军事训练致少见或罕见部位应力性骨折的回顾性分析OACSTPCD

Objective To investigate the regularity of stress fractures located at rare sites in military training.Methods Using "stress fractures or fatigue fractures" as keywords,the confirmed stress fractures in soldiers from January 2018 to May 2023 on PACS were searched,and general data(gender,age and identity),clinical data(current medical history,physical examination and clinical manifesta-tions)and imaging data(X-ray,CT and MRI images)were collected and analyzed.The images of all cases were reviewed independently by two senior imaging diagnostic physicians,and if there were any inconsistent results,a consensus was reached after consultation.Inclusion cri-teria:active military personnel;except four ordinary parts of tibia,metatarsus,femur and fibula;fractures during military training without clear trauma;treatment with rare sites as the first clinical symptom and the course of disease of 1 day to 1 year;X-ray/CT evidence of frac-tures,or MRI evidence of periosteal or bone marrow edema with or without fracture lines.Results A total of 682 cases of stress fractures were collected,of which 49 cases(7.2％)were rare stress fractures.Among the 49 cases,35 were new recruits,accounting for the highest proportion(71.4％).There were 47 males(95.9％)and 2 females(4.1％).The age range is 18-44 years,with a median age of 21 years and an average of(22.41±4.78)years.There were two cases(4.1％)with a course of ≤1 month,26 cases(53.1％)with a course of >1 month and ≤3 months,and 21 cases(42.8％)with a course of >3 months.The 49 cases were classified as follows according to the location:20 cases in the lower limbs,11 cases in the pelvis,4 cases in the lumbar spine,and 8 other cases.Among the 49 cases,24 cases were confirmed by X-ray/CT,16 cases were confirmed by MRI,and 9 cases were confirmed by CT+MRI.Common site stress fractures were observed in 11 cases,bilateral symmetry was found in 7 cases,and 8 cases of lesions involved two or more rare sites.Conclusions Stress fractures in rare sites during military training are often characterized by specific training patterns,specific site of incidence and typical imaging features,which are worthy of further research.