Chapter 92 - part 2 proximal phalanx Flashcards
1
Q
What are the fracture configurations of the proximal phalanx?
A
1) proximal intraarticular osteochondral fractures (no histo confirmation that supports that is true OC)
(2) fractures involving the shaft or diaphyseal region of the proximal phalanx.
2
Q
What are the types of fractures in each group?
A
- DOF
- POF (Type I and type II)
- short dorsal frontal
- Sagittal
3.1 long incomplete
3.2 non-displaced complete
3.3 displaced complete - frontal plane fractures biarticular
- palmar/plantar eminence
3
Q
What are the most common cause of OC fractures?
A
trauma and hyperextension
4
Q
What treatment is preferred for large chip fractures of the proximal phalanx?
A
Surgical removal using arthroscopy
5
Q
What is the size of proximal fragment that can be embebed in the synovia?
A
2 mm and can heal without causing clinical symptoms
6
Q
where is usualy the dorsoproximal fragment?
A
Dorsomedial
7
Q
What percentage of racehorses return to use after arthroscopic surgery for osteochondral fractures of the proximal phalanx?
A
89% with 82% racing
8
Q
Describe the surgical dorsal arthroscopy approch
A
DR - extension of the limb + distension of the joint (35mL)
Arthroscopic portal in proximolateral quadrant - arthro sleeve inserted perpndicular first to skin and after parallel to the articular surface of MCIII
9
Q
What is the postoperative convalescence following arthroscopy OCD DOF?
A
6-12 weeks
10
Q
A
11
Q
A
Palmar/Plantar approach
skin incision with blade 11 proximal part of teh bulging capsule
arthroscopic sheath and conical obturator are inserted perpendicular to the skin initially and then are directed distad
fetlock 30-45º degree flexionat this time to facilitate passage between distal metacarpus/metatarsus and the proximal sesamoid bones
12
Q
A
13
Q
Bonilla VCOT 2019 described Standing Needle Arthroscopy of the Metacarpophalangeal and MetatarsophalangealJoint for Removal of Dorsal Osteochondral Fragmentation in 21 Horses. What is the size of the arthroscope?
A
1.2 mm needle arthroscope
14
Q
What was the key finding about the return to racing post-diagnosis between non-surgically and surgically treated horses Ramzam 2021?
A) Non-surgically treated horses returned faster
B) Surgically treated horses returned faster
C) Both groups returned at the same rate
D) Neither group returned to racing
A
A) Non-surgically treated horses returned faster
15
Q
The proximopalmar and proximoplantar osteochondral fractures can be classified in 2 types name them
A
Type I fractures when they are avulsed from the **axial, proximal, plantar or palmar rim of the proximal phalanx and are mostly articular.
Larger, abaxially located, partly articular osteochondral fragments have been categorized as Type II fractures.
Type II fractures extend distad 2 to 3 cm and contain minimal articular cartilage.**
16
Q
Type I fractures have:
A. Lameness visible at higher speed (minimal)
B. Lameness visible all circumstances
C. Lamenes visible only if flexed
D. No lameness
A
A. Lameness visible at higher speed (minimal)
type II DO NOT PRODUCE LAMENESS
17
Q
What type of proximal phalanx fractures are categorized as Type I fractures?
A
Avulsed from the axial, proximal, plantar or palmar rim
18
Q
What is the success rate of horses returning to racing at or above their preoperative level after surgery for Type I fractures?
A
63%
19
Q
How are Type I proximal plantar osteochondral fracture fragments usually accessed for surgical removal? describe approach
A
Via an arthroscopic approach through the plantar pouch
DR - flexed limb 30 to 45º - distension 35 mL - arthroscopic sheath and conical obturator
are inserted perpendicular to the skin initially and then are directed distad un the bulging capsule
Motorized resectors, radiofrequency cutting loupes or diode CO2 lase may be required
20
Q
What is the incidence of Type II abaxial osteochondral proximal pal/pl fragments fractures in Standardbred yearlings?
