Date Published: June 6, 2013
Publisher: Hindawi Publishing Corporation
Author(s): Breda H. F. Lau, Dale J. Butterwick, Mark R. Lafave, Nicholas G. Mohtadi.
Background. Pectoralis major tendon ruptures have been reported in the literature as occupational injuries, accidental injuries, and sporting activities. Few cases have been reported with respect to rodeo activities. Purpose. To describe a series of PM tendon ruptures in professional steer wrestlers. Study Design. Case series, level of evidence, 4. Methods. A retrospective analysis of PM ruptures in a steer wrestling cohort was performed. Injury data between 1992 and 2008 were reviewed using medical records from the University of Calgary Sport Medicine Center. Results. Nine cases of pectoralis major ruptures in professional steer wrestlers were identified. Injuries occurred during the throwing phase of the steer or while breaking a fall. All athletes reported unexpected or abnormal behavior of the steer that contributed to the mechanism of injury. Seven cases were surgically repaired, while two cases opted for nonsurgical intervention. Eight cases reported successful return to competition following the injury. Conclusion. Steer wrestlers represent a unique cohort of PM rupture case studies. Steer wrestling is a demanding sport that involves throwing maneuvers that may predispose the muscle to rupture. All cases demonstrated good functional outcomes regardless of surgical or non-surgical treatment.
Pectoralis major (PM) tendon ruptures have been reported in the literature. These ruptures present as occupational injuries [1, 2], accidental injuries , and sporting activities [4–7] primarily in weight lifting. Ruptures have also been reported in elderly patients during procedures for transferring, positioning, and dressing the patients [8–10]. Ruptures of the muscle belly typically present as the result of direct trauma or traction injuries. Falls onto outstretched arms often result in ruptures at the musculotendinous junction, whereas excessive tension on a maximally contracted muscle often results in ruptures of the tendinous insertion from the humerus [6, 8]. Sport-related PM ruptures usually result from activities requiring a large amount of upper body strength. Two articles have reported PM ruptures resulting from a rodeo event: one reported a professional bull rider who tore his left PM during a bull riding ; the other reported three cases of PM ruptures during steer wrestling but failed to describe the events surrounding the injuries . These three cases are included in this study and reported in further detail. The purpose of this paper is to describe a series of PM ruptures in professional rodeo steer wrestlers in order to expand upon and understand the nature of this injury behind this particular cohort of athletes. Therefore, descriptive information was gathered about the sport to identify prevalence, characterize PM ruptures, and determine mechanism of injury affecting rupture type and location.
Patient records from the University of Calgary Sport Medicine Center were retrospectively reviewed from 1992 to 2008. Patients were identified through diagnostic codes searching for PM injuries. To ensure that cases were not overlooked, cases were also searched using anatomical location (i.e., shoulder). Cases were also identified from caregivers of the Canadian Pro Rodeo Sport Medicine Team (CPRSMT). All patients diagnosed with a PM injury were reviewed. Clinical assessments were confirmed by a sport medicine physician, orthopaedic surgeon, or athletic therapist. Patient medical records and retrospective interview were used to collect the following information: patient demographics, previous medical history, mechanism of injury, physical findings, diagnostic imaging, treatment, and treatment outcome. This project was approved by the University of Calgary Conjoint Health Research Ethics Board.
During the years 1992 to 2008, a total of 34 patients with a PM muscle injury were treated at the University of Calgary Sport Medicine Center. Six PM ruptures were reported in rodeo athletes, five of which were in steer wrestlers. Four additional cases of PM ruptures not treated at the center were identified by caregivers of the CPRSMT. In total, there were nine professional male steer wrestlers identified with PM ruptures of the right arm at the distal insertion of the PM into the humerus between 1992 and 2008. A complete tear of the PM was determined upon clinical examination of the injury presenting with discontinuity of the tendon at the musculotendinous junction or near insertion into the humerus and loss of muscular contour. The patient’s ages ranged from 30 to 51 years (mean: 35 ± 7 years). Incomplete ruptures of the PM were also identified but were not included in this study. All cases occurred during rodeo competition participating at Canadian Professional Rodeo Association sanctioned rodeos.
The first documented PM rupture case dates back to 1822, and since then, there have been more than 200 cases reported in the literature . This report presents the largest series of ruptured PM tendons reported during steer wrestling. A five-year epidemiological study of injuries in Canadian professional rodeo indicated that steer wrestlers sustained 9.2 injuries/1000 steer wrestling exposures . In the same study, the shoulder complex was the second most frequently injured body part when considering all rodeo events as a whole. Complete ruptures of muscles, tendons, or ligaments constituted 7% of all injuries. Rodeo caregivers found that distal biceps tendon ruptures in bull riders and some bareback riders, as well as complete ruptures of the PM  or latissimus dorsi [17, 18], were significant career interrupting events for these athletes.
Canadian steer wrestlers present a unique cohort of PM ruptures. These cases demonstrate functional successful outcome with a variety of treatments. Treatment and rehabilitation decisions appear to lack evidence-based decision making. Rodeo is a popular international sport that takes place in countries such as the United States of America, Brazil, and Australia. We suspect that this particular injury is not unique to Canadian steer wrestlers. Therefore, this case series may serve as a future stimulus for an international structured approach examining prevention, treatment, rehabilitation, and return to participation.