Clinical Spine Surgery最新文献

The future of space exploration will include a prolonged presence on the Moon, commercial low-orbit spaceflight, and long-range missions to Deep Space, including a prolonged Martian presence. Understanding the effects the space environment will have on astronauts' musculoskeletal system is mission critical and include both microgravity and space radiation. In spaceflight, crewmembers are exposed to a vast mixture of radiation species and energies including cosmic rays (CR) from galactic cosmic radiation (GCR), solar ejections, and neutrons. Any trip beyond the protection of the Earth's electromagnetic field will expose astronauts to the near-maximum levels of lifetime allowable radiation exposure. We have previously reviewed how microgravity induces pathophysiological adaptations in the spine and how countermeasure strategies can play a role in minimizing astronaut morbidity. Now, through the National Aeronautics and Space Administration's (NASA) Human Research Roadmap (HRR), there is a renewed interest in characterizing and mitigating the effects of radiation as astronauts prepare for the Artemis missions and beyond. Thus, our aim in this critical narrative review is to focus on how the second greatest challenge to crewmembers' health, radiation, and identify how potential countermeasures will affect the spine.

Study design: Retrospective analysis.

Objective: To compare sarcopenia to frailty and socioeconomic deprivation as preoperative predictors of mortality and complications in thoracolumbar spine trauma.

Summary of background data: Sarcopenia is a progressive musculoskeletal disorder characterized by the loss of muscle mass and function. Recently, it has gained recognition as an important surgical risk factor. Prior studies have demonstrated its association with adverse outcomes in spine surgery for degenerative, deformity, and neoplastic indications. Currently, there is a dearth of literature investigating the role of sarcopenia in thoracolumbar trauma.

Methods: Adult patients undergoing instrumentation and stabilization of thoracolumbar spine trauma were identified at an urban academic level-1 trauma center. Sarcopenia was measured using the L3 total psoas area over vertebral body area (L3-TPA/VBA) measured from perioperative computed tomography (CT) scans. Area deprivation index (ADI) was determined according to the publicly available Neighborhood Atlas data set. Frailty was measured using the modified 5-factor frailty index (mFI-5). Statistical analysis consisted of Pearson χ 2 tests, univariate logistic regression, determination of Spearman correlation coefficient ( rs ), and multivariable logistic regression controlling for demographics and polytraumatic injuries.

Results: A total of 276 patients were included. A total of 22 mortalities occurred (7.7%), with 18 (6.3%) occurring within 90-days postoperatively. On univariate analysis, only the mFI-5 scale was associated with 1-month (OR=2.42, P <0.001), 3-month (OR=2.61, P <0.001), and overall mortality (OR=2.29, P <0.001). On multivariate analysis, none of the sarcopenia, ADI, or mFI-5 were independently associated with mortality, the occurrence of postoperative complications, or revision.

Conclusions: Frailty is a better predictor of mortality in thoracolumbar trauma when compared with sarcopenia and ADI. However, an mFI threshold of 2+ may act synergistically with sarcopenia to increase mortality rates.

Level of evidence: Level III.

Study design: Secondary analysis of a prospective cross-sectional study at an academic tertiary spine care center.

Objectives: To examine the prevalence and risk factors for preoperative Vitamin D (VitD) deficiency and secondary hyperparathyroidism (SHPT), and to assess the seasonal variation of metabolic bone laboratory parameters in patients undergoing lumbar fusion surgery (LFS).

Summary of background data: LFS relies on adequate connective tissue quality and bone healing capacity. VitD deficiency and SHPT significantly impact bone metabolism and are linked to lower fusion rates and poorer bone quality. However, their seasonal variation in LFS patients remains unexplored.

Methods: Patients undergoing LFS for degenerative conditions received preoperative VitD, parathyroid hormone (PTH), and bone turnover markers laboratory routinely from December 2014 to December 2023. Descriptive and comparative statistics, logistic regression, and univariable and multivariable cosinor regression models were used to evaluate VitD status, SHPT prevalence, their risk-factors and seasonal variations in VitD, PTH, and bone turnover markers.

