Leslie E. Grissom

Radiographic features of bisphosphonate therapy in pediatric patients

BackgroundPediatric patients are being treated with bisphosphonates for low bone mineral density. Skeletal radiographic findings have been described with bisphosphonates given orally and intravenously.ObjectiveTo determine and describe the radiographic findings of cyclic intravenous bisphosphonate therapy in the growing skeleton.Materials and methodsRetrospective review of radiographs of 32 patients with osteogenesis imperfecta or cerebral palsy treated with intravenous bisphosphonates on a quarterly schedule.ResultsPrincipal observations were metaphyseal bands and increased bone mineral density. The bands varied in spacing according to the age of the patient, rate of growth, and the location of the metaphysis. Fractures continued to be seen in patients with osteogenesis imperfecta.ConclusionCyclic bisphosphonate therapy results in distinctive radiographic findings in the growing skeleton.

Bone densitometry in pediatric patients treated with pamidronate

Background: Increasing numbers of children are being treated with the bisphosphonate pamidronate for low bone mineral density, particularly children with increased risk of fractures caused by bone disorders or low/non-weight bearing. Objective: To determine the effect of intravenous pamidronate on the bone mineral density of children with osteogenesis imperfecta and spastic quadriplegic cerebral palsy. Materials and methods: Charts of 38 children with osteogenesis imperfecta (n=20) and spastic quadriplegic cerebral palsy (n=18) treated with pamidronate were retrospectively reviewed. Patients were selected for treatment because of prior fracture and/or abnormally low bone mineral density. All received intravenous pamidronate at two-month to eight-month intervals and were periodically examined using dual energy X-ray absorptiometry. Results: All patients had abnormally low bone mineral density prior to treatment. Lumbar spine bone mineral density and z-scores showed serial improvement in 31 of 32 patients. Spine bone mineral density increased 78±38.1% in OI and 47.4±39.0% in children with cerebral palsy. The area of greatest lateral distal femur bone mineral density improvement was in the metaphysis adjacent to the growth plate, with a 96±87.8% improvement in the osteogenesis imperfecta group and 65.7±55.2% improvement in the cerebral palsy group. Increases in bone mineral density exceeded that expected for age-specific growth. This was demonstrated by improvement in both spine and femur z-scores for both groups. No children with spastic quadriplegic cerebral palsy experienced fractures after the first week of treatment, whereas patients with osteogenesis imperfecta continued to have fractures but at a decreased rate. Conclusions: Intravenous pamidronate given at 3- to 4-month intervals proved to be effective in increasing bone mineral density in patients with osteogenesis imperfecta and spastic quadriplegic cerebral palsy. The greatest gains in bone mineral density were observed in the children with osteogenesis imperfecta, but they did continue to fracture, albeit at a decreased rate. Children with cerebral palsy gained bone mineral density and did not continue to fracture.

Infant hip sonography: current concepts

Sonography of the infant hip has gained wide acceptance in the decade since its introduction. The two principle techniques of Graf and Harcke have been combined with the proposal of a Dynamic Standard Minimum Examination. Whereas sonography is used increasingly to manage developmental dislocation and/or displasia of the hip, there is no agreement on the use of sonography for universal newborn screening. This article describes in detail the Dynamic Standard Minimum Sonographic Examination of the infant hip. In addition, this article reviews the classification and management of infant hip disorders.

Sonography in congenital deficiency of the femur.

Dynamic hip sonography was performed in 15 infants (19 hips) with congenital abnormalities of the hip. Radiographs of all 15 patients revealed congenital deficiency of the femur (CDF), type I-V, using the classification described by Kalamchi et al. Sonography was accurate in delineating hip position and morphology in all cases, and was a helpful adjunct to radiography in defining the hip joints in 13 hips with type II and type III deficiency of the femur.

Infant shoulder sonography: technique, anatomy, and pathology.

Abstract.Background: In the infant, shoulder injury due to birth trauma and infection in joint and bone may be difficult to detect radiographically. Shoulder ultrasound provides a dynamic, noninvasive method of evaluation. Objective: To develop a technique to evaluate the infant shoulder and to successfully demonstrate pathology. Materials and methods: Using a multiplanar, dynamic technique, 24 normal and 12 symptomatic infants (age range, 3 days to 9 months) were examined (49 shoulders). Results: Sonographic findings were normal in 41 shoulders and abnormal in 8 shoulders. Abnormalities included subluxation, fracture, abnormal cartilage, soft-tissue mass, and inflammatory collections, including effusion. Conclusion: Ultrasound can be used successfully to evaluate the infant shoulder for instability, fracture, and infection.

PEDIATRIC HIP SONOGRAPHY: Diagnosis and Differential Diagnosis

As with any sonographic study, the accuracy of the examination is related to the skill and experience of the examiner. In this review of pediatric hip sonography, we have reviewed pitfalls and differential diagnoses for the infant suspected of DDH and for the older child presenting with a painful hip. The learning process for DDH evaluation is prolonged and more difficult than learning to assess the hip for effusion.

Flexion-extension cervical spine MRI in children with skeletal dysplasia: is it safe and effective?

