Risk factors for distal junctional failure in long-construct instrumentation for adult spinal deformity.

PURPOSE: The aim of this study is to identify risk factors associated with postoperative DJF in long constructs for ASD. METHODS: A retrospective review was performed at a tertiary referral spine centre from 01/01/2007 to 31/12/2016. Demographic, clinical and radiographic parameters were collated for patients with DJF in the postoperative period and compared to those without DJF. Survival analyses were performed using univariate logistic regression to identify variables with a p value < 0.05 for inclusion in multivariate analysis. Spearman's correlations were performed where applicable. RESULTS: One hundred two patients were identified. 41 (40.2%) suffered DJF in the postoperative period, with rod fracture being the most common sign of DJF (13/65; 20.0%). Mean time to failure was 32.4 months. On univariate analysis, pedicle subtraction osteotomy (p = 0.03), transforaminal lumbar interbody fusion (p < 0.001), pre-op LL (p < 0.01), pre-op SVA (p < 0.01), pre-op SS (p = 0.02), postop LL (p = 0.03), postop SVA (p = 0.01), postop PI/LL (p < 0.001), LL correction (p < 0.001), SVA correction (p < 0.001), PT correction (p = 0.03), PI/LL correction (p < 0.001), SS correction (p = 0.03) all proved significant. On multivariate analysis, pedicle subtraction osteotomy (OR 27.3; p = 0.03), postop SVA (p < 0.01) and LL correction (p = 0.02) remained statistically significant as independent risk factors for DJF. CONCLUSION: Recently, DJF has received recognition as its own entity due to a notable postoperative incidence. Few studies to date have evaluated risk factors for DJF. The results of our study highlight that pedicle subtraction osteotomy, poor correction of lumbar lordosis, and sagittal vertical axis are significantly associated with postoperative occurrence of DJF.

Achieving Lumbar Fusion: An Evidence-Based Approach to Selecting Technique, Implants, and Biologics.

Many options currently exist for achieving lumbar fusion. A variety of techniques have been described. The challenge for spine surgeons is choosing which approach is ideal for the given circumstances, and to do this, a good understanding of the available evidence is necessary. The evidence regarding fusion approach, interbody cage utilization, bone grafting, biologics, and osteoporosis is reviewed.

Lumbar disc height and vertebral Hounsfield units: association with interbody cage subsidence.

OBJECTIVE: Postoperative subsidence of transforaminal lumbar interbody fusion (TLIF) cages can result in loss of lordosis and foraminal height, and potential recurrence of nerve root impingement. The objectives of this study were to determine factors associated with TLIF cage subsidence. Specifically, the authors sought to determine if preoperative disc height compared to cage height could be used to predict TLIF interbody cage subsidence, and if decreased postoperative vertebral Hounsfield units (HUs) predisposed to cage subsidence. METHODS: The authors retrospectively reviewed all patients undergoing instrumented TLIF from two institutions between July 2004 and June 2014. The preoperative disc height was measured for the operative and adjacent-level disc on MRI. The difference between cage and disc heights was measured and compared between the subsidence and nonsubsidence groups. The average HUs of the L1 vertebral body were measured on CT scans. RESULTS: Eighty-nine patients were identified with complete imaging and follow-up information. Forty-five patients (50.6%) had evidence of interbody cage subsidence on follow-up CT. The average cage subsidence was 5.5 mm (range 2.2-10.8 mm). The average implant height was significantly higher in the subsidence group compared to the nonsubsidence group (12.6 vs 11.2 mm). Additionally, the difference between cage height and preoperative adjacent-level disc height was also significantly larger in the subsidence group (3.8 vs 1.2 mm). First lumbar vertebral body (L1) HUs were significantly higher in the nonsubsidence versus the subsidence group (167.8 vs 137.71 HUs, p = 0.002). Multivariate logistic regression analysis identified suprajacent disc height and L1 HUs to be independent predictors of interbody cage subsidence. Receiver operating characteristic curves identified a suprajacent to cage height difference > 1.3 mm to have a 93.3% sensitivity for cage subsidence. CONCLUSIONS: This study is the first of its kind to demonstrate the association between vertebral body HUs and suprajacent disc height with the development of interbody cage subsidence after TLIF. The authors found that patients with lower HUs in the L1 vertebral body were more likely to experience subsidence, regardless of surgical level. Additionally, the study demonstrated that interbody cage height > 1.3 mm above the height of the suprajacent level is an independent risk factor for cage subsidence, with 93.3% sensitivity. These findings suggest that these factors may be utilized to create a template preoperatively for intraoperative cage selection.

