Return to Full Participation Following Concussion in the National Football League, 2015 Through 2020.

OBJECTIVE: Quantify days missed, games missed, injury burden, and time to return to full participation (RTFP) among National Football League (NFL) players who sustained a concussion. DESIGN: Retrospective cohort study. SETTING: 2015 through 2020 NFL seasons. PARTICIPANTS: National Football League players diagnosed with a concussion from 2015 to 2020. INTERVENTIONS: National Football League-mandated graduated RTFP protocol. MAIN OUTCOME MEASURES: Days missed, games missed, burden, and time to RTFP, overall and by position. RESULTS: An annual average of 3639 player-days of participation and 255 games were missed across NFL because of concussion. Concussed players missed a median of 9 days (mean = 15.0), a relatively stable metric over 6 years, with slight variation by position. Offensive linemen, tight ends, running backs, and linebackers missed the most days per concussion; defensive secondary, offensive linemen, and wide receivers sustained the highest injury burden. Postconcussion, 59% of players missed one or more scheduled games. Among players concussed in a Sunday game, 38% played in a Sunday game one week later. CONCLUSIONS: The 9-day median time missed post-concussion may be related to emphasis on graduated phase-based concussion management. No concussed player returned to competition on the day of injury, and less than 40% participated in games the following week. Further work is needed to better understand characteristics of concussions that take longer to return and movement through stages of return.

Sports Performance and Injury Research: Methodologic Limitations and Recommendations for Future Improvements.

Evidence-based research has resulted in incredible advances in sports medicine and is an important component of minimizing injury risk. Such research is similarly important when applied to care delivery to athletes after injury. For research into injury reduction and treatment outcomes to be most impactful, however, the methods must be of sufficient rigor to generate high-quality evidence. Two recent trends in sports injury research have led to specific concerns about evidence quality: 1) use of athletic performance metrics as an injury or treatment outcome and 2) use of publicly available data for injury or treatment research.

Hip Arthroscopy in Patients Aged 40 Years and Older: Greater Success With Labral Reconstruction Compared With Labral Repair.

PURPOSE: To assess the outcomes of complete, primary, arthroscopic hip labral reconstruction among patients aged 40 years and older compared with those who underwent primary labral repair and compared with patients aged 30 to 39 years who underwent complete, primary labral reconstruction. METHODS: We recruited all patients who underwent arthroscopic labral reconstruction between March 2010 and June 2015 and were aged 30 to 65 years or who underwent arthroscopic labral repair between June 2009 and June 2015 and were aged 40 to 65 years. The modified Harris Hip Score (mHHS), Lower Extremity Function Score, and visual analog scale score for average pain were collected preoperatively and at minimum 2-year follow-up. Failure was defined as the need for revision ipsilateral hip surgery. The rate of conversion to total hip arthroplasty (a subset of failure) was assessed separately. RESULTS: A total of 363 hips in 343 patients met the inclusion criteria. Follow-up was available for 312 hips (86.0%), and the average time to follow-up was 4.2 years (range, 2.0-8.5 years). After adjustment for differences in follow-up time between groups, failure was 3.29 times more likely for hips in the repair group aged 40 years and older than for hips in the reconstruction group aged 40 years and older (relative rate, 3.29; 95% confidence interval, 1.25-8.69; P = .02), and there was no difference in the failure rate for hips in the reconstruction group aged 40 years and older compared with hips in the reconstruction group aged 30 to 39 years (relative rate, 0.58; 95% confidence interval, 0.18-1.89; P = .37). The rate of conversion to total hip arthroplasty was not meaningfully different between the 3 groups. Among hips for which treatment did not fail, average improvement in the mHHS measured 35 points and both labral reconstruction groups saw a greater mHHS improvement than the labral repair group of patients aged 40 years and older (P = .01 and P < .01). CONCLUSIONS: Labral reconstruction led to a lower failure rate, greater average improvement in the mHHS, and equivalent postoperative patient-reported outcome scores compared with labral repair among patients aged 40 years and older in this study population, and the outcomes of labral reconstruction were similar between patients aged 40 years and older and those aged 30 to 39 years. Complete labral reconstruction may be particularly advantageous in patients aged 40 years and older. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Time to Return to School After 10 Common Orthopaedic Surgeries Among Children and Adolescents.

