Summary The iTotal Identity sets a new standard in knee replacement technology Patient-specific implants are designed around individual anatomy to promote physiologic kinematics, stability, and long-term joint health By leveraging advanced imaging technology and a proprietary database, iTotal Identity ensures that each implant is uniquely crafted to match the patient’s individual anatomy The platform personalizes implant geometry and streamlines intraoperative steps to support precise placement and efficient workflows Related Implants Posterior Stabilized Knee Replacement System Cam-and-post mechanics substitute for the posterior cruciate ligament to provide anteroposterior stability in flexion Intended for cemented fixation with patient-specific femoral, tibial, and patellar components plus single-use iJig® guides CR 3DP Porous Cementless Total Knee Cruciate-retaining design that preserves the PCL with additively manufactured porous femoral, tibial, and Ti-backed patellar components to enable biological fixation without cement Compatible with hybrid constructs when clinically indicated Identity platform options include CR, CS, and PS inserts in iPoly® and iPoly® XE, titanium tibial baseplate designs, and 20- and 40-mm stem extensions Indications Posterior Stabilized Knee Replacement System Total knee arthroplasty for painful joint disease including osteoarthritis, traumatic arthritis, rheumatoid arthritis, polyarthritis, and osteonecrosis Post-traumatic loss of joint function and moderate varus, valgus, or flexion deformity when collateral ligaments are stable or reconstructible Failed osteotomies, hemiarthroplasties, and unicondylar, patellofemoral, or bicompartmental implants Select revision procedures when anatomic landmarks are identifiable on patient imaging Cemented use only CR 3DP Porous Cementless Total Knee Indicated for the same spectrum of tricompartmental disease when a fully personalized, uncemented construct is preferred CS insert may be selected when additional A-P constraint is desired Designed for uncemented fixation with option to cement porous implants at surgeon discretion Contraindications Active or recent local or systemic infection Insufficient bone stock, skeletal immaturity, severe neuromuscular or vascular compromise, or severe deformity/instability incompatible with safe implantation Known metal hypersensitivity Anatomy Osteology Distal femur with medial-lateral asymmetry and distinct sagittal radii Proximal tibia with native posterior slope and plateau asymmetry Patella with variable thickness and facet geometry Muscles Quadriceps mechanism for extension and patellar tracking Hamstrings and gastrocnemius affecting flexion and posterior forces Popliteus contributing to posterolateral stability Ligaments MCL and LCL as coronal stabilizers PCL preserved in CR constructs and substituted in PS constructs Capsule and retinaculum contributing to patellofemoral mechanics Nerves Saphenous (infrapatellar branch) at risk during approach Common peroneal near fibular neck Tibial nerve posteriorly protected by capsule and soft tissue Blood supply Genicular anastomoses around the distal femur and proximal tibia Respect for peripatellar vessels during arthrotomy and osteophyte removal Approach Standard midline skin incision with medial parapatellar arthrotomy Extensile options include quadriceps snip, V-Y turndown, or tibial tubercle osteotomy when exposure is limited in severe deformity or revision cases Patient-specific iJig® guides reduce bulk instrumentation and bring plan-based orientation directly to bone surfaces Technique Preoperative planning with CT-based imaging Patient-specific femoral and tibial geometries define component contours, alignment targets, joint-line levels, and sagittal radii Bone preparation using patient-specific guides Verify seating of iJig® guides, perform conservative resections limited to planned surfaces, and minimize accessory drill holes Trialing and balancing Assess range of motion, stability, and patellar tracking Address impingement or instability before definitive implantation Implantation PS system Cement femoral, tibial, and patellar components per plan Maintain clean interfaces and remove debris or excess cement before closure Confirm cam-post engagement throughout flexion and manage posterior slope to balance A-P stability CR 3DP porous system Achieve press-fit seating on porous surfaces for biological fixation Hybrid cementation may be used selectively based on bone quality and surgeon preference Postoperative care Standard protocols with counseling on activity limits Follow-up imaging to assess component position and fixation Technical specifications Materials and manufacturing PS system uses CoCrMo femur, Ti-6Al-4V-ELI tibial tray and stem extensions, and UHMWPE (iPoly®) or cross-linked Vitamin-E-enriched UHMWPE (iPoly® XE) inserts and patellae CR 3DP porous system employs additively manufactured CoCrMo femur, Ti-6Al-4V tibial tray, and a UHMWPE patella with porous Ti-backing, produced with TIDAL Technology™ for osseointegration Fixation strategy PS system is for cemented use only with patient-matched component footprints to preserve joint lines and femoral offset CR 3DP porous system is intended for uncemented fixation Porous implants may be cemented when clinically necessary or used in hybrid constructs Inserts and baseplates CR, CS, and PS inserts are available in iPoly® and iPoly® XE Titanium tibial baseplate options include a patient-specific cement rail and stem extensions in 20- and 40-mm lengths to address metaphyseal/diaphyseal support Instrumentation Sterile, disposable iJig® patient-specific guides are supplied for single-patient use to simplify the surgical technique Sterility and re-sterilization Do not re-sterilize polyethylene components Validated steam parameters exist for uncontaminated metal implants and iJigs® when re-sterilization is required MRI safety PS system is MR Conditional at 1.5 T and 3.0 T with a whole-body SAR limit of 2.0 W/kg Documented artifact radius is defined on gradient-echo sequences CR 3DP porous system has not been evaluated for MR safety Risks of heating or movement are unknown Screws Identity knee constructs do not rely on screw fixation as part of standard assembly PS components achieve fixation with bone cement and patient-specific geometry CR 3DP porous components achieve fixation by biological ingrowth with optional hybrid cementation Notes for the surgical team Patient selection and counseling are essential Elevated failure risk exists with high activity, obesity, heavy labor, or falls Postoperative compliance strongly influences outcomes Training resources are available Surgical technique reviews, live surgery videos, and bioskills labs are offered to support adoption and consistency