Minimally Invasive Approaches to Hip

Minimally Invasive Approaches to the Hip

Traditionally, total hip replacement will be performed through a 10–12 inch long incision made on the side of the hip. A minimally invasive approach has been developed in recent years where surgery is performed through one or two smaller incisions rather than the single long incision as in the traditional approach. Advantages of the newer approach are lesser muscle dissection, minimal pain, quicker recovery, and faster rehabilitation.

Arthritis is inflammation of the joints resulting in pain, swelling, stiffness and limited movement. Hip arthritis is a common cause of chronic hip pain and disability. The most common type of arthritis affecting the hip is osteoarthritis which is characterized by progressive wearing away of the joint cartilage. As the protective cartilage wears down, the bone ends rub against each other and cause pain in the hip. It is more common in individuals aged above 50 years and tends to run in families.

Symptoms

The most common symptom of hip arthritis is dull, aching joint pain and stiffness resulting in limited mobility. There may be pain in the groin, thigh and buttock area and sometimes pain may be referred to the knee. Vigorous activity and walking for long distances can increase the pain and stiffness which may cause limping while walking.

Diagnosis

Diagnosis is made by evaluating your symptoms, medical history, physical examination and X-rays. Sometimes, additional imaging tests such as MRI and CT scans may needed to confirm the diagnosis.

Surgical procedure

Surgery may be recommended in patients with severe cartilage damage and if conservative treatment options such as anti-inflammatory medications and physical therapy do not relieve the symptoms.

For minimally invasive hip replacement, the surgical technique and artificial implants remain the same as traditional hip replacement however the difference is smaller incisions and minimal soft tissue dissection. The surgery is performed through either one or two smaller incisions. The procedure is performed under general anesthesia.

In single incision minimally invasive approach, your surgeon makes a 3–6 inch incision over the side of the hip to expose the hip joint. The muscles are minimally dissected to reach the joint. The femur is dislocated from the acetabulum. The surface of the socket is cleaned and the arthritic bone is removed using a reamer. The acetabular implant is inserted into the socket using screws or special cement. A liner material of plastic, ceramic or metal is placed inside the acetabular component. The femur or thigh bone is then prepared by removing the arthritic bone using special instruments and shaped to exactly fit the new metal femoral component. The femoral stem is then inserted into the femur either by a press fit or using bone cement. Then the femoral head component made of metal or ceramic is placed on the femoral stem. All the new parts are secured in place using special cement. The muscles and tendons around the new joint are repaired and the incision is closed.

If the surgeon uses the two-incision technique, a 2- to 3-inch incision is made over the groin for placement of the socket and a 1- to 2-inch incision is made over the buttock for placement of the femoral stem. This technique requires longer operative time and is performed under X-ray guidance

Advantages

The advantages of minimally invasive total hip replacement as compared with traditional total hip replacement may include:

• Smaller incisions
• Shorter hospital stay
• Less trauma to the surrounding tissues
• Quicker recovery
• Less blood loss
• Less scarring
• Faster rehabilitation
• Minimal post-operative pain

Post-operative precautions

After undergoing minimally invasive total hip replacement, you must take special care to prevent dislocation of the new joint and to ensure proper healing.

• Avoid combined movement of bending your hip and turning your foot inwards
• Keep a pillow between your legs while sleeping for 6 weeks
• Never cross your legs or bend your hips past a right angle (90 degrees)
• Avoid sitting on low chairs
• Avoid bending down to pick up things, instead use a grabber device.
• Use an elevated toilet seat

Risks:

As with any major surgical procedure, there are certain potential risks and complications involved with total hip replacement surgery. They include:

• Infection
• Injury to nerves and blood vessels
• Formation of blood clots in the leg veins
• Implant malposition
• Fracture of the femur or pelvis

Advantages of Minimally Invasive Surgery for Hip Replacement

The information provided in this article is meant to inform the patient on Minimally Invasive Surgery for hip replacement. Your orthopedic surgeon should explain to you which hip replacement is best for you and why.

With the evolution of new surgical methods, better anesthesia techniques, and computer navigation systems, surgeons are now able to reduce recovery times after hip replacement. The effects of such methods and technologies allow the surgeon to operate with greater precision and less injury to the body. Minimally Invasive Surgery for Joint Replacement (MIS) is one surgical approach with this goal in mind.

The term, however, can be misleading. In a broad sense, minimally invasive surgery for hip replacement refers to a surgical method that uses a smaller incision. Many surgeons have this goal in mind already, and incorporate it into the existing techniques for a traditional hip replacement. An article put out by the University of Missouri-Columbia School of Medicine reads:

• Minimally invasive surgery variations of both the posterior approach and the lateral approach are popular today, and these involve re-training surgeons to learn how to do the same approach using a smaller skin opening. Most surgeons refer to an incision that is 4 inches or less in length as ‘minimally invasive.

But there are new surgical methods, also called minimally invasive, which go beyond making the smaller incision. These new surgical methods avoid cutting into the muscle altogether, which distinguishes them from traditional methods. Fewer surgeons are trained in these methods and special instruments and implants are required. One example is the MIS-2 incision hip replacement. The same article put out by the University of Missouri-Columbia School of Medicine describes the difference between a surgical method that makes a smaller incision and the MIS-2:

• What is new is the adaptation of this previously described pathway of reaching the hip joint to a new method of performing hip replacement surgery using two incisions that are very small. More important than the incision size or number is the fact that under the skin, the muscles are spread in their natural planes. The surgeon navigates a path around the muscles, without cutting into them.

The advantage of any minimally invasive surgery is less injury to the body. With more radical approaches, such as MIS-2 incision, there is reduced trauma to the deep muscle tissues and underlying structure of the hip. Because of the reduced trauma, patients feel better and recover faster. However, always remember that the size of the incision will be dictated by the size of the implants and the need to be able to manipulate them inside the joint to get the optimal positioning. Getting accurate positioning is key to the success of the entire procedure. The physicians at the University of Missouri-Columbia School of Medicine write:

• With modern hip replacement surgeries, the person is encouraged to become mobile much earlier than with standard methods of hip replacements. Many people are able to get out of bed either the same day or the next day, with the help of a physical therapist. In many cases outpatient therapy is not necessary, although it can help certain patients.

This should not give the reader the impression that minimally invasive surgical techniques are free of risks and complications. Blood-clots, for example, still occur and surgeons must apply methods to reduce them. In addition, most surgeons will still restrict the patient for six weeks after the surgery.

Keep in mind that all surgery is invasive to the body. These new surgical techniques merely reduce injury and trauma. If you believe you may be a candidate for minimally invasive hip replacement surgery, do research, talks with doctors, and always weigh the short-term benefits and the long-term results.