What/Where is the true source of PFP?
What theories do we use for diagnosing PFP and how does literature support the theories?
How can we better treat “PFPS” patients through a more thorough evaluation and the developing classifications of PF disorders?
1. Erik Nason, MS, ATC, LAT, CSCS
RehabWorks, Kennedy Space Center, FL
Xtreme Action Sports Medicine Services, Inc. (Owner)
2. One of the most common musculoskeletal disorders
11% of musculoskeletal complaints in the office setting
are anterior knee pain
Commonly called:
Anterior Knee Pain
Chondromalacia
Derangement of Knee
Patellofemoral Pain Syndrome
Dr. Scott Dye refers to PFPS as
“The Black Hole of Orthopedics”
3. What/Where is the true source of PFP?
What theories do we use for diagnosising PFP and
how does literature support the theories?
How can we better treat “PFPS” patients through a
more thorough evaluation and the developing
classifications of PF disorders?
4. Clear understanding of the underlying
pathophysiology?
Junk Term Diagnosis
Similar to Impingement Syndrome
Anterior knee pain is more of a symptom than dx.
There is no specific protocol for Patellofemoral Pain
Understanding the source of pain and being able to
classify it can produce a more successful outcome in
rehabilitation.
5. Vague responses from patients
Complain of diffuse patellofemoral pain
Hard to pinpoint location of pain during evaluation
Pain behind or around the patella (usually with flexion)
Imaging can help but is not always necessary at first
History
MOI
Usually gradual onset, no specific MOI
6. Is the source of pain.…
Bone
Articular Cartilage
Meniscus
Soft Tissue
Fat Pad
Capsule
Ligamentous
The cause of pain is..
Malalignment
Neurological
Dysfunction
Weight
Biomechanics
Structural
Dynamic/Activity
7. Examined the mapping of pain and sensations of the author’s own
knee without anesthesia.
Measurement of no sensation to severe pain
Severe pain found
Anterior Synovial Tissues
Retinaculum
Fat Pad
Capsule
Moderate to Severe pain found
Insertion points of the cruciate ligaments
Slight to Moderate pain found
Capsule margins
No sensations were detected on patellar articular surface
Even though pt had asymptomatic Grade II and III chondromalacia.
8. Historic research findings-
Fulkerson et al – 1985
He biopsied the lateral
retinaculum and underlying
synovial tissue of
patellofemoral patients during
lateral releases to treat PFPS.
Found enlarged with
moderate lose of
myelinated fibers
compared to asymptomatic
cadaver
Evidence of the source of
pain
Sanchis-Alfonso -1998
Neuromas were found within
the biopsied tissues
Reported a direct relationship
between the severity of pain and
the severity of neural damage in
the lateral retinaculum.
A follow up study showed
increased levels of substance P
within the lateral retinaculum
Increased pain transmission
9. Sameer Dixit, M., Monique Burton, M., & Brandon Mines, M. (2007). Management of patellofemoral pain syndrome.
American Family Physician, 75(2), 195- 202.
10. Suggested theories of the underlying source of PFPS
Chondromalacia
Pathology of Lateral Retinaculum
Peripatellar synovitis
Excessive Lateral Patellar Pressure
VMO Dysplasia
Patella Malalignment
Limited Contractile Tissue Flexibility
11. Chondromalacia
Research has weaken the theory of chondromalacia being
the source of PFPS
Articular cartilage lacks nociceptive output through
substance-P fibers like other articular tissues of the knee
VMO Dysplasia
Current literature has suggested changes in neuromuscular
activity throughout the lower extremity might be associated
with PFPS
Patellar Malalignment
There is little biomechanical evidence that supports the
hypothesis that translation or tilt of the patella alone is
responsible for patella pain
12. Although PFPS may be caused from maltracking of
the patella through the trochlear grove, the cause of
this poor tracking may not be due to a malalignment
(such as a Q-angle) as much as a neuromechacial
failure.
Decreased functional strength
Decreased proprioception skills
Decreased neuromotor skills
Adversely affects the biomechanics of the articular tissues of
the PFJ
13.