BACKGROUND: Return to school among adolescents is often overlooked in orthopaedic outcome studies. The purpose was to measure the time missed from school after 10 common orthopedic surgeries. METHODS: Patients, 5 to 19 years old enrolled in elementary, middle, or high school, who underwent treatment for fixation of type III supracondylar humerus fracture, midshaft femur fracture fixation, isolated anterior cruciate ligament reconstruction, isolated partial menisectomy, adolescent idiopathic scoliosis fusion, closed reduction of both-bone forearm fracture, arthroscopic Bankart repair, hip arthroscopy with femoroacetabular impingement correction, limb length discrepancy correction, or surgical fixation of slipped capital femoral epiphysis during the 2014/2015 and 2015/2016 school years were identified for this Institutional Review Board-approved study. All patients were contacted after surgery to determine date of return to school, number of days in session, and number of school days missed. RESULTS: Two hundred six patients met the inclusion criteria for this study. Mean age at time of surgery was 13.0±3.8 years. There were 105 males (51%). Mean time to return to school overall was 13.0±15.2 days. Very few students (n=9; 4%) did not miss any school days during recovery from the procedure of interest. The average number of days missed from school for males was 6.6 days compared with 8.4 days in females (P=0.20). There was no difference between patients aged 5 to 12 years compared with those aged 13 to 19 years (7.1 vs. 7.7 d, respectively; P=0.69). On average, patients who underwent closed reduction of a both-bone forearm fracture returned to school the quickest following surgery (3.4±1.2 d) and missed the least amount of in-session school days (1.9±0.9 d), and those who underwent adolescent idiopathic scoliosis fusion were out of school the longest (42.3±21.4 d) and missed the greatest number of in-session school days (27.6±14.7 d). CONCLUSIONS: Information regarding average time missed from school for 10 common orthopaedic surgeries can be used by clinicians to counsel patients and their families regarding expected recovery time. LEVEL OF EVIDENCE: Level IV.

Bilateral Hip Arthroscopy: Direct Comparison of Primary Acetabular Labral Repair and Primary Acetabular Labral Reconstruction.

PURPOSE: Directly compare primary acetabular labral repair versus primary acetabular labral reconstruction using a self-controlled cohort study design. METHODS: Patients who underwent primary labral repair in one hip and primary labral reconstruction using iliotibial band allograft in the other hip by a single surgeon between August 2009 and November 2014 were identified. One patient with inflammatory arthritis was excluded. Patient-reported outcome data included change in Modified Harris Hip Score (MHHS), Lower Extremity Functional Scale (LEFS), average pain using a 10-point visual analog scale (VAS), and patient satisfaction (1: very dissatisfied, 10: very satisfied). Failure was defined as subsequent intra-articular hip surgery. Data were analyzed using McNemar's and Wilcoxon Signed Rank tests. RESULTS: Overall, 29 patients (58 hips) were included in the analysis. There were 23 females and 6 males. The average age at time of surgery was 32.6 years (range: 14.9-51.6 years). Follow-up was obtained from all 29 patients (100%) at a mean of 56 months (range = 27-85 months) postoperative for repaired hips and 40 months (range = 22-61 months) postoperative for reconstructed hips. No labral reconstruction hips failed, and 9 (31%) labral repair hips failed (P < .01). Among those that did not fail treatment, there was no difference in MHHS change (32.2 ± 15.4 vs 29.6 ± 15.4; P = .63), LEFS change (26.6 ± 16.5 vs 23.9 ± 17.8; P = .61), VAS pain change (-3.2 ± 2.4 vs -3.6 ± 2.1; P = .47), or satisfaction (8.6 ± 2.0 vs 8.7 ± 2.4; P = .59) between the repair and reconstruction groups, respectively. CONCLUSIONS: In this cohort of patients, hips that underwent primary labral repair were more likely to fail treatment than hips that underwent labral reconstruction (31% vs 0%, respectively). Among hips that did not fail treatment, patient-reported outcome scores were similar between groups. Excellent clinical results can be obtained with both forms of labral-preserving treatment but were more predictably observed with primary labral reconstruction in this cohort. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Age Predicts Disruption of the Articular Surface of the Femoral Condyles in Knee OCD: Can We Reduce Usage of Arthroscopy and MRI?

