What is Knee Osteotomy?
The term “osteotomy” means “cutting of the bone.” In a knee osteotomy, either the tibia (shinbone) or the femur (thighbone) is surgically cut and reshaped to reduce pressure on one specific area of the knee joint.
This procedure is often recommended for patients with early-stage osteoarthritis that has affected only one side of the knee. By redistributing weight away from the damaged part of the joint, a knee osteotomy can effectively alleviate pain and enhance overall knee function, helping patients maintain an active lifestyle.
Description of Knee Osteotomy
Osteoarthritis often occurs when the bones of the knee and leg are misaligned, leading to uneven pressure on either the inner (medial) or outer (lateral) side of the knee joint. This imbalance increases stress on the affected side, gradually wearing down the protective articular cartilage. As the cartilage deteriorates, the exposed bones can cause pain, stiffness, and reduced mobility in the knee over time.
(Left) This X-ray of a healthy knee shows the normal joint space between the tibia and femur. (Right) In this X-ray, osteoarthritis has damaged the inside portion of the knee. The tibia and femur are rubbing against each other (blue arrow), causing pain.
Advantages and Disadvantages of Knee Osteotomy
Knee osteotomy aims to achieve three primary goals:
- Redistribute weight from the arthritic area of the knee to a healthier region.
- Correct poor knee alignment.
- Extend the functional lifespan of the knee joint.
Advantages
- Preservation of Natural Anatomy: A successful osteotomy maintains your natural knee structure and may delay the need for partial or total knee replacement for several years.
- Unrestricted Activity: Once healed, there are no restrictions on physical activities, including high-impact exercises, allowing you to return to your favorite pastimes.
Disadvantages
- Less Predictable Pain Relief: Compared to partial or total knee replacement, the pain relief achieved through osteotomy can vary.
- Longer Recovery Time: Recovery is typically more prolonged and challenging, as weight-bearing on the operated knee is restricted for approximately six weeks to allow proper healing.
- Future Knee Replacement Challenges: In some cases, having undergone an osteotomy can make subsequent total knee replacement surgery more complex.
Although knee osteotomy is less common today due to the success of partial and total knee replacements, it remains a valuable option for certain patients, particularly those with early-stage osteoarthritis affecting a single area of the knee.
Procedure for Knee Osteotomy
The majority of knee osteotomies performed for arthritis involve the tibia (shinbone) and aim to correct a bowlegged alignment, which places excessive stress on the inner (medial) compartment of the knee. This procedure is commonly referred to as a high tibial osteotomy (HTO).
First introduced in Europe in the 1950s and later adopted in the United States in the 1960s, this technique can be performed in two main ways:
- Medial Opening Wedge Osteotomy: A wedge of bone graft or synthetic material is added to the medial side of the tibia and secured with a plate and screws.
- Lateral Closing Wedge Osteotomy: A wedge of bone is removed from the lateral (outer) side of the tibia.
Both approaches serve to realign the leg by either opening the medial side or closing the lateral side, straightening the bone structure. This adjustment redistributes weight more evenly across the knee joint, reducing pressure on the damaged arthritic side and easing pain.
For cases where the knee has a knock-kneed alignment, an osteotomy of the femur (thighbone) may be performed using a similar technique.
Your orthopedic surgeon will discuss the specific method best suited to your condition and explain how it will address your unique alignment and arthritis issues.
In a tibial osteotomy, a wedge of bone is removed to straighten out the leg.
Candidates for Knee Osteotomy
Knee osteotomy is most suitable for thin, active individuals under 60 years of age. Ideal candidates typically exhibit the following characteristics:
- Pain localized to one side of the knee.
- No discomfort beneath the kneecap.
- Knee pain that primarily occurs during activity or prolonged standing.
- The ability to fully straighten the knee and bend it to at least 90 degrees.
Patients with rheumatoid arthritis are generally not good candidates for knee osteotomy. Your orthopedic surgeon will assess your condition to determine if this procedure is appropriate for your needs.
Preparing for Knee Osteotomy Surgery
Before Surgery
You will likely be admitted to the hospital on the day of your surgery.
- A doctor from the anesthesia team will evaluate your medical history and discuss anesthesia options. Choices typically include:
- General anesthesia, where you are completely asleep.
- Spinal anesthesia, where you remain awake but are numb from the waist down.
- Your surgeon will meet with you to review the procedure and mark the surgical site on your knee for verification.
Surgical Procedure
Knee osteotomy surgery usually takes 1 to 2 hours. The steps include:
- Incision: An incision is made at the front of the knee, starting below the kneecap.
- Planning: Guide wires are inserted to determine the exact size and location of the bone wedge.
- Bone Adjustment: Using an oscillating saw, the surgeon cuts along the guide wires and either inserts or removes a wedge of bone, depending on the chosen technique (opening or closing wedge).
- Stabilization: A plate and screws are used to secure the bones, keeping them in place as the osteotomy heals.
Your surgeon will use precise planning and techniques to ensure proper realignment of your knee joint, improving function and relieving pain.
After the surgery, you will be taken to the recovery room where you will be closely monitored as you recover from the anesthesia.
Complications of Knee Osteotomy
As with any surgical procedure, knee osteotomy carries certain risks. Your surgeon will carefully explain these risks and take precautions to minimize them. While complications are uncommon, the most frequent ones include:
- Infection
- Blood clots
- Stiffness in the knee joint
- Injuries to blood vessels or nerves
- Failure of the osteotomy to heal
In rare cases, a second surgery may be necessary, particularly if the osteotomy does not heal as expected.
Recovery After Knee Osteotomy
Hospital Discharge
Most patients are discharged from the hospital 1 to 2 days after surgery.
Pain Management
Postoperative pain is expected, but your medical team will use various methods to ensure your comfort. Pain control is essential for a faster recovery and improved healing. Options include:
- Opioids: Effective for pain relief but should be used strictly as directed due to their addictive potential. Stop using them as soon as your pain begins to improve.
- Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) and local anesthetics: These can also help manage pain effectively.
Weight-Bearing and Protection
You will likely need crutches for several weeks following surgery. Your knee may also be placed in a brace or cast for added protection while the bone heals. Your surgeon will provide detailed instructions on when you can begin weight-bearing activities.
Follow-Up Visits
A follow-up appointment with your surgeon will include X-rays to evaluate the healing process. Based on these results, your surgeon will guide you on when it is safe to start putting weight on your leg and beginning rehabilitation.
Rehabilitation Exercises
Physical therapy will focus on exercises to maintain knee range of motion and restore strength. This is a crucial step in regaining functionality.
Full Recovery Timeline
Most patients can resume full activities within 3 to 6 months after surgery.
Outcome of Knee Osteotomy
For many patients, a knee osteotomy successfully alleviates pain and slows the progression of arthritis, allowing younger individuals to lead more active lives for years. While a total knee replacement may eventually be required, an osteotomy can effectively delay the need for joint replacement surgery, preserving natural knee function in the meantime.