True or False

Menisci are primarily avascular

True

The inner 2/3 of menisci are avascular

What are menisci?

Structurally not functionally

Fibrocartilagenous discs that are 74% water

Are adolescents more or less prone to meniscal

injuries compared to adults

Less

*Tissue degenerates with aging

When are menisci subject to injury/what

puts them at risk of injury?

Repetitive cyclic loading, cutting, pivoting, jumping

*Most often as a result of sudden rotation of femur on fixed tibia w/ knee in flexion

Which meniscus is more subject to injury

Medial or Lateral?

Medial

Key words with meniscal injuries

Locking

Catching

Clicking

Typical Subjective Report

Meniscal Injuries

• Medial or lateral compartment pain, often posteriorly
• Pain w/ deep knee bending, walking, twisting
• Sensation of giving way
• Catching, locking, clicking (mechanical symptoms)
• Continuous or recurrent effusions

Hemarthrosis

• 1-2 hour onset
• Probable cause: ligament tear, osteochondral fx, peripheral meniscal tear
• S&S: taut skin, doughy/hard feeling, warm surface

Swelling

Purulent or Pus

• warm/hot to touch
• occassionally red
• pt has signs of infection/fever

Swelling

Synovial Fluid

• 8-24 hour onset
• S&S: boggy feeling to the joint
• warm and tender surface
• occurs with activity and disappears after a few days of inactivity

Rehab after Meniscectomy

In General

• No anatomic structure needs protection
• Proceed aggressively
• Goals are as for meniscal repairs

Rehab after Meniscectomy

Acute Phase

*Brotzman

• Diminish inflammation
• Restore ROM
• Re-establish quad activity
• Days 1-10

Rehab after Meniscectomy

Internal Phase

*Brotzman

• Restore and Improve muscular strength and endurance
• Re-establish full non-painful ROM
• Gradual return to functional activities
• Day 10 - Week 4

Rehab after Meniscectomy

Advanced Activity Phase

*Brotzman

• Enhance muscular strength and endurance
• Maintain full ROM
• Return to sport/functional activities
• Weeks 4-7

Rehab after Meniscectomy

Criteria for progression to Phase 3

*Brotzman

• Full, non-painful ROM
• No pain or tenderness
• Satisfactory isokinetic test
• Satisfactory clinical exam (minimal effusion)

Zones of Cartilage

Type 1 Cartilage Injury

• Superficial
• Microscopic damage to chondrocytes and ECM
• Cell Injury

Type II Cartilage Injury

• Partial thickkness (microscopic disruption of surface)
• Chondral fx or fissure
• Does not provoke inflammatory response b/c it doesn't penetrate subchondral bone

Type III Cartilage Injuries

• Full thickness
• Disruption of cartilage
• Penetration into subchondral bone
• Significant inflammatory response

Tidemark Zone

weak link between overlying cartilage and subchondral bone

Rotational force in direct trauma is

 most common cause of ___________

Chondral Injuries

Osteochondritis Dissecans

(OCD)

Fragment of bone or cartilage comes loose and floats  within the knee joint

*AKA chondral fx or loose body

Distribution of OCD

OCD Treatment

• Cartilage need WB and ROM to maintain integrity
• Follow surgeon's ROM restrictions to avoid engaging lesion during exercise
• Generally P/AAROM exercise ok
• Goal of full ext in 1 wk and full flex 3-5 wks
• Closed chain avoided for first 4-6 weeks

8th leading cause of disability in the world

OA

What's OA?

• Fissures, cracks, and thinning of cartilage
• Bone damage
• Synovial inflammation
• Hypertrophy of cartilage
• Prograssive erosion
• RESULT: pain and stiffness

OA Rist Factors

• Previous traumatic joint injury
• obesity (knee > hip)
• Heredity
• Malalignment
• Instability
• Quad weakness
• Occupation

Priamy OA

• No known cause
• Eventual degredation of cartilage until bone is exposed
• appears related to aging and heredity
• believed to be result of excess load or normal loading of previously injured joint

Secondary OA

Occurs as a result of articular injury

-Fx, repetitive joint stress, obesity, metabolic disease (osteoporosis, osteomalacia)

When pt has OA, will stiffness increase, decrease, or stay the same with activity?

Decrease

Mild OA Treatment

• Education
• AROM hip, knee and ankle
• Modalities prn
• knee sleeve
• quad sets
• isometrics PREs for quads, hamstrings, hip ADd/ABd
• Low impact conditioning, aquatics

Moderate-SEvere OA Treatment

• AAROM hip, knee, and ankle
• Stretching (hamstrings, quads, hip add, gastroc)
• Unloaded aerobic conditioning
• strength exs (isometric, progress to hip add/abd, SLR)

Total Knee Arthroplasty

(TKA)

• Most common indication is disabling arthritic knee pain that does not respond to conservative measures

TKA Contraindications

Peripheral vascular disease

history of infection

morbid obesity

Early Goals after TKA

• Restore motion and strength
• Reduce pain
• Prevent DVT

TKA goals during rehab

• Obtain and maintain knee ROM
• Develop knee and hip muscle strength
• Functional independence

TKA Complications

• DVT
• Wound issues
• Infection
• Nerve Palsy
• Femoral Fracture
• Patellofemoral instability
• Knee stiffness

Is infection after TKA more common with RA or OA?

2-3 times more likely in RA over OA

TKA implant longevity

10-15 years

Chondromalacia Patella (CMP)

• Softening of cartilage
• Referes to changes on lateral facet of patella