Binary Tönnis Classification: Simplified Modification Demonstrates Better Inter- and Intra-Observer Reliability as Well as Agreement in Surgical Management of Hip Pathology
Authors
Shapira J, Chen JW, Bheem R, Rosinsky PJ, Maldonado DR, Lall AC, Domb BG
DOI: 10.1186/s12891-020-03520-x
Background
The Tönnis Classification System is used to grade the severity of hip osteoarthritis. However, it is somewhat subjective. This study tests a simplified binary version of the system for better reliability in clinical settings.
Methods
Fifty patients with hip osteoarthritis had their radiographs analyzed using both the traditional and simplified binary Tönnis classification systems. The reliability of both systems was compared by five orthopedic surgeons.
Key Findings
The simplified binary system showed much better reliability, both between different doctors (inter-observer) and when the same doctor re-evaluated the images (intra-observer). It was more consistent and easier to apply.
Conclusions
The binary Tönnis system is a more reliable and practical tool for grading hip osteoarthritis, making it a better choice for clinical use, especially when making decisions about surgery.
What Does This Mean for Patients
If you are being evaluated for hip osteoarthritis, the use of the simplified Tönnis classification may provide more accurate and consistent information about the severity of your condition, helping your doctor plan the best treatment for you.