Knee Anatomy

The knee is made up of four bones. The femur or thighbone is the bone connecting the hip to the knee. The tibia or shinbone connects the knee to the ankle. The patella (kneecap) is the small bone in front of the knee and rides on the knee joint as the knee bends. The fibula is a shorter and thinner bone running parallel to the tibia on its outside. The joint acts like a hinge but with some rotation.

The knee is a synovial joint, which means it is lined by synovium. The synovium produces fluid lubricating and nourishing the inside of the joint. Articular cartilage is the smooth surfaces at the end of the femur and tibia. It is the damage to this surface which causes arthritis.

The knee is made up of four bones. The femur or thighbone is the bone connecting the hip to the knee. The tibia or shinbone connects the knee to the ankle. The patella (kneecap) is the small bone in front of the knee and rides on the knee joint as the knee bends. The fibula is a shorter and thinner bone running parallel to the tibia on its outside. The joint acts like a hinge but with some rotation.


The knee is a synovial joint, which means it is lined by synovium. The synovium produces fluid lubricating and nourishing the inside of the joint. Articular cartilage is the smooth surfaces at the end of the femur and tibia. It is the damage to this surface which causes arthritis.


Why does a knee need to be revised?

Why does a knee need to be revised?

  • Pain is the primary reason for revision. Usually the cause is clear but not always. Those knees without an obvious cause for pain, in general, do not do as well after surgery.

    Pain is the primary reason for revision. Usually the cause is clear but not always. Those knees without an obvious cause for pain, in general, do not do as well after surgery

  • Plastic (polyethylene) wear. This is one of the easier revisions where only the plastic insert is changed.

    Plastic (polyethylene) wear. This is one of the easier revisions where only the plastic insert is changed

  • Instability which means the knee is not stable and may be giving way or not feel safe when you walk.

    Instability which means the knee is not stable and may be giving way or not feel safe when you walk

  • Loosening of either the femoral, tibial or patella component. This usually presents as pain but may be asymptomatic. It is for this reason why you must have your joint followed up for life as there can be changes on X-ray that indicate that the knee should be revised despite having any symptoms.

    Loosening of either the femoral, tibial or patella component. This usually presents as pain but may be asymptomatic. It is for this reason why you must have your joint followed up for life as there can be changes on X-ray that indicate that the knee should be revised despite having any symptoms

  • Infection-usually presents as pain but may present as swelling or an acute fever.

    Infection-usually presents as pain but may present as swelling or an acute fever

  • Osteolysis (bone loss). This can occur due to particles being released into the knee joint which result in bone being destroyed.

    Osteolysis (bone loss). This can occur due to particles being released into the knee joint which result in bone being destroyed

  • Stiffness-this is difficult to improve with revision but can be helped with the right indications.

    Stiffness-this is difficult to improve with revision but can be helped with the right indications

Surgical procedure

Surgical procedure

It will be explained to you prior to surgery what is likely to be done but in revision surgery the unexpected can happen and good planning can prevent most potential problems. The surgery is often, but not always, more extensive than your previous surgery and the complications similar but more frequent than the first operation.

The surgery varies from a simple liner exchange to changing one or all of the components. Extra bone (cadaver bone) may need to be used to make up for any bone loss.

It will be explained to you prior to surgery what is likely to be done but in revision surgery the unexpected can happen and good planning can prevent most potential problems. The surgery is often, but not always, more extensive than your previous surgery and the complications similar but more frequent than the first operation.


The surgery varies from a simple liner exchange to changing one or all of the components. Extra bone (cadaver bone) may need to be used to make up for any bone loss.

  • The surgeon makes an incision in front of the knee exposing the knee joint.

    The surgeon makes an incision in front of the knee exposing the knee joint

  • The knee cap along with its ligament may be moved to make room for the operation.

    The knee cap along with its ligament may be moved to make room for the operation

  • The surgeon first concentrates on the thigh bone to remove the old femoral component.

