Abstract
BACKGROUND: Claims of shoulder injury now account for half of all claims to the Vaccine Injury Compensation Program. Reports from databases of claims or potential adverse events note a relatively high mean age and high prevalences of rotator cuff tendinopathy and adhesive capsulitis-common shoulder problems that might be incidental to vaccination. Published case reports provide much more detail about individual patients than is available in databases. A review of published cases provides an opportunity for more detailed review of symptoms, diagnoses, pathology, treatment, and prognosis. Such a review can better assess the relative likelihood that pathologies associated with new persistent shoulder symptoms after vaccination are coincidental or unique to and caused by vaccine. QUESTIONS/PURPOSES: Regarding published case reports addressing persistent shoulder pain after vaccination: (1) In what proportion of patients was a specific diagnosis made? (2) What diagnoses were most common? (3) Among patients treated nonsurgically, what proportion resolved, and over what time span did they resolve? METHODS: In August 2020, we searched PubMed and Embase between 2006 and 2020 using the following search strategy: Search 1: (shoulder dysfunction OR shoulder pain OR shoulder bursitis OR rotator cuff tendonitis OR adhesive capsulitis OR glenohumeral arthritis AND [vaccine OR vaccination OR immunization]); Search 2: (shoulder injury related to vaccine administration or SIRVA). The search was supplemented by reviewing reference lists of identified studies. Inclusion criteria were any detailed report of three or fewer cases involving shoulder pain after vaccine administration. Twenty published reports of 29 patients were identified and assessed by two reviewers independently. One reported glenohumeral joint infection was excluded because the relationship between this type of relatively uncommon, discrete diagnosis and vaccination raises different considerations. We assumed a high risk of bias, although we are not aware of bias assessment tool for case reports. We recorded and summarized patient demographics, symptoms, examination and imaging findings, surgery findings, diagnoses, treatments, and outcomes. Seventy-five percent (21 of 28) of patients were women, with a mean age of 54 ± 19 years. In search of an underlying pathology, at least one diagnostic study was performed in 82% (23 of 28) of patients including radiographs in seven, ultrasound in seven, and MRI in 16 patients (some patients underwent more than one type of imaging). We distinguished specific pathophysiological diagnosis from shoulder pain and stiffness, counted the most common diagnoses among patients a specific diagnosis, and tracked symptom resolution among patients treated nonoperatively. RESULTS: A specific diagnosis was made in 57% (16 of 28) of patients. Twelve patients had pain and limitation of motion due to pain but no specific pathological diagnosis. The most common specific diagnoses were rotator cuff tendinopathy (9 of 16) and adhesive capsulitis (4 of 16). Less common specific diagnoses included rotator cuff arthropathy (and rheumatoid arthritis) and suspected septic arthritis with nonspecific synovitis on arthroscopy. One patient had transient MRI signal change in the humeral head, which was interpreted as osteonecrosis that resolved in a manner not typical for that diagnosis. Of the 17 patients treated nonsurgically, 15 reported resolution, and two had incomplete symptom resolution with the mean 6-month evaluation period. CONCLUSION: The observation that persistent shoulder pain after vaccination overlaps with common shoulder pathology-both in large databases as well as in more detailed reports of specific patients as analyzed in this review-establishes a high probability of a coincidental rather than a causal association. In the absence of high-quality experimental evidence of vaccine-specific shoulder pathology, in our opinion, it seems safest and healthiest to assume that perceived shoulder injury related to vaccine administration (SIRVA) is due to misinterpretation of new symptoms from established pathology rather than a new, vaccine-specific pathology. LEVEL OF EVIDENCE: Level IV, therapeutic study.