Fig. 2From: Rapidly progressive osteoarthritis of hip: establishing and validating diagnostic criteria in the Southeast Asian populationMeasuring the changes of Tonnis angle and lateral subluxation. The Tonnis angle and lateral subluxation progressed within 9 months with radiological progression from normal (left) to type 1 (middle) and type 2 (right) RPOA. The Tonnis angle increased from 5 to 11 degrees, and lateral subluxation from 5 to 17 mmBack to article page