Spine最新文献

Study design: Retrospective cohort study comparing sagittal spinopelvic alignment in patients with lumbar spinal stenosis (LSS) to age- and sex-matched normative data and evaluating postoperative changes following decompression surgery.

Objective: To determine whether LSS represents a distinct sagittal alignment phenotype beyond normal aging and to assess alignment changes up to two years after decompression surgery.

Summary of background data: Sagittal alignment in healthy populations and adult spinal deformity is has been widely studied. However, the sagittal alignment specific to LSS remains poorly researched.

Methods: Patients undergoing decompression without fusion for LSS between 2014 and 2022 at a single institution were included. Exclusion criteria were prior surgery, infection, tumor, scoliosis, or lack of radiographic data. Sagittal parameters were measured preoperatively and at two-year follow-up. We calculated normative value using a large population-based Japanese cohort. Comparison between LSS and controls were performed using one-sample t-tests.

Results: 448 patients were included for analysis. Compared to controls, LSS patients had significantly higher SVA and PT, and lower LL, SS, and TK. Postoperative alignment improved but did not normalize. Residual malalignment persisted across all age groups, indicating a distinct alignment phenotype in LSS.

Conclusion: LSS is associated with a unique sagittal alignment profile that exaggerates age-related changes. Decompression surgery partially improves sagittal alignment. These findings suggest intrinsic structural differences in LSS and highlight the need for individualized treatment and long-term follow-up.

Level of evidence: 3.

Study design: Retrospective case-control study.

Objective: To determine risk factors for recurrence of pediatric lumbar spondylolysis at L5 after return to sport in patients who achieved bone union with conservative treatment.

Summary of background data: Pediatric lumbar spondylolysis is a stress fracture commonly observed in adolescent athletes, particularly at the L5 vertebra. Because some patients experience a recurrence of spondylolysis after bone fusion with conservative treatment, identifying risk factors for recurrence may help athletes continue sports activities, maintain performance levels, and preserve mental health.

Materials and methods: Of the 375 pediatric patients (below 18 yr of age) who received conservative treatment for lumbar spondylolysis at L5 between 2015 and 2021, 296 patients who achieved bone fusion and returned to their original sports activities were analyzed. Recurrence rate, sports, pathologic stage of spondylolysis at initial examination, presence of spina bifida occulta (SBO), duration of conservative treatment for initial spondylolysis, and radiologic parameters including lumber lordosis, L5-S1 lordosis, and sacral slope were examined. Recurrence and nonrecurrence groups were compared using univariate and multivariate analyses to investigate risk factors for recurrence. A receiver operating characteristic (ROC) curve was drawn to determine cutoff values of the parameters to predict spondylolysis recurrence.

Results: Recurrence was observed in 52 of 296 patients (17.6%). Multivariate logistic regression analysis revealed that a large L5-S1 lordosis was a significant independent risk factor for recurrence. ROC analysis demonstrated a cutoff value of 24.5° for L5-S1 lordosis. Age, sex, SBO, and duration of conservative treatment for initial spondylolysis were not significant predictors of recurrence.

Conclusion: We identified large L5-S1 lordosis as an independent risk factor for recurrence of pediatric lumbar spondylolysis at L5 following conservative treatment. Intensive athletic rehabilitation to prevent recurrence and follow-up measures to monitor and detect recurrence are recommended for patients with large L5-S1 lordosis.

Study design: Retrospective cohort study.

Objective: Evaluate postoperative outcomes in lumbar fusion patients with preoperative iron deficiency anemia (IDA) on iron supplementation.

Background: IDA has been associated with impaired cognition, compromised immune response, and increased risk of morbidity and mortality after surgery. However, little is known about the relationship between IDA and postoperative complications among patients undergoing lumbar fusion, as well as about the impact of preoperative iron supplementation on these outcomes.

Methods: A national all-payer claims database was queried for adult patients who underwent lumbar spinal fusion between 2010 and 2022. Patients were initially stratified by a preoperative diagnosis of IDA and matched 1:1 based on age, sex, and medical comorbidities. IDA patients were further stratified by preoperative iron supplementation use and similarly matched. Postoperative complications and hospital costs were compared using χ 2 , t test, and multivariate logistic regressions.

