Horses 4 Flashcards
What are the main areas of high load in the two main joints of the carpus
○ Midcarpal joint § Distal aspect Radial carpal bone - medial aspect § Radial facet of third carpal bone ○ Antebrachiocarpal joint § Distal radius § Intermediate carpal bone Radial carpal bone
How does carpal bone respond to high loads and what if fail to adapt
- Modelling of subchondral bone in response to exercise (high loads)
○ Thickening of trabecular and subchondral bone
§ Sclerosis of third carpal bone
§ Chip fracture - common -> microdamage and front of bone chipped off
§ Slab fracture -> progress straight down - Failure of subchondral bone to adapt to increased stress
○ Subchondral bone necrosis
○ Chip fracture
○ Slab fracture
Carpal injury what swelling will you see dorsally and laterally
○ Dorsal § Antebrachiocarpal joint - lateral and medial aspect § Midcarpal joint - linear swelling § Extensor tendon sheaths § Subcutaneous - generalised swelling across front of carpus ○ Lateral § Carpal sheath - swell above sheath § Antebrachiocarpal joint
Carpal injury flexion test results and lameness, what causes mild or marked lameness and diagnostic analgesia
Flexion test ○ Limited use ○ Pain on flexion useful Lameness ○ Often bilateral - as cyclically loading both limbs ○ Mild lameness § Chip fracture § OA ○ Marked lameness § Significant pathology Diagnostic anaglesia ○ Regional blocks § Subcarpal block § Median and ulnar block - if block think in carpus ○ Intra-articular blocks § Midcarpal joint § Antebrachiocarpal joint - proximal suspensory as well possible
What are the 4 main views for carpal lameness and why each important
1) flexed lateromedial - radial carpal bone sits lower than intermediate (able to see dital radial and proximal intermediate - where pathology occurs)
2) Dorsolateral palmaromedial oblique - able to see radial carpal bone and proximal of third carpal bone
3) Dorsomedial palmarolateral oblique - proximal intermediate and distal radial - common area of pathology - also second carpal bone is free projected
4) skyline of 3rd carpal bone - mandiotry on racehorse as common area of fracture
Carpal injury ultrasound what structures examining, sctintigraphy what looking for and arthroscopy
Ultrasound § Carpal sheath and flexor tendons § Proximal suspensory ligament § Extensor tendons and sheaths Scintigraphy § Lameness localised to carpus but no radiographic changes § Subchondral bone injuries § Stress fractures § Proximal suspensory desmitis Arthroscopy - often as diagnosis and treatment § Midcarpal and antebrachiocarpal joints - GOOD FOR THIS § Carpal sheath
What treatment would you do for mild subchondral bone injury on carpus or serious pathology found
Mild - rest for 3 months minimum
Serious - arthroscopy - debridement
Shoulder injury what seen on clinical examination and what diagnostic anaglesia generally postitive to
- Swelling not detectable
- Shortened cranial phase of stride - TYPICAL OF PROXIMAL LIMB LAMENESS
○ Brings forward shortened stride but let’s go all the way back - Muscle atrophy - if chronic - which often they are as swelling cannot detect
○ Triceps atrophy - Diagnostic analgesia
○ Intra-articular injection of shoulder joint
○ Intrathecal injection of bicipital bursa
Shoulder injury diagnostic imaging, what views and what structures for each
○ Radiography § Standing mediolateral § General anaesthesia ○ Scintigraphy § Lateral and cranial views ○ Ultrasound § Bicipital bursa - common to perform § Biceps tendon - not common injuries here § Lateral aspect of shoulder joint - cannot detect externally so useful ○ Arthroscopy § Bicipital bursa § Shoulder joint
List the 4 main conditions of the shoulder and the 2 of the elbow
- Osteochondrosis
- Osteoarthritis
- Supraglenoid tubercle fracture
- Bicipetal bursitis
Elbow - Ulnar fractures common paddock injury
- Elbow joint problems rare
○ Subchondral cystic lesions
Conditions of the elbow localising signs, diagnostic anaglesia and diagnostic imaging views and diseases
1. Localising signs ○ Elbow joint problems -> No localising signs ○ Ulnar fractures -> ‘Dropped elbow’ 2. Diagnostic analgesia ○ Intra-articular 3. Diagnostic imaging a. Radiography § Mediolateral § Craniocaudal b. Scintigraphy § Subchondral cystic lesions
Ulnar fractures how common, where generally occur and treatment
- Common fracture
- Generally intra-articular
- Physeal fracture in foals
- Non weightbearing bone - so can do internal fixation
Treatment - Tension band plate - internal fixation
- 70% return to athletic function
Tarsus how complex and the 3 main issues and what important about wounds in this area
