What is subacromial bursitis?
Subacromial bursitis is a name given to inflammation around the tendons encircling the shoulder joint which make up the rotator cuff. The tendons produce fine movement of the shoulder and stabilise the joint to allow the main powerhouse of the shoulder (the deltoid muscle) to produce the main force. Inflammation of the tendons or the lining of the tendons (the bursa) can lead to pain usually felt down the side of the arm and worse with movement, particularly in the painful arc position from waist height to above shoulder height.
Inflammation can occur with unaccustomed use, as in sudden excessive overhead activities. With age, the tendon can degenerate and become inflamed. This is made worse when the acromion (the bone overlying the tendon) is hooked or the space between the tendon and the bone is narrow. The terms bursitis, tendinopathy/tendinitis or rotator cuff syndrome are often used interchangeably, and relate to inflammation and ageing of the tendon and its lining.
The symptoms of bursitis are that of the painful arc, with pain felt in the top of the shoulder radiating down the side of the arm worse with motion, often worse when sleeping and with use of the arm above chest height or when outstretched.
Factors that influence the causation are:-
- Excessive overhead activities (usually unaccustomed)
- Ageing/ degeneration
- Smoking which can lead to degeneration
- Familial history
- Previous fractures/breaks of the shoulder
Usually a general practitioner will make the diagnosis based upon the history and the site of pain.
An examination will confirm a painful arc, with provocative tests making the pain worse, however with some assistance usually the patient will have a reasonable range of motion, albeit painful.
An ultrasound of the shoulder will usually demonstrate an inflamed tendon or bursa, but this is a common finding and has to be matched with the examination to confirm the condition.
If the symptoms have been present for some time, an ultrasound-guided steroid injection may treat the condition and is also useful as an improvement in pain whilst the local anaesthetic ( mixed with the corticosteroid) and placed in the region of the subacromial bursa, can confirm the diagnosis.
Most cases of subacromial bursitis will improve with time and can be helped by avoiding the painful position (the painful arc and overhead activities). The patient should not be immobilised in a sling, which should not be used except for temporary episodes of severe pain.
Physiotherapy should always be tried, working with Theraband (a rubber band system) to retone the rotator cuff (smaller musculature) to help the tendons recover.
An ultrasound-guided steroid injection can help the symptoms, and may settle the inflammation so as to allow the physiotherapy to be of use. A second and occasionally a third injection may be warranted but this should always be considered carefully because of the rare but serious risk of infection, and corticosteroids can weaken the tendon possibly contributing to a tendon tear.
In cases of considerable continuing pain, surgery could be considered. Surgery involves decompressing or debriding (cleaning out) the shoulder region, when the inflamed bursa is partially excised (bursectomy), removal of spurs (bone) which could be catching the tendon or abrading it, and if there is a tear of a tendon of the rotator cuff (muscles that encircle the shoulder), this is repaired at the same time. The surgery can be performed through an open approach (larger cut) or often arthroscopically (minimally invasive), which involves an inspection of both the inside of the shoulder joint, then in the subacromial space, viewing the tendons from the outside view underneath the acromion.
On occasions, the labrum may be torn (tissue encircling the socket and giving stability to the joint) or the long head of the biceps tendon may be inflamed or partially torn. The labrum can be repaired if required or the biceps tendon can either be debrided or more commonly released and either left to retract (tenotomy) or reattached outside the joint (tenodesis), depending upon patient factors. At the time of surgery, an arthritic acromio-clavicular (AC) joint can also be debrided (cleaned out).
For cases of purely subacromial bursitis, there has been a large study published in the Lancet which documented no difference between surgery and nonoperative measures, and documented that most patients will improve with nonoperative care over 12-month period. The Australian Shoulder and Elbow society have released a statement which commends the study but did note some concerns, concluding that in those patients which have not responded to nonoperative measures including injections and physiotherapy, that there may be a role for surgical intervention.
Most cases that would come to surgery, usually have associated pathology, that being a rotator cuff tear (i.e. the tendons around the shoulder have gone on to tear) or arthritis of the acromioclavicular (AC) joint or pathology involving the labrum or biceps tendon. In these cases, the associated pathology is also treated.
Recovery from Surgery
Usually a sling is not required and early movement is encouraged, depending upon the associated pathology treated.
Most patients will require post-operative physiotherapy and would hope for an improvement over a 4 to 6-month period, but full recovery can take up to a full year. Many patients have a much quicker recovery however.
At Glenelg Orthopaedics, we have extensive experience in relieving the symptoms of subacromial bursitis. For more information, contact us.
- Images purchased from Shutterstock (enhanced licence)
- Arthroscopic subacromial decompression for subacromial shoulder pain (CSAW): a multicentre, pragmatic, parallel group, placebo-controlled, three-group, randomised surgical trial: The Lancet open access .November 20, 2017
- Statement from the Shoulder and Elbow Society of Australia (an AOA subspecialty society) to the Medical Observer. December 2017