Have you ever heard of anyone who woke up from anterior hip replacement surgery with numbness on the outside of their thigh?

• June 25, 2020
• teamhri

Have you ever heard of anyone who woke up from anterior hip replacement surgery with numbness on the outside of their thigh? It happens more often than you would think. With the new total hip replacement method being developed by Microport, numbness after hip surgery may be a thing of the past.

The skin nerves that run to the outside of the thigh are right in the way of the traditional incision for anterior hip replacement. Surgeons can easily cut these nerves when performing the procedure. While a numb scar our outer thigh is common, it’s really just a nuisance; however, a small number of patients have a more serious nerve injury. The femoral nerve, which is critical to walking, can be stretched during anterior hip replacement surgery. Researchers report the risk is usually less than 1%, but in some series, it has been as high as 3.5%. That doesn’t seem like much until it happens to you and you can’t walk for six months. Fortunately, most people who have this rare complication make a complete recovery, but it’s a risk. And risks are things we want to eliminate or at least minimize when having surgery.

Enter Microport. The company hopes to eliminate both numbness and weakness after anterior hip replacement and make the surgery easier for your surgeon to perform by moving the incision to a better location. The legacy skin incision for anterior hip replacement was selected to make it easy for your surgeon to see the cup of the hip. Anterior hip replacement was done in France way back in 1947. In the United States many orthopedic surgeons point to Dr. Joel Matta as an original champion. In his own practice Dr. Matta makes an incision over the cup. Dislocation allows the ball to be cut off easily. But the incision over the cup makes it hard to see the ball part of the hip during the procedure.

Dr. Matt Seidel in Scottsdale, Az presented the solution. Dr. Seidel has developed a cannula that is placed through a nick incision in the skin that allows the surgeon to perfectly clean out the cup without having the place the incision right over it. That means the incision can be placed more in the groin area.

There are several advantages to moving the incision:

• Lower risk of cutting the sensory nerves and causing thigh numbness
• Moves the procedure away from the femoral nerve that makes the already low chance of weakness even lower
• Reduces retraction during surgery, which means less pain and quicker healing
• A more natural incision means fewer wound complications

The new Microport approach has other advantages. The tools they have developed allow your surgeon to avoid dislocating the hip during surgery. The original reason surgeons in France tried the anterior approach to hip replacement was to preserve the muscles that prevent dislocation after surgery. In Dr. Matta’s technique to anterior hip replacement he typically dislocated the hip, then cut off the ball, before placing the implant. While there is no hard evidence that this is the case, many surgeons believe that dislocating the ball during surgery increases the risk of dislocation after surgery. Since reducing the risk of dislocation is one of the main goals of the anterior approach, your surgeon will do anything he can to lower that risk. The Microport approach avoids dislocating the hip during surgery entirely by cutting the ball off first, then removing it from the socket.

Surgeons are taking notice. “Microport had a session on November 7th in Dallas. It was a bad time, before the meeting really started, and we had 150 surgeons show up. The interest level has been so high its humbling” said Danny Metcalf from Microport.

Representatives from Microport were at Scottsdale Spine and Joint Surgery Center last Friday doing a cadaver lab. The goal was to perfect the technique and get the right material to present it to other orthopedic surgeons. A video of the lab is shown here:

The results were exciting. Great things are happening, people.