Stress fractures occurring around the pelvis are significantly uncommon although, a majority of them are often considered a differential diagnosis when athletes, specifically long distance runners and triathletes, report hip, groin or buttock pain during and after running. Because stress fractures around the pelvic/hip region, including the sacral, pubic rami and femoral neck region, are rarely diagnosed, understanding and discussing the anatomy of the injury, their clinical presentation, diagnosis and treatment for each of these types of stress fractures is important for an athlete in order to find a solution for those who do encounter it.
Stress fractures occur over a determined period of time when the bone is no longer capable of withstanding submaximal, repetitive forces. They frequently result when normal stresses cause bone fracture with decreased bone density, such as in an elderly osteoporotic individual, or as a result of an abnormal stress being placed against a normal bone and causing a fracture, such as in a long distance runner.
When the bones are exposed to loading, the introductory physiological response is a respective increase in osteoclastic activity, or bone resorption, leading to temporary structural weakening before new bone formation. If these stresses continue to occur without having the bone properly adjust to this additional, ongoing osteoclastic activity, the pressure may exceed bone regeneration, causing microfractures to occur.
The first characteristic of a stress reaction observed through the use of MRI is bone oedema as well as increased activity on bone scan. Bone scan in the acute phase has high sensitivity but an increased uptake may also be due to infection, bone infarction or neoplastic activity. Researchers from previous studies stated that 60 to 70 percent of X-rays in the acute phase of stress fractures, approximately less than 2 weeks after the injury, have a negative result. Due to its high sensitivity as well as a lack of radiation and high specificity, even despite its elevated cost, MRI is often the preferred procedure to identify stress fractures in their early phases
Among the general population of athletes, pelvic stress fractures can be a rare cause of pain and discomfort, accounting for only 2 percent of all reported sports injuries. However, a considerably higher number of pelvic stress fractures are diagnosed in long distance runners and triathletes as the structures surrounding the hip, buttocks and lower extremities are exposed to constant and repetitive motions which cause overexertion. For more information, please feel free to ask Dr. Jimenez or contact us at (915) 850-0900.