The incidence of late-detected developmental dysplasia of the hip and its functional outcomes: a 17-year cohort study using selective ultrasound screening.

BACKGROUND AND PURPOSE: We aimed to establish the incidence of late-detected developmental dysplasia of the hip (DDH) with a selective ultrasound (US) examination over 17 years using the femoral head coverage (FHC) as a US measurement. The secondary aim was to establish the everyday function using patient-reported outcome measures (PROMs). PATIENTS AND METHODS: The incidence of late-detected DDH was based on 60,844 children. Patients diagnosed for the first time after 3 months and before the age of 8 years were included. In the second part of the study, consent to participate was mandatory. PROMIS-25 Pediatric, PROMIS-25 Parent, and EQ-5D-5L were used according to the patient's age to assess everyday function. RESULTS: The incidence of late-detected DDH was 0.48/1,000. The median age at diagnosis was 8 months (range 4-41 months), with a tendency to require repeated treatment with open surgery if DDH was diagnosed later. Most children reported no or minor health problems with a mean of 18 years' follow-up. CONCLUSION: We found that selective US examination of the hips by measuring the FHC is a reliable method to examine newborns for DDH resulting in a low incidence of late-detected DDH amounting to 0.48/1,000 newborn children.

Children treated for developmental dysplasia of the hip at birth and with normal acetabular index at 1 year: How many had residual dysplasia at 5 years?

Purpose: The purpose of the study was to assess the effect of further follow-up for children treated for developmental dysplasia of the hip, with normal clinical and radiological findings at 1-year time point. The effect was quantified by the number of hips with a pathologic deterioration up to 5 years. Methods: Among 47,289 children born in Sør-Trøndelag county in Norway between 2003 and 2015, 265 children had developmental dysplasia of the hip. Of these, 164 children (239 hips) treated for developmental dysplasia of the hip with normal clinical findings and normal acetabular index at the 1-year time point were included in the study. The number of hips with pathologic acetabular index at the 5-year time point were reported. The diagnostic uncertainty related to radiological measurements was quantified together with the effect of introducing a second radiographic measurement, the center edge angle. Results: A total of 239 treated hips were normal at the 1-year time point. At 5-year time point, 10 (4.2%) hips had a pathologic acetabular index measurement and none classified to have developmental dysplasia of the hip caused by measurement inaccuracy. Eight (3.3%) hips had pathologic center edge angle measurement. Four hips had both pathologic acetabular index and center edge angle measurements, with three later treated with surgery. The intra- and interobserver repeatability coefficients were within 3.1°-6.6°. Conclusion: The repeatability coefficient of the acetabular index measurements was high and no hips could be classified to have developmental dysplasia of the hip at the 5-year time point when taking this repeatability into account. Hips classified as pathologic combining acetabular index and center edge angle measurements were likely to be treated with surgery for residual dysplasia. We recommend further follow-up for these children. Level of evidence: level II.

The Value of Visa-Score and Colour Flow Imaging in the Follow-Up of Non-Athletes Operated for Jumpers Knee.

The objective of this study was to assess if the Victorian Institute of Sport Assessment (VISA) questionnaire was suitable in the evaluation of patients from a mixed population with normal levels of sports activity, and if neovascularization of the patellar tendon demonstrated by color flow imaging (CFI) was more frequent in patients with lasting symptoms after surgical treatment for jumpers knee (JK). This study was conducted at St. Olavs Hospital, University Hospital of Trondheim, Norway, and included 21 men and 18 women who were operated for JK. Symptoms were assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and VISA questionnaires. Clinical and ultrasonographic examinations of the knees, including CFI, were done at a mean follow-up duration of 82 (range, 16-136) months after surgery. Patients with positive CFI also had significantly lower KOOS scores, whereas the total VISA-P (Victorian Institute of Sport Assessment - Patella) score showed no association. Patients with a positive clinical examination had significantly more frequent positive CFI findings than did patients with negative examinations. The operated patellar tendon was significantly thicker and had more frequent hypoechoic signal in the proximal part than the contralateral unoperated tendon. The post-operative VISA-P score seems less valuable in the evaluation of patients from a mixed population with normal levels of sports activity. CFI may be a valuable diagnostic tool in the evaluation of patients operated for JK.

Breech presentation is a risk factor for dysplasia of the femoral trochlea.

BACKGROUND AND PURPOSE: Instability of the patellofemoral joint is a common disorder in children and young adults. Although it has multifactorial causes, a shallow femoral trochlea is the single most important factor for instability. There is no consensus as to the etiology of trochlear dysplasia. We assessed whether the presentation of the fetus at birth could be a predisposing factor for trochlear dysplasia. SUBJECTS AND METHODS: We examined 348 knees in 174 newborns using ultrasonography, concentrating especially on the trochlea femoris. We measured the sulcus angle (SA) on a transverse scan. The way of fetal presentation at birth and standard parameters such as sex, gestational age, and length and weight at birth were registered. As breech presentation is a known risk factor for dysplasia of the hip, we also looked for an association between dysplasia of the femoral trochlea and dysplasia of the hips. RESULTS: The mean SA was 148°. 17 knees in 14 children had an SA of >159°, which was defined as the threshold value for dysplasia. The incidence of breech position in these children was 15-fold higher. Of the different groups of breech positions, a child in frank breech with the knees locked in extension had a 45-fold increased risk of having trochlear dysplasia. INTERPRETATION: For some newborns, a high sulcus angle can be found at birth, indicating that trochlear dysplasia can be found from birth. Breech presentation with knees extended appears to be a major risk factor for development of trochlear dysplasia.

Mapping of the femoral trochlea in a newborn population: an ultrasonographic study.

BACKGROUND: The anatomy of the femoral trochlea is of vital importance to the stability of the patellofemoral joint. Knowing the characteristics of the femoral trochlea in newborns might prove useful when considering the predisposing factors to patellar instability. PURPOSE: To define the normal anatomy and the natural variances of the femoral trochlea in a newborn population as well as evaluation of ultrasonography as a method of imaging. MATERIAL AND METHODS: The femoral trochlea of both knees of 174 newborns (82 girls and 92 boys) was examined using ultrasonography within 3 days after birth. For evaluation of the repeatability of the method, a separate population of 40 newborns was examined by two examiners. RESULTS: The sulcus angle (SA) and Trochlear Index (TI) proved to be the most reliable and reproducible parameters. The overall mean SA was 148° (SD 5.6). An angle of more than 159° was defined as dysplastic, and 17 of the knees were categorized in this group. The overall mean TI was 2.21 (SD 0.05). A value of less than 2.11 was defined as dysplastic and 11 of the newborns fell into this category. CONCLUSION: As a method of visualizing the newborn femoral trochlea and the position of the patella, ultrasonography is a reliable tool and might be of vital importance. In a further perspective, knowledge of the anatomy of a normal versus a dysplastic newborn trochlea renders it possible to study the predisposing factors to patellar instability and methods of treatment. Our results indicate that dysplasia of the femoral trochlea may be congenital.