Algorithmic treatment of obligatory lateral dislocation in flexion in a skeletally immature patient. Case presentation including radiographs and MRI demonstrate a patient with obligatory dislocation in flexion and severe trochlear dysplasia. The vastus lateralis lengthening consists of first identifying the vastus lateralis tendon, then releasing it from the patella and quad tendon. The released tendon end is then subsequently attached proximally to the quadriceps. Following the vastus lateralis release, patellofemoral stability is assessed. In this case, there was persistent instability and thus the decision was made to proceed with a quadriceps Z-lengthening. The quadriceps tendon is lengthened approximately 2-3cm and a multiple interrupted suture repair is performed. At this point, the patella no longer dislocates laterally in flexion. Video copyright and courtesy of Daniel W. Green, MD, MS, FACS.