Chapter 93 - part 1 condylar fx Flashcards
What is the function of the MCII and MTII bones in horses?
They serve major weight-bearing functions
How does the cross-section of MCIII change in horses?
It dramatically changes in response to increased loading as the horse ages and trains
What makes the great metatarsal (dorsal MTIII) artery particularly vulnerable in horses?
Its location between MTIII and MTIV
Where is the most common site of major fracture in MCIII/MTIII bones in athletic horses?
In the distal articulation
In the forelimb the major neurovascular structures course along the length of MCIII both medially and laterally dorsal to the flexor tendons but in the hindlimb the artery courses
laterally between MTIII and MTIV
Repetitive loading during intensive exercise leads to focal accumulated injury in the in a specific part of the MC III, where?
parasagittal groove region that can eventually result in complete fracture
Vertical fractures in the sagittal plane occur in the
distal condyle of MCIII/MTIII
In which group of horses are lateral condylar fractures most common?
Young racehorses
Which limb is more likely to be affected by lateral condylar fractures in Thoroughbreds?
Forelimb
What is a typical clinical sign of a lateral condylar fracture in horses?
Acute onset of severe lameness after intense exercise
What percentage of condylar fractures involve the lateral condyle?
Around 85%
In complete displaced fractures of the third MC/MT are displaced by the MCP/MTP joint flexion and reduced extension what is contraindicated in the immobilization?
All immobilization
techniques should therefore include extension; any
that involve flexion are contraindicated.
How do lateral condylar fractures typically propagate?
In a sagittal plane then spiral to oblique/frontal planes
What advanced imaging techniques are increasingly diagnosing unicortical condylar fractures?
CT and MRI
Figure 7.7 Digital pressure applied dorsoproximally frequently
elicits a painful response in horses with non-or
minimally
displaced sagittal/parasagittal fractures of the proximal phalanx.
Complete fractures disarm the_____________ _______________
ligament of the MCP/MTP joint leading to instability and
potential creation of an open fracture or disruption of the
proximal scutum
Complete fractures disarm the lateral collateral
ligament of the MCP/MTP joint leading to instability and
potential creation of an open fracture or disruption of the
proximal scutum
What are the immobilization that should be considered for MC/MT condylar fractures?
Compression boot in the FORELIMBS
Robert Jones bandage for incomplete, with medially and laterally splinted up to the level of thirc carpal or third/fourth tarsal bones
Robert Jones bandages, or a bandage cast for complete fractures.
In the absence of a compression boot, these techniques are also appropriate for forelimbs
What is the main difference of the medial condylar fracture in the immobilization comparing to LAT?
First aid and coaptation for medial condylar fractures does not differ much from lateral fractures with one major exception: horses with medial condylar fractures in the hindlimb should be crosstied until surgery is performed.
Figure 7.18 Construction of a splinted Robert Jones bandage for the distal hindlimb. (a) Splints should be positioned medially and
laterally in contact with the widest point of the hoof from the bearing surface to the level of the third (medially) and fourth (laterally) tarsal bones. The lateral splint is often longer in consequence. Sufficient cotton wool is added to fill the space between limb and splints. Minimal bandage material is applied at the level of the hoof to maintain the hoof/splint interaction. (b) Splint alignment is maintained by application of inelastic tape to prevent twisting or rotation while enclosing elasticated tape is applied. (c and d) The completed splinted bandage.
what is this?
Figure 7.20 Newmarket Compression Boot. Readily applied, radiolucent and rigid construct. The design enables the horse to load the limb in a normal position.
What if it is a diaphyseal fracture of the third metacarpal/metatarsal bone?
marked bending forces, and complete fractures are inherently
unstable even if not displaced. Casts provide the only
contributory support.
The medial condyle is ______in both mediolateral and dorsopalmar/plantar (DP) planes.
The medial condyle is larger in both mediolateral and dorsopalmar/plantar
(DP) planes.
Growth plate closure in MCIII and MTIII is…
Complete closure of the growth plate occurs between 10 and 18 months with radiographic, which is generally thought to
represent functional, closure between six and eight
months
Fractures are generally classified from radiographic features
(Figure 21.1). They may be unicortical (although
this usually involves pa/pl subchondral compacta rather
than cortical bone) or** bicortical. Fractures are classified
as complete if the fractures in dorsal and pa/pl cortices conjoin to exit through the periosteal surface of the metaphysis
or diaphysis of the bone and incomplete if this has
not occurred. Displacement has been variously and
inconsistently defined. The author’s favoured definition
is that displacement involves a change in the anatomic
axis of one fragment with respect to another. In distraction,
orientation is maintained and fragments simply
separate. Displacement can involve abaxial, proximodistal,
DP or rotational movement; frequently, there is a
combination of these. In some fractures, this can only be
determined arthroscopical. Incomplete fractures can distract at the articular surface but cannot displace. Fractures that extend into the diaphysis are described as propagating. These are of
two types. The first remain in a sagittal or parasagittal**
plane, and the second begin in this plane and then change
orientation to oblique or frontal planes; the latter are
generally referred to as** spiral**
Propagating fractures are much more common____________ (medially /laterally)
Propagating
fractures are much more common medially than laterally, almost invariably commence immediately adjacent to the sagittal ridge
Fractures that commence axially
whether medial or lateral are usually __________(longer/shorter) than those
which arise abaxially
Fractures that commence axially
whether medial or lateral are usually longer than those
which arise abaxially
Fractures of the lateral condyle are usually easier or more complex?
