Varas, Emil

Abstract Osteonecrosis (ON) of the femoral head is a significant complication following chronic corticosteroid treatment, especially in adolescents and young adults. While studies in the adult population suggest that early core decompression augmented with bone marrow aspirate concentrate injection (BMAC) may reduce progression, evidence in younger patients remains scarce. This study evaluates survivorship free from femoral head collapse and conversion to total hip arthroplasty following core decompression with BMAC in patients under 25 years old with corticosteroid-induced femoral head ON. A retrospective review was conducted of 13 patients (24 hips) who underwent hip core decompression with BMAC for corticosteroid-induced femoral head ON. Variables analyzed included sex, body-mass index, age at index surgery, continued corticosteroid use, concomitant labral tear, Kerboul angle/grade, and Steinberg classification of osteonecrosis. These variables were assessed for their association with survivorship free of THA, conversion to THA, and patient reported outcomes (PROs) (modified Harris Hip Score [mHHS] and Hip Disability and Osteoarthritis Outcome Score [HOOS-12]). The mean follow-up duration was 10 ± 5.4 years. At the final follow-up, 11 hips (45.8%) required reoperation, including 10 total hip arthroplasties and one femoral head resurfacing. Progression to radiographic femoral head collapse occurred in 9 hips (37.5%), resulting in a collapse-free survival rate of 62.5%. The mean survival time until reoperation was 8.34 years. Continued corticosteroid use (p=0.033), Steinberg stage >2 (p=0.044), male sex (p=0.045), and high BMI (p=0.002) were associated with increased risk for reoperation. On multivariate analysis, ongoing corticosteroid use (OR=6.4, p=0.01) and Steinberg stage >2 (OR=4.3, p=0.04) were predictors of reoperation. Patient-reported outcomes at final follow-up included a mean mHHS of 77.5 and a HOOS-12 score of 80%. Core decompression with BMAC for corticosteroid induced femoral head ON in adolescents and young adults resulted in collapse-free survival rate of 62.5% at average 10 years follow up with an average reoperation-free survival of 8.34 years. Patients with Steinberg stage ≥2 and ongoing corticosteroid use had high rates of reoperation and conversion to total hip arthroplasty. Our data highlights that careful patient selection and shared decision-making remain critical in optimizing patient outcomes in this challenging patient population.