Ch 54 radius and ulna Flashcards
What percentage of weight at the elbow is transmitted through the radius and the ulna?
Radius 51%
Ulna 49%
Anatomy
The tendons of which muscle insert on the medial side of the radius and ulna?
Biceps brachii
Bracialis
What muscles share their origin with both the radius and the ulna in the mid-diaphysis?
Pronator quadratus
Deep digital flexor
Abductor pollicus longus
cranial muscles
What is the radioulnar ligament?
Proximal extension of the antebrachiocarpal joint capsule between the radius and ulna. Attaches proximally to the interosseus ligament
How much of the growth below the elbow is the distal ulna physis responsible for?
Proximal radial physis?
Distal ulnar physis 100%
Proximal radial physis 30-50%
What age do the physes of the antebrachium close?
222-250d (in Beagles)
aLDRA, Anatomic lateral distal radial angle; aMPRA, anatomic medial proximal radial angle.
What is the mean radial procurvatum of Labs?
26.6 degrees
(range, 14 to 39 degrees)
conformation of normal chondrodystrophic dogs possesses values far outside the ranges established
How do you calculate procurvatum?
On sagittal view:
Procurvatum = CORA magnitude + (90-aCdPRA) + (90-aCdDRA)
radius procurvatum
what is considered “normal” for any individual within these breeds, and at what point the characteristic conformation seen becomes pathologic in the sense of resulting pain and disability, is unknown
radial shortening
- compensatory increase in growth at the proximal radius falls short of maintaining appropriate radial length
- radius subsequently shortens > humeroradial and humeroulnar subluxation occur.
- With increasing space, the humeral condyle becomes cranially displaced, putting pressure on the coronoid processes of the ulna
- premature closure of the proximal radial physis can also result in overall radial shortening
What is the sensitivity and specificity of rads for diagnosing radioulnar incongruity?
Sensitivity 78%
Specificity 86%
Radial shortening needed to be between 1.5-4mm for a 90% sensitivty
What is the sensitivty and specificity of arthroscopy for diagnosing radioulnar incongruity?
Sensitivity 94%
Specificity 81.9%
What it he sensitivity, specificity and interobserver agreement for radioulnar incongruency on 3D printed models with a 1mm incongruence
Sensitivity 82%
Specificity 100%
Interobservor agreement 87%
Radial shortening Tx
goal: reestablish radioulnar congruency at the elbow + bone alignment.
- depending on the severity of the condition and the age
- young animals may outgrow the correctional measures
- Elbow joint congruence > either by lengthening the radius or by shortening the ulna
- can be completed acutely or gradually
- gradual > radius should cease its migration when the articular cartilage contacts the humeral capitulum
- in immature > gradual/dynamic best
- in skeletally mature dogs > any of gradual dynamic lengthening procedures (for stretching the soft tissues joining the two bones) OR one-stage radial elongations
- for acute: confirm radial head position requires radiography or, optimally, arthroscopy
What are the Tx options for radial lengthening? (4)
.1. Distraction osteogenesis
- advantages in the young animal, allow some adjustability to adapt to continued growth.
- Semi-controlled, gradual elongation: transverse osteotomy of the proximal radius and the placement of separate pins and radius and humerus with elastic material
- main advantage> little risk that the radial head will reposition too far proximally
- controlled: circular ESF, disadvantage is radial head position is under the direction of the surgeon
.2. Transverse osteotomy and acute correction
- use of bone spreaders for distraction, stabilization with plate or ESF
- large bone gap > lack of load sharing with the implant > consider cortical bone graft
.3. Sagittal sliding osteotomy (acute correction)
- preserving load sharing
- lag screw with neutral plate
.4. ulnar ostectomy above interosseous ligament
- shorten under the progressive use of the limb and the weight of the animal
- with an IM pin> dynamic + gradual shortening
- acutely shortened with hemicerclage
- recommended for mature animals.
- in puppies, the risk ostectomy gap may heal before
How much radial lengthening has been reported with the use of an ESF and distraction osteogenesis?
Up to 50% of the original radial length
ulna shortening
- geometric configuration of the distal growth plate is the primary reason why affected
- Most physes are relatively flat > predispose to shear fractures
- physis of the ulna is conical in shape and thus is unable to shear
- force from any direction can cause compression > injury to the germinal cells
- heritability of premature ulnar physeal closure as related to conformational development of specific breeds
- ulna shortening can affect radius growth too
- can cause humeroulnar incongruity (alter trochlear notch) excessive biomechanical loads on radial head and anconeal process > OA
What percentage off physeal insults is made up of distal ulnar physeal injury?
