Unicompartmental knee arthroplasty, also known as partial knee replacement, is a minimally invasive surgical procedure aimed at replacing only the damaged compartment of the knee with an implant. The knee comprises three compartments: the patellofemoral, located in front of the knee between the kneecap and thigh bone; the medial compartment, situated on the inner portion of the knee; and the lateral compartment, occupying the outer portion of the knee joint.
Disease Overview
Arthritis, characterized by joint inflammation leading to pain, swelling, and stiffness, is a common ailment affecting knee joints. Osteoarthritis, the predominant form, involves gradual deterioration of joint cartilage, typically afflicting older individuals. In arthritic knees, cartilage thins or vanishes entirely, while bone thickening and bony spurs formation occur, resulting in pain and restricted motion.
Causes
Arthritis onset may be linked to various factors, including joint injury, fractures, excessive body weight, repetitive overuse, joint infection, inflammation, and connective tissue disorders.
Symptoms
Knee arthritis manifests as pain exacerbated by activities such as walking, climbing stairs, or kneeling. Stiffness, swelling, and limitations in range of motion are common, alongside potential knee deformities like knock-knees or bow-legs.
Diagnosis
Medical history, physical examination, and X-rays aid in osteoarthritis diagnosis, typically revealing joint space narrowing.
Surgical Procedure
When non-surgical interventions fail, surgery becomes an option. The procedure involves a small incision to access the knee joint. The surgeon removes the damaged meniscus section and implants the components into the bone after shaping the shin and thigh bones. The plastic component fits snugly into the prepared area, secured with bone cement. The damaged femoral segment is replaced with a metal component, also anchored with bone cement. Post-component fixation, the knee undergoes range-of-motion exercises, and the incision is closed.
Post-Operative Care
Initially, walking aids like walkers or canes assist mobility. A physical therapy regimen spanning 4 to 6 months promotes range of motion and strength restoration, incorporating exercises like walking, swimming, and biking, while high-impact activities are discouraged.
Risks and Complications
Potential complications of unicompartmental knee replacement encompass knee stiffness, infection, blood clots, nerve and blood vessel damage, ligament injuries, patella dislocation, and implant wear or loosening.
Advantages
Compared to total knee replacement, unicompartmental knee arthroplasty offers benefits such as smaller incisions, reduced blood loss, quicker recovery, less post-operative pain, improved overall range of motion, and a more natural knee feel.
By comprehensively understanding unicompartmental knee arthroplasty and its advantages, patients and healthcare providers can navigate treatment options effectively, fostering enhanced knee function and improved quality of life.