Comparison of core decompression and conservative treatment for avascular necrosis of femoral head at early stage: a meta-analysis.

The purpose of the current meta-analysis was to compare the efficacy of core decompression (CD) and conservative treatment (CT) for saving femoral heads in patients with avascular necrosis of femoral head (ANFH). Four RCTs and two CCTs involving 323 hips with 24- to 48-months follow-up were included in this review. Our results suggested CD had a trend of favorable results in contrast to other CT (OR 3.28; 95% CI 0.77-14.02; P = 0.11) but saved much less hips compared to biophysical treatments [odds ratio (OR) 0.37; 95% CI 0.18-0.74; P = 0.005]. In the stratified survival rate analysis by ANFH stage, interestingly, CD group got a significantly higher successful rate of hip joint conservation than other CT group in both stage I and stage II-III (stage I: OR 4.43; 95% CI 1.34-14.65; P = 0.01; stage II-III: OR 6.75; 95% CI 2.18-20.90; P = 0.0009). In the biophysical stimulation subgroup, however, an even higher frequency of survived hips were observed compared to CD group at stage II-III (CD vs. biophysical stimulation: OR 0.34; 95% CI 0.17-0.67; P = 0.002). In conclusion, performing CD for ANFH is effective for preventing femoral collapse within a short-term follow-up, but an even higher successful rate were expected by biophysical stimulations. Nevertheless, the short-term follow-up, the small sample size of the current meta-analysis only provide limited quality of evidence, which required confirmation from further large-scale, well-designed RCT with longer follow-up.