A
Low (2.4% of 753 yearlings)
21
Q
What is the convalescent care period for Type I fracture osteochondral proximal pal/pl fragments patients post-surgery?
A
6 to 12 weeks
22
Q
P
A
Elevated oblique radiographic projection (D30Pr70L-PlDiMO) of the rear MTP region of a Standardbred pacer with a Type I (axial) osteochondral fracture (arrow) in the plantar pouch. These fragments need to be differentiated from Type II fractures on the abaxial corner of the proximal phalanx, many of which do not need surgery.
23
Q
What is the best projection to differentiate Type I from type II osteochondral proximal palmar plantar fragments
A
the dorsal (20- to 30-degree) proximal (70-degree) medial—plantarodistal lateral oblique projection, highlight the plantar rim of the phalanx and the associated base of the proximal sesamoid bone
24
Q
diagnosis
A
Figure 20.10 Osteochondral
fragmentation of the proximal plantar
aspect of the proximal phalanx. Lateral to
medial view (A) and elevated oblique view
(B) of plantar proximal phalanx fragment
25
26
diagnosis
27
Are type II proximal osteochondral fragmentation surgical?
No, Type II proximoplantar osteochondral fragments are located on the abaxial tuberosity of the proximal phalanx
and are** predominantly extraarticular = surgery rarely indicated**
28
If type II is giving clinical issues (extremly rare) what are the surgical options?
Nixon fx book
Arthrotomy A v**ertical 4 cm skin incision is made on the
abaxial surface of the fetlock joint at the level of the proximal
tuberosity of the proximal phalanx**, a prominent portion of which is palpable dorsal to the palmar digital artery, vein, and nerve. The incision is continued through the distal part of the annular ligament of the fetlock and the joint capsule immediately distal to the collateral sesamoidean ligament and proximal to the proximal surface of the proximal phalanx. The fetlock is flexed and a retractor is used to expose the fracture. The fragment is
dissected free and removed.
**Lag screw fixation of a large fracture with two 3.5 mm cortical bone **screws also reported.
29
How do you remove the type I pal/pl fractures in yearlings during arhtroscopic approach?
A. Motorized resectors
B.. Diode or Co2 laser
C. Radiofrequency loupes
D. All of them
D. all of them
The fragments are dissected from the covering of synovial membrane and remnants of the attached short sesamoidean ligaments and removed
30
Would you go to surgery with a type II abaxial osteochondral fractures?
No usually extra-articular, very rare 2.4% prevalence, do not cause lameness and if associated to lameness place a 3.5 or 4.5 mm cortex screws inserted in lag fashion to achieve union.
31
Describe the dorsal frontal fractures
Most
involve fragmentation of the dorsal articular surface which may, or may
not, extend distally into the attachment of the fibrous joint capsule (usually extend only 2 to 5 cm from articular surface in the dorsolateral cortex of P1
32
Dorsal frontal fractures are usually complete or incomplete?
complete and minimally displaced
33
what is the ideal treatment?
Better repair with screw fixation in lag fashion one or two 3.5-mm cortex screws
Recover in soft bandage
34
What is the recovery after the lag screw placement for frontal fractures postop rest?
2 w complete stall rest followed by 6 weeks of hand walking
35
In the dorsal frontal fractures do you remove the implantes?
only where lysis or reaction has developed beneath the screw heads
36
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Can you go for conservative treatment in horses with dorsal frontal fracture? prognosis?
Only if not displaced and healing occurs in 4 to 6 months
Favorable prognosis to return to race
37
what are the dyaphyseal fractures in P1?
3. Sagittal
3.1 long incomplete
3.2 non-displaced complete
3.3 displaced complete
4. frontal plane fractures biarticular
38
P1 diaphyseal fractures are more in the FL or HL?
