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中山醫學大學 物理治療學系
Orthopedic Physical Therapy: Knee
授課教師：王靜怡老師 (正心樓 1311A 室 cywang@csmu.edu.tw)

Outline:
I. Anatomy
II. Biomechanics & Pathomechanics
III. Pathomechanics of common loading conditions
IV. Common knee lesions
1) Ligament injuries
2) Meniscal injuries
3) Patellofemoral disorder
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提醒同學：

遵守智慧財產權之觀念，

使用正版教科書、禁止非法影印。

教科書：
1. Hertling D, Kesseler RM. Management of Common Musculoskeletal Disorders: Physical Therapy
Principles and Methods. Chapter 15. Baltimore: Lippincot Williams & Wilkins.
2. Brotzmam SB, Wilk KF. Clinical Orthopaedic Rehabilitation. Chapter 4 Knee injuries. Mosby Inc.
3. Kisner C & Colby LA. Therapeutic Exercise: Foubdations and Techniques. Chapter 21 The Knee.
F.A. Davis.

本單元教學目標：學習完本章節後，應可：
1. 了解重要解剖地標，並能正確觸診
2. 知道常見疾患及症狀
3. 能正確執行相關的物理治療評估與治療
4. 能正確提供患者及家屬衛教資訊及指導居家運動。
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I. Anatomy
1. Osseous structures
– Femur
– Femur and tibia: a valgus angle about 10 degrees (Fig 15-1)
• Medial condyle extend further distally and longer than the lateral condyle
– Lateral condyle extends farther anteriorly than medial condyle
• helping to prevent lateral dislocation of patella (Fig 15-2)
– Tibia
– Patellar
– articular surface consisted of: a lateral facet, medial facet, odd medial facet

2. Meniscus
– Shape:
– Medial meniscus is large “C” shaped, lateral meniscus is small “O” shaped (內大 C，外小 o)

– Supporting tissues:
– Medial meniscus
• Peripheral attach to: coronary ligament, joint capsule, short capsular fibers of MCL
(Fig 15-6)
– Lateral meniscus
• Peripheral attach to tibia, coronary ligament, capsule, but not to LCL
• more mobile than medial meniscus
• Meniscofemoral ligament
• From posterior aspect of lateral meniscus to medial condyle of femur (runs
along with anterior / posterior sides of PCL) (Fig 15-7)
• Popliteus tendon
• also attach to posterior horn of lateral meniscus
• To assist posterior movement of meniscus during knee flexion
– Anterior: Transverse ligament
• Connect two menisci anteriorly (Fig 15-7)

– Several functions:
• Shock absorber,
• Spreading stress over joint surface & decrease cartilage wear
• Aid in lubrication and nutrition of joint
– Total remove meniscus lead to early degeneration
• (when possible, surgically repair a meniscus, the treatment of choice. In certain cases,
meniscal allograft after total meniscectomy may be indicated)

– Blood supply:
– Highly vascular in cartilage outer 1/3 (red zone), partly vascular and fibrous in middle 1/3
(pink zone); avascular inner 1/3 (white zone)

3. Ligaments
– MCL
• Deep capsular fibers attached to medial meniscus
• Tight: KE, tibia ER / abd (valgus) on femur
– LCL
• Not attach to lateral meniscus
• Popliteus tendon run underneath LCL and b/w it and meniscus
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• Tight: KE, tibia ER / add (varus) on femur
– ACL
• To check: KE (forward movement of tibia on femur), and tibia IR on femur
– PCL
• To check: KF (tibia backward movement on femur), tibia IR on femur
• Popliteus aid PCL to check femur forward slide on tibia when squatting
– Patellofemoral ligament
• Thickening patellar retinaculum
• From adductor tubercle of femur ~ medial aspect of patella
• Femoral attachment often become irritated and tender in PF tracking dysfunction case
– Fibrous capsule
• Receive extensive passive and dynamic reinforcement (Fig 15-8, 9)

4. Static & Dynamic capsular reinforcement

– All above mentioned ligaments
– Tissues reinforce Anterior aspects of joint capsule:
– Superiorly: quads tendon
– Inferiorly: patellar tendon

– Anteromedial (AM) reinforcement:

– Medial patella retinaculum (blend with fibrous capsule) (Fig 7-19B)
– Stabilize PFJ during loaded knee extension

– Anterolateral (AL) reinforcement:

– lateral patella retinaculum (blend with fibrous capsule) (Fig 7-19B)
– Stabilize PFJ during loaded knee extension
– Distal ITB
– against excessive tibial IR on femur

– Tissues reinforce Posteromedial (PM) aspects of joint capsule (Fig 15-8) is important
controlling anteromedial rotatory instability
– MCL,
– Pes anserinus tendon (semitendinosus, gracilis, sartorius) and semimembranosus
tendon (Fig 15-8),
– Prevent abnormal ER, abd, anterior displacement of tibia on femur
– Reinforce MCL, posteromedial capsule, and ACL
– Posterior oblique popliteal ligament (Fig 15-10),

– Tissues reinforce posterolateral (PL) joint capsule

– LCL,
– ITB,
– Biceps femoris,
– Help check: Excessive IR, anterior displacement of tibia on femur
– Reinforce cruciate ligaments, assist LCL (preventing add of tibia on femur)
– Arcuate ligament (Fig 15-10): posterolateral capsule
• Y-shaped, attach distally on fibula and fan over posterior capsule to joint posterior
oblique popliteal ligament
• Posterior aspect attach to popliteal muscle fascia, and posterior horn of lateral
meniscus
– Popliteus,
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– Posterior reinforcement
– Gastrocnemius muscles,
– Popliteus muscle (Fig 15-10)
– Popliteus contraction:
– IR of tibia on femur (unlock knee from screw-home position at
beginning of knee flexion)
– Help to
– check ER of tibia on femur;
– check forward displacement of femur on tibia (tibia backward
displacement on femur)
– pull posterior horn of lateral meniscus posteriorly during KF

