AspirinAspirin in the Prevention of Collapse in Osteonecrosis of the Hip

Inclusion Criteria:

1. Age 18-60 years old
2. Patients with early osteonecrosis of the hip as defined above
3. Diagnosis confirmed within 3 months of the screening visit
4. Patients accept to take the study medication

Exclusion Criteria:

1. A history of hip trauma or surgery affecting the hip involved with early stage osteonecrosis as per criteria above
2. Concurrent use of anticoagulants
3. Concurrent use of bisphosphonates
4. Concurrent use of Aspirin for any reason
5. Patients with recent active severe peptic ulcer disease that are not on PPI.
6. Patients with advanced osteonecrosis of the hip with signs of collapse or end-stage joint arthritis of the hip that are immediately referred for surgical consultation for THA
7. Patients who are hypersensitive to ASA, salicylates, or non-steroidal anti-inflammatory drugs
8. Hepatic impairment (Bilirubin total, AST, ALT > 2-3x upper limit of normal), renal failure (creatinine level above normal with glomerular filtration rate < 45 ml/minute), or congestive heart failure
9. Platelets number should be more than 100,000 ( > 100 x 109 /L)
10. Pregnancy. If the patient is not sure whether she may be pregnant or not, a screening for pregnancy should be done.