Illustration of leg straightening after knee osteotomy surgery

Straightening the Curve: Can a Simple Osteotomy Fix Genu Valgum?

Lena Voss in Health & Wellness December 2025 • 4 min read.

"Discover how a lateral open-wedge distal femoral osteotomy can correct genu valgum, improve knee function, and potentially enhance patella stability without needing bone grafts."

Osteotomies around the knee serve as a well-established solution for addressing varus and valgus malalignment in the lower extremity. These procedures work by shifting the mechanical axis, transferring weight from a damaged compartment to a healthier one. In cases where symptoms are absent, knee osteotomies can also restore a more natural mechanical axis, which helps to prevent further joint damage.

The type of corrective osteotomy performed—whether on the proximal tibia or distal femur—depends on the origin of the deformity, as determined by a malalignment test. For valgus malalignment cases with a reduced mechanical lateral distal femoral angle (mLDFA), a distal femur osteotomy using an opening wedge technique is often employed.

While the open-wedge technique is commonly used for tibial correction of varus deformities, its application in femoral corrections has been a subject of debate. However, a new study analyzes the outcomes of patients treated with lateral opening wedge distal femoral osteotomy (LOWDFO), focusing on bone healing without grafting and considering the impact of patient age. This article unpacks the key findings of this research for you.

LOWDFO: A Reliable Solution Without Bone Grafting?

Illustration of leg straightening after knee osteotomy surgery

The study retrospectively analyzed twenty-two consecutive patients with genu valgum. These patients underwent twenty-three LOWDFOs using a Tomofix-locking plate. The average patient age was 23.7 years. Researchers evaluated clinical outcomes using pre- and post-operative Knee injury and Osteoarthritis Outcome Scores (KOOS) and radiographic assessments, including mechanical axis deviation (MAD), mechanical lateral distal femoral angle (mLDFA), leg length discrepancy (LLD), bone healing, and patella parameters.

The results indicated that restoration of MAD and mLDFA led to significantly improved post-operative KOOS5 scores in both younger and older patients (p = 0.001). Importantly, bone healing was reliable in all patients, even without bone grafting. The procedure also resulted in a significant increase in leg length post-operatively (p = 0.001) and improved patella height, as indicated by a reduced Blackburne-Peel ratio (p < 0.001).

Improved Knee Function: Significant improvements were observed in KOOS scores, indicating better overall knee function.
Reliable Bone Healing: Bone grafting wasn't necessary for reliable bone healing, simplifying the procedure.
Leg Length Correction: The surgery led to a measurable increase in leg length, which can be beneficial for patients with discrepancies.
Patella Stability: Changes in the Blackburne-Peel ratio suggest potential for increased patella stability.

These findings suggest that LOWDFO without bone grafting is a reliable and promising treatment option, especially for younger patients with genu valgum. Beyond correcting the mechanical axis deviation, the procedure offers the potential for leg length increase and improved patella stability.

LOWDFO: A Promising Solution for Genu Valgum

The study's findings support the use of lateral opening wedge distal femoral osteotomy (LOWDFO) without bone grafting as a safe and effective method for correcting genu valgum, especially in younger patients. The procedure not only improves knee alignment and function but also offers potential benefits in terms of leg length correction and patella stability.

While the study acknowledges limitations such as its retrospective design and limited sample size, the results provide valuable insights for orthopedic surgeons and patients considering treatment options for genu valgum.

Further research with larger cohorts and prospective designs is encouraged to validate these findings and explore the long-term outcomes of LOWDFO without bone grafting.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1007/s00264-018-4216-0, Alternate LINK

Title: Distal Femoral Varus Osteotomy: Results Of The Lateral Open-Wedge Technique Without Bone Grafting

Subject: Orthopedics and Sports Medicine

Journal: International Orthopaedics

Publisher: Springer Science and Business Media LLC

Authors: Alexander Kolb, Verena Isak, Gerhard M. Hobusch, Catharina Chiari, Reinhard Windhager

Published: 2018-11-13

Everything You Need To Know

1

What is lateral opening wedge distal femoral osteotomy (LOWDFO)?

The lateral opening wedge distal femoral osteotomy (LOWDFO) is a surgical procedure designed to correct genu valgum, commonly known as knock-knee. This involves making a precise cut in the distal femur (the lower part of the thigh bone) and opening it up on the lateral (outer) side to realign the leg. The procedure aims to restore the mechanical axis of the leg, which is the line of force transmission through the knee, improving overall knee function and potentially preventing further joint damage.

2

Why is lateral opening wedge distal femoral osteotomy (LOWDFO) important?

The significance of lateral opening wedge distal femoral osteotomy (LOWDFO) lies in its ability to correct genu valgum, which is a common malalignment that can lead to knee pain, instability, and premature osteoarthritis. The study emphasizes the use of LOWDFO without bone grafting. It's particularly important because it offers a less invasive approach while still achieving reliable bone healing. This treatment is especially beneficial for younger patients as it addresses the malalignment and improves the overall knee function and patella stability, leading to enhanced long-term joint health.

3

What are the implications of having a lateral opening wedge distal femoral osteotomy (LOWDFO)?

The implications of undergoing lateral opening wedge distal femoral osteotomy (LOWDFO) are multifaceted. The procedure directly improves knee function, as evidenced by improved Knee injury and Osteoarthritis Outcome Scores (KOOS). It also corrects the mechanical axis deviation (MAD) and mechanical lateral distal femoral angle (mLDFA) improving leg alignment. Furthermore, the procedure can lead to increased leg length post-operatively and enhanced patella stability. By addressing these aspects, LOWDFO reduces pain, improves mobility, and potentially delays the onset of osteoarthritis, contributing to a better quality of life for the patient.

4

What did the study analyze in relation to lateral opening wedge distal femoral osteotomy (LOWDFO)?

The study analyzed the outcomes of patients treated with lateral opening wedge distal femoral osteotomy (LOWDFO). The study focused on a group of twenty-two consecutive patients with genu valgum who underwent twenty-three LOWDFOs. Researchers evaluated clinical outcomes using pre- and post-operative Knee injury and Osteoarthritis Outcome Scores (KOOS) and radiographic assessments, including mechanical axis deviation (MAD), mechanical lateral distal femoral angle (mLDFA), leg length discrepancy (LLD), bone healing, and patella parameters. These findings show that LOWDFO without bone grafting is a reliable and promising treatment option, especially for younger patients with genu valgum.

5

What were the main conclusions of the study regarding lateral opening wedge distal femoral osteotomy (LOWDFO)?

The study's findings support the use of lateral opening wedge distal femoral osteotomy (LOWDFO) without bone grafting as a safe and effective method for correcting genu valgum, especially in younger patients. The procedure not only improves knee alignment and function but also offers potential benefits in terms of leg length correction and patella stability. The study also emphasizes that the bone healing was reliable in all patients, even without bone grafting, and that the restoration of MAD and mLDFA led to significantly improved post-operative KOOS scores in both younger and older patients.