Bilateral congenital dislocation of the knee (BDK). Case report

Abstract

Background: Congenital dislocation of the knee (CDK) is a very rare condition, with an incidence of 0.017 per thousand live births and approximately 1 percent incidence in patients diagnosed with developing hip dysplasia (DHD). Due to its low incidence, there is controversy regarding definitive treatment. We present the case of a syndromic patient with bilateral congenital dislocation of the knees, satisfactorily treated by surgical management. The purpose of the publication is to describe the clinical case of a patient with bilateral CDK associated with non-genetically classified syndromic syndrome, without the presence of other joint dislocations.
Materials and methods: We describe the clinical case of a 2-year and 6-month-old child who underwent bilateral CDK surgical treatment through open reduction and associated selective quadriceplasty (Distal in one knee and Proximal in the other knee). The right knee was first intervened and then the left knee with a time interval of one month between one surgery and another. Postoperative management consisted of immobilization with closed inguinopedic casts with knee at 90º flexion for two months, then plaster tube with knee at 45º flexion and then anterior gypsum ferrules with 60º flexion at each knee of intermittent use. Functional assessment of the postoperative results was performed by knee mobility arches (active and passive), quadruped position, knee position, crawling and knee extension against gravity, because the patient still does not walk.
Results: At follow-up, the patient’s parents reported being "very satisfied" with the obtained results. The passive arches of mobility of both knees were: flexion of 125º (on average for the two knees), extension of - 5º. No instability or recurrence of dislocation was reported. Controls were performed after 5 months of surgical treatment for the right knee and 4 months after for the left knee.
Discussion: Due to age, failure in previous non-surgical orthopedic treatments in other institutions, and a syndromic association, surgical management of the patient’s deformities were indicated, performing bilateral selective quadriceplasty. A single restricted anterior medial suprapatellar and infrapatellar approach was performed accordingly to each knee, proximal "Z" quadriceplasty for the left knee and distal quadriceplasty for the right knee were also performed, a decreased in co-morbidities was observed by avoiding several approaches as well as a faster postsurgical recovery for the patient. After 5 months follow-up, this approach has provided good results in terms of functionality, satisfaction of the parents and absence of recurrence of dislocation.
Evidence level: IV