Total Knee Arthroplasty in Valgus knee H.Makhmalbaf MD Consultant Knee surgeon Mashad University

The Typical patient Sever valgus deformity Elderly woman in7th or8th decade Has had “knock knees” Also had patellofemoral problems Valgus deformity progresses Loss of lateral joint space Attenuation of MCL

The typical patient PFJ involvement & patella dysplasia on X-Ray Patella subluxation & concave patella Patella alta & a very thin patella Chondrocalcinosis & calcification of menisci Long leg film of tibia shows valgus bow

The typical patient The valgus tibia is problematic if using intramedullary guide The long leg film is necessary to template The diagnosis is usually OA or RA Hypermobile knee or hyperextention In RA might have stiff knee & flexion cont.

Clinical features of valgus vs varus Valgus knees tolerate significant damage In windblown knees varus knee is more symptomatic Varus knee should be operated on 1 st Source of deformity is also different Medial tibial plateau is deficient & tibial joint line in sever varus in varus knees The femoral joint line is still in 5-7 valgus

Valgus vs varus knee In valgus knees, is from the femur The tibial joint line usually in neutral The femoral joint line is in marked valgus Deformity due to hypoplasia of lat.femoral condyle Both distally & posteriorly The tibial defect in valgus is contained

Variants of valgus Based on degree of deformity Status of MCL, osseous deficiency & The amount of release must be performed Variant I: mild & correctable deformity Variant II: greater deformity,intact soft tissue Variant III: stretched MCL, Marked bone loss & deformity & lateral contracture

Type of prosthesis In variant I: P CR or PS may be used In variant II: may require a PS implant Invariant III: a PSC (constrained) should be used Complete set of instruments if preferred

Lateral femoral condyle hypoplasia Is present in sever valgus deformity Exists both distally & posteriorly In distal femoral resection don’t cut to the defect The deficiency must be augmented If not, causes large extension gap And elevation of joint line And mid-flexion laxity, distorting kinematic

The angle of DF cut 5 degree is preferred 7 degree cut is better for balance but? 5 o or less to overcorrect the deformity Less tension on MCL on WB But needs more lateral release Distal metaphyseal bow More medial point of entrance in the notch

Balancing the knee in flex.& extension Create symmetric flexion extension gaps Valgus knees could be balanced in flexion & extension independently In flexion the tissues are not tight Nor the medial tissues are lax in flexion Draw Whiteside line & transepicondylar ax In sever valgus int rotation of femoral component is necessary

Flexion extension balance Lateral release, after bone cuts Put spacers, varus & valgus tests Inverted cruciform release LCL, poplliteal, & Biceps tendon release PS in sever valgus & CR in mild one Surgical approach

Summary Associated with PFJ disease Lat femoral condyle hypoplasia Medial laxity, a valgus tibial bow Conservative bone cuts Cruciform release of ITB & capsule Protect peroneal nerve PS or CR knee

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