Dog and Cat 8 Flashcards
Carpus arthrodesis how common, indications and what need to identify beforehand
- Most frequently arthrodesed joint • Indications: - Carpal hyperextension injury - high-rise syndrome - Joint luxation - Chronic, severe OA • Identify the LEVEL of injury - Palpation - Stress Radiography • Identify concurrent injury: - Collateral ligaments - Metacarpal fracture
Pancarpal arthrodesis what use
- plate fixation
- ESF
- Cross pinning (small animals only)
- THEN at least 8 weeks of a cast or splint
• Evolution of implant design: - DCP (dynamic compression plate) -> Hybrid -> Castless PCA
- Compression holes
Partial carpal arthrodesis what involved and why and the 2 main techniques used
- 80% of carpal motion at antebrachiocarpal joint
- Partial carpal arthrodesis – fusion of intercarpal and carpo- metacarpal joint
- Ensure no involvement of the antebrachiocarpal joint (difficult)
- Cats requirement for supination?
• Techniques: - Plate Fixation - T plate
- Pins (Very small animals only)
Stifle athrodesis indications and technique
• Indications: - Severe degenerative joint disease: - Intra-articular fractures - OCD - Instability from collateral or multiple ligament injury • Technique: - Plate fixation (pin techniques in small animals) - Maximise bone contact area by removal of intra-articular structures: ○ Cranial & Caudal Cruciates ○ Menisci - Long Lever arms – bone fracture - Compression
Stifle arhrodesis complications
1) Implant failure: ○ Insufficient bone contact ○ Cycling 2) Fracture: ○ Long Lever Arms ○ Plate Span 3) Infection: ○ Strict asepsis Consequences - implant removal
Hock arthrodesis how common, indications and what need to idetnfiy
• Indications: - Severe degenerative joint disease: - OCD - Joint Instability - Shearing Injury - Calcanean Tendinopathy - Hyperextension Injury • Identify LEVEL of injury: - Palpation - Stress Radiography • Identify concurrent injury
Hock arthrodesis technqiues and complications
Techniques: - Plate fixation (Cranial vs Medial) -> medial - ESF - Pin and Tension Band Wire - Pantarsal vs Partial Tarsal Arthrodesis: ○ Calcaneoquartal ○ Tarso-metatarsal • Complications - Plantar necrosis
Total hip replacement indications, outcome and complications
Indications:
- Severe degenerative joint disease (CHD) -> due to hip dysplasia
- Fractures of the femoral head/neck
- Salvage following acetabular fracture repair
- Avascular necrosis of the femoral head
- CONSIDERED - gold standard
Outcomes
- Good to excellent outcomes in 80-98% cases
Complications:
- Coxo-femoral Luxation - can revise the surgery and change the head size
- Sciatic neuropraxia
- Aseptic loosening
- Infection - require removal
Total hip replacement what are the 2 main techniques what provides stability
- Cemented:
- Polymethylmethacrylate - cohesive interface btn implant and bone
- Good early stability
- Aseptic loosening:
○ Enzymatic osteolysis
○ Cytokine induction of osteoclasts - > Bone Resorption - Uncemented:
- Press-fit or monocortical screws (early stability)
- Meticulous preparation
- Osseous integration with micro-interlock (Late stability)
Elbow total replacement indications, 2 techniques and 4 complications
Indications: - Severe bi-compartmental disease: - OCD - Coronoid process disease - Not luxation • Techniques - Lowa - TATE • Complications: - may result in amputation or arthrodesis 1. •Fracture 2. • Luxation 3. • Persistent lameness 4. • Infection
Stifle total replacement indications and complications
• Indications: - End-Stage OA: ○ OCD ○ Cruciate disease - Combination System: ○ Press-fit Femoral component ○ Cemented Tibial component • Complications: - Luxation - Infection - Aseptic loosening
Stifle total replacement outcomes
- Improved ROM - RANGE OF MOTION
- Improved objective functional data:
○ PVF 80% normal contralateral
○ Impulse 90% normal contralateral
Femoral head and neck excisional arthroplasty indications
- Fractures of the femoral neck or head
