This document provides an overview of patellofemoral pain syndrome. It defines the syndrome and discusses relevant anatomy, biomechanics, causes, clinical evaluation, imaging, and treatment options. Regarding treatment, non-operative options including rehabilitation are usually successful for 90% of cases. Surgical techniques are reserved for the remaining 10% and include arthroscopic procedures such as debridement and lateral release as well as bony procedures like tibial tubercle transfer to address malalignment issues.

1. Presenter : Dr. Sushil Paudel

2. Introduction

Common clinical problem

Refers to pain in anterior region of knee

It is a symptom not a diagnosis

Mid 1970’s - Sports medicine

Patellofemoral components are subjected to the
highest loads within the knee

3. Definition

‘A syndrome characterized by dysfunction and pain
expressed in the anterior region of the knee. Signs and
symptoms are variable and multiple tissue sources and
etiologies exist’.

It has been referred as
Patellofemoral pain syndrome / chondromalacia patellae
/ recalcitrant anterior knee pain / patellae femoral stress
syndrome / femoropatellar pain syndrome /
patellofemoral arthralgia or patellagia

4. Patellofemoral Anatomy
Femur

Trochlear groove between
Med and Lat femoral
condyles

Lat wall is more prominent

Abnormalities of groove lateral tracking

5. Patella
 Acts
as a lever arm increase
function
of
quadriceps
 Decrease functional load and
abrasions on the anterior soft
tissues
 Thickest articular cartilage of
any human joint
 Central ridge
◦
◦

Longer
lateral
facet
Superior, interior and middle
Shorter medial facet
‘Odd’ facet - medially nonload bearing except in
extreme flexion

6. Articulation
0°-No contact
20°-Inferior facet - upper
trochlear
groove
45°-Middle facet - mid
portion
of
trochlear
90°-Superior facet - lower
trochlear
articular
cartilage
135°-Lateral medial and odd
facet
Along with
undersurface of
quadriceps

7. Quadriceps and other soft
tissues
 Rectus femoris tendon - superior
pole

Vastus medialis obliqus (VMO)
◦
◦



patella
Vastus lateralis
◦
◦
◦

Superomedial border
Primary stabilizer of
medially against VL
Superolateral border
Lateral retinaculum
Lateral patellofemoral lig
Medial PF lig is weaker than lat
Medial and lateral retinaculum
Iliotibial band

8. Biomechanics






Often termed ‘Extensor mechanism’
Resultant force of both quadriceps and
patellar tendon vectors - ‘Patellofemoral
joint reaction force’ (PFJR) force
Directly related to quadriceps force
generation (M1M2)
Increase as the angle of flexion
increases
Load decrease - straight leg raising and
swimming
Increase in - Flexion activities like climbing up and down stains, squatting,
jumping, running and tennis, soccer etc.

9. Quadriceps ‘Q’ angle

‘Angle
between
line
of
application of quadriceps force
and direction of patellar tendon
in coronal plane’

Normal
◦
Males 10 - 12°
◦
Females 15 - 18°
- Greater pelvic width
- Short femoral length

Normally
has
a
patellofemoral vector
valgus

Greatest at full extension External rotation of tibia

10. Factors resisting the
normal lateral vector
of patella

Deeper PF trochlea

Large
lateral
condyle

VMO - inserted more
distally and horizontally
than VL
femoral

11. Factors
predispose
subluxation
 Deficiency
of
intercondylar sulcus
 Deficiency of VMO
 Increase in ‘Q’ angle
◦
◦
◦
Internal femoral torsion
External tibial torsion
Genu valgum
Patella alta
 Patella baja
 Excessive pronation of
foot
 Tight lateral retinaculum


13. Classification
Insall - based on amount and extent of articular cartilage
damage
 Presence of cartilage damage
◦
◦
◦
◦
◦

Chondromalacia patellae
Osteoarthritis
Direct trauma
Osteochondral fractures
Osteochondritis dissecans
Variable cartilage damage
◦
◦
◦
◦
Subluxation
Dislocation
Tilt
Plicae

