Osteoarthritis disables approximately 10% of people who are 60 years or older and compromises the quality of life of more than 20 million Americans every year. Osteoarthritis is caused by the breakdown of cartilage that lines the bones at your joints from daily wear and tear and results in pain and restricted function. Total hip arthroplasty (THA) or total hip replacement, is currently one of the most successful and cost-effective treatments used to eliminate pain and restore function in those suffering from osteoarthritis. There are multiple ways to perform a THA. The main difference between each type is the point of incision in relation to a muscle on the outer surface of your hip bone: gluteus medius. The incision performed can be anterior (in front of the muscle), anterolateral (in front and to the side of the muscle), or posterior (from the back). Each of these approaches has its own advantages and disadvantages, but there is no evidence available that makes one better than the other. The purpose of this study is to determine which of the three approaches to THA is the most effective. The main outcome that will determine the most effective approach is the functional ability of the patients included in this study at 52 weeks. The investigators will also compare whether the patient's: length of hospital stay, use of assistive devices, need for revision surgery, ability to return to work, ability to relieve pain, complication rate, and quality of life. The investigators hypothesize that the anterior approach will be the most effective approach in reducing the rate of post-operative complications after THA.

Inclusion Criteria:

1. Men or women who are 18 years of age or older.
2. Primary diagnosis of hip arthritis (radiographically and clinically).
3. Patients undergoing an unilateral THA.
4. Provision of informed consent by patient.

Exclusion Criteria:

1. Patients being managed with alternative approaches (other than anterior, anterolateral or posterior THA) will be excluded.
2. Patients undergoing a revision THA.
3. Patients undergoing a bilateral THA.
4. Patients with infection around the hip (soft tissue or bone).
5. Patients who have had previous major hip surgery (hip arthroscopy is permitted) or hardware implanted in their hip.
6. Patients who are currently enrolled in another surgical intervention trial.
7. Patient has cognitive or language barriers that would limit completion of quality of life, pain, and function questionnaires in English.
8. Anticipated problems, in the judgment of the investigators, with maintaining follow-up. We will, for example, exclude patients with no fixed address, those who report a plan to move out of town in the next year, or intellectually challenged patients without adequate family support.

Men or women who are 18 years of age or older with a primary diagnosis of hip arthritis (radiographically and clinically). Patients must be undergoing an unilateral THA and have had no previous major hip surgery (hip arthroscopy is permitted) or hardware implanted in their hip.