Chapter 93 - part 2 diaphyseal fractures Flashcards
Figure 22.1 Common configuration of complete fractures of
Mc3/Mt3 in adult horses. (I) Distal metaphyseal, (II) simple
diaphyseal, (III) comminuted diaphyseal and (IV) proximal
metaphyseal.
Figure 22.2 Common Mc3/Mt3 fractures in foals.
(I) Salter–Harris type II. (II) Incomplete, unicortical,
simple transverse mid-diaphyseal.
(III) Simple, transverse/slightly oblique mid-diaphyseal.
(IV) Simple, transverse proximal metaphyseal.
A) A dorsopalmar radiograph of a nondisplaced transverse fracture of the distal diaphysis showing periosteal callus. (B) A dorsopalmar radiograph of a displaced, comminuted transverse fracture.
How do you solve the previous image of fracture of the distal diaphysis?
This fracture was successfully treated with arthrodesis of the metacarpophalangeal joint as seen in C and D. A variable angle-LCP curved condylar plate may also be useful for stabilization of distal diaphyseal fractures in horses where return to athleticism is of utmost importance. A postoperative dorsopalmar (E) and lateromedial (F) radiograph of a transverse fracture repaired with a variable-angle-LCP curved condylar plate.
describe
Postoperative radiographic views taken at right angles to one another of a multifragment MTIII fracture in an adult horse treated with two distal cortex screws applied in lag fashion, a lateral 12-hole, 5.5-mm narrow LCP and a dorsal 14-hole, 5.5-mm narrow LCP. In each plate, two 4.5-mm cortex screws were used with the remainder being of the locking head type. Note the proximal single screw was placed somewhat too far plantarad.
How common are transverse fractures of the distal diaphysis in Thoroughbred racehorses?
Rare! they are common in Arabian and endurance horses
Where have these transverse fractures only been reported?
Forelimbs
What is the likely cause of these fractures?
Stress or fatigue injury
What percentage of these fractures occur bilaterally?
40%
What is recommended for strict stall confinement in nonsurgical management?
6 to 12 weeks
What is a risk associated with both conservative and surgical management of transverse fractures?
Catastrophic fracture
When is surgical stabilization required for transverse fractures?
In moderate to severe cases
What is the recommended timeframe for surgery in cases with displacement of the distal epiphysis?
Within 24 hours
What is a viable option for fracture stabilization in horses where return to athleticism is a priority with displacement of the distal epiphysis?
VA-LCP curved condylar plate
How long should a distal limb cast be maintained postoperatively displacement of the distal epiphysis?
4 to 6 weeks
What is a reported complication following displacement of the distal epiphysis?
Necrosis of the epiphysis
What is the most common major long bone fractured in horses?
MCIII/MTIII diaphyseal fx is most prevalent and commonly is catastrophic
TB is stress fx
Foals are transverse/oblique fractures
Why is cast or splint coaptation not a preferred treatment for displaced diaphyseal MCIII/MTIII fractures in horses?
It causes discomfort and problems in the contralateral limb.
What are the potential consequences of using cast coaptation in young animals with these fractures?
Development of permanent deformities in the contralateral limb and weakness in the cast limb.
What is the stabilisation of diaphysis fractures in the field?
*RJB
*Splints
*Lateral
*FL– Ground to elbow
*HL– Ground to stifle
*Palmar/Plantar
FL– Ground to elbow
HL– Ground to hock
*PVC,aluminum, wood
What factors are in favor for this fracture treatment of diaphyseal?
In favour: 1.Access/exposure of diaphysis
2.Strong bone
3.Immobilisation by external coaptation
What is the treatment for diaphyseal fractures
!!! Internal fixation
*Double plate (always in adults)
NOT RECOMMENDED
*Externa lfixation
*Full limb cast (FL)
*Cast to hock (HL)
*Transfixation pincast
or combination of Internal fixation + cast
Internal fixation + transfixation cast
What is the ideal plate and position?
*DCP
*LC-DCP(if cost an issue)
*Same bending stiffness as DCP
*50%increase in uniformity of bending stiffness than DCP**
or LCP is the best
Place 90º to each other
What are the landmarks for incision?
