High Tibial Osteotomy

OA (Osteoarthritis) is one of the most common types of knee arthritis which can result in disability and pain. Daily activities which you like can become challenging and symptoms may worsen with weight-bearing. 

A high tibial osteotomy (HTO) is a surgical procedure that realigns your knee joint. For some patients who have knee arthritis, this surgery can prevent or delay the need for a total or partial knee replacement by preserving damaged joint tissue.

People with knee issues, particularly when combined with bowleggedness, should talk to their orthopaedic team about HTO as it is recommended to patients on a case-to-case basis after considering the pros and cons. 

What is a High Tibial Osteotomy (HTO)?

An orthopaedic surgical treatment called a high tibial osteotomy treats compartmental osteoarthritis and a varus deformity. Since the procedure’s inception, improvements in technique, fixation technology, and patient selection have allowed HTO to gain popularity among younger, more active patients looking to treat arthritis. Realigning the weight-bearing line of the knee is the surgery’s objective. By realigning the knee, the arthritic medial compartment receives less force from weight-bearing and more comes from the lateral compartment, which is healthy. Delaying the onset or progression of osteoarthritis in the medial compartment of the knee due to this reduction in force or load in the diseased portion of the knee joint also reduces knee discomfort. 

What Are the Selection Criteria for a High Tibial Osteotomy?

The International Society of Arthroscopy, Knee Surgery, and Orthopaedic Sports Medicine (ISAKOS) created the recognized methodology for patient selection in 2004. An ideal patient with this procedure is:

• A non-smoker
• Without ligamentous instability, the lateral and patellofemoral compartments are nearly normal.
• Full range of motion in the knee
• Tibia bone varus angle >5°
• Malalignment <15°
• BMI <30
• Experiencing isolated medial joint line tenderness
• Between 40-60 years old
• Moderately active

Contraindications specified by ISAKOS are:

• Heavy smokers
• a sizable region of exposed bone (more than 15×15 mm) on the tibial or femoral articular surface
• Diagnosed inflammatory arthritis
• Flexion contracture >5°
• Range of motion in the knee <120°
• Patellofemoral osteoarthritis
• tri-compartmental osteoarthritis
• Severe osteoarthritis of the medial compartment (Ahlback grade III or higher)
• Patients older than 65

You Can Also Read: Common Knee Injuries You Should Be Aware Of

What is the Surgical Technique Involved in a High Tibial Osteotomy?

The general surgical technique includes either performing HTO alone or performing HTO in combination with ligament reconstruction. When deciding which treatment avenue to take, one must consider patient demographics, their predominant symptoms, and which ligaments, if any are involved. When ligaments are involved, but the ACL deficiency is chronic and pain is due to arthritis and malalignment, HTO alone should be sufficient. However, if instability is the predominant symptom, for example, an acute ACL deficiency, HTO in combination with ACL reconstruction may be performed to protect the ACL graft that was constructed.

The two most common surgical techniques used in HTO are lateral close wedge osteotomy and medial open wedge osteotomy.

 Medial Open Wedge Osteotomy

The initial cut is made between the posteromedial border of the tibia and the medial aspect of the tibial tubercle. The medial collateral ligament (MCL) is exposed by cutting the sartorius fascia and pulling it medially. MCL is then removed from its insertion medially. Two K-wires are placed towards the lateral cortex, about 4 cm below the joint line. The osteotomy is done below the K-wires and parallel to the joint line.

The advantages of the medial open wedge method include less risk of peroneal nerve injury compared to the lateral close wedge method, no limb shortening, no bone loss, and the use of a single cut with no need to detach muscles.

Lateral Close Wedge Osteotomy

Starting at the anterolateral aspect about 1 cm below the knee joint line, an L-shaped cut is made to the lateral edge of the tibial tubercle and anterior tibial crest. To expose the bone, the fascia of the anterior compartment is cut near the anterior tibial crest and the anterior tibialis is elevated. Osteotomy starts 15 mm below the joint line, just above the tibial tubercle, and is directed parallel to the joint line, medially.

Some of the advantages of the lateral close wedge method are faster healing with less morbidity, greater potential for healing, and no need for bone grafting, unlike the medial open wedge method. 

Methods of Fixation

Two main types of fixation plates are used: spacer plates and plate fixators. Spacer plates are lower-profile implants that require a smaller incision. The disadvantage of using a spacer plate is the decreased rigidity associated with increased rates of delayed union or nonunion. Because of this, spacer plates require a longer period of staying off the leg that was operated on. Plate fixators give a stronger fixation, allowing for earlier weight-bearing and initiation of therapy. A couple of studies attempted to compare these two methods but found no differences in reliability.

Filling the Bone Gap 

After part of the bone is removed, there is a space that may need to be filled. Some prefer using a graft or bone substitute, which will hopefully increase stability and decrease healing time. Bone can also be taken from the hip of the patient to use as a graft. This has a lower complication rate so is considered in someone who is at risk of the bone not healing, like a smoker or obese patient.

What Are the Complications of a High Tibial Osteotomy?

The most common complications are the same as those occurring for any orthopaedic procedure performed on a lower limb. These are:

• Hematoma
• Superficial wound infection
• Deep venous thrombosis

The complications specific to the HTO are rare and include the failure of the bone to heal, common peroneal nerve palsy, decreased range of motion, a low-lying knee cap, and a fracture inside the knee joint. 

Can a High Tibial Osteotomy Be an Alternative to Knee Replacement?

Knee replacement surgery can treat this problem when the joint deterioration is beyond repair or recovery. However, in certain cases, a high tibial osteotomy can realign the knee by wedge-opening the top part of the tibia to reposition the knee joint, relieving pressure from the injured side. Then, the burden of bearing shifts from the unhealthy tissue to the injured or worn tissue.

This sort of osteotomy is normally thought of as a technique to delay the need for a knee replacement because these advantages typically disappear after 8 to 10 years. Younger individuals who experience discomfort from instability and misalignment are often the only ones who benefit from this therapy. To allow cartilage repair tissue to develop without being put under too much strain, an osteotomy may also be carried out in combination with other joint preservation techniques.

Conclusion

An HTO (high tibial osteotomy) is a surgical technique that realigns the knee joint. For individuals with knee arthritis, it is a blessing since it can postpone or eliminate the need for a partial or full knee replacement. It is always advisable to seek medical help from an experienced orthopaedist. Timely care and help can ensure an appropriate diagnosis and treatment of your condition. 

At the CK Birla Hospital, we ensure patients get holistic medical support which includes treatment in a compassionate environment. This patient-centric approach not only helps patients heal better but also ensures they are aware of the preventive measures as well. In case you need to consult an orthopaedist, reach out to us, or book a direct appointment with Dr. Chirag Arora at the CK Birla Hospital.

FAQs

Is a High Tibial Osteotomy a Major Surgery?

A high tibial osteotomy (HTO) is a major surgical procedure that improves the condition of the knee joint. It is also less of an intervention compared to a total knee replacement. 

Can You Walk After a High Tibial Osteotomy?

Following surgery, you must utilise crutches for 12 weeks while wearing your brace for 6 weeks. You progressively put more weight on your leg during the second six weeks while continuing to use crutches as protection. Before progressively increasing the weight you bear on your leg, an x-ray is done at six weeks to monitor bone repair.