Carofino and Leopold review the Neer four-segment classification for proximal humerus fractures. The review covers the system's derivation from 300 surgical cases, its displacement criteria, its reliability data, and where it falls short as a prognostic tool. The question it answers: does the Neer classification reliably predict outcomes and guide treatment in 2013?
When you classify a proximal humerus fracture as "one-part," resist assuming the patient will do well. That group exceeds 80% of all proximal humerus fractures and hides a wide range of injury severity — nearly 1 in 4 treated nonoperatively had fair or poor outcomes in the largest series reviewed.
The 1 cm / 45° thresholds are a shared language, not a precise biologic cutoff. When planning surgery, the Neer part count alone is insufficient. Add varus displacement, medial comminution, metaphyseal hinge length, and bone quality to your assessment. Each independently affects stability after ORIF and risk of varus collapse.
Do not use four-part classification as your sole reason to choose arthroplasty over ORIF. Subsequent research has not confirmed that four-part fractures reliably predict AVN. The valgus-impacted variant, added in 2002, has a distinct prognosis and may tolerate reduction better than the classic four-part pattern.
The Neer classification remains the standard communication framework for these injuries. But treat it as a starting point, not a complete treatment algorithm.
Carofino and Leopold review the Neer four-segment classification for proximal humerus fractures. The review covers the system's derivation from 300 surgical cases, its displacement criteria, its reliability data, and where it falls short as a prognostic tool. The question it answers: does the Neer classification reliably predict outcomes and guide treatment in 2013?
When you classify a proximal humerus fracture as "one-part," resist assuming the patient will do well. That group exceeds 80% of all proximal humerus fractures and hides a wide range of injury severity — nearly 1 in 4 treated nonoperatively had fair or poor outcomes in the largest series reviewed.
The 1 cm / 45° thresholds are a shared language, not a precise biologic cutoff. When planning surgery, the Neer part count alone is insufficient. Add varus displacement, medial comminution, metaphyseal hinge length, and bone quality to your assessment. Each independently affects stability after ORIF and risk of varus collapse.
Do not use four-part classification as your sole reason to choose arthroplasty over ORIF. Subsequent research has not confirmed that four-part fractures reliably predict AVN. The valgus-impacted variant, added in 2002, has a distinct prognosis and may tolerate reduction better than the classic four-part pattern.
The Neer classification remains the standard communication framework for these injuries. But treat it as a starting point, not a complete treatment algorithm.