Proximal Humerus Fractures

Question 1

What is a good sign that vascularity to articular surface is intact in a proximal humerus fracture?

Answer 1

8mm of medial calcar remains attached to articular segment

Question 2

What % of blood supply do each the anterior and posterior circumflex humeral arteries supply to the humeral head?

Answer 2

Posterior ~64%

Anterior ~36%

Question 3

In a proximal humerus fracture that is being treated non-operatively, when should ROM exercises begin?

Answer 3

1) early PROM and pendulum at 7-10 days
2) AROM at 4-6 wks
3) Resisted ROM at 6-12 weeks

Question 4

What are the indications for reverse TSA in a proximal humerus fracture?

Answer 4

Elderly patient with non-reconstructible tuberosities

Question 5

What are the deforming forces on a proximal humerus fracture?

Answer 5

1) supraspinatus and external rotators displace the greater tuberosity superior and posterior.
2) subscapularis displaces the lesser tuberosity medially.
3) pectoralis major displaces the humeral shaft medially.
4) deltoid abducts the proximal fragment

Question 6

What are indications for hemiarthroplasty in a proximal humerus fracture?

Answer 6

1) anatomic neck fractures in elderly or those that are severely comminuted
2) 4-part fractures and fracture-dislocations (3-part if stable internal fixation unachievable)
3) rotator cuff compromise
4) glenoid surface is intact and healthy
5) chronic nonunions or malunions in the elderly
6) head-splitting fractures with incongruity of humeral head
7) humeral head impression defect of > 40%
8) detachment of articular blood supply (most 3- and 4-part fractures)

Question 7

What are predictors of good and bad outcomes in treatment of proximal humerus fractures with hemiarthroplasty?

Answer 7

improved results if:
        performed within 14 days
        accurate tuberosity reduction
        cerclage wire passed through plate and GT/LT           
poor results with:
        tuberosity malunion 
        proud prosthesis
        retroversion of humeral component > 40°

Question 8

What is the most common mode of failure for a locking plate in the tx of proximal humerus fracture?

Answer 8

Screw cut out; esp in osteoporotic bone; a close second is varus malreduction

Question 9

In shoulder hemiarthroplasty superior border of the pectoralis major tendon can be used to determine accurate restoration of?

Answer 9

Prosthesis height and retroversion; From superior border of pectoralis insertion is 56mm

Question 10

What is the most common pattern of malunion for proximal humerus fractures?

Answer 10

Varus, apex anterior or GT malunion; can treat with osteotomy if pt is young

Question 11

What are the greatest risk factors for non-union of proximal humerus fractures?

Answer 11

Smoking (up to 5.5x higher) and age (biggest risk factor)

Question 12

What are the risk factors for AVN in proximal humerus fractures?

Answer 12

1) 4 part fractures
2) head split
3) short calcar segments
4) disrupted medial hinge
5) GH fracture dislocation

Question 13

What is the common metaphyseal fracture deformity seen in proximal humerus fractures?

Answer 13

apex anterior at the surgical neck and in varus angulation; reduce by 1) traction 2) forward arm flexion 3) posterolateral force on arm