What is the meniscus?

The meniscus is a fibrocartilage structure within the knee that’s primary role is to bear load and assist in stabilization of the knee joint (Ghosh, 1987).

Do all meniscus injuries require surgery?

No!

Many meniscus tears can recover without surgery.

A recent randomised controlled trial included 107 young active adults (mean age: 29.7 years), and tegner activity level between 0 to 10 (sedentary to elite competitive sport) with atraumatic, semi-traumatic, or traumatic meniscal tears. Patients were randomised to receive either early meniscus surgery (partial meniscectomy, or repair), or 12 weeks of supervised rehabilitation with the option of delayed surgery.
At 1 year follow-up there was no statistical difference in outcome measures, and 74% of those in the rehabilitation group remained non-surgical, while 26% crossed over to have surgery. 13% of the early surgery group decided not to have surgery, with many reporting resolution of symptoms prior to surgery (Skou et al, 2020).

Duchman (2015) found that in 194 patients with 208 meniscus tears (71 medial, and 137 lateral) that were not operated on, 6 years after ACL reconstruction. At 6 year follow-up 97.8% of lateral and 94.4% of medial meniscus tears did not require operation. In a matched cohort study of 45 meniscus root (15 treated non-operatively, 15 treated with meniscectomy, and 15 treated with surgical repair) there was no difference in patient reported outcomes or activity level between groups at 74 month follow-up (Bernard, 2020).

Between 2 - 32% of asymptomatic individuals with no history of knee pain may have a meniscus injury on MRI. Increased age is closely associated with prevalence of meniscal injuries in asymptomatic adults (Culvenor, 2019; Guermazi, 2012; Horga, 2020).

How do I know if my meniscus tear requires surgery?

At present there are no identifiable patient subgroups that benefit from meniscus surgery. In patients that undergo physiotherapy who are eligible for meniscus surgery, we cannot predict who will require meniscus surgery within 2 years (Noorduyn, 2021; Pihl, 2019). Even experienced surgeons cannot predict who will benefit from meniscal surgery. Graaf (2019) found that experienced surgeons predicted who would benefit from meniscal surgery at a rate of 50.4% (literally chance).

If you have a bucket-handle tear and a locked knee, it is a fair argument that surgery is likely indicated and an orthopaedic assessment is required, although strong scientific evidence is still lacking.

What are the possible risks associated with meniscus surgery?

The risks associated with meniscus surgery include pain, swelling, instability, scarring, infection, muscle atrophy, stiffness, reduced knee function, osteoarthritis, pneumonia, cerebrovascular accident, allergic reaction, wrong-site surgery and although extremely rare, death.

Meniscectomy has been shown at 10 year follow-up to increase the risk of radiographic osteoarthritis compared to sham surgery (Sihvonen, 2019).

Meniscal repair failure rates are between 9 - 48%, and repair failure is associated with an increased risk of osteoarthritis (Petersen, 2021; Ronnblad, 2021).

What are the possible risks associated with rehabilitation without surgery?

The risks associated with not having surgery include pain, swelling, instability, subsequent injury, osteoarthritis, stiffness, reduced knee function.

What should I do if I have a meniscus tear?

Supervised rehabilitation should be the first line treatment for almost all meniscal injuries, high-quality evidence shows most people with meniscal pathologies can recover without surgery. It is recommended to consult a physiotherapist to discuss your rehabilitation options. (Graaff, 2022; Thorlund, 2015, 2018; Sihvonen 2013, 2017, 2019; Skou et al, 2020).

Can a meniscus tear heal?

Yes!

It is possible for some meniscus tears to spontaneously heal, even large bucket handle tears have been reported to spontaneously heal, however evidence on the healing rates of the meniscus is scarce and therefore at present we are unable to determine the likelihood of healing (ESSKA 2019 Meniscus Consensus; Foad, 2012; McCallister, 2001 ;Urzen, 2016). Duchman (2015) evaluated 194 patients with 208 meniscus tears (71 medial, and 137 lateral) that were not operated on, 6 years after ACL reconstruction. At 6 year follow-up 97.8% of lateral and 94.4% of medial meniscus tears did not require operation.

Do I need an MRI?

No.

History of the mechanism of injury, signs and symptoms and clinical tests, such as the Mcmurrays test, joint line tenderness, and Thessalys and Ege test are sufficient to accurately diagnose a meniscus tear.
MRI may be useful if the clinical presentation is unclear (ESSKA 2016 and 2019 consensus).

Does surgery reduce my chances of developing osteoarthritis?

No.
In-fact a recent 5 year follow-up study of 146 patients with degenerative meniscus tears who had been randomized to receive either Arthroscopic Partial Meniscectomy (APM), or Sham surgery (skin incisions only) found that patients who had APM had slightly increased knee osteoarthritis on imaging compared to the sham group (Sihvonen, 2019).
Currently there is no high quality evidence comparing the effect of meniscus repair vs partial meniscectomy vs rehabilitation on the development of knee osteoarthritis (Monk, 2016). Stein (2010) found in a cohort study of 81 patients, those who received repair were half as likely to have progression of osteoarthritis compared to those who had meniscectomy at 8 year follow-up.

What happens if I fail rehabilitation?

If you have a degenerative meniscus tear, evidence shows no benefit to Arthroscopic Partial Meniscectomy compared to sham surgery and is not indicated (Sihvonen, 2013, 2017, 2019). Sihvonen (2017) quoted, in a 2 year follow-up of the FIDELITY sham-controlled trial “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 have failed initial conservative treatment are more likely to benefit from APM.”

If following a 3-12 month period of rehabilitation, you continue to experience pain, swelling, functional deficits and you have a traumatic meniscal tear. Repair or partial meniscectomy may be indicated (Skou et al, 2022). However, Thorlund (2017) found that patients with traumatic tears who received partial meniscectomy did not benefit greater than patients with degenerative tears who had partial meniscectomy, and in-fact those with degenerative tears had significantly greater improvements on KOOS (Knee Injury and Osteoarthritis Outcome Score) questionnaires.
“These results question the current tenet that patients with traumatic meniscus tears experience greater improvements in patient reported outcomes after arthroscopic partial meniscectomy than patients with degenerative tears”.