55. RU Flashcards
how much weight bearing force is carried by the proximal radial articular surface at the level of the elbow
51%
T/Fgrowth of ulna is 100% from distal ulnar physis
True page 760the proximal ulnar physis is only responsible for olecranon elongationdistal ulnar physis is responsible for 100% ulnar growth
procurvatum of radius
27 degrees
amount of radial shortening required to achieve 90% SN on rads
1.5-4.0 mm CT is more SNonly need 1 mm difference to be able to diagnose on CT 3-d recon
tx options for short radius
- gradual dynamic radial lengthening–DO (if young dog)–radial osteotomy and flexible ESF placement to distal humerus–Stader apparatus ESF and controlled distraction–circular ESF2. acute elongation (skeletally mature dogs)–radial sagittal sliding osteotomy with screw stabilization–osteotomy, bone spread, cortical graft and plate/ESF stabilization3. shorten ulna to match radius–ulnar ostectomy proximal to interosseous ligament
tx options short ulna
- dynamic proximal ulnar osteotomy (ostectomy if young)2. distal ulnar osteotomy + interosseous ligament transection3. ulnar lengthening with distraction/ESF4. osteotomy with buttress plating/rigid fixation5. sagittal sliding osteotomy of ulna
secondary changes of distal ulnar physeal injury
- radial procurvatum2. distal valgus3. ulna shortening4. torsion5. +/- UAP
methods needed to prevent premature bone regeneration at ostectomy site
- ostectomy of 1.5x the bone diameter2. remove periosteum3. fat graft insertionkeys hypothesis= the distance that overcomes the regenerative capacity of bone in a mature animal
T/Fdome osteotomy of canine ante brachial ALD models had diminished accuracy in correctly sagittal plane deformities and achieved generally less bone apposition that closing wedge techniques
TRUE
T/FPaleys second rule of osteotomies can be successfully employed to intentionally position the osteotomy proximal to a juxta-articular CORA
TRUEthis will result translational abnormality but still be colinear
surgical repair methods for congenital luxation of the radial head
—nothing–radial head ostectomy (may regrow if young)–closed reduction and transarticular circular ESF–closing or opening wedge osteotomy/ostectomy with olive wire tensioned to draw radial head back in place and transarticular ESF– elbow arthrodesis
distally, the radial nerve course under what muscle
supinator muscle
_________% of radial fractures in toy breed dogs treated with external coaptation result in malalignment or nonunion
83%
what structures may need to be scarified during internal fixation near the distal radius
cephalic veinabductor pollicus longus muscle
how to repair styloid process fracture of either the radius or ulna
lag screw(s) or pin and tension bandorigin of MCL and LCL for radius and ulna respectively
antebrachial vascular differences btwn toy and large breed dogs
small breeds have decreased vascular density at the distal diaphyseal/metaphyseal junction compared with large breed dogscan result in delayed healing
if osteopenia is noted on post op films of toy breed dog with radial fracture repair
stress protection most likelyfixation may require destabilizationstart with removal of a set of screws (one from each side) closest to the fracture and wait 3-4 weeks
pin and tension band considerations for repair of proximal olecranon fracture
wire size is more important than pin sizeretrograde pin placement decreases risk of inadvertent penetration into trochlear notch
types of monteggia fractures
- proximal ulna fracture cranioproximally with radial cranially luxated; MOST COMMON2. proximal ulnar fracture caudally angulated with radial head caudally luxated3. lateral radial head lux4. cranial radial head lux but fracture of radius and ulna
repair options for type I monteggia fracture
- closed reduction and ulnar IM pin placement2. ulnar plate with lag screw into radial head +/- suture annular ligamentCAUDAL SPLINT 3-4 weeks post op!
most common complication following monteggia fracture repair
decreased ROMOAradial head luxation recurrence
