Radiographic classification schemes for avascular necrosis of the femoral head in the paediatric population: Critical appraisal and reliability

Abstract

Background; Avascular necrosis of the capital femoral epiphysis (AVN) is a serious complication in the treatment of developmental dysplasia of the hip (DDH). AVN of the capital femoral epiphysis can also occur in the context of other localized hip disorders such as slipped capital femoral epiphysis (SCFE) or hip trauma, and in the context of systemic disorders such as sickle cell disease, or long-term steroid use. AVN ultimately leads to premature osteoarthritis and consequently to hip replacement surgery at an early age. Hence it is important to recognize AVN early on in order to provide appropriate treatment where indicated. Several classification schemes have been established to grade AVN. They are used to stage AVN initially, to guide treatment and for the evaluation of clinical outcomes. Although in use for many years, the measurement properties of these classification schemes remain unclear. A study is needed to determine which classification schemes are currently available and their respective measurement properties. Objectives; 1.To determine what classification schemes have been developed to grade AVN of the capital femoral epiphysis secondary to DDH, SCFE, steroid intake, hip trauma or sickle cell disease. 2.To establish determine the inter- and intrarater reliability of respective classification schemes. Methods; 1.We have conducted a review of the literature to determine which classification schemes are available to radiographically grade AVN of the hip secondary to localized hip disorders or systemic disorders in patients 18 years old. 2.We have performed a critical appraisal of each of the schemes based on a clinimetric conceptual framework. 3.We have established the inter- and intrarater reliability of some radiographic classification schemes for AVN of the hip in the paediatric population, including the Bucholz and Boyer classifications. X-rays of 95 hips with diagnosed AVN on the basis of the Bucholz, Kalamchi, Boyer or Salter classification will be analysed in the intra-rater reliability part. Of these 95 hips, 48 hips will be randomized selected for the inter-rater reliability part. Outcomes; 1.Number of radiographic classification schemes to grade AVN. 2.Measurement properties of respective schemes using a clinimetric conceptual framework. 3.Inter- and intrarater reliability of Bucholz and Boyer schemes as determined by the simple kappa statistic. Specifically, we will determine the influence of training level on intrarater reliability (medical student, registrar, research fellow).

Datum der Bewilligung	2011
Originalsprache	Englisch
Gradverleihende Hochschule	Medizinische Universität Graz
Betreuer/-in	Wolfgang Linhart (Mitbetreuer*in)