FL
39
SCB trauma and development of short fractures extending from sagittal groove is typical in race or Warmbloods?
Warmbloods
40
What is the prognosis for short diaphyseal fractures?
These are considered stress fractures, have significant variation in their configuration, and often are accompanied by osteoarthritis with a poor prognosis.
41
complete sagittal fractures exit axial or lateral or medial?
Complete fractures exit on either the lateral or, rarely, medial cortex of the proximal phalanx or enter the proximal interphalangeal joint (Figure 92-13, A)
42
Figure 92-13. (A) Dorsopalmar radiographic view of a complete nondisplaced fracture of the proximal phalanx commencing at the sagittal groove within the MCP joint and spiraling distally to enter the PIP joint. (B) Repair using 4.5-mm cortex screws placed in lag fashion through stab incisions.
43
Short sagittal fractures can be difficult to localize on routine dorsopalmar/-plantar radiographs and extend how much?
0.5 to 2 cm
44
when do you advise the owner to treat with screw fixation applying lag technique a short sagittal fracture?
If it doesn't heal after 3 months of conservative therapy
45
short dorsal P1 fractures are more dorsally in FL or HL?
FL
46
when is transfixation device mandatory?
Disruption of weight-bearing support without an intact bony column is generally a contraindication to screw repair alone. In this case transfixation is required
47
If you place a 4.5 mm cortex screw how distal from the first one can you place the screw?
An additional more distal cortex screw can be placed 18 to 20 mm distal to the initial screw, depending on fracture length.
48
Long incomplete and nondisplaced fracture treatment?
For routine nondisplaced fractures, the proximal phalanx can be stabilized by inserting screws in lag fashion through stab incisions (see Figure 92-13, B)
49
In long incomplete and nondisplaced fracture what size should be the most proximal screw?
5.5 cortex screw for additional compression of the articular surface
50
How far from the sagittal groove should pass the proximal 5.5 mm cortex screw in long incomplete fractureS?
the proximal screw should pass within 5 mm of the most distal point of the sagittal groove of the proximal phalanx to provide maximum compression to the articular surface.
51
In long incomplete and nondisplaced fracture of P1 the first 5.5mm screw is placed 5 mm from SGroove and additional screws should be placed at what distance?
Additional screws are placed at intervals of 20 to 22 mm until the entire fracture line has been stabilized.
52
diagnosis
Figure 92-14. (A) Transverse computed tomographic (CT) view of an oblique frontal plane fracture of the proximal phalanx.
53
treatment?
Figure 92-14. (A) Transverse computed tomographic (CT) view of an oblique frontal plane fracture of the proximal phalanx. (B) Postoperative dorsopalmar radiographic view showing the direction the cortex screws were inserted in lag fashion. The CT image allowed the surgeon to orient the screws perpendicular to the fracture plane.
54
which limb in case of P1 fracture require cast for recovery? FL or HL? why?
Proximal phalanx fractures of the hindlimb are more likely to require cast support for the recovery phase because of increased torsional loads on the hindlimbs during recovery
55
displaced complete saggital fractures of P1 requires what type of intervention?
Open approach or arthroscopic approach with debridement and reduction of the fracture under visual guidance
56
Outcome after screw fixation of long incomplete fractures
fair 56% return to race
57
What surgical approach do you perform in multiple sagittal and frontal planes?
require an extensive open approach either using an I-shaped (no collateral ligament destruction) incision that exposes the entire dorsal and abaxial cortices of the proximal phalanx or an S-shaped incision (collateral ligaments excised) require an extensive open approach either using an I-shaped incision that exposes the entire dorsal and abaxial cortices of the proximal phalanx or an S-shaped incision
58
Fractures without an intact strut of bone are good candidates for internal fixation?
Fractures without an intact strut of bone are poor candidates for internal fixation
59
Fractures without an intact strut of bone are result of what?
They are generally high-energy fractures and the bone is extensively fragmented
60
Why cast buyitself is not an option for severly comminuted fractures of P1?
