A total hip replacement replaces a damaged hip joint with an artificial implant. The surgery requires an incision to access the joint, allowing the surgeon to remove diseased bone and cartilage. There is no single standard location for this incision; its placement is determined by the specific surgical technique, or approach, the surgeon utilizes. Differences in incision location and technique affect the muscle groups involved and the patient’s recovery trajectory.
The Posterior Surgical Approach
The posterior approach is a traditional and widely practiced method known for providing excellent visibility of the hip joint. The incision is typically made near the back and side of the hip, often following a curved line behind the greater trochanter (the prominent bony part on the side of the upper thigh). This incision generally spans between four and six inches in length, though it can vary based on the patient’s anatomy.
To access the joint, the surgeon works through the soft tissues at the back of the hip. This involves splitting the large gluteus maximus muscle fibers. It also requires detaching the short external rotators (including muscles like the piriformis and obturators) from the thigh bone. These muscles, important for controlling hip rotation, are carefully repaired and reattached to the bone at the conclusion of the operation.
The Anterior Surgical Approach
The Direct Anterior Approach (DAA) has become popular due to its muscle-sparing nature. The incision is located on the front of the hip, typically starting near the hip crease and extending down the upper thigh. This technique allows the patient to be positioned lying face-up on the operating table.
The DAA is “muscle-sparing” because the surgeon reaches the joint by working through natural intervals between major muscle groups, rather than cutting them. The surgeon navigates the plane between the tensor fascia latae and the sartorius or rectus femoris muscles. By gently pushing these muscles aside, the surgeon avoids detaching key stabilizing muscles. This may contribute to a quicker initial recovery and less restrictive post-operative precautions. The resulting scar is often smaller, sometimes measuring only three to four inches, and is situated on the front of the body.
The Lateral and Anterolateral Approaches
The lateral approach involves an incision made directly over the side of the hip, centered around the greater trochanter. This technique accesses the joint by working through the hip abductor muscles, which stabilize the pelvis during walking. Specifically, the surgeon must split or detach portions of the gluteus medius and gluteus minimus muscles to reach the hip capsule.
The anterolateral approach, sometimes called the Watson-Jones approach, positions the incision slightly more toward the front and side of the hip. This approach uses the natural interval between the tensor fascia lata muscle and the gluteus medius muscle. Both the lateral and anterolateral methods require the detachment or splitting of some abductor muscle fibers, which are repaired at the end of the procedure.
How Surgeons Select the Incision Location
The decision regarding which surgical approach and incision location to use is highly individualized and based on a number of factors. One significant factor is the surgeon’s training, experience, and personal preference. Most surgeons develop expertise in one or two specific approaches, and the surgeon selects the technique they are most comfortable performing, which often leads to the best outcomes.
The patient’s specific anatomy and overall health also play a large role in the selection process. Certain approaches may be more technically challenging for patients with a higher body mass index or those with significant bone deformities. The type of implant being used or the presence of previous surgical scars can also influence the surgeon’s choice of entry point. Ultimately, the goal is to choose the approach that allows for safe and precise placement of the hip components while minimizing soft tissue damage.