LEARNING ISSUES

Elbow clickingÑnumerous etiologies; seen with pathological problems that are usually 
bilateral, or indicative of inflammation and pain, so probably not relevant in this case. 
 
Ortalani sign Ð positive sign indicates hip laxity; used to diagnose hip dysplasia

Grades of lameness Ð Grade 1: barely perceptible 
Grade 2: noticeable lameness but weight-bearing most of the time
Grade 3: only occasionally weight-bearing, usually for balance
Grade 4: non-weight-bearing-leg-carrying lameness

Range of motion (normal vs abnormal) Ð normal range of motion for coxofemoral joint is 
110 degrees; extension Ð 40 degrees; flexion Ð 140 degrees; pain can cause muscle 
spasm, which will affect range of motion

Cranial drawer Ð test to measure displacement of tibia to determine if cruciate ligament is 
ruptured

Joint pain etiology  - multiple etiologies such as ruptured ligaments leading to joint 
instability, inflammation, joint effusion, abnormal articular cartilages. The underlying 
reason for the pain ( esp in the case of the hip) is disruption of the articular cartilage such 
that there is rapid wear and disintegration leading to exposure of the subchondral bone. 
There are no pain receptors ( nociceptors ) in the articular cartilage, but there is in the 
subchondral bone. More of this will be expounded on depending on diagnosis.

Pain in extension vs flexion Ð pain on extension suggests subluxation.

Dietary effects Ð accelerated growth rate (due to improper diet) causes rapidly growing 
skeleton, aberrations in ossification, damage to developing cartilage and growth plates, 
and premature closure of growth plates; relative to hips, premature femoral head closure 
results in improper alignment with acetabulum; improperly formed articular cartilage 
wears faster, and then subchondral bone exposed (causes pain).