Epidemiology of Injuries in Women's Lacrosse: Implications for Sport-, Level-, and Sex-Specific Injury Prevention Strategies.

OBJECTIVE: By the end of 2013, the United States had an estimated 278 000 female lacrosse players, with half of those participating at the youth level. The effects of the sport's rapid growth on injury rates have yet to be determined. The purpose of this clinical review is to synthesize the available published data on injuries that have occurred in the sport of women's lacrosse. Of particular interest was the risk of injury based on the level of play and position. DATA SOURCES: A comprehensive literature search was performed in PubMed, High Wire Press, SPORTDiscus, Google Scholar, and Ovid using the keywords "Lacrosse Injuries," "Epidemiology Lacrosse Injuries," "Lacrosse Injury," "Lacrosse," and "Injury." STUDY SELECTION: The electronic search included material published during or after 1950. In addition, all bibliographies of electronically found sources were cross-referenced to identify any additional publications that were not produced in the electronic searches. DATA EXTRACTION: All articles with data on women's injury rates were categorized by overall injury rates, rates by session (competition vs practice), nature of injury, location, type, severity, and player position. DATA SYNTHESIS: Injury rates increase with age: from youth leagues to high school and finally to the collegiate level. Rates of injury varied from 0.03 to 3.9 injuries/100 athletes. Women's game injury rates are consistently higher than practice injury rates (ranging from 0.2 to 7.1 vs 0.01 to 3.3). Injuries occur most frequently from stick-to-player or player-to-ball contact, rather than player-to-player contact. Women sustain a higher percentage of head and facial injuries relative to male lacrosse players. The most common types of injuries for women are concussions, sprains, contusions, and lacerations. More than half of all injuries are in the mild category resulting in players missing practice and games for 1 to 7 days. Offensive players had the most injuries, followed by defensive players and then midfielders, with goalies having the fewest number of injuries. CONCLUSIONS: In women's lacrosse, the rules and equipment used are substantially different than for the men's game. Face and hand injuries are more prevalent for women when compared with men, and ankle injuries are most prevalent in female youth. Medical professionals who treat lacrosse players can benefit from an improved understanding of the types and rates of the injuries they are likely to encounter. Improved awareness of lacrosse-specific injuries can assist these professionals to be more prepared to treat these athletes, which may lead to improved care and outcomes.

Rate of injury among youth lacrosse players.

OBJECTIVE: This study describes the rate of injury and the types and mechanisms of injuries incurred by girls and boys during youth recreational lacrosse. DESIGN: Prospective cohort study. SETTING: Games were played at a large turf community athletic complex. PARTICIPANTS: Participants included male and female lacrosse players aged 9-15 years. A total of 143 games were played, resulting in 4603 athlete-exposures (AEs). ASSESSMENT OF RISK FACTORS: Youth players were grouped based on sex and 3 age categories: under 11 (U11; 9-10 years), under 13 (U13; 11-12 years), and under 15 (U15; 13-14 years). MAIN OUTCOME MEASURES: Certified athletic trainers collected data on type of injury and injury mechanism. RESULTS: There were 6.3 injuries per 1000 AEs for boys and girls combined. Girls had 7 injuries (3.4 per 1000 AEs) and boys had 22 injuries (8.7 per 1000 AEs). Contusions and lacerations were the most frequent injury (n = 13), and body-to-body contact (n = 10) was the most common injury mechanism. There were 4 concussions among boys (U13 and U15) and none among girls. CONCLUSIONS: Most injuries evaluated in youth lacrosse were contusions/lacerations; however, serious injuries were observed, including concussions in boys in the age group where body contact is allowed.

Biceps tenodesis versus allograft reconstruction for varus instability.

Although effective to restore stability in varus laxity, a fibula-based procedure such as figure-of-8 reconstruction can be technically demanding and requires use of allograft or autograft. Biceps rerouting offers an alternative without the potential complications of allograft or autograft procedures. It is not known whether biceps tenodesis is effective in addressing isolated varus laxity with lateral collateral ligament (LCL) rupture. We compared biceps tenodesis and figure-of-8 allograft reconstruction for restoration of varus stability. Nine knees were loaded at 10 N-m at 0- and 30-degree knee flexion in intact, LCL sectioned, and reconstructed state. Both biceps tenodesis and figure-of-8 reconstruction restored varus stability to at least baseline stability. Normalized displacement with biceps tenodesis measured at time zero was significantly lower than with allograft reconstruction at 0 degrees (0.75 ± 0.26 vs. 1.09 ± 0.31 degrees; p = 0.04) and 30 degrees (0.66 ± 0.14 vs. 0.91 ± 0.27 degrees; p = 0.04). Biceps tenodesis was effective at restoring baseline varus stability in isolated varus laxity.

