Intraoperative Contrast‐Enhanced Ultrasound Imaging of Femoral Head Perfusion in Developmental Dysplasia of the Hip: A Feasibility Study

Abstract

Objectives Developmental dysplasia of the hip (DDH) is one of the most common developmental deformities of the lower extremity. Although many children are successfully treated with a brace or harness, some require intraoperative closed or open reduction and spica casting. Surgical reduction is largely successful to relocate the hip; however, iatrogenic avascular necrosis is a major source of morbidity. Recent research showed that postoperative gadolinium‐enhanced magnetic resonance imaging (MRI) can depict hip perfusion, which may predict a future incidence of avascular necrosis. As contrast‐enhanced ultrasound (CEUS) assesses blood flow in real time, it may be an effective intraoperative alternative to evaluate femoral head perfusion. Here we describe our initial experience regarding the feasibility of intraoperative CEUS of the hip for the assessment of femoral head perfusion before and after DDH reduction. Methods This single‐institution retrospective Institutional Review Board–approved study with a waiver of informed consent evaluated intraoperative hip CEUS in children with DDH compared to postoperative contrast‐enhanced MRI. Pediatric radiologists, blinded to prior imaging findings and outcomes, reviewed both CEUS and MRI examinations separately and some time from the initial examination both independently and in consensus. Results Seventeen patients had 20 intraoperative CEUS examinations. Twelve of 17 (70.6%) had prereduction hip CEUS, postreduction hip CEUS, and postreduction gadolinium‐enhanced MRI. Seven of 12 (58.3%) were evaluable retrospectively. All CEUS studies showed blood flow in the femoral epiphysis before and after reduction, and all MRI studies showed femoral head enhancement after reduction. The CEUS and MRI for all 7 patients also showed physeal blood flow. Conclusions Contrast‐enhanced ultrasound is a feasible intraoperative tool for assessing adequate blood flow after hip reduction surgery in DDH.

Comparison of Contrast-enhanced Ultrasound and Contrast-enhanced Magnetic Resonance Imaging in the Assessment of Infant Hip Perfusion and Prediction of Proximal Femoral Growth Disturbance Following Closed and Open Reduction for Developmental Dysplasia of the Hip: A Preliminary Study

“…Our experience over the past 10 years with CEUS for the evaluation of cartilaginous femoral epiphyses is a novel, off-label application. The technique has now been shared with other institutions who have published their findings which are similar in terms of the ability of CEUS to visualize the vascular channels of femoral epiphyses 30 . Further validation with larger patient numbers, systematic comparison to contrast-enhanced MRI, and long-term follow-up to confirm the ability of CEUS to predict the development of PFGD are required.…”

“…The technique has now been shared with other institutions who have published their findings which are similar in terms of the ability of CEUS to visualize the vascular channels of femoral epiphyses. 30 Further validation with larger patient numbers, systematic comparison to contrast-enhanced MRI, and long-term follow-up to confirm the ability of CEUS to predict the development of PFGD are required. Additional work validating both conventional US and CEUS as a definitive method for the assessment of femoral head reduction and in-cast perfusion will further improve the utility of US as an intraoperative imaging modality and hopefully decrease the risk of developing PFGD in these infants' hips.…”

What Is the Relevance of Post-Reduction MRI Today and Where Do We Go from Here?

“…MRI almost universally necessitates that the patient leave the operating room for transportation to the MRI suite. With the development of low-dose intraoperative CT protocols and the gradual adaptation of perfusion ultrasound, there are faster, more efficient ways to assess hip reduction intraoperatively 3 . Techniques that allow real-time, intraoperative information about the reduction and perfusion of the femoral head are becoming more common.…”

Image-guided surgery and novel intraoperative devices for enhanced visualisation in general and paediatric surgery: a review

“…Prantl et al. explored another application into the intraoperative field by using CEUS to assess the viability of the femoral head before and after developmental dysplasia of the hip reduction [ 58 ]. Finally, the use of CEUS in urology is mainly related to evaluating vesicoureteral reflux’s treatment, where the real-time intraoperative assessment of residual reflux following the injection of endoscopic bulking agents allows for repeated injections to improve the success of the procedure [ 59 ].…”