Medial Epicondylar Elbow Fractures

Etiology

Trauma resulting in valgus stress on the elbow, such as falling on an outstretched hand or through throwing or wrestling, causes an avulsion fracture of the medial epicondyle. These injuries are frequently associated with elbow dislocations. Medial epicondylar fractures are most commonly caused by the pull of the attachments at the medial epicondyle during valgus stress - the ulnar collateral ligament and flexor-pronator mass. The medial epicondyle fracture typically displaces anteriorly as a result of the pull of these muscles. A less common mechanism of medial epicondyle fracture occurs from a direct blow to the elbow.[3]

Epidemiology

Medial epicondyle fractures comprise 12% of elbow fractures in the pediatric population. Most medial epicondyle fractures occur in pediatric patients between the ages of 9 and 14. Approximately 75% of medial epicondylar fractures occur in male pediatric patients. The increased numbers of collisions, falls, and valgus stress events on the elbow in active athletes contribute to patients' demographics at risk for these injuries.

History and Physical

A detailed history is necessary after acute injury, including the mechanism of injury and timing of the event. This history and exam also include the localization of symptoms and any prior history of injuries. In athletes, detailed information regarding hand dominance, sport and workout regimens, and activity changes. It is essential to assess the functional demands of the patient to help tailor care.  Patients may also complain of loss of motion and neurological deficits such as decreased sensation or weakness. The history of any elbow instability events such as dislocation should be elicited.[1]

A physical exam is essential, including beginning with a skin examination for laceration, swelling, ecchymosis, deformity, or effusion. The exam also includes palpating bony landmarks for tenderness and assessing the range of motion.[1] Patients present with tenderness over the medial elbow along with soft tissue swelling. The patient may have pain and crepitation with elbow motion or a mechanical block to the motion of the elbow. Also, an examination of ulnar nerve function is key to physical examination. Ulnar nerve function includes abduction and adduction of fingers and preserved sensation of the ulnar of the fifth digit and ulnar aspect of the ring finger. The examination should also include a thorough vascular exam and looking for other upper extremity fractures, including the radius and ulna. 

Evaluation

Radiographic imaging is recommended to diagnose medial epicondyle fractures. The preferred initial imaging series includes anterior-posterior (AP) and lateral view plain radiographs of the elbow, including an oblique view. The oblique view helps distinguish displacement. X-ray findings suggestive of medial epicondyle fractures include cortical contour disruption on the AP view of plain radiographs. Other findings include loss of parallelism along apophysis smooth margins. Trochlear ossification seen on radiographs in children younger than eight years old may suggest an incarcerated fragment of medial epicondylar fracture as children younger than eight years old have not yet developed trochlear ossification.

Additionally, there are several classification systems present for medial epicondylar fractures. The Watson Jones classification can be useful to guide further treatment and management.  Watson Jone's classification consists of Type I through IV fractures. Type I includes fractures of less than 5 mm displacement with no rotation and are typically treated non-operatively. Type II fractures have greater than 5 mm displacement with rotation. Type III fractures have incarcerated fragments without dislocation. Type IV fractures are incarcerated with dislocation. Types III and Type IV receive operative treatment, while consideration is also given to patient factors for decision making in Type II fractures. Stress reaction or stress fractures in throwing athletes generally are treated conservatively and with a shutdown period to limit the chances of worsening the injury.[3]

Treatment / Management

Nonoperative Management

Isolated nondisplaced medial epicondyle fractures are best managed by nonoperative management. This approach includes a brief period of immobilization in a long arm cast in the first week with the elbow flexed to 90 degrees.[4] After removing the splint, a protected exercise program should start, which will include active range of motion exercises. Stress fractures also receive nonoperative treated nonoperative treatment.[5]

Operative Management

Indications for surgical referral and operative management of medial epicondyle fractures include open fractures, incarcerated intra-articular fragments, and valgus instability. In these cases, surgical intervention for fracture is necessary. Intra-articular fragment entrapment occurs in 5 to 18% of cases of medial epicondylar fractures.[6] Operative techniques include the use of open reduction and internal fixation with a screw and washer construct, Kirschner wires, sutures, and tension band techniques. Also, K-wires are the most common option for fragmented fractures in children.[3]  A posterior-medial approach is preferred to gain better access to the distal humerus. The patient may be placed supine but also laterally with the hand placed on the back for better exposure of medial epicondyle for surgical access.[7][8](B3)

Differential Diagnosis

• Medial condylar fracture
• Supracondylar fracture
• Medial epicondylitis 
• Elbow dislocation
• Olecranon bursitis
• Cubital tunnel syndrome
• Ulnar collateral ligament injury 

Prognosis

Both nonoperative and operative treatment and management have shown to have a good prognosis and outcomes.[2][9] Systematic reviews showed a 92.5% rate of a successful bony union in operatively managed medial epicondylar fractures versus a 49.2% rate of a bony union in nonoperative managed groups.[10] After a 2 to 5-year follow-up of medial epicondylar fractures, case series studies show that nonoperative treatment is successful in minimally displaced medial epicondyle fractures with a stable elbow.[11]

Complications

Approximately 60% of the medial epicondyle fractures in pediatric patients are associated with elbow dislocation.[10][12] Also, about 10% to 15% percent of pediatric medial epicondyle fractures may result in ulnar nerve dysfunction.  Other complications include elbow stiffness, elbow instability, deformity, nonunion, and wound infections.[3][12] Reports of septic arthritis and myositis ossificans have been other observed complications of medial epicondylar fractures.[10]

Ulnar nerve involvement was prevalent in 9.6% of acute pediatric medial epicondyle fractures based on studies from large systematic reviews. Findings of ulnar neuropraxia included loss of sensation over the right radial aspect of the ring finger and the entire small finger after trauma. Patients with ulnar nerve palsy require surgical intervention with ulnar nerve decompression.[6] Studies showed functional outcomes and nerve recovery after post-operative care. Findings showed full recovery of ulnar nerve deficits with early surgical intervention and nerve decompression.[13]