Biomechanical comparison of Tibial-sided supplemental fixation techniques in Bone-Patellar Tendon-Bone anterior cruciate ligament reconstruction.

PURPOSE: The purpose of this study was to compare the biomechanical properties of a commercially available suture anchor and a screw post for supplemental tibial fixation of a bone-patellar tendon-bone (BTB) graft at time zero. We hypothesized that supplemental fixation using a suture anchor would demonstrate similar biomechanical performance in comparison with a screw post. METHODS: Sixteen fresh frozen, healthy human cadaveric knees underwent BTB autograft harvest, placement, and primary tibial-sided interference screw fixation using a standardized technique performed by a single surgeon. Specimens were randomly assigned to one of two tibial-sided supplemental fixation groups (suture anchor or screw post), yielding eight specimens in each group. Each specimen was affixed to a custom loading apparatus, with the tibial tunnel aligned in a vertical position that allowed for parallel "worst-case scenario" loading and eliminated loading variation due to tibial tunnel angle. Grafts were pretensioned to 30 N and biomechanical performance was compared with respect to cyclical loading between 50-250 N for 500 cycles at 0.5 Hz and pull-to-failure loading at 60 mm/min. RESULTS: The suture anchor and screw post supplemental constructs demonstrated similar performance with respect to all biomechanical parameters assessed, including yield strength (294.0 N [IQR 267.2-304.2 N] versus 332.1 N [IQR 313.8-350.4 N]; P = 0.079) and ultimate strength (330.1 N [IQR 306.9-418.7 N] versus 374.7 N [IQR 362.0-387.3 N]; P = 0.3798). However, of the eight original specimens in each group, one suture anchor specimen (12.5%) and six metallic screw post specimens (75%) failed during cyclical testing and were unable to undergo displacement and load to failure testing. CONCLUSION: This study provides preliminary evidence that supplemental tibial-sided fixation of a BTB ACL graft with a suture anchor has similar loading characteristics or load-to-failure strength when compared to supplemental fixation with a screw post construct. STUDY DESIGN: Laboratory Controlled Study. LEVEL OF EVIDENCE: Basic Science Study.

Comorbidity scores reported in anatomic and reverse total shoulder arthroplasty: a systematic review.

BACKGROUND: Due to the aging population, the number of reverse shoulder arthroplasty (RSA) and anatomic shoulder arthroplasty (TSA) continue to increase annually. Although outcome measures are frequently reported in literature for patients who undergo shoulder arthroplasty, no studies have analyzed reporting of patient comorbidities in this population. The purpose of this study was to evaluate reporting of comorbidity indices in shoulder arthroplasty literature and assess how this reporting may inform management and outcomes. METHODS: A database was compiled systematically using PubMed to identify articles pertaining to shoulder arthroplasty published between 2019 and 2021. The search terms, "reverse shoulder arthroplasty" and "anatomic shoulder arthroplasty," were used to identify clinical studies. Non-clinical (e.g., translational and basic science) and review articles were excluded. Included studies were then analyzed for reporting of comorbidity indices. RESULTS: A total of 199 articles were included in this review and reported comorbidities. Of these, 15.6% (31 of 199) pertained to TSA, while 84.4% (168 of 199) pertained to RSA. Within this review, 57.8% (115 of 199) articles utilized comorbidity scores, while 42.2% (84 of 199) reported only comorbid diagnoses. Among the scores utilized, the American Society of Anesthesiologists (ASA) physical status classification system was the most widely used among both the TSA (52.9%, 9 of 17) and the RSA studies (58.2%, 57 of 98). Additional scores within the RSA literature included the Charlson Comorbidity Index (CCI) (35.3%, 6 of 17), the Charlson Comorbidity Index by Deyo et al. (J Clin Epidemiol. 45(6):613-9, 1992) (CCI-Deyo; 5.9%, 1 of 17), the Modified Charlson Comorbidity Index (modified-CCI) (5.9%, 1 of 17), the Elixhauser et al. (Med Care. 36(1):8-27, 1998) Comorbidity Measure (ECM) (11.8%, 2 of 17), and the Modified Frailty Index (mFI) (5.9%, 1 of 17). With the TSA literature, the additional comorbidity scores included the CCI (30.6%, 30 of 98), the CCI-Deyo (6.1%, 6 of 98), the modified-CCI (1.0%, 1 of 98), the ECM (8.2%, 8 of 98), the Factor-5 modified Frailty Index (mFI-5) (1.0%, 1 of 98), and the mFI (1.0%, 1 of 98). CONCLUSION: The reporting of comorbidity indices is an important factor when considering patient outcomes and complications reported in shoulder arthroplasty literature. Although the reporting of these scores appears to be more prevalent in current literature, there is no standard or consistency in terms of which scores are reported. Given this diversity in comorbidity scores, further research is necessary to develop a single standardized score to properly analyze the effect of comorbidities on shoulder arthroplasty patient outcomes.

