The procedure begins by positioning the patient in the supine decubitus position.

A longitudinal incision is made extending 3-5 cm proximal and about 5-8 cm distal to the tip of the greater trochanter . The fascia is split at the interval between the TFL and gluteus. The tendon and muscle fibres of the gluteus medius are then visualized and split . The gluteus minimus and joint capsule are split. The surgeon then dislocates the femoral head, and performs a femoral neck osteotomy.

The acetabulum is prepared .Soft tissue landmarks and reamer positioning relative to the floor are used to verify acetabular version and inclination.

When preparing the proximal femur, the hip is adducted and externally rotated, with the knee flexed. The femural stem is then press-fitted. Once the final implants are in situ and the hip is reduced, the stability of the construct is assessed.

The Oxford hip score (OHS) is a joint specific outcome measure tool designed to assess disability in patients undergoing total hip replacement (THR).The OHS is a patient-centred questionnaire that is designed to assess functional ability, and pain from the patient's perspective. It is a short, twelve-item questionnaire. Each item has five response categories, given a score of between 1-5 (low disability to high disability). Scoring involves summating the total for each item to produce a final score between 12-60, with a higher score indicating greater disability The objective is to assess the dynamics of patient clinical recovery comparing the OHS at predetermined follow-up visits and pre-op.

The SF-36 Survey consists of eight scaled scores, which are the weighted sums of the questions in their section. Each scale is directly transformed into a 0-100 scale on the assumption that each question carries equal weight. The lower the score the more disability.The eight sections are: vitality,physical, functioning,bodily pain,general health perceptions,physical role functioning,emotional role functioning, social role functioning and mental health.The objective is to assess the dynamics of patient clinical recovery comparing the SF-36 survey at predetermined follow-up visits and pre-op.

Performance-based measures such as the 20 meters timed walk (20MTW) Test quantify performance with tasks mimicking activities of daily living, as opposed to relying on individuals perception of performance.Hence, they may provide a more objective measure of functional capacity. The test consists in timing the patient while walking a distance of 20 meters(66feet).

Performance-based measures such as the Stair Climbing Test (SCT) quantify performance with tasks mimicking activities of daily living, as opposed to relying on individuals perception of performance.Hence, they may provide a more objective measure of functional capacity. The test consists in timing the patient while climbing 10 steps.

Postoperative, the amount of analgetics used by each patient is quantified (converted to opioid equivalent doses)

The pain felt by the patient is measured using the Visual Numeric Scale(VNS) consisting of a scale from 0-10 (0 = no pain; 10 = worst imaginable pain).

Creatine kinase (CK) - also known as creatine phosphokinase (CPK) or phospho-creatine kinase - is an enzyme expressed by various damaged tissues. Baseline value is acquired before surgery.CK-total is measured daily, the first post-op week,in the morning, to avoid physiological circadian variations.

Lactate dehydrogenase (LDH or LD) is an enzyme found in nearly all living cells.LDH is expressed extensively in body tissues, such as blood cells and heart muscle. Because it is released during tissue damage, it is a marker of common injuries and disease such as surgical muscle damage. Baseline value is acquired before surgery. LDH is measured daily, the first post-op week,in the morning, to avoid physiological circadian variations.

Aspartate aminotransferase (AST) is found in the liver, heart, skeletal muscle, kidneys, brain, and red blood cells. Serum AST level can be measured clinically as biomarker for muscle health. Baseline value is acquired before surgery. AST is measured daily, the first post-op week,in the morning, to avoid physiological circadian variations.

Using standard X-ray of the hip - Placement of the acetabular component (inclination and version) is assessed on a Anterior-Posterior view (AP) and a Rolled Lateral view. The outcome measured is correct component placement, within the accepted range.

Using standard X-ray of the hip , placement of the stem is assessed on a Anterior-Posterior view (AP) and a Rolled Lateral view. The outcome measured is correct component placement, within the accepted range.

The outcome measured is correct component osteointegration of the acetabular component and femoral stem using standard X-ray of the replaced hip.

The length of stay will be determined for each patient,to evaluate and compare the percentage of patients who are able to be discharged in less than 5 days after undergoing total hip arthroplasty through either a direct anterior or lateral approach, utilizing the identical post operative protocol for physical recovery.