From the Guidelines
The laboratory workup for avascular necrosis (AVN) of the hip should include a comprehensive set of tests to identify underlying causes and risk factors, as outlined in the most recent guidelines 1. The goal of the laboratory workup is to exclude other causes of the patient's pain and to allow for possible early surgical prevention to prevent articular collapse and the need for joint replacements. Key tests to include are:
- Complete blood count (CBC)
- Comprehensive metabolic panel (CMP)
- Erythrocyte sedimentation rate (ESR)
- C-reactive protein (CRP)
- Lipid panel
- Coagulation studies (PT/INR, PTT)
- Tests for hypercoagulable states, such as protein C and S levels, antithrombin III, factor V Leiden, and antiphospholipid antibodies
- Hemoglobin electrophoresis to rule out sickle cell disease
- Tests for autoimmune conditions, including ANA, rheumatoid factor, and anti-CCP antibodies
- Thyroid function tests, parathyroid hormone levels, and vitamin D status
- Consider testing for alcohol markers like GGT if alcohol abuse is suspected, as alcohol use is a known risk factor for osteonecrosis 1. These tests help identify underlying causes of AVN, which occurs when blood supply to the femoral head is compromised, leading to bone death. Early identification of risk factors allows for targeted treatment of underlying conditions that may be contributing to the development or progression of AVN, potentially improving outcomes before significant joint destruction occurs, as emphasized in the recent update of the ACR Appropriateness Criteria for Osteonecrosis 1.
From the Research
AVN Hip Lab Work Up
- Avascular necrosis (AVN) is an ischemic or cytotoxic necrosis of epiphyseal bone, responsible for joint pain and altered life quality, frequently affecting young patients 2.
- The diagnosis of AVN can be challenging, and a thorough workup is necessary to confirm the diagnosis, including MRI imaging, which is the main exploration for diagnostic and staging of the disease 2, 3.
- The ARCO-classification of the Association for the Research of Osseous Circulation is essential in diagnosis, with stage 0 only found histologically, and reversible early stage 1 showing MR signal changes 3.
- Accurate and reliable diagnosis of AVN requires pathologic examination, especially among older patients without known risk factors, as preoperative diagnosis and radiologic data may not always be accurate 4.
- Known risk factors for nontraumatic femoral head necrosis include alcoholism, steroids, sickle cell anaemia, caisson, and Gaucher's disease, as well as chemotherapy, chronic inflammatory bowel disease, systemic lupus erythematosus, and multiple sclerosis 3.
- There is no relevant information in the provided studies regarding lab work up for AVN hip, however, the studies suggest that a combination of clinical evaluation, imaging studies, and pathologic examination are necessary for an accurate diagnosis 2, 3, 4.
- One study is not relevant to the topic of AVN hip lab work up, as it discusses a case of medulloblastoma with multiple metastases beyond the nervous system 5.