Fractures of the** lateral condyle also feature in complex
usually catastrophic fractures **centred on the MCP/MTP
joint.
These generally manifest as racing injuries and commonly
include a displaced fracture of the lateral condyle,
proximal sesamoid fractures and markedly comminuted
fracture of the proximal phalanx.
Figure 21.1 Fractures of Mc3/Mt3 condyles imaged by transverse (a) and reconstructed 3D (b)–(g) CT. (a) Short palmar ‘unicortical’
fracture of the lateral condyle. (b) Bicortical incomplete fracture of the lateral condyle. (c) Complete non-displaced
fracture of the
lateral condyle. (d) Displaced fracture of the lateral condyle. (e) Parasagittal propagating fracture of the medial condyle. (f) ‘Spiral’ propagating fracture of the lateral condyle. (g) ‘Spiral’ propagating fracture of the medial condyle.
When using combined data from comparable UK and USA studies, 220 of 298 (74%) fractures in the UK and 391 of 455 (86%) fractures in the USA were
____________(lat or med).
When
using combined data from comparable UK [18, 21] and
USA [25, 26, 55–57] studies, 220 of 298 **(74%) fractures in
the UK and 391 of 455 (86%) **fractures in the USA were
lateral.
What imaging technique is commonly used to diagnose unicortical condylar fractures?
MRI
Studies revealed that propagation is more common in medial or lateral condylar fractures?
Propagation was identified in 28 of
35 (80%) medial and 12 of 139 (9%) lateral fractures
Name the types of features and presentation of condylar MC/MTIII fractures
- Palmar/Plantar subchondral bone (unicortical incomplete)
- incomplete
- Bicortical Complete non displaced
- Bicortical Complete displaced
- Propagating/spiral
- Complex/comminuted
Fracture of the condyle usually has as symptoms
Lameness preeceding the onset of a more severe lameness
short choppy gait if bilateral
MCP/MTP effusion
Pain over manipulation
LAMENESS NOT CORRELATED with amount of fracture displacement
What are the radiographic views ideal for visualization of the fracture in unicortical palm/plantar subchondral bonel?
horizontal beam Dorsal 35º distal pal/pl proximal oblique
Flexed horizontal beam DP view
Type of Fractures of the MC or MT condyles may be unicortical
palmar/plantar subchondral
bone
Palm/Plantar subchondral fractures are many times silent in radiograph for how long?
frequently radiographically silent for
7–10 days and sometimes for 2–4 weeks
Non displaced condylar fractures are treated how?
can be arthroscopically assisted or standing without arthro with placement of cortex screws through stab incisions
1st screw in the epicondylar fossa
What is the common location for the propagation of lateral condylar fractures?
Proximolaterally toward the lateral cortex
From the mid- to midaxial portion of the lateral condyle, sagittally, then proximolaterally
What does fracture classification indicate about prognosis?
Nondisplaced fractures have a better prognosis than displaced fractures
Lateral condylar fractures are oriented vertically, occur in the sagittal plane, and range from faint, short linear cracks to complete displaced fractures with extensive comminution.
Figure 93-2. For preoperative evaluation of the distal palmar/plantar surface of MCIII/MTIII, a dorsal 120-degree proximal–palmar/plantar distal oblique (A and B) or a flexed horizontal beam DP view (C and D) should be taken. Arrows indicate typical appearance of comminution along that margin that may be very difficult to see on a standard DP projection.
Figure 93-3. (A) A robotic cone beam computed tomography (CBCT) unit being used to obtain computed tomographic images of a metatarsophalangeal joint in a standing horse. Transverse (B), frontal (C), and sagittal (D) CT images of a horse with a left front medial condylar fracture obtained using the robotic CBCT.
Name the type of condylar fractures
What is an incomplete fracture?
An incomplete fracture is defined as one that originates in one cortex or subchondral bone plate, but has no apparent fracture line perforating the opposite cortex or distant subchondral bone plate so SAME AS UNICORTICAL (NIXON)
What is a complete fracture?
