Last updated: March 2019

Degenerative meniscal tear

1. What is the meniscus of the knee joint?

The picture below shows the anatomy of the knee joint. The knee consists of a medial (inner side of the knee) and a lateral (outer side of the knee) meniscus. The meniscus can be described as a thick pad of cartilage. The menisci are C shaped and they function as shock absorbers meaning they absorb any impacts sustained through the upper leg and the lower leg. In addition they aid to improve the stability and general movement of the knee joint.

2. What causes meniscus of the knee joint?

The meniscus can be injured in two main ways:

Acute trauma to the knee and meniscus itself
Sports such as football, skiing and rugby are commonly associated with meniscal tears due to twisting movements whilst weight bearing through the knee joint. The meniscus can be torn partially or fully.

Degenerative meniscal tears
Degenerative meniscal tear can occur at any age. Although more common in older populations due to wear and tear of the joint it is important to note that degeneration can occur at any stage in life. The knee pain can arise with mild or innocuous events. Ageing tends to make the meniscus less flexible thus making it more prone to developing a tear.

Research shows that it is more difficult to heal a tear caused by deterioration than an acute trauma that can occur earlier in life.

3. Symptoms

Symptoms of a degenerative meniscal tear vary. Some patients may not present with any symptoms at all. Some of the symptoms may include:

Pain
Most commonly associated problem caused by a meniscal tear. Intensity may vary from mild to severe to aches and sharper pains. Pain aggravated with twisting movements, impact activities, squatting and kneeling movements.

Swelling
This often develops within a day or two of the tear. Some swelling may last up to several months.

Function of the knee
Straightening the knee may cause pain, and thus people may experience difficulty with walking. If fragments from the torn meniscus interferes with the normal movement of the knee some people may also experience ‘locking’ of the knee.

Some people also report a clicking sound when they walk. You may be unable to straighten the knee fully. In severe cases you may not be able to walk without a lot of pain. On the other hand activities such as going down the stairs may result in giving way of the knee joint.

4. Treatment options

A. Pain relief
Over the counter pain relief medication can be the first line of treatment to manage the pain.

B. PRICE

• Protection – protect the knee from further injury by using a support.
• Rest – avoid exercise and reduce your daily physical activity. A walking aid may help if you can’t weight bear on your knee.
• Ice – apply an ice pack to the knee joint for 15-20 minutes every two to three hours. Wrap the ice pack in a towel so that it doesn’t directly touch your skin and cause an ice burn.
• Compression – an elastic compression bandage may control swelling if any. It is important to keep in mind that this is to be worn only during the day.
• Elevation – keep the knee joint raised above the level of your heart whenever possible. This may also help reduce swelling and thus pain management.

C. Exercises

Physiotherapy is often recommended to help strengthen the supporting muscles around the knee, restore any loss of movement and assist in regaining any lost function.

Exercises are aimed at strengthening the quadriceps, hamstrings and gluteus. These exercises are designed to increase blood flow to the joint, oxygen and nutrients and also to prevent stiffness. Other exercises will be designed to improve neuro muscular control, proprioception and balance.

The physiotherapist can design a personalised home exercise programme that can be performed at home or in a gym but the exercises below may be sufficient to improve your symptoms.

Quadriceps contraction
Lie on your back with legs straight. Bend your ankles and push your knees down firmly against the bed. Hold for 5 seconds and then relax. Repeat 10 times.

Inner range contractions
Lie on your back. Bend one leg, put your foot on the bed and put a cushion under the other knee. Exercise your straight leg by pulling your foot and toes up, tightening your thigh muscle and straightening the knee (keep knee on the cushion). Hold approx. 5 seconds and slowly relax. Repeat 10 times.

Prone knee flexion
Lie face down with your hips straight and knees together. Bend your knee as far as possible keeping hip straight and ankle flexed. Hold approx. 5 to 10 seconds. Repeat 10 times.

Straight leg raise
Lie on your back. Tighten your thigh muscle and straighten your knee. Lift your leg 20cm off the bed. Hold 5 seconds. Repeat 10 times.

Knee bending
Lying down on your back, bend and straighten your hip and knee by sliding your foot up and down the bed. Fully bending the knee, hold the position for 5 to 10 seconds. Repeat 10 times.

Bridging
Lying on your back with knees bent and feet on the floor. Lift your pelvis and lower back (gradually, vertebra by vertebra) off the floor. Hold the position. Lower down slowly returning to  starting position. Repeat 10 times.

Single leg bridge
Lying on your back with knees bent. Lift your hips up and keep them straight while shifting the weight over to one leg. Then straighten the other leg – put it back down and repeat with the other leg. Repeat 10 times.

Squats
Stand behind a chair and support yourself with both hands. Slowly bend your hips and knees, trying to push your bottom back. Your knees should be above your toes. Do not let your knees turn in or out during the movement. Repeat 10 times.

Single leg exercises
Stand on one leg with knee slightly bent and the end of a rubber exercise band under your foot. Hold the other end in your hand. Pull the band to hip height. Straighten your leg and then return to starting position. Repeat 10 times.

Aim to do all exercises 2–3 times daily as your pain allows.

D. Corticosteroid injections

A corticosteroid injection may be recommended if pain and inflammation persists. This may help relieve the pain although research shows that in some cases the pain relief is either minimal or short lived. If deemed appropriate the corticosteroid injection can be repeated up to three times.

5. What happens if pain persists?

The latest evidence shows us that for the majority of people with a degenerative tear of their cartilage that time is the biggest factor in their recovery and an arthroscopy (camera in the knee performed under general anaesthetic), does not provide any long-term benefit. This is particularly the case where there is more extensive osteoarthritis in the knee joint.

Full recovery post surgery may take up to six weeks but this varies between patients and it may take longer than that. Exercises are recommended to control pain and swelling and gradually re-build the strength and stability in the knee joint. Again the physiotherapist will advise the patient further about the appropriate exercises for the individual.

6. References

Musculoskeletal Service (2017). Knee cartilage injury: Information for Patients. Retrieved from http://www.sompar.nhs.uk/media/4685/fact-sheet-musculoskeletal-knee-cartilage-injury-final-061115.pdf

Management of degenerative meniscal tears and the role of surgery. BMJ (2015). doi: https://doi.org/10.1136/bmj.h2212

Stensrud, S., Risberg, M.A., Roos E.M. (2015). Effect of exercise therapy compared with arthroscopic surgery on knee muscle strength and functional performance in middle-aged patients with degenerative meniscus tears: a 3-mo follow-up of a randomized controlled trial. DOI: 10.1097/PHM.0000000000000209

Degenerative Meniscal Tears. (2018). University of Plymouth. Retrieved from https://www.plymouthhospitals.nhs.uk/degenerative-meniscal-tears