Proximal humerus fractures anatomy and classification
BY G T SAI PRASANTH
MODERATOR : DR ARUN KAMAL SIR
ANATOMY OF SHOULDER GIRDLE
PATHOPHYSIOLOGY OF PROXIMAL HUMERUS
CLASSIFICATION OF PROXIMAL HUMERUS
The bones that are involved in the formation of
shoulder girdle include :
Scapula with clavicle
Glenohumeral joint is a ball and socket type of
synovial joint formed between the head of humerus
and glenoid cavity of scapula.
• Flat bone on the postero
lateral aspect of thorax
between 2-7 ribs.
• Spine of scapula divides
the posterior surface into
Supraspinous and infra -
spinous fossa .
• The scapula has three
borders and three angles
• The ant & post surfaces
act as attachments for
muscles acting on
The proximal end of humerus has a head, surgical and
anatomical neck, greater and lesser tubercles.
The anatomical neck separates the head from the tubercles
and is the attachment of shoulder capsule.
The surgical neck – Importance ?
FACTS ABOUT PROXIMAL HUMERUS
The humeral articular segment occupies approximately one
third of a sphere, with a diameter of curvature averaging 46
The inclination of the humeral head relative to the shaft
averages 130 degrees (with a range of 123 to 136 degrees).
The geometric center of the humeral head is offset an average
of 2.6 mm posteriorly (range of -0.8 to 6.1 mm) and 7 mm
(range of 3 to 11 mm) medially from the axis of the humeral
The humeral head is normally retroverted by an average of 20
degrees, with respect to the distal humeral interepicondylar
The muscles around the proximal humerus include :
Rotator cuff muscles : Supraspinatus, Infraspinatus, Teres
minor and Subscapularis.
Teres major and Latissimus dorsi
Supraspinatus, infraspinatus and
teres minor insert on the greater
tubercle and cause lateral rotation .
Subscapularis causes medial rotation
along with pectoralis and T. major
GLENOHUMERAL JOINT AND THE
The shallow glenoid cavity is deepened by the glenoid
Only a third of the head articulates in the glenoid cavity
at a given point.
Stabilized by the overlying muscles.
The ligaments include :
The joint capsule
Transverse humeral ligament
NERVES & VESSELS
The nerves supplying the proximal humerus region include :
The axillary nerve
Lateral pectoral nerves
The vessels supplying the proximal humerus and the
glenohumeral joint include :
Anastomosis around the
The main blood supply to the humeral head comes from
the anterior circumflex humeral vessels through its
anterolateral ascending artery.
The posterior circumflex vasculature becomes important
after a fracture dislocation/ 3 or 4 part fracture.
The chances of osteonecrosis developing in a complex
proximal humeral fracture is somewhat less as the soft
tissue attachments of the fracture fragments maintain
Only fractures with complete comminution with complete
capsular disruption will go for osteonecrosis.
The axillary nerve lying at the surgical neck is prone for
injury after a fracture.
Bursae are synovial fluid filled cavities present around the
joint to reduce friction.
They directly communicate with the shoulder joint.
Subscapular bursa : protects the tendon of subscapularis
Subacromial bursa: between supraspinatus tendon and
shoulder capsule inferiorly and acromion, coracoacromial arch
and deltoid superiorly.
PATHOPHYSIOLOGY OF PROXIMAL HUMERUS
Proximal humerus fractures are mainly osteoporotic fractures
Can either be due to high energy trauma or low energy
The latter are mainly seen in elderly due to osteopenia &
Occur either due to direct impact on the shoulder where the
head gets fractured against the glenoid or indirect impact i.e
fall on outstretched hand.
Patients with direct injuries to shoulder tend to be more
dilapidated as compared to the other group.
The maximum bone density is found in the subchondral
bone right beneath the articular surface.
The posterosuperior quadrant of the humeral head is
the most minerally dense area.
CLASSIFICATION OF PROXIMAL HUMERUS
Codman described that the proximal humerus tends to fracture
along the lines of physeal fusion into four fragments: lesser
tuberosity, greater tuberosity, head and the shaft.
Neers classification is the most commonly used classification
Each of the four fragments are considered as unique parts only if
they are separated by more than 1 cm or angulated by more
than 45 degrees to one another
Undisplaced or minimally displaced fractures are termed
Displaced fractures are classified according to the number
of displaced fragments, regardless of the number of
secondary fracture lines, into two-, three-, or four-part
Fracture-dislocations are also classified according to the
direction of displacement of the humeral head (anterior or
Undisplaced or Minimally Displaced One-Part
Fractures (OTA Types A, B, or C)
Most common type of proximal humerus fracture (>50%)
Occurs in younger and fitter individuals with good bone
Minimally displaced fracture lines can be present on the
radiograph on any of the four parts.
Associated subluxation of shoulder joint may occur due to
hemarthrosis, capsular atony.
Mostly treated by conservative management.