Hip Arthroscopic Microfracture Augmented With Platelet-Rich Plasma-Infused Micronized Cartilage Allograft Significantly Improves Functional Outcomes.

PURPOSE: To evaluate functional outcomes and survivorship in patients at 1 year after undergoing arthroscopic microfracture augmented with hyaline allograft for symptomatic chondral defects of the hip. METHODS: Consecutive patients with and without prior hip procedures presenting with Outerbridge grade IV chondral lesion of the acetabulum or femoral head were prospectively followed. Patients underwent hip microfracture augmented with hyaline allograft suspended in autologous platelet-rich plasma between October 2016 and April 2018. Extent of cartilage degeneration was quantified using the chondromalacia severity index (CMI). Patient functional scores, including Tegner, Hip Outcome Score-Activities of Daily Living (HOS-ADL), Sport-Specific Subscale (HOS-SSS), modified Harris Hip Score (mHHS), and Nonarthritic Hip Score (NAHS) were collected preoperatively and at minimum 1-year postoperatively. Minimal clinically important difference (MCID) was analyzed. Statistical significance was established at P < .05. Pearson's coefficient analysis was performed to identify preoperative variables correlated with clinical outcomes. RESULTS: Fifty-seven patients (86.4%) had minimum 1-year follow-up and were included in the final analysis, with a mean age and body mass index (BMI) of 38.3 ± 9.1 years and 27.7 ± 4.9 kg/m2, respectively. Comparison of baseline and postoperative score averages demonstrated significant improvements in Tegner scores (3.7 ± 2.9 vs 5.1 ± 2.6; P = .003), HOS-ADL (63.3 ± 16.4 vs 89.1 ± 14.5; P < .001), HOS-SSS (40.8 ± 20.4 vs 79.5 ± 21.6; P < .001), mHHS (61.5 ± 16.2 vs 87.0 ± 17.7; P < .001), and NAHS (56.6 ± 14.9 vs 78.7 ± 18.3; P < .001). The percentage of patients who achieved MCID for HOS-ADL, HOS-SSS, mHHS, and NAHS were 89.8%, 83.0%, 75.6%, and 81.6%, respectively. Overall, 91.8% of patients met the threshold for achieving MCID in at least one outcome score. Of the 57 patients, 5 (8.8%) failed clinically, with 1 (1.8%) undergoing revision surgery and 4 (6.9%) undergoing conversion to total hip arthroplasty. There was a direct correlation between preoperative alpha angle and postoperative HOS-ADL. Femoral chondral lesion size and CMI inversely correlated with postoperative HOS-ADL. CONCLUSIONS: Treatment of hip chondral defects with microfracture and hyaline allograft augmentation demonstrated excellent survivorship and significantly improved patient report outcomes at 1 year. LEVEL OF EVIDENCE: IV, retrospective case series.

Current Trends in Orthobiologics: An 11-Year Review of the Orthopaedic Literature.

