I have an op note that is giving me a little trouble and I would appreciate any input.

Op note: "Made incision over Achilles and carried down thru calcaneus. There was thickening along Achilles and the epitenon was excised with sharp dissection. The extosis was in the mid point of the tendon so it was split longitudinally on worked thru the middle of tendon. Elevated tendon, both lateral and medial and then removed extosis with an osteome and ronguers. I then countoured retrocalcaneul region with rasp and then repaired Achilles with sutures proximally and used one anchor in the distal portion. The anterior two thirds of the Achilles were left attached to the calanceus and it was only the very posterior aspect that was elevated. The wound was then irrigated and closed. Dressing and splint were applied."

I am stuck in between two different CPT codes. Is this considered an Ostectomy (28118) or simply an excision of calcaneus (28100)? Is the Achilles division and repair included in either procedure since it was neccessary in order to perform the excision? And finally, is the debridement of the Achilles coded as a separate procedure?
Thanks in advance for any help or advice.