The risk of carcinogenesis from radiographs to pediatric orthopaedic patients. J Pediatr Orthop. 2000;20:251-254. [PMID: 10739292 DOI: 10.1097/00004694-200003000-00023]

Developmental dysplasia of the hip: What has changed in the last 20 years?

Developmental dysplasia of the hip (DDH) describes the spectrum of structural abnormalities that involve the growing hip. Early diagnosis and treatment is critical to provide the best possible functional outcome. Persistence of hip dysplasia into adolescence and adulthood may result in abnormal gait, decreased strength and increased rate of degenerative hip and knee joint disease. Despite efforts to recognize and treat all cases of DDH soon after birth, diagnosis is delayed in some children, and outcomes deteriorate with increasing delay of presentation. Different screening programs for DDH were implicated. The suspicion is raised based on a physical examination soon after birth. Radiography and ultrasonography are used to confirm the diagnosis. The role of other imaging modalities, such as magnetic resonance imaging, is still undetermined; however, extensive research is underway on this subject. Treatment depends on the age of the patient and the reducibility of the hip joint. At an early age and up to 6 mo, the main treatment is an abduction brace like the Pavlik harness. If this fails, closed reduction and spica casting is usually done. After the age of 18 mo, treatment usually consists of open reduction and hip reconstruction surgery. Various treatment protocols have been proposed. We summarize the current practice for detection and treatment of DDH, emphasizing updates in screening and treatment during the last two decades.

Validity and reproducibility of the measurements obtained using the flexicurve instrument to evaluate the angles of thoracic and lumbar curvatures of the spine in the sagittal plane

Objective. to verify the validity and reproducibility of using the flexicurve to measure the angles of the thoracic and lumbar curvatures. Method. 47 subjects were evaluated by: (1) palpation and marking of the spinous processes using lead markers, (2) using X-rays in the sagittal plane to measure the Cobb angles, (3) molding the flexicurve to the spine, and (4) drawing the contour of the flexicurve onto graph paper. The angle of curvature was determined with the flexicurve based on a 3rd order polynomial. Results. No differences were found between the Cobb angles and the angles obtained using the flexicurve in thoracic and lumbar curvatures (P > 0.05). Correlations were strong and significant for the thoracic (r = 0.72, P < 0.01) and lumbar (r = 0.60, P < 0.01) curvatures. Excellent and significant correlations were found for both the intraevaluator and interevaluator measurements. Conclusion. The results show that there is no significant difference between the values obtained using the flexicurve and those obtained using the X-ray procedure and that there is a strong correlation between the two methods. This, together with the excellent level of inter- and intraevaluator reproducibility justifies its recommendation for use in clinical practice.

A study on the radiation dose of the orthopaedic surgeon and staff from a mini C-arm fluoroscopy unit

In this study, radiation exposure to the surgeon and supporting staff from a mini C-arm unit during fluoroscopically guided orthopaedic surgeries was studied. A Diadose dosemeter and Gamma-Scout meter were used for air-kerma measurements for primary and scattered radiations. The entrance dose of hands, eyes and thyroid of the surgeon was measured during direct observation. Scattered air-kerma rate was measured to quantify the received entrance dose of the supporting staff. During direct observation, the skin-entrance exposure rates of the surgeon's hand, eye and thyroid gland were 8036, 0.85 and 0.9 microGy min(-1), respectively. The scattered exposure rate was precipitously dropped beyond the path of the primary radiation beam, and reached 0.51 microGy min(-1) at a distance of 40 cm from the beam's central axis. This study showed that the surgeon's hand was the most dose-limiting organ for fluoroscopically guided orthopaedic surgery procedures when it was exposed to primary radiation. The exposure of supporting staff at a working distance of >20 cm from the beam was minimal during fluoroscopy by mini C-arm unit.

Differences in effective dose and energy imparted estimation from PA–AP, RLAT–LLAT projections in pediatric full spine x-ray examination using the Monte Carlo technique

Effective dose (E) and energy imparted (epsilon) can be used to quantify the risk of radiation-induced carcinogenesis or hereditary effects arising from radiographic exposures. When the children are examined or treated for idiopathic scoliokyphosis it is important to estimate E and epsilon in the patients due to full spine x-ray examination. The aim of this study is to calculate E and epsilon in the case of children of 5 and 10 years old who undergo full spine x-ray examination using the Monte Carlo approach. Dose area product (DAP) and entrance surface dose (ESD) were also used. AP, PA, RLAT, LLAT projections are simulated by using appropriate energy spectra. According to the results, the effective dose (E) and the energy imparted (epsilon) are smaller at PA projection than AP, although for spine the opposite occurs, in agreement with previous studies. On the other hand, E and epsilon do not differ statistically among RLAT and LLAT projections. Moreover, the role of lung and bone as tissue inhomogeneities in epsilon is shown to be very important.