High tibial osteotomy is an orthopaedic surgical procedure which aims to correct a varus deformation with compartmental

osteoarthritis Osteoarthritis (OA) is a type of degenerative joint disease that results from breakdown of joint cartilage and underlying bone which affects 1 in 7 adults in the United States. It is believed to be the fourth leading cause of disability in the w ...

. Since the inception of the procedure, advancements to technique, fixation devices, and a better understanding of patient selection has allowed HTO to become more popular in younger, more active patients hoping to combat

arthritis Arthritis is a term often used to mean any disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, swelling, and decreased range of motion of the affected joints. In som ...

. The idea behind the procedure is to realign the weight-bearing line of the

knee In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia (tibiofemoral joint), and one between the femur and patella (patellofemoral joint). It is the largest joint in the hu ...

. By realigning the

, the force produced from weight-bearing is shifted from the arthritic, medial compartment to the healthy, lateral compartment. This decrease in force or load in the diseased part of the

knee joint In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia (tibiofemoral joint), and one between the femur and patella (patellofemoral joint). It is the largest joint in the hu ...

decreases knee pain and can delay the development or progression of

in the medial compartment.

Patient selection

The accepted protocol used for patient selection was developed in 2004 by the International Society of Arthroscopy, Knee Surgery, and Orthopedic Sports Medicine (ISAKOS). According to this protocol, an ideal patient is: * Moderately active * Between 40 and 60 years old * Experiencing isolated medial joint line tenderness * BMI <30 * Malalignment <15° * Tibia bone varus angle >5° * Full range of motion in the

* Near-normal lateral and patellofemoral compartments without ligamentous instability * A non-smoker Contraindications specified by ISAKOS are: * Patients older than 65 * Severe

of the medial compartment (Ahlback grade III or higher) * Tricompartmental

* Patellofemoral

* Range of motion in the

<120° * Flexion contracture >5° * Diagnosed inflammatory arthritis * A large area of exposed bone on the tibial or femoral articular surface (> 15x15 mm) * Heavy smokers

Surgical technique

The general surgical technique includes either performing HTO alone or performing HTO in combination with

ligament A ligament is the fibrous connective tissue that connects bones to other bones. It is also known as ''articular ligament'', ''articular larua'', ''fibrous ligament'', or ''true ligament''. Other ligaments in the body include the: * Peritoneal li ...

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

and malalignment, HTO alone should be sufficient. However, if instability is the predominant symptom, in 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.

Lateral close wedge osteotomy

Starting at the anterolateral aspect about 1 cm below the joint line of the knee, an L-shaped cut is made to the lateral edge of the tibial tubercle and anterior tibial crest. To expose the bone, the

fascia A fascia (; plural fasciae or fascias; adjective fascial; from Latin: "band") is a band or sheet of connective tissue, primarily collagen, beneath the skin that attaches to, stabilizes, encloses, and separates muscles and other internal organs. ...

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 Bone grafting is a surgical procedure that replaces missing bone in order to repair bone fractures that are extremely complex, pose a significant health risk to the patient, or fail to heal properly. Some small or acute fractures can be cured wit ...

, unlike the medial open wedge method.

Medial open wedge osteotomy

The initial cut is made in between the posteromedial border of the

tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...

and medial aspect of the tibial tubercle. 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.

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 Nonunion is permanent failure of healing following a broken bone unless intervention (such as surgery) is performed. A fracture with nonunion generally forms a structural resemblance to a fibrous joint, and is therefore often called a "false joi ...

. 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 In vertebrate anatomy, hip (or "coxa"Latin ''coxa'' was used by Celsus in the sense "hip", but by Pliny the Elder in the sense "hip bone" (Diab, p 77) in medical terminology) refers to either an anatomical region or a joint. The hip region is ...

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.

Complications

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

Deep venous thrombosis Deep vein thrombosis (DVT) is a type of venous thrombosis involving the formation of a blood clot in a deep vein, most commonly in the legs or pelvis. A minority of DVTs occur in the arms. Symptoms can include pain, swelling, redness, and enla ...

* Superficial wound infection *

Hematoma A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillary, capillaries. A he ...

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

References

External links

* * *{{cite journal, pmid=2922190, year=1989 , last1=Koshino , first1=T. , last2=Morii , first2=T. , last3=Wada , first3=J. , last4=Saito , first4=H. , last5=Ozawa , first5=N. , last6=Noyori , first6=K. , title=High tibial osteotomy with fixation by a blade plate for medial compartment osteoarthritis of the knee , journal=The Orthopedic Clinics of North America , volume=20 , issue=2 , pages=227–243 Orthopedic surgical procedures