Little league elbow: valgus overload injury in the paediatric athlete

This article describes a variety of elbow injuries often seen in young, throwing athletes. Understandings of normal skeletal development, as well as the biomechanics of throwing, provide a basis on which to evaluate, diagnose and manage "little league elbow". With emphasis on an anatomically-based differential diagnosis, the pathologic forces placed upon the young thrower's elbow, and the subsequent injury patterns, are reviewed. Medial side injuries are the most common and relate to chronic forces of valgus overload produced during the early and late cocking phases of throwing. The majority of this force is placed on the medial epicondyle and produces age-dependent injury patterns, such as apophysitis in childhood and epicondylar avulsion fractures in the more mature athlete. With repetitive valgus overload, lateral side injuries such as Panner's disease and osteochondritis dissecans of the capitellum and radial head become more apparent. These injuries relate to the compressive forces produced by the late cocking and early acceleration phases of throwing. Finally, posterior injury patterns consistent with olecranon apophysitis and posteromedial impingement, as well as flexion and capsular contracture, can be seen. The key in the treatment of "little league elbow" is prevention and this responsibility lies not only with the evaluating or team physician, but also with the coach, trainer, parents and officials. Proper throwing mechanics must be emphasised at an early age, and the determinants of elbow injury among young pitchers better understood. Early recognition and proper treatment of such injuries will then prevent later sequelae or functional disability.     

History and examination of the thrower's elbow

Overhead throwing motion imparts enormous forces on the elbow. Repetitive near-failure loads lead to chronic adaptive changes and occasionally acute injury to bone, ligaments, and the elbow's muscle-tendon complexes. Physicians treating the thrower must thoroughly understand the complex anatomy and function of the elbow joint and throwing biomechanics to diagnose and treat elbow pathology. Evaluation of elbow pain begins with a thorough, detailed throwing history, including symptom duration, location of pain, timing during phases of throwing motion, and associated symptoms. Physical examination should include inspection, range of motion, palpation, and specific tests to better define the pathology. A detailed history and physical examination often lead the astute clinician to the proper diagnosis and treatment without reliance on ancillary testing.     

MR imaging of the elbow in baseball pitchers

Baseball pitcher throwing biomechanics are important to understanding the pathophysiology and magnetic resonance (MR) imaging appearances of injuries in baseball pitchers. Baseball pitchers experience repetitive excessive valgus forces at the elbow. Typical injuries are secondary to medial joint distraction, lateral joint compression, and rotatory forces at the olecranon. MR imaging is useful for evaluation of the elbow in baseball pitchers.     

Imaging of the overhead throwing athlete

Knowledge of overhead throwing biomechanics is crucial to understand specific injuries encountered in throwing athletes on diagnostic imaging. Most specific injuries of overhead throwing athletes occur at the shoulder and elbow. Throwing athletes are susceptible to rotator cuff tears from tensile overload and external and internal impingement. The labrum is also commonly degenerated or torn secondary to overuse syndrome, internal impingement, and microtrauma. The elbow is typically injured secondary to excessive valgus forces during throwing. The ulnar collateral ligament, ulnar nerve, and common flexor tendon origin are all at increased risk of injury. Capitellar osteochondral injuries and loose intra-articular bodies are also frequent. Knowledge of injury pathophysiology is crucial to understanding the treatment rationale in throwing athletes.     

Shoulder and elbow injuries in the young athlete

The skeletally immature athlete sustains upper extremity injuries unique to the epiphyseal plate, articular cartilage, musculotendinous units, and specific to the sport itself. Specific shoulder and elbow conditions can be predicted based on the biomechanics of the sport and age of the patient. In the young athlete, recognition of these unique injury patterns with early activity modification and treatment can prevent permanent deformity and functional disability.     

