Objectives Use a deep learning model on computerized tomography images to explore how muscle volume and attenuation relate to preinjury ambulatory levels in patients with intertrochanteric or femoral neck fractures. Methods This retrospective study involved 170 female patients with intertrochanteric or femoral neck fractures who had preoperative hip computed tomography (CT) scans. Using a deep learning–based model, muscles on the unfractured side were automatically segmented, and the muscle volume and attenuation were measured for four groups: gluteal muscles, hip adductors, quadriceps, and hamstrings. Preinjury walking ability was categorized into three groups based on the Koval index: Group 1 (Koval index 1–3; walking outdoors), Group 2 (Koval index 4–6; walking indoors), and Group 3 (Koval index 7; chairbound or bedridden). Finally, associations between preinjury ambulatory status and muscle parameters, patients’ age, body mass index (BMI), hip bone mineral density, geriatric nutritional risk index, and Charlson comorbidity index (CCI) were analyzed using ordinal logistic regression models. Results Ambulatory status was associated with muscle attenuation, CCI, and BMI across all four muscle groups. Other factors did not reach statistical significance. Patients with poorer ambulatory function had lower muscle attenuation, higher CCI, and lower BMI. Conclusions Muscle attenuation on CT images correlated with preinjury ambulatory status, whereas muscle volume did not. This indicates that evaluating muscle quality via CT may more accurately reflect functional decline in older adults than assessing muscle quantity alone.

Closed suction drainage has been used after total hip arthroplasty (THA) to prevent hematoma, muscle swelling, and complications, but its effectiveness remains controversial. This study evaluated the effects of drains on postoperative hematoma, muscle swelling, and clinical outcomes. A total of 168 patients who underwent unilateral cementless THA via the posterior approach for secondary hip osteoarthritis due to developmental dysplasia were retrospectively reviewed. Among them, 60 matched pairs, with and without drains, were selected using propensity score matching based on age, sex, body mass index, operative time, and femoral stem type. The primary outcome was the percentage increase in under-fascial area (UFA) measured on axial computed tomography at the teardrop level. UFA was used as a surrogate marker of postoperative hematoma and muscle swelling and was assessed preoperatively and on postoperative day 7. Secondary outcomes included postoperative estimated blood loss (PEBL), pain (assessed using the numeric rating scale), and laboratory parameters (albumin, hemoglobin, white blood cell count, creatine kinase, and C-reactive protein) on postoperative days 1, 4, 7, and 14. The mean percentage increase in the UFA did not differ between groups (10.7

The stability and durability of ultra-high molecular weight polyethylene (UHMWPE) components are critical to the long-term success of total arthroplasty. Although radiation-induced degradation has been extensively studied and is recognized as a major issue, UHMWPE degradation by synovial lipids has garnered limited attention. Specifically, clinical evidence for lipid-induced degradation is lacking, and the validity of squalene as a model lipid remains unestablished. Therefore, this study was aimed at assessing UHMWPE degradation caused by lipids in clinical practice and developing a clinically relevant model.UHMWPE components and synovial fluid retrieved from revision surgeries were analyzed for lipid content. An in vitro lipid-induced degradation model was developed by introducing these lipids into UHMWPE. Degradation was evaluated using high-spatial-resolution mechanical testing and oxidation index (OI) measurements.Limited squalene was detected in either retrieved components or synovial fluid, whereas cholesterol esters and triglycerides were abundant. In vitro, all tested lipids elevated the OI of UHMWPE, but only lipids containing unsaturated bonds caused minor reductions in mechanical properties. Detailed analysis of retrieved components failed to detect evidence of lipid-induced degradation.These findings indicate that synovial lipids can increase OI without necessarily impairing mechanical properties. Consequently, OI alone is insufficient for evaluating degradation, and mechanical testing is essential. The extent of synovial-lipid-induced degradation was subtle compared with other degradation mechanisms. Squalene-based models do not quantitatively replicate clinical conditions, and their results must be interpreted with caution. These findings can guide the accurate assessment and prevention of lipid-induced degradation of UHMWPE in clinical settings and implant development.

