Background: The aim of this study was to evaluate the management of patellofemoral instability in flexion, using mainly a Judet quadriceps release, combined with "à la carte" realignment procedures.

Methods: A total of 37 knees operated on between 2011 and 2021 were included in this retrospective study. The mean age at surgery was 2.5, 12.2, and 11.7 years, respectively, for true congenital patellar dislocation (TCPD) (n=7), permanent patellar dislocation (PPD) (n=8), and habitual patellar dislocation in flexion (HPDF) (n=22). An extensive quadriceps release was performed in 36 knees and an additional associated release to the posterolateral structures was performed for the 7 knees with TCPD. "À la carte" surgery was also performed, including combined medial patellofemoral ligament (MPFL) reconstruction (n=25) or vastus medialis oblique (VMO) advancement (n=9), trochleoplasty (n=10), soft tissue (n=27) or bony (n=5) distal procedures on the tibial tuberosity, and femoral shortening and derotational osteotomy (4 knees with TCPD). The main outcomes measured were postoperative complications and recurrent dislocations. Functional outcomes were assessed using the Kujala score, simple knee value, quadriceps strength, and active and passive range of knee motion (ROM).

Results: The mean postoperative follow-up was 6.5 years. Four knees had complications (11%), 2 requiring revision surgeries. Three knees (8%) had recurrent dislocation; the recurrence occurred in flexion due to incomplete quadriceps release (n=2) or in extension (n=1). The mean postoperative full flexion was 144.7 degree. The mean Kujala score and simple knee value were 93% and 87%, respectively. None of the children operated on <7 years old showed complications, recurrent dislocation, or a positive apprehension test (Smilie test), despite surgery being performed in more complex situations, including a higher number of syndromic patients.

Conclusions: In combination with "à la carte" combined procedures, Judet procedure provides a good postoperative function with an excellent knee ROM and quadriceps strength and is associated with a low rate of complication or recurrence of dislocation for the management of patellar dislocation in flexion. Methods: Level III.