Understanding Joint Replacements

What is a joint replacement?

Joint replacement surgery is an effective way to remove your joint pain by replacing your diseased or deformed joint with an artificial one. It is also the go-to treatment to correct a joint deformity and improve joint mobility.

Typically, your doctor will consider joint replacement surgery for the knee, shoulder and hip if other treatment options such as weight loss, medications and physiotherapy have been unsuccessful.

Who is joint replacement surgery for?

Joint replacement surgery is most commonly performed on patients with osteoarthritis and rheumatoid arthritis. These diseases destroy the bones and cartilage over time and make moving the joints excruciatingly painful. You may be susceptible to arthritis if any of the following apply to you:

• Family members suffer from arthritis
• Wrongly developed joints from young
• Minor repetitive injuries from work, sports or everyday living
• Past severe injury to the joint cartilage
• Being overweight (can cause early joint problems)

Your doctor will consider your case individually to decide whether having surgery will be beneficial for you, and will take into account your joint problem, your level of disability as a result, the level of pain, your age, your medical history and your current health.

You will be a good candidate for joint replacement surgery if you experience the following complaints and other treatments have failed to provide relief:

• severe joint pain
• joint stiffness
• limping in the case of knee or hip problems
• muscle weakness because of underuse of the joint
• bow-leg or knock-knee deformity or leg shortening
• joint swelling

It is especially recommended when you find that you can't perform simple everyday tasks such as carrying items, walking, putting on socks, getting into and out of a car and climbing stairs, among others.

What happens during joint replacement surgery?

During joint replacement surgery, your orthopaedic surgeon will resurface the damaged joint with an artificial replacement joint. The procedure could either be a partial joint replacement, or a full joint replacement using prosthesis that are made out of either titanium, cobalt chrome, ceramic material, or plastic. This will be attached either with acrylic cement, or press-fitted to allow bone to grow into the implant.

Let’s go a little deeper into the procedures for the 3 most common joint replacement surgeries: shoulder, knee and hip.

Shoulder replacement

If you have advanced arthritis affecting the movement of your shoulder joint or have had severe injury from a shoulder fracture, your doctor may recommend surgery with the main aim to relieve pain.

However, the surgery should also improve motion, strength and function of the joint. The shoulder joint will be replaced with an artificial ball and socket joint.

Knee replacement

Knee replacement surgery is recommended if you have advanced arthritis that prevents you from using the knee and stops you from performing everyday activities such as climbing the stairs or walking to the market for groceries. Arthritis of the knee because of damage to the knee cartilage may also result in you developing knock-knee or bow-legged deformities. Surgery can correct this deformity. Knee replacement surgery is designed to replace the damaged cartilage, as well as remedy any loss of bone structure or ligament support.

Knee replacement procedures generally take between 1 – 2 hours. Your surgeon will make a surgical incision above your knee, retract the muscle to the side and shave away the damaged cartilage and bone. Your surgeon will then attach the new joint to your thigh bone (femur) and lower leg bone (tibia) using specialised cement, before closing the incision with stitches.

Hip replacement

Your doctor will recommend hip replacement if your arthritis means you can no longer bear the pain or do manage daily activities.

During a hip replacement procedure, your surgeon will resurface the hip socket with a plastic and titanium cup and replace the "ball" or head of the femur with a titanium stem attached with a ceramic or metal ball.

What is recovery like following joint replacement surgery?

Your recovery experience will differ depending on the type of joint replacement surgery you have had. Let’s look at each in turn.

Shoulder joint replacement

After your surgery, you will undergo physiotherapy aimed at getting you to use the joint again and regain movement, but this will take time, anywhere from 6 months to a year.

How much movement you regain will also depend on how committed you are to performing the stretching and movement exercises prescribed for you. You will need to manage your expectations as progress may be gradual.

With the improvements that have been made in terms of materials used, joint designs and surgical techniques, you can expect the new joint to last for 15 – 20 years.

Knee joint replacement

Standing and moving the knee a day after surgery should be possible, and within 6 weeks you should be able to walk independently with little support. By the end of month 3, a dramatic improvement should be noticed in the joint, where the pain felt pre-surgery is no longer felt thanks to the new gliding surface in the knee. However, it may take up to 6 months for muscle strength to return and for you to make a full recovery. You will be advised not to run or jump with the new joint if you want it to last. A recent study published in the Lancet journal shows that 80% of knee replacements will last 25 years.

Hip joint replacement

The day after surgery, patients should be able to stand on the new hip and even start exercising. Walking with a walker or crutches should be possible by the second day after surgery and weight can be applied to the hip as tolerated.

At this point, once you are able to confidently engage in basic activities such as walking steadily on your own, using the bathroom and climbing the stairs unassisted, you can be discharged from hospital or be referred to a community hospital for further physiotherapy and rehabilitation if necessary.

Around 4 – 6 weeks after surgery, you should be able to place your full weight on the hip and, you can stop relying on a cane for support as long as your therapist says it’s okay to do so. If your muscles are weaker, you may find you need to rely on your cane or walker for a little longer as you work to build muscle strength.

Once you’ve made a full recovery, you should be able to engage in most activities such as bike riding, skiing and golf. However, do try to limit sports that put more impact on the hip joint if you wish to conserve the joint long term.

If you are experiencing constant joint pain that is affecting your daily life, consult an orthopaedic surgeon for an accurate diagnosis and treatment options.