Proximal Humerus Fracture Nonunion & Malunion Flashcards
fracture characteristics that increase risk for nonunion
2-part (surgical neck) fracture patterns
humeral head split
displaced tuberosity fractures
patient factors that increase risk for nonunion
osteoporosis
chronic renal disease
chronic alcohol or steriod use
smoking
origin of malunion:
initial fracture displacement
secondary displacement after loss of reduction
failure of internal fixation
humeral head malunion:
initial fracture displacement
secondary displacement after loss of reduction
failure of internal fixation
greater tuberosity malunion
usually displaced posterior, superior and _____
externally rotated
____ tuberosity malunion
usually displaced posterior, superior and externally rotated
greater
_____ tuberosity malunion
usually displaced medial
lesser
lesser tuberosity malunion
usually displaced ____
medial
associated conditions
rotator cuff tearing
osteonecrosis of humeral head
glenohumeral joint issues
associated glenohumeral joint issues may include:
stiffness
post-traumatic arthritis
subluxation or dislocation
subacromial impingement
average humeral head diameter
43 mm
humeral head is retroverted _____° from transepicondylar axis of the distal humerus
30
humeral neck-shaft angle usually ____
130-140 degrees
position important for rotator cuff muscle fuction
greater tuberosity
medial edge of greater tuberosity is _____ mm lateral to humeral canal axis
10
medial edge of tuberosity is 10mm lateral to _____
humeral canal axis
superior edge of greater tuberosity is _____ mm inferior to upper edge of humeral head
6
superior edge of greater tuberosity is 6mm inferior to _____
upper edge of humeral head
physical exam inspection:
features of systemic disease
muscle atrophy
diffuse tenderness
_____ malunion = apprehension test
humeral head
humeral head malunion = _____ test
apprehension
_____ malunion = weakness with abduction, external rotation
greater tuberosity
greater tuberosity malunion = weakness with _____
abduction and ER
_____ malunion = weakness with internal rotation
lesser tuberosity
lesser tuberosity malunion = weakness with _____
internal rotation
radiographic views
true AP, scapular Y, axillary
radiographic findings
neck-shaft angle = varus or valgus
greater tuberosity = superiorly and posteriorly displaced, externally rotated
lesser tuberosity = medialized
humeral head radiographic measurements
> 45° of deformity in any plane
symptomatic articular incongruity
neck-shaft angle <120° or >150°
greater or lesser tuberosity radiographic findings
> 1 cm from native anatomical position
CT indications
preoperative planning
assess bone stock, orientation and articular surface
CT findings
humeral head and greater tuberosity displacement
glenoid version and glenoid bone stock
articular injury
MRI indications
preoperative planning
soft-tissue structures
MRI findings
rotator cuff or labral injury
deltoid atrophy secondary to axillary nerve injury
long-head biceps injury
osteonecrosis
labs to obtain
CBC, ESR, CRP, blood cultures to rule out infection
non op treatment modalities:
NSAIDS, physical therapy, occasional corticosteroid injection
non op indications
low-demand patient
painless shoulder limitations
unable to comply with the rehabilitation protocol
non op outcomes
return to 90% of normal function
operative options
ORIF +/- osteotomy, subacromial decompression, and soft tissue technique
shoulder arthroplasty
ORIF indications
symptomatic malunion following
nonoperative treatment
failed internal fixation
anatomic requirements for ORIF
adequate bone stock for fixation
preserved articular surface
intact blood supply to humeral head
complication rates associated with surgical management of malunions are _____ than those associated with acute fractures
higher
shoulder arthroplasty indications
symptomatic malunion following
nonoperative treatment
failed internal fixation
anatomic requirements for shoulder arthroplasty
inadequate bone stock for fixation techniques
articular incongruity, destruction or collapse (e.g. osteonecrosis or head-split)
compromised blood supply
chronic dislocation
greater improvement in functional outcome scores than hemiarthroplasty
lower complication rates than hemiarthroplasty
reverse total shoulder
ORIF-minor deformity techniques
open/arthroscopic tuberoplasty
+/- acromioplasty
+/- capsular release
+/- bursectomy
ORIF severe deformity techniques
varus/valgus osteotomy
+/- rotational osteotomy and lateral plate fixation
greater tuberosity deformities
<1.5 cm displacement what to do in ORIF
arthroscopic subacromial decompression +/- rotator cuff repair
greater tuberosity deformities >1.5 cm displacement what to do in ORIF
open/arthroscopic tuberosity osteotomy +/- subacromial decompression
complications
Persistent pain and weakness
Stiffness
Loss of fixation
Infection
Bleeding
