Physiotherapy in Banff for Hip

Welcome to Active Motion Physiotherapy's patient resource about Avascular Necrosis of the Hip.

Bones are living tissue, and like all living tissue they rely on blood vessels to bring blood to keep them alive. Most living tissues have blood vessels that come from many directions into the tissue. If one blood vessel is damaged it may not cause problems, since there may be a backup blood supply coming in from a different direction. But certain joints of the body have only a few blood vessels that bring in blood. One of these joints is the hip. This document will describe what happens when this blood supply is damaged and results in what is called avascular necrosis (AVN) of the hip. 

This guide will help you understand: 

• how AVN develops
• how doctors diagnose the condition
• what treatments are available

Where does AVN develop? 

The hip joint is one of the true ball-and-socket joints of the body. The hip socket is called the acetabulum and forms a deep cup that surrounds the ball of the upper thigh bone. The thigh bone itself is called the femur, and the ball on the end is the femoral head. Thick muscles of the buttock at the back and the thick muscles of the thigh in the front surround the hip. 

The surface of the femoral head and the inside of the acetabulum are covered with articular cartilage. This material is about one-quarter of an inch thick in most large joints. Articular cartilage is a tough, slick material that allows the surfaces to slide against one another without damage. 

All of the blood supply comes into the ball that forms the hip joint through the neck of the femur (the femoral neck). The femoral neck is a thinner area of bone that connects the ball to the shaft. If this blood supply is damaged, there is no backup. Damage to the blood supply can cause death of the bone that makes up the ball portion of the femur. Once this occurs, the bone is no longer able to maintain itself. 

Living bone is always changing. To maintain a bone's strength, bone cells are constantly repairing the wear and tear that affects the bone tissue. If this process stops the bone can begin to weaken, just like rust can affect the metal structure of a bridge. Eventually, just like a rusty bridge, the bone structure begins to collapse. 

When AVN occurs in the hip joint, the top of the femoral head (the ball portion) collapses and begins to flatten. This occurs because this is where most of the weight is concentrated. The flattening creates a situation where the ball no longer fits perfectly inside the socket. Like two pieces of a mismatched piece of machinery, the joint begins to wear itself out. This leads to osteoarthritis of the hip joint, and pain. 

Femoral Heads Flattens

Related Document: Active Motion Physiotherapy's Guide to Osteoarthritis of the Hip

Related Document: Active Motion Physiotherapy's Patient's Guide to Hip Anatomy

Why do I have this problem? 

There are many causes of AVN. Anything that damages the blood supply to the hip can cause AVN. 

Injury to the hip itself can damage the blood vessels. Fractures of the femoral neck (the area connecting the ball of the hip joint) can damage the blood vessels. A dislocation of the hip out of the socket can tear the blood vessels. It usually takes several months for AVN to show up, and it can even become a problem up to two years following this type of injury. 

Some medications are known to cause AVN. Cortisone is the most common drug known to lead to AVN. This is usually only a problem in patients who must take cortisone every day due to other diseases, such as advanced arthritis, or to prevent rejection of an organ transplant. Sometimes there is no choice, and cortisone has to be prescribed to treat a condition, knowing full well that AVN could occur. AVN has not been proven to be caused by short courses of treatment with cortisone, such as one or two injections into joints to treat arthritis or bursitis. 

A clear link exists between AVN and alcoholism. Excessive alcohol intake somehow damages the blood vessels and leads to AVN. Deep sea divers and miners who work under great atmospheric pressures also are at risk for damage to the blood vessels. The pressure causes tiny bubbles to form in the blood stream which can block the blood vessels to the hip, damaging the blood supply.

What does AVN feel like? 

The first symptom of AVN is pain when weight is placed on the hip. The pain can be felt in the groin area, the buttock area, and down the front of the thigh. As the problem progresses, the symptoms include development of a limp when walking and stiffness in the hip joint. Eventually, the pain will also be present at rest and may even interfere with sleep.

When you first visit Active Motion Physiotherapy, diagnosis of AVN begins with a history and physical examination. We will want to know about your occupation, what other medical problems you have, and your medication use. You'll be asked whether you drink alcohol. A physical examination will be done to determine how much stiffness you have in the hip and whether you have a limp. You may be referred to a physician for additional testing and diagnostics before beginning a physiotherapy rehabilitation program.

Our Treatment 

What can be done for the condition? 

Once AVN has occurred, the treatment choices are determined by how far along the problem is and by your symptoms. While the symptoms may be reduced with pain medications and anti-inflammatory medications, no medical treatments will restore the blood supply to the femoral head and reverse the AVN. Ensure that you consult with your doctor or pharmacist regarding the use of pain relief or anti-inflammatory medication.

Non-surgical Rehabilitation 

If AVN is caught early, keeping weight off the sore-side foot when standing and walking may be helpful. Your physiotherapist will show you how to properly use a walker or crutches to protect the hip. Keeping weight off your hip while you are standing or walking may help the bone to heal while protecting the femur from further damage.  During this time, you may be advised to use anti-inflammatory medicine to ease pain. 

In addition to helping you develop safe basic mobility, we will also instruct you in exercises designed to help you safely move and stretch your hip. The goal is to keep your hip mobile and to avoid losing range of motion.  

In some cases, an electrical stimulator may be employed to help the bone heal. These non-surgical measures may help delay the need for surgery, but they rarely reverse the problem. 

After Surgery 

After a simple drilling operation, you will probably use crutches for six weeks or so. The drill holes weaken the bone around the hip, increasing the possibility of fracture. Using crutches allows the bone to heal safely and reduce the risk that you may fracture your hip. Patients who have had bone and blood vessels grafted are required to limit how much weight they place on the hip for up to six months. 

When you are safe in putting full weight through the leg, you can begin your physiotherapy program help you regain hip range of motion and strength. 

Active Motion Physiotherapy provides services for physiotherapy in Banff.

Portions of this document copyright MMG, LLC.