What is hip replacement surgery?
Hip replacement, also called total hip arthroplasty, is a surgical procedure to replace a worn out or damaged hip with a prosthesis (an artificial joint). This surgery may be considered following a hip fracture (breaking of the bone) or for someone who has severe pain due to arthritis.
Various types of arthritis may affect the hip joint. Osteoarthritis, a degenerative joint disease that affects mostly middle-aged and older adults, may cause the breakdown of joint cartilage and adjacent bone in the hips. Rheumatoid arthritis, which causes inflammation of the synovial lining of the joint and results in an excessive synovial fluid, may lead to severe pain and stiffness. Traumatic arthritis, arthritis due to injury, may also cause damage to the articular cartilage of the hip.
The goal of hip replacement surgery is to replace the parts of the hip joint that have been damaged and to relieve hip pain that cannot be controlled by other treatments.
A traditional hip replacement involves an incision several inches long over the hip joint. A newer approach that uses 1 or 2 smaller incisions to perform the procedure is called minimally invasive hip replacement. However, the minimally invasive procedure is not suited for all candidates for hip replacement. The doctor will determine the best procedure for a person, based on that individual’s situation.
Occasionally, a patient may need both hips replaced. Depending on the condition of the patient surgeons may opt to perform both hip replacements during one operation. This is known as a bilateral hip replacement. Patients who cannot tolerate a long procedure or anesthetic may be advised to have two separate hip replacements. A bilateral hip replacement takes double the time on the table and under anesthesia – about three to four hours. Be sure to talk with your surgeon about cardiovascular, pulmonary or other health problems which might make longer surgery inappropriate. The benefit of undergoing bilateral hip replacement is in having one procedure and one recovery. The precautions needed after bilateral hip surgery are the same as they are for a single joint replacement unless your surgeon or physiotherapist tells you otherwise.
Anatomy of the hip
Joints are formed where bones meet. Most joints are mobile, allowing the bones to move without friction or discomfort. The hip joint is a ball-and-socket joint, which allows backward, forward, sideways, and rotating movements. The ball part of the hip joint is the head of the femur (thigh bone), and the acetabulum is the socket, a cup-like structure in the pelvis. The hip joint has significantly more bony contact and stability compared with other joints, such as the shoulder.
A hip joint consists of the following:
- Cartilage. A type of tissue that covers the surface of a bone at a joint. Cartilage helps reduce the friction of movement within a joint.
- Synovial membrane. A tissue that lines the joint and seals it into a joint capsule. The synovial membrane secretes synovial fluid (a clear, sticky fluid) around the joint to lubricate it.
- Ligament. A type of tough, elastic connective tissue that surrounds the joint to give support and limits the joint’s movement.
- Tendon. A type of tough connective tissue that connects muscles to bones and helps to control the movement of the joint.
- Bursa. A fluid-filled sac located between bones, ligaments, or other adjacent structures that helps cushion joints.
- Femur. Thighbone or upper leg bone.
- Acetabulum. A socket or cuplike structure that holds the femur head.
Reasons for the procedure
Hip replacement surgery is a treatment for pain and disability in the hip(s).
- The most common condition that results in the need for hip replacement surgery is osteoarthritis. It is characterized by the loss of joint cartilage in the hip. Damage to the cartilage and bones limits movement and may cause pain. People with severe pain due to degenerative joint disease may be unable to do normal activities that involve bending at the hip, such as walking or sitting, because they are painful.
- Rheumatoid arthritis is caused by an overactive immune system, which produces a type of inflammation that can erode bone and cartilage and deform joints.
- Other forms of arthritis, such as arthritis resulting from a hip injury, can lead to degeneration of the hip joint.
- Osteonecrosis is a condition that arises if there is inadequate blood supply to the ball portion of the hip joint, due to which the bone may collapse and deform.
- Hip replacement may also be used as a method of treating certain hip fractures. A fracture is a traumatic event that may result from a fall. Pain from a fracture is severe and walking or even moving the leg is difficult.
If medical treatments are not satisfactory at controlling pain due to arthritis, hip replacement surgery may be an effective treatment. Some medical treatments for a degenerative joint disease may include, but are not limited to, the following:
- Anti-inflammatory medications.
- Glucosamine and chondroitin sulfate.
- Pain medications.
- Limiting painful activities.
- Assistive devices for walking (such as a cane).
- Physical therapy.
There may be other reasons for your doctor to recommend a hip replacement surgery.
One might consider hip replacement if they’re experiencing hip pain that:
- Persists, despite pain medication.
- Worsens with walking, even with a cane or walker.
- Interferes with your sleep.
- Affects their ability to go up or downstairs.
