Introduction

Approximately 30 million children and teenagers participate in organized sports in the United States (Adirim and Cheng 2003). Despite the fact that sports are the leading cause of injury in adolescent athletes, it is estimated that more than half of those injuries are preventable (Emery 2003). Pain in the elbow is a common occurrence in young baseball players, especially pitchers. Table 2-1 lists possible differential diagnoses in adolescents with elbow pain. One study found that elbow pain in youth baseball pitchers was associated with multiple factors including age, weight, height, number of pitches thrown during the season, satisfaction with performance, fatigue, lifting weights, and playing outside of the league (Lyman et al. 2001). Studies have found that, during a season, 26% to 35% of youth baseball players have either shoulder or elbow pain, with self-reported shoulder pain in more than 30% of pitchers and elbow pain in more than 25% immediately following a game (Lyman et al. 2001, Lyman et al. 2002). The simple act of throwing is violent because of the stresses it places on the elbow. Because ligaments and muscles are attached to the bone at the medial elbow at a time when the secondary ossification centers are not fused, a traction apophysitis can occur when this growth plate is not able to withstand the forces placed on it. Conversely, compression on the lateral side of the elbow commonly is a cause for Panner’s disease or osteonecrosis of the capitellum.

Table 2-1 Adolescent Elbow Pain Differential Diagnosis

Little Leaguer’s elbow

Little Leaguer’s elbow is considered a host of elbow pathology in a young throwing athlete. The various types of injuries that can be considered Little Leaguer’s elbow are listed in Table 2-2.

Table 2-2 Forms of Little Leaguer’s Elbow

Medial tension injuries

Medial tension injuries most commonly include medial epicondylar apophysitis. With repetitive stress to the medial elbow in the throwing adolescent, the flexor pronator mass and the ulnar collateral ligament apply tensile forces that cause medial epicondyle apophysitis (Pappas 1982, Rudzki and Paletta 2004). This apophysitis is thought to occur rather than rupture of the ulnar collateral ligament (Joyce et al. 1995). Chronic attritional tears of the ulnar collateral ligament are fairly rare in adolescent athletes (Ireland and Andrews 1988). Despite this rarity, it appears that ulnar collateral injuries are increasing in high school athletes. Petty et al. (2004) reported that the percentage of high school athletes who required ulnar collateral ligament reconstruction in their center jumped from 8% between 1988 and 1994 to 13% between 1995 and mid-2003. Injuries to the ulnar collateral ligament in adolescent athletes generally occur as acute events, rather than through attrition as in older, more skeletally mature athletes.

Lateral compression injuries

Several conditions caused by compression of the lateral side of the elbow can occur in younger pitchers. Two of the more common are osteochondritis dissecans (OCD) and Panner’s disease. Although traditionally these have been thought to be the same condition by some, they are separate entities. Osteochondritis is a localized condition involving articular cartilage that has separated from the underlying subchondral bone and is caused by repetitive trauma (Yadao et al. 2004). Panner’s disease is a focal osteonecrosis of the entire capitellum seen primarily in boys aged 7 to 12 years old and is not associated with trauma (Yadao et al. 2004).

Posterior compression injuries

Whereas medial and lateral elbow pain occurs as a result of “valgus extension overload” during the late cocking–early acceleration phase of throwing, posterior pain occurs during the terminal phase of throwing as the elbow is locked into full extension. The synovium can be pinched in the olecranon when the elbow is in full extension, resulting in posterior impingement syndrome, or the posterior apophysis can be stressed by triceps traction, causing olecranon apophysitis (Crowther 2009).

Prevention

Parents and coaches need to take more control of players, especially those who are at risk. Unfortunately, these are most commonly the “better players,” which is why they may develop these problems to begin with. Petty et al. suggested that the risk of elbow problems in younger athletes can be reduced by following these guidelines:

Several associations have provided recommendations regarding adolescent athletes and prevention of both elbow and shoulder problems. The American Academy of Pediatrics and USA Baseball each have guidelines regarding pitch counts. The American Academy of Pediatrics recommends limits of 200 pitches per week or 90 per outing, while the USA Baseball Medical and Safety Advisory Committee recommends a more stringent 75 to 125 pitches per week or 50 to 75 pitches per outing depending on age (Committee on Sports Medicine and Fitness, USA Baseball Medical and Safety Advisory Committee 2001).

USA baseball guidelines

USA Baseball has developed guidelines and recommendations in an effort to decrease the risk of elbow or shoulder injury in vulnerable adolescent athletes.

Anatomy and biomechanics

The MCL is composed of two primary bundles. The anterior bundle runs from the sublime tubercle of the ulna and inserts on the inferior surface of the medial epicondyle. The anterior bundle tightens in extension and loosens in flexion. The posterior band runs from the posterior portion of the medial epicondyle and inserts at the ulna proximal and posterior to the sublime tubercle (Fig. 2-1). The posterior bundle tightens in flexion and loosens in extension. The anterior bundle is the prime focus of the MCL reconstruction. The ulnar nerve runs in the space posterior to the medial epicondyle. The space is referred to as the cubital tunnel. The roof of the tunnel is referred to as the cubital tunnel retinaculum. At this location, the nerve is significantly exposed.