BACKGROUND: The purpose of this study was to determine if patient age could accurately identify disrupted articular cartilage overlying an osteochondritis dissecans (OCD) lesion of the femoral condyle in adolescents. This could have important implications for imaging and treatment decisions. METHODS: All patients from 2001 to 2014 who were arthroscopically treated for a femoral condyle OCD were included in this Institutional Review Board-approved study. Exclusion criteria were trochlear and patellar OCD lesions, idiopathic arthritis, and traumatic osteochondral injuries. Arthroscopy was performed to visualize and probe the articular surface. Arthroscopic and magnetic resonance imaging (MRI) findings were recorded as "intact" or "disrupted" cartilage. Extra-articular drilling was performed when the articular cartilage was intact. RESULTS: There were 119 patients (81 male, 68%) with 139 OCD lesions in 136 knees. The mean age at time of surgery was 13.0 years (range, 7.2 to 19.3 y). At arthroscopy, 115 knees had intact cartilage and 24 had disrupted cartilage. There was a significant difference in age between patients with intact versus disrupted cartilage at arthroscopy (12.5 vs. 15.3 y; P<0.0001). Eighty-eight OCD lesions had MRIs preoperatively, showing 69 as intact and 19 (24%) disrupted. MRI reading for cartilage status had 94% sensitivity and 97% specificity. Multivariable regression analysis revealed that age (P<0.01) and MRI status (P<0.0001) were strong predictors of cartilage status. Sixteen years was the critical age in which both sensitivity was maximized and false positive probability was minimized. Over the age of 17 years, 7 of 7 (100%) had disrupted cartilage. Age alone was 100% sensitive for children below the age of 10, and 96% sensitive below the age of 13. CONCLUSIONS: Age was a good predictor of cartilage status in both younger (<13 y) and older (≥17 y) patients in this study. For patients in the mid-range group (13 through 16 y), age alone is not an adequate predictor of cartilage status, but adding MRI increased accuracy. SIGNIFICANCE: Age can be used to stratify patients and thereby influence diagnostic and treatment strategies. LEVEL OF EVIDENCE: Level IV.

Revision Arthroscopic Acetabular Labral Treatment: Repair or Reconstruct?

PURPOSE: To compare the outcome of labral repair versus labral reconstruction in patients presenting to a single surgeon for revision hip arthroscopy following previous labral treatment. METHODS: Patients who underwent revision labral repair or labral reconstruction using iliotibial band allograft, after previous labral debridement or repair, between 2009 and 2013 were identified. Hips that underwent revision labral reconstruction were further stratified into 2 graft groups (freeze-dried vs frozen allograft). Exclusion criteria were age <16 years, previous open hip surgery, or previous labral reconstruction. Failure was defined by subsequent intra-articular hip surgery. RESULTS: 113 hips (15 repair, 98 reconstruction) met the inclusion criteria. Patients who underwent revision labral repair were younger than patients who underwent revision labral reconstruction (27.8 years vs 34.6 years; P = .02). Follow-up was obtained from 14 (93%) labral repairs at an average of 4.7 years postoperation (range: 2.0-6.0 years) and 90 (92%) labral reconstructions at an average of 2.4 years postoperation (range: 2.0-4.0 years). Seven of 14 (50%) labral repair hips failed compared with 11/90 (12%) labral reconstruction hips (P < .01). Six of 61 (10%) frozen allografts failed compared with 5/29 (17%) freeze-dried allografts (P = .32). Patients who underwent revision labral repair were 4.1 (95% confidence interval 1.9, 8.8) times more likely to fail than patients who underwent revision labral reconstruction. CONCLUSIONS: Patients who underwent revision labral repair following previous repair or debridement were 2.6 times more likely to fail than patients who underwent revision labral reconstruction, controlling for calendar time. In addition, revision labral reconstruction with frozen allograft had lower propensity of failure than freeze-dried allograft. However, there was no statistically significant difference in patient-reported outcome scores between the 2 groups. Based on these results, complete labral reconstruction with longer, nonsegmental graft led to a lower failure rate in this study population and can be considered for treatment of patients presenting for revision labral treatment. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Allograft Use in Arthroscopic Labral Reconstruction of the Hip With Front-to-Back Fixation Technique: Minimum 2-Year Follow-up.

PURPOSE: To present minimum 2-year outcomes in patients who underwent a modified technique for arthroscopic labral reconstruction using iliotibial band allograft tissue and a front-to-back fixation. METHODS: From April 2011 to July 2012, all consecutive arthroscopic labral reconstruction patients were included in this Institutional Review Board-approved, prospective case series study. Inclusion criteria were arthroscopic iliotibial band allograft labral reconstruction performed by a single surgeon, age ≥16 years at the time of arthroscopy, and a minimum of 2 years of follow-up. Patients completed subjective questionnaires both preoperatively and postoperatively, including Modified Harris Hip Score (MHHS), the Lower Extremity Function Score (LEFS), Visual Analogue Scale (VAS) pain scores, and patient satisfaction. A modified front-to-back fixation technique for labral reconstruction was used. RESULTS: One hundred fifty-two hips (142 patients) met the inclusion criteria for this study; 131 hips (86.2%) had complete follow-up at a minimum of 2 years, and 21 hips (13.8%) were lost to follow-up or had incomplete data during the study period. Seventy hips had concomitant procedures performed; 27 microfracture, 30 chondroplasty, 26 psoas release, 5 os acetabuli resection, and 3 Ganz osteotomy. Overall, 18 hips (13.7%) required revision procedures at a mean of 17 months (range, 1 to 37 months) after the labral reconstruction. In the remaining 113 hips, there was significant improvement in all outcome measures from preoperative to most recent follow-up (P < .0001). The mean MHHS improved by 34 points (P < .0001), and the mean LEFS improved by 27 points (P < .0001). The mean VAS pain score improved by 3 points at rest (P < .0001), 4 points with average pain with daily activities (P < .0001), and 5 points with sport (P < .0001). Patients reported an overall satisfaction of 9 (range, 1 to 10). CONCLUSIONS: Arthroscopic iliotibial band allograft labral reconstruction of the hip shows promising outcomes at minimum 2-year follow-up. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Performance outcomes in professional hockey players following arthroscopic treatment of FAI and microfracture of the hip.

