Patelllofemoral pain syndrome
Patellofemoral pain syndrome refers to retropatellar or peripatellar pain resulting from
physical and biomechanical changes in the patellofemoral joint. It is aggravated during knee
loading activities such as squats, stair climbing, and running.
Chondromalacia patellae: condition which involves degeneration of articular cartilage of
patellofemoral joint.
Static and dynamic stabilizers of the patellofemoral joint
Static stabilizers/passive structures:
Patellar tendon
Superficial and deep lateral retinaculum
Medial patellofemoral ligament, menisco-patellar ligament
Dynamic stabilizers/active structures:
Quadriceps muscle
Resultant pull of the four muscles that constitute the quadriceps and patellar tendon
Q angle
Quadriceps forces
Patella’s mediolateral excursion is controlled by quadriceps muscles, particularly VMO and
vastus lateralis components.
With increasing knee flexion, a greater area of patellar articular surface comes into contact
with femur, and this will increase PFJ load.
Contributing factors for PFPS
• Excessive foot pronation:
• Excessive foot pronation causes a compensatory internal rotation of the tibia or
femur and upsets the patellofemoral mechanism
• Pes planus
• Loss of the medial longitudinal arch of the foot with weight-bearing causes the ankle
to roll medially
• To compensate, femur/tibia rotates internally, increasing valgus and increased stress
on PF mechanism
• Pes cavus
• Compared with a normal foot, a high arched foot provides less cushioning for the leg
when it strikes the ground
• Supination causes lateral rotation of tibia, inward Q angle and lateral tracking
• Increased Q angle and valgus vector
• Femoral neck anteversion
• External tibial torsion
• Wide pelvis in females
• Genu valgum
• Tightness in the fascia lata and the IT band or abnormal attachment of the IT band
• Weakness in the gluteus medius
• Internal rotation of femur
• Poor pelvic control
• The association of internal rotation of the femur with inward looking patellae, external tibial
torsion, pronated foot is known as miserable malalignment syndrome
• Overuse and overload
• Increase in knee flexion will increase PFJ load.
• Repeated weightbearing impact may be a contributing factor, particularly in runners
• Slope, hills and uneven surfaces tend to exacerbate patellofemoral pain
• Prolonged sitting can be painful because of the extra pressure between the patella
and the femur during knee flexion
• Muscular etiologies for PFPS
• Weakness of quadriceps
• Weakness of the medial quadriceps specifically VMO dysplasia
• Tight IT band
• Tight hamstring muscles – place more posterior force on the knee
• Weakness or tightness of hip muscles
• Tight calf muscles – can lead to compensatory foot pronation
• Can increase posterior force on knee
• VMO insufficiency – vital role in dynamic stabilization of the patella against lateral
patellar tracking during initial stages of flexion
Clinical features
• Chief complaint – diffuse pain
• Aggravated by loading activities like running, squatting, prolonged sitting
• History of recurrent crepitus may suggest patellofemoral pain
• Instability occasionally because of the reflex inhibition of the quads, giving away
• Patellar dislocation, spontaneously reducing or reducible on pushing the patella medially or
extending the knee
• Pseudo locking
• May mimic a meniscal tear or a loose body
• Signs – occasionally limp, over pronation of the foot on one or both sides
• On palpation, there may be tenderness under the lateral or medial facet of the patella
• Occasionally effusion
• At about 30 degrees of flexion – palpable click
• Tight lateral retinaculum, lateral patella
• Diminished function of the VMO muscle
Tests
• Clark’s test
• Grind test
• Mc Connel test
• Assessment of Q angle
Mc Connel assessment for patellar position
Medial/lateral glide:
• Distance from midpoint of patella to
o Medial epicondyle
o Lateral epicondyle
• Equidistant – means normal
• Medial distance > 0.5 cm – lateral rotated patella
Medial/lateral tilt:
• Medial and lateral borders should be in same height
• Both borders can be palpated and if height is equal = Normal
• Lower/lateral border = abnormal
Management of PFPS
Acute stage management:
• Reduction of pain and inflammation
• Rest
• Ice
• NSAIDs
• Ultrasound therapy
• LASER
• TENS
PT management of PFPS includes:
• Running modifications
• Water running
• Stimulated running on resistance apparatus
• Stair climbing machines
• Quadriceps exercises
• Isometric quadriceps setting and leg raising
• Isometric or isokinetic concentric knee extension
• Isotonic – eccentric work in leg extension pattern
• Taping – correction of patellar position
• VMO strengthening
• Isometric adductor activity reduce adductor activity isolated VMO activity
VMO activity in positions specific to patient activity
• Coordination and balance training
• Retraining of functional activities (including sports- or work-related)
• Manual therapy – Mulligan mobilization, Mobilization with movement
• Stretching: lateral retinaculum, quadriceps, hamstrings, calf muscles, IT band
• Strengthening the gluteus medius and hip extensors
• Foot orthoses
• For shock absorption, alignment correction, to control pronation, relief of pressure
points
• Mc Connel regimen
• Evaluate static and dynamic alignment
• Establish functional painful and pain free ranges
• Evaluate muscle and soft tissue tightness
• Evaluate patellar position
• Use stretching and taping to correct patellar position
• Teach control of VMO by biofeedback
• Progress by increasing to more difficult functional activities
• Home program
