Ortho 2: Knee

Knee Outcome Survey (KOS)

ADL and sport scale 0-100, 100=fully functional

MDC 8.4

Lower Extremity Functional Scale (LEFS)

For any LE Ortho problem

0-80, 80=fully functional

MDC 9

Knee Injury and OA Outcome Scale (KOOS)

Pain, daily function, sport and recreation function, knee related quality of life

0-100, 100=fully functional

Tegner Activity Level Scale

0-10 scale, 0=on sick leave/disability, 10=participation in competitive sports at national elite level

Marx Activity Level Scale

0-16 scale

High level activities like running, cutting, decelerating, and pivoting

Each rated on 4 point scale

Osteosarcoma

Most common malignant bone tumor

Onset: 10-25 y/o

50% located in femur above the knee

Pain, swelling/mass, decreased ROM

Chondrosarcoma

Second most common malignant tumor in adults

Common in long bones

Ewigs Sarcoma

2nd most common bone tumor in children

Onset: 5-16 y/o

Laxity

Movement of tibia relative to femur in a specific direction

(anterior/posterior translation, varus/valgus angulation)

Instability

Excessive joint laxity

Structural Instability

Instability based on testing

Functional Instability

Instability the impacts function (does not allow functional activity)

Frequency of Ligamentous Injury

MCL>ACL>PCL & LCL

MCL Injury

>80% are contact injuries with valgus stress (direct blow to lateral knee with planted foot)

Non-contact: Valgus and rotational force

LCL Injury

Contact injury with varus force with or without rotation stress to knee

Why Are LCL Injuries Less Common

Shielded on inside of knee

Collateral Ligament Conservative Intervention: Phase 1

Pain and swelling control

WBAT with crutches in brace if grade 2 & 3

Isometric quad and hamstring exercise

Collateral Ligament Conservative Intervention: Phase 2

Progress to FWB

Isotonic open and closed chain exercise

Stationary cycling, stair climber, swimming

Proprioceptive exercise

Monitor ROM, pain, and swelling

Collateral Ligament Conservative Intervention: Phase 3

Functional/skill training

Full ROM

Strength 75-85% of contralateral limb

Collateral Ligament Conservative Intervention Return to Play Time: Grade 1

10 days-2 weeks

Collateral Ligament Conservative Intervention Return to Play Time: Grade 2

3-8 weeks

Collateral Ligament Conservative Intervention Return to Play Time: Grade 3

8-12 weeks (may require surgery)

Indications For Collateral Ligament Surgery

Avulsion fracture

Combined ligament injury

Grade 3 tear with functional instability

ACL MOI: Non-contact

Rotation of fixed foot, Deceleration with knee hyperextension

ACL MOI: Contact

Valgus/Varus force

Hyperextension force

ACL Injury Risk Factors

Increased BMI, Hyperlaxity, Female, Narrow femoral notch

What Is The Terrible Triad

ACL/MCL/Meniscus

Why Females Have Higher ACL Risk

Greater knee valgus, Quad dominant, Slower muscle activation, Jump mechanics

ACL Surgical Indications

Multiple structures injured, Desire to return to specific demand activities

ACL Non-surgical Indications

Little exposure to high risk activities, >40 y/o, Prolonged deficiency with no functional instability

Graft Ligamentization: Phase 1

Incorporation

Inflammatory response, graft degenerates, fibroblasts die, remaining tissue is scaffold

Graft Ligamentization: Phase 2

Revascularization

Ingrowth of capillaries from synovium, migration of host fibroblasts into the graft tissue

Graft Ligamentization: Phase 3

Graft healing and maturation

Graft strength and stiffness drops very low, but improves over time, Increase in collagen content and realignment

PCL Function

Resists posterior translation of tibia

PCL Non-surgical Intervention: Phase 1

Pain/swelling control

Ambulation starting WBAt with crutches moving to FWB

Isometric quad exercie, Mini-squats

What ROM is PCL Rehab Limited To

0-60 degrees

PCL Non-surgical Intervention: Phase 2

Stationary cycling, stair climber, LE concentric/dynamic strengthening, proprioceptve exercise, Monitor ROM, pain, and swelling

