Stress fractures in military recruits: A prospective study for evaluation of incidence, patterns of injury and invalidments out of service.

BACKGROUND

Stress fractures (SFs) occur because of repetitive submaximal stresses to the bone over a period of time. SFs cause an economic loss to the organization and to the individuals who get invalided out of army because of SFs. This study was conducted to determine the incidence, distribution, onset of SFs, and invalidment patterns due to SFs.

METHODS

This prospective study was carried out among recruits undergoing training at training centres in a cantonment of Central India. The recruits enrolled were followed up through their training period for occurrence of SF. On occurrence of SF, the clinical features, site of bone involved, and the weeks of completed military training were noted. The SFs were graded into four grades based on clinicoradiological features and managed accordingly.

RESULTS

A total of 8974 recruits were enrolled into the study, of which 208 recruits suffered SFs. The commonest bone involved was the tibia (86.5%), commonest site being the proximal one-third of the tibia shaft (46.2%). Average week of developing SF was the 15th week of training. Seven recruits were invalided out of army because of SFs, the commonest cause being femoral neck SFs.

CONCLUSION

Prevention is the best approach for SFs. It is suggested to increase the intensity of training gradually over the first 16 weeks and recruits are to be given a training pause at around the 12th week for healing of stressed bones just before the peak time of occurrence of SFs. Femoral neck SFs are the commonest SFs responsible for invalidment of recruits.