63%
What are the typical changes in the radius secondary to premature closure of the distal ulnar physis?
PTSDv
Procurvatum
Torsion
Shortening
Distal valgus
What are the surgical options for ulnar lengthening? (5)
(immature or mature)
Dynamic ulnar ostectomy/osteotomy
Distal ulnar ostectomy
ESF and distraction osteogenesis
(mature)
Distracted osteotomy and plating
Sagittal sliding osteotomy
proximal ulna guided in semi-controlled or controlled, dynamic or static
dynamic ulnar ostectomy
semi-controlled woth IM pin
- skeletally immature patients, treatment of choice.
- frees the proximal ulna, so it is no longer constrained by retarded growth of the distal physis, move proximally and optimize congruency with the humerus.
- goal is to allow unrestricted longitudinal bone growth of the radius, may prevent worsening of radial angulation if growth potential still reside
- In the immature, ostectomy is preferable > larger gap will help prevent osseous union before cessation of radial growth
- mature dog, “osteotomy” because premature union is less of a concern
- ostectomy just distal to the coronoid processes (semi-controlled), contraction of the triceps brachii muscle group exerts a traction force
- Placement of Hohmann retractors around the ulna will isolate the ulna and protect the radius > sawing may be ceased, completed with osteotome
complications: - pulling force of the triceps not perfectly axial but an angle, exerting a bending moment at ostectomy
- bending/caudal displacement causes an iatrogenic recurvatum deformity (methods to counteract: IM pin, oblique ostectomy but wont work if large gap)
- accidentally score the radius, result in a synostosing callus between the two bones.
- Instability > formation of an exuberant callus > syostosis or irritate soft tisssue caudal ulna
- pin migration
- irritation of triceps brachii muscle
- pin failure
What can done to aid in stability of a proximal dynamic ulnar osteotomy/ostectomy? (2)
to prevent bending moment
Oblique cut (proximocaudal to craniodistal)
IM pin (in immature)
revision sx: graft + plate
method used to avoid instability and recurvatum of the ostectomized ulna
ostectomy of the distal part of the ulnar diaphysis or removal of the distal physis itself
- interosseous ligament to help stabilize
- unknown is the comparative efficacy of low versus high dynamic ulnar ostectomies in the skeletally immature dog in reestablishing humeroulnar congruence
- in vitro: distal to the interosseous ligament did not allow adequate movement of the ulna in one study
What methods can reduce the chances of permature healing of the ulna ostectomy? (3)
goal: unrestricted longitudinal bone growth of the radius
- Ostectomy gap greater than 1.5x diameter of the bone (Key’s hypothesis)
- Removal of all periosteum in the vicinity
- Insertion of free fat graft into ostectomy
What is the Heuter-Volkmann law (aka Delpech’s law)?
Physeal growth is slowed by excessive compression and is accelerated by distraction
Developmental antebrachial angulation
(1) asymmetric premature closure of the proximal or distal physis of the radius or both
(2) premature closure of the distal physis of the ulna with continued radial development
(3) a combination of the two
- decisions regarding timing and the type of correction to be completed
- skeletally immature risk: correction before development ceases is that the angulation can return
- delay surgery until mature risk: angulation will negatively affect biomechanical loads at joints, creating stress + OA
- success rate of ulnar ostectomy as the sole treatment for premature ulna closure of juvenile dogs is relatively unknown
- reestablishing normal antebrachial bone and joint alignment, or resolution of lameness, not prospectively studied
- PUO utility as the sole corrective procedure limited to mild radial changes
- > > radial corrective measures are often necessary
- likely that distal radial physis also damaged, resulting in more complex deformity
What had been associated with unsuccessful outcomes after a distal ulnar ostectomy to treat ulnar shortening?
