High Tibial Osteotomy
High tibial osteotomy is a surgical procedure to relieve pressure on the damaged site of an arthritic knee joint. In high tibial osteotomy, a triangular wedge of bone is cut at the upper end of the tibia and either removed or filled with bone graft depending on the patient’s needs. It is commonly used to relieve pain when non-operative treatments have failed.
High tibial osteotomy is commonly recommended for patients under 55 years of age with a mobile knee. It has proven beneficial for the young and also middle aged patients who want to delay surgery for total knee replacement.
Osteoarthritis.
Osteoarthritis (OA) is a condition involving breakdown of cartilage due to mechanical stress or daily wear and tear. Risk factors for developing osteoarthritis include being overweight, excessive strain over prolonged periods of time, previous fracture or any joint diseases, injury and deformity. OA is a slowly progressive degenerative joint disease that commonly affects middle aged to elderly people and is rated as a leading disabling disease affecting millions of people around the world. It tends to affect the commonly used joints such as hands, spine, hips, and knees.
The disease affects the tissues or cartilages covering the ends of bones in a joint and leads to degeneration of the bones. The common symptoms of osteoarthritis include:
Joint pain
Joint stiffness, particularly in the morning.
Swelling around the joint.
Grinding or cracking sounds during joint movement and
Functional deterioration of the joint.
Candidates for the surgery.
Good candidates for high tibial osteotomy includes young, active arthritis patients who are unable to have arthroplasty due to excessive wear; patients with good vascular support; non-obese patients with only one knee compartment affected; and the patient who is able to follow the postoperative protocol.
Contraindications.
The surgery is contraindicated in patients with:
inflammatory arthritis,
obese patients with BMI above 35,
presence of flexion contracture of 15 degrees or more,
knee flexion greater than 90 degrees, patellofemoral arthritis,
ligament instability or
varus thrust during gait.
Procedure.
The goal of the surgery is to release the involved joint compartment by correcting the malalignment of the tibia and to maintain the joint line perpendicular to the mechanical axis of the leg. There are two techniques that may be used: closing wedge osteotomy and opening wedge osteotomy. The surgeon determines the choice of the technique based on the requirement of the patient.
Closing wedge osteotomy.
Closing wedge osteotomy is the most commonly used technique to perform high tibial osteotomy. In this procedure the surgeon makes an incision in front of the knee and removes a small wedge of bone from the upper part of the tibia or shin bone. This manipulation brings the bones together and fills the space left by the removed bone. The surgeon then uses plates and screws to bind the bones together while the osteotomy heals. This procedure unloads the pressure off the damaged joint area and helps to transfer some of the weight to the outer part of the knee, where the cartilage is still intact.
Opening wedge osteotomy
In this procedure, the surgeon makes an incision in front of the knee, just below the knee cap and makes a wedge-shaped cut in the bone. Bone graft is used to fill the space of the wedge-shaped opening and if required plates and screws can be attached to further support the surgical site during the healing process. This realignment increases the angle of the knee to relieve the painful symptoms.
Post-operative care
After osteotomy surgery patients may require two to four days of hospitalization. Immediately after surgery a light compressive knee brace or splint may be used to protect the knee and pain medications are given to reduce pain or swelling. During this time patients are instructed to follow post-operative protocols for a successful outcome.
Post-operative instructions include the use of TED stockings to reduce the risk of clot formation, crutch walking and physical therapy. Physical therapy includes range of motion exercises and strengthening exercises to restore range of motion and improve muscle strength. Physical therapy may begin the day after surgery to help the patient to move in and out of bed and to learn to use crutches in a safe manner. Crutch walking involves using crutches without weight bearing on the operated leg immediately after the surgery to allow the bone to heal. After a few weeks, progression to partial weight bearing in the operated leg will be encouraged.
Complications.
As with any surgery, patients undergoing High tibial osteotomy surgery are at risk for developing certain complications following the surgery. Common risks and complications of the surgery are pain, swelling, numbness or injury to the surrounding nerves or vessels, infection, compartment syndrome, deep vein thrombosis, loosening of instrumentation (plates and screws) and non-union of the bone.
High tibial osteotomy is a successful surgical method for moderate unicompartmental degenerative arthritis of the knee.
