aaep case study - pioneer equine hospital case study a case of front limb lameness ... chestnut mare...
TRANSCRIPT
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AAEP Case Study
A case of front limb lameness
Signalment
• 8 year old
Thoroughbred x
Quarter Horse
Chestnut mare
• Used for dressage
and eventing
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History
• Resides in a training barn
• Purchased 16 months prior to lameness
• Right front intermittent lameness –
4 months duration
• Periods of rest and non steroidal anti-
inflammatory therapy
• No previous lameness examination
Clinical Findings
• Physical Examination
- No significant joint effusion or soft tissue swelling
- Flat steel shoes on all four feet
- Hoof tester examination� No abnormal response; right front & left front
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Clinical Findings
• Lameness Examination
- Grade 2/5 lame (AAEP scale) – Right front (RF)
- Best seen on firm ground & clockwise direction
- RF distal limb flexion - Negative
- RF carpal flexion - Negative
Diagnostic Plan
• Regional Anesthesia
– Palmar digital (PD) perineural anesthesia� RF Lameness resolved – 100% improvement
• Intrasynovial Anesthesia
– Three hours elapsed prior to intrasynovial
anesthesia
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Diagnostic Plan
• Intrasynovial Anesthesia
- Distal interphalangeal (DIP) anesthesia� 5 min- 50% improvement
� 15 min- 70% improvement
• The following day, the digital tendon sheath was blocked to further investigate the right front limb lameness
Diagnostic Plan
• Digital flexor tendon sheath anesthesia
– 25% improvement
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Problem List
• Right front lameness that is localized to
the palmar aspect of the right front foot
Differential Diagnosis
• Coffin joint arthrosis/synovitis
• Deep digital flexor (DDFT) tendonitis
• Navicular bursitis
• Navicular syndrome
• Palmar heel pain
• Distal sesamoidean impar ligament
desmitis
• Combination
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Diagnostic Plan
• Digital radiographic foot series was
performed
Radiographic Examination
• Navicular bone (NB)– Several enlarged central synovial fossae
– Good cortical-medullary definition with central flexor cortex shadowing
• Findings considered normal variant for age and breed
• Results of lameness localization & radiographs inconclusive
• Recommendation– Ultrasound of palmar pastern and foot
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Ultrasound Examination
• Deep digital flexion
tendonitis - RF
• Navicular bursa &
fibrocartilage of
flexor surface of
navicular bone (RF)
measured less than
contralateral limb
Deep digital flexor tendon
Navicular bone
U/S image view using transcuneal approach
Magnetic Resonance Imaging
• To characterize DDFT tendonitis and evaluate potential concurrent lesions, MRI was recommended
• MRI was conducted using 1.5 T Siemens Magnetom Espree at Alamo Pintado Equine Medical Center
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Magnetic Resonance Imaging
Deep digital flexor
tendon tear
Adhesion between DDFT and navicular bursa
Navicular bone flexor cortex erosion
Diagnosis
• Right fore DDFT tear at level of the
proximal navicular bursa with adhesions
to navicular bone
• Right fore navicular flexor cortex
erosion and articular cartilage loss
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Treatment Options
• Intrasynovial medications
• Extracorpeal shockwave therapy
• Stem cells
• Bursoscopy
• Intrabursal tissue plasminogen activator
(tPA) injection
Bursoscopy
• Surgical approach – via
digital flexor tendon
sheath
• Navicular bursa entrance
– transection of the T
ligament
Endoscopic view of normal
navicular bursa
Navicular
Bone
DDFT
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Bursoscopy
• Surgical Findings
– Multiple adhesions between the bursa and deep
digital flexor tendon
• Intraoperative therapy
– Arthrocare® coblation
technique
J of Equine Vet Sci. 2003;23:258-265
Arthrocare® Coblation
• Use of radiofrequency to break
molecular bonds within tissue
• Results in removal of target tissue at
relatively low temperatures (40-70°C)
with minimal damage to surrounding
tissue
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Post Operative Therapeutic
Plan
• Non steroidal anti-inflammatory medications
• Tissue plasminogen activator injection (fibrinolytic agent) into navicular bursa
• Adipose-derived stem cell injection to navicular bursa
• Rehabilitation period
• Follow-up MRI
Navicular Bursa Injection
• Midline palmar approach to
navicular bursa
• Radiographic guidance of
500µg of tissue plasminogen
activator performed at 4 and 6
days post operative
• Unknown quantity of tPA
leakage due to communication
of tendon sheath during
bursoscopy
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Adipose-Derived Stem Cells
• Tail-head collection technique
• 6 million total cells
• Radiographic guidance - Injection to navicular bursa performed on day 20 post operation
Rehabilitation Period
• Stall rest for 14 days followed by
stall rest with 10 min hand-walking for 14 days
• At 28 days post surgery,
tack walk - 10 min for 7 days, 20 min for 7 days, & 30 min for
7 days
• Increase exercise slowly if no lameness is present
*All times are in reference to surgery
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Outcome
• Current exercise- Flatwork with
increasing intensity
• No lameness reported 4 months after
operation
Follow up Recommendations
• Follow up MRI - 8
months post operative
to assess deep digital
flexor tendon tear &
adhesions to navicular
bursa
• Return to full work
dependent on MRI
findings & re check
evaluation
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Further Reading
• Dyson, SJ, and Murray, RC. Lameness and Diagnostic Imaging in the Sports Horse: Recent Advances Related to the Digit. 2007 AAEP Proceedings, p.262-275.
• Dyson, SJ, and Murray R. MRI evaluation of 264 horses with foot pain: The podotrochlear apparatus, DDFT and collateral ligaments of the DIP joint. Equine Vet J. 2007;39:340-343.
• Maher, O, Synder, JR, et al. DDFT injuries in the equine foot. 2007 ACVS Proceedings.
• Rossignol, F, and Perrin R. Tenoscopy of the Navicular Bursa: Endoscopic Approach and Anatomy. J of Equine Vet Sci. 2003;23:258-265.
• Schramme, MC, Murray, RC, et al. A comparison between MRI, pathology, and radiology in 34 limbs with navicular syndrome. 2005 AAEP Proceedings, p.348-358.