Impingement in Your Shoulder – Best Treatment Options based on New Research  


What is Impingement?

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Repeated overhead sports can cause impingement

Impingement is irritation of the rotator cuff tendons in the tunnel that is formed underneath the end of the collar bone (the acromion) and the top of the upper arm (humerus).

The reason for the impingement (subacromial pain) has long been thought to be due to the mechanical contact that occurs between the rotator cuff tendons and an overlying bone spur that often forms at the undersurface of the end of the collar bone, which  narrows the tunnel (subacromial space). If the space for the tendons to move in is narrower, then the idea is that the more likely the bone over the top is going to press on the tendons from above and irritate the top of them thus causing pain, particularly when you raise your arm, which narrows that space even further. This condition is sometimes referred to as impingement.

This can occur from overhead jobs such as plastering, or playing a lot of over head sports like basketball, tennis or swimming or even just repeatedly opening a stiff up and over garage door.

However, other experts believe that impingement or irritation of the tendons occurs when the head of the upper arm moves up too much in the shoulder joint when you move your arm which irritates the tendons from below.

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swimming can cause impingement


What Are Usual Treatment Options?


During the past three decades, clinicians have advised patients with subacromial shoulder pain to undergo minimally invasive arthroscopic subacromial decompression surgery in the belief that it provides reliable relief of symptoms at low risk of adverse events and complications. However, the findings from this new study suggest that surgery might not provide clinically significant benefit over no treatment, and that there is no benefit of decompression over arthroscopy only. Thus new advice is that these results should be shared with patients considering surgery.

The rationale has been that the shoulder pain is caused by physical contact during arm movement between the rotator cuff tendons and a spur of bone or associated soft tissue projecting from the acromion of the scapula, and that surgical removal of the bone spur and soft tissue (decompression) eliminates this contact and, thereby cures or reduces symptoms.

This intervention involves decompressing the subacromial space by removing the bone spur and any involved soft tissue arthroscopically, a procedure known as arthroscopic subacromial decompression. The indications for surgery are persistent and severe subacromial shoulder pain combined with functional restrictions that are resistant to conservative measures

Why Should You Try Other Treatment First?

Subacromial decompression was introduced in 1972 as a treatment for subacromial shoulder pain, however, even then there was actually low level evidence of its effectiveness for impingement. Nevertheless it is now one of the most common surgical procedures in orthopaedics!

Really, you would be better advised following from this research to try a course of physical therapy before considering surgery. This treatment may include soft tissue massage, treatment of the neck and mid back to take pressure off the shoulder (as discussed in previous shoulder articles), exercises, ultrasound therapy, postural advice and ergonomic advice.

Why Is This New Research Important?

Although many patients with subacromial pain are treated with, and will respond to, non-operative treatment alone, it has long been suspected that surgical intervention is used too often as an early treatment choice or in cases that are slow to respond to treatment and objectives of this research study were to investigate the mechanism for surgical decompression, and to compare surgery (decompression and arthroscopy only) for subacromial shoulder pain against no treatment to assess the effectiveness of surgical intervention.

Research findings were published in 2017 by Prof J Beard et al for Arthritis Research UK after the researchers undertook a multicentre, pragmatic, parallel group, placebo controlled, three group, randomised surgical trial involving 32 hospitals in the UK with 51 surgeons. The patients involved had experienced subacromial pain for at least 3 months and had intact rotator cuff tendons and they had tried a corticosteroid injection and also exercises.

Some patients underwent subacromial decompression, some had investigational arthroscopy only and some had no treatment at all.

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tennis can cause impingement


Arthroscopy only was a placebo as the essential surgical element (bone and soft tissue removal) was omitted.  Patients did not know what intervention they had had and they were checked 6 months and 1 year after randomisation.  Patients underwent standardised postoperative care and exercise therapy in both surgical groups.


Some reports in the past have suggested that surgery is no more effective than exercise therapy and yet others reported good outcomes from surgery. However, the number of patients undergoing subacromial decompression in the UK has risen by seven times from 2,523 in 2000 to 21,355 in 2010. Therefore if you have had shoulder pain for a while, you may be offered this surgery.

You need to consider whether you should try it or is there just not enough evidence that it works.

We were interested in this research because it means that we can better advise you.

Some other studies have tried to assess the effectiveness of subacromial decompression against a control, another was a randomised controlled trial that compared decompression plus subacromial bursectomy (removal of a bursa – sack of fluid ) with bursectomy alone and reported no significant difference in clinical outcome between groups. These studies support the theory that undergoing a surgical intervention for subacromial pain results in a significant placebo effect and that removal of the subacromial bone spur and soft tissue might not be necessary. No randomised trials have been reported with patients with subacromial pain to assess whether decompression is more effective than a diagnostic investigative arthroscopy, or doing nothing (no treatment).

The Research

Between Sept 14, 2012, and June 16, 2015, they randomly assigned 313 patients to 2 treatment groups (106 to decompression surgery, 103 to arthroscopy only) and 104 to no treatment

Both surgical groups showed a small benefit over no treatment, but these differences were not clinically important. The two surgical groups had better outcomes for shoulder pain and function compared with no treatment but again this difference was not clinically important. Additionally, surgical decompression appeared to offer no extra benefit over arthroscopy only. The difference between the surgical groups and no treatment might be the result of, for instance, a placebo effect or postoperative physiotherapy. The conclusions of the researchers were that “the value of this operation for these indications should be questioned, and this should be communicated to patients” hence I am passing this information on to you,

There were also no differences in outcome between the two surgical groups at any timepoint. This finding suggests that the treatment effect is NOT due to the principal clinical justification for the surgery, which is the removal of bone, bursa, and soft tissue to relieve impingement on the underlying tendons during movement of the arm. It is thought that any improvement from surgery is more likely to be due to the physical therapy after the surgery than to the surgery itself! Therefore the question is … why undergo the surgery in the first place – why not just follow the course of physical therapy instead!

The main conclusion from this study was this:

In the light of the results, other management strategies apart from surgery clearly should be assessed. Call us now to try our management of your shoulder pain!