M87.166
BillableOsteonecrosis due to drugs, unspecified fibula
HCC Category Mapping
V24HCC 39 — Bone/Joint/Muscle Infections/Necrosis
0.482ESRDHCC 39 — Bone/Joint/Muscle Infections/Necrosis
0.000RxHCCHCC 80 — Bone/Joint/Muscle Infections/Necrosis
0.000What This Code Means
Death of bone tissue in the fibula (smaller bone in the lower leg) caused by medication side effects when the specific side is not identified.
Coding Tips
- •This unspecified code should be used only when laterality is truly unknown or undocumented
- •Request clarification from the clinical team to assign a more specific laterality code when possible
Clinical Significance
Drug-induced osteonecrosis of unspecified fibula represents medication-related bone death when the affected side cannot be determined from documentation. This condition still requires orthopedic evaluation and management as fibular involvement can affect ankle stability and lower extremity function.
Documentation Requirements
- ✓Documentation confirming fibular involvement in osteonecrosis
- ✓Specific causative medication or drug class identification
- ✓Imaging studies demonstrating fibular osteonecrosis
- ✓Assessment of ankle stability and lower leg function
- ✓Rationale for why laterality cannot be determined
- ✓Drug exposure history with temporal correlation to symptoms
- ✓Treatment approach addressing functional concerns
- ✓Provider confirmation of drug-induced etiology
Commonly Confused Codes
M87.164/M87.165 — Use specific laterality when right/left is documentedM87.163 — Unspecified tibia affects major weight-bearing boneM87.266 — Post-traumatic unspecified fibula requires injury historyM87.066 — Idiopathic fibula osteonecrosis lacks drug causationS82.4 — Unspecified fibula fracture is acute trauma, not chronic necrosis
Code Hierarchy
└M87Osteonecrosis└M87.1Osteonecrosis due to drugs└M87.16Osteonecrosis due to drugs, tibia and fibula└M87.166Osteonecrosis due to drugs, unspecified fibula
└M87.166Osteonecrosis due to drugs, unspecified fibula