Results: The matched cohorts consisted of 27,669 patients, with a mean age of 59 years and 89% female sex. IDA patients had higher rates of pulmonary embolism, acute kidney infection, deep venous thromboembolism, surgical site infection, urinary tract infection, blood transfusion, 90-day readmission rates, and hospital length of stay (all P <0.001). IDA patients on preoperative iron supplementation had lower rates of acute kidney injury, hematoma, pulmonary embolism, surgical site infection, urinary tract infection, stroke, 90-day readmission rates, and 90-day total hospital costs (all P <0.001). Non-IDA patients on preoperative iron supplementation similarly had lower rates of many of these complications as well.

Conclusion: IDA was associated with an increased risk of 90-day postoperative medical complications and hospital resource utilization. However, preoperative oral iron supplementation mitigated these risks. Further research is critical to understand how preoperative or perioperative iron supplementation can be used to optimize patients' hematologic status before lumbar fusion to maximize clinical outcomes.

Level of evidence: Level IV.

Study design: Retrospective cohort.

Objective: Investigate how home care (HC) services impact utilization of postoperative resources and outcomes after lumbar fusion.

Summary of background data: Utilization of spinal fusion has increased over the past decade-it has become important to coordinate postoperative discharge that maximizes rehabilitation and cost-effectiveness.

Methods: Bundled payment information of lumbar fusion episodes of care from a private payer (2019-2021) was reviewed to identify patients. Manual chart review was conducted to evaluate demographic/surgical details, complications, and readmissions. Insurance claims data were reviewed to identify HC utilization after discharge-disposition was designated as home with HC versus no HC.

Results: Seven hundred fifty-eight patients were included (13.6% HC, 86.4% no HC). Patients with HC were older (68.6±9.76 vs. 59.5±11.2; P <0.001), had higher BMI (31.1±6.17 vs. 30±5.9; P <0.001), and CCI (1.07±1.24 vs. 0.59±0.91; P =0.002), and longer operative time (211±86.7 vs. 178±78.9; P <0.001). HC was associated with 90-day reoperation (13.6% vs. 1.07%; P <0.001), and readmission (30-day: 7.77% vs. 1.98%; 90-day: 12.6% vs. 3.51%; P <0.001). HC was associated with reoperation for compressive fluid/dural repair (2.91% vs. 0.31%), and wound complication/infections (3.88% vs. 0%), and with medical readmissions (4.85% vs. 1.53%; P <0.001). On multivariate analysis, HC was an independent predictor of further health care utilization-office visits [incidence rate ratio (IRR): 1.14; P =0.049], phone calls (IRR: 1.38; P =0.02), and ED visits (IRR: 6.5; P <0.001). Despite similar preoperative physical function scores (SF-12 PCS), HC was associated with worse six-month ( P <0.001) and one-year scores ( P =0.05).

Conclusion: Patients receiving HC were older, sicker, and had longer surgeries. Patients with HC experienced more readmissions and reoperations particularly for wound and medical issues. HC independently predicted further postoperative health care utilization through office calls/visits and ED visits. These findings suggest that patients requiring HC are a particularly vulnerable population and that HC does not exert a protective effect against additional health care utilization. Further research is needed to identify proactive interventions that can decrease cost and improve outcomes.

Study design: Longitudinal cohort study.

Objective: To explore the association between preoperative lumbar paraspinal intramuscular fat (IMF) and recovery over a five-year period following surgical decompression for lumbar spinal stenosis (LSS)-related intermittent neurogenic claudication.

Summary of background data: The literature is inconclusive whether higher IMF concentrations on MRI are related to unfavorable outcomes following lumbar decompressive surgery for intermittent neurogenic claudication due to LSS.

Materials and methods: Patients (N=149) with LSS-related intermittent neurogenic claudication [52% male; mean (SD) age: 65.5 (9.1) yr; BMI: 27.9 (4.3)] were included for this study. Preoperative lumbar paraspinal IMF was quantified and categorized as nonsevere (<50%) and severe (≥50%) IMF for each muscle (left and right lumbar multifidus and erector spinae) from axial T 2 -weighted MRI scans using automated computer-vision models. Logistic regression was used to investigate the association between IMF and global perceived effect as well as surgical success. Linear mixed-effects models were used to assess the difference in the clinical course of leg and back pain and disability between the IMF groups. The models were corrected for potential confounders.

