With AVN being both a rare and little-understood disease, it stands to reason that there are no clear-cut rules on how patients should adjust weight-bearing practices. In fact, doctor recommendations on weight-bearing can differ widely. In the end, the patient is often put in a difficult predicament of trying to decide which doctor and which treatment regime to trust. Here are some key concepts that can help patients with lower extremity joint AVN make the best decision possible in regards to weight-bearing:

• Treating AVN is a balancing act where the body is breaking down and reabsorbing the dead bone tissue and attempting to generate new bone tissue at the same time. In the case of load-bearing joints, the largest risk is that stresses on the joint will cause the resorption process to out-pace healing and the joint will collapse.
• If weight-bearing on the legs is completely discontinued:
  • Muscles will atrophy and weaken, putting more stress on the joints.
  • Bone density will decrease, resulting in thinner and weaker bones. While in the active cycle of decreasing bone density, the body is less active in generating and repairing bone.
• Some joint activity is critical in order to counter bone density loss and to prime the body's natural healing response.
• The stage of AVN bone decay drastically affects how much stress weight-bearing will inflict on the joints. Once bone surfaces begin to deform, they become rough and much more abrasive on counter opposing tissues. A pitted and flattening femoral head will often rapidly wear away cartilage, for example.
• Preserving and protecting joint cartilage should be a top priority. Joint cartilage prevents bone-on-bone contact and offers a very effective protective buffer against shock and abrasion. With this in mind, patients with lower extremity AVN should avoid activities that cause joint impact, grinding, or excessive stress.
• Typical healthy activities like running, squatting, aerobics, and many other sporting activities can definitely hasten cartilage and bone loss. Consequently, these types of activities need to be reevaluated and discussed in detail with your orthopedic surgeon.