Spine Journal最新文献

Background context: Pedicle screw instrumentation is widely used in spine surgery. Axial screw misplacement is a common complication. In addition to the recognized neurovascular risks associated with screw misplacement, the biomechanical stability of misplaced screws remains a subject of debate.

Purpose: The present study investigates whether screw misplacement in the lumbar spine reduces mechanical screw hold.

Study design/setting: Cadaveric biomechanical study.

Methods: Pedicle screw (mis)placement was planned for 12 fresh frozen cadaveric spines between the T12 and the L5 levels. The screws were then implanted into the vertebrae with the help of 3D-printed template guides. Pre- and postinstrumentation computed tomography (CT) scans were acquired for instrumentation planning and quantification of the misplacement. The instrumented vertebrae were potted into CT transparent boxes using Polymethyl methacrylate and mounted on a standardized biomechanical setup for pull-out (PO) testing with uniaxial tensile load.

Results: The bone density of all the specimens as per HU was comparable. The predicted pull-out force (POF) for screws medially misplaced by 2 , 4, and 6 mm was respectively 985 N (SD 474), 968 N (SD 476) and 822 N (SD 478). For screws laterally misplaced by 2 , 4, and 6 mm the POF was respectively 605 N (SD 473), 411 N (SD 475), and 334 N (SD 477). Screws that did not perforate the pedicle (control) resisted pull-out forces of 837 N (SD 471).

Conclusions: Medial misplacement is associated with increased axial screw hold against static loads compared to correctly placed screws and laterally placed screws.

Clinical significance: In clinical settings, the reinsertion of medially misplaced screws should primarily aim to prevent neurological complications while the reinsertion of lateral misplaced screws should aim to prevent screw loosening.

Background context: Low back pain (LBP) among children and adolescents is a growing global concern. Disc degeneration (DD) is considered a significant factor in the clinical symptom of LBP. Both LBP and DD become more prevalent as adolescents transition into emerging adulthood. However, the relationship between growth during the pubertal growth spurt and the morphology of lumbar discs has yet to be elucidated.

Purpose: This study aimed to assess the relationship between bodily growth during the pubertal growth spurt and the morphology of lumbar discs at age 18.

Study design: This study was a prospective longitudinal cohort study.

Patient sample: A randomly selected cohort of healthy children was examined at ages 8, 11, and 18. Participants with complete data sets (semi-structured interview, anthropometric measurements and lumbar spine MRI) at age 11 and 18 were included in this analysis (n=59).

Outcome measures: The morphological characteristics of lumbar discs were evaluated on MRI. Anthropometric measures including height, sitting height and weight were obtained to calculate the Body Surface Area (BSA) and the Body Mass Index (BMI).

Methods: The morphology of the lumbar discs was evaluated on T2-weighted midsagittal MRI using the Pfirrmann classification. A disc with a Pfirrmann grade of 3 or higher was considered degenerated at age 18. The relationship between relative growth between ages 11 and 18 (adjusted to sex and baseline values) and DD at age 18 was assessed. To analyze the relationship between the relative increase in BSA and DD, the participants were categorized into three equal-sized categories (tertiles). For all other anthropometric measures, the analysis was based on the relative increase in each measure between ages 11 and 18.

Results: In the highest tertile of relative increase in BSA (≥43%), 76% of participants had at least 1 disc with a Pfirrmann grade 3 or higher at age 18 while only 10% and 21% of participants in the lowest and medium tertiles had DD, respectively. The sex- and baseline-adjusted odds ratio (OR) for DD at age 18 for every additional 10% increase in BSA was 1.08 (1.02-1.15). The sex- and baseline-adjusted OR (95% CI) for DD at age 18 was 10.5 (1.60-68.7) and 7.92 (1.19-52.72) with every additional 10% increase in height and sitting height, respectively. For every additional 10% increase in weight, the adjusted OR for DD at age 18 was 1.51 (1.12-2.04) and for BMI 1.05 (1.01-1.09).

Conclusions: More relative growth between ages 11 and 18 is significantly associated with the occurrence of DD in emerging adulthood. Among the measures investigated, height and sitting height are nonmodifiable. Maintaining an ideal body weight during the pubertal growth spurt may be beneficial for the health of the lumbar discs.

Background context: Osteoporosis has been proposed as a risk factor for reoperation after anterior cervical discectomy and fusion (ACDF), yet this potential association has been understudied, with conflicting results to date.

Purpose: This study examines the hypothesis that adults with osteoporosis would have an increased risk of reoperation after ACDF compared to matched adults without osteoporosis.

Study design/setting: Retrospective cohort study.

Patient sample: Two matched cohorts (mean age: 62 years; 75% female), each with 1,019 patients, who underwent primary ACDF. Cohorts were determined by the presence or absence of a diagnosis of osteoporosis.

