Total Hip Replacement
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, modern 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 300,000 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.
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 (also commonly referred to as “osteonecrosis”). 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.
In hip osteoarthritis, the smooth articular cartilage wears away and becomes frayed and rough.
In a total hip replacement (also called total hip arthroplasty), the damaged bone and cartilage is removed and replaced with prosthetic components.
- The damaged femoral head is removed and replaced with a metal stem that is placed into the hollow center of the femur. The femoral stem may be either cemented or “press fit” into the bone.
- 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.
Is Hip Replacement Surgery for You?
The decision to have hip replacement surgery should be a cooperative one made by you, your family, your primary care doctor, and your orthopaedic surgeon. The process of making this decision typically begins with a referral by your doctor to an orthopaedic surgeon for an initial evaluation.
Candidates for Surgery
There are no absolute age or weight restrictions for total hip replacements. Recommendations for surgery are based on a patient’s pain and disability, not age. Most patients who undergo total hip replacement are age 50 to 80, but orthopaedic surgeons evaluate patients individually. Total hip replacements have been performed successfully at all ages, from the young teenager with juvenile arthritis to the elderly patient with degenerative arthritis.
When Surgery Is Recommended
There are several reasons why your doctor may recommend hip replacement surgery. People who benefit from hip replacement surgery often have:
The diagnosis of osteoarthritis is made on history, physical examination & X-rays. There is no blood test to diagnose Osteoarthritis (wear & tear arthritis)
THR is indicated for arthritis of the hip that has failed to respond to conservative (non-operative) treatment.
- Hip pain that limits everyday activities, such as walking or bending
- Hip pain that continues while resting, either day or night
- Stiffness in a hip that limits the ability to move or lift the leg
- Inadequate pain relief from anti-inflammatory drugs, physical therapy, or walking supports
The Orthopaedic Evaluation
An evaluation with an orthopaedic surgeon consists of several components.
- Medical history. Your orthopaedic surgeon will gather information about your general health and ask questions about the extent of your hip pain and how it affects your ability to perform everyday activities.
- Physical examination. This will assess hip mobility, strength, and alignment.
- X-rays. These images help to determine the extent of damage or deformity in your hip.
- Other tests. Occasionally other tests, such as a magnetic resonance imaging (MRI) scan, may be needed to determine the condition of the bone and soft tissues of your hip.
(Left) In this x-ray of a normal hip, the space between the ball and socket indicates healthy cartilage. (Right) This x-ray of an arthritic hip shows severe loss of joint space.
Deciding to Have Hip Replacement Surgery Talk With Your Doctor
Your orthopaedic surgeon will review the results of your evaluation with you and discuss whether hip replacement surgery is the best method to relieve your pain and improve your mobility. Other treatment options — such as medications, physical therapy, or other types of surgery — also may be considered. In addition, your orthopaedic surgeon will explain the potential risks and complications of hip replacement surgery, including those related to the surgery itself and those that can occur over time after your surgery. Never hesitate to ask your doctor questions when you do not understand. The more you know, the better you will be able to manage the changes that hip replacement surgery will make in your life.
An important factor in deciding whether to have hip replacement surgery is understanding what the procedure can and cannot do. Most people who undergo hip replacement surgery experience a dramatic reduction of hip pain and a significant improvement in their ability to perform the common activities of daily living. With normal use and activity, the material between the head and the socket of every hip replacement implant begins to wear. Excessive activity or being overweight may speed up this normal wear and cause the hip replacement to loosen and become painful. Therefore, most surgeons advise against high-impact activities such as running, jogging, jumping, or other high-impact sports.
Realistic activities following total hip replacement include unlimited walking, swimming, golf, driving, hiking, biking, dancing, and other low-impact sports. With appropriate activity modification, hip replacements can last for many years.
Preparing for Surgery
If you decide to have hip replacement surgery, your orthopaedic surgeon may ask you to have a complete physical examination by your primary care doctor before your surgical procedure. This is needed to make sure you are healthy enough to have the surgery and complete the recovery process. Many patients with chronic medical conditions, like heart disease, may also be evaluated by a specialist, such a cardiologist, before the surgery.
Several tests, such as blood and urine samples, an electrocardiogram (EKG), and chest x-rays, may be needed to help plan your surgery.
Preparing Your Skin Your skin should not have any infections or irritations before surgery. If either is present, contact your orthopaedic surgeon for treatment to improve your skin before surgery.
Tell your orthopaedic surgeon about the medications you are taking. He or she or your primary care doctor will advise you which medications you should stop taking and which you can continue to take before surgery.
