A Study of the KineSpring System Versus High Tibial Osteotomy Surgery for the Treatment of Medial Compartment Knee Osteoarthritis (GOAL)

Inclusion Criteria:

• Male or female subjects ≥25 years of age
• Documented diagnosis of knee OA with a minimum of 12 months duration
• Radiographic confirmation of medial compartment knee OA as demonstrated by a Kellgren-Lawrence grade of ≥ 2 (scale 0-4) as assessed by the Investigator
• Undergone at least six months of conservative treatment prior to surgery
• Knee flexion range ≥90 - ≤140 degrees
• WOMAC pain score of at least 40 (scale 0-100) at both the screening and baseline visits
• BMI < 35 or weight < 300 lbs
• Candidate for a high tibial osteotomy procedure
• Subjects who are able to give voluntary, written informed consent to participate in this clinical investigation and from whom consent has been obtained
• Subjects, who, in the opinion of the Clinical Investigator, are able to understand this clinical investigation, cooperate with the investigational procedures and are willing to return for all the required post-treatment follow-ups.

Exclusion Criteria:

• Significant OA in lateral compartment as measured by Kellgren Lawrence grade of ≥2 or significant OA in patellofemoral compartment
• Significant OA in the contralateral knee likely to necessitate surgical intervention within 12 months of enrollment
• Tibial-femoral varus or valgus alignment >10 degrees
• Flexion deformity > 10 degrees
• Hyperextension >5 degrees
• Ligamentous instability as assessed by the Investigator on physical examination
• Active infection, sepsis or osteomyelitis, history of infection in the target knee or distant foci of infections which may spread to the implant site
• Previous joint modifying surgery in the target knee are excluded within 12 months prior to planned study surgery date, such as ligament reconstruction or meniscus repair, cartilage transplantation, and microfracture. Arthroscopic surgeries for joint lavage, menisectomy, chondral debridement, and loose body removal are excluded within 3 months prior to planned study surgery date.
• Previous osteotomy or failed knee joint replacement in the target knee
• Known sensitivity to metal implants
• Rheumatoid arthritis, other forms of inflammatory joint disease or autoimmune disorder
• Paget's disease or metabolic disorders which may impair bone formation
• Moderate to severe osteoporosis as evidenced by radiolucency of the femoral or tibial cortex on x-ray
• Charcot's joint disease or other severe neurosensory deficits
• Immunologically suppressed or immunocompromised
• Currently undergoing long-term steroid therapy (treated in the last 6 months with systemic corticosteroids)
• Any significant medical condition (e.g., uncontrolled diabetes mellitus, significant psychiatric disorders, active alcohol/drug abuse, etc) or other factor (e.g. planned relocation, uncooperative patient) that the Investigator feels would interfere with study participation.
• Litigation for or workers compensation for musculoskeletal injuries or disorders
• Is either pregnant or interested in becoming pregnant during the duration of the study
• Subjects who are currently enrolled in the treatment phase of another clinical investigation that could affect the results of this trial