Chapter 101 - Stifle II - stifle disorders Flashcards
1
Q
A
Figure 101-21. Postmortem dissection showing horizontal clefts (arrow) in the articular cartilage on the weight-bearing surface of the medial femoral condyle (a). b, Cranial horn of the medial meniscus; c, medial intercondylar eminence of the tibia.
1
Q
A
Figure 101-20. Mild (A) and severe (B) cartilage injury to the distal aspect of the medial femoral condyle in two different horses.
2
Q
What is the most commonly diagnosed stifle disorder in horses?
A
Osteochondrosis.
3
Q
What percentage of stifle issues in horses is due to osteochondrosis?
A
Specific data varies, but osteochondrosis is highly prevalent among stifle disorders
4
Q
What factors contribute to the pathogenesis of osteochondrosis?
A
It is multifactorial, involving developmental issues and trauma.
5
Q
What is the prognosis for mild osteochondrosis with early intervention?
A
Generally good, with potential for full recovery.
6
Q
What percentage of horses with stifle osteoarthritis (OA) can return to performance after treatment?
A
Varies by case, but often around 50-70% depending on severity.
7
Q
What is the typical outcome for horses with severe cartilage damage in OA?
A
Poor prognosis for athletic function.However McCoy 2019 (VS) mentions that full thickness cartilage the odds to return are higher
8
Q
What initial sign of OA is most often observed in the medial femoral condyle?
A
Cartilage damage.
9
Q
What is the prognosis for horses with early-stage OA after appropriate rest and therapy?
A
Prognosis can be fair to good with rest, therapy, and joint protection.
10
Q
How does cartilage loss affect the prognosis in OA?
A
Severe cartilage loss worsens the prognosis significantly.
11
Q
In what percentage of horses with stifle OA is there no radiographic evidence initially?
A
Radiographic changes are often absent in early stages, especially in mild OA cases.
12
Q
What arthroscopic procedure can help with early diagnosis of stifle OA?
A
Arthroscopic exploration of the joint.
13
Q
What is the common prognosis for horses with “mogul-like” cartilage defects?
A
Typically poor for long-term soundness.
14
Q
How can extensive cartilage débridement impact the prognosis?
A
Large-scale débridement has a poor prognosis due to limited cartilage regeneration.
15
Q
What percentage of horses experience improvement with cartilage lesion rest (4–6 months)?
A
Improvement can occur, but with a low percentage of cases achieving long-term soundness.
16
Q
Why is corticosteroid injection contraindicated for advanced cartilage degeneration?
A
It can accelerate irreversible cartilage damage.
17
Q
What radiographic view best detects advanced stifle OA?
A
Caudocranial view.
18
Q
What percentage of femorotibial OA cases show lipping of the medial tibial plateau as an early sign?
A
A high percentage, as it is often the first visible radiographic sign.
19
Q
What is the significance of joint space narrowing in stifle OA?
A
It indicates advanced disease and correlates with a poor prognosis.
20
Q
Why is positioning critical for accurate radiographic diagnosis of OA?
A
Proper weight-bearing positioning is necessary for clear visualization of joint spaces.
21
Q
What is the prognosis for horses with FP OA seen in the lateromedial view?
A
Typically poor for athletic performance, as it indicates advanced joint changes.
22
Q
What is the recommended treatment for advanced OA in the femorotibial joint?
A
Arthroscopic cartilage débridement and chondroprotective therapy.
23
Q
How does meniscal injury affect prognosis in stifle OA cases?
A
It worsens the prognosis due to joint instability.
24
What arthroscopic technique has shown benefits in full-thickness cartilage defects?
Subchondral bone microfracture.
25
What is the expected outcome after microfracture for full-thickness cartilage defects?
Fair prognosis; some horses return to limited performance.
26
What experimental technique shows promise for cartilage healing?
MSC (mesenchymal stem cell) implantation and other regenerative therapies. 84% raced after mesen stem ç - Klein et al 2022 VS in subchondral cystic lesion
27
What percentage of experimental treatments have shown positive results for cartilage healing?
Early studies show promising results in select cases, with varying percentages.
28
What is the prognosis for horses after autologous chondrocyte transplantation?
Potentially good in experimental cases, though more research is needed.
29
How does chondromalacia on the patella affect prognosis?
Prognosis varies; mild cases can improve with débridement.
30
What is a common symptom in Quarter Horses with horizontal cartilage clefts?
