Humeral Shaft Nonunion

Question 1

what is humeral shaft nonunion?

Answer 1

characterized by the arrest of the fracture repair process of a humeral shaft fracture which may occur following nonoperative or operative management

Question 2

characterized by the arrest of the fracture repair process of a humeral shaft fracture which may occur following nonoperative or operative management

Answer 2

humeral shaft nonunion

Question 3

incidence of nonunion with nonoperative management

Answer 3

2 to 33%

Question 4

incidence of nonunion with operative management

Answer 4

5-10%

Question 5

_____ third humeral shaft fractures are felt to have higher rates of nonunion

Answer 5

proximal

Question 6

biological risk factors

Answer 6

metabolic/endocrine abnormalities (osteoporosis, Vitamin D deficiency most common)
infection
patient factors (smoking, obesity, malnutrition, noncompliance)
open fracture

Question 7

metabolic/endocrine abnormalities that increase risk for nonunion

Answer 7

osteoporosis
vitamin D deficiency

Question 8

mechanical risk factors

Answer 8

unstable fracture patterns with inadequate stability
shoulder or elbow stiffness (motion directed to fracture site)

Question 9

pathophysiology:

Answer 9

inadequate stability at fracture site with operative or nonoperative treatment

Question 10

associated conditions

Answer 10

radial nerve palsy

Question 11

____ vessel of humerus courses along the medial aspect of the mid to distal third of the diaphysis

Answer 11

nutrient

Question 12

nutrient vessel of humerus courses along the ____ aspect of the mid to distal third of the diaphysis

Answer 12

medial

Question 13

pectoralis major and ____ create strong deforming forces on proximal diaphyseal fractures

Answer 13

deltoid

Question 14

_____ and deltoid create strong deforming forces on proximal diaphyseal fractures

Answer 14

pec major

Question 15

_____ tendon interposition in proximal diaphyseal fractures may lead nonunion

Answer 15

biceps

Question 16

biceps tendon interposition in proximal diaphyseal fractures may lead to _____

Answer 16

nonunion

Question 17

physical exam:

Answer 17

assess the fit of functional brace and skin irritation
atrophy
angulation
motion
gross motion at the fracture site
neurovascular
assess radial nerve function

Question 18

recommended radiographic views

Answer 18

AP and lateral of the humerus, shoulder, and elbow

Question 19

radiographic findings

Answer 19

lack of fracture consolidation
hypertrophic callous formation
pseudarthrosis

Question 20

to evaluate for the extent of bridging callous and preoperative planning

Answer 20

CT

Question 21

CT indications

Answer 21

to evaluate for the extent of bridging callous and preoperative planning

Question 22

serum labs to order

Answer 22

CRP, ESR, CBC (must rule out infection)
total protein and serum albumin
vitamin D, TSH, PTH

Question 23

nonoperative treatment involves:

Answer 23

functional bracing +/- bone stimulation

Question 24

non op indications

Answer 24

rarely indicated unless low demand, high-risk surgical candidate, and asymptomatic nonunion

Question 25

nonunion over a period greater than 9 months or no progressive healing 3 months from injury indicates use of ___

Answer 25

bone stimulator

Question 26

bone stimulator indications

Answer 26

nonunion over a period greater than 9 months or no progressive healing 3 months from injury

Question 27

bone stimulator contraindications

Answer 27

contraindicated if pseudarthrosis, fracture gap >5mm, or poor blood supply

Question 28

contraindicated if pseudarthrosis, fracture gap >5mm, or poor blood supply

Answer 28

bone stimulator

Question 29

gold standard operative technique

Answer 29

compression plating with bone grafting

Question 30

operative options

Answer 30

compression plating with bone grafting dual plating cortical strut allograft/autograft bone morphogenic proteins

Question 31

compression plating with bone grafting indications

Answer 31

symptomatic nonunion

Question 32

dual plating indications

Answer 32

very proximal or distal fracture nonunion poor metaphyseal bone quality micromotion noted at fracture site following single plate fixation

Question 33

very proximal or distal fracture nonunion poor metaphyseal bone quality micromotion noted at fracture site following single plate fixation

Answer 33

dual plating indications

Question 34

dual plating shows ____% union at 16 weeks

Answer 34

92-100

Question 35

cortical strut allograft/autograft indications

Answer 35

severe osteopenia from disuse, age, or prior surgery severe bone loss recalcitrant nonunion

Question 36

severe osteopenia from disuse, age, or prior surgery severe bone loss recalcitrant nonunion

Answer 36

cortical strut allograft/autograft

Question 37

bone morphogenic proteins indications

Answer 37

limited role as no studies show improved outcomes

Question 38

compression plating complications

Answer 38

radial nerve neuropraxia or injury ICBG donor site morbidity

Question 39

compression plating instrumentation

Answer 39

4.5mm compression plate placed anterior, lateral, or posterior

Question 40

dual plating instrumentation

Answer 40

place additional plate orthogonal to the first plate

Question 41

cortical strut bone work

Answer 41

place strut intramedullary and then place the plate place strut medially and place laterally based compression plate

Question 42

complications:

Answer 42

nerve injury persistent nonunion

Question 43

most common nerve injury

Answer 43

radial

Question 44

treatment of persistent non union

Answer 44

free fibular grafting

Question 45

free fibular grafting indications

Answer 45

recalcitrant atrophic nonunions

Question 46

With operative treatment of nonunion, _____% of patients go on to union

Answer 46

83-100