ICD-10-CM > M00-M99 > M65-M67 > M65 > M65.8 > M65.85 M65.85 Other synovitis and tenosynovitis, thigh Non-Billable/Non-Specific Codes M65.851Other synovitis and tenosynovitis, right thighM65.852Other synovitis and tenosynovitis, left thighM65.859Other synovitis and tenosynovitis, unspecified thigh