10 Weeks Out and I Couldn't Help it

[KirkM]

** Disclaimer: I am not a doctor, I don't play one on TV.  My statements are a combination of personal pre-op research, my own rehab and a HUGE dose of opinion based on my own deductions.  I think there is a lot of interpretive gray area all over the theories of proper rehab. 

That said, there are certain constants I believe hold true for all patients:

1.
Fact: The acetabular cup has been press-fit into the hip bone.  There is no glue. The knurled back allows for bony in-growth over time.  This is the "glue" that will hold it in place so that it can withstand the pressures of activity.  The key phrase here is "over time".  Bone growth is slow.  During the first 6 months to a year (depending on what surgeon you ask), this bony in-growth is not complete and, therefore, not a completely solid bond. 

My Opinion: Significant pressure on this cup (what I have referred to as "torquing") early on can make it move in the socket.  I think of it as gluing something and then twisting the parts before the glue is dry and it comes loose.  Not only is the glue probably not going to ever permanently bond the two pieces because of this movement, they are now misaligned, and probably going to continue to move around, preventing any future bonding.  You now have a permanent failure of the mechanism.

2.
Fact: During the surgery, the femoral vascular system is temporarily disrupted.  Over the next (approximately) 3 months, the bone density of the upper femur, including the femoral head, weakens as the body rebuilds the supply damage within the femur.  The theoretical peak of this weakness is supposedly at the 3 month mark. From month 3 to month 6 (or month 12, depending upon what surgeon you ask), the density slowly gets better and better.  Some of the research documentation suggested that in many cases, the density after one year was actually better than before surgery.  I believe that they attributed this to a higher level of activity post-op than pre-op for those who were significantly immobile before surgery.  Moderate impact (AFTER THE HEALING PERIOD) keeps bone density up.

My opinion: Pretty much the same as #1 - Any high pressure on the femoral head when it is in this weakened state could subject it to breakage.  This danger is two-pronged.  You also can engage in activities that risk trauma (falling off a bike or while skiing) during the "weak" period that will snap the femoral head off like a toothpick.  This I know as a good friend of mine did exactly that.  A very light fall from a bike at about 3 months and it snapped.

So, what exactly is the right amount of effort to get the muscles and body back while not risking the device or the femur?  From what I can gather, nobody knows.  And I am sure we have all heard the tired cliche "Listen to your body."  It's not the body I don't trust, its the mind drowning it out with a lot of "I want, I want, I want" whining.  Face it, we are all a bunch of overgrown, spoiled 5 year olds who want what we want...NOW!

I think there are obvious no-no's of high impact that we have all heard.  If you don't know what these are, you haven't done your homework and need to stay after school to catch up with the rest of the class.

Personally, I didn't do anything that put a high resistance on the joint: leg weightlifting, hard bike resistance, any upper-body weights that put twisting leverage on my core.  I strongly feel you should not put either hard pressure nor leveraged twisting on the joint in the healing period.

There are two points I'd like to make here:

1. I know from over 30 years of strength training that you can fully work you soft tissue (muscles) without having to use huge weights that put a lot of pressure on the joints. High reps with very low weight taken to muscle fatigue is very effective.

2. YOU ARE NOT TRAINING, YOU ARE HEALING.  I think that this point is being missed by many.  Yes, this operation is so you can get back to doing everything - AFTER YOU HEAL.  Nobody said you can do everything as soon as you check out of the hospital.  If you insist on acting like a spoiled 5 year old and do something impulsively stupid, your hip will punish you like an angry nun in catholic school. 

Everyone must do what they feel is right for them.  Personally, I gave up some overall fitness and did a very conservative rehab to give myself the best chance of success with the device.  I realized that all I had to do was face the fact that it is all ego.  I have been in Ironman shape for over 20 years, and I didn't want to lose that.  Boo Hoo.  Once I got over myself and this whole B.S. about tying a good deal of my identity to my fitness lifestyle, I realized that I wasn't losing that lifestyle.  I was moving through a phase of my lifestyle that required the same amount of discipline it took to get there in the first place.  And I would work with both my body and my common sense so that I could achieve this goal just like all the other goals that came before.

If ever a cliche fit this situation I think this one does:

"Train smarter, not harder."

Best to all my fellow hippies.  Please take care of yourselves.

[hernanu]

Here's where it does get a bit off, I started doing leg presses at about two and a half months, but supervised by my PT (she insisted) and very light (for me) at 190 lbs, about thirty repetitions. I found that to be fine for me.

Like I said, my surgeon was fine with some things, but contact sports, high impact sports he ruled out until one year. I think he was fine with some running and definitely with bicycling by 6 months, but I had a hard time with running then.

