Dislocation

Diagnosis :

•Ask
•Look : SWEATS, deformity, muscle strength.
•Feel : location, sensation, warmth.
•Move : flex, extend.
•Tests :
i)Lateral & medial collateral ligament.
ii)Drawer test
iii)Patellar tap
iv)Mc Murray

Investigation :

*the ones used in the fracture plus.. these few *


MRI
- extremely sensitive for identifying soft-tissue anomalies of the knee.
- identify injuries occurring secondary to acute patellar dislocation.
- help determine if joint laxity is present in the absence of bony deformities.
- helpful in assessing the extensor mechanism and its relationship to the patellofemoral apparatus.
- is more effective than CT scanning in determining if patellar chondral lesions are present and for determining cartilage thickness and volume. Assessment of patellar cartilage thickness and volume is important to evaluate for osteoarthritis, and it is useful to preoperatively calculate the effect of joint contact and load transmission after surgical procedures.

Ultrasonography
- not typically used in the assessment of patellar injury and dislocation.
-better than CT scanning for distinguishing between cysts, granulation tissue, metaplasia, mucinoid degeneration, and congenial defects of the patellar ligament.
- help determine the cause of anterior knee pain is important.

http://emedicine.medscape.com/article/90068-diagnosis