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Osteotomy

Osteotomy is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Osteotomy rather than just read about it. In short: An osteotomy is a surgical operation whereby a bone is cut to shorten or lengthen it or to change its alignment. It is sometimes performed to correct a hallux valgus, or to straighten a bone that has healed crookedly following a fracture.

Osteotomy — main illustration
Osteotomy — illustration

Key takeaways

  • Osteotomy belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Osteotomy to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Osteotomy from memory before moving on to harder problems.

Reference excerpt

An osteotomy is a surgical operation whereby a bone is cut to shorten or lengthen it or to change its alignment. It is sometimes performed to correct a hallux valgus, or to straighten a bone that has healed crookedly following a fracture. It is also used to correct a coxa vara, genu valgum, and genu varum. The operation is done under a general anaesthetic. Osteotomy is one method to relieve pain of arthritis, especially of the hip and knee. It is being replaced by joint replacement in the older patient. Due to the serious nature of this procedure, recovery may be extensive. Careful consultation with a physician is important in order to ensure proper planning during a recovery phase. Tools exist to assist recovering patients who may have non–weight bearing requirements and include bedpans, dressing sticks, long-handled shoe-horns, grabbers/reachers and specialized walkers and wheelchairs.

Osteotomies of the hip

Two main types of osteotomies are used in the correction of hip dysplasias and deformities to improve alignment/interaction of acetabulum – (socket) – and femoral head (femur head) – (ball), innominate osteotomies and femoral osteotomies. The bones are cut, reshaped or partially removed to realign the load-bearing surfaces of the joint.

Adjustments are made to part of the hip-bone. Many operating methods and variations have been developed. They are defined by the type of cut and adjustment made. Some acetabular procedures are named after the surgeons who first described them as Salter (R. Salter), Dega (W. Dega), Sutherland (D.H. Sutherland), Chiari (K. Chiari): other names one may encounter are Ludlov, P. Pemberton, and James B. Steele. Some are named after the shape of cut (e.g. Chevron, Wedge) or the way the bones are aligned (Dial=old style rotary dial phone). A femoral derotation osteotomy can be performed to correct version abnormalities such as excessive anteversion or retroversion of the hip joint. Excessive anteversion of the femur results in anterior instability of the hip joint while excessive retroversion results in femoroacetabular hip impingement. A subtrochanteric blade plate or an intramedullary rod can be used to stabilize the osteotomy site in a femoral derotation osteotomy until compete bone healing is achieved; an approach employing an intramedullary rod is much less invasive than one using a subtrochanteric blade plate. Femoral osteotomies, as the name indicates, involves adjustments made to the femur head and/or the femur.

Osteotomy of the knee

Knee osteotomy is commonly used to realign arthritic damage on one side of the knee. The goal is to shift the patient's body weight off the damaged area to the other side of the knee, where the cartilage is still healthy. Surgeons remove a wedge of the tibia from underneath the healthy side of the knee, which allows the tibia and femur to bend away from the damaged cartilage. A model for this is the hinges on a door. When the door is shut, the hinges are flush against the wall. As the door swings open, one side of the door remains pressed against the wall as space opens up on the other side. Removing just a small wedge of bone can "swing" the knee open, pressing the healthy tissue together as space opens up between the femur and tibia on the damaged side so that the arthritic surfaces do not rub against each other. Osteotomy is also used as an alternative treatment to total knee replacement in younger and active patients. Because prosthetic knees may wear out over time, an osteotomy procedure can enable younger, active osteoarthritis patients to continue using the healthy portion of their knee. The procedure can delay the need for a total knee replacement for up to ten years.

Surgery The location of the removed wedge of bone depends on where osteoarthritis has damaged the knee cartilage. The most common type of osteotomy performed on arthritic knees is a high tibial osteotomy, which addresses cartilage damage on the inside (medial) portion of the knee. The procedure usually takes 60 to 90 minutes to perform. During a high tibial osteotomy, surgeons remove a wedge of bone from the outside of the knee, which causes the leg to bend slightly inward. This resembles the realigning of a bowlegged knee to a knock-kneed position. The patient's weight is transferred to the outside (lateral) portion of the knee, where the cartilage is still healthy. After regional or general anesthesia is administered, the surgical team sterilizes the leg with antibacterial solution. Surgeons map out the exact size of the bone wedge they will remove, using an X-ray, CT scan, or 3D computer modeling. A four- to five-inch incision is made down the front and outside of the knee, starting below the kneecap and extending below the top of the shinbone.Guide wires are drilled into the top of the shinbone (tibia plateau) from the outside (lateral side) of the knee. The wires usually outline a triangle form in the shinbone. A standard oscillating saw is run along the guide wires, removing most of the bone wedge from underneath the outside of the knee, below the healthy cartilage. The cartilage surface on the top of the outside (lateral side) of the shinbone is left intact. The top of the shinbone is then lowered on the outside and attached with surgical staples or screws, depending on the size of the wedge that was removed. The layers of tissue in the knee are stitched together, usually with absorbable sutures.

Rehabilitation and prevention A fall or torque to the leg during the first two months after surgery may jeopardize healing. Patients must exercise extreme caution during all activities, including walking, until healing is complete. After rehabilitation, preventing osteoarthritis involves slowing the progression and spread of the disease. Maintaining aerobic cardiovascular fitness has been an effective method for preventing the progression of osteoarthritis. Light, daily exercise is much better for an arthritic knee than occasional, heavy exercise. It is especially important to avoid any serious knee injuries, such as torn ligaments or fractured bones, because arthritis can complicate knee injury treatment. High-impact or repetitive stress sports, like football and distance running, should be avoided. Because osteoarthritis has multiple causes and may be related to genetic factors, no universal prevention tactic exists. General recommendations include:

… excerpt ends here. Continue reading the full article.

Illustrations

Osteotomy: a. X-ray of a hip after capsulorrhaphy and Dega surgery.b. Same hip after addition of Chiari medial displacementosteotomy.[4]
a. X-ray of a hip after capsulorrhaphy and Dega surgery.b. Same hip after addition of Chiari medial displacementosteotomy.[4]
Osteotomy: Valgus osteotomy. The black line is the mechanical axis.
Valgus osteotomy. The black line is the mechanical axis.

Worked examples

Example 1 — a first encounter with Osteotomy

Start with the simplest possible case. Write down what Osteotomy claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Osteotomy before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Osteotomy ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Osteotomy

In research
Osteotomy appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Osteotomy in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Osteotomy is common in secondary-school and first-year university syllabi. It links to neighbouring topics Oral and maxillofacial surgery, Orthopedic surgical procedures, so understanding it makes those chapters shorter.
In everyday life
Look for Osteotomy outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Osteotomy in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Osteotomy means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Osteotomy out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Osteotomy in simple terms?

An osteotomy is a surgical operation whereby a bone is cut to shorten or lengthen it or to change its alignment. It is sometimes performed to correct a hallux valgus, or to straighten a bone that has healed crookedly following a fracture.

Why does Osteotomy matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Osteotomy?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Osteotomy.

Tags

  • Oral and maxillofacial surgery
  • Orthopedic surgical procedures

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