Results: Data from 431 patients (49% female, median age 64 y) was analyzed. VitD insufficiency (<30 ng/mL) was observed in 34% of patients, ranging from 48% in winter to 25% in summer. SHPT was present in 24%, with winter prevalence at 28%. Surgery during winter and spring was associated with a 7.5-fold increased risk of VitD deficiency and a 2.1-fold increased risk of SHPT. Seasonal changes with peaks for VitD, PTH, and bone-specific alkaline phosphatase were observed in July, February, and November, respectively, with no significant annual variation in other bone metabolism markers.

Conclusions: The prevalence of VitD deficiency and SHPT in LFS patients is high, especially during winter and spring. Seasonal variations in VitD and bone metabolism markers suggest that single-timepoint laboratory evaluations may not reflect bone metabolism throughout the year, highlighting the need for further studies investigating whether seasonal factors in preoperative assessments could affect outcomes.

Study design: Retrospective study.

Objective: To evaluate clinical and radiologic outcomes of fusionless lumbar spine stabilization using a tendon allograft loop through the spinous process, following microsurgical decompression to address procedure-related destabilization.

Summary of background data: The limitations of traditional spinal fusion and decompression surgeries have driven the development of motion-preserving alternatives that maintain natural vertebral mobility while providing structural stability, thereby reducing complications and long-term consequences associated with rigid fixation.

Methods: Twenty patients with low-grade stable degenerative spondylolisthesis who underwent primary lumbar decompression for spinal stenosis and ligamentous stabilization using the trans-spinous tendon allograft technique between 2022 and 2023 were included. The Oswestry disability index (ODI) and visual analog scale (VAS) for back/leg pain were recorded. Radiographs assessed adjacent segment degeneration and spinous process integrity, and MRI scans evaluated decompression and tendon allograft status.

Results: Median ODI improved significantly at all time points compared with baseline: 6-month ODI: 16 points (IQR=4.5-26), P =0.0013; 1-year ODI: 16.5 points (IQR=4-22), P =0.0013, with no significant difference between 6-month and 1-year results ( P =1). Similar trends were observed for scores. One patient required revision surgery due to a facet joint cyst compressing a nerve root. Eleven patients (55%) experienced spinous process fractures, but clinical outcomes did not differ between patients with and without fractures: 6-month ODI: P =0.921, 1-year ODI: P =0.985; 6-month VAS back: P =0.507, 1-year VAS back: P =0.767; 6-month VAS leg: P =0.826, 1-year VAS leg: P =0.747. Patients with fractures were significantly older ( P =0.023).

Conclusion: The trans-spinous process vertebropexy technique with decompressive bilateral laminotomy compromises spinous process integrity, causing high fracture rates. Although these fractures have minimal clinical impact, the current stabilization technique should be abandoned due to inadequate safety and efficacy. Technique refinement, larger prospective studies, and extended follow-up are necessary before clinical implementation.

Level of evidence: Level III-retrospective analysis.

Study design: Retrospective cohort study.

Objective: To understand the strengths of titanium cages for ACDF using a propensity score matched analysis while characterizing radiologic and clinical outcomes associated with graft material.

Summary of background evidence: Structural allografts and synthetic grafts such as titanium cages have been frequently utilized for anterior cervical discectomy and fusion (ACDF). Although the biomechanical properties have been compared between these 2 graft types, there remains limited data on their comparative performance for cervical procedures.

Methods: We assembled a cohort of patients who underwent an ACDF with a structural allograft or titanium cage at a tertiary care medical center and community hospital by a single surgeon. To compare outcomes, 1:1 propensity score matching was performed using optimal pair matching and a generalized linear model.

Results: Of 376 patients, 269 received a structural allograft and 107 a titanium cage [median age: 56 y, 51.6% (n=194) female, 22.9% (n=86) current smokers]. Almost half of ACDFs (161 patients, 42.8%) were multilevel fusions. Across both graft materials, ACDFs had a relatively safe complication profile with a low intraoperative blood loss. There was durable symptom relief, with 94.5% (n=345 of 365) of patients reporting improved to resolved symptoms at last follow-up. Patients with titanium cages had significantly greater cervical Cobb angle change compared with patients with structural allografts (P<0.001). After propensity score matching, patients with titanium cages had a lower estimated blood loss (P=0.03) and shorter hospital length of stay (P<0.001). However, there were no significant differences in rates of fusion, cage subsidence, pseudoarthrosis, or revision surgery.

Conclusions: Titanium cages demonstrate a similar safety and efficacy profile to structural allografts and may enable greater cervical Cobb angle changes. Longer neurosurgical follow-up may be required to assess need for revision procedures and quantitative patient-reported outcomes across cage materials.

