How Should Degenerative MRI Findings Be Interpreted in a Previously Asymptomatic Shoulder?
Quick description
A common SIRVA scenario looks like this:
A patient reports no meaningful shoulder pain or functional limitation before vaccination. New shoulder pain develops afterward.
MRI is obtained and shows findings such as:
rotator cuff tendinopathy,
partial-thickness tearing,
labral degeneration,
AC joint arthritis,
glenohumeral osteoarthritis,
or other age-related changes.
Does the presence of “degenerative” pathology mean that the patient's symptoms were already present before vaccination? No.
But it also does not mean that vaccination caused every abnormality visible on the MRI.
The important distinction is:
Structural abnormality and symptomatic disease are not the same thing.
Degenerative MRI Findings Are Common
Shoulder MRI is highly sensitive. It frequently identifies structural abnormalities that may have existed for years without producing pain or functional impairment.
This is particularly important for rotator cuff pathology. Tendinopathy and partial-thickness tears become increasingly common with age and may be found in people who consider their shoulder completely normal.
This issue is central enough to the SIRVA literature that Slette, Rohrback, and Ring titled their systematic review “Persistent Shoulder Pain After Vaccine Administration Is Associated With Common Incidental Pathology.” Their work emphasizes the danger of automatically attributing common structural abnormalities discovered after vaccination to the vaccine itself.
That is an important caution. But it does not resolve every case.
Hesse and colleagues evaluated 476 conceded SIRVA claims and found MRI abnormalities including:
tendinopathy/tendinosis,
rotator cuff tearing,
bursitis,
and less commonly osseous abnormalities.
Their interpretation is particularly useful. They specifically cautioned that MRI findings should not be equated with prima facie evidence of a causally associated injury, because many of these abnormalities are common in middle-aged and older adults independent of vaccination.
That principle works in both directions. An abnormal MRI does not prove vaccine causation.
But a degenerative MRI does not prove that the patient's symptoms predated vaccination either.
Previously Asymptomatic Does Not Mean Structurally Normal
This is probably the most important concept. A patient may have had:
no shoulder pain
no loss of motion
no weakness affecting function
no shoulder treatment, and
no prior diagnosis
while still having an underlying partial rotator cuff tear, tendinopathy, arthritis, or labral degeneration.
Therefore:
“The abnormality looks chronic” does not necessarily mean “the patient's pain was chronic.”
The structural disease may be old while the clinical syndrome is new.
The Reverse Is Also True
A previously asymptomatic shoulder does not prove that every MRI abnormality appearing afterward was created by vaccination. For example, if MRI shortly after vaccination shows:
moderate AC arthritis + degenerative labral tearing + chronic supraspinatus tendinosis
it would generally be difficult to argue that vaccination created all of those abnormalities within days.
The more appropriate question becomes:
What explains why this previously asymptomatic shoulder became symptomatic at this particular time?
Possible answers may include:
an unrelated coincidental onset of degenerative shoulder pain,
a new inflammatory SIRVA process superimposed on preexisting disease,
aggravation of previously asymptomatic pathology,
direct injury to another structure,
or another independent diagnosis.
Incidental Does Not Mean Irrelevant
A degenerative MRI abnormality may be incidental to the patient's new symptoms.
But it may also become clinically relevant after a new event then consider an asymptomatic partial rotator cuff tear.
If a patient subsequently develops substantial subacromial inflammation, the previously silent tendon abnormality may become painful even if the tear itself was not newly created.
That creates an important causation distinction:
Structural causation Did vaccination create the degenerative tear?
versus
Symptom causation Did the vaccination-related event cause or materially contribute to the previously asymptomatic shoulder becoming symptomatic?
Those are different medical questions. Boonsri and Chuaychoosakoon reported a patient who developed substantial shoulder pain within approximately three hours of COVID-19 vaccination.
Imaging demonstrated marked subacromial/subdeltoid bursitis together with a small full-thickness supraspinatus tear. The authors proposed that the high injection location and 1.5-inch needle created the possibility of penetration into the bursa or rotator cuff.
However, in our systematic evidence extraction, the case was specifically flagged because a preexisting asymptomatic cuff tear could not be excluded.
That is the appropriate level of caution. The tear may have been old. The bursitis may have been new. Both may have contributed to the subsequent symptoms.
Look for Features Suggesting Chronicity
MRI can sometimes provide evidence that an abnormality is longstanding. Features that may favor chronicity include:
tendon retraction,
muscle atrophy,
fatty infiltration,
chronic cortical remodeling,
established osteoarthritis,
longstanding degenerative labral changes,
and substantial chronic tendinosis.
