Rotator Cuff Introduction
The rotator cuff is a very strong combination of 4 muscles, that inserts onto the head of the humerus and these muscles rotate the head of the humerus to allow one to elevate your arm. With elevation, we mean that you can lift your elbow up and also lift your hand to reach above your head. These rotator cuff muscles are the ones that initiate the movement and allow you to move your elbow away from your body, when your arm hangs down the side of your body. Once the arm has been elevated to about 45º, the deltoid muscle now takes over and completes the elevation to above the head. Therefore the rotator cuff muscles are really important to initiate the elevation of the arm and without these muscles, it is impossible to elevate the arm and the arm is functionless hanging down the side of the body. Four muscles form this rotator cuff tendon. The subscapularus, supraspinatus, infraspinatus and teros minor muscles. These insert onto the greater tuberosity on the humerus.
Meganism of rotator cuff tear
Most of these tears are mainly degenerative in nature, in other words as one grows older, the rotator cuff muscle softens and loses its normal intrinsic strength, simply due to aging. This process might be enhanced by the rotator cuff rubbing against the acromion, hanging down onto the upper surface of the rotator cuff. This condition is known as impingement. Refer to the section on impingement in this regard.
The point is that this rotator cuff will gradually weaken as time goes by and will eventually tear off completely.
Some of these tears are actually traumatic in nature. Usually the history is that the patient has forcefully elevated the arm lifting something heavy and developed an acute pain in the shoulder, with the inability thereafter to elevate the arm. This is called a traumatic rotator cuff tear. It also sometimes happen when people walk up or down stairs and slip a step and grab onto the railing to prevent them falling. This acute pull on the shoulder might rupture the cuff, and again an acute pain in the shoulder and the inability to elevate the arm, thereafter. Whatever the cause of the rotator cuff tear, these injuries should be dealt with as it can leave the patient with permanent disability in the form of an inability to elevate the arm. There is also a time limit to treatment. If these tears are left untreated, the muscle will contract and shorten and it will become impossible to reduce the muscle back to the insertion on the greater tuberosity. This then becomes an irreparable rotator cuff tear, with all the complications thereof. (Refer to irreparable rotator cuff tear).
The patients with rotator cuff tears, usually present with symptoms depending on what the cause of the tear is. If the tear is caused by an acute injury, the patient will usually tell you the story of what has actually caused the tear and it is quite obvious what has happened.
In the chronic cases it might be a little bit more difficult, as the patient might have had shoulder pain for a prolonged period of time and the cuff might have developed a gradual tear over a period of time. When examining the shoulder however, one will easily see that there is weakness of the tear and that the tear is complete. This can be confirmed with an ultra sound examination.
If the tear has started gradually over time, the patient would have developed shoulder pain, which is usually present on elevating the arm and trying to work overhead. They will also have night pain present. The reason for the night pain is that during day time gravity pulls the arm down and the space between the head and the overlaying acromion bone is opened, and therefore the pain is relieved. During night time however, the head migrates upwards as the gravity is eliminated and causes compression onto the acromion. These patients might also sometimes have a clear weakness of power, especially on elevating the arm.
The diagnosis can usually be made with ultra sound in the doctor’s room. Alternatively MR scanning can be requested. The function of MR scanning is usually not to make the diagnosis, but rather to assess the patient for the reparability of the cuff. If the tear has been longstanding, the possibility of an irreparable cuff must be excluded before surgery with MR scanning. Rotator cuff tears are potentially severe disability causing entities. Therefore they should be assessed carefully by a trained shoulder specialist, for decision making regarding the treatment. The philosophy would however be, rather to treat and repair the tear, than to wait for an irreparable situation.
There are 2 techniques of operating the rotator cuff and repairing the rotator cuff.
1. Arthroscopic technique – the arthroscopic technique is more demanding and the surgeon should be really experienced with arthroscopic repair to attempt this procedure, arthroscopically. During the arthroscopic procedure, a video camera is inserted to the shoulder joint and the cuff can be visualised and mobilised for the repair. Once the cuff has been mobilised, anchors are screwed into the humeral head and the stitches are passed through the rotator cuff and the stitches are tied down, to tie the cuff down onto the greater tuberosity. There are different ways of doing this technique (refer video) for our preferred method and consist of a single or double row suturing technique.
2. Open Surgery – at the open surgery, the incision is made over the front of the shoulder joint. The deltoid muscle is divided and the rotator cuff is directly inspected under direct vision. The rotator cuff is then mobilised and again sutured with exactly the same anchoring technique than used for an arthroscopic procedure. The only disadvantage of the open technique is the invasion of the deltoid muscle and the scar tissue. The long term outcome of the 2 procedures are however the same.
3. There are definite advantages on the arthroscopic technique, as the cuff can be visualised more extensively and the mobilisation techniques for the cuff is certainly better if done arthroscopically. Therefore our practice has progressed to the stage where we do virtually all rotator cuff repairs now, arthroscopically.
The post operative period is divided into 4 time periods. The initial period is the first two weeks after the operation. During this period of time, the patient will certainly have a fair amount of pain and will be treated in a shoulder sling. During this period of time the patient will usually re-visit the rooms for an inspection of the wounds and to ensure every aspect of the operation is uncomplicated. Usually after two weeks most of the pain has disappeared and the patient will then start active physiotherapy. The physiotherapeutic treatment is divided into 3 definitive phases.
At the operation the surgeon will see how much tension the rotator cuff can take during movement of the shoulder joint. This is noted and this information is passed on to the physiotherapist. Depending on the quality of the rotator cuff and the amount of movement the cuff can tolerate, post operative physiotherapeutic regime is advised. For the first 5 – 6 weeks the patient will be mobilized passively, in other words the patient will not be allowed to elevate the arm by himself. The physiotherapist will however be able to move the shoulder within the restricted motion as determined at the operation. The risk of elevating the arm and tensioning the muscle and rupturing the rotator cuff suture line, is obvious and therefore the patient is not allowed to lift the arm himself at all.
After the first 5 – 6 weeks, the cuff has repaired itself to a large extent to the greater tuberosity. The second phase can now be entered.
During this phase, the patient will start to elevate his arm actively himself with the help of the physiotherapist. In other words the patient will still not be allowed to elevate the arm himself (only with the assistance of the physiotherapist). The risk of rupture of the cuff is still prominent at this stage. After 3 more weeks, the cuff is usually now healed to a large extent.
This is the active phase of the rehabilitation and the patient can now start to lift the arm himself. This is usually started at week 9. We will not allow the patient to do heavy physical activities, before 16 weeks, after the surgery.
Driving a vehicle requires the arm to be elevated to the level of the steering wheel and therefore these patients are not allowed to drive a vehicle for the first 3 months after the operation. This is a major disability and should be discussed with the patient beforehand. It is also illegal to drive a vehicle while being incapacitated.
Usually these patients recover very well, if the cuff is of good quality and if the procedure has been done in time. The message in this regard is not to leave the painful shoulder untreated for a prolonged period of time, as the cuff might become irreparable.