Purpose and Methods: Dislocation remains a leading cause of revision in total hip arthroplasty (THA). While Lewinnek's “safe zone” for acetabular component placement has historically guided surgical orientation, dislocations still occur within this range, highlighting its limitations. Recent research has emphasized the importance of spinopelvic dynamics, particularly the relationship between pelvic tilt and spinal alignment, in influencing functional component orientation and dislocation risk. Result: Patients with spinal stiffness, prior fusion, or spinopelvic imbalance are at higher risk for instability after THA. Several spinopelvic classification systems have been developed to stratify risk and guide implant positioning. However, these systems often rely on static imaging and fail to capture post-operative or age-related changes in spinopelvic mobility. Furthermore, they do not account for femoral motion or multidirectional impingement. Virtual range of motion (VROM) simulation offers a dynamic, patient-specific alternative by modeling critical movements, such as flexion, extension, and rotation, relative to the functional pelvic plane. This enables pre-operative planning of impingement-free zones tailored to individual pelvic and femoral alignment. Even in patients with altered spinopelvic dynamics, implants planned within these parameters may achieve stability without depending solely on sagittal spinopelvic classification. Conclusion: Although spinopelvic classification systems contribute valuable insights, their clinical utility is limited by post-operative variability and omission of femoral alignment. Patient-specific, VROM-based planning may offer clinical relevant implant orientation, improving THA stability and outcomes through individualized functional alignment strategies.

Osteoporosis in patients awaiting total hip arthroplasty remains undiagnosed. Although hip radiographic indices have been proposed for screening, they have not been compared. We compared the diagnostic accuracy of eight indices for osteoporosis. The canal–bone ratio measured 7 cm below the lesser trochanter may be a useful screening tool. Osteoporosis increases the risk of perioperative and postoperative fractures in patients undergoing total hip arthroplasty (THA). However, osteoporosis remains undiagnosed and untreated preoperatively. Several indices measured on hip anteroposterior radiographs have been proposed to screen for osteoporosis. Nevertheless, few studies have compared these indices, necessitating investigations to identify a practical and effective radiographic index. Osteoporosis prevalence was assessed in 317 female patients who underwent dual-energy X-ray absorptiometry before primary THA. The screening performance of eight radiographic indices was evaluated using anteroposterior hip radiographs for patients without previous diagnosis or treatment of osteoporosis: canal flare index (CFI), morphological cortical index (MCI), canal–bone ratio (CBR) at 2, 7, and 10 cm below the lesser trochanter and canal–bone area ratio (CBAR) measured at 2–7, 2–10, and 7–10 cm segments. Receiver operating characteristic analyses were performed, and the areas under the curve (AUCs) were calculated and compared among indices. Osteoporosis was identified in 129 patients (40.7

This study aims to investigate the risk factors and onset timing of second contralateral hip fractures (SHFx) following initial femoral fractures, with a particular focus on early events occurring within one year. This retrospective study utilized a nationwide hospital claims database (Medical Data Vision, MDV) covering over 30

To review Japan’s major contributions to hip joint preservation and reconstruction, spanning joint-preservingosteotomy, biomaterials innovation, and computer-assisted precision arthroplasty. A narrative review was performed to summarize landmark clinical and scientific advances originating from Japan in the management of osteonecrosis of the femoral head (ONFH), developmental dysplasia of the hip (DDH), total hiparthroplasty (THA), bearing surface technology, and computer-assisted surgery. Japanese research has advanced the understanding and treatment of ONFH through nationwide epidemiological studies, development of classification systems, clarification of steroid-associated pathophysiology, and long-term validation of joint-preserving procedures, particularly transtrochanteric rotational osteotomy. In DDH, Japanese surgeons refined reconstructive osteotomies and established surgical strategies for complex primary and high-dislocation THA. Early clinical adoption of highly cross-linked polyethylene and advances in ceramic bearing technology improved implant longevity by reducing wear and osteolysis. Japan also pioneered CT-based navigation for both acetabular and femoral component placement and introduced the functional pelvic plane concept, shifting implant alignment from fixed safe zones toward individualized functional positioning that incorporates stem anteversion and spinopelvic dynamics. These innovations have subsequently expanded to robotic-assisted surgery and advanced three-dimensional reconstruction. Japan has made substantial contributions to modern hip surgery, from biological joint preservation to precision arthroplasty. This integrated approach—emphasizing anatomical accuracy, biomechanical restoration, and long-term durability—continues to influence contemporary practice and provides a foundation for future advances in robotics, artificial intelligence, and personalized hip reconstruction.

