Injuries - Meniscus

MENISCUS CARTILAGE TEAR

The Injury

The term cartilage tear is slightly misleading, since it is the meniscus within the knee that is actually damaged.
There are 2 menisci within each knee joint that are made from tough fibrocartilage.
The menisci are roughly semicircular in shape and are thicker around the rim.
They are located on the tibial plateau (the top surface of the shin bone) between the tibia (shin bone) and the femur (thigh bone).
The function of the menisci is to increase the congruence of the knee joint and to act as shock absorbers during weight-bearing activity.
As the knee joint bends the thigh bone usually rolls, spins and glides on the top surface of the shin bone. However, if there is rotation caused by a twist while the joint is bearing weight, the menisci can get jammed and nipped in between the two bones. If the force is sufficient, a tear of the meniscus will occur.

Signs and Symptoms

The meniscus itself does not have a nerve supply, so no pain emanates from this structure.

However, due to the force of the twist there is often associated damage to other knee structures. The most common structures to be damaged are the MCL and the coronary ligaments, which help attach the menisci to the top of the shin bone.
The damage to the joint will cause the knee to swell up.

In addition to the lack of nerve supply, the menisci also has a poor blood supply, which means that the tear is unlikely to heal.

As a consequence the tear produces a flap that interferes with normal joint mechanics. This produces a characteristic 'clunk' within the knee when it is bent and straightened and it may cause the joint to lock in one position. Frequently the knee gives way, particularly when walking downstairs.

Treatment

In some cases, after the initial swelling and pain, the joint settles down and normal activities can be resumed. This is because the tear in the meniscus is small or the flap does not affect the joint mechanics.
However, in the case of a sporting individual, if the flap causes locking or giving way, surgery is required. This is carried out arthroscopically, whereby a small camera and burring device are used by the surgeon to remove the flap and smooth off the surface of the meniscus. The patient is usually in hospital for one night and can then begin rehabilitation.

Rehabilitation

The following program is that typically used by an athlete playing on grass and who has undergone an arthroscopic meniscectomy. The length of rehabilitation is dependent upon:

which meniscus is affected:
(1) Medial Meniscus (inner side of the knee) - rehab is usually 3-4 weeks
(2) Lateral Meniscus - the rehab will usually take 6 -8 weeks.
exactly where the tear is
the size of the tear
the amount of meniscus which is removed by the surgeon.

Stage 1: the first 10 days

(1) On discharge from hospital the patient may be on crutches.

The patient can resume walking normally.
If there is still a limp it is too early to walk without crutches.

(2) Any residual swelling should be controlled:

with a compression device such as a cryocuff
a flowtron pneumatic unit.
These both have the effect of squeezing the knee joint, helping the excess fluid within the joint to disperse.

(3) Strengthening: Isometric quadriceps and hamstring exercises should be initiated. Work should be done in 5 sets of 10, repeated 3-4 times per day.

An isometric quads contraction is achieved by sitting on the floor with the legs straight and then pushing the back of the knee down towards the floor. This contraction should be held for 4 seconds and then relaxed.
To do an isometric hamstring contraction the patient should sit in a chair with the heel to the floor, and then dig the heel into the floor, as if trying to drag the foot backwards. Again this contraction should be held for 4 seconds.

(4) Range-of-movement exercises should be initiated as soon as possible.

Extension of the knee is achieved via the isometric quads exercises.
Knee flexion is regained by sitting on the floor with the knees out straight, and then attempting to bend the knee. This can be made easier by placing something that slides easily, like a plastic bag, under the heel, then sliding the heel towards the body and out again.
Another method of increasing the knee's range of movement is to sit in a high chair with the feet hanging free. The affected leg should be swung backwards and forwards, with the range of movement gradually increased over time.

Stage 2: Days 5-14

(1) As early as the patient can comfortably bear weight through the affected knee, proprioceptive exercises should be initiated. These improve the stimuli within the body relating to position and movement.

Wobble board exercises: The patient should balance on the affected leg for 1 minute, then rest. This can be repeated several times.
Gymnastic ball: The patient should balance on the affected leg for 1 minute, then rest. This can be repeated several times.
More advanced proprioceptive exercises using the gymnastic ball: The patient balances on the affected foot with their weight against the gymnastic ball. This can be done with the knee joint at various angles, from straight to bent, according to what the patient can stand. Whilst in these positions the therapist throws the ball and the patient has to balance. 3 sets of 20 catches are normally done, with a rest in between each set.

