Computed tomographic evaluation of the acetabulum for age estimation in an Indian population using principal component analysis and regression models

The acetabulum presents as a well-preserved evidence, resistant to taphonomic degradation changes and can thus aid in the age estimation process. A CT-based examination of the acetabulum can further help simplify the process of age estimation by overcoming the time-consuming process of maceration and by doing away with the interference resulting from tissue remnants. The aim of the present study was to evaluate the role of the acetabulum for age estimation in an Indian population through a CT-based examination, using principal component analysis and regression models. CT images of 400 individuals aged 10 years and above were evaluated according to the features defined in the San-Millán-Rissech method of age estimation. Five of the seven morphological features defined by San-Millán-Rissech were appreciable on CT scans, and, to enable further statistical analysis, a cumulative score was computed using these five features. A significant correlation of 0.835 and 0.830 for the right and left acetabulum, respectively, was obtained between computed cumulative scores and chronological age of individuals. No significant sex differences were observed in the scoring of different age-related morphological changes. Regression models were generated using individual features and cumulative scores. Regression models derived using the cumulative score yielded inaccuracy values of 9.67 years for the right acetabulum and 9.15 years for the left acetabulum. Inaccuracy and bias values were computed for each individual feature, as well as for each decade, using mean point ages established within the original study. Amongst the various features, acetabular rim porosity was seen to have the lowest values of inaccuracy (11.50 years) and bias (2.32 years) and activity on outer edge of acetabular fossa the highest (inaccuracy and bias values of 22.36 years and 21.50 years, respectively). Taking into consideration this differential contribution towards age estimation, weighted coefficients and mean point ages for different morphological features were determined using principal component analysis. Subsequently, summary age models were generated from the obtained weighted coefficients and mean age values. Summary age models derived in the present study yield lower estimates of inaccuracy of 7.60 years for the right acetabulum and 7.82 years for the left acetabulum. While regression models derived in the present study allow for age estimation using even a single appreciable feature, summary age models take into account the contribution of each feature and generate more accurate estimates of age. Both statistical computations yield reduced error rates and thus can render greater applicability to the acetabulum in forensic age estimation.

     

Test of the usefulness of acetabular size for stature estimation

Only one study to date has explored the potential of innominate measurements for the estimation of stature in forensic contexts. The acetabulum, however, is among the skeletal regions most resistant to the processes of destruction and often survives intact. In this investigation, diameter, area and perimeter dimensions of the acetabulum were recorded from digital photographs in a documented French sample, consisting of 36 males and 33 females. Linear regression equations for estimating stature were then generated for each dimension in both males and females. Correlation coefficients for the models ranged from r?=?0.401 to r?=?0.474, and standard error of the estimate (SEE) values were between 5.7?cm and 6.1?cm. The highest correlation coefficients in both sexes were observed for the diameter of the acetabulum. These results indicate that acetabular dimensions should only be used for stature estimation when more accurate bones are unavailable for analysis.     

Acetabulum protrusio and center edge angle: new MR-imaging measurement criteria—a correlative study with measurement derived from conventional radiography