Results: Overall, participants with nonsevere IMF in the lumbar multifidus reported a higher percentage of successful recovery (53.7% vs. 37.5%) and surgical success (76.5% vs . 59.9%) compared with the severe IMF group. This association was not present for erector spinae IMF. After adjusting for the potential confounders, the associations between lumbar multifidus IMF and successful recovery and surgical success remained significant for most timepoints across the five-year follow-up (odds ratios: 2.26-7.32, P ≤0.049). Patients with nonsevere IMF in the right lumbar multifidus experienced less disability ( P =0.035). No between-group differences were found for the clinical course of leg and back pain ( P ≥0.143).

Conclusions: Preoperative levels of IMF in the lumbar multifidus, but not the erector spinae, were associated with five-year recovery and success following surgery for LSS-related intermittent neurogenic claudication.

Study design: Single-center retrospective study.

Objective: Identify changes in complication profiles after anterior vertebral body tethering (VBT).

Background: VBT is associated with complications such as overcorrection and breakage. We reviewed our decade-long series of complications after VBT and hypothesize that overall complication rates have decreased over time, transitioning from overcorrection to undercorrection and tether breakages.

Materials and methods: We reviewed all patients who underwent VBT between 2011 and 2020 with minimum two-year follow-up and divided them into three groups by treatment epoch: 2011 to 2015, 2016 to 2017, and 2018 to 2020. Complications were categorized as tether breakage, overcorrection, adding-on, curve progression, and miscellaneous. Breakage was defined as >5° interscrew angle change or >5° Cobb angle change between any follow-up. Baseline demographics, radiographic parameters, and complication rates were compared across groups.

Results: 200/388 patients (52%) developed radiographic complications and 75 (19%) required revision. Mean follow-up was 55.9±22.3 months. Mean age was 12.6±1.4 years, and most patients were skeletally immature. Sixty-five percent of patients underwent single thoracic tethers. Over time, there has been an increase in age at surgery ( P <0.05), curve magnitude ( P <0.05), closed triradiates ( P <0.05), and a trend towards more lumbar curves ( P =0.09). Complication types changed significantly over time with overcorrection occurring in 13% (2011-2015) then decreasing to 4% (2016-2017) and subsequently 2% (2018-2020) ( P <0.05). Incidence of breakage was 49% (2011-2015), then 55% (2016-2017), and then 59% (2018-2020), with respective revision rates of 6%, 11%, and 13% ( P >0.05). There was a significant increase in lumbar breakage and decrease in thoracic breakage ( P <0.05), likely related to more double and lumbar VBTs. At last follow-up, mean thoracic Cobb angle of the entire cohort was 24°±14°.

Conclusion: Our 10-year experience reflects lessons learned where overcorrection diminished over time with a subsequent increase in tether breakages.

Level of evidence: Level III, prognostic.

Study design: Biomechanical/basic science.

Objective: To evaluate the efficacy of dental cement augmentation of lateral mass screws in the cervical spine.

Summary of background data: Premature loosening and fixation failure are known problems of screw fixation of the spine, especially in cases of poor bone quality. Cement augmentation of screws with PMMA has limited utility in the cervical spine due to the small size of the bone and high risk of extravasation. Augmentation with dental cement may present a viable solution for posterior cervical spinal screw fixation.

Methods: Fifteen cadaveric cervical vertebrae were prepared. Lateral mass screw fixation (3.5×12 mm) was performed bilaterally with standard freehand technique by an attending spine surgeon. For augmented screws, dental composite was applied to the screw hole before placement of the screw. Nine vertebrae were used for pullout testing. Screws were attached to a material testing machine and axially loaded until failure. In the remaining 6 vertebrae, peak torque required to remove the screws from the bone was measured via a digital torque driver. A t test was used to analyze the results between the augmented and nonaugmented groups, with significance set to P <0.05.

Results: Augmented lateral mass screws exhibited significantly higher pullout strength (263.8±79.4 N) compared with nonaugmented screws (127.7±21.2 N). ( P =0.0005) There was no significant difference in the mean torque required for screw removal between the augmented (4.20±2.83 lb-in) and nonaugmented groups (4.49±2.09 lb-in) ( P =0.9). The dental composite was radio-opaque and observable on x-ray.

Conclusions: Augmentation with dental composite enhanced pullout strength without altering the removal torque of cervical lateral mass screws in human bone. Dental cement augmentation of lateral mass screws during subaxial cervical spine fusion may be a safe and effective method of improving fixation strength without affecting ease of revision.