- Slipped capital physis (cats)
- Avascular necrosis of the femoral head (dogs)
- Chronic coxofemoral luxation
- Failed total hip arthroplasty
- Severe OA secondary to CHD & not palliated by medical management)
Femoral head and neck excisional arthroplasty technique and what equipment used and what done at the end
- Craniolateral approach to the hip joint
- Disarticulation if required
- External rotation of the femur
- Parallel to sagittal plane of neck:
○ Prevent caudal spur formation - limits the range of motion
1. • Oscilating Saw (preferred)
2. • Gigli Wire
3. • Osteotome & Mallet - Check cut surface of proximal femur before you close -> need to ensure take whole neck out
4. Rasp if spur present
5. Post-operative radiograph - to ensure you take enough
Femoral head and neck excisional arhtroplasty what are the 7 complications
- Infection
- Seroma
- Persistent lameness (leg shortening)
- Muscle atrophy
- Decreased ROM (extension and abduction)
- Patellar luxation
- Sciatic neuropathy
Femoral head and neck excisional biopsy outcome and how modified
- Never return to normal function based on PVF (PEAK VERTICAL FORCE) and impulse.
- Modified by:
○ Surgical technique (failure to remove all femoral neck)
○ Duration of clinical signs (muscle atrophy)
○ Age (immature vs mature)
○ Post-operative care (physiotherapy)
○ Body weight/condition
• Published outcomes: - Largely subjective
- Acceptable function
Excision arthroplasty of the glenoid when used, indications and outcomes
- Salvage for severe OA of the glenohumeral joint in small dogs
• Indications: - Glenoid dysplasia
- Chronic shoulder luxation
• Acceptable outcomes in limited numbers of cases in small dogs
Intraoesseous transcutaneous amputation prosthesis what are they, used for and complications
- Osseous and dermal integration of implants – robust prosthetic integration
- Partial amputation
• Complications: - Infection
- Epidermal ingrowth
- Marsupialisation
- Peri-prosthetic fracture
Oncologic limb sparing 2 main indications what is involved
• Indications: - Neoplasia of the extermities (OSA) - Distal radius • The affected bone is resected with appropriate margins (3cm) • Antebrachiocarpal disarticulation • Replacement of the missing segment: - Cortical allograft (bone bank) - Metal endoprosthesis - Ulnar rollover - Bone transport osteogenesis
Axial skeleton disease what commonly lead to and conditions involved
- Diseases that affect the axial skeleton frequently cause dysfunction of the bone or nervous system (brain and spinal cord)
- These conditions include congenital malformation, neoplasia, infection, and trauma resulting in fracture / luxation.
Congenital malformation and neoplasia of axial skeleton what involved
- Congenital malformation
- Atlantoaxial luxation/subluxation
- Cervical vertebral malformation (Wobbler) -
stenosis - Neoplasia
- Oral and skull neoplasia (MLOs)
- Primary and metastatic neoplasia of vertebral body
Infection of axial skeleton what called, common infection, how arrive, what leads to
Discospondylytis
- Infection in vertebral endplates
- Most commonly bacterial infection but can be fungal infection
- Haematogenous spread -> from urinary tract infection
- Lumbosacral disc space
- Loss of structural stability of the vertebrae and impingement of the spinal cord causing pain and neurological dysfunction
Instability/degeneration/trauma of oxial skeleton what are the 3 main diseases and what result in
1) Vertebral fracture / luxation
○ Severe trauma results in unstable vertebral column and varying degrees of spinal cord compromise
○ Can result in complete core transection -> BAD
2) Lumbosacral disease / instability
○ Can lead to budging of the disc - putting pressure on nerve
§ Lumbosacral pain and ataxia can result
3) Intervertebral disc disease
Musculoskeletal neoplasia what is the most common form and some other causes
- The most common form of primary bone cancer (85% of all cases) in dogs and cats is osteosarcoma (OSA).
