The medical machine acts quickly. This is a good thing when situations are dire and life or limb is at stake. However, in less serious situations the expediency of the process may fail to consider all of the current evidence regarding diagnosis, treatment options, and their overall effect on prognosis. The urgency of the process may at first seem reassuring to the patient; instilling confidence the clinician knows what they are doing and making informed decisions. This process should be collaborative but often it becomes authoritative. Patients are expected to make quick decisions as a lay person to the field. Thus the process necessitates trust. Trust in the clinician, trust in the decision making, and trust in the information being delivered to them is the best we have (hopefully based on current research evidence). This discussion could quickly become about informed consent and perhaps in the future we will write a post about the positive and negatives of the topic. However, we’d rather focus on prevalent issues in the athletic world that typically are accompanied with imaging and a looming question of, how should we manage this issue.


If you’ve been following our blog, then it’s apparent things are becoming harder and harder to call pathologies or abnormalities based on imaging. The knee region is no different. Issues such as meniscal damage and osteoarthritis are readily identifiable in asymptomatic populations (For Not Your Image references for the knee see Culvenor et al, Beals et al, Pappas et al, van der Heijden et al, and Guermazi et al).1,2,3,4,5

This post will be all about the bee’s knees….more specifically their meniscus. Which ironically, the bee’s knees used to mean – “something small and insignificant”. Which is the question we will set out to answer in this blog, how significant is the meniscus and when damaged what should we likely do about it based on current best evidence.

So, what is the meniscus?

The meniscus is primarily a type 1 collagen based fibrocartilaginous structure located in the tibiofemoral joint. The anatomy and anatomical location of the structure implies a function of shock absorption and transmission of force. There are two aspects of the meniscus, medial and lateral.

The meniscus may be damaged from contact (trauma) based injuries or age-related degeneration over time. Meniscal based injuries are considered the second most common knee injury with an incidence of 12% – 14% (61 cases / 1000,000 people in U.S.). It is estimated that 10-20% of all orthopedic surgeries involve the 

knee meniscus (850,000 patients / year).6 Classification of meniscus damage is typically based on location and orientation of a tear (see figure1).7 Tears can include: vertical longitudinal, vertical radial, horizontal, oblique, and complex.7 A complete vertical tear has the potential to flip within the joint space creating what is known as a “bucket-handle” tear.7 Typically a bucket-handle tear is considered an unstable tear provoking locking of the knee joint i.e. mechanical symptoms. Previously, such symptoms were thought to warrant surgical intervention.8 However, most recently evidence has been emerging contradicting usual practice.

The underlying theme that is problematic for addressing this issue appropriately is our premise – a structural deficit causative of symptomatology. With this in mind we will now discuss the current evidence regarding the best possible management of meniscal tears.

Based on the recent British Journal of Sports Medicine clinical practice guidelines, arthroscopic surgery for degenerative knee OA and meniscal tears is NOT recommended. The authors conclude,

“We make a strong recommendation against the use of arthroscopy in nearly all patients with degenerative knee disease, based on linked systematic reviews; further research is unlikely to alter this recommendation.

This recommendation applies to patients with or without imaging evidence of osteoarthritis, mechanical symptoms, or sudden symptom onset.”9

In those guidelines they discuss a systematic review by Brignardello-Peterson. This is a review article that finds knee arthroscopy is no better than conservative management for patients with degenerative changes.10

The BJSM’s recommendation certainly falls in line with what the overall research has been demonstrating on the topic of chronic degenerative meniscal tears.

Now, this paradigm shift will likely continue to take time. Immediately after the BJSM release, an open letter to the editor was written in the Arthroscopy Journal (go figure….) demonstrating a major appeal to authority, post-hoc fallacy, and confirmation bias.11

Excerpts from the letter:

“I question how the authors have the required knowledge base to critically analyze the articles they have chosen to review. Once again they seem to be predominately epidemiologists, with the only orthopaedic input coming from an “orthopaedic resident” whose major interest seems to be research methodology. I personally would not have the confidence to cast judgment on a paper from a different specialty of orthopaedics, let alone a subject about which I do not have an intimate knowledge or extensive professional background.”

“I strongly believe that these (BMJ) conclusions cannot be justified based on the evidence presented and that they are wrong. I would be happy to discuss my detailed
reasoning with you further and to introduce you to some of my patients.

I appreciate that this is anecdotal but in the last two weeks I have seen a 50 year old joiner who was struggling to work because every time he knelt down his knee locked and in desperation had come to see me privately as he had been denied surgical referral after a “normal MRI.” After taking out his degenerate bucket handle tear he was back at work after a week.”

If you are in need of a neurophysiological effect that will spike your BP, go read the entire letter.

Where does this leave us for case management?

