EXERCISE-INDUCED STRESS INJURIES TO THE FEMUR

Seventy-one athletes with 74 stress injuries to the femur were studied using a case-controlled design. Forty-three were females (26.6 yrs) a nd 28 were males (31.2 yrs). Each patient had exercise-induced pain in the hip, groin or thigh and a Tec-99m-MDP bone scan showing focal upt ake of radionuclide in the femur. Running was the most common activity at the time of injury (89.2 %) followed by triathlon (4.6 %) and aero bic dance (4.6 %). Thirty per cent of the runners had increased their training duration immediately prior to their first symptom. Anterior t high pain was the most frequent site of exercise-induced pain (45.9 %) followed by hip pain (27 %) and groin pain (8.1 %). During the clinic al examination, when asked to hop on the affected limb, 70.3 % of the patients had pain reproduced in the hip, groin or anterior thigh. Ther e were 39 cases (53 %) involving focal uptake of radionuclide in the f emoral shaft, 15 (20 %) in the lesser trochanter, 11 (15 %) in the int ertrochanteric region between the femoral neck and the greater trochan ter, 8 (11 %) in the femoral neck and 1 (1 %) in the greater trochante r. Two patients suffered displaced fractures, one at the femoral neck and the other in the shaft of the femur. Neither patient had previousl y sought medical attention for their leg pain. Of 46 plain radiographs taken, only 11 (24 %) were abnormal. The mean time to diagnosis and r ecovery were 6.6 and 10.4 weeks respectively Substitution of cycling a nd water exercise for running were the most common therapeutic interve ntions.