Unicompartment knee replacement

The knee is composed of three compartments namely – medial, lateral and the patella-femoral compartment. Knee arthritis can affect all the three compartments but usually starts with one compartment. In the sitting of a single compartment knee arthritis, the replacement of a single compartment can be contemplated.


  • Single compartment involvement
  • Non obese patient
  • Moderate deformity
  • Non Inflammatory arthritis
  • Intact cruciate and collateral ligaments.

Opposite compartment ? Meniscus: Must be intact, slight fibrillation. Articular cartilage: The opposite compartment must be intact. Superficial fibrillation is acceptable.

Fairly good patella-femoral compartment.

Advantages –

  • Smaller incision
  • Faster recovery
  • Avoids sacrificing normal knee compartments

Surgical procedure

There are three basic steps in the procedure:

  • Prepare the bone. Your surgeon will use special saws to remove the cartilage from the damaged compartment of your knee.
  • Position the metal implants. The removed cartilage and bone is replaced with metal coverings that recreate the surface of the joint. These metal parts are typically held to the bone with cement.
  • Insert a spacer. A plastic insert is placed between the two metal components to create a smooth gliding surface.


Hospital discharge. Partial knee replacement patients usually experience less postoperative pain, less swelling, and have easier rehabilitation than patients undergoing total knee replacement. In most cases, patients go home 1 to 3 days after the operation. Some patients go home the day of the surgery.

Pain management. After surgery, you will feel some pain, but your surgeon and nurses will make every effort to help you feel as comfortable as possible.

Many types of medicines are available to help control pain, including opioids, non-steroidal anti-inflammatory drugs (NSAIDs), and local anesthetics. Treating pain with medication can help you feel more comfortable, which will help your body heal and recover from surgery faster.

Opioids can provide excellent pain relief, however, they are a narcotic and can be addictive. It is important to use opioids only as directed by your doctor. You should stop taking these medications as soon as your pain starts to improve.

Weightbearing. You will begin putting weight on your knee immediately after surgery. You may need a walker, cane, or crutches for the first several days or weeks until you become comfortable enough to walk without assistance.

Rehabilitation exercise. A physical therapist will give you exercises to help maintain your range of motion and restore your strength.

Doctor visits. You will continue to see your orthopaedic surgeon for follow-up visits in his or her clinic at regular intervals.