5. Bursae, synovia, fat pad

– synovium
– Antero-superiorly
• Superior to patella, beneath quads tendon, form a pouch and insert on distal femur
above condyles
• Supra-patellar pouch
– Antero-inferiorly:
• extend to the back of infra-patellar fat pad (Fig 15-11)
– Medial /lateral:
• Unit centrally to form ligamentum mucosa (infra-patella plica), extend into
intercondylar notch
– Posteriorly
• Into intercondylar notch, to pass in front of cruciate ligaments
• Cruciate ligaments are intra-capsular, but extra-synovial
– Bursa
– Anteriorly
• Suprapatellar pouch
• Pre-patellar bursa (prolonged kneeling, inflamed, “housemaid’s knee”)
• Deep infra-patellar bursa (b/w patellar tendon & tibia)
• Superficial infra-patellar bursa (b/w patellar tendon & skin)
– Posteriorly
• Main bursa (b/w semimembranosus tendon & medial gastrocnemius)
• Communicate with joint, become swollen with articular effusion (Backer’s cyst)
• Also extend b/w gastrocnemius and capsule (or a separate bursa)
• May extend beneath pes anserinus tendon and ITB (or other bursa)
– Infra-patellar fat pad
– b/w patellar tendon & front femoral condyles
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B. Biomechanics & Patho-mechanics

I. Structural alignment

1. Frontal Plane:
 Slight valgus angulation (5~10 degrees) b/w tibia & femur
◆ WB force acting on knee: bisect the joint (Fig 15-14 A)
Alterations:
1.Excessive: Genu valgum (Fig 15-14B)
– WB force: shift to lateral side of knee joint
– Contributing factors:
– ITB tightness, femoral anteversion, abnormal foot pronation
2. Less: Genu varum (Fig 15-14C)
– WB force: medial shift on knee joint
– Contributing factors:
– Femoral retroversion
Such alterations in force distribution may lead to accelerated wear on joint

2. Transverse plane:
(1). (Femoral shaft torsion)
 Femur neck anteversion: neck is directed about 8~15 degrees forward
• as a result of normal femoral shaft internal torsion (Femoral torsion) respect to femur
neck
• With trans-condylar axis of femur in frontal plane, patella faces straight forward
(2). (Tibial torsion)
 Trans-malleolar axis at ankle is rotated outward about 25 (12~18) degrees (Magee p932, Fig 13-
74)
• as a result of tibial shaft external torsion (Tibial torsion)
• Long axis of foot is directed 5~10 degrees outward (toe-out angle)
Alterations:
1. Increased femoral anteversion
• With hip in neutral position: patellae and condyles will face inward (hip IR)
• With patella and condyles face forward: then, hip will be in ER position
– During gait, tends to maintain hip in neutral, thus walk with knee IR, toe-in
foot, abnormal pronation, knee in valgus when knee is semi-flexed (LE IR,
toe-in, pronated foot, knee valgus)
2. Abnormal retroversion of hip
• With hip in neutral position: patella face outward
• With patella and condyles face forward: hip in IR position
– During gait, tends to maintain hip in neutral, thus walk with knee ER, toe-
out foot or supinated, knee in varus position when knee is semi-flexed (LE
ER, toe-out, supinated foot, knee varus)
Compensatory structural tibia rotation (to achieve normal foot placement)
– Increased Femoral anteversion: → hip in neutral →toe-in
• increased tibial external torsion → normal toe-out angle
– abnormal Femoral retroversion: → hip in neutral →toe-out
• internal tibial torsion → normal toe-out angle
Such compensation, seems to enhance valgus-varus deviations

II. Movement
 Biaxial
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• Flexion, extension (around horizontal axis)
• Axial rotation (around vertical axis)

1. Flexion-Extension
Meniscus (move with tibia)
• Anterior horn are somewhat mobile; Posterior horn of menisci are relatively fixed
– As knee extends, anterior aspects of menisci glide forward, as knee flexed,
anterior horn recede (Fig 15-13)
• Flexion > 60 degrees: result in significant changes in AP position of menisci
Pathology:
Capsular tightness
– Accompany progression of chronic joint disease such as DJD or RA

2. Transverse rotation
⚫ (Terminal rotation): Conjunct with knee flexion and extension
• During terminal 15~20 degrees of extension: (Tibial ER on femur) (Screw home
mechanism)
• During initial 15~20 degrees of flexion: (Tibial IR on femur)
⚫ (Axial rotation): Can be actively and passively produced with knee flexed
Meniscus
• tend to move with femur (much movement occurs b/w menisci and tibia)
Pathology:
Rotatory dysfunction
– Full KE is possible in absence of normal tibial ER, at expenses of increased articular tissues
deformation
• Abnormal stresses to medial joint surfaces
• Increase tensile stress to cruciate ligaments (pull tight when knee in extension and
tibial IR)
– Consequences
• Progressive DJD
• Fatigue disruption and fraying ACL
– Test (Helfet):
• Comparing femoro-tibial rotatory alignment in semi-flexed and fully extended
position
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B. Patho-mechanics of common loading conditions

Trauma
• Knee injuries are commonly traumatic origin
– Tibia, femur long lever arm

Valgus-External rotation
• Knee in semi-flexed position, tibial rotate laterally (ER), Lateral side of knee sustain traumatic valgus
stresses
– Most common in contact sports (football), skiing
– Joint loading accentuated by foot fixed on ground or by force act over long lever arm
• Valgus and ER are checked by
– First: Deep capsular fibers of MCL,
– Then: Long superficial fibers of MCL, PM capsule,
– Finally: ACL, medial meniscus (terrible triad)

Hyperextension
• Quite common; In violent contact sports and skiers
• Tearing
– First: posterior capsule
– Then ACL
– Finally PCL

Anteroposterior displacement
• Less common than previous two
• “dashboard” injury is most common
– Tibia is forced posteriorly on femur, stressing PCL to rupture