Lameness and poor performance.
31
What percentage of horses benefit clinically from patellar chondromalacia débridement?
Most show improvement, though it may not fully restore athletic function.
32
Why is extensive cartilage removal avoided for horizontal clefts?
It can compromise joint integrity without significant benefit.
33
What is the effect of early rest on horizontal cartilage lesions?
Rest can help, but the prognosis for long-term soundness is poor.
34
What joint feature forms in stifle OA as seen in advanced cases?
Periarticular osteophytes and sclerosis.
35
Osteoarthritis is commonly established in the ____________________ joint secondary to meniscal or ligamentous injury;
Osteoarthritis is commonly established in the femorotibial joint secondary to meniscal or ligamentous injury;
36
Cartilage lesions on the articular surface of the patella are referred to as
chondromalacia
37
What is the primary diagnostic method for collateral ligament injury?
Ultrasonography is commonly used to diagnose collateral ligament injuries.
38
In what percentage of horses does the MCL attach to the medial meniscus?
Approximately 15% of horses.
39
What is the prognosis for horses with partial collateral ligament tears?
Guarded to favorable, depending on tear degree and joint stability.
40
What treatment is recommended for a partial MCL tear?
Anti-inflammatory medications and rest with periodic ultrasonographic monitoring.
41
What is the prognosis for complete MCL rupture in horses?
Poor, with euthanasia often recommended due to unsuccessful long-term outcomes.
42
Which structure is more commonly involved in concurrent injuries with the MCL?
The medial meniscus is frequently involved in severe injuries.
43
Which patellar ligament is most commonly injured in horses?
The middle patellar ligament.
44
Which type of horses are more prone to patellar ligament injuries?
Jumping horses are overrepresented in patellar ligament injuries.
45
What is the prognosis for recovery from patellar ligament injuries with conservative management?
Guarded.
46
How long is rest recommended for patellar ligament injuries?
Approximately 3–12 months.
47
What diagnostic tool is best for identifying patellar ligament injuries?
Ultrasonography.
48
What ligament experiences the highest tension during stifle extension?
The cranial cruciate ligament (CrCL).
48
What is the prognosis for complete CrCL rupture?
Unfavorable, particularly for a return to athletic function.
49
What percentage of CrCL injuries lead to secondary cartilage disease?
61%.
50
What grading system is used for cruciate ligament injuries?
Grade I (mild), Grade II (moderate), Grade III (severe).
51
What are the recovery rates for Grade I, II, and III cruciate ligament injuries?
46% (Grade I),
59% (Grade II),
33% (Grade III).
52
What is the most common arthroscopically identified meniscal lesion location?
The cranial horn of the medial meniscus.
53
What percentage of equine meniscal tears are associated with CrCL injury?
Only 14%.
54
What imaging modality aids in assessing extensive meniscal injury?
Large-bore MRI is valuable for detailed assessment.
55
What are the grades of cranial meniscal tears?
Grade I (minimal tissue separation), Grade II (moderate tissue separation), Grade III (severe tear, difficult to visualize).
56
What percentage of horses with grade I meniscal tears return to athletic function?
63%.
57
What percentage of horses with grade III meniscal tears return to athletic function?
6%.
58
What diagnostic tool is beneficial for identifying meniscal tears?
Ultrasonography, though MRI is preferred for detailed analysis.
59
How frequently does joint effusion occur with meniscal injuries?
Joint effusion is seen in approximately 39% of cases.
60
What are the signs of chronic CrCL injury on radiographs?
Enthesiophyte formation, subchondral cystic lesions, and MICET proliferation.
61
What is the prognosis for CrCL injuries with over 50% damage or multiple lesions?
Prognosis is poor.
62
What is the success rate for horses with MICET fractures after fragment removal and débridement?
Reported fair-to-good prognosis.
63
What percentage of horses with grade II cranial meniscal tears return to function?
56%.
64
What is a common secondary issue in meniscal injuries affecting prognosis?
Articular cartilage disease, found in 71% of cases.
65
How do dystrophic mineralization findings impact meniscal injury prognosis?
They reduce the prognosis for athletic return.
66
What percentage of cases show bone changes at the MICET on radiographs?
Approximately 29%.
67
What treatment enhances prognosis for meniscal tears with MSC therapy?
Intraarticular MSC therapy improves outcomes to approximately 75%.
68
What is the recurrence rate of joint flares with MSC treatment in meniscal tears?
