M87.873
BillableOther osteonecrosis, unspecified ankle
HCC Category Mapping
V28HCC 92 — Bone/Joint/Muscle Infections/Necrosis
0.209V24HCC 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 when the specific side is not documented or affects both ankles.
Coding Tips
- •Query provider for laterality when not specified, as unilateral codes are preferred
- •Use this code only when bilateral involvement is confirmed or laterality is truly indeterminate
Clinical Significance
Unspecified ankle osteonecrosis represents avascular bone death in a critical weight-bearing joint without documented laterality, suggesting bilateral involvement or incomplete documentation. This condition poses significant risk for joint collapse and functional disability.
Documentation Requirements
- ✓Documentation of ankle osteonecrosis without side specification
- ✓Comprehensive imaging studies of both ankles if bilateral
- ✓Exclusion of trauma, infection, and radiation as causes
- ✓Bilateral functional assessment if both ankles affected
- ✓Pain evaluation and mobility restrictions
- ✓Underlying disease evaluation and management
- ✓Coordinated care plan with orthopedic specialists
- ✓Long-term prognosis and disability risk assessment
Commonly Confused Codes
M87.373 — Drug-induced osteonecrosis requires specific medication documentationM87.173 — Post-traumatic osteonecrosis needs clear trauma historyM87.073 — Idiopathic osteonecrosis has no identifiable underlying etiologyM19.079 — Unspecified ankle osteoarthritis is degenerative joint diseaseM25.579 — Ankle pain is symptomatic without structural bone death
Code Hierarchy
└M87Osteonecrosis└M87.8Other osteonecrosis└M87.87Other osteonecrosis, ankle, foot and toes└M87.873Other osteonecrosis, unspecified ankle
└M87.873Other osteonecrosis, unspecified ankle