Study design: Retrospective review.

Objective: Determine the rate of bony union of an integrated cage/screw polyether-ethyl ketone (PEEK) cervical interbody fusion device with computed tomography (CT) and provide long-term outcomes of patients treated with such.

Summary of background data: Anterior cervical discectomy and fusion (ACDF) is a common treatment option for patients with degenerative cervical conditions that have failed conservative treatment. Stand-alone anchored cages offer the theoretical advantage of decreasing soft tissue dissection off the anterior vertebral body and mitigating risk to surrounding structures while still achieving solid fusion.

Methods: A retrospective review was conducted from a single institution's enrollment data during a postmarket surveillance study for the Stalif-C (Centinel Spine, West Chester, PA). Three surgeons independently reviewed CT scans from 1 and 2-year follow-up visits to assess for fusion. The criteria for fusion were the presence of bridging bone in at least one of 5 regions (anterior, posterior, right, left uncovertebral joint, and intracage) on 2 consecutive slices of the CT scan using 1 mm coronal and sagittal reformats. These same surgeons repeated their assessment of the imaging studies at a minimum of 2 weeks after the initial review. The resulting fusion rates were then averaged to provide a mean fusion rate at the 1 and 2-year points.

Results: A total of 34 patients were enrolled in the study with 2 patients withdrawing consent after the procedure. Thirty had completed their 1-year follow-up with imaging studies comprising 32 levels treated. Twenty-three patients (25 levels) completed a 2-year follow-up at the time of this study. The average bony fusion rate at 1 year was 37% (range: 19%-56%) and at 2 years was 50% (range: 40%-60%).

Conclusion: The rate of bony fusion as assessed by CT scans at 1 and 2 years was 37% and 50%, respectively. This is well below previously published fusion rates for standalone constructs.

Level of evidence: Level III.

Study design: Retrospective cohort study.

Objectives: To assess the impact of frailty, using modified 5-item frailty index (mFI-5), and sarcopenia, using temporalis muscle thickness (TMT), on motor and functional outcomes in patients with acute traumatic central cord syndrome (ATCCS).

Summary of background data: Patients who suffer from ATCCS often are elderly patients who may be frail and sarcopenic. It would be useful to know the impact it has on their outcome, to see how they fair and identify the areas that need improvement.

Methods: Receiver operating characteristic analysis determined the optimal cut-off value of TMT at 3.965 mm. Patients were considered sarcopenic if their average TMT value was less than 3.965 mm. Primary outcomes were significant improvement in the American Spinal Injury Association Motor Score (AMS) scores at 6 and 12 months. Secondary outcomes were significant improvement in Functional Independence Measure (FIM) at 6 months, and significant recovery of Modified Japanese Orthopedic Association (mJOA) at 6 months. Logistic regression was performed to assess the influence of mFI-5 and TMT on these outcomes.

Results: A total of 80 patients were used in this study. Significant improvement in AMS improvement (71.4% vs. 90.4%, P=0.028), significant improvement in FIM (42.9% vs. 71.2%, P=0.013), and significant recovery in mJOA (14% vs. 38%, P=0.039) were all significantly lower in sarcopenic patients. Multivariate analysis found that the presence of sarcopenia was inversely related to significant improvement in FIM at 6 months (OR 0.026, 95% CI 0.002-0.414, P=0.010). The MFI score of 0 was positively associated with significant improvement in FIM at 6 months (OR 64.189, 95% CI 2.643-1412.016, P=0.010).

Conclusions: Frailty and sarcopenia have a significant effect on motor and functional outcomes in ATCCS patients.

Study design: Retrospective case series.

Objective: To report on the early clinical safety profile and accuracy of Augmented reality (AR)-assisted pedicle screw placement in patients undergoing minimally invasive spinal surgery.

Summary of background data: While navigation-guided pedicle screw placement has improved accuracy rates to 89-100%, current systems face challenges, including line-of-sight interruptions and attention shift from patient to remote screens. AR technology projects navigation data directly onto the surgical field, potentially overcoming these limitations while maintaining high accuracy.

