Table 6.

Probability of THA based on combinations of predictors from multivariate analysis

Age at arthroscopy (years)	Femoral head Outerbridge grade	Acetabular Outerbridge grade	Probability of THA (%)	95% Confidence interval
40 or younger	0–II	0–II	10	5–22
40 or younger	0–II	III–IV	70	40–90
40 or younger	III–IV	0–II	88	47–98
40 or younger	III–IV	III–IV	99	93–99
Older than 40	0–II	0–II	30	15–50
Older than 40	0–II	III–IV	90	70–97
Older than 40	III–IV	0–II	96	74–99
Older than 40	III–IV	III–IV	99	98–100