TRIAL OBJECTIVES The primary objective of this study is to evaluate the radiologic progression of ONFH on either radiographs or MRI. A successful outcome is defined as no difference in ONFH staging according to the Ficat & Arlet or Steinberg classifications at last patient follow-up compared to initial radiological staging. This translates into lack of progression over the course of the study while the natural evolution is progression over time.~The secondary objective is to evaluate the percentage of involvement of the femoral head on radiographs and/or MRI which measures the extent of the disease. We expect that the extent of the disease will be reduced at 2 years.~STUDY DESIGN AND DURATION This study is a multicenter, prospective, randomized, double-blind, placebo-controlled trial that aims to test the efficacy of the proposed medical intervention (ASA). The design is intended to be parallel group where a total of 114 patients will be randomized in a 1:1 ratio to the treatment (ASA) and the control (Placebo) arms.~All patients presenting to the osteonecrosis clinic of one of the participating centres will be first evaluated by an orthopedic surgeon to confirm the diagnosis of early ONFH on at least one hip. Selected patients will be screened for eligibility according to specific inclusion and exclusion criteria.~Eligible patients who accept to participate in this study will be randomized to either a control arm (placebo) or a treatment arm (Aspirin). Recruited patient will take their assigned treatment daily at breakfast from enrolment and for a minimum of two years They will be followed over a period of 2 years. Evaluations will be taken at baseline and every 6 months (5 visits in total).
The purpose of this study is to determine if prolonged administration of low-dose aspirin will prevent the progression of early-stage osteonecrosis of the femoral head and may even reduce the extent of involvement of the femoral head by the necrotic process The design is intended to be parallel group where a total of 114 patients will be randomized in a 1:1 ratio to the treatment (ASA) and the control (Placebo) arms.