This is a significant concern because the lifetime prevalence of frozen shoulder is 4-5 per cent in the general population. To give them an informed answer, we contacted our last 50 patients with shoulder pain and shoulder disorders, to learn about their experiences and whether anyone has experienced any side effects because of the vaccine. Fifteen of our patients with ages ranging from 40 to 80 years and with shoulder pain had been vaccinated in the recent past. Half of these patients were jabbed in the contralateral non-involved limb and half of them were jabbed in the same shoulder as the painful one. However, none of them reported any side effects and no increase in shoulder pain. These patients had been diagnosed with a frozen shoulder or had undergone a recent (5-month-old) shoulder surgery.
COVID vaccines are being given in the upper arm- in the deltoid muscle because it is one of the strongest muscles of the body. Muscles have an excellent blood supply and help to dissipate the vaccine faster, ensuring minimal or no local side effects due to the vaccine. The mRNA vaccine that is given in the deltoid muscle, induces the production of the spike protein either in the muscle or in the lymphatic channels which are the meeting points of all the immune cells. Deep to the deltoid muscle lies the bursal tissue, and as you go deeper you find the rotator cuff tendons, with the shoulder joint capsule being the deepest soft tissue.
It is a well-known fact that in the frozen shoulder, the affected structure and thus the source of pain is the deepest- the shoulder joint capsule. Additionally, in patients with pain due to bursitis, the pain arises from deeper structures known as the bursal tissue. Hence a vaccine, which is given in the deltoid muscle, is safe because the deltoid muscle is a superficial, thick and very bulky tissue, that lies below the skin and the subcutaneous fat. Therefore, a vaccine reaching the capsule is a very remote and rare possibility. Then, the vaccine may not possibly affect the frozen shoulder in any way.
With regards to the vaccination site, it is hard to miss the deltoid muscle. There are clear instructions that the vaccine should be given 3 centimetres below the acromion bone in a triangular safe area. Theoretically, a vaccine can, in a rare circumstance, miss the deltoid muscle and land in the bursa, but the possibility of that happening is rare because the needles used are only one inch and the plunge of the needle never goes deeper to the deltoid while injecting the vaccine. Additionally, the nursing staff administering the vaccine are extensively trained and have vaccinated countless times earlier, such as for influenza and several other diseases.
In almost all shoulder pathologies barring few rare exceptions, the shoulder pain never starts in the deltoid muscle. Only when the deltoid muscle is specifically injured by a fall or an accident, will a deltoid muscle be the initiator of the pain. There have been no incidences of increased shoulder pain after vaccination in frozen shoulder patients, and we haven’t found literature evidence of any contraindications for vaccination on the same side as the frozen shoulder. Hence the vaccine can be safely given in the deltoid muscle in the shoulder, even if the same shoulder is affected by the frozen shoulder.
Localized reactions and a mild increase in shoulder pain have been reported after vaccination in normal individuals but they have been transient and have completely disappeared in 1-2 days. Moreover, these mild pain and reactions are reconfirming the fact that your immune system is working well. However, in cases of acute severe shoulder pain or a recent injury to the shoulder, we may advise you to wait a few days before you can go ahead with the vaccination. Overall, we think that people should not hesitate for vaccination and go ahead confidently because COVID-19 is far from over and maybe be amongst us for a long uncertain duration; one of the most effective ways to fight it is by way of vaccination.
-By Dr Dipit Sahu, M.S. Consultant Shoulder Surgeon, Sir H.N. Reliance foundation hospital, Jupiter Hospital, Mumbai.
Disclaimer: The views and opinions expressed by the doctor is his/her independent professional judgment and we do not take any responsibility for the accuracy of his/her views. This should not be considered as a substitute for a physician’s advice. Please consult your treating physician for more details.