Conversation with Dr. Gross 7/31/07

On Testosterone Levels

He has no information and does not feel qualified to comment. I'm consulting an endocrinologist in a month. As I relayed to my local doctor, Dr. Gross isn't a big fan of Fosamax, or biphosphonates in general. The cause of my osteoporosis is still not established and I continue to study this issue.

On Medial Femoral Circumflex Artery and Revascularization

The MFCA is indeed cut during surgery. He said the blood supply is sacrificed to the femoral capitus anyway, regardless of surgical approach, when the head is prepared for accepting the cap. He has at times been able to save the MFCA from damage during the initial surgery and dislocation, but securing the femoral head in preparation for the machining will damage that artery. No one knows in detail how the femoral blood supply re-routes itself, but it is a general phenomenon that other blood supplies will enlarge and provide increased flow if one supply is sacrificed. Happens in the heart I know, and Dr. Gross mentioned it happens elsewhere. He assumes it happens in hip resurfacing as well. He believes that there are likely to be areas of AVN in the top of the femoral head in many or most patients. These AVN areas will keep good bone from being able to grow into the in-growth cap, permanently. However, good fixation elsewhere will prevent any major problems. He does not know how compromised the femoral blood supply is, and for how long. He does not remember how much bleeding (hence blood flow into) there was on my femoral head after preparation.

On Post-Surgical AVN

If it happens, it'll probably be evident only after 1 to 2 years post-surgery. If you make it past 2 years, you're in the clear. AVN may be happening right now, but I won't know till much later. I'd hoped that I would be able to tell with a distinctive kind of pain, but he was skeptical that someone could distinguish AVN pain from the other pains in the soft tissues as they heal. He said that my very low bone density is completely independent of AVN. I am at no higher risk of post-surgical AVN than anyone else. However, I am at a higher risk of fracture. (Of course, fracture is one of the main causes of AVN, so in this sense I would think that I am at increased risk). He agreed that I'm in a bit of a pickle as far as guarding against fracture. You can't get bone to build without mechanical stress, but that also risks causing a fracture. In fact, even normal walking can lead to a fracture. I did not ask about vibration platforms, but am already convinced by the studies done so far that these are valuable for bone building. For me, I'll wait till at least 6 months post-surgery before using a platform, time enough for the bone to already be in the building phase and hopefully better able to handle the stress, low as it may be.

On Physical Therapy

The bone is weakened by the surgery, both mechanically and by the sacrifice of blood supply. The bottom of this weakening cycle is at 3 months. That's mid September for me. After that, the bone blood supply should have re-established well enough to be strengthening the bone. I asked if my very weak bone should've meant I needed a more conservative PT than other cementless people. He said no, because I need stress to get the bone to strengthen and so I need to be progressively increasing the loading of the hip.The 6-weeks on crutches followed by 4 weeks on a cane already incorporates the conservative rehab needed for cases like mine.