MRI versus computed tomography as an imaging modality for postreduction assessment of irreducible hips in developmental dysplasia of the hip: an interobserver and intraobserver reliability study

Abstract

Following surgical reduction of an irreducible hip in developmental dysplasia of the hip, imaging is required to ascertain successful reduction. Recent studies have compared MRI versus computed tomography (CT) in terms of cost, time, sensitivity and specificity. This is the first study to compare intraobserver and interobserver reliability for both modalities. Nineteen CT scans of 38 hips in 10 patients and nine MRI scans of 18 hips in six patients were reviewed on two separate occasions by three clinicians. Image clarity, confidence of diagnosis, time taken to perform the scan as well as radiation dose for CT were recorded. Intraobserver and interobserver reliability κ values were calculated. There were 14 female patients and one male patient. The mean age at the time of the scan was 12 months (range 3-25 months). Intraobserver reliability was greater than 0.8 (both CT and MRI). Interobserver reliability was greater than 0.8 (both CT and MRI). Image clarity was higher for CT for two out of the three clinicians (9.47 vs. 6.33 P<0.05; 9.89 vs. 8.11, P<0.05). All clinicians were equally confident in the diagnosis when using CT or MRI. The time taken to perform the investigation was not significantly different (3.32 vs. 4.88 min, P>0.05). The mean radiation dose for CT was 91.75 DLP (dose length product, mGy×cm) (95% confidence interval±26.95). Our results show that MRI is equal to CT as an imaging modality in the assessment of postreduction hips in developmental dysplasia of the hip. Intraobserver and interobserver reliability was excellent for both. The image clarity was higher for CT, but this method of imaging carries a significant risk of radiation exposure. We recommend that MRI should supersede CT as an imaging modality for this clinical situation.

MRI hip morphology is abnormal in unilateral DDH and increased lateral limbus thickness is associated with residual DDH at minimum 10-year follow-up

“…MRI has gained popularity over post-reduction CT scans due to its increasing availability and minimization of patients’ exposure to ionizing radiation. 2,22,23 Post-reduction MRI has the additional benefit of improved soft tissue and cartilage analysis. Potentially, the role of post-reduction MRI could be expanded beyond the dichotomous assessment of acceptable versus non-acceptable reduction, incorporating measurements of the femoral head position and acetabular morphology, which may have long-term implications for joint development.…”

Anteroposterior pelvic radiograph is not sufficient to confirm hip reduction after conservative treatment of developmental dysplasia of the hip

“…At present, some studies have suggested that MRI should be used as an imaging method for routine examination after conservative treatment of DDH [28,30], and some improvements have been made. For example, Fukuda et al [31] proposed using a 1.0-s ultrafast MRI without the need for anesthesia, and Barkatali et al [12] suggested that MRI could be performed with the child still sedated after manual reduction. Moreover, Dibello et al [32] and Jadhav et al [33] proposed MRI with fewer sequences [32][33][34], which meant that only the hip joint needed to be scanned to reduce examination time.…”

“…[31] proposed using a 1.0-s ultrafast MRI without the need for anesthesia, and Barkatali et al . [12] suggested that MRI could be performed with the child still sedated after manual reduction. Moreover, Dibello et al .…”

“…In addition, posterior dislocation of the femoral head is confusing and often results in false negatives [10,11]. Although a few studies have suggested using computed tomography or MRI instead of anteroposterior pelvic radiographs for postoperative review, these studies did not evaluate the accuracy of anteroposterior pelvic radiographs in judging hip reduction [12][13][14][15]. Therefore, there is a lack of strong evidence to support the use of MRI in children with DDH after conservative treatment.…”

Application Value of Combined Diagnosis of Ultrasound, MRI, and X‐Ray in Developmental Dysplasia of the Hip in Children

“…Imaging examination, an important basis for early diagnosis, treatment, and follow-up after intervention of DDH, can directly reflect the hip structure and development of children [19][20][21][22]. Since DDH mostly occurs in infants and young children, the subjects for examination are special.…”