If you are overweight, your doctor may ask you to lose some weight before surgery to minimize the stress on your new hip and possibly decrease the risks of surgery.
Although infections after hip replacement are not common, an infection can occur if bacteria enter your bloodstream. Because bacteria can enter the bloodstream during dental procedures, major dental procedures (such as tooth extractions and periodontal work) should be completed before your hip replacement surgery. Routine cleaning of your teeth should be delayed for several weeks after surgery.
Individuals with a history of recent or frequent urinary infections should have a urological evaluation before surgery. Older men with prostate disease should consider completing required treatment before having surgery.
Although you will be able to walk with crutches or a walker soon after surgery, you will need some help for several weeks with such tasks as cooking, shopping, bathing, and laundry. If you live alone, your orthopaedic surgeon’s office, a social worker, or a discharge planner at the hospital can help you make advance arrangements to have someone assist you at your home. Rarely a short stay in an extended care facility (SNF) during your recovery after surgery may be needed.
Several modifications can make your home easier to navigate during your recovery. The following items may help with daily activities:
- Secure handrails along all stairways
- A stable chair for your early recovery with a firm seat cushion (that allows your knees to remain lower than your hips), a firm back, and two arms
- A stable shower bench or chair for bathing
- A long-handled sponge and shower hose
- A dressing stick, a sock aid, and a long-handled shoe horn for putting on and taking off shoes and socks without excessively bending your new hip
- A reacher that will allow you to grab objects without excessive bending of your hips
- Firm pillows for your chairs, sofas, and car that enable you to sit with your knees lower than your hips
- Removal of all loose carpets, electrical cords and low furniture that may be a tripping risk from the areas where you walk in your home
Your surgery will be done as an outpatient or you will be admitted to the hospital on the day of your surgery. Most patients will spend one night in the hospital if admitted.
After admission, you will be evaluated by a member of the anesthesia team. The most common types of anesthesia are general anesthesia (you are put to sleep) or spinal, epidural, or regional nerve block anesthesia (you are awake but your body is numb from the waist down). The anesthesia team, with your input, will determine which type of anesthesia will be best for you.
Many different types of designs and materials are currently used in artificial hip joints. All of them consist of two basic components: the ball component (made of highly polished strong metal or ceramic material) and the socket component (a durable cup of plastic, ceramic or metal, which may have an outer metal shell). The prosthetic components may be “press fit” into the bone to allow your bone to grow onto the components or they may be cemented into place. The decision to press fit or to cement the components is based on a number of factors, such as the quality and strength of your bone. A combination of a cemented stem and a non-cemented socket may also be used. Your orthopaedic surgeon will choose the type of prosthesis that best meets your needs.
The surgical procedure takes about one hour. Your orthopaedic surgeon will remove the damaged cartilage and bone and then position new metal, plastic, or ceramic implants to restore the alignment and function of your hip.
X-rays before and after total hip replacement. In this case, non-cemented components were used.
After surgery, you will be moved to the recovery room where you will remain for 1-2 hours while your recovery from anesthesia is monitored. After you wake up you will be discharged home or taken to your hospital room.
The success of your surgery will depend in large measure on how well you follow your orthopaedic surgeon’s instructions regarding home care during the first few weeks after surgery.
You may have stitches or staples running along your wound or a suture beneath your skin. The stitches or staples will be removed approximately 2 weeks after surgery. Avoid getting the wound wet until it has thoroughly sealed and dried. You may continue to bandage the wound to prevent irritation from clothing or support stockings.
Some loss of appetite is common for several weeks after surgery. A balanced diet, often with an iron supplement, is important to promote proper tissue healing and restore muscle strength. Be sure to drink plenty of fluids.
Exercise is a critical component of home care, particularly during the first few weeks after surgery. You should be able to resume most normal light activities of daily living within 3 to 6 weeks following surgery. Some discomfort with activity and at night is common for several weeks.
Your activity program should include:
- A graduated walking program to slowly increase your mobility, initially in your home and later outside
- Resuming other normal household activities, such as sitting, standing, and climbing stairs
- Specific exercises several times a day to restore movement and strengthen your hip. You probably will be able to perform the exercises without help. Physical therapy will be prescribed if needed.
Possible Complications of Surgery
The complication rate following hip replacement surgery is low. Serious complications, such as joint infection, occur in less than 2% of patients. Major medical complications, such as heart attack or stroke, occur even less frequently. However, chronic illnesses may increase the potential for complications. Although uncommon, when these complications occur they can prolong or limit full recovery.