Complete fractures represent full cis‐ and transcortical discontinuity, but may be further subdivided into stable
or unstable fractures, since this state affects the repair methods and prognosi (NIXON)
Unstable fractures meaning and when should they be repaired?
Unstable fractures have little or no remaining cortical continuity to prevent axial, rotational, and bending motion. Unstable fractures not only carry a poorer prognosis for repair due to their inherent instability, but also need to be repaired without delay to prevent continued damage (NIXON)
Palm/Plantar suchondral fractures are usually lateral or medial?
71% lateral with no difference to FL or HL
which imaging tx is the best to diagnose palm/plantar subchondral plate fractures?
MRI
Figure 21.2 Fracture of the medial palmar subchondral bone and adjacent dense epiphyseal spongiosa. (a) Transverse CT image at the level of the base of the proximal sesamoid bones (with the MCP at a neutral angle). Fracture (arrow) identified in flexed (b) and standard (c) DP radiographs.
MC
Figure 21.4 Short bicortical fracture of the lateral condyle of Mc3. (a) DP radiograph demonstrating an abaxial fracture course. (b) Fracture
location in a transverse CT image at the level of the epicondylar fossa.
Figure 21.5 Long incomplete fracture of the lateral condyle of Mc3 imaged on a DP radiograph and in transverse CT images at the depicted levels (hashed lines).
Incomplete fractures can be difficult to dx on radiographs (because sometimes they are complete) what do certain authors say about size estimation to know if is complete or incomplete?
Some authors consider that fractures
that extended ≥75% of the distance from the distal
articular surface to their projected metaphyseal or
diaphyseal exit point should be considered complete
even if radiographic evidence of such is lacking
Non displaced fracuters with minimal soft tissue dissection are surgically managed with
cortex scrw fixation in lag technique using radiographs and CT and radiopaque markers
In nondisplaced fractures what is the reference for the most distal screw?
by taking the midpoint of an imaginaryline drawn between the proximal palmar/plantar prominence of P1 and the most dorsal aspect of the lateral condyle, both readily palpable landmarks.
What is the primary goal of surgical management for lateral condylar fractures?
To prevent proximal propagation and enhance articular healing
What factor often influences the decision between conservative and surgical treatment in non-displaced fractures?
B) Owner/trainer preference
How much time is the conservative box rest?
4-8wk box rest, progressive rehabprogram, training not resumed <120d
What is the most common technical error in lag screw fixation of nondisplaced condylar fractures?
Inadequate compression
Compression of the fracture is optimized if the screw is midway between the dorsal and palmar/plantar articular surfaces, and perpendicular to the bone in both proximodistal and lateromedial planes. (wright)
Which screw is most critical? What additional procedure is recommended at the time of surgery to assess fracture reduction?
The distal screw is most critical and is always placed
first. This should be positioned in the** center of the bone,
at the junction of the proximal and middle thirds of the
epicondylar fossa** and do arthroscopic examination
The lateral condylar non-displaced fractures can be surgically corrected standing under LA, what is the number of screws required?
the majority of lateral condylar fractures can be treated with two screws. A few propagate proximad enough to justify more screws but usually the more proximal portion of the fragment is quite narrow in its dorsopalmar/-plantar thickness, and accurate positioning of the screw in the center of that part of the fragment is difficult.
Placing 3 or 4th screw would have better outcome?
There is little evidence to suggest that placing a third or fourth screw in the longer fractures results in a better outcome, particularly in nondisplaced fractures.
What can prevent inadequate compression during lag screw fixation of nondisplaced condylar fractures?
Drilling the thread hole fully through the far cortex
How can incorrect aiming of the drill be minimized during surgery?
By placing the fractured bone parallel to the ground
what is the size of the incision and which blade do you use in condylar fracture screw fixation?
A longitudinal 10 mm skin incision is made, followed
by a longitudinal stab incision through the collateral ligament
to the bone surface, using a #11 or #15 blade.
What is the size of incision? size of the blade?
Longitudinal 10 mm skin incision is made, followed
by a longitudinal stab incision through the** collateral ligament**
to the bone surface, using a #11 or #15 blade.
The origin of the collateral ligament is spread along its long
axis with hemostats. Standard lag screw technique follows.
The epiphyseal bone is very dense and frequent
cleaning of the drill flutes and use of irrigating fluid over
the bit are important. The** thread hole** should be drilled
with particular caution, as undue bending or pressure on
the 3.2 mm drill bit can result in breakage. With this scenario,
removal is not generally possible or advocated. The surgeon should also prevent the
drill bit protruding excessively into the trans cortex fossa
and the medial collateral ligament.
Countersinking the distal most screw is controversial avoided because the fossa is already concave and countersinking can damage the collateral ligament.However, there is a marked incongruity between screw head and bone surface, particularly at the recommended site for screw insertion.