Diagnosis,treatment, and rehabilitation of the thrower’s elbow

The overhead throwing motion generates enormous force in the elbow. Repetitive near failure loads lead to chronic adaptive changes and occasionally acute injury. The physician caring for the thrower must understand the complex anatomy and function of the elbow joint, along with the biomechanics of throwing, to accurately diagnose and treat elbow pathology. Evaluation of elbow pain in the throwing athlete must begin with a thorough and detailed throwing history including duration of symptoms, location of pain, timing during the phases of throwing motion, and associated symptoms. Physical examination should include inspection, range of motion, palpation, and specific tests to better define the pathology. A detailed history and physical examination will allow the astute clinician to obtain the proper diagnosis and start the appropriate operative or nonoperative treatment often without reliance on ancillary testing. Treatment and rehabilitation of these injuries must be tailored to the pathology present and focused towards a return to the athlete’s activity.     

Elbow injuries in the throwing athlete. Difficult diagnoses and surgical complications.

Elbow injuries in throwing athletes can be challenging from the diagnostic and management perspectives. The stress of repetitive throwing does predispose athletes to certain conditions with which treating clinicians need to be familiar. An understanding of the anatomy of the elbow and the biomechanics of throwing is essential to making the correct diagnosis and instituting proper care. Failure of nonoperative measures often requires surgical intervention. A thorough understanding of the anatomy and the spectrum of conditions that can occur is needed before decisions regarding surgical management can be made. The operative approach to elbow pathology, whether performed open or arthroscopically, should be completed by orthopedists who have experience with the clinical conditions and the appropriate technical facility to provide comprehensive care. This article has reviewed the anatomy, biomechanics, and spectrum of conditions that affect throwing athletes' elbows as well as the potential complications that can be associated with surgical management.     

Elbow injuries in the throwing athlete: Diagnosis and arthroscopic treatment

The elbow is a frequent site of pathology in sports injuries, especially in the throwing athlete. This is because of thesignificant stresses that are produced at the elbow joint by the throwing activity. Many of these injuries occur insidiously over time from accumulated microtrauma caused by repetitive overuse and can be quite debilitating if not properly diagnosed. Recent advances in knowledge of elbow anatomy, function, and biomechanics have greatly increased our awareness of the diagnosis and treatment of sports-related elbow injuries. Elbow arthroscopy has been invaluable in the diagnosis and treatment of intra-articular pathology frequently observed in the elbow. In addition, treatment of elbow throwing injuries has been greatly facilitated by allowing an accelerated rehabilitation and return to competition over open procedures. Meticulous arthroscopic technique and knowledge of regional elbow anatomy is essential to avoid neurovascular complications and articular damage. When performed by an experienced arthroscopist, the procedure carries minimal morbidity and allows a rapid return to competition.     

Immature skeletal lesions of the elbow

Excessive repetitive loading of the elbow may produce a myriad of elbow complaints in the adolescent athlete. Osteochondrosis, stress apophysitis of the medial epicondyle, displaced fracture of the medial epicondyle, and osteochondritis desiccans (OCD) of the capitellum and radial head are unique to the skeletally immature elbow and differ from the adult athlete.     

Elbow injuries in throwing athletes: a current concepts review

Repetitive overhead throwing imparts high valgus and extension loads to the athlete's elbow, often leading to either acute or chronic injury or progressive structural change. Tensile force is applied to the medial stabilizing structures with compression on the lateral compartment and shear stress posteriorly. Common injuries encountered in the throwing elbow include ulnar collateral ligament tears, ulnar neuritis, flexor-pronator muscle strain or tendinitis, medial epicondyle apophysitis or avulsion, valgus extension overload syndrome with olecranon osteophytes, olecranon stress fractures, osteochondritis dissecans of the capitellum, and loose bodies. Knowledge of the anatomy and function of the elbow complex, along with an understanding of throwing biomechanics, is imperative to properly diagnose and treat the throwing athlete. Recent advantages in arthroscopic surgical techniques and ligament reconstruction in the elbow have improved the prognosis for return to competition for the highly motivated athlete. However, continued overhead throwing often results in subsequent injury and symptom recurrence in the competitive athlete.     

Clinical anatomy, histology, & pathomechanics of the elbow in sports

The elbow is an integral link in the athlete's upper extremity function transferring force, position, and load-bearingcapability to the hand. This paper focuses upon the salient clinical anatomy and biomechanics of the elbow relative to specific athletic skills. First, the pertintent anatomy of the elbow will be discussed emphasizing those aspects that are clinically relevant. In the second section, the pathomechanics of the elbow will be reviewed using the throwing motion as the representative athletic skill. An understanding of the functional anatomy and pathomechanics of the elbow will aid in developing a rational approach to the evaluation, treatment, and rehabilitation of sports-related injuries.     