BACKGROUND: The use of "orthobiologics" or regenerative therapies in orthopaedic surgery has grown in recent years. Particular interest has been raised with regard to platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cells. Although studies have analyzed outcomes after orthobiologic treatment, no study has analyzed how the literature as a whole has evolved. PURPOSE: To evaluate trends in platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cell publications and to assess how these might inform efforts to establish minimum reporting standards and forecast future use. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A database was compiled systematically using PubMed to identify articles published between 2009 and 2019 within 9 prominent orthopaedic journals and pertaining to the use of platelet-rich plasma, bone marrow aspirate, adipose-derived cells, and amniotic cells in the treatment of musculoskeletal conditions. Included articles were classified as clinical, nonclinical (translational or basic science), or review, and a variety of study parameters were recorded for each. Additional queries were performed to identify articles that utilized minimum reporting standards. RESULTS: A total of 474 articles (132 clinical, 271 nonclinical, 71 review) were included, consisting of 244 (51.5%) platelet-rich plasma, 146 (30.8%) bone marrow aspirate, 72 (15.2%) adipose-derived cells, and 12 (2.5%) amniotic cells. The greatest annual increase in publications for each orthobiologic topic was from 2018 to 2019. The American Journal of Sports Medicine demonstrated the highest number of overall (34.2%) and clinical (50.0%) publications, and accounted for 44.3% of all platelet-rich plasma publications. The Journal of Orthopaedic Research accounted for the second highest overall number of publications (24.9%) and highest nonclinical publications (41.0%). Platelet-rich plasma accounted for 91.5% of all level 1 clinical studies, while much greater than half of bone marrow aspirate, adipose-derived cells, and amniotic cell publications were level 3 or lower. Out of the 207 articles that used some form of reporting protocol, 59 (28.5%) used an established algorithm and 125 (60.4%) used their own. CONCLUSION: Interest in orthobiologics continues to grow, as evidenced by an increasing trend in publications over an 11-year period. However, current reporting on orthobiologic formulations is largely heterogeneous, emphasizing the need for minimum reporting standards and higher-quality studies.

Lumbar microdecompression in elderly versus general adult patients: Comparable outcomes and costs despite group differences.

This study investigated differences between patients <65 and ≥65 years of age following lumbar microdecompression. Differences between age groups were investigated with univariate analyses. A linear mixed effects model was fit to the study outcomes. 144 patients were studied. There was no difference in two-year outcomes between the age groups. Outcome measures showed improvement compared to baseline at one- and two-years (p < 0.001). Age group had a significant effect on back pain (p = 0.016). Patients ≥65 years of age may experience greater relief in back pain following microdecompression. Nonetheless, significant improvement is observed in both age groups at two-years.

Unilateral Laminotomy with Bilateral Decompression: A Case Series Studying One- and Two-Year Outcomes with Predictors of Minimal Clinical Improvement.

OBJECTIVE: To assess factors that may predict failure to improve at 12 and 24 months after unilateral laminotomy with bilateral decompression (ULBD) for the management of lumbar spinal stenosis. METHODS: A database of 255 patients who underwent microdecompression surgery by a single orthopedic spine surgeon between 2014 and 2018 was queried. Patients who underwent primary single-level ULBD of the lumbar spine were included. Visual analog scale (VAS) for back pain and leg pain and Oswestry Disability Index (ODI) results were collected preoperatively and at 12 and 24 months postoperatively. Demographic, radiographic, and operative factors were assessed for associations with failure to improve. Clinically important improvement was defined as reaching or surpassing the previously established minimum clinically important difference for ODI (12.8) and not requiring revision. RESULTS: A total of 68 patients were included. Compared with preoperative values for back pain, leg pain, and ODI (7.32, 7.53, and 51.22, respectively), there were significant improvements on follow-up at 12 months (2.89, 2.23, and 22.40, respectively; P < 0.001) and 24 months (2.80, 2.11, 20.32, respectively; P < 0.001). Based on the defined criteria, 50 patients showed clinically important improvement after ULBD. Of the 18 patients who failed to improve, 12 required revision. Independent predictors of failure to improve included female sex (adjusted odds ratio, 5.06; 95% confidence interval, 1.49-21.12; P = 0.014) and current smoker status (adjusted odds ratio, 5.39; 95% confidence interval, 1.39-23.97; P = 0.018). CONCLUSIONS: ULBD for the management of lumbar spinal stenosis leads to clinically important improvement that is maintained over a 24-month follow-up period. Female sex and tobacco smoking are associated with poorer outcomes.

Diabetic hip arthropathy is associated with a higher prevalence of femoral head chondromalacia: a case-controlled study.

