To Cut or Not to Cut, That is the Question (with Meniscus Tears)

Employment-related meniscus tears are among the more common worker’s compensation claims.  The reasons are myriad but are influenced by the fact that most people develop degenerative meniscus tears as they age and the mechanism of injury for an acute tear merely involves twisting the knee, which can occur in even the lightest and most sedentary occupations because all workers who are not wheelchair-bound walk which means all workers are at risk of twisting their knee in a slip, trip, or fall at the workplace.  Setting aside the possibility that such an event is idiopathic, if a worker seeks medical treatment for knee pain following an industrial event and a meniscus tear is discovered on an MRI the treating physician usually relates the tear to the event.  Standard treatment in most such cases is usually surgical excision of the loose or torn meniscal tissue, more commonly known as a meniscectomy.  The assumption driving the surgery is that the meniscus tear is causing the knee pain and resecting the tear will eliminate the pain.  The problem with this scenario is that most meniscus tears are degenerative and there is no high quality research demonstrating that meniscectomy is an effective treatment for degenerative meniscus tears.  In fact, when researchers recently studied the question they found that exercise was equally effective as meniscectomy to treat knee pain in the presence of a degenerative meniscus tear, according to results published in the British Medical Journal (“BMJ”).

In the worker’s compensation setting, the argument is often made that an industrial event extended a preexisting degenerative meniscus tear in order to justify the surgical intervention (and coverage of the procedure under a worker’s compensation insurance policy).  The cost of meniscectomies to the worker’s compensation system is substantial.  The medical expenses alone are significantly higher for surgery than for conservative care.  In addition, meniscectomies often result in some permanent partial disability.  For example, a meniscectomy in Wisconsin carries with it a 5% minimum PPD rating to the lower extremity at the level of the knee and under the AMA Guides a meniscectomy typically results in at least a 1% impairment rating.  Surgery also typically necessitates a period of temporary total disability in non-sedentary workers.  The findings of the BMJ study should give every employer and worker’s compensation insurer pause and an editorial advocating systemic prohibition of using arthroscopy to treat knee pain that appears in the same issue should spur change.

First, a few things about the study itself.  The BMJ study is a level 1, properly designed randomized controlled trial.  This is the highest category of medical studies and is considered to produce the best and most reliable evidence available.  The BMJ study was conducted in Norway and was a randomized control trial with two parallel intervention groups of 70 patients per group.  One group received exercise alone and the other group received partial meniscectomy alone.  The participants were 35-60 year old persons of both sexes with a 2+ month history of unilateral knee pain without a major trauma but with a verified medial meniscus tear verified on MRI and no worse than grade 2 arthritic changes on x-ray.  The study found that there was no difference in outcomes between the two groups at 3 months and 24 months post-intervention.  The meniscectomy group reported better function and greater participation in sports and recreation at 12 months post-intervention, but the effect was gone by 24 months.  The authors could “not exclude the possibility that the greater placebo effect from surgery on patient outcomes” may have “mask[ed] the ‘real’ difference in treatment between the groups,” which they postulated could explain the temporary effects observed in the meniscectomy group.

More striking even than the study findings is the accompanying editorial.  The authors of the editorial call for a systemic level rule to prevent unnecessary knee arthroscopies from being performed to treat knee pain.  As they note, in the last decade:

A series of rigorous trials, summarized in two recent reviews and meta-analyses, provide compelling evidence that arthroscopic knee surgery offers little benefit for most patients with knee pain.  The latest nail into what should be a sealing coffin appears in a linked paper by Kise and colleagues (doi:10.1136/bmj.i3740):  a rigorous comparison between exercise alone and arthroscopic partial meniscectomy alone (without any postoperative rehabilitation) in adults with degenerative meniscus tear.  The authors found no between group difference in patient reported function at the two year follow-up…

The editorial authors note there has never been high quality research supporting meniscectomy in an older population with degenerative meniscus tears, but that the procedure was extended to this population based on unverified assumptions:

With no support aside from biological rationale, the indication crept from locked knees in young patients to all patients of all ages with knee pain and meniscus tears of any sort; tears which, on magnetic resonance imaging, have proved poorly associated with symptoms. 

The conclusion they reach is both astonishing and harsh:

We are at the point where any careful scrutiny, by, for instance, public health administrators or officials of an insurance company, would conclude that the estimated two million arthroscopic partial meniscectomies undertaken globally each year at a cost of several billion US dollars is potentially nothing but medical waste. Because frontline practitioners and local commissioners have not responded appropriately to the evidence, it follows that system level measures that result in more appropriate use of scarce medical resources are necessary—and perhaps urgently required.

In short, the authors believe the evidence against arthroscopy to treat knee pain is so strong and the evidence for it is so weak that health systems as a whole should stop paying for these procedures.  Such a rule would have a significant impact on worker’s compensation claims where meniscectomies are routinely performed to treat degenerative meniscus tears.


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