(2) Range of knee motion can be increased through cycling and wall sliding exercises.

Wall sliding exercises to increase knee range of motion involve sliding the foot up and down as shown. The patient will normally be instructed to perform 5 sets of 20 repetitions.

(3) Once the portals from the arthrosopic surgery have healed and the surgeon has given the go-ahead, exercises in water can begin.

These have the advantage of improving and maintaining knee joint range of motion and also strengthening the joint without putting weight through the joint.

Stage 3: Weeks 2 to 6

All the exercises of the previous two phases can be continued. Once the surgeon has given the go-ahead more intense weight-bearing and running can be initiated.

Plyometric exercises using a box, involving landing and taking off in quick succession. Start off slowly and then build the speed at which the exercises are done. The number of repetitions and sets should be gradually progressed.

Jogging - Progress to next day activity if there is no swelling or pain:

DAY 1: Jog 100 meters, walk 50 meters, with 6 repetitions.
DAY 2: Jog 150 meters, walk 50 meters, with 6 repetitions.
DAY 3: Jog 200 meters, walk 50 meters, with 8 repetitions.
DAY 4: Jog 200 meters, walk 50 meters, with 12 repetitions.
DAY 5: Jog 2000 meters.

Stage 4: Functional Rehab Stage

The progression to functional activities can begin once the patient can jog without pain and is comfortable doing plyometric drills. The idea of this stage is to progress from gentle exercise to the high intensity at which games are played. All exercises are preceded by a warm up.

Since each exercise is a progression, they should be completed at least one day apart.

EXERCISE 1 - 25 minutes: Variable pace running with the gradual introduction of turns. This involves running round a 20m diameter figure-of-eight course. The figure-of-eight course puts very gentle stress on the knee and prepares the player for later turning drills. The pace is limited to walk, jog or half pace running and is determined by the physiotherapist who shouts out the desired pace. The physiotherapist also shouts the commands stop and start. This re- introduces the player to the variable demands of a game of football.
EXERCISE 2 - 20 runs: Variable pace running with gradual turns and various starting positions. The player starts at one end of the course and makes a 30m run up to a 20m diameter semicircle, around which they gently turn before completing another straight 30m run back to the finish. The pace of the run is dictated by the physiotherapist and is either a jog or half pace. The starting position should be different for each run (standing, lying on back, lying on front, sprint start position, squatting, right side lying, left side lying, jumping, hopping, facing backwards).
EXERCISE 3 - 25 minutes: A progression of exercise 1. Variable pace running with slightly tighter turns. The player runs round a 10m diameter figure-of-eight course. The figure-of-eight course puts stress on the knee and prepares the player for later turning drills. The paces used are walking, jogging, half pace running, or three-quarter pace running and is determined by the physiotherapist who shouts out the desired pace. The physiotherapist also shouts the commands stop and start. This re-introduces the player to the variable demands of a game of football.
EXERCISE 4 - 20 runs: A progression of Exercise 2. Variable pace running with gradual turns and various starting positions. The player starts at one end of the course and makes a 30m run up to a 20m diameter semicircle, around which they gently turn before completing another straight 30m run back to the finish. The pace of the run is dictated by the physiotherapist and is either three-quarter or full pace. The starting position should be different for each run (standing, lying on back, lying on front, sprint start position, squatting, right side lying, left side lying, jumping, hopping, facing backwards).
EXERCISE 5 - 20 repeats: Two 5m diameter circles are placed 30m apart. Traveling at full pace the player makes a run, with a football at the feet, goes around the far circle and then back to the finish.
EXERCISE 6: As Exercise 5, but single cones are used instead of 5m diameter circles.
EXERCISE 7 - 10 repeats: Six cones are placed 5m apart in a straight line. The player completes a shuttle run at full pace, turning alternately to the left and right.

Before a gradual return to full training the player should be happy with all normal ball work drills, all types of passing (instep, side foot, front foot, outside of foot, side foot volley, laces volley, half volley) over all distances, heading, jumping and heading, and tackling.