Swollen ischiopubic synchondrosis: a dilemma for the radiologist

Bilateral Van Neck-Odelberg Disease: A Case Report

Van Neck-Odelberg disease, also known as ischiopubic osteochondritis, is a rare cause of buttock or groin pain in the pediatric age group. The challenge in its diagnosis is due to its radiologic similarity. Ischiopubic synchondrosis occurs in childhood and is seen before the fusion of the pubis and ischium. With the advancement of age toward skeletal maturity, ischiopubic synchondrosis reduces in size and gradually vanishes due to synostosis or bony union. Here, we report the case of a 13-year-old girl who came to our outpatient department with complaints of bilateral groin pain for one year. After a thorough evaluation, she was diagnosed with a case of bilateral Van Neck-Odelberg disease, or ischiopubic osteochondritis, and conservative management was planned. Closure of ischiopubic synchondrosis varies with age and is usually finished before puberty. In a typical scenario, such fusion of the pubis and ischium does not lead to any clinical symptoms. However, in a few instances, children may experience some pain in the groin, hip, or gluteal region, which results in restricted movements at the hip joint and can lead to limping while walking. Van Neck-Odelberg disease is rare in children, causing pain in the groin region. As it is a rare condition, diagnosis is often missed. The radiological appearance suggests many differential diagnoses, such as a stress fracture, neoplasm, or infection. Prompt diagnosis and treatment can relieve the symptoms.

Pubic osteomyelitis after surgery for perforated colonic diverticulitis with fecal peritonitis: A case report

INTRODUCTION

Pubic osteomyelitis is a rare type of suppurative osteomyelitis. Early diagnosis of pubic osteomyelitis is difficult, and prolonged inflammation results in progressive bone degradation, severe pelvic pain and a wide-based gait.

PRESENTATION OF CASE

We report the case of an 82-year-old woman who was admitted to a previous hospital with severe abdominal pain caused by a perforated colonic diverticulum with fecal peritonitis. She underwent an emergency operation and a postoperative wound infection occurred. Despite treatment of the infection, purulent exudate was discharged for three months and she gradually showed a gait disturbance. CT and MRI revealed that pubic symphysis showed osteolysis and there was severe inflammation around the wound. After administration of appropriate antibiotics, an operation, which included the removal of a fistula, debridement of sequestra and lavage of the abscess cavity, was performed. The inflammation improved promptly after the operation, and the patient was discharged on postoperative day 27 without any complications.

DISCUSSION

Pubic osteomyelitis does not show the findings of typical acute suppurative osteomyelitis and hematological findings are nonspecific. It is important for early diagnosis to consider the risk factors of pubic osteomyelitis during examination.

CONCLUSION

We would emphasize that a definitive diagnosis by CT and MRI and appropriate antimicrobial therapy combined with surgical treatment are important for pubic osteomyelitis.

Case report: Multimodality imaging of van Neck-Odelberg disease

Synchondrosis ischiopubic syndrome (SIS), also known as van Neck-Odelberg disease, is a syndrome characterized by an atypical ossification pattern of the ischiopubic synchondrosis. Its radiological features may mimic stress fracture, neoplasm, osteomyelitis, or posttraumatic osteolysis, causing problems in diagnosis, sometimes leading to unnecessary workup. We report two cases in which the correlation between the clinical and multimodality imaging data enabled the correct diagnosis of SIS.

Osteomyelitis of the ischiopubic synchondrosis: imaging findings

Osteomyelitis of the ischiopubic synchondrosis in children is not rare and presents a diagnostic problem because of the diversity of presentation and the deceptive nature of symptoms. Radiological assessment is extremely difficult because of the variation in normal ossification on radiography and normal physiological uptake on radioisotope bone scan. We present two cases of osteomyelitis of the ischiopubic synchondrosis and describe findings on radiographs, isotope bone scan, computed tomography (CT) and magnetic resonance imaging (MRI). MRI changes have not been described in any of the case reports in the English literature. Aspiration and biopsy remain the gold standard for diagnosis. However, MRI appearances can significantly increase diagnostic confidence prior to intervention.

Asymmetric Closure of Ischiopubic Synchondrosis in Pediatric Patients: Correlation with Foot Dominance

OBJECTIVE

The enlarged ischiopubic synchondrosis is a well-known anatomic structure; however, little is known about its physiology. In early childhood, enlargement of this synchondrosis occurs bilaterally, whereas before complete ossification, it is frequently found unilaterally. In most children, the unilateral enlarged ischiopubic synchondrosis is observed in the left hemipelvis, a finding that was hitherto unexplained. During common athletic activities, increased ground reaction forces are exerted on the weight-bearing nondominant limb, which in up to 87% of the general population is the left leg. The asymmetric exertion of these forces may explain the distinct closure sequence of this temporary joint. The purpose of this study was to correlate unilateral enlarged ischiopubic synchondrosis with foot dominance.

MATERIALS AND METHODS

The study cohort comprised 32 children who had undergone unenhanced radiography, CT, or MRI for reasons other than bone disorders and who presented with enlarged ischiopubic synchondroses. In these children, the distribution of enlarged ischiopubic synchondrosis and foot dominance were evaluated either retrospectively (n = 11) or prospectively (n = 21).

RESULTS

In this cohort, 78% of patients were right-footed and 22% were left-footed. Nine of the 32 children presented with unilateral enlarged ischiopubic synchondrosis (left, seven [78%] of nine; right, two [22%] of nine). All children with enlarged left ischiopubic synchondrosis were right-footed, and all children with enlarged right ischiopubic synchondrosis were left-footed.

CONCLUSION

Unilateral enlarged ischiopubic synchondrosis is closely correlated with foot dominance. The asymmetric ossification pattern of the ischiopubic synchondrosis indicates delayed ossification of this anatomic structure due to asymmetrically applied mechanical forces to the nondominant limb.

MR imaging of the ischiopubic synchondrosis

The ischiopubic synchondrosis (IPS) is a temporary joint, occurring in childhood prior to fusion of the ischial and pubic bones. On conventional radiographs this tumor-like appearance is a well known normal anatomic variant, however, there are no reports in the literature of the appearance of IPS on MRI. Therefore the purpose of this study was to evaluate typical magnetic resonance features of the IPS. All pelvic MRIs from 1/1992 to 4/1998 of children ranging in age from 4 to 16 years, who were scanned for reasons other than bone disorders, were retrospectively investigated. Twenty-eight children were included and the morphologic appearance of IPS on MRI was evaluated. Seventeen (61%) of these 28 children had the following findings of IPS on MRI. Listed in order of frequency we found signal alteration of the ischiopubic fusion zone [hyperintense on T(2) with fat-saturation (89%) or STIR (74%), hypointense on T(1) (71%)], fibrous "bridging" (68%) [hypointense band on all sequences in perpendicular orientation to the axis of the inferior pubic ramus], fusiform swelling (68%), signal alteration of the adjacent soft tissue (57%) and irregular margins (56%). In 10 children contrast enhanced scans were available for evaluation, showing contrast enhancement of the bone marrow in 83.3% and of the adjacent soft tissue in 66.7%. Fusiform swelling of the ischiopubic fusion zone, signal alteration and contrast enhancement of both the bone marrow and the adjacent soft-tissue are characteristic features of the IPS on MRI, which may be due to mechanical stress at this temporary joint. These features are nonspecific and may resemble tumor, infection or trauma. Fibrous "bridging" was the only finding on MRI, which has not been described for any other entity and thus, it seems to be a characteristic MRI-feature.