Osteitis deformans of left upper arm

This code signifies Paget's disease affecting the left humerus or other bones of the left upper arm. It describes a chronic bone disorder characterized by abnormal bone remodeling, leading to enlarged, weakened, and often deformed bones in this specific anatomical location.

Apply this code when documentation explicitly states a diagnosis of osteitis deformans (Paget's disease) localized to the left upper arm. This typically includes findings from imaging studies (X-rays, bone scans) showing characteristic lesions, elevated alkaline phosphatase, and clinical symptoms such as pain, deformity, or fracture in the left upper extremity.

• Ensure laterality is clearly documented as "left upper arm" to support this specific code.
• Do not confuse with other bone disorders like osteomyelitis or osteoporosis; Paget's disease has distinct pathological features.
• Code any associated pathological fractures of the left upper arm separately, following the sequencing guidelines for complications.