Arthritis, Knee Joint Replacement

Hip and Knee Joints

The hip joint, scientifically referred to as the acetabulofemoral joint (art. coxae), is the joint between the femur and acetabulum of the pelvis and its primary function is to support the weight of the body in both static (e. g. standing) and dynamic (e. g. walking or running) postures. The hip joints are the most important part in retaining balance. The pelvic inclination angle, which is the single most important element of human body posture, is adjusted at the hips. The knee joint joins the thigh with the lower leg and consists of two articulations: one between the femur and tibia, and one between the femur and patella. It is the largest joint in the human body and is very complicated. The knee is a mobile trocho-ginglymus (a pivotal hinge joint), which permits flexion and extension as well as a slight medial and lateral rotation. Since in humans the knee supports nearly the whole weight of the body, it is vulnerable to both acute injury and the development of osteoarthritis. hip-1

  • ”Joint

    Osteoarthritis is the most common type of hip and knee arthritis which is characterized by progressive wearing away of the cartilage of the joint. As the protective cartilage is worn away by hip arthritis, bare bone is exposed within the joint. Arthritis typically affects patients over 50 years of age. It is more common in people who are overweight, and weight loss tends to reduce the symptoms associated with hip arthritis. There is also a genetic predisposition of this condition. Other factors that can contribute to developing arthritis include traumatic injuries to the joint and fractures to the bone around the joint.

  • ”Signs

    The most common symptoms of hip and knee arthritis are:

    • Pain with activities
    • Limited range of motion
    • Stiffness of the hip
    • Walking with a limp

    In the case of knee arthritis, in addition to the abovementioned symptoms, the following are also probable:

    • Swelling of the joint and Tenderness along the joint
    • A feeling the joint may “give out”
    • Deformity of the joint (knock-knees or bow-legs)
  • ”Diagnosis”

    Evaluation of a patient with hip arthritis should begin with a physical examination and x-rays. These can serve as a baseline to evaluate later examinations and determine progression of the condition. In situations where a hip fracture is suspected but not obvious on x-ray, an MRI is the next test of choice. If an MRI is not available or the patient cannot be placed into the scanner a CT may be used as a substitute.

  • ”Treatment”

    Treatment of hip arthritis should begin with the most basic steps, and progress to the more involved, possibly including surgery. Not all treatments are appropriate in every patient, and you should have a discussion with your doctor to determine which treatments are appropriate for your hip arthritis.

    • Weight Loss Probably one of the most important, yet least commonly performed treatments. The less weight the joint has to carry, the less painful activities will be.
    • Activity Modification Limiting certain activities may be necessary, and learning new exercise methods may be helpful.
    • Walking Aids Use of a cane or a single crutch is the hand opposite the affected hip will help decrease the demand placed on the arthritic joint.
    • Physical Therapy Strengthening of the muscles around the hip joint may help decrease the burden on the hip. Preventing atrophy of the muscles is an important part of maintaining functional use of the hip.
    • Anti-Inflammatory Medications Anti-inflammatory pain medications (NSAIDs) are prescription and nonprescription drugs that help treat pain and inflammation.
    • Hip Replacement Surgery In this procedure the cartilage is removed and a metal & plastic implant is placed in the hip.

    In the case of knee arthritis, Cortisone injections, Sinvisc and knee osteotomy and in the case of hip arthritis, Hip Resurfacing Surgery might also serve as a treatment criteria.

Joint Replacement Surgery

Joint Arthritis is the main reason of joint replacement surgeries in Hip and Knee. Hip fracture is the second reason for the former surgery and joint tumors might also bring the necessity for surgery.

Pre-surgical Operation:

Before the surgery starts, patient will have one of the following types of anesthesia:

  • General anesthesia. This means you will be asleep and unable to feel pain.
  • Regional (spinal or epidural anesthesia). Medicine is put into your back to make you numb below your waist. You will also get medicine to make you sleepy. And you may get medicine that will make you forget about the procedure, even though you will not be fully asleep.
  • ”Hip

    Hip joint replacement is surgery to replace all or part of the hip joint with a man-made (artificial) joint. The artificial joint is called a prosthesis.