Intrawound Antibiotic Powder Decreases Frequency of Deep Infection and Severity of Heterotopic Ossification in Combat Lower Extremity Amputations.

BACKGROUND: Amputations sustained owing to combat-related blast injuries are at high risk for deep infection and development of heterotopic ossification, which can necessitate reoperation and place immense strain on the patient. Surgeons at our institution began use of intrawound antibiotic powder at the time of closure in an effort to decrease the rate of these surgical complications after initial and revision amputations, supported by compelling clinical evidence and animal models of blast injuries. Antibiotic powder may be useful in reducing the risk of these infections, but human studies on this topic thus far have been inconclusive. PURPOSE: We sought to determine whether administration of intrawound antibiotic powder at the time of closure would (1) decrease the risk of subsequent deep infections of major lower-extremity combat-related amputations, and (2) limit formation and decrease severity of heterotopic ossification common in the combat-related traumatic residual limb. METHODS: Between 2009 and 2015, 252 major lower extremity initial and revision amputations were performed by a single surgeon. Revision cases were excluded if performed specifically to address deep infection, leaving 223 amputations (88.5%) for this retrospective analysis. We reviewed medical records to collect patient information, returns to the operating room for subsequent infection, and microbiologic culture results. We also reviewed radiographs taken at least 3 months after surgery to determine the presence and severity of heterotopic ossification using the Walter Reed classification system. We grouped cases according to whether limbs underwent initial or revision amputations, and whether the limbs had a history of a prior infection. Apart from the use of antibiotic powder and duration of followup, the groups did not differ in terms of age, mechanism of injury, or sex. We then calculated the absolute risk reduction for infection and heterotopic ossification and the number needed to treat to prevent an infection. RESULTS: Overall, administration of antibiotic powder resulted in a 13% absolute risk reduction of deep infection (14 of 82 [17%] versus 42 of 141 [30%]; p = 0.03; 95% CI, 0.20%-24.72%). In revision amputation surgery, the absolute risk reduction of infection with antibiotic powder use was 16% overall (eight of 58 versus 17 of 57; 95% CI, 1.21%-30.86%), and 25% for previously infected limbs (eight of 46 versus 14 of 33; 95% CI, 4.93%-45.14%). The number needed to treat to prevent one additional deep infection in amputation surgery is eight in initial amputations, seven in revision amputations, and four for revision amputation surgery on previously infected limbs. With the numbers available, we observed no reduction in the risk of heterotopic ossification with antibiotic powder use, but severity was decreased in the treatment group in terms of the number of residual limbs with moderate or severe heterotopic ossification (three of 12 versus 19 of 34; p = 0.03). CONCLUSIONS: Our findings show that administration of intrawound antibiotic powder reduces deep infection in residual limbs of combat amputees, particularly in the setting of revision amputation surgery in apparently aseptic residual limbs at the time of the surgery. Furthermore, administration of antibiotic powder for amputations at time of initial closure decreases the severity of heterotopic ossification formation, providing a low-cost adjunct to decrease the risk of two complications common to amputation surgery.Level of Evidence Level III, therapeutic study.

The Use of Distal Ulnar Hounsfield Units to Predict Future Fragility Fracture Risk.