S
imple cast fixation does not provide resistance to axial collapse of the fracture within the cast. The complications of collapse include continued lameness, a high risk for development of pressure necrosis of the skin leading to an open fracture, and laminitis of the unaffected weight-bearing limb.
61
where do you place the tansfixation pins in severly fragmented comminuted fractures?
Transfixation techniques limit the collapse of the fracture within the cast by using transcortical pins in the distal and midportion of the MCIII or MTIII.
Pins with positive threads located in the center are preferable, and slow sequential drilling followed by preparation of the threads in the hole with a suitably sized tap are generally required before the pin is inserted
62
what is the most common complication fo transfixation devices?
ring sequestrum formation around the pin tracts, especially in heavy horses, and subsequent fracture through a pin hole
63
Figure 13.19 (A, C) Lateromedial and (B) dorsolateral to palmaromedial oblique and (D) dorsopalmar radiographs of the metacarpus during treatment of a severely comminuted P2 fracture with a pin cast. (A, B) Radiographs the day of pin removal, six weeks after pin placement, demonstrate ring sequestration around the proximal and distal pin holes, as well as a large sequestrum of bone between the two pin tracts. Ring sequestration is likely due to excessive heat generation during drilling, tapping, and pin placement. There is also a marked amount of periosteal bone production, which is likely due to pin tract infection. (C) Lateromedial and (D) dorsopalmar radiographs five weeks later: there is resolution of the ring sequestra with improved but continued evidence of bone sequestration between the pin tracts. The tracts were no longer draining, the horse was continued on parenteral antibiotics, and the sequestra resolved without additional treatment.
64
diagnosis
images from left MTP in 3yo THO in flat race training a) lateromedial b) D70ºLPMO radiographs and c) transverse CT image of proximal phalanx at the level of the sagittal groove = fracture Wright et al 2017
65
In which horse breed do dorsal frontal fractures predominantly occur?
Thoroughbreds
66
Where are dorsal frontal fractures more prevalent in Thoroughbreds?
Hindlimbs
67
Which aspect of the proximal phalanx is commonly involved in short dorsal frontal fractures of P1?
dorsomedially
68
How far do dorsal frontal fractures typically extend from the articular surface?
2 to 5 cm
69
What is the nature of most dorsal frontal fractures?
Complete and minimally displaced
70
What percentage of dorsal frontal fractures were reported to have involved the **dorsomedial aspect of the proximal phalanx**?
90%
71
What surgical tool is recommended for the repair of complete fractures dorsal frontal fractures?
3.5-mm cortex screws
72
What kind of bandage is used for recovery in most horses of dorsal frontal fractures?
Soft bandage
73
What was the prognosis for horses after surgery for dorsal frontal fracture Wright 2021?
Good 76% success
74
Elzer and Bramlage EVJ 2020 describe arthroscopic debridement of short frontal plane proximal phalanx fractures preserves racing performance - what % of treated horses race d post-operatively?
91%
75
Name the projections
Pre-operative lateromedial (A) and 1-d post-operative lateromedial (B) and D75-85°LPMO (c) radiographs of one horse. In the
post-operative radiograph, the affected eminence has been debrided below the level of the parent bone
76
F I G U R E 1 Intraoperative arthroscopic views of a fracture
(arrows) before (A) and after (B,C) debridement. The affected
proximodorsal eminence is lowered to the level of the joint
capsule attachment, below the level of the opposite proximodorsal
eminence. SR, sagittal ridge; MC, medial metacarpal condyle; ME,
medial proximodorsal eminence of the proximal phalanx; LE, lateral
proximodorsal eminence Elzer and Bramalage 2020
77
Elzer and Bramlage 2020 contrary to Wright 2017 in short frontal plane proximal phalanx fractures they did what?
