Title: The Patellofemoral Articulation
1Chapter 7
- The Patellofemoral Articulation
2Introduction
- Separated from the knee chapter because of
differences in the mechanisms and onset of injury - Injury is usually due to overuse, congenital
malalignment, or structural insufficiency
3Clinical Anatomy
- Patella is largest sesamoid bone in body
- Anatomical design allows for
- Increased efficiency of quadriceps muscle group
- Protection of anterior portion of knee joint
- Absorption and transmission of patellofemoral
joint reaction forces (forces transmitted through
articular surfaces) - Shape of patella
- Figure 7-1, page 244
4Clinical Anatomy
- Articular surface of patella
- Figure 7-2, page 244
- Patella tracks medially during range of 45o to
18o as knee moves from flexion to extension - During final 18o of extension, patella tracks
laterally - During flexion and extension patella tracks
within femoral trochlear groove (between the 2
femoral condyles lined with articular cartilage)
5Clinical Anatomy
- Articulation of patellofemoral joint
- Table 7-1, page 245
- Compressive forces
- Walking .5 times body weight
- Walking up/down stairs or running hills 3.3
times body weight - Lateral retinaculum
- From vastus lateralis and IT band to lateral
border
6Clinical Anatomy
- Medial retinaculum
- Vastus medialis and adductor magnus to medial
border - Medial and lateral patellofemoral ligaments
- Superior portion on fibrous capsule thickens and
inserts on patellas superior border
7Muscular Anatomy and Related Soft Tissue
- Quadriceps muscles
- Flexion patella is pulled inferiorly by patella
tendons attachment to tibial tuberosity - Extension quadriceps femoris and its tendon
pull patella superiorly - Length of patella is approximately same length as
the long axis of the patella - Figure 7-4, page 245
8Muscular Anatomy and Related Soft Tissue
- Vastus lateralis pulls patella laterally
- Vastus medialis (VMO) guides patella medially
and prevents lateral patellar subluxation - Tight IT band can accentuate the lateral tracking
of patella, resulting in subluxations or patellar
malalignment
9Muscular Anatomy and Related Soft Tissue
- Alignment of foot and normal flexibility of
triceps surae and hamstring muscles are needed
for adequate knee ROM and normal patellofemoral
mechanics - Example increased foot pronation increased
internal tibial rotation rotation of tibial
tuberosity toward midline
10Bursa of the Extensor Mechanism
- Varying numbers of bursa being directly involved
with extensor mechanism - 4 found consistently in population
- Suprapatellar bursa
- Prepatellar bursa
- Subcutaneous infrapatellar bursa
- Deep infrapatellar bursa
- Figure 7-5, page 246
11Clinical Evaluation of the Patellofemoral
Articulation
- Dysfunction of joints superior to or inferior to
knee may manifest themselves as patellofemoral
pain - Patient preparedness
- Clinician preparedness
12History
- Mechanism and onset of injury
- Acute vs. chronic or insidious onset
- Chondromalacia Patella
- Softening and wearing away of patellas hyaline
cartilage grinding - Box 7-1, page 247
- Clarkes sign - Box 7-5, page 253
- When pain occurs
- Location of pain
13History
- Level of activity
- Prior surgery
- Relevant past history
14Inspection
- Patella alignment
- Patellar alignment
- Figure 7-6, page 247
- Patellar malalignment
- Box 7-2, page 248
- Figure 7-7, page 247
- Posture of knee
- Genu varum, valgum, recurvatum
15Inspection
- Q angle
- Relationship between line of pull of quadriceps
and the patellar tendon - Box 7-3, page 250
- Box 7-4, page 251
- Tubercle sulcus angle
- Relationship between tibial tuberosity and
inferior patellar pole - Leg length difference
- Foot posture
- Areas of scars
16Palpation
- Refer to clinical proficiencies
- Utilize pages 249 253
17Range of Motion Testing
- AROM
- Flexion to extension patella glides superiorly
