patellofemoral conditions Flashcards
what is the function of the patella/ ie what does it do?
- increases the** movement arm** of the quadriceps muscle
- bony protection to underlying joint surfaces
- reduces compressive forces on the quads tendon with resisted knee extension
- allows transfer of forces evenly to the underlying bone
what is patellofemoral joint pain?
- diffuse pain at the front or behind or around the knee cap
what is patellofemoral pain aggravated by?
- knee flexion activities eg walking down the stairs
why does it hurt into flexion?
- minimal joint compression in extension
- 20 degree flexion - fontact with inferior patella and femur
- 30-60 degree - middle 1/3 of patella contacts
- 60-90 degrees - superior 1/3 contacts
- by 90 degrees, the entire articular surface has artioculated with the femur
where does patellofemoral OA occur mainly in the PFJ?
- lateral compartment of the PFJ
Describe the epidemiology of PFP
- often gradual onset but can occur after trauma
- female and younger population more common
- up to 50% may still present with pain 1 year after presentation
- can affect sport, physical activity and work related activities
what are examples of causes of PFP?
- biomechanical infleunces
- over or underloading the PFJ
- structural changes to subchondral bone and articular cartilage
- anxiety and depression (its associated with psychological factors)
- altered pain processing which affects function
what are examples of biomechanical deficits associated with PFP?
- quads weakness
- reduced peak flexion going downstairs
- reduced hip abduction and external rotation
- increased hipp add and internal rotation with runing
- muscle tightness
how would the subjective assessment of PFP present ?
- vague, non specific pain around or behind the kneecap
- aggravated by stairs (going down), waling/running, kneeling or squatting
- pain often after a change in activity or load
- patient may also present with patellar crepitus, pain on prolonged sitting
what might you observe in a physical test for PFP?
- minor or no swelling
- may be abnormal gait
- weak and wasted quads
- hip strength may be reduced
- muscle tightness observed with muscle length tests
- pain should improve after the McConnell test
how is PFP related to teenagers?
- 4/10 adolescents may continue to experience knee pain 5 years after initial ondet
- gluteal weakness in older teens not younger
what are examples of exercises that can be prescribed for patients with PFP?
- closed kinetic chain exercise s- ie distal segment (feet) are fixed on object
- quad and glute strengthening
- core and distall strength if they are deficient
what would early rehab for PFP involve?
- open kinetic chain exercises
- supervision
- visual feedback
what is patellar instability?
- dislocation or subluxation of patella
- patella moves out of its groove onto the lateral femoral condyle
- may involve tear of the medial patellafemoral ligament
what are risk factors for patellar instability?
- general hypermobility
- patella alta ( ie high positioned patella)
- patella dysplacia
- increased Q angle (angle between quads and patellar tendon)
is patellar or quadriceps tendon rupture more common?
- quadriceps is 3 times more common than patellar tendon rupture
how is a patellar or quadricep tendon rupture managed?
surgical, non surgical and physio management
- surgical repair is treatment of choice
- donjoy brace for 6-8 weeks and partial weight bearing
- if surgery is not possible, then immobilisation in cast for 6 weeks in full extension
- physio - focus on increasing ROM and strength
what is the plica in the knee?
a fold in the membrane that protects your knee joint
