iTotal™ Tricompartmental Knee Resurfacing Device
A traditional total knee replacement is the gold standard for treatment in older patients with end stage degenerative arthritis of the knee. However, with the possibility of multiple revisions as a result of implant component loosening or wear, there are many younger patients for whom a total knee replacement carries a potential risk of a more invasive revision surgery later on in life.
The ConforMIS iTotal is designed as a less invasive, less traumatic option for patients with tricompartmental osteoarthritis. It is designed to resurface the weight bearing articular surface of the knee joint while preserving the underlying femoral subchondral bone plate. By resurfacing the femur and minimizing the tibial resection, the joint is preserved for possible revision to a standard total knee replacement in the future.
How it Works
 The patient-specific iTotal is designed from a CT scan of an individual patient’s knee using the ConforMIS iFit technology. The iFit design process interactively maps the diseased area and defines the extent of misalignment present in the knee. Using the patient-specific bone geometry, iFit defines the shape and size of the femoral and tibial components as well as the patient-specific instrumentation.
The femoral component conforms to the surface of the patient’s femoral condyle, replacing the damaged cartilage with a cobalt chrome articulating surface. Because of its patient-specific conformity to the subchondral bone, it is a true resurfacing product, requiring only cartilage removal and two small posterior bone cuts. The weight bearing portion of the subchondral plate is kept intact.
The femoral component is made of cobalt chrome. The tibial component is made of polyethylene and the patellar component uses a standard polyethylene button. The design of the implant allows for a minimally invasive approach to be used, requiring a small incision size. In bioskills testing, the iTotal allows for full range of motion following the procedure.
Because the procedure requires minimum resection and utilizes patient specific instrumentation, risk from complications of surgery can be lessened. Alignment is facilitated by iJig instrumentation that incorporates the biomechanical axis into its design, eliminating the need for an IM rod. With less bone resection and the elimination of the IM rod, the patient is able to avoid one of the primary causes of cardiopulmonary complications and lower their overall blood loss during the procedure.
iTotal Features
- Only total knee system with a resurfacing approach
- Achieves full range of motion following the procedure
- Protects soft tissue structures, including the PCL
- Avoids problems related to implant subsidence by resting on subchondral bone
- Simplified surgical technique utilizing iJig instrumentation
- Preserves options for future surgery using standard, primary total knee systems
- Provides an option for younger, more active patients
Who is a Candidate
The iTotal addresses the needs of the younger patient with advanced osteoarthritis or partial knee osteoarthritis with an insufficient anterior cruciate ligament, with mild correctable deformity, mild contractures and good range of motion.
Indications
The ConforMIS iTotal is intended for use in patients with severe knee joint pain and disability. The indications for use include restoring joint function and relief of pain due to:
- painful joint disease due to osteoarthritis, traumatic arthritis or rheumatoid arthritis of the knee
- post traumatic loss of joint function
- valgus or varus deformity of the knee
Contraindications
Absolute
- Active infection
- Severe instability due to advanced loss of osteochondral structure or the absence of collateral or cruciate ligament integrity
- Flexion contracture > 15 degrees
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