Unicompartmental knee arthroplasty is a partial knee replacement used when arthritis is limited to one portion of the knee.
The procedure resurfaces only the damaged compartment while preserving the other compartments that remain in good condition. Dr. Chudik uses computer and robotic technology and measurements to assist with positioning the unicompartmental implants.
What Is Unicompartmental Knee Arthroplasty?
Arthritis is the breakdown of the protective cartilage surface covering the ends of bones at a joint. As the cartilage wears away over time or after injury, contact between the exposed ends of the bones can cause pain, swelling, and stiffness.
The knee has three compartments:
- The medial tibiofemoral compartment on the inside of the knee
- The lateral tibiofemoral compartment on the outside of the knee
- The patellofemoral compartment between the kneecap and thigh bone
Unicompartmental knee replacement can resurface a damaged and arthritic joint surface in any one of these compartments when the other compartments remain in good condition.
This less-invasive procedure is an alternative to total knee replacement when arthritis is limited to one portion of the knee. Robotic and computer navigation are used to improve the technical ability to accurately position the unicompartmental implants.
Who Is a Candidate?
A partial knee replacement may be considered when:
- Arthritis is limited to one portion of the knee
- Reasonable conservative treatment has been exhausted
- Pain continues to significantly affect quality of life
Arthritis should initially be treated conservatively with measures such as:
- Physical therapy
- Injections
- Medications
- Activity modifications
Contraindications include:
- Inability or unwillingness to complete the necessary postoperative rehabilitation program
- Current or previous knee infection, although this is not an absolute contraindication
How the Procedure Is Performed
Through a limited incision along the front of the knee, the damaged and arthritic joint surface is resurfaced and replaced with artificial materials.
Dr. Chudik uses computer and robotic technology and measurements during the procedure to assist with positioning the unicompartmental implants.
The implants are typically fixed to the ends of the bones with methylmethacrylate bone cement.
Outpatient and inpatient surgery options are available and are discussed before surgery. General anesthesia and a spinal nerve block may be used.
Recovery and Rehabilitation
Following unicompartmental knee replacement:
- Weight bearing is allowed as tolerated, with crutches or a walker used for comfort
- The wound should be kept clean and dry for the first 10 to 14 days
- Light showering is allowed after two weeks, but the wound should not be submerged in water for at least three weeks
- Driving may resume at approximately four to six weeks once motion and strength have returned in the driving leg
- Return to sedentary work may occur at about two weeks as long as the leg can be elevated
- Physical therapy to restore motion, strength, and proprioception (balance) may continue for about four months
Patients may return to walking and regular daily activities as soon as comfortable. Most activities may be resumed at approximately three to four months after surgery.
High-impact activities such as running and jumping are not recommended following unicompartmental knee arthroplasty.
Risks and Outcomes
Potential surgical risks and complications include:
- Infection
- Rare nerve injury resulting in numbness around the knee; a small area of temporary or permanent numbness around the incision is not uncommon
- Postoperative infection that may require removal of the implants
- Knee stiffness or loss of motion requiring prolonged rehabilitation or repeat surgery
- Pain from the implant
- Rarely, a blood clot in the veins of the calf or thigh that may travel to the lungs
A unicompartmental knee replacement preserves compartments of the knee that remain in good condition. However, if arthritis later progresses in other compartments, revision to a total knee arthroplasty may be needed.
The soft tissues surrounding the knee have been shown to recover faster following unicompartmental knee replacement than after total knee replacement.
Why Dr. Chudik for Unicompartmental Knee Arthroplasty
Dr. Chudik uses computer and robotic technology and measurements to assist with accurate positioning of unicompartmental knee implants.
For patients whose arthritis is limited to one portion of the knee, he can use this less-invasive approach to resurface the damaged compartment while preserving the other compartments that remain in good condition.