Chapter 101 - Stifle II - stifle disorders Flashcards
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.
Figure 101-20. Mild (A) and severe (B) cartilage injury to the distal aspect of the medial femoral condyle in two different horses.
What is the most commonly diagnosed stifle disorder in horses?
Osteochondrosis.
What percentage of stifle issues in horses is due to osteochondrosis?
Specific data varies, but osteochondrosis is highly prevalent among stifle disorders
What factors contribute to the pathogenesis of osteochondrosis?
It is multifactorial, involving developmental issues and trauma.
What is the prognosis for mild osteochondrosis with early intervention?
Generally good, with potential for full recovery.
What percentage of horses with stifle osteoarthritis (OA) can return to performance after treatment?
Varies by case, but often around 50-70% depending on severity.
What is the typical outcome for horses with severe cartilage damage in OA?
Poor prognosis for athletic function.However McCoy 2019 (VS) mentions that full thickness cartilage the odds to return are higher
What initial sign of OA is most often observed in the medial femoral condyle?
Cartilage damage.
What is the prognosis for horses with early-stage OA after appropriate rest and therapy?
Prognosis can be fair to good with rest, therapy, and joint protection.
How does cartilage loss affect the prognosis in OA?
Severe cartilage loss worsens the prognosis significantly.
In what percentage of horses with stifle OA is there no radiographic evidence initially?
Radiographic changes are often absent in early stages, especially in mild OA cases.
What arthroscopic procedure can help with early diagnosis of stifle OA?
Arthroscopic exploration of the joint.
What is the common prognosis for horses with “mogul-like” cartilage defects?
Typically poor for long-term soundness.
How can extensive cartilage débridement impact the prognosis?
Large-scale débridement has a poor prognosis due to limited cartilage regeneration.
What percentage of horses experience improvement with cartilage lesion rest (4–6 months)?
Improvement can occur, but with a low percentage of cases achieving long-term soundness.
Why is corticosteroid injection contraindicated for advanced cartilage degeneration?
It can accelerate irreversible cartilage damage.
What radiographic view best detects advanced stifle OA?
Caudocranial view.
What percentage of femorotibial OA cases show lipping of the medial tibial plateau as an early sign?
A high percentage, as it is often the first visible radiographic sign.
What is the significance of joint space narrowing in stifle OA?
It indicates advanced disease and correlates with a poor prognosis.
Why is positioning critical for accurate radiographic diagnosis of OA?
Proper weight-bearing positioning is necessary for clear visualization of joint spaces.
What is the prognosis for horses with FP OA seen in the lateromedial view?
Typically poor for athletic performance, as it indicates advanced joint changes.
What is the recommended treatment for advanced OA in the femorotibial joint?
Arthroscopic cartilage débridement and chondroprotective therapy.
How does meniscal injury affect prognosis in stifle OA cases?
It worsens the prognosis due to joint instability.
What arthroscopic technique has shown benefits in full-thickness cartilage defects?
Subchondral bone microfracture.
What is the expected outcome after microfracture for full-thickness cartilage defects?
Fair prognosis; some horses return to limited performance.
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
What percentage of experimental treatments have shown positive results for cartilage healing?
Early studies show promising results in select cases, with varying percentages.
What is the prognosis for horses after autologous chondrocyte transplantation?
Potentially good in experimental cases, though more research is needed.
How does chondromalacia on the patella affect prognosis?
Prognosis varies; mild cases can improve with débridement.
What is a common symptom in Quarter Horses with horizontal cartilage clefts?
Lameness and poor performance.
What percentage of horses benefit clinically from patellar chondromalacia débridement?
Most show improvement, though it may not fully restore athletic function.
Why is extensive cartilage removal avoided for horizontal clefts?
It can compromise joint integrity without significant benefit.
What is the effect of early rest on horizontal cartilage lesions?
Rest can help, but the prognosis for long-term soundness is poor.
What joint feature forms in stifle OA as seen in advanced cases?
Periarticular osteophytes and sclerosis.
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;
Cartilage lesions on the articular surface of the patella are referred to as
chondromalacia
What is the primary diagnostic method for collateral ligament injury?
Ultrasonography is commonly used to diagnose collateral ligament injuries.
In what percentage of horses does the MCL attach to the medial meniscus?
Approximately 15% of horses.
What is the prognosis for horses with partial collateral ligament tears?
Guarded to favorable, depending on tear degree and joint stability.
What treatment is recommended for a partial MCL tear?
Anti-inflammatory medications and rest with periodic ultrasonographic monitoring.
What is the prognosis for complete MCL rupture in horses?
Poor, with euthanasia often recommended due to unsuccessful long-term outcomes.
Which structure is more commonly involved in concurrent injuries with the MCL?
The medial meniscus is frequently involved in severe injuries.
Which patellar ligament is most commonly injured in horses?
The middle patellar ligament.
Which type of horses are more prone to patellar ligament injuries?
Jumping horses are overrepresented in patellar ligament injuries.
What is the prognosis for recovery from patellar ligament injuries with conservative management?
Guarded.
How long is rest recommended for patellar ligament injuries?
Approximately 3–12 months.