and somewhat laterally - Tightness of lateral structures may accentuate
lateral displacement - Flexion patella glides inferiorly and medially
- RROM
- Pain during movement may indicate malalignment
- Open and closed kinetic chain
18Range of Motion Testing
- Lower extremity flexibility
- Quadriceps, hamstrings, IT band, triceps surae
- Tightness may
- Result in decreased functional ROM
- Force the quadriceps to exert more pressure on
patella - Cause patellar tracking deficits
19Ligamentous Testing
- Evaluate knee ligaments
- Laxity in knee joint can result in abnormal
patellar tracking, secondary to uniplanar or
rotatory shifting of tibia or femur, causing
patellofemoral pain - Ligamentous and capsular stability of patella is
based on presence of patellar tilt and amount of
glide available to patella
20Ligamentous Testing
- Patellar Glide
- Figure 7-9, page 254
- Box 7-6, page 255
- Patellar Tilt
- Box 7-7, page 256
- Synthesis of Findings
- Relationship between patellar glide and tilt
21Neurologic Testing
- Same as described in Chapter 6
22Pathologies and Related Special Tests
- patellofemoral dysfunction and patellofemoral
pain syndrome used to describe wide range of
symptoms - Onset may occur during inactivity (theater knee)
and/or during or after activity - Differentiation between meniscal and patellar
pain - Table 7-2, page 257
- Evaluation Map page 257
23Patellofemoral Pain Syndrome
- All-inclusive diagnosis for pain in and around
the joint that cannot be explained by a specific
pathology - Signs and symptoms
- Insidious onset occasionally caused by trauma
- Primary complaint of anterior knee pain caused by
activity, pain may be constant - Stair climbing, sitting for long periods
- swelling
24Patellofemoral Pain Syndrome
- Signs and symptoms continued
- Pain increased with AROM and RROM
- Surrounding tissues evaluate for tightness and
hyperlaxity by assessing patellar glide and tilt - Assess subtalar joint
- Treatment
- Modify activity, NSAIDs, ice, patellar
mobilization and passive stretching, flexibility
and strength training - Orthotics, patellar taping
25Patellar Maltracking
- Normal tracking depends on relationships between
- Alignment of femur on tibia
- Q angle
- Integrity of soft tissue restraints
- Foot mechanics
- Flexibility of triceps surae, quads, hamstrings,
IT band - Table 7-3, page 258
26Patellar Maltracking
- Predisposing factors
- Congenital dysfunction
- Injury to patella or knee
- Increased body weight
- Gait mechanics
- Gradual onset of symptoms
- Redistribution of forces along patellar facets
- Pain during ADLs
27Patellar Subluxation and Dislocation
- Acute, chronic, or congenital laxity of medial
patellar restraints or abnormal tightness of
lateral retinaculum results in increased lateral
glide of patella - Predisposes patient to subluxation or dislocation
- Subluxations can occur without patient knowing it
- Dislocations shift patella laterally and lock out
of place, obvious deformity and quadriceps spasm - Figure 7-10, page 259
28Patellar Subluxation and Dislocation
- Most apt to dislocate or subluxate within 20 to
30 degrees of knee flexion or after valgus blow
to knee - May result in fractured patella, osteochondral
damage, bone bruises, osteochondritis dissecans - Multiple incidences result in wearing of
articular cartilage
29Patellar Subluxation and Dislocation
- Predisposing factors
- Hypomobile medial glide
- Flattened posterior articulating surface
- External tibial rotation and hyperpronated feet
increase Q angle - Family history
30Patellar Subluxation and Dislocation
- Evaluative Findings
- Table 7-4, page 260
- Apprehension Test
- Box 7-8, page 261
- Radiographic examination
- Rule out MCL sprain
- Treatment
- Conservative vs. surgical
31Patellar Tendinitis
- Insidious onset
- Jumping activities, running sports, weight
lifting - Acute onset
- Blow to tendon
- Repetitive motions on a biomechanically
