The Effect of a Femoral Fracture Sustained before Skeletal Maturity on Bone Mineral Density: A Long-Term Follow-Up Study

Background and Purpose. The possible effect of pediatric femoral fractures on the bone mineral density (BMD) is largely unknown. We conducted a study to investigate BMD in adults who had sustained a femoral shaft fracture in childhood treated with skeletal traction. Materials and Methods. Forty-four adults, who had had a femoral fracture before skeletal maturity, were reexamined on average 21 (range 11.4) years after treatment. Our follow-up study included a questionnaire, a clinical examination, length and angle measurements of the lower extremities from follow-up radiographs, and a DEXA examination with regional BMD values obtained for both legs separately. Results. At follow-up femoral varus-valgus and ante-/recurvatum angles were slightly larger in the injured lower-limb compared to the contralateral limb. The mean BMD of the entire injured lower-limb was lower than that of the noninjured (1.323？g/cm2 versus 1.346？g/cm2, ). Duration of traction was the only factor in multiple linear regression analysis that was positively correlated with the BMD discrepancy between the injured and noninjured lower-limb explaining about 17% of its variation. Conclusion. The effect of a femoral fracture sustained during growth is small even in patients treated with traction. 1. Introduction Decreased bone mineral density (BMD) has been diagnosed in adults as sequel of immobilisation and reduced weight bearing in the injured limb [1]. Henderson et al. [2] have reported a decreased BMD in proximal femur two years after tibial and femoral fractures in children that were immobilised for eight weeks or longer. Ferrari et al. [3] have found an association between a childhood fracture and low BMD in adulthood suggesting low peak bone mass and persistent bone fragility. We studied long-term effects of pediatric femoral shaft fractures treated with skeletal traction on BMD. 2. Materials and Methods Sixty-two pediatric patients (<16 years old, all Scandinavian Caucasian) that had sustained a femoral fracture were treated with skeletal traction (in a hospital bed) in Aurora Hospital, Helsinki, during 1980–1989. The most common injury type was a motor-vehicle accident. Patient files and primary radiographs of these patients were analysed. A questionnaire about subjective treatment results as well as an invitation to participate in a follow-up examination (mean 21, range 11.4, standard deviation (SD) 2.8 years) was mailed to all patients [4]. Fifty-two of the patients agreed to participate. They all gave written informed consent approved by the local Ethics Committee of the