Review the case study below and code the correct procedure(s) using ICD-10-PCS. How many codes will you be using? Provide the rationale for your code selection. Provide any guidelines that may be used to code in ICD 10-PCS. Must be at least 250 words with two cited sources in APA format

PREOPERATIVE DIAGNOSIS:
1. Gangrene right foot.
POSTOPERATIVE DIAGNOSIS:
1. Gangrene right foot.
OPERATION:
1. Right below the knee amputation.
ANESTHESIA: General LMA.

PROCEDURE: The patient was brought to the operative suite where a general LMA anesthesia was induced.
A Foley catheter was inserted and the right foot was secluded in an isolation bag and the lright lower extremity circumferentially prepped and draped in its entirety. Beginning on the right side, the skin was marked with a marking pen 4 finger breadths below the tibial tuberosity anteriorly with a long posterior flap. The skin was incised circumferentially and the anterior musculature sharply divided, exposing the tibia. The tibia was cleaned with a periosteal elevator and then transected with the Stryker saw. The fibula was exposed and transected with the bone cutter and the amputation completed by sharply incising the posterior musculature. Bleeding vessels were ligated with 2-0 silk ligature. There appeared to be adequate bleeding at this level for primary healing the tibia was then cleaned with a bone rasp and the fibula with a tongeur. The would was irrigated and ultimately closed without significant tension utilizing interrupted 2-0 vicryl sutures for reapproimation of the fascia and skin staples for reapproimation of the skin.
The right side was dressed with sterile gauze fluff dressing and a Kerlix roll. Estimated blood loss throughout the procedure was approximately 150 ml. The patient received one unit intraoperatively of packed cells because of preoperative anemia. She was transported in stable condition to the recovery room.