Abos Day 34 A 1-3

Front 1

Adolescent Blount's definition?
characteristics Adolescent Blount's ? (horse)
what is Infantile Blount's

Back 1

- pathologic genu varum in children > 10 years of age centered at the tibia, >16 degrees
-1 more likely to have femoral deformity; 2-less common; 3-less severe; 4-more likely to be unilateral
-pathologic genu varum in children 0-3 years of age

Front 2

Etiology- Blount's is thought to be caused by ?
Risk factors ? (elevator)

Back 2

-Blount's is thought to be caused by a dyschondrosis of medial physis of proximal tibia; likely multifactorial but related to mechanical overload in genetically susceptible individuals
-obesity; african-american descent

Front 3

what xray measurements is abnormal and is therefor define Adolescent Bount's disease?
(aka)

Back 3

(b)-metaphyseal-diaphyseal angle (Drennan) ;
>16 degrees is considered abnormal
angle between line connecting metaphyseal beaks and a line perpendicular to the longitudinal axis of the tibia

Front 4

name 3 Operative txs, classification of type of Tx and indications for each, outcomes?
goals of correction?

Back 4

1 lateral tibia and fibular epiphysiodesis; transient hemiepiphysiodesis or permanent hemiepiphysiodesis indications- mild to moderate deformity with growth remaining & up to 25% may require formal osteotomy due to residual deformity
2 proximal tibia/fibula osteotomy; high tibial osteotomy with rigid internal fixation or osteotomy with external fixation and gradual correction; indications-more severe cases in the skeletally mature & multiplanar external fixation following osteotomy allows gradual angle and length correction and decreases risk on neurovascular structures
3 distal femoral osteotomy or epiphysiodesis; indications- for distal femoral varus deformity of 8 degrees or greater
goals of correction
strive for neutral mechanical axis

Front 5

infantile Blount's; definition re normal?
describe normal development?

Back 5

Infantile Blount's disease is pathologic cause of genu varum in children less than 3 years of age.
-Genu varum is a normal physiologic process in children
(bowed legs) is normal in children less than 2 years
-genu varum migrates to a neutral at ~ 14 months
continues on to a peak genu valgum (knocked knees) at ~ 3 years of age; genu valgum then migrates back to normal physiologic valgus at ~ 4 years of age

Front 6

A 32-month-old male with severe infantile Blounts disease has been treated with full time bracing for the past year. At most recent follow-up, the varus deformity of his bilateral legs has worsened despite compliance with bracing. What treatment is now recommended?

Back 6

Bilateral proximal tibial osteotomies
Infantile Blount’s disease is a pathologic type of tibia vara which develops in children 0-4 years of age. Bracing is indicated in patients < 3 years of age with Langenskiöld stage I-II disease, and is more effective in patients with unilateral disease. Surgery is indicated if varus secondary to Blount's disease persists at the age of 4 or if bracing fails in 2-3 year olds after 12 months (answer 3). Correction is achieved surgically with a proximal tibial realignment osteotomy. Answer 5 is incorrect because closing down the medial side will cause further varus. Answer 4 is wrong because the pathology is in the tibia and not the femur in infantile blount’s.

Front 7

n the treatement of Blount's disease, how do plates or staples help correct the genu varum deformity?

Back 7

Increasing compression forces across the physis to slow longitudinal growth
Blount’s disease, also called tibia vara, is the most common cause of genu varum that is not physiologic. The pathoanatomy is thought to involve excessive medial pressure (eg, heavy, early walkers who are in physiologic varus alignment) that produces an osteochondrosis of the physis and adjacent epiphysis that can progress to a complete physeal bar. The Hueter-Volkmann law states that increasing compression across a growth plate leads to decreasing growth and increasing tension stimulates growth.

Front 8

A 30-month-old boy has worsening bilateral bowleg deformities, and radiographs are shown in Figure A. The most appropriate initial management should consist of which of the following?

Back 8

Full-time bracing with knee-ankle-foot orthoses
-Initial treatment is non-operative in children less than 3 years of age consists of full time bracing with a knee-ankle-foot orthosis.
Radiographically, a widened and irregular medial physeal line and an irregularly ossified and medially sloped epiphysis are seen.
Operative management in children older than 3 is considered if non-operative management has failed, or in Langenskiold classes V and VI, where there is a congenital bar across the physis.
When osteotomy is required, overcorrection to at least 5 degrees of valgus should be done.