PURPOSE: Distal ulnar Hounsfield unit (HU) measurements obtained from computed tomography (CT) scans of the wrist can be used to accurately screen for low bone mineral density. It is unknown whether HU measurements can also predict the risk of future fragility fractures. Therefore, the purpose of this study was to determine if the HU values of the distal ulna correlate to fragility fracture risk. METHODS: An electronic database of radiographs at a single institution was searched for all wrist CT scans, obtained for any reason, between January 1, 2002, and December 31, 2008, to allow a minimum of 5-year follow-up. Manual measurement of HU on sequential coronal CT slices of the distal ulnar head was taken, and mean values were recorded. Previously determined cutoff values for the diagnosis of low bone mineral density were implemented to stratify patients as at risk or not at risk for future fragility fracture. Medical records were then manually reviewed for the occurrence of any future fragility fracture (hip, spine, proximal humerus, or rib). RESULTS: There were 161 CTs in 157 patients and 34 fragility fractures in 21 patients, with a prevalence of 13.4%. The mean HU in the fragility fracture group was significantly lower (134.2 vs 197.1 HU). The percentage of low HU patients with fragility fractures was significantly higher (22.7% vs 3.8%). The odds ratio for fragility fracture in the low HU group was 7.4 (95% confidence interval, 2.1-26.2). Using previously determined cutoff values, the sensitivity and specificity of distal ulna HU values for identifying patients who would sustain at least 1 future fragility fracture were 85.7% and 55.2%, respectively. CONCLUSIONS: Patients with low distal ulnar HU were significantly more likely to sustain a subsequent fragility fracture. A determination of distal ulnar HUs represents a quick, simple tool to identify patients potentially at risk for fragility fractures. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Fifty Most-Cited Articles in the Orthopaedic Treatment of the Hip.

This study sought to identify the 50 most-cited articles in the literature pertaining to the surgical treatment of the hip, which has not yet been done to the authors' knowledge. In December 2014, an all-years search of the Thompson Institute for Scientific Information Web of Science was conducted for the term ``hip.'' Articles were sorted from most to least cited. Citations per article ranged from 3176 to 372. The majority of the articles were clinical in nature (64%) and hip arthroplasty was the predominant focus (70%). Eight different journals were included. The majority of the articles were published since the 1990s. Sixty-two percent of the articles originated from U.S. institutions. Only 12% of the articles were level I or II evidence with the majority being level IV evidence (44%). This study highlights the paucity of high-quality evidence, and further well-designed studies are needed to guide the future direction of hip surgery.

Pathophysiologic Spine Adaptations and Countermeasures for Prolonged Spaceflight.

Low back pain due to spaceflight is a common complaint of returning astronauts. Alterations in musculoskeletal anatomy during spaceflight and the effects of microgravity (µg) have been well-studied; however, the mechanisms behind these changes remain unclear. The National Aeronautics and Space Administration has released the Human Research Roadmap to guide investigators in developing effective countermeasure strategies for the Artemis Program, as well as commercial low-orbit spaceflight. Based on the Human Research Roadmap, the existing literature was examined to determine the current understanding of the effects of microgravity on the musculoskeletal components of the spinal column. In addition, countermeasure strategies will be required to mitigate these effects for long-duration spaceflight. Current pharmacologic and nonpharmacologic countermeasure strategies are suboptimal, as evidenced by continued muscle and bone loss, alterations in muscle phenotype, and bone metabolism. However, studies incorporating the use of ultrasound, beta-blockers, and other pharmacologic agents have shown some promise. Understanding these mechanisms will not only benefit space technology but likely lead to a return on investment for the management of Earth-bound diseases.