14. 
Usually normal cartilage
◦
Patellar tendinitis (Jumper’s Knee)
◦
Traction apophysitis
 Patella - Sinding - Larsen Johansson disease
 Tibial tubercle - osgood - Schlatter disease
◦
Prepatellar bursitis (Housemaid’s knee)
◦
Hoffa’s (infrapatellar fat pad) syndrome
◦
Patellar anomalies
◦
Reflex sympathetic dystrophy
◦
Iliotibial band friction syndrome

15. Other causes

Referred pain from hip
◦
◦

Perthes disease
Slipped capital femoral epiphysis
Tumor
Gaint cell tumour , others

Post operative causes
◦
Interlocking nailing of tibia
◦
Arthroscopic ACL reconstruction
◦
Total knee replacement

16. History

Pain
◦
Dull aching, retro patellar, often bilateral
◦
Aggravate - going up and down stairs, squatting, kneeling and
sitting with knee flexed (Movie Sign or Theatre ache)

Giving way - subluxation and dislocation

Grating sound on movement of patella, flexion and
extension of knee

17. Mechanisms of PF pain
 Overloading
of
the
subchondral bone
 Synovial source
 Retinacular source
Cartilage is aneuric and
cannot be source of pain
It has limited power of repair
or
regenaration
once
fibrillation or ulceration has
occurred

18. Physical Examination
 Contralateral
“Normal” knee
should also be examined
 Patient
standing
limb
alignment G-varum /
Gvalgum, femoral or tibial rotation
◦
“Squinting”
medially
patellae
-
Foot-excess pronation
 Deficient VMO - 30° flexion

point

19. 
Patellar position in sitting
◦

Patella alta
 Grasshopper eye
 Camelback sign
Tracking of patella
◦
Shape of Hockey Stick ‘J’ Sign
Tenderness
 Crepitus
 Q-angle - > 20° abnormal
 Tubercle sulcus angle > 10°
abnormal
 Patellar mobility


20. Tubercle sulcus angle
Apprehension test
Patellar tilt test

21. 
Apprehension sign of Fairbanks

Patellar tilt test - retinacular contracture or laxity

Passive and Active lateral glide test

Generalised laxity of other joints

Examination of hip – tenderness, ROM

Examination spine - Straight leg raising

Ober’s test - Iliotibial band contracture, lateral knee pain

22. ◦ Pt stands facing examiner with one leg
on stool, other on floor
◦ Hold pt for balance only
◦ Pt lifts toes off the floor and shifts
weight to that on stool gradually
◦ He lowers the opp leg to floor trying not
to drop last inches
◦ Requires good control of PF extensor
mechanism
◦ It applies lot of stress on ant
compartment
◦ If pathology –elicits pain andweakness

23. IMAGING
 Anterioposterior view
in full weight bearing on
one leg
 Posteroanterior view
in 45° flexion weight
bearing
view
of
Rosenberg
for
assessment of articular
cartilage loss in posterior
compartment

24.  Lateral
view
◦ Best assessment
of patellar height Patella alta or baja
◦ Black borne - peel
ratio - 1:1 (± 20%)
◦ Insall - salvati ratio
- 1:1 (± 20%)

25.  Axial
view
◦ X-ray
beam
perpendicular to
film
◦ Knee flexed 30°
to 45°
◦ Both
knees
together

26.  Sulcus
angle
◦ Between
condyles
and
sulcus
◦ Mean 138° ± 6°
◦ Correlates with instability

27.  Congruence
angle
◦ Zero reference line bisects sulcus
angle
◦ Mean 6° ± 6°
◦ Measures subluxation

28.  Lateral
angle
patellofemoral
◦ Between intercondylar
and lateral facet
◦ Should open laterally
◦ Tilt with subluxation
line

29. 
Patellofemoral index
◦
◦
M - closest distance between articular ridge
and medial condyle
L - closest distance between lateral facet and
condyle
Indicates - Tilt with subluxation

