proximal humerus #s anatomy

1. BY G T SAI PRASANTH
MODERATOR : DR ARUN KAMAL SIR
01-10-2014

2.  ANATOMY OF SHOULDER GIRDLE
 PATHOPHYSIOLOGY OF PROXIMAL HUMERUS
FRACTURES
 CLASSIFICATION OF PROXIMAL HUMERUS
FRACTURES
 RECENT ADVANCES

3. BONES
 The bones that are involved in the formation of
shoulder girdle include :
 Humerus
 Scapula with clavicle
 Glenohumeral joint
 Glenohumeral joint is a ball and socket type of
synovial joint formed between the head of humerus
and glenoid cavity of scapula.

4. 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
shoulder joint.

5. HUMERUS
 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 ?

6. FACTS ABOUT PROXIMAL HUMERUS
 The humeral articular segment occupies approximately one
third of a sphere, with a diameter of curvature averaging 46
mm.
 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
shaft.
 The humeral head is normally retroverted by an average of 20
degrees, with respect to the distal humeral interepicondylar
axis.

7. MUSCLES
 The muscles around the proximal humerus include :
 Rotator cuff muscles : Supraspinatus, Infraspinatus, Teres
minor and Subscapularis.
 Deltoid
 Pectoralis major
 Teres major and Latissimus dorsi

8. Supraspinatus, infraspinatus and
teres minor insert on the greater
tubercle and cause lateral rotation .
Subscapularis causes medial rotation
along with pectoralis and T. major

11. GLENOHUMERAL JOINT AND THE
LIGAMENTS
 The shallow glenoid cavity is deepened by the glenoid
labrum (fibrocartilagenous).
 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
 Glenohumeral ligaments
 Coracohumeral ligament
 Coracoacromial arch
 Transverse humeral ligament

13. NERVES & VESSELS
 The nerves supplying the proximal humerus region include :
 The axillary nerve
 Suprascapular nerve
 Lateral pectoral nerves
 The vessels supplying the proximal humerus and the
glenohumeral joint include :
 Circumflex humeral
arteries
 Anterior circumflex
 Posterior circumflex
 Anastomosis around the
shoulder joint.

14.  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
blood supply.
 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.

15. BURSAE
 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.

16. PATHOPHYSIOLOGY OF PROXIMAL HUMERUS
FRACTURES
 Proximal humerus fractures are mainly osteoporotic fractures
 Can either be due to high energy trauma or low energy
trauma.
 The latter are mainly seen in elderly due to osteopenia &
osteoporosis.
 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.

17.  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.

18. CLASSIFICATION OF PROXIMAL HUMERUS
FRACTURES
 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
presently.
 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

19.  Undisplaced or minimally displaced fractures are termed
one-part fractures.
 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
configuration.
 Fracture-dislocations are also classified according to the
direction of displacement of the humeral head (anterior or
posterior).

20. Normal anatomy

22. 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
stock.
 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.

23. Undisplaced and stable one part
fracture configurations

24. Two-Part Greater Tuberosity Fractures and
Fracture-Dislocations (OTA Types A1.1, A1.2, and
A1.3)
 The spectrum includes : Isolated fractures & fractures with
glenohumeral dislocation and nerve injury.
 Terrible triad of shoulder ?
 Mechanism:
 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
fractures
 Due to the risk of redislocation due to the muscle pull even
5mm displacement must be operated upon.

25. Seemingly isolated
GT # may also have
Anatomical neck #
Properly oriented
AP view needed

26. Rotator cuff
deficient
High riding
humerus
Retraction
Causing pull
Large frgmnt
Small
frgmnt

27. 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
force.
 Forced external rotation causing isolated fractures or
associated with posterior dislocation of shoulder.
 The attached subscapularis tendon pulls the fragment
medially.

28. 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
 Angulated fractures:
 Neutral alignment or head tilted in varus or valgus.
 The shaft is usually impacted into the head hence good
healing potential.
 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

29. IMPACTED TRANSLATED
COMMINUTED

30. Two-Part Anatomic Neck Fractures (OTA Type
C1.3)
 Extremely uncommon injury
 Associated with a high risk of osteonecrosis
 When present occurs with posterior dislocation of shoulder
joint

31. 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
#’s:
 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
tuberosities.
 Impacted varus fracture :
 The fractured humeral head is tilted into varus.

32. Valgus angulation fractures
The 1 & 2nd pictures show
undisplaced and mild valgus
displacement
The 3 & 4th pictures show
severe valgus angulation
with lateral translation
of head with increased
chances of osteonecrosis

33. Varus angulation with Inferior
subluxation of humeral head

34.  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
osteonecrosis.
 Articular surface involvement :
 Humeral head impacted into the glenoid causing head split.
 The tuberosity fragments carry parts of humeral articular surface.

35. Pic 1: “Double shadow “of humeral
Head pathognomic of head split
fractures

36. Complex Fractures with Glenohumeral Dislocation
(OTA Types B3 and C3)
 Complete dislocation of fractured humeral head from
glenoid cavity
 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

37.  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
ON.

38. TYPE I INJURY WITH ANTERO-
INFERIOR DISLOCATION OF
HEAD

39. TYPE II INJURIES

40.  Current classification systems for these fractures are based on
anatomical and pathological principles, and not on systematic
image reading.
 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
image types.
 21 fracture characteristics are identified & they are applied along
with classical Codman approaches to classify fractures.

41.  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
groups.

43. Bibliography
 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.
 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC27052
77/

44. THANK YOU