PURPOSE: Previous studies report professional athletes return to play following arthroscopic microfracture of the hip for chondral defects. Our hypothesis is that professional hockey players undergoing arthroscopic microfracture for chondral defects of the hip achieve the same performance they had pre-injury and compared to matched controls. METHODS: Seventeen professional hockey players underwent arthroscopic microfracture for an Outerbridge grade IV chondral lesion. Concomitant procedures for labral pathology or FAI were included. Performance data for the full season preceding and following index procedure were analysed, in addition to two matched control players per subject. Data were collected at two points, 2 years apart. RESULTS: Eighty-two per cent (14/17) of players who underwent arthroscopic microfracture returned to play. The year prior to injury for the 14 players who returned was compared to the average of their individual controls. There was no statistical difference between the groups for age, number of seasons in the league, games played, time on ice, points, save percentage, and shots against goal. Post-operatively, there was no statistical difference between the treatment and control groups regarding performance measures. There was a trend towards a decrease in games played and points post-operatively compared with controls. The treatment group decreased 11 games played, while the controls decreased five games. The treatment group also decreased 14 points, while the controls decreased three points for the season. CONCLUSIONS: Professional hockey players with a discrete, full-thickness chondral defect of the hip are able to return to elite performance level following an arthroscopic microfracture procedure when compared to pre-injury outcomes and controls.

Epidemiology of Injuries Among National Basketball Association Players: 2013-2014 Through 2018-2019.

BACKGROUND: Understanding the epidemiology of injuries to athletes is essential to informing injury prevention efforts. HYPOTHESIS: The incidence and impact of basketball-related injuries among National Basketball Association (NBA) players from 2013-2014 through 2018-2019 is relatively stable over time. STUDY DESIGN: Descriptive epidemiology study. LEVEL OF EVIDENCE: Level 3. METHODS: Injuries from 2013-2014 through 2018-2019 were analyzed using the NBA Injury and Illness Database from an electronic medical record system. Descriptive statistics were calculated for injuries by season, game-loss, and onset. Incidence rates were estimated using Poisson models and linear trend tests. RESULTS: Between 552 and 606 players participated in ≥1 game per season during the study. Annual injury incidence ranged from 1550 to 1892, with 33.6% to 38.5% resulting in a missed NBA game. Game-loss injury rates ranged from 5.6 to 7.0 injuries per 10,000 player-minutes from 2014-2015 through 2018-2019 (P = 0.19); the rate was lower in 2013-2014 (5.0 injuries per 10,000 player-minutes), partly due to increased preseason injury rates and transition of reporting processes. The 6-year game-loss injury rate in preseason and regular season games was 6.9 (95% CI 6.0, 8.0) and 6.2 (95% CI 6.0, 6.5) injuries per 10,000 player-minutes; the rate in playoff games was lower (P < 0.01) at 2.8 (95% CI 2.2, 3.6). Most (73%) game-loss injuries had acute onset; 44.4% to 52.5% of these involved contact with another player. CONCLUSION: From 2013-2014 through 2018-2019, over one-third of injuries resulted in missed NBA games, with highest rates of game-loss injuries in preseason games and lowest rates in playoff games. Most game-loss injuries had acute onset, and half of those involved contact with another player. CLINICAL RELEVANCE: These findings - through reliable data reporting by team medical staff in an audited system - can guide evidence-based injury reduction strategies and inform player health priorities.

Epidemiology of Stingers in the National Football League, 2015-2019.

