Metal on Metal articulation should be avoided in -

Based on the articulating surfaces of the prosthesis, THR may be of the following type:- Metal on poly: One surface is metallic (femoral side) and the other is of polyethene (on the acetabular side). Metal on metal: Both articulating surfaces are of metal. Ceramic on ceramic: Both articulating surfaces are of ceramic. Contraindications to Metal on Metal Bearing surfaces (Metal on Metal Total Hip Replacement or Metal on Metal Hip Resurfacing) Patients with Renal Insufficiency (Chronic Renal failure) (Kidney are chiefly responsible for eliminating metal ions from the blood) Young females of childbearing age (Women who may potentially still have children) (Elevated levels of metal ions have harmful effects on the fetus) Patients with metal hypersensitivity Contraindications to (Metal on Metal) Hip Resurfacing (Not contraindications to Metal on metal articulation) Loss of femoral head (severe bone loss: poor bone stock) Large femoral neck cysts (poor bone stock: found at surgery) The small or bone deficient acetabulum Conditions that require caution: Associated with increased risk of failure Tall thin patients Female patients Patients with femoral head cysts > 1 cm (on preoperative radiographs) Patients with high body mass index > 35 Rheumatoid arthritis (Inflammatory arthritis) and Osteonecrosis (AVIV) Rheumatoid arthritis (Inflammatory arthritis) and osteonecrosis of the hip/ perthe's disease were earlier considered contraindications/ semi- contraindications for Resurfacing. These have now shown to have successful results.