Biomechanical Comparison of Anterior Cervical Plate Fixation Versus Integrated Fixation Cage for Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Cadaveric, biomechanic study. OBJECTIVE: To compare the range of motion profiles of the cervical spine following one-level anterior cervical discectomy and fusion (ACDF) constructs instrumented with either an interbody cage and anterior plate or integrated fixation cage in a cadaveric model. SUMMARY OF BACKGROUND DATA: While anterior plates with interbody cages are the most common construct of fixation in ACDF, newer integrated cage-plate devices seek to provide similar stability with a decreased implant profile. However, differences in postoperative cervical range of motion between the 2 constructs remain unclear. METHODS: Six cadaveric spines were segmented into 2 functional spine units (FSUs): C2-C5 and C6-T2. Each FSU was nondestructively bent in flexion-extension (FE), right-left lateral bending (LB), and right-left axial rotation (AR) at a rate of 0.5°/s under a constant axial load until a limit of 2-Nm was reached to evaluate baseline range of motion (ROM). Matched pairs were then randomly assigned to undergo instrumentation with either the standard anterior cage and plate (CP) or the integrated fixation cage (IF). Following instrumentation, ROM was then remeasured as previously described. RESULTS: For CP fixation, ROM increased by 61.2±31.7% for FE, 36.3±20.4% for LB, and 31.7±19.1% for AR. For IF fixation, ROM increased by 64.2±15.5% for FE, 56.7±39.8% for LB, and 94.5±65.1% for AR. There was no significant difference in motion between each group across FE, LB, and AR. CONCLUSION: This biomechanical study demonstrated increased motion in both the CP and IF groups relative to the intact, un-instrumented state. However, our model showed no differences in ROM between CP and IF constructs in any direction of motion. These results suggest that either method of instrumentation is a suitable option for ACDF with respect to constructing stiffness at time zero.

Rates and Predictors of Surgery for Lumbar Disc Herniation Between the Military and Civilian Health Care Systems.

STUDY DESIGN: Retrospective review (level of evidence III). OBJECTIVE: Surgical care patterns for lumbar disc herniation (LDH), a common musculoskeletal condition of high relevance to the Military Health System (MHS), have not been described or compared across the direct care and purchased care MHS components. This study aimed to describe surgery rates in MHS beneficiaries who were diagnosed with LDH in direct care versus purchased care and to evaluate characteristics associated with the location of surgery. Differences in care patterns for LDH may suggest unexpected variation within the centrally managed MHS. METHODS: We described 1-year rates of surgery among beneficiaries who were diagnosed with LDH in direct care versus purchased care. Among beneficiaries who were diagnosed in direct care and had surgery, multivariable logistic regression models were used to identify characteristics associated with surgery location. RESULTS: We identified 726,638 MHS beneficiaries who were diagnosed with LDH in direct care or purchased care during the 9-year study period. One-year surgery rates were 10.1% in beneficiaries who were diagnosed in direct care versus 11.3% in beneficiaries who were diagnosed in purchased care. Among the 7467 patients who were diagnosed in direct care and had surgery within 1 year, characteristics associated with lower probability of surgery in purchased care versus direct care included diagnosing facility type (hospital with a neurosurgery or spine specialty versus clinic (odds ratio [OR], 0.12 (95% CI, 0.10-0.15)), Navy versus Army (OR, 0.24 (95% CI, 0.21-0.28)), and diagnosing facility specialty (Medical Expense and Performance Reporting System) (surgical care (OR, 0.33 (95% CI, 0.27-0.40)) and orthopedic care (OR, 0.39 (95% CI, 0.33-0.46)) versus primary care. The presence of comorbidities was associated with higher probability of surgery in purchased care versus direct care (OR, 1.20 (95% CI, 1.06-1.36)). CONCLUSIONS: The 1-year rate of surgery for LDH was modestly higher in beneficiaries who were diagnosed in purchased care versus direct care. Among patients who were diagnosed in direct care, several patient-level and facility-level characteristics were associated with receiving surgery in purchased care, suggesting potentially unexpected variation in care utilization across components of the MHS.

Hooks Versus Pedicle Screws at the Upper Instrumented Level: An In Vitro Biomechanical Comparison.