Validity of Research Based on Public Data in Sports Medicine: A Quantitative Assessment of Anterior Cruciate Ligament Injuries in the National Football League.

BACKGROUND: Numerous researchers have leveraged publicly available Internet sources to publish publicly obtained data (POD) studies concerning various orthopaedic injuries in National Football League (NFL) players. PURPOSE: To provide a comprehensive systematic review of all POD studies regarding musculoskeletal injuries in NFL athletes and to use anterior cruciate ligament (ACL) injuries in NFL players to quantify the percentage of injuries identified by these studies. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A systematic review was conducted to identify all published studies utilizing POD regarding ACL injury in NFL athletes from 2000 to 2019. Data regarding player demographics were extracted from each publication. These results were compared with prospectively collected data reported by the teams' medical staff to the NFL Injury Surveillance System database linked to the League's electronic health record. An ACL "capture rate" for each article was calculated by dividing the number of ACL injuries in the POD study by the total number of ACL injuries in the NFL injury database occurring in the study period of interest. RESULTS: A total of 42 studies were extracted that met the definition of a POD study: 28 evaluated a variety of injuries and 14 dealt specifically with ACL injuries, with 35 (83%) of the 42 studies published during or since 2015. POD studies captured a mean of 66% (range, 31%-90%) of ACL injuries reported by the teams' medical staff. This inability to capture all injury rates varied by position, with 86% capture of ACL injuries in skill athletes, 72% in midskill athletes, and 61% in linemen. POD studies captured 35% of injuries occurring during special teams play. CONCLUSION: The frequency of studies leveraging publicly obtained injury data in NFL players has rapidly increased since 2000. There is significant heterogeneity in the degree to which POD studies correctly identify ACL injuries from public reports. Sports medicine research relying solely on publicly obtained sources should be interpreted with an understanding of their inherent limitations and biases. These studies underreport the true incidence of injuries, with a bias toward capturing injuries in more popular players.

Interference Screw Versus Suture Anchors for Femoral Fixation in Medial Patellofemoral Ligament Reconstruction: A Biomechanical Study.

BACKGROUND: Femoral-sided graft fixation in medial patellofemoral ligament (MPFL) reconstruction is commonly performed using an interference screw (IS). However, the IS method is associated with several clinical disadvantages that may be ameliorated by the use of suture anchors (SAs) for femoral fixation. PURPOSE: To compare the load to failure and stiffness of SAs versus an IS for the femoral fixation of a semitendinosus autograft in MPFL reconstruction. STUDY DESIGN: Controlled laboratory study. METHODS: Based on a priori power analysis, a total of 6 matched pairs of cadaveric knees were included. Specimens in each pair were randomly assigned to receive either SA or IS fixation. After an appropriate reconstruction procedure, the looped end of the MPFL graft was pulled laterally at a rate of 6 mm/s until construct failure. The best-fit slope of the load-displacement curve was then used to calculate the stiffness (N/mm) in a post hoc fashion. A paired t test was used to compare the mean load to failure and the mean stiffness between groups. RESULTS: No significant difference in load to failure was observed between the IS and the SA fixation groups (294.0 ± 61.1 vs 250.0 ± 55.9; P = .352), although the mean stiffness was significantly higher in IS specimens (34.5 ± 9.6 vs 14.7 ± 1.2; P = .004). All IS reconstructions failed by graft pullout from the femoral tunnel, whereas 5 of the 6 SA reconstructions failed by anchor pullout. CONCLUSION: In this biomechanical study using a cadaveric model of MPFL reconstruction, SA femoral fixation was not significantly different from IS fixation in terms of load to failure. The mean load-to-failure values for both reconstruction techniques were greater than the literature-reported values for the native MPFL. CLINICAL RELEVANCE: These results suggest that SAs are a biomechanically viable alternative for femoral-sided graft fixation in MPFL reconstruction.

Krackow locking stitch versus locking premanufactured loop stitch for soft-tissue fixation: a biomechanical study.

