New Study - OATS vs. Microfracture (cross-posted)

[blackbeltgirl]

Just an FYI - This article was recently published.

OAT better than microfracture in younger athletes’ knees

Significantly more OAT-treated patients returned to their preinjury sports activity level.


1st on the web (September 30, 2005)



September 2005

Osteochondral autologous transplantation repairs articular cartilage knee defects in younger, active patients better than microfracture, a prospective study shows.

Rimatutas Gudas, MD, PhD, and colleagues at Kaunas University Hospital in Kaunas, Lithuania, randomly assigned 60 patients to undergo treatment with one of the two surgical procedures. All patients had either a single symptomatic osteochondritis dissecans (OCD) or a full-thickness cartilage lesion in a stable knee. No knees had generalized chondromalacia or osteoarthritis, and none had lesions larger than 4 cm², according to the study.

After eliminating three patients who did not complete follow-up, the final data analysis included 57 patients — 28 patients treated with osteochondral autologous transplantation (OAT) and 29 patients treated with microfracture. All patients were younger than 40 years, according to the study.

Using the International Cartilage Repair Society (ICRS) grading system, the researchers classified 23 patients (40%) as highly competitive athletes and 34 patients (60%) as well-trained and frequently sporting.

All knees had lesions classified as ICRS grade 3 or grade 4. Thirty-two knees (56%) had post-traumatic symptomatic full-thickness articular cartilage lesions and 25 knees (44%) had OCD defects. The mean preoperative defect size was 2.8 ± 0.65 cm² for OAT-treated patients and was 2.77 ± 0.68 cm² for microfracture-treated patients. Most defects — 84% — were located on the medial femoral condyle, with the remaining defects located on the lateral femoral condyle, according to the study.

At a mean 37 months follow-up, 27 of 28 (96%) OAT-treated patients had good or excellent results compared with 15 of the 29 (52%) microfracture patients (P<.0001). Both groups had significant improvements in Hospital for Special Surgery (HSS) scores. However, OAT-treated patients had significantly better improvements than microfracture patients.

For OAT-treated patients, mean HSS score improved from 77.88 ± 6.23 at preop to 91.08 ± 4.15 at a mean 37.1 months follow-up (P<.0001). For microfracture patients, mean HSS score improved from 77.22 ± 8.12 at preop to 80.6 ± 4.55 (P<.05), according to the study.

Microfracture patients also began showing deterioration at 37.1 months follow-up, the authors noted.

Both groups also had significant improvements in ICRS scores, although OAT-treated patients again had significantly better improvements. Among microfracture patients, mean ICRS score improved from 50.84 ± 4.07 at preop to 75.59 ± 4.64 at 12 months follow-up (P<.05). For OAT-treated patients, mean ICRS score increased from 50.67 ± 4.05 to 85.88 ± 4.69 (P<.001), according to the study.

Additionally, significantly more OAT-treated patients returned to their preinjury level of sports; 26 (93%) OAT-treated patients vs. 15 (52%) microfracture patients returned to sports at an average of 6.5 months postop.

Second-look arthroscopies also identified nine failures in the microfracture group at a mean 8.4 months postop vs. one failure at 3 months in the OAT group. All failed cases were revised using OAT, the authors said.

Radiographic evaluation showed no evidence of arthritic changes in either treatment group, they noted.

For more information:

Gudas R, Kalesinskas RJ, Kimtys V, et al. A prospective randomized clinical study of mosaic osteochondral autologous transplantation versus microfracture for the treatment of osteochondral defects in the knee joint in young athletes. Arthroscopy. 2005;21:1066-1075.

[stgiles16]

Good article Jess, too darn bad that mine was microfracture instead of OATS. I dont think that I am going to make that 37 mnth time span. I wish that I were.

missy

[John1]

Thanks for the info Jess, BUT THIS ARTICLE IS VERY MISLEADING. I'm not yelling at you, Jess. I just want to get people's attention. I was able to read the whole article so I'll explain why I say this.

They selected patients with articular cartilage defects and osteochondritis dissecans (OCD) and lumped them all together. (12 of 29 in the microfracture group had OCD and 13 of the 28 in the OATS group had OCD.)

Since microfracture relies on the subchondral bone being intact it's not fair to compare the results of OATS and microfracture on this subset of patients. Since OATS replaces the cartilage and underlying bone it's not entirely surprising that this procedure would work better on the OCD patients.

They reported "27 of 28 (96%) OAT-treated patients had good or excellent results compared with 15 of the 29 (52%) microfracture patients", but they also said, "In both groups, full-thickness articular cartilage defects had significantly better clinical results (according to ICRS) than did OCD (P < .004)." If you put these last two statements together you see that the only way the second statement can be true is if the non-OCD microfracture patients did really well (because their wasn't much room for improvement with the OATS patients). In other words, it seems like the group that did the worst was microfracture for OCD patients whereas OATS for OCD, OATS for non-OCD and microfracture for non-OCD did well.

