The purpose of this study was to use MR imaging to evaluate the prevalence and extent of rotator cuff tears in paraplegic patients. who are at increased risk for impingement caused by overuse. MATERIALS AND METHODS. Sixty-Iiur MR examinations ofthe shoulder were evaluated for partial or full-thickness rotator cuff' tears and for single or multiple rotator cuff tendon tears. Thirty-seven MR studies were from paraplegic subjects (26 symptomatic. I I asymptornatic). and 27 MR studies were from able-bodied subjects (I 7 symptomatic. 10 asymptomatic). RESULTS. Among subjects who were symptomatic and paraplegic. 73(4 of' shoulders imaged showed evidence of rotator cuff tear on MR images compared with 59Y of shoulders in able-bodied symptomatic subjects. Of' all subjects with paraplegia. 57C% of shoulders imaged showed rotator cuf'f tears. Among all paraplegic subjects. prevalence and severity of tears correlated positively with age and duration of spinal cord injury. Tears that involved the posterior portion of the rotator cuff were revealed on MR images in 74'7 of the paraplegic subjects cornpared with 50 4 of the able-bodied subjects. CONCLUSION. MR imaging revealed a high percentage and degree of severity of rotator cuff tears in individuals with paraplegia and thus proved useful in evaluating shoulders in these patients.

Limb defects from 25 fetuses with limb-body wall (LBW) complex were evaluated to determine the mechanism of limb damage. The limb defects could be divided into 3 pathogenetic groups: (1) secondary to disruption of embryonic vessels and surrounding tissue (84%), (2) secondary to amniotic bands or adhesions (16%), and (3) deformation versus hemorrhage (44% with club feet), with some fetuses having more than one pathogenetic mechanism causing limb defects. The hypothesis that the majority of limb defects resulted from disruption of embryonic vessels was supported by the following findings: 96% of the LBW complex fetuses had limb defects; the lower limbs were at greater risk of damage than the upper limbs (28% rt arm, 52% lt arm, 60% rt leg, 72% lt leg); there was a distal to proximal progression of limb damage in 92% of the fetuses; statistical analysis of comparing the location of the most severe limb defect and the body wall defect did not find concordance between the side (p = 1.0) and the region (p = 0.18) of the body wall defect; and limb defects found in the human specimens were similar to those produced in experimental animals following disruption of embryonic vessels at a corresponding gestation. In the specimens with amniotic band related limb defects (16%), the most likely pathogenesis is mechanical rupture through the amnion in the presence of a persistent extraembryonic coelom or from adhesion of the amnion to necrotic embryonic tissue after the initial disruptive event. Club feet were present in 44% and may be due either to disruption of embryonic vessels or to deformation. Further studies are needed to resolve this question.

Initial conventional radiography is relatively insensitive in the detection of transverse process fractures of the lumbar spine. There is a statistically significant association between transverse process fractures and abdominal injury.

In this retrospective study, the sonographic appearance of fracture of the greater tuberosity of the humerus was evaluated in 17 men and 14 women aged 20-69 years with acute, semiacute, or remote shoulder trauma in whom results of rotator cuff sonography had suggested the diagnosis of such a fracture. Clinical data, radiologic reports, sonograms, and initial plain radiographs of the shoulder were analyzed; clinical follow-up information was assessed in 22 patients. Sonography showed discontinuity and irregularity of the humeral cortex in all patients. In 25 patients (81%), displaced fracture fragments could be seen. Sonographic findings were suggestive of, but not specific for, fracture. Cortical abnormalities of the humerus were identified without modification of standard scanning protocols. A humeral fracture was confirmed with radiography in 24 patients; in 10 of them, the fracture had been missed initially on plain radiographs. It is concluded that, in evaluation of soft tissues in shoulder trauma, sonography may define rotator cuff abnormalities and occasionally help in detection of occult humeral fractures.

The normal sonographic appearance of fetal colon and small bowel is reported in a prospective study of 130 fetuses. The colon, which appeared as a continuous tubular structure located around the perimeter of the abdominal cavity, was seen in some fetuses as early as 22 menstrual weeks and in all fetuses examined after 28 weeks. Colon diameter demonstrated a linear relation (r = 0.82) with menstrual age, reaching a maximum of 18 mm at term. In comparison, small bowel was located centrally and individual segments never exceeded 7 mm in diameter or 15 mm in length. Small bowel loops were seen in only 30% of fetuses examined after 34 weeks. Peristalsis was routinely demonstrated of the small bowel, but was not observed in the colon.