Characteristics of skeletal stress fractures in female military recruits of the Israel defense forces on bone scintigraphy.

AIM: Clinical surveys on stress fractures (SF) in female military recruits are scarce. The aim of this study was to characterize the scintigraphic findings and classify the distribution and pattern of SF in a group of female recruits of the Israel Defense Forces (IDF).

MATERIALS AND METHODS: The bone scans of 146 female recruits (age range, 19-20.6 years) with suspected SF were assessed retrospectively. The SF lesions were classified qualitatively into 4 grades of bone response according to the classification criteria introduced by Zwas et al. SF location and distribution were analyzed, and in several cases, the abnormalities were correlated radiographically.

RESULTS: One hundred forty-six female recruits were examined, of which 93 (64%) had bone scan findings of SF with a total of 247 SF. Forty-eight patients (with or without SF) had shin splints, 32 had thigh splints, and 34 had normal scans. Several SF were detected in sites that were not clinically suspected. Thirty-nine percent of the SF were located in the feet (tarsal bones 22.7%, metatarsal 16.2%), 36.8% in tibiae (predominantly in the midthird), 15.7% in femurs, 6.5% in the pubic and sacroiliac regions, and 2% in the fibula. SF in the tibiae and femurs were mainly located in the posterior aspect of the medial cortical region. Forty-nine percent of the patients had bilateral SF. The SF were classified on a 4-grade scale: 41.3% were grade I, 37.2% grade II, 15.8% grade III, and 5.7% grade IV. Thirty-three percent of the patients had one site of SF, 31% had 2 sites, 7.5% had 3 sites, 12% had 4 sites, 7.5% had 5 sites, and 9% had more than 5 sites of SF. Different grades of lesions were often found in the same patient. Sixty-five percent of the patients had SF in the feet, 59% in the tibiae, 26% in the femurs, 14% in the pubic or sacroiliac regions, and 5% in the fibula. Radiography was performed in 15% of the patients. Only one patient had a positive finding on radiography.

CONCLUSIONS: This study shows that lower leg SF are not uncommon in female military recruits. We clearly distinguished between SF and shin splints, which have important clinical consequences on treatment. Most of the SF were mild (grade I and II) located in the feet and tibiae. This study supports the experience gained in other studies, and emphasizes the significant number of pubic and sacroiliac SF in female soldiers, which is significantly higher in comparison with previous reports on male soldiers.