A Multicenter Study of Radiographic Measures Predicting Failure of Arthroscopy in Borderline Hip Dysplasia: Beware of the Tönnis Angle
Authors
McQuivey KS, Secretov E, Domb BG, Levy BA, Krych AJ, Neville M, Hartigan DE
DOI: 10.1177/0363546520914942
Background
Hip arthroscopy is commonly used to treat mild hip dysplasia, a condition where the hip socket is slightly shallow. This study explores which preoperative radiographic measurements are most predictive of surgical failure in patients with borderline hip dysplasia.
Methods
The study analyzed radiographic measurements (like the Tönnis angle) from patients with borderline hip dysplasia who underwent hip arthroscopy. The goal was to identify which measurements were associated with poor outcomes, such as failure to achieve improvement in pain or function.
Key Findings
A higher Tönnis angle (which measures the slope of the hip socket) was linked to an increased risk of needing additional surgery. In patients with a Tönnis angle greater than 10°, the likelihood of requiring revision surgery was very high (84%).
Conclusions
The Tönnis angle is a key predictor of surgical success in borderline hip dysplasia patients. A higher angle suggests a greater risk for the need for revision surgery after hip arthroscopy.
What Does This Mean for Patients
If you have borderline hip dysplasia and are considering hip arthroscopy, your Tönnis angle is an important factor to consider. If your angle is above 10°, your risk for needing another surgery after the procedure may be higher.