Abstract
Introduction
In recent years, there has been a significant advancement in our understanding of femoro-acetabular impingement and associated labral and chondral pathology. Surgeons worldwide have demonstrated the successful treatment of these lesions via arthroscopic and open techniques. The aim of this study is to validate a simple and reproducible classification system for acetabular chondral lesions.
Methods
In our classification system, the acetabulum is first divided into 6 zones as described by Ilizalithurri VM et al [Arthroscopy 24(5) 534-539]. The cartilage is then graded as 0 to 4 as follows: Grade 0 – normal articular cartilage lesions; Grade 1 softening or wave sign; Grade 2 - cleavage lesion; Grade 3 - delamination and Grade 4 –exposed bone. The site of the lesion is further typed as A, B or C based on whether the lesion is 1/3 distance from acetabular rim to cotyloid fossa, 1/3 to 2/3 distance from acetabular rim to cotyloid fossa and > 2/3 distance from acetabular rim to cotyloid fossa.
For validating the classification system, six surgeons reviewed 14 hip arthroscopy video clips. All surgeons were provided with written explanation of our classification system. Each surgeon then individually graded the cartilage lesion. A single observer then compared results for observer variability using kappa statistics.
Results
We observed a high inter-observer reliability of the classification system with a kappa coefficient of 0.89 (range 0.78 to 0.91) and high intra-observer reliability with a kappa coefficient of 0.91 (range 0.89 to 0.96).
In conclusion we have developed a simple reproducible classification system for acetabular cartilage lesions seen at hip arthroscopy.