Objective  The goal of this study was to identify a method of measurement for acetabulum protrusio and center edge angle (CEA) using MR imaging of the pelvis that correlated with classic methods using radiographic landmarks. Materials and methods  MR images and radiographs of the pelvis in 67 patients (132 hips) were used to identify reliable MR-imaging methods for measuring protrusio acetabulum and CEA that correlated strongly with established radiographic measurements. Protrusio acetabulum was determined using the radiographic criterion that the acetabular line projects medial to the ilioischial line by 3 mm or more in men and 6 mm or more in women. Pearson correlation factor was used to determine inter-observer variability and those methods that demonstrated the strongest correlation. The mean and standard deviation of MR-imaging and radiographic measurements for both the normal and protrusio hips were established. Results  Several MR methods correlated strongly with radiographic measurements. The preferred method employed axial MR images at the level of the ischial spine with measurement of the distance between the medial most point of the acetabular fossa and a line perpendicular to the horizontal axis that passed through the lateral margin of the posterior inner pelvic wall. The Pearson’s correlation factor between radiographic and MR measurements using this method was 0.84, and inter-observer correlation was 0.80. There were 126 hips in 63 patients (17 female and 44 male) that did not meet the radiographic criteria for protrusio acetabula. In this group of normal hips, the mean and standard deviation of radiographic measurements were 1.9 and 2.8 mm in male patients and −0.5 and 1.7 mm in female patients, and the mean and standard deviation for the preferred MR method was 1.3 and 2.5 mm in male patients and −0.8 and 1.9 mm in female patients. A total of six hips in four patients (two female and two male) met the radiographic criteria for protrusio acetabula. In this group of patients, the mean and standard deviation of radiographic measurements were −3.7 and 1 mm in male patients and −5.4 and 0.9 mm in female patients, and the mean and standard deviation for the preferred MR method was −4.1 and 0.4 mm in male patients and −6.5 and 0.3 mm in female patients. Our study also showed that the CEA was best measured using anterior to middle coronal MR images. Posterior coronal MR-imaging measurements correlated poorly with radiographic measurements. Conclusion  MR imaging can be used to assess acetabular morphology and measure acetabulum protrusio. The research was performed at VASDHS, La Jolla, CA.     

Applicability of the Calce method for age estimation in an Indian population: A clinical CT-based study

Age estimation is one of the prerequisites of human identification. Age-progressive changes in the pelvis offer useful evidence for forensic age estimation across all age groups. The acetabulum presents as a durable and taphonomic degradation resistant age marker, and, can be employed for analysing age-progressive changes described by Calce. The present study aimed at determining the applicability of the Calce method for age estimation in an Indian population based on a computed tomographic examination of the acetabulum. Additionally, different morphological features defined by Calce were evaluated to identify the feature which contributes most towards the process of age estimation. CT images obtained from clinically undertaken examinations of individuals aged 17 years and above were scrutinized according to the features defined within the Calce method. No statistically significant bilateral or sex differences were observed. An overall accuracy of 76.66% was observed on applying the Calce method to an Indian population, with lower accuracy percentages for individuals aged 40 years and above. The associated overall inaccuracy and bias were found to be 9.45 and 8.88 years, respectively. Within the various features, acetabular groove was found to contribute most towards the overall accuracy, and apex growth the least. Considering this weighted proportion, population specific models should be derived to render greater applicability to the method for age estimation.     

Age-related changes in the craniofacial region in a modern Greek population sample of known age and sex

The aim of this paper is to investigate ageing changes in craniofacial region in both sexes and evaluate whether these shape changes are substantial to achieve age discrimination of samples used in anthropological analyses. The study sample consisted of 157 crania of known sex and age (81 males and 76 females) belonging to individuals who lived in Greece during the twentieth century. The sample was divided in three age groups: young adults (YA, 18–39 years old), middle adults (MA, 40–59 years old) and old adults (OA, >60 years old). The three-dimensional coordinates of 31 ecto-cranial landmarks were digitized using a Microscribe 3DX contact digitizer, and landmark configurations were analyzed using the generalized least-squares Procrustes method. The results indicate that both males and females show significant difference among the age groups; however, shape differences can not be used for age group discrimination due to a large range on the accuracy of age group classification. The morphometric changes related to age were different between sexes.

