Total Knee Arthroplasty in Varus Knee H.Makhmalbaf MD Consultant Orthopaedic & Knee Surgeon Ghaem Hospital Medical School

The most important factor in maintaining satisfactory long-term outcome in TKA is anatomic alignment This depends significantly on ligamentous balance

The most favorable results are observed with femorotibial angle 3-7ovalgus , the tibial component in neutral,& the femoral component in 4-6o valgus

The typical patient Severe varus deformity Some varus alignment since childhood H/O medial menisectomy Gradually progresses Lateral subluxation of the tibia on the femur

Exposure Standard medial parapatellar arthrotomy Resect medial meniscus Release deep MCL Resect ACL Externally rotate & deliver the tibia Remove all osteophytes

Mediolateral Balancing Ligament balance in flexion & extention are interrelated (unlike valgus knee) In a varus knee , the knee should be balanced in extention first then in flexion

Shift & resect technique Tibia is delivered in front of the tibia Initial conservative tibial resection Based on the intact lateral side 10mm lateral resection Angle of resection is perpendicular to the long axis of the tibia & 3-5o posterior slope Choose tibia one size smaller

Shift & resect Choose tibia one size smaller & Shifted laterally to the edge of tibia Align tibial rotation with tibial tubercle Outline the nucapped portion of tibia Free the MCL from bone Resect bone perpedicular

Formal MCL release from the tibia Release deep MCL Posteromedial capsule Remove osteophytes Release PCL Resect PCL & put PS knee

Distal femoral resection Pre-op X-ray Varus in the femoral shaft ? Usually 5-7deg.cut More resection of medial fem. condyle The amount of resection depends on the thickness of metallic femoral component

Femoral component rotation Establish a balanced, symmetric flexion gap to maximize flex. Stability In varus knee balance in ext.1st Use the Whiteside line or trans epi. 30 external rotation Then posterior condyles in flexion

Tibial bone stock deficiency Medial tibial plateau is always deficient in varus knee Resect enough bone not too much Bone graft Cement & screws Metal wedges Allograft

Residual lateral laxity How much laxity is acceptable The bony alignment should not be in varus The lateral should not gap open on the tab Correct significant laxity More medial release Fibula head advancement?

summary Tibia is responsible for varus Release MCL, remove osteopytes Bone resection, undersize, sift Balance flexion gap PCL retention in severe varus? Release PCL ? Accept some residual laxity if Fill bony defects in tibia

Thank you