As technology and techniques have advanced, so have the approaches to performing total hip arthroplasties (THA). Our last blog discussed the typical approaches to performing this surgery. In more recent years, however, minimally invasive total hip replacements have started to become more popular.
Now, don’t let the name fool you. A minimally invasive THA is still a very invasive surgery. What sets a minimally invasive THA apart from a traditional THA is the size of the incision and the amount of muscles that are cut. As discussed in our last blog, a posterior approach THA consists of a 10 to 12 inch incision along the back and side of the hip along with cutting through muscles that stabilize the hip in order to replace the joint surfaces.
Minimally invasive total hip replacements use the same prosthetic hip components, but the incision used is smaller; therefore, special tools are needed to perform the procedure. The theory behind using smaller incisions is that less tissue is damaged in the course of the surgery, thus healing time is quicker.
Minimally invasive THAs can be performed with either one or two small incisions. The single incision surgery is much like a posterior THA. The difference is that the incision measures 3 to 6 inches in length. Muscles and tendons must still be split or detached with this procedure, but to a lesser extent than with a traditional posterior THA. The two incision surgery, also known as MIS-2, consists of a 2 to 3 inch incision over the groin for placement of the socket and a 1 to 2 inch incision over the buttocks for placement of the stem that creates the ball of the hip. The surgeon uses special instruments and x-ray guidance to move around muscle layers without cutting them. The two incision surgery takes longer than a traditional hip replacement and is much more technical, so a highly skilled surgeon is required. Hospital recover time is approximately 1 to 4 days and rehabilitation with a physical therapist is a key component to proper function.
Unfortunately, the minimally invasive THA procedure is not for everyone. The best candidates are those who are thin, young, healthy, and highly motivated to participate in rehab. Individuals who are obese, have undergone other hip surgeries, have significant deformities of the hip, or are highly muscular are not ideal candidates. Currently, minimally invasive THAs are not as readily performed likely due to the limited pool of appropriate candidates, higher skill level required to perform the procedure, and the procedures overall level of difficulty. Some statistics suggest that the procedure has a higher chance of failure than a traditional THA due there being a higher chance of improper placement of the prosthetic components. The decrease in visibility of the hip joint during the operation and use of a surgeon who is not experienced enough in the procedure could increase the chances of this complication occurring. Other assessments suggest that the recovery time is much quicker following a minimally invasive THA and requires a shorter duration of rehab following surgery. So far, the long term benefits do not appear any different from that of a traditional THA; but, more research is needed on the effectiveness and long term benefits of these procedures.
If you have any questions on this topic or any others in which you are interested, feel free to leave any questions, comments, or suggestions.