Proximal Humerus Fractures: Neer Classification, Anatomy, Imaging and Treatment

Proximal humerus fractures are common accounting 5% of all adult fractures

These fractures mostly occur in elderly patients, especially patients who are osteoporotic (e.g. postmenopausal women), after low energy falls

There is options for operative and non operative treatment for these fractures and deciding between them can be very difficult

Anatomy of proximal humerus

Proximal humerus consist of four major parts, they include:

Anatomical head
Greater tuberosity
Lesser tuberosity
Shaft

Proximal humerus; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

The anatomical head articulate with the glenoid cavity of the scapula

Humeral head is directed predominantly medially, and oriented superiorly by 130 degrees and anteriorly by 30 degree

The anatomical neck of the humerus is formed by a groove around the anatomical head and it separates the head from the tuberosities

Anatomical neck is the line of attachment of the glenohumeral joint capsule

Anatomical and surgical necks of the humerus; Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

The greater tuberosity is at the lateral aspect of the humeral head, it is the site of the insertion of three of the rotator cuff muscles: supraspinatus, infraspinatus and teres minor

The lesser tuberosity is placed more anteriorly and it is the site of insertion for the subscapularis muscle

Greater and lesser tuberosities are separated by the intertubercular sulcus (bicipital groove)

When a tuberosity fractures and gets displaced, the attached muscles loss their function and this is equivalent to a rotator cuff tear

The anatomical head and tuberosities make up the surgical head of the humerus

The surgical neck of the humerus lies at the junction of the surgical head and the shaft

Surgical neck is a common site of fractures

Nerves and vessels

Brachial plexus and axillary artery both run together medial to the coracoid process of the scapula and medial to the conjoint tendon (coracobrachialis + short head of biceps) into the arm

Both could be injured in proximal humerus fractures

Nerves and vessels crossing the shoulder joint; Internet Archive Book Images, No restrictions, via Wikimedia Commons

Nerves and vessels crossing the Proximal humerus; Internet Archive Book Images, No restrictions, via Wikimedia Commons

Mechanism of injury

Proximal humerus fractures usually caused by a fall on the outstretched arm or a fall on the shoulder in elderly patients or associated with a high energy trauma in younger patients

Same mechanism might cause a shoulder dislocation and sometimes a fracture and a dislocation will present together

Neer classification of proximal humerus fractures

In Neer classification, Proximal humeral fractures are classified according to the number of parts involved

Proximal humeral parts include: anatomical head, greater tuberosity, lesser tuberosity and the shaft

For a part to be counted, it has to be displaced

Displaced part is defined as a part displaced by more than 1 cm of translation or more than 45 degrees of angulation; if displaced less than that then the part is not counted

Proximal humeral fractures are classified into:

One-part fractures (minimally displaced fractures)
Two-part fractures
Three-part fractures
Four-part fractures

Minimally displaced fractures

Neer type I proximal humerus fracture ; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

Neer type I proximal humerus fracture ; by Doctor Jana, CC BY-SA 4.0, via Wikimedia CommonsNeer type I proximal humerus fracture ; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

Two-part fractures

These classified into:

Surgical neck fractures (most common proximal humeral fracture type)
Greater tuberosity fractures
Lesser tuberosity fractures
Anatomical neck fractures

Neer type II proximal humerus fracture ; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

Neer type II proximal humerus fracture ; by Doctor Jana, CC BY-SA 4.0, via Wikimedia CommonsNeer type II proximal humerus fracture ; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

Three-part fractures

Neer type III proximal humerus fracture ; by Doctor Jana, CC BY-SA 4.0, via Wikimedia CommonsNeer type III proximal humerus fracture ; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

Neer type III proximal humerus fracture ; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

Four-part fractures

Neer type IV proximal humerus fracture ; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

Not included in the Classification

A fracture dislocation: occurs when there is a fracture at the proximal humerus with a dislocation of the humeral head out of the glenoid
Valgus impacted fracture has intact periosteal hinge medially and despite the displacement of the anatomical head, it can be reduced by surgical leverage on the hinge

Clinical features

Patient present holding the affected arm close to the chest supported by the other hand and they complain of moderate to severe pain
On looking to the upper arm, there might be a little swelling but no bruising initially but after a few hours, extensive and deep bruise may develop on the arm and down to the elbow
Skin puckering anterolaterally suggest that deltoid muscle became interposed within the fracture (slows healing)
Patient can’t move their shoulder
Examine for neurovascular injuries
Look for other injuries

Imaging

X ray imaging

In elderly patients fracture lines are not seen well and it mostly one fracture line extending through the surgical neck

In younger patient, fracture lines are seen better and fragments are more clearly separated

Axillary and lateral shoulder views should be obtained to exclude dislocation and look for greater tuberosity displacement

AP Shoulder X-ray showing proximal humerus fracture; by Thomas Zimmermann (THWZ), CC BY-SA 3.0, via Wikimedia Commons

CT scan

Ct scan shows fracture lines and displacement much better and it is essential for planning surgical reconstruction of complex fractures

With repeated x rays through the healing process, humeral head is seen to be subluxated downward and that is due to muscle atony, it usually recovers once exercise are begun

Treatment

These fractures can be treated by many options:

Sling or collar and cuff immobilization (non operative)
Percutaneous fixation (operative)
Open reduction and internal fixation (operative)
Arthroplasty (operative)

Closed reduction is not required, because these fractures tend to realign over time as a result of the traction exerted by the weight of the arm, if a sling or collar and cuff is used

