Distal Femoral Osteotomy
A realignment procedure to correct knock-knees and relieve pressure on the outer knee joint
A distal femoral osteotomy (DFO) is a surgical procedure designed to correct alignment issues in the knee, particularly for patients with valgus deformity, commonly known as “knock knees.” This condition occurs when the femur (thighbone) angles inward, causing uneven wear on the knee joint, typically affecting the outer (lateral) compartment. Over time, this misalignment can lead to pain, reduced mobility, and the development of osteoarthritis in the affected knee compartment.
DFO aims to redistribute the load across the knee joint by realigning the femur, shifting the weight-bearing axis away from the damaged or arthritic part of the knee and onto healthier cartilage. This procedure can effectively relieve pain, improve function, and delay or even prevent the need for a total knee replacement, particularly in younger, more active patients.
INDICATIONS FOR DISTAL FEMORAL OSTEOTOMY SURGERY
A distal femoral osteotomy is typically recommended for patients who:
- Have Valgus Deformity (Knock Knees): The primary indication for DFO is a valgus deformity where the knee joint is misaligned, causing excessive stress on the lateral compartment of the knee.
- Suffer from Lateral Compartment Osteoarthritis: DFO is particularly effective for patients with early to moderate osteoarthritis that is confined to the outer side of the knee.
- Experience Knee Pain and Instability: Patients who experience persistent pain and instability due to knee malalignment may benefit from a DFO to restore proper joint function.
- Wish to Preserve Their Natural Knee Joint: For younger, active individuals, DFO offers an alternative to knee replacement surgery, allowing them to maintain their natural knee joint and remain active for many more years.
DISTAL FEMORAL OSTEOTOMY FOR LIGAMENT TEARS
Distal femoral osteotomy (DFO) is often performed in conjunction with the treatment of chronic medial collateral ligament (MCL) or anterior cruciate ligament (ACL) tears, particularly in cases where knee malalignment, such as valgus deformity (“knock knees”), is present.
For patients with chronic MCL tears that cause ongoing symptoms, research indicates that those with valgus alignment face a significantly higher risk of graft stretching or failure following MCL reconstruction if the underlying malalignment is not corrected. To address this, performing a DFO at the same time as MCL reconstruction has been shown to be effective, avoiding the need for multiple separate surgeries.
In patients with ACL deficiencies, especially those with substantial arthritis in the lateral compartment of the knee and valgus alignment, a combined approach involving ACL reconstruction and DFO may be recommended. Some patients may also require cartilage replacement surgery or a lateral meniscal transplant alongside their ACL reconstruction.
For these patients, correcting the valgus alignment with a concurrent or staged DFO is crucial to optimise the success and longevity of the cartilage repair or meniscal transplant. By realigning the knee, DFO helps to reduce the stress on the repaired structures, giving them the best chance for a successful long-term outcome.
DISTAL FEMORAL OSTEOTOMY FOR OSTEOARTHRITIS
A distal femoral osteotomy (DFO) is an effective surgical option for treating osteoarthritis in patients who have developed arthritis on the outer (lateral) side of the knee and whose knee alignment has shifted into a valgus position, commonly known as “knock knee.” This procedure is particularly beneficial when the cartilage and meniscus on the inner (medial) side of the knee are still in good condition. By shifting the weight-bearing axis from the worn outer compartment to the healthier inner compartment, DFO can significantly relieve pain and improve function.
Typically, candidates for DFO are between the ages of 16 (once growth plates have closed) and 55, as this age range is optimal for the procedure’s success. The evaluation process includes long-leg X-rays to confirm valgus alignment and knee malalignment. Additionally, an MRI or arthroscopy may be performed to ensure that the cartilage and meniscus on the medial side of the knee are intact, and that the knee ligaments are either intact or can be reconstructed concurrently or after the osteotomy.
As part of the diagnostic workup, patients may be fitted with a lateral compartment unloader brace to assess whether shifting weight off the lateral compartment provides pain relief. Patients who experience significant pain relief with the brace often achieve similar or better outcomes following a distal femoral osteotomy. This makes DFO a strong option for patients with valgus knee alignment and lateral compartment osteoarthritis.
THE DISTAL FEMORAL OSTEOTOMY SURGICAL PROCEDURE
There are two main surgical techniques for a distal femoral osteotomy. These are the lateral opening wedge osteotomy, whereby a bone wedge is placed into the outside portion of the femur to change the alignment or a closing wedge medial distal femoral osteotomy, whereby a bone wedge is taken out and the bone is collapsed down to change the alignment.
Regardless of the technique used, a DFO is a highly specialised procedure that requires precise planning and execution by an experienced joint preservation surgeon, using advanced techniques to ensure the best possible outcome for you
The procedure involves the following steps:
Before surgery, detailed imaging studies, such as X-rays and CT scans, are performed to assess the degree of knee misalignment and to plan the osteotomy. Dr Liddell uses this information to design a custom surgical plan tailored to your specific anatomy.
Under general or spinal anaesthesia, Dr Liddell makes an incision on the outer side of the femur near the knee joint. A precise cut (osteotomy) is made in the femur, allowing the bone to be realigned. Depending on your condition, Dr Liddell with use either an open wedge or closed wedge technique to correct the alignment.
Once the bone is realigned, the osteotomy is stabilised using a metal plate and screws. This fixation holds the bone in its new position while it heals. In some cases, a bone graft may be used to fill any gaps created during the osteotomy, especially if significant correction is needed.
After the surgery, the incision is closed, and a dressing is applied. The patient is then taken to the recovery area, where they are monitored until they wake up from the anaesthesia.
RECOVERY FOLLOWING DISTAL FEMORAL OSTEOTOMY
Recovery from a DFO requires a commitment to rehabilitation and follow-up care to ensure proper healing and the best possible outcomes.
The general recovery timeline includes:
In the first few days following surgery, the knee will be protected with a brace, and weight-bearing will be limited. Crutches are typically used to assist with mobility, and pain management will be provided as needed. It’s crucial to keep the incision site clean and dry during this period to prevent infection.
During this phase, you will begin a guided physiotherapy program focusing on restoring knee mobility and strength. Gentle range-of-motion exercises will be introduced, and weight-bearing will gradually increase as the knee heals. X-rays may be taken to monitor the progress of bone healing.
As the knee continues to heal, more intensive physiotherapy exercises will be introduced to build strength and improve stability. Full weight-bearing is usually allowed by this stage, and patients will work on regaining full knee function.
Most patients can expect to return to normal daily activities within 3 to 6 months, although high-impact activities should be approached cautiously and only after Dr Liddell’s approval. Follow-up appointments and X-rays will ensure that the osteotomy site has fully healed.
LONG-TERM BENEFITS OF DISTAL FEMORAL OSTEOTOMY
The primary goal of DFO is to preserve the natural knee joint by correcting misalignment and reducing pressure on the damaged compartment. By realigning the knee, this procedure can significantly reduce pain, improve function, and delay the need for a knee replacement, allowing patients to maintain an active lifestyle for many years.
DFO is particularly beneficial for younger, active patients who wish to avoid or delay knee replacement surgery. By addressing the root cause of the problem—knee malalignment—DFO offers a long-term solution that can enhance joint function and quality of life.If you are experiencing knee pain due to valgus deformity or lateral compartment osteoarthritis, and are considering a distal femoral osteotomy, Dr Liddell can guide you through the process. He will work with you to develop a customised treatment plan that meets your specific needs and helps you achieve long-lasting relief from knee pain.