FAQs on Unicompartmental Knee Arthroplasty in Gilbert, Chandler and Mesa AZ
Unicompartmental knee arthroplasty accounts for about 8 to 10 percent of all knee replacement surgeries performed by US surgeons. An alternative for those with partial knee damage, the procedure has minimum post-operative complications and patients have faster recovery with only a part of the knee is replaced with artificial implants.
What is unicompartmental knee arthroplasty?
Unicompartmental knee arthroplasty refers to replacement of one of the three knee compartments. The knee joint has three important compartments – the inner side or medial part, the outer side or lateral part, and the front or patellofemoral area. The procedure involves replacing only the damaged compartment with artificial implants and leaving other two compartments untouched.
The partial knee replacement surgical procedure is for patients with just one of the three knee compartments affected by arthritis and having strong, healthy ligaments.
What are the benefits of unicompartmental knee arthroplasty?
The biggest advantage of unicompartmental knee arthroplasty is that a major part of the knee is left untouched and healthy bone, cartilage, and ligaments continue to provide more natural strength and functional flexibility compared to total knee replacement. The surgery also offers less pain, reduced post-operative complication, less bleeding, and faster recovery. It delays the need for total knee replacement and if the need arises, the total replacement can be performed after years.
What are conditions treated with unicompartmental knee arthroplasty?
Unicompartmental knee arthroplasty is best suited for patients suffering from moderate joint pain and disability due to one of the knee compartments affected conditions, such as
- traumatic injury
- low bone density
Who is a candidate for unicompartmental knee arthroplasty?
A patient is recommended for unicompartmental knee arthroplasty if
- he has severe localized arthritis in one of the three compartments of the knee
- No damage to the ligament or other compartments
- he has used all nonsurgical options without any major relief
- the condition is significantly affecting the knee function and causing pain
Who is not a candidate for unicompartmental knee arthroplasty?
The procedure is not for those with significant arthritis damage to the knee joint, inflammatory arthritis, or with knee or bone infection. Another important element is the condition of the anterior cruciate ligament. Those without a healthy ligament may not be suggested for partial knee replacement. Knee deformities, obesity, immature bones, loss of significant tibia bone, frequent knee joint subluxation, patellofemoral damage, unhealthy knee ligaments, and neuromuscular stability disorder also write off one as a candidate for unicompartmental knee arthroplasty.
How is unicompartmental knee arthroplasty performed?
Surgery is carried out after the patient is placed under general anesthesia an incision made through the front knee. An assessment is made to evaluate cartilage damage across all three compartments. If the damage limited to one compartment with no ligament injury, the option for unicompartmental knee arthroplasty is considered.
For lateral and media compartment arthroplasty, special saws are used to resurface the bones and remove damaged part of the cartilage. Metal implants are used to cover tibia and femur surfaces. A plastic component is inserted between reconstructed metal surfaces to act like the cartilage and ensure smooth gliding surface.
If the arthroplasty is performed to replace the patellofemoral compartment, an open incision is made in the midline on your front knee. Surgeons remove the worn out or damaged portions. A metal surface is attached to the thighbone and a plastic surface is fixed to the posterior side of the kneecap. While dome-like plastic implant is attached to the kneecap, a metallic shield is placed around the trochlear groove.
A local anesthetic is injected to ensure pain relief after the surgery.
How long does unicompartmental knee arthroplasty surgery take?
The surgery takes around 1 to 2 hours depending on the complexity and the knee damage.
Do I need to stay at the hospital after unicompartmental knee arthroplasty?
Most patients are advised for hospital stay that varies from 1 to 3 nights depending on the knee surgery. They are discharged with adequate instructions on pain management, blood clot prevention, and rehabilitation process.
Do I need rest after unicompartmental knee arthroplasty?
Patients are advised to take rest for a week to avoid any complication or failure of implants due to stress.
What are the restrictions following unicompartmental knee arthroplasty?
- Keep the incision bandage clean and dry
- No showering for 3 days
- Rest and RICE therapy (rest, ice, compression, and elevation)for a week
- No driving for 4 weeks
- Use crutches for 4 weeks
- Avoid weight bearing for 12 weeks
- Use a brace between 4 and 12 weeks
- No jumping or running for life
- Shun high-impact activities to avoid implant wear and tear
What kind of rehabilitation is needed following unicompartmental knee arthroplasty?
Knee mobilization through passive exercises starts on the next day and continues along with soft tissue activation for week. Patients need to join physical therapy program in the second week and continue the same until full recovery.
The rehabilitation includes stretching of leg muscles, knee flexion, and pain free motion. The patient gradually turns to progressive aerobic and strength-training workouts after 3-4 weeks. Light weight impact exercises give way to high-impact ones after 6-8 weeks.
How long is the recovery period following unicompartmental knee arthroplasty?
Complete recovery takes 3 to 6 months depending on the patient and the rehabilitation program. You can join office work in 2 weeks. But heavy activities must be avoided until 8 weeks.
What are the potential complications of unicompartmental knee arthroplasty?
There may be common surgical complications, including pain, stiffness, nerve or blood vessel injury, swelling, bleeding, and infection. Blood clot is common following unicompartmental knee arthroplasty and it needs special attention to avoid heart attack and stroke. Loosening, dislocation, or failure of implants may also occur.
Borus T, Thornhill T (January 2008). “Unicompartmental knee arthroplasty”. J Am Acad Orthop Surg 16 (1): 9–18
Newman JH (April 2000). “Unicompartmental knee replacement”. Knee 7 (2): 63–70.
Laskin RS (March 1978). “Unicompartmental tibiofemoral resurfacing arthroplasty”. J Bone Joint Surg Am 60 (2): 182–5
Swienckowski JJ, Pennington DW (September 2004). “Unicompartmental knee arthroplasty in patients sixty years of age or younger”. J Bone Joint Surg Am. 86-A Suppl 1 (Pt 2): 131–42
Jamali AA, Scott RD, Rubash HE, Freiberg AA. Unicompartmental knee arthroplasty: past, present, and future. Am J Orthop. 2009 Jan. 38(1):17-23
Bert JM (October 2005). “Unicompartmental knee replacement”. Orthop. Clin. North Am. 36 (4): 513–22.