12 week post op- Femoral neck at its weakest???

[PistolPete]

Is this really true that at 12 weeks post op the femoral neck is at its weakest?  I know I needed this surgery but now hearing this really puts me back mentally.  UGGG I want my life back.

[imgetinold]

I do not know, and hopefully others will reply.

What I THINK is more likely is that 12 weeks is the time when the risk of femoral neck fractures is greatest.  I imagine that this is not because the femoral neck is at its weakest, but that people's recovery is to a point where they feel 100%, and so they start doing stupid things to a not-yet-fully-healed bone.

However, if you look at the statistics, the risk is still a small percentage.  Only you can decide, but statistically, it's not a huge risk.  And, if you follow your surgeon's advice, your risk is very low.

Anyone?

[obxpelican]

Yes, I've read that the femoral neck is weakest post-op, I've ready anywhere between 4-8 weeks though.  Post op your blood supply is just coming back, it can take at least 6 full months to get back to full strength. 

Dr. Gross has said he's never had a neck fracture after 6 months, so he's very conservative post-op with weight restrictions.

Although if you pick a surgeon who can get the angles correct and does not end up notching your femoral neck your chance for a very positive results are 97% +


Chuck

[einreb]

I was curious about this too and asked Lee Webb about it after I had my surgery since I was restricted for the first 10 weeks then allowed to walk on it at what I assumed was near its weakest point.

Q:This is one thing that I would really appreciate some insight.  If my bone is weakest at 3 months... why would I be off the crutches and cane at that point?  It seems to be an interesting balance of some impact to stimulate bone growth vs not breaking the bone?

A: A femoral neck fracture does not just suddenly happen at 3 months post op, it is a gradual occurance related to stress on the bone. This stress starts early post op and eventually results in a "stress" fracture of the femoral neck. We have you 10% weight bearing to take the load off the hip, in particular the femoral neck to avoid this stress impact. You are correct, there is a balance of impact to stimulate bone, after the 6 weeks, it actually helps the bone by weight bearing. We just don't want you to be doing high level activity at 3 months when the bone is still weak (we know you won't but trust me, there are some who push the limit). Hope this helps.

[obxpelican]

einreb,

You were restricted because you had some other issue going on though, like bone density or problems with your socket.

Most Dr. Gross patients walk with almost 100%, even post-op, they basically told me to listen to my body.


Chuck

[John C]

Hi PistolPete,
I will throw my 2 cents in, but please do not take this as medical fact, just a layman's impression from what I have read.
All of the bones on our body are constantly breaking down old bone cells, and building new ones. When a bone is injured, or for some reason the loads on that bone change, the bone goes through a process sometimes called "remodeling". The bone is basically trying to rebuild itself to align with the new situation. Bone cells are eliminated from areas that the body feels are no longer needed, and bone is added in areas that the body feels needs more strength. Even though resurfacing attempts to keep the original load bearing lines of force, there are bound to be subtle changes, which will cause bone remodeling to take place. During the middle of this process, when some bone cells are being eliminated, and new cells along the new force lines are being created, the bone may be more vulnerable, than before or after the remodeling process.
This vulnerability during the remodeling process is very common in the body. One good example is in ACL (anterior cruciate ligament) repair for injured athletes. The replaced ligament is strong when it is first put in, then gets weaker during the first few months as the body reworks the tissue into its final form. Three months is often quoted as being the most vulnerable time after this surgery.
Again, this is just a layman's impression from what I have read. Personally, I was pretty careful about the loads that I put on the femoral neck at three months after resurfacing surgery. Then I cut lose at six months.

[Dannywayoflife]

John that's very well put.

[einreb]

einreb,

You were restricted because you had some other issue going on though, like bone density or problems with your socket.

Most Dr. Gross patients walk with almost 100%, even post-op, they basically told me to listen to my body.


Chuck

Ha! very much aware of that fact.  :)   I had a bone density issue in that hip.

What I thought was interesting was the concept of being allowed to do more at the point where I had been told it would be weakest.  Just food for thought that the key is to avoid the stress leading up to that point of being weakest at 3 months. 

[Two4One]

Really Great and Informative Post, Einreb!  I will be even more careful not to carry more than ten pounds around!

Thank You,
2-4

[mountaingoat]

Good thread - very informative. I too have wondered about this seeming incongruity between being allowed to be more active by 3 months but that also being the highest risk for fractures. I talked to Lee Webb about this quite a bit because both of my hips are slightly osteopenic and I'm on crutches for 6 weeks using the 4-point gate. What I'd like to understand is whether the people who end up with femoral neck fractures were, in general, doing stupid stuff like playing tennis or lifting heavy weights at 3 months OR whether it just happened with daily activities. What worries me the most is that once my 10 week restrictions are up I am definitely going to need to start carrying my daughter around (she is approx. 20lbs). I can be careful and not do things like carry her car seat with her in it or carry her in a backpack for walks but I just hope that my daily life doesn't result in disaster to my hips. Yes, I worry too much. That's what happens when you're on your 4th and 5th hip surgery at age 36!

JohnC - your description of the bone issue is very articulate. Lee explained it to me in much the same way.

[Tin Soldier]

I think John's post is excellent.  There were some x-rays posted ahwile back on femoral necks after a certain period of time and you could see how the bone was remodeling.  The neck actually gets a little thinner, sometimes.  That freaks people out, but I think its all part of the remodeling process and doesn't necessarilly mean it's a weaker neck. 

[John C]

Hey Tin,
Very interesting insight about the narrower neck not necessarily being weaker. A great example is in windsurfing masts. The top masts are made out of carbon fibre, and years ago I used to break a few of these every year in big surf. Then a few years back, the manufacturers switched to a much narrower mast (called a "skinny") that had thicker walls. Ever since then, broken masts have dropped by 90%, and I have not broken a skinny mast yet, over about a ten year period. I think that your theory about some of the narrower femoral necks has some merit. Thanks for sharing the thought.

[Tin Soldier]

I asked my suregon about the whole neck thinning deal and he said it doesn't necessarrilly mean it's weaker, but you do see a "thinnning" radiographically after a year or so, then it stabilizes.  That's a good example, the skinny mast.