Kathleen H. Emery

The Healing Potential of Stable Juvenile Osteochondritis Dissecans Knee Lesions

BACKGROUND The purpose of the present study was to determine if patient age, lesion size, lesion location, presenting knee symptoms, and sex predict the healing status after six months of a standard protocol of nonoperative treatment for stable juvenile osteochondritis dissecans of the knee. METHODS Forty-two skeletally immature patients (forty-seven knees) who presented with a stable osteochondritis dissecans lesion were included in the present study. All patients were managed with temporary immobilization followed by knee bracing and activity restriction. The primary outcome measure of progressive lesion reossification was determined from serial radiographs every six weeks, for up to six months of nonoperative treatment. A multivariable logistic regression model was used to determine potential predictors of healing status from the listed independent variables. RESULTS After six months of nonoperative treatment, sixteen (34%) of forty-seven stable lesions had failed to progress toward healing. The mean surface area (and standard deviation) of the lesions that showed progression toward healing (208.7 +/- 135.4 mm(2)) was significantly smaller than that of the lesions that failed to show progression toward healing (288.0 +/- 102.6 mm(2)) (p = 0.05). A logistic regression model that included patient age, normalized lesion size (relative to the femoral condyle), and presenting symptoms (giving-way, swelling, locking, or clicking) was predictive of healing status. Age was not a significant contributor to the predictive model (p = 0.25). CONCLUSIONS In two-thirds of immature patients, six months of nonoperative treatment that includes activity modification and immobilization results in progressive healing of stable osteochondritis dissecans lesions. Lesions with an increased size and associated swelling and/or mechanical symptoms at presentation are less likely to heal.

MRI Appearance of Chronic Stress Injury of the Iliac Crest Apophysis in Adolescent Athletes

OBJECTIVE The objective of our study was to describe the MRI appearance of chronic repetitive stress injury of the iliac crest apophysis in adolescent athletes. CONCLUSION Increased signal intensity on water-sensitive sequences and mild widening of the physis, often with adjacent bone marrow and muscle edema, are characteristic of chronic stress injury of the iliac apophysis in adolescent athletes who may present with hip, pelvic, or back pain.

MR findings of synovial disease in children and young adults: Part 2

Synovium is the thin membranous lining of a joint. It produces synovial fluid, which lubricates and nourishes the cartilage and bone in the joint capsule. Synovial diseases in children can be classified as normal structures as potential sources of pathology (synovial folds: plicae, infrapatellar fat pad clefts), noninfectious synovial proliferation (juvenile idiopathic arthritis, hemophilic arthropathy, lipoma arborescens, synovial osteochondromatosis, pigmented villonodular synovitis, reactive synovitis), infectious synovial proliferation (pyogenic arthritis, tuberculous arthritis), deposition disease (gouty arthropathy), vascular malformation, malignancy (metastasis) and intra-/periarticular cysts and cyst-like structures. Other intra-articular neoplasms, such as intra-articular synovial sarcoma, can mimic synovial disease in children.

Juvenile Dermatomyositis: Correlation of MRI at Presentation With Clinical Outcome

OBJECTIVE The clinical course of juvenile dermatomyositis (JDMS) is unpredictable. MRI is used to determine muscle biopsy site and to monitor disease activity. It is unknown whether soft-tissue features on MRI obtained at diagnosis correlate with clinical outcome. The purpose of our study is to determine whether initial MRI findings in the pelvis and thighs in children with JDMS can predict clinical disease course. MATERIALS AND METHODS Forty-five children (31 girls and 14 boys; median age, 6 years; range, 1-18 years) with clinically diagnosed biopsy-proven JDMS and at least 24 months of clinical follow-up were included. Clinical outcome was categorized as limited or chronic disease, according to the established Crowe clinical classification scheme. Pretreatment MRI examinations of the pelvis and thighs were evaluated for signal abnormalities of muscle and fascia and reticulated signal changes in subcutaneous fat; associations with clinical outcome were examined. RESULTS Twenty-two patients had limited disease and 23 had chronic disease. Signal intensity ranged from normal (n = 3) to floridly increased in all muscle compartments (n = 17). Muscle and fascial involvement were not associated with clinical outcome. Controlling for duration of symptoms, the adjusted odds of progressing to chronic disease were higher for patients with abnormal subcutaneous fat signal than for those with normal fat signal (odds ratio, 9.0; 95% CI, 1.5-53.5; p < 0.02). CONCLUSION MRI findings of muscle or fascia involvement do not predict clinical outcome in children with newly diagnosed JDMS. Abnormal subcutaneous fat signal appears to have a significant association with a more aggressive chronic disease course.

