Effect of Ventral vs Dorsal Spinal Surgery on Patient-Reported Physical Functioning in Patients With Cervical Spondylotic Myelopathy: A Randomized Clinical Trial.

Importance: Cervical spondylotic myelopathy is the most common cause of spinal cord dysfunction worldwide. It remains unknown whether a ventral or dorsal surgical approach provides the best results. Objective: To determine whether a ventral surgical approach compared with a dorsal surgical approach for treatment of cervical spondylotic myelopathy improves patient-reported physical functioning at 1 year. Design, Setting, and Participants: Randomized clinical trial of patients aged 45 to 80 years with multilevel cervical spondylotic myelopathy enrolled at 15 large North American hospitals from April 1, 2014, to March 30, 2018; final follow-up was April 15, 2020. Interventions: Patients were randomized to undergo ventral surgery (n = 63) or dorsal surgery (n = 100). Ventral surgery involved anterior cervical disk removal and instrumented fusion. Dorsal surgery involved laminectomy with instrumented fusion or open-door laminoplasty. Type of dorsal surgery (fusion or laminoplasty) was at surgeon's discretion. Main Outcomes and Measures: The primary outcome was 1-year change in the Short Form 36 physical component summary (SF-36 PCS) score (range, 0 [worst] to 100 [best]; minimum clinically important difference = 5). Secondary outcomes included 1-year change in modified Japanese Orthopaedic Association scale score, complications, work status, sagittal vertical axis, health resource utilization, and 1- and 2-year changes in the Neck Disability Index and the EuroQol 5 Dimensions score. Results: Among 163 patients who were randomized (mean age, 62 years; 80 [49%] women), 155 (95%) completed the trial at 1 year (80% at 2 years). All patients had surgery, but 5 patients did not receive their allocated surgery (ventral: n = 1; dorsal: n = 4). One-year SF-36 PCS mean improvement was not significantly different between ventral surgery (5.9 points) and dorsal surgery (6.2 points) (estimated mean difference, 0.3; 95% CI, -2.6 to 3.1; P = .86). Of 7 prespecified secondary outcomes, 6 showed no significant difference. Rates of complications in the ventral and dorsal surgery groups, respectively, were 48% vs 24% (difference, 24%; 95% CI, 8.7%-38.5%; P = .002) and included dysphagia (41% vs 0%), new neurological deficit (2% vs 9%), reoperations (6% vs 4%), and readmissions within 30 days (0% vs 7%). Conclusions and Relevance: Among patients with cervical spondylotic myelopathy undergoing cervical spinal surgery, a ventral surgical approach did not significantly improve patient-reported physical functioning at 1 year compared with outcomes after a dorsal surgical approach. Trial Registration: ClinicalTrials.gov Identifier: NCT02076113.

Association of Poor Bone Quality with Pseudarthrosis and Poor Clinical Outcomes in Single-Level Instrumented Lumbar Arthrodesis Using Local Autologous Bone Graft.

INTRODUCTION: Although osteoporosis and low bone mineral density is thought to lead to poor fusion outcomes, few studies have adequately addressed the correlation, and they were limited by small sample size at a single institution. METHODS: We completed a secondary analysis of 182 patients enrolled at 26 spine centers across the United States in the EXO-SPINE FDA-approved clinical trial with 12-month CT-based fusion status determined by two independent, blinded radiologists. Using previously described CT-based techniques, we measured local and global Hounsfield units (HU) and examined the relationship with radiographic and clinical outcomes. RESULTS: CT scans were available for review from 95 patients, with a mean age of 56.2 years and mean global density of 153.0 HU. No relationship was observed between HU and radiographic fusion status or clinical outcomes. Although 12% of patients had lumbar vertebral body HU measurements consistent with osteoporosis, this classification had no relation with fusion or clinical outcomes. Patients with pseudarthrosis had higher Oswestry Disability Index (22.2 vs. 16.6, P = 0.037) and back pain visual analog scale (7.0 vs. 4.9, P = 0.014) scores than patients with at least unilateral fusion at the 12-month follow-up. DISCUSSION: In this large, multicenter study, lower vertebral body HU was not associated with worse fusion status after single-level instrumented posterolateral lumbar fusion using only local autologous bone graft. However, there was an association between radiographic fusion status and clinical outcomes, validating the importance of determining predictors of successful fusion. Assessment of fusion status with CT scans yielded a much lower fusion success rate with local bone graft than previously reported and may warrant additional investigation.