Radial valgus greater than 25 degrees
If varus, recurvatum or internal torsion are present then radial corrective measures will be necessary
Antebrachial Angular Limb Deformity Surgical Planning
presurgical planning called the center of rotation of angulation (CORA) method
goal of this technique is to determine the apex of the deformity or deformities (also referred to as CORAs) using the radial anatomic or mechanical axis in conjunction with the joint orientation angles
1. normal contralateral antebrachium agles used or mean joint orientation angles (bilateral dz)
2. frontal plane joint orientation lines
3. frontal plane radial anatomic axes
4. Determine where the anatomic axes intersect within the cortical confines of the bone > CORA
5. repreat in sagital
6. If angulation in both orthogonal planes, then an oblique plane deformity is present
radioulnar angular limb deformities frequently include torsion
ALD torsion
- torsion in excess of 15 degrees results in radiographic miscalculation greater than 5 degrees in the frontal plane
- surgical planning based on orthogonal radiographs alone appears unreliable when severe torsion is present
- require additional diagnostics such as CT +/- stereolithographic modeling (perform a rehearsal surgery)
rads of dog affected by angular and torsional deformities
- Radiographs of the elbow are prioritized. > “straight elbow” radiograph, which will allow determination of elbow joint orientation lines and the anatomic axis of the proximal portion of the radius.
- Radiographs of the carpus are prioritized. > “straight carpus” view that can be assessed for the joint orientation line and the distal radial anatomic axis.
Uniapical Deformities
- premature closure of the distal physis of the ulna and possible associated premature closure of the lateral aspect of the distal radial physis
- valgus, procurvatum, and torsion of the radius.
- gross appearance of cranial bowing of the antebrachium, valgus deviation and external rotation of the distal limb
- CORA may occur anywhere > most frequently localized on/proximal to, the distal physis
- radial deformities in distal diaphysis or metaphysis can occur congenitally and may result in lateral deviation and luxation of the radial head
- deformities occur secondary to malunion
premature closure of the lateral aspect of the distal radial physis causing distal radioulnar separation, ulnar recurvatum, and radiocarpal incongruity
Biapical Deformities
- two CORAs within the cortical confines of the radius
.1.Partially compensated - planes of the proximal and distal CORAs occur in opposite directions
- result of the Hueter-Volkmann law
- proximal CORA with varus deviation, partially compensated by a distal CORA with valgus deviation
- many chondrodystrophic dogs naturally possess biapical, partially compensated
.2. Noncompensated - planes of the two CORAs exist in the same direction, thus magnifying the overall deviation of the deformity in one direction
What percentage of antebrachial deformities are biapical in chondrodystrophic breeds?
80%
Multiapical Deformities
possess more than two CORAs
Surgical Correction planning
integrity of the carpus
- should be assessed through palpation or stress radiography (laxity)
- may result from severe radioulnar angulation due to substantial stretching of the joint capsule and collateral ligaments on the convex side of the deformation
- often laxity subsides once the limb is straightened and biomechanical loads across the carpus are normalized
- persistent laxity following surgery could negatively affect the long-term function and require additional surgery (imbrication, pancarpal arthrodesis)
uniapical
- single corrective osteotomy or ostectomy on the transverse bisecting line of the CORA.
- closing wedge
- cylindrical (incapable of achieving accurate correction of torsional deformities)
- dome osteotomies (diminished accuracy in correcting sagittal plane, less bone apposition)
- ESF with opening wedge osteotomy
Biapical
- may require correction of both CORAs, challenging + invasive due to small size of bone
- ulna typically requires a releasing osteotomy at the level of each radial osteotomy (torsion may prevent fixation of ulna)
- Gradual with bi-hinged circular ESF
- bone plates and screw
care: avoid radial nerve, runs deep to supinator muscle
antebrachial angular limb deformity correction
knowledge of the CORA location, magnitude, and plane
- internal fixation with bone plates
- linear external skeletal fixators
- circular external skeletal fixators
- hybrid linear-circular external skeletal fixator constructs
each offers advantages and disadvantages:
PLATE
- less intensive post-op
- no postoperative modification possible
ESF
- accuracy of correction and the adaptability,
- opening wedge osteotomy has the advantage of preserving some limb length
- disadvantage that fixation must be applied in buttress fashion
- hinged circular ESF used, the angulation correction axis is determined by the axis of the hinges of the fixation frame
- complications: wire breakage, skin irritation, osteomyelitis, and radial re-fracture
What percentage of dogs with an antebrachial deformity corrected with a CESF has improvement in function?
60%
What percentage of radial deformities in an oblique plane were accurately correced using a radial or cylindrical saw?
44%
A true domes osteotomy ascribes to which low of osteotomies?