STUDY DESIGN: Controlled laboratory study. OBJECTIVE: The aim was to compare motions at the upper instrumented vertebra (UIV) and supra-adjacent level (UIV+1) between two fixation techniques in thoracic posterior spinal fusion constructs. We hypothesized there would be greater motion at UIV+1 after cyclic loading across all constructs and bilateral pedicle screws (BPSs) with posterior ligamentous compromise would demonstrate the greatest UIV+1 range of motion. SUMMARY OF BACKGROUND DATA: Proximal junctional kyphosis is a well-recognized complication following long thoracolumbar posterior spinal fusion, however, its mechanism is poorly understood. MATERIALS AND METHODS: Twenty-seven thoracic functional spine units were randomly divided into three UIV fixation groups (n=9): (1) BPS, (2) bilateral transverse process hooks (TPHs), and (3) BPS with compromise of the posterior elements between UIV and UIV+1 (BPS-C). Specimens were tested on a servohydraulic materials testing system in native state, following instrumentation, and after cyclic loading. functional spine units were loaded in flexion-extension (FE), lateral bending, and axial rotation. RESULTS: After cyclic testing, the TPH group had a mean 29.4% increase in FE range of motion at UIV+1 versus 76.6% in the BPS group ( P <0.05). The BPS-C group showed an increased FE of 49.9% and 62.19% with sectioning of the facet joints and interspinous ligament respectively prior to cyclic testing. CONCLUSION: BPSs at the UIV led to greater motion at UIV+1 compared to bilateral TPH after cyclic loading. This is likely due to the increased rigidity of BPS compared to TPH leading to a "softer" transition between the TPH construct and native anatomy at the supra-adjacent level. Facet capsule compromise led to a 49.9% increase in UIV+1 motion, underscoring the importance of preserving the posterior ligamentous complex. Clinical studies that account for fusion rates are warranted to determine if constructs with a "soft transition" result in less proximal junctional kyphosis in vivo .

Biomechanical Analysis of Multilevel Posterior Cervical Spinal Fusion Constructs.

STUDY DESIGN: Controlled Laboratory Study. OBJECTIVE: To compare multilevel posterior cervical fusion (PCF) constructs stopping at C7, T1, and T2 under cyclic load to determine the range of motion (ROM) between the lowest instrumented level and lowest instrumented-adjacent level (LIV-1). SUMMARY OF BACKGROUND DATA: PCF is a mainstay of treatment for various cervical spine conditions. The transition between the flexible cervical spine and rigid thoracic spine can lead to construct failure at the cervicothoracic junction. There is little evidence to determine the most appropriate level at which to stop a multilevel PCF. METHODS: Fifteen human cadaveric cervicothoracic spines were randomly assigned to 1 of 3 treatment groups: PCF stopping at C7, T1, or T2. Specimens were tested in their native state, following a simulated PCF, and after cyclic loading. Specimens were loaded in flexion-extension), lateral bending, and axial rotation. Three-dimensional kinematics were recorded to evaluate ROM. RESULTS: The C7 group had greater flexion-extension motion than the T1 and T2 groups following instrumentation (10.17±0.83 degree vs. 2.77±1.66 degree and 1.06±0.55 degree, P <0.001), and after cyclic loading (10.42±2.30 degree vs. 2.47±0.64 degree and 1.99±1.23 degree, P <0.001). There was no significant difference between the T1 and T2 groups. The C7 group had greater lateral bending ROM than both thoracic groups after instrumentation (8.81±3.44 degree vs. 3.51±2.52 degree, P =0.013 and 1.99±1.99 degree, P =0.003) and after cyclic loading. The C7 group had greater axial rotation motion than the thoracic groups (4.46±2.27 degree vs. 1.26±0.69 degree, P =0.010; and 0.73±0.74 degree, P =0.003) following cyclic loading. CONCLUSION: Motion at the cervicothoracic junction is significantly greater when a multilevel PCF stops at C7 rather than T1 or T2. This is likely attributable to the transition from a flexible cervical spine to a rigid thoracic spine. Although this does not account for in vivo fusion, surgeons should consider extending multilevel PCF constructs to T1 when feasible. LEVEL OF EVIDENCE: Not applicable.