Rehab clinicians are uniquely poised to handle these cases. During initial consultation a discussion should be had regarding patient’s beliefs about the issue and previous narratives supplied. Followed by an open discussion about current pain science information (curious about this info? – read HERE) along with setting expectations for the future. Exercises can then be implemented specific to the patient’s goals to help return them to previous level of activity. Symptoms will likely improve with time and we simply need to guide the process back to desired activities while setting appropriate expectations and instilling behaviors to cope with any potential future symptoms.

Many patients may be concerned about locking symptoms aka mechanical symptoms.

Sihvonen has a study from 2016, Mechanical symptoms as an indication for knee arthroscopy in patients with degenerative meniscus tear: a prospective cohort study. 900 patients recruited, underwent arthroscopy, and followed-up with 1 year later.8

The authors found 47% (243 out of 513 cases reporting mechanical symptoms) of participants reported persistent symptoms 12 months post-operatively. Additionally, the sample reporting no mechanical symptoms pre-operatively (282 participants), 11% (32) reported mechanical symptoms at 12-month follow-up. The authors’ findings continue to question the attempted validation for meniscal surgery based on mechanical symptoms, often attributed to bucket-handle tears.

Arthroscopic knee surgery for patients dealing with degenerative knee disease remains the most common orthopedic surgical procedure in many countries despite evidence contradicting support.9

There are several common narratives that continue to permeate the field to substantiate the intervention for degenerative knee disease as it relates to the meniscus.

Sihvonen et al explains these narratives in his article,  Arthroscopic partial meniscectomy versus placebo surgery for a degenerative meniscus tear: a 2-year follow-up of the randomised controlled trial12:

  1. Failed conservative management
  2. Mechanical Symptoms
  3. Unstable tears

The authors compared arthroscopic partial meniscectomy (APM) versus placebo surgery in participants with mechanical symptoms and those presenting with unastable meniscus tears. The authors found,

“……no statistically significant difference between the APM and placebo surgery for symptomatic patients with a degenerative meniscus tear and no osteoarthritis (OA) in any of the used outcome measures over the course of 24-month follow-up. No evidence could be found to support the prevailing ideas that patients with presence of mechanical symptoms or certain meniscus tear characteristics or those who failed initial conservative treatment are more likely to benefit from APM.”12

Their findings continue to question the attempted validation for meniscal surgery based on mechanical symptoms.

At this point, it would appear the evidence is almost insurmountable regarding the appropriate plan of care for chronic degenerative meniscal tears.

Which begs the question, what about traumatic tears? This is a difficult question to answer because what designates a trauma? Sihovnen excluded patients with reported acute traumas in this latest study but explains how convoluted this line of thinking is and current evidence still isn’t supportive:

“Obviously, the concepts ‘degenerative’ or ‘traumatic’ in the context of meniscal injuries are very vague by nature. In this trial, all patients with sudden injuries related to their own voluntary muscle activities (such as kneeling, bending or kicking) and patients with a minor twisting of the knee were included. In essence, our criteria for labelling a tear as ‘traumatic’ required a more substantial event, such as falling from a chair, stairs or bicycle, or slipping on ice.”12

Now this is typically where we can argue regarding athletes and timeframe for return to sport. Unfortunately, there still isn’t sufficient evidence to make informed decisions about this population.

As an aside – be sure to review included studies in review articles.

THIS article exists with the following conclusion:

“In conclusion, meniscal tears in patients 18 years old or younger are not uncommon, and they can be associated with a long period between the onset of symptoms and surgical treatment. Repairs of this injury produced good to excellent outcomes in most patients, regardless of the injury pattern, zone, or technique. Reported complications are minimal, increasing the potential application of this surgical treatment modality. Higher quality studies are needed to confirm the findings of this systematic review.”13

After reviewing the included studies, the review was completed on 8 case series studies and NO randomized controlled trials. We already have good evidence that in other populations (older) meniscal surgery is no better than sham, which is why we need RCTs to make informed decisions. Also, the authors stated reported complications were minimal, but yet 44 participants went on to have meniscectomy after an initial meniscal repair; this is out of 287 total participants.