INTRODUCTION: No previous studies have characterised hip joint disease in diabetic patients undergoing hip arthroscopy. The purpose of our study was to evaluate intra-articular hip pathology and surgical variables in patients with diabetes compared to matched, non-diabetic controls. We hypothesised that diabetic patients would demonstrate a higher prevalence and severity of hip chondral pathology. METHODS: We retrospectively reviewed 795 consecutive hip arthroscopies performed by a single surgeon between 2010 and 2015. Patients ⩾18 years of age without a history of diabetes served as controls and were matched based on age, sex, body mass index, duration of symptoms, and operative side. Clinical symptoms, preoperative physical examination, and radiologic and intraoperative findings were assessed. The primary outcomes were the acetabular and femoral head chondromalacia index (CMI), calculated as the product of the Outerbridge chondromalacia grade and surface area (mm2*severity). RESULTS: 15 diabetic patients were matched to 137 non-diabetic controls. Diabetic patients demonstrated a higher prevalence of femoral head chondromalacia compared to controls both on magnetic resonance imaging (45.5% vs. 7.5%, p = 0.002) and during arthroscopy (100% vs. 75.9%, p = 0.042). Femoral head chondromalacia in diabetic patients had higher Outerbridge grade (2.4 vs. 2.0, p = 0.030) but similar CMI (513.0 vs. 416.4, p = 0.298) compared to controls. DISCUSSION: Femoral head chondral pathology was more prevalent and of higher severity grade in diabetic patients. The prevalence, size, and severity of acetabular chondral disease were similar between diabetic and non-diabetic patients. Multivariate analysis demonstrated that diabetic status was independently associated with the presence of femoral head chondromalacia.

Arthroscopic Treatment of Hip Chondral Defect With Microfracture and Platelet-Rich Plasma-Infused Micronized Cartilage Allograft Augmentation.

Over the past decade, arthroscopic microfracture has become increasingly popular to treat full-thickness (Outerbridge grade IV) chondral defects of the hip. This procedure borrows marrow stimulation treatment principles and techniques from knee arthroscopy, with similar mixed clinical outcomes that may be more favorable in the short term (<2 years) and poorer in the long term. Despite these varied outcomes, microfracture remains the most frequently used technique to treat small focal chondral defects because of the relative ease and cost-effectiveness of the procedure. Consequently, recent efforts have been aimed at improving or augmenting traditional microfracture to achieve more consistent success. BioCartilage (Arthrex, Naples, FL) is a biologically active scaffold containing allograft cartilage that, when combined with autologous conditioned platelet-rich plasma and placed in a defect in which microfracture was performed, may provide a superior repair that mimics native hyaline cartilage rather than the less-durable fibrocartilage that is formed with microfracture alone. This Technical Note and accompanying video review the pertinent techniques, pearls, and potential pitfalls of the microfracture procedure augmented with BioCartilage in the treatment of symptomatic full-thickness chondral defects of the hip.

Return-to-Play and Performance Outcomes of Professional Athletes in North America After Hip Arthroscopy From 1999 to 2016.

BACKGROUND: The effect of hip arthroscopy on athletic performance compared with preinjury levels for professional athletes in different sports remains unknown. In addition, while return rates have been reported for professional baseball, football, and hockey players, return rates have not been reported for professional basketball players. HYPOTHESIS: Professional athletes in 4 major North American sports would be able to return to their sport and preoperative level of performance at a high rate after arthroscopic hip surgery. STUDY DESIGN: Descriptive epidemiology study. METHODS: Major League Baseball (MLB), National Basketball Association (NBA), National Football League (NFL), and National Hockey League (NHL) athletes who underwent hip arthroscopy were identified through a previously reported protocol based on public sources. Successful return to play (RTP) was defined as returning for at least 1 professional regular season game after surgery. Performance scores were calculated by use of previously established scoring systems. Each player served as his own control, with the season prior to surgery defined as baseline. To make comparisons across sports, the authors adjusted for expected season and career length differences between sports and calculated percentage changes in performance. RESULTS: The authors identified 227 procedures performed on 180 professional athletes between 1999 and 2016. Successful RTP was achieved in 84.6% (192/227) of the procedures. Compared with all other athletes, NBA athletes returned at a similar rate (85.7%, P ≥ .999). NFL offensive linemen returned at a significantly lower rate than all other athletes (61.1%, P = .010). NHL athletes returned at a significantly higher rate than all other athletes (91.8%, P = .048) and demonstrated significantly decreased performance during postoperative season 1 compared with baseline (-35.1%, P = .002). Lead leg surgery for MLB athletes (batting stance for hitters, pitching stance for pitchers) resulted in a 12.7% reduction in hitter performance score ( P = .041), a 1.3% reduction in pitcher fastball velocity ( P = .004), and a 60.7% reduction in pitch count ( P = .007) one season after surgery compared with baseline. Players in nearly every sport demonstrated significant reductions in game participation after surgery. CONCLUSION: This study supports the hypothesis that hip arthroscopy in professional athletes is associated with excellent rates of return at the professional level. However, postoperative performance outcomes varied based on sport and position.

