Tossy Classification

Name: Tossy Classification calculator — MedScore
Creator: Nabil Alzein

Acromioclavicular (AC) joint injury — three grades by ligament injury

Tossy grade

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

I — AC and CC ligaments stretched, not torn; no displacement

II — AC ligaments torn, CC ligaments stretched; subluxation

III — AC and CC ligaments torn; complete dislocation

About this score

When to use

Grades acromioclavicular separations into three grades by injury to the acromioclavicular and coracoclavicular ligaments and the resulting joint displacement. ⁦[1]⁩

Pearls and pitfalls

Current reviews use the six-type Rockwood classification, which subdivides Tossy's complete dislocation by the degree and direction of displacement. ⁦[2]⁩

About the condition

The stability of the joint depends on the acromioclavicular ligaments and capsule, the coracoclavicular ligaments and the trapezius and deltoid muscles. ⁦[2]⁩

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

Evidence

[1] Original publication

Tossy JD, Mead NC, Sigmond HM. Acromioclavicular separations: useful and practical classification for treatment. Introduced the three grades used here, by injury to the acromioclavicular and coracoclavicular ligaments and the resulting AC joint displacement.

Clinical Orthopaedics and Related Research, 1963

Open source

[2] Guideline

Simovitch R, Sanders B, Ozbaydar M, Lavery K, Warner JJ. Acromioclavicular joint injuries: diagnosis and management. Current reviews grade AC joint injuries with the six-type Rockwood classification, which subdivides Tossy’s complete dislocation by the degree and direction of displacement; management is decided per local orthopaedic pathway.

Journal of the American Academy of Orthopaedic Surgeons, 2009

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.