4in1 Procedure in Treating Congenital Dislocation of Patella in Children.

Objectives: Congenital dislocation of patella (CDP) is a rare condition and surgery is needed to treat CDP once a diagnosis is made. The 4in1 procedure includes lateral release, correction of quadriceps, Roux-Goldthwait procedure, and medial patello-femoral ligament (MPFL) reconstruction. This study was aimed at evaluating the efficacy and outcome of the 4in1 procedure in the operative treatment of CDP.

Methods: CDP patients were retrospectively collected from two operative centers from January 2013 to December 2024. For all patients, patellae on both sides were examined by x-ray, CT, and MR bilaterally. Ten patients (14 patellae) underwent 4in1 procedure. Gradual passive and active exercises of knee motion and quadriceps were begun as tolerated. Kujala Score was collected before and after the operation.

Results: This cohort included 10 patients (4 males, 6 females), with 4 cases of bilateral involvement and 6 unilateral cases (total 14 limbs). The mean age at surgery was 8.36 years (4-14 years), with an average surgical duration of 157.7 min and intraoperative blood loss of 35.6 mL. Kujala scores improved from 39.9 preoperatively to 82.9 postoperatively (p < 0.001). All patients were followed up for at least 1 year. All patellae were centerized on the groove postoperatively with no recurrence.

Conclusion: CDP is a rare lower limb skeletal disorder requiring thorough evaluation. Early diagnosis and 4in1 procedure optimize patellar stability and knee function, preventing long-term complications.