Shoulder disorders in the skeletally immature throwing athlete

Pediatric musculoskeletal injuries: role of ultrasound and magnetic resonance imaging

Pediatric musculoskeletal system is particularly prone to traumatic and sports-related injuries, both acute and chronic, i.e., overuse injuries, because of inherent conditions of weakness, such as the open physis, representing the weakest aspect within the bone, the ligamentous supports and changing biomechanics. Being aware that a quick diagnosis is essential to preserve the good functionality of the limb involved, it is mandatory for the radiologist to recognize the most common patterns of these injuries, identifying those requiring a prompt surgery, as well as be confident with the technique performed, and be supported by an important background experience and knowledge skills.

Reducing Cumulative Arm Overuse Injuries in Young Throwers

As year-round participation in youth sports continues to increase, health care practitioners treating child and adolescent athletes will commonly see injuries that are secondary to overuse. Starting with a clinical vignette, this article describes proximal humeral physeal injuries in youth throwers, examines causative factors, reviews common therapeutic modalities, and focuses on preventive measures aimed at reducing such cumulative arm overuse injuries.

MR imaging in congenital and acquired disorders of the pediatric upper extremity

Various congenital and acquired disorders can affect the upper extremity in pediatric and adolescent patients. MR imaging can provide unique anatomic and diagnostic information in the evaluation of many of these disorders, including inflammatory, infectious, neoplastic, and arthritic conditions. This article rounds out the issue on pediatric musculoskeletal MR imaging. It focuses on the evaluation of more common congenital disorders, and mainly sports-related injuries of the shoulder, elbow, and wrist in children. MR imaging can be more challenging in diagnosis of some of these disorders. Features of overuse injuries in skeletally immature athletes are a unifying theme throughout the article.

The effect of physical characteristics and field position on the shoulder and elbow injuries of 490 baseball players: confirmation of diagnosis by magnetic resonance imaging

OBJECTIVE

To evaluate the distribution of shoulder and elbow injuries confirmed by magnetic resonance imaging in throwing athletes.

STUDY DESIGN

Descriptive epidemiological study.

SETTING

Tertiary institution.

PARTICIPANTS

Five hundred fifty-four baseball players referred to our institute for shoulder and elbow rehabilitation.

INTERVENTIONS

All injured players except those with fractures underwent magnetic resonance imagings, which were read by a radiologist, and players were diagnosed by orthopedic surgeons based on the clinical and imaging findings.

MAIN OUTCOME MEASURES

Analysis of baseball-related injuries was performed according to the physical characteristics of each athlete and his positions on the team.

RESULTS

Junior high school players sustained a higher proportion of osteochondritis dissecans compared with high school and collegiate players. High school and collegiate players were more likely to have ulnar collateral ligament (UCL) injuries or superior labrum anterior-posterior (SLAP) lesions than junior high school players. Pitchers and outfielders were more likely to have UCL injuries than the infielders. In the junior high school group, the players with UCL injuries were taller and heavier than the players in the control group. In the high school group with UCL injuries or SLAP lesions, the players were both taller and heavier than the players in the control group.

CONCLUSIONS

These data support the conclusion that there is a significant difference in the distribution of injuries according to the player's age and position. For the age-matched comparison, taller and heavier players are more likely to be affected by UCL injury or SLAP lesion.

Sport injuries in the paediatric and adolescent patient: a growing problem

With an increasing number of paediatric and adolescent athletes presenting with injuries due to overuse, a greater demand is put on clinicians and radiologists to assess the specific type of injury. Repetitive forces applied to the immature skeleton cause a different type of injury than those seen in adults due to the differences in vulnerability of the musculoskeletal system, especially at the site of the growth cartilage. Intrinsic and extrinsic risk factors all play a role in the development of overuse injuries. MRI plays a key role in imaging overuse injuries due to its high potential for depicting cartilaginous and soft-tissue structures. Sport-specific biomechanics are described, since this knowledge is essential for adequate MRI assessment. An overview of several sport-related injuries is presented, based on anatomical location.

Isokinetic peak torque ratios and shoulder injury history in adolescent female volleyball athletes

CONTEXT

Few researchers have examined shoulder strength in adolescent volleyball athletes despite increasing levels of participation in this age group.

OBJECTIVE

To compare medial and lateral isokinetic peak torque of the rotator cuff among skill levels and between athletes with and without a history of shoulder injury.

DESIGN

Cross-sectional design.

SETTING

The Human Performance Lab and Athletic Training Lab.

PATIENTS OR OTHER PARTICIPANTS

Thirty-eight female adolescent club volleyball athletes from 10 to 15 years of age (mean = 13.02 +/- 1.60 years).

MAIN OUTCOME MEASURE(S)

We measured concentric and eccentric peak torque of the medial and lateral rotators of the shoulder and calculated resultant cocking and spiking ratios based on peak torque values.