Background: Skeletal dysplasias may be associated with cervical spinal instability or stenosis. Cervical spine flexion-extension plain radiographs in children with skeletal dysplasia are difficult to interpret. The purpose of this study was to review the indications, efficacy, and safety of performing flexion-extension magnetic resonance imaging (MRI) under sedation/anesthesia in these children. Methods: Retrospective, Institutional Review Board–approved review of 31 children with skeletal dysplasia who underwent 38 cervical spine flexion-extension MRI studies under sedation/anesthesia. Indications included abnormal neurological examination, suspected instability, stenosis, or inconclusive findings on flexion-extension radiographs. Studies were performed by the radiology technologist as directed by the radiologist with an anesthesiologist present. MRI was evaluated for odontoid hypoplasia, os odontoideum, cerebrospinal fluid effacement, cord compression, spinal cord changes, cervical canal narrowing in the neutral, flexion, and extension positions. Neurological examinations were recorded before and after MRI to assess safety. Results: The average age at MRI was 3 years, 2 months. In 6 patients whose plain radiographs showed C1-C2 or subaxial instability, flexion-extension MRI showed no cord compression. Nine patients with inconclusive plain radiographs had abnormal MRI findings. An os odontoideum not seen on plain radiographs was diagnosed in 3 patients on flexion-extension MRI. On the basis of the MRI findings, 14 patients underwent surgery, 9/14 had increased cord compression in flexion or extension compared with neutral, and observation was continued in 17 others. Patients who underwent surgery had significant cord compression on MRI. There were no significant changes in the neurological examinations after MRI. Conclusions: Cervical spine flexion-extension MRI under sedation/anesthesia in children with skeletal dysplasia is safe under adequate supervision and is necessary to guide accurate medical and surgical decision making. Flexion-extension MRI is useful for identifying dynamic changes in canal diameter resulting in cord compression not seen on plain radiographs, and it is also useful for identifying patients with suspected plain film instability who may not have stenosis or cord compression on MRI. Study Design: Level IV—retrospective case series.

Protocol for MRI of the hips after spica cast placement.

Background: In reduction of hip displacement in developmental dysplasia, concentric placement of the femoral head within the acetabulum is key. Magnetic resonance imaging (MRI) is an effective modality to assess the adequacy of the reduction, but sedation may be required due to the length of the examination. MRI is also more expensive than other imaging modalities. Our goal was to provide an MRI protocol that does not require sedation and can be performed in <15 minutes. Methods: We retrospectively reviewed 34 consecutive MRI studies performed without sedation after spica cast placement in 24 developmental hip dysplasia patients. The MRI examinations were performed with a variety of techniques. Sequences used were evaluated for contrast, resolution, and motion artifact. Results: Ninety-seven percent of studies were diagnostic, although 18% of examinations had significant motion artifact. Seven sequences were analyzed. T2-weighted fast spin echo sequences had the best overall scores and were performed in <3 minutes. T1 and fat-suppressed T2-weighted fast spin echo sequences did not score as well, and also required <3 minutes. Single-shot fast spin echo sequences scored poorly due to decreased contrast and resolution, despite shorter acquisition times of 20 to 40 seconds. Three-dimensional (3D) gradient recovery imaging scored poorly due to lower contrast and increased motion due to longer acquisition times of approximately 4 minutes. Both coronally and axially oriented sequences satisfactorily assessed femoral head position within the acetabulum. Conclusions: MRI is a useful tool in evaluating the hips without radiation exposure and without sedation in infants and toddlers after spica cast placement. Both axial and coronal T2 fast spin echo MRI sequences provided excellent anatomic definition and required ⩽3 minutes per sequence. Orthopaedic surgeons can request these 2 sequences for accurate assessment of concentric reduction with a potential study time of 15 minutes, obviating the need for sedation. Level of Evidence: Level II.

Magnetic Resonance Imaging of Renal Abnormalities in Patients with Congenital Osseous Anomalies of the Spine

BACKGROUND Patients with congenital osseous anomalies of the spine are known to have a high prevalence of abnormalities in the renal system and of the spinal cord. Today, the screening tools of choice to detect these abnormalities include ultrasonography of the kidneys and collecting system and magnetic resonance imaging of the spine. A single screening tool that can identify both renal and intraspinal anomalies would be ideal. METHODS Imaging studies of all patients with a congenital osseous anomaly of the spine seen at our institution during a ten-year period were retrospectively reviewed. Only patients who had had both a sonogram of the renal system and a magnetic resonance imaging study of the entire spine were included in the investigation. All studies were reviewed blindly by a pediatric radiologist for this study. RESULTS One hundred and fifty-three patients met the criteria for inclusion in the study. Forty-one patients (27%) had a total of forty-seven renal abnormalities noted on both the sonogram and the magnetic resonance imaging scan. In no instance was a renal anomaly seen on one study and not on the other. CONCLUSIONS When properly performed, screening magnetic resonance imaging scans of the spine can show renal abnormalities, thus obviating the need for a separate screening renal ultrasound study.

High failure rate of the Pavlik harness in dislocated hips: is it bilaterality?

Background: The purpose of this study was to evaluate the efficacy of Pavlik harness treatment in patients with bilaterally dislocated Graf type IV hips and compare them to cases with unilaterally dislocated hips. Methods: Twenty-one patients (42 hips) who presented with bilaterally dislocated hips with no prior treatment were studied. The comparison group consisted of 33 patients (33 hips) with unilateral hip dislocation treated with the same protocol. Successful treatment was defined as relocation of the hips within 3 weeks of Pavlik harness application. Results: Twelve of 21 patients (57%) in the bilateral group (6 failed bilaterally, 6 unilaterally) and 18/33 patients (54.5%) in the unilateral group failed harness treatment. Conclusions: The use of the Pavlik harness in dislocated hips is associated with a high failure rate. Patients presenting with bilaterally dislocated hips however, are at no greater risk for failure than patients presenting with unilateral hip dislocation. Level of Evidence: Level III.