Infection may occur superficially in the wound or deep around the prosthesis. It may happen while in the hospital or after you go home. It may even occur years later. Minor infections of the wound are generally treated with antibiotics. Major or deep infections may require more surgery and removal of the prosthesis. Any infection in your body can spread to your joint replacement.
Blood clots in the leg veins or pelvis are one of the most common complications of hip replacement surgery. These clots can be life-threatening if they break free and travel to your lungs. Your orthopaedic surgeon will outline a prevention program which may include blood thinning medications, support hose, inflatable leg coverings, ankle pump exercises, and early mobilization.
Sometimes after a hip replacement, one leg may feel longer or shorter than the other. Your orthopaedic surgeon will make every effort to make your leg lengths even, but may lengthen or shorten your leg slightly in order to maximize the stability and biomechanics of the hip. Some patients may feel more comfortable with a shoe lift after surgery.
Hip implant dislocation.
This occurs when the ball comes out of the socket. The risk for dislocation is greatest in the first few months after surgery while the tissues are healing. Dislocation is uncommon. If the ball does come out of the socket, a closed reduction usually can put it back into place without the need for more surgery. In situations in which the hip continues to dislocate, further surgery may be necessary.
Loosening and Implant Wear
Over years, the hip prosthesis may wear out or loosen. This is most often due to everyday activity. It can also result from a biologic thinning of the bone called osteolysis. If loosening is painful, a second surgery called a revision may be necessary.
Nerve and blood vessel injury, bleeding, fracture, and stiffness can occur. In a small number of patients, some pain can continue or new pain can occur after surgery.
Avoiding Problems After Surgery
Recognizing the Signs of a Blood Clot
Follow your orthopaedic surgeon’s instructions carefully to reduce the risk of blood clots developing during the first several weeks of your recovery. Notify your doctor immediately if you develop any of the following warning signs.
Warning signs of blood clots. The warning signs of possible blood clot in your leg include:
- Pain in your calf and leg that is unrelated to your incision
- Tenderness or redness of your calf
- New or increasing swelling of your thigh, calf, ankle, or foot that doesn’t respond to elevation and ice.
Warning signs of pulmonary embolism. The warning signs that a blood clot has traveled to your lung include:
- Sudden shortness of breath
- Sudden onset of chest pain
- Localized chest pain with coughing
A common cause of infection following hip replacement surgery is from bacteria that enter the bloodstream during dental procedures, urinary tract infections, or skin infections. Following surgery, patients with certain risk factors may need to take antibiotics prior to dental work, including dental cleanings, or before any surgical procedure that could allow bacteria to enter your bloodstream. Your orthopaedic surgeon will discuss with you whether taking preventive antibiotics before dental procedures is needed in your situation.
Warning signs of infection. Notify your doctor immediately if you develop any of the following signs of a possible hip replacement infection:
- Persistent fever (higher than 101°F orally)
- Shaking chills
- Increasing redness, tenderness, or swelling of the hip wound
- Drainage from the hip wound
- Increasing hip pain with both activity and rest
A fall during the first few weeks after surgery can damage your new hip and may result in a need for more surgery. Stairs are a particular hazard until your hip is strong and mobile. You should use a cane, crutches, a walker, or handrails or have someone help you until you improve your balance, flexibility, and strength. Your orthopaedic surgeon and physical therapist will help you decide which assistive aides will be required following surgery, and when those aides can safely be discontinued.
To assure proper recovery and prevent dislocation of the prosthesis, you may be asked to take special precautions when sitting, bending, or sleeping — usually for the first 6 weeks after surgery. These precautions will vary from patient to patient, depending on the surgical approach your surgeon used to perform your hip replacement. Prior to discharge from the hospital, your surgeon and physical therapist will provide you with any specific precautions you should follow.
How Your New Hip Is Different
You may feel some numbness in the skin around your incision. You also may feel some stiffness, particularly with excessive bending. These differences often diminish with time, and most patients find these are minor compared with the pain and limited function they experienced prior to surgery. Your new hip may activate metal detectors required for security in airports and some buildings. Tell the security agent about your hip replacement if the alarm is activated.
Protecting Your Hip Replacement
There are many things you can do to protect your hip replacement and extend the life of your hip implant.
- Participate in a regular light exercise program to maintain proper strength and mobility of your new hip.
- Take special precautions to avoid falls and injuries. If you break a bone in your leg, you may require more surgery.