malaligned extensor mechanism can result in
unequal loads on the extensor mechanism - Microtearing of fibers
32Patellar Tendinitis
- Most common site of pain inferior pole
- Pain at superior pole quadriceps tendinitis
(jumpers knee) - Evaluative Findings
- Table 7-5, page 262
- MRI may be useful
- Conservative vs. surgical treatment
33Patellar Tendon Rupture
- Predisposing factors
- Rheumatoid arthritis, diabetes, lupus, chronic
renal disease, gout - Chronic inflammation of tendon
- Corticosteroid medications
- Tension developed within quadriceps unit
overloads the patellar tendon, resulting in
rupture in midsubstance or avulsion from patella
or patellar tuberosity
34Patellar Tendon Rupture
- Evaluative Findings
- Table 7-6, page 262
- No ligamentous stability tests should be
performed until examined by physician - Treatment
- Immediate immobilization and transport
- Surgical intervention within 7 to 10 days
- Rehabilitation to restore knee function full
return to activity in 12 months
35Patellar Bursitis
- Bursa inflamed secondary to
- Single traumatic blow
- Repeated low-intensity blows
- Overuse
- Infection (redness, warmth, refer to physician)
- Evaluative Findings
- Table 7-7, page 264
- Figure 7-11, page 263
- Treatment modify activity control inflammation
36Synovial Plica
- Fold of the fibrous membrane that projects into
joint cavity - During maturation, folds are absorbed into
capsule however, in majority of population, a
thickened area or crease remains - Remains asymptomatic until area is traumatized
- Most commonly affects medial joint capsule
37Synovial Plica
- When symptomatic, plica loses elastic properties
and alters biomechanics of patellar gliding
mechanism - Evaluative Findings
- Table 7-8, page 264
- Test for medial plica syndrome
- Box 7-9, page 265
- Stutter Test
- Box 7-10, page 266
38Synovial Plica
- Confirmed through MRI
- Treatment
- Modify activity
- Control inflammatory response
- Strengthen VMO to lessen symptoms by reducing
tensile forces placed on plica
39Osgood-Schlatter Disease
- Adolescent inflammatory condition that strikes
the tibial tuberositys growth plate where
patellar tendon attached - Onset due to repeated avulsion fractures of
tendon from its attachment caused by rapid
growth and/or increased quad strength - Results in osteochondritis of tubercle
40Osgood-Schlatter Disease
- Evaluative Findings
- Table 7-9, page 267
- Figure 7-12 page 266
- Conservative treatment by reducing activity,
controlling inflammation - Surgical intervention if conservative treatment
fails
41Sinding-Larsen-Johansson Disease
- Found at attachment of tendon into inferior
patellar pole (or quad tendon at proximal pole) - Caused by stress fracture or avulsion because of
repetitive forces associated with running and
jumping - Affects males more often, ages 10-14 yrs
42Sinding-Larsen-Johansson Disease
- Evaluative Findings
- Table 7-10, page 268
- Treatment
- Rest, immobilization
- Decrease inflammation
- Modalities, NSAIDs
- Stretching and strengthening
- May be symptomatic until maturation
43Patellar Fracture
- Blunt trauma
- May rupture of bursa palpation reveals crepitus
or false joint - Figure 7-13, page 268
- Active knee extension and passive knee flexion
produce severe pain - Resisted knee extension cannot be performed due
to pain
44On-Field Evaluation of Patellofemoral Injuries
- Equipment considerations
- On-field History
- On-field Palpation
- On-field Functional Tests
- Willingness to move the involved limb
- Willingness to bear weight
45Initial Management of On-Field Injuries
- Patellar Tendon Rupture
- Gross deformity, immediate loss of function
- Splint in extension and transport
- Patellar Dislocation
- Obvious deformity
- Reduction should not be attempted spontaneous
reduction may occur - Splint in position if not reduced, in extension
if reduced transport - Figure 7-14, page 270