Methods: A multi-center retrospective analysis was conducted across two institutions, reviewing 31 procedures involving 200 pedicle screws placed using the Xvision AR navigation system (Augmedics Inc.). All procedures were performed by fellowship-trained spine surgeons. Accuracy was assessed using pre- and post-instrumentation CT O-arm imaging according to the Gertzbein and Robbins classification system. Novel angular deviation analysis was performed to evaluate trajectory accuracy. Clinical outcomes, including complications and revision rates, were recorded.

Results: Among 200 pedicle screws analyzed, 84.5% were classified as Gertzbein-Robbins grade A (complete containment), 13.5% as grade B (trivial breach), and 2% as grade C, yielding an overall accuracy rate of 98%. The pedicle breach rate was 15.5%, with no instances of superior endplate or facet joint violations. Mean angular deviation from the ideal trajectory was 0.78±4.56 degrees. No screw revisions, hardware-related complications, or symptomatic nerve encroachment occurred. Two patients experienced non-hardware-related systemic infections.

Conclusions: AR-assisted navigation demonstrates high accuracy for pedicle screw placement with minimal angular deviation and low complication rates. This technology offers promising potential for improving surgical precision while maintaining workflow efficiency.

Level of evidence: Level IV.

Odontoid fractures comprise 10%-15% of all cervical fractures in adults, of which Anderson and D'Alonzo type II odontoid fractures are the most common subtype. Anterior screw fixation for type IIB odontoid fractures is a safe and effective treatment option in the properly selected patient. This less invasive technique preserves the C1-C2 motion while stabilizing the dens and yields a high union rate with minimum morbidity in appropriately indicated patients. Younger patients and nonosteoporotic patients with anterior superior to posterior inferior (type IIB) fracture patterns are ideal candidates. The authors recommend using a noncannulated system with a single fully threaded screw and a lag technique to achieve bicortical fixation across the fracture. This paper presents an anterior odontoid screw fixation for type II odontoid fractures with a detailed technical guide in written and accompanying video format. We also discuss appropriate indications, contraindications, complications, and technical pearls. The full video illustrating this surgical technique and approach can be found at: https://www.youtube.com/watch?v=HKW4JO3HBxo&list=PL_UtVTe4NFuIYo3BabDnWtCiInnkelbJy&index=6.

Study design: A retrospective study using the TriNetX Research Network.

Objective: Evaluate the prevalence of malnutrition and its impact on postoperative complications in patients undergoing posterior cervical spinal instrumentation.

Summary of background data: Malnutrition, commonly identified by serum albumin <3.5 g/dL, has been linked to surgical site infections (SSI) and wound dehiscence (WD). However, data specific to posterior cervical spine surgery remain limited.

Methods: Using TriNetX, adult patients who had single- or multilevel posterior cervical spine instrumentation with diagnoses including stenosis, myelopathy, disc disorder, radiculopathy, spondylosis, or spondylolisthesis, and a preoperative albumin measurement within 30 days, were identified. Patients grouped by albumin <3.5 g/dL or ≥3.5 g/dL. Propensity score matching controlled for age, sex, race, and comorbidities. Primary outcomes were SSI and WD, with reoperation as a secondary outcome, identified within 90 days postsurgery.

Results: Of 7607 patients (mean age: 61.8±12.6 y, 54.8% male), 1790 (23.5%) had albumin <3.5 g/dL. Before matching, malnourished patients had higher odds of SSI/WD (OR=1.400, 95% CI: 1.105-1.775) and reoperation (OR=1.472, 95% CI: 1.241-1.745) compared with patients with adequate nutritional status. After matching (1785 patients/group), malnourished patients showed elevated odds of SSI/WD (OR=1.377, 95% CI: 1.016-1.866) and reoperation (OR=1.380, 95% CI: 1.111-1.716) within 90 days.

Conclusion: In this large retrospective matched analysis, malnutrition (albumin <3.5 g/dL) was present in 23.5% of adults undergoing posterior cervical spinal instrumentation. Malnourished patients had ∼40% higher odds of postoperative SSI, WD, and reoperation within 90 days compared with those with albumin ≥3.5 g/dL. These complications prolong hospitalization, increase health care costs, and negatively affect patient outcomes. Minimizing them is critical, and malnutrition is a modifiable risk factor. Our findings underscore the importance of routine nutritional evaluation and interventions before posterior cervical spine surgery. Further studies should explore nutritional supplementation and its impact on reducing postoperative morbidity in malnourished patients.

Level of evidence: Level III.