S80.00XA Contusion of unspecified knee, initial encounter

ICD-10-CM S80.00XA: Contusion of unspecified knee, initial encounter

ICD-10-CM code S80.00XA identifies a contusion of an unspecified knee during an initial encounter. The code belongs to the S80.0 category and is distinguished from codes specifying right or left knees. Clinical sources establish that knee contusions involve blunt soft-tissue trauma, while research excerpts detail bone contusion patterns and broader knee pain management. 3 4

Plain-language overview

ICD-10-CM code S80.00XA reflects blunt soft-tissue trauma to the knee and is documented as an initial encounter. Presentation with this condition is driven by pain severity, functional limitation, and progression pattern. 3

What this code represents

Code S80.00XA is listed under the S80.0 category for a contusion of an unspecified knee during an initial encounter. This code is distinct from S80.01XA and S80.02XA, which specify right and left knees respectively. 4

Coding details

The S80.0 category includes distinct codes for subsequent encounters and sequela. For an unspecified knee, S80.00XD represents a subsequent encounter and S80.00XS represents a sequela. 4

Documentation considerations

Clinicians link S80.00XA to objective findings, time course, and plan of care. Chart review for this code supports decision continuity from triage through discharge. 3

The differential diagnosis for S80.00XA includes high-risk alternatives such as occult fracture, vascular compromise, nerve injury, infection, and referred pain syndromes. Diagnostic workup is proportionate to mechanism and exam findings. 3

Clinical context

Bone contusions in knees can be evaluated using the MRI Osteoarthritis Knee Score to record location, combined number of compartments, and volume. The reported time for the resolution of bone bruising varies from 3 weeks to 2 years. 2

Knee pain treatment options include conservative, interventional, and surgical approaches. Radiographs are the initial imaging modality utilized for the evaluation of knee pain according to the American College of Radiology Appropriateness Criteria. 1

What the sources add

The clinical coding guide for S80.00XA focuses on blunt soft-tissue trauma and documentation continuity, whereas the STEP guidelines address broader knee pain management including osteoarthritis and soft tissue injuries. 3 1

Research on bone contusion patterns specifically examines patients with acute isolated posterior cruciate ligament tears within 4 weeks after injury. This study excluded patients with associated bone fractures or previous knee trauma. 2

Sources

1. Consensus Guidelines on Interventional Therapies for Knee Pain (STEP Guidelines) from the American Society of Pain and Neuroscience — pmc.ncbi.nlm.nih.gov; accessed 2026-07-25.
2. Distribution of Bone Contusion Patterns in Knees with Acute Isolated Posterior Cruciate Ligament Tears — pmc.ncbi.nlm.nih.gov; accessed 2026-07-25.
3. Contusion Of Unspecified Knee, Initial Encounter | ICD-10-CM S80.00XA Clinical Guide — sprypt.com; accessed 2026-07-25.
4. ICD-10-CM 2024 | S80.0 - Contusion of knee — unboundmedicine.com; accessed 2026-07-25.