The Shoulder Joint
Most problems with the shoulder fall into one of five basic categories. (Not in order of frequency)
- Arthritis of the shoulder joint
- Instability of the shoulder joint
- Adhesive capsulitis (Frozen shoulder)
- Rotator cuff problems
- Acromioclavicular problems (ACJ)
There are other rarer causes of shoulder pain like nerve entrapment and biceps tendon “inflammation” but most are related to these 5 most common complaints.
In order to understand the explanations you may want to look at the anatomy of the shoulder joint.
Arthritis
This is a condition where the lining cartilage of the shoulder joint becomes worn out. This is a degenerative process and most commonly occurs in the elderly. It does affect some young people but usually only after they have had a serious injury that has damaged the cartilage, or in patients who have had radiotherapy, or long term steroid therapy that has caused disruption of the blood supply to the head of the humerus.
People with arthritis usually develop stiffness in the shoulder and pain. Often they will feel a grating within their shoulder when the raw bone from the glenoid (Cup part of the joint) rubs on the bone on the humerus (ball part of the joint) as they move the shoulder.
This grating is different to the “crepitus” that patient with inflammation around their tendons feel. (See note under impingement below)
Patients who have arthritis can be treated with physiotherapy, steroid injections into the shoulder joint, arthroscopic debridement (Key hole surgery – washout) or shoulder replacement. The shoulder replacement can be done in the form of a surface replacement of the humeral head or with a “traditional” stemmed implant that goes down the shaft of the humeral bone.
(If you would like more information on these two operations select Shoulder resurfacing or Total shoulder replacement.)
Instability
Instability of the shoulder is a condition usually seen in young patients. This can be a spectrum of complaints. At the one end we have people who dislocate their shoulder joint after an injury and then repeatedly put the shoulder joint out whenever they put the joint “at risk”. Some of these patients need to go to hospital to have the shoulder joint replaced and some learn to put the shoulder back themselves. At the other end of the spectrum there are patients that are born with flexible joints and they are able to “dislocate” the shoulder and put it back themselves. These patients often “sublux” their shoulders when they don’t actually dislocate the shoulder but “almost” dislocate the shoulder.
In the group of patients who dislocate their shoulders after an injury they usually pull off one of the ligaments. (This is called a Bankart lesion) Until such time as the ligament is re-attached they will continue to have a shoulder that is unstable. Sometimes the ligament can heal back in the right place and some people will never put their shoulder at risk so not every one needs an operation. However if the shoulder continues to come out then they will invariably need surgery to re-attach the ligament. This can be done as key-hole surgery or as a more formal open procedure. The amount of damage done at the time of the dislocation usually determines whether the operation can safely be done purely as key-hole surgery or whether it needs to be done as an open operation.
(If you would like more information on repair of the bankart lesion select Arthroscopic Bankart repair.)
In the group of patients that have hyperlax ligaments the treatment usually revolves around physiotherapy and muscle balancing. If this is not successful then the ligaments can be “shortened” by condensing the protein using a radiofrequency technique through key-hole surgery or a more formal shift of the ligaments by means of an open operation. The key-hole surgery is called capsular shrinkage and the open surgery is called a capsular shift. The capsular shrinkage operation was adopted with much enthusiasm when it first became available and unfortunately surgeons that were not shoulder specialists attempted this with disastrous results. Sadly therefore the procedure was “given a bad name”. However in the hands of shoulder specialist this procedure has produced very good results and has no greater risk of complications than other key-hole operations.
(Click here to see a video of capsular shrinkage.)
Adhesive Capsulitis
Adhesive capsulitis is a problem that involved the lining of the shoulder joint. It tends to affect middle aged people. This is a disease process that goes through three distinct phases. In the first phase which is the inflammatory phase the lining of the shoulder joint becomes very aggressively inflamed. As a result the patient usually feels a great deal of pain, worse at night and as a result they are reluctant to move their shoulder. After roughly 6 months the inflammation “burns out” and the patient then moves into the scarring phase. During this phase the cells that make scar tissue behave in the same irrational way they the cells that control the inflammatory reponse do during the first phase. During this phase the lining of the joint becomes scarred. The patient no longer has the same severe pain but when they attempt to move their shoulder they experience sharp pains as they stretch on the newly formed scar tissue. This too lasts about 6 months and thereafter the patient moves into the “recovery phase” during which time the scarring is gradually broken down and the movement slowly returns. This process is said to take about 12 months.
We have no idea why people develop this problem. There are many theories including the most popular one that a viral infection triggers this reaction. We do know that people with diabetes are more prone to suffering from this condition and often take longer to recover.
Traditionally it has been said that left alone the condition gets better after 2 years. Despite what has been believed and taught for many years, this is not necessarily always the case. In many cases patients probably stop coming back to their doctor after two years or learn to live with the condition but in some cases patients do make a full recovery.
Despite the known phasic process of this disease, each patients experience will be slightly different. Some patients inflammatory phase is so severe that it compromises their lives while others pass through this phase without any significant disruption.