Patients May Return to Work Sooner After Laminoplasty: Occupational Outcomes of the Cervical Spondylotic Myelopathy Surgical Trial.

BACKGROUND AND OBJECTIVES: Return-to-work (RTW) is an important outcome for employed patients considering surgery for cervical spondylotic myelopathy (CSM). We conducted a post hoc analysis of patients as-treated in the Cervical Spondylotic Myelopathy Surgical Trial, a prospective, randomized trial comparing surgical approaches for CSM to evaluate factors associated with RTW. METHODS: In the trial, patients were randomized (2:3) to either anterior surgery (anterior cervical decompression/fusion [ACDF]) or posterior surgery (laminoplasty [LP], or posterior cervical decompression/fusion [PCDF], at surgeon's discretion). Work status was recorded at 1, 3, 6, and 12 months postoperatively. For patients working full-time or part-time on enrollment, time to RTW was compared across as-treated surgical groups using discrete-time survival analysis. Multivariate logistic regression was used to assess predictors of RTW. Clinical outcomes were compared using a linear mixed-effects model. RESULTS: A total of 68 (42%) of 163 patients were working preoperatively and were analyzed. In total, 27 patients underwent ACDF, 29 underwent PCDF, and 12 underwent LP. 45 (66%) of 68 patients returned to work by 12 months. Median time to RTW differed by surgical approach (LP = 1 month, ACDF = 3 months, PCDF = 6 months; P = .02). Patients with longer length-of-stay were less likely to be working at 1 month (odds ratio 0.51; 95% CI, 0.29-0.91; P = .022) and 3 months (odds ratio 0.39; 95% CI, 0.16-0.96; P = .04). At 3 months, PCDF was associated with lower Short-Form 36 physical component summary scores than ACDF (estimated mean difference [EMD]: 6.42; 95% CI, 1.4-11.4; P = .007) and LP (EMD: 7.98; 95% CI, 2.7-13.3; P = .003), and higher Neck Disability Index scores than ACDF (EMD: 12.48; 95% CI, 2.3-22.7; P = .01) and LP (EMD: 15.22; 95% CI, 2.3-28.1; P = .014), indicating worse perceived physical functioning and greater disability, respectively. CONCLUSION: Most employed patients returned to work within 1 year. LP patients resumed employment earliest, while PCDF patients returned to work latest, with greater disability at follow-up, suggesting that choice of surgical intervention may influence occupational outcomes.

Assessing the Influence of Climate Change and Environmental Factors on the Top Tick-Borne Diseases in the United States: A Systematic Review.

In the United States (US), tick-borne diseases (TBDs) have more than doubled in the past fifteen years and are a major contributor to the overall burden of vector-borne diseases. The most common TBDs in the US-Lyme disease, rickettsioses (including Rocky Mountain spotted fever), and anaplasmosis-have gradually shifted in recent years, resulting in increased morbidity and mortality. In this systematic review, we examined climate change and other environmental factors that have influenced the epidemiology of these TBDs in the US while highlighting the opportunities for a One Health approach to mitigating their impact. We searched Medline Plus, PUBMED, and Google Scholar for studies focused on these three TBDs in the US from January 2018 to August 2023. Data selection and extraction were completed using Covidence, and the risk of bias was assessed with the ROBINS-I tool. The review included 84 papers covering multiple states across the US. We found that climate, seasonality and temporality, and land use are important environmental factors that impact the epidemiology and patterns of TBDs. The emerging trends, influenced by environmental factors, emphasize the need for region-specific research to aid in the prediction and prevention of TBDs.

Influence of participant and reviewer characteristics in application scores for a hematology research training program.

