The overall goal with this procedure is to provide information about bone quality in forensically relevant remains. This method can help answer pertinent questions for forensic anthropologists such as non-destructive assessments of juvenile fatal starvations and neglect cases. This method can also differentiate between elder abuse and pathologies, as well as distinguishing taphonomic artifacts from pathology or trauma.
The main advantage of this technique is that it is reproducible and provides a quantitative assessment that can be substantiated with clinical standards. To begin this procedure, prepare the machine as outlined in the text protocol. Next, create a new patient profile for each new individual to be scanned to maintain chain of custody and to ensure scans are correctly associated.
If the individual being scanned is unidentified, establish the biological profile prior to scanning. Enter the demographic information into the patient profile, including the estimated stature if the actual stature is unknown. For anterior-posterior lumbar spine scans, select Perform Scan, choose Patient, select Scan Type, AP Lumbar Spine, and then Next.
Then select a container that is at least as large as the articulated segment of L1 through L4.Fill the bottom of the container with rice, which will act as a soft tissue proxy. Place the segment in anatomical position into the rice with approximately 0.7 centimeters between each vertebral body. Make sure that the superior and inferior articular facets are articulated, but that the vertebral bodies are not in contact with one another.
Next, center the scanning table. Place the container on the table so that L1 is oriented toward the head of the scanning table and L4 is placed one centimeter superior to the intersecting cross hairs. The vertical laser line should be bisecting the vertebrate bodies of all four vertebrae.
After this, cover the exposed bone with rice. Following the scan, an Exit Exam prompt box will appear. Select Analyze Scan.
In the Scan Analysis window, select Results. If the vertebrae were not properly separated, select Vertebral Lines to make minor adjustments. Then collect the results graph for visualization of the individual relative to the reference population.
To perform a left or right hip scan, first select Perform Exam, choose Patient, select Scan Type, Left Hip or Right Hip, and then Next. Select an open container that is at least as large as the articulated os coxa and femur being scanned. Then fill the bottom of the container with rice.
Place the ox coxa into the rice with the acetabulum and obturator foramen facing laterally and the pubic bone oriented medially. Position the ischial tuberosity beneath the femoral head as it articulates with the acetabulum. Next, place the femurs such that the femoral head is in the acetabulum with the greater trochanter and femoral head in line parallel to the scanning table.
Make sure that the femoral shaft is medially rotated with the lateral condyle rotated medially and slightly higher than the medial condyle. Then center the scanning table. Move the scanning arm and table until the laser cross hairs are oriented with the center directly above the subtrochanteric area of the femur.
The laser's vertical line should bisect the top half of the femoral shaft. After this, cover the remaining visible portion of the femoral acetabular joint with rice. Select Start Scan.
An Exit Exam prompt will appear after the scan is completed. Select Analyze Scan. Next, select the Bone Map tool to add or delete areas that are not part of the femoral neck and trochanteric region.
Select the Neck tool and reposition the midline to realign adjustments directly on the scan. In the Scan Analysis window, select Results. For adults, compare the scan to re reference data for the femoral neck, trochanteric region, and intertrochanteric region.
In this study, skeletal remains are scanned for use in forensic context. Representative scans show that the scanning positions typically used for living individuals for clinical BMD scans can be reproduced with skeletal remains. The first case studies of a 40-year old male who exhibited a rare fracture series.
A DXA scan of the left hip is obtained to determine if these fractures were the results of fracture fragility or simply a post-mortem artifact from natural drying processes. The determined total BMD is 1.299 grams per square centimeter with the corresponding T-score of 1.8, indicating that bone insufficiency was not the cause. The second case study is a 13-year old girl with a suspected history of long-term abuse, recovered from a clandestine grave.
The total BMD is 0.660 grams per square centimeter with the Z-score of 2.2. The Z-score is consistent with the low BMD for chronological age, supporting other methods suggesting chronic malnutrition. The third and final case study is a 14-month old infant with starvation as the suspected cause of death.
The total BMD of the lumbar spine is measured at 0.190 grams per square centimeter, while the age-matched reference group's average is approximately 0.399 grams per square centimeter. The Z-score is calculated to be 5.225 with the relevant age-matched mean. These low values suggest that the infant is below the third percentile of spine BMD for 12-month olds.
Once mastered, this technique can be done in one hour if it is performed properly. While attempting this procedure, it's important to remember that anatomical orientation is the primary determinate for a successful scan. After watching this video, you should have a good understanding of how to adapt clinical BMD to forensic cases.
