Stress fracture was first described by a Prussian military doctor in 1855 after observing metatarsal bone fractures in soldiers. Stress fractures account for 10% of sports injuries, with 0.7-15.6% of athletes presenting with stress fractures. In a study of 320 cases of stress fractures in athletes, it was reported that the tibia was most often involved (49%), followed by the tarsus (25.3%), the metatarsus (8.8%), the femur (7.2%), the fibula (6.6%), and the pelvis and spine (
A 24-year-old female ice dancer (international level and member of the Italian National Team) presented to the outpatient sports rehabilitation clinic of our institute in November 2013 because of dull persistent pain in the left forearm that had worsened over the previous 10 days. Physical examination disclosed a tender swelling (diameter, about 1 cm) over the middle third of the ulna. Palpation along the forearm and resisted pronation elicited tenderness. The athlete reported having sustained no acute injuries during the previous months and that the pain had begun to worsen starting in late September. On further questioning, she described a technical element in the free dance segment which prompted suspicion as a potential triggering factor of the pain. A stationary lift is a required element of the competitive ice dance program. In the stationary lift, the lifting partner (male) rotates in place for six seconds while executing and mantaining the lifted position of the female partner. During this time the lifted partner (female) must mantain a "difficult position" for 3 seconds. By definition the ring position is one of the "difficult positions" which is executed by holding the body as a ring with the head and a foot almost touching, maximum half a blade length between the head and the blade (Figure 1). She had begun practicing this specific stationary lift in early August, having repeated the technique about 500 times between August and current presentation. The number of repetitions of the technical element was within the range of similar or identical technical elements she had practiced during previous training seasons.
Additional diagnostic tests were performed. Plain x-rays revealed cortical thickening of the middle third of the ulnar diaphysis. Magnetic resonance (MR) images were acquired in a 1.5 Tesla MR system using a surface coil (Avanto, Siemens Medical Solutions, Forchheim, Germany): PD fat suppressed sequences in the coronal plane, axial and sagittal T1-weighted and axial T2weighted sequences, and axial and coronal short-tau inversion recovery (STIR) sequences. The MR scans confirmed focal thickening of the cortical bone in the middle ulnar diaphysis, more pronounced on the lateral side, a hypointense oblique cortical fracture line on the T1weighted image, and intense bone marrow and periosteal edema (Figure 2). These findings were strongly suggestive of stress fracture. Thin slice computed tomography (thickness, 1 mm) of the left forearm showed cortical thickening, indicating bone remodeling at the stress fracture site but no other concomitant bone disorders and ruled out focal...