The goal of this Prospective Randomized Study is to confirm presence or absence of differences in gait mechanics in direct anterior and lateral approaches for total hip arthroplasty. and to compare the clinical outcomes of both approaches.

The main questions it aims to answer are:

if the anterior approach to the hip is faster recovery than lateral approach? if the anterior approach to the hip has better gait mechanics than lateral approach?

Participants will:

undergo one of the two approaches for total hip arthroplasty. All patients will be followed up at 2 weeks, 6 weeks, 3 months and 18 months. gait analysis will be done at 6wks, 3m, and 18months.

Inclusion Criteria:

• Patients with primary osteoarthritis or osteonecrosis of the hip who consented for treatment with a total hip arthroplasty (THA) through an anterior or lateral approach.
• Age between 20 - 60 years of age.
• The participant had to be independent and physically active, which characterized as having the capacity to carry out daily tasks, ascend two flights of stairs, and able to walk for 15 minutes.

Exclusion Criteria:

• Patients with bilateral hip affection.
• Body mass index (BMI) greater than 40.
• Diagnosis other than primary osteoarthritis or osteonecrosis.
• Prior hip or spine surgery.
• chronic uncontrolled comorbidities, psychological disorders.
• American Society of Anaesthesiologists score (ASA) higher than 2
• chronic neurological deficits that influence gait.
• any limb length discrepancy more than 1 cm.
• Any postoperative complication that will lead to delay in weight bearing.