High tibial osteotomy is a surgical procedure performed to relieve pressure on the damaged site of an arthritic knee joint. It is usually performed in arthritic conditions affecting only one side of your knee and the aim is to take pressure off the damaged area and shift it to the other side of your knee with healthy cartilage. During the surgery, your surgeon will remove or add a wedge of bone either below or above the knee joint depending on the site of arthritic damage.

High tibial osteotomy is commonly used for patients with osteoarthritis that is isolated to a single compartment (unicompartmental osteoarthritis). It is also performed for treating a variety of knee conditions such as gonarthrosis with varus or valgus malalignment, osteochondritis dissecans, osteonecrosis, posterolateral instability, and chondral resurfacing.

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.

Complications following high tibial osteotomy may include infection, skin necrosis, non-union (failure of the bones to heal), nerve injury, blood vessel injury, failure to correct the varus deformity, compartment syndrome and deep vein thrombosis or blood clots.

Tibial Tubercule osteotomy

Tibial tubercle osteotomy is a surgical procedure which is performed along with other procedures to treat patellar instability, patellofemoral pain, and osteoarthritis. This is a quite safe procedure and provides excellent access and surgical exposure during a difficult primary or revision total knee arthroplasty. Surgical treatment is indicated when physical therapy and other nonsurgical methods have failed and there is history of multiple knee dislocations. Tibial tubercle transfer technique involves realignment of the tibial tubercle (a bump in the front of the shin bone) such that the knee cap (patella) traverses in the center of the femoral groove. The patellar maltracking is corrected by moving the tibial tubercle medially, towards the inside portion of the leg. This removes the load off the painful portions of the knee cap and reduces the pain.

Surgical technique

The procedure is performed under general anesthesia and you will be completely unaware of the surgery until you wake up in the recovery room. At first, knee arthroscopy will be performed to inspect the inside portions of the knee joint. It involves small incisions or portals through which small instruments are passed and a video camera is used to visualize the anatomy of the knee joint, evaluate patella cartilage and assess patella tracking.

Tibial tubercle osteotomy and transfer is done through an incision made in the front of your leg just below the patella. In osteotomy procedure, a periosteal incision of 8-10 cm length is made at a distance of 1cm medial to the tibial tubercle. With the help of an oscillating saw, a cut is made medial to the tuberosity and a distal cut is also made. The tapered design of the distal cut avoids the risk of tibial fracture. Similarly, a proximal cut is made using appropriate instruments such as curved osteotome or reciprocating saw. Then an osteotomy through the bone cortex is performed without cutting off the lateral periosteum. The lateral periosteum serves as a point of attachment for the osteotomy segment. By doing this, a tibial tubercle segment which is more than 2 cm in width, more than 1 cm in thickness and 8-10 cm length can be obtained. It should include all portions of insertion of the patellar tendon. The segment from the tibia is then levered using osteotome so as to provide access to the medullary canal of the tibia.

The osteotomy segment is then moved under direct vision into a position that assures proper tracking of the patella. The tracking pattern can be confirmed arthroscopically. The mobilized bone is then fixed into its new place using screws, which can be removed later if they cause irritation.

Post-surgery Care

You may have minimal to moderate knee discomfort for several days or weeks after the surgery. Oral pain medications will be prescribed that helps control your pain. Keep the operated leg elevated and apply ice bag over the area for 20 minutes. This decrease swelling as well as pain. You will have a leg brace which may be removed only while sitting with your leg elevated and when using the continuous passive motion (CPM) unit. Physical therapy exercises should be done as it helps in regaining mobility. Eat healthy food and drink plenty of water.

Risks and complications

Risks following tibial tubercle osteotomy surgery are rare but may include compartment syndrome, deep vein thrombosis, infections and delayed bone healing.