engleski

Combined, novel management of bilateral varus hip deformity using “Eight-plate” in children with spondyloepiphyseal dysplasia congenita

Background Spondyloepiphysal dysplasia congenita (SEDc) is a rare autosomal dominant genetic disorder characterized with collagen dysfunction. The major feature of SEDc is the femoral head ossification delay and the proximal femur varus deformity i.e. coxa vara (CV). Accepted treatment is valgus hip osteotomy, indicated due to progressive natural history of the proximal femur varus deformity and subsequent early osteoarthritis. Data on the hip surgery in SEDc are scarce. The aim of this paper is to present the results of individualized temporo- spatial surgical approach in 8 hips (4 patients) and highlight the novel application of the guided growth principle. Objectives The purpose of this study is to determine whether a minimally invasive method using an “Eight- plate”, applied early to greater trochanter apophysis in SEDc patients with bilateral CV, could reduce the need for more aggressive surgery. Design and Methods In our database from 2006 to 2020, there were 6 SEDc patients. Charts and radiographic review were performed. Four patients (3 females) at the age of 4 to 14 years, had surgery at 8 hips. Two patients (4 hips) were not surgically treated due to parents’ refusal and those hips served as controls. The indication for surgical treatment was a progressive CV deformity i.e. decreasing neck-shaft angle (NSA), pain, limited hip abduction, gait disturbances. In 1 patient (age 9.5 years), the surgical treatment was proximal femur valgus osteotomy while in 3 female patients 4, 6 and 7 years of age, a novel approach i.e. guided growth principle with a greater trochanter apo-physiodesis using “Eight-plate” was applied. Patients were evaluated clinically at the last follow-up visit. Radiological measurement included NSA as a measure of mechanical aspect, and Hilgenreiner-trochanteric angle (HTA) as a measure of CV’s biological domain (HTA is physis angle as a measure of weak femoral head growth plate). Measurements were made before surgery and at the final follow-up. Difference was calculated. Results SEDc was diagnosed based on phenotype evaluation, clinical and radiological measurements in 4 patients, while in 2 patients genetic analysis showed mutation of a COL2A1 gene. The follow up period after initial surgery was from 3 to 14 years. Out of 4 operated patients in 1 patient after greater trochanter apo-physiodesis with "Eight-plate”, a progressive nature of CV has been stopped, (NSA 118º to 128 º ; HTA 8º to -2º). In the second patient treated with an “Eight-plate” apo-physiodesis of a greater trochanter at an age of 4 there was evidence of NSA improvement. However, a second surgery is pending due to small size of implants. In the third patient, the “Eight-plate” did not produce a good result and valgus osteotomy was done, (NSA 106º to 152º ; HTA -8º to 21º). Two patients needed additional surgery. Although operated for second time, both patients were asymptomatic: the first after “Eight-plate” greater trochanter apo-physiodesis at 5 years follow- up, and the second after 2 valgus osteotomies at 12 years follow-up. Interestingly, last patient won disc-throw medal on 2016 Paralympic Games, in his category. Overall, our results showed improved clinical and numerical parameters in comparison with natural history of the controls. Conclusion SEDc is a rare disease that has severe effect on the hip biomechanics. According to our limited experience, we believe that guided growth principle in patients with SEDc and CV could be utilized as the first line of defence when two prerequisites are fulfilled: 1. age of patient is less than 8 years ; 2. NSA is not less than 115º and HTA is around 8º. If the patient does not fit to those criteria, a full knowledge of valgus hip osteotomy is needed.

Spondyloepiphysal dysplasia congenita, hip, guided growth, surgery

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