Total knee arthroplasty in a patient with ipsilateral calcific myonecrosis

Calcific myonecrosis (CM) is a rare soft tissue condition associated with previous trauma that presents with a large lower extremity mass and can be misdiagnosed as a malignancy. Biopsy, accidental entry, or disturbance to the lesion can be accompanied by a high risk of complications. We present the case of a 72-year-old man with severe post-traumatic knee arthritis, as well as a large pretibial mass consistent with CM, who successfully underwent total knee arthroplasty. To our knowledge, this is the first report focusing on total knee arthroplasty in a patient with CM and we discuss considerations for evaluation, tourniquet usage, component positioning and placement, postoperative care, and range-of-motion expectations.