The American Society of Hematology Clinical Research Training Institute (CRTI) is a clinical research training program with a competitive application process. The objectives were to compare application scores based on applicant and reviewer sex and underrepresented minority (URM) status. We included applications to CRTI from 2003 to 2019. The application scores were transformed into a scale from 0 to 100 (100 was the strongest). The factors considered were applicant and reviewer sex and URM status. We evaluated whether there was an interaction between the characteristics and time related to application scores. In total, 713 applicants and 2106 reviews were included. There was no significant difference in scores according to applicant sex. URM applicants had significantly worse scores than non-URM applicants (mean [standard error] 67.9 [1.56] vs 71.4 [0.63]; P = .0355). There were significant interactions between reviewer sex and time (P = .0030) and reviewer URM status and time (P = .0424); thus, results were stratified by time. For the 2 earlier time periods, male reviewers gave significantly worse scores than did female reviewers; this difference did not persist for the most recent time period. The URM reviewers did not give significantly different scores across time periods. URM applicants received significantly lower scores than non-URM applicants. The impact of reviewer sex and URM status changed over time. Although male reviewers gave lower scores in the early periods, this effect did not persist in the late period. Efforts are required to mitigate the impact of applicant URM status on application scores.

Using Electrical Stimulation of the Ulnar Nerve Trunk to Predict Postoperative Improvement in Hand Clumsiness in Patients With Cervical Spondylotic Myelopathy.

STUDY DESIGN: A prospective cohort study. OBJECTIVE: To investigate whether the immediate and short-term effects of preoperative electrical peripheral nerve stimulation (ePNS) on performance of the 10-second test could predict the early postoperative outcomes of patients with cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA: Previous studies have shown that early clinical improvement in CSM patients may be because of reversal of spinal cord ischemia after spinal cord compression. MATERIALS AND METHODS: We conducted a 10-second test before surgery, after ePNS, and at discharge (one week after surgery) in 44 patients with CSM who underwent C3-C7 laminoplasty and evaluated their correlations. The effects of the procedures (ePNS or operation) and sides (stimulated or nonstimulated side) for the 10-second test were analyzed using repeated measures analysis of variance. The Pearson correlation coefficient was used to measure the relationship between the 10-second test values according to the method (after ePNS vs. surgery). In addition, the Bland-Altman method was used to evaluate the degree of agreement between the 10-second test obtained after ePNS versus shortly after surgery. RESULTS: The preoperative 10-second test showed the most improvement immediately after the administration of ePNS, with a gradual decrease for the first 30 minutes after completion. After the initial 30 minutes, performance decreased rapidly, and by 60 minutes performance essentially returned to baseline. The 10-second post-ePNS had a strong positive correlation with the 10-second test in the early postoperative period (at discharge=one week after surgery). These phenomena were observed with the left hand, the side stimulated with ePNS, as well as the right hand, the side not stimulated. CONCLUSIONS: Early postoperative outcomes after CSM surgery may be predicted by the results of preoperative ePNS. LEVEL OF EVIDENCE: Level 3.

Prospective comparison of dysphagia following anterior cervical discectomy and fusion (ACDF) with and without rhBMP-2.

BACKGROUND CONTEXT: Previous studies have called into question the safety of using rhBMP-2 in anterior cervical fusion due to the possibility of airway compromise and dysphagia. A retrospective chart review identified a significant increase in the severity of dysphagia after II-level ACDF with rhBMP-2 compared to patients who did not receive rhBMP-2. To date, this topic has not been studied prospectively. PURPOSE: Compare the incidence of dysphagia following anterior cervical discectomy and fusion (ACDF) when recombinant human bone morphogenetic protein-2 (rhBMP-2) is used with allograft compared to allograft alone. STUDY DESIGN: Prospective cohort study. PATIENT SAMPLE: A total of 114 patients completed a baseline SWAL-QOL survey and met the inclusion criteria. Thirty-nine patients underwent I- or II-level ACDF with allograft plus 0.5mg rhBMP-2/level. 44 patients underwent ACDF with allograft alone. Thirty-one patients undergoing a lumbar decompression were enrolled in a third cohort to control for dysphagia secondary to intubation. OUTCOME MEASURES: The primary outcome measure was the 14-point SWAL-QOL dysphagia questionnaire. Other patient factors obtained from anesthesia and operative records were examined to evaluate their potential relationship to postoperative dysphagia. METHODS: The 14-point SWAL-QOL questionnaire was administered at multiple time points (pre-op, post-op 7 days, 6 weeks, 6 months, and at least 1 year). Multivariable repeated-measures analysis was applied to data. RESULTS: Baseline adjusted SWAL-QOL means 7 days after surgery were significantly different between the three study groups. These differences resolved by 6 weeks postoperative, beyond which point there were no differences. At final follow-up, baseline adjusted SWAL-QOL means at 1 year were similar for the three study groups. CONCLUSIONS: This single-center study of anterior cervical surgery demonstrated that the addition of rhBMP-2 to an ACDF increased postoperative dysphagia at 7 days after surgery, but these patients recover to levels comparable to those who underwent ACDF without rhBMP-2 or lumbar surgery within 6 weeks.

