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

[blackbeltgirl]

Just an FYI -

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.

[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

[blackbeltgirl]

John -

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.  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 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?  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.

 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.

Jess

[John1]

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]

John, I really have a bad memory, I am not joking there, where did I say that I wished that I had OATS   instead of microfracture. If I had a choice, I would decline them both. Bad Knees suck.

I may have said it but I swear that I have no memory of it., Point me to it john

missy

[blackbeltgirl]

John -

Thanks for providing some quotes.  I have not read your post-op diary, but I've read numerous posts from you on a variety of threads.  (Ahhh, the power of kneeguru.)  After my surgery, which like so many of us, was supposed to be a simple meniscectomy, I logged onto kneeguru.  Got myself into a panic, because my doctor was not following Steadman's post-op protocol.  At my 2nd post-op appointment, when I had started to realize that this surgery was not the simple procedure I'd expected, I started to ask a lot more questions.  Why did he perform microfracture, what were his expectations, why was I weight-bearing, when Steadman said not to be....  I get frustrated when every response to questions from newbies about microfracture point to Steadman, because lots of other new kneegeeks have ended up in the same uncomfortable panic I was in.  Reading 1 or 2 Steadman articles, or something published on his website, AFTER surgery, leads to doubts and mistrust of the physician treating you - the individual patient.

My point - when I asked my doctor these questions he had good answers.  Most studies on microfracture consider a 2sq. cm lesion a "large lesion".  The article I posted at the top of the thread, with mean lesions near 3 sq. cm. may actually be the largest size lesion i've seen studied.  OATS, Microfracture, ACI - all the studies are on more "ideal" candidates, with smaller lesions.  As you can see from my signature, my smallest lesion doesn't meet these study criteria, let alone my larger lesions.  From what I've read of Steadman's work, I'm guessing he wouldn't have touched my knee - not with any of those procedures.  There are others, however, with reputations as salvage experts, who are more willing to take on cases that stretch the boundaries of different procedures.  They search for incremental improvements, even if the end is still less than ideal.  My surgeon trained with Dr. Minas.  He is a sports medicine OS, specializing in knees and shoulders.  As a combination of his specialty, his training, the mentors he has sought out, he is more aggressive - more willing to allow the patient to take an active role in healing. 

I have posted, over the last few months, a few articles on microfracture - none of them authored by Dr. Steadman, or Dr. Steadman et al.  None of them focused specifically on the post-op protocol, but they each discussed the indicators of success, and the importance of patient selection, etc.  There is research that doesn't involve Dr. S.  One of the first rules of statistics and research is to find multiple sources.  If you can find the same results in multiple studies by different experts, the results gain significant credibility.  Experiments and studies that can only be duplicated by the same physician or researcher are consistently called into question.  I AM NOT DOUBTING DR. S'S CREDENTIALS.  Simply pointing out that multiple independent sources add more credibility.

Have you visited Dr. Cole's website?  www.cartilagedoc.org.  If you enter the site, go to the resources section, and click on knee, you will find entire series of articles relating to management of articular cartilage.  These articles discuss the indications for different procedures, outline and educate on the procedures themselves, and do discuss the rehab as well.  I found this site to be a fantastic tool as I educated myself on articular cartilage injuries and treatment options.  It allowed me to ask intelligent questions of my own physician.  Which is really what I think kneeguru should be doing.  Allowing each of us to share our research, and our experience - but only to help new kneegeeks understand their injuries, their surgeries, their recovery - and to ask questions of their own physician.  No one can benefit from new research retro-actively.  We can't go back to our OS and say "undo the microfracture, I want OATS".  It's just another piece of our patient education.

Thanks for keeping the debate alive.  As long as we keep everything positive, I have hope that we are actually helping others, and not scaring them away.
Jess

[John1]

Missy, your post about wishing you had OATS was in the bone marrow stimulation version of this thread. The thread is kind of cross posted and I responded to both threads so they appear almost the same.

John

[stgiles16]

John, I was referring to the longevity stated in the article that Jess had posted. I do wish that I would have gotten 37 mnths out of my micro but I think that it is wearing thin at 18 mnths. It isnt bad enough to go thru another surgery but it makes the prospect of another surgery much closer than I had hoped. I would have volunteered for just about any surgery that would have fixed me for the rest of my life but I knew going into it that micro was a temporary fix. I had just hoped that it was longer than a year and a half for me. I have read stories of people with micro lasting for up to 10 yrs, I just wish that I were one of them. I seem to be unlucky because even the stuff that the OS has cut out in the past (plica, fat pad and some scar tissue) have grown back. I am still not negative about it, more resigned to. Micro does work well for some people, I guess it just didnt work well for me.

missy

[bridaman51]

I had microfracture done about 8 years ago (I have OCD).  4 years after I had it I had a very large (about i inch in total diameter) piece of something floating around my knee.  I did not get it fixed right away for two reasons
 1. I had no insurance at the tiem
2.  It really did not bother me so much so I did not worry about it.

But after 4 years (and getting insurance) it start to cause my knee to lock up quit often so I went to get it fixed.  The OS removed the loose body and all seemed well.  Until about 2 and half monthes ago when my knee gave out and down to the ground I went.    I went back to the OS and we thought maybe (but probably not) i had torn a ligament.  We decided to wait and see if the swelling went down and how I felt after 2 weeks.  Well I was walking better, or as good as could be expected cause my knee does ache alot but I told the OS i had been dealing with knee pain for years so i was set to go.  She on the other hand was not to happy I still had significant pain on my joint line and showed more instability in my knee so she wanted the MRI just to be sure. Well got the MRI done and it did not show any tears of ligaments.  It did show that I had lost about 80 percent of my cartlidge and had a 1.8 cm on my weight bearing side.  She then sent me to the specialist (my originial OS) who specializes in sports injuries and was the guru for this type of situation.  He informed me of the OATS procedure and I have had my doubts about it and have been reading about it on here.  Now I am not real sure what type of rehab or the affects yet I will discuss more with him on that next week and I will post the notes here.  But he did tell me that I would probably not be able to play ball (basketball, baseball, or softball) again.  Now for my Microfracture I was back to playing sports about 10 monthes afterwards, did not use a CPM, and was never non weight bearing.  Maybe that is why it failed but it last for a little while.  I will defenitely ask my OS some questions and post the answers here

thanks

[Beauzer]

I had a microfracture in 1999.  My OS also didn't make me NWB either.  A year later, I definitely had cartilage regrowth.  In 4/2005, I ended up having an OATS for OCD in the same area.  Now less than 6 months later, I have AVN around my OATS plugs.  The OATS was worth it though.  I had 3 months of absolutely no pain or disability and felt normal. 

OATS is a rough procedure though.  6 weeks NWB, a few weeks PWB.  Lots and lots of rehab to make it work (or not, as my case would be).  Also, any procedures for OCD have a higher failure rate, just because of the underlying disease process.  Also, any activity that stresses the knee is bad.  I was told that I could stationary bike and swim and that was really it.  Still, what do you do if you're young and have OCD?  There's no easy answer, as I'm certainly discovering.  I'm currently NWB again for 6 weeks to try to heal the AVN and fracture around my plugs.  If it doesn't go away, we're not really sure what to do at this point, as I'm only 31.

Anyway, good luck.  If you want more info about stuff on OATS, just IM me
Danielle