The incision is curved at its proximal and distal ends,
with the free edge of the flap located over the dorsal
aspect of the bone.
Areas of poor vascularity and open
wounds should be avoided to decrease the chance of
infection.
Due to the strength of the closure that can be
obtained when the extensor tendon is split, the dorsolateral
approach is preferred.
When making this approach, the tendon (lateral digital extensor–forelimb, long digital extensor–hindlimb) is incised longitudinally to expose the underlying bone.
how do you immobilize diaphyseal fracture of MCIII MTIII?
The fractured MC/MT3 can be stabilized with a
Robert Jones bandage and the application of **rigid splints
on the lateral and palmar/plantar aspects of the limb.
Two splints at 90° angles are necessary to counteract
both dorsopalmar/plantar and lateromedial bending
forces. Polyvinylchloride (PVC) pipe is an effective, inexpensive
splint material; it is light‐weight, strong, and can
be penetrated by X‐rays. Splints on the forelimb should
extend from the ground to the elbow.** On the hindlimb,
due to the natural bend of the tarsus, the plantar splint
can only extend from the ground to the level of the point
of the hock. The **lateral splint should extend proximally
to the level of the stifle joint. **This lateral splint can be
made from strong aluminum rod that can be conformed
to the angle of the hock and secured to the tibia proximally
and to the limb distal to the hock. Splints should be
secured to the limb with nonelastic tape to avoid loosening.
Appropriate splinting is vital to successful fracture
treatment. Splinting of the fracture protects the limb
from further trauma and minimizes the chance that a
closed fracture will become open.
once you immobilize you perform radiographs, what should you take in consideration?
The joint above and below the fracture should always be included to evaluate
the integrity of the articular surfaces. A minimum of four
views should be obtained: lateromedial, dorsopalmar/
plantar, and both oblique projections.
Figure 24.4 (Continued). (E) The first plate is applied to the dorsal surface in neutralization or limited compression; (F) A plate screw can
also be inserted across a fracture line using lag technique to further secure the butterfly fragment; (G) A second plate is applied laterally or
medially, directly over the butterfly, remaining screws inserted in the dorsal plate, and tendons apposed.
Distal physeal fractures are common in…
Distal physeal fractures in foals most communally have a
type II configuration with a variable length of the meta or diaphyseal spike
Nutrient foramen artery should be avoided during reconstruction. Where is it?
The nutrient foramen is usually located in the **proximal
palmar/plantar cortex **and should be avoided by screws.
The nutrient artery of Mc3, a branch of the medial palmar
metacarpal artery, is accompanied by a corresponding vein
and a branch of the palmar metacarpal nerve [2].
Neurovascular supplies to the dorsal periosteal surface of
Mc3 are provided by small medial and lateral dorsal metacarpal
arteries and the medial cutaneous antebrachial and
dorsal branch of the** ulnar nerves** [3, 4]. The nutrient artery
and satellite vein of Mt3 are from the proximal deep plantar
arch, the former arising from the medial plantar and
perforating tarsal arteries. The periosteal blood supply of
the dorsal Mt3 comes from branches of the** dorsal metatarsal
arteries**
Simle compelte diaphyseal fractures in adults are usually (name the type)
adults, simple complete diaphyseal fractures can occur at all levels of Mc3/Mt3 and are usually transverse or
slightly oblique (Figure 22.1). Comminuted fractures
which are most common in older horses can exhibit all levels
of complexity. Some of these have one larger butterfly
fragment on either the medial or lateral side
comminuted diaphyseal fractures are common in
Comminuted fractures
which are most common** in older horses** can exhibit all levels
of complexity.
Should you preserve the periosteum?
YES!! If periosteum lost, more Haversian systems of the cortical exposed →** susceptible to infection**
What are the steps that are previous placement of plates?
Reduction of the fracture
*Reduction (may be difficult)
*Comminuted#s reconstruct into 2 pieces
*Tent fracture ends out of surgical wound → align and interdigitate or
*Traction+ bone reduction forceps
Oncereduced maintain using lag screw (3.5mm)Contourand apply plate to bone
*Ideally 2 broad but dependent on skin closure
*4.5/5.5mmscrews?
