Evaluation of Femoral Head Necrosis Using a Volumetric Method Based on MRI
Abstract
Most studies agree that the fate of femoral head osteonecrosis is associated with the size and location of the necrotic lesion. Most recent studies agree that osteonecrosis assessment should be based on magnetic resonance imaging (MRI) that reveals the 3D distribution of the lesion and is more sensitive than other techniques (e.g., radiographs) at the early stages of the disease. The authors present a volumetric method for assessing osteonecrosis based on MRI. The method evaluates the percentage of the necrotic volume in the femoral head and in each of the head segments (octants). A major problem in the estimation of the necrotic percentage is the definition of the anatomical limits of the head. The authors used the sphere equivalent concept to resolve this problem. The sphere equivalent of the femoral head is the sphere with the smallest radius that encloses the head. Along with the method, the authors present a classification system based on the geometrical features of the lesion. This system was used to classify 106 hips with osteonecrosis before treatment with vascularized fibular grafting. The followup study indicates that the fate of the disease is associated with the size and distribution of the lesion. The method, in combination with the proposed classification system, can be a useful tool for the orthopedist in the diagnosis, treatment, prognosis, and outcome evaluation of femoral head necrosis. Future work should focus on improving the lesion detection and on automatic detection of the head circle, reducing the effort required from the human operator.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 25, 2001
- Accession Number
- ADA410855
Entities
People
- A. Bassounas
- D. I. Fotiadis
- K. N. Malizos
Organizations
- University of Ioannina