Outcome Prognostic Factors in MRI during Spica Cast Therapy Treating Developmental Hip Dysplasia with Midterm Follow-Up

Abstract

Closed reduction followed by spica casting is a conservative treatment for developmental dysplasia of the hip (DDH). Magnetic resonance imaging (MRI) can verify proper closed reduction of the dysplastic hip. Our aim was to find prognostic factors in the first MRI to predict the possible outcome of the initial treatment success by means of ultrasound monitoring according to Graf and the further development of the hip dysplasia or risk of recurrence in the radiological follow-up examinations. A total of 48 patients (96 hips) with DDH on at least one side, and who were treated with closed reduction and spica cast were included in this retrospective cohort study. Treatment began at a mean age of 9.9 weeks. The children were followed for 47.4 months on average. We performed closed reduction and spica casting under general balanced anaesthesia. This was directly followed by MRI to control the position/reduction of the femoral head without anaesthesia. The following parameters were measured in the MRI: hip abduction angle, coronal, anterior and posterior bony axial acetabular angles and pelvic width. A Graf alpha angle of at least 60° was considered successful. In the radiological follow-up controls, we evaluated for residual dysplasia or recurrence. In our cohort, we only found the abduction angle to be an influencing factor for improvement of the DDH. No other prognostic factors in MRI measurements, such as gender, age at time of the first spica cast, or treatment involving overhead extension were found to be predictive of mid-term outcomes. This may, however, be due to the relatively small number of treatment failures.

Residual acetabular dysplasia after Pavlik harness treatment for Graf type II hips

“…In some studies, the treatment goal was defined as an α angle more than 64°. 18 , 39 Some authors argued rounding or blunt acetabular rim might affect the measurement of the α angle and influence the treatment strategy. 40 – 42 Hareendranathan et al 42 proposed a contour-based α angle and a rounding index to improve the reliability and accuracy of DDH diagnosis, and they found that the apex point moved 8 mm leading to a 10° change of α angle.…”

Fifty percent of patients undergoing periacetabular osteotomy for hip dysplasia showed normal findings upon neonatal ultrasound screening

“…Hip joint dysplasia cannot be excluded with certainty by inconspicuous ultrasound findings in infancy imately 20-40% of all cases of adult hip osteoarthritis are due to unrecognized or untreated DDH [1]. Postnatal infant examination at 3-8 weeks detected in early childhood, it can be often addressed with non-surgical methods of splinting [8]. In skeletally mature patients, reorientation osteotomy represents the gold standard for treatment of the underlying pathomorphology.…”

Follow-up Value of Hip Medial Ultrasound in Infants and Children With Developmental Dysplasia of the Hip Treated With Reduction and Spica Casting

“…11 MRI is advantageous in terms of the nonexposure of sensitive developing tissues to ionizing radiation and providing more information about the soft tissues in and around the hip joint and the cartilaginous epiphysis. 12 Moreover, the fast sequence MRI can be performed in patients with spica cast and does not require sedation or anesthesia, although the mean study time of ultrafast MRI was 6 ± 1 minute. 13 Ultrasonography is a noninvasive examination method that does not involve radiation exposure and can provide detailed imaging of the cartilage and soft tissues.…”

“…The sensitivity and specificity of CT and MRI for the detection of hip dislocation in the spica cast have been found to be equivalent 11 . MRI is advantageous in terms of the nonexposure of sensitive developing tissues to ionizing radiation and providing more information about the soft tissues in and around the hip joint and the cartilaginous epiphysis 12 . Moreover, the fast sequence MRI can be performed in patients with spica cast and does not require sedation or anesthesia, although the mean study time of ultrafast MRI was 6 ± 1 minute 13 .…”