Radiographic calibration for pubic diastasis assessment in bladder exstrophy-epispadias complex: a phantom study.

BACKGROUND: The assessment of pubic diastasis is important for the surgical planning of patients with bladder exstrophy-epispadias complex. Understanding how the diastasis changes during surgical follow-up may help predict patient morbidity. Radiography can follow diastasis but may be affected by patient and technical imaging factors including body size, imaging protocol, and equipment. Using imaging calibration and anatomic ratios may mitigate differences due to these aspects. OBJECTIVE: Use imaging phantoms to assess the effect of radiographic calibration on measurements of pubic diastasis and an internal anatomic ratio as a child grows. MATERIALS AND METHODS: Radiographic images were obtained of three different sizes of computed tomography phantoms (older child, child, and infant) using three imaging techniques that include the osseous pelvis in children. All phantoms were imaged with abdomen and pelvis techniques. The infant phantom was additionally imaged using a thoracoabdominal technique. These exposures were all repeated with systems from three manufacturers. Linear measurements were made between radiographic markers placed to simulate pubic diastasis and sacral width. A ratio was also created between these distances. Measurements with and without image calibration were made by two pediatric radiologists using rulers placed at the time of image acquisition. RESULTS: There was excellent interrater agreement for measurements, ICC >0.99. Anterior distances were more affected by magnification than posterior ones with a significant difference between uncalibrated versus calibrated anterior distances (p=0.04) and not for posterior ones (p=0.65). There was no difference between radiographic equipment manufacturers without or with calibration (p values 0.66 to 0.99). There was a significant difference in simulated pubic distance between thoracoabdominal and abdomen (p=0.04) as well as pelvic (p=0.04) techniques which resolved with calibration, each p=0.6. The ratio between the simulated pubic diastasis and sacral width differed by phantom size (all p<0.01) and imaging technique (p values 0.01 to 0.03) with or without calibration. However, the numerical differences may not be clinically significant. CONCLUSION: Image calibration results in more uniform measurements that are more accurate than uncalibrated ones across patient size, imaging techniques, and equipment. Image calibration is necessary for accurate measurement of inter-pubic distances on all projection imaging. Small differences in the pelvic ratio likely are not clinically significant, but until there is a better understanding, image calibration may be prudent.

Interobserver reliability in the Gustilo and Anderson classification of open fractures.

The Gustilo and Anderson classification system is widely used to categorize open fractures. To assess its interobserver reliability, 10 patients with open fractures had photographic slides taken of their wound before and after operative treatment. These slides were then shown to a group of orthopaedic surgeons. After an explanation of the Gustilo and Anderson classification system and each patient's pertinent history and physical examination, the physicians were asked to classify the fracture. Agreement among the various raters was determined by Kappa analysis, which is the preferred measurement of interobserver reliability for nominal data such as classification schemes. Kappa analysis demonstrated only moderate agreement among the observers classifying open fractures using the Gustilo and Anderson system. This seems to indicate that, although useful, the Gustilo and Anderson open fracture classification system does have limitations; studies and treatment recommendations based on it should be interpreted with caution.

Current concepts in the management of pediatric hip disease.

A wide variety of disorders affects the pediatric hip. The most common of these are developmental dysplasia of the hip, Legg-Calvé-Perthes disease, and slipped capital femoral epiphysis. Magnetic resonance imaging and ultrasound improve the imaging of these diseases, but the ultimate impact of this technology on treatment is unknown. Complications of treatment for these and other pediatric hip diseases can be devastating; so much recent research concentrates on the etiology, prevention, and effects of these complications. Finally, these diseases occur in skeletally immature individuals, and long-term follow-up is essential for accurate evaluation of results.

Treatment of posttraumatic cubitus varus in the pediatric population with humeral osteotomy and external fixation.

Cubitus varus may occur after supracondylar humerus fractures. Poor fixation, however, complicates operative treatment of cubitus varus. We discuss the use of external fixation in the treatment of cubitus varus. Five patients had humeral osteotomies with external fixation. The preoperative humeroulnar angle (HUA) averaged -24.2 degrees. The immediate postoperative HUA averaged 12 degrees, and the final angle averaged 13 degrees. Duration of external fixation averaged 8.9 weeks. Complications were one transient radial neurapraxia, one superficial pin infection, and one keloid. No loss of correction or motion occurred with external fixation; we recommend external fixation as safe and effective.

