The study design comprises a randomized trial of patients undergoing primary total hip arthroplasty using the G7 acetabular system and Taperloc Complete stem comparing regular plasma porous spray with HA coating using Bonemaster (BM) in an uncemented cup. DEXA scanning will be used to measure periprosthetic bone mineral density. Clinical evaluations will be conducted .

The study design comprises a randomized trial of patients undergoing primary total hip arthroplasty using the G7 acetabular system and Taperloc Complete stem comparing regular plasma porous spray with HA coating using Bonemaster (BM) in an uncemented cup. DEXA scanning will be used to measure periprosthetic bone mineral density preoperatively and post-operatively at 6 weeks, 12 weeks, 26 weeks, and 12 months for both the treated and contralateral hip joint. Clinical evaluations will be conducted preoperatively, and postoperatively at 6, 12, 26 weeks, 12 months and 24 months.

Inclusion Criteria:

1. Patients with osteoarthritis who are candidates for a primary total hip replacement with uncemented acetabular and femoral components as determined by the surgeon.
2. Male and non-pregnant female patient aged 18 to 70.
3. Patients who understand the conditions of the study and are willing to participate for the length of the prescribed follow-up.

Exclusion Criteria:

1. Patients requiring total hip replacement surgery for a fresh hip fracture.
2. Patients with inflammatory arthritis
3. Patients with metabolic bone disease or taking drugs that affect bone turnover. 4 .Patients requiring revision surgery of a previously implanted total hip replacement system or patients requiring a conversion surgery from a previous fracture fixation or hip fusion.

5. Patients with presence of malignancy in the area of the involved hip joint. 6. Patients who, as judged by the surgeon, are mentally incompetent or are reasonably unlikely to be compliant with the prescribed postoperative routine and the follow-up evaluation schedule.

7. Patients with other concurrent illnesses that are likely to affect their outcome such as sickle cell anaemia, systemic lupus erythematosus or renal disease requiring dialysis.