Maroon B. Khoury

Calcification of Entheses Associated with X-Linked Hypophosphatemic Osteomalacia

We undertook a retrospective analysis of 26 patients with X-linked hypophosphatemic osteomalacia (or rickets), whose ages ranged from 1 to 62 years and who were from 11 different kindreds, to determine the prevalence and clinical characteristics of a unique disorder of the entheses (tendons, ligaments, and joint capsules). We found a generalized involvement of the entheses, with exuberant calcification of tendon and ligament insertions and of joint capsules, in 69 per cent of the subjects. The prevalence and extent of disease increased with age but were not correlated with sex. Commonly affected sites included the hand and sacroiliac joints. Histologic evaluation in a selected patient revealed intratendinous lamellar bone but no inflammatory cells. Our observations indicate that this disorder is an integral part of X-linked hypophosphatemic osteomalacia and exhibits clinical, radiographic, and histologic characteristics that differentiate it from degenerative disorders of these tissues and seronegative spondyloarthropathies.

Bilateral avulsion fractures of the anterior superior iliac spines in sprinters

Three cases of bilateral pelvic avulsion fractures in adolescent sprinters are reviewed. Anacute avulsion fracture of the anterior superior iliac spine (ASIS) occurred during active running in three teenaged sprinters. Radiography confirmed a healed fracture of the contralateral ASIS. The clinical features and radiologic appearances are characteristic. The pathophysiology of this type of unique pediatric fracture is discussed. Conservative treatment is successful.

CT of obstructive lobar collapse.

The varied computed tomographic (CT) appearance of obstructive lobar collapse is described in 25 cases. CT is helpful in understanding the morphology and mechanisms of lobar collapse and in diagnosing atypical cases. The final shape of the collapsed lobe is dependent on the size and location of the obstructing tumor and on the amount of retained lung fluid. Focal bulging of the fissure (S-sign) is the most helpful sign in identifying the obstructing tumor. Differential enhancement could not separate the tumor from collapsed lung in six of eight (75%) of the cases studied with intravenous contrast, a finding at variance with previous reports. The limitations of CT in evaluating mediastinal or pleural invasion in the presence of lobar collapse are discussed.

Case report 376

A 24-year-old woman school teacher noticed swelling behind her left ankle when she started jogging two or three miles a day, approximately nine months prior to admission. She stopped jogging for three months, and the swelling receded. However, the swelling returned along with pain, when she resumed jogging three months before to admission. The ankle also became swollen and painful when she attended classes for physical exercise. The patient denied any ecchymosis, numbness or weakness of the left foot or ankle. Physical exami-

Occult carpal pathology: tomographic evaluation

Pluridirectional tomography in coronal and sagittal planes has been used to identify occult carpal pathology in 23 patients with chronic wrist pain following recent or remote trauma. The tomographic studies have detected or further defined the carpal pathology in 22 of the 23 patients studied adding useful information concerning their clinical management.