Association of masking policies with mask adherence and distancing during the SARS-COV-2 pandemic.

BACKGROUND: Quantification of the impact of local masking policies may help guide future policy interventions to reduce SARS-COV-2 disease transmission. This study's objective was to identify factors associated with adherence to masking and social distancing guidelines. METHODS: Faculty from 16 U.S. colleges and universities trained 231 students in systematic direct observation. They assessed correct mask use and distancing in public settings in 126 US cities from September 2020 through August 2021. RESULTS: Of 109,999 individuals observed in 126 US cities, 48% wore masks correctly with highest adherence among females, teens and seniors and lowest among non-Hispanic whites, those in vigorous physical activity, and in larger groups (P < .0001). Having a local mask mandate increased the odds of wearing a mask by nearly 3-fold (OR = 2.99, P = .0003) compared to no recommendation. People observed in non-commercial areas were least likely to wear masks. Correct mask use was greatest in December 2020 and remained high until June 2021 (P < .0001). Masking policy requirements were not associated with distancing. DISCUSSION: The strong association between mask mandates and correct mask use suggests that public policy has a powerful influence on individual behavior. CONCLUSIONS: Mask mandates should be considered in future pandemics to increase adherence.

Fusarium falciforme vertebral abscess and osteomyelitis: case report and molecular classification.

Fusarium is a ubiquitous mold that can cause superficial infections such as keratitis and onychomycosis in immunocompetent humans; however, infections in immunocompromised hosts can be fatal. We report an unusual case of epidural abscess and vertebral osteomyelitis in a patient with an autoimmune disorder who was on long-term glucocorticoids. Multilocus DNA sequence-based typing revealed that the infection was caused by a novel three-locus haplotype of Fusarium falciforme designated FSSC 3+4qqq.

Smokeless Tobacco Point of Sale Advertising, Placement and Promotion: Associations With Store and Neighborhood Characteristics.

Introduction: Objectives of this study were to determine retail and neighborhood characteristics associated with smokeless tobacco (ST) product promotion, price promotion, and storefront advertising among retailers in Oklahoma. Methods: In this statewide point-of-sale study, we collected data from 1,354 ST retailers. Using store characteristics and census tract information, we estimated summary statistics and adjusted prevalence ratios during 2019-2020. Results: Of ST retailers audited, 11.0% demonstrated ST youth promotion, 43.0% ST price promotions, and 19.6% ST storefront advertising. The adjusted prevalence ratio (aPR) for convenience stores was higher for all three ST strategies: youth promotion (aPR = 3.4, 95% CI 1.9, 6.2), price promotion (aPR = 3.8, 95% CI 2.9, 5.0), and storefront advertising (aPR=16.4, 95% CI 6.7, 40.3) compared to other store types. Metropolitan tobacco retailers had higher aPRs for youth promotion (aPR = 1.7, 95% CI 1.12 2.6) and storefront advertising (aPR = 1.5, 95% CI 1.2, 1.9). Conclusions: Findings of this study suggest there are currently ample opportunities for youth and adults at risk for tobacco initiation to be exposed to ST products in the retail environment. Convenience stores, more likely to be found and utilized in rural areas compared to metropolitan areas, are disproportionately more likely to engage in marketing strategies that could lure youth into trying smokeless tobacco.

Historical Perspective: Thomas E. Whitesides, Jr.

: Dr. Thomas Whitesides was a pioneer in general orthopedics and spine surgery. He brought the anterior approach to the United States in the management of thoracolumbar trauma, a revolutionary step at the time. At Emory, he taught 100s of residents and fellows using the Socratic method. Dr. Whitesides remains a valuable consultant for complex spine cases to this day.

Anterior exposure of the lumbar spine with and without an "access surgeon": morbidity analysis of 265 consecutive cases.