The diagnosis and nonoperative treatment of elbow problems in the athlete

An understanding of the anatomy and biomechanics of the elbow is essential for accurate diagnosis and treatment. In the athlete, the lateral compressive and medial traction forces account for the majority of problems. Lesions range from the valgus extension overloads to osteochondritis dissecans. Soft-tissue problems, be they "tennis elbow" or ulnar collateral ligament injuries, are frequently the greatest diagnostic and therapeutic challenge.     

Das Ellenbogengelenk – eine diagnostische Herausforderung

The elbow is one of the most commonly injured joints in sports activities. In particular, weight lifters, golfers, tennis players, and pitchers are affected. Injuries in sports involving overhead throwing are commonly based on the pathophysiologic model of valgus extension overload syndrome. The injuries are commonly complex and demand a good knowledge of the symptoms, the exact anatomy, and the biomechanics to arrive at a precise radiologic diagnosis. The characteristic patterns of injury that occur in specific sports activities are related to a combination of increased varus or valgus and extension or flexion overload that results in tensile forces and/or compression and shear stress. Acute symptoms are frequently based on chronic degeneration of the tendons and ligamentous structures due to repetitive microtrauma from overuse syndrome.     

The elbow joint - a diagnostic challenge : anatomy, biomechanics, and pathology

The elbow is one of the most commonly injured joints in sports activities. In particular, weight lifters, golfers, tennis players, and pitchers are affected. Injuries in sports involving overhead throwing are commonly based on the pathophysiologic model of valgus extension overload syndrome. The injuries are commonly complex and demand a good knowledge of the symptoms, the exact anatomy, and the biomechanics to arrive at a precise radiologic diagnosis. The characteristic patterns of injury that occur in specific sports activities are related to a combination of increased varus or valgus and extension or flexion overload that results in tensile forces and/or compression and shear stress. Acute symptoms are frequently based on chronic degeneration of the tendons and ligamentous structures due to repetitive microtrauma from overuse syndrome.     

MRI of anterior cruciate ligament injuries and associated findings in the pediatric knee: changes with skeletal maturation

OBJECTIVE: The objective of our study was to evaluate the MRI characteristics of anterior cruciate ligament (ACL) injuries and associated findings relative to skeletal maturity. We also contrast the frequency of findings in this younger population to adult data. MATERIALS AND METHODS: Eighty-two consecutive knees with an MRI report diagnosis of ACL injury (partial tear, sprain, or complete tear) or tibial spine avulsion fracture imaged over 4 years were retrospectively reviewed. Patients were grouped by degree of skeletal maturity as determined from the MR images. The examinations were reviewed for the type of ACL injury, secondary imaging findings, and associated knee injuries. Findings were correlated to skeletal maturity, and frequencies were compared with adult data. RESULTS: ACL injuries were more common in boys in the skeletally immature group, but more common in girls in the skeletally mature group (p = 0.03). Tibial spine avulsion fractures were most common in skeletally immature patients (p < 0.01), whereas complete tears of the ACL were most common in skeletally mature patients. Associated injuries were less common in the skeletally immature group, but this trend did not reach statistical significance. Most secondary signs of ACL injuries occurred at similar rates in all groups with frequencies similar to those reported in adults. CONCLUSION: ACL injuries in skeletally immature patients are seen more often in boys. Tibial avulsion fractures and partial tears are more common in younger, less rigid skeletons that may absorb the forces of trauma. As children mature, complete ACL tears and associated injuries occur in frequencies approaching those patterns seen in adults. Similarly, skeletally mature girls are affected more often than mature boys.     

Biomechanics of the elbow in sports

In throwing activities, the elbow is sometimes stressed to its biomechanical limits. In this article, forces, torques, angular velocities, and muscle activity about the elbow are reviewed for the baseball pitch, the football pass, the javelin throw, the windmill softball pitch, the tennis serve, and the golf swing. The elbow goes through rapid extension in baseball pitching (about 2400 degrees/s) and rapid flexion in the javelin throw (about 1900 degrees/s). During baseball pitching, the elbow joint is subject to a valgus torque reaching 64 Nm, and requires proximal forces as high as 1000 N to prevent elbow distraction. The ulnar collateral ligament (UCL) rupture in baseball pitching, lateral epicondylitis in the tennis backhand, and other injury mechanisms are also discussed.     