Undisplaced and stable one part
Two-Part Greater Tuberosity Fractures and
Fracture-Dislocations (OTA Types A1.1, A1.2, and
The spectrum includes : Isolated fractures & fractures with
glenohumeral dislocation and nerve injury.
Terrible triad of shoulder ?
Axial loading causing anatomical neck # with greater
tuberosity #( 10 % prevalence).
Traction injury during a glenohumeral dislocation which
causes greater tuberosity fracture due to avulsion injury.
Multifragmentary vs single fragment greater tuberosity
Due to the risk of redislocation due to the muscle pull even
5mm displacement must be operated upon.
GT # may also have
Anatomical neck #
AP view needed
Two-Part Lesser Tuberosity Fractures and Fracture-
Dislocations (OTA Type A1.3, Subgroup 4)
Very rare fractures, middle aged males, due to a very high
Forced external rotation causing isolated fractures or
associated with posterior dislocation of shoulder.
The attached subscapularis tendon pulls the fragment
Two-Part Extra-Articular (Surgical Neck) Fractures
(OTA Types A2 and A3)
25 %, older individuals, low risk of osteonecrosis.
Three types of surgical neck fractures:
angulated, translated/separated, and comminuted
Neutral alignment or head tilted in varus or valgus.
The shaft is usually impacted into the head hence good
Translation/separation & comminution:
Can be mild or complete translation. Severe
comminution – cortical discontinuity.
The head usually adopts a varus position due to pull of
the rotator cuff and shaft dispalces anteromedially due
to the pull of P. major
Two-Part Anatomic Neck Fractures (OTA Type
Extremely uncommon injury
Associated with a high risk of osteonecrosis
When present occurs with posterior dislocation of shoulder
Three- and Four-Part Fractures Without Dislocation
(OTA Types B1, B2, C1, and C2)
10 %, multifragementary, the variation in these fractures
depend on the nature of deforming forces.
Anatomical neck fracture is a constant feature - movement of
shaft in relation to head – 2* tuberosity fracture.
The various factors that play a part in the outcome of these
Humeral head angulation and displacement :
Neutral angulation :
Head in neutral/internal rotated if three part greater tuberosity #
Impacted valgus fracture :
The head faces superiorly (increased neck shaft angle) with splaying of
Impacted varus fracture :
The fractured humeral head is tilted into varus.
Valgus angulation fractures
The 1 & 2nd pictures show
undisplaced and mild valgus
The 3 & 4th pictures show
severe valgus angulation
with lateral translation
of head with increased
chances of osteonecrosis
Varus angulation with Inferior
subluxation of humeral head
Tuberosity fracture configuration & Displacement :
The tuberosities # secondary to head displacement.
The deformity tends to progress due to the muscle pull.
The three part G T # >>>>>>>>> L T #
The avulsed G T fragement moves posterosuperiomedially whereas the
avulsed L T fragment anteromedially.
Humeral head viability and risk of osteonecrosis:
The risk of osteonecrosis increases with loss of capsular attachment to
the head fragment.
Long posteromedial metaphyseal spike of bone attached to the
humeral head--- better perfusion.
Preservation of a medial hinge in a valgus fracture
No reliable method is present to predict the occurrence of
Articular surface involvement :
Humeral head impacted into the glenoid causing head split.
The tuberosity fragments carry parts of humeral articular surface.
Pic 1: “Double shadow “of humeral
Head pathognomic of head split
Complex Fractures with Glenohumeral Dislocation
(OTA Types B3 and C3)
Complete dislocation of fractured humeral head from
Anterior fracture dislocations are more common than
posterior fracture dislocations.
Most severe and have higher chances of developing ON.
Three part and four part anterior fracture dislocation are
divided into :
Type I injuries
Type II injuries
Type I injuries:
Viable Humeral Head With Retained Capsular Attachments
Young adults, high velocity injury.
The dislocated humeral head retains the capsule attachments
through periosteal sleeve around lesser tuberosity.
Type II injuries :
more common, occurs in older females.
low-energy trauma, non viable humeral head.
the fracture resembles a three or four part valgus fracture, but
with the humeral head dislocated anteroinferiorly, and not
engaged on the glenoid.
The humeral head fractures in a valgus position and the
exposed sharp medial calcar tears the capsule.
The capsule is torn which leads to increased risk of developing
TYPE I INJURY WITH ANTERO-
INFERIOR DISLOCATION OF
Current classification systems for these fractures are based on
anatomical and pathological principles, and not on systematic
These fractures can appear in many different forms, with many
characteristics that must be identified.
However, many current classification systems lack good
reliability, both inter-observer and intra-observer for different
21 fracture characteristics are identified & they are applied along
with classical Codman approaches to classify fractures.
The new classification system, based on fracture characterization
and using Codman classification graphs, presents a new image
reading protocol with 21 fracture characteristics divided into five
Rockwood and Greens fractures in adults 7th edition
Keith L Moore Clinically applied anatomy 6th edition
Frank H Netter atlas of Human anatomy, 4th edition.