CLINICAL RATIONALE FOR A PATIENT-SPECIFIC CRUCIATE-RETAINING KNEE REPLACEMENT SYSTEM

1 in 5 patients are not satised with the results of their total knee replacement. 1 Patient dissatisfaction clinical reference

Over 5 million people are living with total knee replacements. Therefore, millions are likely dissatised with their knee replacement. This number continues to grow as over 1.2 million knee replacement procedures are done every year worldwide. 9 Leading Causes of Patient Dissatisfaction Residual Pain • Fit: Data suggests that 27% of clinically signicant knee pain is attributable to femoral implant overhang.11 • Rotation: Internal rotational errors, particularly of the tibial component, are a major cause of pain and functional decit after TKA.12 Functional Limitations • Poor Function: Patients...

Residual pain: Improper t Implant overhang causes residual pain and dissatisfaction Off-the-shelf total knees force compromises between sizing and coverage. Variations in anatomy make it virtually impossible for off-the-shelf designs to t the femur. increase in the risk of pain with overhang12 • In a series of 437 TKR femoral components, 68% of women and 40% of men had overhang of 3mm. Overhang was correlated with a 1.9x increase in the risk of pain.11 • Impingement of the femoral component can cause a snapping of the popliteus tendon which may be painful or disconcerting to the patient.15 The...

Rotational errors Component malrotation is a leading cause of residual pain • Among painful knees, 44% were found to have signicant rotational errors of the tibial tray.16 • Off-the-shelf tibial component designs maximize coverage at the expense of proper rotational alignment. One study of 120 tibial components found that only 30% were aligned within ±5° of proper rotation.17 to experience knee pain if excess internal component rotation is present 18 • In a study of anterior knee pain, patients with excess internal component rotation were more than 5x as likely to experience knee pain versus...

Functional limitations: Poor kinematics Unnatural feel and poor kinematics lead to patient dissatisfaction • According to published data, 2 to 3 times as many patients with TKA report some degree of difculty with activities relative to a similar control group.13 • Off-the-shelf total knee implants, including single radius designs, have been shown to alter kinematics.19 In one study, dissatised patients reported that their knee did not feel normal at more than twice the rate of racquet sports Age-matched control subjects Instability leads to patient dissatisfaction • Studies of early implant failures...

and mid-exion instability The iTotal G2 Solution: Patient-specic J-curves iTotal G2 is intended to restore each patient’s natural articulating geometry by: • Using the patient’s natural medial, lateral and patellofemoral J-curves, corrected for deformity, as the basis for femoral implant design. Patient’s natural J-curves • Facilitating proper balancing of offset femur and joint line with femur-matched offset polys. • Reducing lateral constraint to facilitate rollback. In a study comparing iTotal G2 to an off-theshelf TKR, iTotal restored natural kinematics: • iTotal more closely approximated...

Early implant failure: Poor alignment Cause of early implant failure: Poor overall alignment • Studies have shown that varus tibial malalignment (<90°) was associated with a 10.6x greater risk of failure, while >8° valgus femoral malalignment was associated with a 5.1x greater risk of failure.24 Failure rate according to overall alignment in degrees24 3.5% failure rate post operative alignment The iTotal G2 Solution: Mechanical axis alignment iTotal G2 is intended to achieve neutral mechanical alignment: • iFit® image-to-implant™ technology virtually aligns to mechanical axis using anatomic landmarks...

Polyethylene wear Cause of implant failure: Polyethylene wear Overall causes of revision surgery14 Polyethylene wear • Signicant polyethylene wear was observed in 25% of revision surgeries, making it the most prevalent mechanism of implant failure.14 The iTotal G2 Solution: Engineered for low contact stress • Due to its broad coronal radius, iTotal G2 allows for high contact area with low constraint. • The coronal radius on the femur interfaces with the poly throughout the range of motion. Contact area (mm2) at 0°, 60° and 90° of exion

why iTotal? Designed with features to address the leading causes of patient dissatisfaction, iTotal G2 is the only individualized total knee system on the market today. FIT • Individualized t that virtually eliminates overhang and sizing compromises • Designed to follow the contour of each patient’s anatomy • Tibial tray designed for maximized coverage and proper rotational alignment SHAPE • Individualized medial, lateral and patellofemoral J-curves with matching offset poly inserts • Designed for optimal bone preservation • Wear optimized by matching femur and tibial inserts for maximized surface...

references 1. Bourne, et al; Patient Satisfaction after Total Knee Arthroplasty. Who is Satised and Who is Not? Clinical Orthopaedics and Related Research; 2010, 468: 57-63 15. Barnes, et al; Popliteus Tendon Dysfunction Following Total Knee Arthroplasty. The Journal of Arthroplasty; 1995, 10: 543-545 2. Anderson, et al; Functional Outcome and Patient Satisfaction in Total Knee Patients Over the Age of 75. Journal of Arthroplasty; 1996, 11 # 7: 831-840 16. Nicoll, et al; Internal Rotational Error of the Tibial Component is a Major Cause of Pain after Total Knee Replacement. The Journal of Bone...

ConforMIS, Inc. 28 Crosby Dr., Bedford, MA 01730 Phone: 781.345.9001 | Fax: 781.345.0147 www.conformis.com Authorized Representative: Medical Device Safety Service, GMBH • Schiffgraben 41, 30175 Hannover, Germany P: +49 (511) 6262.8630 • F: +49 (511) 6262.86333 Copyright © by ConforMIS, Inc. All rights reserved. iDuo and ConforMIS are registered trademarks of ConforMIS. CAUTION: USA federal law restricts this device to sale by or on the order of a physician. The ConforMIS Cruciate Retaining Total Knee Replacement System (iTotal G2) is intended for use only by fully trained physicians. Prior to...