Thorlund recently released this study, Risk factors, diagnosis and non-surgical treatment for meniscal tears: evidence and recommendations: a statement paper commissioned by the Danish Society of Sports Physical Therapy (DSSF).14

The authors state:


“No randomised trials comparing non-surgical treatments with surgery in patients younger than 40 years of age or patients with traumatic meniscal tears were identified.”14

This is a major problem. Currently, it would seem we allow youth surgical intervention on meniscus for unsupported narratives. However, it looks like we will have some evidence very soon. Thorlund et al states at the end of the article:

“Given the lack of evidence there is a need for high-quality randomised trials comparing surgical and non-surgical treatments of meniscal tears in younger patients and patients with a traumatic tear. Two such studies, one Dutch and one Danish, are currently underway.”14

Closing Thoughts:

For now, based on the current totality of evidence, our best bet is conservative management via education and exercise for meniscus issues, regardless of population. Perhaps future evidence will emerge identifying subsets of populations warranting of meniscal surgery but as of now the evidence isn’t supportive or completely lacking. The premise surgery is warranted requires teasing out qualifiers to necessitate surgery from a biological perspective which would be difficult given the current research on pain science and lack of biological pain “drivers” (see citations in introduction). When and how much does biology matter, we are not entirely sure and don’t have enough evidence to make informed decisions regarding the topic outside of extreme traumatic situations. The jury is still out on youth athletic populations, but given what we’ve seen thus far with ACL reconstruction long-term outcomes – skepticism is high.15

As always, if you want to discuss the article with us on Twitter, or just recommend a beer for us to try you can find us at:

@DMilesPT

@MichaelRayDC

References:

  1. Culvenor AG, Øiestad BE, Hart HF, Stefanik JJ, Guermazi A, Crossley KM. Prevalence of knee osteoarthritis features on magnetic resonance imaging in asymptomatic uninjured adults: a systematic review and meta-analysis. British journal of sports medicine. 2018;
  2. Beals CT, Magnussen RA, Graham WC, Flanigan DC. The Prevalence of Meniscal Pathology in Asymptomatic Athletes. Sports medicine (Auckland, N.Z.). 2016; 46(10):1517-24.
  3. Pappas GP, Vogelsong MA, Staroswiecki E, Gold GE, Safran MR. Magnetic Resonance Imaging of Asymptomatic Knees in Collegiate Basketball Players: The Effect of One Season of Play. Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine. 2016; 26(6):483-489.
  4. van der Heijden RA, de Kanter JL, Bierma-Zeinstra SM, et al. Structural Abnormalities on Magnetic Resonance Imaging in Patients With Patellofemoral Pain: A Cross-sectional Case-Control Study. The American journal of sports medicine. 2016; 44(9):2339-46.
  5. Guermazi A, Niu J, Hayashi D, et al. Prevalence of abnormalities in knees detected by MRI in adults without knee osteoarthritis: population based observational study (Framingham Osteoarthritis Study) BMJ. 2012; 345(aug29 1):e5339-e5339.
  6. Logerstedt DS, Snyder-Mackler L, Ritter RC, Axe MJ, Godges J. Knee Pain and Mobility Impairments: Meniscal and Articular Cartilage Lesions J Orthop Sports Phys Ther. 2010; 40(6):A1-597.
  7. Mordecai SC. Treatment of meniscal tears: An evidence based approach WJO. 2014; 5(3):233-.
  8. Sihvonen R, Englund M, Turkiewicz A, Järvinen T. Mechanical symptoms as an indication for knee arthroscopy in patients with degenerative meniscus tear: a prospective cohort study Osteoarthritis and Cartilage. 2016; 24(8):1367-1375.
  9. Siemieniuk RAC, Harris IA, Agoritsas T, et al. Arthroscopic surgery for degenerative knee arthritis and meniscal tears: a clinical practice guideline Br J Sports Med. 2018; 52(5):313-313.
  10. Brignardello-Petersen R, Guyatt GH, Buchbinder R, et al. Knee arthroscopy versus conservative management in patients with degenerative knee disease: a systematic review BMJ Open. 2017; 7(5):e016114-.
  11. Bollen S. An Open Letter to the Editor of The BMJ Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2018; 34(1):8-11.
  12. Sihvonen R, Paavola M, Malmivaara A, et al. Arthroscopic partial meniscectomy versus placebo surgery for a degenerative meniscus tear: a 2-year follow-up of the randomised controlled trial. Annals of the rheumatic diseases. 2018; 77(2):188-195.
  13. Ferrari M, Murphy C, Gomes J. Meniscus Repair in Children and Adolescents: A Systematic Review of Treatment Approaches, Meniscal Healing, and Outcomes J Knee Surg. 2018;
  14. Thorlund JB, Juhl CB, Ingelsrud LH, Skou ST. Risk factors, diagnosis and non-surgical treatment for meniscal tears: evidence and recommendations: a statement paper commissioned by the Danish Society of Sports Physical Therapy (DSSF) Br J Sports Med. 2018; 52(9):557-565.
  15. van Yperen DT, Reijman M, van Es EM, Bierma-Zeinstra SM, Meuffels DE. Twenty-Year Follow-up Study Comparing Operative Versus Nonoperative Treatment of Anterior Cruciate Ligament Ruptures in High-Level Athletes Am J Sports Med. 2018; 46(5):1129-1136.