PURPOSE: To biomechanically compare construct elongation under loading conditions and to compare load to failure for the locking premanufactured loop stitch versus the Krackow stitch. METHODS: Twenty porcine Achilles tendons were randomly assigned to receive the locking Krackow stitch with No. 2 FiberWire (Arthrex, Naples, FL) or the locking premanufactured loop stitch with No. 2 FiberLoop (SpeedWhip; Arthrex). Each tendon was pre-tensioned 3 times at 100 mm/min to 100 N for removal of slack, preloaded to 50 N to simulate tension applied clinically, and cyclically loaded at 200 mm/min to 200 N for 200 cycles. Total elongation of both suture strands was measured at each stage. Each tendon was loaded to failure. RESULTS: Elongation (mean ± standard deviation) in the Krackow group and the SpeedWhip group did not differ with initial loading at 50 N (4.5 ± 1.0 mm and 5.0 ± 1.7 mm, respectively; P = .4) or with cyclic loading (15.6 ± 5.7 mm and 17.0 ± 2.6 mm, respectively; P = .5). Load to failure was significantly higher in the SpeedWhip group as compared with the Krackow group (344.0 ± 23.1 N and 301.3 ± 24.4 N, respectively; P = .001). CONCLUSIONS: In a porcine tendon model, the locking loop stitch group was not significantly different regarding construct elongation with initial or cyclic loading compared with the Krackow stitch group. These findings suggest that the locking loop stitch has adequate strength to serve as an alternative to the Krackow stitch in procedures where the Krackow stitch is used. The elongation data suggest that augmentation or protection with early stress postoperatively would be needed with the locking loop stitch as with the Krackow stitch clinically. CLINICAL RELEVANCE: Similar elongation in the 2 constructs suggests that this locking loop stitch has adequate strength to serve as an alternative to the Krackow stitch in procedures where the Krackow stitch is used.

Incidence of Knee Injuries on Artificial Turf Versus Natural Grass in National Collegiate Athletic Association American Football: 2004-2005 Through 2013-2014 Seasons.

BACKGROUND: The use of artificial turf in American football continues to grow in popularity, and the effect of these playing surfaces on athletic injuries remains controversial. Knee injuries account for a significant portion of injuries in the National Collegiate Athletic Association (NCAA) football league; however, the effect of artificial surfaces on knee injuries remains ill-defined. HYPOTHESIS: There is no difference in the rate or mechanism of knee ligament and meniscal injuries during NCAA football events on natural grass and artificial turf playing surfaces. STUDY DESIGN: Descriptive epidemiology study. METHODS: The NCAA Injury Surveillance System Men's Football Injury and Exposure Data Sets for the 2004-2005 through 2013-2014 seasons were analyzed to determine the incidence of anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), medial meniscus, and lateral meniscal tear injuries. Injury rates were calculated per 10,000 athlete exposures, and rate ratios (RRs) were used to compare injury rates during practices and competitions on natural grass and artificial turf in NCAA football as a whole and by competition level (Divisions I, Divisions II and III). Mechanisms of injury were calculated for each injury on natural grass and artificial turf surfaces. RESULTS: A total of 3,009,205 athlete exposures and 2460 knee injuries were reported from 2004 to 2014: 1389 MCL, 522 ACL, 269 lateral meniscal, 164 medial meniscal, and 116 PCL. Athletes experienced all knee injuries at a significantly higher rate when participating in competitions as compared with practices. Athletes participating in competitions on artificial turf experienced PCL injuries at 2.94 times the rate as those playing on grass (RR = 2.94; 95% CI, 1.61-5.68). When stratified by competition level, Division I athletes participating in competitions on artificial turf experienced PCL injuries at 2.99 times the rate as those playing on grass (RR = 2.99; 95% CI, 1.39-6.99), and athletes in lower NCAA divisions (II and III) experienced ACL injuries at 1.63 times the rate (RR = 1.63; 95% CI, 1.10-2.45) and PCL injuries at 3.13 times the rate (RR = 3.13; 95% CI, 1.14-10.69) on artificial turf as compared with grass. There was no statistically significant difference in the rate of MCL, medial meniscal, or lateral meniscal injuries on artificial turf versus grass when stratified by event type or level of NCAA competition. No difference was found in the mechanisms of knee injuries on natural grass and artificial turf. CONCLUSION: Artificial turf is an important risk factor for specific knee ligament injuries in NCAA football. Injury rates for PCL tears were significantly increased during competitions played on artificial turf as compared with natural grass. Lower NCAA divisions (II and III) also showed higher rates of ACL injuries during competitions on artificial turf versus natural grass.

Krackow locking stitch versus nonlocking premanufactured loop stitch for soft-tissue fixation: a biomechanical study.