A cross-sport comparison of performance-based outcomes of professional athletes following primary microfracture of the knee.

BACKGROUND: The purpose of this study was to compare performance-based outcomes among professional athletes in four major North American sports following microfracture to treat symptomatic chondral defects of the knee. METHODS: Major League Baseball (MLB), National Basketball Association (NBA), National Football League (NFL), and National Hockey League (NHL) athletes who underwent primary unilateral microfracture of the knee were identified through a previously reported protocol based on public sources. Successful return-to-play was defined as returning for at least one professional regular season game after surgery. Regular season player statistics and sport-specific performance scores were compiled for each player. Each player served as his own control, with the season prior to surgery defined as baseline. Comparisons across sports were enabled by adjusting for expected season and career length differences between sports and by calculating percent changes in performance. RESULTS: One hundred thirty one professional athletes who underwent microfracture were included. One hundred three athletes (78.6%) successfully returned to play. The ratio of games started-to-games played before surgery was found to be a significant positive independent predictor of returning (p = 0.002). Compared with their preoperative season, basketball and baseball players demonstrated significantly decreased performance one season after surgery (-14.8%, p = 0.029 and -12.9%, p = 0.002, respectively) that was recoverable to baseline by postoperative seasons 2-3 for baseball players but not for basketball players (-9.7%, p = 0.024). CONCLUSION: Knee microfracture surgery is associated with a high rate of return to the professional level. However, the impact of this procedure on postoperative performance varied significantly depending on sport.

Aryl Hydrocarbon Receptor Antagonists Mitigate the Effects of Dioxin on Critical Cellular Functions in Differentiating Human Osteoblast-Like Cells.

The inhibition of bone healing in humans is a well-established effect associated with cigarette smoking, but the underlying mechanisms are still unclear. Recent work using animal cell lines have implicated the aryl hydrocarbon receptor (AhR) as a mediator of the anti-osteogenic effects of cigarette smoke, but the complexity of cigarette smoke mixtures makes understanding the mechanisms of action a major challenge. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin) is a high-affinity AhR ligand that is frequently used to investigate biological processes impacted by AhR activation. Since there are dozens of AhR ligands present in cigarette smoke, we utilized dioxin as a prototype ligand to activate the receptor and explore its effects on pro-osteogenic biomarkers and other factors critical to osteogenesis using a human osteoblast-like cell line. We also explored the capacity for AhR antagonists to protect against dioxin action in this context. We found dioxin to inhibit osteogenic differentiation, whereas co-treatment with various AhR antagonists protected against dioxin action. Dioxin also negatively impacted cell adhesion with a corresponding reduction in the expression of integrin and cadherin proteins, which are known to be involved in this process. Similarly, the dioxin-mediated inhibition of cell migration correlated with reduced expression of the chemokine receptor CXCR4 and its ligand, CXCL12, and co-treatment with antagonists restored migratory capacity. Our results suggest that AhR activation may play a role in the bone regenerative response in humans exposed to AhR activators, such as those present in cigarette smoke. Given the similarity of our results using a human cell line to previous work done in murine cells, animal models may yield data relevant to the human setting. In addition, the AhR may represent a potential therapeutic target for orthopedic patients who smoke cigarettes, or those who are exposed to secondhand smoke or other environmental sources of aryl hydrocarbons.

Can Surgeon Demographic Factors Predict Postoperative Complication Rates After Elective Spinal Fusion?