Point contact not only compromises compression, but
also predisposes to screw bending or breakage. A countersink
therefore should be used. Osseous debris that
interferes with the depth gauge and subsequent screwhead
seating should then be removed by spreading the
soft tissues over the drill tract, and copiously flushing
with irrigating fluid
Which type of screws do you use for nondisplaced condylar fracture
Either 5.5 mm (nixon) or 4.5 mm.
The advantage of 4.5mm is that if one of the screws the thread are stripped it can be replaced by a larger screw
Describe the surgical procedure step by step
Figure 9.2 Lag screw technique demonstrated on a lateral condylar fracture of the third metacarpal bone. The distal screw is already inserted. (A) the** glide hole** is drilled with the large drill bit and the double drill guide; (B) the insert portion of the double drill guide is inserted into the glide hole and the **concentric thread hole cut with the small drill bit; (C) the countersink depression **is prepared on the
surface of the near cortex; (D) the length of the screw needed is determined with the depth gauge; (E) the threads are cut in the far cortex
with the** tap through the double drill guide; and (F) a screw of the predetermined length is inserted and tightened with the hexagonal t** ipped screwdriver.
In standing lag screw fixation what is important to administrate to the horse in the leg?
Local anesthesia at the level of the proximal MCIII/MTIII should be administered with generous volumes over the major nerves as well as performing a subcutaneous dorsal ring block.
How many screws are necessary for non-displaced condylar fractures in general?
The majority of lateral condylar fractures can be treated with two screws.
Most horses have some degree of _______________ (external/internal) rotation of the limb (especially hindlimbs) that has to be taken into account.
Most horses have some degree of external rotation of the limb (especially hindlimbs) when they are in lateral recumbency. The surgeon must account for this or the drill will be directed toward the palmar/plantar articular surfaces.
What is a benefit of headless, variable-taper screws compared to standard cortex screws?
They lack a screw head which may be beneficial in certain locations
Cianci et al VS 2021 CT assessment of fracture charateristics and SC bone injury in THO racehorses with lateral condylar fractures and their relationship to outcome. What was the % of incomplete and complete fractures?
64% incomplete and 36% complete
Cianci et al VS What was the % of non-displaced fractures in the same study? and displaced?
74% non-diisplaced and 26% displaced
Cianci et al VS The comminution in the same study was mainly:
A. dorsal
B. palmar/plantar
76%palmar/plantar comminution and 32% dorsal comminution
Cianci et al VS 84% of the cases was submited to arthroscopy were they:
A. displaced
B. non-displaced
A. displaced
Cianci et al VS What was the outcome and factors that contributed?
66% raced postusregy but sesamoid bone fractures
comminution
sex =fillies were less likely to race
FIGURE 3 Transverse (A-C) and dorsal (D-F) plane computed tomography images of horses with linear subchondral bone injury (A,D), crescentic subchondral bone injury (B,E), and ovoid subchondral bone injury (C,F) lesions in the lateral condyle of horses with lateral condylar fractures
VCOT James et al 2020 Ex vivo comparision of the accuracy of a clamped with a hand-held drill guide for drilling distal third MC MT in equids what was significantly shorter thanks to the guide?
A. shorter time and better accuracy
B. shorter error
C. shorter movement
D. shorter deviation
A. shorter time and better accuracy
What technique is used for the treatment of displaced lateral condylar fractures?
A) Lag technique
B) External fixation
C) Cast immobilization
D) Bone grafting
A) Lag technique
Why do displaced fractures require accurate anatomic reduction?
A) To prevent laminitis
B) Due to the severity of joint surface injury
C) To ensure immediate mobility
D) To simplify the surgical procedure
B) Due to the severity of joint surface injury
What might remain after correct technique and screw placement in displaced fractures?
Visible fracture line due to fibrin or bone loss
What can result from a significant malalignment of the condyle after reduction and screw tightening?
Likely development of osteoarthritis
What is essential for reduction and repair of displaced lateral condylar fractures?
Arthroscopic and fluoroscopic/radiographic guidance
When preparing the glide hole through the fracture fragment, when is the fracture not reduced?
Before screw insertion
How is the pin used during the surgical repair of displaced fractures?
As a “handle” for fracture manipulation
What is checked arthroscopically after the first screw is inserted but not fully tightened?
Articular compression and alignment
What can complicate the alignment of the main fragment during repair of displaced fractures?
Interposed comminuted fragments
When preparing the glide hole through the fracture fragment, when is the fracture not reduced?
Before screw insertion
How is the pin used during the surgical repair of displaced fractures?
The insert drill sleeve and a 3-mm pin are placed in the fragment to use as a “handle.” The arthroscope is then introduced into the proximal dorsolateral joint pouch.
Lateral Proximal sesamoid fracture
The arthro camera is inserted in ______________pouch and the instrument portal is at the _________________
arthro is dorsolateral
instrument is in the base of the LATERAL proximal sesamoid bone
What is checked arthroscopically after the first screw is inserted but not fully tightened?