OBJECTIVES:Alcohol consumption is a recognized risk factor for osteonecrosis of the femoral head (ONFH), as well as hypertension, and malignant tumors. Aldehyde dehydrogenase 2 (ALDH2) activity influences alcohol-associated risks by modulating acetaldehyde metabolism; however, its role in ONFH remains unclear. This study aimed to investigate whether the alcohol flushing response, a proxy for ALDH2, modifies the relationship between alcohol consumption and ONFH. METHODS:A hospital-based case-control study was conducted on newly diagnosed patients with ONFH and controls recruited. Information on alcohol flushing responses was collected using a self-administered questionnaire and categorized into current/former flushers (inactive ALDH2) and never flushers (active ALDH2). Odds ratios (OR) and their 95% confidence intervals (CI) of various levels of alcohol consumption (habitual drinking, heavy drinking, and drinking of ≥320 g/week) were assessed for ONFH using a logistic regression model. Stratified analysis and multiplicative interaction were used to investigate the effect modification by the alcohol flushing response on the association between alcohol consumption and ONFH. RESULTS:A total of 118 cases with ONFH and 213 controls were included (mean age, 45 years; 197 men and 134 women). The adjusted ORs of alcohol consumption for the development of ONFH were 1.5 (95% CI: 0.4-6.0) and 3.7 (0.3-41.3) for habitual drinking, 1.6 (0.4-5.6) and 2.0 (0.1-24.2) for heavy drinking, and 3.8 (0.8-17.6) and 4.5 (0.4-49.2) for drinking of ≥320 g/week among current/former and never flushers, respectively. No significant multiplicative interactions were observed. CONCLUSIONS:Alcohol flushing response may not modify the relationship between alcohol consumption and the risk of ONFH.

BACKGROUND:Modular neck prostheses in total hip arthroplasty (THA) offer intraoperative flexibility for adequate femoral anteversion and offset, which is particularly beneficial in anatomically complex cases such as developmental dysplasia of the hip. However, the efficacy of current modular neck options on range of motion in addressing abnormal femoral anteversion is unclear. This study aimed to evaluate the effectiveness of current modular neck configurations with a 32-mm femoral head, in accommodating various femoral anteversion. METHODS:A prosthetic impingement analyses was conducted by collision detection using computer-aided design models of a dual modular neck femoral stem with four neck configurations: 15° anteverted, straight, 15° retroverted, and 30° retroverted. The cup safe zone, defined as the combination of cup inclination and anteversion that satisfied all the required range of motion criteria without prosthetic impingement, was assessed across stem anteversion angles (-25° to 85°). FINDINGS:The four modular neck configurations collectively provided continuous safe zones for stem anteversion ranging from 0° to 75°, at a clinically recommended cup inclination of 40°. In contrast, the straight neck alone provided it in limited range (10°-40°), making it inadequate for managing abnormal femoral anteversion. Notably, the constant combined anteversion concept did not hold at extreme anteversion values. INTERPRETATION:A modular neck system offering configurations from 15° anteverted to 30° retroverted, when combined with 40° cup inclination, effectively accommodates various femoral anteversion. These findings support the clinical utility of modularity in THA and underscore the importance of optimizing stem anteversion to address complex anatomical variations.

In the analysis of 82 participants using quantitative computed tomography (QCT) images, side-to-side differences in hip bone mineral density were 3.0

BACKGROUND:Accurately evaluating bone mineral density (BMD) in patients with unilateral hip osteoarthritis (OA) is crucial for diagnosing osteoporosis and selecting implants for hip arthroplasty. Our goal was to measure the BMD differences between sides, examine contributing factors, and identify the optimal side for BMD assessment in these patients. METHODS:We analyzed 108 women with unilateral hip OA. Bilateral hip BMD was assessed automatically through quantitative CT (QCT) utilizing a validated, deep-learning-based approach. We evaluated BMD variations between the OA and healthy hips across total, neck, and distal regions. To determine their contributions, we analyzed factors, including patient demographics, Crowe classification, Bombelli classification, knee OA status, hip functional score, and gluteal muscle volume and density. Furthermore, we examined how side-to-side BMD differences influenced osteoporosis diagnosis using T-scores based on QCT. RESULTS:The average BMD on the OA side was 6.9 % lower in the total region, 14.5 % higher in the neck region, and 9.4 % lower in the distal region than on the healthy side. Contributing factors to the reduced BMD in the OA hip included younger age, Bombelli classification (atrophic type), and significant gluteal muscle atrophy. Diagnoses from the OA side revealed lower sensitivity (61 %) than those from the healthy side (88 %). CONCLUSIONS:Analysis on one side alone yields a more precise osteoporosis diagnosis from the healthy side. Nonetheless, bilateral BMD assessment remains crucial, particularly in younger individuals and those with atrophic OA types. Although based on QCT, our findings support bilateral analysis by dual-energy X-ray absorptiometry for these patients.