Paley’s second rule
craniomedial approach
distal radius juxta-articular (metaphyseal or epiphyseal) deformity
- if hinged ring fixator > opening osteotomy may be placed on the CORA
- insufficient bone or using a bone plate, then Paley’s second rule can be employed > osteotomy proximal to the CORA.
- result in a translational deformity
- use cylindrical or true dome osteotomy blade
distal diaphyseal deformity, which results in congenital, laterally deviated radial head luxation
poorly understood etiopathogenesis
open or closed reduction
Open > acute correction and thus require the release of soft tissues constraining the radial head, can result in an unstable joint
- TA-ESF humeroradial distraction
- closing or opening wedge osteotomy positioned on the defined CORA.
- The radial head is moved by placing the olive wire, reduced over a period of 7 to 10 days
- radial head is maintained > pin through the radial head into the ulna
- concurrent dynamic ulnar osteotomy will help to prevent humeroulnar subluxation
- young: articular cartilage of the radial head is able to remodel in response to the forces
- mature: reduction of the head may result in more severe incongruity between the radial head and the capitulum of the humerus, may be limited to salage tx only (amp, arthrodesis, Cx, head ostectomy)
- Regardless of technique, early postoperative physical therapy is advocated
What are the treatment options for congenital radial head luxation?
- Conservative managment
- Open surgical reducation and fixation (50% retained reduction of between 50-80%, 50% reluxated)
- Radial head ostectomy (in young dog regrowth become exuberant, humeroulnar articulation in the adult dog)
- Arthrodesis
ALD post-op care
ESF
- monitoring of the pin–soft tissue interface (irritation or drainage)
- pin failure or underlying osteomyelitis, which may require pin replacement or antimicrobial therapy, respectively.
- frequent radiographic examination: presence of regenerative bone in the osteotomy gap, to allow appropriate modifications in distraction speed.
internal fixation
- rigid caudal splint or a bivalved cast
- 4-6 weeks
- destabilized over time as radiographs indicate increased healing.
prognosis
- severity of elbow osteoarthritis and more severe functional impairments were significant prognostic indicators
- dogs with biapical deformities are more likely to possess joint pathology affecting the elbow, carpus, or both joints at the time of presentation
- chondrodystrophic dog more likely to be severely afffected
- discussed with the owners before surgery because osteoarthritic changes may mitigate postoperative results
Antebrachial Fracture in the Juvenile Patient
- Salter-Harris fracture of proximal or distal radial physes or the distal physis of the ulna
proximal radius - challenging because of the small size of the epiphysis, the complexity of surrounding soft tissue, and the constraints of the elbow joint
- ORIF, craniolateral approach
- epiphysis is cross-pinned to the metaphysis with Kirschner wires
distal physis of the radius
- usually accompanied by a fracture of distal ulna
- fluoroscopically guided closed reduction
- Kirschner wires crossed, starting at the radial and ulnar styloid processes and directed proximally
- caudal splint for 1 to 2 weeks to gain additional stability (protect against the force generated by the long lever arm)
- removal of the implants in 4 to 6 weeks
- possibility of premature closing of the radial or ulnar physes, may result in 3 issues:
.1. radial shortening,
.2. elbow joint incongruity
.3. antebrachial angulation
greenstick, or incomplete, fractures
- nondisplaced nature, successfully achieved with external coaptation
- immobilize both carpus and elbow
What is the tension surface of the radius?
cranial
Fractures of the Proximal Region of the Radius
fracture of the proximal radius, concurrent fracture of the ulna or dislocation of the elbow joint occurs frequently.
- lateral approach
- Identification of the radial nerve as it passes beneath the supinator
- identification of small articular fragments may require arthroscopic assistance.
- comminuted radial head and neck (with no load sharing) > internal fixation + circular external skeletal fixator
- radial head does not possess enough bone for implant > used proximal ulna. Radial head attached to the ulna through soft tissues (annular ligament, cranial crura of the collateral ligaments, and joint capsule)
What are the surgical options for proximal radial fractures?
T-plate
CESF
Proximal ulna stabilised to distal radius with ESF (type Ib or type II)
Fractures of the Radial Diaphysis tx options
External Coaptation
- Indications: isolated fracture of the radial or ulnar and stable fractures involving both radius and ulna.