Articular compression and alignment
Figure 93-6. Arthroscopically assisted repair of a displaced lateral condylar fracture can be performed by drilling the glide hole and placing the insert drill sleeve before placing the scope. Fracture reduction is checked with the scope as the fragment is manipulated by flexion/extension/rotation of the hoof and manipulation of the fragment using the insert sleeve. Pointed reduction clamps are used to hold the fragment after reduction is achieved.
Nearly all lateral condylar fractures can be repaired with two cortex screws placed in lag fashion, one in the epicondylar fossa and the other near the physeal scar.
Figure 93-9. Axial sesamoid fractures associated with displaced lateral condylar fractures are a strong indication of major damage to the MCP joint. They can be seen on standard DP (A) and flexed DP
(B) projections. (C) If the fragment is completely separated (arrows), the best option is probably MCP arthrodesis. LABBE 2022 EVE A 20-degree DMPLO view is the most sensitive radiographic projection to identify sagittal axial fracture of the lateral proximal sesamoid bone.
Figure 93-8. Badly damaged and displaced lateral fractures are inherently less stable, and the screws are subjected to more bending loads. Both 5.5-mm screws and extra screws in the distal condyle should be considered to enhance stability. No effort is made to reconstruct the comminuted fragments at the proximal end of lateral condylar fractures.
name projection
Fig 4: a) DP and b) 20-degree DMPLO views of a 3-year-old
Thoroughbred filly with a right forelimb complete and displaced
lateral condylar fracture. This dorsopalmar projection results in the
condylar fracture line being superimposed over the axial aspect
of the lateral proximal sesamoid bone in a), preventing complete
evaluation of the axial border. The 20-degree DMPLO view
revealed a complete and displaced sagittal axial fracture of the
lateral proximal sesamoid bone (arrows). Lateral is located to the
left side of radiograph a) and b). Labbe EVE 2021
How are most axial proximal sesamoid fractures shaped?
Crescent
What is the radiographic tx to improve diagnosis of sagittal axial sesamoid fracture in racing THO with lateral condylar fracture accordingly to Labbe et Pigot in EVE 2021
20º degree DMPLO view
MC2
diagnosis and description
Fig 3: Axial computed tomography images of a 3-year-old Thoroughbred filly with a right forelimb complete and displaced lateral
condylar fracture and complete, comminuted, sagittal axial fracture of the lateral proximal sesamoid bone. Dorsal is to the top of the
images and lateral is to the right of the images. The approximate 20 degree medial oblique radiographic angle measurement is
demonstrated in b).
What is the prognosis for a horse with an axial sesamoid fracture associated with a displaced condylar fracture?
Very unfavorable
What is the ouctome accordingly to Colgate et al 2023 Outcome and racing performance following standing fracture repair in 245 horsesof MCIII and P1?
A. 60%
B. 70%
C. 80%
D. 90%
D. 90%- 95% discharged and 75% raced
When is observed the osseous resorption in the palmar/plantar subchondral bone adjacent to the fracture line after surgery?
A. 6 monhts
B. 4 months
C. 2 months
D. 1 month
C. 2 months
Osseous resorption inpalmar/plantar subchondral bone adjacent to the fx line commonly develops inthe initialtwo months afterfxRadiologically this may manifest asthe reappearanceof a fracture line, usually distal to the most distal screw
Constant et al 2022 Vs studied the influence of screw head diameter on ex vivo fixation of equine lateral condylar fractures with 5.5 mm cortical screws concluded that a modified screw with 10 mm head instead of :
A. 6 mm
B. 8 mm
C. 4 mm
D. 2 mm
B. 8 mm
5.5mm larg eanimal cortical screw has thesame head diameter (8mm) as the 4.5 mm cortical screw.
Constant 2022 realized that using a 10 mm head diameter had greater resistance agianst overload failures, greater maximal manual insertion torque and:
A. less subject to head stripping or sinking
B. provided less overload resistance
C. provided few articular congruity
A. less subject to head stripping or sinking
Constant 2022 The disadvantage of this 10 mm 5.5 mm screw was
Disadvantage:adds height to the screw head andcould increase soft tissue impingement.
Lateral condylar fractures can all be treated with screws alone?
Nearly all lateral condylar fractures can be successfully treated with screws alone, but a small proportion of lateral condylar fractures of MCIII also have diaphyseal spiral or oblique components that demand they be treated with more extensive fixation
If the reduction of the displaced fracture is not possible to observe through arthroscopy what can you do? where?