STUDY DESIGN: Retrospective review OBJECTIVE: To compare the incidence and type of exposure-related complications for anterior lumbar surgery performed with and without an "access" surgeon. SUMMARY OF BACKGROUND DATA: No data exist comparing the incidence and type of exposure-related complications for anterior lumbar surgery performed with and without a vascular surgeon's assistance. METHODS: A retrospective review was performed for 265 consecutive patients who underwent anterior lumbar spine surgery at our institution from 2003 to 2005. Each patient's records were reviewed for diagnosis, procedure, whether the surgical exposure was conducted by the spine surgeon (Spine) or with a vascular surgeon's assistance (Team), levels exposed, complications, and any lasting sequelae. RESULTS: The percentage of patients with at least 1 intraoperative complication was 8% and 12% for the Spine and Team cases, respectively. Two percent of the Spine patients experienced an intraoperative vascular complication compared with 7% of the Team cases. No intraoperative vascular complication occurred in the single-level Spine exposures. Four percent of the patients with single-level exposures with Team approaches sustained an intraoperative vascular complication. Eight percent of the multilevel Spine cases sustained an intraoperative vascular complication compared with 9% of the multilevel Team exposures. There were 14 vascular injuries appreciated intraoperatively in a total of 13 patients. These injuries were directly repaired in 10 patients without any residual sequelae. The rate of vascular complications was statistically higher for multiple-level exposures (9%) versus single-level exposure (3%; P = 0.0357). The rate of retrograde ejaculation was 6% in the Spine cases whereas it was 7% in the Team approach. CONCLUSIONS: Our results do not support the notion that the presence of an "access" surgeon will change the type and rate of complications. With adequate training and judgment, spine surgeons may safely perform such exposures, provided vascular surgical assistance is readily available.

The impact of prophylactic intraoperative vancomycin powder on microbial profile, antibiotic regimen, length of stay, and reoperation rate in elective spine surgery.

BACKGROUND CONTEXT: There is growing concern that the microbial profile of surgical site infection (SSI) in the setting of prophylactic vancomycin powder may favor more resistant and uncommon organisms. PURPOSE: To demonstrate the impact of prophylactic intraoperative vancomycin powder on microbial profile, antibiotic regimen, length of stay (LOS), and reoperation rate in spine surgical site infection. STUDY DESIGN AND/OR SETTING: Retrospective cohort study. PATIENT SAMPLE: the study included 115 postoperative spine patients who were required to return to the operating room for SSI. OUTCOME MEASURES: The outcome measures were microbial profile, reoperation rate, antibiotic regimen, and LOS for patients with postoperative spine infection who either did (treated) or did not (untreated) receive prophylactic vancomycin powder during their index procedure. METHODS: A retrospective review of patients who underwent posterior thoracic and/or lumbar spine surgery between 2010 and 2017 was conducted. Those undergoing surgical treatment of SSI were identified, and patients were divided into two groups - those who were treated with intraoperative vancomycin (treated) and those who were not (untreated). The organism profile for each group was compared. The average LOS, reoperation rate, and number of patients requiring more than 1 antibiotic were calculated for each patient in both groups. RESULTS: There were 5,909 procedures performed. One hundred and fifteen SSIs were identified, resulting in a 1.9% infection rate. Prophylactic vancomycin powder was used in the index procedure for 42 of those cases. 23.8% of cultures in the vancomycin group were polymicrobial and 16.7% were gram-negative compared with 9.6% (p=0.039) and 4.1% (p=0.021) in the untreated group, respectively. In the vancomycin-treated group, 26.1% of patients underwent repeat irrigation and debridement compared with 38.4% in the untreated group (p=0.184). The percentage of patients in the treatment and untreated group who required more than 1 antibiotic was 26.0% and 26.1%, respectively (p=0.984). Mean LOS in the treatment group was 8.0 versus 7.9 for the untreated group (p=0.945) CONCLUSIONS: In this series, vancomycin powder was associated with a higher prevalence of gram-negative and polymicrobial organisms in patients that ultimately developed postoperative SSI. However, this did not adversely affect the need for multiple reoperations, antibiotic regimen, or LOS for these patients.

Motion-preserving, 2-stage transoral and posterior treatment of an unstable Jefferson fracture in a professional football player.

