Anteroposterior Hip Radiographs Research Articles

Soft-tissue thickness radiographic measurement: a marker to evaluate acute periprosthetic joint infection risk in total hip replacement.

The objective of our study was to evaluate the association between acute periprosthetic joint infection (APJI) and radiographic measurement of soft-tissue thickness in elective total hip replacement surgery. A case-control study was conducted to compare the soft-tissue thickness radiographic measurement (SRM) at the hip in patients diagnosed with APJI based on Tsukayama et al. (2003) criteria after total hip replacement with patients that were not infected, at a single institution from 2013 to 2019. To minimize selection bias, each case was matched with two controls using the following methodology: patients of the same sex, with an age variation of 5 years, and nearest in surgery date to the cases were selected. All postoperative radiographs were performed in the first 24 h after total hip arthroplasty (THA) surgery as it is protocolized in our institution. Soft-tissue thickness radiographic measurement was defined as the distance from the tip of the greater trochanter to the skin following a perpendicular line to the femoral diaphysis in postoperative anteroposterior hip radiographs. In total, 78 patients were included (26 cases and 52 controls). The SRM median of the cases was 76.19 mm (SD: 26.518) and 53.5 mm (SD: 20.47) in controls. A multivariate logistic regression model showed an independent association between APJI and SRM (odds ratio (OR) 1.033, 95 % confidence interval (CI) 1.007–1.059, .012). Patients with an SRM greater than 60 mm had a 7-fold increase in the odds of APJI (OR 7.295, 95 % CI 2.364–22.511, .001). The results of our study suggest an association between large SRM at the hip and the risk of APJI in patients with primary total hip arthroplasty. SRM may be a helpful and easy tool for evaluating the risk of APJI before elective primary total hip replacement surgery.

Differences between proximal bone remodeling in femoral revisions for aseptic loosening and periprosthetic fractures using the Wagner SL stem

BackgroundMonoblock taper fluted stems have been reliably used to treat proximal femoral periprosthetic fractures (PFF) and femoral aseptic loosening (AL). Although proximal femoral remodeling has been observed around the Wagner Self-Locking (SL) stem, the exact characteristics of this process are yet to be established. Our aim was to compare the remodeling that takes place after femoral revisions for PFF and AL.MethodsConsecutive patients between January 2015 and December 2017 undergoing femoral revision using the Wagner SL stem for PFF or AL without an extended trochanteric osteotomy (ETO) or bone grafting were selected from our database. Radiological follow-up was performed using plain antero-posterior hip radiographs taken postoperatively and at 3, 6, 12 months and at 24 months. The Global Radiological Score (GRxS) was utilized by four blinded observers. Intra and interobserver variability was calculated. Secondary outcome measures included the Oxford Hip Score and the Visual Analog Scale for pain.ResultsWe identified 20 patients from our database, 10 PFF and 10 AL cases. The severity of AL was Paprosky 2 in 2 cases, Paprosky 3A in 2 cases and Paprosky 3B in 6. PFF were classified as Vancouver B2 in 7 cases and Vancouver B3 in 3 cases. Patients undergoing femoral revision for PFF regained 89% (GRxS: 17.7/20) of their bone stock by 6 months, whilst patients with AL, required almost 2 years to achieve similar reconstitution of proximal femoral bony architecture 86% (GRxS: 17.1/20). Inter-observer reproducibility for numerical GRxS values showed a “good” correlation with 0.68, whilst the intra-observer agreement was “very good” with 0.89. Except immediate after the revision, we found a significant difference between the GRxS results of the two groups at each timepoint with pair-wise comparisons. Functional results were similar in the two groups. We were not able to show a correlation between GRxS and functional results.ConclusionsProximal femoral bone stock reconstitutes much quicker around PFF, than in the cases of AL, where revision is performed without an ETO. The accuracy of GRxS measurements on plain radiographs showed good reproducibility, making it suitable for everyday use in a revision arthroplasty practice.

Timing of Repeat Ultrasound Examination in Treatment of Stable Developmental Dysplasia of the Hip.

Background:Worldwide a wide variation exists in duration of Pavlik harness treatment for infants up to 6 months with stable developmental dysplasia of the hip (DDH). The purpose of this study was to evaluate whether shortening the time to first routine follow-up ultrasound after initiation of Pavlik harness treatment would reduce treatment duration and whether this influenced radiologic outcome at 1 year of age. Furthermore, predictors of higher acetabular index (AI) at 1 year of age were investigated.Methods:A retrospective study was conducted in infants with stable DDH (Graf IIb and IIc) diagnosed and treated between 2015 and 2017. Two groups were identified: first routine follow-up ultrasound at 12 weeks after Pavlik harness initiation (group I) and first routine follow-up ultrasound at 6 weeks after Pavlik harness initiation (group II). In both groups, treatment was continued until repeat ultrasound measurements (every 6 wk) showed a normalized hip. Radiologic outcome at 1 year of age was defined as residual dysplasia measured on an anteroposterior hip radiograph according to the Tönnis table.Results:A total of 222 infants were included. The median time of Pavlik harness treatment was 12 weeks (interquartile range, 11.9 to 12.3) in group I compared with 6.1 weeks (interquartile range, 6.0 to 7.5) in group II (P<0.001). Residual dysplasia at 1 year of age was detected in 20 infants (16.8%) in group I compared with 11 infants (10.7%) in group II (P=0.189). The multivariable prediction model showed that positive family history and lower baseline alpha angle correlate with a higher AI at 1 year of age.Conclusions:First routine follow-up ultrasound can be safely brought forward from 12 to 6 weeks after Pavlik harness initiation. Furthermore, infants with a positive family history for DDH and an initial low alpha angle are at higher risk to have a higher AI at 1 year of age.Level of Evidence:Level III—retrospective study.

