Determining the best approach for a total hip arthroplasty (THA) implies that the procedure is kind on soft tissues, with the lowest complication rates, and easily reproducible. Although there have been several attempts to resolve this issue in the last decade, a definitive answer has not been found. Therefore, the investigators performed a prospective study to compare direct anterior versus posterior approach based on (1) hospital stay, (2) functional outcome, (3) pain, (4) implant position (5) complications and (6) surgical time.

In this multicentric, prospective, randomized clinical trial, 55 total hip arthroplasties were performed on 50 patients between February 2011 and July 2013. Patients meeting the inclusion criteria underwent surgical treatment using the DAA or PA, according to a randomization process. Radiological analysis assessed implant position, limb lengthening, and potential implant related complications. X-rays were performed at subsequent follow-up visits and consisted of an antero-posterior (AP) pelvic X-ray and a lateral projection of the hip. Two independent observers, not involved with patients or surgeries, reviewed all postoperative radiographs independently.Two fellowship-trained surgeons in two separate hospitals performed all procedures. Both surgeons had previously performed over 100 cases with each approach, before initiating this study.

Patients underwent either the posterior or direct anterior approach.

Inclusion Criteria:

• primary total hip replacement due to osteoarthrosis or osteonecrosis
• patients older than 50 years.

Exclusion Criteria:

• inflammatory arthritis,
• any previous ipsilateral hip surgery
• suffering from proximal femoral deformity
• BMI over 40
• active infection
• severe contralateral hip disease, muscle contractures or neuromuscular pathology
• requiring structural bone grafts.

There is no plan to share IPD

However, the decision to discharge subjects was made by physiotherapists blinded to treatment and based on objective criteria. These criteria were: 1) being autonomous for transfer from bed/chair to upright position 2) being able to walk with walking aid 3) climbing stairs in a safe way 4) having a pain level contained by painkillers. No restrictions were recommended for either group. The same rehabilitation and pain protocols were used for both approaches. In addition, statistical analyses were performed by an independent consultant who remained blinded to treatment group assignment.