30. 
Patellar tilt
◦
◦
◦
◦
Angle between transverse plane of patella and a horizontal
line parallel with x-ray table
Normal 5° or less
Tilt can occur without subluxation
Indicates tight lateral retinaculum

31.  Longstanding
lateral
patellar
compression
syndrome
◦ Pain increases on
flexion of knee
◦ Sclerosis of lateral
patellar facet
◦ Trabeculae
perpendicular
to
lateral facet
◦ Lateral
traction

32. 
CT Scan
◦
To evaluate patellar position
and lateral tilt in too obese
patient
◦
CT Scan classification of
malalignment
 Type 1 – lateral subluxation
 Type 2 – lateral subluxation
with tilt
 Type 3 – lateral tilt without
subluxation
 Type 4 – radiographically
normal alignment

33. 
MRI
◦ Suspected tumour
◦ Medial patellofemoral ligament tear
◦ No diagnosis can be established

Bone scan
◦ Reflex sympathetic dystrophy
◦ To document progress during treatment

34. TREATMENT
Non-operative treatment of patellofemoral
pain

Will be successful in about 90% of cases

Rehabilitation program includes
◦
Patient education
◦
Pain modalities
 RICE
 NSAIDS
 Ultrasound
 TENS

Transcutaneous electrical nerve stimulation (Gate theory)

35. ◦
Stretching
 Stretching of tight muscles ITB,
hamstrings,
gastrocnemius and quadriceps
Short arch extensions
 Increasing patellar mobility
 Slow sustained, five times on
each side for 10 secs.
◦
Strengthening
Straight leg raising
 Isometric quadriceps
exercises - VMO
strengthening, cycling
 Hip adductors and abductors
 Never use knee extensors
against resistance
 Mc Connell - closed chain
kinetic exercises and taping of
Isometric quadriceps
Stationary
cycling

36. ◦
Extrinsic support - Bracing
 Patellar strap - patellar
tendinitis
 Patellar brace with full ring
support with lateral buttress
pad - resist lateral vectors
Patellar straps
 Longitudinal arch supports medial correction for pronated
foot
 They effect changes in patellar
tracking
Patellar braces

37. Surgical Techniques
- Needed in 10%
cases
Arthroscopic
patellar
debridement
(shaving)
 Without a leg holder
 Minimal portals
 Conservative - remove
only unstable cartilage

38. Patellofemoral malalignment with or without articular degenaration
Arthroscopic lateral release
 Indication
Tight
lateral
retinaculum, producing symptoms,
not responding to conservative
treatment
 Proximal Superomedial portal
 Coagulate
lateral
superior
geniculate artery
 Avoid injury to lat meniscus
 Release until muscle fibers of
Vastus lateralis
 complication– haemarthrosis,
Residual band, post op scarring
 Medial subluxation

39. Medial
tibial
tubercle
transfer
 Indicated in large ‘Q’ angle
causing symptoms - not
responding to non-operative
treatment
 Combined with arthroscopic
lateral release
 Cut osteotomy and move
proximal
end
medially
correcting ‘Q’ angle
 Avoid overcorrection
 Three screw, bicortical, lag
fixation
 Avoid
injury to anterior
recurrent tibial artery

40. Proximal quadriceps plasty
 Indication
‘Q’ angle is normal or has been
corrected but patella remain subluxated
laterally causing symptom or that
recurrently dislocated
 Used
for moderate alignment
 Release
lower third or half of vastus
lateralis
and
perform
derotation
quadriceps plasty
 Tubulization
of extensor tendon

41. Medial patellofemoral ligament reconstruction

Chronic dislocation of patella

Recurrent dislocation in which ligament is absent or
irrepairable

Use central area of quadriceps tendon

Sutured medial edge of patella

Staple over medial epicondyle of femur

42. Articular degeneration in a normally aligned patellofemoral joint
Anteromedial
tubercle
(fulkerson)
tibial
plasty

Increases the tibial linear
arm of extensor mechanism

Reduces patellofemoral joint
reaction time

Indicated in Gr III or IV
chondromalacia

Anterior transfer is indicated
only when the extensor
mechanism is already well

43. 
Flat ledge on medial side of
tibia

Rotate the tibial tubercle
with bone block medially
and anteriorly with distal
end attached

