Clinical value of grading the scintigraphic appearances of tibial stress fractures in military recruits

Purpose: This study evaluated the relation between the scintigraphic appearances of tibial stress fracture in military recruits and the likelihood that they would complete basic military training. Materials and Methods: The authors retrospectively reviewed 58 Tc-99m MDP scans of recruits referred for possible tibial stress fracture and graded them according to the criteria of Zwas et al. (1987). Stress fracture appearances were correlated with clinical information such as the duration of rehabilitation and final outcome with regard to completion of the initial basic military training program. Results: Thirty-seven of the 58 patients (64%) had tibia[ stress fractures, all of which were located in the tibial diaphysis, with most occurring in the middle and lower thirds. Most (23 of 37) patients had stress fractures of grade I or II, and the others had grade III or IV stress fractures. There was no statistical difference in the proportion of patients with bilateral fractures between grades I-II and III-IV. There was no significant difference in the duration of rehabilitation for recruits successfully recovering from grade III-IV fractures compared with grade I-II fracture. There was a greater proportion of patients with lower grade fractures than higher grade fractures (P = 0.0006) who, despite rehabilitation, could not continue training because of unremitting or recurring pain at the fracture site and were medically discharged from military service. Conclusions: Contrary to expectation, recruits with higher-grade stress fractures were not less likely to complete basic military training compared with recruits with lower grade stress fractures.