Richard Y. Hinton

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.

Use of Autologous Platelet-rich Plasma to Treat Muscle Strain Injuries

Background Standard nonoperative therapy for acute muscle strains usually involves short-term rest, ice, and nonsteroidal anti-inflammatory medications, but there is no clear consensus on how to accelerate recovery. Hypothesis Local delivery of platelet-rich plasma to injured muscles hastens recovery of function. Study Design Controlled laboratory study. Methods In vivo, the tibialis anterior muscles of anesthetized Sprague-Dawley rats were injured by a single (large strain) lengthening contraction or multiple (small strain) lengthening contractions, both of which resulted in a significant injury. The tibialis anterior either was injected with platelet-rich plasma, was injected with platelet-poor plasma as a sham treatment, or received no treatment. Results Both injury protocols yielded a similar loss of force. The platelet-rich plasma only had a beneficial effect at 1 time point after the single contraction injury protocol. However, platelet-rich plasma had a beneficial effect at 2 time points after the multiple contraction injury protocol and resulted in a faster recovery time to full contractile function. The sham injections had no effect compared with no treatment. Conclusion Local delivery of platelet-rich plasma can shorten recovery time after a muscle strain injury in a small-animal model. Recovery of muscle from the high-repetition protocol has already been shown to require myogenesis, whereas recovery from a single strain does not. This difference in mechanism of recovery may explain why platelet-rich plasma was more effective in the high-repetition protocol, because platelet-rich plasma is rich in growth factors that can stimulate myogenesis. Clinical Relevance Because autologous blood products are safe, platelet-rich plasma may be a useful product in clinical treatment of muscle injuries.

Fractures of the Femoral Shaft in Children. Incidence, Mechanisms, and Sociodemographic Risk Factors*

BACKGROUND Fractures of the femoral shaft in children are caused by major musculoskeletal trauma and result in high direct and indirect medical costs. To date, the American literature has focused on treatment options and outcomes, but the epidemiology of these injuries has been generalized from Scandinavian studies reported in the 1970s and early 1980s. The goals of the current study were (1) to determine the age, gender, and race-specific rates and mechanisms of fractures of the femoral shaft in children in a large United-States-based population and (2) to identify associations between the rates of these fractures and multiple sociodemographic indicators. Such information is vital for preventive efforts. METHODS The Hospital Discharge Database of the Maryland Health Services Cost Review Commission for the years 1990 through 1996 was used to obtain demographic data on 1485 cases of acute fracture of the femoral shaft in patients who were less than eighteen years old, and data from the United States Bureau of the Census for the state of Maryland for the year 1990 were used to obtain denominator data. Reliable external-cause data were available from the 1995 and 1996 databases for 472 patients. Small-area analysis was performed at the zip-code level to determine associations between numerous sociodemographic indicators and the rate of femoral shaft fracture. RESULTS The annual rate of femoral shaft fracture in children was 19.15 per 100,000. With regard to age, there was a bimodal distribution, with peaks at two and seventeen years. Boys had higher rates of fracture than did girls at all ages, and blacks had higher rates than did whites. The primary mechanisms of fracture were age-dependent and included falls, for children less than six years old; motor vehicle-pedestrian accidents, for those six to nine years old; and motor-vehicle accidents, for teenagers. Firearm-related injuries accounted for 15 percent of the fractures among black adolescents. Adverse socioeconomic conditions were significantly associated with higher rates of fracture. CONCLUSIONS The rates and mechanisms of femoral shaft fractures in children depend on age, gender, and race. For children living in the United States today, the epidemiology of these fractures is different than that described in earlier, Scandinavian reports.

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.

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.

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 mens and womens 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 womens and mens 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 womens injuries involved the face and orbital area. Conclusion Although permitting only incidental contact, womens 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; womens 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.

Relative rates of fracture of the hip in the United States: geographic, sex and age variations

We studied the Medicare data from 1984 through 1987 for 687,850 fractures of the hip that had occurred in the United States. Our purpose was to determine the geographic, sex-specific, and age-interval variations in the relative risk of fracture of the hip in elderly white individuals. The rates of cervical, trochanteric, and subtrochanteric fracture, and the over-all rate of fracture at any of the three levels, increased with age, were greater for women than for men, and were higher in the Southern part of the country. However, there were regional, sex, and age variations. The ratio of cervical to trochanteric fractures was significantly higher in the East South Central region and lower in the Middle Atlantic and New England regions (p < 0.05). These were the same areas with the highest and lowest over-all rates, respectively, of fracture of the hip. The ratio of cervical to trochanteric fractures decreased from 1.52 in women who were sixty-five to sixty-nine years old to 0.81 in women who were at least eighty-five years old, but it stayed at approximately 1.00 for the corresponding age-groups of men. The ratio of fracture of the hip in women to fracture of the hip in men varied depending on the level of the fracture.

Clinical Results Following Revision Tibial Nerve Release

The results following revision tarsal tunnel release in 12 patients (13 feet), including three men and nine women aged 28 to 66 years, are presented. The indication for surgery was incapacitating focal pain, associated with paresthesias and hyperesthesias, refractory to nonoperative treatment modalities. Electrodiagnostic studies were abnormal in nine and normal in four cases. Revision surgery was performed a mean 3.5 years (range 1–10 years) after the initial tarsal tunnel release. Epineurolysis was performed in nine of the 13 cases where the nerve was encased in a scar. An insufficient previous distal release was identified in nine of the 13 cases. Wound infection occurred in two patients, one of whom ultimately underwent a below the knee amputation. With the exception of this patient, all patients were evaluated a mean 31 months (range 12–59 months) after the revision surgery. Three groups of patients were identified based on similarities in presentation, intraoperative findings, and clinical outcome. The first group (four feet), characterized by encasement of the tibial nerve in scar and an adequate distal release at the previous tarsal tunnel surgery, did poorly. The second group (five feet), with both scarring of the tibial nerve and an inadequate prior distal release, had somewhat mixed results, but overall were improved. The final group (four feet), who had no significant tibial nerve scarring but had had an inadequate prior distal release, did well. Clinical history and physical examination were more helpful than electrodiagnostic studies in determining the extent and location of the tibial nerve irritation following previous tarsal tunnel release surgery.

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.

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.