Joint flares occurred in 9% of MSC-treated cases.
69
How often are secondary soft tissue injuries seen in severe meniscal trauma?
Common, with frequent concurrent collateral or cruciate ligament damage.
70
What treatment approach is recommended for MICET fractures with ligament involvement?
Fragment removal and débridement with monitored recovery.
71
What are typical recovery protocols for meniscal injury post-surgery?
4–6 weeks of stall rest, followed by 6+ months in a small paddock.
72
What degenerative feature may be seen in older horses with stifle arthritis?
Diffuse degenerative changes in the menisci, especially the medial meniscus.
73
What is a common injury in equine athletes with stifle lameness?
Meniscal tears, especially in the cranial horn of the medial meniscus.
74
What therapeutic approaches are explored for patellar ligament injuries?
Regenerative therapies like PRP, MSC, and shock wave therapy are being researched.
75
What is the typical progression for severe CrCL tears without repair?
Progressive osteoarthritis limits potential recovery.
76
Figure 101-22. A caudocranial radiographic view of a stifle with advanced osteoarthritis showing narrowing of the MFT joint space and large osteophytes on the distal femur and proximal tibia (arrows).
77
Figure 101-23. Arthroscopic appearance of advanced osteoarthritis of the medial femoral condyle. Articular cartilage débridement was accomplished using a motorized resector.
78
Figure 101-24. Arthroscopic appearance of the medial femoral condyle showing the subchondral bone microfracture technique.
79
Figure 101-25. Arthroscopic appearance of chondromalacia of the patella (arrow). The intertrochanteric groove of the femur is seen in the lower half of the image.
80
Figure 101-26. Endoscopic view of a torn cranial cruciate ligament as viewed from the cranial approach to the MFT. A probe easily separates the fibers of this ligament.
81
Figure 101-27. Arthroscopic appearance of a minor tear (arrow) in the cranial cruciate ligament (Cr) as seen in the LFT. The lateral femoral condyle (LFC), the meniscotibial ligament (M), and the tibial condyle (T) are visible.
82
Figure 101-28. Example of a grade I meniscal tear that can be resected.
83
Figure 101-29. The arthroscopic appearance of a chronic medial meniscal tear before (A) and after (B) meniscal débridement.
84
Figure 101-30. Proximal to distal view of the medial meniscus from the right stifle of a cadaveric specimen used to model a grade III meniscal tear. The tear extends longitudinally through the cranial meniscotibial ligament (a) into the cranial horn of the medial meniscus (b). c, Medial intercondylar eminence of the tibia.
85
Figure 101-31. Extensive pathology of the cartilage on the distal aspect of the medial femoral condyle (b) is seen concurrently with fraying (arrow) of the axial aspect of the cranial meniscotibial ligament of the medial meniscus (a).
86
What percentage of cases showed articular cartilage disease at diagnosis of menscal tear?
71%
87
How does articular cartilage disease affect prognosis?
Negatively.
88
What structural function loss of the meniscus can lead to secondary cartilage injury?
Equitable load transmission.
89
Where does secondary cartilage injury typically occur?
Central portion of the medial femoral condyle.
90
What radiographic change lowers the prognosis of return to athletic function?
Dystrophic mineralization of the meniscus.
91
How does prognosis change with severe injuries involving multiple structures?
Prognosis is poor.
92
hat percentage of horses had a successful outcome among those with meniscal tears and subchondral bone cysts?
~21% (4 out of 19 horses).
93
What therapy showed a higher percentage of horses returning to work after meniscal tears?
Intraarticular MSC therapy (75%)
94
What percentage of cases experienced joint flares with MSC therapy?
9%.
95
What mechanism is suggested as a cause for primary meniscal tears?
Hyperextension causing compression and cranial displacement.
96
Which ligament experiences differential tensile forces due to stifle joint extension?
Cranial meniscotibial ligament (CrMTL).
97
How do horses commonly sustain patella fractures?
Direct trauma, such as jumping or kicks.
98
Where do characteristic tears occur in meniscal injuries?
CrMTL and cranial horn of the medial meniscus.
99
Which patellar fractures are most common from jumping accidents?
Parasagittal fractures of the proximal medial patella.
100
What type of soft tissue injury often accompanies patella fractures?
Medial femoropatellar ligament avulsion.
101
What gait changes do horses with patella fractures exhibit?
Partial flexion and careful weight-bearing.
