Exam Principles

Macrotrauma vs Microtrauma

Macro: Excess load compared to tissue tolerance in a certain event

Micro: Repetitive overload of the involved tissue

Stress Strain Curve

• Tissue deformation fine in - -, - - is where damage occurs

Elastic zone, yield point

Repair vs Regeneration of tissue

Repair: CT scar

Regeneration: Re-creation of original tissue

Phases and timelines

1. Inflammatory (5 days)

2. Proliferative/Inflammatory (21 days)

3. Remodeling (1+ years)

Remodeling type by structure

• Muscle

• Tendon

• Ligament

• Bone

• Repair

• Regeneration

• Repair and Regeneration

• Regeneration

Common Muscle Injuries

Strain, contusion, laceration

Muscle Strain Grades!

I: small # of fibers injured, localized pain, minimal/no loss of muscle performance

II: tear of greater # of muscle fibers, pain, swelling, pain reproduction with muscle contraction

III: complete tear across muscle, significant pain, loss of anatomic continuity of muscle, loss of muscle function

What muscles are most susceptible to strain?

Two-joint, more type II fibers

Contusion vs laceration

Contusion: direct blow to muscle (bleeding)

Laceration: deep cut or gash

Contusion adverse effect

Bone forms inside muscle after contusion

Differences between tendinitis vs tendinosis

Tendinitis is inflammatory response to injury/overuse

• (Inflammatory cells, hypervascularization, collagen disorganization, fibroblast proliferation)

Tendinosis is a chronic degenerative state

• (Absence of inflammatory cells, neovascularity, increased proteoglycan content, increased type III collagen, collagen disorganization)

Other tendon issues

Tendon rupture: complete rupture

Tendinopathy: painful tendon w/o identified histopathology

Ligaments can either be attached to a joint (-) or not (-). They are most often damaged from increased -

Intrinsic, extrinsic, lengthening

Ligament Sprain Grades

Grade I: Stretching of ligament but minimal collagen fiber damage (little/no laxity)

Grade II: Stretching with some tearing (increased laxity with end feel)

Grade III: Stretching with near/total ligament disruption (excessive laxity with no firm end feel)

Bone injury types and main concerns

Fracture and contusion, stabilization + infection + acute compartment syndrome

Compartment Syndrome 5 p’s

Pain, Pallor, Paresthesia, Pulselessness, Paralysis

Compartment Syndrome is excessive -, related to - from -

Swelling, blood, fracture

Delayed Union vs Malunion

DU: Long healing of bone

M: Improper healing (alignment)

Cartilage Function

Absorb compressive forces and decrease frictional resistance to movement

Cartilage injury grades

Grade 0: normal cartilage

Grade 1: nearly normal cartilage, soft indentation/surface lesions only

Grade 2: abnormal cartilage, lesion from surface to <1/2 depth

Grade 3: severely abnormal cartilage, lesion ½ depth or may extend into subchondral bone

Grade 4: severely abnormal cartilage, lesion extends through subchondral bone

Challenge with cartilage healing

Healing process replaces hyaline cartilage with fibrocartilage

Segmental demyelination (temporary) is -

Disruption of axon/myelin is -

Transection of nerve is -

Neurapraxia

Axonotmesis

Neurotmesis

Arthrokinematics glide rule

Convex on concave: roll and glide opposite

Concave on convex: roll and glide same

Close-packed is when joint is more - and -

Congruent and compressed

Normal end feels

Soft (st approximation), Firm (st stretch), Hard (bone to bone)

Joint mobility differences

Hypo: decreased arthro/osteokinematics, pain with ranging

Hyper: increased a/o, pain and stiffness with prolonged positioning

Muscle Strength is -, Power is -, Endurance is -

Force, Speed, Time

Isotonic vs Isokinetic

Isotonic is lifting fixed mass against gravity, Isokinetic is force production at fixed velocity movement