Modification of surgery used to correct flatfoot deformity may reduce pain and improve outcomes

Virginia Commonwealth University physicians and engineers studying foot and ankle biomechanics have developed a modification to a procedure used to correct adult-acquired flatfoot deformity that may reduce the pressure and pain that often persists after surgery.

In the May 1 issue of the journal Foot & Ankle International, a publication of the American Orthopaedic Foot and Ankle Society, researchers found that alone, medializing calcaneal osteotomy (MCO) - the bone surgery used to correct adult-acquired flatfoot deformity and reduce forefoot pain - results in increased pressure on the outer border of the forefoot. Therefore, researchers adjusted how they performed the bone surgery to improve patient outcomes and decrease the post-surgery discomfort and pain.

More than 5 million Americans suffer from posterior tibial tendon (PTT) dysfunction or adult-acquired flat foot deformity – a condition that may be caused by the stretching or tearing of the tendon. The PTT helps to support the arch of the foot and lift the heel off the ground when a person walks. Patients who suffer from the condition experience pain inside of the arch and outside of the ankle. Surgery can help to stabilize the foot and the ankle and prevent further damage.

“We wanted to determine if patients with this procedure shifted more weight on to the lateral border of their foot to account for some of their pain and discomfort following surgery,” said Robert Adelaar, M.D., the lead author of the study and the chair in the Department of Orthopaedic Surgery at the VCU Medical Center.

“We developed a modification of the calcaneal osteotomy which creates less foot pain following the procedure,” he said.

Adelaar and his team assessed the biomechanics of the MCO in a cadaver model and examined various components of the foot and ankle, including the Achilles tendon. The study showed that the calcaneal osteotomy shifted force to the outer border of the forefoot – which results in pain. By understanding these biomechanics of the foot and ankle, the team was able to modify the procedure.

Acquired adult flat foot deformity is more prevalent in women over 50, but can occur with anyone. Trauma or overuse of the PTT may lead to tearing or stretching of the tendon. In addition, other medical conditions such as obesity, diabetes, previous surgery and steroid injections may contribute to adult-acquired flatfoot deformity.

The condition is divided into three stages. In stage one, patients may experience pain, swelling and weakness to the tendon; in stage two, patients experience flattening of the foot arch, but the foot is still flexible; and in stage three, the flattening of the foot becomes rigid and patients may experience ankle pain.

Earlier this year, the VCU team was honored for this research with the Roger A. Mann Award for best clinical research presented at the Annual Meeting of the American Orthopaedic Foot and Ankle Society.

Jennifer Wayne, Ph.D., associate professor of biomedical engineering in the VCU School of Engineering, and Mark Hadfield, M.D., who is completing his orthopaedics residency, collaborated with Adelaar.