- Other types of primary bone cancer
○ Chondrosarcoma
○ Fibrosarcoma
○ Haemangiosarcoma - Metastatic (secondary) neoplasia of the bone is less common in companion animals than it is in people.
Osteosarcoma distribution - common signs and signalment
Distribution
- OSA most commonly affects the appendicular (75%) vs. axial skeleton (25%)
○ ‘Away from the elbow, towards the knee’ - mainly in forelimb
○ FL 2.5 x HL - more common in forelimb
§ Proximal humerus
§ Distal radius ** - MOST COMMON SITE
§ Distal femur
§ Proximal / Distal tibia - hindlimb
§ Axial skeleton (skull, spine, ribs)
Signalment
- Typically affects large to giant breed dogs
- Middle to older aged (7-9 yrs)
- ? Males > females, neutered > non neutered
Osteosarcoma character and prognosis with different treatmetn options
- OSA is an aggressive tumour with local invasion and destruction and high metastatic potential - NOT GOOD
- Expected median survival time (MST):
○ Amputation and chemotherapy - curative intent treatment -> CANNOT CURE but best option
§ MST 250-350 days (8-11months) - quality of life is good
§ 2 year survival time of 20%
§ 3 year survival time of 10%
○ Amputation alone
§ MST 4-5 months
Osteosarcoma risk factors and poorer prognosis
- Negative prognostic factors for both mortality and metastasis
- Tumor location
○ Proximal humerus, distal femur, proximal tibia -> higher muscle mass so less likely to detect mass earlier
○ MST for prox. humerus is 132 days < other locations - High ALP levels
○ Dogs with ↑ ALP lived 156 days less than dogs with normal ALP - Increasing body weight
- Stage III disease (mets to lungs, bones, LNs)
○ Mets to bone (130d) longer MST than mets to lung (59d) or LN (59d)
Osteosarcoma diagnosis 6 options
- Signalment
- Clinical history - can present as lameness
- Clinical Pathology –ALP
- Radiographs
○ mixed lytic and proliferative pattern - sunburst affect - Cytology (ALP staining)
○ Fine needle aspirates -> medullary sample - Biopsy (Jamshidi needle core)
Want to get the central part of lesion -> don’t want to go through the bone
Osteosarcoma what are the 5 steps in staging
- 3 view thoracic radiographs - 2 laterals and ventrodorsal
○ 10% dogs have macroscopic mets at Dx - Thorough orthopaedic exam - can they tolerate an amputation
○ Bone is 2nd most common site of metastasis - Nuclear Scintigraphy –Tc99-m - screen whole body for metastasis to other bones
- Evaluate regional lymph nodes
○ Axially and prescapular lymph nodes if forelimb - Whole body CT or MRI or radiographic survey
Osteosarcoma treatment goal and the 2 main types of treatment
- Effective treatment requires careful diagnostic workup and communication with the patient owner about expected outcome of treatment
- Goal of therapy is best QOL for patient
a. Curative Intent
b. Palliative therapy
1. Curative Intent
2. pallitative therapy
Curative intent treatment for osteosarcoma what is the goal, how achieve and the 2 main options and complications with this
- Goal is to provide best quality of life AND extend life for as long as possible
- Local tumour control can be achieved with either amputation or limb salvage
- Control of metastatic spread requires the use of adjuvant chemotherapy
○ Carboplatin
1. Amputation -> steps on previous lecture
2. Limb salvage - forelimb - Resect OSA affected bone
- Replace bone defect with metal endoprosthesis or cortical allograft
- Distal radius most successful
- Complications
○ Implant failure
○ Infection -↑ survival time
○ Local recurrence - 30% of cases - Equivalent MST with chemotherapy to amputation + chemotherapy
