<p>CT LEFT KNEE (patellar tracking and dislocation protocol)</p><p>Technique: Non-contrast CT imaging through the knees with rotational measurements.</p><p>FINDINGS:</p><p>Mechanical axis: Genu valgus/varus: TL:PL: 0.9 (normal 1.2) Congruence angle: (average '-' 6 degrees i.e. medial 6 degrees) Lateral patellofemoral angle : (if opens medially indicates patella tilt) Femoro-tibial rotation: Tibial torsion: (greater than 40 associated with maltracking) Femoral torsion: (average anteversion 15-24 degrees with range of 3-48 degrees) T-TT distance: (15-19mm considered borderline, 20 mm or greater associated with instability) Sulcus angle: (normal 138 degrees plus or minus 6) Lateral trochlear inclination: (if less than 11 degrees indicates trochlea dysplasia) Trochlear facet ratio: (should be at least 40% of lateral) Trochlear depth: (3mm or less indicates trochlear dysplasia) Patellar shape: Nipple sign of trochlea dysplasia: Other (OCD, retinaculum): </p><p>Conclusion: </p>