PURPOSE: The purpose of this study was to biomechanically compare the Krackow stitch, an established locking stitch, with a new nonlocking premanufactured stitch for soft-tissue fixation. We evaluated suture construct elongation under loading and load to failure to compare the 2 stitches. METHODS: Twenty porcine Achilles tendons were randomly assigned to receive the locking Krackow stitch with No. 2 FiberWire or the nonlocking SpeedWhip stitch with No. 2 FiberLoop (Arthrex, Naples, FL). Each prepared tendon was mounted in a servohydraulic load frame, and the 2 free suture strands were knotted over the bar of the machine. Each tendon was pretensioned to 100 N to simulate the removal of slack, preloaded to 50 N to simulate tension applied clinically with suture tying over the post, and cyclically loaded at 200 mm/min to 200 N for 200 cycles. Total elongation of both suture strands was measured at each stage. Each tendon was loaded to failure. RESULTS: During preloading, the SpeedWhip group elongated significantly more than the Krackow group (65.6 +/- 22.5 mm v 14.9 +/- 5.9 mm, P < .001). During cyclic loading, the SpeedWhip group also showed significantly higher elongation than the Krackow group (23.5 +/- 8.7 mm v 11 +/- 4.5 mm, P = .02). The load to failure for the Krackow and SpeedWhip groups was not significantly different (376.2 +/- 39.8 N and 337.3 +/- 103.8 N, respectively; P = .65). With load to failure, suture breakage at the knot occurred in every specimen without further pullout of the suture. CONCLUSIONS: The nonlocking stitch applied in a manner consistent with manufacturer guidelines was significantly less secure than the locking Krackow stitch in a porcine Achilles tendon model. CLINICAL RELEVANCE: On the basis of these findings, the Krackow stitch remains the preferred method for suture fixation of soft-tissue grafts.

Head, face, and eye injuries in scholastic and collegiate lacrosse: a 4-year prospective study.

BACKGROUND: Risks and mechanisms of head, face, and eye injuries in high school and college lacrosse are not well documented. PURPOSE: To identify (1) primary mechanisms of head, face, and eye injuries in lacrosse and (2) differences in injury risk between the men's and women's game and between high school and collegiate levels. STUDY DESIGN: Descriptive epidemiological study. METHODS: The authors gathered data on 507,000 girls' and boys' high school and 649,573 women's and men's college lacrosse athletic exposures using sport-specific injury surveillance systems over 4 seasons. They identified the most common scenarios for head, face, and eye injuries. RESULTS: The high school girls' head, face, and eye injury rate (0.54 per 1000 athletic exposures) was significantly higher (incident rate ratio, 1.42; 95% confidence interval, 1.09-1.86) than that for boys (0.38 per 1000 athletic exposures); college women (0.77 per 1000 athletic exposures) sustained a higher rate of injuries (incident rate ratio, 1.76; 95% confidence interval, 1.42-2.19) than did men (0.44 per 1000 athletic exposures). Concussions constituted a higher percentage of injuries among boys (73%) and men (85%) than among girls (40%) and women (41%). Men sustained few facial injuries, whereas a substantial proportion of women's injuries involved the face and orbital area. CONCLUSION: Although permitting only incidental contact, women's lacrosse had higher rates of head, face, and eye injuries at both the high school and collegiate levels. Concussion was the most common injury. For men, the primary injury mechanism was player-to-player contact; women's injuries primarily resulted from stick or ball contact. High school injury rates were lower than were college rates, but the nature of injuries, body parts affected, and mechanisms were similar.

Five-Strand versus Four-Strand Hamstring Tendon Graft Technique for Anterior Cruciate Ligament Reconstruction: A Biomechanical Comparison.

The aim of this article is to compare diameter and stiffness, displacement, and strain in a five-strand versus four-strand hamstring graft for anterior cruciate ligament reconstruction. Eight matched pairs of lower extremities underwent four-strand or five-strand hamstring graft reconstruction. Diameter was significantly higher in the five-strand versus the four-strand construct (p = 0.002). No significant difference was found between the groups in construct displacement or stiffness. Significantly higher strain was observed in the inner limb versus the outer limb in the four-strand construct (p = 0.001) and in the inner limb versus the fifth limb in the 5-strand construct (p = 0.004). A fifth limb added to a four-strand hamstring graft significantly increased graft diameter but did not significantly change stiffness or displacement, suggesting that attachment of additional graft material via suture did not provide for full incorporation of the added limb into the graft at time zero. The inner limb in both constructs absorbed significantly greater load than did other limbs. The use of suture to attach additional material to a four-strand hamstring graft may not contribute to improved biomechanical qualities of the graft at time zero.

