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were retrieved for analysis, of which 19 were obtained from the identified eligible studies (n = 16) and one was an unpublished case from our center.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.

[Subtalar screw-arthroereisis for correction of flat foot in children]

Minimally invasive subtalar screw-arthroereisis has gained interest in the correction of flat feet in children. Between 1990 and 2004, this technique was used on 152 children, 74 bilaterally, for a total of 226 feet. There were 82 boys and 70 girls, with an average age of 10.6+/-1.9 years. The results were good in 95.4% of cases, whilst there were complications in 4.6%. For well corrected feet, 55 screws have now been removed, on average 2.9 years after implantation. The indications for such treatment are: talipes calcaneovalgus, which develops into a flat foot (spontaneous correction can be expected to 10-11 years), juvenile flat foot with medial protrusion of the talar head and complete absence of the longitudinal arch, symptomatic talipes calcaneovalgus with pain on the insertion of the tibialis posterior tendon, a minimum age of 6 years if a correction with conservative treatment does not show any improvement; a maximum age of 12-13 years considering that there always has to be a manual reducibility of the deformity.

CONTRAINDICATIONS

posttraumatic flat foot, congenital flat foot, stiff flat foot, age over 13 years.

Early ultrasound diagnosis of developmental dysplasia of the hip

The results of ultrasound diagnosis of developmental dysplasia of the hip (DDH) in several studies of 1,000 and 1,332 consecutive patients, performed according to Graf's method from 1984 to the present, are presented. Prior to 1984 the authors used radiography exclusively in suspected cases of DDH, however, the change from radiography to ultrasonography resulted in significant improvement in the ability to diagnose and treat DDH. Different standard methods of treatment have been developed for the management of each morphological type of the newborn's and infant's hip. Ultrasound is more sensitive than clinical assessment for diagnosing DDH since it detects the dysplastic morphology of the hip when Ortolani's test is negative. Instability can be demonstrated directly. The success of treatment of DDH depends on the time of diagnosis the early diagnosis obtained by ultrasound screening can significantly improve the results of treatment.

[Persistent coxalgia in the child. The value of magnetic resonance]

This study was aimed at assessing the Magnetic Resonance (MR) features of persistent hip pain in children. Twenty-six patients aged 1.6 to 15.2 years (mean: 6.5 years) were clinically selected for the study; at clinics, all patients had persistent hip pain after 10 days' therapy. All patients were examined with radiography, US and MRI at 0.5 T. SE T1-weighted sequences, with and without fat suppression (FS), SE T2-weighted and gradient echo (GE) T1-weighted-like (T1*) sequences were acquired on the coronal plane. Slices were 5 and 3 mm thick on SE and GE T1* sequences, respectively. Morphology and signal intensity of epiphysis, growth plate and metaphysis were prospectively studied with MRI. Clinical and/or imaging follow-up (3 months) was the reference standard in our study. Final diagnoses were: no evidence of alteration (n = 3), transient synovitis (n = 6), rheumatic fever (n = 3), Perthes' disease (n = 7), Meyer's dysplasia (dysplasia epiphysealis capitis femoris, DECF) (n = 2), early slipped capital femoral epiphysis (n = 2), incomplete fracture (n = 1), extraarticular cause of pain (muscular abscess, osteomyelitis) (n = 2). In 23 of 26 patients MRI confirmed clinical, radiographic and US findings. MRI was particularly helpful in making an unquestionable diagnosis in the other 3 cases; in a patient with suspected slipped capital femoral epiphysis MRI revealed an incomplete fracture, in a patient with suspected Meyer's dysplasia MRI revealed early Perthes' disease and finally in a patient with suspected transient synovitis MRI revealed Perthes' disease. To conclude, MRI allows the condition causing persistent hip pain to be assessed and accurately depicted, integrating clinical, radiographic and US findings and in some cases also changing diagnosis and therapy.

Morphological or functional criteria in evaluation of the newborn hip?

Classifying the infant hip as normal or dysplastic before the stage of radiological significance, in other words during the first three months of life, has always been trusted to functional maneuvers causing clinical signs. From the results it is possible to deduce if the hip morphology is normal or somehow altered. In other words, because insufficient radiographic significance makes it impossible to directly assess the "morphological" criterion, diagnosis of the state of the hip is carried out using an indirect "functional" criterion. In contrast to radiographic imaging, ultrasound screening is already significant in the first weeks of life; it is therefore now possible to obtain real images of the infant hip earlier than it was possible using radiography. This eliminates the need for symptomatic evidence of dislocation. As a result, the "functional" indirect criterion used up till now for early diagnosis of infant hip can today be replaced by a direct "morphological" criterion. This innovation is not without epidemiological consequences, and this must be taken into account in order to rationalise between the opposing risks of over or under estimating the incidence of congenital hip dysplasia.

Ultrasound screening for congenital dislocation of the hip. Results and correlations between clinical and ultrasound findings

The author reports the findings of clinical and ultrasound screening for congenital dislocation of the hip in 1000 consecutively examined newborns. This study found that medical history and clinical signs do not always guarantee diagnosis of congenital hip dislocation. The disease can in fact be present even in the absence of clinical signs, including the Ortolani click sign. Ultrasound is a safe and reliable diagnostic tool which should be used together with clinical examination in the screening of newborns for congenital dislocation of the hip.

[Potentials of the echographic documentation of hip epiphysiolysis]

The results are presented of a study on patients affected by hip joint epiphyseolysis. The sonographic examination was performed using a unit with a linear 5 MHz probe; oblique scans were obtained, along the axis of the neck of the femur. Typical US findings are described, namely a small step corresponding to a positioning defect of the cartilage between head and neck of the femur and dilatation of the infracapsular space due to the presence of intra-articular fluid.

The personalized hip prosthesis

The authors discuss the general concept, method of use and first clinical results obtained with a "personalized" femoral component of a hip arthroprosthesis based on the computer-graphic processing of measurements obtained from radiography and CT scan. This prosthesis is considered to be innovative as compared to traditional cementless prostheses.