The stubbed great toe: importance of early recognition and treatment of open fractures of the distal phalanx.

Stubbing injuries to the great toe can be a cause of occult open fractures and osteomyelitis. Five such patients were identified after conducting a retrospective review of injuries to the hallux between January 1998 and December 1998. The study was conducted to draw attention to the association between this trivial trauma and its possible complications. All five children had open fractures of the distal phalanx of the great toe. Osteomyelitis did not develop in the children whose injuries were recognized early and who were treated with antibiotics. However, three children with delayed diagnoses and treatment developed osteomyelitis. At a mean follow-up of 10 months (range, 9-11) after injury, all five fractures had healed with no active signs of infection. Two of these children experienced a partial growth arrest and two experienced a full growth arrest of the distal phalanx of the great toe, the significance of which is yet unknown. Clinical signs such as bleeding from the eponychium and a laceration proximal to the nail bed should alert physicians to the presence of a possible open fracture. Early detection and treatment of these injuries may reduce or eliminate hospital stays and prolonged intravenous antibiotic treatment for osteomyelitis.

Radiologic evaluation of juvenile tillaux fractures of the distal tibia.

This study evaluated the accuracy of plain radiographs and computerized tomography (CT) in assessing juvenile Tillaux fractures of the distal tibia. A simulated Tillaux fracture was made in four cadaver specimens and displaced 0, 1, 2, 3, and 5 mm. Plain radiographs and CT were performed on each specimen at each amount of displacement, and the results were compared with the actual amount of displacement present. Plain radiographs and CT were accurate within 1 mm in depicting the actual fracture displacement about 50% of the time. CT was more sensitive than plain radiographs in detecting fractures with >2 mm of displacement. Fracture displacement of >2 mm is generally considered an indication for fracture reduction. Because of its sensitivity in detecting fractures displaced >2 mm, CT is the preferred imaging modality in the assessment of juvenile Tillaux fractures.

Tarsal coalition: depiction and characterization with CT and MR imaging.

PURPOSE: To compare computed tomography (CT) and magnetic resonance (MR) imaging in the detection, localization, and characterization of tarsal coalitions. MATERIALS AND METHODS: Preoperative CT and MR images were obtained for 10 feet in nine patients (eight male and one female patients), aged 11-18 years who were unresponsive to conservative therapy. Results from two blinded readers were compared with results from surgery. RESULTS: Five calcaneonavicular and four medial subtalar coalitions were found at surgery. One patient had synovitis. CT depicted six coalitions and four were characterized correctly, but the fibrous coalitions were not characterized correctly. MR depicted all coalitions and seven were characterized correctly, including the fibrous coalitions. At MR imaging, proliferative synovitis was incorrectly characterized as a fibrous coalition. CONCLUSION: These results suggest that MR imaging depicts all coalitions but may not be able to help differentiate synovitis from fibrous coalitions and that CT has limitations in the depiction of fibrous coalitions.

Treatment of femoral fractures in children by pediatric orthopedists: results of a 1998 survey.

SUMMARY: This study aimed to determine treatment preference of various femoral fracture patterns in children by pediatric orthopedists and whether it is practice dependent. In September 1998, members of the Pediatric Orthopedic Society of North America were surveyed to determine their current preferences in treating each of four middle one-third femoral fracture patterns in four age groups. Forty-four percent (286/656) of those surveyed responded. For each fracture pattern, operative treatment was increasingly preferred over nonoperative as patient age increased, and the preferred treatments within the operative and nonoperative categories changed significantly as patient age increased. Fourteen specific cases of femoral head avascular necrosis were noted after rigid reamed and unreamed rodding. There is a statistically significant trend by pediatric orthopedists to treat older children's femur fractures operatively and younger children's nonoperatively. The consensus treatment is age dependent. The numerous cases of avascular necrosis after rigid rodding are a concern.