    Your hip joint is made up of two major parts. One or both parts may be replaced during surgery:

    • The hip socket (a part of the pelvic bone called the acetabulum)
    • The upper end of the thighbone (called the femoral head)

    The new hip that replaces the old one is made up of these parts:

    • A cup, which is usually made of strong metal
    • A metal cap, which is placed on the ball of the ball-and-socket hip joint
    • A metal stem, attached to the cap

    After you receive anesthesia, your surgeon will make a surgical cut to open up your hip joint. Often this cut is over the buttocks. Then your surgeon will:

    • Cut and remove the head of your thigh bone
    • Clean out your hip socket and remove the rest of the cartilage and damaged or arthritic bone
    • Put the new hip socket in place, then insert the metal stem into your thigh bone
    • Place the correct-sized ball for the new joint
    • Secure all of the new parts in place, sometimes with a special cement
    • Repair the muscles and tendons around the new joint
    • Close the surgical cut

    This surgery usually takes 1 to 3 hours. hip-3

    Hip Precautions

    After Hip Surgery, you will need to follow HIP PRECAUTIONS for 3 MONTHS unless otherwise advised by your surgeon. These activity restrictions will help your joint to heal and reduce the risk of hip dislocation. Arthritis-6Arthritis-7 Arthritis-8 Things you CAN DO after hip surgery: DO sit on a raised chair or use a high-density foam cushion to increase surface heights. Use a raised toilet seat. Arthritis-9 DO use long-handled aids, such as a shoehorn and reacher, to help you dress and pick up items.


    Do sleep with pillows between your legs for the first 3 months after surgery. You may require assistance placing the pillows or choose to use an extra-long pillow. 1

  • ”Knee

    Knee joint replacement is surgery to replace a knee joint with a man-made (artificial) joint. The artificial joint is called a prosthesis.


    During knee joint replacement surgery, damaged cartilage and bone are removed from the knee joint. Man-made (artificial) pieces, called prostheses, are then placed in the knee. These pieces may be placed in up to three surfaces in the knee joint:

    • Lower end of the thigh bone. This bone is called the femur. The replacement part is usually made of metal.
    • Upper end of the shin bone–the large bone in your lower leg. This bone is called the tibia. The replacement part is usually made from metal and a strong plastic.
    • Back side of your kneecap. Your kneecap is called the patella. The replacement part is usually made from a strong plastic.

    hip-4 You will not feel any pain during the surgery because you will have a type of anesthesia. After you receive anesthesia, your surgeon will make a cut over your knee to open it up. This cut is often 8 to 10 inches long. Then your surgeon will:

    • Move your kneecap (patella) out of the way, then cut the ends of your thigh bone and shin (lower leg) bone to fit the replacement part.
    • Cut the underside of your kneecap to prepare it for the new pieces that will be attached there.
    • Fasten the two parts of the prosthesis to your bones. One part will be attached to the end of your thigh bone and the other part will be attached to your shin bone.
    • Attach both parts to the underside of your kneecap. A special bone cement is used to attach these parts.
    • Repair your muscles and tendons around the new joint and close the surgical cut.

    The surgery usually takes around 2 hours. Usually, artificial knees have both metal and plastic parts. Some surgeons now use different materials, including metal on metal, ceramic on ceramic, or ceramic on plastic. Arthritis-14

    Knee Precautions

    After Knee Surgery, you will need to follow KNEE PRECAUTIONS for 3 months unless otherwise advised by your surgeon. These activity restrictions will help your joint to heal and reduce stiffness in the new joint. Arthritis-15Arthritis-16 Arthritis-17

  • ”Why

    The most common reason to have a hip/knee joint replaced is to relieve severe arthritis pain that is limiting your activities. Joint replacement is usually done in people age 60 and older, but many people who have this surgery are younger. Your doctor may recommend hip/knee joint replacement if:

      • You’re having symptoms of hip/knee arthritis, such as:
        • You can’t sleep through the night because of pain
        • Your pain limits or keeps you from doing your normal activities, such as bathing, preparing meals, and household chores
        • You can’t walk and take care of yourself
      • Your pain has not improved with other treatment
      • You understand what surgery and recovery will be like

    But there are other reasons for replacing the hip joint which are:

    • Fractures in the thigh bone. Older adults often have a hip replacement for this reason.
    • Hip joint tumors


Risks for any surgery are:

    • Bleeding
    • Blood clots in the legs that may travel to the lungs
    • Heart attack or stroke during surgery
    • Infection, including in the lungs, urinary tract, and chest

Before Surgery

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After Surgery

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Surgery Result

Hip/knee replacement surgery results are usually excellent. Most or all of your pain and stiffness should go away. Although some people may have problems with infection, loosening, or even dislocation of the new hip joint. Over time (sometimes as long as 15 – 20 years for the hip and 10 – 15 years for the knee) the artificial joint will loosen. You may need a second replacement. Younger, more active people may wear out parts of their new hip. It may need to be replaced before the artificial hip loosens.

Companies Providing Prosthesis

One of the main parameters in the hip and knee joint replacement surgery is the quality of the prosthesis. Dr. Almasizadeh benefits top brands of hip and knee prosthesis to achieve the best results after surgery. Some of famous companies in this field are

Zimmer ( Tehran Sutures Company in Iran), DePuy (Arkandarman Company in Iran), Stryker (Dahi Teb Company in Iran), Wright Medical (Dabir Company in Iran), Smith & Nephew ( Jalalara Company in Iran ) and Mathys ( Irantomel Company in Iran).

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