Front 9

A 15-year-old high level Little League pitcher sustains an injury to his dominant elbow shown in Figure A. Radiographs demonstrate 7mm of displacement. Which of the following treatments will result in the highest rate of bony union?

Back 9

Open reduction and internal fixation
Surgical treatment indications based on displacement vary across the literature from 2 to 10mm. Fracture fragment incarceration and open fractures are absolute indications while relative indications include valgus instability and ulnar nerve dysfunction. Non-operative treatment can lead to fibrous unions which may be symptomatic in some cases.

Front 10

Which of the following fracture patterns (Figures A-E) is most commonly associated with a combined ulnohumeral and radiocapitellar elbow dislocation in children?

Back 10

Medial epicondyle fractures are the most common fractures patterns associated with elbow dislocations in a child.

Rasool reports in a Level 4 study that 33% of the children sustaining elbow dislocations had concomitant medial epicondyle fractures.

Front 11

A 9-year-old boy fell off of a swing set and injured his left elbow. Radiographs are shown in Figures A and B. Open reduction and internal fixation of this fracture is indicated secondary to which of the following:

Back 11

An irreducible, incarcerated fragment in the ulnohumeral joint.
Medial epicondyle avulsion fractures can be treated with open reduction and internal fixation when the fractured fragment is incarcerated in the ulnohumeral joint or if there is significant ulnar nerve dysfunction. Figures A and B show a displaced medial epicondyle fracture that is incarcerated in the ulnohumeral joint, thus requiring ORIF.

Front 12

Which of the following muscles is involved in the avulsion injury that creates the fracture shown in Figure A?

Back 12

Pronator teres
The radiographs show a displaced medial epicondyle fracture, which results from extreme valgus loads or violent muscle contractions in overhead athletes during the throwing motion and commonly occur in adolescents as the medial epicondyle begins to fuse. The medial epicondyle is avulsed by forceful contraction of the common flexor wad, which includes the pronator teres, flexor carpi radialis, palmaris longus, flexor digitorum superficialis, and flexor carpi ulnaris.

Front 13

A 7-year-old boy presents the emergency room with a left elbow injury after falling off of the monkey bars. His neurovascular examination in the extremity is normal and his pain is controlled. Post-reduction radiographs are shown in Figure A. What is the next most appropriate step in management

Back 13

Open reduction and internal fixation
Figures A shows a displaced medial epicondyle fracture that is incarcerated in the ulnohumeral joint following an attempt at closed reduction. Closed reduction manuever to extricate the incarcerated fragment can be performed with the Roberts' technique, which includes placing valgus stress on the elbow, supinating the forearm, and extending the wrist and fingers. Medial epicondyle fractures with incarcerated fragments that fail manipulative closed reduction require open reduction. In contrast, displaced medial epicondyle fractures can be treated with closed management if the fragment is not incarcerated in the joint.
the magnitude of acceptable displacement of these fractures is highly variable among surgeons.

Front 14

An 11-year-old child sustains an elbow dislocation. The elbow is reduced, but post-reduction radiographs demostrate that the ulnohumeral joint remains slightly incongruent. What is the most likely etiology for this continued incongruency? Topic

Back 14

Interposed medial epicondyle fragment
as many as 50% of medial epicondyle fractures are associated with elbow dislocations. Illustration A and B display a medial epicondyle incarcerated within the ulnohumeral joint following an elbow dislocation. Fractures of the medial epicondyle tend to occur in older children between the ages of 10 and 14. Simple fractures of the medial epicondyle are extra-articular injuries with limited soft-tissue involvement.

Minimally displaced fractures may be treated conservatively with initial splinting in 90 degrees and then initiation of AROM within one week with with protective splinting for another few weeks. Absolute indications for operative treatment are irreducible incarceration of the medial epicondyle in the joint and the rare open fracture. Functional demands of the patient (thrower, gymnast) and magnitude of displacement may be considered as well, but are not absolute indications. Closed reduction of an incarcerated fragment may be attempted by supinating the forearm, placing a valgus stress on the elbow, and extending the wrist and fingers. If unsuccessful, ORIF while protecting the ulnar nerve is necessary.

Front 15

Medial Approach to the Elbow
-Incision describe, centered over?
-Superficial dissection, isolate what, expose?
-develop between what and what muscles?
-avoid what stucture?
-what can be done to improve exposure for bony work?
-key matter to remember if doing osteotomy?
-where develope muscle interval?
Deep dissection proximately and distally?