The authors report the case of a patient who suffered a Jefferson fracture during a professional football game. The C-1 (atlas) fracture was widely displaced anteriorly, but the transverse ligament was intact. In an effort to enable a return to play and avoid intersegmental (C1-2) fusion, the patient underwent a transoral approach for open reduction and internal fixation of the fracture. The associated posterior ring fracture displacement widened after this procedure, and a subsequent posterior arthrodesis and fixation of the fracture site was performed 6 months later when the fracture failed to heal with rigid collar immobilization. The approach maintained the normal range of motion at the atlantoaxial and atlantooccipital joints, which would have been sacrificed by an atlantoaxial or occipitocervical fusion, as is traditionally performed. Ultimately, the patient decided not to return to the football field, but this approach could avoid the more significant loss of motion associated with atlantoaxial or occipitocervical fusion for unstable Jefferson fractures.

Progressive Bone Formation After Cervical Disc Replacement: Minimum of 5-Year Follow-up.

STUDY DESIGN: Retrospective review. OBJECTIVE: Our objective was to examine the prevalence, clinical significance, ramifications, and possible etiology of postoperative bone formation at the index level after cervical disc replacement (CDR) with a minimum of 5 years of follow-up. SUMMARY OF BACKGROUND DATA: CDR can be complicated by postoperative ossification and unwanted ankylosis at the index level, which some authors have termed "heterotopic ossification." This terminology may be inaccurate as it assumes the postoperative bone formation is unnatural and a consequence of the CDR surgery. We advocate that this phenomenon has more to do with individual patient factors rather than the surgery. METHODS: Patients who underwent Bryan CDR for cervical myelopathy or radiculopathy between 12/2003 and 8/2008 with a minimum of 5-years follow-up were analyzed. They were divided into two groups, those with and without postoperative bone formation. Patient-reported outcomes (Japanese Orthopaedic Association score, Neck Disability Index, Visual Analogue Scale for neck and arm pain) and radiographic parameters were collected pre- and postoperatively and compared between groups. RESULTS: Sixty-one patients (76 levels) were identified (mean follow-up 94.2 mo). The overall incidence of postoperative ossification was 50%. Both groups had sustained significant improvements across all patient-reported outcome measures at final follow-up. Notably, patients with more severe preoperative cervical spondylosis had higher rates of postoperative ossification (P = 0.036) and adjacent segment degeneration (P = 0.010). CONCLUSION: Although the long-term incidence of postoperative bone formation after CDR was relatively high, this did not adversely affect patient outcomes. Patients with more severe preoperative spondylosis had higher rates of postoperative ossification, suggesting that postoperative ossification at the CDR segment is likely one of progressive bone formation in individuals already predisposed to forming bone rather than one of alleged heterotopic ossification as a consequence of the surgery. LEVEL OF EVIDENCE: 3.

Epidemiology and treatment of central cord syndrome in the United States.

BACKGROUND: The objective of this study is to demonstrate the epidemiology and trends in management of patients with central cord syndrome (CCS) who present to the emergency department. Recent literature has reported that surgical treatment for CCS have increased over the previous decades. METHODS: The National Emergency Department Sample (NEDS) was queried from 2009 through 2012 to generate national estimates of patients who presented to the emergency department in the United States and were diagnosed with CCS. RESULTS: From 2009 through 2012, there were 11,975 emergency room visits for CCS (mean age 60 years). The two most common injury mechanisms were: fall (55%) and motor vehicle accident (15%). Concomitant cervical fractures were found in 10% patients. Ninety-three percent of patients were admitted to the hospital directly or after transfer to another facility, and 7% were discharged home. Fifty-five percent of patients were treated non-operatively, 39% were treated with cervical fusion surgery and 6% were treated with laminoplasty. Of patients who underwent cervical fusion, 62% received anterior decompression and fusion, 32% received posterior decompression and fusion, and 6% received combined anterior-posterior decompression and fusion. The incidence of in-hospital mortality was 2.6%. Mortality was associated with older patient age (OR 1.06, P<0.001) and greater comorbidities (OR 1.72, P<0.001). CONCLUSIONS: Majority of patients who presented to the emergency room for CCS in the United States were treated non-operatively. Advanced age and greater comorbidities were the factors that were most associated with increased risk of in-hospital mortality in patients with CCS.

rhBMP-2 enhancement of posterolateral spinal fusion in a rabbit model in the presence of concurrently administered doxorubicin.