Titanium Cervical Cage Subsidence: Postoperative Computed Tomography Analysis Defining Incidence and Associated Risk Factors.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Substantial variability in both the measurement and classification of subsidence limits the strength of conclusions that can be drawn from previous studies. The purpose of this study was to precisely characterize patterns of cervical cage subsidence utilizing computed tomography (CT) scans, determine risk factors for cervical cage subsidence, and investigate the impact of subsidence on pseudarthrosis rates. METHODS: We performed a retrospective review of patients who underwent one- to three-levels of anterior cervical discectomy and fusion (ACDF) utilizing titanium interbodies with anterior plating between the years 2018 and 2020. Subsidence measurements were performed by two independent reviewers on CT scans obtained 6 months postoperatively. Subsidence was then classified as mild if subsidence into the inferior and superior endplate were both ≤2 mm, moderate if the worst subsidence into the inferior or superior endplate was between 2 to 4 mm, or severe if the worst subsidence into the inferior or superior endplate was ≥4 mm. RESULTS: A total of 51 patients (100 levels) were included in this study. A total of 48 levels demonstrated mild subsidence (≤2 mm), 38 demonstrated moderate subsidence (2-4 mm), and 14 demonstrated severe subsidence (≥4 mm). Risk factors for severe subsidence included male gender, multilevel constructs, greater mean vertebral height loss, increased cage height, lower Taillard index, and lower screw tip to vertebral body height ratio. Severe subsidence was not associated with an increased rate of pseudarthrosis. CONCLUSION: Following ACDF with titanium cervical cages, subsidence is an anticipated postoperative occurrence and is not associated with an increased risk of pseudarthrosis.

No Difference in Neck Pain or Health-Related Quality Measures Between Patients With or Without Degenerative Cervical Spondylolisthesis.

STUDY DESIGN: This study is a retrospective case control. OBJECTIVES: This study aims to determine whether cervical degenerative spondylolisthesis (DS) is associated with increased baseline neck/arm pain and inferior health quality states compared to a similar population without DS. METHODS: Patient demographics, pre-operative radiographs, and baseline PROMs were reviewed for 315 patients undergoing anterior cervical decompression and fusion (ACDF) with at least 1 year of follow-up. Patients were categorized based on the presence (S) or absence of a spondylolisthesis (NS). Statistically significant variables were further explored using multiple linear regression analysis. RESULTS: 49/242 (20%) patients were diagnosed with DS, most commonly at the C4-5 level (27/49). The S group was significantly older than the NS group (58.0 ± 10.7 vs 51.9 ± 9.81, P = .001), but otherwise, no demographic differences were identified. Although a higher degree of C2 slope was found among the S cohort (22.5 ± 8.63 vs 19.8 ± 7.78, P = .044), no differences were identified in terms of preoperative visual analogue scale (VAS) neck pain or NDI. In the univariate analysis, the NS group had significantly increased VAS arm pain relative to the S group (4.93 ± 3.16 vs 3.86 ± 3.30, P = .045), which was no longer significant in the multivariate analysis. CONCLUSIONS: Although previous reports have suggested an association between cervical DS and neck pain, we could not associate the presence of DS with increased baseline neck or arm pain. Instead, DS appears to be a relatively frequent (20% in this series) age-related condition reflecting radiographic, rather than necessarily clinical, disease.

Ergonomics in Spine Surgery.

As physician burnout and wellness become increasingly recognized as vital themes for the medical community to address, the topic of chronic work-related conditions in surgeons must be further evaluated. While improving ergonomics and occupational health have been long emphasized in the executive and business worlds, particularly in relation to company morale and productivity, information within the surgical community remains relatively scarce. Chronic peripheral nerve compression syndromes, hand osteoarthritis, cervicalgia and back pain, as well as other repetitive musculoskeletal ailments affect many spinal surgeons. The use of ergonomic training programs, an operating microscope or exoscope, powered instruments for pedicle screw placement, pneumatic Kerrison punches and ultrasonic osteotomes, as well as utilizing multiple surgeons or microbreaks for larger cases comprise several methods by which spinal surgeons can potentially improve workspace health. As such, it is worthwhile exploring these areas to potentially improve operating room ergonomics and overall surgeon longevity.