Rotation
• Forced ER of tibia on femur:
– stress collateral ligaments, PM capsule
– Occurred in conjunction with valgus stress, affect medial stabilizing structures
• Forced IR of tibia on femur
– Checked by cruciate ligaments
– isolated ACL injury (primary mechanism)
• Forced rotation injury the menisci
– Medial meniscus less mobile, more frequently injured
– Twist suddenly on WB leg; Rotation of fully flexed knee (i.e., wrestling)
• Most traumatic meniscus tear, affect posterior segment of meniscus
• Tear in longitudinal direction
• Successive injury can cause tear to extend anterior and to form “bucket-handle
tear”
• To block full KE, knee is locked
• full KE can occur only at expense of further damage to meniscus or
excessive stretching of ACL
ACL
– the most common contact mechanism: a large valgus moment (terrible or unholy triad)
• the most common non-contact mechanism: rotational mechanism (a running or jumping
athlete who suddenly decelerates and changes direction (eg, cutting) or pivots or lands in
a way that involves rotation and/or lateral bending (ie, valgus stress) of the knee)
nd
– the 2 most common mechanism: forceful hyperextension of knee
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• prolonged ambulation on a knee with ACL deficit: quadriceps avoidance gait (afraid to
use quads, thus decrease knee flexion moment during gait, loading phase)

PCL
– forceful trauma to anterior tibia while knee is flexed
• the most common: “dash-board” (anterior injury mechanism)
• the 2nd : fall on flexed knee with foot PF
• 3rd : sudden, violent hyper-flexion of knee joint

C. Common Knee Lesions

I. Ligamentous injuries (MCL, LCL, ACL, PCL)

History
• Traumatic event (determine the exact mechanism of injury)
– Valgus-ER: (Football player): Knee slight flexed, foot planted, struck while trying to turn or
cut away
• Knee sustained a valgus stress, tibia ER and anterior movement on femur,
• Medial capsule tear, MCL, then ACL, medial meniscus (terrible triad)
– IR: force tibia to IR (IR strain is primary cause of isolated ACL lesions)
• ACL rupture
– Dashboard injury: Force tibia backward on femur
• Stress PCL
– Hyperextension: Force knee into hyperextension
• Posterior capsule tear, then ACL, finally PCL
– Force against anterior thigh, drive femur backward on tibia,
• ACL tear

• Continue of activity
– Partial ligament tear
• Less likely to continue (due to persisting pain)
– Complete MCL tear (Severe ligament injury)
• can continue activities, no pain, no effusion

• Joint effusion
– Painful effusion within a few minutes after injury
• Hemarthrosis is highly likely
• Intra-articular fracture must be rule out
– Slower development of effusion, several hours after injury
• Synovial effusion secondary to capsule irritation
• Common with mild, moderate ligamentous injuries

• Site of pain
– Point to localized area (site of tear)
• Except
• isolate ACL tear (More generalized discomfort)
• Effusion, especially hemarthrosis
• Entire knee area to be painful
• Less able to localize site of injury
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• Severe injury (several structures involved)
• Less able to localize site of pain
• Generalized pain
– Knee is largely innervated by L3, also from L2, L4
• Chronic degenerative problems will cause refer pain

• Nature of pain and disability

– In absent of significant effusion,
• pain is continuous, deep, fairly localized pain
• Increased by movement tend to further stress the ligament (partial tear)
– When considerable effusion exist
• More intense, aching, throbbing pain
• Aggravated by weight bearing, any movement
• Hemarthrosis is more painful than synovial effusion
– Moderately severe tear or complete tear
• Pain will largely subside; Walk quite comfortably
• Cannot perform some particular activity such as running, jumping, cutting, down
stairs, squatting without having knee give way, activities tend to move knee into
directions that stretches or ruptured ligament
1. Inability to turn quickly: MCL or LCL
2. Inability to run forward: ACL
3. Inability to descend stairs easily, squat, or run backward: PCL or posterior
capsule
• Isolated cruciate tears may cause little or no disability if quads function is good

PE
Acute stage: Once joint effusion, considerable pain, muscle guarding
– Difficult for assessment
– Immediate, on-site examination before onset of effusion is important

• Acute lesion with effusion

– Observation
• Hobble, may be on crutches, knee slightly flexed with only toe-touch WB
• Shoe, sock, trousers are removed with difficulty

– Inspection
• Joint effusion (suprapatellar region: girth measure)
• Stand with leg semi-flexed (often unable to place heel on floor)
• Some redness of skin over knee, shiny

– STTT
• Active movement
– WB (standing): flexion, extension is impossible
– NWB (Supine): limited in capsule pattern because joint effusion
– Pain at extremes of both motions
• Passive movement
– Flexion, extension is limited in capsular pattern, no crepitus,
– Passive overpressure: muscle spasm (boggy, empty) end feel
• Resisted movements
– Strong, painless
• Passive joint-play
– Hypermobile (depends on severity of joint effusion, muscle spasm), painful
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– Be aware of possible false-negative results from muscular guarding,
joint effusion

– Palpation
• Localized tenderness at site of tear, may be referred tenderness nearby
• Effusion is confirmed by Tap test (Ballotable patella) or by Fluctuation test (emptying
suprapatellar pouch, while palpate lateral patellar margins)
– Hemarthrosis may accompany cruciate tear, a meniscus extending to
peripheral attachment, severe capsular tear, an intra-articular fracture
• Joint is warm, slightly moist

• Acute lesion without effusion

– Less pain and disability
– Less gait disturbance, walk without aids
– Available ROM is greater
– Careful exam joint play to determine if it’s a minor lesion or very severe injury

– Absent significant effusion does not necessary mean injury is mild

• Complete medial capsule rupture, tearing all or part of MCL,
– Not much joint effusion (because fluid escape through defect)

• Chronic ligament ruptures

– Primary complain
• Functional instability, giving way with particular activities
• May Walk without limp or obvious disability, the only significant findings
(1) Difficulty performing some specific function such as running, turning sharply,
squatting, descending stairs, running backward
(2) Quads atrophy, if joint was swollen or immobilized
(3) Hypermobility on one or more joint-play movements or ligamentous stability tests
(4) Helfet test (+)
Management
• Approaches depend on
– Age, desired activity level, nature of pathology process (severity of injury, acute or chronic)
– Grade I:
• Mild sprain, no gross loss of ligament integrity, no joint play hypermobility
– Grade II:
• Moderate tear, partial loss of integrity, mild joint play instability
– Grade III:
• Severe tear, complete rupture, moderate to marked joint play hypermobility