Figure 2-1 MCL complex of the elbow, consisting of three bundles: anterior, posterior, and transverse oblique.

Mechanism of injury

Injury to the MCL is a result of the repetitive, extreme valgus loads to the elbow while throwing. The MCL is the primary restraint to valgus stress at the elbow. Dillman et al. (1995) demonstrated that a fastball thrown by an elite baseball pitcher produces a load that approaches the actual tensile strength of the MCL. The MCL attempts to withstand these forces during the late cocking and acceleration phases of throwing. Repetitive overloading can result in inflammation and microtears of the ligament, which can eventually lead to failure. Continuing to throw with instability can lead to degenerative changes in the elbow.

Repetitive valgus stresses can also result in injury to the ulnar nerve, which may be exacerbated by ligamentous insufficiency. These stresses may lead to medial traction on the ulnar nerve, resulting in chronic subluxation or dislocation of the nerve outside the ulnar groove. In addition, throwers often have a hypertrophied flexor–pronator mass, which can result in compression of the nerve during muscle contraction. Injuries to the ulnar nerve may be isolated or associated with an MCL injury.

Evaluation

Diagnosis of MCL insufficiency is based on the history, physical examination, magnetic resonance imaging (MRI), and arthroscopic testing. The history is often chronic medial elbow pain with throwing, especially during the late cocking and early acceleration phases. It often prevents throwing completely. Physical examination includes a valgus stress test that reproduces the symptoms of increased valgus laxity. MRI findings clearly consistent with an MCL injury assist in making the diagnosis. Finally, a positive arthroscopic test, which is defined as more than 1 mm of opening between the coronoid and the medial humerus, is often used.

Surgical treatment

Medial Collateral Ligament Reconstruction

Reconstruction of the medial collateral ligament is performed using the “docking technique” described by Altchek et al. (2000). The anterior bundle is the primary focus of the reconstruction. The ipsilateral palmaris longus is the graft of choice. In the absence of this muscle, the gracilus is used. Our rehabilitation guidelines are not affected by graft choice; however, when using the gracilis, the affected lower extremity must be considered.

This procedure includes a routine arthroscopic evaluation of the elbow through a muscle-splitting approach that preserves the flexor–pronator origin (Fig. 2-2). Bone tunnels are created in the humerus and ulna. The graft is “docked” securely in the tunnels with sutures (Fig. 2-3). This technique also minimizes the number of tunnels and reduces the size of the drill holes. Finally, this technique avoids an obligatory ulnar nerve transposition.

Figure 2-2 Exposure is created by splitting the flexor carpi ulnaris muscle.

(Redrawn from Levinson M: Ulnar Collateral Reconstruction in Postsurgical Rehabilitation Guidelines for the Orthopedic Clinician. 1^st edition, St. Louis, Elsevier, 2006.)

Figure 2-3 Docking technique: The graft is “docked” securely into the bone tunnels using sutures.

(Redrawn from Levinson M: Ulnar Collateral Reconstruction in Postsurgical Rehabilitation Guidelines for the Orthopedic Clinician. 1^st edition, St. Louis, Elsevier, 2006.)

Definition

The elbow contains three major articulating surfaces. The articulation of the humeral trochlea and the trochlear notch of the ulna is the major facilitator of flexion and extension about the elbow. The radiocapitellar articulation supports motion in both the flexion and extension of the elbow in addition to supination and pronation of the forearm. The proximal radioulnar joint allows supination and pronation movements of the forearm.

The physiologic range of motion has been defined by the American Academy of Orthopaedic Surgeons to be 0 to 146 degrees with respect to extension and flexion, 71 degrees of forearm pronation, and 84 degrees of forearm supination. More important, the functional arc of motion as defined by Morrey et al. (1981) is elbow flexion from 30 to 130 degrees and 100 degrees of forearm rotation, including 50 degrees of supination and 50 degrees of pronation. The functional impairment caused by elbow stiffness is delineated by the individual needs of each patient.

Classification

The etiology of elbow stiffness has been classified by various authors. Kay (1998) based his scheme on the anatomic components involved. Type I involves soft tissue contractures; type II involves soft tissue contractures with ossification; type III involves nondisplaced articular fracture with soft tissue contracture; type IV involves displaced intra-articular fractures with soft tissue contracture; and type V involves post-traumatic bony bars blocking elbow motion.

Morrey (1990) classified elbow stiffness into intrinsic, extrinsic, and mixed causes (Table 2-5). Intrinsic causes are related to intra-articular pathology resulting from deformities or malalignment of the articular surface, intra-articular adhesions, loose bodies, impinging osteophytes, and fibrosis within the olecranon or coronoid fossa. Extrinsic causes are related to all entities aside from the articular surface. Examples include skin contracture from scars or burns, capsular and collateral ligament contracture, and heterotopic ossification. Another important extrinsic cause is injury to brachialis or triceps resulting in a hemarthrosis, which may cause scarring, fibrosis, and limitation of motion. Entrapment of the ulnar nerve can lead to pain resulting in loss of motion and eventual capsular contracture. Mixed etiologies are defined as extrinsic contractures resulting from intrinsic pathology.

Table 2-5 Morrey’s Causes of Elbow Stiffness by Location of Pathology

History