102
What imaging views are essential for patellar fracture evaluation?
Caudocranial,
lateromedial,
cranioproximal-craniodistal (skyline) views.
103
What condition is associated with distal patella fragmentation?
patella fragmentation?
104
Figure 101-32. The typical stance acquired following a patella fracture associated with swelling in the stifle region is demonstrated on two different horses.
105
Figure 101-33. A lateromedial, a caudal 30-degree lateral craniomedial oblique and a cranioproximal-craniodistal (skyline) radiographic projection of a horse with a medial patellar fragment. The fragment can only be seen on the skyline projection demonstrating the importance of obtaining this radiographic view in horses with a suspected patellar injury.
106
How are nondisplaced patellar fractures typically managed?
Conservatively or with simple débridement.
107
What conservative management is recommended for young horses with proximal patellar fractures?
Stall rest and hand walking over 3-4 months.
108
When is surgical intervention recommended for patellar fractures?
With displaced gaps >5 mm or quadriceps disruption.
109
What is the prognosis for athletic function after partial patellectomy in certain cases?
83–100% return to function without preexisting arthritis.
110
What are two primary methods for partial patellectomy?
Arthrotomy and arthroscopy.
111
What tool is essential for fragment removal during patellectomy?
Mechanical resector and arthroscopic scalpel.
112
How are large patellar fragments removed if necessary?
Divided with an osteotome and mallet.
113
What should be evaluated concurrently during patellar fracture surgery?
Femoral trochlear ridge trauma.
114
What type of fractures require lag screw fixation with tension-band wiring?
Transverse fractures with quadriceps disruption.
115
Which screw size offers greater bending strength for patellar fixation?
5.5-mm screws.
116
What protective measures are recommended post-surgery for patellar fractures?
Sling or cross-tie restraint.
117
What is the prognosis for cases with quadriceps apparatus disruption?
Guarded to unfavorable.
118
What is the recommended intraoperative position for patellar fracture surgery?
Stifle in extension.
119
Partial patellectomy is indicated in parasagittal medial articular fractures that involve less than
one third of the patella
120
describe in detail the screw fixation technique in the patella
Surgery can be performed in dorsal or lateral
recumbency, provided the stifle can be maintained in extension. Large pointed reduction forceps are used to achieve and maintain fracture alignment as standard lag screw technique is used. Stab incisions away from the primary incision are usually needed for drilling, tapping, and screw placement. Intraoperative imaging must be used to assess reduction and screw placement. Although screw fixation in lag technique with 4.5-mm cortex screws has been described, 5.5-mm screws are usually a better choice because of their far greater bending strength (Figure 101-37). Washers should definitely be used with 5.5-mm screws because the screw head (same size as a 4.5-mm screw) can readily sink through the thin cortical shell and into the larger glide hole (Figure 101-38). An aiming device can be helpful for accurate screw placement. The incision should be closed with tension-relieving sutures with or without stents and covered for recovery. Specialized recovery systems such as a pool or sling are highly recommended following internal fixation of patellar fractures.
121
disruption of quadriceps muscle gives as symptom
inability to extend the stifle
122
Figure 101-34. Lateromedial radiographic view of the stifle showing a fracture at the base of the patella (arrow).
123
Figure 101-35. An arthroscopic image of a parasagittal medial patellar fracture. The medial trochlear ridge is located at the top of the image and the patella is located at the bottom of the image. The articular fracture line in the patella is clearly visible. The fracture fragment was removed arthroscopically.
124
Figure 101-36. Parapatellar arthrotomy showing the fracture plane and a pin placed through a centering sleeve in the glide hole prior to fracture reduction.
125
Disruption of the quadriceps apparatus most commonly occurs with transverse fractures (Figure 101-39). These fractures require screw fixation in lag technique with tension-band wiring using _________________mm diameter wire or cranially placed small dynamic compression plates (DCPs) or locking compression plates (LCPs)
Disruption of the quadriceps apparatus most commonly occurs with transverse fractures (Figure 101-39). These fractures require screw fixation in lag technique with tension-band wiring using 1.25-mm diameter wire or cranially placed small dynamic compression plates (DCPs) or locking compression plates (LCPs)
126
Figure 101-37. Preoperative and intraoperative radiographic images of a sagittal patellar fracture repaired with 5.5-mm cortex screws and washers.