They also had both groups do identical rehab, but "No continuous passive movement was used." Continuous passive movement (CPM) has been shown to improve the results of microfracture. The durability of the repair tissue with microfracture depends on the mesenchymal stem cells from the bone marrow differentiating into chondrocytes (cartilage cells). The differentiation into chondrocytes depends on the mechanical forces applied to the stem cells. This is believed to be the reason continuous passive motion helps the outcome of microfracture. Using CPM or not probably won't change the outcome with the OATS patients but will with the microfracture patients, so I don't think it's fair to compare the results since the optimum rehab protocol wasn't followed with the microfracture patients.

Nobody should feel bad that they had microfracture instead of OATS for a full-thickness articular cartilage defect, but perhaps they should feel bad if they had OCD and microfracture. Microfracture with the proper rehab has been shown by Dr. Steadman to have good results long-term (7 to 17 years) for full-thickness cartilage defects. 80% (59 of 71) of patients rated themselves as improved at 7 years follow-up in his report.

John

[John1]

I'm re-posting this response to Jess' (blackbeltgirl's) response in the OATS section since it really has more to do with microfracture.

Jess, let me see if I can respond to these statements.

You quote research all the time - let me see it.  Find me links to the articles you mention. I've NEVER seen any article mentioning use of a CPM with microfracture.

Most medical journal articles on microfracture mention CPM. If you search on scholar.google.com you can find links to articles, but a lot are unavailable unless you have a subscription. I have access to a lot of them through a university.

Steadman (and his coauthors) say to use CPM with microfracture. Almost every other author says they follow Steadman's rehab protocol.

Here is one article that definitely isn't available online and I haven't read it. I'm going to see if I can get a copy through my library. It's one that a lot of others cite when they say they use CPM:
Rodrigo JJ, Steadman JR, Silliman JF, et al: Improvement of full-thickness chondral defect healing in the human knee after debridement and microfracture using continuous passive motion. Am J Knee Surg 7:109-116, 1994

Some of these articles cite it after the following statements:

"In the human, microfracture treatment of full-thickness cartilage defects in the knee has resulted in better gross healing of the lesion, as compared with non-treated lesions, when evaluated by followup arthroscopy."
Frisbie, Oxford, Southwood, Trotter, Rodkey, Steadman, Goodnight, McIlwraith: Early Events in Cartilage Repair After Subchondral Bone Microfracture. Clinical Orthopaedics and Related Research No. 407, pp. 215–227, 2003 (Feb)


"...continuous passive motion has been shown to improve the quantity of repair tissue."
James Hoi Po Hui and Anthony Marchie: Current management of cartilage defects: a review. APLAR Journal of Rheumatology 2003; 6: 170–177


"Rodrigo et al, have demonstrated significant improvement of cartilage repair in patients treated with microfracture and a continuous passive motion rehabilitation program than without such a program."
Nehrer, Minas: Treatment of Articular Cartilage Defects. Investigative Radiology: Volume 35(10) October 2000 pp 639-646

It's not clear to me exactly what they were comparing, so I'd like to get a copy to see for myself. It sounds like they could have compared microfracture with CPM to non-microfracture and no CPM. If this is the case, then all of these citations are a little misleading.

Second, there are numerous studies of the effect of continuous passive motion and healing in general. And there are many animal studies on the effect of continuous motion on cartilage. It's interesting to read the history of CPM. Robert Bruce Salter came up with the idea of CPM 30 years ago. From An Overview of Continuous Passive Motion(CPM). Historical background. The Limited Potential of Articular Cartilage to Heal or to Regenerate.:

"The three hypotheses of CPM of synovial joints are that it should have the following
beneficial effects:
1. Enhance the nutrition and metabolic activity of articular cartilage.
2. Stimulate pluripotential mesenchymal cells to differentiate into articular cartilage, as
opposed to either fibrous tissue or bone, and thereby lead to regeneration of cartilage (and
achieve the "impossible dream").
3. Accelerate healing of both articular cartilage and periarticular tissues, such as tendons and
ligaments.
The purpose of the numerous experimental investigations undertaken over the past 28 years
has been to test the validity of these hypotheses in a variety of experimental models."

In my post-op diary on the 4th page, 3rd post I wrote about some of the basic research and basis for CPM with microfracture. Keep in mind that I mixed in my opinion on how I interpreted the research I quoted. I cited five papers:
http://www.kneeguru.co.uk/KNEEtalk/index.php?topic=14645.45

I haven't found any studies that take, say, 100 patients and do microfracture on them, then have 50 use CPM and 50 not use CPM and see what the results are. There was one report comparing weight bearing to non-weight bearing protocols and they reported there was no difference. I can't remember the study now.

