title: Does the crack silently break the back? Long-term follow-up and assessment of risk factors for regional osteoporosis following tibial shaft fractures.
abstract: The aim of this study is to determine the incidence and to quantify the risk factors for developing long-term regional osteopenia/osteoporosis (RO) following tibial fractures. We studied 42 adult subjects (8 females and 34 males) who had sustained a tibial fracture 16 yr prior to the study. Mechanism and type of injury, method of treatment, length of immobilization, weight-bearing status, and healing time were determined from the patient records. A questionnaire covering known causes of generalized osteoporosis (GO), including history of smoking, alcohol consumption, medications, other fractures, thyroid/parathyroid disorders, epilepsy, and renal disorders, was answered by all the subjects. Bone mineral density (BMD) of lumbar vertebrae 1-4 and both proximal femurs was assessed using dual-energy X-ray absorptiometry (DXA) scanning. T- and Z-scores were generated. Assessment of risk factors was done by calculating the odds ratio (OR) and 95% confidence interval (CI). The incidence of significant loss of BMD as defined by the World Health Organization (T-score <-1) of the ipsilateral neck of femur and/or lumbar spine was found to be 40%. None of our subjects had any known cause for GO. The following risk factors were found to be statistically significant in unadjusted models: smoking (OR 22, 95% CI = 4 - >40), alcohol >20 units/wk (OR 11, 95% CI 2 = 2-54), open fracture (OR 17, 95% CI = 2.9 - >40), nonweight bearing >4 wk (OR 15, 95% CI 2.9- >40), and delayed union defined as healing time more than 6 mo (OR 15, 95% CI 1.54 - >40). Permanent regional loss of BMD occurs in a significant proportion of tibial shaft fracture patients. Modern fracture management should include identifying "at-risk" patients and appropriate preventive measures to prevent fragility fractures.
authors.affiliation: Mid-Western Regional Orthopaedic Hospital, Croom, Limerick, Irel, Limerick, Ireland. Khalidbones@hotmail.com
authors.forename: Mohamed
authors.initials: M
authors.lastname: Khalid
authors.forename: Gregory
authors.initials: G
authors.lastname: Heffernan
authors.forename: Ann
authors.initials: A
authors.lastname: Brannigan
authors.forename: Thomas
authors.initials: T
authors.lastname: Burke
authors.forename: Pierce
authors.initials: P
authors.lastname: Grace
authors.forename: Declan
authors.initials: D
authors.lastname: Lyons
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D015519:Bone Density; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D016017:Odds Ratio; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D013978:Tibial Fractures / Q000150:complications* / Q000000981:diagnostic imaging / Q000453:epidemiology; D013997:Time Factors