Triple arthrodesis is a surgical procedure designed to permanently fuse three specific joints in the hindfoot and midfoot region to relieve chronic pain and correct severe deformities. The primary goal of this intervention is to stabilize the foot, creating a solid, plantigrade base that allows for pain-free walking when non-surgical treatments have failed. This procedure is not typically a first-line treatment but is reserved for end-stage conditions that have significantly impaired a person’s quality of life and mobility.
Conditions Requiring Triple Arthrodesis
Patients are candidates for this surgery when they suffer from severe, debilitating foot conditions that have not responded to conservative management like bracing, physical therapy, or injections. One of the most common reasons is severe pes planus, often referred to as flatfoot deformity, which causes chronic pain and progressive instability. This often occurs alongside advanced posterior tibial tendon dysfunction, where the main stabilizing tendon of the arch fails.
The procedure is frequently indicated for various forms of end-stage arthritis affecting the hindfoot joints, including degenerative, post-traumatic, or rheumatoid arthritis. Neuromuscular disorders that lead to muscle imbalance and foot instability, such as Charcot-Marie-Tooth disease, cerebral palsy, or polio, may also necessitate this fusion. Furthermore, complex deformities like rigid cavus foot (high arch) or Charcot arthropathy are often treated with triple arthrodesis to restore a stable alignment.
Details of the Surgical Procedure
The “triple” aspect of the surgery involves fusing three distinct joints: the subtalar joint, the talonavicular joint, and the calcaneocuboid joint. The subtalar joint, also known as the talocalcaneal joint, is located directly below the ankle and contributes significantly to side-to-side foot motion. The talonavicular joint and the calcaneocuboid joint together form the transverse tarsal joint complex, which is located in the midfoot.
The surgeon typically makes two incisions to access all three joints. The procedure involves removing all remaining articular cartilage from the surfaces of the three bones that meet at each joint. This removal exposes the bleeding subchondral bone, which is essential for promoting a successful bony fusion.
The foot is then manually positioned into the desired, corrected alignment, aiming for a neutral heel position and a stable base for walking. To encourage the bones to grow together, bone graft material is often packed into the spaces between the prepared joint surfaces. Final fixation is achieved using specialized hardware, such as screws, plates, or staples, which compress and hold the bones firmly in place until they fuse into a single solid structure.
Post-Surgical Recovery and Rehabilitation
The initial stage of recovery focuses on protecting the surgical site and achieving bony union, which is the complete fusion of the three joints. Immediately after the procedure, the foot is immobilized in a splint or cast and must be kept elevated to manage post-operative swelling and pain. Patients are strictly non-weight bearing on the operated limb for a period that typically lasts between six and twelve weeks.
The non-weight bearing phase is essential for successful fusion, as putting pressure on the joints too early can lead to hardware failure or a non-union, where the bones fail to fuse. Around six to eight weeks post-surgery, X-rays are taken to assess the initial signs of healing. If progress is satisfactory, the patient may transition into a protective boot, marking the beginning of the partial weight-bearing phase where weight is gradually introduced under the surgeon’s guidance.
Physical therapy usually begins during the partial weight-bearing phase or shortly thereafter, focusing on non-fused joints like the ankle, as well as strengthening the hip and core muscles. The rehabilitation program emphasizes regaining a normal walking pattern and improving overall lower extremity strength, avoiding any motion that would stress the fused joints. While many patients begin walking in a stiff-soled shoe around three months post-operation, the foot and ankle continue to strengthen and improve for up to 9 to 18 months until maximum recovery is reached.
Long-Term Functional Outcomes
The successful fusion of the three hindfoot joints provides a stable, pain-free foot, which is the most significant long-term benefit for patients who previously suffered from chronic pain and instability. This stability allows for improved balance and a more propulsive, efficient gait during daily activities. Many patients report high levels of satisfaction with the outcome.
The main consequence of the fusion is a permanent loss of motion in the midfoot and hindfoot, specifically the side-to-side movements known as inversion and eversion. Since these movements allow the foot to adapt to uneven terrain, patients often report limitations when walking on rough ground. To accommodate the lack of internal flexibility, patients typically require stiff-soled footwear or custom orthotics to support the foot and aid in shock absorption.
Although the ankle joint (tibiotalar joint) is not directly fused, the altered biomechanics can place increased stress on it over time. Long-term studies have shown that a percentage of patients may develop degenerative changes or arthritis in the adjacent ankle joint years after the procedure. However, this radiographic evidence of arthritis does not always correlate with increased pain or reduced satisfaction for the patient.