Femoral Head Core Decompression and Bone Marrow Concentrate Injection in Pediatric Sickle-cell Related Avascular Necrosis

Abstract

Background: Femoral head avascular necrosis affects 10% to 40% of patients with sickle cell disease (SCD). The purpose of this study was to evaluate the results of femoral head core decompression and bone marrow aspirate concentrate (CD-BMAC) injection in pediatric patients with SCD.

Methods: Eligible patients were enrolled in this retrospective study of patients undergoing CD-BMAC. Patients with SCD who were younger than 18 at the time of surgery and had >1 year of follow-up were included in this analysis. Hips were staged based on the Ficat system by 2 raters. The visual analog score for pain, hip outcome score, modified Harris hip score, and the University of California, Los Angeles activity score were used as patient-reported outcome measures preoperatively, at 5 to 9 months postoperatively, and final follow-up. Treatment failure was defined as total hip arthroplasty or visual analog score >3 at the final follow-up.

Results: Twenty-three hips in 17 patients were included, with a median age at the time of surgery of 15.8 years (interquartile range: 13.1 to 17.8 y). Patients were followed for 4.25 ± 1.7 years. Ten hips showed a 1-stage increase in the Ficat stage at the final follow-up, whereas 11 retained the same stage, and 1 hip had a 1-stage regression. All patient-reported outcome measures showed significant improvement from the preoperative visit to short-term follow-up, but the preoperative to final follow-up improvement was not significant. Six treatment failures were recorded, including 3 total hip arthroplasties and 3 painful hips at the final follow-up. In a multivariate logistic regression model, only skeletal maturity (odds ratio = 16.2, 95% CI: 1.44-183.0, P = 0.024) and femoral head collapse (odds ratio = 12.0, 95% CI: 1.1-130.5, P = 0.041) were significant predictors of treatment failure.

Conclusions: In the largest study on pediatric SCD patients undergoing CD-BMAC, we found that CD-BMAC injection offers significant improvement in pain and functional outcomes in the short term, with a very low risk for complications. Skeletal maturity and femoral head collapse were significant predictors of treatment failure. Patients with a collapsed femoral head experienced functional deterioration over time after initial improvement, whereas precollapse hips maintained their functional improvement up to the latest follow-up.

Level of evidence: Level III, retrospective cohort study.