127
Figure 101-38. Intraoperative image of a patellar fracture repaired with 5.5-mm cortex screws placed in lag fashion. Washers have been used under the head of the 5.5-mm screws to prevent the screws from sinking into the thin cortical bone.
128
Figure 101-39. (A) A lateromedial radiographic view of a patella fracture that resulted in complete disruption of the quadriceps apparatus. (B) One 5.5-mm cortex screw used in lag fashion and two DCPs were used in the repair.
129
Figure 101-40. A comminuted patellar fracture repaired with lag screws and tension band wiring. (A) Preoperative radiograph of the fracture. (B) Postoperative radiograph of the fracture demonstrating use of a tension band. (C) Intraoperative image of the fracture following an arthrotomy. (D) Intraoperative image of the fracture following open reduction.
130
Figure 101-41. Lateromedial view of the stifle in a foal showing avulsion (arrow) of the femoral origin of the peroneus tertius and long digital extensor tendon.
131
Figure 101-42. Arthroscopic appearance of OCD of the lateral trochlear ridge.
132
What is an SCL?
A pathological lesion within the subchondral bone, ranging from flattening to large cystic lesions.
133
What are the most common sites for SCLs in the stifle?
The medial femoral condyle (MFC), with occasional occurrences in the lateral femoral condyle, proximal tibia, and patella.
134
What are two proposed etiologies of SCLs?
Developmental orthopedic disease (DOD) in the form of osteochondrosis (OC) and trauma to the cartilage/subchondral bone.
135
What is the prognosis for horses with SCLs after debridement if the lesion is under 15 mm?
Approximately 70% of horses return to racing if debridement is less than 15 mm.
136
What is the success rate for horses with SCLs >15 mm in diameter?
Only about 30% return to racing after >15 mm surface debridement.
137
How does SCL size relate to clinical prognosis?
Larger SCLs with more cartilage involvement generally have a poorer prognosis.
138
What percentage of horses in a study showed radiographic improvement or worsening of MFC lesions over time?
Approximately 45%, with 23% improving and 22% worsening.
138
Why might arthroscopic debridement be contraindicated for small, asymptomatic condylar defects?
It may provoke cyst enlargement.
139
What are the recommended projections for radiographic assessment of SCLs?
Bilateral caudocranial, lateromedial, and caudo 30-degree lateral-craniomedial oblique.
140
What postoperative care is generally recommended after surgical debridement of an SCL?
Stall rest for 1-2 months, followed by at least 4 months of small paddock rest.
141
What percentage of cases experienced joint flares with MSC therapy?
9%.
142
What is the general success rate for surgical debridement of SCLs?
Between 64% and 95%.
143
How does age affect the prognosis of horses with SCLs?
Horses younger than 3 years have a 64% return to soundness, while those older than 3 have only a 35% return rate.
144
What is the prognosis if SCLs occur alongside meniscal tears?
Poor prognosis.
145
How effective is compacted cancellous bone grafting in treating SCLs?
It does not improve outcomes significantly.
146
What percentage of horses returned to function after mosaic arthroplasty for SCLs?
50% shown to resutl in successful graft incorporation returning to equal or higher level
147
What is the success rate for using fibrin plugs with chondrocytes and growth factors in SCLs?
Approximately 74%.
148
What alternative grafting technique has shown promising results for rapid bone formation?
Using bone marrow aspirate concentrate or platelet-rich plasma with tricalcium phosphate (TCP).
149
What is the success rate of intralesional corticosteroid injection as a primary treatment for unilateral SCLs?
Around 90%
150
What is the patella’s role in the quadriceps apparatus?
It is integral.
151
What is the success rate for conservative management of SCLs?
DBetween 45% and 64%.
152
What percentage of SCL cases resolved lameness after transcondylar screw placement?
Approximately 75%.
153
Is screw removal necessary after transcondylar screw placement?
No, but it can be done if desired.
154
What is the primary benefit of transcondylar screw placement in SCL cases?
Increased opacity within the cyst and decreased cyst size, although complete radiographic resolution is uncommon.
155
How does age influence success rates for transcondylar screw treatment in SCLs?
Horses over 3 years are less likely to have successful outcomes.
156
What is the prognosis for SCLs in the proximal cranial tibia in mature horses?
Generally poor for return to athletic performance. Santischi 2020 VS 82% were lame
18% lameness resolved with screw fixation
only 30% reduced size after screw
157
What is lateral luxation of the patella, and which horses are most affected?