Epidemiology of lacrosse injuries in high school-aged girls and boys: a 3-year prospective study.

OBJECTIVE: To report the types, mechanisms, and circumstances of lacrosse injuries incurred by high school-aged girls and boys during organized interscholastic and summer camp games. STUDY DESIGN: Descriptive epidemiology study. METHODS: For 3 years, the authors gathered data on girls' and boys' lacrosse injuries for 359 040 high school and 28 318 summer camp athletic exposures using a lacrosse-specific computerized injury surveillance system. The most prevalent injuries were organized into multifactorial injury scenarios. RESULTS: In high school play, the injury rate for adolescent boys (2.89 per 1000 athletic exposures) was slightly higher than that for girls (2.54 per 1000 athletic exposures) (incidence rate ratio = 1.14; 95% confidence interval, 1.00-1.30). The most prevalent injuries for adolescent girls and boys were knee and ankle sprains resulting from noncontact mechanisms. Male players had significantly higher rates of shoulder, neck, trunk, and back injuries and higher game-to-practice injury ratios. In addition, they had higher rates of concussive events from player-to-player contact. Female players had higher rates of overall head injuries, many involving contusions and abrasions from stick and ball contact. CONCLUSIONS: The overall injury rates for boys' and girls' high school lacrosse were significantly lower than those for collegiate play. Significant differences existed between adolescent boys and girls with respect to injury mechanisms, body parts injured, and player and team activity at the time of injury.

Occupational disability after hospitalization for the treatment of an injury of the anterior cruciate ligament.

BACKGROUND: To date, no large population-based studies have focused on permanent occupational disability after injury of the anterior cruciate ligament as far as we know. The purpose of our study was to determine the risk factors for occupational disability after an injury of the anterior cruciate ligament. METHODS: We identified a cohort of 2192 active-duty personnel in the Army who had been hospitalized between 1989 and 1997 because of an injury of the anterior cruciate ligament and had completed a health risk-assessment survey. With use of the Total Army Injury and Health Outcomes Database, we retrospectively followed these individuals for up to nine years and collected clinical, demographic, occupational, and psychosocial data. These data were then evaluated with bivariate and proportional-hazards regression analyses to identify risk factors for receiving a disability discharge related to an injury of the anterior cruciate ligament. RESULTS: Overall, 209 (9.5%) of 2192 initial anterior cruciate ligament injuries resulted in a permanent disability discharge. In bivariate analyses, the following factors were related to a disability discharge: lower job satisfaction (p < 0.0001), lower education level (p < 0.0001), shorter length of service (p < 0.0001), lower pay grade or rank (p < 0.0001), occupational classification (p < 0.0001), older age (p < 0.01), cigarette-smoking (p = 0.01), and greater mental stress at work (p = 0.02). Associated cartilage injury (p = 0.07) and occupational physical demands (p = 0.08) approached significance; however, with the numbers available, other variables that were hypothesized to contribute to the development of disability, such as gender (p = 0.85), reconstruction of the anterior cruciate ligament (p = 0.52), and other secondary comorbidities of the knee, demonstrated no significant association. Proportional-hazards regression analysis confirmed that pay grade or rank, occupational classification, job satisfaction, age, and length of service were independent predictors of disability discharge. CONCLUSIONS: In keeping with risk profiles of several other musculoskeletal disorders, such as low-back pain and carpal tunnel syndrome, the results revealed a multifactorial risk profile in which psychosocial factors were strongly associated with disability discharge from active military duty after injury of the anterior cruciate ligament.

Acute and recurrent patellar instability in the young athlete.

Many reports of patellofemoral instability treatment suffer the same flaws of inappropriate patient selection, poor injury definition, insufficient activity assessment, and, especially in skeletally immature patients, limited followup found in other orthopedic literature. A significant number of dogmatic statements concerning risk factors and treatment interventions continue to be recycled through the literature without adequate clinical or laboratory substantiation, even in the face of contradictory data. Traditionally, patellar instability has been treated with variable periods of immobilization, sporadic rehabilitation, and an expected full return to sports activity. The reality is that many young athletes have long-term retropatella pain and sport-limiting extensor mechanism impairment following patellar dislocations. Most athletes benefit from an initial nonoperative program that is aggressive, multidimensional, and responsive to early treatment outcomes. Concurrent osteochondral injuries are common and a major contributor to adverse outcomes. Diagnostically, MRI is improving in its ability to detail osteochondral injury and it plays an important role in determining the location and extent of MPFL injury. The primary stabilizing role of the MPFL in the normal knee and its injury as an essential lesion of patella instability has been appreciated only recently. There is growing interest in exchanging the myriad of nonanatomic extensor mechanism reconstructions for more anatomic procedures based on restitution of the MPFL.

