Background: Hip dysplasia leads to abnormal loading of articular
cartilage, which results in osteoarthritis. Pelvic osteotomies such as the
Bernese periacetabular osteotomy can improve the mechanics of the joint, but
the results are variable and appear to depend on the amount of preexisting
arthritis. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage
(dGEMRIC) is a technique designed to measure early arthritis, and it
potentially could be used to select hips with too severe arthritis to benefit
from a joint-preserving reconstructive procedure. The purpose of our study was
to identify radiographic, clinical, and magnetic resonance imaging
measurements that predict failure after pelvic osteotomy.
Methods: We performed a cohort study of forty-seven patients
undergoing a Bernese periacetabular osteotomy for the treatment of hip
dysplasia. Our goal was to identify preoperative radiographic factors, such as
the grade of arthritis, joint congruency, and the dGEMRIC index, that are
associated with a poor outcome after osteotomy.
Results: Hips in which the osteotomy did not fail had a significant
decrease in pain compared with their status preoperatively (p < 0.0001).
Hips in which the osteotomy did fail had had significantly more arthritis on
preoperative radiographs (as demonstrated by the joint space width and the
Tönnis grade [p = 0.01]), more subluxation (p = 0.02), and a lower
dGEMRIC index (p < 0.001) than the hips in which the osteotomy did not
fail. Multivariate analysis identified the dGEMRIC index as the most important
predictor of failure of the osteotomy.
Conclusions: Bernese periacetabular osteotomy for the treatment of
hip dysplasia can decrease pain and improve function in symptomatic dysplastic
hips. The dGEMRIC index, as an early measure of osteoarthritis, appears to be
useful for identifying poor candidates for a pelvic osteotomy.
Level of Evidence: Prognostic Level II. See Instructions
to Authors for a complete description of levels of evidence.