Equine Hind limb Flashcards
What are some of the main causes of hindlimb lameness?
- Hock and stifle are most common causes of hindlimb lameness.
- Cellulitis, lymphangitis, splints
- Degenerative joint disease of the small tarsal joints
- Meniscal disease of the stifle
- Subchondral bone cysts of the stifle
- Osteochondrosis of the stifle and hock
- Proximal suspensory desmitis
- Fetlock and pastern joint disease
What are some critical conditions that cna cause hindlimb lameness?
Critical conditions:
- Joint infections (hock is very common site of synovial sepsis)
- Fractures (identify stress fracture sites from Year 1 lecture)
- Tendon ruptures (gastrocnemius and peroneus tertius rupture, SDFT luxation)
- Luxations (fetlock, hock, patella, hip)
What is the innervation of the hindlimb?
- Sciatic nerve (L6-S2)
- Branching into tibial and peroneal nerves
- Tibial nerve – supplies:
- Extensors of hock and flexors of digit
- Skin on caudomedial aspect of limb and plantar aspect of foot (+ dorsal aspect in horse)
- Peronal nerve – supplies:
- Flexors of hock and extensors of digit
- Skin on craniolateral aspect of limb and dorsal aspect of foot (not in horse)
Name the nerves in this picture of the innervation of the digit and the hoof of the hindlimb
Black, green and pink
Black: superficial peroneal nerve
Green: Deep peroneal nerve
pink: Branches of tibial nerve
Which nerve block is important in helping to diagnose proximal suspensory desmitis?
Where is it done?
High plantar nerve block: important to help diagnose proximal suspensory desmitis
Usually done with leg lifted, site is just distal to the tarsometarsal joint, axial to the 4th metatarsal bone, needle inserted to hit Metatarsal III, using a volume of 5-10ml
When is radiography a first line diagnostic for the hindlimb?
Radiography
- First line of diagnostics in
- Suspected fracture
- Suspected bone lesions
- Joint pain
- Usually first line of diagnostics after nerve blocks
- Standard views:
What is ultrasonography a first line diagnostic for?
Ultrasonography
- First line of diagnostics for suspected soft tissue lesions (e.g. tendonitis, bursal swellings)
- don’t block or trot suspected tendonitis
What should you NOT do with suspected tendonitis?
Do not block or trot with suspected tendonitis
What is gamma scintigraphy a first line diagnostic for?
First line diagnostics in suspected fractures – don’t block these cases
What is arthrocentesis a first line diagnostic for?
Suspected joint sepsis
When is MRI used?
For some difficult soft tissue injuries e.g. proximal suspensory desmitis
When is CT used for the hind limb?
Complicated fracture/bone lesions
What are the main causes of hindlimb lameness?
- Cellulitis / lymphangitis
- Degenerative joint disease of the small tarsal joints
- Meniscal disease of the stifle
- Subchondral bone cysts of the stifle
- Osteochondrosis of the stifle and hock
- Proximal suspensory desmitis
- Synovial sepsis
- Fractures
- Luxations
- Tendon ruptures
Label tarsal joints?
Tarsometatarsal and distal intertarsal usually affected –Proximal intertarsal can be affected by DJD.
What is a spavin?
Degenerative joint disease of the small tarsal joints ‘spavin’
Discuss DJD of the small tarsal joints (Spavin)?
- Lameness can be unilateral or bilateral
- Bilateral lameness can present as stiffness or gait problems (esp in canter)
- Degree of lameness can be mild or severe –Often have pain on flexion (difficult to shoe)
How is a spavin diagnose?
Diagnosis of spavin
Intra-articular anaesthesia
- TMT sometimes communicates with DIT (block seperately)
- PIT communicates with tarsocrural joint
Perineural anaesthesia
- Tibial and peroneal nerve block (images from In Practice articles by S Dyson)
How should radiography be done for the hock?
Technique: Lateromedial and DP
Describe technique for radiography of the hock?
Technique: D45 o LPM and P45 o LDM obliques
What are the radiographic changes seen in DJD (Spavin)?
Radiographic signs of joint disease
- Narrowing of joint space
- Peri-articular osteophyte formation
- Subchondral bone sclerosis –bone re model (white)
- Subchondral bone lucency (can look like lytic, destructive disease) –eroded down (black)
Severity of radiographic signs may not relate to severity of lameness
- Can see horses with radiographic signs and no clinical signs
- Need diagnostic anaesthesia to confirm diagnosis