Biomechanical analysis of distal clavicle excision with acromioclavicular joint reconstruction.

BACKGROUND: Acromioclavicular (AC) joint separation is a common injury, usually affecting young adults. Controversy exists regarding whether to excise the distal clavicle when surgical intervention is required. PURPOSE: To evaluate the biomechanical strength of AC and coracoclavicular (CC) ligament reconstruction with and without concurrent distal clavicle excision. STUDY DESIGN: Controlled laboratory study. METHODS: Nine matched pairs of cadaver shoulders were used. All shoulders were tested with intact CC and AC ligaments, and the ligaments were sectioned. For 1 shoulder in each pair, a 7-mm distal clavicle excision was performed. The contralateral distal clavicle was left intact. Single-tunnel CC ligament reconstruction was performed, and excess graft length was extended and secured across the AC joint to reconstruct the superior AC joint ligaments in all specimens. Specimens were then potted and cyclically loaded for 500 cycles in the anterior-posterior and superior-inferior planes using an MTS Minibionix load frame to evaluate displacement across the AC joint. RESULTS: Regarding the clavicle-intact reconstructed versus the intact state, there was significantly greater AC joint translation in the reconstructed state in the anterior-posterior (20.2 ± 7.0 mm vs 6.0 ± 1.5 mm; P < .001) and superior-inferior directions (12.3 ± 3.3 mm vs 4.2 ± 1.2 mm; P < .001). In the clavicle-excised reconstructed versus the intact state, there was also significantly greater translation in the reconstructed state in the anterior-posterior (21.7 ± 5.1 mm vs 8.9 ± 4.3 mm; P < .001) and superior-inferior directions (12.3 ± 6.1 mm vs 5.8 ± 3.1 mm; P < .001). When the difference in translation between the reconstructed and intact groups in the clavicle-intact versus the clavicle-excised group was compared, no statistically significant difference was noted in anterior-posterior (14.2 ± 7.8 mm vs 12.8 ± 5.0 mm; P = .67) or superior-inferior translation (8.1 ± 2.9 mm vs 6.6 ± 3.9 mm; P = .39). CONCLUSION: Excision of the distal clavicle did not have a significant effect on anterior-posterior or superior-inferior motion at the AC joint following single-tunnel CC and AC ligament reconstruction. CLINICAL RELEVANCE: The study suggests that excision of the distal clavicle in this procedure is not associated with increased anterior-posterior or superior-inferior instability in this model.

Video incident analysis of concussions in boys' high school lacrosse.

BACKGROUND: Boys' lacrosse has one of the highest rates of concussion among boys' high school sports. A thorough understanding of injury mechanisms and game situations associated with concussions in boys' high school lacrosse is necessary to target injury prevention efforts. PURPOSE: To characterize common game-play scenarios and mechanisms of injury associated with concussions in boys' high school lacrosse using game video. STUDY DESIGN: Descriptive epidemiological study. METHODS: In 25 public high schools of a single school system, 518 boys' lacrosse games were videotaped by trained videographers during the 2008 and 2009 seasons. Video of concussion incidents was examined to identify game characteristics and injury mechanisms using a lacrosse-specific coding instrument. RESULTS: A total of 34 concussions were captured on video. All concussions resulted from player-to-player bodily contact. Players were most often injured when contact was unanticipated or players were defenseless (n = 19; 56%), attempting to pick up a loose ball (n = 16; 47%), and/or ball handling (n = 14; 41%). Most frequently, the striking player's head (n = 27; 79%) was involved in the collision, and the struck player's head was the initial point of impact in 20 incidents (59%). In 68% (n = 23) of cases, a subsequent impact with the playing surface occurred immediately after the initial impact. A penalty was called in 26% (n = 9) of collisions. CONCLUSION: Player-to-player contact was the mechanism for all concussions. Most commonly, injured players were unaware of the pending contact, and the striking player used his head to initiate contact. Further investigation of preventive measures such as education of coaches and officials and enforcement of rules designed to prevent intentional head-to-head contact is warranted to reduce the incidence of concussions in boys' lacrosse.

Video incident analysis of head injuries in high school girls' lacrosse.