[KirkM]

Again, we all make our own choices and if that works for you that is great.  As you said, it was light for you but I still felt better being very conservative and not forcing weight onto my joint while in the early healing.  There is a delicate balance between necessary muscle rebuilding and risking the joint.  I don't think anyone knows where that is and all of us are certainly different.

I have to disclose that I am not particularly sold on PT's, especially for this specific surgery.  I have had a few experiences for various rehabs over the years and have not been impressed by the techniques or abilities of the practitioners I have used.  Maybe just bad luck or choices on my part, but I certainly wouldn't take a PT's word as law.  If it doesn't feel right, I say no.

In fact, at the HSS rehab facility after my surgery, the PT who had my case kept insisting I do the side leg lifts and that it was OK that it was a bit painful.  It just felt wrong to me.  It wasn't the "push through it" kind of pain, it was the "this is very bad for me" kind of pain.  I tried it two sessions in a row and had to argue them down to get them to stop asking me to do it.  It hurt in the very bad way and I KNEW it was not the thing to do.  And I have an ultra-high pain threshold.  Plus, these people specialize in hip rehab.  I just think you can't put a template on it for everyone.  You really need to tune into your body and you can feel what is going on and what is pushing it in the wrong way.  However, I think you must push aside what you want it to be and focus on the feedback that is really being sent from your body.

Again, just my experience and opinion.

[Tin Soldier]

HnH - where are you?  Looking for a response after your beat down.  Sorry dude, you asked for it. 

Kirk, Hern, and others - those are some good, hefty, and detailed responses.  This is one of those threads that would provide future Hipsters a lot of valuable info.  Maybe the search keys should include something like "HnH is an idiot", or "how to increase your odds of a revision" or "how not to get 40 posts ragging on you for telling everyone that you didn't listen to your doc"

On the other hand, I totally understand where HnH is coming from. 

[Dannywayoflife]

Good post kirk. The only thing though is the early return to demanding activity/impact doesn't as far as I'm aware move the cup. What it can do is rather than normal hard bone growing into the rough surface a fibre like substance grows instead.

[KirkM]

That's interesting info.  If you search slipped cups on any of the hip forums or Yahoo hip resurfacing groups, you will see there have been a number of cases where the cup has slipped, so the question is why.  I think it is really difficult to know exactly in any given case.  There are a few possibilities: surgeon error (reaming too big for a good pressure fit), body rejection of the device or true metalosis causing bone loss, etc.  Certainly more possible causes than I could come up with here.

Since we are dealing with a purely mechanical concept here, I don't see why this would be different from any other mechanical device of a ball and attached socket nature.  Specifically, leveraged force on a pressure-fit socket device that has not had any bonding agent used to attach it to the host framework will be far more likely to dislodge than one that has also had a bonding agent applied.  The boney in-growth is the bonding agent in this case, of course.  So it would stand to reason that the risk for dislodging the cup due to leverage or stress against the device is far greater before the bone has bonded into the knurled back of the cup.  Perhaps they both will have such high resistance to movement that the bonding agent is irrelevant overkill.  Maybe, but why then do they even put the knurled material on the back of the cup for the bone to grow into?  I'll take the overkill and peace of mind myself.

So my thinking is that I would not just blindly assume that the reaming is absolutely perfect, that my hip bone is without flaws or weakness in the area of the cup, there are absolutely no other mitigating factors in my body and the cup is rock solid without the boney in-growth and can't be slipped by putting pressure or leverage on it before the bone has grown in.  That seems like betting the farm against the house in Vegas and I don't see that risk being worth the extra few months of patience to get as much reinforcement in there as possible.

I didn't do this for the first 6 to 12 months after the surgery.  I did it for the lifetime after that.

[Dannywayoflife]

Kirk good points well made. I know from reading the rsa studies that the cups and heads placed properly hardly move at all. Your talking .1ths of a mm. And bone growth has been observed into the cup within 2-3 weeks. As I said I know that impact early on can have an effect on the type bone that grows into the cup. But I agree that a conservative early approach is a good idea!

[stephen1254]

I agree totally about the need for bony ingrowth into the cup, but the question mark still revolves around adequate force/excessive force. If you think about it, walking places considerable force on the femoral head/cup. At some point in every step you have your entire body weight less a lower leg pressing on the joint. Since all doctors seem to recommend walking for rehab, a certain amount of force on the cup is likely beneficial in promoting bony ingrowth. For all I know doing a leg press might place less stress on the joint than walking - I just don't know.

And, for the record, I agree 100% with everything Kirk has written. This is a period of healing, not training. I've placed running off for a year, and will ease into it at that. I will not do a leg press, or any of a number of other exercises, until I have my Dr''s approval, and I will ease into them. It's finding the balance in all of this that is tough - I could lie in bed for a year and pretty much assure myself of healing without placing stress on the joint. I'd also have no muscle tone, no ROM, and pretty inflexible scar tissue.