And I've read a lot of medical articles that mention anything about focal lesions in articular cartilage, and repair methods.  Tell me where I can find this research, I'd be interested to read it.

I'm not sure if you meant to say "never mention" here and I'm not sure if you're referring to something I wrote, so I can't respond.

I had full range of motion within 24 hours of my microfracture surgery - and I had well over 20 square centimeters microfractured.  What would the CPM have added to my recovery?

Perhaps in your case it wouldn't have helped and maybe that's why your doctor didn't want CPM for you. A certain amount of motion throughout the day is believed to circulate nutrients into you joint fluid. If you moved around frequently after your surgery, then perhaps CPM wouldn't help at all.

And do me a favor - f ind me something from a researcher other than Dr. Steadman to back up your statements.  One man, and one man's work, is not the full body of research on the subject.

Sorry, I've been a little careless when I say Steadman. He usually publishes articles with other authors, so I really should say Steadman et al.

But your statement is exactly what I was complaining about in the weeks after my surgery. I'd love to quote other people's research. I tried to find research on microfracture and the only articles I could find were either coauthored by Steadman or cited Steadman and said they used Steadman's rehab protocol. But then a lot of people on this board said their doctor used a different rehab protocol than Steadman. I wanted to know what THEY were basing their decisions on because there doesn't seem to be any non-Steadman protocols published.

If your doctor doesn't use CPM or non-weight bearing and he believes that this is superior to Steadman's protocol, then I wonder what his basis for this is. So really you should ask him to back up his reasoning.

i"m not saying that all medical studies are well-designed, BUT - professional researchers design studies.  I've had mores statistics classes than I ever wanted, and I understand the value of study design.  That's why, when I find information, I post the article, or direct links or references to the article.  I allow others to read for themseves, as you did, and draw their own conculsions.

And I thank you for posting it. Missy replied and said she wished that she had OATS instead of microfracture. I didn't want all the people who had microfracture to think that it was a big mistake, so I posted my opinion. My response to the article was not an attack on you, Jess.

John

[stgiles16]

I know for a fact that there are 3 posts missing from this thread. I wrote one of them and I know that it was not controversial so should not have been removed by a moderator.
Where are the posts? I read one of them this morning then responded to it and then another was added but they are all now gone.

HELP??? ? missy

[stgiles16]

Completely Ignore that last post, I do believe that I am loosing my mine.

sorry
missy

[cholt]

Jess,

Just a question.  Can OATS work with osteoarthritis?  In the first paragraph you posted, it says none of them had it.  So does that mean that it doesn't work if you do?  That is my interpretation from my OS.  You seem to know more than most, so thought I would ask you.  Thanks,

Cindy

[shadehawk]

Cindy,

Here are a couple of sites that might help some.... It just seems like there are not alot of available procedures for the patella.  The stone clinic does not recommend OATS on patella at all.....

First one is about OATS and second one is about Mosaicplasty

http://www.stoneclinic.com/oats_knee_surgery_failure.htm

http://www.maitrise-orthop.com/corpusmaitri/orthopaedic/mo76_mosaicplasty/index.shtml

[cholt]

Thanks Shade,

My understanding is that you really can't have OA with either of these procedures.  I guess that's what my OS meant when he said, there was not anything he could do, because I didn't have anywhere to pull from.  I didn't understand what he meant until now.  I guess he was thinking of harvesting some but there was not any to harvest for the OATS procedure.  As far as from a donor, I thought that they would not do this procedure on someone who has OA. The reason being that it was such an expensive procedure for someone who would probably just loose the cartilage again with the OA.  Am I reading my oS and the other info wrong?  Thanks for having patience with me.  I am still a "dummy" when it comes to this stuff, unless I have been through it myself. 

Cindy

[blackbeltgirl]

Cindy -

Osteoarthritis is something of a vague term.  If you need cartilage regeneration, you have arthritis.  Whether or not you are eligible for these procedures depends on the specific condition of your knee.  Both OATS (allograft or autograft) and ACI are possible for focal lesions.  Meaning you need to have a pothole in the knee, surrounded by good cartilage.  If the entire knee is shot, or somewhere in the degenerative process, there is nothing healthy to help hold the  new tissue in place, and even if you could, the stuff around it would be wearing out, etc.  That's why they say arthritis is contra-indicative.  But again - it's a vague term.  I've seen lots of people on these boards with focal lesions and their OS told them it was arthritis.  I HATE that!  Focal lesions can be treated, arthritis care is much more palliative. 

