Total hip replacement is a surgical procedure that replaces the native hip joint with an artificial implant. Both the femoral head (“ball of the hip”) and the acetabulum (“socket of the hip”) are replaced. A total hip replacement is a very successful procedure with satisfaction rates as high as 96% in multiple research studies.
Once a patient has been deemed to benefit from a total hip replacement a surgical plan is formulated. This plan takes into consideration the patient’s hip joint deformity, surgical anatomy, previous surgical procedures, medical co-morbidities. The surgical plan includes the surgical approach, type of implants to be used, postoperative recovery and rehabilitation.
The surgical approaches available to perform a hip replacement include direct anterior approach, posterior approach, lateral approach, anterolateral approach. At the Limb Reconstruction Centre, the most common approach used is the direct anterior approach. This approach is a minimally invasive approach that protects the integrity of the muscles around the hip joint and provides an earlier recovery compared to other hip approaches. The approach is done in the plane between the tensor fascia lata muscle and the sartorius muscle with preservation of both muscles. Next an incision in made into the capsule of the hip joint and the hip is dislocated. The femoral head is then resected, the acetabulum is prepared and an acetabular implant is inserted. A press-fit implant with a biologically active surface is implanted in the majority of patients. This allows early bone-implant integration. The next step of the procedure involves the femoral exposure and femoral preparation for the implantation of the femoral component of the total hip replacement. In patients where the surgical anatomy allows, a femoral neck preserving implant (“mini hip”) is used to preserve as much of the native bone as possible. Otherwise a standard femoral component is used. Both these implants are coated with a biologically active surface for bone-implant integration and are press-fitted into the native bone. A ceramic on ceramic bearing surface is used and the hip joint is reduced. Prior to wound closure, an intraoperative X-ray is taken to ensure correct implant positioning with accurate reconstruction of the leg length and femoral offset (“width of the hip”).
In a small group of patients, due to abnormal surgical anatomy, requirement for custom, patient specific implants, posterior acetabular wall fracture, a posterior approach hip replacement may be required. This approach is done through the posterior aspect of hip joint and requires the short external rotator muscles of the hip joint to be reflected of the femur in order to access the hip joint. These muscles will be repaired back to their anatomical insertion site once the hip replacement has been performed. Patients requiring a posterior hip replacement will have minor mobility restrictions in the first three months after surgery to allow the short external rotator muscles to heal back to the femoral bone.
Some patients require custom implants to ensure accurate reconstruction of the hip joint. These patients will need to undergo further investigations such as CT or MRI scans in order to plan and design the patient specific implant. The implant is usually manufactured from Titanium using modern 3D printing technology. The surgeons at the Limb Reconstruction Centre have significant experience and expertise in the design and use of custom hip joint implants.
