range of motion

[ozcanvarli]

http://www.ncbi.nlm.nih.gov/pubmed/19085491?ordinalpos=20&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

I read that article today.


and I am scared..

what do you think there??

[Pat Walter]

Hi

I would not be scared since there are over 100,000+ people world wide that have had hip resurfacing.

You have to realize the most of the established orthpedic surgeons do not like or support hip resurfacing and will do any kind of testing to try to prove how bad it is.  This study you posted, which I removed except for the link, was not TEST RESULTS from REAL PEOPLE.  This was a scientific STUDY on EXPERIMENTAL MODELS. 

My opinion is to stick with real world statistics from real people and real experienced surgeons.  I have hundreds of personal sucessful stories on my website.  I have many doctor interviews explaining that ROM for resurfacing is as good if not better than a THR.  Remember that all these surgeons do both THRS and resurfaicng.  I have many live chat transcripts that people ask the question about ROM and the expeirnced surgeons explain it is as good if not better than a THR.

I think you are looking far and wide to find something to scare you.  If you are worried, ask the experinced surgeons about the ROM for their patients and base your information on reality of real patients.

Ask the 1000+ folks here how their ROM is.  Look at the videos of surface hippies in action  http://www.surfacehippy.info/shvideos/videosathletes.php and read stories of athletes  http://www.surfacehippy.info/athletes.php

Please don't base your fears on some small study done in a laboratory to prove how bad hip resurfacing is.  Look at the real information posted on this site by real people and real doctors.  Listen to the people on this board who have had hip resurfacing.  They are real and have returned to actiities that they have always done all their lives.  You can't talk to mechanical equipment set up in labs - it won't talk with you.

I don't mean to carry on, but I always feel discouraged when doctors and labs work so hard to try to prove that us Surface Hippies are not doing well and have not had sucessful surgeries.  We are walking and talking live human beings that are very happy with our hip resurfacings.

[Bionic]

It makes sense that THRs would provide a theoretically greater ROM than resurfacings because there is no femoral neck!  In fact, THRs should provide a much greater theoretical ROM than normal human anatomy.  THRs replace the femoral neck, which is typically a couple of inches in diameter, with a titanium stem, which is typically less than an inch in diameter.  Of course there is less impingement with the stem! 

The question is whether that additional ROM is useful or even usable.  Most people don't rotate their hips to extremes of motion.  I suppose gymnasts and martial artists might come close, so maybe this is relevant to them.  Maybe they could get greater ROM with a THR than with their normal hips?

But the other issue is usability.  THRs (at least the non-Metal-on-Metal kind) come with a higher risk of dislocation.  Is rotating the hip to those theoretical extremes of motion even possible with a THR without dislocating the joint?

The study may or may not be applicable to real living people (in vitro literally means "in glass," not in living patients).  Typically, people's ROM is limited by their ligaments long before it is limited by their skeletal/implant structure.  So the additional ROM that is theoretically attainable with a THR may never be realizable in a living patient.

The assertion that people might knock their acetabular implants out of place by rotating their resurfaced hips to extremes of motion could benefit from some evidentiary support.  I'm not aware that there is any evidence that this has ever happened.  Once the acetabular implant is well fixed, it is mighty hard to break it loose, since it is basically integrated into the surrounding bone.

A very poorly placed acetabular cup could present an impingement problem, I suppose.  Think of a cup placed horizontally, for example.  But that would be a clear surgeon's error, and not an indictment of resurfacing generally.

Is impingement a factor in femoral neck fracture?  The evidence shows that femoral neck fracture always occurs between 6 weeks and 6 months post-op.  If it doesn't happen by 6 months, it never happens (same incidence as general population).  If it were true that neck impingement against the cup caused femoral neck fracture, wouldn't it be happening well beyond the 6-month mark?  People are just getting back to normal activities and sports at 6 months.  If impingement caused femoral neck fracture, wouldn't you see a huge surge in the numbers at 6 months?  Instead, you see the numbers drop to zero.  So that argument just does not hold up.

Like Pat said, the proof is in how real patients are doing.  Pick a good doctor who will do a good job placing your cup, and don't let this bother you.

[karenj_m]

You forgot to look to the right of that article that says:

"The effect of the orientation of the acetabular and femoral components on the range of
motion of the hip at different head-neck ratios."

http://www.ncbi.nlm.nih.gov/pubmed/10724224?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DiscoveryPanel.Pubmed_Discovery_RA&linkpos=2&log$=relatedarticles&logdbfrom=pubmed


Once again proving that the surgeon YOU pick is very important, because placement of the parts is VERY important for your success with resurfacing.

[takilasunrise]

Wow, go get 'em, Bionic!  You sound like you did some major research on the subject! All I know is that I celebrated my one year anniversary last month and everything is going great!  Here's to a speedy recovery! 

[nwugrad]

Great post Bionic!