BACKGROUND: Transient traumatic neuropraxia of either the brachial plexus or cervical nerve root(s) is commonly described as a "stinger" or "burner" by the athlete. Stingers in American Football commonly occur acutely as isolated injuries; however, concomitant injuries, including cervical spine pathologies, have also been reported. HYPOTHESIS: Among National Football League (NFL) athletes, the incidence rate of stingers is higher during the regular season than during the preseason and among positions with high velocity impacts such as running backs, linebackers, defensive backs, and receivers. STUDY DESIGN: Retrospective epidemiology study. LEVEL OF EVIDENCE: Level 4. METHODS: Aggregation of all in-game injuries with a clinical impression of "neck brachial plexus stretch" or "neck brachial plexus compression" entered into the NFL injury surveillance database through the centralized league-wide electronic medical record system over 5 years (2015-2019 seasons). Incidence rates per player-play were calculated and reported. RESULTS: A total of 691 in-game stingers occurred during the study period, with a mean of 138.2 per year. Average single-season injury risk for incident stinger was 3.74% (95% CI, 3.46%-4.05%). The incidence rate was higher during regular season games than during preseason games (12.26 per 100,000 player-plays [11.30-13.31] vs 8.87 [7.31-10.76], P < 0.01, respectively). The highest reported stinger incidence rates were among running backs and linebackers (both >15 per 100,000 player-plays). Among stingers, 76.41% did not miss time. Of those that resulted in time lost from football activities, mean time missed due to injury was 4.79 days (range, 3.17-6.41 days). Concomitant injuries were relatively low (7.09%). CONCLUSION: In-game stinger incidence was stable across the study period and occurred most frequently in running backs and linebackers. Stingers were more common during the regular season, and most players did not miss time. Concomitant injuries were relatively rare. CLINICAL RELEVANCE: An improved understanding of the expected time loss due to stinger and concomitant injuries may provide insight for medical personnel in managing these injuries.

Distal Tibiofibular Syndesmosis Injuries in the National Football League (NFL): A Spectrum of Pathology That Correlates With Time to Return to Full Participation.

BACKGROUND: Studies routinely evaluate high ankle sprains in isolation, but recent data suggest that these injuries are often associated with concomitant pathology, potentially influencing return to full participation. HYPOTHESIS: In National Football League (NFL) players, isolated high ankle sprains are rare and syndesmosis injuries with concomitant pathology will result in increased time to return to full participation. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 3. METHODS: Distal tibiofibular syndesmosis injuries sustained by NFL players between 2017 and 2019 were identified through NFL Injury Surveillance Database queries and verified with video analysis. Each injury underwent a comprehensive magnetic resonance imaging (MRI) review. Regression modeling was utilized to explore the influence of numerous imaging findings on time to return to full participation. RESULTS: There were 83 external rotation ankle injuries involving the syndesmosis. Isolated distal tibiofibular syndesmosis injuries were rare (n = 11; 13%) and more often associated with other ligamentous injury (deltoid ligament and lateral ligamentous complex) and/or fractures. Regression modeling resulted in clustering of 3 injury pattern groups for time to return to full participation across numerous imaging findings: syndesmosis injury-fracture combinations (250 days [interquartile range [IQR,] 142-266 days]), syndesmosis injury with complete deep deltoid tear or acute diastasis (175 days [IQR, 20-248 days]), and all other syndesmosis injuries (27 days [IQR, 18-46 days]). CONCLUSION: In NFL athletes with external rotation ankle injuries, isolated distal tibiofibular syndesmosis injuries were rare and more often associated with concomitant pathology. Time to return to full participation was affected by an associated fracture and complete deep deltoid ligament tear or diastasis but no other relevant MRI variables such as lateral ligament complex involvement or the presence of osteochondral lesions or bone contusions.

Return to play after hip arthroscopy with microfracture in elite athletes.

PURPOSE: The purpose of this study was to compare elite athletes who underwent hip arthroscopy with and without microfracture with respect to their ability to return to sport at the professional level. METHODS: All elite male athletes who underwent hip arthroscopy between 1999 and 2010 were identified. Inclusion criteria were hip arthroscopy with treatment of labrum, femoroacetabular impingement, cartilage, ligamentum teres, capsule, and/or loose body removal. Exclusion criteria were diffuse degenerative joint disease, previous surgery, plans to retire, labral reconstruction, soft tissue release, and concomitant lower extremity injury. Thirty-nine athletes underwent hip arthroscopy with microfracture and were assigned to the microfracture treatment group. Eighty-one elite athletes (94 hips) underwent hip arthroscopy without microfracture and were assigned to the control group. Sports played included hockey, soccer, football, baseball, tennis, and golf. RESULTS: Seventy-seven percent (30 of 39) of athletes in the microfracture treatment group and 84% (79 of 94) in the control group returned to play. There was no statistical difference in rate of return to play between groups (odds ratio = 1.6; 95% confidence interval, 0.633 to 4.049). Those players who did return were followed for an average of 3 years (range, 2 to 12). Athletes in the microfracture treatment group who returned have averaged 3 seasons thus far, and 73% are still playing. We found no significant difference in the microfracture group in age, time from injury to surgery, number of seasons played preoperatively, or size of lesion for return versus no return. We also found no increased risk of not returning because of contact sport, multiple lesions, or lesion on weightbearing surface. CONCLUSIONS: There was no detectable statistically significant difference in return to play rate after hip arthroscopy with microfracture and hip arthroscopy without microfracture. Professional athletes who underwent hip arthroscopy with microfracture procedure were able to return to the same high level of competition after surgery at a high rate. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Determining the True Incidence of Glenohumeral Instability Among Players in the National Football League: An Epidemiological Study of Non-Missed Time Shoulder Instability Injuries.

