A 20-Year Retrospective Study of Children and Adolescents Treated by the Three-in-One Procedure for Patellar Realignment

Abstract

Background: Patellar instability is the most common disorder of the knee during childhood and adolescence. Surgical treatment significantly reduces the rate of redislocation, but the underlying pathologies and pattern of instability may affect the results. We aimed to report the clinical and functional outcomes of the three-in-one procedure for patellar realignment in a cohort of skeletally immature patients with or without syndromes and various patterns of chronic patellar instability. Methods: We retrospectively investigated 126 skeletally immature patients (168 knees) affected by idiopathic or syndromic patellar instability, who underwent patella realignment through a three-in-one procedure. We classified the instability according to the score proposed by Parikh and Lykissas. Results: Patellar dislocation was idiopathic in 71 patients (94 knees; 56.0%) and syndromic in 55 (74 knees; 44.0%). The mean age at surgery was 11.5 years (range 4–18) and was significantly lower in syndromic patients. Syndromic patients also exhibited more severe clinical pattern at presentation, based on the Parikh and Lykissas score. The mean follow-up was 5.3 years (range 1.0–15.4). Redislocation occurred in 19 cases, with 10 cases requiring further realignment. The Parikh and Lykissas score and the presence of congenital ligamentous laxity were independent predictors of failure. A total of 22 knees in 18 patients required additional surgical procedures. The post-operative Kujala score was significantly lower in patients with syndromic patellar instability. Conclusions: The type of instability and the presence of underlying syndromes negatively affect the rate of redislocation and the clinical and functional outcome following patellar realignment through the three-in-one procedure. We recommend the consideration of alternative surgical strategies, especially in children with severe syndromic patellar dislocation.

A Modified 4-in-1 Stanisavljevic Procedure for Treating Obligatory or Congenital Patellar Dislocations in Children: A Surgical Technique

“…We noted a residual instability rate of 11% (4/35) after the modified 4-in-1 Stanisavljevic technique; 2 patients with Ehlers-Danlos syndrome displayed recurrent instability, and 2 patients with nail-patella syndrome exhibited a positive J-sign. This rate remains notably advantageous in comparison to recurrence rates of up to 19% observed in patients with hypermobility syndrome undergoing similar procedures [20]. It highlights the intricate nature of managing these conditions, even with aggressive techniques like the Stanisavljevic approach, given the possibility of failures.…”

Acute Treatment of Osteochondral Detachment Following Patellar Dislocation: Clinical and Short-Term MRI Follow-Up

“…Analyzing the epidemiology of the different types of patellar instability in Table 1, it is important to underline how each dislocation is more found in subjects of different ages than in older adults. Type 1 and type 2 dislocations are found more frequently among adolescents, type 3 is mostly congenital, while type 4 dislocations are less frequent [6].…”

Quadriceps Muscle and Medial Retinaculum Combinate Effects on Patellar Instability during Knee Flexion

“…The risk of recurrent dislocation may be increased by anatomical problems, i.e., MPFL incompetence, trochlear anatomical changes, and tibial tubercle lateralisation [26- Patellar instability occurs when the patella does not slide correctly over the femur, causing a dislocation, and accounts for 2-3% of knee accidents with 6/100,000 patients' yearly incidence, rising to 29/100,000 in teenagers [16][17][18]. This condition can be caused by injury to the patellar ligaments, muscle imbalances, anatomical deformity, or changes in biomechanics, often leading to pain and disability [19][20][21].…”