Gender Solutions Natural Knee Post-Market Study

Inclusion Criteria: * Patient 18-75 years of age, inclusive; * Patient qualifies for a total knee arthroplasty based on physical exam and medical history including at least one of the following: osteoarthritis, inflammatory arthritis, post-traumatic arthritis, rheumatoid arthritis, or valgus, varus, or flexion deformities; * Patient has undergone a study related informed consent process; * Patient is willing and able to provide written consent; * Patient is willing and able to cooperate in the required post-operative therapy; * Patient is willing and able to complete scheduled follow-up evaluations. Exclusion Criteria: * Patient has previous history of infection in the affected joint and/or a local or systemic infection that could affect the prosthetic joint; * Insufficient bone stock on femoral or tibial surfaces; * Skeletal immaturity * Neuropathic arthropathy * Osteoporosis or any loss of musculature or neuromuscular disease that compromises the affected limb; * Stable, painless arthrodesis in a satisfactory functional position; * Severe instability secondary to the absence of collateral ligament integrity; * Patient has rheumatoid arthritis and an ulcer of the skin or a history of recurrent breakdown of the skin because of their risk of postoperative infection is greater; * Patient has known sensitivity or allergy to one or more of the implanted materials; * Patients pregnant or considered a member of a protected population (e.g., prisoner, mental incompetence, unable to understand what clinical trial participation entails, etc.)