Tier 1 — must know
Canine
Musculoskeletal / Nervous
High yield
Luxating patella
Toy-breed stifle topic · intermittent skipping gait · palpation and surgery selection
⏱ 2–3 min read · Topic 22 of 33
5
Practice Qs
4
Traps
High
Exam freq.
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Your status
Study step
Exam core — read this first
Classic signalment → small-breed dog with intermittent hindlimb skip
Diagnosis → orthopedic palpation and grading are central
Management split → mild incidental cases may be conservative, persistent dysfunction pushes surgery
Board comparison → separate this from cranial cruciate disease and hip disease
Clinical mechanism — only what matters
Patellar instability → disrupts normal extensor mechanism tracking
Intermittent luxation → causes the classic skipping or kicking-out gait
Chronic malalignment → can drive cartilage wear and osteoarthritis over time
The exam mainly cares about signalment, gait pattern, and when the case becomes a surgical problem.
Pattern recognition
Core pattern
Toy breedSkipping gaitIntermittent hindlimb lameness
Supporting clues
Often medial luxationNormal between episodesStifle click or palpable displacementYoung dog historyChronic osteoarthritis if longstanding
NAVLE trigger: The “skip a few steps then looks normal again” description is a classic clue.
Decision core — what NAVLE actually asks
Persistent functional lameness or higher-grade luxation
→ Surgical correction becomes more likely to be the expected answer
Comfortable mild intermittent case
→ Weight control, conditioning, and monitoring may be reasonable initially
Painful stifle with effusion or marked instability
→ Re-check for concurrent cranial cruciate disease rather than assuming isolated luxation
Key interpretation
Signalment
Small breed common
High-yield pattern clue
Exam
Patellar palpation
Core diagnostic step
Gait
Skipping / bunny hop
Intermittent mechanical pattern
Grade
Matters
Helps predict management and chronicity
OA
Can develop
Chronic consequence of maltracking
Concurrent CCL
Possible
Do not miss other stifle disease
⚠ A dog can have both patellar luxation and cruciate disease. A painful unstable stifle deserves a full exam, not a shortcut diagnosis.
Treatment
Step 1
Orthopedic exam, grade the luxation, and assess functional impact
That is the foundation for every next step.
Step 2
Conservative management for selected mild comfortable cases
Weight control and conditioning still matter.
Step 3
Surgical realignment for persistent lameness or significant instability
This is the common board answer for clinically important cases.
NAVLE traps — where students lose marks
The classic gait can be intermittent and easy to dismiss
That does not make the diagnosis trivial.
Palpation is central
Radiographs support the case but do not replace the orthopedic exam.
Mild incidental luxation is not the same as functionally important disease
The surgery decision depends on clinical impact.
Painful stifle effusion should trigger CCL thinking too
The exam often hides a second lesion in the same limb.
Differentials — how to separate these on NAVLE
Fast separator: Luxating patella is the intermittent skipping small-dog stifle problem. Compare it with cranial cruciate rupture and hip disease.
| Problem | Pattern | Key exam clue | Key separator |
|---|---|---|---|
| Luxating patella | Skipping gait | Patella can be displaced | Intermittent mechanical stifle problem |
| Cranial cruciate rupture | Persistent lameness | Drawer / tibial thrust | Instability rather than simple skipping |
| Hip dysplasia | Hip pain / bunny hopping | Hip exam changes | Not a patellar tracking problem |
| Iliopsoas strain | Soft tissue pain | No luxating patella on palpation | Different orthopedic localization |
| Neurologic disease | Ataxia / paresis | Abnormal neuro exam | Not purely stifle mechanical |
Clinical application tools
These support general orthopedic reference work; the diagnosis still depends on exam and gait interpretation.
30-second revision
SignalmentToy-breed dog
Classic gaitSkip then normal stride
Core examPatellar palpation and grading
When surgery risesPersistent dysfunction / significant grade
Critical trapDo not miss concurrent CCL disease
Practice questions
Pre-built NAVLE-style · Luxating patella
0 / 0
Which signalment and gait description is most classic for canine luxating patella?
What is the most important core diagnostic maneuver for suspected luxating patella?
Which scenario most strongly pushes canine patellar luxation toward surgical correction?
Which finding more strongly suggests cranial cruciate rupture than isolated luxating patella?
Which statement about luxating patella is most accurate?