STUDY DESIGN: Retrospective cohort. OBJECTIVE: Determine whether surgeon demographic factors influence postoperative complication rates after elective spine fusion procedures. BACKGROUND: Surgeon demographic factors have been shown to impact decision making in the management of degenerative disease of the lumbar spine. Complication rates are frequently reported outcome measurements used to evaluate surgical treatments, quality-of-care, and determine health care reimbursements. However, there are few studies investigating the association between surgeon demographic factors and complication outcomes after elective spine fusions. METHODS: A database of US spine surgeons with corresponding postoperative complications data after elective spine fusions was compiled utilizing public data provided by the Centers for Medicare and Medicaid Services (2011-2013) and ProPublica Surgeon Scorecard (2009-2013). Demographic data for each surgeon was collected and consisted of: surgical specialty (orthopedic vs. neurosurgery), years in practice, practice setting (private vs. academic), type of medical degree (MD vs. DO), medical school location (United States vs. foreign), sex, and geographic region of practice. General linear mixed models using a Beta distribution with a logit link and pairwise comparison with post hoc Tukey-Kramer were used to assess the relationship between surgeon demographics and complication rates. RESULTS: 2110 US-practicing spine surgeons who performed spine fusions on 125,787 Medicare patients from 2011 to 2013 met inclusion criteria for this study. None of the surgeon demographic factors analyzed were found to significantly affect overall complication rates in lumbar (posterior approach) or cervical spine fusion. CONCLUSIONS: Publicly available complication rates for individual spine surgeons are being utilized by hospital systems and patients to assess aptitude and gauge expectations. The increasing demand for transparency will likely lead to emphasis of these statistics to improve outcomes. We conclude that none of the surgeon demographic factors analyzed in this study are associated with differences in overall complications rates in patients undergoing elective spine fusion as published by the ProPublica Surgeon Scorecard. LEVEL OF EVIDENCE: Level 3.

Factors Associated With Financial Relationships Between Spine Surgeons and Industry: An Analysis of the Open Payments Database.

STUDY DESIGN: A retrospective review of Centers for Medicare and Medicaid Services Database. OBJECTIVE: Utilizing Open Payments data, we aimed to determine the prevalence of industry payments to orthopedic and neurospine surgeons, report the magnitude of those relationships, and help outline the surgeon demographic factors associated with industry relationships. SUMMARY OF BACKGROUND DATA: Previous Open Payments data revealed that orthopedic surgeons receive the highest value of industry payments. No study has investigated the financial relationship between spine surgeons and industry using the most recent release of Open Payments data. METHODS: A database of 5898 spine surgeons in the United States was derived from the Open Payments website. Demographic data were collected, including the type of residency training, years of experience, practice setting, type of medical degree, place of training, gender, and region of practice. Multivariate generalized linear mixed models were utilized to determine the relationship between demographics and industry payments. RESULTS: A total of 5898 spine surgeons met inclusion criteria. About 91.6% of surgeons reported at least one financial relationship with industry. The median total value of payments was $994.07. Surgeons receiving over $1,000,000 from industry during the reporting period represented 6.6% of the database and accounted for 83.5% of the total value exchanged. Orthopedic training (P < 0.001), academic practice setting (P < 0.0001), male gender (P < 0.0001), and West or South region of practice (P < 0.0001) were associated with industry payments. Linear regression analysis revealed a strong inverse relationship between years of experience and number of payments from industry (r = -0.967, P < 0.0001). CONCLUSION: Financial relationships between spine surgeons and industry are highly prevalent. Surgeon demographics have a significant association with industry-surgeon financial relationships. Our reported value of payments did not include ownership or research payments and thus likely underestimates the magnitude of these financial relationships. LEVEL OF EVIDENCE: 3.

Do Demographic Factors of Spine Surgeons Affect the Rate at Which Spinal Fusion Is Performed on Patients?

