Closing wedge distal femoral osteotomy (CWDFO) is a key surgical procedure for correcting knee deformities and improving joint alignment. However, a significant challenge associated with this technique has traditionally been the high rate of hinge fractures, which can compromise the stability of the osteotomy and negatively impact patient recovery. A recent study, published in Knee Surgery, Sports Traumatology, Arthroscopy, presents a promising new approach that may significantly reduce this risk, enhancing the safety and efficacy of CWDFO.
The Challenge of Hinge Fractures in CWDFO
Hinge fractures are a well-documented complication of CWDFO, an operation used to realign the limb and shift the load from a damaged area of the knee to a healthier one. When a fracture occurs at the hinge site, it can lead to instability, delayed bone healing, and a loss of the desired correction. For surgeons and patients alike, mitigating this risk is a top priority, as it directly influences the speed of recovery and the long-term success of the osteotomy. The study highlights a clear need for refined surgical techniques that can maintain the integrity of the hinge while achieving proper alignment.
A Novel Technique for Enhanced Stability
The retrospective study analysed 39 consecutive cases where a specific surgical technique was employed to address this issue. The key innovation was the distal placement of the hinge site, positioned at the inferior margin of the metaphyseal flare, below the origin of the gastrocnemius muscle. This new hinge location, combined with the use of a hinge wire, was designed to reduce stress on the bone during the procedure. The hinge was created with a thickness of 10 mm, meticulously planned to ensure a robust connection while allowing for the necessary bone correction.
This approach is particularly noteworthy for its focus on biomechanics. By moving the hinge to a stronger, more stable area of the bone and using a protective wire, surgeons can better control the osteotomy, minimising the risk of an unintended fracture. This improved control is crucial for achieving the precise alignment needed to offload the knee joint effectively.
Positive Outcomes and Accelerated Recovery
The results of the study were highly encouraging. The observed hinge fracture rate was just 7.69%, a significant improvement over traditionally reported rates. Furthermore, all patients who experienced a fracture went on to achieve union, demonstrating that even when a fracture occurred, the stability provided by the technique allowed for successful healing. All patients in the study were able to progress to weight-bearing as tolerated by two months post-osteotomy, indicating a faster and more effective recovery compared to historical benchmarks.
This research provides compelling evidence that a modified CWDFO technique with a distally placed hinge and protective wire is a reliable method for minimising hinge fractures. The findings offer valuable guidance for orthopaedic surgeons seeking to improve their surgical practice and, most importantly, deliver better outcomes for their patients.
Professor Wilson’s Comments
“We first introduced the hinge wire concept for use in opening wedge high tibial osteotomy surgery, and later applied the same principle to distal femoral osteotomy, where it provides equally important protection to the hinge.
This is particularly valuable in the femur, as hinge fractures are more common in this location and can lead to significant complications for both the patient and the surgeon if not adequately stabilised.
Building on this concept, we went on to develop the hinge screw, which has now become a recognised standard of care in osteotomy surgery worldwide, offering even greater stability and protection of the hinge during early mobilisation.”
To get the full picture of the study’s data and methodology, we recommend consulting the complete research paper:Distalization of Hinge Site with Use of Hinge Wire Reduces Hinge Fracture Rates in Closing Wedge Distal Femoral Osteotomy.
