Ronald P. Pfeiffer

Anterior cruciate ligament injury in pediatric and adolescent soccer players: an analysis of insurance data.

Injury claims from an insurance company specializing in soccer coverage were reviewed for a 5-year period. A total of 8215 injury claims (3340 females, 4875 males) were divided into three categories: (1) all injury, (2) knee injury, and (3) ACL injury. Knee injuries accounted for 22% of all injuries (30% female, 16% male). ACL injury claims represented 31% of total knee injury claims (37% female, 24% males). The youngest ACL injury was age 5. The ratio of knee injury/all injury increased with age. Compared with males, females demonstrated a higher ratio of knee injury/all injury and a higher ratio of ACL injury/all injury. This study demonstrates that ACL injury occurs in skeletally immature soccer players and that females appear to have an increased risk of ACL injury and knee injury compared with males, even in the skeletally immature. Future research related to ACL injury in females will need to consider skeletally immature patients.

Lack of effect of a knee ligament injury prevention program on the incidence of noncontact anterior cruciate ligament injury

BACKGROUND Studies have suggested that exercise programs can reduce the incidence of noncontact injuries of the anterior cruciate ligament in female athletes. We conducted a two-year prospective study to assess the effects of a knee ligament injury prevention exercise program on the incidence of noncontact anterior cruciate ligament injuries in high-school female athletes. METHODS A prospective cohort design was used to study high-school female athletes (playing soccer, basketball, and volleyball) from fifteen schools (112 teams) for two consecutive seasons. The schools were divided into treatment and control groups. The treatment group participated in a plyometric-based exercise program twice a week throughout the season. Practice and game exposures and compliance with the exercise program were recorded on a weekly basis. Suspected noncontact anterior cruciate ligament injuries were confirmed on the basis of the history as well as at the time of surgery and/or with magnetic resonance imaging. RESULTS A total of 1439 athletes (862 in the control group and 577 in the treatment group) were monitored. There were six confirmed noncontact anterior cruciate ligament injuries: three in the treatment group, and three in the control group. The incidence of noncontact anterior cruciate ligament injuries per 1000 exposures was 0.167 in the treatment group and 0.078 in the control group, yielding an odds ratio of 2.05, which was not significant (p > 0.05). CONCLUSIONS Our results suggest that a twenty-minute plyometric-based exercise program that focuses on the mechanics of landing from a jump and deceleration when running performed twice a week throughout the season will not reduce the rate of noncontact anterior cruciate ligament injuries in high-school female athletes.

Effects of a knee ligament injury prevention exercise program on impact forces in women.

Previous research suggests high impact forces generated during landings contribute to noncontact anterior cruciate ligament (ACL) injuries. In women, neuromuscular differences appear to modify the ability to dissipate landing forces when compared to men. This study examined peak vertical impact forces (Fp) and rate of force development (RFD) following a 9-week, low-intensity (simple jump-landing-jump tasks) and volume (number of foot contacts per workout) plyometric-based knee ligament injury prevention (KLIP) program. Female subjects were randomly assigned into control (n = 14) and treatment (n = 14) groups. Treatment subjects attended KLIP sessions twice a week for 9 weeks, and control subjects received no intervention. Ground reaction forces (Fp and RFD) generated during a step-land protocol were assessed at study onset and termination. Significant reductions in Fp (p = 0.0004) and RFD (p = 0.0205) were observed in the treatment group. Our results indicate that 9 weeks of KLIP training altered landing strategies in women to lower Fp and RFD. These changes are considered conducive to a reduced risk of knee injury while landing.

Anterior Cruciate Ligament Injury in Paediatric and Adolescent Patients A Review of Basic Science and Clinical Research

Anterior cruciate ligament (ACL) injuries are recognised with greater frequency in children and adolescents. Non-operative treatment of ACL injuries in children may lead to knee instability and secondary injuries, especially in those who return to sports. ACL reconstruction is controversial in skeletally immature patients because of potential damage to the proximal tibial and distal femoral physes, which may lead to premature arrest and/or leg length discrepancies. This paper reviews studies of ACL injuries in children and adolescents, and examines basic science and clinical studies concerning physeal arrest secondary to ACL reconstruction tunnels. Some animal studies support the conclusion that ACL reconstructions in children have the potential to cause growth disturbances, and there are reports of growth plate complications due to ACL reconstruction in skeletally immature patients. There is evidence that ACL reconstruction can be performed in select skeletally immature patients, but the risk of growth plate complications must be considered.