Outcome measures: Incidence of reoperation occurring over 4 years postoperatively, with our primary outcome being the risk ratio (RR) of reoperation with 95% confidence intervals (CI). Secondary outcomes included risk and mean count of oral opioid prescriptions and risk of pseudoarthrosis.

Methods: We utilized the TriNetX network to identify adults undergoing their first ACDF from 2004 to 2020, excluding those with serious pathology, and divided patients into 2 cohorts: osteoporosis and nonosteoporosis. Patients were propensity matched according to key risk factors for reoperation.

Results: Patients with osteoporosis had no statistically significant or meaningful difference in risk of reoperation compared to nonosteoporotic patients over 4-years' follow-up [95% CI] (17.3% vs 16.5%; RR: 1.05 [0.86, 1.27]; p=.6361). Similarly, there were no significant differences in the risk of pseudoarthrosis (26.5% vs 29.1%; RR: 0.91 [0.79, 1.05]; p=.1820), oral opioid prescription (75.0% vs 76.0%; RR: 0.99 [0.94, 1.04]; p=.6067), or mean oral opioid prescription count (11.5 vs 11.8; p=.7040).

Conclusions: Compared to matched nonosteoporosis controls, osteoporosis was not associated with a statistically significant or clinically meaningful increase in risk of reoperation in adults over 4 years after ACDF. Furthermore, osteoporosis was not associated with a significant or meaningful risk of pseudoarthrosis or oral opioid prescription after ACDF, although more research is needed for corroboration. Additional research is needed to clarify whether those with osteoporosis have meaningful differences in pain and function compared to those without osteoporosis following ACDF.

Background context: Native Vertebral Osteomyelitis (NVO) has seen a rise in incidence, yet clinical outcomes remain poor with high relapse rates and significant long-term sequelae. The 2015 IDSA Clinical Practice Guidelines initiated a surge in scholarly activity on NVO, revealing a patchwork of definitions and numerous synonyms used interchangeably for this syndrome.

Purpose: To systematically summarize these definitions, evaluate their content, distribution over time, and thematic clustering.

Study design/setting: Meta-epidemiological study with a systematic review of definitions.

Patients sample: An extensive search of multiple databases was conducted, targeting trials and cohort studies dating from 2005 to present, providing a definition for NVO and its synonyms.

Outcome measures: Analysis of the diagnostic criteria that composed the definitions and the breaking up of the definitions in the possible combinations of diagnostic criteria.

Methods: We pursued a thematic synthesis of the published definitions with Boolean logic, yielding single or multiple definitions per included study. Using 8 predefined diagnostic criteria, we standardized definitions, focusing on the minimum necessary combinations used. Definition components were visualized using Sankey diagrams.

Results: The literature search identified 8,460 references, leading to 171 studies reporting on 21,963 patients. Of these, 91.2% were retrospective, 7.6% prospective, and 1.2% RCTs. Most definitions originated from authors, with 29.2% referencing sources. We identified 92 unique combinations of diagnostic criteria across the literature. Thirteen main patterns emerged, with the most common being clinical features with imaging, followed by clinical features combined with imaging and microbiology, and lastly, imaging paired with microbiology.

Conclusions: Our findings underscore the need for a collaborative effort to develop standardized diagnostic criteria. We advocate for a future Delphi consensus among experts to establish a unified diagnostic framework for NVO, emphasizing the core components of clinical features and MRI while incorporating microbiological and histopathological insights to improve both patient outcomes and research advancements.

Background context: In cases of basilar invagination-atlantoaxial dislocation (BI-AAD) complicated by atlas occipitalization (AOZ), the approach to cranial end fixation has consistently sparked debate, generally falling into two categories: C1-C2 fixation and occipitocervical fixation. Several authors believe that C1-C2 fixation carries a lower risk of fixation failure than occipitocervical fixation.

Purpose: To study the biomechanical differences among 3 different cranial end fixation methods for BI-AAD with AOZ.

Study design: This was a finite element analysis.

Patient sample: A 35-year-old female patient diagnosed with congenital BI-AAD and AOZ.

Outcome measures: range of motion (ROM), peak von Mise stress (PVMS), cage micro-subsidence, cage micro-slippage.

Method: Four finite element models were constructed, including unstable group (BI-AAD with AOZ), C1 lateral mass screw group, occipital plate group, occipitocervical rod group. The flexion and extension (FE), lateral bending (LB) as well as axial rotation (AR) were simulated under a torque of 1.5 Nm. Parameters include C1-C2 ROM, PVMS on screw-rod construct, cage micro-subsidence, cage micro-slippage.