BACKGROUND: Knowledge of injury mechanisms and game situations associated with head injuries in girls' high school lacrosse is necessary to target prevention efforts. PURPOSE: To use video analysis and injury data to provide an objective and comprehensive visual record to identify mechanisms of injury, game characteristics, and penalties associated with head injury in girls' high school lacrosse. STUDY DESIGN: Descriptive epidemiology study. METHODS: In the 25 public high schools of 1 school system, 529 varsity and junior varsity girls' lacrosse games were videotaped by trained videographers during the 2008 and 2009 seasons. Video of head injury incidents was examined to identify associated mechanisms and game characteristics using a lacrosse-specific coding instrument. RESULTS: Of the 25 head injuries (21 concussions and 4 contusions) recorded as game-related incidents by athletic trainers during the 2 seasons, 20 head injuries were captured on video, and 14 incidents had sufficient image quality for analysis. All 14 incidents of head injury (11 concussions, 3 contusions) involved varsity-level athletes. Most head injuries resulted from stick-to-head contact (n = 8), followed by body-to-head contact (n = 4). The most frequent player activities were defending a shot (n = 4) and competing for a loose ball (n = 4). Ten of the 14 head injuries occurred inside the 12-m arc and in front of the goal, and no penalty was called in 12 injury incidents. All injuries involved 2 players, and most resulted from unintentional actions. Turf versus grass did not appear to influence number of head injuries. CONCLUSION: Comprehensive video analysis suggests that play near the goal at the varsity high school level is associated with head injuries. Absence of penalty calls on most of these plays suggests an area for exploration, such as the extent to which current rules are enforced and the effectiveness of existing rules for the prevention of head injury.

Effectiveness of the women's lacrosse protective eyewear mandate in the reduction of eye injuries.

BACKGROUND: In an effort to minimize the risk of catastrophic eye injury, US Lacrosse initiated mandatory use of protective eyewear in women's lacrosse in the 2004-2005 season. PURPOSE: The authors compared eye injury rates in girls' scholastic lacrosse before and after implementation of protective eyewear. They also compared head/face injury rates, concussion rates, and overall injury rates before and after the rule change to assess possible unintended consequences of the change. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The study group included female scholastic lacrosse players in the 25 public high schools in Fairfax County, Virginia, during the 2004-2009 spring seasons. Injury rates were compared with those from the same data source for the 2000-2003 seasons. Premandate versus postmandate injury rates were adjusted for athlete exposures, or total opportunities for injury throughout the season. RESULTS: The rate of eye injuries was reduced from 0.10 injuries per 1000 athlete exposures (AEs) in 2000 through 2003 before the use of protective eyewear to 0.016 injuries per 1000 AEs in 2004 through 2009 (incident rate ratio [IRR], 0.16; 95% confidence interval [CI], 0.06-0.42). The rate ratio of head/face injuries excluding concussion also decreased (IRR, 0.44; 95% CI, 0.26-0.76). There was no change in the rate ratio of total injuries involving all body parts (IRR, 0.93; 95% CI, 0.82-1.1) after introduction of protective eyewear. However, the rate ratio of concussion increased (IRR, 1.6; 95% CI, 1.1-2.3). CONCLUSION: The use of protective eyewear in women's lacrosse was associated with a reduction in the number of eye injuries. The number of head/face injuries decreased in this study group after introduction of protective eyewear, and there was no change in overall injury rates. The reason for the increase in concussion rate cannot be determined conclusively based on this study, but the authors speculate that this increase resulted largely from increased recognition and diagnosis because overall injury rates do not indicate rougher play with introduction of protective equipment.

Trends in concussion incidence in high school sports: a prospective 11-year study.

BACKGROUND: Understanding the risk and trends of sports-related concussion among 12 scholastic sports may contribute to concussion detection, treatment, and prevention. PURPOSE: To examine the incidence and relative risk of concussion in 12 high school boys' and girls' sports between academic years 1997-1998 and 2007-2008. STUDY DESIGN: Descriptive epidemiology study. METHODS: Data were prospectively gathered for 25 schools in a large public high school system. All schools used an electronic medical record-keeping program. A certified athletic trainer was on-site for games and practices and electronically recorded all injuries daily. RESULTS: In sum, 2651 concussions were observed in 10 926 892 athlete-exposures, with an incidence rate of 0.24 per 1000. Boys' sports accounted for 53% of athlete-exposures and 75% of all concussions. Football accounted for more than half of all concussions, and it had the highest incidence rate (0.60). Girls' soccer had the most concussions among the girls' sports and the second-highest incidence rate of all 12 sports (0.35). Concussion rate increased 4.2-fold (95% confidence interval, 3.4-5.2) over the 11 years (15.5% annual increase). In similar boys' and girls' sports (baseball/softball, basketball, and soccer), girls had roughly twice the concussion risk of boys. Concussion rate increased over time in all 12 sports. CONCLUSION: Although the collision sports of football and boys' lacrosse had the highest number of concussions and football the highest concussion rate, concussion occurred in all other sports and was observed in girls' sports at rates similar to or higher than those of boys' sports. The increase over time in all sports may reflect actual increased occurrence or greater coding sensitivity with widely disseminated guidance on concussion detection and treatment. The high-participation collision sports of football and boys' lacrosse warrant continued vigilance, but the findings suggest that focus on concussion detection, treatment, and prevention should not be limited to those sports traditionally associated with concussion risk.

