This evaluation is conducted to evaluate the safety and performance of two different stem lengths of the Taperloc Total Hip System. Per implant bone loss and migration of the stem are compared between the two groups with Dual-energy X-ray absorptiometry (DEXA) and radiostereomektric analysis

Consecutive patients between 50 - 70 years diagnosed with primary osteoarthritis of the hip and eligible for total hip arthroplasty will be asked to participate in the study.

Periprosthetic bone loss, migration of the components and clinical scores will be recorded prospectively at 3,6,12 and 24 months.

Inclusion criteria:

• Patients with primary osteoarthritis of the hip scheduled for THA.
• Suitable anatomy for both stems
• Willingness and ability to follow study-protocol

Exclusion Criteria

• Malignancy or metastatic bone disease.
• Any other disease severely affecting bone and mineral metabolism
• Ongoing or previous treatment (within 5 years prior to inclusion) with steroids
• Ongoing or previous treatment (within 5 years prior to inclusion) with antiresorptives.
• Ongoing or previous treatment (within 5 years prior to inclusion) with immunosuppressive drugs.
• Ongoing or previous treatment (within 5 years prior to inclusion) with anticonvulsive therapy.
• Ongoing or previous treatment (within 5 years prior to inclusion) with hormonal therapy.