A rare condition, often congenital in foals or Miniature horses, causing displacement of the patella.
158
What is the prognosis for patellar luxation in foals if left untreated?
Severe cases can prevent foals from standing.
159
What surgical methods are used for patellar luxation correction?
Lateral release incisions with medial reinforcement of support structures.
160
What surgical technique is used to deepen the trochlear groove in patellar luxation cases?
Sulcoplasty, which may involve a cartilage flap or wedge removal.
161
How does cartilage involvement in SCLs impact prognosis?
More extensive cartilage damage decreases the odds of a successful outcome.
162
How successful is autologous osteochondral grafting in SCL treatment?
It has shown a 50% success rate.
163
What imaging is crucial to avoid misdiagnosis of SCLs in young horses?
Caudocranial and lateromedial radiographic views to differentiate from subchondral ossification issues.
164
How often do bilateral SCLs occur in MFC cases?
Most cases are unilateral, but bilateral cases do occur.
165
What are the complications of patellar luxation surgery in mature horses?
Risks of incomplete correction and seroma formation postoperatively.
166
What impact does patellar luxation have on gait?
It can cause limb stiffness and lameness, especially at the walk and trot.
167
How do corticosteroids assist in managing SCL inflammation?
They depress inflammatory mediators when injected into the lesion.
168
How does radiographic monitoring affect SCL treatment timelines?
Lesions may progress or resolve, so monitoring can delay surgical decisions until a horse matures.
169
What is the effect of SCLs on weanling and yearling sales?
MFC SCLs may reduce likelihood of sale and purchase price.
170
How does subchondral bone drilling affect SCL lesions?
It may cause lesion enlargement, making it contraindicated.
171
What is the purpose of multiple needle redirections during corticosteroid injection for SCLs?
To distribute medication evenly throughout the cyst lining.
172
Why is sulcoplasty reserved for young animals in patellar luxation cases?
Young animals have thick hyaline cartilage that can be reshaped to stabilize the patella.
173
What is upward fixation of the patella (UFP) in horses?
It’s a condition where the patella fails to unlock, causing issues in hindlimb movement.
174
What are the two main populations affected by UFP?
Young Warmbloods in training and ponies/donkeys, often with more severe symptoms.
175
What type of muscle development is recommended to treat mild UFP cases?
Strengthening of the quadriceps muscle.
176
What percentage of horses developed long-term lameness issues after medial patellar desmotomy (MPD)?
About 6% of horses.
177
What is the role of quadriceps muscle contraction in UFP?
It helps to lift and release the patella from its locked position.
178
How is MPL desmoplasty different from MPD?
MPL desmoplasty involves splitting the ligament to thicken it, while MPD severs it.
179
What are “heel wedges” and how are they used in UFP treatment?
They are wedges used under the hoof to adjust limb alignment, possibly easing ligament tension.
180
What percentage of cases resolved with MPL desmoplasty in two studies?
Between 98% to 100%.
181
What complications may occur post-medial patellar desmotomy (MPD) surgery?
Potential issues include chondromalacia, osteolysis, and patellar fragmentation.
182
What success rate did MPD have for resolving UFP according to one study?
98% success rate.
183
What was the recurrence rate of UFP in MPL desmoplasty cases in one study?
33% recurrence rate.
184
What percentage of client satisfaction was reported in the same MPL desmoplasty study?
Only 50% client satisfaction.
185
What is the suggested impact of 5-degree lateral heel wedges on the stifle joint?
It caused a 1.8-degree adduction, potentially reducing ligament tension.
186
How does a straight hindlimb conformation relate to UFP?
It’s associated with a higher risk of UFP in young horses.
187
How effective are injections of counterirritants in treating UFP?
Anecdotal evidence suggests they may help but lacks extensive research.
188
What is the typical MPD rest period before returning to athletic use?
A minimum of 120 days (4 months).
189
Why are heel wedges not yet fully validated in UFP treatment?
More clinical studies are needed to confirm effectiveness.
190
What percentage of horses may show gait abnormalities after medial patellar desmotomy MPD with less than one month of stall rest?
Approximately 67% vs only 25% if rested for 3 months
191
What % gait abnormalities was find in a study regarding MPD with more than three months of stall rest?
25% showed gait abnormalities, lower than those with shorter rest.
192
Why is cantering in circles avoided for horses with UFP?
It can increase trauma to the patella and prevent quadriceps development.
