Juvenile Bone Disease, Pt. 2 Flashcards
What is the most common cause of an ununited anconeal process? When does it normally become ossified?
delay or cessation in normal physeal development
5 months of age
What signalment is most commonly associated with an ununited anconeal process?
- large or chondrodystrophic breeds
- M > F
- 30% bilateral disease
How does breed affect etiology of ununited anconeal processes?
BASSET HOUNDS - elbow incongruity
GSDs - osteochondrosis
What are the most common signs of an ununited anconeal process? How is it diagnosed?
intermittent lameness, joint effusion, and pain on extension in patients that are 4 months to 3 y/o at presentation
flexed lateral radiograph
What treatment is used for ununited anconeal process? What is prognosis like?
surgical removal of the anconeal process
guarded to good, depending on degenerative changes at the time of surgery
Ununited anconeal process removal:
Other than removal, how can an ununited anconeal process be treated? When is this performed over removal? What risk is associated?
stabilization
- large bone fragment to permit lag screw fixation
- minimal degenerative changes at the time of surgery
implant failure
What is a fragmented coronoid process? What signalment is most commonly associated?
disruption of the coronoid process prior to ossification
- 3 months to 7 y/o
- M > F
- 30% bilateral
What 3 signs are associated with fragmented coronoid processes? How is it diagnosed?
- intermittent lameness
- pain on deep palpation of the coronoid process
- joint effusion
two view radiographs or CT
What are the 2 options for fragmented coronoid processes? What is prognosis like?
- open arthrotomy - osteotomy, tendon transection, tendon spreading
- arthroscopy
guarded to good depending on the degenerative changes at the time of surgery
Fragmented coronoid process, open arthrotomy:
What is osteochondrosis of the medial humeral condyle?
progressive degenerative joint disease - cartilage of the growing elbow joint fails to develop normally and becomes abnormally thickened and damaged
- 3-6 m/o, large or giant breeds
- 50% bilateral
What are 3 signs of osteochondrosis of the medial humeral condyle? When do radiographic changes manifest?
- insidious onset lameness
- joint effusion
- secondary degenerative changes, commonly occuring with other forms of osteochondrosis (FCP, UAP)
6-8 months
What are the 2 options for treating osteochondrosis of the medial humeral condyle?
- arthroscopic - minimally invasive, technically demanding, high equipment cost
- open arthrotomy - invasive, low cost, high success
What are the 2 major limitations of surgical treatment of osteochondrosis of the medial humeral condyle?
- surgical removal of all joint mice and curettage of the cartilage defect is difficult
- difficult to inspect all joint compartments from one approach
What 2 treatments are recommended post-op for osteochondrosis of the medial humeral condyle?
- glucosamine/chondroitin sulfate
- physical therapy
What signalment is associated with congenital elbow luxation? What causes it?
5-6 weeks old toy and small breeds
abnormal boney development causes secondary laxity in the ligamentous support structures of the joint —> ligamentous hypoplasia = radial/ulnar luxation
Why is prognosis for congenital elbow luxation so poor?
surgical reduction is often impossible —> arthrodesis usually necessary
What is the most common etiology of premature closure of the distal ulna physis? What is a sign of this on radiographs?
- trauma**
- hypertrophic osteodystrophy = excessive callus formation restrict physis
physis/fracture lines not visible
What are 3 reasons that the antebrachium so susceptible to premature closure of physes?
- growth distribution
- physeal anatomic differences
- interdependency of the radius and ulna
What is the growth distribution of the radius and ulna?
RADIUS - 60% of length from distal physis
ULNA - 85% of length from distal physis
Why does a majority of growth in length arise from the distal physis of the ulna? What disadvantage does this have?
conical shape of distal physis and increased diameter provide increased surface area for germinal cells
conical shape is unique to the dog and results in an increased susceptibility to Salter-Harris Type V (crush) physeal injuries
Salter-Harris physeal fractures:
Physis
Metaphysis + physis
Epiphysis + physis
(BOTH) metaphysis + epiphysos + physis
Compression of physis
How does the Salter-Harris fracture type contribute to prognosis?
Type I = slip fracture due to lateral traumatic forces applied to the distal radius —> good prognosis
Type V = compression/crush fracture due to lateral forces applied to the distal ulna —> poor prognosis
What 2 bones must grow in synchrony for normal development?
radius and ulna
What are 5 signs of premature compression of the distal ulnar physis?
- cranial bow
- carpal valgum
- decreased length
- supination
- proximal subluxation of the humeral condyle
Premature compression of the distal ulnar physis, cranial bow:
Premature compression of the distal ulnar physis, carpal valgum:
displacement of part of a limb lateral from the midline
Premature compression of the distal ulnar physis, supination:
rotation lateral to midline
(+ decreased length)
What treatments for premature compression of the distal ulnar physis are recommended for growing and mature dogs?
< 8 months = multiple ulna ostectomies, distraction osteogenesis, physeal stapling, periosteal stripping
> 8 months = dome, stair step, or wedge radial osteotomy, ulna osteotomy/ostectomy