Femoral shaft fractures in children and adolescents; stability, residual deformity and recovery of physical function

Abstract: Femoral shaft fracture is the most common injury requiring hospital admission among children. The limited number of studies makes it challenging to provide accurate prognosis for recovery after femoral shaft fractures in children and adolescents. Aim: The overall aim of this thesis was to analyse different aspects of femoral shaft fractures in children and adolescents in terms of fracture stability after treatment and presence of residual leg length discrepancy (LLD). Another aim was to study recovery of gait and physical function, and to explore the prevalence of kinesiophobia (fear of movement) and its potential influence on recovery. Methods: The thesis is based on a descriptive approach involving multiple methods. In a biomechanical study, stability was assessed in a synthetic femur model with either two or four elastic intramedullary nails (ESINs) or a Pediatric Locking Nail (PLN). In a retrospective cohort study on adults treated with ESINs during childhood, radiographs were performed for measurement of LLD. A questionnaire regarding perception of LLD was completed. In two prospective longitudinal studies, patients 6–16 years of age with a femoral shaft fracture, treated with intramedullary nails (IMNs), were included. At 6 and 12 weeks, assessments of mobilisation and weight-bearing were performed at clinical follow-ups. At 3, 6, 9 and 12 months, physical examinations of range of motion and physical performance tests (PPTs), including three-dimensional gait analysis, were performed. Patient-reported outcome measures on physical function, kinesiophobia, and catastrophic thoughts were completed at the time of fracture and at follow-up. Results: The biomechanical study showed that a PLN provided greater stability than ESINs, though the difference compared with 2x4.0-mm or 4x3.0-mm ESINs was small. The retrospective cohort study showed that 11 of 35 participants had an LLD of > 10 mm and 24 had an LLD ≤ 10 mm. Fourteen (40%) had perception of LLD at follow-up, of whom eight had a radiographic LLD of 10–24 mm. The prospective longitudinal studies showed that 88% used walking aids at six weeks, and 25% did at twelve weeks. At 3 months, three patients walked slowly and had clear deviations in gait pattern. Gait pattern had normalised in all but one patient at 6 months, and in the remaining patient at 9 months. Seven out of the 17 patients were recovered, meaning that they could accomplish all PPTs at the 12-month follow-up without signs of limb asymmetry. Kinesiophobia was noted in seven patients at the time of injury, two at 3 months, and none at 12 months. Six patients with kinesiophobia reported a reduced activity level at 3 months. Conclusions: The PLN was found to be a more stable construct than ESINs. Treatment with ESINs after femoral shaft fracture in childhood resulted in residual LLD in some patients. Improvements in basic performance tests were observed in the early recovery period, and gait pattern was normalised at the 6-month follow-up among children and adolescents treated with IMNs. Ten of 17 patients treated with IMNs did not recover within 12 months. Kinesiophobia was only observed at the time of injury and had resolved by the 12-month follow-up.