Orthoteers homepage Advertise on Orthoteers
Orthoteers Junior Orthoteers Orthopaedic Biomechanics Orthopaedic World Literature Society Educational Resources Image Gallery About Orthoteers Orthoteers Members search

Patellofemoral Disorders

Anatomy

Wiberg’s Classification of patella shape:

(Descriptive only and has no correlation to pathological conditions)

Type I

Concave facets, symmetrical and equal in size (10%)

Type II

Medial facet is smaller. Lateral facet is concave (65%)

Type III

Medial is distinctly smaller with marked lateral predominance (25%)

 Patellofemoral kinematics

  • Patella increases the moment arm of the quadriceps thus increasing quad strength by 33-50%

  • The femur articulates only with a portion of the patella in each position of flexion, moving from proximal to distal with increasing flexion

  • Patellofemoral joint reaction force

    • 0.5 times body weight with walking

    • 3.3 times body weight with stairs


CLINICAL

History

  • Determine if complaint is instability or pain

Examination (Also see Torsional Profile Assessment)

  • Standing examination

    • Varus/ valgus alignment

    • Examination of gait

    • Pelvic obliquity and leg length inequality

    • Q-angle

    • Femoral and tibial torsion

    • Miserable malalignment syndrome:

      • internal torsion of the femur, external torsion of the tibia and pronated feet

      • Position of subtalar joint. Pes planus.

  • Sitting examination

    • Grasshopper eyes appearance: high and lateral patellas

    • VMO atrophy

    • Lateral patellar tilt

    • Patellar tracking: pain and crepitation, 'J' sign

    • Position of the tibial tubercle with respect to the midline of the trochlea - Should lie < 20mm lateral to the midline of the femur

  • Supine examination

    • Q angle (Normal M 10° F 15)   

    • Quadriceps mass (VMO atrophy)

    • Hamstring tightness (popliteal angle)

    • Examination for medial plica

    • Tibial torsion

    • Tenderness on quadriceps or patellar tendon insertion, patellar facets, retinaculum tightness hamstrings, or heel cord

    • Crepitation and patellar compression

    • Apprehension test (20-30°flexion)                                           

    • Clarke's Snatch test (pain on contraction of the quadriceps with the patella fixed)

    • Patellar tilt (evaluates tension of the lateral restraint)

    • Patellar glide test (knee flexed 20 to 30°)

      • Decreased: 1 quadrant or less medial glide is indicative of tight lateral restraint

      • increased: subluxable, or dislocatable patella

  • Prone examination

    • Hip motion - femoral neck anteversion (abnormal if IR exceeds ER by more than 30°)

    • Quadriceps tightness - Ely test (especially rectus femoris)

    • Leg-heel alignment (Normal 2-3° of varus)

    • Hindfoot-forefoot alignment: (Normal: long axis of heel 90° perpendicular to transverse axis of forefoot)




This is a preview of the site content. To view the full text for this site, you need to log in.
If you are having problems logging in, please refer to the login help page.


© 2005-2007 Orthoteers.co.uk - last updated by Len Funk on 14 February 2005Medical Merketing and SEO by Blue Medical 
Biomet supporting orthoteersThe British Orthopedic Association supporting OrthoteersOrthoteers is a non-profit educational resource. Click here for more details
Total Knee Replacement
Anterior Cruciate Ligament Injuries
Knee - Osteotomies
Knee Anatomy
Knee Arthrodesis
Knee Ligament - Sectioning Studies
Knee Ligament Injuries
Knee Mechanics
Lateral Meniscus Syndrome:
Medial Meniscus Syndrome
Meniscal Injuries
Meniscal Special Tests
Osteochondritis dissecans
Patellofemoral Disorders
Patello-Femoral Instability
Posterior cruciate ligament injury
Spontaneous Osteonecrosis of the Kn...
Hide Menu