Valgus TKR


TKR Moderate Valgus OAValgus Malalignment




A valgus knee has a tibiofemoral angle of > 10o





- RA


TKR Bilateral Valgus OA



- rickets, renal



- tibial malunion

- plateau fracture



- physeal arrest




Primary OA

- most common

- females

- unresolved physiological valgus deformity




Soft tissue abnormalities


A.  Contraction of lateral structures



- Popliteus

- PL capsule

- Lateral head gastrocnemius

- Lateral IM septum

- Long head of biceps


B.  Lax medial structures


Bony abnormalities


A.  LFC hypoplasia

- beware posterior condyle referencing

- cause IR of the femoral component

- use Whiteside's AP axis / epicondylar axis


B.  Posterior aspect lateral tibial plateau


Krackow Classification


Type 1 / Lateral bone loss


TKR Valgus OA Lateral Bone Loss


Type 2 / MCL deficient


TKR Valgus OA MCL Insufficiency


Type 3 / Secondary to HTO


TKR Valgus Secondary HTO


Surgical Problems


1.  Approach


Medial approach



A.  Easy to evert patella because

- increased Q angle

- tibial tuberosity lateralised



A.  More difficult to reach contracted lateral side

B.  If perform lateral release, risk devascularising the patella

C.  Must not perform any medial release


Lateral approach Keblish 1991



A.  Direct access to lateral structures

- makes these easier to release

B.  Preserves blood supply to patella



A.  Wound closure at end of case

- not enough capsule to close after correction valgus

- closing only skin and soft tissue, may need to utilise the fat pad


Keblish Technique

- midline incision

- lateral release along lateral border of patella

- coronal z step cut in vastus lateralis

- is 6 - 9 mm thick

- lower 50% taken off patella

- superficial 50% attached to patella


2.  Bony alignment



- deficient LFC 

- don't use posterior condylar axis to set rotation

- use Whiteside's AP axis and epicondylar axis

- can place a osteotome under LFC when placing sizing block


Tibial resection

- don't take 10 mm as bone worn laterally in valgus OA

- can't take 2mm off medial side as is the normal side

- need to estimate

- take 6 mm from lateral tibia intially, stay above fibula head

- much more symmetric proximal tibial resection

- use trial blocks to assess flexion / extension gaps


TKR Valgus OA Tibial Resection


Deficient lateral tibial plateau

- don't take > 10 mm medial plateau

- will get down into soft bone

- preop plan

- may need augments laterally and therefore stems

- below xray is borderline / but just ok


TKR Severe Valgus Tibial Resection Planning


3.  Soft tissue balancing


Best to sacrifice PCL early


Tight Extension

- pie crust or release ITB 

- +/- lat gastrocneumius off femur

- +/- Z lengthen biceps


Tight Flexion

- PL corner

- release popliteus proximally


Tight Extension & Flexion

- release LCL from lateral epicondyle

- usually done last

- periosteal sleeve as per popliteus


4.  Management MCL Deficiency


A.  Young Patient


Tighten MCL

- advance femoral insertion (Krackow)

- cut mid-substance and imbricate (Krackow)

- take off femur with bone plug / advance


CCK Prosthesis

- acts as an internal splint whilst MCL heals


B.  Older patient


Consider hinged prosthesis


5.  Prosthesis


PS to aid balancing

CCK / MCL Deficient

Augments / lateral bone loss


5.  Patella tracking


Tends to track laterally after correction

- resurface / place button medially

- lateral release may be required

- issue if have done medial approach

- may get patella AVN


6.  CPN


Need to check in recovery

- splint the knee in flexion post operatively




ML instability

- release too many lateral structures

- can develop late

- incidence 6-25%

- may need CCK on hand


Avoid by

- pie crusting ITB

- releasing popliteus / LCL as sleeve


Recurrent / residual valgus

- prone to maltracking


Wound healing


Patella maltracking 


Patella fracture

- secondary to AVN from medial approach and lateral release





- more common if valgus > 12o