M87.173
BillableOsteonecrosis due to drugs, unspecified ankle
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 ankle caused by medication side effects when the specific side (left or right) is not documented.
Coding Tips
- •Use only when laterality is genuinely unspecified in the documentation
- •Attempt to obtain imaging reports or clinical notes that may clarify which ankle is affected
Clinical Significance
Drug-induced osteonecrosis of unspecified ankle indicates medication-related bone death when laterality cannot be determined from documentation. This condition represents significant functional impairment potential and requires comprehensive orthopedic management despite the side specification limitation.
Documentation Requirements
- ✓Documentation confirming ankle involvement in osteonecrosis
- ✓Specific causative medication or drug class identification
- ✓Imaging studies demonstrating ankle osteonecrosis
- ✓Assessment of joint function and weight-bearing capacity
- ✓Explanation for inability to determine affected ankle
- ✓Drug exposure history with temporal relationship to symptoms
- ✓Treatment approach addressing functional preservation
- ✓Provider confirmation of drug-induced etiology
Commonly Confused Codes
M87.171/M87.172 — Use specific laterality when right/left is documentedM87.176 — Unspecified foot involves broader foot structuresM87.273 — Post-traumatic unspecified ankle requires injury historyM87.073 — Idiopathic ankle osteonecrosis lacks drug causationS93.4 — Unspecified ankle sprain is acute soft tissue injury
Code Hierarchy
└M87Osteonecrosis└M87.1Osteonecrosis due to drugs└M87.17Osteonecrosis due to drugs, ankle, foot and toes└M87.173Osteonecrosis due to drugs, unspecified ankle
└M87.173Osteonecrosis due to drugs, unspecified ankle