If arthroscopic reduction is not feasible for some reason, displaced fractures should have enough of the fracture line exposed through an open approach to allow the surgeon to verify that reduction is accurate. In some cases, this** means a 2- to 3-cm incision** over the proximal tip of the condylar fragment. In rare instances, it might mean a longitudinal arthrotomy along the dorsal fracture plane extending nearly to the proximal phalanx, but this is necessary only on very rare occasions. It is worth noting that in many horses accurate reduction seems to get more difficult as the exposure is increased, presumably because more attachments are disrupted. It is always worthwhile trying to achieve accurate reduction using minimal exposure
What is the best radiographic projection for visualization of non-displaced fractures?
flexed DP, ordorsal 35° distal‐palmar/plantar proximal oblique (D35°Di‐Pa/Pl Pr oblique
How many screws are required for complete non-displaced fractures?
A. 1-2 screws
B. 2-3 screws
C.3-4 screws
D 4-5 screws
C.3-4 screws
The majority of displaced lateral condylar fractures can be successfully treated with …
The majority of displaced lateral condylar fractures can be successfully treated with two distal screws, one in the epicondylar fossa and another 18 to 20 mm proximal to it (Figure 93-7). The fracture narrows quickly as it propagates proximad and comminution, sometimes occult, is common proximal to the physeal scar. More severe and displaced condylar fractures require more stability, so 5.5-mm screws should be considered. Alternately, placing three 4.5-mm screws in a triangular pattern within the condyle also can increase the strength of the repair
(Figure 93-8).
Could you attempt conservative treatment for complete non-displaced fractures?
Not advised, *Inherently unstable, sx recommended
What is the prognosis complete non-displaced fractures?
A. 40%
B. 58%
C. 70%
D. 90%
B. 58%
What is mandatory for recovery in case of displaced fracture?
Cast for recoveryenclose foot & extend to thelevel of the distal row of carpal/tarsal bones, withmetacarpophalangeal/metatarsophalangeal and interphalangeal joints inextension)
*Fx repair is not reliant on external immobilization BUT soft tissue healing maybe enhanced by a short period of cast support
What is the postoperative plan for a complete displaced fracture in postop?
Box rest 60d, hand walking 60d then smallpaddock turnout, minimum 6m before training
What is the date for follow up radiographs?
A. 15 days
B. 60 days
C. 80 days
D. 90 days
D. 90 days
What is a key factor in managing medial condylar fractures?
A) They should be managed more carefully than lateral fractures
B) They are treated similarly to lateral fractures
C) Immediate return to exercise is recommended
D) Surgery is rarely needed
A) They should be managed more carefully than lateral fractures
What is typically developed by horses with medial condylar fractures?
A) Mild discomfort
B) Severe lameness
C) Swelling in the affected limb
D) Behavioral changes
B) Severe lameness
What kind of swelling is associated with medial condylar fractures?
A) Significant soft-tissue swelling
B) No significant soft-tissue swelling
C) Constant, increasing swelling
D) Swelling that decreases with rest
B) No significant soft-tissue swelling
How do medial condylar fractures typically propagate?
Toward the axial aspect of MCIII/MTIII
What is the complication risk for medial condylar fractures in the hindlimb after repair?
High risk
What is a major difference in first aid for medial condylar fractures compared to lateral fractures?
Horses with medial fractures in the hindlimb should be crosstied
What is the most successful technique for treating medial condylar fractures?
Plating techniques
Why should a plating technique be advised for certain fractures?
For any fracture with a known oblique diaphyseal component
What approach can be used to place the plate and screws for medial condylar fractures?
Medial or lateral side
Figure 93-11. Medial condylar fractures of MTIII that have an oblique diaphyseal component (arrow) are extremely dangerous fractures, prone to catastrophic dehiscence.
Figure 93-12. Open exposure of a spiraling MTIII fracture with the fracture line (arrows) “disappearing” in the middiaphysis. The simplest method of defining the configuration of a medial condylar fracture in the diaphyseal region is to make an open approach with periosteal elevation. Implants can subsequently be placed accurately more easily.
Horses with medial condylar fracture while they wait for surgery it is very important that they are
crosstied!!
Medial condylar fractures of MTIII are prone to propagae and to do ____________________
Medial condylar fractures of MTIII are particularly prone to catastrophic failure with or without screw fixation, especially when the horse stands following general anesthesia. The risk extends for several weeks after repair.
Better do plating in the medial condylar fractures than screws alone because screws are not good for 2 reasons name them
Screws alone are not optimal for any fracture with a known oblique diaphyseal component, especially in a hindlimb.
If oblique or transverse diaphyseal fracture is ID what do you do?
oblique or transverse diaphyseal fracture is identified in the preoperative radiographs, a plating technique should be advised.
