2-Year Post-Approval Study to Investigate the Scandinavian Total Ankle Replacement System (STAR) Ankle Under Actual Conditions of Use

This investigation is a prospective, multi-center, single-arm study. 98 subjects are to be enrolled in this clinical investigation. Enrolled subjects will be assessed at Pre-Operative, Operative/Discharge, and at 6 Weeks, 6, 12, and 24 Months after the index procedure. Safety, efficacy, and effectiveness analyses will be performed for all follow-up points during the study.

Inclusion criteria

• Moderate or severe pain, loss of mobility and function of the ankle (Buechel-Pappas Scale)
• Primary arthrosis, post traumatic arthrosis or rheumatoid arthrosis
• At least six months of conservative treatment for severe ankle conditions, confirmed by the patient medical history, radiograph studies and medication record
• Willing and able to give informed consent

Exclusion criteria

• Patients who have not reached skeletal maturity
• Active or prior deep infection inthe ankle joint or adjacent bones
• Prior arthrodesis at the involved site
• History of prior mental illness or patient demonstrates that their mental capacity may interfere with their ability to follow the study protocol
• Obesity (weight greater than 250 lbs)
• History of current prior drug abuse or alcoholism
• Any physical condition precluding major surgery
• Hindfoot malpositioned by more than 35 degrees or forefoot malalignment which would preclude a plantigrade foot
• Lower extremity vascular insufficiency demonstrated by Doppler arterial pressure
• Avascular necrosis of the talus
• Inadequate skin coverage above the ankle joint
• Patients under the age of 35 who are unwilling or unable to accept the physical limitations imposed by ankle arthroplasty, including limitations on certain vigorous physical activities (e.g. basketball, football) and on manual labor
• Juvenile onset Type I diabetes
• Adult onset Type II diabetes when accompanied by neuropathic changes or a history of foot infection in either foot
• Pregnancy
• Avascular necrosis of the tibia
• Significant bone tumor of the foot or ankle
• Severe deformity that would not normally be eligible for ankle surgery
• Prior surgery and/or injury that has adversely affected the ankle bone stock
• Severe osteoporotic or osteopenic condition or other conditions that may lead to inadequate implant fixation in the bone
• Insufficient ligament support
• Motor dysfunction due to neuromuscular impairment