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.
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
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
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
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%)
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
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
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
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