Abstract
Aim
To establish the incidence of clinically significant avascular necrosis (AVN) and the resultant influence on radiological outcome following medial open reduction for DDH.
Method
A systematic review of the literature was performed using Medline and Embase, from 1946 to 2012, to identify all relevant clinical studies. We excluded papers with a mean follow-up under 5 years. The effect of length of follow-up, outcome according to Severin, age at surgery, and type of growth disturbance were reviewed.
Results
2439 citations were identified. 17 papers reporting 734 hips met the inclusion criteria. These were submitted for data extraction. Mean follow-up was 10.9 years (2–28 years). The rate of clinically significant AVN (types 2–4) was 20%. From these papers 221 hips had sufficient information to permit more detailed analysis. The AVN incidence increased with follow-up to 24% at skeletal maturity. Type 2 AVN predominated after 5 years follow-up. The presence of AVN resulted in a higher incidence of unsatisfactory outcome (55% vs 20% in hips without AVN, p <0.01). There was a greater rate of AVN when surgery was performed under 12 months of age (22.5% vs 12.9% >12 months, p 0.022). However, more subsequent surgery was performed in the older group (18.3% vs 35.6%, p 0.004).
Conclusion
Medial open reduction is associated with a 24% incidence of AVN at skeletal maturity. The rate of AVN increases with longer follow-up with type 2 predominating. AVN results in a significantly higher rate of unsatisfactory outcomes. When surgery is performed under 12 months of age the rate of AVN is higher, however the overall need for subsequent surgery is less.
