Age: 69.0
Sex: F
Vaccine: FLUX
Symptoms: Asthenia, Bursitis, Drug administered at inappropriate site, Immediate post-injection reaction, Injected limb mobility decreased
Clinical narrative: Case number PHHY2017US045004, is an initial literature report received on 20 Mar 2017. The author discussed about a report of rotator cuff tear resulting from intratendinous injection during attempted deltoid intramuscular vaccination. This report refers to a 69-year-old female patient. Medical history and concomitant medications were not reported. On an unknown date, the patient was vaccinated with an  influenza virus vaccine (manufacturer and batch number: not reported). On an unknown date, the patient presented to the Orthopaedic clinic with left shoulder pain. The patient stated that she experienced an acute onset of sharp severe pain in her shoulder during an influenza vaccination and was unable to lift her arm overhead immediately after the injection. The patient noted that the injection was performed "unusually high" in her shoulder directly underneath the lateral aspect of the acromion and the needle was inserted as deeply as possible. She also stated that  an "unusually long needle was used during the  injection". She was initially treated conservatively by her primary care physician with a  subacromial corticosteroid injection and physical therapy for presumed rotator cuff tendinitis for 5 weeks; however, her pain and weakness persisted. She had no prior shoulder pain, injury, or surgery in either shoulder, and she was able to pinpoint the influenza vaccination as the exact time when her shoulder pain began. Magnetic resonance imaging (MRI) with intraarticular contrast was performed, which showed a high-grade,  partial articular sided tear of the supraspinatus with a delaminated component. The contrast further delineated the delaminated nature of the tear. The patient underwent arthroscopic subacromial decompression with transtendinous rotator cuff repair with a double-row, suture-bridge construct and mini-open subpectoral biceps  tendinosis.  At  the  time  of  surgery,  she  was  found  to  have  a  severely  delaminated,  nearly  complete  rotator  cuff  tear  with  significant  synovitis in the glenohumeral joint and bursitis in the subacromial space. She was immobilized in a shoulder abduction brace for 4 weeks, with physical therapy beginning the day after surgery for passive range of motion. The patient progressed well through her rehabilitation protocol, and was doing well at 1-year follow-up with nearly full strength, no pain, and full range of motion. The author concluded the article stating that this is the first report of rotator cuff tear as a complication from intended intramuscular injection. Deltoid intramuscular injection is generally safe and effective for administration of medications and vaccines; however, complications are possible. Care in the starting point, depth, and direction of needle placement into the deltoid is critical to avoid inadvertent intratendinous rotator cuff injection. The size of the injection needle should be matched to the sex and size of the patient to ensure adequate muscle penetration, and  [Due to memory limitations, the remainder of this text could not be compared.]  on, and injection should be stopped if resistance is felt to allow for redirection of the needle.