Novel Surgical Approach to Knee Flexion Contractures May Reduce Complications

Research study background

Orthopedic surgeons at Children’s Hospital Colorado have developed a novel operative approach to correcting knee flexion contractures and crouch gait, progressive complications commonly seen in children with orthopedic conditions, such as cerebral palsy and spina bifida. Traditionally, anterior distal femoral hemiepiphysiodesis (ADFH) procedures are performed using an antegrade approach, in which surgical hardware is inserted into the femur near the knee, across the growth plate from above. Although effective and low risk, this technique requires inserting two screws through substantial soft tissue, which makes direct alignment with the femur’s natural axis more difficult.

Seeking to improve upon this method, our orthopedic surgeons pioneered the retrograde approach, in which two screws are inserted across the growth plate through the knee joint. This creates a shorter path through soft tissue and a broader surface entry point, simplifying both insertion and removal of surgical hardware. Although other institutions have begun to adopt the retrograde approach, Children’s Colorado is currently the only center using it routinely.

In an effort to compare the two approaches, experts in the Orthopedics Institute at Children’s Colorado examined surgical times, knee extension angles and complication rates. Their retrospective study reviewed 28 patients who underwent ADFH at Children’s Colorado between 2009 and 2023. Of these patients, 12 had the antegrade approach and 16 had the retrograde approach. The antegrade technique was performed by a single surgeon, while several surgeons performed the retrograde technique. The team reported these findings in a recent issue of the Journal of Pediatric Orthopedics.

“Typically, ADFH is performed as part of a multilevel surgery, so efficiency of procedures is important to reduce overall operative time and complication probability for the patient,” says Jason Rhodes, MD, pediatric orthopedic surgeon and co-senior author.

Overall, there were no significant differences between the two methods. The retrograde ADFH had a slightly faster insertion time than antegrade ADFH (24 to 141 minutes compared to 54 to 144 minutes). Hardware removal time was slightly faster in retrograde ADFH (16 to 91 minutes compared to 20 to 322 minutes). The general complication rate was the same for both at 3.6%.

Both approaches were found to be effective, demonstrating improvements in knee extension at patients’ two-year follow up visits. The study authors noted that the retrograde ADFH may have allowed for these improvements with fewer complexities related to insertion and removal, highlighting its efficacy as an alternative surgical technique.

Relevance to practice

A related case report, published in late 2024, offered additional detail on the successful surgical course and recovery of a 13-year-old boy with cerebral palsy who underwent a bilateral retrograde ADFH at Children’s Colorado. At the two-year follow-up appointment, he achieved full active knee extension, lower extremity function improvement and experienced no surgical complications.