Rotational acetabular osteotomy (RAO) is an effective surgical technique for hip dysplasia that requires precise spherical osteotomy of the acetabulum. While curved osteotomes are commonly used, the quantitative relationship between osteotome design and its movement characteristics within bone remains poorly understood. This study aimed to analyze how osteotome shape parameters and insertion angles affect the trajectory of the osteotome tip using an optical navigation system. Using sawbone models, we tested curved osteotomes with three different radii (R40, R45, R50mm) and two blade configurations (single-sided and double-sided). Osteotomes were inserted at three angles (30°, 45°, and 60°) relative to the bone surface. The osteotome tip trajectory was tracked using an optical navigation system (Vicra, NDI). We compared the actual trajectory with four predicted paths: circles tangent to the inner blade edge, outer blade edge, inner curve, and outer curve of the osteotome. Each condition was tested three times. For all osteotome designs and insertion angles, the actual trajectory most closely followed the circle tangent to the inner blade edge. At 45mm depth with R50 osteotome at 45° insertion angle, the mean deviation from this predicted path was 0.6±0.3mm. The second closest prediction was the inner curve path, with a deviation of 9.5±0.3mm. Similar patterns were observed across all radii and insertion angles, except for 30° insertion with single-sided osteotomes, which caused bone fracture. Despite the intuitive assumption that the osteotome would follow its curved shape, our findings demonstrate that the initial trajectory is primarily determined by the inner blade edge angle. This is likely due to the force distribution at the bone-blade interface during initial insertion. As insertion depth increases, the curved portion of the osteotome becomes more influential in guiding the trajectory. This understanding is crucial for preventing complications like intra-articular penetration or posterior column fracture, and could improve the accuracy of navigation-assisted RAO. The initial trajectory of curved osteotomes in RAO is predominantly influenced by the inner blade edge angle rather than the osteotome's overall curvature.

Identifying muscles linked to postoperative physical function can guide protocols to enhance early recovery following total hip arthroplasty (THA). This study aimed to evaluate the association of preoperative pelvic and thigh muscle volume and quality with early physical function after THA in patients with unilateral hip osteoarthritis (HOA). Preoperative Computed tomography (CT) images of 61 patients (eight males and 53 females) with HOA were analyzed. Six muscle groups were segmented from CT images, and muscle volume and quality were calculated on the healthy and affected sides. Muscle quality was quantified using the mean CT values (Hounsfield units [HU]). Early postoperative physical function was evaluated using the Timed Up Go test (TUG) at three weeks after THA. The effect of preoperative muscle volume and quality of both sides on early postoperative physical function was assessed. On the healthy and affected sides, mean muscle mass was 9.7 cm3/kg and 8.1 cm3/kg, and mean muscle HU values were 46.0 HU and 39.1 HU, respectively. Significant differences in muscle volume and quality were observed between the affected and healthy sides. On analyzing the function of various muscle groups, the TUG score showed a significant association with the gluteus maximum volume and the gluteus medius/minimus quality on the affected side. Patients with HOA showed significant muscle atrophy and fatty degeneration in the affected pelvic and thigh regions. The gluteus maximum volume and gluteus medius/minimus quality were associated with early postoperative physical function. Preoperative rehabilitation targeting the gluteal muscles on the affected side could potentially enhance recovery of physical function in the early postoperative period.

