Abstract
Purpose
To compare the early medial open approach (MO) with the anterior approach (AO) performed after the appearance of the ossific nucleus for DDH that has failed closed reduction or presented late.
Methods
We present the experience of 2 UK surgeons with prospectively gathered data for MO (26 hips) compared with that of a third surgeon in the same unit for the AO (21 hips) in 41 children under 24 months of age at index surgery. Femoral head osteonecrosis (FHO) risk was predicted using the height-to-width index of Bruce et al, measured at 12–18 months post reduction, and graded with the Kalamchi and MacEwen classification where follow-up exceeded 3 years. Acetabular index (AI) was measured at or close to 2 years post reduction.
Results
Age at time of surgery averaged 11.2 months (3.1–24) for the MO group and 17.8 months (12–24) for the AO group. Average follow-up was 4.3 years (13 months to 12 years). FHO was evident or strongly predicted in 2/26 hips (7.7%) in the MO group and 2/21 (9.5%) in the AO group. AI improved by 8.8° (4–12°) and 7.9° (6–10°) respectively at 2 years post reduction (p>0.05). One case of early recurrent dislocation in the MO group required revision surgery via an anterior approach. The height to width index cut-off value of 0.357 at 12–18 months post reduction accurately predicted FHO risk in cases with longer follow-up.
Conclusions
The medial open approach was not associated with a higher risk of FHO compared to a protocol of waiting for the appearance of the ossific nucleus before proceeding to reduction via an anterior approach. There was no significant difference in acetabular remodeling in the first two postoperative years between the protocols despite earlier reduction in the MO group.
