Everyone is different and thus, no two bunion surgeries are exactly alike. Similarly, no two patients will respond to bunion surgery in the exact same manner. The size of the bunion has very little to do with the pain it causes in the foot. Even small bunions can cause a significant amount of pain in the ball of the foot. However, surgery on smaller bunions causes less damage because they need less correction than larger bunions. These surgeries heal faster and allow for a rapid return to activity.
For example, a Distal Chevron bunion correction (figure 1), my preferred procedure for small to medium sized deformities, involves a very small injury to the surrounding soft tissues and it heals rapidly within 4-6 weeks. I stabilize the cut in the bone with screws. This has many advantages over pin or absorbable fixation as it permits early motion, return to full weight bearing by 2 weeks, and a careful return to light jogging by 4-6 weeks. Some patients have surprised me by running down stairs 3 weeks after surgery. Strengthening the foot with special intrinsic muscle exercises during recovery is key to a fast return. After 6 weeks the bone is healed but, the muscles of the foot are weak. Injury to other joints and tendons of the foot and ankle can come from landing on the foot incorrectly. Stress fractures are always a danger.
Large bunions often require a proximally based osteotomy and sometimes even a double osteotomy (two separate cuts in the bone). More soft tissue dissection is required and the bone will take longer to heal. My preferred procedure for most large bunions is the Scarf osteotomy (figure 2) for many reasons. This procedure also allows early range of motion of the big toe and early return to full weight bearing. Because this is a more involved procedure, the foot takes longer to recover. The post-operative protocol is similar to the less invasive procedure but, I expect return to jogging to be delayed for at least 8 weeks.
Finally, patients with either midfoot instabilty or midfoot arthritis require a Lapidus procedure.
This involves a partial midfoot fusion. This procedure requires at least 6 weeks of non-weight bearing and immobilization inside a cast or a boot. Despite the use of the latest plates and screws, this procedure has the highest nonunion (bones not healing) rate. All the body’s core muscles: the hip, thigh, leg, and foot musculature become weaker. Jogging and running is routinely held until 10-12 weeks post surgery. Furthermore, after a partial midfoot fusion, added stresses on the remaining joints make running less comfortable.
Returning to marathon training after bunion surgery is expected, but the recovery time it takes before returning depends greatly on which surgery was performed.