BACKGROUND:An accurate diagnosis for staging osteonecrosis of the femoral head (ONFH), particularly in early-stage collapse, is essential for determining therapeutic strategies. Various radiographic views in different femoral positions have been used to detect femoral head collapse. However, previous studies have not established the optimal femoral position that can sensitively detect initial collapse on plain radiography. This study aimed to identify the most sensitive radiographic view for visualizing collapse in early-stage ONFH by analyzing reconstructed frontal images of the femoral head at multiple femoral positions on computed tomography (CT). METHODS:This study included 30 hips with early-stage ONFH (10 hips without collapse and 20 hips with collapse [< three mm] based on the anteroposterior and lateral radiographic images). The presence or absence of collapse in 10 reconstructed frontal images of the femoral head on CT scans, corresponding to 10 different femoral positions, was classified. Furthermore, the ability to detect collapse in each image was compared. RESULTS:The reconstructed frontal image of the femoral head on CT scans at 45° flexion and 20° abduction had the highest sensitivity for detecting collapse among the analyzed positions. Hence, it had a significantly greater sensitivity than the neutral position (86 versus 53%, P < 0.01). Of 70% who did not present with collapse on plain radiography had collapse on the reconstructed frontal image at 45° flexion and 20° abduction. CONCLUSIONS:The plain radiographic image taken at 45° flexion and 20° abduction, referred to as the 45° Dunn view, had a greater diagnostic potential for early collapse in ONFH compared with the anteroposterior radiographic image. Nevertheless, further research should be performed to comprehensively investigate the areas where collapse occurs in ONFH and to identify the most effective femoral position for detecting collapse on plain radiography.

Aims:After total hip arthroplasty (THA), dual-energy x-ray absorptiometry (DXA) is used as necessary to assess the bone mineral density (BMD) in the Gruen zones around the femoral stem implants. Although periprosthetic BMD may serve as a potential indicator for evaluating stress adaptive remodelling and stem fixation, several factors can introduce measurement errors. Therefore, an automated method was applied using quantitative CT, verified for the total hip with correlation coefficient > 0.9, for BMD assessment in the Gruen zones. Methods:This was a retrospective analysis of 71 hips from 58 participants (9 male and 49 female) who underwent THA using the same taper-wedge type stem. Preoperative and postoperative CT scans were acquired alongside DXA measurements of the Gruen zones. A deep-learning method was used to measure BMD in the Gruen zones from preoperative CT images by embedding the stem position information acquired from postoperative CT images through iterative closest point registration. CT images were rotated to the neutral position and were projected anteroposteriorly to generate a digitally reconstructed radiograph to measure the BMD at each zone (CT-aBMD). Correlations between CT-aBMD and DXA measurements were assessed for each zone. Results:The correlations between CT-aBMD and DXA measurements for zones 1 to 7 were 0.924, 0.783, 0.817, 0.921, 0.731, 0.847, and 0.677, respectively (p < 0.001 for all). Conclusion:Our results based on CT analysis suggest that DXA is generally reliable for assessing BMD in the Gruen zones. However, caution may be advised for zones 5 and 7 because of limited correlations. As zone 7 plays a crucial role in stem fixation, during longitudinal evaluation of post-THA stress adaptive remodelling, we recommend ensuring cautious interpretation and consistent BMD measurements using the image attached to the DXA report. It is imperative to calculate the least significant change for accurate BMD evaluation.

Aims:This study aimed to evaluate the efficacy of porous titanium acetabular augments in primary total hip arthroplasty (THA) for reconstruction of superolateral acetabular bone defects in patients with Crowe II or higher classes of developmental dysplasia of the hip (DDH) or rapidly destructive coxopathy (RDC). Methods:We conducted a retrospective evaluation of 27 patients (30 hips) who underwent primary THA using cementless cups and porous titanium acetabular augments. The follow-up periods ranged from two to 11 years, with a mean of 5.0 years. The cohort included 22 females (24 hips) and five males (six hips), with a mean age of 67 years (45 to 83) at the time of surgery. Results:At the final follow-up, there was no radiological evidence of loosening or radiolucency around the cups and augments, indicating successful biological fixation in all cases. Clinically, there was a significant improvement in the Western Ontario and McMaster Universities Osteoarthritis Index score, which improved from a mean of 39.1 (SD 14.7) preoperatively to 5.1 (SD 6.4) postoperatively. Conclusion:The use of cementless cups and porous acetabular titanium augments in primary THA for patients with DDH and RDC can lead to considerable clinical improvements and reliable biological fixation, suggesting their potential as a viable solution for managing challenging acetabular defects in these conditions.