• Grade I and II sprains

– Should able to return to normal level of activity
– 1st degree sprains
• Prevent pain
nd
– 2 degree sprains
• Protection to allow healing
• Medial lesion: avoid valgus stress
• Lateral lesion: avoid varus stress
• DFM with knee in different degrees of flexion-extension (Box 8-3)

• ACL tear (Grade III sprain)

– Rehabilitation
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• Non-operative rehabilitation
• Control of swelling, pain,
• ROM is limited (90 degrees of flexion ~ 45 degrees of extension) and
protected
• Isometric contraction of hamstring, quads
• Special emphasis place on hamstring exercises,
• Once has 90 degrees of flexion, added isometric IR / ER
exercises, decrease any abnormal tibial rotation
• Minimizing quads activity involve anterior translation of tibia
• Midrange quads work, avoid terminal KE
• ES with maximum contraction to maintain muscle integrity
• Sports involve cutting or rotational stresses, functional knee brace for
permanent use
• Advance phase: ECC exercises, removal of extension stop
• Surgical rehabilitation
• Operative methods
• Extra-articular
• Intra-articular
• Extra-articular reconstruction
• Taking structure lies outside of joint capsule,
• ITB is most commonly used structure
• Long-term results has been disappointed
• Rehabilitation:
• Aggressive,
• Permit an earlier return to functional activities but is not
recommended for high-level patients
• Intra-articular reconstruction
• Placing a structure within knee to replace ACL
• Bone-patellar tendon-bone graft (current state of the art)
• Using human autografts or allografts
• ITB, patellar tendon, combinations of hamstring
tendons (semitendinosus, semitendinosus-gracilis)
• Had strength of ACL: patellar tendon (168%),
semitendinosus (70%), gracilis (49%), quads or patellar
retinaculum (21%)
• Patella tendon, semitendinosus autografts are most
widely used ACL substitute to reconstructed ACL-
deficient knee
• Require a slower, longer rehabilitation process than extra-articular
reconstruction
• Most frequent encountered problem after ACL reconstruction
• Quads weakness, flexion contractures, patellar instability, joint
stiffness
• Accelerated protocol (Kisner & Colby, p814, Table 21.5)
• Immobilization / Bracing
• Immediate motion, full extension,
• 1~4 weeks, Early restore full KE
• 4~6 weeks: 0~90/110
• Bracing (insufficient evidence support)
• Rehabilitation brace: 1~6 weeks, weaning when
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full extension is achieved
• Functional brace: wear during advanced
rehabilitation, high-demand sports or manual
labor
• Weight bearing consideration
• Protective WB: Immediate WB within tolerance with
two crutches,
• By 4 weeks: if WB pain-free, active full KE, sufficient
quads strength to control knee: FWB & without
crutches
• Exercise progression
• Pre-op exercises
• Restore full knee range (especially KE),
• Prevent atrophy and weakness of leg muscles,
• Address hip & ankle muscle strength &
flexibility
• Post-op exercises
• Maximum protection phase (POP 1~4 weeks)
• Goals:
- protect graft
- control pain, swelling
- prevent adhesion, contracture,
weakness, atrophy
- Initiating ambulation with crutches
ROM: 1~2 wks: 0~90 (full passive KE)
3~4 wk: 0~110/125
• Moderate protection phase (POP 4~5 weeks to
10~12 weeks)
• Goals:
- full ROM (0~125/135)
- Improve muscle strength and endurance
- walk in normal pattern without device,
brace
- continue CKC exercise
Avoid KF 60~90 quads
strengthening (could create
excessive anterior tibia translation
to stress graft)
- Initiate OKC exercise
Before 6th weeks (or as long as 12
weeks): Avoid resisted OKC KE
quads strengthening between 45~30
to full extension (could create
excessive anterior tibia translation
to stress graft)
• Minimum protection phase (POP 10~12 weeks
to 6 Months)
• Goals:
- Increase strength, endurance, power,
NM control, agility
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- progressive demanding functional
activities
• Early CKC exercise for strengthening and
neuromuscular control
• Increasing joint compressive forces,
minimizing antero-posterior tibia
translation, less stress on graft, more
balanced b/w CCC, ECC, and isometric
contraction
• PNF strengthening pattern that stress
tibial rotation
• Early controlled WB and CKC
exercises to establish balance and
neuromuscular control (Fig 14-44~46,
Fig 15-63~65)
• Early goal of proprioceptive training is
to achieve symmetrical bipedal gait
• Gait training
• Aquatic therapy program
• Gait training on treadmill in front of a mirror
(provide visual, verbal feedback)
• progressive plyometric program
• Functional exercises
• balance beam walking, vertical jump, single-leg
/ double-leg hopping, shuttle runs (折返跑), rope
skipping

Kisner C, Colby LA. Therapeutic Exercise. Foundations and Techniques. Chapter 21 The Knee.
Table 21.5 (ACL reconstruction: Interventions for accelerated postoperative rehabilitation)
(P812~822)
Box 21.10 (Exercise precautions after ACL reconstruction) (P818)
Box 21.11 (Criteria to return to high-demand activities after ACL reconstruction) (P821)

• PCL tear (grade III sprain)

– Isolated PCL tear is uncommon (Often combined injuries of ACL, MCL, LCL or meniscus)
• Combined injury to PCL and posterolateral corner can be troublesome (flexor
mechanism disorder)
– isolated PCL lesion: Non-operative reach good prognosis
– Surgical reconstruction reach better prognosis than ACL injury (because more generous blood
supply)
– Rehabilitation (follow ACL protocol, with a few exceptions)
• Early motion (KF, tibia posterior displacement) is not recommend: 4~6 weeks of
immobilization to allow bone graft to heal
• 1st 6~8 weeks: avoid isolated hamstring exercises
• Focus on quads exercises, ECC quads exercise can start as soon as tolerable
• CKC exercises emphasized, allow hamstring strengthening but protect against
posterior tibial translation through quads-hamstring force-couple and
compressive forces across the joint
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Kisner C, Colby LA. Therapeutic Exercise. Foundations and Techniques. Chapter 21 The Knee.
Box 21.12 (Suggested criteria for ambulation without crutches after PCL reconstruction) (p823)
Box 21.13 (Exercise precautions after PCL reconstruction) (P823)

UpToDate (Feb 2022)

PRINCIPLES OF REHABILITATION
Rehabilitation, or physical therapy, for knee-related injuries or conditions is performed in a progressive
manner, each stage building on the prior one. Each phase of knee rehabilitation need not occur
independently, but the goal is to move through each phase expeditiously until function is restored.