To describe a new approach, arthroscopic debridement, of short frontal
plane fractures of the proximal phalanx in flat-racing Thoroughbreds and post-operative
racing outcome instead of short frontal plane fixation (Wright 2017)
78
Deescribe surgical approach of Elzer and Bramlage 2020
LR with fracture on lower side of the limb
Distended the MCP/MTP joint
4-mm 30º arthroscope was inserted on teh side opposite to the fracture
Using Ferris-Smith rongeurs and Spratt curetteseminence was debrided to the level of joint capsule attachment
Lavage the joint and close
Stall confiment 2 weeks with 3 w hand walking
30 days with bandage
79
Why Elzer and Bramlage advocate the debridement in nondisplaced short frontal fractures of P1?
Recent literature has emphasised internal fixation techniques for
this fracture.3 However, for nondisplaced fractures, arthroscopic debridement
is effective, simpler, requires less equipment and is technically
less challenging. It also avoids potential complications related
to the implant. The procedure is similar in difficulty to osteochondral
fragment remov
80
What was the mean depth of the short frontal fractures of Bramlage 2020 vs Wright 2017?
Wright and Minshall describe arthroscopically guided placement of 3.5 and 2.7 mm screws The dorsopalmar/plantar depth of these fractures as measured on a lateromedial radiograph ranged from **5 to 15 mm (mean 9.4 mm).** **76 % returned to racing**
Bramlage the majority (84%) had a depth of fracture 5-10 mm but the **median was 6.5 mm 94% returned to race**
81
Did the fracture configuration (complete vs incomplete), sex, raced preop, FL vs HL influence the result in Bramlage 2020?
No, tehere was no association btw likehood racing postop and any of the factors
82
Elzer and Bramlage 2020 What was the difference in post-operative earnings between treated horses and controls?
No difference
83
Dorsopalmar (A) and lateromedial (B) preoperative radiographic projections of a multifragment fracture of the proximal phalanx showing sagittal and frontal plane components. There is an intact medial strut of bone that is to be used in reconstructing the fragmented portions. Dorsopalmar. **Treatment?**
Dorsopalmar (C) and lateromedial (D) postoperative radiographic projections show the repaired fracture.
84
What is the typical location for axial fractures of the proximal phalanx?
Sagittal plane
midsagittal groove is mechanically predisposed to initiation of the fracture
85
What is a common cause for the initiation of proximal phalanx fractures?
Torsion applied to the sagittal groove
86
In which limbs are proximal phalanx fractures more common?
Forelimbs
87
What are proximal phalanx fractures in non-racehorses often accompanied by?
88
Subchondral bone trauma ande development of short fractures are well characterized in which breed?
Warmbloods
89
Could you use nerve block to confirm in diaphyseal fractures?
No!!! It would propragate the fracture line1) proximal intraarticular osteochondral fractures and
90
Landmarks of placement of the screws in proximal aspect
Extensor branch
5 mm distal to the sagittal ridge and dorsal to the extensor branch of the suspensory ligament
91
Bryner et al 2019 VS Long-term clinical and radiographic results after lag screwosthe osynthesis of short incomplete proximal sagittal fracture sof the proximal phalanx in horses not used for racing - How many horses returned to their previous athletic activity level?
27 out 31 = 87%
92
Bryner et al 2019 VS Was the position of the proximal screw associated with radiographic fracture healing or return to soundness?
A) Yes, strongly associated
B) Yes, but only in a few cases
C) No association found
D) The study did not assess this aspect
No association found
93
Bryner et al 2019 VS What was the result regarding radiographic fracture healing after 12 months or more?
Healing remained incomplete
94
What screw size is preferred for additional compression of the articular surface?
5.5 m, although 4.5-mm screws usually suffice.