- young, medium-sized or larger dogs
- unlikely to result in satisfactory healing of unstable fractures
- regular reexamination at 1- to 2-week intervals + replacement (can increase $$$)
- skin irritation, bandage sores, and ulcers
- dealyed, malunion or nonunion
internal fixation
- open reduction (anatom. recon.) or via minimally invasive
- indication: small- or toy-breed dog
- plate on cranial surface
- medial plate: ease of application and less interference with the tendons
- polytrauma, large- or giant-breed, ulna can be simultaneously repaired
- locking plates allow MIO: without complete disruption of the fracture hematoma or devascularization of bone fragments, plate is applied in distal-to-proximal fashion
- postoperative rigid external coaptation is advocated > depends on age, fracture configuration, and degree of load sharing
ESF
- especially for comminuted and open #
- advantage of being easily removable
- positively threaded pins, more secure clamps, and stronger connecting rods, have obviated the need for more complex frame configurations + reduced complications associated with their use.
- type Ia, Ib, and II frames
- type Ib corridors minimize pin-associated morbidity + utilizes a larger bone surface area compared to type II
- staged disassembly of this construct can be completed
- circular: minimize interference with the motion of the elbow joint, “stretch” and “horseshoe” rings
- prognosis for healing and good use of the limb was excellent, despite 100% of cases had some degree of drainage
Fractures of the Distal Region of the Radius
divided into articular and nonarticular fractures.
- T-plate if sufficient bone is available or Circular ESF for the juxta-articular fracture (opposing olive wires are based on the ring)
- cephalic vein and the tendon of the abductor pollicis longus muscle may be sacrificed
fracture of the radial styloid process
- avulsion injury at the site where the medial collateral ligament is attached
- Kirschner wires and a tension band or a screw in lag fashion
- salvage > pancarpal arthrodesis.
Fractures of the Radius and Ulna in Toy-Breed Dogs
Studies toy vs large breed:
- toy-breed antebrachii are more susceptible to fracture when loaded because of morphologic differences in the bone
- small-breed dogs possess decreased vascular density > can result in a delayed healing
- small cross-sectional area cause trick apposition
- tx should focus on: rigid stabilization and optimizing apposition while preserving the surrounding blood supply
Tx
- ESF with acrylic connecting bars (predrill/low speed to avoid necrosis)
- ORIF interrupting the overlying soft tissues, but ensure rigid stabilization, excellent apposition, interfragmentary compression, and access to apply a bone graft
- supportive soft-padded bandage or caudal splint for 3 to 4 weeks
What percentage of r/u fracture in toy breed treated with external coaptation resulted in malalignment or nonunion?
Successful return to function with bone plate?
Complication rate?
Coaptation 83%
Bone plate
- Successful 70 - 85%
- Complications 54%
(skin irritation, cold conduction, synostosis, angulation, osteopenia, plate failure, and screw loosening)
What should you do if there is evidence of stress protection (osteopaenia) on rads?
thinning cortices or reduced opacity of the underlying bone
Staged screw removal once clinical union is evident
- Start with screws closest to the fracture on each side
- Waiting 3-4 weeks after removal prior to removing the next set (allows holes to fill in)
What is the tension surface of the ulna?
Caudal
Fractures of the proximal Ulna
radius transmits load between elbow and carpus
Nonarticular ulnar fractures proximal to the elbow joint are usually avulsion fractures of the olecranon
- pull of the triceps brachii muscle group, tensile forces must be counteracted
- caudal or lateral approach > lateral has less pressure when lying sternally; thus, incision dehiscence may be avoided
- two Kirschner wires and a tension band along the caudal aspect
- retrograde fashion reduces the risk inadvertently directed into the trochlear notch
- fixation strength increases with increasing implant diameter, and wire diameter is more critical than pin diameter
articular #
- minimize changes associated with secondary osteoarthritis
- bone plate and screws along the caudal or lateral cortex of the bone
- caudal: biomechnically because tension surface, disadvantage soft tissue coverage is sparse, may become irritated
- comminuted fractures of the proximal part of the ulna may require interfragmentary compression techniques
- Nonreducible fractures > ESF, severe osteoarthritis and loss ROM are certain sequelae.