15-18 mm anterior elevation
can obtained

Three screw bicortical lag
fixation

44. Anteriorization (Maquet)
◦ Bandi and Maquet
◦ Increases the efficiency of
quadriceps
by
increasing the lever arm
◦ Decreases the PF joint reaction
force
◦ Modified Maquet procedure
 Lateral release
 Anterior elevation of at
Least 2cm
 Medialization by appx 1 cm
◦ Notched iliac crest graft
◦ No internal fixation
◦ Complications





Skin necrosis over tubercle
Acute or stress #s
DVT
Arthrofibrosis
Compartment syndrome

45. Patellectomy

Salvage procedure

Best done for comminuted
patellar fracture with a normal
trochlea

Realign the extensor mechanism

Soto-Hall technique - lateral
release and transposition and
repair

Vastus medialis advancement

Can do with anteromedial
transfer of tubercle

46. Total patellofemoral
arthroplasty

Indications
◦ Isolated patellofemoral arthritis
◦ Trochear chondrosis is present

Extensor mechanism should be aligned

Chrome - Cobalt molybdenum trochlear
implant

Modified Mckeever-type prosthesis

Geometry of trochlear implant should be
identical with that of femoral component
from TKR system by same manufacturer

47. Rehabilitation
Post-op - 2 main goals

Regaining quadriceps strengths

Restoring knee flexibility
◦
Extension knee splint (knee immobilizer) for 6 wks
◦
Weight bearing with splint - immediately
◦
Gradual flexion - Active and passive heel slides
◦
Quadriceps exercise - immediately after surgery
◦
Assisted straight leg raising - 3 weeks
◦
Full straight leg raising - 6 weeks

48. Complications

Reflex sympathetic dystrophy

Infrapatellar contraction syndrome

Compartment syndromes

Iatrogenic medial subluxation of patella

Loss of correction

49. plica
◦ Remnants of Synovial
tissue
◦ MC – Infrapatellar
(ligamentus mucosum) no
clinical significance
◦ Next is Suprapatellar –
act as tethering band
◦ Medial plica least
common – produces most
symptom
◦ Incidence 9.1%-50%
◦ Tenderness one finger
breadth prox to distal
pole of patella medially
◦ Treatment – NSAIDS,
stretching, strengthing,
injection, surgical
resection

50. Prepatellar
bursitis
◦ Common in wrestlers
◦ Cause – acute –trauma
(rupture of vessels)
chronic – irritation
(inflammation)
◦ High recurrance rate
◦ Swelling superficial to
patella
◦ High incidence of septic
arthritis (staph aureus)
◦ Surgery – thickened bursal
wall
◦ Treatment – RICE, NSAIDS,
aspiration, cortisone

51. Iliotibial band friction
syndrome
◦ Common in runners, bikers
◦ Symtoms can be at hip, knee or both
◦ Pain at - hip – greater trocanter
- knee – lat femoral condyle
◦ Tight ITB (Obers test) and tight
hamstrings are diagnostic
◦ Asses alignment and treat underlying
cause
◦ Treatment – ICE, NSAIDS, activity
modification, treat malalignment,
flexibility
◦ Surgery – chronic unresponsive
cases ‘window’ in ITB in area of
irritation

52. Fat pad syndrome
◦ Rare problem , not painful in many
◦ Can be acute or chronic
◦ May be related to malalignment
◦ Squat sitting is painful
◦ Tenderness medial andor lateral to patellar
tendon on fat pad
◦ Treatment – NSAIDS, RICE, cortisone
injection, correction of cause, surgical
resection

