Stress Fractures in Sport: Shoulder

Abstract

Athletes who perform repetitive tasks with the upper extremity are at risk to develop stress fractures about the shoulder girdle. Stress fractures about the shoulder girdle account for 10% of all stress fractures, and the vast majority of these injuries are reported in rowers and throwing athletes (Jones, Clin Sports Med 25: 159–174, 2006; Verma, Am J Orthop 12: 848–860, 2001; Matheson et al., Am J Sports Med 15: 46–58, 1987; Fredericson et al., Top Magn Reson Imaging 17: 309–325, 2006; Brukner, Sports Med 26: 415–424, 1998; Allen, Radiology 167: 799–801, 1988). The other 90% of stress fractures occur predominantly in the lower extremity. The most common mechanisms for these injuries involve repetitive bony torsion, weight bearing, and muscle contraction overload about the proximal humerus, scapula, and clavicle (the shoulder girdle). Any athlete complaining of the non-traumatic onset of pain in the upper extremity that occurs during or after the repetitive activity should raise concern for a stress injury or fracture (Jones, Clin Sports Med 25: 159–174, 2006). Most of these injuries are low-risk and do not require surgical stabilization. The vast majority of patients may be treated with a period of relative rest, complete rest, or activity modification with improved biomechanics and nutritional support. These treatments ultimately allow for fracture healing and full return to sport. An understanding of the most common locations of upper extremity stress fractures and their associated causative activities is key for rapid diagnosis and targeted treatment initiation.

Review

1.1 Questions

• 1. A 23 year old male high performing collegiate rower presents with a 3 week history of left chest wall discomfort. He has no trouble breathing and denies any recent trauma. Which of the following physical exam tests or signs has been shown to have high sensitivity for evaluation of first rib stress fractures?

  • (a) Loss of internal range of motion

  • (b) Pain with resisted arm forward elevation

  • (c) Pain with trapezius squeeze test

  • (d) Pain with shoulder external rotation

  • (e) Reduction in shoulder girdle range of motion

• 2. Which of the following choices corresponds to the common time-period when proximal humeral physeal stress injuries occur?

  • (a) 5–8 years old

  • (b) 7–10 years old

  • (c) 11–14 years old

  • (d) 13–16 years old

  • (e) 15–18 years old

• 3. A 28 year-old female professional power lifter presents with a multiple month history of recurrent activity-related left shoulder pain. She notes this pain usually occurs during repetitive lifting sessions of greater than 30 repetitions. On physical examination, she has point tenderness over the scapular spine. Her radiographs do not demonstrate any abnormalities. Which of the following choices demonstrates the next best step in treatment?

  • (a) Continued activity as tolerated

  • (b) MRI of left shoulder

  • (c) Repeat radiographs in 2 weeks

  • (d) Surgical stabilization

  • (e) Whole body bone scan

1.2 Answers

• 1. Choice C: The rib stress fractures section describes the trapezius squeeze test as described by Prisk et al. This test has demonstrated high sensitivity for first rib stress fractures. Rowers are at particularly high risk for rib stress injuries in general due to the high tensile loads placed on ribs during repetitive rowing activity.

• 2. Choice C: In general the proximal humeral physis fuses between approximately 14 and 17 years of age among females and between 16 and 18 years among males. As such, league shoulder injuries are commonly found among pitchers between the ages of 11–14, just prior to physeal fusion.

• 3. Choice B: The athlete likely has a stress fracture of the shoulder girdle; likely of her scapula given her physical exam and clinical history. An MRI would yield the most useful data to diagnose a shoulder girdle stress fracture. A bone scan is not as specific and sensitive as an MRI.