Hope this helps.
Jess

[cholt]

Jess,

Hi, and thanks for the info.  My Os said he did microfracture on my right patella and MFC but could not do it on my right patella only on the MFC.  He said that I have no cartilage left on 3/4 of my patella on left knee and no cartilage left on a nickel sized portion of my right (He said grade IV or so I could understand it he said, "all bone to bone".) Both MFC had osteochondral defects -on right; a whole & on left a flap. 

My question is, from this info, does it look like anything else can be done on either knee?  He told me his next step would be a PKR before he would do a TKR. 

Thanks for your help.

Cindy

[blackbeltgirl]

Cindy -

I don't know how old you are, but generally, if they can microfracture the area, they may be able to do one of the other procedures.  A nickel sized hole is probably 2-3 square cm.  I've got 1 hole that's 18sq cm.  The back of the patella seems to be one of the hardest areas to treat, and even harder to get insurance approval to do so.  and since the back of the patella and the trochela take so much abuse just from day-to-day living (walking, stairs, etc.) even if they got everything else to 100% perfection and left that alone, you might still be in pain.  When he talks about PKR, is he talking about the patella-femoral joint replacement?  I know almost nothing about it, but I seem to remember reading something about practically replacing the patella.  OH - for what it's worth, OATS and ACI are generally for patients under 45 or 50.  As I said, I don't know how old you are, but age may be on eof the limiting factors.  It's always worth asking about - if your OS says you're not eligible, and gives you reasons that make sense, it may not be worth pursuing.  But if he doesn't justify his decision, or just doesn't really do the procedures, then you should see someone who specializes in cartilage treatment before deciding on any further surgery.  MY OS only does ACI, and when I asked about OATS he told me I would be a very challengoing case.  As such, there was only 1 surgeon in the area he thought was up to the task, and asked if I'd like a referral to meet with the other OS.  In the end, I have made an appointment with an out-of-state physician with a reputation for successfully treating salvage cases.  ANd this guy does all of the procedures, so I believe he will be able to determine which has the best odds of success for me.

Good luck-
Jess

[cholt]

Thanks Jess, it sounds like you won't be getting it done either huh?  I may have hope on my right but not my left.  3/4 of my left is gone completely but only nickel size on right and he could do microfrx on right but not left.  I see him on Tues. and now I know what to ask about.  I am 44 yrs. old.  Thanks for your help. 

Cindy

[blackbeltgirl]

Cindy -

I'm totally undecided.  I have modified my life and activities to accomodate my knee.  I was always a person who ignored the pain and kept on going.  Now every time I have pain I'm afraid I'm making things worse.  That's one of the reasons I'm seeing the out-of-state guy in Nov.  My OS will do ACI, but I need to lose another 50 pounds before he'll do it.  Being overweight has a huge impact on the success rate.  (To put that in context, I've already lost 50 pounds.)  My point though - by not doing the things that hurt, I don't think I'm in enough pain to be willing to go through with such a major surgery.  What I'm trying to decide is if I need to view this as a preventive procedure.  I'm 31 years old.  If I wait until I am in enough pain, I probably won't be eligible, since I"m already pushing the boundaires of the technology.  So I need to figure out if it's more of a now or never situation for me.

Good luck.
Jess

[cholt]

Jess,

For the past few hours I have been reading about ACI.  It seems pretty successful if you meet all the criteria.  Not for patella though.  Where is the majority of your damage?  I wish you all the best.  You help so many people on here.  Shade has really helped me also.  This is the best site!

Cindy

[blackbeltgirl]

Cindy -

They have started studying ACI for the patella.  Dr. Minas has published some research on the subject.  But I think people are still fighting their insurance companies on the subject.  My damage os to the lateral femoral condoyle, trochlear groove, and lateral tibial plateau.  On the plus side - I don't have damage to the back of the patella.  On the down side, if there is damage to the trochlear groove, damage to the patella is likely to happen sooner or later.  Oh well.  Glad I've spent so many years ignoring pain.  It may come in handy.

Jess

[shadehawk]

Jess,

It is always so helpful reading your posts, thank you...

Wish that I was within the age group that could benefit from these procedures, but that is not the case.  Hopefully, microfracture could be done if necessary. 

It is very nice that some experts are studying ACI for the patella.  Everything I have read seems to have bad results due to the stresses on that area.

I also have patella-femoral OA as well as the patella defect & it is interesting reading these research articles, but my age seems to be my biggest enemy.  It is hard to give up all these activities to preserve your knee joint - hopefully, you shall get some answers and treatment options for your situation.  You are young and definately should persue treatment so you can become more pain free.

Good luck, Jess.

Shade

[blackbeltgirl]

Thanks for the kind words.  I guess, as with everything else in life, it helps to focus on the positive.  I rarely think about the things I don't do anymore.  I just look for things I can do.  A lot less physical pain that way, and you don't end up on the emotional roller coaster of disappointment.