The effectiveness of different minimally invasive epiphysiodesis techniques in the management of paediatric leg length discrepancies: a systematic review

Abstract

Paediatric leg length discrepancies (LLDs) are more common than might be expected with the literature reporting that between 0.1 and 7% of the paediatric population has a LLD of >2 cm. Causes can be subdivided into congenital and acquired aetiologies. LLDs greater than 2 cm can lead to functional complications such as altered gait kinetics and abnormal loading of joints. For children predicted to have a LLD of 2-5 cm, minimally invasive epiphysiodesis (MIE) is the current management of choice. Presently, there are four MIE techniques commonly used throughout the world, however, no systematic reviews have compared these techniques. The objective of this thesis was to conduct a systematic review to synthesise the best available evidence on the use of MIE for the management of paediatric LLD. The effectiveness of four different techniques was compared: percutaneous epiphysiodesis using transphyseal screws (PETS); physeal drilling and curettage (PDC); physeal stapling; and guided growth with eight-Plates. Studies that evaluated two or more of the interventions or those that investigated a single intervention were considered for inclusion. Primary outcomes for the review included absolute LLD at skeletal maturity; rate of correction; percentage of correction; and incidence of long term complications. This review found that all techniques were sufficient at reducing the burden of a LLD with the mean final LLD of each being calculated to be <2 cm. Despite this, the rate of complications was higher in the eight-Plates and staples groups than the PDC and PETS groups. The PETS cohort had a reported failure of growth plate arrest (GPA) of 2.5% compared with 6% in the PDC and staples groups and 14% in the eight-Plate groups. The rate of inadequate correction (i.e. over or under correction), were also higher in the eight-Plate and staples groups (15% and 23%, respectively) than the PETS and PDC groups (8% and 13%, respectively). The incidence of angular deformities was much higher in the staples cohort (33%) than in the other groups (PDC 2%; PETS 9%; and eight-Plates 5%). The incidence of acute complications, such as haematoma, infection and acute knee pain, was similar across all techniques. Unfortunately, the overall level of evidence was low, due to the suboptimal and heterogeneous nature of the study designs included in this systematic review, and thus, treatment guidelines could not be developed. Notwithstanding this, the available evidence showed that all the evaluated techniques can adequately reduce a LLD, although PDC and PETS appear to be more effective at this. Further research is required to substantiate these claims; for now, all techniques remain an acceptable technique for addressing LLDs of 2-5 cm.