11/1 - PFPS Flashcards
what population is PFP most common in
frequent injury in runners
females > males
what injuries is PFP a common complaint of
ACL injury
meniscal injury
what is the most common knee disorder
PFPS
what is the etiology of PFPS
repetitive micro traumas
what are 3 factors that impact the etiology of PFPS
- posture & alignment
- LE biomechanics / motor control
- neuromuscular factors
how can posture and alignment can lead to PFPS
Q angle
foot pronation
what are LE biomechanics/motor control factors that can lead to PFPS
hip IR (hip control)
knee valgus
PFJ stress
what are neuromuscular factors that can lead to PFPS
gluteal strength
quad strength
- importance of prox strength and instability as influences entire lower kinetic chain*
what is the primary function of the patella
facilitate knee ext
how does the patella facilitate knee ext
inc functional lever arm of ext mechanism (aka inc mechanical advantage)
-> inc force of extensor mechanism by as much as 50%
what are pathomechanics at the knee that can lead to PFPS
inc joint stresses & subsequent articular cartilage wear
traumatic vs acquired PFPS
think bilateral in absence of trauma
if cartilage is aneural, why is there pain associated w worn down articular cartilage
get pain if enough cartilage is worn down to get load on the subchondral bone
what are 3 risk factors for PFPS
- excessive foot pronation
- ms imbalances
- dec knee flex angles
top down vs bottom up mechanics
top down: hip influencing knee
bottom up: foot influencing knee
how can excessive foot pronation lead to PFPS
tibial IR -> femoral IR ->inc contact pressure on lat facets of patella
what ms imbalances can lead to PFPS and how
VMO and VL weakness
- dynamic stabilizers of knee
hip ABD & ER weakness
- valgus angle inc lat compressive forces
why can dec knee flexion angles lead to PFPS
dec contact area of patella
how are risk factors of hip IR, hip strength, and femoral inclination angle reflected in PFPS
inc hip IR
- not well controlled by musculature
dec hip strength
- ext, ABD, and overall
inc femoral inclination
- bony predisposition
does every patient w glut weakness develop PFPS
no
- other things besides prox strength
what is “movie goer’s sign”
pain w prolonged sitting
- seen in PFPS
PFPS incidence by gender
female > male
PFPS onset?
insidious, progresses
location of PFPS pain
peripatellar pain
- not really localized
what main ms weakness does PFPS present w
quad
gluts
what are 2 functions that cause PFPS pain
- pain w prolonged sitting
- inc pain w stairs & rising from chair
palpation to r/o meniscal pain
meniscus = very specific pain on palpation along joint line
palpation to r/o patellar tendinopathy
tendinopathy = localized and density changes in tissue
what are the 3 dx criteria for PFPS
- presence of retropatellar or peripatellar pain
- pain reproduced w squatting, stairs, prolonged sitting or PFJ loading activity in flex position
- exclusion of all other conditions that may cause ant knee pain (via palpation)
what are 3 types of assessment tools for PFPS
- patient reported outcome measures
- physical impairments measures
- physical performance measures
what are 5 physical impairment tests for PFPS
patella provocation
patellar mobility
foot position (pronated?)
hip & thigh ms strength
ms length
what are physical performance measures for PFPS
clinical tests that reproduce pain/assess LE movement coordination
- ex: squat, step-down, single leg squats
what are normal Q values
male: 10-15
female: 15-20
what is abnormal Q value
> 20deg
what is the Q angle usually in PFPS and how does this reflect down the chain to call PFPS
inc Q angle (>20deg)
genu valgum
femoral anteversion
tibial torsion
lat tibial tubercle
what is a more important thing to consider about Q angle
how will it change during dynamic activities
- static position doesn’t tell us much
what ms lengths are often shortened in exam findings of PFPS
hamstrings
why is pronation a difficult issue to address in terms of PFPS
pronation is a triplanar movement (encompassing frontal and transverse) and PFPS is a predominantly sagittal plane problem
how did foot mobility present in PFPS
inc mobility
- inc pronation
describe the ratio that is preferred with the poles of patella
superior pole to inferior pole and inferior pole to tibial tub should be 1:1 ratio
patella alta vs baja
alta:
- high
- unstable
- <0.8
baja:
- low
- compressive
- >1.2
why is patella alta more unstable
need to get into inc and deeper position of flexion before patella engaged in trochlea
what are 4 differential dx for PFPS
- tendinitis/tendinosis
- osgood-schlatters dz
- ITB friction syndrome
- meniscal or ligament path
why is tendinitis/tendinosis a relevant differential dx for PFPS and how can you differentiate
both activity induced
palpation is key to differentiate
- PFP = diffuse, less localized
- patellar tendon = uncomfortable, specifically when palpate
what is osgood-schlatters dz and what is the main population you see this in
bony deformity at tibial tub
younger pts w growth plates
what is ITB friction syndrome
snapping as ITB crosses Gerdy’s tub at 30deg flex thought to be crepitus
how does ITB syndrome present and why is it difficult to differentiate from PFPS? How can you try to differentiate?