These features can make it less plausible that the structural abnormality itself was created by a recent vaccination. But even when chronic structural pathology is present, the imaging does not establish whether it was symptomatic before the event.
That determination requires the medical history.
Look Separately for Evidence of a New Active Process
A degenerative MRI may coexist with findings suggesting more active inflammation. Depending on the clinical context, potentially relevant associated findings include:
substantial bursal inflammation,
synovitis,
capsular inflammation,
marrow edema,
focal soft-tissue edema,
joint effusion,
or evolving abnormalities on serial imaging.
The Obeidat MRI study explicitly acknowledged this problem. Although patients with known prior shoulder pathology were excluded, the authors noted that asymptomatic degenerative changes, particularly tendon abnormalities, erosions, or partial cuff tears, could still be present and might not reflect vaccine-related injury. They therefore emphasized the need for controlled studies to distinguish reported SIRVA findings from background shoulder abnormalities.
That is one of the strongest limitations in the current SIRVA imaging literature.
Prior Imaging Is Extremely Valuable
The most useful evidence is often a prior MRI or ultrasound. Suppose a patient had MRI six months before vaccination showing:
partial supraspinatus tearing and AC arthritis
and post-vaccination MRI shows essentially the same abnormalities.
That is strong evidence that those structural findings were preexisting. But it does not necessarily answer why the patient subsequently developed pain.
Conversely, if recent pre-vaccination imaging is normal and early post-vaccination imaging shows a new focal abnormality, the temporal imaging evidence becomes substantially stronger.
Unfortunately, most published SIRVA cases do not have baseline MRI examinations.
Even the larger MRI studies identify absence of pre-vaccination imaging as an important limitation. Obeidat specifically noted the absence of baseline MRI as a limitation affecting interpretation of causation.
The Pre-Vaccination Medical Record May Be More Important Than the Word “Degenerative”
When no prior imaging exists, the clinical history becomes critical. Relevant questions include:
Was there documented shoulder pain?
Was motion restricted?
Was the patient receiving physical therapy?
Had injections been performed?
Was there an orthopedic consultation?
Was there prior shoulder surgery?
Was the patient modifying activities because of shoulder symptoms?
A chart showing active treatment for the same shoulder problem immediately before vaccination provides a very different causal context from a chart showing years of unrestricted shoulder function and no treatment.
Absence of Prior Symptoms Is Not Proof, but It Is Evidence
A patient saying “my shoulder never hurt before” cannot establish that the shoulder was anatomically normal. But documented absence of prior symptoms is still relevant.
It helps define the patient's clinical baseline. This is consistent with traditional SIRVA definitions, which focus on absence of prior shoulder pain, inflammation, or dysfunction sufficient to explain the current condition—not necessarily absence of every structural imaging abnormality.
Natanzi and colleagues, for example, summarize the traditional SIRVA framework as requiring symptoms within 48 hours in someone without prior pain, inflammation, or dysfunction of the affected shoulder.
Degenerative Findings Can Also Provide an Alternative Explanation
The analysis must remain balanced. Sometimes the degenerative disease itself may provide the better explanation.
For example:
A patient has longstanding intermittent shoulder pain. MRI demonstrates a large retracted cuff tear with substantial muscle atrophy and fatty replacement. Symptoms worsen gradually several weeks after vaccination without a distinct acute event. There is no associated inflammatory imaging abnormality.
In that scenario, ordinary progression of chronic rotator cuff disease may be a more persuasive explanation than SIRVA.
The term “previously asymptomatic” should therefore be supported by the actual record whenever possible rather than assumed.
Timing Still Matters
The more abrupt the clinical transition, the more meaningful the timing becomes.
Compare:
No symptoms → vaccination → immediate substantial shoulder pain → persistent dysfunction
with:
No symptoms → vaccination → several symptom-free weeks → gradual development of shoulder pain.
A degenerative MRI may be present in both. But the first timeline provides a substantially stronger temporal relationship to the vaccination.
This does not prove causation, but it changes the weight of the evidence.
Imaging and Symptoms Should Be Anatomically Correlated
Another question is whether the degenerative abnormality actually corresponds to the patient's clinical syndrome.
An MRI may report:
AC joint arthritis,
degenerative labral tearing,
supraspinatus tendinosis,
mild glenohumeral osteoarthritis,
and bursitis.
The patient may nevertheless have symptoms predominantly localizing to only one region.
Clinical examination, ultrasound, sonopalpation, and appropriately selected diagnostic injections can sometimes help determine which abnormality is actually contributing to pain.
Again:
Finding pathology is different from identifying the pain generator.
And identifying the pain generator is different from determining its cause.
