It is possible to perform a total hip replacement from an anterior (front) approach as well as from the side lateral or posterolateral (halfway between the back and side). But over the years, studies have shown the best results and easiest access is from the posteriolateral direction.
Some of the success with this incision location is the fact that it gives the surgeon access to the entire joint. It also makes it possible to put the implant in its best location for optimal motion and function. Even a degree or two off in one direction or the other can cause long-term problems. To avoid that, the surgeon likes an open enough incision and open wound site to see what he or she is doing.
The posterior approach also makes it possible for the surgeon to size up the bone and choose the best size of implant for the patient. Getting a just the right size implant on the femoral side and placing it in the optimal location is key to full, pain-free motion. Newer techniques are being developed all the time. One surgeon has already mastered a minimally invasive technique for hip joint resurfacing.
Using a three and three quarters- to four-inch length incision, the head of the femur can be accessed and cut off all inside the body. There’s no need to pull the head of the femur out of the open wound site to gain access to the arthritic component. Muscles are split in two rather than cutting them off and moving them out of the way. The joint capsule still has to be cut through to get to the joint, but these other refinements in surgical technique certainly reduce the overall trauma.