Periprosthetic modelling of femoral component fit using computed tomography data for total hip arthroplasty: a feasibility study

The aim of the work was to create a new three-dimensional periprosthetic multi-criteria optimisation technique to identify the best six degrees of freedom transform to position a porous-coated anatomic cementless femoral component for three factors, including: first, maximisation of the degree of contact achieved between designated bone ingrowth surfaces and the periprosthetic bone; secondly, minimisation of the bone mass to be removed to accommodate the component and thirdly, the extreme constraint of the component to be positioned so that it does not project beyond the periosteum. Discrete integrals were computed over regions of interest derived from the polyhedral component mesh in transaxial CT scan planes, using a polygon scan-conversion algorithm. A new biomedical imaging volume rendering technique utilising dynamic virtual textures was developed to visualise the design trade-offs.Pareto-optima were identified for four femora that matched an average-sized component. The non-linear, multi-modal fit metric was quadratic near minima, with a narrow trough of equivalent fit values within 3 mm of translation and 3 degrees of rotation with respect to the canal axis, and possessed a dependence most pronounced for distal-directed insertion against varus/valgus rotation. The study gives previously unavailable data on the three-dimensional femoral component fit and is the first report that demonstrates that fitting the implant using several design criteria in a multi-criteria optimisation scheme is feasible.     

Gender differences in distal femoral morphology and the role of gender specific implants in total knee replacement: a prospective clinical study

Gender differences in distal femoral morphology may affect femoral component fit using a standard range of prostheses. The clinical relevance of this is controversial.Standardised measurements were taken from the distal femora of 50 males and 50 females during total knee replacement (TKR). Corresponding measurements were taken from the respective gender specific and standard femoral components. No demographic differences were noted.Significant differences in both frequency and magnitude existed in the medial-lateral femoral component overhang between the sexes. In females, standard implants overhung at the anterior flange width (AFW) by > 2 mm in 24/50 (48%) and by > 3 mm in 17/50 (34%) (p < 0.001). Also at the anterior medial-lateral width (MLA) 29/50 (58%) overhung by > 2 mm and 24/50 (48%) by > 3 mm (p < 0.001). In males, standard implants overhung by > 2 mm in 1/50 (2%). In females, gender specific implants overhung by > 2 mm in 3/50 (6%). Females had a mean aspect ratio of 1.02 (0.82 to 1.35) and men 0.98 (0.79 to 1.19).Femoral component overhang can occur in females undergoing TKR and a gender specific implant would reduce the potential for medial-lateral overhang. Long term studies are awaited to quantify the clinical implications of overhang.     

Gender differences of the morphology of the distal femur and proximal tibia in a Korean population

PurposeWe conducted this study to determine whether the sizes of distal femurs and proximal tibiae in Korean men and women are different, and to assess suitability of the sizes of prostheses currently used in Korea.Materials and methodsWe performed morphological analysis of proximal tibia and distal femur on 115 patients (56 male, 59 female) using MRI to investigate a gender difference. Tibial mediolateral dimension (tMAP), tibial medial anteroposterior dimension (tMAP), tibial lateral anteroposterior dimension (tLAP) femoral mediolateral dimension (fML), femoral medial anteroposterior dimension (fMAP), and femoral lateral anteroposterior dimension (fLAP) were measured. The ratio of tMAP and tLAP to tML (plateau aspect ratio, tAP/tML × 100%), and that of fMAP and fLAP to fML (condylar aspect ratio, fAP/fML × 100%) were calculated. The measurements were compared with the similar dimensions of four total knee implants currently used.ResultsThe tML and tAP lengths showed a significant gender difference (P < 0.05). The plateau aspect ratio (tMAP/tML) revealed a significant difference between male (0.74 ± 0.05) and female (0.68 ± 0.04, P < 0.05). For morphotype of distal femur, males were found to have significantly large values (P < 0.05) in the parameters, except for fLAP. With regards to the ratio of the ML width to the AP length, the women showed a narrower ML width than the men. Both genders were distributed within the range of the dimensions of the prostheses currently used prostheses.ConclusionsKorean population revealed that women have smaller dimensions than male counterparts. In both genders, a relatively small size of prostheses matches distal femur and proximal tibia better among the implants currently used in Korea.     