Validation of a High-Fidelity Fracture Fixation Model for Skill Acquisition in Orthopedic Surgery Residents.

OBJECTIVE: Simulation has become a widely accepted part of training and credentialing processes due to its ability to supplement technical skill acquisition outside of the operating room (OR). This project explores implementation of a bench-top simulation of open reduction with internal fixation (ORIF) as a cost-effective method for practicing and evaluating surgical skill. DESIGN, SETTING, AND PARTICIPANTS: Participants ranging from intern to attending surgeon performed ORIF using a standard fixation set and a bovine or porcine tibia/radius model. Performance was recorded and scored by blinded reviewers based on a modified global rating scale (GRS), objective structured assessment of technical skills (OSATS) procedure-specific checklist, and critical-mistakes (CM) model. We calculated Fleiss' kappa for inter-rater reliability, Cronbach's alpha for internal consistency of scoring systems, and used univariate analysis to determine the ability of this model to discriminate between training levels. We also performed a normalized performance-versus-cost analysis to characterize perceived value of this simulation compared to other modalities. RESULTS: Twenty subjects completed the fracture fixation exercise. Fleiss' kappa for all scoring systems indicated substantial inter-rater agreement (k = 0.81, 0.80, and 0.74 for GRS, OSATS, and CM, respectively). Internal consistency reliability for GRS and OSATS were high with Cronbach's alpha 0.96(95%CI 0.94-0.97) and 0.94(95%CI 0.91-0.96), respectively. Using a Kuskal-Wallis rank sum test, GRS, OSATS, and CM were found effective for measuring differences between resident levels (p < 0.001, p < 0.001, and p = 0.002, respectively). Qualitative valuation of the exercise indicated similar value for education compared to time spent in the OR and surgical skills labs. CONCLUSIONS: This benchtop surgical simulation provides quantitative measurement of operative skills progression, increases trainee familiarity with ORIF principles, and permits targeted education by senior surgeons with the goal of training safe graduates. Procedure-specific checklist grading tools reliably differentiated between training levels with high internal validity. Implementing this model may decrease training costs and accelerate skill acquisition.

Indicators for Substantial Neurological Recovery Following Elective Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The purposes of this study were to determine the rate of improvement of significant preoperative weakness, identify risk factors for failure to improve, and characterize the motor recovery of individual motor groups. SUMMARY OF BACKGROUND DATA: While neck and arm pain reliably improve following anterior cervical discectomy and fusion (ACDF), the frequency and magnitude of motor recovery following ACDF remain unclear. METHODS: We performed a retrospective review of patients undergoing 1-4-level ACDF at a single institution between September 2015 and June 2016. Patients were subdivided into 2 groups based upon the presence or absence of significant preoperative weakness, which was defined as a motor grade <4 in any single upper extremity muscle group. Clinical notes were reviewed to determine affected muscle groups, rates of motor recovery, and risk factors for failure to improve. RESULTS: We identified 618 patients for inclusion. Significant preoperative upper extremity weakness was present in 27 patients (4.4%). Postoperatively, 19 of the affected patients (70.3%) experienced complete strength recovery, and 5 patients (18.5%) experienced an improvement in muscle strength to a motor grade ≥4. The rate of motor recovery postoperatively was 85.7% in the triceps, 83.3% in the finger flexors, 83.3% in the hand intrinsics, 50.0% in the biceps, and 25.0% in the deltoids. Risk factors for failure to experience significant motor improvement were the presence of myelomalacia (odds ratio: 28.9, P <0.01) and the performance of >2 levels of ACDF (odds ratio: 10.1, P <0.01). CONCLUSIONS: Patients with substantial preoperative upper extremity weakness can expect high rates of motor recovery following ACDF, though patients with deltoid weakness, myelomalacia, and >2 levels of ACDF are less likely to experience significant motor improvement.

The Effect of Preoperative Mental Health Status on Outcomes After Anterior Cervical Discectomy and Fusion.

