This 1970 landmark paper by Neer introduces the four-segment classification for displaced proximal humeral fractures. It replaces prior systems based on fracture level and mechanism with a single practical question: which segments are displaced more than 1 cm or 45°? The classification is derived from 300 surgically reviewed cases treated at Columbia-Presbyterian between 1953 and 1967.
Every proximal humerus fracture you evaluate starts with one question: which segments are displaced, and by how much? That question is Neer's. Before 1970, classifications based on fracture level (anatomical vs. Surgical neck) or mechanism (abduction vs. Adduction) produced contradictory literature because they ignored displacement, the one variable that determines prognosis and treatment.
In practice, two decision rules from this paper apply directly to patient care. If greater tuberosity displacement exceeds 1 cm, treat it as a rotator cuff tear until proven otherwise. When you confirm a four-part pattern, counsel the patient that AVN is the expected outcome, not a complication — the blood supply is anatomically gone.
For impression fractures after posterior dislocation, apply the 20/50 rule: below 20% can be reduced and observed, 20–50% requires subscapularis transfer into the defect, and above 50% warrants prosthetic replacement because soft-tissue reconstruction alone will not hold the joint.
This paper directly justified the expansion of shoulder hemiarthroplasty for four-part fractures, a procedure Neer had been refining since 1952. Making it both the classification and the surgical rationale that shaped modern proximal humerus fracture management.
This 1970 landmark paper by Neer introduces the four-segment classification for displaced proximal humeral fractures. It replaces prior systems based on fracture level and mechanism with a single practical question: which segments are displaced more than 1 cm or 45°? The classification is derived from 300 surgically reviewed cases treated at Columbia-Presbyterian between 1953 and 1967.
Every proximal humerus fracture you evaluate starts with one question: which segments are displaced, and by how much? That question is Neer's. Before 1970, classifications based on fracture level (anatomical vs. Surgical neck) or mechanism (abduction vs. Adduction) produced contradictory literature because they ignored displacement, the one variable that determines prognosis and treatment.
In practice, two decision rules from this paper apply directly to patient care. If greater tuberosity displacement exceeds 1 cm, treat it as a rotator cuff tear until proven otherwise. When you confirm a four-part pattern, counsel the patient that AVN is the expected outcome, not a complication — the blood supply is anatomically gone.
For impression fractures after posterior dislocation, apply the 20/50 rule: below 20% can be reduced and observed, 20–50% requires subscapularis transfer into the defect, and above 50% warrants prosthetic replacement because soft-tissue reconstruction alone will not hold the joint.
This paper directly justified the expansion of shoulder hemiarthroplasty for four-part fractures, a procedure Neer had been refining since 1952. Making it both the classification and the surgical rationale that shaped modern proximal humerus fracture management.