Knee- PFPS Flashcards
What are some other terms for patello-femoral pain syndrome?
- PFPS
- anterior knee pain
- retropatellar pain syndrome
What are the patello-femoral GRF with walking?
50% body weight
What are the patello-femoral GRF near 30 degrees of flexion?
= to body weight
What are the patello-femoral GRF during stair climbing?
3x body weight
What are the patello-femoral GRF during squatting?
> 7x body weight
When are the patello-femoral GRF at their peak?
at 90 degrees flexion
What happens with the patello-femoral GRF in those with PFPS?
EVEN GREATER
What is the prevalence of PFPS?
- 37% of military recruits
- 70-90% recurrent and persistent
Why is PFPS so common in military recruits?
- overuse, bending squatting and harder activities with CC knee flexion
What are risk factors for PFPS?
- military recruits
- dynamic NOT static excessive pronation
- Biological females > males
- Patellar and femoral bone shape (FAI?)
Why is PFPS more prevalent in females?
- larger Q angle
- Less hip strength and coordination
Is PFPS usually due to trauma?
NO- rare
What is the typical etiology for PFPS?
Idiopathic (largest % of patients)
What is the theory of PF malalignment and/or maltracking?
- patella glides and tilts more laterally relative to femur
What does the PF malalignment and or maltracking theory involve?
- DECREASED surface area contact between patella and femur
Why could there be DECREASED surface area contact between patella and the femur?
- patellar and femoral bone shape
- excessive femoral IR
- quad weakness, incoordination, and atrophy
- unclear contribution from excessive pronation and tibial IR
What are the pathomechanics of PFPS?
- overload of patellar subchondral bone, especially lateral facet
- tissue ischemia
- loss of tissue homeostasis
- neural ingrowth and increase in substance P nerve fibers that transmit more pain
What are the structures involved with PFPS?
- subchondral bone of patella
- infra patellar fat pad
- bursae
- quad and pat tendons
- synovium
- med and lat retinaculum (holds patella and tendon in positioning)
Where is the infra patellar fat pad located?
- behind the patellar tendon and in front of the capsule
How can the infra patellar fat pad get inflamed?
- with excessive tibial IR and patellar hypermobility
Where can the pain from the infra patellar fat pad refer to?
the groin
Where are the bursae of the knee?
- superficial infrapatellar inbetween skin and patellar tendon
- deep infra patellar between patellar tendon and tibia
What is the onset of PFPS?
more often a gradual onset
Where is the pain with PFPS?
- anteromedial knee pain
- involved structures
** fearful of pain - inhibits VM activity
What increases pain with PFPS?
- stairs, squatting, or kneeling or prolonged sitting
Why can prolonged sitting cause pain with PFPS?
- compression during the knee flexion positioning is the CPP of the PF joint. prolonged sitting holds it there without the best contact under compression causing pain if the patient sits long enough
What can we observe with PFPS?
- increased Q angle
- OC maltracking of patella
- quad atrophy
- impaired LE control
What comes along with impaired LE control with PFPS?
- proprioceptive deficits
- dynamic excessive pronation
What can dynamic excessive pronation lead to?
- possibly tibial IR
- may contribute to greater genu valgus
- possible contributions from impaired DF bc if DF limited = more EV occurs
What makes up pronation? Why is this important for DF with PFPS?
forefoot abduction, eversion, DF
- if impaired DF, abduction and eversion get larger to compensate
What kind of impaired LE control can we observe with PFPS?
- abnormal planar motions, esp in biological females
What are some impaired LE control aspects in the frontal and sagittal plane with PFPS?
- increased hip add
- hip ext and abd weakness
What are some impaired LE control aspects in the transverse plane with pFPS?
- hip ER weakness and incoordination
- mixed conclusions with contributions from rotational impairements
What other muscle groups can contribute with PFPS impaired LE control?
- glut med and max incoordination
- possible contributions from lumbar regional interdependence to hip
What kind of trunk weakness can we observe with PFPS?
- excessive trunk lean or SB
- possible contributions from lumbar regional interdependence or hypermobility/instability
What will we find with ROM for PFPS?
- limited and painful, particularly at end ranges if symptomatic
> flex - greater PF compression
> ext - greater fat pad irritation
What will we find with resisted testing / MMT with PFPS?
- possible pain with extension MMT and weakness
- likely inhibited quad activity, particularly VM
- potential trunk and anti-gravity hip muscle inhibition
What will we find with stress tests for PFPS?
- possible pain with PF compression
What will we find with neuro tests for PFPS??
limited neurodynamic mobility of femoral nerve in 1/3 of patients
What will we find with accessory motion for PFPS?