The Effects of a Commercially Available Warm-Up Program on Landing Mechanics in Female Youth Soccer Players

The purpose of this study was to examine lower extremity kinematics following implementation of the Sportsmetrics Warm-Up for Injury Prevention and Performance (WIPP) training program. The hypothesis was that there would be no difference in landing mechanics between 2 groups of female youth soccer players (9–11 years of age), with 1 group (Treatment) completing the 8-week–duration (2 days per week) WIPP program and the other serving as a Control group. We recruited 21 female youth soccer players. Treatment (n = 12) and Control (n = 9) groups were established. Using the Sportsmetrics Software for Analysis of Jumping Mechanics, we analyzed lower extremity movement during landing after subjects jumped off a 30.5-cm box and immediately went into a vertical jump. No significant changes in knee separation values were observed in the Treatment group after 8 weeks of WIPP training. The results indicate that 8 weeks of WIPP training did not significantly alter landing strategies.

Mountain Biking Injuries An Update

AbstractThis article reviews the available literature regarding injuries in off-road bicyclists. Recent progress in injury research has allowed the description of several patterns of injury in this sport. Mountain biking remains popular, particularly among young males, although sales and participation figures have decreased in the last several years. Competition in downhill racing has increased, while crosscountry racing has decreased somewhat in popularity. Recreational riders comprise the largest segment of participants, but little is known about the demographics and injury epidemiology of noncompetitive mountain cyclists.Most mountain bikers participating in surveys reported a history of previous injuries, but prospective studies conducted at mountain bike races have found injury rates of <1%. The most common mechanism of injury involves a forward fall over the handlebars, usually while riding downhill, which can result in direct trauma to the head, torso and upper extremities. Avariety of factors can be associated with this type of fall, including trail surface irregularities, mechanical failures and loss of control. In mountain bike racing the risk of injury may be higher for women than men.Minor injuries such as abrasions and contusions occur frequently, but are usually of little consequence. Fractures usually involve the torso or upper extremities, and shoulder injuries are common. Head and face injuries are not always prevented by current helmet designs. Fatal injuries are rare but have been reported.Improvements in safety equipment, rider training and racecourse design are suggested injury prevention measures. The authors encourage continued research in this sport.

Off-road cycling injuries. An overview.

SummaryOff-road bicycles, commonly called ‘mountain bikes’, have become increasingly popular worldwide since their introduction in the western US in the late 1970s. This popularity is partly because these vehicles can be ridden on a wide variety of terrain which is not accessible to other types of bicycle. Although early versions were rather crude, off-road bicycles today typically include high strength, lightweight frames with a wide array of available suspension and braking systems. Virtually all aspects of the technology continue to evolve, including components and protective equipment. As the popularity of off-road cycling has increased, so too has the interest and level of participation in the competitive aspects of the sport. Currently, 2 organisations — the National Off-Road Bicycle Association (NORBA) and the Union Cycliste Internationale (UCI) — sponsor the major events within the US and around the world.To date, the majority of studies have been descriptive in nature, with data collected via self-report, questionnaire formats. Only 1 prospective study has been reported thus far, which surveyed a major international competition held in the US in 1994. Injury rates calculated on the basis of injuries per ride or event in competitive venues have been reported, ranging from 0.2 to 0.39% compared with 0.30% for recreational participants. Retrospective data collected from recreational and competitive riders indicate that from 20 to 88% of those surveyed reported having sustained an injury during the previous year of participation. The majority of injuries appear to be acute, traumatic episodes involving the extremities, with contusions and abrasions being the most common. In general, the incidence of more severe injuries such as dislocations, fractures and concussions is low. Comparisons between road and off-road cycling events indicate that off-road cyclists sustain more fractures, dislocations and concussions than their road-event counterparts.Future research should incorporate epidemiological methods of data collection to determine the relationships between vehicle design, terrain and safety equipment and riding-related accidents. Further, those engaged in such research should attempt to set a standard definition for injury.

