Primary Total Knee Arthroplasty

Indications

Total Knee Replacement - Valgus Knee, radiographs of a total knee arthroplasty
Radiographs of a total knee arthroplasty. Image by fpjacquot, Wikimedia Commons, CC BY-SA 3.0.
  • End stage knee arthritis failing non-operative care
  • Inflammatory arthritis and post-traumatic arthritis
  • Unicompartmental arthroplasty or osteotomy for isolated disease in selected patients
  • Contraindicated with active infection
  • Age, weight and expectations are discussed before surgery

Position

  • Supine, side and foot supports to hold flexion, thigh tourniquet
  • Tourniquet use is optional

Operative Steps

  1. Medial parapatellar arthrotomy
  2. Distal femoral cut perpendicular to the mechanical axis, about 5 to 7 degrees valgus to the anatomical axis
  3. Proximal tibial cut perpendicular to the mechanical axis with the slope of the implant
  4. Femoral rotation parallel to the transepicondylar axis, about 3 degrees external to the posterior condyles
  5. Balance flexion and extension gaps by measured resection or gap balancing
  6. Varus knee releases are medial. Valgus knee releases are lateral
  7. Resurface the patella if planned and check tracking
  8. Cemented fixation is most common in Australia (AOANJRR)
  9. Remove posterior osteophytes to improve extension
  10. Wash and dry bone surfaces before cementing

Postoperative Care

  • Early motion and weight bearing as tolerated
  • VTE prophylaxis
  • Multimodal analgesia and early mobilisation
  • Physiotherapy to achieve 90 degrees flexion early and full extension

Complications

  • Infection
  • Stiffness
  • Instability
  • Periprosthetic fracture
  • Common peroneal nerve palsy after correcting a valgus flexion deformity
  • Patellofemoral problems
  • Aseptic loosening
  • Periprosthetic fracture

Related Pages

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.