Background: Shoulder instability encompasses a spectrum of glenohumeral pathology ranging from subluxation to dislocation. While dislocation frequently leads to removal from play, athletes are often able to play through subluxation. Previous research on glenohumeral instability among athletes has largely focused on missed-time injuries, which has likely disproportionately excluded subluxation injuries and underestimated the overall incidence of shoulder instability. Purpose: To describe the epidemiology of shoulder instability injuries resulting in no missed time beyond the date of injury (non-missed time injuries) among athletes in the National Football League (NFL). Study Design: Descriptive epidemiology study. Methods: The NFL's electronic medical record was retrospectively reviewed to identify non-missed time shoulder instability injuries during the 2015 through 2019 seasons. For each injury, player age, player position, shoulder laterality, instability type, instability direction, injury timing, injury setting, and injury mechanism were recorded. For injuries that occurred during games, incidence rates were calculated based on time during the season as well as player position. The influence of player position on instability direction was also investigated. Results: Of the 546 shoulder instability injuries documented during the study period, 162 were non-missed time injuries. The majority of non-missed time injuries were subluxations (97.4%), occurred during games (70.7%), and resulted from a contact mechanism (91.2%). The overall incidence rate of game-related instability was 1.6 injuries per 100,000 player-plays and was highest during the postseason (3.5 per 100,000 player-plays). The greatest proportion of non-missed time injuries occurred in defensive secondary players (28.4%) and offensive linemen (19.8%), while kickers/punters and defensive secondary players had the highest game incidence rates (5.5 and 2.1 per 100,000 player-plays, respectively). In terms of direction, 54.3% of instability events were posterior, 31.9% anterior, 8.5% multidirectional, and 5.3% inferior. Instability events were most often anterior among linebackers and wide receivers (50% and 100%, respectively), while posterior instability was most common in defensive linemen (66.7%), defensive secondary players (58.6%), quarterbacks (100.0%), running backs (55.6%), and tight ends (75.0%). Conclusion: The majority of non-missed time shoulder instability injuries (97.4%) were subluxations, which were likely excluded from or underreported in previous shoulder instability studies due to the inherent difficulty of detecting and diagnosing shoulder subluxation.

MRI Findings Associated With Anterior Cruciate Ligament Tears in National Football League Athletes.

Background: Anterior cruciate ligament (ACL) tears are a high-frequency injury requiring a lengthy recovery in professional American football players. Concomitant pathology associated with ACL tears as identified on magnetic resonance imaging (MRI) is not well understood in these athletes. Purpose: To describe the MRI findings of concomitant injuries associated with ACL tears among athletes in the National Football League (NFL). Study Design: Cross-sectional study; Level of evidence, 3. Methods: Of 314 ACL injuries in NFL athletes from 2015 through 2019, 191 complete MRI scans from the time of primary ACL injury were identified and reviewed by 2 fellowship-trained musculoskeletal radiologists. Data were collected on ACL tear type and location, as well as presence and location of bone bruises, meniscal tears, articular cartilage pathology, and concomitant ligament pathology. Mechanism data from video review were linked with imaging data to assess association between injury mechanism (contact vs noncontact) and presence of concomitant pathology. Results: Bone bruises were evident in 94.8% of ACL tears in this cohort, most often in the lateral tibial plateau (81%). Meniscal, additional ligamentous, and/or cartilage injury was present in 89% of these knees. Meniscal tears were present in 70% of knees, lateral (59%) more than medial (41%). Additional ligamentous injury was present in 71% of all MRI scans, more often a grade 1/2 sprain (67%) rather than a grade 3 tear (33%), and most often involving the medial collateral ligament (MCL) (57%) and least often the posterior cruciate ligament (10%). Chondral damage was evident in 49% of all MRI scans, with ≥1 full-thickness defect in 25% of all MRI scans, most often lateral. Most (79%) ACL tears did not involve direct contact to the injured lower extremity. Direct contact injuries (21%) were more likely to have a concomitant MCL tear and/or medial patellofemoral ligament injury and less likely to have a medial meniscal tear. Conclusion: ACL tears were rarely isolated injuries in this cohort of professional American football athletes. Bone bruises were almost always present, and additional meniscal, ligamentous, and chondral injuries were also common. MRI findings varied by injury mechanism.

Lower Extremity Strains in the US National Football League, 2015-2019.