Rehabilitation of the thrower's elbow

The elbow joint is frequently injured in the overhead athlete, due to the large amount of forces in throwing. Injuries often occur due to repetitive microtrauma, especially in pitching. Rehabilitation following injury or surgery is vital to fully restore normal elbow function and return the athlete to competition as quickly and safely as possible. Elbow rehabilitation must follow a progressive and sequential order to ensure that healing tissues have not been compromised. Emphasis is on restoring full motion, muscular strength, and neuromuscular control, and gradually applying loads to healing tissue. This article provides an overview of a multiphased rehabilitation program for the thrower's elbow. Rehabilitation for specific nonoperative and postoperative pathologies often observed in the throwing athlete is also discussed.     

Pitching biomechanics as a pitcher approaches muscular fatigue during a simulated baseball game

BACKGROUND: The effects of approaching muscular fatigue on pitching biomechanics are currently unknown. As a pitcher fatigues, pitching mechanics may change, leading to a decrease in performance and an increased risk of injury. HYPOTHESIS: As a pitcher approaches muscular fatigue, select pitching biomechanical variables will be significantly different than they were before muscular fatigue. STUDY DESIGN: Controlled laboratory study. METHODS: Ten collegiate baseball pitchers threw 15 pitches per inning for 7 to 9 innings off an indoor throwing mound during a simulated baseball game. A pitching session ended when each pitcher felt he could no longer continue owing to a subjective perception of muscular fatigue. A 6-camera 3D automatic digitizing system collected 200-Hz video data. Twenty kinematic and 11 kinetic variables were calculated throughout 4 phases of the pitch. A repeated-measure analysis of variance (P < .01) was used to compare biomechanical variables between innings. RESULTS: Compared with the initial 2 innings, as a pitcher approached muscular fatigue during the final 2 innings he was able to pitch, there was a significant decrease in ball velocity, and the trunk was significantly closer to a vertical position. There were no other significant differences in kinematics or kinetics variables. CONCLUSION: The relatively few differences observed imply that pitching biomechanics remained remarkably similar between collegiate starting pitchers who threw between 105 and 135 pitches for 7 to 9 innings and approached muscular fatigue. CLINICAL RELEVANCE: This study did not support the idea that there is an increase in shoulder and elbow forces and torques as muscular fatigue is approached. It is possible that if a pitcher remained in a fatigued state for a longer period of time, additional changes in pitching mechanics may occur and the risk of injury may increase.     

Glenoid labrum tears related to the long head of the biceps

Tears of the glenoid labrum were observed in 73 baseball pitchers and other throwing athletes who underwent arthroscopic examination of the dominant shoulder. Most of the tears were located over the anterosuperior portion of the glenoid labrum near the origin of the tendon of the long head of the biceps muscle into the glenoid. At arthroscopy, the tendon of the long head of the biceps appeared to originate through and be continuous with the superior portion of the glenoid labrum. In many cases it appeared to have pulled the anterosuperior portion of the labrum off the glenoid. This observation was verified at arthroscopy by viewing the origin of the biceps tendon into the glenoid labrum as the muscle was electrically stimulated. With stimulation of the muscle, the tendinous portion became quite taut, particularly near its attachment to the glenoid labrum, and actually lifted the labrum off the glenoid. Three-dimensional high-speed cinematography with computer analysis revealed that the moment acting about the elbow joint to extend the joint through an arc of about 50 degrees was in excess of 600 inch-pounds. The extremely high velocity of elbow extension which is generated must be decelerated through the final 30 degrees of elbow extension. Of the muscles of the arm that provide the large deceleration forces in the follow-through phase of throwing, only the biceps brachii traverses both the elbow joint and the shoulder joint. Additional forces are generated in the biceps tendon in its function as a "shunt" muscle to stabilize the glenohumeral joint during the throwing act.(ABSTRACT TRUNCATED AT 250 WORDS)