Thursday, February 25, 2010

Thursday, February 18, 2010

Lateral Patella Subluxation, Patella Tilt, Shallow Trochlea Groove and Borderline Patella Alta






MRI criteria for patella alta and baja
Patellar length (PL) and patellar tendon length (TL) were measured .....on sagittal images by a line connecting the superior and inferior patellar poles and the shortest length of the inner margin of the tendon respectively. TL/PL ratio was subsequently calculated
Ratios defined for patella alta and baja were 1.52 and 0.79 respectively in females and 1.32 and 0.74 respectively in males
Skeletal Radiol. 2004 Aug;33(8):445-50. Epub 2004 Jun 24.
http://www.ncbi.nlm.nih.gov/pubmed/15221214


Factors predisposing to Patella Instability:
1. Trochlea dysplasia
2. Patella  alta (TL/PL > 1.3 abnormal)
3. Lateralisation of tibial tuberosity

MR Imaging of Patellar Instability: Injury Patterns and Assessment of Risk Factors
http://radiographics.rsna.org/content/30/4/961.full