- Make sure your dentist knows that you have a hip replacement. Talk with your orthopaedic surgeon about whether you need to take antibiotics prior to dental procedures.
Total Hip Replacement
Normal Anatomy of the Hip joint
How does the hip joint work?
Find out more in this web based movie.
Hip replacement has become necessary for your arthritic hip: this is one of the most effective operations known and should give you many years of freedom from pain.
Once you have arthritis which has not responded to conservative treatment, you may well be a candidate for total hip replacement surgery.
Arthritis is a general term covering numerous conditions where the joint surface (cartilage) wears out. The joint surface is covered by a smooth articular surface that allows pain free movement in the joint. This surface can wear out for a number of reasons, often the definite cause is not known. When the articular cartilage wears out, the bone ends rub on one another and cause pain. There are numerous conditions that can cause arthritis and often the exact cause is never known. In general, but not always, it affects people as they get older (Osteoarthritis).
Other causes include
- Childhood disorders e.g., dislocated hip, Perthe’s disease, slipped epiphysis etc
- Growth abnormalities of the hip (such as a shallow socket) may lead to premature arthritis
- Trauma (fracture)
- Increased stress e.g., overuse, overweight, etc.
- Avascular necrosis (loss of blood supply)
- Connective tissue disorders
- Inactive lifestyle- e.g., Obesity, as additional weight puts extra force through your joints which can lead to arthritis over a period of time
- Inflammation e.g., Rheumatoid arthritis
In an Arthritic Hip
- The cartilage lining is thinner than normal or completely absent
- The degree of cartilage damage and inflammation varies with the type and stage of arthritis
- The capsule of the arthritic hip is swollen
- The joint space is narrowed and irregular in outline; this can be seen in an X-ray image
- Bone spurs or excessive bone can also build up around the edges of the joint
- The combinations of these factors make the arthritic hip stiff and limit activities due to pain or fatigue
The diagnosis of osteoarthritis is made on history, physical examination & X-rays. There is no blood test to diagnose Osteoarthritis (wear & tear arthritis)
THR is indicated for arthritis of the hip that has failed to respond to conservative (non-operative) treatment.
You should consider a THR when you have
- Arthritis confirmed on X-ray
- Pain not responding to analgesics or anti-inflammatories
- Limitations of activities of daily living including your leisure activities, sportor work
- Pain keeping you awake at night
- Stiffness in the hip making mobility difficult
Prior to surgery you will usually have tried some simple treatments such as simple analgesics, weight loss, anti-inflammatory medications, modification of your activities, walking sticks, physiotherapy.
The decision to proceed with THR surgery is a cooperative one between you, your surgeon, family and your local doctor. Benefits of surgery include
- Reduced hip pain
- Increased mobility and movement
- Correction of deformity
- Equalization of leg length (not guaranteed)
- Increased leg strength
- Improved quality of life, ability to return to normal activities
- Enables you to sleep without pain
- Your surgeon will send you for routine blood tests and any other investigations required prior to your surgery
- You will asked to undertake a general medical check-up with a physician
- You should have any other medical, surgical or dental problems attended to prior to your surgery
- Make arrangements around the house prior to surgery
- Cease aspirin or anti-inflammatory medications 10 days prior to surgery as they can cause bleeding
- Cease any naturopathic or herbal medications 10 days before surgery
- Stop smoking as long as possible prior to surgery
Day of your surgery
- You will be admitted to hospital usually on the day of your surgery
- Further tests may be required on admission
- You will meet the nurses and answer some questions for the hospital records
- You will meet your anaesthetist, who will ask you a few questions
- You will be given hospital clothes to change into and have a shower prior to surgery
- The operation site will be shaved and cleaned
- Approximately 30 mins prior to surgery, you will be transferred to the operating theatre
An incision is made over the hip to expose the hip joint
The acetabulum (socket) is prepared using a special instrument called a reamer. The acetabular component is then inserted into the socket. This is sometimes reinforced with screws or occasionally cemented. A liner which can be made of plastic, metal or ceramic material is then placed inside the acetabular component.
The femur (thigh bone) is then prepared. The femoral head which is arthritic is cut off and the bone prepared using special instruments, to exactly fit the new metal femoral component. The femoral component is then inserted into the femur. This may be press fit relying on bone to grow into it or cemented depending on a number of factors such as bone quality and surgeon’s preference.
The real femoral head component is then placed on the femoral stem. This can be made of metal or ceramic.
The hip is then reduced again, for the last time.
The muscles and soft tissues are then closed carefully.