Depending upon the stage at which you see your specialist the treatment may vary. Invariably patients will be sent for physiotherapy to try and maintain their range of movement. This is often a futile exercise as the pain is too severe to allow adequate movement (if in the inflammatory phase) or the scar tissue is too severe to allow movement (if in the scarring phase). Injection of a steroid into the glenohumeral joint often helps a great deal and will also allow the physiotherapist the opportunity to move the shoulder more. This injection is most helpful if given during the inflammatory phase. Sadly many patients only seek specialist opinion once they are well through this phase.
When physiotherapy fails, the traditional treatment for this has been a manipulation under anaesthesia. This is essentially putting the patient to sleep and then moving the shoulder through its range to tear the scar tissue that is formed. Depending upon which phase the patient is at the time of the manipulation this can either improved things dramatically (If they just have scar tissue present) or aggravate the situation (If they have a very inflamed lining of the joint).
Many surgeons have moved away from always doing just an MUA and carry out a capsular release and synovectomy. This involves inserting the arthroscope into the joint and “dissolving” the inflamed lining and “melting” the scar tissue. This is done using a radiofrequency wand. (The radiofrequency wand is the same wand that is used to “shrink” the capsule when it is lax. However when shrinking the capsule the setting is on very low and when melting or ablating the capsule it is set on a higher setting.)
(Click here to see video of capsular ablation.)
Rotator Cuff Problems
Impingement syndrome
The rotator cuff is a term given to three main tendons that wrap around the joint. These tendons come from the three muscles that come off the shoulder blade. One in front (the subscapularis muscle,) one on top, (the supraspinatus tendon) and one behind. (the infraspinatus muscle).
The cup part of the shoulder is very shallow (More mini-saucer like than cup like). This is the glenoid. It is shallow in order to allow the kind of movement that the shoulder is able to perform. The cup is “deepened” by the rotator cuff muscles that wrap around the head of the humerus and hold the ball centred on the cup/saucer. These tendons are essential to the normal function of the shoulder. These muscles stabilise the joint allowing the much bigger and stronger muscles like the deltoid and pectoralis muscle to move the joint.
The most common problem encountered in the shoulder is when the upper of the three tendons (The supraspinatus tendon) gets trapped between the humeral head and the acromion which is the hook of bone off the shoulder blade. (The piece of bone you put your hand on if you cup your shoulder with your opposite hand.)
This gives rise to a condition that is called impimgement syndrome. In this condition the tendon will rub on the underside of the acromion whenever the arm is moved into certain positions. Typically when the arm is at the patient’s side they tend to be pain free or relatively pain free. When the arm is lifted out to the side the tendon comes up against the underside of the acromion and induces pain. This gives rise to what is commonly called the “painful arc syndrome”. Other actions like reaching out, putting on a jacket, putting on a bra, changing gears (left shoulder) or closing the drivers door(right shoulder) are commonly described as aggravating factors by patients.
If a patient has impingement syndrome they get into a vicious cycle where the tendon is “swollen” and therefore rubs on the bone, which in turn makes the tendon swollen. This condition can usually be treated by injecting steroid into the bursa that sits on top of the tendon and beneath the acromion. (The subacromial bursa). Sometimes it is necessary to repeat the injection 2 or 3 times. Some people have an acromion that is shaped in such a way that the bone will continue to rub the tendon irrespective of the steroid injection.
The shape of the bone may simply be the individuals genetic make up or in some cases a hook of bone develops on the underside of the acromion. When the patient fails to respond to injections then a decompression of the tendon is performed. This involves inserting an arthroscope into the bursa and then a shaver which is used to shave the piece of bone off the acromion.
Unfortunately it is not possible to simply do an MRI scan and look at the shape of the acomion, as some people who have what look like normal acromions will get the condition while others with obvious hooks don’t seem to have any problems. As a result it is often by a process of elimination that candidates for surgery are selected.
Rotator cuff tears
If the tendon is allowed to rub on the acromion for long enough there is a risk that eventually a hole will form in the rotator cuff. If this occurs the continuous action of the muscles pulling on the tendon will typically enlarge the hole if it is not repaired. Usually the repair can be performed by means of key-hole surgery. If left long enough the hole will become so large that an open operation may be necessary. If totally neglected eventually the tendons retracts so far that the muscle becomes functionless and the tendon become irreparable.
Most rotator cuff tears occur gradually but many will be associated with an injury. In particular if an elderly patient dislocates their shoulder but continues to have pain in the shoulder there they may well have a tear of the cuff and should be attended to urgently.
(If you would like more information on rotator cuff repairs or subacromial decompression select Arthroscopic cuff repair or mini-open Rotator cuff repair.)
