Common orthopedic conditions Flashcards
(24 cards)
Give 3 examples of noninflammaotry arthritis.
osteoarthritis (both idiopathic and secondary)
traumatic arthritis
coagulopathic arthritis
Give 3 examples of inflammaotry arthritis.
immune mediated: erosive (e.g. rheumatoid) and non-erosive (idiopathic)
infective (e.g. borrelial)
crystal-induced (e.g. gout)
Pathophysiology of osteoarthritis
Exact mechanism unknown
Stress on cartilage →
fibrillation of the superficial cartilage layer → roughening of the articular surface →
fissures eventually extending to subchondral bone
→
free cartilage fragments initiate inflammatory response →
production of inflammatory mediators →
affected cartilage more susceptible to breakdown from the loads of weight bearing.
Pathological Changes in the osteoarthritic Joint, 6
- Articular fibrillation
- Cartilage loss
- Subchondral bone sclerosis
- Osteophyte formation
- Periarticular soft tissue fibrosis
- Synovial membrane inflammation
Articular fibrillation is the fraying or splitting of the cartilage surface at a microscopic or macroscopic level. It is one of the earliest signs of cartilage degeneration in osteoarthritis.
Surgical treatment options for OA (4)
- Treatment of the underlying problem (usually does not prevent progression of degenerative changes) - early detection essential.
- Joint replacement (prosthesis)
- Limb salvage procedures (e.g. arthrodesis – surgical fusion of the joint)
- Amputation/euthanasia
amantadine for canine osteoarthritis
Amantadine is an NMDA (N-methyl-D-aspartate) receptor antagonist used as an adjunctive treatment for canine osteoarthritis, particularly in cases where pain is no longer adequately controlled by traditional analgesics such as NSAIDs.
It works by blocking central sensitization, a key mechanism in chronic pain where the nervous system becomes hyper-responsive to stimuli. Although not a primary analgesic, amantadine can help reduce neuropathic and chronic pain by modulating pain perception at the spinal cord level.
Dysplasia = Abnormal development of tissues, organs or cells. Frequently diagnosed in dogs as hip or elbow dysplasia.
Name 4 characteristics of Elbow dysplasia
- Fragmented medial coronoid process (FCP)
- Osteochondrosis(/-chondritis) dissecans (OCD)
- Ununited anconeal process (UAP)
- Elbow incongruity
- Medial compartment disease
- Incomplete ossification of the humeral condyle
Hip Dysplasia: Diagnosis typically involves 3 measurements. What are they?
Norberg angle
PennHIP distraction index
Femoral head coverage %
4 surgical hip dysplasia tx’s
- Juvenile pubic symphysiodesis
- Pelvic osteotomy
- Total hip replacement
- Femoral head and neck excision
what are those 3 abbreviations
Fragmented medial coronoid process (FCP)
Osteochondrosis(/-chondritis) dissecans (OCD)
Ununited anconeal process (UAP)
Describe FCP
- Common type of medial coronoid disease
- A separation of a small portion of the medial coronoid process of
the ulna - Exact etiology unknown, several theories
- Generally bilateral
- The most common form of elbow dysplasia
- Early diagnosis difficult with radiographs
- Visible fragments are rarely seen
- Standard craniocaudal, standard lateral and flexed lateral views
- CT helpful
- Arthroscopy most precise
FCP: Treatment
- May be treated conservatively, but delay in surgical removal of a loose fragment may allow continued cartilage damage.
Surgical treatment – may include fragment removal, debridement of necrotic bone, subtotal coronoidectomy.
- If surgery is to be performed, it should be done as early in the disease process as possible to minimize progression of osteoarthritis.
- Advanced osteoarthritis – benefit of surgery questionable.
Describe OCD
Osteochondrosis(/-chondritis) dissecans
Osteochondrosis – disturbance in endochondral ossification that leads to retention of cartilage (clinically irrelevant).
Osteochondritis - fissure formation in the abnormal cartilage leads to development of a flap of cartilage (clinically relevant).
- Immature large dogs, exact origin unknown (genetic factors, rapid growth, overnutrition, trauma, ischemia, and hormonal factors)
- Commonly bilateral
- Leads to development of osteoarthritis
Diagnosis:
* Standard lateral, flexed lateral and craniocaudal views
* Radiolucent concavity observed
* Arthroscopy more precise
OCD: Treatment
Treatment not necessary without symptoms (probably only osteochondrosis aka cartilage retention).