Dynamiccondylar screw (DCS) plate
What should be placed to fill defects?
Autogenous cancellous grafts obtain from TX sternum
Describe the closure of the surgical wound
Antibiotic impregnated beads (or other)
Suture tendon (if split)0or 2-0 PDS IIContinuouspattern
*SQtissue
Skin0or 2-0 prolene
*Vertical mattress
*RJB or full limb cast
*Assisted recovery:
-Raft/swimmingpool
-RopesHandassisted
IWhat is the most common complication of fractures of diaphysis treatment?
*Infection
*Osteomyelitis
*Nonunion
*Sequestrum
*Contralaterallimb failure
*Laminitis
You could remove the implant by stages. The first plate is removed in foals by:
3 months
And how much time after the removal of the first plate you remove the second?
45-60 days
Adults you remove the plate when?
- months
In what age group of horses are distal physeal fractures of MCIII/MTIII most common?
Suckling and weanling foals
What type of Salter-Harris fracture is most commonly associated with distal physeal fractures in these horses?
Type II
How are young foals (less than 6 weeks old) with these fractures typically treated
Cast coaptation for 2 to 3 weeks, followed by a splinted bandage
In older or heavier foals with marked instability of the fracture, what additional treatment is recommended?
Surgical repair with screws in lag fashion
When should implants be removed in neonates with significant remaining potential growth?
As early as 3 to 4 weeks
proximal articular fractures in carpus and tarsus can be similar, but are treated different why?
Proximal articular fractures have been treated conservatively with good success, but displaced frontal plane fractures are best repaired with** internal fixation** through cortex screws inserted in lag fashion (Figure 93-21).
The** sagittal plane fractures** are rarely displaced and usually heal with stall rest alone
How is lameness typically eliminated in racehorses with proximal articular fractures of MCIII/MTIII?
With local anesthetic injected into the middle carpal or tarsometatarsal joint
What is the success rate of treating incomplete sagittal fractures conservatively with 3 months of box rest?
98%
What is the rest treatment in the case of palmar articular fractures?
90-120 days
What condition in young Thoroughbred horses is associated with pain and lameness in the dorsal cortex of MCIII?
Bucked shins
In horses with bucked shins, what specific feature indicates the development of a stress fracture?
Oblique radiolucent lines in the dorsal cortex
At what age do these stress fractures most commonly occur in Thoroughbreds?
As 3-year-olds
What is the typical angle of the fracture line from the surface of the middistal dorsolateral cortex of the left MCIII?
30 to 40 degrees
What percentage does the fissure typically extend through the dorsal cortex?
60% to 70%
What is a common conservative treatment for dorsal cortical fractures?
Anti-inflammatory agents and rest
How do some trainers monitor the healing process of these fractures?
Through sequential radiographs
What percentage of horses with dorsal cortical fractures heal without surgical intervention?
A significant percentage
Where do fractures that are best candidates for conservative treatment typically occur?
Distal or proximal metaphyseal regions of MCIII
What is the primary effect of extracorporeal shock wave therapy in managing these fractures?
Providing local analgesia
What is one advantage of osteostixis alone in the surgical treatment of dorsal cortical fractures?
Avoiding a second operation to remove the screw
What type of anesthesia is preferred for the surgery to treat these fractures?
Local anesthesia
Why is it important to accurately locate the fracture site preoperatively?
Because it is often difficult to identify visually during surgery
Why should the screw not be countersunk during surgery?
Because it is easier to remove later
What is the recommended postoperative care after surgery for dorsal cortical fractures?
Postoperative care includes stall rest and hand walking for 2 to 4 weeks followed by 4 to 6 weeks of stall rest and paddock exercise. At 60 days postoperatively, the horse is returned for screw removal
Describe the placement of the screws and landmarks in the case of cortical fractures
A4- to 6-cm incision is made over the fracture site.
In the typical dorsolateral fracture, the incision is between the common digital and lateral digital extensor tendons.