95
Very important to consider:USE the two dorsal thirds of the phalanx and not the palmar to not touch tendonsGo 5 mm distal from sagittal groove
96
Describe the placement of a cortex screw in lag fashion
1. Drill glide hole 4.5 mm until the fracture line
2. Thread hole 3.2 mm we ALL the way to the other side of the fracture and we want the cortex of the transcortex (VERY IMPORTANT to engage the thin cortex)
3. COunterskin
4. Depth gauch
5. Tap
6. Insert screw 4.5 mm
97
How should the screw head be positioned to avoid torque on the screw shaft?
A) Parallel to the cortex
B) Perpendicular to the cortex
C) At an oblique angle
D) Adequately countersunk
D) Adequately countersunk
98
Common errors
1. Go to the very end and pass the transcortex side other wise no purchase and will strip the screw and tap until the end
2. countersink with shape of the phalanx is important to avoid torque on the screw shaft
3. Measure with the tip up in proximal aspect to measure the correct and not less as indicated in the bottom
99
What type of fractures can be repaired standing?
Some incomplete sagittal fractures
100
What is the benefit of using two cortical screws in the proximal aspect of the phalanx?
ncreased stabilization
101
EVJ 2021 Outcome following repair of 63 sagittal fractures of the proximal phalanx in UK Thoroughbreds using either a triangular or linear screw configuration. What is best?
102
What is the primary concern when inserting the proximal screw ins agittal fracture?
Avoiding joint penetration
103
Complete fractures exit on either:
lateral, medial (rare) or PIP
104
Radiographs from different limbs of the same horsethree years apart showing a common configuration of a proximalphalangeal fracture, with the fracture starting in a sagittal planeand then propagating in an oblique plane toward the lateralcortex.
105
What type of incision is used for extensive fractures?
"I" or "S"-shaped incision
106
Tx?
This is a frontal fracture collapsing, open approach everything came together proximally because it was intact distally
107
In comminuted fractures what type of fractures are generally not suitable for internal fixation?
Fractures without an intact strut of bone
108
TYPICAL CASE NOT POSSIBLE without Transfixation cast
Figure 92-16. Dorsopalmar radiographic projection of a severely fragmented fracture of the proximal phalanx, without an intact strut and lacking inherent stability. Screw repair is generally inadequate, and transfixation casting or external fixators are required for salvage.
109
In severe comminuted P1 fractures without an intract struct what can you apply?
6.3- mm diameter threaded positive profile pins with 3 to 4 cm distance throught the metaphysis of the metacarpal/metatarsal bone and distal diaphysis midway between the dorsal and palmar cortex
109
What is a complication of simple cast fixation for comminuted fractures?
Axial collapse of the fracture within the cast
109
describe the surgery of transfixation pin for higly comminuted P1 fractures
A stab incision was made through the skin and the lateral collateral ligament of
the fetlock joint. Holes of increasing diameters (3.2, 4.5, 5.5, and 6.3 mm) were drilled and continually irrigated with saline
(0.9% NaCl) solution. A skin stab incision was made on themedial side to allow exit of the drill bit. Tapping was performed slowly using a 17W drill. Rotation of the drill was regularly
reversed to prevent bone packing and heat generation. The hole in the epiphysis of the MC3 or MT3 could not be tapped manually because of high bone density. A 6.3mm positive profile centrally threaded pin was
slowly inserted using the drill until the threads could be seen on the medial side. A 2nd pin was placed 3–4 cm proximal to the 1st pin, through the metaphysis, using the same technique. The 2nd pin was placed in a coplanar position (Fig 4). Care was
taken to place it midway between the dorsal and palmar (plantar) cortex (checked radiographically).
Pins were maintained for 6–8 weeks
110
What is palmar/plantar metacarpal/metatarsal fragmentation in racehorses also known as?
Palmar Osteochondral Disease (POD)- However, there are no histologic data to verify this etiology, and classification as an OC D lesion has been abandoned.
111
How is the disorder thought to be induced POD?
Accumulated stress and sclerosis during racing
112
At what age are most Thoroughbred racehorses affected by POD?
3 years old or older
113
What is a typical radiographic appearance of POD?