Gap formation in transpatellar patellar tendon repair: pretensioning Krackow sutures versus standard repair in a cadaver model.

BACKGROUND: Postfixation loosening within the Krackow stitch-tendon construct may be associated with gap formation in patellar tendon repair. HYPOTHESIS: Pretensioning the Krackow stitch-tendon construct decreases postfixation gap formation in transpatellar patellar tendon repair. STUDY DESIGN: Controlled laboratory study. METHODS: Patellar tendon rupture was simulated in 8 pairs of cadaveric knees. Standard manual traction was used in all specimens to remove Krackow stitch slack. In the experimental group, specimens were pretensioned with a simulated active concentric quadriceps contraction with cycling of the knee 10 times from 90 degrees to 5 degrees of flexion. All specimens were then cycled at 0.25 Hz from 90 degrees to 5 degrees for 1000 cycles until failure, which was defined as 3 or 5 mm of gap formation. RESULTS: A 3-mm gap occurred at 1 cycle (mean, 3.5 mm) and 35 cycles (4.0 mm) in the control and experimental groups, respectively. Gapping of 5 mm occurred at 35 (5.9 mm) and 100 cycles (5.0 mm) in the control and experimental specimens, respectively. Gap formation was smaller in the experimental group through 100 cycles (P < .05). CONCLUSION: Gapping was lower with pretensioning in the early cycling stages. However, significant gapping occurred in both groups with repetitive concentric active loading ranging from 90 degrees to 5 degrees of flexion. CLINICAL RELEVANCE: Tightening of the Krackow stitch as done in this study does not result in a clinically important decrease in gapping. This observation may be generalizable to other applications of the Krackow stitch.

TightRope versus fiber mesh tape augmentation of acromioclavicular joint reconstruction: a biomechanical study.

BACKGROUND: The standard Weaver-Dunn reconstruction of the acromioclavicular (AC) joint does not provide adequate superoinferior or anteroposterior stability. Augmentation methods such as tape cerclage have been described. A new method of augmentation with the Arthrex TightRope is available. HYPOTHESIS: A Weaver-Dunn reconstruction augmented with the TightRope will provide superior superoinferior and anteroposterior stability to the AC joint as compared with a Weaver-Dunn reconstruction augmented with Mersilene fiber tape cerclage. STUDY DESIGN: Controlled laboratory study. METHODS: Six matched pairs of cadaveric shoulders underwent Weaver-Dunn AC joint reconstructions and were randomly assigned to receive either the TightRope device or tape cerclage augmentation. Translation in 2 planes was measured in the intact state under load and after 1 load cycle and 2000 load cycles. RESULTS: TightRope-augmented repair showed less superoinferior translation (mean +/- standard error) than cerclage-augmented repair in initially repaired (1.6 +/- 0.1 mm vs 5.0 +/- 1.1 mm, P = 0.03) and cyclically loaded (2.1 +/- 0.1 mm vs 5.8 +/- 1.2 mm, P = 0.02) conditions. TightRope repairs were stiffer than the native ligaments in the superoinferior plane. Less anteroposterior translation was observed with TightRope versus cerclage augmentation (initially repaired, 6.8 +/- 0.4 mm vs 18.8 +/- 2.6 mm, P < 0.001; cycled, 15.0 +/- 1.4 mm vs 28.3 +/- 2.7 mm, P = 0.01), but neither method maintained normal anteroposterior laxity after 1500 cycles compared with the intact state. CONCLUSION: Superoinferior and anteroposterior translation with TightRope augmentation was lower than with tape cerclage. CLINICAL RELEVANCE: TightRope augmentation of a Weaver-Dunn procedure could provide increased protection for AC joint reconstruction, allowing for earlier mobilization and more aggressive early rehabilitation. The potential clinical effect of additional tightening in the superoinferior direction beyond that of the native joint remains an issue for further study.