Minimally Invasive Total Hip Replacement
Total hip replacement (also known as hip arthroplasty) is a common orthopaedic procedure and, as the population ages, it is expected to become even more common. Replacing the hip joint with an implant or "prosthesis" relieves pain and improves mobility so that you are able to resume your normal, everyday activities.
The traditional surgical approach to total hip replacement uses a single, long incision to view and access the hip joint. A variation of this approach is a minimally invasive procedure in which one or two shorter incisions are used. The goal of using shorter incisions is to reduce pain and speed recovery. Unlike traditional total hip replacement, the minimally invasive technique is not suitable for all patients. Your orthopaedic surgeon will discuss different surgical options with you.
During any hip replacement surgery, the damaged bone is cut and removed, along with some soft tissues. In minimally invasive surgery, a smaller surgical incision is used and fewer muscles around the hip are cut or detached. Despite this difference, however, both traditional hip replacement surgery and minimally invasive surgery are technically demanding and have better outcomes if the surgeon and operating team have considerable experience.
Traditional Hip Replacement
To perform a traditional hip replacement:
- A 10- to 12-inch incision is made on the side of the hip. The muscles are split or detached from the hip, allowing the hip to be dislocated and fully viewed by the surgical team.
- The damaged femoral head is removed and replaced with a metal stem that is placed into the hollow center of the femur, then a metal or ceramic ball is placed on the upper part of the stem. This ball replaces the damaged femoral head that was removed.
- The damaged cartilage surface of the socket (acetabulum) is removed and replaced with a metal socket. Screws or cement are sometimes used to hold the socket in place.
- A plastic, ceramic or metal spacer is inserted between the new ball and the socket to allow for a smooth gliding surface.
(Left) The individual components of a total hip replacement. (Center) The components merged into an implant. (Right) The implant as it fits into the hip.
Minimally Invasive Hip Replacement
In minimally invasive total hip replacement, the surgical procedure is similar, but there is less cutting of the tissue surrounding the hip. The artificial implants used are the same as those used for traditional hip replacement. However, specially designed surgical instruments are needed to prepare the socket and femur and to place the implants properly.
Minimally invasive total hip replacement can be performed with either one or two small incisions. Smaller incisions allow for less tissue disturbance.
Single-incision surgery. In this type of minimally invasive hip replacement, the surgeon makes a single incision that usually measures from 3 to 6 inches. The length of the incision depends on the size of the patient and the difficulty of the procedure.
The incision is usually placed over the outside of the hip. The muscles and tendons are split or detached from the hip, but to a lesser extent than in traditional hip replacement surgery. They are routinely repaired after the surgeon places the implants. This encourages healing and helps prevent dislocation of the hip.
Two-incision surgery. In this type of minimally invasive hip replacement, the surgeon makes two small incisions:
- A 2- to 3-inch incision over the groin for placement of the socket, and
- A 1- to 2-inch incision over the buttock for placement of the femoral stem.
To perform the two-incision procedure, the surgeon may need guidance from x-rays. It may take longer to perform the two-incision surgery than it does to perform traditional hip replacement surgery.
The hospital stay after minimally invasive surgery is similar in length to the stay after traditional hip replacement surgery--ranging from 1 to 4 days. Physical rehabilitation is a critical component of recovery. Your surgeon or a physical therapist will provide you with specific exercises to help increase your range of motion and restore your strength.
Patients with advanced arthritis of the hip may be candidates for either traditional total hip replacement (arthroplasty) or hip resurfacing (hip resurfacing arthroplasty). Each of these procedures is a type of hip replacement, but there are important differences. Your orthopaedic surgeon will talk with you about the different procedures and which operation would be best for you.
The hip is a ball-and-socket joint. In a healthy hip, the bones are covered with smooth cartilage that enables the femoral head and acetabulum to glide painlessly against each other.
In a traditional total hip replacement, the head of the thighbone (femoral head) and the damaged socket (acetabulum) are both removed and replaced with metal, plastic, or ceramic components.
In hip resurfacing, the femoral head is notremoved, but is instead trimmed and capped with a smooth metal covering. The damaged bone and cartilage within the socket is removed and replaced with a metal shell, just as in a traditional total hip replacement.
Advantages of Hip Resurfacing
The advantages of hip resurfacing over traditional total hip replacements is an area of controversy among orthopaedic surgeons. A great deal of research is currently being done on this topic.
- Hip resurfacings may be easier to revise. Because the components (called implants) used in hip replacements and hip resurfacings are mechanical parts, they can — and do — wear out or loosen over time. This typically occurs between 10 and 20 years after the procedure, although implants may last longer or shorter periods of time.
- If an implant fails, an additional operation may be necessary. This second procedure is called a revision and it can be more complicated than the initial operation. Because hip resurfacing removes less bone from the femur (thighbone) than a traditional hip replacement, many surgeons believe it is easier to exchange implants that fail after hip resurfacing.
