Prenatal diagnosis and postnatal outcome of fetal congenital knee dislocation: systematic review of literature

OBJECTIVES

Congenital knee dislocation (CKD) is a rare condition, affecting 1 in 100 000 newborns. Its prenatal diagnosis is challenging and not well described in the literature, especially when it appears isolated and not as part of a complex malformation or syndromic pattern. The purpose of this study was to provide a comprehensive review of the available literature on the prenatal diagnosis and postnatal outcome of CKD and to summarize the current evidence on this topic.

METHODS

A systematic review of the literature on the prenatal diagnosis of CKD was performed in PubMed, Scopus and EMBASE. A predefined combination of specific keywords was used, focusing on intrauterine manifestations, diagnostic methods, prenatal behavior, postnatal treatment and neonatal outcome as well as long-term outcome in terms of ambulation, motion and joint stability. The quality of studies was assessed using the National Institutes of Health tool for quality assessment of case series. A summary of results was carried out providing proportions and rates of diagnostic and prognostic features associated with this rare condition.

RESULTS

In total, 20 cases were retrieved for analysis, of which 19 were obtained from the identified eligible studies (n = 16) and one was an unpublished case from our center. The median gestational age at prenatal diagnosis, which was made using ultrasound in most cases, was 20 weeks (range, 14-38 weeks). Bilaterality was observed in 11/20 (55%) cases. The condition was isolated in 7/20 (35%) cases and associated with other anomalies in 13/20 (65%) cases. An association was observed with oligohydramnios (4/20 (20%)), and an invasive procedure was performed in 13/20 (65%) cases, including 11 cases with an invasive procedure performed for diagnostic purposes. Genetic testing was normal in all isolated cases for which information was available (4/7), while a genetic syndrome was present in 10/13 (77%) non-isolated cases (Larsen, Noonan, Grebe, Desbuquois or Escobar syndrome). There were seven terminations of pregnancy, of which six were performed in cases with associated anomalies and one in an isolated case, 11 cases of postnatal survival, one case of intrauterine death and one of neonatal death. The fetal and neonatal deaths occurred in cases with associated anomalies or abnormal genetic findings. Postnatal treatment was mostly conservative, with only two reports (18% of the 11 surviving neonates) of surgical intervention, both in cases with associated anomalies. Postnatal follow-up was up to 1 year in most cases, and motor outlook appeared normal in all isolated cases.

CONCLUSIONS

CKD is a rare fetal anomaly with a prenatal diagnosis achievable from the early second trimester, for which a favorable outcome can be expected when no associated anomalies are present. Prenatal diagnosis should include detailed ultrasound assessment and amniocentesis for extensive genetic studies, particularly in non-isolated cases. Early postnatal treatment achieves success in most cases without surgical intervention and leads to a normal motor outlook. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Early diagnosis and treatment of DDH: a sonographic approach

This study reviews the data regarding clinical and ultrasound (US) examinations, collected during an 11-year period, in a DDH dedicated outpatient clinic. The material was analysed in order to verify the importance of US hip examination and Ortolani's test for early DDH diagnosis, to select dysplastic, unstable hips, to identify the role of the labrum in DDH, and to analyse the treatment strategy. Of the 21709 newborns (43418 hips) examined with US and Ortolani's manoeuvre for DDH diagnosis, 431 patients (356 F; 75 M; average age 42+/-33 days) had 574 unstable, dysplastic hips (1.32%). The hips identified according to Graf's classification were: 298 type D, 252 type IIIa, 4 type IIIb, 20 type IV. In 73.09% of the patients, no risk factors were identified; 18.56% had positive family history for DDH, 5.57% had breech presentation, 2.78% had both risk factors. Only 10.63% had a positive Ortolani's test. The diagnosis was made in 21.5% of cases by the 2nd week of life, in 52.9% between the 2nd-8th week, and in 25.5% after the 8th week. Unstable dislocated hips were treated, after reduction with or without sedation, by applying a cast; dysplastic hips were treated using a Gekeler splint. No open reductions or reconstruction surgery were needed. The labrum was always positioned on top of the femoral head, never inverted, and it was not an obstacle to closed reduction. Neither the Ortolani's sign, nor the risk factors are sure signs for the early diagnosis of DDH and its instability. Only US examination permits an early diagnosis of dysplasia and instability of the hip.