The early phase of rehabilitation is focused on (1) reducing pain and (2) optimizing functional knee
motion. Once pain is manageable and mobility is restored, attention can (3) turn to improving strength,
proprioception, and neuromuscular coordination. Ultimately, rehabilitation exercises should (4) simulate
the sport-specific or occupation-specific movements and activities that an athlete or worker must
perform.
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II. Meniscal injuries

Clinical background
• Functions of menisci
– Increasing effective contact area b/w femur and tibia,
– Transmit central compressive loads outward to periphery, further decreasing the contact
pressures on articular cartilage
• When knee in full extension: 50% of compressive load pass through menisci
• When knee in 90 degrees of flexion: 85% of load pass through menisci
• Meniscectomy
– Reduce shock absorption capacity of knee by 20%
– Partial meniscectomy has reduced morbidity than total meniscectomy
• 88~95% reported good ~ excellent results
• Degenerative change is in-frequently reported
Meniscal movement
• Mobility
– Lateral meniscus > medial meniscus
– Anterior horn > posterior horn
– Reduced mobility of the medial posterior meniscus
• Increased vulnerability to injury
• Higher rate of tears
• Move with tibia (flexion, extension); with femur (rotation)
• Weight bearing
– Meniscal loading may lead to distraction of radial tears
– ROM (especially increasing rotation and flexion pass 60 degrees) result in significant
changes in antero-posterior position of the menisci
Meniscus lesions
• Classify
– Tear confined to periphery
– Tear involving the body of meniscus
• Tear of Medial meniscus body often accompany medial coronary ligament sprain
• History
– Onset
• Sudden onset
• Twisting on semi-flexed knee (Valgus-ER)
• Knee flexion, forced tibia ER
• Knee flexion / extension, absent of normal tibia rotation
• Knee extension, forced tibia IR
• Hyper-flexed knee during weight bearing,
• Certain occupation (e.g., mining) sport (e.g., wrestler) must move in squatting
position
– Site of pain
• Deep
• Often can point to the spot on the joint line correspond to the site of tear where
coronary ligament sprained
– Giving way,
– Locking
• If longitudinal tear of medial meniscus extends anteriorly past the midpoint of
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meniscus, lateral portion may slip over the dome of medial femoral condyle (bucket
handle)
• Interfere normal knee mechanics, locking the joint, the last 20~30 degrees of
extension is lost
Meniscal healing
• Peripheral blood supply is critical for meniscal healing
– Blood supply is limited to only the outer 6 mm or
about 1/3 of the width of meniscus (Healing potential
of meniscus tear is greatest in this region)
• Pattern of tear also influence the healing of meniscal tear
(Fig. 4-60)
– Longitudinal (vertical) tear > radial tear
– Simple tear > complex tear
– Traumatic tears > degenerative tear
– Acute tear > chronic tear
– Bucket handle meniscal tear, locking the knee (inability to fully straighten) when tear
displaced toward midline

Physical Examination
A. Observation
• Stands with knee held semi-flexed
• Hobble in on crutches with knee held slight flexed
• Touching down only the toe
• Obvious effusion
• Difficult removing shoe, sock, trousers
B. Inspection
• Effusion in supra-patellar region
• Skin slightly red and shiny
C. STTT
• Active movement
– Flexion-extension is impossible
– If effusion is present: capsular pattern
» End feel:
• at extremes of flexion and extension: muscle-guarding end feel
• Considerable loss of extension if knee is locked
• If knee is locked, springy block end feel as knee is
moving into extension
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• Passive movement
– If tear on posterior medial meniscus, KE + ER will elicit a painful click
– If tear on posterior lateral meniscus, KE + IR will elicit painful click
• Resisted isometric movements
– Strong, painless
– Unless a tendon or muscle also injured
• Passive joint play
– Apley’s test
• with compression (meniscus): rotation to opposite side of lesion is
painful
• Distraction (ligaments) with rotation relieve the pain
D. Palpation
• Joint line tenderness
• Effusion
• Joint is warm, skin somewhat moist
• Coronary ligament sprain
A. History
• A twisting injury, some minor swelling and pain over antero-medial knee region
• Usually does not seek medical attention in acute stage
• Acute symptoms subside within few days
B. Objective findings
• Point tenderness over antero-medial joint line
• Pain on
• Tibial ER on femur, not in valgus stress
• Occasionally forced extension hurt,
• Long duration may be minimal quads atrophy
Management for Coronary ligament tear
– Cyriax: the first to recognize this injury
• Very common but mostly undiagnosed
• Resemble a meniscus lesion or coronary ligament sprain
– Persistent intermittent knee pain
• Adherence recurs during healing
– Scarring result in diminished meniscal movement during knee motion (flexion,
extension, rotation)
– Object of Tx
• Restore mobility to this part of meniscus
– US, DFM to lesion site (Box 8-3)
– DFM: 10~15 min massage, 3~4 sessions
• Teach patient to perform
– Quads strengthening
 19
Management
• Acute tear of meniscus body
– Repair (growing trend)
• Immobilization after repair
• If successful, recovery is expected in about 6 months
– Removal (Meniscectomy, partial / total)
• Most injuries still require removal of torn portion (arthroscopy)
– If no surgery planned,
• Treatment is the same for an acute, minor ligamentous sprain
• No WB on a locked knee and a knee cannot fully extended
• Should not force to extend the knee, may hurt ACL or cartilage
Rehabilitation after Meniscal repair (Kisner & Colby, p824~827)
POP management
⚫ The 1st week: Protective bracing (Limit KF to 60)
⚫ The 1st 4weeks: Limit weight-bearing
◼ Peripheral zone repair
◆ Immediate POP (1st 2 weeks): PWB (25~50%), with crutches, brace locked
in full extension
◆ FWB is permitted by POP 4 weeks, if quads control is sufficient
◼ Central zone repair
◆ WB progressed more cautiously
◆ FWB is permitted by POP 6~8 weeks, if quads control is sufficient
⚫ Exercise (Goals)
◼ To discuss with surgeon about POP tx plan
◼ CKC exercise: Should be emphasized
◆ OKC exercise: Generate significant shear and compression force
⚫ Deforming reconstructed cruciate ligaments and healing meniscus,
repairs, allografts
◼ Early phase
◆ using PNF: Manual resistance (either dynamic or static muscle contraction)
◆ on therapy ball (Fig 15-58~61) (less compression load on knee): Parallel to
the floor, in half-kneeling, in supported plantigrade,
⚫ Anatomic planes, then multi-angled and diagonal patterns
⚫ Double leg support, then single leg support (Fig 15-60, 61)
◼ Once full WB restriction lifted, higher levels of FWB CKC exercises can begin
◼ Total meniscectomy, activity modification is required
◼ For athlete, sport-specific agility training is necessary
 20