- varies
- typically, excessive lateral motion and hypo mobile medial motion
- all glides could also be hypermobile
What are some PFPS special tests?
- medial patella plica test
- Hoffa’s sign
- apprehension test
What muscle lengths could be shortened with PFPS?
- Thomas for rectus
- Ober’s for TFL/IT band
- SLR for hamstrings
- gastroc
Where would we have TTP with PFPS?
- peri-patellar
Where should the patella be?
inf pole aligned with joint space at 90 degrees
What is a patella that is too superior called?
Patella alta
What is a patella that is too inferior called?
Patella baja
What are some pT RX for PFPS?
- POLICED
- Patellar taping
- Knee orthotic
- J-lat brace
- DOES NOT INTERFERE WITH MUSCLE ACTIVITY
What direction can we tape the patella with PFPS most often?
- most often medial
What direction can we tape the patella with PFPS to unload the fat pad?
- inferior
What does taping do for the patella with PFPS?
- improves positioning for better surface contact
- effective for pain, kinematics, and function
- proprioception benefits
What kind of patients is patella taping less effective in?
higher BMI and smaller Q angle
What is patellar taping not as effective as for PFPS?
exercise
What kind of knee orthotic can be useful with pFPS?
- neoprene sleeve with hole
Why can knee orthotics help with PFPS?
- increased surface contact between patella and femur, some 30-40%
- may help with function when added to exercise
- proprioception benefits
- self reported benefits
What is a benefit of foot orthotics for PFPS?
- effective immediately
- effective in short and mid term
What does a foot orthotic for PFPS NOT do?
- no difference at a year
How does a foot orthotic work for PFPS?
- exact mechanism unclear, but likely improving LE control
What should we know about prefabricated vs custom orthotics?
- prefabricated as effective as custom if right fit
What are some predictors of success prior to orthotics?
- lower initial symptoms
- impaired DF (remember how impaired DF may lead to excessive EV or pronation)
- greater mid-foot mobility
- less supportive shoes
What should we know about dry needling for PFPS?
NOT effective
What should we know about STM and JM for PFPS?
- clinically important difference in pain in short term
- improvements but less for function
- better when added to exercise
What should we know about MET for the Quads for PFPS?
- best evidence of treatment effect with quad exercise
What should we know about quad force and PF symptoms for PFPS?
- direct relationship as the knee extends with non-WBing
- indirect relationship as the knee extends with WBing
What should we avoid when doing quad exercises with PFPS during early stages?
- last 45 degrees in open chain and more than 45 degrees flexion in closed chain with early met
Why do we want to avoid certain ranges with quad extension / flexion with early PFPS?
- decreased contact of PF joint at some level
- less contact with more quad activation
Why do we also want to add hip exercises when treating PFPS?
- may allow an earlier dissipation of pain than exercises just focused on the quads, esp the addition of ERs and ABDs and extensors
Why can adding hip exercise lead to earlier benefits with PFPS?
improved neuromuscular control
What can hip exercise lead to with PFPS?
better strength, LE kinematics and functional progress
- LONG TERM benefits
What should we know about combined treatments with PFPS?
- quad stretching and strengthening resulted in more improvements than taping
- best progress occurs when combined with MET
What should we know about planes with LE control to improve pain and function?
- frontal plane change is more influential than transverse plane (mod evidence)
What should we know about verbal feedback with LE control to improve pain and function?
- cued to “run softly” led to less rear foot initial contact
- cueing to NOT let your knee fall in helped mechanics
What should we know about verbal and visual feedback with LE control to improve pain and function?
- contract glutes and keep knee facing straight ahead
- visual of hip angle with mirror
- also helped hip mechanics
What should we know about the prognosis with PFPS?
- 80% of individuals who completed a rehabilitation program for PFPS still reported pain
- 74% had reduced their physical activity at a 5-year follow up
- NOT good and actually BAD
How can PFPS lead to OA?
age related joint changes
How is the prognosis WORSE with PFPS?
- higher initial pain levels, longer duration of pain and lower function
What is a lateral reticular release?
- arthroscopic procedure
- longitudinal incision of lateral retinaculum
- designed to “free up” or release tight lateral structures and to allow the patella better anatomic alignment
When should a lateral reticular release be used?
- in RARE instances and 10% of unsuccessful PT cases that have hyper pressure of lateral facet without instability
What will a lateral release lead to if used on the wrong patient or wrong tissue is cut?
- medial instability
What is an extensor mechanism re-alignment with PFPS?
- repositioning of insertion site
- open procedure so longer rehab with long term extensor lag problems