Managment of congenital knee dislocation by gradual reduction with serial casting

Background Congenital knee dislocation (CKD) is deformity of the knee characterized by unnatural hyperextension with severely restricted knee flexion. It may either be idiopathic or a part of any syndrome (Larsen’s syndrome, myelomeningocele, and arthrogryposis multiplex congenita). As the incidence of CDK is very low (~1/100 000 live births, which is about 1% of the incidence of congenital hip dislocation). Aim To identify the results of conservative management of the group of CKD at birth, especially grade I and grade II according to Tarek CDK grading system (Abdelaziz and Samir grading of CDK) and identify the problems encountered during the process. Patients and methods Between January 2016 and February 2021, 24 infants with 34 CDK were treated at Al-Azhar University Hospital, Assiut branch. Age at the time of initial treatment ranged from 3 to 45 days, average 17 days. Fourteen infants were male and 10 infants were female. Eight cases were affected on the right side, six cases were affected on the left side, and 10 cases were affected bilaterality. Follow-up ranged from 1 to 3 years, average 2.3 years. The serial casting was started weekly, aiming to achieve more than 90° passive flexion, the number of the cast ranged from one to six casts, average three casts. Then, the cast was discontinued and a back splint has been given to the 14 patients to be used at nighttime only. Results All parents were satisfied with the outcome. Satisfaction was assessed by asking the parent(s) to grade their child’s condition at the final follow-up on a scale of 0 to 5, with ‘0’ meaning totally unsatisfied and ‘5’ meaning extremely satisfied. Parent(s) who graded their child at ‘3 or more’ were considered satisfied. Twenty-two knees achieved excellent results, 10 knees achieved good results, and two knees achieved fair results. All knees that achieved excellent results were grade I/grade II and had been treated by serial casting only. The cast was changed every 1 week, average duration of cast was 21 days. The only two knees were grade III that underwent V-Y quadricepsplasty and had excellent results. Conclusion If CDK was diagnosed early after birth and timely treatment initiated successful, conservative management can be easily done even in the higher grades of classification of CKD.