MRI Knee Pain

Long Term Study Confirmation!

Do Not Rely on MRI Findings for Knee Pain Etiology!

We like to comment on medical literature so that you as our loyal readers can know that everything you read must be taken in the proper context. Here is a recent article from Science Daily, June 2008 issue entitled Meniscal damage and the development of persistent knee pain. The link to the article can be found here:

http://www.sciencedaily.com/releases/2007/11/071129085757.htm.
The author of this article is commenting on the articles referenced at the end of this article.

Marked by cartilage and bone degradation, progressive knee osteoarthritis (OA) is believed to result in part from a combination of several local mechanical factors. Lack of joint stability, poor joint alignment and injuries to the disks of meniscal tissue that cushion the knee all affect load distribution and the toll to the vulnerable OA knee. However, in studies of knee OA progression, either meniscal damage or malalignment has been considered, but not both together, and no studies have included joint laxity.

Unlike radiographs, magnetic resonance imaging (MRI) can distinguish articular cartilage (see also Articular Cartilage Growth) from meniscal tissue and detect the impact of specific factors on OA progression. Almost all studies of knee OA progression with MRI outcomes define cartilage loss with qualitative cartilage assessments. For a clearer picture of the role of various mechanical factors in knee OA, researchers at Northwestern University and Salzburg Univeristy applied quantitative measures of cartilage loss—decreases in cartilage volume and thickness and an increase in bare bone area—as well as cartilage integrity score.

Their results indicate three factors that independently predict cartilage loss with a direct impact on knee OA: medial meniscal damage, lateral meniscal damage, and varus, or bow-legged, malalignment of the knee joint. Notably, quantitative cartilage loss outcome measures were more sensitive in revealing these relationships than previously applied qualitative approaches.

The study’s participants, 153 women and men with radiographic evidence of knee OA, were recruited from local senior citizens groups and the registry of the Beuhler Center on Aging at Northwestern University. The mean age was 66 years and the mean BMI was 30. None of the subjects had a history of Rheumatoid Arthritis, gout, joint infection, or meniscectomy. A total of 251 osteoarthritic knees were thoroughly scanned with MRI and rigorously studied. Meniscal damage and meniscal extrusion were graded using the Whole-Organ MRI Score (WORMS). Varus-valgus alignment and medial-lateral laxity were also measured.

Focusing separately on medial and lateral segments of tibial and weightbearing femur cartilage of the knee joint, cartilage volume, percentage of subchondral bone covered with cartilage, exposed subchondral bone area, and the average thickness of cartilage were measured using specialized software. Cartilage integrity was also scored. Two years later, the entire process was repeated. Odds ratios were determined for each of the four mechanical factors using logistic regression analysis, adjusting for age, sex, BMI, and the other factors.

Medial meniscal damage significantly increased the likelihood of cartilage volume loss, cartilage thickness decrease, and denuded bone increase in both the medial tibial and the medial weightbearing femoral segments. Similarly, lateral meniscal damage predicted quantitative cartilage loss in both the lateral tibial and the lateral weightbearing femoral segments. Varus malalignment was strongly associated with cartilage loss from each medial surface; valgus (knock-knee) malalignment was not associated with lateral surface loss. Meniscal extrusion and joint laxity had inconsistent effects. Using the qualitative cartilage assessment, however, no significant relationship with outcome was detected for either meniscal damage or malalignment.

Dr. Leena Sharma, the study’s leading author and spokesperson, commented “It is important to note that local factors, such as those examined in this study, may participate in vicious circles with the worsening of knee OA. Whenever along the OA disease timeline a local impairment develops, it may contribute to subsequent OA progression and cartilage loss, especially given the vulnerable milieu of the already damaged OA knee. Ultimately, strategies that interrupt these vicious circles may be especially powerful."

Sharma, L. et al. Relationship of Meniscal Damage, Meniscal Extrusion, Malalignment, and Joint Laxity to Subsequent Cartilage Loss in Osteoarthritis Knees. Arthritis & Rheumatism, June 2008; 58:6 pp. 1716-1726

Wiley-Blackwell (2008, June 2). Meniscal Damage And Joint Malalignment Predictors Of Cartilage Loss. ScienceDaily. Retrieved August 28, 2008, from http://www.sciencedaily.com/releases/2008/06/080602160758.htm

Caring Medical’s Opinion:

Ross Hauser, MD

“Doctor my MRI showed…” Oh, I hate those words. People are still under the impression that MRI’s will reveal the cause of their pain. In my opinion, the main piece of the puzzle that will tell people what is wrong with them is their very own history! Physical examination should confirm what is suspected from talking to the patient (their symptoms). An MRI is ordered to prepare someone for surgery and/or to confirm what is already known from the history and physical examination!

Let’s take a look at this article. Over 3000 people were monitored over eight years. Initial MRI’s were taken, and then again eight years later. Here is their summary, “When considering the co-occurrence of OA (osteoarthritis of the knee) and performing a stratified analysis, researchers found no independent association between meniscal damage and the development of frequent knee symptoms.”

What does this mean? The bottom line is that an MRI cannot tell you what is wrong based just on the MRI finding. It must be taken in context with the history and physical examination of the patient. In my opinion what is the “best” MRI? If you have read our books, you know that it is “my reproducibility instrument,” which is my thumb. I poke my thumb into the injured structure which elicits a “positive jump sign.” The doctor and the patient both know what is causing the pain. The patient receives Prolotherapy to the injured structure to induce repair and the pain goes away. Even if three to five visits are required, the whole cost of the Prolotherapy is often less than the cost of one MRI.

I’d like to bring up another point in the above article. The author states that, “Stressing the importance of treating OA as a whole-joint disorder, this order calls attention to the risk of misinterpreting meniscal damage as the direct cause of knee pain.”

What does this mean? The bottom line here is this! What treatment actually treats OA as a whole-joint disorder? Prolotherapy does! That is why it works for osteoarthritis! Typically, Prolotherapy for knee pain is given around the whole joint because osteoarthritis is a “whole joint” disorder.

This was a great study and a great article! Since we are using the word great, Prolotherapy is a great treatment for knee pain!