     

CT-based evaluation of the acetabulum for age estimation in an Indian population

Age estimation constitutes an important aspect of forensic research, investigation and human identification. For the purpose of age estimation, various markers within the skeletal framework are employed. Degenerative morphological changes in the skeleton can be used for age estimation in adults. Amongst the various bones, age-progressive changes in the innominate bone are of particular significance in age estimation. Within the pelvis, the acetabulum presents as a durable and well-preserved evidence, characteristic manifestations of which can be employed for age estimation. The present study aimed at a CT-based evaluation of acetabular changes for the purpose of age estimation in an Indian population. CT images of 250 individuals aged 10–88 years were scrutinized according to the features defined in the Calce method of acetabular age estimation. Scores were allotted to the various features and a cumulative score was calculated. No significant bilateral and sex differences were observed. Significant correlation was obtained between the scores for these defined characteristics and the chronological age of individuals. Population-specific regression models were generated for age estimation. The scoring method devised in the present research requires further validation as it represents a new tool for age estimation in medico-legal cases.

     

Relationship between Wiberg's lateral center edge angle,Lequesne's acetabular index,and medial acetabular bone stock

Objective  

Knowledge of acetabular anatomy is crucial for cup positioning in total hip replacement. Medial wall thickness of the acetabulum is known to correlate with the degree of developmental dysplasia of the hip (DDH). No data exist about the relationship of routinely used radiographic parameters such as Wiberg's lateral center edge angle (LCE-angle) or Lequesne's acetabular index (AI) with thickness of the medial acetabular wall in the general population. The aim of our study was to clarify the relationship between LCE, AI, and thickness of the medial acetabular wall.     

Accuracy of the use of radiographic visibility of root pulp in the mandibular third molar as a maturity marker at age thresholds of 18 and 21

Evaluation of the radiographic visibility of root pulp in mandibular third molars has been suggested as an alternative method for estimation of legal age threshold in living individuals when the root apices are mature. Here, we assessed the accuracy of this method for age thresholds of 18 and 21 years. A sample of 463 panoramic radiographs of individuals aged between 16 and 34 years was examined. The root pulp visibility of the mandibular third molars was scored; the stages ranged from 0 to 3. A receiver operating characteristic (ROC) curve and the area under the ROC curve (AUC) were used to select optimal cut-offs for 18- and 21-year-old thresholds. As prognostic predictors, the selected cut-offs were stages 1 and 2 for the 18- and 21-year-old thresholds of both sexes, respectively. For the 18-year-old threshold, the AUC, sensitivity and specificity were 0.829, 83.1% and 66.7% in females; and 0.930, 89.4% and 90.9% in males, respectively. For the 21-year-old threshold, the AUC, sensitivity and specificity were 0.874, 72.8% and 92.0% in females; and 0.906, 85.5% and 88.2% in males, respectively. The accuracy of the method for estimating the 18- and 21-year-old thresholds ranged from moderate to high. Therefore, the method must be used in conjunction with other age estimation methods, especially to predict whether a female has reached 18 years of age.

     

Early results in the use of the oblong S-ROM uncemented acetabular component

Massive deficiency of acetabular bone stock is a challenging problem in the increasing number of patients who need a revision of the failed hip arthroplasty. Oblong acetabular cup has been presented as an alternative reconstruction technique for hips with extensive acetabular bone loss. The aim of this study was to present our results with the use of a bilobed acetabular component inserted during revisional surgery, to define indications, and to introduce this method into our orthopaedic practice. Seven patients underwent revisional hip arthroplasty with a cementless oblong acetabular component between September 2000 and June 2002. Six patients underwent revisional hip arthroplasty, and in one primary hip arthroplasty by oblong acetabular component was performed because of bone defect of acetabulum after gunshot fracture. The average follow up was thirteen months. Radiographic analysis in all patients demonstrated stable, bone incorporated acetabular component with the restored hip. All the patients walked with full weight bearing and were without pain. On the basis of our experience we find this method satisfactory in certain types of bone defects of acetabulum, and that it provides stable reconstruction of acetabulum with the correction of hip joint.     

Acetabular ossicles: normal variant or disease entity?