- Decreased risk of hip dislocation. In hip resurfacing, the size of the ball is larger than in a traditional hip replacement, and it is closer to the size of the natural ball of your hip. Because of this, it may be harder to dislocate. This stance is controversial because several factors can affect the risk of dislocation, such as surgical approach, and the type and size of the implants used.
- More normal walking pattern. Several studies have shown that walking patterns are more natural following hip resurfacing compared to traditional hip replacement. These differences in walking are quite subtle, however, and special instruments are needed to measure them.
- Greater hip range of motion. Hip resurfacing patients are usually able to move their hips in a greater range of motion than total hip patients. However, certain total hip implants can achieve the same range of motion as hip resurfacings.
Arthroscopy is a surgical procedure that gives doctors a clear view of the inside of a joint. This helps them diagnose and treat joint problems
During hip arthroscopy, your surgeon inserts a small camera, called an arthroscope, into your hip joint. The camera displays pictures on a television screen, and your surgeon uses these images to guide miniature surgical instruments.
Hip arthroscopy has been performed for many years, but is not as common as knee or shoulder arthroscopy.
During arthroscopy, your surgeon can see the structures of your hip in great detail. (Right) Small instruments are used to repair a labral tear.
The hip is a ball-and-socket joint. The socket is formed by the acetabulum, which is part of the large pelvis bone. The ball is the femoral head, which is the upper end of the femur (thighbone).
A slippery tissue called articular cartilage covers the surface of the ball and the socket. It creates a smooth, frictionless surface that helps the bones glide easily across each other.
The acetabulum is ringed by strong fibrocartilage called the labrum. The labrum forms a gasket around the socket.
The joint is surrounded by bands of tissue called ligaments. They form a capsule that holds the joint together. The undersurface of the capsule is lined by a thin membrane called the synovium. It produces synovial fluid that lubricates the hip joint.
In a healthy hip, the femoral head fits perfectly into the acetabulum.
Total Hip Replacement
Whether you have just begun exploring treatment options or have already decided to undergo hip replacement surgery, this information will help you understand the benefits and limitations of total hip replacement. This article describes how a normal hip works, the causes of hip pain, what to expect from hip replacement surgery, and what exercises and activities will help restore your mobility and strength, and enable you to return to everyday activities.
If your hip has been damaged by arthritis, a fracture, or other conditions, common activities such as walking or getting in and out of a chair may be painful and difficult. Your hip may be stiff, and it may be hard to put on your shoes and socks. You may even feel uncomfortable while resting.
If medications, changes in your everyday activities, and the use of walking supports do not adequately help your symptoms, you may consider hip replacement surgery. Hip replacement surgery is a safe and effective procedure that can relieve your pain, increase motion, and help you get back to enjoying normal, everyday activities.
First performed in 1960, hip replacement surgery is one of the most successful operations in all of medicine. Since 1960, improvements in joint replacement surgical techniques and technology have greatly increased the effectiveness of total hip replacement. According to the Agency for Healthcare Research and Quality, more than 285,000 total hip replacements are performed each year in the United States.
The hip is one of the body's largest joints. It is a ball-and-socket joint. The socket is formed by the acetabulum, which is part of the large pelvis bone. The ball is the femoral head, which is the upper end of the femur (thighbone).
The bone surfaces of the ball and socket are covered with articular cartilage, a smooth tissue that cushions the ends of the bones and enables them to move easily.
A thin tissue called synovial membrane surrounds the hip joint. In a healthy hip, this membrane makes a small amount of fluid that lubricates the cartilage and eliminates almost all friction during hip movement.
Bands of tissue called ligaments (the hip capsule) connect the ball to the socket and provide stability to the joint.
Normal hip anatomy.
Common Causes of Hip Pain
The most common cause of chronic hip pain and disability is arthritis. Osteoarthritis, rheumatoid arthritis, and traumatic arthritis are the most common forms of this disease.
- Osteoarthritis. This is an age-related "wear and tear" type of arthritis. It usually occurs in people 50 years of age and older and often in individuals with a family history of arthritis. The cartilage cushioning the bones of the hip wears away. The bones then rub against each other, causing hip pain and stiffness. Osteoarthritis may also be caused or accelerated by subtle irregularities in how the hip developed in childhood.
- Rheumatoid arthritis. This is an autoimmune disease in which the synovial membrane becomes inflamed and thickened. This chronic inflammation can damage the cartilage, leading to pain and stiffness. Rheumatoid arthritis is the most common type of a group of disorders termed "inflammatory arthritis."
- Post-traumatic arthritis. This can follow a serious hip injury or fracture. The cartilage may become damaged and lead to hip pain and stiffness over time.
- Avascular necrosis. An injury to the hip, such as a dislocation or fracture, may limit the blood supply to the femoral head. This is called avascular necrosis. The lack of blood may cause the surface of the bone to collapse, and arthritis will result. Some diseases can also cause avascular necrosis.
- Childhood hip disease. Some infants and children have hip problems. Even though the problems are successfully treated during childhood, they may still cause arthritis later on in life. This happens because the hip may not grow normally, and the joint surfaces are affected.
A hip with osteoarthritis.