Maximum protection phase Moderate protection Minimal protection (return

(1~4 weeks) (controlled motion) phase to function) phase
第一個月 (5~12 weeks) (13~16 weeks ~6/9 months)
第二~三個月 第四~六個月
➢ Regain functional ROM ➢ Restore full knee ROM ➢ Prepare resume full
◼ KE: ➢ Improving LE flexibility, level of functional
◆ By 4th week, achieve strength, endurance, activity using normal
full, active KE ➢ Reestablish muscle movement pattern
◼ KF: control and balance ➢ (Pay attention to select
◆ 1st 2 weeks, Maximum ➢ Improve aerobic fitness activities not overstress
KF 60~90 repaired meniscus)
◆ After 4th week, attain KF
120
➢ Prevent patellar restriction
➢ Improve strength / flexibility of
hip / ankle
➢ Restore postural stability
➢ Maintain cardiopulmonary fitness

Kisner C, Colby LA. Therapeutic Exercise. Foundations and Techniques. Chapter 21 The Knee.
Box 21.15 (Factors influencing the progression of rehabilitation after meniscus repair) (P824)
Box 21.16 (Exercise precautions after meniscus repair) (P824)

Rehabilitation after partial meniscectomy

– Goals:
• Early control of pain & swelling
• Immediate weight bearing
• Obtain and maintain a full ROM
 21
• Regain quadriceps strength

– Kisner & Colby (p827~828)

• Immediate after surgery,
– begin muscle setting exercises, SLRs,
– AROM of knee,
» Full KE, KF90 (0~90): by 10th days
– WB as tolerable (taught Pre-OP, initiate immediately after surgery)
» Full WB: by 4~7 days
• POP 3~4 weeks: achieve
– Full, pain-free, active knee ROM,
– Normal gait pattern
• POP 4~6 weeks to 6~8 weeks: Advanced activities initiated
 22
III. Extensor Mechanism Disorders
1. Patellofemoral disorder
2. Quadriceps contusion
3. Patella tendinitis
4. Osgood-Schilatter disease in knee
5. Plica syndrome

Patello-Femoral (PF) disorders

• Patellofemoral joint reaction forces (PFJRFs) increase with flexion of knee (Fig 4-67)
– Level walking: 0.5 times BW
– Stair climbing: 3~4 times BW
– Squatting: 7~8 times BW
• PFPS likely to lead to develop of PF OA later in life

• Patellofemoral pain syndrome (PFPS)

– Anterior knee pain
• One of most common injuries in physically active people (1/4)
• The most common injury in active young women

• Biomechanical consideration
– Above: quads tendon
– Inferiorly: patellar tendon
– Sides: patellar retinaculum

– When knee flexed: patella glide inferiorly on femoral trochlea

– When knee extend: patella glide superiorly & laterally
Lateral patella movement
– Femoral medial condyle extend more distally, knee joint in
slight valgus angulation when standing (Fig 15-1, 15-14A, 15-
30)
– Quads line of pull in line with femur, patellar tendon line of pull in line with long axis of
tibia
1. Angle formed between two lines (ASIS-patella midpoint ~ patella midpoint-
tibial tuberosity): Q angle
2. The lateral vector during loaded KE (Fig 15-30) cause a tendency for patella to
pull laterally (bowstring effect)

• Prevent excessive lateral patellar movement during loaded KE depends on structural and dynamic
mechanisms of patellar stabilization
– Knee in flexion ( Structural factors)
1. Prominent lateral femoral condyle
• Deep patellar groove
2. Angle b/w pull of quads and pull of patellar tendon
• When knee flexed: angle b/w both lines projected onto sagittal plane (Fig 15-
31), result in a PF compressive force, loaded patella against patellar groove,
dis-allowing extraneous movement
 23

– As knee approach extension (depends on dynamic patellar stabilizing factors)

1. VMO (vastus medialis obliques) (Fig 15-32)
• Distal fibers runs almost horizontally to insert on
medial aspect of patella by way of medial
retinaculum
• Prevent excessive lateral movement of patella
during loaded KE

• Etiology
– Each time KE, patella tend to be pulled too far laterally
– Causes
1. Increased Q angle (Fig 15-30) (Alter the orientation of
quadriceps reaction force)
• Increased femoral anteversion
• Increased tibia external torsion
• Increased foot pronation
2. Not sufficient prominent femoral lateral condyle (Fig 15-33)
3. Patella alta (a small, high-riding patella)
• Sit more superior, less time spend in deep portion of patellar groove, not easy
been stabilized
4. Weak VMO
• Disuse atrophy associated with immobilization or after knee injury
• De-conditioning
5. Tightness muscle & fascia:
• IT band, lateral retinaculum (pull patella laterally, prevent medial translation)
• Ankle plantar flexors: pronated foot
• Rectus femoris, hamstring:
6. Fatigued athletes participate strenuous athletics prone to have abnormal lower
extremity mechanics and PFPS symptoms
7. Women with PFPS often possess ipsilateral decreased hip strength
• Weakness of Hip abductors, hip external rotators, trunk lateral flexors
» Increase contra-lateral pelvic drop, greater hip adduction
» Increase tendency of hip add and IR during weight-bearing (Dynamic
knee valgus)
• during jump-landing task
– Dynamic knee valgus (Fig 4-11):
» Foot fixed on ground, knee move inward (hip add, IR), tibia abd and
foot pronate
 24
» A contributor to ACL injury and PF joint dysfunction
» Increase retropatellar stress
• Insufficient utilization of hip extensors during deceleration of body COM

