Knee Assessment Tools

·       Knee Outcome Survey (KOS)

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

o   MDC 8.4

·       Lower Extremity Functional Scale (LEFS)

o   For any LE Ortho Problem

o   0-80, 80=fully functional

o   MDC 9

·       Knee Injury and OA Outcome Scale (KOOS)

o   Pain, other sx, function in daily living, function in sport and recreation and knee related quality of life

o   0-100, 100=fully functional

·       Tegner Activity Level Scale

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

·       Marx Activity Level Scale

o   0-16 scale

o   High lvl activities such as running, cutting, decelerating, and pivoting

o   Each rated on a 4 point scale

Non-musculoskeletal Conditions That Refer Pain to Knee

·       Benign

o   Tumors

o   PVNS (Pigmented villonodular synovitis)

·       Malignant

o   Osteosarcoma

§  Most common malignant bone tumor

§  Onset 10-25 y/o

§  50% located in femur above the knee

§  Pain, swelling/mass, decreased ROM

o   Chondrosarcoma

§  Second most common malignant tumor in adults

§  Common in long bones

o   Ewigs Sarcoma

§  2^nd most common bone tumor in children

§  Onset 5-16 y/o

Knee Exam

·       Girth Measurements

o   15 cm above knee, 7 cm  above knee, 15 cm below knee

·       Standard other Tests and Measures (ROM, MMT, Muscle length, Tendon stress testing, etc)

Laxity Vs Instability

·       Laxity

o   Movement of tibia relative to the femur in a specific direction (anterior/posterior translation, varus/valgus angulation)

·       Instability

o   Excessive knee joint laxity

o   Structural Instability: Knee joint instability based on testing

o   Functional Instability: Knee joint instability which adversely effects function

§  Knee instability does not allow functional activity

Ligamentous Injury

·       Frequency of Injury

o   MCL> ACL> PCL & LCL

·       MCL Injury

o   >80% are contact injuries

§  Typically direct blow to lateral knee with foot planted (valgus stress)

o   Non-contact

§  Valgus force

§  Rotational force

·       LCL Injury

o   Much less common because shielded on inside of knee

o   MOI: Contact injury with varus force with or without rotation stress to knee

·       SX       

o   Pain location is specific to ligament

o   Sense of instability

o   Increased pain with full knee extension

o   Swelling

o   Lateral leg tingling with LCL injury

o   If positive Valgus stress test in 0 deg, may have multi joint involvement

·       Collateral Ligament Non-Surgical Intervention

o   Phase 1 (week 1)

§  Pain and welling control

§  WBAT with crutches in brace if grade 2 & 3

§  Isometric Quad and Hamstring exercise

o   Phase 2 (weeks 2-3)

§  Progress to FWB without limp

§  Isotonic open and closed chain exercise

§  Stationary cycling, stair climber, swimming

§  Proprioceptive exercise

§  Monitor ROM, pain, swelling

o   Phase 3 (weeks 4-6+)

§  Functional/skill training

§  Full ROM

§  Strength 75-85% contralateral limb

§  Completion of functional progression

§  Use of bracing

§  Time to Return

·       Grade 1: 10 days- 2 weeks

·       Grade 2: 3-8 weeks

·       Grade 3: 8-12 weeks (may require surgery)

§  Good success with conservative treatment of grade 1 and 2 ligamentous injuries 1 year post

·       Collateral Ligament Surgical Tx

o   Indications

§  Avulsion fracture

§  Grade 3 tears with functional instability

§  Combined ligament injury

·       ACL

o   Highest incidence

§  15-25 y/o

§  Pivot sport athletes

o   70% non-contact

§  Rotation of trunk over fixed foot

§  Deceleration with knee hyperextension

o   Contact

§  Valgus/Varus force

§  Hyperextension force

o   Risk Factors

§  Increased BMI

§  Narrow femoral notch

§  Hyperlaxity

§  Female athletes greater risk than male athletes

·       Greater knee valgus

·       Tend to be quad dominant

·       Slower muscle activation

·       Jump mechanics

o   Terrible Triad

§  ACL/MCL/Meniscus

o   Surgical Indication

§  Desire to return to ACL demand activities

§  Multiple structures injured

o   Non-surgical

§  Little exposure to high risk activities

§  >40 y/o

§  Prolonged ACL deficiency with no functional instability

o   Graft Ligamentization

§  Phase 1: Incorporation (first 3 weeks)

·       Inflammatory response, graft degenerates, fibroblasts die

·       Remaining tissue is scaffold

§  Phase 2: Revascularization (week 3-16ish)

·       Ingrowth of capillaries from synovium

·       Migration of host fibroblasts into the graft tissue

§  Phase 3: Graft healing & maturation

·       Graft strength and stiffness drops very low, but improves after time

·       Increase in collagen content and realignment

o   Priority Rehab

§  Decrease pain and swelling

§  Restore extension ROM ASAP

§  Restore quad recruitment ASAP

·       PCL

o   Resist posterior translation of tibia

o   Isolated PCL injury is Less common

o   Combined injury is More common

o   Tends to be disability rather than instability

o   Godfry’s test/Sag sign

o   Non-sugical Intervention

§  Phase 1 (weeks 1-3)

·       Pain/swelling control

·       Ambulation

o   Week 1: WBAT with crutches and brace

o   Week 2: Progress to FWB

·       Mobility exercise (0-60 deg)

·       Strengthening

o   Isometric quad exercise (week 1)

o   Mini-squats (0-45 deg week 2-3)

§  Phase 2 (weeks 3-6)

·       Stationary cycling, stair climber

·       ROM to tolerance

·       Leg press (0-60)

·       Step-ups

·       Calf raise

·       Proprioceptive exercise

·       Monitor ROM, pain, swelling

§  Phase 3 (weeks 6-12)

