Uni Compartmental Knee Replacement

The single compartment of your knee which has worn and developed arthritis down to bone-on-bone is replaced by a new joint surface made of a metal component on the thigh bone “femur” and high-density polyethylene on the shin bone (tibia). This is designed to stop the bone-on-bone rubbing and to allow pain relief and improvement in function. This is fortunately a much simpler operation than a complete knee replacement, and allows patients to mobilize and rehabilitate quickly.

At the time of your surgery, the operative site will be injected with pain medicine (Marcaine) and for most patients a pain pump will be used to reduce post-operative pain. The pain pump works by giving a controlled dose of the pain medicine (Marcaine) through a small tubing to the surgical site and greatly helps reduce post-operative discomfort. There is nothing special that needs to be done to have the pain pump operate. It is self contained and will function on its own. The pain pump is normally removed at 1-3 days after surgery, at which time the dressings are changed. You will also be discharged with 1 or 2 prescriptions for pain medicines that can be filled either at the hospital or local pharmacy. The pain medicine can be taken every 3 to 12 hours as needed (please follow instructions). The medicine will help to decrease pain level, but it is not expected that the pain pump or the pain medicines will completely eliminate all pain. Some pain is expected and normal. If you develop major reactions such as itching, skin rash, nausea or vomiting, discontinue the medicine and call for additional recommendations. Narcotic pain medications may cause constipation, which can be helped with increased fluids, roughage and fruit intake in your diet.

The use of ice or cold therapy will also help to decrease both swelling and pain (please follow discharge instructions). The cold therapy will be of greatest help during the first 2-5 days, but may be used additionally thereafter.

Elevation of your leg above the level of your heart while at rest and the use of a surgical stocking will also help to decrease swelling and secondarily relieve pain.

Dressings will be applied to your incision at the time of surgery. Bloody drainage from the incision or pinkish drainage from the pain pump is expected during the first 24 to 48 hours. If this occurs, reinforce the dressing with additional sterile gauze. At 1-3 days, in conjunction with removal of the pain pump, the dressing will be changed. A new dressing of sterile gauze can be applied thereafter on a daily basis as needed and if there is any drainage.

The surgical incision is expected to have soreness and swelling during the first few days post-operatively. You may develop bruising around the area of surgery and over the front of your leg for the next 1-2 weeks. This will go away and no special care is expected to be needed.

We would like you to keep your wound dry for the first two weeks and until 24 hours after the stitches are removed, to ensure that wound healing is occurring. This will help to minimize the risk of infection or delayed wound healing. Bathing in a tub with the knee bent up out of the water or showering with the wound well covered will be satisfactory. 24 hours after the stitches are removed, you may wash the knee, but do not scrub the incision or soak it for an extended period of time. You would not want to take a chance on bursting the wound open.

When discharged home, you would be best to rest, relax and make sure everything is going well. You would be best to have someone at home to help you during the first 2-3 days. You may go ahead with straightening and bending of your knee as much as you are comfortable following surgery. You may go ahead with full weight bearing as comfortable on the surgical knee as soon as you are able. It is important to regain maximum ROM by 2-3 weeks post-operatively. Use of a walker, crutches or a cane is recommended until you are fully capable, secure, no longer limping, and no longer at risk of falling. Doing your strengthening exercises will be very important during the post-operative program.

Do not drive a vehicle or operate mechanical equipment for several days after surgery until you are sure you can safely handle this with no risk of injury or incident.

You may resume basic activity in 3-5 days unless otherwise instructed.

Drink clear liquids (apple juice, ginger ale, broth, 7-Up, etc.). Progress to your regular diet as you feel able. Do not drink alcoholic beverages during the first 24 hours post-operative.

A common occurrence after anesthesia is a low-grade fever during the first 24 to 48 hours post-operatively. The fever is usually below 101° and slowly abates. Tylenol works well to keep it in check. If you develop a high fever (temperature over 101°) shaking, chills, unexpected/severe pain, redness or swelling, please contact our office for consultation or examination. It is normal to have swelling on the affected foot and leg during the first 1-2 weeks. This can be relieved by elevation of the leg, moving the ankle up and down to exercise the calf muscles, and by use of the post-operative stocking. If you develop major pain, tenderness, warmth, or swelling in your calf, contact our office.

A post-operative assessment with your surgeon, his nurse practitioner, or your local family doctor will be made at 1-3 days following surgery for removal of the pain pump, wound assessment and dressing change. Physical therapy may begin after this dressing change for range of motion, strengthening and progressing with weight bearing as comfortable. Your therapy program is equally as important as your operation to regain your range of motion, your muscle strength and return to function since this has been limited by your arthritis for many months prior to surgery. Your surgeon, nurse practitioner and therapist will monitor your rehabilitation and progress, and if you have questions or concerns, please feel free to discuss your situation with them.

Emergency Calls:
If you have a problem of an emergency nature and are unable to reach your doctor, go to the Altru Hospital Emergency Room (phone: 701-780-5280); or your nearest hospital or emergency facility.

Contact Your Physician (Or His Alternate) If You Have Any Problems:

  • Fever greater than 101 degrees orally or if at all questionable.
  • Chills
  • Excessive bleeding
  • Separation of the incision
  • Excessive swelling or tenderness
  • Unusual drainage: pus-like drainage (white, yellow, or greenish in color); any excessive drainage
    from the area; foul odor from the incision or dressing.
  • Change in color around the area; excessive redness may indicate infection
  • Change in temperature around the area: unusual warmth
  • Increased pain in operative area