Ossicles located in the acetabular fossa may confuse diagnostic and therapeutic work-up. An accessory ossification centre may persist unfused as an os acetabuli centrale which is surrounded by intact hyaline cartilage representing an anatomic variant. Bone islands located in the pillars of the acetabulum can project into the acetabular fossa simulating acetabular ossicles. Osteochondrosis dissecans, posttraumatic articular bodies, degenerative disease and other rare lesions may be responsible for clinical symptoms and are of similar appearance than anatomic variants. Plain film radiography, X-ray tomography, CT and MRI are used to categorize these lesions. MRI is very valuable to assess cartilage integrity in a noninvasive way, but arthro-CT or arthro-MRI have to be used in unclear cases. Therefore the purpose of this presentation is to discuss the appearance, the possible etiology and the differential diagnosis of acetabular ossicles and how they can be evaluated to avoid an unnecessary arthrotomy. Received: 22 December 1998; Revised: 28 May 1999; Accepted: 8 July 1999     

A novel method to estimate adult age from the lumbar vertebral body using 3D PMCT images in Japanese

This study evaluated the age-related changes in the vertebral body using 3D Postmortem CT (PMCT) images and proposed an alternative age estimation formula. The PMCT images of 200 deceased individuals aged 25 to 99 years (126 males, 74 females) were retrospectively reviewed and included in the study. Using the open-source software ITK-SNAP and MeshLab, a 3D surface mesh of the fourth lumbar vertebral body (L4) and its convex hull models were created from the PMCT data. Using their inbuilt tools, volumes (in mm3) of the L4 surface mesh and convex hull models were subsequently computed. We derived VD, defined as the difference in volumes between the convex hull and L4 surface mesh normalized by L4 mesh volume, and VR, defined as the ratio of L4 mesh volume to convex hull volume based on individual L4. Correlation and regression analyses were performed between VD, VR, and chronological age. A statistically significant positive correlation (P < 0.001) between chronological age and VD, (r_s = 0.764, males; r_s = 0.725, females), and a significant negative correlation between chronological age and VR (r_s = -0.764, males; r_s = -0.725, females) was obtained in both sexes. The lowest standard error of the estimate was demonstrated by the VR at 11.9 years and 12.5 years for males and females, respectively. As such, their regression models to estimate adult age were Age = 248.9–2.5VR years, males; Age = 258.1–2.5VR years, females. These regression equations may be useful for estimating age in Japanese adults in forensic settings.     

Preliminary study on sexual dimorphism of metric traits of cranium and mandible in a modern Italian skeletal population and review of population literature

This study aims to assess the sexual dimorphism of skull in a modern skeletal collection through a direct anthropometric methodology by using a logistic regression analysis as statistical approach in order to provide specific regression formulae for the Italian population.Thirtyfour measurements (24 from cranium, 10 from mandible; 33 linear distances, one angle) were taken on 80 individuals (40 males, 40 females). A stepwise discriminant function analysis selected the combination of variables which best discriminated between sexes, and a cross-validation assessed the accuracy rate of the original sample.Most distances resulted longer in males than in females, but differences were statistically significant only for 12 and 6 out of respectively 24 cranium and 10 mandibular distances. Five combined cranium features returned a prediction accuracy of 88.6% (y = −81.01 + 0.14* Maximum cranial length + 0.16* Basion-bregma height −0.05* Cranial base length +0.20* Bizygomatic breadth +0.31* Nasal height; adjusted R² = 47.0%). Nine mandibular features were required to reach 74.7% accuracy (y = −93.08 + 0.19* Bigonial width +0.14* Bicondylar breadth +0.11* Mandibular length +0.18* Height of the mandibular body at mental foramen +0.21* Chin height −0.09* Mandibular angle −0.06* Minimum ramus breadth −0.05* Maximum ramus height −0.01* Maximum ramus breadth; adjusted R² = 23.92%).Current results and existing literature suggested that only few cranial measurements can be used for diagnosis of sex: the same variables showed similar accuracy in different ethnic contexts. In conclusion, some aspects of sexual dimorphism of skull seem to be independent from ancestry.     

