I have a posterior Achilles heel spur. What do you recommend other than surgery?

Padding. You can pad the back of your shoes to keep the heel from rubbing too much. You may also try heel lifts to take pressure off the achilles tendon and keep it from rubbing the spur so much. Anti inflammatory medication would be helpful as well.
Pallative treatment. If the spur, also called a pump bump, is bothering you in your shoes you can use a horseshoe shaped pad to pad the heel of the shoe so the shoe does not rub on the bump. Changing shoegear may also be in order. If it is not painful, just leave it alone. Sometimes ice can reduce the irritation and make it feel better.
Heel cord stretches. Bone is made where there is increased stress. By reducing stress in the achilles tendon by stretching, the spur can improve and even resolve. Stand on the edge of a step and allow your heel to lower down until you fell the pull (often painful) in the back of the ankle and calf. Hold the stretch for 10=15 seconds and repeat on the other side. Do 3-4 cycles 2x/day. It will improve in 4-6 wks.
Heel lift. Heel lift to take pressure off of tendon.
Heel lifts. 1/4" to 1/2" heel lift in affected limb. Calf stretching exercises.
Lifts-streching-meds. A Medrol (methylprednisolone) dose pack can calm down the inflamation and pain. A heel lift in both shoes will help take pressure off the area. Streching exercises will help to loosen the tightness of the tendon. Iceing can also help relive pain .
See below. A very accurate diagnosis to determine whether an injection in the right spot is needed.
Shoe modification. You can wear a heel lift in your shoe to raise the irritated area above the counter of the shoe. You can also get serapen injections in the area of maximum pain.
A heel lift. A backless shoe during the summer and topical antinflammatory cream. .