Treatment Response Can Help With Localization, Not Etiology
If a subacromial injection substantially relieves pain, that may support the subacromial region as an important pain generator.
It does not prove whether the pathology was:
preexisting,
vaccine-induced,
vaccine-aggravated,
or coincidental.
Likewise, improvement following treatment of a rotator cuff abnormality confirms that the cuff may have been clinically relevant. It does not tell us when the structural abnormality first developed.
This distinction is especially important in medical-legal causation analysis.
A Useful Four-Step Framework
When degenerative abnormalities are found in a previously asymptomatic shoulder, it is useful to separate four questions:
1. Is the structural abnormality probably chronic? MRI may sometimes help answer this.
2. Was it clinically symptomatic before vaccination? The medical history and records are more important than MRI for this question.
3. Is there evidence of a new superimposed process? Look at symptom timing, inflammatory imaging findings, anatomy, serial imaging, and clinical examination.
4. What best explains the patient's new symptoms? This is the actual causation question.
Avoid collapsing all four questions into:
“The MRI says degenerative, therefore it was preexisting and caused the pain.”
That conclusion is often too simplistic.
Why This Distinction Matters in SIRVA Cases
SIRVA frequently occurs in the same age groups in which degenerative shoulder disease becomes common.
The overlap is therefore unavoidable. Hesse's warning is particularly important: common MRI abnormalities should not be treated as proof of a causally associated vaccine injury.
But Slette's incidental-pathology argument should also not be transformed into the opposite absolute proposition—that any degenerative abnormality automatically disproves a superimposed acute event.
The evidence requires a more individualized analysis.
The Bottom Line
How should degenerative MRI findings be interpreted in a previously asymptomatic shoulder?
The most appropriate answer is:
As evidence of structural pathology whose age and clinical significance must be determined separately from the onset and cause of the patient's symptoms.
A degenerative MRI abnormality may be:
preexisting and incidental,
preexisting but newly symptomatic,
aggravated by a new inflammatory or mechanical event,
or
the primary manifestation of ordinary degenerative shoulder disease unrelated to vaccination.
MRI alone often cannot distinguish among these possibilities. The causation analysis should therefore ask:
What changed clinically after vaccination, what findings appear chronic versus active, does the anatomy and timing support a new superimposed process, and is there a better alternative explanation for the transition from an asymptomatic to symptomatic shoulder?
That approach avoids both major interpretive errors:
“The MRI is abnormal, therefore vaccination caused it.”
and
“The MRI is degenerative, therefore vaccination could not have contributed to the patient's new symptoms.”
References
Hesse EM, Atanasoff S, Hibbs BF, et al. Shoulder Injury Related to Vaccine Administration (SIRVA): petitioner claims to the National Vaccine Injury Compensation Program, 2010-2016. Vaccine. 2020;38(5):1076-1083.
Slette E, Rohrback M, Ring D. Persistent shoulder pain after vaccine administration is associated with common incidental pathology: a systematic review. Clin Orthop Relat Res. 2022;480(7):1251-1258.
MacMahon A, Nayar SK, Srikumaran U. What do we know about shoulder injury related to vaccine administration? An updated systematic review. Clin Orthop Relat Res. 2022;480(7):1241-1250.
Wright JO, Wiggins W, Smith MS, King JJ, Wright TW. Shoulder pain and dysfunction after vaccination: a systematic review. JBJS Rev. 2023;11(1).
Boonsri P, Chuaychoosakoon C. Combined subacromial-subdeltoid bursitis and supraspinatus tear following a COVID-19 vaccination: a case report. Ann Med Surg (Lond). 2021;69:102819.
Natanzi N, Hebroni F, Bodor M. Teres minor injury related to vaccine administration. Radiol Case Rep. 2020;15(5):552-555.
Donners R, Gehweiler JE, Kovacs BK, et al. Chronic stage magnetic resonance imaging findings in patients with shoulder injury related to vaccine administration (SIRVA). Skeletal Radiol. 2023;52:1695-1701.
Obeidat N, Khasawneh R, Alrawashdeh A, et al. Shoulder Injury Related to Vaccine Administration (SIRVA) following COVID-19 vaccination: correlating MRI findings with patient demographics. Tomography. 2025;11(5):53.
Sanders S, Ibounig T, Haas R, et al. Rotator cuff imaging abnormalities in asymptomatic shoulders: a systematic review. J Orthop Sports Phys Ther. 2025;55:1-16.
Ibounig T, Järvinen TLN, Raatikainen S, et al. Incidental rotator cuff abnormalities on magnetic resonance imaging. JAMA Intern Med. 2026;186:406-414.
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