Medial collateral ligament of the knee on magnetic resonance imaging: does the site of the femoral origin change at different patient ages in children and young adults?

Background The medial patellofemoral ligament (MPFL), a chief medial restraint preventing lateral patellar dislocation, often is reconstructed in children with recurrent dislocation. The femoral MPFL attachment can be difficult to delineate at surgery. Therefore, the origin of the medial collateral ligament (MCL) frequently is used to approximate the reattachment site. The purpose of our study was to compile normative data from MR imaging examinations over different patient ages, to determine the effect of growth on the relationship of the MCL origin site to the distal femoral physis and medial femoral condyle (MFC). Subjects and Methods This HIPAA-compliant study was IRB approved. Informed consent requirement was waived. Three hundred knee MR imaging examinations (143 boys, 157 girls, 0–20 y) were evaluated. MCL origin to femoral physis distance, MFC height, and MCL origin-physis distance: MFC height ratio (MCL:MFC ratio) were calculated. Relationships between these values and age, gender, and physeal patency were assessed using linear regression models. Results With physeal patency, MCL origin-physis distance was significantly associated with increasing age in boys (P=0.0394), and trended toward significance in girls (P=0.0557). Distance increased 0.01 cm/y in both genders. MFC height increased 0.15 cm/y in boys and 0.13 cm/y in girls (P<0.0001). MCL:MFC ratio decreased 0.01/y (P<0.0001). With physeal closure, no significant change was measured for any variable. Conclusions During growth, there are statistically significant, albeit minimal, changes of the MCL origin-physis distance and MFC height. As these changes are essentially negligible, no adjustment for age is needed during restorative MPFL surgery in growing children. Clinical Relevance As there is neglible change in location of the origin of the MCL relative to the distal femoral physis during skeletal growth in both boys and girls, no adjustment for patient age is necessary when using the origin of the MCL as a landmark to locate the site of femoral reattachment of a disrupted MPFL.

Postoperative Pelvic MRI of Anorectal Malformations

OBJECTIVE Patients operated on for anorectal malformations can experience technical complications related to the initial corrective surgery. Many of these complications may necessitate reoperation. Pelvic MRI is part of the evaluation to assess the position of the pulled-through bowel, the sphincter muscles, and the critical area of the posterior urethra. This article reviews the various pelvic MRI findings in these patients. CONCLUSION Pelvic MRI is a valuable tool in the assessment of postoperative anorectal malformations that may necessitate additional surgery.

Tailgut cyst in a child

Tailgut cyst, or retrorectal cystic hamartoma, is a rare congenital lesion found in the presacral space. The lesion has been infrequently reported in the literature. We report the MRI findings of a tailgut cyst in a 2-year-old girl who presented with a sacral dimple and skin discoloration.

Lap belt iliac wing fracture: a predictor of bowel injury in children

Abstract. Lap belt restraints in motor vehicle collisions have been associated with a variety of injuries, mainly bowel and lumbar spine. Cephalad positioning of the belt over the intended position across the anterior superior iliac spines (which typically occurs in younger children) is thought to be responsible for the observed bowel injuries. We report two pediatric patients, both restrained by lap belts in high-speed collisions, who suffered iliac wing fractures in addition to bowel injuries. Unexplained free peritoneal fluid was the sole CT finding in one patient (a teenage girl) who had a delay in diagnosis of bowel perforation. These cases illustrate the high frequency of bowel injury in pediatric patients with iliac wing fractures associated with lap belt use.

Tibial nerve intraneural ganglion cyst in a 10-year-old boy

Intraneural ganglion cysts are uncommon cystic lesions of peripheral nerves that are typically encountered in adults. In the lower extremity, the peroneal nerve is most frequently affected with involvement of the tibial nerve much less common. This article describes a tibial intraneural ganglion cyst in a 10-year-old boy. Although extremely rare, intraneural ganglion cysts of the tibial nerve should be considered when a nonenhancing cystic structure with intra-articular extension is identified along the course of the nerve. This report also details the unsuccessful attempt at percutaneous treatment with US-guided cyst aspiration and steroid injection, an option recently reported as a viable alternative to open surgical resection.

Elbow plica syndrome: presenting with elbow locking in a pediatric patient

This case report is of a symptomatic posterior-lateral elbow plica in a child who presented with elbow locking. MR images demonstrated thickening of a posterior-lateral plica between the radius and capitellum of the elbow. Surgery confirmed a thickened and inflamed posterior-lateral plica, which was resected with subsequent improvement of the child’s symptoms. This case shows the clinical importance of identifying thickening of posterior-lateral plicae in children and suggesting the diagnosis of plica syndrome, an entity that has not been previously reported in children in the radiologic literature.