Triple arthrodesis is a major surgical procedure used to address severe pain and deformity within the hindfoot, which is the back section of the foot. The term “arthrodesis” refers to the surgical fusion of a joint. This fusion creates a single, stable bone structure where there was once painful or unstable motion, offering a definitive treatment when non-surgical methods have failed to provide relief. This operation is typically reserved for advanced conditions that affect the foot’s structural integrity and overall function.
Anatomy of the Fusion
The procedure derives its name from the three specific joints in the hindfoot that are fused together. These joints include the subtalar, the talonavicular, and the calcaneocuboid joints, all of which are part of the complex mid- and hindfoot structure. The subtalar joint sits directly below the ankle joint and is primarily responsible for the side-to-side rocking motion of the foot, known as inversion and eversion. The talonavicular joint and the calcaneocuboid joint are situated forward of the subtalar joint and together form the transverse tarsal joint. These two joints are instrumental in allowing the foot to adapt to uneven terrain, helping to lock or unlock the midfoot for flexibility or rigidity as needed. By fusing these three joints, the surgeon eliminates the source of painful motion and corrects severe, fixed deformities of the hindfoot.
Conditions Treated by the Procedure
A primary indication is advanced arthritis, whether it is degenerative osteoarthritis from wear and tear or inflammatory rheumatoid arthritis, affecting the involved joints. Fusion provides pain relief by eliminating the bone-on-bone friction that occurs when damaged cartilage is completely worn away. The surgery is also frequently performed to correct severe, non-correctable deformities, such as end-stage flatfoot deformity (pes planus) or a high-arched foot (pes cavus). In these cases, the fusion stabilizes the foot in a corrected position that allows for more normal walking mechanics. Additionally, neuromuscular deformities, such as those caused by Charcot arthropathy or residual effects from conditions like poliomyelitis, often lead to instability that only fusion can adequately address.
Details of the Operation
The procedure is typically performed through two separate incisions on the side of the foot to allow the surgeon access to all three joint surfaces. Once the joints are exposed, the surgeon carefully removes the remaining cartilage and a thin layer of underlying bone from the surfaces of the talus, calcaneus, cuboid, and navicular bones. During the operation, the foot is meticulously realigned to a functional, neutral position before the bones are permanently joined. To hold the bones together while the fusion process takes place, internal fixation hardware is used, such as screws, plates, or surgical staples. A bone graft, which may be taken from the patient’s own body (autograft) or from a donor (allograft), is often packed into the joint spaces to stimulate and accelerate the natural healing process; the entire surgical procedure generally takes between two and three hours, after which the foot is placed into a splint or cast for immediate immobilization.
Post-Surgical Recovery and Rehabilitation
Patients are typically immobilized in a cast or splint for the first two to four weeks post-operation, and they must use crutches or a knee scooter for mobility. The non-weight bearing period generally lasts from six to 12 weeks, with the exact duration determined by the surgeon based on radiographic evidence of bone healing. Once initial healing is confirmed by X-ray, the patient transitions to a partial weight-bearing phase, often utilizing a protective walking boot. This gradual increase in load is critical to ensure the developing bone bridges are not fractured. Full radiographic confirmation of a solid fusion can take three to six months, though the foot will continue to remodel and improve for up to a year. Physical therapy plays a substantial role in this later stage, focusing on strengthening the surrounding muscles and re-establishing a natural gait pattern. Full return to activities, such as manual labor or sports, is a prolonged process.