BACKGROUND: Prior studies have identified some risk factors for stress fracture in athletes and military recruits. OBJECTIVE: To determine whether historical factors, physical measures, biochemical variables of skeletal metabolism, genetic factors, bone density (BMD) and bone size could predict risk of stress fracture over 4 years in physically fit cadets at the US Military Academy (USMA). METHODS: Baseline surveys, assessments of height, weight, scores on the Army Physical Fitness Test, and peripheral BMD were obtained in all cadets (755 men, 136 women), and central BMD in a subset. Blood samples were analyzed for variables of calcium homeostasis, bone turnover, and selected hormones and genetic factors. Stress fractures were adjudicated by review of orthopedic notes and imaging reports. RESULTS: 5.7% of male and 19.1% of female cadets had at least 1 stress fracture (58% metatarsal and 29% tibial), most within 3 months of entry to USMA. In males, risk of stress fracture was higher in those who exercised <7 h per week during the prior year (RR 2.31; CI 1.29,4.12), and in those with smaller tibial cortical area (RR 1.12; CI 1.03,1.23), lower tibial bone mineral content (RR 1.11; CI 1.03,1.20) and smaller femoral neck diameter (RR 1.35, CI 1.01, 1.81). In women, higher stress fracture risk was seen in those with shorter time since menarche (RR 1.44 per year; CI 1.19, 1.73) and smaller femoral neck diameter (RR 1.16; CI 1.01, 1.33.). CONCLUSION: Although prior physical training in men, length of prior estrogen exposure in women and leg bone dimensions in both genders played a role, the maximum variance explained by all of these factors was below 10%. We conclude these factors play a minor role in the development of stress fractures in physically fit USMA cadets.
BACKGROUND: Prior studies have identified some risk factors for stress fracture in athletes and military recruits. OBJECTIVE: To determine whether historical factors, physical measures, biochemical variables of skeletal metabolism, genetic factors, bone density (BMD) and bone size could predict risk of stress fracture over 4 years in physically fit cadets at the US Military Academy (USMA). METHODS: Baseline surveys, assessments of height, weight, scores on the Army Physical Fitness Test, and peripheral BMD were obtained in all cadets (755 men, 136 women), and central BMD in a subset. Blood samples were analyzed for variables of calcium homeostasis, bone turnover, and selected hormones and genetic factors. Stress fractures were adjudicated by review of orthopedic notes and imaging reports. RESULTS: 5.7% of male and 19.1% of female cadets had at least 1 stress fracture (58% metatarsal and 29% tibial), most within 3 months of entry to USMA. In males, risk of stress fracture was higher in those who exercised <7 h per week during the prior year (RR 2.31; CI 1.29,4.12), and in those with smaller tibial cortical area (RR 1.12; CI 1.03,1.23), lower tibial bone mineral content (RR 1.11; CI 1.03,1.20) and smaller femoral neck diameter (RR 1.35, CI 1.01, 1.81). In women, higher stress fracture risk was seen in those with shorter time since menarche (RR 1.44 per year; CI 1.19, 1.73) and smaller femoral neck diameter (RR 1.16; CI 1.01, 1.33.). CONCLUSION: Although prior physical training in men, length of prior estrogen exposure in women and leg bone dimensions in both genders played a role, the maximum variance explained by all of these factors was below 10%. We conclude these factors play a minor role in the development of stress fractures in physically fit USMA cadets.
Authors: Patrick G Robinson; Victoria Bd Campbell; Andrew D Murray; Alastair Nicol; James Robson Journal: Br J Gen Pract Date: 2019-04 Impact factor: 5.386
Authors: C M Weaver; C M Gordon; K F Janz; H J Kalkwarf; J M Lappe; R Lewis; M O'Karma; T C Wallace; B S Zemel Journal: Osteoporos Int Date: 2016-02-08 Impact factor: 4.507
Authors: Tim Hoenig; Kathryn E Ackerman; Belinda R Beck; Mary L Bouxsein; David B Burr; Karsten Hollander; Kristin L Popp; Tim Rolvien; Adam S Tenforde; Stuart J Warden Journal: Nat Rev Dis Primers Date: 2022-04-28 Impact factor: 52.329
Authors: T Davey; S A Lanham-New; A M Shaw; B Hale; R Cobley; J L Berry; M Roch; A J Allsopp; J L Fallowfield Journal: Osteoporos Int Date: 2015-07-10 Impact factor: 4.507
Authors: Sara E Rudolph; Signe Caksa; Sarah Gehman; Margaret Garrahan; Julie M Hughes; Adam S Tenforde; Kathryn E Ackerman; Mary L Bouxsein; Kristin L Popp Journal: Med Sci Sports Exerc Date: 2021-10-01