Minimally invasive hip replacement surgery has been described as keyhole hip replacement surgery. Minimally invasive surgery is quite a different philosophy and approach in the manner in which hip replacements are performed. We will discuss and describe the cutting edge technique and technology used to perform a minimally invasive surgical hip replacement (MIS hip replacement).

It is important to understand the difference between a normal hip and an arthritic hip. When two bones come together to form a joint, the surfaces that make contact are covered by cartilage. In the case of a hip joint, the socket (acetabulum) and the ball (femoral head) are covered with cartilage. The cartilage acts as a shock absorber to reduce stress and provide for a low friction surface for smooth gliding motion. The deterioration of the cartilage results in loss of the shock absorber as well as the low friction surface. This condition is called arthritis. The arthritis not only affects the femoral head and the socket, but it also affects the surrounding joint capsule, ligaments, tendons, and muscle, to produce the arthritic condition, which includes pain, swelling, and stiffness.

Essentially, arthritis is the wearing down of joint cartilage. It affects 30 million Americans and has multifactorial causes. The most common causes are previous trauma, family history (genes), and a history of being overweight. I use the analogy of a flat tire to help in understanding the condition of arthritis. Consider the cartilage of a joint like the treads of a tire. When the treads of a tire begin to wear out, the ride becomes rougher and bumpier. Eventually, the tire becomes bald, breaks down, and becomes flat, much like the natural history of an arthritic hip.

The non-operative treatments can be effective in the early stages of arthritis. However, the non-operative strategies treat the symptoms and not the cause.

The operative choices are limited for advanced hip arthritis. Hip arthroscopy has very little place in the treatment of hip arthritis. Hip arthroscopy has the ability to evaluate and diagnose a hip. However, there is a significant limitation in what a hip arthroscopy can produce. If there is a loose body or a torn labral cartilage, treatment can be obtained with hip arthroscopy. However, with advanced arthritis, because of the joint space narrowing from the loss of articular cartilage, damage can occur with attempted arthroscopy in an individual with advanced hip arthritis. The definitive treatment for advanced hip arthritis is hip replacement surgery.

Over 200,000 hip replacements were performed in the United States last year. Hip replacement is excellent at alleviating pain from arthritis. It is an important tool in the treatment of debilitating arthritis.

Indications for hip replacement include arthritis, pain which has failed non-operative treatment, and altered lifestyle, as well as deformity. Deformity can be in the form of severe bony distortion from the loss of the stress-relieving joint cartilage, or a significant leg length discrepancy.

Mobility is an important component in an individual’s lifestyle. When you are younger, there is opportunity for a greater variety of activity without restriction and pain.

As we age, for some of us the arthritis matures and the ability to move becomes significantly restricted. With a painful and the loss of mobility, independence is lost. A hip replacement can provide painless mobility and restore independence.

Comparing the mini single incision to the traditional standard incision, you will see that the incision site is significantly smaller. The approach, however, is almost the same. The smaller incision allows for less dissection. This is felt to produce less blood loss and less pain The same high-quality traditional implants can be utilized in the mini technique as is utilized in the traditional technique. Both cemented and non-cemented type implants can be utilized with this technique.

How does one go from a 12 to 14 inch incision to a 2.5 to 3.5 inch incision? This is accomplished by specialized instruments that allow for excellent retraction. Retractors have been designed with light sources to illuminate an area of dissection. Specialized angulated inserters to place the sockets and stems have also been designed to work through small incisions.

The advantages of minimally invasive hip replacement surgery includes less pain, less blood loss, quicker recovery, more stability, and it is cosmetically more pleasing.

Several features of the surgery demonstrated are that of the ability to look down a deep wound through a small incision when utilizing the lighted retractors.

The specialized socket reamer has side cut-outs to reduce the profile in order to pass this instrument through a small incision. The small raised circles of this instrument provide the cutting blades for the reaming action.

The hip angle is an important consideration. The lower hip angle indicates the need for a wider incision.

The pictures indicate different widths of the femoral components.

The white lines indicate the critical distance which is required to pass the implant through a small incision.

The criteria for the minimally invasive single incision hip replacement technique requires evidence of arthritis on a hip x-ray, history of pain and failure of conservative treatment, as well as appropriate weight. An overweight individual eliminates a person from the minimally invasive single incision hip replacement technique.

If you feel that you are a candidate for hip replacement surgery and would like to learn more, please contact our office.

Michael T. Reilly, M.D.