steroid injection in left knee four weeks ago after booster dose, My knee was bothering me and doctor took x-rays and said it was arthritis; This spontaneous case was reported by a consumer and describes the occurrence of ARTHRITIS (steroid injection in left knee four weeks ago after booster dose, My knee was bothering me and doctor took x-rays and said it was arthritis) in an elderly female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 017F21A, 013A21A and 007B21A) for COVID-19 vaccination.     The patient's past medical history included Unspecified disorder of knee joint (Had trouble with right knee a few years back).   On 04-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 02-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 01-Dec-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On an unknown date, the patient experienced ARTHRITIS (steroid injection in left knee four weeks ago after booster dose, My knee was bothering me and doctor took x-rays and said it was arthritis). At the time of the report, ARTHRITIS (steroid injection in left knee four weeks ago after booster dose, My knee was bothering me and doctor took x-rays and said it was arthritis) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, X-ray: arthritis (abnormal) it was arthritis.         No concomitant medications reported. Patient did not have history of COVID.  It was reported that patient took steroid injection 4 weeks ago in the knee joint. Her knee was bothering her and the doctor took X-rays and said it was Arthritis. Patient stated the doctor said the steroid injection could help as pain relief for knee arthritis. Injection was given in the left knee (on the) outside. The injection hadn't really helped. It was reported that the doctor said to wait for 3 to 4 weeks after the injection for the second booster.  Company Comment: This spontaneous case concerns a 73-year-old, female patient with medical history of Right knee disorder (unspecified), who experienced the unexpected, non-serious AESI of arthritis (knee arthritis). The event occurred on an unspecified date after receiving the third (first booster) dose of the mRNA-1273 vaccine. It was reported that the X-ray of the Knee showed 'Arthritis'. Four weeks prior to the report, the patient was given an unspecified steroid injection in the knee joint which afforded no relief. The medical history of Right knee disorder remains a confounder. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This spontaneous case concerns a 73-year-old, female patient with medical history of Right knee disorder (unspecified), who experienced the unexpected, non-serious AESI of arthritis (knee arthritis). The event occurred on an unspecified date after receiving the third (first booster) dose of the mRNA-1273 vaccine. It was reported that the X-ray of the Knee showed 'Arthritis'. Four weeks prior to the report, the patient was given an unspecified steroid injection in the knee joint which afforded no relief. The medical history of Right knee disorder remains a confounder. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.