STUDY DESIGN: Retrospective study. OBJECTIVE: The purpose of this study was to evaluate associations between spine surgeon demographics and the rate at which elective spine fusion is performed. SUMMARY OF BACKGROUND DATA: Rapidly increasing rates of elective spinal fusion in the United States have given rise to important questions about what factors may drive spine surgeon decision making. METHODS: Publicly available spine surgeon practice pattern data from Centers for Medicare and Medicaid Services were reviewed retrospectively. Fusion rate was defined as the number of fusion procedures performed on Medicare beneficiaries by a surgeon per total number of unique Medicare beneficiaries seen. Inclusion criteria were neurological or orthopedic spine surgeons who performed 11 or more separate spine fusion procedures on Medicare patients between 2011 and 2013 as defined by this database. Demographic information was collected from public record. The increased probability of a surgeon performing spine fusion was assessed using a relative risk (RR) and corresponding 95% confidence interval (CI). RESULTS: A total of 3979 spine surgeons who practice in the United States and performed spine fusion on 171,676 Medicare patients from 2011 to 2013 met the inclusion criteria. The average rate of spine fusion for surgeons in this database was 7.5%. Surgeons with higher fusion rates practiced in an academic versus private setting (RR = 1.44, 95% CI [1.35-1.53]; P < 0.0001), were more likely neurological versus orthopedic surgeons (RR = 1.10, 95% CI [1.05-1.15]; P < 0.0001), and practiced in the West versus Midwest, South, and Northeast region of the United States (RR = 1.20, 95% CI [1.14-1.27]; P < 0.0001). Number of years in practice was significantly associated negatively with fusion rate (P < 0.0001). CONCLUSION: Significant variation in the rate of spine fusion based on practice type, training, region, and experience suggests poor consensus on indications for this procedure. Knowledge of these relationships may help identify underlying reasons for variations in surgical care and improve surgical outcomes. LEVEL OF EVIDENCE: 3.

Sport and Sex-Specific Reporting Trends in the Epidemiology of Concussions Sustained by High School Athletes.

BACKGROUND: Approximately 300,000 U.S. adolescents sustain concussions annually while participating in organized athletics. This study aimed to track sex and sport-specific trends among high school sports-related concussions over time, to identify whether a particular sport predisposes athletes to a higher risk, and to assess whether traumatic brain injury law enactments have been successful in improving recognition. METHODS: Injury data for academic years 2005 to 2014 were collected from annual reports generated by High School RIO (Reporting Information Online). The relative proportions of total estimated concussions to total estimated injuries were compared using an injury proportion ratio. The concussion rate was defined as the number of concussions per 10,000 athlete exposures (1 athlete participating in 1 practice or competition), with rates compared using a rate ratio. To evaluate the impact of legislation on sports-related concussions in this population, trends in concussion rates and proportions were analyzed before enactment (academic years 2005-2009) and after enactment (academic years 2010-2014). RESULTS: Between 2005-2006 and 2014-2015, a significant increase (p < 0.0001) in the overall number of concussions for all sports combined, the overall concussion rate (rate ratio, 2.30 [95% confidence interval, 2.04 to 2.59]), and the overall proportion of concussions (injury proportion ratio, 2.68 [95% confidence interval, 2.66 to 2.70]) was seen. Based on the injury proportion ratio, during the 2014-2015 academic year, concussions were more common in girls' soccer than in any other sport (p < 0.0001). CONCLUSIONS: Because of potentially devastating consequences, concussion prevention and recognition measures continue to be emphasized in high school contact sports. The data in our study suggest that significant increases in the overall rate and proportion of reported concussions during the past decade could have been affected by traumatic brain injury legislation. To our knowledge, this is the first study to show that girls' soccer players may have an even greater risk of sustaining a concussion than all other sports. CLINICAL RELEVANCE: Sports-related concussions in adolescent athletes can have devastating consequences, and we now know that female athletes, especially girls' soccer players, may be at an even greater risk for sustaining this injury than all other athletes. Knowledge of the trends identified by this study may help lead to policy and prevention measures that can accommodate each sport effectively and potentially halt these trends.

Sulfated glycopeptide nanostructures for multipotent protein activation.