- Makes it difficult to rise from a seated position.
Risks of the procedure
The complication rate following hip replacement surgery is low.
The most common complication of hip replacement is that something goes wrong with the joint, which occurs in around 1 in 10 cases. 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.
As with any surgical procedure, complications can occur. Some possible complications may include, but are not limited to, the following:
Clots can form in your leg veins after surgery. This can be dangerous because a piece of a clot can break off and travel to your lung, heart or rarely your brain. Your doctor may prescribe blood-thinning medications to reduce this risk. The risk for a post-operative blood clot tends to be slightly higher for people undergoing bilateral hip replacement surgery than it is for those having surgery on just one hip.
Infections can occur at the site of your incision and in the deeper tissue near your new hip. Most infections are treated with antibiotics, but a major infection near your prosthesis may require surgery to remove and replace the prosthesis.
During surgery, healthy portions of your hip joint may fracture. Sometimes the fractures are so small that they heal on their own, but larger fractures may need to be corrected with wires, pins and possibly bone grafts.
Certain positions can cause the ball of your new joint to become dislodged. To avoid this, it is often recommended that after surgery you don’t bend more than 90 degrees at the hip and don’t let your leg cross the midline of your body. If the hip dislocates, your doctor may fit you with a brace to keep the hip in the correct position. If your hip keeps dislocating, surgery is often required to stabilize it.
Change in leg length.
Your surgeon takes steps to avoid the problem, but occasionally a new hip makes one leg longer or shorter than the other. Sometimes this is caused by weakness in the muscles surrounding the hip. In this case, progressively strengthening and stretching those muscles may help.
Although this complication is rare with newer implants, your new joint may not become solidly fixed to your bone or may loosen over time, causing pain in your hip. Surgery might be needed to fix the problem.
Need for second hip replacement.
Your prosthetic hip joint may wear out eventually, so if you have hip replacement surgery when you’re relatively young and active, you eventually may need a second hip replacement. However, new materials are making implants last longer, so a second replacement may not be needed for many years.
Most artificial hip joints have a polished metal or ceramic ball that fits into a cup liner that’s made of very hard plastic. Some types of prostheses use a metal cup liner, which may last longer but can cause other problems. Metal-on-metal prostheses are more likely to release metal ions into your bloodstream, which can cause inflammation and bone erosion. Because of these concerns, metal-on-metal prostheses are now rarely used.
Before the procedure
- Your doctor will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure.
- You may be asked to sign a consent form that gives your permission to do the procedure. Read the form carefully and ask questions if something is not clear.
- In addition to a complete medical history, your doctor may perform a complete physical examination to ensure you are in good health before undergoing the procedure. You may undergo blood tests or other diagnostic tests.
- Notify your doctor if you are sensitive to or are allergic to any medications, latex, tape, and anesthetic agents (local and general).
- Notify your doctor of all medications (prescribed and over-the-counter) and herbal supplements that you are taking.
- Notify your doctor if you have a history of bleeding disorders or if you are taking any anticoagulant (blood-thinning) medications, aspirin, or other medications that affect blood clotting. It may be necessary for you to stop these medications prior to the procedure.
- If you are pregnant or suspect that you are pregnant, you should notify your healthcare provider.
- You will be asked to fast for eight hours before the procedure, generally after midnight.
- You may receive a sedative prior to the procedure to help you relax.
- You may meet with a physical therapist prior to your surgery to discuss rehabilitation.
- Stop smoking, as smoking can delay wound healing and slow down the recovery period.
- Lose weight if needed.
- Perform conditioning exercises as prescribed to strengthen muscles.
- Arrange for someone to help around the house for a week or 2 after you are discharged from the hospital.
- Based on your medical condition, your doctor may request other specific tests or examinations.
Anesthesia assessment or evaluation refers to the series of interviews, physical examinations, and laboratory tests that are generally used to assess the general fitness of patients scheduled for surgery and to determine the need for special precautions or additional testing.
A mnemonic has been suggested for pre-anesthetic assessment, to ensure that all aspects are covered. It runs alphabetically :
- A – Affirmative history; Airway
- B – Blood hemoglobin, blood loss estimation, and blood availability; Breathing
- C – Clinical examination; Co-morbidities
- D – Drugs being used by the patient; Details of previous anesthesia and surgeries
- E – Evaluate investigations; End-point to take up the case for surgery
- F – Fluid status; Fasting
- G – Give physical status; Get Consent
Patients may have a meeting with their anesthetist a day before the surgery and ask all kinds of questions pertaining to the surgery, and provide all information as mentioned above.
