M87.366

HCC Category Mapping

What This Code Means

Death of bone tissue in the fibula (smaller bone in the lower leg) caused by an underlying condition or treatment, with the side not specified.

Coding Tips

• •Use this code only when laterality cannot be determined from documentation; query provider if possible to obtain specific side
• •Document the underlying etiology of secondary osteonecrosis in the medical record for complete coding

Clinical Significance

This diagnosis represents secondary osteonecrosis of the fibula when laterality is not specified, caused by underlying conditions that may affect ankle stability and cause lateral leg symptoms. It requires identification of the causative factor and monitoring for progression.

Documentation Requirements

• ✓Documentation of osteonecrosis affecting fibula without side specification
• ✓Identification of underlying cause (e.g., corticosteroid use, radiation therapy, sickle cell disease)
• ✓Imaging findings confirming fibular bone necrosis
• ✓Clinical symptoms such as lateral leg pain or ankle instability
• ✓Functional impact on walking or weight-bearing
• ✓Duration and progression of condition
• ✓Treatment history and response
• ✓Reason why laterality cannot be determined or if bilateral involvement

Commonly Confused Codes