Biological systems have evolved to utilize numerous proteins with capacity to bind polysaccharides for the purpose of optimizing their function. A well-known subset of these proteins with binding domains for the highly diverse sulfated polysaccharides are important growth factors involved in biological development and tissue repair. We report here on supramolecular sulfated glycopeptide nanostructures, which display a trisulfated monosaccharide on their surfaces and bind five critical proteins with different polysaccharide-binding domains. Binding does not disrupt the filamentous shape of the nanostructures or their internal ß-sheet backbone, but must involve accessible adaptive configurations to interact with such different proteins. The glycopeptide nanostructures amplified signalling of bone morphogenetic protein 2 significantly more than the natural sulfated polysaccharide heparin, and promoted regeneration of bone in the spine with a protein dose that is 100-fold lower than that required in the animal model. These highly bioactive nanostructures may enable many therapies in the future involving proteins.

Effects of Conflicts of Interest on Practice Patterns and Complication Rates in Spine Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: We sought to determine whether financial relationships with industry had any impact on operative and/or complication rates of spine surgeons performing fusion surgeries. SUMMARY OF BACKGROUND DATA: Recent actions from Congress and the Institute of Medicine have highlighted the importance of conflicts of interest among physicians. Orthopedic surgeons and neurosurgeons have been identified as receiving the highest amount of industry payments among all specialties. No study has yet investigated the potential effects of disclosed industry payments with quality and choices of patient care. METHODS: A comprehensive database of spine surgeons in the United States with compiled data of industry payments, operative fusion rates, and complication rates was created. Practice pattern data were derived from a publicly available Medicare-based database generated from selected CPT codes from 2011 to 2012. Complication rate data from 2009 to 2013 were extracted from the ProPublica-Surgeon-Scorecard database, which utilizes postoperative inhospital mortality and 30-day-readmission for designated conditions as complications of surgery. Data regarding industry payments from 2013 to 2014 were derived from the Open Payments website. Surgeons performing <10 fusions, those without complication data, and those whose identity could not be verified through public records were excluded. Pearson correlation coefficients and multivariate regression analyses were used to determine the relationship between industry payments, operative fusion rate, and/or complication rate. RESULTS: A total of 2110 surgeons met the inclusion criteria for our database. The average operative fusion rate was 8.8% (SD 4.8%), whereas the average complication rate for lumbar and cervical fusion was 4.1% and 1.9%, respectively. Pearson correlation analysis revealed a statistically significant but negligible relationship between disclosed payments/transactions and both operative fusion and complication rates. CONCLUSION: Our findings do not support a strong correlation between the payments a surgeon receives from industry and their decisions to perform spine fusion or associated complication rates. Large variability in the rate of fusions performed suggests a poor consensus for indications for spine fusion surgery. LEVEL OF EVIDENCE: 3.

Mechanistic insight into the effects of Aryl Hydrocarbon Receptor activation on osteogenic differentiation.

While inhibition of bone healing and increased rates of pseudarthrosis are known adverse outcomes associated with cigarette smoking, the underlying mechanisms by which this occurs are not well understood. Recent work has implicated the Aryl Hydrocarbon Receptor (Ahr) as one mediator of the anti-osteogenic effects of cigarette smoke (CS), which contains numerous toxic ligands for the Ahr. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) is a high-affinity Ahr ligand frequently used to evaluate Ahr pathway activation. The purpose of this study was to elucidate the downstream mechanisms of dioxin action on bone regeneration and investigate Ahr antagonism as a potential therapeutic approach to mitigate the effects of dioxin on bone. Markers of osteogenic activity and differentiation were assessed in primary rat bone marrow stromal cells (BMSC) after exposure to dioxin, Ahr antagonists, or antagonist + dioxin. Four Ahr antagonists were evaluated: α-Naphthoflavone (ANF), resveratrol (Res), 3,3'-Diindolylmethane (DIM), and luteolin (Lut). Our results demonstrate that dioxin inhibited ALP activity, migratory capacity, and matrix mineralization, whereas co-treatment with each of the antagonists mitigated these effects. Dioxin also inhibited BMSC chemotaxis, while co-treatment with several antagonists partially rescued this effect. RNA and protein expression studies found that dioxin down-regulated numerous pro-osteogenic targets, whereas co-treatment with Ahr antagonists prevented these dioxin-induced expression changes to varying degrees. Our results suggest that dioxin adversely affects bone regeneration in a myriad of ways, many of which appear to be mediated by the Ahr. Our work suggests that the Ahr should be investigated as a therapeutic target to combat the adverse effects of CS on bone healing.