Rapid remineralization of the distal radius after forearm fracture in children.

BACKGROUND: Bone mineral content (BMC) and density (BMD) have been shown to diminish after fracture and immobilization in adults. Distal radius fractures are common in children, and unlike adults, there is a low incidence of refracture. The primary aim of this study was to assess the change in radial BMC and BMD after upper extremity fracture and casting in healthy pediatric patients. METHODS: Patients were recruited at the time of distal radius fractures casting. The nonfractured (non-Fx) distal radius was initially scanned by dual energy x-ray absorptiometry (baseline), and then both arms were scanned at the time of cast removal (CastOff), and 4, 8, 12, 24, and 52 weeks post CastOff. RESULTS: Twenty-one patients were enrolled (13 male, 13 Caucasian; 10.4±2.5 y) with an average length of casting of 38±11 days. Eighteen patients (86%) completed all protocol requirements. At CastOff, there was no significant difference in total BMC or BMD between the Fx and non-Fx arms. From CastOff to 24 weeks, the overall change in BMC and BMD for the non-Fx arm was +4.2% and +0.2%, respectively, whereas for the Fx arm, the change was +8.3% and +3.4%, respectively. By 24 weeks, the difference in the overall change in BMD between the Fx and non-Fx arms was statistically significant (greater than instrumental error; P<0.05). However, by 52 weeks, these differences were no longer significant. The increased mineralization was unrelated to age, sex, arm dominance, or calcium intake. CONCLUSIONS: These data show that there is rapid remineralization after a simple forearm fracture in children, with a transient elevation in BMD in the Fx arm after casting. This novel finding suggests that bone may be stronger around the site of fracture and could significantly change how we counsel young patients recovering from forearm fracture. Future research should focus on children immobilized for varying lengths of time and those with repeat fractures, using volumetric techniques of bone geometry and strength assessment. CASE SERIES: Therapeutic Studies-investigating the results of treatment, Level IV.

Retention of flexible intramedullary nails following treatment of pediatric femur fractures.

INTRODUCTION: Flexible intramedullary nails are commonly used for the treatment of diaphyseal femur fractures in children. Although, their removal after fracture healing is advocated by some, there are no definitive studies to support the routine removal of these implants. The purpose of this study is to determine the natural history of children with diaphyseal fractures of the femur treated with flexible intramedullary nails and no scheduled nail removal. MATERIAL AND METHODS: We performed a retrospective case series of 24 consecutive children treated at our tertiary pediatric referral center for closed diaphyseal femur fractures. All children had intramedullary fixation with flexible titanium nails. The main outcomes measured are fracture healing, incidence of hardware removal, and pain assessment with the use of a follow-up telephone questionnaire. RESULTS: All the patients healed their fractures. The average follow-up time was 3.6 years. A total of six patients had removal of nails for any reason at an average of 15 months post-injury. The survivorship free of revision due to persistent pain was 72% at 5 years of follow-up. Twenty-two patients were reached by phone for a final follow-up questionnaire. There was no difference in reports of residual symptoms of pain among those who did have nails removed and those who did not (P = 0.626). CONCLUSIONS: Among children with femur fractures treated with flexible intramedullary nailing without scheduled implant removal, about a quarter may ultimately require a second procedure for nail removal due to persistent discomfort. Moreover, up to half of patients can have residual non-debilitating pain at 2-5 years post-injury regardless of presence or absence of the implant. Whether this is a previously unrecognized adverse outcome of this injury or treatment approach, or due to routinely leaving nails in will have to be assessed in future controlled trials.