14. Go one step further in your evaluation
Stop using “Patellofemoral Pain” as a diagnosis
Separate the symptoms into classifications:
Classification should:
Clearly define diagnostic categories
Aid in the selection of appropriate interventions
Allow the comparison of treatment approaches for a
specific diagnosis.
16. Excessive Lateral Pressure Syndrome (ELPS)
Patella is over-constrained by soft tissue tightness
Usually the lateral retinaculum
Pt will have decreased medial glide
Some soreness medially with more acute cases
Pain with palpation of medial patellofemoral ligaments
Global Patellar Pressure Syndrome (GPPS)
Bilateral tightness surrounding patella
Causing an excessive compression within the trochlea
More common with direct trauma or fractures
17. Chronic patella subluxation
Often associated with shallow trochlea
Medial tissues are scarred over…poor medial sensitivity
Acute patellar dislocation
Possible rupture of medial patellofemoral ligament
Look for medial pain
Recurrent patellar dislocation
What is the common factor
Location of pain
18. Alterations that can impact the forces of the PFJ
Foot and Ankle mechanics
Hip Strength
Leg Length Discrepancy
Flexibility deficiencies
Take thorough Hx.
Any past ankle injuries, any muscular imbalances, etc.
Biomechanical dysfunction can lead to chronic
adaptations over time
For Example: Weak hip ER = Femur to IR = mimic ELPS
19. Articular cartilage lesion (isolated)
Fracture
Fracture/Dislocation
Articular cartilage lesion with associated
malalignment
May need to rule out soft tissue irritation such as fat
pad or tendon injury
20. Suprapatellar plica
Hard to evaluate, but easy to forget
Fat pad syndrome
Highly vascularized and rich nerve fibers
Typical in direct trauma
Medial patellofemoral ligament pain
Result of ELPS
Illiotibial band friction syndrome
Typical in runners, physically active individuals
Bursitis
More acute, direct trauma, repetitive stress
21. Tendinitis
Most commonly patellar tendinitis
Occasionally but rarely quadriceps tendinitis
Apophysitis
Most common is Osgood-Schlatter
Common in the adolescent
Sindig-Larsen-Johansson – inferior patellar pole
22. Use these classifications to identify the sources of pain
Fine tune your evaluation to establish the root cause of
the source of pain
DON’T RUSH THE EVAL.
Evals can last two, three or more visits.
While you’re implementing acute care, the evaluation
window needs to be open to change
Evaluation is also built upon how the patient responds.
Don’t get locked into a PFPS protocol…everyone is
different.
23. Stop using Patellofemoral Pain Syndrome as a
diagnosis.
Evaluate deeper to find the source of pain and the
cause of pain
Place the PF disorder into a classification to better
label the source of pain
Create a more injury specific rehabilitation protocol to
help treat the source of pain and not the general dx
Implement proprioception exercises ASAP to stimulate
and recruit all available neuro elements to strengthen
the neuromotor loop.
During this talk I am not going to give you specific exercises that will guide you towards successful rehabilitation but I want to encourge you to fully examine and understand the source of anterior knee pain and remind you that there is no one specific protocol for all PFPS patients.
The authors state that nerves within the retinaculum may degenerate from the chronic stretching associated with muscular imbalances around the patellofemoral joint and present as a potential source of PF pain.
If you have one protocol for Anterior Knee Pain then you are saying that you can treat all these disorders.
Wouldn’t you treat each one of these differently even though there may be a significant overlap in exercise and modality protocols.
Optimal neuromotor control at the knee demonstrates signaling of neural input from mechanoreceptors at the patellofemoral and tibiofemoral joints to the central nervous system.
The signals are processed and sent to the lower extremity musculature to regulate reflexes and motor control
Failure in this neuromotor loop can cause excessive stress on articular or extra-articular tissues.
Research has shown that the malalignment is not from poor mechanical arrangement but poor timing of muscle firing and from poor neuro control.
To vaguely classify each patient as “patellofemoral pain syndrome” would be doing a disservice to the patient and will likely not result in optimal outcomes. A clear and accurate differential diagnosis is by far the most important aspect of treating the patellofemoral joint