全髋关节置换术中髋臼假体定位的研究进展

目前全髋关节置换术已成为治疗终末期髋关节疾病的有效手段,由于髋臼侧结构的特殊性,髋臼杯位置的定位方法尚有争议。髋臼假体定位方法主要有根据术前、术中影像学资料定位,根据髋臼局部解剖特征和(或)结合机械设备定位等,本文就髋臼假体位置定位的研究进展作一综述。     

严重髋臼骨折

严重髋臼骨折是一种复杂损伤。可分为前、后柱、横、Y／T形和臼顶骨折五类。大多数髋臼骨折均有错位和股骨头中心脱位。牵引不能复位者应行手术治疗。本文报告17例严重髓臼骨折，其中9例行手术治疗效果满意。     

Age-at-death estimation based on the macroscopic examination of Spheno-occipital sutures

ObjectiveTo examine the closure degree of spheno-occipital synchondrosis and its relationship with chronological age.Materials and MethodsCross-sectional analysis of the closure degree of spheno-occipital suture was done through direct inspection of 376 autopsies from both sexes whose ages ranged between 8 and 26 years in Legal Medicine Organization of Tehran, Iran from 1st of July 2007 to 1st of July 2009. The correlation between the degree of closure and chronological age was investigated.ResultsMean ages of open, semi-closed and closed sutures were 12.27, 16.12 and 21.17 years in males, and 9.04, 12.38 and 19.44 in females, respectively. Seemingly, their difference was significant (p < 0.001). Partial fusion (semi-closed) was seen at the age of 12 in both sexes while complete fusion (closed) was seen at 15 year olds or above in males and 12 year olds or above in females. Spearman’s correlation ratio coefficient showed a linear correlation between age and suture situation in both sexes (rho = 0.788, P < 0.001 in males and r = 0.645, P < 0.001 in females).ConclusionThe study showed that the closure degree of spheno-occipital suture can be used as a good indicator for age estimation in both sexes. Cadavers can be correctly grouped above or below 16 years old with sensitivity of 79.82% and specificity of 89.47% in males and above or below 13 years old with sensitivity of 100.00% and specificity of 81.58% in females.     

Acetabular fractures revisited: part 2, a new CT-based classification

OBJECTIVE: The objective of this investigation was to provide a new CT-based classification of acetabular fractures. MATERIALS AND METHODS: The axial CT scans of 112 randomly selected acetabular fractures in patients admitted to a level 1 trauma center between January 1998 and December 2000 were analyzed by an experienced orthopedic trauma surgeon and two experienced emergency radiologists. When available, 3D reformatted images were analyzed as well. The fracture pattern for each acetabular fracture, with respect to column walls and extension beyond the acetabulum, when present, was recorded. Fracture comminution was not a defining characteristic. RESULTS: Analysis of the 112 acetabular fracture patterns showed that each fracture fell into one of four broad categories. Category 0 included wall fractures only. Category I included acetabular fractures limited to a single (anterior or posterior) column. Category II fractures included those involving both the anterior and posterior columns; category II fractures were further subdivided into those with no fracture extension beyond the acetabulum, those with superior or inferior extension, and those with both superior and inferior extensions beyond the acetabulum. Category III fractures included only the "floating" acetabulum, which is defined as an acetabular fracture in which the acetabulum is separated from the axial skeleton both anteriorly and posteriorly. CONCLUSION: The axial CT display of acetabular fracture patterns provides a basis for a classification of acetabular fractures that is simple, unambiguous, readily understood by both radiologists and orthopedic surgeons and provides clear direction for both diagnosis and surgical treatment planning. Category and subcategory fracture specificity creates a mechanism for intra- and interdepartmental postoperative assessment of any of the individual acetabular fracture types.     