53. Osgood schlatters
disease
◦ Tibial tuberosity apophysitis – result
of tensile force
◦ Self limiting problem with pain and
enlargement of tibial tuberosity
◦ Incidence with sports -20%,
uninvolved -4.5%
overall
– 12.9%
◦ male:female – 1.5:1 to 4:1
◦ Bilateral in 51% average age of
onset 13 years
◦ Dull ache increases with running and
jumping with local tenderness

54. Osgood schlatters
disease
◦ Etiology - avulsion of portion
of ossification centre
Inflammatory changes sec
to micro avulsion fractures
of tuberosity
◦ X-ray soft tissue swelling
ant to tuberosity
◦ Treatment –ice, NSAIDS,
stretching, strengthing,
activity modification, rarely
immobilize
◦ Complication – tibial
tuberosity # (rare) requres
surgical resection

55. Sinding-LarsenJohansson disease
◦ Similar to Osgood’s disease but
symtoms at inferior pole of
◦
◦
◦
◦
patella (with tenderness)
Age 10-13 years, no ho trauma
Etiology avulsion of periosteum
at inf pole of patella with
ossification or repetitive traction
at patellar tendon attachment
X –ray show irregular calcification
Treatment same as Osgood’s
disease

56. ◦
◦
◦
◦
◦
Patellar tendinitis and quadriceps tendinitis
Blazina referred these as “jumper’s knee”
Usually over 40 years
Difficult to treat, usually present very late
Point tenderness over distal pole of patella
Blazina’s phases
 Phase 1 – pain after activity only, no functional impairment
 Phase 2 – pain during and after activity, still able to perform at a
satisfactory level
 Phase 3 – pain during and after and more prolonged progressively
increases not able to perform satisfactorily
◦ Treatment – controlled activites, medications, excersies

57. Chondromalacia patellae (Runner’s
knee)
◦ Definition: “it is softening or wearing away and
cracking of the articular cartilage under the patella,
resulting in pain and inflammation.”
◦ Acute – direct trauma
◦ Chronic – inflammation , repetitive rubbing
◦ Resultant force – retro patellar compression force
◦ Increase in ‘Q’ angle – malalignment of patella
◦ symptoms-
 Ant knee pain while walking, running, squatting, climbing
stairs
 Recurrent effusion
 Crepitation or grating on flexion and extension of knee

58. Chondromalacia patellae
◦ Clinical signs
Crepitation on passive movement of patella
Pain on compression of patella
‘Q’ angle usually>15°
Tenderness – along borders and underside of
patella
 G . Valgum ,external tibial rotation
 Femoral anteversion combined with external
tibial torsion ( miserable malalignment
syndrome )




◦ X ray




Patella alta
Shallow femoral groove
Shallow patellar angle
Tilting or gliding of patella

59. Chondromalacia patellae
◦ Eisele (1991) grading of cartilage damage
 Grade 1 - articular cartilage only shows softening
or blistering
 Grade 2 - fissures appear in cartilage
 Grade 3 - fibrillation of cartilage occurs, causing
'crabmeat' appearance
 Grade 4 - full cartilage defects are present and
subchondral bone is exposed
◦ Treatment
◦ Conservative





modification of activities
Patellar tapping
Quadriceps strengthing – most important
NSAIDS and rest
Orthotics and braces

60. Chondromalacia patellae

Surgical treatment
◦ Shaving
◦ Drilling
◦ Realignment procedure
 Tightening of the medial capsule
 Lateral releaseMedial shift of tibial tubercle
◦
◦
◦
◦
◦
Chondrectomy
Partialfull patellectomy
Maquet procedure
Patellar prosthesis
Future directions – autologous chondrocyte transplantation for
femoral articular surfaces

61. Conclusion
◦ Common problem in this era of sports medicine
◦ Can be diagnostic and therapeutic challenge
◦ Evalution needs careful history, physical examination and
radiography
◦ No single cause or successful solution has been identified
◦ Conservative treatment is the cornerstone in
management
(90%)
◦ Surgery in minority cases (10%)
◦ Currently arthroscopic procedures