Restoring Anatomy
The primary surgical goal of hip replacement surgery is to change the hip from a worn out, bone on bone, arthritic joint surface to an artificial joint surface.
For me, however, the real primary goal is to help patients get back to the activities that their hip osteoarthritis prevents them from doing.
A critical aspect to having a successful hip replacement is the restoration of anatomy. Everyone’s hip is a little bit different and the implants are designed so that everyone’s anatomy can be matched. While the many options in implants have been available for a long time, how we choose the correct sizes has changed in recent years.
The Anterior Approach
In the past surgeons would typically feel the hip to decide which sizes to put in. They put in trial components and then could put the legs side by side to compare them. The comparison involved feeling the knee and the foot to decide how close the new leg length was to the opposite side. While this method often worked, it could also result in a leg that was slightly shortly or longer than the other side.
Surgeons utilized this technique in the past simply because it was the best option available to them. When the procedure is performed through a posterior approach, taking X-rays during the surgery is very difficult. With the development of the anterior approach, however, the ability to take X-rays during the surgery became much easier.
Most surgeons who adopted the anterior approached started taking X-rays routinely through the procedure. These instantaneous X-rays allowed the surgeon to see the changes being made to the hip while they were still doing the surgery. If they didn’t like what they were seeing, they still had the opportunity to make changes.
“Good enough” was no longer good enough.
Digital Solutions
Taking X-rays during the procedure allowed me to be more critical of how good of a job I was doing restoring anatomy in the new hip. Eventually a digital platform was developed to help me do this even better.
I currently utilize computer software called Jointpoint. Before I start the surgery, I take an X-ray of the hip and I use Jointpoint to evaluate that hip making measurements of key landmarks. As I perform the procedure I take new X-rays and I get an update on how good of a job I am doing. By the end of the procedure, I have an understanding of the new anatomy and how close it is to the normal anatomy with measurements within one millimeter.
With the help of Jointpoint, my expectation is for the anatomy to be perfect.
Better Anatomy = Better Hip Replacement
While we do not completely understand all of the benefits to the patient when we do a better job making their new hip like their old one, it does make sense. It can certainly help reduce the risk of dislocation. I hope that it will help our patients recovery more quickly since the muscles will be in their normal relationship.
I do believe that patients that have an anatomic hip replacement, however, will likely see their hip last longer than those who do not. When I perform a hip replacement today, there is reason to think that the hip will last upwards of twenty or forty years, and maybe even longer.
