The knee joint is one of the most complex joints in the human body. It is also one of the most commonly injured joints amongst the sporting population.
One of the most common knee injuries is injury to the meniscus. The meniscus are tough C shaped fibrocartilage structures which sit on the tibial plateau. The meniscus are important as they distribute load and help absorbing shock.
One of the most important things you can do assessing someone with an acute knee injury is make sure yet get the entire subjective history from the client. Key things to consider are;
- Mechanism of Injury. Meniscus injuries usually occur when the knee is flexed and the person twists. Injury can be degenerative as well as traumatic.
- Degree and onset of any swelling. This will let you know if the injury is intra- articular are extra-articular (or both). Meniscus damage will usually swell immediately.
- The location of the pain (get the client to point this out). Pain from the collateral ligaments is generally well localised, Cruciate ligament injury is generally more diffuse.
- Severity of pain. With large Meniscus tears, severe sharp pain can occur as the cartilage gets stuck and “locks” the joint.
- If the patient could walk post injury.
- If they heard a noise or felt a “giving away”.
- If there are any symptoms of catching and locking.
Note: the hyperflexion of the Mcmurrays test is usually enough to evoke a pain response.
Thessaly Test in 20 degrees flexion
Objective findings that indicate a Meniscus tear include:
· Joint line tenderness at 45-90 degrees flexion
· Pain with hyperflexion (and at rest).
· Restricted ROM and catching or locking.
For a concise and complete objective examination for acute knee injuries, the below video is a good watch.
MRI is the image of choice as it can aid in management by showing if the tear is a complex tear. If the tear is minimal and non-displaced, conservative management is advised. If the tear is peripheral and displaced, depending on the length and severity, it can be fixed surgically (Brukner & Khan, 2012).
Most Meniscus injuries will fall between major bucket handle tears and a small tear which presents with pain yet with no mechanical locking or restrictive ROM symptoms. This is where it can become tricky to decide whether or not to proceed with conservative or surgical management. When this is the case, the decision needs to be made on the basis of how severe the symptoms are, and what the patient wants to get back to (ie the sportsman versus the older more sedentary patient).
In terms of guidelines as when to opt for surgical treatment the following generally applies (Brukner & Khan, 2012).
- Increasing pain (as opposed to stable pain).
- Correlating MRI findings with a displaced tear.
Meniscus Repair or Meniscectomy?
There has been much debate over meniscus repair or meniscectomy over the years but emerging evidence is now pushing for meniscus repair over meniscectomy. Maintaining the meniscus by means of repair versus removal obviously means that the joint has a greater ability to absorb shock and disperse load. The results of a study by Stein et al showed that at 8 years follow up there were no signs of osteoarthritic changes in 80.8% of those who underwent Mensical repair, versus only 40% of those who underwent Meniscectomy.(2010).
For a great summary of the pros/cons and evidence for meniscus repair over meniscectomy click here.
The following is a general guide only taken from Brukner and Khan’s Clinical Sports Medicine. Each person will respond differently to rehabilitation and at different rates.
a. Control swelling, maintain knee extension, knee flexion to 100 degrees +, quads and hamstring strength
b. VMO setting, Gentle ROM, supported calf raises, hip work, gait re-education, light exercise bike.
a. Eliminate swelling, Full ROM, full strength
b. ROM drills, VMO setting, mini squats and lunges, leg press, step ups, bridges, resisted hip work, gait re-education, single leg calf raise, balance and proprioceptive work (single leg), gentle swimming, walking, exercise bike.
a. Full ROM, dull strength, full squat, dynamic proprioceptive training, return to running and restricted sport specific drills.
b. As for weeks 1-2 yet increase difficulty, reps and weights, jump and land drills, agility drills,
a. Full ROM, Strength and endurance. Restricted training and match play.
b. High level sport specific training.
As always, treat each patient as an individual. Often meniscus injuries are accompanied by other structural injuries such as an MCL tear. Remeber to work with the patient and educate them each step of the way. Without the knowledge of what is wrong with them and relating this back to why it is important that they follow rehab protocols, progress will be difficult and the outcomes sub-optimal.
Sports Medicine Australia: Meniscus Injuries
The diagnostic accuracy of clinical tests.
Meniscus repair or meniscectomy?
Long-Term Outcome After Arthroscopic Meniscal Repair Versus Arthroscopic Partial Meniscectomy for Traumatic Meniscal Tears
Clinical Sports Medicine. (2012). Brukner & Khan