BACKGROUND: The effect of preoperative mental health on outcomes after anterior cervical discectomy and fusion (ACDF) is of increasing interest. The purpose of this study was to utilize patient-reported outcome measures (PROMs) to compare outcomes after ACDF in patients with and without poor mental health. We hypothesized that patients with worse baseline mental health would report worse outcomes after surgery. METHODS: Patients undergoing ACDF for degenerative cervical spondylosis with at least 12 months of follow-up were included. Outcomes collected before and after surgery included the RAND-36, Neck Disability Index (NDI), EuroQol 5-dimension (EQ-5D), and Single Assessment Numeric Evaluation (SANE) score. RESULTS: Seventy-one patients were included and assigned to the depression or nondepression group based on baseline mental health. The depression group had worse baseline preoperative scores across all PROMs: NDI (44.2 vs 36.8, P = 0.05), RAND (1511.4 vs 2198.18, P < 0.001), EQ-5D (12.55 vs 10.14, P < 0.001), and SANE (56.3 vs 72.9, P < 0.001). Postoperatively, the depression group had worse scores at the final follow-up for RAND (2242.8 vs 2662.2, P = 0.03) and SANE (71.5 vs 80.8, P = 0.02). Both groups experienced improvements with ACDF across all PROMs. The changes in each PROM were not statistically significant between groups. There were no statistically significant differences in the percentage of patients achieving the minimal clinically important difference across PROMs. CONCLUSION: This study is the first to utilize the RAND-36, EQ-5D, NDI, and SANE scores to assess preoperative mental health and its effect on postoperative outcomes after ACDF. While poor preoperative mental health status yielded significantly worse baseline and postoperative outcomes scores, patients experienced significant improvement in symptoms after ACDF. CLINICAL RELEVANCE: Clinicians should be aware of the effects of poor mental health status on clinical outcomes in patients undergoing anterior cervical fusion, but can still expect significant clinical improvements after surgery.

Multifidus Sarcopenia Is Associated With Worse Patient-reported Outcomes Following Posterior Cervical Decompression and Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The present study is the first to assess the impact of paraspinal sarcopenia on patient-reported outcome measures (PROMs) following posterior cervical decompression and fusion (PCDF). SUMMARY OF BACKGROUND DATA: While the impact of sarcopenia on PROMs following lumbar spine surgery is well-established, the impact of sarcopenia on PROMs following PCDF has not been investigated. MATERIALS AND METHODS: We performed a retrospective review of patients undergoing PCDF from C2 to T2 at a single institution between the years 2017 and 2020. Two independent reviewers who were blinded to the clinical outcome scores utilized axial cuts of T2-weighted magnetic resonance imaging sequences to assess fatty infiltration of the bilateral multifidus muscles at the C5-C6 level and classify patients according to the Fuchs Modification of the Goutalier grading system. PROMs were then compared between subgroups. RESULTS: We identified 99 patients for inclusion in this study, including 28 patients with mild sarcopenia, 45 patients with moderate sarcopenia, and 26 patients with severe sarcopenia. There was no difference in any preoperative PROM between the subgroups. Mean postoperative Neck Disability Index scores were lower in the mild and moderate sarcopenia subgroups (12.8 and 13.4, respectively) than in the severe sarcopenia subgroup (21.0, P <0.001). A higher percentage of patients with severe multifidus sarcopenia reported postoperative worsening of their Neck Disability Index (10 patients, 38.5%; P =0.003), Visual Analog Scale Neck scores (7 patients, 26.9%; P =0.02), Patient-Reported Outcome Measurement Information System Physical Component Scores (10 patients, 38.5%; P =0.02), and Patient-Reported Outcome Measurement Information System Mental Component Scores (14 patients, 53.8%; P =0.02). CONCLUSION: Patients with more severe paraspinal sarcopenia demonstrate less improvement in neck disability and physical function postoperatively and are substantially more likely to report worsening PROMs postoperatively. LEVEL OF EVIDENCE: 3.