Salvage - arthroplasty and arthrodeses Flashcards
Define arthroplasty
= joint moulding
- replacement or excision both allow movement
- elective orthopaedic procedure where the joint is either commonly excised or replaced
- replacement aims to remove pain and restore/maintain normal movement (ROM)
- Excision removes pain and has altered movement (ROM)
- load transfer mechanics differ
Define arthrodesis
= joint binding
- irreversible sx fusion of 2 or more joints. Creation of osseous bridging that prevents joint motion and allows the joint to withstand weight bearing forces
Define amputation
normally considered as a fallback after other tx has proved ineffective but may be used if finance is a problem
Species indications - arthroplasties
- dogs
- cats
- (small ponies)
- other small animals
- alpacas
Species indications - arthrodesis
- all spp depending on joint
- e.g. pancarpal/ partial carpal and pantarsal/ partial tarsal
Species indications - amputation
- dogs
- cats (limb, digit, tail)
- limbs in small caged pets
- occasionally larger animals
Indications - arthroplasty
- dysplasia (juvenile pain)
- intractable arthritis/ joint pain
- articular fx (un-reconstructable)
- persistent luxation
- avascular necrosis
What is the most common joint for excision arthroplasty?
- HIP
- Also described in: TMJ, radial head (humans), shoulder, MT/MC phalangeal joint, phalangeal joints
Define FHNE
Femoral Head and Neck Excision
Indications - FHNE
- hip dysplasia (juvenile pain)
- intractable OA / DJD
- femoral head and neck fractures/ acetabular fractures
- persistent luxation
- Legg-Calve-Perthes disease (avascular necrosis of the femoral head)
- all dog sizes, good results up to 30kg
- some restriction in ROM will affect full athletic performance
- sx technique critical
Aftercare - FHNE
- vital to outcome
- early return to controlled exercise
- pain-relief
- physio/hydro
What is FHNE outcome influenced by? 3
- obesity
- preop mm wastage
- other orthopaedic problems
Where is the femur cut in FHNE?
- cut medial to greater trochanter of femur
- cut exits above lesser trochanter
What is another name for replacement arthroplasty?
joint replacement
Which joints can undergo replacement arthroplasty?
- canine and feline hip
- canine stifle (limited case reports for feline)
- canine elbow
- canine hock? (anecdotal)
Define THA
Total Hip Arthroplasty (= hip replacement, THR)
Describe THA
- any dog
- typically large, active or working dogs >30kg
- any time after skeletal maturity
- outcome influenced by: obesity, other orthopaedic problems
- expensive but excellent results thus gold standard.
Ideal patient for a THA
- painful hip (non-responsive to meds)
- large breed dog
- previously active lifestyle
- sensible, well-trained dog
- compliant owners
- (insured)/ committed owners
How do THA and FHNE compare?
- THA more expensive
- 10% risk of severe complications in THA but low risk of minor cx for FHNE
- THA aftercare is cage rest for 6 weeks whilst for FHNE activity encouraged asap
- THA function is excellent/ normal but for FHNE is reduced but often acceptable in smaller animals
Ideal patient joint arthroplasty in joints other than hips
- similar indications/ ideal patient
- currently elbow (and knee)
- long term outcome for elbow and knee replacement are not as established as the hip
Outline total arthroplasty
- sx technique complex and critical
- variable risk of serious complications in sx and postop
- infxn control critical
- variety of techniques and equipment based on cemented or un-cemented bone-implant interface/ prosthesis
What is arthrodesis also known as?
= ‘artificial ankylosis’
= ‘syndesis’
- the artificial induction of joint ossification b/w two bones via sx
Define ankylosis
the gradual development of joint siffness d/t pathologic processes. Joint stiffness develops d/t fibrosis of the joint capsule and the periarticular tissues, and the formation of intra-articular adhesions and OPs
Arthrodesis - indications - 5
- intractable arthritis/ joint pain
- articular fx (un-reconstructable)
- persistent luxation or instability
- low grade pain interfering with performance
- revision of failed joint sx
Principles - arthrodesis (REALLY IMPORTANT TO REMEMBER)
- absolute stability, ideally though compression
- remove cartilage from contact areas
- contour opposing joint surfaces
- bone graft (osteogenesis, osteoinduction and osteoconduction)
- fuse at functional angle
- external support?
Define osteogenesis (bone graft)
source of osteoprogenitor cells
Define osteoinduction (bone graft)
scaffold for bone to grow across
Define osteoconduction (bone graft)
conduction of bone growth factors
Outline long term implications of arthrodesis
- long recovery may require transarticular support (ESF, cast)
- implants mechanically vulnerable (break or back out over time)
- problems with high motion joints
Generally what should you expect form stifle arthrodesis?
high motion joint so might expect poor function but there are exceptions
Indications - amputation
- neoplasia (malignant or locally invasive)
- trauma (excessive tissue damage or ischaemia)
- paralysis (brachial plexus avulsion)
- unmanageable joint conditions, intractable pain, congenital deformity
- client finances
Amputation - considerations
- temperament
- concurrent orthopaedic dz
- paralysis (brachial plexus avulsion, less good an option if there is a chance sensation will come back)
- owner
- mechanically better to lose a HL than TL
Name 2 sites for TL amputation
- forequarter amputation has cosmetic and margin advantage (take scapula and whole TL off)
- mid. humerus (technically easier but cosmetically worse because mm whither)
Name 2 sites for HL amputation
- mid/high femur
- transarticular (coxofemoral - best if OSA in distal limb, care in males as will increase exposure of prepuce)
- hemipelvectomy
Name digit amputation sites
- PIPJ with cartilage removal in cattle
- Distal P1 or P2 in SA
- careful dressing postop
Describe tail amputation
normally related to trauma - leave enough to cover perineum if possible
Principles - amputation
- choose suitable margin of excision (remember neoplasia considerations)
- local block + fresh scalpel for neurectomies
- make sure its not possible for stump to be traumatised postop and leave sufficient tissue (mm/ skin) to cover
- careful reconstruction of tissue to eliminate dead space +/- drain
How do you know if a limb is salvageable?
- limb has distal pulse
- cut nails short (if quick bleeds - limb viable)
- limb cold/warm/ does it bleed?
- neuro status of limbs
- time is your friend!
Pro’s - amputaiton
- predictable
- straightforward
- minor complications
- cost-effective
- instant palliation of signs
- short recovery period
Con’s amputation
- worse balance?
- temperament change?
- knock-on effects on other joints/ spine?
- posturing problems?
- phantom limb?
- neuropathic pain?
Tx choice considerations
- cost (owner, animal morbidity)
- risk (complications, side-effects, success rate)
- benefit (predictability of return to full function)
- animal/limb/joint outcome are not the same
Define ITAP
Intraosseous Transcutaneous Amputation Prosthesis
- think supervet!
- big risk of infxn ascending up prosthesis