The incision is made boldly directly to the level of the periosteum to minimize dissection. The periosteum is elevated, and self-retaining retractors are placed to expose the bone surface.
a position screw (without a glide hole) within the dorsal cortex is usually placed. In the middiaphysis of MCIII, bending occurs, therefore insertion of a screw engaging both cortices is not recommended.
Drilling with a small bit in dorsal MCIII must be done with irrigation and frequent cleaning of the bit to avoid breakage or causing thermal injury
An oblique drill hole is made into the medullary cavity in what is estimated to be the correct location. Subsequently an intraoperative radiograph is taken (Figure 93-25) and if the hole is correctly positioned, it can be used for the screw. If the trial hole is too proximal or distal, an adjustment is made and the first hole serves as just another osteostixis hole
Why lag technique is not necessary in this fracture type dorsal cortical?
Although some surgeons use lag technique, typical dorsal cortical metacarpal stress fractures have no displacement and the effect of compression would be trivial. Because compression of the fracture is not necessary for successful treatment,33 a position screw (without a glide hole) within the dorsal cortex is usually placed.
Why you don’t countersink?
Why you don’t countersink?
Because you will remove the screw in 60-80 days
Common error during this procedure of not doing countersink in dorsal cortical fx?
Because the screw is not countersunk, it should not be excessively tightened or it will bend. Perhaps the easiest error to make is not tapping completely through the dorsal cortex. The consequence of this is that a 3.5-mm screw will easily break during tightening.
All holes must be drilled toward the medullary cavity and separated at least:
10 mm
Dx and tx
Figure 22.3 (a) Incomplete stress fracture in the dorsolateral
Mc3 cortex with a typical dorsodistal to palmaroproximal course
(black arrows). (b) Surgical treatment with a unicortical 4.5 mm
cortex screw and osteostixis (white arrows).
Figure 22.4 Acute, incomplete longitudinal
spiralling fracture of the Mc3 crossing the nutrient
foramen and continuing into the carpometacarpal
joint (arrows). Multiple radiographs in different
projections are necessary to follow the fracture
plane.
Figure 22.5 An acute, incomplete, longitudinal fracture of Mc3
(arrows) (a) two days after the injury and (b) 14 days later
consistent with osteoclast activity
Figure 22.7 Lateromedial (a) and oblique (b) (a) (b)
radiographs of a Thoroughbred racehorse with
a transverse stress fracture in the distal
metaphysis of Mc3. Note the palmar callus
formation and incomplete fractures of palmar
(white arrows) and dorsal (black arrows)
cortices.
Figure 22.8 Lateromedial radiographs of a transverse fracture
of the distal diaphysis of Mc3 in a two-year-
old
Thoroughbred.
(a) Two months after acute onset lameness demonstrating
abundant periosteal and endosteal callus and (b) 15 months
later. The filly had trained and raced in the interim.
Figure 22.9 Comminuted fracture of the Mc3 in a 200 kg pony. (a) Dorsopalmar and lateromedial radiographs. The fracture was
reduced following an open approach with multiple lag screws. A DCP plate was applied dorsally and included engagement of the third
carpal bone. A transfixation cast was then applied utilizing metaphyseal and distal diaphyseal pins in the radius. (b) Radiographs
taken at the end of surgery before application of the cast.
Figure 22.12 Open, displaced transverse diaphyseal fracture of
Mt3 in a foal and repair with LCPs dorsolaterally and
dorsomedially.
Figure 22.13 Intra-operative
photograph and radiograph of a
transverse mid-diaphyseal
fracture after reduction and
placement of dorsal and lateral LCPs. The fracture is temporarily
fixed with a lag screw and both plates are compressed to the
bone with cortical screws. Drill guides for LHSs are inserted at
the proximal and distal end of the lateral plate to assess the
direction of the screws near the joint.
Figure 22.14 (a, b) Oblique fracture in the proximal diaphysis of Mc3 in a three-month-
old
foal. (c, d) Stable repair with a dorsal
8-hole
4.5/5.0 LCP T-plate
and a lateral 10-hole
narrow 4.5/5.0 LCP.