What are the 4 types of Monteggia fracture?
ulna # accompanied by subluxation or luxation of the radial head
Type I: Cranial luxation of the radial head with cranioproximal angulation of ulnar fracture
Type II: Caudal luxations of the radius and caudal angulation of ulnar fracture
Type III: Lateral luxation of the radius
Type IV: Fracture of the proximal part of the radius and the ulna diaphysis with cranial luxation of the radial head
- annular ligament is still intact, closed reduction of the radial head + IM pin (and cast)
- fractures of the ulna distal to the coronoid processes, the radioulnar joint is also luxated, thus necessarily disrupting the annular ligament
- If the radioulnar joint is no longer intact, will have to stabilise once radial head is reduced (screw from caudal to cranial) + plate for ulna
- radioulnar screws are subject to tremendous shear forces, To eliminate the effect on limiting radioulnar motion and prevent screw failure, screws may be removed 4 to 6 weeks following repair.
ulna is most frequently fractured just distal to the coronoid processes
Fractures of the Distal Region of the Ulna
Most fractures of the distal part of the ulna are associated with fracture of the radius; epair of the radius, stabilization of the ulna is not necessary.
- large dogs, or in situations in which bilateral thoracic limb injuries are present, additional support may be required
- bone plate to the lateral surface of the ulna
- normograde IM pin
ulnar styloid process
- proximal attachment of the lateral collateral ligament of the antebrachiocarpal joint and thus provides stability to the joint, must be repaired
- Kirschner wire and a figure of eight tension band
rate of non-union of radius and ulna
- in cats?
- dogs?
cats: 16.7%,
dogs
- 17.9% delayed union
- 3.4% non-union
Ulnar resorption or non-union has been reported in 35–80% of cases of radial and ulnar fracture in dogs
17% of all radial and ulnar fracture repairs combined with external coaptation were associated with soft tissue injuries which
represented 69% of all confirmed complications (De Arburn Parent
et al. 2017).
Effects of simulated radioulnar synostosis on supination
and pronation in cats. A cadaveric study
Senn 2024
Ex vivo biomechanical study.
Sample population: A total of 58 feline forelimbs.
Induced radioulnar synostosis decreases antebrachial rotation by
more than two-thirds, regardless of location.
Clinical significance: Implants fixating the radius to the ulna should be
avoided in cats, regardless where they are located along the radial diaphysis.
could lead to impairment of forelimb function
and lameness in affected cats. Therefore, radioulnar
rotation should be preserved and, if possible, reconstruction
of the annular ligament would be preferable
dogs prevalence of 11%, cats 12%, for radioulnar synostosis reported after radioulnar fractures
motion not only plays a higher role
in maintaining functional limb activities like grooming or climbing but it is also important in locomotion
synostosis can cause malformations and deformities in growing animals
Feline radial and ulnar diaphyseal
fractures: a retrospective study of
49 cases comparing single bone
fixation and dual bone fixation
Makar 2024
retrospectively, 6 referral clinics,
Dual bone fixation was used in 13/49 (26.5%)
cases, with only 1/13 (7.7%) having major complications. By comparison, 4/36 (11.1%) of single plated fractures had
major complications. Single bone fixation was 14.25 times more likely to have a successful outcome compared with dual bone fixation
no significant difference in the rate of minor
and major complications between the SBF and DBF groups
increase in stiffness with DBF
clinical decision bias where DBF may be
used in more complex fractures
(36%) of the SBF cases had either an intact radius or ulna
majority located in the distal diaphysis
incidence of major complications
in cases requiring revision surgery or even limb amputation was 10.2%
cats having almost double the range of supination.
Comminution of the fracture and concurrent orthopaedic issues did not significantly affect the outcome
CI
When confidence intervals are narrow, we can be relatively certain about how effective a treatment is, but when they are wide, the opposite is true.
With a 95 percent confidence interval, you have a 5 percent chance of being wrong
orientaEvaluation
of computer-aided design software methods for assessment of the three-dimensional geometry
of the canine radius
Karen M. Park
Results indicated that use of CADS to assess the 3-D orientation of the proximal, diaphyseal, and distal segments of normal and abnormal canine radii yielded highly repeatable and reliable measurements
Anatomy of the distal radioulnar
ligament in cats
Basa 2023
In the cat, there appears to be a less extensive interosseous component of the distal radioulnar ligament compared with the dog
These anatomical differences may account for increased rotation of the feline antebrachium and have clinical implications, particularly with regard to the management of antebrachiocarpal joint injuries
Clinical outcomes of orthogonal plating to treat radial and ulnar fractures in
toy-breed dogs
Higuchi + Katayama 2021
medical records, Fifteen limbs that underwent initial fracture repair and five that underwent revision surgery met the inclusion criteria.