There is no form of cast that is beneficial for these fractures

Patients who are treated non operatively will get a satisfactory functional recovery most of the times while patients treated operatively will not regain a satisfactory function of the shoulder (stiffness, weakness and pain)

Minimally displaced fractures

Minimally displaced fractures (one-part fractures)

Treated non operatively with sling immobilization for 4-6 weeks
Patient advised to remove their cuff or sling several times a day and begin pendular exercises immediately when pain allows and progression to shoulder exercises as soon as possible to prevent stiffness
Elbow and hand exercises are done from the start

Minimally displaced proximal humerus fracture; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

Two-part fractures treatment

Surgical neck fractures treatment

Treated non operatively with sling immobilization for 4-6 weeks
If the fracture is unstable then operative method is used: Percutaneous pins, Plate fixation (ORIF), Intramedullary nails (ORIF)
Exercises started as soon as possible

Two-part proximal humerus fracture; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

Greater tuberosity fractures treatment

If these fractures are not displaced or displaced by less than 0.5 cm then Treated non operatively with sling immobilization for 4-6 weeks
If displaced more than 0.5 cm then treated operatively with isolated screw fixation or non absorbable suture or tension band wiring
Sometimes these fractures are associated with anterior shoulder dislocation, and they reduce when the shoulder relocates in most of the cases

Two-part proximal humerus fracture; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

Lesser tuberosity fractures

Might be associated with posterior shoulder dislocation
If minimal displacement then Treated non operatively with sling immobilization for 4-6 weeks
If large fragment or displaced then treated with open reduction internal fixation

Two-part proximal humerus fracture; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

Anatomical neck fractures

These are rare
If patient is young then open reduction and internal fixation
If old patient then prosthetic replacement (hemiarthroplasty) is preferable due to high risk of avascular necrosis

Two-part proximal humerus fracture; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

Three-part fractures treatment

These usually involve displacement of the surgical neck and greater tuberosity and sometimes surgical neck and lesser tuberosity and they are difficult to reduce by closed methods

So they are treated operatively with percutaneous pinning or open reduction and internal fixation using various methods

If elderly patient then arthroplasty is needed

Three-part proximal humerus fracture; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

Four-part fractures treatment

In this type, surgical neck and both tuberosities are displaced

If patient is young then ORIF if proximal humerus is reconstructible, if not then hemiarthroplasty, if elderly then hemiarthroplasty

These injuries are severe with high risk of complications such as vascular injuries, brachial plexus damage, chest wall injuries and late avascular necrosis of the humeral head

Four-part proximal humerus fracture; by Doctor Jana, CC BY-SA 4.0, via Wikimedia Commons

Complications

Neurovascular injuries: patient should be assessed for signs of these injuries, axillary nerve especially is at high risk of getting injured
Infection
Non union: especially in two-part surgical neck fractures
Malunion: causes little disability, it lead to loss of rotation which make it harder for the patient to reach behind neck or up the back
Rotator cuff tear
Adhesive capsulitis: it is Stiffness of the shoulder which is also called frozen shoulder and it is a common complication, especially in elderly patients, it can be minimized by starting exercises early
Avascular necrosis

Avascular necrosis of the humeral head

Segmental necrosis of devascularized anatomical head, this is seen by the X-rays.

Spontaneous revascularization commonly occurs but sometimes it doesn’t and the head collapses (in this case hemiarthroplasty is required)

AVN of the humeral head occurs in up to 30% in three-part fractures and up to 50% in four-part fractures

Avascular necrosis occurs when the vascular supply to the humeral head gets disrupted

Vascular supply to the humeral head arise from the anterior and posterior circumflex humeral arteries

Both are branches of the axillary artery

The arcuate artery (branch of the anterior circumflex humeral artery) will run in the bicipital groove to supply the humeral head

Humeral head also supplied from the tendon insertions into the two tuberosities and the periosteum

In three and four-part fractures, the anterior supply is compromised, and blood supply is mainly coming from the posterior side, this increase the risk for ischemia and AVN

Neurovascular structures passing the proximal humerus; By Mikael Häggström, used with permission, via Wikimedia Commons

Ischemia and AVN

Humeral head ischemia predictors (Hertel criteria)

< 8 mm of calcar length (calcar length is inferomedial cortical extension of the anatomical head to the surgical neck)
Disrupted medial hinge
Multiple part fractures
Displacement > 1 cm
Angulation > 45 degrees

Hertel criteria predict ischemia but not AVN

Proximal humeral fractures in children

In infants and children, proximal humeral fractures involve the physis and classified according to Salter-Harris classification

In infants, it is mostly a transverse fracture (Salter-Harris I), reduction doesn’t need to be perfect and those fractures have good prognosis

In children, it is mostly Salter-Harris type 2, reduction doesn’t have to be perfect too, and even if there is malunion, these fractures still have good prognosis due to the high potential for growth and remodeling

Pathological fractures are possible due to the proximal humerus being a common site of a bone cysts and tumors, fracture through a simple cyst usually heals spontaneously if arm was rested in a sling for 4-6 weeks

Course Menu

This article is a part of the Shoulder and Arm Trauma Free Course, this course also contains:

Course Introduction

Clavicle Bone Fractures

Scapula Bone Fractures

Acromioclavicular Joint Injuries

Sternoclavicular Joint Injuries

Anterior Shoulder Dislocation

Posterior Shoulder Dislocation

Inferior Shoulder Dislocation

Proximal Humerus Fractures

Humeral Shaft fractures

Shoulder X-ray Interpretation