Gender and age related differences in foot morphology

Objective

This study has assessed age-related changes of foot morphology for developing appropriate footwear with particular reference to the elderly.

Methods

Anatomical parameters such as foot length, circumference and height and ankle length, circumference and height were assessed in a sample of males (n = 577) and females (n = 528) divided into three age groups. The groups included young-adult, aged between 20 and 25 years; adult, aged between 35 and 55 years; and old, aged between 65 and 70 years individuals.

Results

In terms of gender differences, in young-adult individuals the sex-related morphological differences observed, are just related to a significantly lower length of foot in females. In adult subjects morphological parameters investigated were significantly lower in females even after normalization for foot length. In old individuals, no differences of the parameters were found after normalization for foot length. Comparative analysis of morphometric data between young-adult and adult individuals revealed that the instep length was smaller in adults. The opposite was observed for the great toe and medial foot arch height. Length of ankle was higher in adult than in young-adult individuals, whereas ankle circumference and height were smaller. In old vs adult individuals foot circumference showed the most relevant age-related differences.

Conclusions

Feet anatomy presents specific characteristics in different ages of life. The ideal footwear should take into account these characteristics. This is true primarily for the elderly for minimizing the risk of falls or of other problems related to inappropriate footwear.     

Gender differences in emotional responses: A psychophysiological study

Gender differences in emotional responses have been investigated in two groups of students, 22 males and 21 females. Participants watched a set of sixty emotional standardized slides divided into pleasant, neutral and unpleasant, while Startle reflex, Evoked Potentials, Heart Rate, facial EMG and Skin Conductance were recorded. Startle reflex amplitude, an index modulated by amygdala and orbitofrontal cortex and sensitive to aversive emotional stimuli, was overall larger in women. In addition, startle emotion modulation was greater in women with respect to men. Slow Evoked Potentials (400–800 ms), a measure representing the cognitive component of the emotional response, revealed gender differences in the left prefrontal site, with women showing greater positivity to unpleasant compared with pleasant slides while men had greater positivity to pleasant vs. neutral slides. Women, compared with men, perceived all slides as less pleasant and reported greater arousal to unpleasant condition. Results are in line with known functional brain differences, at level of limbic and paralimbic structures, between men and women, and point to biologically grounded greater sensitivity and vulnerability of women to adverse/stressful events.     

Intra- and interobserver reliability and agreement in three-dimensional computed tomography measurements of component positions after total knee arthroplasty

BackgroundAccurate evaluation of the postoperative position of total knee arthroplasty (TKA) components is crucial in the analysis of the association of alignments with clinical outcomes. The aim of this study was to investigate the reliability of measurements of component positions after TKA using three-dimensional computed tomography (3D-CT) reconstruction.MethodsTwo independent orthopedic surgeons (an attending surgeon and a fellow) examined 30 knees after primary TKA. The coronal, sagittal, and rotational positions of the femoral and tibial components were measured twice at an interval of six weeks on 3D-CT images reconstructed using ZedKnee software. Mean intra- and interobserver differences of measured angles were calculated, and the intra- and interobserver reliability was determined using intraclass correlation coefficients (ICCs), with agreement assessed by Bland–Altman analysis.ResultsThe mean intraobserver difference between alignment measurements for femoral and tibial components was < 2° (range 0.23–1.17°) and the mean interobserver difference was < 1° (range 0.22–0.97°). The intra- and interobserver ICCs were > 0.8 for all component positions. The only systematic bias found in the intra- and interobserver agreements occurred for the sagittal position of the femoral component.ConclusionThree-dimensional-CT measurements of component positions after TKA showed good intra- and interobserver reliability for the femoral and tibial components in coronal, sagittal and rotational positions. The intra- and interobserver agreements were favorable for all but the sagittal position of the femur. These results suggest that 3D-CT can be used to evaluate the alignment of all TKA components except for the sagittal position of the femur.     