In hospitals (or horses) without options for controlled anesthetic recovery (e.g., pool or sling) what do you do in medial condylar or transverse diaphyseal fractures?
standing screw fixation of the distal portion of the fracture has been shown to be a reasonably successful option. Preoperative CT imaging to evaluate fracture configuration and help optimize internal fixation may improve outcome, but a diaphyseal MTIII fracture of any configuration always poses a very serious risk
Advantages of dorsolateral plate placement
The advantages of a dorsolateral approach are that the operated limb is uppermost and a lateral plate is easier to remove under local anesthesia in the standing horse after the fracture has healed
Describe the open approach for plate placement dorsolateral
dorsolateral or dorsomedial incision is made in one layer down to the level of the bone surface. The skin and underlying subcutaneous tissues are retracted together. The periosteum may be elevated to expose the surface of the bone such that the fracture line or lines can be clearly identified (Figure 93-12). The incision is continued distad to the level of the joint capsule, but the capsule is not incised. The distal two screws are placed through stab incisions using radiographic control similar to nondisplaced lateral condylar fractures. If the limb is positioned uppermost, the glide hole must traverse the fracture plane and the thread holes engage the medial condylar fragment. This is ensured with intraoperative radiographs or fluoroscopy. A broad dynamic compression plate (DCP) or locking compression plate (LC P) is then positioned on the lateral aspect of the bone extending from just above the second screw to the most proximal portion of the bone.
what plate size is used in dyphyseal or oblique fractures of MCIII?
10- to 12-hole plates are used in MCIII and 12- to 14-hole in MTIII.
What is a risk when placing screws through the plate in the Open Approach?
Injury to the suspensory ligament and splint bones
What is the length of the initial incision in the Minimally Invasive Approach?
2 cm incision is made adjacent to the common digital extensor tendon at the level of the proximal MCIII/MTIII.
Medial condylar fractures can be recovered how in absence of pool/sling?
**available, a full-length hindlimb cast should be considered for metatarsal fractures. Half-limb casts should never be used for metatarsal fractures.
Forelimb medial condylar fractures are usually recovered in a full-limb Robert Jones bandage.
Could be recommended no surgery in a case of medial condylar fragmentation?
NON-SX MANAGEMENT - NOT RECOMMENDED (highmorbidity/mortality, contralateral laminitis, propagate/catastrophic)
What are the 2 forms of fracture propagation recognized in medial condylar fragments?
1 - propagating medial fractures, 6 (33%) remained parasagittal all terminated within the middle one-thirdof the diaphysis. **
The remaining 12 (67%) had spiral configurations** beginning sagittally and turning into an oblique frontal plane in the** middle one-third of the diaphysis.** - Spiral fractures that extended into the proximal one-third of the diaphysis had a less predictable course;
after 2 cm incision in minimally invasive approach what do you do next?
After the subcutaneous (not subperiosteal) tunnel is made, a roughly contoured 10- or 12-hole broad 4.5/5.0-mm LC P is slid down along the bone (Figure 93-14).
You made tunnel subcutaneously what do you do next in condylar fracture?
The “fit” of the plate is assessed palpably and with fluoroscopy. The plate is recontoured as needed and replaced. The holes in the plate can be easily palpated distally. Stab incisions are made over holes and screws are inserted routinely. A **push-pull device or cortex screw **can be used to pull the plate down to the bone. After two screws are inserted, a plate of the same length is placed on the surface of the skin and incisions are made through that plate’s holes. The remaining screws are inserted in routine fashion (Figure 93-15). The distal few screws in the plate may be placed in lag fashion if the fracture plane is radiographically visible at that level. Fluoroscopy or intraoperative radiography is used to check implant positioning. One or two skin sutures are used to close each stab incision.
How is the safest way to induce into anesthesia a horse with medial condylar fracture medial condylar fx?
*Induction ofanesthesia is safest with the horse positioned with the nonfractured side against the wall of the induction box
*Two handlers ensure that the horse can slide down the induction box wall, while a third person controls the fractured limb
Loading can be removed entirely from a forelimb by flexing
the carpus and supporting the distal limb as the animal begins to sink to the ground. Hindlimbs should be kept
under the horse’s body, preventing abduction.
What is the preop contention of the limb medial condylar fx?
Bandage cast or splinted Robert Jones
*Commercial compression boots frequently do not extend sufficiently proximally tosupport the full length of the MC/MT
The surgical intervention requires minimal how many distal screws for medial condylar fx?
A. 2
B.6
C.4
D. 3
D. 3 screws
*At least distal 3 screws placed in LMplane
The screw placement is based on what?
fracture configuration
*openlateral approach generally allows the surgeon to seethe spiral fracture as it propagates in the dorsalcortex and as the palmar component exits from the palmar/plantar cortex intothe lateral cortex *Directfracture observation enables the surgeon to insertscrews in a biomechanically optimal position along the entire length of thefracture
Figure 21.27 Intra-operative dorsal (a) and lateral (b) views of
percutaneous needles at sites of proposed screw placement for
repair of a spiral fracture of Mt3. Note distal lateromedial
orientation progressing through increasing dorsolateral to
plantaromedial oblique to dorsoplantar trajectories proximally
in line with CT determination of the fracture plane.
