Example 2: Yesterday I received another female patient (71 years) who was treated by me 3 months ago for left sided OA hip. This patient has developed similar features on the Rt side of her hip. My examination revealed typical capsular pattern.
Now the question is can we predict the outcome of the other hip if one of the hip is affected by OA? Vossinaskis IC et al has the same question. They examined the anteroposterior radiographs of the pelvis of 95 white patients with unilateral idiopathic (56 patients) or secondary to congenital hip diseases (39 patients) OA. The other hip was free from symptoms (pain or limping) at the initial examination and without radiographic evidence of OA; it was what we call a "normal" hip.
They evaluated 2 parameters:
a. the type of osteoarthritis of the involved hip and
b. the range of four radiographic indices of the contralateral hip:
1) The weight-bearing surface,
2) The acetabular angle,
3) The Wiberg's center-edge angle, and
4) The neck-shaft angle.
The conclusions drawn from this study are as follows:
1. Patient with idiopathic OA of one hip is at increased risk of developing OA in the other hip.
2. The outcome of the other hip cannot be predicted only on the basis of the evaluation of its radiographic indices.
3. Among the different indices, weight-bearing surface seems to have a strong influence toward the development of OA.
For researchers: for this type of study involving predictive question, regression analysis is used. This group of researchers has used a special technique called Logistic regression analysis. Logistic regression analysis showed that the presence of idiopathic OA in one hip had a statistically significant effect on the development of OA on the other hip (p <>