We present a case report of total knee arthroplasty complicated by spasticity and contractures in a patient with multiple sclerosis (MS). Four previous case reports in the literature describe adverse outcomes after total knee arthroplasty in persons with MS secondary to severe spasticity. Preoperative, intraoperative, and postoperative considerations for persons with MS, which may help to improve functional outcomes, are discussed. Prospective research is needed among persons with MS to help determine the timing and selection of persons for arthroplasty and to minimize complications related to spasticity.