PELVIC STRESS INJURIES - THE RELATIONSHIP BETWEEN OSTEITIS PUBIS (SYMPHYSIS PUBIS STRESS INJURY) AND SACROILIAC ABNORMALITIES IN ATHLETES

Objective. To demonstrate with radiographic imaging the association be tween pubic stress injury and sacroiliac abnormalities in athletes. De sign and patients. Eleven athletes (9 men and 2 women), comprising sev en male long-distance runners, one male soccer player, one male and tw o female basketball players, were imaged with plain films for complain ts of pubic symphysis pain, sciatica, groin pain, or a combination of these complaints. In addition to the plain films, four patients were i maged with CT, two patients had MR imaging, and a bone scan was perfor med in three patients, Anteroposterior plain films of the pelvis of 20 patients without back pain or pubic pain were evaluated for compariso n as a control group (ages 18-72 years, average 49 years; 11 women and 9 men). Results. All athletes showed plain film evidence of either sc lerosis, erosions or offset at the pubic symphysis. Four had avulsion of cortical bone at the site of insertion of the gracilis tendon. Four patients demonstrated sacroiliac joint abnormalities on plain films c onsisting of sclerosis, erosions and osteophytes, and in one of these athletes, bilateral sacroiliac changes are present. Two patients with normal sacroiliac joints on plain films had a bone scan showing increa sed radionuclide uptake bilaterally at the sacroiliac joints. One pati ent with both plain film and CT evidence of sacroiliac abnormalities h ad an MR examination showing abnormal signal at both sacroiliac joints and at the pubic symphysis. A sacral stress fracture was found on CT in one patient with complaints of sciatica. In the control group, six patients, all over the age of 55 years, had mild sclerosis of the symp hysis, but no plain film evidence of sacroiliac abnormalities. Conclus ion. We have found a group of athletes in whom stress injuries to the pubic symphysis are associated with changes in the sacroiliac joint as demonstrated by degenerative changes or in the sacrum as manifested a s a sacral stress fracture. These findings are probably due to abnorma l stresses across the pelvic ring structure that lead to a second abno rmality in the pelvic ring. The abnormality in the sacrum is not alway s well seen with conventional imaging. Recognition of the association of stress injury of the symphysis with back pain is important in that it can help avoid inappropriate studies and diagnostic confusion.