Osteosarcoma palliative therapy what is the goal and 5 options
- Goal is to provide best quality of life but not necessarily extend duration of life
1. Amputation –pain control
2. NSAIDs, Analgesics
3. Bisphosphonates –pamidronate, zoledronicacid -> inhibit osteolysis -> used for osteoporosis in people
○ Inhibits osteoblasts -> inhibits ongoing bone destruction
4. Radiation therapy
○ 75% good to excellent analgesic response for 3-4 months
○ Radiopharmaceuticals –Samarium-153
5. Combination therapy
○ XRT + Chemo + bisphosphonates
Palliative therapy osteosarcoma disease progression within
- Disease Progression
○ Development of metastatic disease
○ Pathologic fracture - generally leads to euthanasia decision -> cannot heal
○ MST > amputation alone but < curative intent
§ XRT + Chemo longest MST
Chondrosarcoma how common, common sites, character and median survival
○ Second most common primary bone
○ Nasal cavity = most common site
○ Flat bones (ribs, pelvis, scapula)
○ Slower progression, slower metastasis - chemotherapy not needed
○ *Grade may influence
○ Median survival = 979 days (2.7 yrs) surgery alone
Metastatic bone neoplasia how common in dogs, commonly from what cancers
- Rare in dogs compared to people
- Commonly from carcinomas
○ bladder, prostate, mammary
○ squamous cell carcinoma
○ diaphysis (nutrient foramen) - Sarcomas
○ especially following chemotherapy
Skull neoplasia what is the most common one, location, breed, radiographic findings, character, histological grade prognosis, prognosis and adjuvant therapy
MLO - Multilobular Osteochondrosarcoma (MLO)
- Affects flat bones of the skull
○ Maxilla, mandible, calvarium
- Older, medium-to large-breed dogs
- On radiographs, mass with nodular or stippled mineralized densities and lysis of bone
○ “Popcorn ball” appearance
- Slow-growing, locally invasive tumor with moderate metastatic potential
- Histological grade prognostic
○ Higher grade more aggressive biological behaviour
- Good Px if complete excision
- Adjuvant therapy no proven benefit
Oral neoplasia what are the 6 general appraoch to the diagnosis and management of oral massess
1. Biopsy the lesion THROUGH THE MOUTH (inside out) -malignant or benign ○ Bx from oral side not from skin side ○ Tumour type, grade 2. Radiology / CT of mouth / head / neck ○ Sx planning, staging, osteolysis 3. Assess regional lymph nodes ○ Palpation, FNA Cytology +/-biopsy 4. Tumour Staging ○ Thoracic radiographs or CT ○ Regional LN evaluation 5. Radical surgical excision ○ Maxillectomy or mandibulectomy 6. Adjunct therapy ○ Radiation (XRT), Cryotherapy, tumour vaccine
Oral neoplasia clinical signs and most common ones in dogs and cats
Clinical Signs - Mass in mouth - Halitosis - Dysphagia - Bloody discharge - Loose teeth (esp. SCC) - Drooling* - Poor grooming* -> * esp. cats Dogs - melanoma, then SCC, then fibrosarcoma Cats - SCC - can look like resorptive lesions
Malignant oral tumours list the 3 main ones and the 2 main benign ones
1) malignant melanoma
2) squamous cell carcinoma
3) fibrosarcoma
Benign
1) papillomas
2) fibromas
3) odontogenic tumours
4) epulides
Malignant melanoma what age generally occur in, location, character, types, treatment and prognosis
- Older animals
- Gingiva, mucosa, palate and tongue
- Locally invasive
- Met rapidly to the lungsand regional LNs
- Melanotic or amelanotic form - doesn’t have to have pigment
- Treatment: Wide excision, cryotherapy, immunotherapy (Oncoceptvaccine) - quite effective
- Prognosis: Guarded MST 8-9 months