ant/lat knee pain
challenging bc mechanism predisposing PFP is same that drives ITB syndrome
think ab prox influence
how to differentiate meniscal/ligament path from PFPS
meniscal/ligament - event or MOI
- mechanical sx if meniscus
- special testing - ant/post drawer, varus/valgus testing of ligaments
PFPS is insidious onset
what are 4 rehab interventions for overuse patellar tendinitis
NSAIDs, ionto, ice
restore ROM
restore flexibility
improve strength
why is the rehab process longer in tendinosis vs tendinitis
change in quality of tissue takes longer in tendinosis bc of degenerative change
what are 4 rehab interventions for overuse patellar tendinosis
active warm-up
friction massage
stretch quad
eccentric strengthening
- ie of quads
how does osgood schlatters present on imaging and why is imaging an important component to have
separation
pronounced tibial tub
see amt of separation on XR
what is a common population that is susceptible to osgood schlatters
inc running/jumping activity
adolescents - growth spurt component
- boys > girls
what is the growth spurt component of osgood schlatters dz
bones growing faster than ms can keep up w –> inc tension
what aggravates osgood schlatters sx
more pronounced w inc activity
- activity modification is important
how does osgood schlatters resolve
self limiting as physes begin to close, will feel better
what are the 3 primary functions of the ITB
- stabilize lat hip and knee
- resist hip ADD and knee IR
- fem and tib attachments
why are the fem and tib attachments relevant to ITBS
atypical hip and foot mechanics potential causes of ITBS
what population is ITBS really common in and why
common cause of lat knee pain in runners and cyclists
- lot of sagittal plane activity
what are 2 risk factors in runners and cyclists that can lead to ITBS
- hip ABD weakness
- inc weekly mileage
what are common running proximal mechanics seen in individuals w ITBS? how does this lead to ITBS? what is the suggested goal for treatment considering this
greater hip ADD and knee IR
- dynamic valgus position
inc ITB strain and compression against lat fem condyle
treatment should focus on controlling secondary plane motions
what are distal mechanisms responsible for ITBS (3)
- greater rearfoot inversion angle at heel strike
- greater tibial IR thru stance phase
- overpronation
when do you usually see overuse/overload w/o other impairments in PFPS
inc magnitude and/or frequency of PFJ loading
what ms performance deficits are often seen in PFPS
hip - post-lat (gluts)
quads
what are the 3 main impairments/deficits seen in PFPS
- ms performance deficits
- movement coordination deficits
- mobility impairments
what movement coordination deficits are seen in PFPS and what is an important consideration of their cause
excessive/poorly controlled knee valgus during dynamic tasks
NOT d/t weakness
what mobility impairments are seen PFPS
foot hypermobility
ms length
- HS, quad, GS, lat retinaculum, ITB
what are recommended treatments specific to overuse/overload w/o other impairments leading to PFPS
activity modification
- relative rest in acute phase
- targeted interventions that can be performed w/o inc reactivity
- patellar taping
what are recommended treatments for ms performance deficits seen in PFPS
hip and knee targeted exercise is best
posterolateral hip focus in early stages
- until reactivity is better
what exercise has the greatest VMO activation
quad set
why wouldn’t we want to introduce a ball to squeeze between legs during exercises with PFPS
drives them toward ADD or valgus
- not something we necessarily want to promote
what was found in exercises that were working to target the VMO
no exercise that can preferentially activate vastus med over vastus lat
what was found in the vastus med with pts w ant knee pain
no selective weakness of vastus med in pts w ant knee pain
how should quad strengthening be viewed given what was found of the VMO activation in exercises
try to strengthen quads as one unit w VMO
- not isolating VMO
why has VMO been getting more attention to target it for exercises
tends to be targetted bc irritation and fluid can pool and get swelling there
- contribute to dec ROM, pain around joint, and dec ms activation
why should prox strengthening (at hip) be added to knee strengthening and stretching
improved function
dec pain
how can treatment target movement coordination deficits
quality of movement
- motor control strategies
- feedback strategies (tactile, visual, mirror)
what did concurrent hip and knee strengthening show gains in and what didn’t it show gains in compared to just knee strengthening
gains: dec pain, improve tolerance, improve function
no gains in strength
influencing motor control more than anything
when addressing mobility impairments in PFPS, what should be considered with the treatments
consider kinetic chain
consider cause vs sx
what ms lengths should be stretched in treatment of PFPS and why
rectus fem
ITB
- tension lat retinaculum
hamstrings
- knee flex
- patella engaged in trochlea
gastroc soleus
- compensatory pronation -> can drive valgus
when is manual therapy an appropriate intervention for PFPS
when in combination w strengthenin
what are 5 interventions that aren’t recommended for PFPS
dry needling
manual therapy (in isolation)
PF bracing
biofeedback
modalities
- US, ice, phono, ionto, estim, laser
why was biofeedback used as an intervention in the past and why isn’t it used now for PFPS
used in past when giving feedback on med vs lat quad activation
limited evidence to support this now
when is blood flow restriction (BFR) a viable option for PFPS
if pt can’t tolerate load or has contraindications to load w sx
what is the first priority of treating PFPS and why
immediate pain relief
- to gain pt trust