BACKGROUND CONTEXT: Spinal fusions can be necessary in patients undergoing chemotherapy with doxorubicin. In a previous study, doxorubicin was shown to decrease spinal fusion rates in a rabbit model of lumbar intertransverse process spinal fusion with autograft iliac crest bone. In the current study, we determine whether spinal fusion with recombinant human bone morphogenetic protein-2 (rhBMP-2) can overcome the inhibitory effect of doxorubicin in spinal fusion. PURPOSE: To determine if rhBMP-2 can overcome the inhibitory effects of doxorubicin (adriamycin) in an animal model of posterolateral spinal fusion. STUDY DESIGN/SETTING: Prospective, controlled, rabbit model of posterolateral lumbar fusion. OUTCOME MEASURES: Spine fusion was assessed by manual palpation (by observers blinded to the treatment group) at the level of arthrodesis. Fusion was graded according to a five-tiered classification (0-4). Posteroanterior radiographs of the excised spines were also graded in a blinded fashion using a six-point scoring system (0-5) devised to describe the amount of bone observed between the L5-L6 transverse processes. METHODS: Thirty-two New Zealand White rabbits underwent posterolateral fusion at L5-L6 with either autograft (iliac crest autograft bone) or rhBMP-2 (rhBMP-2/absorbable collagen sponge (0.86 mg/level). All animals received a dose of doxorubicin (2.5 mg/kg) known to inhibit spine fusion via the central vein of the ear immediately postoperatively. Five weeks postoperatively the rabbits were euthanized. Spine fusion was assessed by manual palpation, and graft quality was assessed with posteroanterior radiographs. RESULTS: Four of the 16 spines (25%) in the autograft group and 16 of the 16 spines (100%) in the rhBMP-2 group fused in the presence of doxorubicin administration (p<.05). There was significantly increased bone formation in the rhBMP-2 group (p<.05). One unilateral, subclinical wound infection was observed in each group at the time of euthanization (autograft [n=1, 6%] and rhBMP-2 [n=1, 6%]). CONCLUSIONS: We confirm that when autograft is used, doxorubicin decreases spinal fusion rate (25%) compared with historical controls (60-75%). More importantly, using rhBMP-2 overcomes the inhibitory effect of doxorubicin, resulting in 100% fusion in our animal model. This study suggests that rhBMP-2 has the potential to improve fusion rates in human patients undergoing chemotherapy with doxorubicin.

Posterolateral Fusion Versus Interbody Fusion for Degenerative Spondylolisthesis: A Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic literature review and meta-analysis. OBJECTIVE: This study is a meta-analysis assessing the clinical outcomes of degenerative lumbar spondylolisthesis treated with either a posterolateral fusion (PLF) or interbody fusion (IBF) SUMMARY OF BACKGROUND DATA.: Degenerative spondylolisthesis remains one of the most common reasons for which lumbar fusion is performed in the United States. Both PLF and IBF have been advanced as adequate surgical techniques that result in successful fusion and improved clinical outcomes. METHODS: A systematic review of PubMed, Cochrane, and Embase was performed. The pooled results were performed by calculating the effect size based on the Hedges g standardized difference in means or odds ratio. Studies were weighted by the inverse of the variance. Heterogeneity was assessed using the Q statistic and I. Sensitivity analysis was performed through single elimination of studies. Publication bias was assessed by funnel plot assessment and the Egger-Harbord test. RESULTS: The systematic review resulted in 865 articles. After two-reviewer assessment, five articles were found to match all of the inclusion criteria and were included in the meta-analysis. The combined effect size was found to be in favor of PLF for length of stay (P = 0.002); however, there were no differences in fusion rate, operative time, Estimated blood loss, Oswestry Disability Index, Short Form 36, Visual Analog Scale, or complication rate between PLF and IBF. All of the variables demonstrated relative homogeneity, with I < 25. The sensitivity analysis validated the results of the model and there was no publication bias detected. CONCLUSION: Patients with degenerative spondylolisthesis can be effectively managed with either a PLF or IBF with no significant differences in clinical outcomes or fusion rate between the two groups. Length of stay was the only variable that was found to be in favor of either group, with the PLF group demonstrating a shortened hospitalization. LEVEL OF EVIDENCE: 3.