Figure 21.27 Intra-operative dorsal (a) and lateral (b) views of
percutaneous needles at sites of proposed screw placement for
repair of a spiral fracture of Mt3. Note distal lateromedial
orientation progressing through increasing dorsolateral to
plantaromedial oblique to dorsoplantar trajectories proximally
in line with CT determination of the fracture plane.
“Backward”fixation - Although the glide hole is typically drilled through the smaller fragment and the thread hole across the larger fragment, this particular fracture medial condyle is often repaired in the opposite manner.Why?
The major reason is that it is much safer and easier to approach the leg from the lateral side than the medial side during implant removal, which is routinely performed in the standing position.
Fortunately medial condylar fractures tend to be very close to the midline so there is little difference between the width of the two fragments.The bone in this location is so strong, that 25 mm of thread engaged with a 4.5mm cortex screw is already exceeding the strength of the screw. Although someterm the lag screw technique “backward”, the strength of fixation is equally adequate.
Describe the surgical technique for medial condylar fragment
Positioning/Initial Steps
*Lateralrecumbency, affected limb uppermost, extended,and horizontal
*Esmarch– helps ID fx lines - fixed in an extended position prior to this procedure, asthe tourniquet will cause limb flexion, which can compromise drill alignment
*Outwardrotation of hindlimbs is controlled by support under the point of the hock *
*Insertionof interfragmentary screws - distaltwo screws across the condyle are usually placed routinely through stabincisions as described for non-displaced condylar fractures
*
*Dorsolateralapproach - distolateralto proximodorsal curvilinear incision - made from the level of the fetlockjoint to a point on the diaphysis proximal to the radiologically determinedtermination of the fracture *Proximalto the joint capsule and collateral ligament and lateral to the extensortendons, the incision is continued through the metacarpal/metatarsal fascia andperiosteum
*Reflected(Hohmann retractors) to permit inspectionof the metacarpal/metatarsal cortex for fracture lines
*Preservationof the periosteum has advantages to bone healing in some circumstances – BUTin this situation it precludes identification of fracture lines,and as a consequenceshould be reflected up to the lateral interosseous space between splint and MC/MT3, and beneath the lateral and common or long digital extensor tendons
*Screw insertion
- Cortical screws are inserted at 25–35 mm intervals, using standard lag screw technique, from the epicondylar fossa to the proximal limit of the identifiable fracture
*Useof 4.5mm screws is generally satisfactory (Wright), although one of the authorsprefers 5.5mm screws, particularly in the distal aspect
*When the fracture is visible in both cortices,screws are placed halfway between the fracture lines and angled perpendicular to the anticipated fracture plane
*If the fracture is visible in the dorsal cortex only, screws are angled dorsolateral to palmar/plantaromedial to follow the spiral configuration of the fracture.
*avoid impingement on the MCII MTII
*Four screws were used in parasagittal fractures and between five and nine screws in spiral fractures described in the literature
*Wound closure - metacarpal/metatarsal fascia, subcutis/intradermal, and skin.
*extensor tendons should be appose dby suture of surrounding fascia
average time btw surgery and race?
11 months
do you remove the screws from the condylar surgeries?
When fractures extend into the middiaphyseal region, the screws are more likely to cause pain when horses return to intensive exercise. Therefore diaphyseal screws are removed** 3 to 4 months after surgery**, usually with the horse under sedation and local anesthesia
after screws removal when does the horse go back to training and gallop?
After screw removal, the horse is continued in a walking and jogging program for 60 to 90 days before returning to galloping
exercise.
how many days after initial surgery do you remove the plates?
These plates are typically removed about 70 to 80 days following surgery
Figure 93-17. Plate removal is performed with the horse standing, using local anesthesia. (A) A matching plate facilitates accurate stabs over the screw heads. (B) All of the screws are partially removed. After all are loosened and counted, they are removed. (C) A nail set and a mallet can be used to loosen the plate. If necessary, the proximal end is grasped with vise grips for removal.
explain the procedure of plate removal standing and how you explain to the owner the exercise protocol
A 12-mm osteotome is used to pry the plate up at its proximal end. The osteotome is left under the end of the plate and then the plate is grasped with sterile vise grips and extracted proximally. A single skin suture per screw is placed and the larger proximal incision is closed in two layers. The horse is hand walked for 60 days, receives paddock turnout for another month, then returns gradually to training.
prgonosis for non displaced and displaced condylar fractures to go back to racing
The prognosis for
non displaced: 0%–80% return to full function
displaced : 50% for return to racing, less if there is serious comminution or sesamoid injury
medial propagating: 40%
