The Evans Osteotomy is a specialized surgical procedure performed on the foot, primarily to address deformities that affect its natural alignment. This operation involves a precise modification of the heel bone, known as the calcaneus. By carefully altering this bone, surgeons aim to restore proper foot structure and function, which can significantly improve a patient’s mobility and comfort. The procedure is named after Dr. Dillwyn Evans, who initially described this approach for treating foot deformities.
Understanding the Procedure
The Evans Osteotomy is designed to correct conditions like flexible flatfoot deformity, also known as pes planus or fallen arches. In this condition, the arch of the foot collapses when standing or walking, causing the front of the foot to splay outward, a problem called forefoot abduction. This misalignment can lead to discomfort, pain, and difficulty with daily activities. The procedure specifically lengthens the outer side of the heel bone, which is referred to as the lateral column of the foot.
Lengthening the lateral column helps realign the midtarsal joint and reduce the outward rolling of the heel bone, known as calcaneal eversion. This action also increases tension on the long plantar ligaments, contributing to arch elevation and stabilization. The Evans osteotomy corrects complex flatfoot deformities in both children and adults. It is considered when non-surgical treatments, such as custom orthotics and physical therapy, have not provided sufficient relief for individuals experiencing significant pain or functional limitations.
The Surgical Process
The Evans Osteotomy is performed under general anesthesia. A small incision is made on the outer side of the foot, near the calcaneocuboid joint, where the heel bone meets the cuboid bone of the midfoot. The surgeon accesses the calcaneus and makes a cut, or osteotomy, in the heel bone. This cut is made to prepare for lengthening.
After the bone is cut, the two pieces of the calcaneus are spread apart, creating an opening wedge. A bone graft or implant is then inserted into this wedge to lengthen the bone. This graft can be sourced from the patient’s own hip bone or from a donor. Once the desired lengthening and alignment are achieved, the bone graft is stabilized using fixation methods such as screws, plates, or pins. Over time, the graft will fuse with the calcaneus.
Recovery and Rehabilitation
Following an Evans Osteotomy, the foot is immobilized in a cast for six to twelve weeks. Stitches are removed within 10 to 14 days after surgery. Patients are advised to remain non-weight bearing during the first four weeks.
Around four weeks post-surgery, patients transition to a walking boot or supportive shoe, and light weight-bearing activities can begin. The transition to supportive shoes occurs around six weeks, with a gradual increase in activity levels. Physical therapy is initiated for gait training and strengthening exercises. Patients typically return to full activity around three months after the procedure, though individual recovery times can vary.
Potential Considerations
Undergoing an Evans Osteotomy offers several positive outcomes, including improved foot alignment, reduced pain, and improved foot function. By correcting the flatfoot deformity, the procedure creates a more stable and functional arch, alleviating discomfort during standing and walking. Patients experience a more normal foot appearance and improved ability to participate in daily activities.
Despite these benefits, risks are associated with any surgical procedure. These risks include infection, bone graft non-union, or nerve damage in the foot. Persistent pain or discomfort can occur even after surgery. A thorough discussion with a surgeon is important to understand the specific benefits and risks based on individual circumstances, ensuring informed decision-making regarding the procedure.