Knee pain Flashcards
Differential
Osteoarthitis Meniscal Ligamentous RA/inflammatory Referred pain Osteochondritis Bursitis Septic arthritis Anterior knee pain/patellofemoral disorders
History
Age and occupation
Site:
-Generalised->arthritis, effusion, septic
-Localised-> anterior (patelloF, prepatellar/infrapatellar, anterior knee pain), medial/lateral (arthritis, meniscal, collateral), posterior (bakers cyst, bursitis), down back of knee (spine), front of thigh into knee (hip)
Mode of onset
Pain and stiff in morning, improves in the day-> inflammatory arthritis
Nature of pain->stabbing meniscal, deep gnawing of arthritis, pain not affected by activity in AKP
Aggrevating/releiving
-arthritis worse on activity, releived by rest
-patellofemoral worse on walking up/down stairs
-meniscal -ve in deep flexion or when twisting
-crystals intense, any moveM +++
-kneeling worsens prepatellar
Loss of function
Deformity
Associated
PMHx
Drug history->analgesics
Important associated symptoms
Ill health Injury Snap How long to swelling (rapid in ACL) Play on Locking in meniscal tear/loose body Giving way in ligamentous/ACL rupture
What must you always examine with the knee
The hip
Examination
Inspection->deformity, scar, swelling Palpation->joint line tender in meniscal Movement -Loss of extension in locked knee -Fixed flexed in osteoarthritis Special tests
Special tests
Collateral ligament tears are apparent on
abnormal opening up of the joint on the
affected side.
Anterior cruciate ligament laxity is
demonstrated by positive Lachmann’s and
anterior drawer tests.
Posterior cruciate ligament laxity is seen as a sag
of the tibia at 90° and can be misdiagnosed as
an ACL tear when performing the anterior
drawer test (the abnormal forward movement
of the tibia is due to its sagging back in the fi rst
place).
Maltracking of the patella can be seen when
observing the knee bending from fl exion to
extension (so-called J sign).
Patella apprehension will be positive in a
patient with previous dislocation
Investigations
FBC and CRP/ESR in suspected infectious
Xray->confirm RA, show a fracture, be normal
?MRI->confirm meniscal or ligamentous Aspiration: -Straw/yellow->simple effusion, crystal -Green/dirty->septic -Blood->haemarthrosis
?Arthroscopy
Differential for swollen knee
Haemarthrosis Patellar dislocation Meniscus Collateral Most commonly ACL Fracture
Anterior knee pain
Patellar tendinopathy
Patellofemoral
OA
Osteonecrosis
Locking
Meniscal tear
Torn ACL
Dislocation
Loose bodies
Cause of loose bodies
Osteochondritis dissecans (usually lateral side of medial femoral condyle) Retropatellar fragment (e.g. from dislocation of patella) Dislodged osteophyte Osteochondral fracture—post injury Synovial chondromatosis
What is osteochondritis dissecans
small segment of bone begins to separate from its surrounding region due to a lack of blood supply. As a result, the small piece of bone and the cartilage covering it begin to crack and loosen.
Clicking
Normal
Meniscal
Loose bodies
First decade knee pain
Infection
Juvenile chronic arthritis
Second decade of life
Second decade Patellofemoral syndrome Subluxation/dislocation of patella Slipped femoral epiphysis (referred) ‘ Hamstrung’ knee Osteochondritis dissecans Osgood–Schlatter disorder
Anserinus tendonopathy