A three-dimensional study of the atlantodental interval in a normal Chinese population using reformatted computed tomography

The atlantodental interval has been usually used for the evaluation of atlantoaxial instability. However, the asymmetry of the lateral atlantodental interval is occasionally found in healthy individuals. Controversy therefore exists as to the clinical significance of this asymmetry in patients after trauma. The purpose of this study was to determine the normal range of atlantodental intervals in normal individuals using reformatted computed tomography. In this study, C1–C2 vertebrae were imaged in 230 adult patients by a Lightspeed Vct CT (General Electric, CT, USA) with a slice thickness of 0.625 mm. After reformatting the original images, the anterior atlantodental interval (AADI) and lateral atlantodental interval (LADI) were measured. The AADI was found to be 1.83 ± 0.46 mm (0.9–3.4 mm) in males and 1.63 ± 0.43 mm (0.5–3.2 mm) in females. The AADI was significantly greater in males than in females (p < 0.05). The 95% confidence interval for AADI was 1.75–1.90 mm in males and 1.54–1.72 mm in females. No statistically significant differences were found between males and females in the left and right LADI, and LADI asymmetry. The left LADI was found to be 3.38 ± 0.87 mm (1.7–6.0 mm), and the right LADI was 3.42 ± 0.84 mm (1.7–5.9 mm) in males, while the left LADI was 3.30 ± 0.73 mm (1.5–5.3 mm) and the right LADI was 3.37 ± 0.92 mm (1.7–5.9 mm) in females. The 95% confidence interval for left LADI was 3.23–3.52 and 2.94–3.25 mm, and for right LADI was 3.27–3.56 and 3.18–3.56 mm in males and females, respectively. The mean asymmetry of LADI was 0.76 ± 0.66 mm (0.0–3.5 mm) in males and 0.73 ± 0.70 mm (0.0–3.7 mm) in females. The 95% confidence interval for LADI asymmetry was 0.65–0.87 mm in males and 0.59–0.88 mm in females. Most of the population was found to have an asymmetry ranging between 0.1 and 2.0 mm. The current study shows that LADI asymmetry is common in patients without any cervical spine abnormalities. LADI asymmetry may be a normal anatomic variant and there is no evidence to confirm that LADI asymmetry is a sensitive or specific indicator of traumatic atlantoaxial instability. Radiologists and clinicians should be aware of this normal range of asymmetry when interpreting CT scans of the atlantoaxial region.     

Developmental morphology of the cervical vertebrae and the emergence of sexual dimorphism in size and shape: A computed tomography study

Cervical vertebral bodies undergo substantial morphological development during the first two decades of life that are used clinically to visually determine skeletal maturation with the cervical vertebral maturation index (CVMI). CVMI defines six stages that capture the morphological transformations from 6 years to 18 years. However, CVMI has poor reproducibility given its qualitative nature and does not account for sexual dimorphism. This study aims to quantify the morphological development of the cervical vertebral bodies C2–C7 in size (height and depth) and shape and examine the emergence of sexual dimorphism. Using 115 (70 M;45F) computed tomography studies from typically developing individuals ages 6 months to 20 years, landmarks were placed at the margins of the C2–C7 cervical vertebral bodies in the midsagittal plane for size and shape analysis. Findings revealed a dichotomy in the growth trends of height versus depth. The C2–C7 growth in depth gained the majority of the adult size by age 5 years, while the C3–C7 growth in height displayed two periods of accelerated growth during early childhood and puberty. Significant sex differences were found in height and depth growth trends and the form-space ontogenetic trajectories during puberty, with minor but evident differences emerging at age 3 years. Female C2–C7 depth measures were smaller than males at all ages. However, sex differences in height became evident due to males continuing to grow after females reach maturity. Findings quantify the morphological developmental stages of CVMI and emphasize the need to account for sex differences when assessing skeletal maturation.     