- Conservative treatment (management of osteoarthritis) an option, but delaying surgery may encourage additional damage to the opposing cartilage.
- Surgery – removal of the cartilage flap, arthroscopy preferred.
- If surgery is to be performed, it should be done as early in the disease process as possible to minimize progression of osteoarthritis.
Describe UAP
- Disease of large growing dogs in which the anconeal process does not form a bony union with the proximal ulnar metaphysis.
- Commonly bilateral
- Usually attached to the ulna with fibrous tissue
- May be free within the joint
- Unstable in both cases, leading to osteoarthritis
- Standard lateral, flexed lateral and a craniocaudal views
- Lucent, indistinct line separating the anconeal process from the ulna visible
UAP: Treatment
- Medical therapy generally used to treat (older) dogs with established osteoarthritis.
- Surgery recommended only in dogs under 1 year of age. Surgical removal of the anconeal process has been the standard treatment.
- Surgical reduction and lag screw fixation not uniformly successful
- Ulnar osteotomy with or without screw fixation an option
the most common form of elbow incongruity
Radioulnar incongruity (RUI) =
* Short ulna/long radius
* Long radius/short ulna
Caused by physeal trauma or congenital factors
Mainly large dogs are affected
- Routine radiography inaccurate in case of mild incongruity
- More accurately evaluated on flexed lateral views
- CT more accurate
- Arthroscopy has been reported to be accurate as well
Elbow Incongruity: Treatment
- May be treated conservatively (osteoarthritis management), but may allow continued cartilage damage.
- Surgery usually preferred, but many dogs with radiographic signs of osteoarthritis remain asymptomatic for several years.
- Aim of surgery to restore the normal congruence. Surgery – lengthening the radius or lengthening or shortering the ulna.
- should be done as early in the disease process as possible to minimize progression of osteoarthritis.
Describe Cranial Cruciate Ligament Rupture event
- CCL limits cranial translation of the tibia relative to the femur and internal rotation of the tibia.
- CCL failure can result from degenerative and traumatic causes
- Underlying premature degeneration in dogs likely (in most cases)
- Ligament degeneration – normal repetitive activities can cause progressive rupturing
- Or Acute injury caused by hyperextension and internal rotation of the leg
- CCL injury with stifle instability is part of a cascade of events that include progressive osteoarthritis and medial meniscus injury.
Can be acute, chronic or partial.
* Acute injury: Sudden onset of non/partial-weight-bearing, decreases within 6 weeks
* Chronic injury: Prolonged weight-bearing lameness associated with secondary osteoarthritis
* Partial tear: Mild weight-bearing lameness, difficult to diagnose at first
CCLR: Treatment
Medical management is generally unsuccessful in dogs, they need Surgical treatment
* Intracapsular reconstruction techniques
* Extracapsular reconstruction techniques
* Corrective osteotomies
Most retrospective studies have shown the success rate to be near 90% regardless of the technique used. No ideal technique available.
for diagnosis of CCLR in addition to cranial drawer test: Tibial Compression Test (Tibial Thrust)
CCLR: Intra- and Extracapsular surgical Techniques
Recreation of the passive constraints of the stifle joint (elimination of static cranial drawer movement).
* CCL
* Joint capsule fibrosis
Intracapsular (usually using fascia lata)
* Advantage: original position and biology of the original CCL mimicked
* Disadvantages: invasiveness, tendency of the graft to stretch or fail
Extracapsular (placement of sutures outside the joint)
* Advantage: less invasive
* Disadvantage: risk of suture tearing
CCLR: Corrective Osteotomies
- Instability approached from a different perspective
- Geometry of the stifle joint changed
- Elimination of shear forces (cranial tibial thrust) during ambulation.
- Advantages: quicker weight-bearing, preferred in larger dogs
- Disadvantages: more expensive, implant failure/infection potentially catastrophic
Patellar Luxation: Treatment
Surgery seldom warranted in asymptomatic older patients. Young/lame animals usually benefit from surgery.
A combination of methods can be used (correction of malalignment):
* Tibial tuberosity transposition
* Medial/lateral restraint release
* Lateral/medial restraint reinforcement
* Trochlear groove deepening
* Femoral osteotomy
* Tibial osteotomy
* Antirotational sutures
* Transposition of the origin of the rectus femoris
