Region 1 |
Heterotopic ossifications strictly below tip of greater trochanter |
Region 2 |
Heterotopic ossifications below and above tip of greater trochanter |
Region 3 |
Heterotopic ossifications strictly above tip of greater trochanter |
Grade A |
Single or multiple heterotopic ossifications < 10 mm in maximal extent without contact with pelvis or femur |
Grade B |
Heterotopic ossifications > 10 mm without contact with pelvis but with possible contact with femur; no bridging from femur to proximal part of greater trochanter, with no evidence of ankylosis |
Grade C |
Ankylosis by means of firm bridging from femur to pelvis |