*4.2.1 Arthroscopic assessment*

A thorough arthroscopic evaluation of the knee joint should be performed. The articular surfaces of the patella and femoral trochlea should be assessed. The extent and type of chondral lesion are determined by probing the articular surface. Large, unstable chondral lesions should be fixed, whereas the small fragments are excised. The superomedial portal is particularly useful in evaluating patellar tracking and patellar tilt [76]. The lateral facet should align with the trochlea by 20 to 25 degrees of knee flexion and the mid-patellar ridge should align with the trochlea by 35 to 40 degrees of knee flexion. Any lateral overhang of the patella should be documented while the patella is engaging the femoral trochlea. Evidence of patellar tilt should be noted.