For me personally I've reached a point where I feel I'm doing enough for now to promote healing. I alternate spin bike days with longer walk days, and have the spin bike at a resistance where I can just feel some fatigue in the muscles at the end of two 30 minute sessions. I'm going to keep the activity at this level for the forseeable future. When I get clearance from the Dr. I'll start riding my road bike and hiking. No tri's again till next year.

We'll be in the islands in 2.5 weeks. Does Kona Brewing produce an IPA?

[KirkM]

First, the important info:

konabrewingco.com/our-beers/

I completely agree with Stephen.  That is exactly my point.  Walking is certainly impact, but it is low impact.  One must have movement and a certain degree of "stress" on the body for general health at all times, not just for building athletic strength.  Movement, movement, movement.  And it is critical for this healing process.

I put a clear defining line between high acute stress on the body (weights, burst movements, etc) and low acute stress on the body (long walking or spinning with little resistance).  Both make the body work, but the latter has a distinct double advantage in this healing period of allowing extended sessions of elevated circulation (which promotes healing) AND a low, tolerable impact on the joints and bones to stimulate strengthening without putting high shear loads on the joint.

It actually has a third benefit that you can spend the long sessions of repetitive motion to focus on developing (or re-developing) correct bio mechanics.  Most who have had resurfacing were limping or compensating for an extended period before the surgery.  I think it is often overlooked how important it is to relearn how to move properly immediately after the operation.

I walked 3 miles from day 5 on my crutches and worked from that day forward on the way my body was working and moving.  For me, putting load on before I did the foundational healing work AND could walk straight and strong without aids didn't make sense. 

I swam, rode the stationary bike on light resistance and walked and walked.  Lots of time in motion.  My recovery was miraculous.  I ditched the crutches and cane in a fraction of what I heard was the "average" time.  I had regular soreness and fatigue, but no terrible setbacks.  And I ICED, ICED, ICED.

I didn't load the legs until I go outside on my bike at about month 4.  Aside from the expected soreness, it has all gone well so far.  Not to say it is going as fast and strong as I would like.  The progress is steady, but I want to go strong and hard NOW.  Ain't going to happen.  I can see that it is going to be well over a year to get full strength back.  That is just the reality.

Back to the old saying again, "Do what works for you."  So far, this has worked extremely well for me.

[hernanu]

Good points, Kirk. I think the biggest thing to remember is that we are talking about activities that stress our hips at times when the healing is happening.

I think that with the appropriate type of stress, the healing bone can not only support it, but is enhanced by the force - bone is made denser by applied pressure. The important thing is not to do things that will compromise the bone either by a catastrophic immediate failure (neck break, slippage) or by introducing something that weakens the device's interface to the body long term (the fibrous growth Danny describes, instead of fully grown in bone).

I agree with taking it as easy as possible during the healing period, especially early on.

To Stephen's comment about walking vs. running, here's a mathematical approach to the comparison among walking, speed walking and running:

http://mathaware.org/mam/2010/essays/TongenWunderlichRunWalk.pdf

I'd read it and skip the formulas if you're not into math. The conclusions and graphs show some very interesting things. To summarize (I may miss some things):

The individual measured for this weighed 77.51 kg (about 171 lbs), so the forces listed go up commensurately as you increase the weight.

• Running impact measured as force contributed from three directions of movement is three times as high (2400 Newtons) for the individual measured as compared to walking (~900 Newtons). Speed walking clocked in at about 1200 Newtons
• Impact is much more diffuse if the walking / running knee is bent on impact rather than straight. This would support running styles that minimize impact on the heel (IMO).
• The higher the peak impact, the more force is distributed through the skeletal system - led by the knees and hips.
• In order to run faster, the foot contact has to be shorter, while still applying the same force. So more impacts over the same amount of time needs to be supported. This is much lower with a bent knee running style.
• Due to the above, the more we can lessen the peak impact, the less drastic force will be applied on our hips. Our goal in running, exercising, etc. should be to lessen that dramatic impact until the hips can deal with it.
• There is a linear correlation found between the force generated by any of these activities and weight. As a matter of fact, they came up with a way to calculate the approximate weight of the individual being measured from the peak impact. So as is obvious, but important to us, reducing body weight either before or after the surgery gives large benefits in reducing the peak impact from any activity, but especially for running.
• The force per pound of weight as gotten from this for running is about 14 Newtons / pound, we can calculate the force we are experiencing when running by multiplying it times your weight. The force per pound for walking is 5.2 N/lb.
  
• For our metric hippies, running is about 30.96 Newtons / kg, walking is 11.61 N/kg.
  