Focal radiolucencies and sclerosis in the condyles
114
Which condyle is more severely affected in the forelimb by POD?
medial condyle
115
What is a common secondary feature in this disease?
intense sclerosis of the condyle
116
Figure 92-17. Lateromedial radiographic projection of a 5-year-old Thoroughbred with marked palmar fragmentation, bone loss, and extensive subchondral sclerosis of the metacarpal condyles (arrows). Enthesiophyte formation is noted at the proximal and distal ends of the proximal sesamoid bones, indicating chronic arthritis.
117
What imaging technique is sensitive in detecting early stress fractures POD?
Scintigraphy
118
What radiographic projections are ideal for POD?
125-degree dorsopalmar/-plantar projections.82 Better visualization of the palmar/plantar surface is provided by the flexed dorsopalmar/-plantar projection
119
what is the tx for POD?
Rest from active race training for 60 to 90 days allows most horses to return to racing
120
can POD be accessed by arhtroscopy?
Surgical access to the palmar/plantar region of the distal metacarpus/metatarsus **is very limited** and is made more difficult because most of these** lesions are close to the sagittal ridge.**
121
How successful is the return to racing for horses with POD following treatment?
Mostly successful
122
Labens et al 2021 Ex vivo comparison of standing and recumbent repair ofincomplete parasagittal fractures of the first phalanx inhorses. What was the primary objective of the study?
To assess suspensory ligament extensor branch location and fracture gap reduction
123
How were changes in fracture gap width assessed in the study of Labens et al 2021 repair of incomplete parasagittal fractures of P1?
Computed tomography (CT) images
124
What was a significant finding regarding the simulated standing repair in Labens et al 2021?
Allowed more of P1 width to be approachable palmar to extensor branche.
Conclusion: Simulated standing repair was not associated with inferior fracturereduction compared with loaded simulations of recumbent repairs. Limbloading affected extensor branch location relevant to implant positioning
125
James et al Arthro evaluation of MCP MTP joint in horses with parasagittal fractures of the proximal phalanx. What additional finding was noted during arthroscopic evaluation of these fractures?
A) No additional lesions
B) Joint capsule and dorsal synovial plica tears
C) Complete healing of the bone
D) Lack of articular surface disruption
Joint capsule and dorsal synovial plica tears
126
James et al 2020 How did the arthroscopic findings of articular incongruity compare with pre-operative radiographs?
In some cases, incongruity was not predicted by radiographs
127
James et al 2020 What limitation was noted in the study regarding arthroscopic data?
Inconsistent evaluation of the entire dorsal joint space
128
James et al 2020 What conclusion can be drawn regarding the reliance on pre-operative radiographs for these fractures?
they cannot confidently exclude fracture displacement and incongruity
129
F I G U R E 1 A and B, Original and magnified dorsopalmar radiographs of the right metacarpophalangeal joint of horse 20 showing
proximodistal and lateromedial displacement of the fracture fragments at the proximal articular surface
130
F I G U R E 2 Arthroscopic image of a left metacarpophalangeal
joint of horse 80 demonstrating lateromedial (red arrows) and
dorsopalmar (blue arrows) incongruity of the proximal articular
surface: SR = sagittal ridge of MCIII; L = proximal P1 lateral
fragment; M = proximal P1 medial fragment
Incongruency was mos commonly ID in dorsopal/plantar direction --> but on radiograph NONE was visible in DP direction
James et al 2020
131
F I G U R E 3 Arthroscopic appearance of tearing of the dorsal
synovial plica (P) from distal MCIII (arrows) in horse 40, a long
incomplete parasagittal fracture; proximal is to the left of the image
James et al 2020
132
F I G U R E 4 Arthroscopic appearance of an acute tear of the
lateral joint capsule with extrusion into the joint (arrows) in horse
42; MC3 = lateral condyle of distal MC3; P1 = proximal phalanx
James et al 2020