BACKGROUND: Lower extremity (LEX) strains, including hamstring, quadriceps, adductor, and calf strains, are among the most common injuries in sports. These injuries lead to high burden, resulting in significant missed participation time. PURPOSE: To describe the incidence of LEX strains in professional American football. STUDY DESIGN: Descriptive epidemiology study. METHODS: This study included all players who played in ≥1 National Football League (NFL) game or sustained a LEX strain during participation in the 2015-2019 seasons. LEX strain frequency was calculated by setting (game, practice, conditioning), timing in season (offseason, preseason, regular season, postseason), and roster position. Game incidence rates were calculated for season, roster position, and play type. LEX strains were identified in the standardized leaguewide electronic health record (n = 32 teams). RESULTS: Across 5 years, 5780 LEX strains were reported among 2769 players (1-year risk, 26.7%; 95% CI, 26.0%-27.3%); 69% (n = 4015) resulted in time loss. Among all LEX strains, 54.7% were hamstring (n = 3163), 24.1% adductor (n = 1393), 12.6% calf (n = 728), 8.3% quadriceps (n = 477), and 0.3% multiple muscle groups (n = 19). Most were reported during preseason practices (n = 1076; 27%) and regular season games (n = 1060; 26%). The 2-week period of training camp practices comprised 19% of all time-loss strains. Among game injuries, preseason games had the highest rate of LEX strain (2.9/10,000 player-plays; 95% CI, 2.6-3.2). Defensive secondary players accounted for the highest proportion of time-loss LEX strains (27%; n = 1082). In games, punt plays had nearly twice the injury rate of kickoff plays (14.9/1000 plays [95% CI, 13.1-17.0] vs 7.5/1000 plays [95% CI, 6.2-8.9], respectively) and >3 times the rate of pass plays (4.3/1000 plays; 95% CI, 4.0-4.7) and run plays (2.6/1000 plays; 95% CI, 2.3-2.9). In aggregate, LEX strains led to an estimated 16,748 participation days missed each year and a median 12 days missed per injury. CONCLUSION: LEX strains affected 1 in 4 NFL players each year, resulting in a high burden of injury in terms of time lost from practice and competition. Safe return to the NFL season during training camp and reduction of injuries during regular season games are key focuses for future injury reduction.

Fluoroquinolone Antibiotics and Tendon Injury in Adolescents.

OBJECTIVES: To estimate the association between fluoroquinolone use and tendon injury in adolescents. METHODS: We conducted an active-comparator, new-user cohort study using population-based claims data from 2000 to 2018. We included adolescents (aged 12-18 years) with an outpatient prescription fill for an oral fluoroquinolone or comparator broad-spectrum antibiotic. The primary outcome was Achilles, quadricep, patellar, or tibial tendon rupture identified by diagnosis and procedure codes. Tendinitis was a secondary outcome. We used weighting to adjust for measured confounding and a negative control outcome to assess residual confounding. RESULTS: The cohort included 4.4 million adolescents with 7.6 million fills for fluoroquinolone (275 767 fills) or comparator (7 365 684) antibiotics. In the 90 days after the index antibiotic prescription, there were 842 tendon ruptures and 16 750 tendinitis diagnoses (crude rates 0.47 and 9.34 per 1000 person-years, respectively). The weighted 90-day tendon rupture risks were 13.6 per 100 000 fluoroquinolone-treated adolescents and 11.6 per 100 000 comparator-treated adolescents (fluoroquinolone-associated excess risk: 1.9 per 100 000 adolescents; 95% confidence interval -2.6 to 6.4); the corresponding number needed to treat to harm was 52 632. For tendinitis, the weighted 90-day risks were 200.8 per 100 000 fluoroquinolone-treated adolescents and 178.1 per 100 000 comparator-treated adolescents (excess risk: 22.7 per 100 000; 95% confidence interval 4.1 to 41.3); the number needed to treat to harm was 4405. CONCLUSIONS: The excess risk of tendon rupture associated with fluoroquinolone treatment was extremely small, and these events were rare. The excess risk of tendinitis associated with fluoroquinolone treatment was also small. Other more common potential adverse drug effects may be more important to consider for treatment decision-making, particularly in adolescents without other risk factors for tendon injury.

Epidemiology of Shoulder Instability in the National Football League.

