The Rotator Cuff
I see so many rotator cuff tears and it is also quite often mispronounced! Here is some information…
Cause
The cause can be acute or chronic; Acute causes tend to be things like falling on an outstretched arm. Chronic causes are usually degenerative changes and repetitive motions. Changes narrow the subacromial space. This narrowing compresses the blood supply to the cuff tendons which can cause further degeneration, partial and full tears. The shape of the acromion can also cause damage and there also may be things like bone spurs and other bony changes.
Symptoms
Dull ache in the shoulder usually worse at night time
Pain when lifting or lowering your arm
Weakness when lifting or lowering your arm
Crepitus (crackling noise) when moving your arm in certain positions
Anatomy & Function
The rotator cuff comprises of four muscles; the supraspinatus, infraspinatus, teres minor and the subscapularis. They each have their own function but collectively they stabilise the ball and socket joint of the shoulder.
The supraspinatus sits in the supraspinatus fossa of the scapula and inserts at the top of the humerus and the capsule of the shoulder joint. This muscle is a major contributor in shoulder pain whether it is the causative factor for the pain or just a symptomatic one from something else going on.
Its function is to initiate shoulder abduction (first 10-15 degrees) while also being responsible for externally rotating the humerus. Basically it makes sure that the head of the humerus is in the correct position for the deltoid to take over and carry on with shoulder abduction.
If the supraspinatus is not performing its job and the deltoid is left to abduct the arm by itself the humerus tends to glide superiorly and causes a jamming of the head of the humerus. This can cause issues such as subacromial bursitis, tendon issues and restrictive movement or frozen shoulder type symptoms.
The infraspinatus sits below the supraspinatus in the infraspinatus fossa and attaches onto the greater tubercle of the humerus. The teres minor originates from the lateral border of the scapula and inserts just below the infraspinatus tendon. They both work together to externally rotate the greater tubercle of the humerus externally, posteriorly and inferiorly. This provides space for the supraspinatus tendon and subacromial bursa to glide within the subacromial space.
If these muscles are compromised then the head of the humerus would likely stay in internal rotation and cause impingement.
The subscapularis originates on the anterior side of the scapular and inserts on to the lesser tubercle of the humerus. It is responsible for internal rotation of the humerus and also stabilises the shoulder joint in overhead movements. It works collectively with the other three muscles to centralise the humeral head in the socket.
Weakness in the subscapularis causes the humeral head to glide anteriorly, other muscles then take over the job of internal rotation and it loses its ability to control the humeral head. This can cause impingement and also tendinopathies of the long head of the biceps brachii muscle.
As mentioned before, the supraspinatus tends to be the main culprit in rotator cuff problems and the subacromial bursa also joins in. The shape of the acromion process can be a contributing factor as well as any thickenings in the soft tissues which are common as we age.
The subacromial space is as it sounds a space below the acromion. If the space narrows then this can cause tears. There is also a bursa here. Bursas are fluid filled sacs that act to protect the joint surfaces and allow smooth running of the tendons etc. These tend to become inflamed with cuff injuries.
The other tendons can be damaged, however it is pretty hard to isolate the individual tendons of the rotator cuff muscles in a clinical assessment. Mainly because there is a lack of correlation between the symptoms people get and the results found on imaging. Other things like the actual structure of the rotator cuff muscles and the subacromial bursa make this difficult too. This means that getting an accurate diagnosis can be really difficult without doing an ultrasound or MRI. X Rays are usually done first to check for boney changes in the shoulder joint.
There are tests in a clinical environment that can be used to see if the rotator cuff muscles are involved however they can not diagnose the extent of the damage or reliably isolate the different tendons.
How can they be fixed?
Rehab - PEACE & LOVE protocol. I love cold laser for treating the subacromial bursa inflammation as well as the inflamed tendons. Massage helps get a blood supply to the affected area which can help with healing and prescriptive exercises can help with improving range of motion. Care would be taken to make sure the tear can not get bigger.
Anti-inflammatories may be prescribed
Steroid injections - can be effective but not always or permanently
Surgery which can include lots of different options depending on the tear. You can then rehab as above.
With the current climate, I’d usually see someone presenting with cuff issues prior to them being seen by the NHS. It can be hard to gauge how quickly they heal and what damage there is without doing scans. Some people walk in with high amounts of pain and limited movement but make a huge improvement quickly and others don’t. I usually suggest if no improvement in symptoms after 2 maybe 3 sessions then referral is required.
Attributions and References
Jmarchn, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons
OpenStax College, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons
Gibbons, J. (2019). The Vital Shoulder Complex. Lotus Publishing; Chichester