| name | orthopedic-exam |
| description | Lameness grading (AAHA scale), joint assessment (drawer sign/tibial thrust for CCL, Ortolani for hip dysplasia), patellar luxation grading I-IV, OFA scoring, breed predispositions, common conditions by species. |
Orthopedic Exam
Overview
Systematic orthopedic assessment including lameness quantification, specific joint tests with diagnostic criteria, and breed-based disease prediction. Includes both clinical examination techniques and imaging interpretation guidance.
When to Use
- User presents lameness or orthopedic pathology
- User needs specific examination technique interpretation or lameness grading
- Keywords: lameness, orthopedic, CCL, cruciate ligament, hip dysplasia, patellar luxation, Ortolani, drawer test, lameness grade, OFA, HD score
Lameness Grading (AAHA Scale)
| Grade | Description | Clinical Significance |
|---|
| 0 | No lameness | Normal gait |
| 1 | Lameness evident only with exercise | Mild; may detect with trotting |
| 2 | Lameness evident at walk and trot | Moderate; consistent weight-bearing abnormality |
| 3 | Lameness evident at walk; affected limb partially non-weight-bearing | Moderate-severe; obvious gait abnormality |
| 4 | Non-weight-bearing lameness | Severe; complete avoidance of limb use |
| 5 | Inability to move limb | Critical; paralysis or complete dysfunction |
Assessment Protocol: Observe walk/trot on hard surface; note weight distribution, stride length symmetry, pain response; repeat after exercise (fatigue may unmask mild lameness)
Cranial Cruciate Ligament (CCL) Assessment
Drawer Test (Anterior Drawer Sign)
- Position: Dog in lateral recumbency; examiner stabilizes femur above knee with one hand, applies gentle anterior pressure on proximal tibia below knee with other
- Positive test: Anterior tibial translation relative to femur (1-3 mm movement possible)
- Sensitivity/Specificity: 70-90% for CCL rupture depending on chronicity and observer experience
- Limitation: False negatives in partial tears or acute cases with protective muscle tone; false positives in excessive ligamentous laxity
Tibial Thrust (Cranial Tibial Thrust)
- Position: Dog standing or in lateral recumbency with knee flexed to 90°; examiner stabilizes femur, applies dorsal pressure at proximal tibia while extending stifle
- Positive test: Cranial tibial displacement during extension (concurrent with straightening)
- Sensitivity: 72-98% in CCL-deficient stifles (more sensitive than drawer test in early disease)
- Interpretation: May be positive with partial tears when drawer test is negative
Diagnostic Approach: Positive drawer test + positive tibial thrust = highly suggestive CCL rupture; confirm with radiography/MRI
Hip Dysplasia Assessment
Ortolani Test
- Position: Dog supine; hip and knee flexed to 90°; examiner abducts femur gently
- Positive test: Audible/palpable "click" or "clunk" as femoral head subluxates into acetabulum (indicates underlying dysplasia)
- Sensitivity/Specificity: 64-82% sensitivity; useful in puppies <6 months; becomes unreliable as fibrosis develops
- Interpretation: Positive Ortolani suggests hip dysplasia; negative result does not rule out disease
Distraction Index (radiographic measurement)
- Radiographic assessment required for definitive diagnosis
- PennHIP method: Measures femoral head displacement; DI = 0.3-0.5 (normal), >0.7 (dysplastic)
- Laxity threshold: DI >0.3 suggests increased risk of osteoarthritis
OFA (Orthopedic Foundation for Animals) Scoring
- Classification: Normal, borderline, dysplastic (based on radiographic features: remodeling, bone proliferation, subluxation)
- Age: Radiographs at ≥24 months for certification
- Breed-specific prevalence: German Shepherd (19%), Labrador retriever (12%), Golden retriever (20%)
Patellar Luxation Grading (Putnam Scale)
| Grade | Description | Clinical Findings |
|---|
| I | Intermittent; manual reduction possible; weight-bearing normal | May go undetected clinically; incidental finding |
| II | Intermittent; manual reduction or spontaneous; weight-bearing abnormal intermittently | Sporadic lameness; palpable luxation during examination |
| III | Permanent; manual reduction difficult; weight-bearing compromised; structural changes present | Chronic lameness; muscle atrophy; secondary OA |
| IV | Permanent; manual reduction impossible; severe lameness or non-weight-bearing; marked structural changes | Surgical candidate; significant joint remodeling |
Diagnosis: Palpation during extension/flexion; ±radiography (assess for trochlear dysplasia, medial angulation); ultrasound if soft tissue damage suspected
Breed Predisposition: Small breeds (Chihuahua, Pomeranian, Toy Poodle); large breed medial luxation less common
Common Conditions by Species and Location
Dogs - Forelimb
- Shoulder Osteoarthritis (OA): Older dogs; German Shepherd, Labrador predisposed; limited extension; pain on manipulation
- Elbow Dysplasia: Large/giant breeds; medial coronoid process disease (MCPD), osteochondrosis dissecans (OCD), ununited anconeal process (UAP); radiography required
- Carpal/Metacarpal Injuries: Partial tears, ligament sprains; may be career-ending in performance dogs
Dogs - Hindlimb
- Hip Dysplasia: Large/giant breeds (German Shepherd, Labrador, Golden Retriever); OA secondary; manifests as hindlimb lameness, reluctance to jump, bunny-hopping gait
- Cranial Cruciate Ligament (CCL) Rupture: Common; large breed predisposition; acute grade 3-4 lameness or insidious chronic grade 1-2
- Patellar Luxation: Small breeds primarily; intermittent lameness or persistent non-weight-bearing
- Meniscal Tear: Often concurrent with CCL rupture; secondary to OA progression; medial meniscus most common
Cats
- Hip Dysplasia: Less common than in dogs; Maine Coons, Persians predisposed; may go undiagnosed (cats compensate well)
- Patellar Luxation: Less common; similar presentation to dogs
- Osteoarthritis: Underdiagnosed; manifests as reduced jumping, reluctance to climb, behavioral changes; not traditional lameness
- Fractures: Falls, trauma; radiography essential
Horses
- Lameness Assessment: AAEP scale (0 = sound, 5 = non-weight-bearing); joint flexion tests; response to intra-articular anesthesia diagnostic
- Suspensory Ligament Injury: Common in sport horses; ultrasound assessment essential
- Navicular Disease: Chronic forelimb lameness; radiographic changes (demineralization, ossification); associated with deep digital flexor tendon pathology
OFA Hip Dysplasia Score Interpretation
| Score | Meaning | Breeding Recommendation |
|---|
| 1-6 | Normal | Excellent candidate for breeding |
| 7-12 | Borderline | Consider breeding only if mate scores excellent/good |
| 13+ | Dysplastic | Not recommended for breeding |
Limitations
- Drawer test: Insensitive in early CCL disease or with protective muscle guarding; serial examinations more reliable than single assessment
- Ortolani test: Unreliable >6 months of age as fibrosis prevents subluxation; PennHIP method more sensitive in adult dogs
- Palpation: Limited sensitivity for meniscal tears; MRI required for definitive diagnosis
- Radiographic interpretation: Subtle early changes may be missed; positioning essential for accurate assessment
- Breed predispositions: Wide individual variation; screening recommendations vary by breed and organization
- Referral to board-certified surgeon recommended for: CCL rupture with surgical consideration, multiple joint involvement, fracture management, advanced OA, undiagnosed lameness after clinical/radiographic workup