- Complex joint
- Prone to trauma
- Osteochondrosis
- Osteoarthritis
Wound in tarsus often involve synovial structures - must assess with ultrasound
Tarsus what swelling can occur, when get pain on flexion and flexion test
- Swelling
○ Tarsocrural joint - most common
§ Swelling noticed on the dorsal aspect -> medial and lateral to extensor tendons and palmar aspect -> between calcaneus and the tibia laterally and medially
○ Tarsal sheath
○ Calcaneal bursa
○ Extra-synovial - Pain on flexion
○ Only severe inflammatory disease (septic arthritis) or injury - Flexion test - get metacarpus parallel
○ Not specific because flexing all joints - hip, stifle, tarsus and fetlock
○ Fetlock and stifle problems often positive
Tarsus diagnostic anaglesia positive for regional and intra-articular blocks
○ Regional blocks § Subtarsal block § Tibial and peroneal - if positive to this but not above - then tarsus ○ Intra-articular blocks § Tarsometatarsal joint § Centrodistal joint § Tarsocrural joint
Radiography for tarsus what are the 4 minimum views and the 3 special views
1) lateromedial
2) dorsoplantar
3) dorsomedial plantarolateral oblique
4) dorsolateral plantarmedial oblique
Special views
1) proximodistal alignment
2) skyline of calcaneus
3) flexed lateromedial
Ultrasound and scintigraphy what assessing with tarsus injuries
Ultrasound - Assessment of tendons and ligaments - Determining involvement of synovial structures - Locating osteochondral fragments Scintigraphy - Must combine with local analgesic techniques - Osteoarthritis of distal tarsal joints - Subchondral bone injuries
Bone spavin in tarsus define, radiographic changes, what need to use for diagnosis and treatment
- Osteoarthritis distal tarsal joints
- Over diagnosed condition
- Radiographic changes unreliable -> looks like osteophytes
- Must use diagnostic analgesia - LOCALISE TO JOINT FIRST
- Treatment
§ Phenylbutazone - generally not as good
§ Intra-articular corticosteroid - within the tarso-metatarsal joint
§ Arthrodesis - last resort
If have generalised tarsal sweling with lameness and open wound on medial aspect what would you do in terms of diagnosis
- take radiographs -> NADA -> assess the bony structures
- Ultrasound - to assess the soft tissue structures
- Effusion in tarsocrural joint
- Tarsal sheath synovial swelling
§ If wound going out the fluid will leave -> possible in this case
- Calcaneal bursa structure normal - Synovial fluid sample analysis
- Collect fluid from tarsocrural joint
§ 60% neutrophils -> INFLAMMED BUT NOT INFECTED (if infected >90% neutrophils)
- Cannot collect from tarsal sheath as not fluid - Palpation/ surgical exploration
- Need to clean it up, sterile glove
- Feel where the open wound goes -> feel tendon
Stifle what structures are prone to trauma, possible swelling, where palpate and flexion test
Bony prominences - Prone to trauma 1. Patellar 2. Tibial crest Clinical examination 1. Examine for swelling - Femoropatellar joint - Medial femorotibial joint 2. Palpate patellar ligaments - Assess for Medial patellar ligmanet resection - common surgery 3. Flexion test - May be pain
Stifle diagnostic analgesia and what are the 3 main radiograpah views needed and why and the 2 special view
Diagnostic analgesia
- Intra-articular injection of ALL 3 compartments (communications vary)
Radiograph - if stifle swelling ALWAYS
1. lateromedial - patellar, two trochlea ridges, tibial plateu
2. flexed lateral media - condyle of the femur
3. caudocranial - condyles of femur, intracondyle eminencies of the tibia
Other view - flexed skyline view of patellar
Stifle injuries what looking for with ulrasound, scintigraphy and arthroscopy
Ultrasound § Patellar ligaments § Abaxial aspects of menisci § Femortibial joints for effusion Scintigraphy § Complex appearance - hard to interpret § Poor access to medial aspect - often where trauma occurs Arthroscopy § Articular cartilage § Cruciate ligaments § Menisci and meniscal ligaments
Pelvis what are the 3 important aspects of the clinical exam and diagnostic anaglesia
- Palpate - bony prominences - tuber coxa, ischi
- Pelvic symmetry - tuber coxa how symmetrical, also muscle mass
- Rectal examination
○ Can palpate -> Iliac shaft, acetabulum, pelvis
Diagnostic analgesia
○ Sacroiliac joint
○ Sacroiliac ligaments
Pelvis diagnostic imaging what important to assess and the 3 ones used
Radiography
§ General anaesthesia in adult horses
§ Harder to align the horse as needed
Ultrasound
§ Assessment of ligaments and muscles
§ Bony surface of pelvis -> tuber ischi, coxa etc.