193
What was the reported success rate of MPL desmoplasty in one study?
in one study?100% of cases showed resolution of clinical signs
194
What is the primary benefit of MPL desmoplasty over MPD?
Fewer complications post-surgery.
195
What are the two anesthesia methods for MPL desmoplasty?
Standing sedation or general anesthesia.
196
Figure 101-43. (A) Arthroscopic appearance of a subchondral bone cyst of the medial femoral condyle showing the typical narrow opening at the articular surface. (B) Appearance of the medial femoral condyle after débridement of the cyst.
197
Figure 101-44. Postoperative caudal–cranial radiograph showing a 4.5-mm transcondylar screw placed across a subchondral bone cyst in the medial femoral condyle.
198
Figure 101-45. (A) This 3-month-old Shetland pony foal shows the typical stance of an animal with bilateral complete lateral luxation of the patella. (B) The caudocranial radiographic views of both stifles show the patella located lateral to the distal femur.
199
What muscle complications can delay UFP release?
Underdeveloped quadriceps can delay release of the patella.
200
How do acute traumatic cases of UFP sometimes resolve?
With anti-inflammatories and rest.
201
What complication rate was found with MPD in ponies and donkeys?
Ponies and donkeys have fewer complications post-MPD.
202
What common complication may develop post-MPD if a horse returns to work too early?
Osteoarthritis and patellar fragmentation.
203
How does MPD affect patella alignment and ligament strain?
Alters alignment, increasing strain on remaining ligaments.
204
Why is anti-inflammatory medication used in UFP treatment?
To reduce pain and inflammation in the stifle.
205
How is the success of MPL splitting measured in UFP cases?
By the resolution of clinical signs and reduced recurrence rates.
206
Why might clients be dissatisfied with MPL splitting results?
Due to recurrence rates and variable success.
207
What post-operative care is essential after MPD?
Prolonged stall rest and gradual return to activity.
208
What issue arises with short stall rest following MPD?
Increased risk of gait abnormalities and radiographic changes.
209
How does MPD potentially lead to osteoarthritis?
Misalignment stresses remaining ligaments, causing joint wear.
210
What type of horses most commonly undergo MPD for UFP?
Ponies, Miniature horses, and donkeys with severe UFP.
211
What did one study find about MPD in horses older than three months?
Higher incidence of gait issues compared to younger horses.
211
How effective is rest alone in resolving UFP in some cases?
Effective in mild or acute traumatic cases.
212
Why might counterirritants like iodine be injected in UFP treatment?
To stimulate healing and address ligament issues.
213
What did one study find about UFP recurrence after MPL desmoplasty?
Recurrence was found in 33% of cases.
214
What is a primary reason for MPD in ponies?
.
Higher severity and lower postoperative complications
215
Figure 101-46. Sulcoplasty involving elevation of a U-shaped cartilage flap (a) and removal of the subchondral bone with rongeurs and a curette (b). The flap is repositioned (arrow) and, if necessary, the edges are smoothed out. The flap can be secured with suture. by experienced riders and lameness clinicians, to permanent fixation of the patella that cannot be manually corrected. UFP is classically seen in two different populations of equids: generally, a milder form in young Warmbloods in training and a more severe form in ponies and donkeys. UFP is recognized after initiation of training in young horses and is related to a straight hindlimb
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Figure 101-47. Sulcoplasty involving wedge (a) osteotomy of the intertrochlear groove. If necessary, an additional piece of bone (b) is removed (arrow) with an additional saw cut parallel to a previous one. The wedge (a) is replaced in the trough and pressed into position (arrow), resulting in a functional intertrochlear groove.
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What is lateral luxation of the patella and in which horses is it most common?
A rare condition often congenital, most common in foals and Miniature horses.
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What is the likely cause of lateral patellar luxation in foals?
It is believed to be a heritable condition. In old horses is traumatic origin
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How does patellar luxation affect a foal’s movement?
Foals with complete luxation cannot stand due to improper muscle function, causing a crouched position.
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What is a common symptom of incomplete patellar luxation?
Limb stiffness or lameness at the walk and trot.
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What imaging is essential for assessing lateral patellar luxation, and what factors are analyzed?
Radiographs, evaluating joint degeneration, trochlear groove depth, patella shape, and ossification.
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How should irregularities in subchondral ossification in foals be interpreted?
Such irregularities up to 5 months of age are normal and not pathological
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What is the goal of surgical correction for lateral patellar luxation?
