iForma™ Knee Interpositional Device:
 The iForma is an FDA cleared and CE Marked implant designed for the treatment of moderate osteoarthritis isolated to the medial or lateral compartments.
How it Works
Based on a clinically proven concept1,2,3, the iForma is seated between the femur and tibia and resembles the shape of a healthy meniscus. A polished superior surface provides a smooth articulating platform for the femur, while the personalized shape restores joint geometry and redistributes stress loads.
By utilizing MRI data to customize the implant for each patient, the iForma represents a significant advance in interpositional devices. The implant is sized and shaped based on the surface measurements of the joint and degree of cartilage loss apparent on the femur and tibia. The undersuface of the iForma represents an imprint of the tibial surface to facilitate fixation.
This personalized fit enables the implant to achieve 'functional fixation' without the need for invasive tissue removal, screws, pegs or cement.
iForma Features
- Typically performed as a 40-60 minute outpatient procedure
- 4-6 cm average incision length for implant insertion
- Only one specialized instrument required for implant insertion
- Requires no bone resection, only osteophyte removal
- Requires no shaping or remodeling of cartilage
- Preserves the joint for future treatment options
- Available for medial and lateral compartments
- Less post-operative pain and early return to activity with proper patient selection
Who is a Candidate
 Patients with early to moderate osteoarthritis limited to either the medial or lateral compartment may be good candidates for the iForma. In particular, patients who have exhausted non-surgical therapies, but are looking for less invasive alternative than traditional surgical options.
The iForma allows the patient to preserve their joint for future surgery options while receiving an implant treatment with the potential to prevent or delay the need for a more invasive surgery. The bone and cartilage preserving features of the iForma may be especially valuable for young and active patients who are considered too early for traditional knee replacement.
Indications
The ConforMIS iForma is intended for use in patients with isolated osteoarthritis of the medial or lateral tibiofemoral compartment of the knee (moderate degeneration, Grade II – IV chondromalacia) and minimal degeneration (Grade I – II chrondomalacia) in the contralateral tibiofemoral compartment and in the patellofemoral compartment.
Contraindications
Absolute
- Active infection
- Severe instability due to advanced loss of osteochondral structure or the absence of collateral or cruciate ligament integrity
- Flexion contractuve >15%
Relative
- Tricompartmental disease > Grade III
- Femoropatellar arthritis > Grade III
1 Springer BD, et al. McKeever hemiarthroplasty of the knee in patients less than sixty years old. JBJS. 2006.
2 Scott RD , et. al. McKeever metallic hemiarthroplasty of the knee in unicondylar degenerative osteoarthritis: Long-term clinical follow-up and current indications. JBJS. 1985.
3 Emerson RH et. al. The use of the McKeever metallic hemiarthroplasty for unicompartmental arthritis. JBJS. 1985. |