PCL Non-surgical Intervention: Phase 3

Running program, continued strengthening, functional/sport specific training

Criteria For Return From PCL

Full ROM

Strength 75-85% contralateral limb

Possible bracing

PCL Surgical Intervention

If avulsion fracture

MCL-ACL Combined Ligament Injury

AMRI

PCL-LCL Combined Ligament Injury

PLRI

Knee Dislocation

High Trauma, Medical Emergency, Requires surgical intervention, usually includes vascular and neuro injury

Meniscus Function

Distributes load

Removal can lead to increase load and lead to OA

Non-contact Meniscus Injury

Rotation of flexed knee of planted foot

Is Medial or Lateral Tear of Meniscus More Common

Medial (3x more)

Bucket Handle Tear

Flap of meniscus can flip over joint space and cause locking/catching

Meniscus Cluster Tests

Locking

Joint Line Tenderness

McMurray’s

Pain with Flexion

Pain with Hyper Extension

Discoid Meniscus

Anatomical variant, May be complete or incomplete, May have lateral compartment pain or loss of ROM, Surgery can reshape

Osteochondritis Dissecans (OCD)

Defect of articular cartilage due to Trauma, Ischemic necrosis, or Genetic Factors

Medial Femoral Condyle, Patella, Lateral Femoral Condyle

Signs/Sx of OCD

Not well localized pain

Variable swelling

Mechanical locking

Knee OA

60+ y/o

Major cause of stair navigation difficulty

2nd to heart disease as cause of work disability in men 50+ y/o

Knee OA Risk Factors

BMI >30, Increased age, Female, Black, Knee Trauma, Physical workload, Bone mineral density

Decreased space, subchondral sclerosis, bone spurs on imaging

Patellar Tendinopathy

Prevalent in Athletes (volleyball, basketball, high and long jumpers)

Palpation of inferior patellar pole has high sensitivity and moderate specificity

Patellar Tendinopathy Risk Factors

Decreased eccentric quad muscle performance

Decreased quad/hamstring flexibility

Increased foot pronation velocity

Excessive training volume

Phases of Patellar Tendinopathy Intervention: Phase 1

Isometrics

Phases of Patellar Tendinopathy Intervention: Phase 2

Slow heavy load

Phases of Patellar Tendinopathy Intervention: Phase 3

Power

Phases of Patellar Tendinopathy Intervention: Phase 4

Sport specific/elastic function

IT Band Syndrome

Short ITB/TFL, Glute and hip lateral rotator weakness, Pain over lateral femoral epicondyle

Common in runners and cyclists

Bursitis

Overuse

Traumatic

Infection: Staph aureus

Pain and Swelling

Fat Embolism

Medical Emergency

Shortness of breath, tachypnea, tachycardia, chest pain

Complication of Fracture

Saphenous Nerve Entrapments

Inpingement of cutaneus branch of femoral nerve at adductor canal

Pain in medial calf and knee

Fibular Nerve Entrapments

Entrapmet at fibular head

Pain in lateral calf

Patellofemoral Pain

Common in young, physically active pts

Females>males

Pain with squatting and jumping

Quad weakness, pes planus

Biomechanical Theories for PFP: Structural Malalignment

How you’re built

Q-angle not associated with PFP

Biomechanical Theories for PFP: Dynamic Malalignment

How you move

Impairment driven: Muscle strength impairment, flexibility issues, Neuromuscular, Etc

Tibiofemoral Alignment’s Contribution to PFP

Tibiofemoral rotation, Genurecurvatu, Tibial Torsion

Lateral Compression’s Contribution to PFP

Increased loading lateraly

“tight joint”

Patellar Instability’s Contribution to PFP

Lateral Subluxation, Increased lateral loading, Increased tension medially

“lose joint”

Chondromalacia

Excessive cartilage degeneration on posterior side of patella

Cartilage is pitted, soft, and fragmented