[Comparison of Two Methods of Minimally Invasive Osteosynthesis for Proximal Radius Fractures in Paediatric Patients]

PURPOSE OF THE STUDY The presented study was construed as a retrospective multicentric clinical study focused on paediatric skeletal injuries of the proximal radius. As a general rule, the Type I displaced fractures (Judet classification) are treated conservatively, with no reduction. In the case of Type II-IV displacement, the fracture necessitates reduction or is also transfixed by a Kirschner wire (K-wire) or a Prevot nail (P-nail) where subsequent fragment instability occurs. The comparison aimed to ascertain whether there is a statistically significant difference between the two methods. No difference was expected by the authors, therefore a null hypothesis was set. MATERIAL AND METHODS The patients were treated at the Clinic of Paediatric Surgery, Orthopaedics and Traumatology (CPSOT) of the Faculty of Medicine of the Masaryk University and at the Clinic of Orthopaedics and Traumatology of the Musculoskeletal System of the University Hospital in Pilsen in the period from 2006 to 2015. Two methods of closed reduction and minimally- invasive osteosynthesis were evaluated. The first method was the elastic stable intramedullary nailing (ESIN) with a P-nail, the second method was an osteosynthesis using a K-wire. In the clinical part of the study, comparisons were made based on the monitoring of the same parameters - final restriction of movement, time to full weight bearing of the extremity and incidence of serious complications. RESULTS The final group comprised a total of 31 patients, of whom 7 boys and 24 girls aged 3-16 years with the median of 9-10 years. Some restriction of movement following the treatment occurred in a total of seven patients (44%) with the K-wire and in four patients (27%) with the P-nail. When comparing the movement at 5% level of significance using the Chi-Square tests, no significant difference was found (p = 0.446). When evaluating the serious complications at 5% level of significance using the Chi-Square tests, the difference between the two methods of treatment was again insignificant (p = 0.365). When the full weight bearing was compared (median K-wire 8 weeks, median P-nail 10 weeks), a statistically significant difference was obtained at 5% level of significance using the Fischer exact test (p = 0.003). DISCUSSION In these fractures, usually the metaphysis or the physis are involved in the injury, in which case the fractures are classified according to Salter and Harris, with the most frequent occurrence of SHII epiphyseal separation and rare SHIII and SHIV epiphyseal fractures. The radial head fractures are mostly caused by valgus force. Therefore, the individuals with a higher elbow valgosity are more prone to injuries. The girls strongly prevail (77%) also in our study. In general, our results as well as the literature have proven that as the displacement increases, the necessity of closed reduction and osteosynthesis grows. The post-treatment complications in our group were observed in 35.5% of patients, namely most often in the form of limited movement. The literature refers to complications in 26.5-53% of patients. CONCLUSIONS The clinical results clearly show that when comparing the complications after the radial head fracture in children there is no statistically significant difference between the methods of osteosynthesis. This study shall serve as a starting point for the currently ongoing prospective multicentric study evaluating the modified ESIN technique using a pre-bent Kirschner wire. Key words:children, fracture, radius, proximal, osteosynthesis.