All Ligaments Left In Knee Arthroplasty Trial

Inclusion Criteria: * Primary Osteoarthritis of the knee involving one or more compartments of the joint. * Intact Anterior and Posterior Cruciate Ligaments. * Intact collateral ligaments. * Correctable coronal deformity. * No more than 15 degrees of fixed flexion deformity. Exclusion Criteria: * Age under 18 years. * Revision knee replacement surgery. * Rheumatoid Arthritis. * Traumatic aetiology. * History or clinical signs of ACL rupture. * Previous arthroscopy related to ACL injury or reconstruction. * Correction of a flexion contracture that may require extensive resection of distal femur. * Altered pain perception and / or neurologic affection (for example as a complication arising from diabetes). * Unable to consent for themselves. * Patients with language or cognitive issues that may prevent them completing the follow up requirements. * Contraindications for the device: * Cementless application of components. * BMI ≥40 kg/m2. * Use of Anterior Stabilized Bearings. * Patients with severe pre-operative varus or valgus deformity ≥ 15 degrees. * Correction or revision of previous joint replacement procedure on index knee. * Infection. * Sepsis.Osteomyelitis. * Osteoporosis (requiring treatment). * Relative contraindications include: * Unco-operative patient or patient with neurologic disorders who is incapable of following directions. * Osteoporosis. * Metabolic disorders which may impair bone formation. * Osteomalacia. * Distant foci of infections which may spread to the implant site. * Rapid joint destruction, marked bone loss or bone resorption apparent on roentgenogram. * Vascular insufficiency, muscular atrophy, neuromuscular disease. * Incomplete or deficient soft tissue surrounding the knee, including the anterior cruciate ligament.