Study design: Cross-sectional analysis of prospectively collected registry data.

Objective: To better understand the distribution of patient expectations for lumbar and cervical spine surgery and examine the relationship between preoperative patient expectations and patient demographic/clinical characteristics and patient-reported measures.

Summary of background data: Patient expectations is a critical determinant of recovery after spine surgery. The Hospital for Special Surgery (HSS) Lumbar and Cervical Spine Surgery Expectations surveys are promising tools for spine surgery. Additional research is needed to establish the utility and generalizability of these multidimensional surveys.

Methods: Patients undergoing lumbar (N=641) and cervical (N=516) spine surgery completed the 20-item HSS surveys. Disability and pain were measured with the Oswestry/Neck Disability Index and an 11-point Numeric Rating Scale. The PROMIS-29 evaluated physical function and depression. Descriptive statistics examined the distribution of item responses. Univariate tests and multivariable linear regression models examined associations between preoperative expectations and demographic/clinical factors and patient-reported measures.

Results: The items most frequently endorsed as expecting complete improvement were related to condition getting worse, need for pain medications, control spine condition has on life, and fulfilling job responsibilities. Higher leg/arm pain was significantly associated with higher preoperative expectations in multivariable models, whereas lower depression was associated with higher expectations in the cervical model only ( P <0.05). Significant demographic/clinical factors varied for the lumbar and cervical models, with planned posterior decompression versus ACDF associated with lower preoperative expectations ( P <0.05).

Conclusions: Results support the use of spine-specific multidimensional HSS Expectations surveys for lumbar and cervical spine surgery. Overall, the study underscores the importance of leg/arm pain and depression to preoperative expectations. A better understanding of preoperative expectations and the factors influencing them can help surgeons set realistic expectations with their patients.

Study design: Single-institution retrospective cohort study.

Objective: To compare patients undergoing ASD surgery with an upper instrumented vertebrae (UIV) in the upper-thoracic, mid-thoracic, or lower-thoracic spine regarding: (1) preoperative factors, (2) perioperative variables, and (3) postoperative outcomes.

Background: The classic teaching in adult spinal deformity surgery (ASD) is to avoid stopping a construct in the mid-thoracic spine; however, this theory remains untested.

Materials and methods: Patients undergoing ASD surgery from 2009 to 2021 with a 2-year follow-up were reviewed. Standard demographic, radiographic, and perioperative data were collected. The primary independent variable was UIV location: upper-thoracic: C7-T4, mid-thoracic: T5-T8, and lower-thoracic: T9-L2. Outcomes included mechanical complications, reoperations, and patient-reported outcome measures.

Results: Of 190 patients, the UIV region was: 29 (15.3%) upper-thoracic UIV, 42 (22.1%) mid-thoracic, and 119 (62.6%) lower-thoracic. Preoperatively, mid-thoracic UIV patients were older than upper-thoracic UIV (71.7±10.8 vs . 60.6±14.1, P <0.001). Perioperatively, mid-thoracic UIV had higher estimated blood loss than both upper-thoracic ( P =0.047) and lower-thoracic ( P <0.001) groups. Radiographically, C7-plumb line (C7PL) correction was greater in mid-thoracic versus lower-thoracic UIV (27.9±28.0° vs . 16.8±17.7°, P =0.045). Postoperatively, mid-thoracic UIV had higher rates of pseudarthrosis (47.6% vs . 20.7%, P =0.021), reoperation for mechanical complications (50.0% vs . 20.7%, P =0.012), and reoperation for any reason (52.4% vs . 20.7%, P =0.007) versus upper-thoracic UIVs. Compared with lower-thoracic UIVs, mid-thoracic UIVs had higher rates of pseudarthrosis (47.6% vs . 28.6%, P =0.025) and rod fracture (38.1% vs . 20.2%, P =0.021). No difference was found in proximal junctional kyphosis/failure or PROMs.

Conclusion: Mid-thoracic UIVs had higher rates of pseudarthrosis and both mechanical and all-cause reoperations compared with upper-thoracic UIVs, as well as higher rates of pseudarthrosis and rod fractures compared with lower-thoracic UIVs. The only superior outcome of a mid-thoracic UIV was greater coronal C7PL correction versus lower-thoracic UIV. These findings suggest stopping ASD constructs in the mid-thoracic spine may yield worse outcomes and should be approached cautiously.