Gender and temporal differences in sleep-wake patterns in Japanese schoolchildren

STUDY OBJECTIVE: To determine gender and weekly differences in sleep patterns in Japanese children in junior high school. DESIGN: A school-based study. SETTING: N/A. PARTICIPANTS: Ninety-one children, aged 13 to 14 years, from junior high schools in Japan. INTERVENTIONS: N/A. MEASUREMENTS: Sleep patterns were measured using actigraphy (Actiwatch) for 7 consecutive days, in parallel with daily logs and a questionnaire. RESULTS: Girls showed better indicators of sleep and higher degrees of motionless sleep during the week. Actual sleep values and sleep efficiency were higher and the fragmentation index was lower in girls compared to in boys. On weekends, bedtime was delayed, especially for boys--11:17 PM versus 10:49 PM for girls. A higher level of activity during sleep was more evident among boys, especially during weekends. Boys also showed a higher number of nighttime awakenings. Subjective complaints such as drowsiness and desire for a longer sleep time were significantly higher for the boys. CONCLUSION: Our findings support the hypothesis that, during the junior high school period, the majority of sleep-quality indicators in Japanese schoolchildren were better for girls than for boys. Boys' sleep was less efficient and more fragmented during the entire week in comparison to that of the girls. These objective findings are supported by subjective assessments. Additional studies should clarify whether these disparities are culturally determined or represent a universal gender-specific characteristic.     

Calcaneal and pelvic fractures: Diagnostic evaluation by three-dimensional computed tomography scans

A major application of three-dimensional (3D) computed tomography (CT) is in the imaging of the skeleton. 3D CT has a potentially important role in determining the presence, type, and extent of fractures, especially of the calcaneus and pelvis. The objective of this study was to compare the diagnostic sensitivity and specificity of 3D CT, CT slices, and plain radiography in the detection and characterization of calcaneal and pelvic fractures. 3D CT reconstructions were obtained by two methods, surface reconstruction and volumetric techniques. Twenty-eight patients were imaged with CT, 3D CT, and plain radiography. The opinion of a musculoskeletal radiologist with access to all images plus clinical history, surgical findings, and follow-up findings was taken as truth. Four additional musculoskeletal radiologists read these cases in a blinded fashion and ranked the modalities with regard to perceived utility. Receiver operating characteristic analysis was used to determine the relative value of each modality in terms of diagnostic quality. All imaging modalities performed comparably in the diagnosis of fractures. CT slices and plain-films were the most useful for more difficult diagnostic tasks such as fracture stability, and the presence of comminution and estimation of the number of fragments. The results suggest that for skeletal areas with complicated anatomy (such as the pelvis and calcaneus), the diagnostic value of 3D CT is often equivalent to that of conventional methods.     

翼腭窝区域的影像学解剖研究及其临床意义

目的　研究多层螺旋CT测量翼腭窝解剖相关标志与实体解剖的关系,为临床手术治疗翼腭窝区病变提供解剖学依据。 方法　成人头部标本5例（10侧）,采用MSCT及三维重建技术,观察翼腭窝结构,分别测量一些内镜下重要解剖结构的影像数据,然后对头颅标本行翼腭窝区内镜解剖,并测量得到相应解剖学数据,比较两者解剖测量数据。 结果　影像学方法与解剖学方法测量的解剖数据都可反映实体情况,两者无明显统计学差异。 结论　翼腭窝影像解剖数据可靠,具有鼻内镜手术临床指导价值。     

Three-dimensional motion patterns of the carpal bones: an in vivo study using three-dimensional computed tomography and clinical applications

A three-dimensional (3D) CT technique was developed to analyze in vivo segmental carpal kinematics. Transverse CT data of the distal forearm, carpals and proximal metacarpals was acquired and 3D reconstructed in various wrist positions. Carpal kinematics were analyzed in two groups of 20 asymptomatic volunteers, one group in neutral position, flexion and extension (45°), and the other group in neutral position, radial (15°) and ulnar deviation (30°). Qualitative analysis included the 3D study of carpal anatomy, and comparison of carpal bone position between the different sets of data obtained. Carpal bone motion was quantified using rigid body and finite helical axis concepts. The results, although agreeing in principle with previous findings, showed important individual variations in carpal bone motion. Clinical applications were conducted in a series of 25 patients with various wrist disorders. There was no significant difference between the injured wrist and the heterolateral, asymptomatic wrist, but there was a significant difference between asymptomatic volunteers and both the injured wrist and heterolateral wrist of patients. In particular, scaphoid motion was altered bilaterally in our patient group, suggesting the existence of anatomic and/or kinematic factors predisposing to certain carpal pathologies. This hypothesis needs to be confirmed and refined.     

