A JAB TO THE SHOULDER
It is common to experience shoulder pain after having a jab (vaccination) into the deltoid muscle. This pain is typically mild and transient and does not affect shoulder mobility BUT a small subset of patients develop prolonged functional deficits with severe pain and limited motion. Many of you will have already seen this in your patients.
Having a sore shoulder after vaccination is something most of us have experienced. I certainly had a sore shoulder for a day or two after all 3 of my Covid vaccines but for me the Tetanus injection was by far the worst ‘heavy dead arm’ I have experienced.
Shoulder injury related to vaccine administration (SIRVA) is a rare but well recognized complication of immunization. SIRVA is actually a medicolegal term rather than a true diagnosis and was introduced in 2010 by the Vaccine Injury Compensation Program (in America). SIRVA is defined by the American National Vaccine Injury Compensation Program as “shoulder pain with limited range of motion within 48 hours after vaccine receipt in individuals with no prior history of pain, inflammation, or dysfunction of the affected shoulder before vaccine administration.”
In response to the Covid pandemic, in NSW we have achieved a more than 95% vaccination rate. Many people have received 3 vaccinations, adding up to nearly 15 million injections. This compares to a typical year where about 2.5 million people receive a single flu vaccine. Never before have so many vaccinations been administered in such a short period of time and been given by people who have not traditionally been involved injecting vaccines before. They are being given by pharmacists, medical students, nurses, general practitioners and I know of 2 Orthopaedic surgeons who volunteered in vaccine hubs during the lockdowns. They are also being given to young, fit healthy people who probably have not had a vaccine in many years (often since childhood), compared to vaccines usually given to children or much older adults.
SIRVA is a constellation of shoulder pain and reduced range of motion that occurs within 48 hours of vaccination (90% within 24 hours and 54% at the time of the vaccination) and does not resolve within 1 week.
This means that several different clinical entities can all be called SIRVA. There are some cases that present in a delayed fashion up to 2 months later. Reduced shoulder ROM is commonly reported; with weakness, altered sensation and fever being less common.
The differential diagnosis of SIRVA includes septic arthritis, local inflammation (bursitis, adhesive capsulitis, tendinitis), axillary nerve injury, impingement and trauma (tearing of 1 or more of the rotator cuff tendons). In rare cases, bone erosion, humeral head osteonecrosis, septic arthritis and progressive chondrolysis have been reported.
About half of the patients who experience SIRVA will seek treatment for it. Most patients will start with their general practitioner and physiotherapist and about one third will be referred to a specialist. Very few will need advanced imaging and most will settle with time.
History: The symptomatic hallmark of SIRVA is shoulder pain that occurs within 1 to 2 days of vaccination in a previously asymptomatic shoulder. Unlike shoulder pain that commonly occurs after vaccination, the pain associated with SIRVA does not resolve within 1 week and most patients will attend for treatment at about the 2 week mark. About 1/3 to 1/2 of patients describe loss of motion and interference with their activities of daily life and about ¼ describe needing time off work. Weakness, numbness and paraesthesia are not common complaints but many patients say that they think the vaccine was not given correctly.
Physical Examination: A routine shoulder examination should be performed for all patients. The most common finding is that of globally limited and painful shoulder range of motion. The loss of motion is not typically in any particular direction. Tenderness is not usually still present several weeks down the track but might be present if seen early. Skin and local injection site reactions are quite rare. Many patients report altered sensation but this is typically normal on formal objective testing. Provocative tests are most useful to diagnose underlying pathology such as rotator cuff tears or impingement. Remember to look for systemic signs of infection, such as fever, joint pain, swelling and erythema. To view Orthosports Shoulder Examination Series please Click Here
Investigations: If there is any doubt then some simple screening blood tests for infection are worthwhile:
- A full blood count looking at the white cell and platelet counts, CRP and ESR.
- Plain xrays of the shoulder are useful to exclude any underlying bone problems if symptoms persists beyond a week.
- Ultrasound may be able to detect a haematoma but it has a low sensitivity looking for bursitis or underlying cuff pathology and is generally not useful.
- Remember that ultrasonography is operator-dependent and may underestimate the findings because of direct pressure while scanning.
- MRI has a higher sensitivity for detecting shoulder pathology.
When ordering an MRI, it is important to remember that most structural anomalies are unrelated to vaccination. MRI may be useful in identifying concomitant and potentially symptomatic conditions within the shoulder, but it cannot be used to define a causal relationship between immunization and visualized pathology.
Treatment and prevention: For most patients lifestyle and job modifications, physiotherapy, and nonsteroidal anti-inflammatory drugs are the mainstays of management. A subacromial corticosteroid injection should be considered if symptoms are severe and are not improving with conservative measures. Patients can be reassured that their shoulder symptoms are likely self-limiting and that they should expect progressive improvement over 4 to 6 weeks. Surgery is usually not required.
There seem to be 3 groups of patients with SIRVA:
- Vaccine injected through the deltoid into underlying non-muscular tissues, producing a prolonged inflammatory response. This is typically when the injection is ‘too high’ and goes into the subacromial bursa (or perhaps the needle was too long). This group includes intramuscular haematoma formation.
- Those that experience an immune-mediated reaction to both viral antigens and vaccine adjuvants (although this has not been definitively proven). The inflammatory response is not vaccine-specific, but is theorized to be caused by exposing a previously sensitized patient, either naturally or through previous vaccines, to the viral antigen.
- The presence of pre-existing, asymptomatic shoulder pathology, which becomes provoked by the trauma or injury after vaccine administration (This seems to be the most common group at the moment).
Since there are different causes of SIRVA there is no single surgical procedure that can be used to treat it. Surgical intervention rates can vary from 3% to 30% depending on the study but in my experience the need for surgery is very rare. The operations performed are the common shoulder operations generally done anyway: subacromial decompression, joint debridement, rotator cuff repair, synovectomy and bursectomy.
As a general rule SIRVA should be treated as a chronic (idiopathic) inflammatory response within the deltoid muscle. For most patients SIRVA is relatively mild and self-limited and can be improved with local treatments and physiotherapy. It is not clear why but in a small number of patients’ symptoms can be significant and long-lasting or permanent (perhaps like workers compensation results can be affected by the potential for compensation). While it is possible for SIRVA to aggravate pre-existing shoulder pathology seen on MRI, care should be taken before proceeding with surgical treatment for these conditions because they are often not the primary cause of the patient’s symptoms. As a surgeon I typically use a series of local anaesthetic injections to try to localise the exact source of the patient’s pain.
Summary: In my opinion the personal and public health benefits of vaccinations far outweigh the risks of SIRVA for most people. SIRVA is primarily a clinical diagnosis but most patients in Australia presenting with shoulder pain after vaccination will end up having advanced imaging studies to exclude other pathology. Treatment with physiotherapy and corticosteroid injections does impart some functional benefit but it is difficult to predict which patients will have ongoing pain and functional limitations. High-quality clinical studies are needed in population groups not potentially motivated by compensation to understand the true long term affects. It is important to confirm the source of the pain before offering surgery to these patients because MRI scans will often detect pathology which otherwise would not have been seen or needed treatment.
To view article on avoiding shoulder injury form the Australian Vaccination handbook please Click Here
Macomb CV, Evans MO, Dockstader JE, Montgomery JR, Beakes DE: Treating SIRVA early with corticosteroid injections: A case series. Mil Med 2020;185:e298-e300).
Atanasoff S, Ryan T, Lightfoot R, Johann-Liang R: Shoulder injury related to vaccine administration (SIRVA). Vaccine 2010;28:8049-8052