Left ulnar nerve entrapment at the elbow

What is the correct CPT  code with modifier for the following scenario 

REOPERATIVE DIAGNOSIS: Left ulnar nerve entrapment at the elbow

 POSTOPERATIVE DIAGNOSIS: Left ulnar nerve entrapment at the elbow

PROCEDURE: Left ulnar nerve decompression at the elbow

INDICATIONS: The patient has a history of numbness in the fourth and fifth digits of the left hand and

also some weakness in the grip. He complains of pain in the ulnar side of the left arm. He had an

EMG, which was positive for entrapment of the left ulnar nerve at the elbow, and he had conservation

treatment with some improvement of the mode of function, with severe significant numbness and pain.

Because of the symptoms, the decision was made to proceed with a decompression of the left ulnar

nerve at the elbow.

DESCRIPTION OF SURGERY: The patient was placed in supine position with the left hand on the surgical

stand. The arm was then prepped, draped, and then an incision was marked at the level of the left

elbow. The incision was infiltrated with lidocaine 1 percent and then the incision was made with a

#15 blade. With the use of bipolar coagulator, the bleeding was easily controlled and then the ulnar

nerve was exposed at the level of the elbow proximally and distally. The ulnar nerve was completely

compressed and was released from a dense scar. Antibiotic solution was used to irrigate the area, and

then the area was closed with #3-0 Vicryl and staples.

What is the appropriate CPT code?