A morphological study of the multi infraorbital canals of the maxilla in the Japanese macaque by cone-beam computed tomography

The infraorbital canal in the Japanese macaque is composed of main and accessory canals. However, the morphological features of the infraorbital canal, such as the canal course and the supply of infraorbital vessels and nerves in the maxilla, are poorly characterized. In this study, we show the structure of the infraorbital canal of the Japanese macaque (adults; 10 male, 9 female), including the distribution of these vessels and nerves, using cone-beam computed tomography and a macroscopic apparatus. The superior and lateral margins of the orbit were correlated with the infraorbital canal on three-dimensional reconstruction images (P < 0.05). We classified three types of multi infraorbital foramina as follows: type 1 had one accessory foramen, type 2 had two accessory foramina, and type 3 had three accessory foramina in the infraorbital canal. The infraorbital canal also formed three structures, specifically, a tube-like shape, a funnel shape, and a pinched shape. The accessory canals also contained nerves and blood vessels, and the canals ran downward and supplied the maxillary sinus, teeth, and midfacial region of the craniofacial skeleton, while passing through a few branch canals. These accessory canals proved valuable for blood vessels and nerves and allowed us to recognize the maxilla in the Japanese macaque skull.     

Gender differences in treatment outcomes of tuberculosis patients in Taiwan: a prospective observational study

Gender disparities in tuberculosis (TB) cases are reported worldwide, and socio-cultural factors have been proposed as possible causes. To date, gender differences in treatment outcomes of TB patients remain controversial. In this prospective observational study, newly diagnosed, culture-proven TB patients from six hospitals in Taiwan were enrolled for analysis. Gender differences in demographic characteristics and treatment outcomes, including sputum conversion and on-treatment mortality, were analysed accordingly. From January 2007 through to December 2009, a total of 1059 patients were enrolled, including 819 (77.3%) males and 240 (22.7%) females. The ratio of male gender was around 50~60% in TB patients below 35 years and >80% for those older than 65 years. When compared with the female patients, the male patients were older, more likely to have the habit of smoking, chronic obstructive pulmonary disorder, malignancy and liver cirrhosis, and more likely to present with haemoptysis, body weight loss and pleural effusion. Regarding treatment outcomes, male gender is associated with a lower 2-month sputum culture conversion rate (78.8% vs. 89.3%, p 0.002) and higher on-treatment mortality (21.1% vs. 12.1%, p 0.002). Kaplan-Meier survival analysis demonstrated significantly higher mortality in the men (p 0.005). In multivariate analysis, male gender was an independent risk factor for 2-month sputum culture un-conversion (OR, 1.96; 95% CI, 1.12–3.41). Our findings suggest that male gender is associated with older age, more co-morbidities and worse treatment outcomes. Gender-specific strategies, including active case finding in elderly women and smoking cessation in male patients, are warranted to optimize TB management.     

Gender differences in emotional responses: a psychophysiological study

Gender differences in emotional responses have been investigated in two groups of students, 22 males and 21 females. Participants watched a set of sixty emotional standardized slides divided into pleasant, neutral and unpleasant, while Startle reflex, Evoked Potentials, Heart Rate, facial EMG and Skin Conductance were recorded. Startle reflex amplitude, an index modulated by amygdala and orbitofrontal cortex and sensitive to aversive emotional stimuli, was overall larger in women. In addition, startle emotion modulation was greater in women with respect to men. Slow Evoked Potentials (400-800 ms), a measure representing the cognitive component of the emotional response, revealed gender differences in the left prefrontal site, with women showing greater positivity to unpleasant compared with pleasant slides while men had greater positivity to pleasant vs. neutral slides. Women, compared with men, perceived all slides as less pleasant and reported greater arousal to unpleasant condition. Results are in line with known functional brain differences, at level of limbic and paralimbic structures, between men and women, and point to biologically grounded greater sensitivity and vulnerability of women to adverse/stressful events.