using non-locking cuttable plates
long plate working length resulted in
minimal compression of the periosteal blood vessels close
cancellous bone grafting applied in all cases
Synostosis + Re-fracture after cranial plate removal was observed in one case each
radial and ulnar radiographic union was achievedafter a mean of 6.1 ± 1.5 and 5.7 ± 1.7 weeks,
> open reduction with OP to the fracture
region did not adversely influence radial and ulnar fracture
removed the cranial plate after radial or ulnar bone union became evident
destabilisation by removal of the OP cranial
plate may be beneficial, leading to increased loading of the bone which could accelerate healing (Claes et al. 2011)
A Retrospective Study of Postoperative Development of Implant-Induced Osteoporosis in Radial–Ulnar Fractures inToy Breed Dogs Treated with Plate Fixation
Muroi 2021
226 cases (236 limbs) of toy breed dogs, Pixel values were measured on radiographs
significant decrease in the PVR at 1 to 12 months postoperatively for all cases, no dofference bewteen DCP or LP. Implant-induced osteoporosis persisted at 1 to 12 months postoperatively in dogs aged >6 months
following destabilization, there was a significant increase in the PVR
This study suggests that IIO occurs in small dogs treated with plates and
screws, screw and plate removal could contribute to the recovery of bone mineral areal density.
osteoporosis (IIO) and is the major cause of refractures after implant removal. Implant-induced osteoporosis shows a biphasic change; 8 to12 weeks due to impaired periosteal blood flow caused by plate compression on the bone and at 24 to 36 weeks due to reduced mechanical stress on the bone.
According toWolff’s law, reduction in bone mineral density can occur due to reduced mechanical stress (stress shielding)
osteopenia
caused by the locking system occurs when a part of the
plate is compressed on the bone surface when using bone
holding forceps during the placement of the LP
toy breed dogs are more predisposed to
serious postoperative complications such as osteopenia, refracture
or non-union after radial fracture
decreased bone mineral density in the radius and changes in the apatite orientation (altered by decreased mechanical stress on the bone) at 28 weeks after the placement
of the plate
In this study, staged removal of the plate was more effective in increasing the PVR as compared with removal of the screw alone.
IIO is affectedmore by the age at the time of injury than
the fixation procedure
reduction in mechanical stress on bone by
plate placement affects bone metabolism
Stabilization of Olecranon Fractures by Tension
Band Wiring or Plate Osteosynthesis:
A Retrospective Study of 41 Cases
Fournet 2018
Complications
occurred more commonly after tension band wiring (74%) compared with plate
osteosynthesis (27%) (p ¼ 0.002) and these were probably related to it being used in
comminuted fractures (p ¼ 0.01) or to errors in technique. Minor complications
included Kirschner wires migration (n ¼ 5), pain (n ¼ 3), osteomyelitis (n ¼ 3), skin
breakdown (n ¼ 3) and seroma (n ¼ 1). Implant failure requiring further fixation
(n ¼ 4) was observed only in the tension bandwiring group
two Kirschner
wires should be used to prevent rotational instability;
should be inserted through the cranial
cortex of the ulna to prevent being ‘pulled-out
should ideally
be secured with two twist knots
Previous clinical and biomechanical studies demonstrated
that TBW provided marginal stability of olecranon fractures
compared with PO, making themmore prone to complication
occurrence
In our study, the overall complication rate after olecranon fracture repair was 52.2%.
Long-term functional outcomes were excellent regardless of the technique used
fractures are usually articular, but are comminuted and open in about a third of cases
Randomized, controlled, prospective clinical trial
of autologous greater omentum free graft versus
autogenous cancellous bone graft in radial
and ulnar fractures in miniature breed dogs
baltzer 2018
Prospective, randomized, controlled clinical trial
25 dogs
Power Doppler ultrasonographic,
computed tomographic (CT), and radiographic examinations
Pressure-sensitive walkway gait analysis
Radiographic healing occurred earlier in bones treated with OG (median,
9 weeks) than in those treated with BG (12 weeks).
bones retained
more vessels and greater signal intensity when treated with OG compared with treatment
with BG
in dogs perceived
to be at risk for such complications
OG did not result in major complications but led to limb swelling and erythema in 64% of dogs
Conclusion: Omental grafting was not associated with major complications, and it
accelerated bone healing and return to weight bearing in dogs.
the effect of OG to improve healing
and function postoperatively compared to no augmentation
remains unknown.
