Valgus Extension Overload Syndrome and Olecranon Stress Fractures:

Classification of Olecranon Stress Fractures in Baseball Players

BACKGROUND

Although the onset mechanism of an olecranon stress fracture (OSF) due to a throwing disorder is believed to involve valgus extension overload, olecranon posteromedial impingement, or triceps traction force, this issue is still debated in the literature.

PURPOSE

To establish a classification system for the different types of OSFs to improve diagnosis and clarify the onset mechanism.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 200 baseball players (198 male, 2 female; mean age, 16.1 years; age range, 13-27 years) who were diagnosed with an OSF from January 1987 to July 2012 were studied. Combined disorders as well as the direction and form of the fracture line were analyzed on plain radiographs, computed tomography, and magnetic resonance imaging. Furthermore, the presence or absence of ulnar collateral ligament (UCL) injuries and avulsion fractures of the lower pole of the medial epicondyle was determined by imaging findings to calculate the combined percentage of OSFs. In addition, the prevalence of OSFs was evaluated among patients who were evaluated between April 2008 and March 2011 for throwing elbow disorders.

RESULTS

There were 5 types of OSFs identified in the new classification system: physeal, classic, transitional, sclerotic, and distal. The physeal type was further separated into stages 1 to 4 based on severity. The mean age for each type identified was as follows: physeal, 14.1 years; classic, 18.6 years; transitional, 16.9 years; sclerotic, 18.0 years; and distal, 19.6 years. A concomitant UCL injury and/or medial epicondyle avulsion fracture was diagnosed in 71% to 95% of cases, depending on the OSF type. Among baseball-related elbow disorders, the incidence of OSFs was 5.4%.

CONCLUSION

This study presents a new classification system for the different types of OSFs based on the origin and direction of the fracture plane. This new system was strongly influenced by the age at symptom onset. Such information is essential for successful open reduction and internal fixation by ensuring that fixation pressure is perpendicular to the fracture plane, which will avoid the recurrence of stress fractures. In addition, the prevalence of UCL injuries suggests that it is a major risk factor for the development of OSFs.

Stress fractures: classification and management

Stress fractures occur as a result of microdamage secondary to repetitive strains. A mechanism for the development of stress fractures involves the accumulation of microdamage, which occurs with multiple subultimate failure loads applied to the bone. Stress fractures may be classified as high or low risk, depending on the grade of the injury. The most common site of injury is the lower extremity. In this article, we review the pathophysiology, etiology, diagnosis, and management of stress fractures, and present treatment guidelines for return to play.

Classification and return-to-play considerations for stress fractures

Stress fractures are common injuries, particularly in endurance athletes. Stress fracture management should take into consideration the injury site (low risk versus high risk), the grade (extent of microdamage accumulation), and the individual's competitive situation. The authors briefly discuss the pathophysiology and diagnostic process of stress fractures and expand on the classification of stress fractures and its impact on return-to-play decision making based on the relative risk of the fracture.

Management and return to play of stress fractures

OBJECTIVE

The purpose of this article is to provide the clinician an evidence/experience-based algorithm for the management of stress fractures.

DATA SOURCES

Medline search of peer reviewed publications regarding stress fracture etiology, classification, treatment, and natural history.

DATA SYNTHESIS/METHODS

The algorithm was developed from a review of retrospective case series, a few evidence-based papers, and the clinical experience of 4 sports medicine team physicians with a combined experience of over 40 years in the care of athletes at the college and professional level. The literature is almost entirely case series without control groups; therefore, clinical consensus is included as the next best guide to treatment.

RESULTS

The emphasis of this article is to provide a clear and simple approach to the management of these fractures by classifying them as either high-risk or low-risk. This separation into 2 groups is based on the biomechanical environment and natural history of the fracture. High-risk stress fractures occur in the superolateral femoral neck, anterior tibial shaft, tarsal navicular, proximal fifth metatarsal, and talar neck. Low-risk stress fractures occur in the lateral malleolus, calcaneus, 2nd through 4th metatarsals, and the femoral shaft.

CONCLUSIONS

The undertreatment of high-risk stress fractures can lead to catastrophic bone failure and/or prolonged loss of playing time. Overtreatment of low-risk stress fractures can result in unnecessary deconditioning and unneeded loss of playing time. We propose that the use of the simple and clinically relevant algorithm will help guide appropriate management and return to play decision-making as well as encourage future prospective research.

Return to sport following elbow surgery

Although less common than injuries to the knee or shoulder, elbow injuries can be a substantial challenge to sports medicine providers. Many elbow problems respond to routine nonoperative measures including periods of activity modification and physical therapy, but others may ultimately require surgery. Following surgery, appropriate attention to rehabilitation is important to achieve optimal function. This article addresses some of the more common sports-related operative elbow pathology, basic principals of surgery (with an emphasis on techniques only where it may impact rehabilitation or return-to-sport decisions), and return-to-play decisions (including typical "targeted" time frames). The emphasis is on an understanding of sport-specific functional demands and the difficult assessment of reinjury risk following surgery.