Medically Reviewed by Alex Kroft, PA-C
A partial knee replacement, also called a unicompartmental knee replacement, is a surgical procedure that replaces only the damaged part of the knee while conserving knee ligaments and unaffected cartilage. It is an alternative to total knee replacement for people with osteoarthritis of the knee. Partial knee replacement was once restricted to older individuals who were involved in few activities. Now, it is often used on younger patients to accelerate recovery time and reduce pain.
What is Unicompartmental Knee Arthritis?
Osteoarthritis is the wearing away of connective tissue, or articular cartilage, within a joint. The cartilage acts as a cushion and shock absorber, which allows for smooth and stable movement in the joint. Unicompartmental arthritis of the knee can occur in any one of the three compartments that make up the knee joint. The inner (medial) and outer (lateral) compartments are formed by the joining of the thigh bone (femur) and highest part of the shinbone (tibia). The third compartment of the knee is formed by the kneecap (patella) and front part of the femur. The most frequent site of osteoarthritis in the knee is the medial compartment.
Candidates for Partial Knee Replacement
Candidates for partial knee replacement are evaluated on a case-by-case basis and eligibility is dependent on a variety of factors. People with medial or lateral knee osteoarthritis can be considered for partial knee replacement. The surgery is not appropriate for patients with marked stiffness in the knee or significant angular deformity. In addition, partial knee replacement is recommended in patients who are:
- Over 55 years of age
- Not overweight
- Not heavy laborers or athletes
- Have intact ligaments
If you are unsure whether or not partial knee replacement is right for you, talk to your healthcare provider about individual risk factors and alternative treatment options.
Benefits of Partial Knee Replacement
Patient selection is one of the most important steps to ensuring an optimal functional outcome and long-term success. Compared to total knee replacement, partial knee replacement aims to preserve full range of motion and knee function by keeping the healthy tissue and bone intact. Patients tend to be satisfied with partial knee replacement due to decreased blood loss, faster recovery, and longevity.
What Happens During a Partial Knee Replacement?
Partial knee replacement is a minimally-invasive surgical procedure which typically lasts between 1 and 2 hours. Before surgery, your doctor will discuss anesthesia options with you, including:
- General anesthesia – you are completely asleep for the procedure
- Spinal anesthesia – you are awake, but your body is numb from the waist down
Next, your surgeon will make a small incision at the front of the knee and explore the three compartments to confirm that cartilage damage is, in fact, limited to only one compartment. Then, special saws are used to remove the cartilage from the damaged compartment. The removed cartilage and bone are replaced with metal coverings to recreate the surface of the joint. Cement is used to secure these components. Finally, a plastic insert is placed in between the two metal components to create a smooth, gliding effect. After surgery, you will be closely monitored as you recover from anesthesia.
Partial Knee Replacement Recovery
Most patients go home the same day as surgery. Otherwise, 1 or 2 nights in the hospital may be needed in the hospital following partial knee replacement surgery. Ultimately your total joint specialist will work with you to determine if your patient knee replacement surgery will occur in an outpatient or inpatient setting. Patients usually experience less postoperative pain and swelling, and have easier rehabilitation than those undergoing total knee replacement. There are several types of medication available to help control the pain, including opioids, nonsteroidal anti-inflammatory drugs (NSAIDs), and local anesthetics. With the help of physical therapy, patients may be back to full activity as soon as 6-8 weeks, however for some it may take up to 3 months. Schedule follow-up visits with your orthopedic surgeon to monitor any changes and ensure proper healing.Â
Schedule an Appointment with Raleigh Orthopaedic
If you’re dealing with pain, discomfort, or an injury, don’t wait to get the care you need. Our expert team at Raleigh Orthopaedic is here to help you feel better, move better, and get back to doing what you love. Schedule an appointment online or call us at 919-781-5600 to be seen—often within 48 hours. For immediate care, we offer walk-in orthopedic urgent care services. Click here for hours and locations.
Disclaimer:Â The information on this site is for general informational purposes only and is not intended as medical advice. It should not be used as a substitute for professional diagnosis, treatment, or medical judgment. Always consult a physician or qualified healthcare provider with any questions you may have about a medical condition or treatment.