To reposition the patella by releasing lateral structures and reinforcing medial support.
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What structures are incised for lateral release during surgery?
transecting the:
1) biceps femoris insertion,
2) lateral femoropatellar ligament,
3) lateral patellar ligament origin
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What additional surgical method is used to decrease tension on sutures during patella reinforcement?
Removal of excessive synovial fluid prior to medial imbrication.
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What type of suture is used to imbricate the medial joint capsule?
No. 5 braided polyester suture.
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What additional reinforcements may be used in older or heavier horses during medial imbrication?
A mesh implant to strengthen the repair.
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What condition is sulcoplasty used to address in horses with patellar luxation?
Lateral ridge hypoplasia or instability in the trochlear groove.
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Describe the basic steps of the cartilage flap technique in sulcoplasty.
Elevate a U-shaped cartilage flap, remove subchondral bone, smooth the surface, then reposition and suture the flap.
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What is the purpose of removing bone in the wedge technique of sulcoplasty?
To deepen the trochlear groove by adjusting and replacing the wedge.
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What is a critical postoperative care measure after patella repositioning surgery?
Administering systemic antibiotics and nonsteroidal anti-inflammatory drugs.
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What common complication may occur post-surgery sulcoplasty, and how is it managed?
Seromas may develop but often resolve without intervention.
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How are sulcoplasty techniques beneficial in young animals?
They are effective due to the thick hyaline cartilage over the developing bone.
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What is a sign of successful sulcoplasty observed in postoperative radiographs?
Correct positioning of the patella in the trochlear groove.
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What are the two types of incisions used for surgical exposure in patellar luxation repair?
A single medially based curved incision or two separate craniomedial and craniolateral incisions.
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Why might lateral luxation in mature horses differ from foals in origin?
In mature horses, it is generally caused by trauma, not congenital factors.
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describe the surgical lateral release incisions combined with reinforcement of the medial patellar support structures. in detail for lateral patelar luxation
DR - GA - one large, medially based, curved incision extending from **6 cm proximal to the patella distad to the tibial crest.** Alternatively, two curved incisions (craniomedial and craniolateral) can be used. Lateral release of the patella is accomplished by incising the i**nsertion of the biceps femoris, transecting the lateral femoropatellar ligament** and the origin of the l**ateral patellar ligament** without invading the joint.
Lateral release can sometimes be accomplished by **partially transecting the tensor fascia **and **fibrous joint capsule** while preserving the lateral femoropatellar ligament. Removal of excessive FP synovial fluid with a needle and syringe may be beneficial prior to medial imbrication to decrease tension on the sutures. The m**edial joint capsule **from the base to the apex of the patella is imbricated with **No. 5 braided polyester suture.** suturing the tendon of the s**artorius muscle** and the **parapatellar fascia to the joint capsule **and the medial patellar ligament may be necessary. A m**esh implant can be used to reinforce this imbrication in older** and/or **heavier **cases and in cases where the holding capacity of friable tissue is
a concern
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describe sulcoplasty has been advocated for lateral ridge hypoplasia or instability of the patella in the trochlear groove in detail one of 2 tx
DR - GA - one large, medially based, curved incision extending from **6 cm proximal to the patella distad to the tibial crest**. One technique involves elevation of a **U-shaped cartilage flap within the trochlear groove** and r**emoval of the subchondral bone** (Figure 101-46). The cartilage is incised at an angle (from superficial to deep toward the flap) and is carefully elevated with the help of a periosteal elevator. The soft bone is removed with rongeurs, and the surface is evened out with a curette. The cartilage flap is then repositioned and stabilized with sutures. If an abrupt change in trough angle on either side is noticed, additional cartilage can be removed with a scalpel to provide a smooth articular surface.
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describe sulcoplasty has been advocated for lateral ridge hypoplasia or instability of the patella in the trochlear groove in detail the second tx that involves wedge removal from trochlear groove
The other sulcoplasty technique involves the **removal of a wedge from the trochlear groove **(Figure 101-47) with a **hand-held saw**. Each saw cut removes some bone, and consequently by simply replacing the wedge, some **deepening of the groove is achieved**. If additional deepening is desired, a parallel saw cutis carried out on one side, and the wedge is replaced. The edges are smoothed out with a scalpel. If the wedge is properly seated, no fixation is required. The soft tissue release and imbrication techniques discussed earlier are also performed.
