The lateral parapatellar approach provides direct access to the pathological area in a valgus knee deformity and allows sequential titrated release of contracted lateral soft tissues during total knee arthroplasty.
Step 1: Preoperative Planning
Differentiate the flexible and fixed components of the valgus deformity by clinical and radiographic examination.
Step 2: Expansile Lateral Arthrotomy
Open the knee joint from the lateral side by coronal z-plasty of the lateral retinaculum, oblique lateral tenotomy of the quadriceps tendon, and iliotibial band release.
Step 3: Quadriceps Snip and Joint Exposure
Perform a quadriceps snip and expose the knee joint.
Step 4: Tibial and Distal Femoral Cuts
Make proximal tibial and distal femoral cuts in appropriate alignment.
Step 5: Extension Gap Balancing
A rectangular extension gap is the goal.
Step 6: Flexion Gap Balancing
Determine the femoral component size and femoral rotation, and balance the flexion gap.
Step 7: Component Fixation
Confirm tibial rotational alignment, fix the components, and assess patellar tracking.
Step 8: Prosthetic Joint Closure
Perform closure of the prosthetic joint with expanded lateral structures.
Between 2003 and 2009, thirty-two knees with clinical valgus deformity of >10° underwent total knee arthroplasty with an expansile lateral arthrotomy technique11.
Pitfalls & Challenges