Results: The ROM of the C1 lateral mass screw group was smaller than that of the other fixation groups in LB and AR, but not FE. Compared with the occipitocervical rod group, the ROM in LB and AR of the occipital plate group was higher, but not in FE. The PVMS of C1 lateral mass screw group was significantly higher than that of the other groups. The ROM and PVMS of the occipitocervical rod group were in between the other 2 groups. Regarding the screws at the cranial end, the PVMS of the 4-screw occipitocervical rod group was significantly lower than that of the other groups. In general, the cage micro-motion follows the ascending order: C1 lateral mass group < occipitocervical rod group < occipital plate group.

Conclusions: In cases of BI-AAD with AOZ, the C1 lateral mass screw group provided the least ROM and cage micro-motion, but the screw-rod PVMS was the largest. The advantage of occipital plate fixation lies in the lowest screw-rod PVMS, but the ROM and cage micro-motion is the highest. Four-screw fixation at the cranial end of occipitocervical rod group helps to reduce the PVMS and may prevent screw failure at the cranial end.

Background context: Numerous prognostic models are utilized for surgical decision and prognostication in metastatic spine tumors. However, these models often fail to consider the whole-body tumor burden into account, which may be crucial for the prognosis of metastatic cancers. A potential surrogate marker for tumor burden, whole-body metabolic tumor burden (wMTB), can be calculated from total lesion glycolysis (TLG) obtained from ¹⁸F-Fludeoxyglucose positive emission tomography (¹⁸F-FDG PET) images.

Purpose: We aimed to improve prognostic power of current models by incorporating wMTB for nonsmall cell lung cancer (NSCLC) patients with spine metastases.

Design: Retrospective analysis using a review of electrical medical records and survival data.

Patient sample: In this study, we included 74 NSCLC patients with image proven spine metastases.

Outcome measures: Increase in Integrated Discrimination Improvement (IDI) index after incorporation of wMTB into prognostic scores.

Methods: Enrolled patients' baseline data, cancer characteristics and survival status were retrospectively collected. Five widely used prognostic scores (Tomita, Katagiri, Tokuhashi, Global Spine Tumor Study Group [GSTSG], New England Spine Metastasis Score [NESMS]), and TLG indexes were calculated for all patients. The relationships among survival time, prognostic models and TLG values were analyzed. Improvement of prognostic power was validated by incorporating significant TLG index into significant current models.

Results: Among current prognostic models, Tomita (EGFR wild-type), Katagiri, GSTSG and Tokuhashi were significantly related to patient survival. Among TLG indexes, LogTLG3 was significantly related to survival. Incorporation of LogTLG3 into significant prognostic models resulted in positive IDI index until 3 years in all models.

Conclusions: This study showed that incorporation of wMTB improved prognostic power of current prognostic models of metastatic spine tumors.

Background context: Healthcare reimbursement is evolving towards a value-based model, entwined and emphasizing patient satisfaction. Factors associated with satisfaction after degenerative cervical myelopathy (DCM) surgery have not been previously established.

Purpose: Our primary objective was to ascertain satisfaction rates and satisfaction predictors at 3 and 12 months following surgical treatment for DCM.

Design: This is a prospective cohort study within Canadian Spine Outcomes and Research Network (CSORN).

Patient sample: Patients in the study were surgically treated for DCM patients who completed 3-month and 12-month follow-ups within CSORN between 2015 and 2021.

Outcome measures: Data analyzed included patient demographic, surgical variables, patient-reported outcomes (NDI, NRS-NP, NRS-AP, SF-12-MCS, SF-12-PCS, ED-5Q, PHQ-8), MJOA and self-reported satisfaction on a Likert scale.

Methods: Multivariable regression analysis was conducted to identify significant factors associated with satisfaction, address multicollinearity and ensure predictive accuracy. This process was conducted separately for the 3-month and 12-month follow-ups.

Results: Six hundred and sixty-three patients were included, with an average age of 60, and an even distribution across MJOA scores (mild, moderate, severe). At 3-month and 12-month follow-up, satisfaction rates were 86% and 82%, respectively. At 12 months, logistic regression showed the odds of being satisfied varied by +24%, -3%, -10%, -14%, +3%, and +12% for each 1-point change between baseline and 12 months in MJOA, NDI, NRS-NP, NRS-AP, SF-12-MCS, SF-12-PCS. Satisfaction increased 11-fold for each 0.1-point increased in ED-5Q from baseline to 12 months. At baseline, for every 1-point increase in SF-12-MCS, the odds of being satisfied increased by 7%. At 3 months, all PROs (except for NRS-AP change and baseline SF-12-MCS) predicted satisfaction. All logistic regression analyses demonstrated excellent predictive accuracy, with the highest 12-month AUC of 0.86 (95%CI=0.81-0.90). No patient demographic or surgical factors influenced satisfaction.

Conclusions: Improvement in Patient Reported Outcomes and MJOA are strongly associated with patient satisfaction after surgery for DCM. The only baseline PRO associated with 12-months satisfaction was SF-12-MCS. No modifiable patient baseline characteristic or surgical variables were associated with satisfaction.