Surgical wounds take time to heal. Make sure his blood sugar is under control as wound healing is delayed due to high blood sugar. Give him enough of protein rich foods and Vitamin C both of which are important for wound healing. If he is a non-vegetarian, you can give him boiled eggwhites, skinless chicken and fish, lean cuts of meat. Give low fat milk/curd and cheese as they are good sources of proteins as well. Give him fresh fruits like citrus fruits, guava, as they are good sources of vitamin C. Make sure no pressure is exerted on the area where wound healing has to take place. Since blood flow is drastically reduced, avoid postures which will affect blood flow to the feet. Keep the foot with wound elevated on a stool to allow maximum blood flow and crossing of legs or bending the leg while sitting on a chair must be avoided as it restricts blood flow to the feet. Hope this will aid in faster recovery.