BACKGROUND: Shoulder instability is a common and potentially debilitating injury among collision sport athletes that can lead to long-term damage of the glenohumeral joint. Limited data exist regarding instability among elite athletes in the National Football League (NFL). PURPOSE: To describe the epidemiology of shoulder instability in the NFL from 2012 through 2017. STUDY DESIGN: Descriptive epidemiology study. METHODS: The NFL's injury database was reviewed for shoulder instability injuries resulting in missed time during the study inclusion dates. Injuries were classified by type and direction, as well as timing, setting, and mechanism. Median missed time was determined for the different types and directions of instability. Incidence rates for game-related injuries were calculated based on timing during the season and player position. Finally, the relationship between player position and instability direction was assessed. RESULTS: During the 6-year study period, 355 players sustained 403 missed-time shoulder instability injuries. Most injuries occurred during games (65%) via a contact mechanism (85%). The overall incidence rate of game-related instability was 3.6 injuries per 100,000 player-plays and was highest during the preseason (4.9 per 100,000 player-plays). The defensive secondary position accounted for the most injuries, but quarterbacks had the highest incidence rate in games (5.5 per 100,000 player-plays). Excluding unspecified events (n = 128; 32%), 70% (n = 192) of injuries were subluxations and 30% (n = 83) were dislocations; 75% of dislocations were anterior, while subluxations were more evenly distributed between the anterior and posterior directions (45% vs 52%, respectively). Players missed substantially more time after dislocation compared with subluxation (median, 47 days vs 13 days, respectively). When instability direction was known, the majority of instability events among quarterbacks and offensive linemen were posterior (73% and 53%, respectively), while anterior instability was most common for all other positions. CONCLUSION: Shoulder instability is a common injury in the NFL and can result in considerable missed time. Dislocations occur less frequently than subluxations but lead to greater time lost. While most dislocations are anterior, more than half of subluxations are posterior, which is likely the result of repetitive microtrauma to the posterior capsulolabral complex sustained during sport-specific motions such as blocking. The risk of instability varies by player position, and position may also influence instability direction.

Factors Associated With the Mechanism of ACL Tears in the National Football League: A Video-Based Analysis.

BACKGROUND: The factors associated with anterior cruciate ligament (ACL) injury mechanism in professional American football players are not well-understood. HYPOTHESIS: It was hypothesized that football-related and player-specific factors, such as position and body mass index (BMI), are associated with ACL injury mechanism in these athletes. STUDY DESIGN: Descriptive epidemiology study. METHODS: Videos of ACL tears occurring in National Football League (NFL) games over 6 consecutive seasons from 2014 to 2019 were reviewed by 2 orthopaedic surgeons who specialize in sports medicine. For each injury, the role of contact (direct contact [contact to the injured knee/lower extremity], indirect contact [contact not involving the injured knee/lower extremity], or no contact) as well as playing situation and lower extremity position were recorded. Additional player characteristics, timing of injury, and surface information were obtained from NFL game-day and injury database statistics. RESULTS: Of the 140 ACL tears, a minority occurred via direct contact to the injured lower extremity (30%), although this varied by position. Just over two-thirds (70%) of ACL tears in offensive linemen occurred via direct contact to the injured lower extremity, while wide receivers had no direct contact ACL tears. Elevated BMI was associated with a greater likelihood of ACL tears occurring via direct contact (53% in players with BMI ≥35 kg/m2 vs 24% in players with BMI <35 kg/m2; P = <.01). Rookies had the lowest percentage of direct contact ACL tears (18%; P = .22). ACL tears that occurred during the middle 8 weeks of the regular season resulted more often from direct contact (38%; P = .06). ACL tears that occurred in the third quarter were the most likely to occur via direct contact (44%), while those that occurred in the fourth quarter were the least likely to occur via direct contact (13%; P < .01). CONCLUSION: Although most NFL players sustained ACL tears via a noncontact mechanism (ie, through indirect or no contact), players with an elevated BMI, especially on the offensive line, were more likely to injure their ACL through direct contact. Position-dependent variance in injury mechanism may help guide injury prevention efforts in these athletes.

Epidemiology of Anterior Cruciate Ligament Tears in the National Football League.

BACKGROUND: Anterior cruciate ligament (ACL) tears are common in contact athletics and have a significant effect on the athletic performance and well-being of affected players. The prevalence, timing, and characteristics of ACL tears in National Football League (NFL) athletes are lacking. PURPOSE: To define the epidemiology of ACL tears among NFL athletes. STUDY DESIGN: Descriptive epidemiology study. METHODS: This retrospective study includes all ACL injuries entered into the NFL injury database through the centralized leaguewide electronic health record system for the 2015-2019 seasons. RESULTS: A total of 314 ACL injuries occurred during the 5-year study period, with a mean of 62 per year. The overall 1-season injury risk of an NFL player sustaining an ACL injury was 1.9% (95% CI, 1.7%-2.1%). Most ACL injuries occurred during games (n = 199), with a higher rate observed in the preseason games as compared with the regular season games (6.1 vs 2.7 per 10,000 player-plays; P < .01). NFL players with ≤3 of experience had a higher preseason injury rate (9.57 ACL tears per 1000 player-seasons) than those with ≥4 years of experience (5.12 ACL tears per 1000 player-seasons; P < .01). NFL athletes playing on special teams had the highest rate of ACL injuries (7.6 per 10,000 player-plays) in comparison with all other player positions. CONCLUSION: ACL injury incidence was fairly consistent across all years studied and occurred more frequently in players with ≤3 years of NFL experience. Tears were more common during games, special teams play, and the preseason.