You will wake up in the recovery room with a number of monitors to record your vitals. (Blood pressure, Pulse, Oxygen saturation, temperature, etc.) You will have a dressing on your hip and drains coming out of your wound.
Post-operative X-rays will be performed in recovery.
Once you are stable and awake you will be taken back to the ward.
You will have one or two drips in your arm for fluid and pain relief. This will be explained to you by your anaesthetist.
On the day following surgery, your drains will usually be removed and you will be allowed to sit out of bed or walk depending on your surgeons preference. Pain is normal but if you are in a lot of pain, inform your nurse.
You will be able to put all your weight on your hip and your Physiotherapist will help you with the post-op hip exercises.
You will be discharged to go home or a rehabilitation hospital approximately 5-7 days depending on your pain and help at home.
Sutures are usually dissolvable but if not are removed at about 10 days.
A post-operative visit will be arranged prior o your discharge.
You will be advised about how to walk with crutches for two weeks following surgery and then using walking aids for another four to six weeks.
Remember this is an artificial hip and must be treated with care.
AVOID THE COMBINED MOVEMENT OF BENDING YOUR HIP AND TURNING YOUR FOOT IN. This can cause DISLOCATION. Other precautions to avoid dislocation are
- You should sleep with a pillow between your legs for 6 weeks. Avoid crossing your legs and bending your hip past a right angle
- Avoid low chairs
- Avoid bending over to pick things up. Grabbers are helpful as are shoe horns or slip on shoes
- Elevated toilet seat helpful
- You can shower once the wound has healed
- You can apply Vitamin E or moisturizing cream into the wound once the wound has healed
- If you have increasing redness or swelling in the wound or temperatures over 100.5° you should call your doctor
- If you are having any procedures such as dental work or any other surgery you should take antibiotics before and after to prevent infection in your new prosthesis. Consult your surgeon for details
- Your hip replacement may go off in a metal detector at the airport
Risks and complications
As with any major surgery, there are potential risks involved. The decision to proceed with the surgery is made because the advantages of surgery outweigh the potential disadvantages.
It is important that you are informed of these risks before the surgery takes place.
Complications can be medical (general) or specific to the hip
Medical Complications include those of the anesthetic and your general well being. Almost any medical condition can occur so this list is not complete.
- Allergic reactions to medications
- Blood loss requiring transfusion with its low risk of disease transmission
- Heart attacks, strokes, kidney failure, pneumonia, bladder infections
- Complications from nerve blocks such as infection or nerve damage
- Serious medical problems can lead to ongoing health concerns, prolonged hospitalization or rarely death
Specific complications include
Infection can occur with any operation. In the hip this can be superficial or deep. Infection rates are approximately 1%, if it occurs it can be treated with antibiotics but may require further surgery. Very rarely your hip may need to be removed to eradicate infection.
This means the hip comes out of its socket. Precautions need to be taken with your new hip forever. It a dislocation occurs it needs to be put back into place with an anaesthetic. Rarely this becomes a recurrent problem needing further surgery.
Blood clots (Deep Venous Thrombosis)
These can form in the calf muscles and can travel to the lung (Pulmonary embolism). These can occasionally be serious and even life threatening. If you get calf pain or shortness of breath at any stage, you should notify your surgeon.
Damage to nerves or blood vessels
Also rare but can lead to weakness and loss of sensation in part of the leg. Damage to blood vessels may require further surgery if bleeding is ongoing.
Your scar can be sensitive or have a surrounding area of numbness. This normally decreases over time and does not lead to any problems with your new joint.
Leg length inequality
It is very difficult to make the leg exactly the same length as the other one. Occasionally the leg is deliberately lengthened to make the hip stable during surgery. There are some occasions when it is simply not possible to match the leg lengths. All leg length inequalities can be treated by a simple shoe raise on the shorter side.
All joints eventually wear out. The more active you are, the quicker this will occur. In general 80-90% of hip replacements survive 15-20 years.
Failure to relieve pain
Very rare but may occur especially if some pain is coming from other areas such as the spine.
Unsightly or thickened scar
Limp due to muscle weakness
Fractures (break) of the femur (thigh bone) or pelvis (hipbone)
This is also rare but can occur during or after surgery. This may prolong your recovery, or require further surgery. Discuss your concerns thoroughly with your orthopaedic surgeon prior to surgery.
Surgery is not a pleasant prospect for anyone, but for some people with arthritis, it could mean the difference between leading a normal life or putting up with a debilitating condition. Surgery can be regarded as part of your treatment plan- it may help to restore function to your damaged joints as well as relieve pain.