The American College of Rheumatology (ACR) developed clinical criteria for the diagnosis of osteoarthritis involving the hip. The criteria can be represented in either classification tree or traditional formats.
Clinical criteria using the classification tree format (Table 4, page 511): hip pain AND one of the following
(1) hip internal rotation < 15° AND ESR <= 45 mm/h
(2) hip internal rotation >= 15° AND pain on hip with internal rotation AND morning stiffness of the hip <= 60 minutes AND age > 50 years
where:
• If the ESR is not available, then substitute hip flexion <= 115°
Combined clinical and radiographic criteria using the traditional format (Table 5, page 511): both of the following:
(1) presence of hip pain, AND
(2) 2 or 3 of the following
(2a) ESR < 20 mm/h
(2b) radiographic demonstration of femoral and/or acetabular osteophytes
(2c) radiographic joint space narrowing (superior, axial and/or medial)
Combined clinical and radiographic criteria using the classification tree format (Table 6, page 512): hip pain AND one of the following
(1) radiographic demonstration of femoral and/or acetabular osteophytes
(2) ESR < 20 mm/h AND radiographic axial joint space narrowing
where:
• Table 6 gives the ESR <= 20 mm/h but the data in Table 2 states < 20 mm/h.
Performance of criteria:
• Classification tree: 86% sensitive, 75% specific
• Traditional format: 89% sensitive, 91% specific
• Combined format: 91% sensitive, 89% specific