• Functional strength testing for entire LE (supplement static or isometric strength testing)
– Step-down test (Fig 4-65)
• Involved limb stand on edge of step
• Slowly lower opposite foot to floor
• Return to starting position
• Watch for
– hip abductor weakness (uninvolved limb pelvic drop)
– weak Quads and hip muscles (weight-bearing limb into dynamic genu
valgum at low flexion angle)

• Causative factors
Kisner & Colby. Therapeutic Exercise. 7 Eds. Ch. 21: Knee. (p792~4)
➢ Local factors: Structures around the knee (infrapatella fat pad, ligaments, quads tendon,
retinaculum, subchondral bone)
➢ Distal factors: arising from foot
➢ Proximal factors: arising from hip and pelvic region (dynamic valgus)

• Clinical manifestations
– Subjective complains
• Gradual onset of pain
• Pain felt in generalized area over medial aspect of knee and peri-patellar regions
• Aggravated by: activities involving increased PFJ compressive stresses (descending
stairs, sitting with knee bent for long time)

– Objective PE
• Rotatory limb mal-alignment
– Femoral ante-torsion (IR),
» Squinting patella
» Tight ITB
» Poor posterior gluteus medius muscle
– Tibial lateral rotation (ER)
– Knee varus or valgus, with/without tibial torsion
• Patellar mal-alignment
 25
– McConnell: 4 abnormal patellar orientations
» Glide, tilt, rotation (Using patellar poles as landmarks), antero-
posterior position (Fig 15-37)
» Patellar glide
• Patella moves from neutral position
• The distance from center of patella to medial / lateral femoral
condyle (Fig 15-37A)
• Usually showed lateralization of patella (tight lateral
retinaculum)
» Patellar tilt
• Evaluate the position of medial / lateral facets of patella
• Usual shows: more prominent medial facet (Fig 15-37B)
» Patellar rotation
• Inferior pole deviates from resting position (Fig 15-37 C)
• Internal rotation (to medial side)
• External rotation (to lateral side)
» Antero-posterior position
• Assessed during quadriceps contraction
• Normally: inferior pole remain inferior and not tilt above the
plane of superior pole (Fig 15-37D)

• Increased foot pronation

– Normal WB foot, mild amount of pronation

• Abnormal patellar tracking and PF crepitus during WB

– Test of dynamic function (LE WB mechanics during gait)
» Single-leg squats
» Step-downs
– Abnormal patellar tracking can be observe in sitting KF & KE
» Normally, 5~7 cm of longitudinal excursion with KF and KE (as it
enters and exist trochlear groove)
» (J-sign) Any abrupt or sudden movement (abrupt lateral translation, or
semicircular route of patella pivot around lateral trochlear facet) at
10~30 degrees flexion are considered abnormal
• “Grasshopper eye” patella (high & lateral position of patella)
• Soft tissue restrictions
– Lateral retinaculum tightness
– Quads tightness
» Increase PFJ compression
– Hamstrings tightness
» Increase quads demand when KE, increase PFJ forces
– Gastrocnemius tightness
» Walk with slightly knee flexed
– Anterior hip structures flexibility
» Limited hip ext and ER (test of Figure of 4)
• Muscles weakness
– VMO
» Short arc quads (Fig 15-26) observe and palpate for VMO contraction
– Hip abductors and lateral rotators
– Gluteus maximums
 26
• If medial retinaculum is irritated
– Discomfort when patella is passively moved laterally
– Tenderness to deep palpation of the backside of medial patella and to palpation
of adductor tubercle (medial retinaculum attaches)
• Patellar discomfort with provocation tests (Clarke’s sign)
– maintain patellar inferior glide and with Quads isometric contraction, (resisted
quads contraction) with knee at 30~45 degrees of flexion

• PE
– Both LE (knee, hip, ankle & foot) should be examined
• In shorts only, without shoes
• In standing, walking, sitting, lying supine
– Alignment
• Extensor mechanism alignment
• Q angle (standing, sitting)
• Femoral anteversion
• Tibial torsion
• Genu valgum, varum, recurvatum (Fig 4-2)
• Patellar malposition (baja, alta, squinting)
• Pes planus, foot pronation
– Muscles strength
• For symmetry, thigh muscular girth,
• Strength (hip abductor, and others)
– Flexibility
• Ligament laxity (possible patellar subluxation)
– Functional strength testing (step-down test, Fig 4-65)
– Gait pattern
• Clinical tests for PF disorders
1. Standing alignment of extensor mechanism
• Inspect
– Alignment of extensor mechanism
– Pes planus,
– Tibial torsion
– Genu varum, valgum, recurvatum
– Femoral anteversion
– Limb-length discrepancy
– Q angle (Fig 4-69) Normal Q angle for men (10 degrees), for women (15
degrees)

2. Range of motion (Hip, knee, ankle)

• J-sign (Fig 4-73)
– Inverted J path
• In early knee flexion (or terminal knee extension)
– Indicate: possible patellar mal-tracking, patellar instability
• Patellar grind / compression test
– Applies compression force to patella as knee brought through a ROM
– Reproduction of pain with/without crepitus indicates: articular cartilage
damage

