Rockwood Classification

Name: Rockwood Classification calculator — MedScore
Creator: Nabil Alzein

Acromioclavicular (AC) joint injury — six types by ligament injury and clavicle displacement

Rockwood type

Tap the one that applies — its meaning opens right below.

I — AC ligaments sprained, CC ligaments intact; X-ray normal

II — AC ligaments torn, CC sprained; AC joint widened, CC distance increased < 25%

III — AC and CC ligaments torn; CC distance increased 25–100%

IV — clavicle displaced posteriorly into or through the trapezius

V — AC and CC ligaments torn; CC distance increased > 100%

VI — clavicle displaced inferiorly (below the acromion or coracoid)

About this score

When to use

Classifies acromioclavicular joint injuries into six types by which ligaments are torn and by the degree and direction of clavicular displacement. ⁦[1, 2]⁩

Pearls and pitfalls

• There is broad agreement on types I–II and IV–VI, while the handling of type III and V injuries remains debated. ⁦[3]⁩

• It extends Tossy's three grades (1963) to six types. ⁦[1]⁩

About the condition

Acromioclavicular joint injuries make up nearly half of all athletic shoulder injuries, often from a fall onto the tip of the shoulder with the arm adducted. ⁦[2]⁩

Summarised from the numbered sources under Evidence. Check the source before relying on a statement.

Evidence

[1] Original publication

Rockwood CA Jr. Injuries to the acromioclavicular joint — a chapter in the textbook Rockwood and Green’s Fractures in Adults (not indexed in PubMed). Extended Tossy’s three grades (1963) to six types by which ligaments are torn and by the degree and direction of clavicular displacement.

[2] Validation

Simovitch R, Sanders B, Ozbaydar M, Lavery K, Warner JJ. Acromioclavicular joint injuries: diagnosis and management. Review of AC joint stability (AC and CC ligaments, capsule, deltoid and trapezius) and radiographic evaluation using the Rockwood types I–VI.

Journal of the American Academy of Orthopaedic Surgeons, 2009

Open source

[3] Guideline

Frank RM, Cotter EJ, Leroux TS, Romeo AA. Acromioclavicular joint injuries: evidence-based treatment. The review reports that types I and II are typically managed non-operatively and types IV and VI operatively, while the indications for types III and V remain debated — management is decided per local orthopaedic pathway.

Journal of the American Academy of Orthopaedic Surgeons, 2019

Open source

Last reviewed: 2026-10

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MedScore is an educational and clinical decision-support tool. It does not provide a diagnosis, a treatment, or a drug-dosing recommendation, and it does not replace clinical judgement or local guidelines. Confirm every result against the original source before acting on it. The treating clinician remains responsible for all decisions.