·       Running program

·       Continue strengthening

·       Functional progression to sport

·       Criteria for return

o   Full ROM

o   Strength 75-85% contralateral limb

o   Completion of full progression

o   Possible bracing

o   Surgical Intervention

§  If avulsion fracture

·       Combined Ligament Injury

o   MCL-ACL (AMRI)

o   PCL-LCL (PLRI)

·       Knee Dislocation

o   High Trauma

o   Usually includes vascular and neuro injury

o   Medical Emergency

o   Requires surgical intervention

·       Meniscal Injury

o   Meniscus distributes load

§  Any removel/menisectomy can lead to increase load on the joint potentially leading to OA

o   Usually non-contact

§  Rotation of flexed knee n planted foot

§  May be combined with ligament injury in contact injury

o   Can be degenerative tears in older adults

o   Medial tears 3x as common as lateral tears

o   Red/pink/white zones indicate vascularity/how easy to heal

o   Bucket handle tear

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

o   Tests and Measures

§  May have flexed knee pattern

§  May have loss of full extension

§  Usually pain increases with flexion past 90

§  Cluster Tests

·       Locking

·       Joint line tenderness

·       Mcmurray’s

·       Pain with flexion

·       Pain with hyper extension

o   Discoid Meniscus

§  Anatomical variant

§  May be complete or incomplete

§  May result in lateral compartment pain or loss of ROM in knee

§  Surgery can reshape meniscus

o   Meniscal repair rehab:

§  Usually wb limitations early, most protocols will not allow OKC resisted hamstring exercise 

·       Osteochondritis Dissecans (OCD)

o   Defect of articular cartilage

§  Medial femoral condyle

§  Patella

§  Lateral femoral condyle

o   Eitology

§  Trauma

§  Ischemic necrosis

§  Genetic factors

o   Signs/Sx

§  Not well localized pain

§  Variable swelling

§  Mechanical locking            

o   Intervention

§  Is stable fragment: conservative

·       Protected WB

·       Activity modification

§  If unstable: surgery

·       Microfracture

·       Osteochondral graft

·       Autologus chondrocyte implantation

o   For both grafts/implantation=fibrocartilage, which is not as absorbent as hyaline cart, which was original

·       Knee OA

o   Adults over 60

o   Major cause of stair navigation difficulty

o   2^nd to heart disease as cause of work disability in men >50

o   Risk factors

§  BMI >30

§  Increased age

§  Female

§  Black

§  Knee trauma

§  Physical workload

§  Bone mineral density

o   Not risk factors

§  ADLs

§  Running

§  Marathon training

§  Walking/jogging

o   OA History/Presentation

§  Age >38

§  Knee pain for most days in prior month

§  Joint crepitation

§  Morning stiffness

§  Enlarged Knee

§  Knee extensor weakness

§  Hip muscle weakness

§  Imaging shows decreased space, subchondral sclerosis, bone spurs

·       Patellar Tendinopathy

o   Prevalent in athletic poulations

§  “common” in basketball and volleyball athletes, high and long jumpers

§  1/3 athletes unable to perform for 3+months due to pain/sx

§  Risk factors

·       Decreased eccentric quad muscle performance

·       Decreased quad/hamstring flexibility

·       Increased foot pronation velocity

·       Excessive training volume

§  Palpation of inferior patellar pole has high sensitivity and moderate specificity

§  Clinical Exam

·       Decline Squat test

o   Tendo pain is positive test

o   Most discriminative test

§  Intervention

·       Eccentric exercise

·       Hamstring and quad muscle stretching

·       Broken into phases:

o   Phase 1: isometrics

o   Phase 2: slow heavy load

o   Phase 3: power

o   Phase 4: sport specific/elastic fxn

·       IT Band Syndrome

o   Common in runners and cyclists

§  Sugested to be compression problem

o   History            

§  Gradual onset

§  Lateral knee pain

§  Snapping sensation over lateral knee

o   Presentation

§  Pain over lateral femoral epicondyle

§  Short ITB/TFL

§  Glute and hip lateral rotator wekness

·       Bursitis

o   Overuse syndrome: Repeated kneeling

o   Traumatic: blow to anterior knee

o   Infectious: staph aureus

o   Pain & swelling

·       Fractures

o   Complications

§  Nerve Damage

§  Fat embolism

·       Medical emergency

·       Shortness of breath, tachypnea, tachycardia, chest pain

·       Peripheral Nerve Entrapments

o   Saphenous Nerve

§  Impingement of cutaneus branch of femoral nerve at adductor canal

§  Pain in medial calf and knee

o   Fibular Nerve

§  Entrapment at fibular head

§  Pain in lateral calf

·       Patellofemoral Pain

o   Common in young, physically active pts

o   Females>Males

o   Pain with squatting and jumping

o   Quad weakness

o   Pes Planus

o   Biomechanical Theories

§  Structural Malalignment (how you’re built)

·       Q-angle not associated with PFPS

§  Dynamic Malalignment (how you move)

·       Impairment driven

o   Muscle strength impairment

o   Flexibility issues

o   Neuromuscular

o   Etc

o   Tibiofemoral Alignment

§  Tibiofemoral rotation

§  Genurecurvatum

§  Tibial Torsion

o   Lateral Compression

§  Increased loading lateraly

§  “tight joint”

o   Patellar Instability

§  Lateral subluxation

§  Increased lateral loading

§  Increased tension medially

§  “lose joint”

o   Chondromalacia

§  Excessive cartilage degeneration on posterior side of patella

§  Cartilage is pitted, soft, and fragmented

·       PFP Intervention

o   Non-operative:

§  Education

§  Taping/bracing

§  Foot orthoses

§  Motion and strength improvements

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