Rotator Cuff Arthropathy
In some patients who have an irreparable rotator cuff tear the lack of cuff means that the humerus is no longer held in place centred on the glenoid and starts to sublux or dislocate upwards. This will often interfere with function in the arm and can become very painful for some patients. In some cases the change in biomechanics will also cause arthritic changes in the joint. This condition tends to affect the elderly and depending upon the patient’s general health can be treated in a number of ways. If the patient is not well enough for any surgery sometimes repeated injections at regular intervals can keep the patient comfortable. If able to tolerate a short anaesthetic key hole surgery to decompress the bone sometimes relieves the symptoms. If all of this fails and the patient is able to tolerate a longer anaesthetic then a reverse shoulder replacement can be carried out which is very affective in treating the pain. This condition is one of the more difficult conditions to treat in shoulder surgery and is one that individual surgeons will approach differently. Not every surgeon will perform the reverse shoulder replacement.
Acromioclavicular Joint problems
The ACJ is where the collar bone and the shoulder blade meet. There are two conditions that typically effect the ACJ.
1) The less common of the two is a dislocation of the ACJ. This is usually injury related and often happens in rugby players and people who fall off their bicycles and land o nthe point of their shoulder. When this happens the end of the collar bone will ”Spring-up” and create a bump on the top of the shoulder. This condition is usually treated without intervention in the first instance and in special circumstances can be “reconstructed” if it becomes symptomatic. Different surgeons will approach this problem differently. Some will attempt a repair while the injury is fresh. In this case an attempt to sow the torn ligaments together is performed and the collar bone is held in place with a screw or wires to protect the ligaments while they recover.
Most surgeons feel this is futile and prefer to “wait and see” if the condition becomes a limiting factor in the patients life. Many sportsmen have completed successful international careers with permanently dislocated ACJ’s. In those who are limited a reconstruction of the damaged ligaments is carried out. This is done by taking a locally based ligament and re-routing it through the end of the collar bone to hold the joint in place. This may also be “augmented” by a screw or wires or tapes to help hole the joint in place while the ligament heals.
2) The more common condition is degeneration of the ACJ. This is also referred to as osteoarthritis or arthritis of the acromioclavicular joint. The common way of treating this is to inject steroid into the ACJ. Because of the anatomical location of the ACJ being right above the rotator cuff, it is common to have impingement syndrome and ACJ degeneration simultaneously. As a consequence when the patient is injected for impingement syndrome, their pain may improve but not completely dissipate if the ACJ is part of the cause of their pain.
If the injection is not long lasting, then the surgical option is to resect the outer end of the collar bone. This can be done as an open operation but most shoulder surgeons will do this as key-hole surgery. In many cases the ACJ is “resected” at the same time that the cuff is decompressed.
Common Misunderstandings Around the Shoulder Joint
Arthritis
Many patients will be sent by their GPs for an X-ray of their shoulder when they first present. In most cases the X-ray will be normal because arthritis as a cause of shoulder pain is relatively unusual. However the x-ray report will often mention that there is degenerative change or early arthritis in the acromioclavicular joint. This is not the shoulder joint. This is the “joint” where the collar bone (clavicle) and the shoulder blade (acromion) meet. Many patients present to their specialist telling the surgeon that they have arthritis.
Frozen Shoulder
Mr Codman in his book on shoulder problems written in the 1950’s coined the phrase “frozen shoulder”. He listed the typical symptoms that included pretty much every symptom ever experienced in the shoulder. As a result the diagnosis of Frozen shoulder is often used as a generic for “shoulder” problem. Most patients that are told that they have a frozen shoulder do not actually have what is more correctly called Adhesive Capsulitis.
Steroid Injections
Many patients come with the fear that steroid injections are bad for you. It is true that to inject your Achilles tendon when you have tendonitis can increase your risk of rupturing the tendon. Similarly injecting a young professional sportsman’s joint to relieve his pain and get him back on the sportsfield without a diagnosis could do irreparable damage to his joint.
It is also true that patients that suffer from conditions such as asthma or ulcerative colitis or similar that require long term daily systemic steroid tablets do develop complications.
However the injections given around the shoulder are very useful as diagnostic tests since if the local anaesthetic that is injected at the same time, relieves the patients pain then this helps to confirm the location of the problem. In addition the dosage and frequency of the injections is far below the kinds of exposure that patients on long term steroids receive.
The other misunderstanding is that many patients feel that these injections are painful. The reason that most injections are painful is because a small volume of fluid is inserted into tissue that has to be stretched in order to accommodate this new volume. This stretching is not dissimilar to stretching your skin or somebody standing on your leg. Uncomfortable to very painful.
However the shoulder injections are given in one of 3 places. The 1st is into the shoulder joint. The 2nd is into the bursa beneath the acromion and the 3rd is into the ACJ. With the exception of the later these spaces all readily accommodate additional fluid without discomfort. The ACJ is a much smaller space and a little more difficult to enter, especially when it has new bone formation around it. (Degenerative change) However in all these injections careful technique should mean that the experience is nothing more than mild discomfort. Nothing like going to the dentist!!!
Consultant: David Selvey
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