Kinematic MRI Assessment of McConnell Taping Before and After Exercise

Background The authors assessed the effectiveness of McConnell medial glide taping after exercise using an MRI extremity scanner. Hypothesis McConnell taping would not be effective in maintaining medial glide of the patella after exercise. Methods Eighteen healthy women (mean age 22.28 ± 2.02 years) participated in the study. The patellofemoral joint was imaged at 4 knee flexion angles (0°, 12°, 24°, and 36°) in 3 conditions (no tape, with McConnell taping–medial glide, and with tape after exercise). Effectiveness was determined by measuring lateral patellar displacement. ANOVA and post hoc paired ttests were used to test for changes in lateral patellar displacement at each knee angle and condition. Results Statistical analysis revealed significant differences in lateral patellar displacement at all test angles, between the tape and no tape and between tape and tape after exercise conditions. Conclusions McConnell medial glide taping resulted in significant medial glide of the patellofemoral joint at all 4 knee angles before but not after exercise. However, McConnell medial glide taping may be effective under controlled rehabilitation conditions in which exercise is less intense. Clinical Relevance Beneficial effects of McConnell medial glide taping may be related to factors other than altered patellar alignment.

Volumetric Injury of the Physis During Single-Bundle Anterior Cruciate Ligament Reconstruction in Children: A 3-Dimensional Study Using Magnetic Resonance Imaging

PURPOSE To determine the volume of injury to the physis during anterior cruciate ligament (ACL) reconstruction in pediatric patients. METHODS Magnetic resonance imaging scans of 10 pediatric knees were converted into 3-dimensional models. Computer-aided design/computer-aided manufacturing software placed drill holes (6, 7, 8, and 9 mm in diameter) in these models, simulating tunnels used for ACL reconstruction. The software was used to calculate total physeal volume and volume of physis removed by the tunnel. The ratio of physeal volume removed to the total physeal volume was determined. RESULTS For 6-, 7-, 8-, and 9-mm-diameter drill holes, the mean percent of physeal volume removed/total physeal volume was 1.6%, 2.2%, 2.9%, and 3.8%, respectively, for the tibia and 2.4%, 3.2%, 4.2%, and 5.4%, respectively, for the femur. For all subjects, the volume removed was less than 7.0% for the tibia and 9.0% for the femur by use of drill holes from 6 to 9 mm. The tibial drill hole was centrally placed in all cases compared with a more peripheral drill hole placement of the femur. CONCLUSIONS Drill hole placement during ACL reconstruction produces a zone of physeal injury. The overall volume of injury is relatively low, which reduces the risk of physeal arrest. With careful drill hole placement, the region of injury is central on the tibia, and the total volume of injury can be less than 5.0% of the physeal volume. For the femur, the total volume can be less than 5.0% as well. However, the region of injury is peripheral, which carries a higher risk of physeal arrest. CLINICAL RELEVANCE A better understanding of the relation between the ACL and physis may guide the placement of drill holes, which have a lower risk of producing physeal arrest.

The Relation of the Femoral Physis and the Medial Patellofemoral Ligament

PURPOSE The purpose of this study was to determine the origin of the medial patellofemoral ligament (MPFL) relative to the distal femoral physis by use of an indirect radiologic method. METHODS Twenty radiographs from adolescent male and female subjects (10 samples from each group) were used. The subjects studied were all skeletally immature, with an open distal femoral physis. The radiographic technique described by Schöttle et al. was used to identify the origin of the MPFL. Imaging software was used to determine the approximate distance of the MPFL origin relative to the open growth plate of the subjects involved. RESULTS In all 20 radiographs the medial physis was found to be distal to the average MPFL insertion point. The mean location for the female physis was 2.7 +/- 1.1 mm distal to the MPFL origin. The mean location for the male physis was 4.6 +/- 2.4 mm distal to the MPFL origin. CONCLUSIONS Based on an indirect radiographic technique, we found that the origin of the MPFL is just proximal to the femoral physis. CLINICAL RELEVANCE This information may be useful when planning medial retinacular surgical procedures in skeletally immature athletes to help avoid clinically significant physeal injury.