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Supernumerary kidney is a highly uncommon congenital anomaly characterized by the presence of at least 1 or more extra kidneys in variable positions and morphology. Due to the scarcity in the medical literature, not much is known about this condition. The additional kidney typically has its own collecting system, vascular supply, and distinct encapsulated parenchyma. In this case, we present a 38-year-old male with a right supernumerary kidney who was initially investigated for a renal artery aneurysm. In the case of our patient, the discovery of a supernumerary kidney influenced the course of management and prevented unnecessary intervention and procedure. This emphasizes the importance of thorough imaging and diagnostic techniques in patients to accurately identify and characterize such anomalies.

Head injuries are the most common severe injuries sustained by pediatric occupants in road traffic crashes. Preventing children from adopting positions that can result in an increased injury risk due to unfavorable interactions with the restraints is fundamental. The objective of this paper was to assess the effect of a head support system (SS) on the lateral position of the head, the vertical position of the sternum and the shoulder belt fit. Thirty pediatric rear-seat passengers were exposed to two 75-minute trials. Volunteers were restrained by a three-point belt and, if needed, used the appropriate child restraint system for their anthropometry (high-back booster, low-back booster, no booster). A case crossover study was designed in which the volunteers used the head support system (SS) during one of the trials, acting as their own controls (No SS) in the other. Compared to the control group, the head support reduced significantly the 90(th) percentile value of the absolute value of the relative lateral motion of the head, regardless of the restraint used. The system also reduced the maximum downward position of the sternal notch within the low-back booster group. As for the belt fit, the use of the head support improved significantly the position of the shoulder belt on the occupant in the low-back booster and in the no booster groups.

Understanding pediatric occupant postures can help researchers indentify injury risk factors, and provide information for prospective injury prediction. This study sought to observe lateral head positions and shoulder belt fit among older child automobile occupants during a scenario likely to result in sleeping - extended travel during the night. An observational, volunteer, in-transit study was performed with 30 pediatric rear-seat passengers, ages 7 to 14. Each was restrained by a three-point seatbelt and was driven for seventy-five minutes at night. Ten subjects used a high-back booster seat, ten used a low-back booster seat, and ten used none (based on the subject height and weight). The subjects were recorded with a low-light video camera, and one frame was analyzed per each minute of video. The high-back booster group exhibited a statistically significant (p<0.05) decrease in the mean frequency of poor shoulder belt fit compared to the no-booster and low-back booster groups. The high-back booster group also exhibited statistically significant decreases in the 90(th) percentile of the absolute value of the relative lateral motion of the head. The low-back booster group did not result in statistically significant decreases in poor shoulder belt fit or lateral head motion compared to the no-booster group. These results are consistent with the presence of large lateral supports of the high-back booster which provided support to the head while sleeping, reducing voluntary lateral occupant motion and improving shoulder belt fit. Future work includes examining lap belt fit in-transit, and examining the effects of these observations on predicted injury risk.

The purpose of this study was to investigate the magnitude of bending moment that results in fracture of the pedicles when lumbar vertebrae are loaded in four-point bending. Nine human second lumbar vertebrae (L2) were harvested from donors aged 59-75 years. The specimens were potted and then subjected to quasi-static sagittal-plane four-point bending, which allowed for a constant bending moment applied over a 3.8 cm span centered on the vertebral pedicles until fracture. The failure bending moment calculated for the pedicles varied widely (30.7 +/- 12.3 Nm) and was poorly correlated with subject age (y = -0.91x + 91.5, R(2) = -0.27). With increasing displacement, the bending moment applied to the pedicles increased, first linearly, followed by a non-linear portion, prior to specimen fracture. In general, the specimens failed at the interface of the pedicles and vertebral bodies, but failures were observed elsewhere as well. These data provide sufficient response and boundary condition information for finite element modeling and model validation.

This study presents the results of indentation tests on the superior vertebral endplate of the 4th lumbar vertebra (L4) of eleven male cadaveric subjects (65 +/- 7 years). Three locations on the superior endplate surface were loaded with a 7.9 mm spherical indentor at either a low (1 mm/s) or high (1000 mm/s) rate. Anterior midline and posterior right and left indentation locations were chosen to prevent local deformations and fractures from influencing the results of subsequent and preceding tests. Peak forces were higher in the dynamic tests (498 +/- 261 N) than in the quasi-static tests (451 +/- 256 N) on the posterior side, although the difference was not significant (p = 0.139). However, the peak forces in the anterior tests (304 +/-166 N) were significantly lower (p =0.0157) than in the posterior tests with the same loading rate. The variation in failure forces in the current study correlates with the variation in thickness of endplate cortical bone (between specimens and between anterior and posterior locations on the same specimen) as measured from small field of view computed tomography scans.

The purpose of this study was to investigate the response and failure properties of the transverse and spinous vertebral processes under cantilever bending. Twelve human third lumbar vertebrae (L3) were harvested from donors aged 56-79 years, and the processes were loaded in either dynamic (1000 mm/s) or quasi-static (1 mm/s) cantilever bending. All of the spinous processes were loaded dynamically, and transverse process loading was alternated between dynamic and quasi-static and between right and left. Peak forces measured for the transverse processes were 252 +/- 77 N and 234 +/- 50 N in the dynamic and quasi-static tests, respectively, which corresponded to lack of rate sensitivity in the transverse process peak force for the range of loading rates considered (p=0.6). Peak forces measured for the spinous processes were 1179.6 +/- 587.1 N, and both subject mass (p=0.038) and subject age (p=0.006) were found to be significant predictors of peak force.