Back 15

-curved incision 8 to 10 cm long on the medial aspect of the elbow & centered over the medial epicondyle
Superficial dissection- incise the fascia over the ulnar nerve starting proximally; isolate nerve along the entire length of the incision; expose the common flexor origin on the medial epicondyle
- develop brachialis and PT interval
-avoid the median nerve which enters PT near the midline
-if necessary can perform osteotomy of the medial epicondyle to fix the coronoid; osteotomy is reflected distally; ensure retained MCL ligament into osteotomy fragment
- develop brachialis and triceps interval
Deep dissection- incise capsule and medial collateral ligament
-Extension; local- abduction of forearm opens medial aspect of joint can dislocate laterally by dissecting off joint capsule and periosteum
proximal- anterior surface of distal fourth of humerus can be exposed by developing plane between brachialis and triceps
distal-limited by the branches of the median nerve

Front 16

Dangers with Medial Approach to the Elbow?

Back 16

Ulnar nerve
is at risk during approach
must be dissected out to ensure protection
Median nerve
aggressive traction on the osteotomy fragment can cause a traction injury to the median and anterior interosseous nerves

Front 17

Complications Medial Epicondylar Fractures - Pediatric
(horse)
indications absolute & relative (elevator)

Back 17

1Nerve injury- ulnar nerve can become entrapped
neuropathy with dislocatoin which usually resolves
2 Missed incarceration- missed incarceration of fragment in elbow joint
3Elbow stiffness-loss of elbow extension, avoid prolonged immobilization
4 Non-union
indications

-absolute- displaced fx with entrapment of medial epicondyle fragment in joint & relative- ulnar nerve dysfunction; > 5-15mm displacement
displacement in high level athletes

Front 18

Dwarfism caused by a defect of fibroblast growth factor receptor-3 (FGFR3) is associated with all of the following traits EXCEPT: -dwarfism affects which zone of physis and is expressed as? (gold characteristics (5,4,4)inheritance pattern?
-which skeletal dysplasia is Cervical spine instability present & its defect is due to?

Back 18

Cervical spine instability
Achondroplasia, caused by a defective FGFR3 affecting --> proliferative zone of the physis,
Characteristic findings of achondroplasia include;
1 achondroplasia, the most common skeletal dysplasia, 2-normal intelligence; 3-frontal bossing, 4. midface hypoplasia, 5. otolaryngeal system dysfunction;

6- foramen magnum stenosis during infancy, spinal stenosis as early as the second decade caused by 7-shortened pedicles; 8-thoracolumbar kyphosis when sitting begins, 9-Cervical spine instability is not prevalent in achondroplasia,

10-rhizomelic short stature,Rhizomelic shortening is defined as disproportionate shortening of the proximal segment of limbs; 11-trident hands; 12-genu varum; 13 muscular hypotonia;.
-Inheritance is typically AD, although spontaneous mutations are not uncommon.
cervical instability is present in pseudoachondroplasia, a skeletal dysplasia due to cartilage oligometric matrix protein (COMP) gene.

Front 19

) Which of the following conditions is associated with a mutation in fibroblast growth factor receptor-3 (FGFR3)?

Back 19

Achondroplasia
Achondroplasia, the most common skeletal dysplasia,
--> proliferative zone of the physis,

Front 20

Gaucher's disease results from a mutation in?
football characteristics?

Back 20

a mutation in glucocerebrosidase. AR
- enzyme deficiency leads to a build-up of fatty substances in liver, kidneys, lungs, brain, spleen, bones, and bone marrow.

Front 21

Marfan syndrome is caused by a mutation in?

Back 21

fibrillin gene.

Front 22

Fibrous dysplasia results from a mutation ?

Back 22

Fibrous dysplasia in cAMP.
Shepard's hock

Front 23

Diastrophic dysplasia most commonly results from a mutation in ?

Back 23

Diastrophic dysplasia most commonly results from a mutation in the SLC26A2 gene which affects a sulfate transporter.

Front 24

Achondroplasia results from abnormal chondrocyte function in the physis. What receptor is defective and what region of the physis is affected?
rz-elevator;pz-anten;ahz-horse;Sz-elevator

Back 24

FGFR-3 receptor, zone of proliferation ;rhizomelic short stature; mutation enhances tyrosine kinase activity resulting in increased inhibition of chondrocyte proliferation and differentiation.