□ Ilium and ischium easy but not acetabulum
Scintigraphy
§ Use when struggling to localise lameness
§ Pelvic fractures
§ Hip joints
Osteochondrosis define, and the 3 main presentations
- Osteochondral fragmentation of articular surface in young growing horses Three presentations 1. Flap and fragment formation 2. Fragmentation alone 3. Subchondral bone cyst
In general with a young horse if swelling what disease and if lameness what disease
SWELLING -> osteochondrosis
LAMENESS -> subchondral cystic lesions
Flap and fragment formation and osteochondral fragmentation what apart of, what results from and where occurs
Osteochondrosis
Flap and fragment formation
- Retained cartilage -> with exercise may get fissures -> may then stay or move within joint (very bad if do this - inflammation and swelling -> Flap and fragment formation
- Occur at margin of weight bearing and non-weight bearing cartilage
○ Trochlear ridges femur, talus, sagittal ridge of MC/MT3, caudal humerus
Osteochondral Fragmentation
- Traumatic fractures at sites susceptible due to stage of growth
- Non weight bearing areas
○ Distal intermediate ridge of tibia
○ Proximal plantar P1 fragments
Subchondral cysts what apart of, results from and where occurs commonly
osteochondrosis
- Secondary change following injury to cartilage or subchondral bone
Most common in young growing horses at predictable sites
- Weight bearing areas
○ Medial condyle femur
○ Medial proximal radius
○ Glenoid of the shoulder
○ Proximal interphalangeal joint of the pastern
Osteochondrosis pathogensis and predisposing factors
- Weak cartilage and bone subjected to excessive forces Multifactorial 1. Genetic -- Large breeds predisposed ○ Thoroughbreds ○ Warmblood - Standardbreds ○ Fragments 2. Dietary - High CHO (carbohydrate) intake - Mineral imbalances ○ Cu deficiency ○ Ca/P ratio 3. Exercise
Osteochondrosis what are the main affected sites in the tarsus, stifle, fetlock and shoulder
1. Tarsus (top to bottom most common) ○ Distal intermediate ridge ○ Lateral trochlear ridge ○ Medial malleolus 2. Stifle ○ Lateral trochlear ridge ○ Medial trochlear ridge ○ Patellar 3. Fetlock ○ Sagittal ridge MC3 ○ Ununited palmar/plantar eminence 4. Shoulder ○ Humeral head Glenoid cavity
Osteochondrosis swelling and lameness are they present if so what involved
Swelling ○ Most common presenting sign ○ Swelling not detectable in shoulder ○ Subchondralbone cysts § Swelling less obvious § Medial FT joint swelling Lameness ○ Generally absent or mild ○ Exceptions § Shoulder - as swelling is not detectable § Subchondral bone cysts
Osteochondrosis what is the best diagnostic imaging and what can examine
Radiographs
§ Diagnostic in most cases - good as young animals are generally hard to nerve block
§ Occasional lesion cartilage only
§ Subchondral cysts in areas of dense bone
§ Always radiograph contra lateral joint
Osteochondrosis treatment the two types and things within
- Conservative ○ Restrict exercise ○ Restrict diet ○ Monitor radiographically - Surgical ○ Removal of osteochondral fragments ○ Debridement of subchondral cystic lesions
Stifle osteochondrosis what general present and what is diagnostic
- Swelling in yearling
- Occasionally present as older horse
Radiographs - diagnostic - Caudolateral craniomedial view - best one to highlight lateral trochlear ridge where may see flattening or fragmentation
○ Lateral trochlear ridge sits in behind the medial trochlear ridge which is the larger one
Stifle osteochondrosis treatment options and prognosis
Treatment 1. Conservative ○ Lytic lesions ○ Minimal lameness ○ Younger horses 2. Arthroscopy ○ Fragmentation ○ Lameness ○ Older horses Prognosis - Dependant on size of lesion
tarsal osteochondrosis how common, swelling, lameness and diagnostic views
- Most common site
- Tarsocrural swelling - obvious
- Minimal lameness
Radiographs - Dorsomedial plantarolateral
○ DIR (distal intermediate ridge) tibia
○ Lateral trochlear ridge - Dorsoplantar
Medial malleolus
Tarsal osteochondrosis treatment for the 2 main sites
1) DIRT (distal intermediate ridge of tibia) lesions ○ Arthroscopy 2) Lateral trochlear ridge lesions ○ Lytic lesions-conservative ○ Flaps or fragments-arthroscopy
Fetlock osteochondrosis clinical presentation, what age common and locations
- Fetlock swelling young horse
- Often bilateral, occasionally quadrilateral
- Common incidental finding in yearling radiographs - generally resolve, only once fragment that we worry about them
- Locations
○ Sagittal ridge lesions
○ Proximal P1 osteochondral fragments
○ Plantar P1 OC fragments
○ Ununited plantar eminence P1
Fetlock osteochondrosis radiographs and treatment
Radiograph - Flexed lateral - Dorsopalmar/plantar Treatment - Conservative ○ Most cases - Arthroscopy ○ If fragment present
Shoulder osteochondrosis how present generally and treatment and prognosis
- Often presents in older horses (2yo)
- Lameness
- Muscle wastage
- Upright foot - long heel, breaking of the heel - due to chronic osteochondrosis lesion
- Significant degenerative changes present when diagnosed
Treatment - Arthroscopy
○ Prognosis poor
○ 50% success rate - as generally advanced by the time you see them and secondary osteoarthritis
Subchondral bone cysts clinical signs and diagnosis
Clinical signs - Lameness - Swelling difficult to detect Diagnosis - Local analgesia - Radiographs - diagnostic - HAVE TO BE GOOD QUALITY - CONTRAST IMPORTANT - Scintigraphy