    The surgeon first concentrates on the thigh bone to remove the old femoral component

  • The surgeon removes the old femoral component.

    The surgeon removes the old femoral component

  • Sometimes the damaged bone will be cut.

    Sometimes the damaged bone will be cut

  • The femur is then prepared to take the new component. Sometimes the damaged bone may be removed.

    The femur is then prepared to take the new component. Sometimes the damaged bone may be removed

  • The femoral component is then fixed in place. Sometimes extra bone or a metal wedge may be used to make up for the lost bone.

    The femoral component is then fixed in place. Sometimes extra bone or a metal wedge may be used to make up for the lost bone

  • Occasionally cement may be used depending on surgeons' preference.

    Occasionally cement may be used depending on surgeons' preference

  • The surgeon then concentrates on the tibia to remove the tibial component along with the old plastic liner. The damaged bone is cut.

    The surgeon then concentrates on the tibia to remove the tibial component along with the old plastic liner. The damaged bone is cut

  • The tibia is then prepared to take the new tibial component. The lost bone is then replaced either by a metal wedge or bone graft depending on surgeons' preference.

    The tibia is then prepared to take the new tibial component. The lost bone is then replaced either by a metal wedge or bone graft depending on surgeons' preference

  • The new tibial component is fixed in place. Cement may be used to fix the component in place.

    The new tibial component is fixed in place. Cement may be used to fix the component in place

  • A plastic liner is placed on the tibial component. Occasionally, the knee cap may also be prepared and resurfaced to receive a plastic component.The femoral and the tibial component are fixed in place to form the new knee joint. The muscles and tendons are then approximated.

    Drains are usually inserted to drain excessive blood.

    A plastic liner is placed on the tibial component. Occasionally, the knee cap may also be prepared and resurfaced to receive a plastic component.The femoral and the tibial component are fixed in place to form the new knee joint. The muscles and tendons are then approximated.

    Drains are usually inserted to drain excessive blood.

Risks and Complications

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 local complications specific to the knee.

To learn more about the risks and complications involved with knee surgery click here

A total hip replacement is one of the most successful operations that orthopedic surgeons perform.  A hip replacement is an elective surgery, which means patients decide if and when to have their hip replaced. As a physician, I never tell patients they have to have a hip replacement surgery, but many times surgery may offer the only possibility for pain relief. Although the surgery is elective, it is covered by most insurance companies; however, depending on your policy you maybe required to make a small co-payment. My philosophy is to give my patients as much information as they need to make informed decisions regarding their health and hip pain and then treat their hip pain according to their wishes.


A hip joint is basically a ball and socket joint.  A hip replacement involves removing the ball (femoral head) and replacing it with a metal prosthetic ball. The femoral prosthesis is inserted into the hollow part of the femoral shaft. The socket of the pelvis is machined into a hemisphere and a metal hemisphere is inserted into the socket. The new metal ball and new metal socket form the new hip joint and allow the same and often times more motion than the native hip joint. The femoral and acetabular prosthesis are attached to your bones by creating a space in the bone that is slightly smaller than the metal prosthesis and then pressing the metal prosthesis into this tight space. Occasionally, the metal prosthesis is attached to the bone with bone cement. The parts are made of stainless steel, titanium, ceramic and/or polyethylene. I typically make an incision about 3-4 inches long for a hip replacement.


The purpose of this web page is to educate patients about the major aspects of hip replacement surgery. Many studies have shown that an informed patient will have less surprises and more satisfaction with their surgery. I do not intend to scare people away from getting their hip pain treated. Although the following information is a reasonable overview of what I consider the major aspects of hip surgery, it is not a substitute for a clinical consultation where I can directly answer your questions. If you would like more information, please schedule an appointment to see me.

Complications can be medical (general) or local complications specific to the knee

1
Hello, and Thank you for stopping by my practice website!

Contact Me