What diagnostic tool is best for identifying patellar ligament injuries?
Ultrasonography.
What ligament experiences the highest tension during stifle extension?
The cranial cruciate ligament (CrCL).
What is the prognosis for complete CrCL rupture?
Unfavorable, particularly for a return to athletic function.
What percentage of CrCL injuries lead to secondary cartilage disease?
61%.
What grading system is used for cruciate ligament injuries?
Grade I (mild), Grade II (moderate), Grade III (severe).
What are the recovery rates for Grade I, II, and III cruciate ligament injuries?
46% (Grade I),
59% (Grade II),
33% (Grade III).
What is the most common arthroscopically identified meniscal lesion location?
The cranial horn of the medial meniscus.
What percentage of equine meniscal tears are associated with CrCL injury?
Only 14%.
What imaging modality aids in assessing extensive meniscal injury?
Large-bore MRI is valuable for detailed assessment.
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).
What percentage of horses with grade I meniscal tears return to athletic function?
63%.
What percentage of horses with grade III meniscal tears return to athletic function?
6%.
What diagnostic tool is beneficial for identifying meniscal tears?
Ultrasonography, though MRI is preferred for detailed analysis.
How frequently does joint effusion occur with meniscal injuries?
Joint effusion is seen in approximately 39% of cases.
What are the signs of chronic CrCL injury on radiographs?
Enthesiophyte formation, subchondral cystic lesions, and MICET proliferation.
What is the prognosis for CrCL injuries with over 50% damage or multiple lesions?
Prognosis is poor.
What is the success rate for horses with MICET fractures after fragment removal and débridement?
Reported fair-to-good prognosis.
What percentage of horses with grade II cranial meniscal tears return to function?
56%.
What is a common secondary issue in meniscal injuries affecting prognosis?
Articular cartilage disease, found in 71% of cases.
How do dystrophic mineralization findings impact meniscal injury prognosis?
They reduce the prognosis for athletic return.
What percentage of cases show bone changes at the MICET on radiographs?
Approximately 29%.
What treatment enhances prognosis for meniscal tears with MSC therapy?
Intraarticular MSC therapy improves outcomes to approximately 75%.
What is the recurrence rate of joint flares with MSC treatment in meniscal tears?
Joint flares occurred in 9% of MSC-treated cases.
How often are secondary soft tissue injuries seen in severe meniscal trauma?
Common, with frequent concurrent collateral or cruciate ligament damage.
What treatment approach is recommended for MICET fractures with ligament involvement?
Fragment removal and débridement with monitored recovery.
What are typical recovery protocols for meniscal injury post-surgery?
4–6 weeks of stall rest, followed by 6+ months in a small paddock.
What degenerative feature may be seen in older horses with stifle arthritis?
Diffuse degenerative changes in the menisci, especially the medial meniscus.
What is a common injury in equine athletes with stifle lameness?
Meniscal tears, especially in the cranial horn of the medial meniscus.
What therapeutic approaches are explored for patellar ligament injuries?
Regenerative therapies like PRP, MSC, and shock wave therapy are being researched.
What is the typical progression for severe CrCL tears without repair?
Progressive osteoarthritis limits potential recovery.
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).
Figure 101-23. Arthroscopic appearance of advanced osteoarthritis of the medial femoral condyle. Articular cartilage débridement was accomplished using a motorized resector.
Figure 101-24. Arthroscopic appearance of the medial femoral condyle showing the subchondral bone microfracture technique.
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.
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.
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.
Figure 101-28. Example of a grade I meniscal tear that can be resected.
Figure 101-29. The arthroscopic appearance of a chronic medial meniscal tear before (A) and after (B) meniscal débridement.
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.
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).
What percentage of cases showed articular cartilage disease at diagnosis of menscal tear?
71%
How does articular cartilage disease affect prognosis?
Negatively.
What structural function loss of the meniscus can lead to secondary cartilage injury?
Equitable load transmission.
Where does secondary cartilage injury typically occur?
Central portion of the medial femoral condyle.
What radiographic change lowers the prognosis of return to athletic function?
Dystrophic mineralization of the meniscus.
How does prognosis change with severe injuries involving multiple structures?
Prognosis is poor.
hat percentage of horses had a successful outcome among those with meniscal tears and subchondral bone cysts?
~21% (4 out of 19 horses).
What therapy showed a higher percentage of horses returning to work after meniscal tears?
Intraarticular MSC therapy (75%)
What percentage of cases experienced joint flares with MSC therapy?
9%.
What mechanism is suggested as a cause for primary meniscal tears?
Hyperextension causing compression and cranial displacement.
Figure 101-32. The typical stance acquired following a patella fracture associated with swelling in the stifle region is demonstrated on two different horses.
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.
Figure 101-34. Lateromedial radiographic view of the stifle showing a fracture at the base of the patella (arrow).
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.
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.
Figure 101-37. Preoperative and intraoperative radiographic images of a sagittal patellar fracture repaired with 5.5-mm cortex screws and washers.
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.
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.
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.
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.
Figure 101-42. Arthroscopic appearance of OCD of the lateral trochlear ridge.
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.
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.
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.
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
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.