The funny thing is that the study done was not done by medical people, but by mathematicians looking for an interesting problem to investigate and model. Their goal is to come up with a model for the resulting force impact on the body of running, speed walking and walking. It's yet another example of beneficial results coming from folks who are incidentally interested in the medical side of things.

Their models, though (once they get them right) could be great for devising proper recuperation protocols guided by force impact projections per person, based on their weight, bone density, bone growth, etc. Very interesting (for me).  One really interesting graph was figure 4, where they did a surface graph that modeled the transition from walking to running and the force transition from one to the other. Anyways, the math geek in me was very pleased.

[KirkM]

Great stuff!  And great data to support exactly the theory upon which I based my rehab.

It also shows support for the "natural running" and "Pose running" techniques regarding body attitude and forefoot strike.
The expansion of those schools of thought claim the modern running shoes with all the stability and cushioning are actually causing problems they claim to solve.

The new barefoot running shoes and foot gloves are quite popular and are thought to be a way to get the body to properly "feel" the ground and cushion by landing on the forefoot or midfoot and then naturally pronate through the  contact phase.

Most of the math stuff flew WAAAAY over my head, but the basic theory was quite interesting and seems to back up the natural running proponents.

Thanks for that Hernanu!

[Dan L]

Hern;

"I was told there would be no math in this debate"...

Chevy Chase playing Gerald Ford in a SNL debate sketch

Just kidding, incredibly well presented.

Dan

[hernanu]

Hilarious, Dan... 

[Dannywayoflife]

Wow there are some smart cookies on here!

[Tin Soldier]

That is some juicy math.  I like the surface graph of the transition from walking to running.

A couple questions/comments -

1.  If the doc gets you on your feet the day of surgery, and actually wants you to be full weight-bearing that day or within a few days, wouldn't you expect that the press-fit is good enough for walking? At least for short durations, but at the presumed impact/force that you would expect your joint to receive with moderate walking.

2.  If the cup slipped just a mm, wouldn't that be noticeable with some pain or excessive clunking?  We hardly ever hear about a slipped cup in the first few months of recovery.  It tends to be later on, a couple years down the road and metallosis is usually involved.

3.  Is there a microscopic or magnified form of x-ray/imaging, where one could look at the bony in-growth into the back of the knurled cup?  Seems like one could do a study using that sort of a tool and show the rate of bony in-growth at certain intervals.  Regular x-ray might get too muddy.  We all have different rates of laying down bone and it seems to me being able to track how much in-filling would answer some of these questions before waiting a full year.  Also be useful to look at cemented vs. uncemented fem component.

HnH is missing out.  I think I really owe him some cookies now.

 

[hernanu]

Good points, Tin - I was certainly full weight bearing both times, and I would think (given the success rate) that the press fit is just fine for most to be weight bearing within the restrictions. The surgeons seem to be pretty good at assessing when full weight bearing is not called for.

I think (read something I believe) that some amount of slippage is expected over the first couple of years, then it is totally stopped. I think that unless you venture into areas where it is overt (80 degrees?, who knows? ) then metallosis is not necessarily guaranteed.

Good question about the back of the cup. The missing information in this study as far as our uses are concerned (the authors were not even thinking of it), is:

• what is the mechanical force that the cup construct can withstand? Both initially (supported by the tight fit only), at mid term (partial bone growth) and in the final state (bone fully grown in)
• How about the femoral component?
• How about lateral pressure, what is the impact there?

If those could be investigated / modeled with confidence, then we would have a full model with the impact models and a realistic approximation of walking / running / speed walking (which I think we'd be awesome at) dynamics of the resurfaced hip.

It would be an elegant, sophisticated way to predict with some statistical reliability what activities a hippy could do at different stages. Everyone is different, so there would be some deviation from the norm expected, but there would be a nice band within which we could feel safer about activities that we all want to do.

 

[Dannywayoflife]

Hern,
        The rsa study that Mcminn and Treacy did shows a 3 diminutional migration of .2mm at 24 months after that it doesn't move.   

[hernanu]

Thanks, Danny, couldn't remember where I'd seen it.

[Tin Soldier]

Danny - I didn't see a reference to that paper?  Was it summarized in McMinn's book.  Interesting deal about the slight movement of the cup.

I recall the doc and his assistant providing some solid hammer blows to my right hip.  Sure I was a little fuzzy, but it seemed like they hammered the crap out of it. 

[Arrojo]

Good thread. For some reason, Dr. Su told me I could run on trails at four months. Regardless, I'm not going to do that. I plan on doing light jogging at six months, and do not plan on busting ass on the track until 12 months (looking forward to that).

As aggressive as I am, even I know enough not to run at 10 1/2 weeks, and I'm an idiot.

Dr. Su
RBHR 4/9/12