Ryan D. Freshman

The NFL Orthopaedic Surgery Outcomes Database (NO-SOD) The Effect of Common Orthopaedic Procedures on Football Careers

Background: Injuries are inherent to the sport of American football and often require operative management. Outcomes have been reported for certain surgical procedures in professional athletes in the National Football League (NFL), but there is little information comparing the career effect of these procedures. Purpose: To catalog the postoperative outcomes of orthopaedic procedures in NFL athletes and to compare respective prognoses and effects on careers. Study Design: Case series; Level of evidence, 4. Methods: Athletes in the NFL undergoing procedures for anterior cruciate ligament (ACL) tears, Achilles tendon tears, patellar tendon tears, cervical disc herniation, lumbar disc herniation, sports hernia, knee articular cartilage repair (microfracture technique), forearm fractures, tibial shaft fractures, and ankle fractures were identified through team injury reports or other public records. Game and performance statistics during the regular season were collected before and after surgery. Statistical analysis was performed with significance accepted as P < .05. Results: A total of 559 NFL athletes were included. Overall, 79.4% of NFL athletes returned to play after an orthopaedic procedure. Forearm open reduction and internal fixation (ORIF), sports hernia repair, and tibia intramedullary nailing (IMN) led to significantly higher return-to-play (RTP) rates (90.2%-96.3%), while patellar tendon repair led to a significantly lower rate (50%) (P < .001). Athletes undergoing ACL reconstruction (ACLR), Achilles tendon repair, patellar tendon repair, and ankle fracture ORIF had significant declines in games played at 1 year and recovered to baseline at 2 to 3 years after surgery. Athletes undergoing ACLR, Achilles tendon repair, patellar tendon repair, and tibia IMN had decreased performance in postoperative season 1. Athletes in the Achilles tendon repair and tibia IMN cohorts recovered to baseline performance, while those in the ACLR and patellar tendon repair cohorts demonstrated sustained decreases in performance. Conclusion: ACLR, Achilles tendon repair, and patellar tendon repair have the greatest effect on NFL careers, with patellar tendon repair faring worst with respect to the RTP rate, career length after surgery, games played, and performance at 1 year and 2 to 3 years after surgery.

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 very different polysaccharide binding domains. Binding does not disrupt the filamentous shape of the nanostructures or their internal β-sheet backbone, but must involve accessible adaptive configurations to interact with such different proteins. The glycopeptide nanostructures amplified signaling 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 expected. These super-bioactive nanostructures may enable many therapies in the horizon involving proteins.

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.

Performance-Based Outcomes after Anterior Cruciate Ligament Reconstruction in Professional Athletes Differ between Sports

Background: Excellent outcomes have been reported for anterior cruciate ligament (ACL) reconstruction (ACLR) in professional athletes in a number of different sports. However, no study has directly compared these outcomes between sports. Purpose: To determine if differences in performance-based outcomes exist after ACLR between professional athletes of each sport. Study Design: Cohort study; Level of evidence, 3. Methods: National Football League (NFL), National Basketball Association (NBA), National Hockey League (NHL), and Major League Baseball (MLB) athletes undergoing primary ACLR for an acute rupture were identified through an established protocol of injury reports and public archives. Sport-specific performance statistics were collected before and after surgery for each athlete. Return to play (RTP) was defined as a successful return to the active roster for at least 1 regular-season game after ACLR. Results: Of 344 professional athletes who met the inclusion criteria, a total of 298 (86.6%) returned to play. NHL players had a significantly higher rate of RTP (95.8% vs 83.4%, respectively; P = .04) and a shorter recovery time (258 ± 110 days vs 367 ± 268 days, respectively; P < .001) than athletes in all the other sports. NFL athletes experienced significantly shorter careers postoperatively than players in all the other sports (2.1 vs 3.2 years, respectively; P < .001). All athletes played fewer games (P ≤ .02) 1 season postoperatively, while those in the NFL had the lowest rate of active players 2 and 3 seasons postoperatively (60%; P = .002). NBA and NFL players showed decreased performance at season 1 after ACLR (P ≤ .001). NFL players continued to have lower performance at seasons 2 and 3 (P = .002), while NBA players recovered to baseline performance. Conclusion: The data indicate that NFL athletes fare the worst after ACLR with the lowest survival rate, shortest postoperative career length, and sustained decreases in performance. NHL athletes fare the best with the highest rates of RTP, highest survival rates, longest postoperative career lengths, and no significant changes in performance. The unique physical demand that each sport requires is likely one of the explanations for these differences in outcomes.

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.

Performance-based Outcomes among American Professional Athletes Following Microfracture of the Knee: A Cross-sport Analysis:

Objectives: Damage to the articular cartilage of the knee is a common and potentially career-threatening injury among professional athletes. Microfracture is a technique frequently used to treat chondral defects, but the potential benefits of this procedure in the elite athlete population remain unclear. This study sought to assess outcomes after microfracture of the knee among American professional athletes in different sports. 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 while on the active roster of a professional team and had a definitive date of surgery were identified through a well-established algorithmic approach based on public sources. Demographic information, as well as both pre- and post-surgery regular season player statistics, was compiled for each player. Successful return-to-play (RTP) was defined as returning for at least one professional regular season game after surgery. RTP time was defined as the number of days elapsed between date of surgery and date of first professional game back. Performance scores were calculated for each sport using previously established scoring systems. Players across different sports were compared by adjusting for season and career length differences between sports and by calculating percent change in performance. Results: A total of 131 professional athletes treated with microfracture from 1991 to 2015 met the inclusion criteria. Of these athletes, 103 (78.6%) successfully returned to play (Figure 1). Average time to RTP was 293±146 days. A player’s total career games started-to-games played ratio (GS:GP) before surgery was a significant positive independent predictor of RTP (p=0.039). NBA athletes who returned showed a significant reduction in adjusted games played during their first season post-surgery (61) compared to baseline (100) (p<0.0001). NBA and MLB athletes demonstrated significantly decreased performance one season after surgery (p=0.029 and p=0.002, respectively), and NBA athletes also demonstrated significantly decreased performance during post-operative seasons 2-3 (p=0.024) (Figure 2). BMI, age, career experience (years), games played during index season and total pre-operative career, and GS:GP during index season and total pre-operative career were not found to be predictors of RTP time, career length after surgery (years and games played), or change in performance score. Conclusion: Microfracture of the knee is a serious procedure that has the potential to negatively impact a professional athlete’s career. NFL athletes demonstrated the lowest probability of returning after surgery (71.1%), but for those who returned, performance was recoverable to baseline. NBA athletes had a higher-than-average probability of returning to play (82.4%), but those who returned showed a significant decline in performance one season after surgery that was sustained 2-3 seasons post-surgery, and a reduction in games played one season after surgery that was recoverable to baseline by seasons 2-3 post-surgery. Given the small sample size for NHL, microfracture of the knee may be uncommon in these athletes and definitive conclusions cannot be made. The findings of this study demonstrate that outcomes following microfracture vary significantly depending on sport, which is likely due in part to differences in sport-specific tasks. Figure 1: Return-to-play rates following primary unilateral microfracture of the knee for American professional athletes. *MLB athletes returned to play at a significantly higher rate than athletes of all other sports (p=0.013). **NFL athletes returned to play at a significantly lower rate than athletes of all other sports (p=0.017). Figure 2: Performance-based outcomes among American professional athletes following primary unilateral knee microfracture surgery. “Denotes significant difference (p<0.135) compared with pre-surgery season (baseline) for each athlete in cohort. NHL excluded due to small sample size.