Figure 22.15 Minimally invasive repair of an oblique mid-diaphyseal
fracture of Mt3 in a neonate. (a) Dorsoplantar and (b)
lateromedial radiographs taken in a splinted bandaged on arrival demonstrating valgus displacement and overriding. (c) The foal is
positioned in dorsal recumbency with traction applied by an overhead hoist. (d, e) DP radiographs in surgery demonstrating
progressive reduction with increasing traction. (f) Haemostats inserted dorsodistally to create a sub tendinous tunnel. The long digital
extensor tendon is gripped in the surgeons left hand. (g) Stacked LHS drill guides used to create a handle for insertion of the LCP.
(h) LCP location confirmed in a LM radiograph (i) Plate/bone contact created by insertion of 2 × 4.5 mm cortical screws. (j) Construct at
the end of surgery with the remaining plate holes filled with 4 mm LHS. (k, l) DP radiographs and (m) clinical appearance 12 days after
surgery.
Figure 22.17 Dorsoplantar radiographs of an open, oblique fracture of the mid-diaphysis
of Mt3 in an Icelandic horse. (a) At presentation.
(b) Repair with dorsal and lateral LCPs. Implants were removed due to chronic low grade lameness. (c) The dorsal implant was removed
one year after repair and the lateral plate six months later. Lameness resolved after implant removal. (d) 3.5 years after fracture repair.
Figure 24.12 Radiographs showing a longitudinal palmar fracture (arrows) of the third metacarpus in a two‐year‐old Thoroughbred.
Lameness had been intermittently severe and was unresolved after two months of stall confinement. (A) Dorsopalmar radiograph
and (B) standing robotic computed tomographic image confirm the palmar location and length of the fracture. (C, D) Dorsopalmar
and lateromedial radiographs two days after insertion of two 4.5 mm screws in the palmar cortex. (E) Dorsopalmar radiograph
60 days after repair showing resolution of the fracture. The horse returned to training 90 days after surgery.
Figure 25.3 Radiographic appearance of dorsal cortical fractures.
(A) Dorsodistal angled focal cortical stress fracture of the third
metacarpus. (B) Saucer fracture, with extensive periosteal reaction,
proximal (arrow) and distal aspects (arrowheads) of the saucer
fracture.
Figure 25.9 Preparation for standing dorsal cortical fracture
repair with cortical screw insertion and limited osteostixis. Plastic
adhesive drapes are applied and proximal and distal hand towels
are secured with sterile VetrapTM (3M Healthcare). A sterile glove
over the foot can substitute for the distal hand towel.
Figure 93-20. Although many methods can be successful for treatment of distal Salter-Harris type II MC/MTIII fractures, a very reliable technique is to combine simple lag technique of the metaphyseal spike with a screw and wire transphyseal bridge.
Figure 93-21. Displaced dorsal plane proximal MTIII fracture treated with a cortex screw placed in lag fashion. This horse won multiple graded stakes races after surgery.
Figure 93-22. Proximal sagittal plane fracture of MCIII (arrows), which was treated conservatively.
Figure 93-25. (A) A single intraoperative image with a pin in the drill hole allows accurate repositioning if needed. (B) Postoperative image showing the screw inserted and the surrounding osteostixis holes.
Figure 93-26. When drilling dorsal cortical stress fractures, it is important to aim toward the medullary cavity.
Figure 93-23. (A) The most common configuration of dorsal cortical stress fractures of MCIII is shown with the arrow. Less distinct lucencies (arrowheads) can be seen separately or in combination with larger fractures. (B) Occasionally, the opposite (“upside down”) configuration is seen. The quality of digital imaging has made identification of these fractures more reliable.
M
Figure 93-18. (A) A dorsopalmar radiograph of a nondisplaced transverse fracture of the distal diaphysis showing periosteal callus. (B) A dorsopalmar radiograph of a displaced, comminuted transverse fracture. This fracture was successfully treated with arthrodesis of the metacarpophalangeal joint as seen in C and D. A variable angle-LCP curved condylar plate may also be useful for stabilization of distal diaphyseal fractures in horses where return to athleticism is of utmost importance. A postoperative dorsopalmar (E) and lateromedial (F) radiograph of a transverse fracture repaired with a variable-angle-LCP curved condylar plate.
