Hip Ultrasounds Research Articles

Ultrasound findings in asymptomatic patients with modular metal on metal total hip arthroplasty.

The use of metal-on-metal and modular total hip arthroplasty is associated with potentially serious local and systemic complications. The primary aim of this study was to identify the prevalence of a pseudotumor in asymptomatic patients with a particular metal-on-metal hip prosthesis after a minimum follow-up of 5years using ultrasound evaluation. A secondary purpose was to identify associations between the presence of pseudotumor and serum metal ion levels following implantation. We prospectively evaluated data collected from 36 asymptomatic patients who underwent implantation of a Profemur Z metal-on-metal total hip arthroplasty from January 2004 to January 2010. Serum metal ion levels were collected in 2012 and 2015. Hip ultrasounds were performed in 2015. Pseudotumors were found in 7/36 patients (19.4%). The average pseudotumor size measured 38.2cm3 (range 7.35cm3-130.81cm3). Elevated metal ion levels were found in all patients at all time points. No statistical correlation was found between the presence of pseudotumor and patient age, age of the implant, component design, and any of the serum metal ion levels or ratios. One in every five asymptomatic patients with metal-on-metal implants was found to have a periarticular pseudotumor. There was no dose-dependent relationship found between elevated serum metal ion levels and the development of a pseudotumor. Our findings suggest that in patients with known elevated metal ion levels, continued monitoring of ion levels may not be a reliable predictor of pseudotumor formation, and ultrasound surveillance can and should be routinely used to document the presence and progression of pseudotumor.

Sonographic screening for developmental dysplasia of the hip in preterm breech infants: do current guidelines address the specific needs of premature infants?

To assess the association between gestational age versus corrected age at the time of hip ultrasound with findings for developmental dysplasia of the hip (DDH) in preterm breech infants. A retrospective medical chart review was conducted to examine hip ultrasounds of 318 premature breech infants for findings associated with DDH. Positive findings for DDH occurred in 3/135 (2%) of infants <32 weeks gestational age and 17/183 (9%) of infants 32 to <37 weeks gestational age (odds ratio: 0.22, 95% CI: 0.04 to 0.79, P<0.015). No infants born <32 weeks gestational age had abnormal findings for DDH upon follow-up ultrasound. Infants <40 weeks corrected age at the time of hip ultrasound were more likely to have DDH findings compared with infants ⩾44 weeks corrected age (odds ratio: 7.83, 95% CI: 2.20 to 29.65, P<0.001). Current hip ultrasonography policies that include screening of premature breech infants may need to be revised.

Inter- und intraindividuelle Messabweichungen in der Säuglingshüftsonografie nach Graf

Inter- and intraobserver reliability and learning curve using Graf's ultrasonographic hip examination were assessed. 189 participants of the basic, advanced and final courses on hip ultrasound using the Graf method (DEGUM) were asked to answer a questionnaire and to measure 34 normal and pathological sonographic hip examinations. Measurement differences and the learning curve during the different courses were evaluated. There was a significant (p = 0.001) improvement of the average angle between the basic (6.74 degrees [+/- 1.46 degrees ]) and the advanced course (6.22 degrees [+/- 1.17 degrees ]). However, there were no better results in the final course and no additional improvement. Participants had higher variations when measuring the beta-angle than the alpha-angle. A significant improvement was seen if the participants performed a large number of hip ultrasounds between the courses. Higher measurement differences were seen in pathological hip ultrasounds and in ultrasonographic examinations of poorer quality. During the educational courses on hip ultrasound using the Graf method, a high intra- and interobserver variability was seen. These findings were most prominent in measurement of the beta-angle, in pathological hip ultrasounds and in ultrasonographic hip examinations of poorer quality. The best results were achieved by participants who had performed a large number of examinations between courses. For the improvement of ultrasonographic measurements, a large number of self-performed examinations and a training in potential mistakes seem to be of great importance.

Rate of Referral of Breech Infants for Hip Ultrasound: An Audit Cycle

Infants with risk factors for developmental dysplasia of the hip (DDH) should have hip ultrasounds performed shortly after birth to detect and treat the condition at an early stage. Breech presentation is associated with increased risk of DDH. We embarked on an audit cycle to assess and improve our rate of referral of breech infants for hip ultrasound. Two retrospective audits (phases I and II) were carried out before, and after, the introduction of a new pro-forma which encouraged recognition of breech presentation at the time of the routine neonatal examination. Breech infants were identified from labour ward records. Multiple births and infants < 35 weeks gestation were excluded. Infants were considered to have been referred for ultrasound if the computer system at our affiliated children's hospital held a record of an ultrasound appointment. In phase I 56% of breech infants born in our hospital had been referred for hip ultrasound. In phase II the referral rate had risen to 76% (p = 0.034). We conclude that the change in practice was effective. Further improvement might be achieved by increasing staff awareness of risk factors for DDH and by enlisting the help of advanced neonatal nurse practitioners (ANNPs) in routine neonatal examinations.

Avaliação ultra-sonográfica pelo método de Graf no quadril infantil

Ultrasonography of the hip performed by the Graf method is widely accepted as an important diagnostic and treatment tool for hip dysplasia. This study aims to examine the reliability and reproducibility of the interpretations of ultrasound scans by general orthopedists. Thirteen examiners evaluated five hip ultrasounds of the same normal child. The examiners measured alpha and beta angles according to Graf. Statistical analysis was performed by variance analysis (ANOVA) and agreement was calculated and expressed as the intraclass correlation coefficient (ICC). The alpha angle mean was 37.32 degrees (11.12) and the beta angle mean was 45.05 degrees (10.49). Error of the intra-observer was 17.65 for the alpha angle and 17.63 for the beta. Error of the inter-observer was 7.68 for the alpha angle and 17.21 for the beta. ICC intra-observer was 0.18 for the alpha angle and 0.29 for the beta. ICC inter-observer was -0.02 for the alpha angle and 0.3 for the beta. Ultrasound of the infantile hip using the Graf method is an important tool for the assessment of developmental dysplasia of the hip, however, it must be emphasized that preciseness of interpretation requires training and frequent use.

Ultrasonography in developmental hip dysplasia.

With the evolving use of ultrasonography, there has been an increasing emphasis on the technically oriented diagnosis of developmental hip dysplasia. Graf's alpha and beta angles and Harcke's bony rim percentage are two of the more common criteria, but their repeatability and reliability have not been well documented. Fifty-eight hip ultrasounds of 29 infants were measured independently by three physicians, and statistical analysis was performed. It was concluded that Graf's and Harcke's methods could be repeatable with training and frequent use of ultrasonography. Harcke's guidelines have a large equivocal zone, which limited their clinical usefulness. Graf's angles gave a better classification, but their clinical relevance has not been proven.