|Year : 2023 | Volume
| Issue : 3 | Page : 195-196
Congenital dislocation of the knee – Not commonly seen by pediatricians
Sangeeta Priyadarshi Sawant
Department of Pediatrics, Bhabha Atomic Research Centre Hospital, Mumbai, Maharashtra, India
|Date of Submission||26-May-2023|
|Date of Decision||29-Jun-2023|
|Date of Acceptance||09-Jul-2023|
|Date of Web Publication||14-Aug-2023|
Dr. Sangeeta Priyadarshi Sawant
Department of Pediatrics, Bhabha Atomic Research Centre Hospital, Anushakti Nagar, Mumbai - 400 094, Maharashtra
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Sawant SP. Congenital dislocation of the knee – Not commonly seen by pediatricians. Indian Pediatr Case Rep 2023;3:195-6
A full-term baby girl, delivered through vaginal route, with a birth weight of 3.06 kg, length of 50 cm, and head circumference of 34.5 cm, with clear liquor and no history of birth asphyxia, was noted to have unusual position of the right lower limb [Figure 1].
On detailed examination, the child was pink and euthermic with normal activity and reflexes. She had a heart rate of 130/min, respiratory rate of 48/min, with normal volume pulses, and a capillary filling time of <2 s, maintaining oxygen saturation at room air. Evaluation of the right knee showed hyperextension of the knee. Active movements of the right lower limb were preserved, however, the knee only moved in extensions, with no active flexion movements. On passive flexion at the knee joint, the movement was limited and associated with an audible clunk. There was no evidence of hyperextensibility or contractures in other joints nor any features of dysmorphic facies. The rest systemic examination was within the normal limit.
A radiograph of the knee joint was done, which revealed anterior displacement of the tibia on the femur [Figure 2]. Ultrasonography of the hip joint was normal and ruled out developmental dysplasia of the hip. She was diagnosed with congenital dislocation of the knee of Grade II.
|Figure 2: X-ray, right knee showing anterior displacement of tibia on femur|
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The baby was otherwise stable and feeding well. The dislocation was managed conservatively, including manipulation, passive stretching, and splinting. The manipulation was very gentle with mild traction, ensuring the tibia remained centered over the femur. In the course of next 5–6 weeks, the knee adopted the normal position. Splint was removed and passive stretching was continued. The follow-up at 3 and 6 months demonstrated normal position and movement of the knee joint [Figure 3].
Congenital dislocation of the knee (CDK) is an uncommon condition, with an approximate incidence of 1/100,000 live births. It may be isolated or combined with other congenital musculoskeletal and neurological disorders such as dislocation of the hip or clubfoot, arthrogryposis multiplex congenita, meningomyelocele, Larsen syndrome, spina bifida, developmental dysplasia of the hip, forefoot adduction deformity, and calcaneovalgus foot deformities. The exact etiology is not known. Fetal molding due to oligohydramnios, breech delivery, absence or hypoplasia of the anterior cruciate ligament, and shortened and fibrotic quadriceps muscle have been reported either as causes or effects of this condition.,
The condition is obvious at birth, with the typical position of knee recurvatum, diagnosis being confirmed by radiograph. The classification of CDK is based on the radiographic findings of the femorotibial relationship. There are three grades: Grade I representing simple recurvatum (congenital hyperextension); Grade II representing congenital hyperextension with anterior subluxation of the tibia on the femur; and Grade III representing congenital hyperextension with dislocation of the knee joint on the tibia.,
The early recognition of congenital dislocation is important, and careful evaluation of rest of the musculoskeletal system is necessary to rule out any associated abnormality. It has been said that the number of anterior skin grooves is a major prognostic factor; a greater number of grooves implying a recent in utero development of dislocation and a less severe deformity, whereas absence of grooves suggests long-standing dislocation and a more severe deformity.
The treatment depends on the severity of the dislocation. Grades I and II CDK respond to the conservative management in the form of gentle manipulation and casting/splinting, with most cases achieving good results when manipulation is initiated immediately after birth. Surgical correction is required in Grade III CDK, bilateral dislocations, syndromic cases, and failed response to conservative management. It consists of joint capsule release, collateral ligaments reconstruction, quadriceps tendon lengthening, hamstring tendon posterior transposition, and femoral shortening to achieve stable joint.
By reporting this case, we intend to resurface this known, yet rarely seen condition and its diagnosis and treatment, for general awareness among pediatricians, so that they may refer and counsel parents accordingly.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given his consent for images and other clinical information to be reported in the journal. The guardian understands that names and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.
The authors would like to thank Head of the Department, Orthopedics Department, Bhabha Atomic Research Center Hospital, Anushakti Nagar.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]