To use CT images and segmentation of the skin and muscles of the upper leg to determine a reliable location for measuring thigh circumference (TC) to assess the upper leg muscle volume and cross-sectional area (CSA). This research analyzed 140 limbs from 77 patients (22 male and 55 female) who had undergone CT imaging before hip surgery. The skin and individual upper leg muscles were automatically segmented from the CT images to measure the TC and CSA of each upper leg muscle across all axial slices. TC and CSA were measured from the patella upward at 1 cm up to 20 cm intervals, resulting in 21 analyses per limb. The volume of each muscle was calculated by adding the CSAs across all axial slices. Pearson’s correlation was used to analyze the relationship between muscle volume and CSA to identify the level with the strongest correlation as the “reliable” level. The correlation coefficient and the regression equation were calculated. The reliable level for muscle CSAs exhibiting the strongest correlation varied across the muscles, ranging from 9 to 20 cm from the patella. However, strong correlations were found between each muscle’s TC, ranging from 0.64 to 0.83. In terms of muscle volume, 10 cm above the patella was found to be the reasonable level for predicting the volume of each muscle from TC. Moderate to strong correlations (ranging from 0.57 to 0.70) were found between the TC. To predict the muscle volume of the whole upper leg (cm³), the following equation was used: (TC at 10 cm from the patella) × 114.7–2,194.9. TC measurement 10 cm above the patella is suitable for assessing upper leg muscle volume. Modifications in measurement levels across muscles may be needed to assess muscle CSAs. Cite this article: Bone Joint Res 2025;14(8):666–673.

Collapse of the femoral head is a critical event in osteonecrosis (ONFH) that often leads to debilitating hip pain and necessitates total hip arthroplasty. Early and accurate prediction of collapse risk is crucial for personalized treatment planning. While many studies focus on the automated diagnosis of ONFH, prognosis remains less explored. In this study, we propose a robust tri-stream deep learning framework that extracts features from T1-weighted MRI, region-of-interest (ROI) labels, and ONFH grades to estimate patient-specific collapse risk. We introduce an independent Spatial Label Encoder (SLE) module that tokenizes discrete ROI labels into dense, context-rich embeddings, thereby facilitating multi-modality model training. Experiments on 92 hips (70 patients) show that our approach performs competitively with state-of-the-art (SOTA) methods across most metrics, achieving a concordance index (CI) of 0.847±0.087 and an integrated AUC of 0.884 in 5-fold cross-validation. Notably, the SLE module enhances long-term discrimination by up to 2.4% on AUC at 60 months compared to our base network. These findings highlight the potential benefits of late-fusion strategies with label tokenization for predicting femoral head collapse in ONFH, contributing to improved early intervention and prognosis.

This study developed a method for assessing lower-limb lean mass measured by dual-energy X-ray absorptiometry (DXA-LMleg), using lower-limb muscle mass derived from computed tomography images (CT-MM). Further, the diagnostic performance of the model in detecting whole-body muscle mass (MM) loss, a key component in the assessment of sarcopenia, was evaluated using CT-MM to facilitate the timely initiation of treatment as needed. This retrospective study enrolled 227 patients who underwent hip surgery at two institutions. A deep neural network (DNN)-based method was employed in segmenting lower-limb CT images taken for surgical planning, and the CT-MM was calculated using two different density conversion methods: CT-MM1 (CT-MM calculated using the conventional method) and CT-MM2 (CT-MM calculated using the method by Aubrey et al.). Both CT-MMs were correlated with DXA-LMleg, and receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic accuracy of CT-MMs in detecting whole-body MM loss. In 222 cases that were successfully automatically analyzed, strong correlations were observed between CT-MM1 and DXA-LMleg (rs = 0.92–0.96) and between CT-MM2 and DXA-LMleg (rs = 0.86–0.92). ROC curve analysis revealed high diagnostic accuracy for whole-body MM loss (CT-MM1, area under the curve (AUC) = 0.96–0.97; CT-MM2, AUC = 0.91–0.93), with CT-MM1 demonstrating significantly better performance. CT-MMs were strongly correlated with DXA-LMleg and had a high diagnostic performance (AUC > 0.9) in detecting whole-body MM loss, supporting sarcopenia screening and preoperative clinical decision-making using routine CT scan.