During the procedure
Hip replacement requires a stay in the hospital. Procedures may vary depending on your condition and your doctor’s practices.
Hip replacement surgery is performed while you are asleep under general anesthesia or sedated under spinal anesthesia. Your anesthesiologist will discuss this with you in advance.
Generally, hip replacement surgery follows this process:
- You will be asked to remove clothing and will be given a gown to wear.
- An intravenous (IV) line may be started in your arm or hand.
- You will be positioned on the operating table.
- A urinary catheter may be inserted (after you are asleep).
- The anesthesiologist will continuously monitor your heart rate, blood pressure, breathing, and blood oxygen level during the surgery.
- The skin over the surgical site will be cleansed with an antiseptic solution.
- The doctor will make an incision in the hip area.
- The doctor will remove the damaged parts of the hip joint and replace them with the prosthesis. The hip prosthesis is made up of a stem that goes into the femur (thighbone), the ball (head joint) that fits into the stem, and a cup that is inserted into the socket of the hip joint. The stem and cup are made of metal. The ball may be made of metal or ceramic. The cup has a liner that may be made of plastic or ceramic. The 2 most common types of artificial hip prostheses used are cemented prostheses and uncemented prostheses. A cemented prosthesis attaches to the bone with surgical cement. An uncemented prosthesis attaches to the bone with a porous surface onto which the bone grows to attach to the prosthesis. Sometimes, a combination of the 2 types is used to replace a hip.
- The incision will be closed with stitches or surgical staples.
- A drain may be placed in the incision site to remove fluid.
- A sterile bandage or dressing will be applied.
After the procedure
In the hospital
After the surgery, you will be taken to the recovery room for observation. Once your blood pressure, pulse, and breathing are stable and you are alert, you will be taken to your hospital room. Hip replacement surgery usually requires an in-hospital stay of several days.
It is important to begin moving the new joint after surgery. A physical therapist will meet with you soon after your surgery and plan an exercise program for you. Your pain will be controlled with medication so that you can participate in the exercise. You will be given an exercise plan to follow both in the hospital and after discharge.
You will be discharged home or to a rehabilitation center. In either case, your doctor will arrange for continuation of physical therapy until you regain muscle strength and a good range of motion.
In case of a bilateral hip replacement, the stay in the hospital is longer.
Taking care of your new hip
Once you are home, it is important to keep the surgical area clean and dry. Your doctor will give you specific bathing instructions. The stitches or surgical staples will be removed during a follow-up office visit. Take a pain reliever for soreness as recommended by your doctor. Aspirin or certain other pain medications may increase the chance of bleeding. Be sure to take only recommended medications.
Notify your doctor to report any of the following:
- Redness, swelling, bleeding, or other drainages from the incision site.
- Increased pain around the incision site.
- Numbness and/or tingling in the affected leg.
You may resume your normal diet unless your health care provider advises you differently.
You should not drive until your doctor tells you to. Other activity restrictions may apply. Full recovery from the surgery may take several months.
It is important that you avoid falls after your hip replacement surgery because a fall can result in damage to the new joint. Your therapist may recommend an assistive device (cane or walker) to help you walk until your strength and balance improve.
Making certain modifications to your home may help you during your recovery. These modifications include, but are not limited to, the following:
- Proper handrails along all stairs.
- Safety handrails in the bathroom.
- Shower bench or chair.
- Raised toilet seat.
- Stable chair with firm seat cushion and firm back with two arms, which will allow your knees to be positioned lower than your hips.
- Dressing stick.
- Sock aid.
- Long-handled shoe horn.
- Reaching stick to grab objects.
- Firm pillows to raise the hips above the knees when sitting.
- Removing loose carpets and electrical cords that may cause you to trip.
Your doctor may give you additional or alternate instructions after the procedure, depending on your particular situation.
About six to eight weeks after surgery, you’ll have a follow-up appointment with your surgeon to make sure your hip is healing properly. If recovery is progressing well, most people resume their normal activities by this time — even if in a limited fashion. Further recovery with improving strength will often occur for six to 12 months.
In the case of people undergoing bilateral hip replacement surgery, the in-hospital recovery time is somewhat longer than it is for those having surgery only one hip. You may need to spend some more time in a rehabilitation hospital setting where you will receive therapy. If you’re employed, you should allow for at least six weeks off from work after bilateral hip replacement surgery, depending on the physical demands of your workplace.
Expect your new hip joint to reduce the pain you felt before your surgery and increase the range of motion in your joint. But don’t expect to do everything you couldn’t do before surgery. High-impact activities — such as running or playing basketball — may be too stressful on your artificial joint. But in time, you may be able to swim, play golf, hike or ride a bike comfortably