Dental age estimation in Somali children and sub-adults combining permanent teeth and third molar development

Estimation of an individual’s age has important applications in forensics. In young individuals, it often relies on separate evaluations of permanent teeth (PT) and third molars (TM) development. Here, we analysed the age prediction performance of combined information from PT and TM in an unusual sample of healthy Somalis, born and living in Finland. PT development was staged according to Demirjian et al. (Hum Biol, 1973) and TM development according to Köhler et al. (Ann Anat, 1994), using panoramic radiographs from 803 subjects (397 males, 406 females) aged 3–23 years. A sex-specific Bayesian age-estimation model for the multivariate distribution of the stages conditional on age was fitted on PT, TM and PT and TM combined. The age-estimation performances were validated and quantified. The approach combining PT and TM only overestimated age with an ME of − 0.031 years in males and − 0.011 years in females, indicating the best age prediction performance.

     

Pelvic synovial cyst formation secondary to perforation of the quadrilateral plate: a case report

A seventy seven-year-old female presented to her gynaecologist with right-sided pelvic pain and irregular per vaginal bleeding. Ten years earlier she had undergone a right cementless total hip arthroplasty. The press fit acetabular component had been augmented by screws. Radiological investigation requested by her gynaecologist identified a right iliac fossa mass. This communicated with the hip joint via a screw track formed by a fixation screw that had penetrated the medial wall of the acetabulum at total hip arthroplasty. Following aspiration of the fluid within the cyst, microscopy demonstrated it to be of synovial origin. Her symptoms subsequently resolved. This condition has not been reported previously.     

Evaluation of the radiographic visibility of the root pulp in the lower third molars for the purpose of forensic age estimation in living individuals

The question of whether an individual has reached the age of 18 is of crucial importance in forensic age estimation practice. In some countries, the age threshold of 21 years is relevant as well. A completed mineralization of third molars is not a sufficient criterion for a diagnosis of a minimum age of 18 years with the required probability. In a material of 1,198 orthopantomograms from 629 females and 569 males aged between 15 and 40 years, the visibility of the root pulp of fully mineralized lower third molars was evaluated according to stages 0, 1, 2, and 3. In females, stage 0 was first noticed at age 17.2 years, in males at age 17.6 years. In either sex, the earliest observation of stage 1 was between 21.0 and 22.4 years. Stage 2 was first achieved by males between 22.3 and 22.7 years, by females between 23.4 and 24.7 years. The occurrence of stage 3 was first found in both sexes between 25.1 and 25.9 years. These findings indicate that for stage 0, an age below 18 years cannot be excluded. However, for stage 1, the examined individual must be over 18 years of age and most probably over 21 years of age. For stages 2 and 3, the age can safely be stated to be over 21 years of age. This method may be a powerful tool for forensic dentists in age estimation in asylum and criminal proceedings.     

DXAGE 2.0 — adult age at death estimation using bone loss in the proximal femur and the second metacarpal

The accurate age at death assessment of unidentified adult skeletal individuals is a critical research task in forensic anthropology, being a key feature for the determination of biological profiles of individual skeletal remains. We have previously shown that the age-related decrease of bone mineral density (BMD) in the proximal femur could be used to assess age at death in women (Navega et al., J Forensic Sci 63:497–503, 2018). The present study aims to generate models for age estimation in both sexes through bone densitometry of the femur and radiogrammetry of the second metacarpal. The training sample comprised 224 adults (120 females, 104 males) from the “Coimbra Identified Skeletal Collection,” and different models were generated through least squares regression and general regression neural networks (GRNN). The models were operationalized in a user-friendly online interface at https://osteomics.com/DXAGE2/. The mean absolute difference between the known and estimated age at death ranges from 9.39 to 13.18 years among women and from 10.33 to 15.76 among men with the least squares regression models. For the GRNN models, the mean absolute difference between documented and projected age ranges from 8.44 to 12.58 years in women and from 10.56 to 16.18 years in men. DXAGE 2.0 enables age estimation in incomplete and/or fragmentary skeletal remains, using alternative skeletal regions, with reliable results.