3. Patellar glide test

 27
• Used to assess medial / lateral patellar restraints
• In full extension,
– Patella lies above trochlear groove, freely mobile both medially and laterally
a. Lateral glide test
• Assess the integrity of medial restraints
• Lateral translation is measured as % of patellar width (Fig 4-74)
– Normal: translate 25% of patellar width
– Laxity within medial restraint: lateral translations >50%
– Reproduction of symptoms with passive lateral translation of the patella: (+)
lateral apprehension sign, (lateral patella instability)
b. Medial glide test
• Knee in full extension
– Measured in mm
• 6~10 mm: normal
• >10 mm: abnormal
• <6mm: tight lateral restraints, ITB (Excessive lateral patellar
compression syndrome, ELPS)
• Lateral retinacular laxity may result from
– Hypermobile patella
– Medial instability
c. Patellar tilt
• Knee in full extension → to elevate lateral border of patella
– Normal: elevate 0~20 degrees above lateral border
– Tight lateral restraint (retinaculum, ITB, VL): < 0 degree
• Evaluated by patellofemoral angle
– Draw lines along articular surfaces of lateral patella facet and lateral wall of
trochlear groove
• Two lines should roughly parallel
• Divergence of lines: normal
• Convergence of lines: negative angle: abnormal patellar tilt

4a. Flexibility of LE
• Quads (prone),
• Hip flexors
• Hamstring (supine 90-90),
• ITB (Ober test)
• Calf (Gastrocnemius, soleus)

4b. Soft tissue stabilizers of patella

• Medial restrains
– Medial retinaculum
– Medial PF ligament
– VMO (vastus medialis oblique) (most important stabilizer to resist lateral
 28
displacement)
» Its fibers oriented at about 50~55 degrees angle to long axis of femur
(Fig 4-70)
» In cases of instability, VMO is absent or hypoplastic, may insert
proximal to the patella
• Lateral restraints
– Lateral retinaculum
– VL (vastus lateralis)
– ITB
– Tightness or contracture will exert a tethering effect on patella

5. Local palpation
• Soft tissue around knee tenderness
– Medial retinacular structures: injury from patella lateral dislocation
– lateral pain: inflammation in lateral restrains (ITB)
– Joint line tenderness: meniscal tear
– localized point tenderness on site of tendinitis or apophysitis: Quadriceps or
patellar tendon
– Medial patella border tenderness: Snapping or painful plicae

6. Radiographic evaluation
• 3 views of patella (AP, lateral, axial image)
– AP:
» presence of fractures, overall size, shape, and gross alignment of
patella
» Presence or location of any loose bodies or osteochondral defects
– Lateral view: (30 KF)
» Patellofemoral joint space, patella alta / baja, presence of
fragmentation of tibial tubercle or inferior patellar pole
» Presence or location of any loose bodies or osteochondral defects
– Axial image (skyline view) (KF 45 degrees, x-ray beam angled 30 degrees to
axis of femur)
» Patellar tilt, patellar subluxation, anatomy of trochlear groove, depth
and presence of condylar dysplasia
» Sulcus angle (Fig 4-77)
• Abnormal: > 150 degrees (indicate: shallow or dysplastic
groove, predisposition for patellar instability)
» Congruency angle (Fig 4-77)
• Assess patellofemoral subluxation
• Normal: -6 ± 6 degrees
• (+): lateral position of patellar apex relative to apex of trochlea
• Management (Kisner & Colby. Therapeutic Exercise. 7 Eds. Ch. 21: Knee. (p795~8))
1. Initial: conservative
• To reduce activities involving high or prolonged PF compressive loads
– Such as, descending stairs, bend-knee sitting,
• Regain optimal patellar positioning and tracking
– Stretching tight lateral structures
– Correcting patellar orientation
– Improving VMO timing and force
 29
2. Stretching

• Flexibility exercise (Fig 4-68)

– lateral retinaculum,
– IT band,
– Quadriceps flexibility deficit (common in PFPS and in chronic cases)
– Hamstrings (Fig 7-32, Box 8-9)
– Hip flexors
– Calf

Arthroscopic lateral release (Fig 4-66)

– Only effective in:
• positive lateral tile and with failed exhaustive conservative measures
– POP Rehab protocol 4-10
– Never use to treat
• Patellar instability
• Generalized ligamentous laxity and associated patellar hypermobility
– Incorrectly used for patellar instability will result in Common complication
• Medial patellar subluxation
• Worsened instability

3. Strengthening exercises
(1). VMO strengthening
• Current
– Quads strengthening using CKC
» In WB and Emphasize ECC
» Mini squat, wall slide from 0~40 degrees (Fig 14-37), lateral step-up
(Fig 14-41), fitter or slide board exercise, stationary bike, leg press
from 0 to 60 degrees
(2). Pelvic, hip, foot muscle re-education

4. Taping and Bracing

• Reduce pain, improve quads output
• Influence patellar alignment (not sufficient evidence yet)
• To enhance normal tracking
– 3 components of patellar should be assessed before taping
» Glide
• Medial glide mobilization (Fig 15-52B)
• Taping: Place tape from lateral border of patella and pulling it
to just past medial femoral condyle (Fig 15-39)
» Tilt
• Lateral tilt: Positive tilt sign (0 degrees or less) (Fig 15-28A)
• Stretching and soft tissue mobilization (Fig 8-20)
• Taping: tape from midline of patella medially to lift lateral
border and passive stretch lateral structure (Fig 15-40)
» Rotation (Fig 15-37C)
• Longitudinal axis of femur and patella should be in line with
one another
• To correct external rotation: tape from the middle inferior pole
upward (Fig 15-41)
 30
• To correct internal rotation: tape from middle superior pole
downward
5. Neuromuscular control
• Re-establish balance, neuromuscular control (timing & force of VMO), coordination
– Monitor VMO and VL EMG activity
• Functional activities training (Once strength sufficient)
• Balance boards, unstable surfaces useful for proprioceptive training
6. Functional biomechanics
• Shoes or orthoses
• Abnormal pronation

IV. Flexors mechanism disorders

1. Hamstring insertion tendinitis
2. Popliteus muscle strain
3. Gastrocnemius insertional tendinous lesion (Tennis leg)
4. Posterolateral knee injuries & lesion of proximal tibiofibular joint (Fibular collateral ligament
lesion)