RESULTS

Athletes at higher skill levels had higher peak torque measurements in concentric and eccentric medial and lateral rotation compared with the athletes at lower skill levels. No differences in peak torque existed between participants with or without an injury history 6 months before the study. Strength ratios did not differ across skill levels, but previously injured participants produced lower eccentric medial rotation to concentric lateral rotation ratios compared with participants without a history of injury (P = .02). At the highest skill level, previously injured participants produced lower eccentric lateral rotation to concentric medial rotation ratios compared with participants without an injury history (P = .04).

CONCLUSIONS

Differences in medial and lateral shoulder rotator strength ratios appear to be related more to injury prevalence than to absolute strength. Shoulder dysfunction related to strength ratio deficits also may exist in adolescent female volleyball athletes. Preventive shoulder strengthening programs focused on improving eccentric strength and correcting imbalances between medial and lateral rotators may be warranted for all female adolescent volleyball athletes.

Three-Dimensional Scapular Kinematics during the Throwing Motion

Proper scapular motion is crucial for normal shoulder mechanics. Scapular motion affects glenohumeral joint function during throwing, yet little is known about this dynamic activity. Asymptomatic subjects (10 male and 10 female), ages 21 to 45, were analyzed. Electromagnetic surface sensors on the sternum, acromion, and humerus were used to collect 3-D motion data during three trials of low-velocity throwing. Scapular angular position data were described for five predetermined events throughout the throw corresponding with classic descriptions of throwing phases, and trial-to-trial reliability was determined. ANOVA compared scapular angles across events. Subjects demonstrated good to excellent reliability between trials of the throw (ICC 0.74–0.98). The scapula demonstrated a pattern of external rotation, upward rotation (peak of approx. 40°), and posterior tilting during the initial phases of the throw, progressing into internal rotation after maximum humeral horizontal abduction. During the arm acceleration phase, the scapula moved toward greater internal rotation and began anteriorly tilting. At maximum humeral internal rotation, the scapula ended in internal rotation (55°), upward rotation (20°), and anterior tilting (3°).

Scapular angular positioning at end range internal rotation in cases of glenohumeral internal rotation deficit

STUDY DESIGN

Controlled laboratory study.

OBJECTIVES

Investigate the relationship between glenohumeral internal rotation range-of-motion deficit and 3-dimensional scapular angular positioning during active arm movements in participants with recent participation in overhead sports activity.

BACKGROUND

Subacromial impingement is one of the most common shoulder pathologies and is multifactorial in etiology. Posterior glenohumeral joint capsule tightness has been theorized to contribute to one potential causal factor: abnormal scapular positioning.

METHODS AND MEASURES

Twenty-three subjects, who had participated in competitive sports involving overhead activity within the last 5 years, were categorized into 2 groups based on the degree of glenohumeral internal rotation deficit (20% deficit threshold). Scapular angular positioning of subjects performing shoulder internal rotation from 90 degrees flexion and abduction shoulder positions was evaluated using 3-dimensional electromagnetic surface tracking. Additional sensors monitored trunk and humeral motion. Scapular position data at end range glenohumeral internal rotation, along with glenohumeral internal rotation range of motion measurements, were used to analyze the relationship between glenohumeral internal rotation deficit and scapular position using 2-way ANOVA and regression analyses.

RESULTS

The internal rotation deficit group had significantly greater scapular anterior tilt (9.2 degrees difference, P = .04) across positions, as compared to the control group. Regression analysis demonstrated a significant association between glenohumeral internal rotation deficit and scapular position (tilting) during flexed internal rotation (r(2) = 0.37, P = .03) and for scapular position (anterior tilting and upward rotation) during abducted internal rotation (r = 0.35, P = .036).

CONCLUSIONS

These findings demonstrate a significant relationship between glenohumeral internal rotation deficit and abnormal scapular positioning, particularly increased anterior tilt. This relationship identifies a possible mechanism for development of excessive scapular anterior tilt.

Musculoskeletal injuries in sports

A large number of adolescents participate in various sports. Not withstanding the methodologic problems with epidemiologic data, a large percentage of athletes sustain musculoskeletal injuries. In most instances, the athlete first presents to his or her primary care physician, who must perform the initial assessment and decide on further management. Many injuries can be managed by the primary care physician. It is important to recognize the unique characteristics of adolescent growth and development that have implications for the diagnosis and management of musculoskeletal injuries.

Imaging of sports injuries of the upper extremity in children

Competitive athletics in school-aged children has become the norm rather than the exception. The increased repetitive stresses placed on the upper extremity in a wide variety of sports result in a host of injuries unique to the skeletally immature athlete. This article focuses on a discussion of the more common upper extremity injuries encountered in the child athlete and the role of radiography and MRI in diagnosis and management.

Stress-induced Salter-Harris I growth plate injury of the proximal tibia: first report

We describe a case of chronic Salter-Harris I injury of the proximal tibial epiphysis. To our knowledge such an injury has not been described in the English language literature. The radiological appearance can mimic chronic infection. The possibility of chronic athletic stress-related change should be considered in such scenarios to avoid a misdiagnosis.