Other hypertrophic osteoarthropathy, left lower leg

This code signifies a non-inflammatory, proliferative bone and joint condition affecting the left lower leg, characterized by abnormal bone growth, often at the ends of long bones. It is typically a secondary manifestation of an underlying systemic disease, such as lung cancer or inflammatory bowel disease.

Apply this code when documentation specifies hypertrophic osteoarthropathy impacting the left lower leg, excluding primary hypertrophic osteoarthropathy. Supporting documentation should detail the location and laterality of the osteoarthropathy, along with any associated symptoms like clubbing or periostosis.

• Always code the underlying systemic condition first, as hypertrophic osteoarthropathy is usually a secondary manifestation.
• Ensure documentation clearly specifies "left lower leg" to avoid laterality errors.
• Distinguish from primary hypertrophic osteoarthropathy (M89.40-M89.42, M89.48-M89.49), which has a different etiology.