Osteoarthritis is the commonest form of arthritis and is a common cause of hip pain, especially amongst older people. It affects about 7% of men and 10% of women over the age of 45 years.
The main problem in this condition is the degeneration of the cartilage covering the ends of the bones. The loss of cartilage and its shock absorbing, cushioning effect leads to the bones coming closer to each other and their thickening in an attempt to protect the joint. Bony growth called osteophytes form around the joint edges. The joints and the surrounding ligaments, tissues may also develop swelling (inflammation).
Pain in arthritis may result from
Many people are not able to able to identify the symptoms of hip arthritis and often ignore it as a minor injury which would heal in a few days. They are unable to appreciate that the arthritis pain is not the same and cannot be treated like any other injury pain. Some of the other causes of hip pain include
There are several factors that contribute to one’s chances of is developing this condition. These can be classified as those related to an individual and those related to the joint.
Individual factors include
Joint related factors such as
Often the pain originating from neighbouring structures such as the lower part of spine is felt in the hip and the correct diagnosis is essential for successful treatment.
Common symptoms include
Your doctor can often diagnose osteoarthritis on the basis of your symptoms and examination findings. Tests such as x-rays are commonly requested to confirm the diagnosis. Other tests such as blood tests, CT scan or MRI may also be requested for further evaluation.
The treatment of hip OA begins with education and self-management. The self-management options for hip arthritis include:
Your pain specialist can help with
PRP injections. The use of platelet-rich plasma for hip OA is under investigation in clinical trials with limited guidance available on their clinical role.
When it comes to managing hip pain, there is a large lacuna in the treatment options as medications often offer limited relief or are limited by side effects and surgery is not always the answer as many are unwilling or unfit to have one. Some in their 40s and 50s are considered to be too young to undergo a joint replacement. Besides 5 to 15% of patients have persisting pain even after having a hip replacement.
For all these subgroups the new options including radiofrequency ablation, cooled radiofrequency and cryoablation offer a ray of hope. These options have been used most often for hip arthritis pain (as it is more common) although they work equally well for other hip joint pain conditions such as avascular necrosis (AVN). The primary aim in these treatments remains the interruption or reduction of the pain signals travelling from the hip joint to the brain. This is achieved by deactivating or stunning the nerves responsible for transmitting the pain signals from these joints. The method used for achieving deactivation is where these treatments differ.
These options can be considered for anyone with hip joint pain who has not responded well to non-surgical or surgical options. Typical indications include someone who
All the above mentioned treatment options share some common advantages such as
Diagnostic test injections are often performed prior to the radiofrequency procedure. This involves using small amount of local anaesthetic to numb the nerves in order to gauge the chances of success of the subsequent treatment. 50% or more reduction in pain after the test injection is considered a positive response and an indication to proceed with the treatment.
These new treatment options are discussed further in the section below
This procedure uses heat generated by radio waves to target specific nerves carrying pain from the hip joint. Specialised needles are used for controlled, targeted application of heat to these nerves, impairing their ability to send pain signals from hip to brain thereby resulting in pain relief.
The procedure involves placement of needles at specific locations under x ray and ultrasound guidance. For hip pain, branches of two specific nerves are targeted. These nerves are very small to be actually seen under ultrasound but are located in a specific area which is targeted using x-ray and ultrasound guidance. Once the needles are correctly placed they are connected to the radiofrequency machine. As a safety precaution testing is done to ensure there is no other nerve close to the needle location. This is followed by the actual treatment involving the application of heat generated by radio waves.
Post procedure, pain relief usually begins within one to two weeks and may last up to 24 months. Like most medical treatments, individual responses to RFA treatment will vary with different levels of pain reduction. Those with a successful test injection have more chances of responding to the RFA treatment. Over time the nerves regenerate, at which point the treatment can be repeated if required. RFA is safe to administer repeatedly in patients with consistent pain reduction.
This procedure involves placement of needles at the same location as described previously in the radiofrequency procedure. However the needles and the radiofrequency equipment used is different. Cooled Radiofrequency has water circulating through the device and the needle tip. cRFA is able to deliver more energy to the surrounding tissues, thereby creating a larger treatment area and increasing the chances of achieving effective pain relief.
Cryoablation refers to the technique of inactivation or blocking the nerves for a long time by freezing the nerves sending pain signals to the brain. The procedure is performed using a special probe called cryoprobe, which is a hollow needle through which the super-cooled gas such as nitrous oxide or carbon dioxide is delivered directly to the treatment area. The extremely low temperatures achieved in the area being treated can inactivate the nerves thereby reducing the pain.
The probe is guided to the correct location using ultrasound and x-rays. Prior to cryoablation the nerve is identified with the help of a stimulation tests. Gas is delivered once the probe is in the correct place. An ice ball is created by a rapid decrease in the temperature at the tip of the probe and this can be visualised using ultrasound. Once the procedure is finished, the cryoprobe is removed and the procedure site covered with a small bandage.