Re: Problem Subtalar Revision Arthrodesis
To answer your questions:
1) When a screw is used for a subtalar joint fusion and inserted from the heel, the pain associated with the screw is almost always directly at the heel pad. This is resolved when the screw is removed, which is usually a simple procedure. There is no reason to remove them other than if they become painful.
2) When you have a failed fusion within the subtalar joint, whether once or multiple times, your options are limited. Most often this would involve a change in surgical procedure including bone graft from your hip or lower leg, an internal bone stimulator, platlet rich plasma at the surgical site, and more extensive non-weight bearing post-operatively. Other things to consider are diet, cessation or smoking, etc.
Reasons for a non-union are the patients health status (healing potential), improper immobilization (not allowing the fusion site to heal), vascular deficiency, or infection. You physician should absolutely consider all of these factors if a fusion site does not heal especially after multiple procedures.