narrow FH group. FH did not significantly change postoperatively in either group.

Conclusions: Narrow FH adversely affects clinical outcomes and increases the risk of revision surgery following PCF. Surgeons should consider alternative approaches, such as ACDF, for patients with preoperative FH < 6 mm.

Objective: The Patient-Reported Outcomes Measurement Information System Global Health-10 (PROMIS-10) has not been validated for use in anterior cervical spine surgery (ACSS). The PROMIS-10 distinctly measures global physical health (GPH) and global mental health (GMH) domains, setting it apart from other patient-reported outcome measures (PROMs). This study aimed to validate the PROMIS-10 and identify minimum clinically important differences (MCIDs) in PROMIS-10 GPH and GMH scores in ACSS.

Methods: A prospectively collected quality registry was retrospectively reviewed. PROMIS-10 scores were obtained from patients undergoing ACSS at baseline, 3 months, and 12 months postoperatively. Other validated PROMs assessing quality of life (QOL) were also collected, including the Neck Disability Index (NDI), EuroQol 5-Dimension (EQ-5D) Index, EuroQol visual analog scale (EQ-VAS), and visual analog scales for neck (NP-VAS) and arm pain (AP-VAS). Pearson correlation coefficients assessed the relationship between the PROMIS-10 and other PROMs at baseline (r0) and 12 months (r12), as well as changes from baseline to 12 months (rΔ12). Cronbach's alpha was used to evaluate the internal consistency of PROMIS-10 GPH and GMH at the same time points (α0, α12, and αΔ12). MCIDs were calculated for GPH and GMH using 4 established anchor-based methods, with North American Spine Society patient satisfaction index scores as the anchor.

Results: A total of 700 patients completed baseline and 12-month PROMIS-10 questionnaires. GPH demonstrated moderate to strong correlations with the EQ-5D (r0 = 0.68, r12 = 0.75, rΔ12 = 0.49), NDI (r0 = -0.66, r12 = -0.67, rΔ12 = -0.52), EQ-VAS (r0 = 0.58, r12 = 0.68, rΔ12 = 0.51), NP-VAS (r0 = -0.50, r12 = -0.57, rΔ12 = -0.46), and AP-VAS (r0 = -0.38, r12 = -0.47, rΔ12 = -0.37). GMH had moderate correlations with the EQ-5D (r0 = 0.58, r12 = 0.68, rΔ12 = 0.45), NDI (r0 = -0.49, r12 = -0.54, rΔ12 = -0.37), EQ-VAS (r0 = 0.55, r12 = 0.63, rΔ12 = 0.44), NP-VAS (r0 = -0.32, r12 = -0.45, rΔ12 = -0.31), and AP-VAS (r0 = -0.24, r12 = -0.36, rΔ12 = -0.21). Strong internal consistency reliability was observed in GPH (α0 = 0.71, α12 = 0.78, αΔ12 = 0.60) and GMH (α0 = 0.76, α12 = 0.87, αΔ12 = 0.74). Based on 12-month score changes, MCID thresholds ranged from 4.4 to 10.1 for GPH and 4.7 to 8.6 for GMH. The receiver operating characteristic (ROC) approach was deemed most appropriate for calculating MCIDs.

Conclusions: PROMIS-10 GPH and GMH have strong validity and reliability, with moderate to strong correlations to established PROMs and high internal consistency. Based on the ROC approach, MCID thresholds were 9.05 for GPH and 7.25 for GMH. These findings support the use of the PROMIS-10 in capturing QOL in patients undergoing ACSS.

Objective: The objective of this study was to determine minimal clinically important difference (MCID) values for patient-reported outcomes (PROs) including the 12-Item Short-Form Health Survey (SF-12) Physical Component Summary (PCS), SF-12 Mental Component Summary (MCS), and Neck Disability Index (NDI) in patients with degenerative cervical myelopathy (DCM) undergoing surgery, and to assess whether MCID values vary by baseline disease severity.

Methods: The authors retrospectively analyzed prospectively collected data from the Canadian Spine Outcomes and Research Network for DCM patients treated surgically between 2015 and 2023. Inclusion required a baseline modified Japanese Orthopaedic Association (mJOA) score and 3- or 12-month follow-up PROs with domain-specific anchor responses. Patients were stratified by baseline mJOA score into mild (score ≥ 15), moderate (score 12-14), and severe (score < 12) groups. MCID values for the SF-12 PCS, SF-12 MCS, and NDI were calculated using anchor-based receiver operating characteristic curve analysis, with responder status defined by anchor questions. Discriminative performance was assessed via area under the curve, and 95% confidence intervals were estimated by bootstrapping.

Results: Among 290 patients meeting inclusion criteria, 77 (26.6%) were classified as having mild myelopathy, 120 (41.4%) moderate, and 93 (32.1%) severe. In the overall cohort, the MCID values were estimated as 8.9 (95% CI 7.5-10.9) for SF-12 PCS, 4.3 (95% CI 2.3-5.6) for SF-12 MCS, and 13.5 (95% CI 11.5-15.5) for NDI. Stratified SF-12 PCS MCID values increased from an estimated 4.8 (95% CI 1.1-7.7) in mild cases to 8.4 (95% CI 6.1-11.3) in moderate and 14.8 (95% CI 10.4-17.7) in severe cases. The NDI MCID values similarly rose from 10.5 (95% CI 6.5-12.5) to 15.0 (95% CI 10.5-19.0) to 17.5 (95% CI 14.5-21.0) across the mild, moderate, and severe groups, respectively. In contrast, the SF-12 MCS MCID values were 4.5 (95% CI 1.4-7.4) for mild, 3.8 (95% CI 0.4-5.8) for moderate, and 4.4 (95% CI 1.9-8.3) for severe patients, which did not differ significantly across severities.

Conclusions: MCID values for PROs in DCM patients undergoing surgery increase with baseline severity. These findings indicate the importance of stratifying patients by disease severity to enhance the clinical relevance of MCID values, facilitate personalized treatment goals, and improve outcome assessments.