Malalignment and distal contact of short tapered stems could be associated with postoperative thigh pain in primary total hip arthroplasty

PurposeShort tapered stem placement has been extensively employed in total hip arthroplasty (THA). Suboptimal fixation tends to cause postoperative complications, such as thigh pain. However, it remains unclear whether poor seating/alignment of short tapered stems contributes to thigh pain. In this study, we retrospectively examined the factors that might be associated with thigh pain.MethodsMedical records of 230 patients who had undergone THAs at our hospital were reviewed retrospectively. All patients received the same mediolateral (ML) short tapered femoral stems. The association between thigh pain and patients’ demographics, radiographic findings, or the type of fitting of the femoral stems was investigated.ResultsIn our cohort, 68 patients (27.8%) presented with thigh pain. Among 203 type I fit patients, 62 (30.5%) developed thigh pain, while only 6 out of 43 (12.2%) type II fit patients had thigh pain, with the differences being statistically significant (x2 = 6.706, p = 0.01). In addition, hip anteroposterior radiographs exhibited that the stem angulation (mean 2.52°), the variation in angulation (mean 1.32°), and the extent of femoral stem subsidence (mean 0.29 cm) were greater in patients with thigh pain than in their counterparts without thigh pain (all p < 0.05).ConclusionMalalignment and improper seating of short tapered stems could be at least one of the reasons for post-THA thigh pain. The distal contact between the stem tip and the medial femoral cortex might result in thigh pain. Our study suggested that distal implant contact should be avoided, and stem alignment should be meticulously performed in the placement of ML short tapered femoral stems for THA.

Artificial intelligence accurately identifies total hip arthroplasty implants: a tool for revision surgery.

A critical part in preoperative planning for revision arthroplasty surgery involves the identification of the failed implant. Using a predictive artificial neural network (ANN) model, the objectives of this study were: (1) to develop a machine-learning algorithm using operative big data to identify an implant from a radiograph; and (2) to compare algorithms that optimise accuracy in a timely fashion. Using 2116 postoperative anteroposterior (AP) hip radiographs of total hip arthroplasties from 2002 to 2019, 10 artificial neural networks were modeled and trained to classify the radiograph according to the femoral stem implanted. Stem brand and model was confirmed with 1594 operative reports. Model performance was determined by classification accuracy toward a random 706 AP hip radiographs, and again on a consecutive series of 324 radiographs prospectively collected over 2019. The Dense-Net 201 architecture outperformed all others with 100.00% accuracy in training data, 95.15% accuracy on validation data, and 91.16% accuracy in the unique prospective series of patients. This outperformed all other models on the validation (p < 0.0001) and novel series (p < 0.0001). The convolutional neural network also displayed the probability (confidence) of the femoral stem classification for any input radiograph. This neural network averaged a runtime of 0.96 (SD 0.02) seconds for an iPhone 6 to calculate from a given radiograph when converted to an application. Neural networks offer a useful adjunct to the surgeon in preoperative identification of the prior implant.

Comparison of Radiographic Singh Index with Dual-Energy X-Ray Absorptiometry Scan in Diagnosing Osteoporosis

Objective: The objective of this study was to assess the accuracy of radiographic Singh index (SI) with respect to dual-energy X-ray absorptiometry (DEXA) scan in diagnosing osteoporosis. Materials and Methods: We conducted a cross-sectional study on 100 postmenopausal women in the Department of Radiodiagnosis, SKIMS, Soura, Srinagar, from June 2019 to December 2019. We obtained right or left standard anteroposterior hip radiograph in each patient and compared its SI grade to the densitometry results obtained from the DEXA study of the corresponding hip. Results: Out of the selected patients, 7% had DEXA bone mineral density (BMD) values in normal range (T-score ≤1), 81% in osteopenic range (T-score >1.00–<2.5), and 12% in osteoporotic range (T-score ≥2.5). There was no statistically significant correlation (r = −0.108, P = 0.286) between SI grade and WHO BMD category (normal, osteopenia, or osteoporosis). There was no statistically significant correlation (r = 0.191, P = 0.057) between the SI grade and the mean absolute DEXA BMD value. There was also no statistically significant correlation (r = −0.195, P = 0.052) between SI grade and mean DEXA T-score. Conclusion: Our study found a poor correlation between radiographic SI and DEXA densitometry results. We concluded that the SI cannot be used as a substitute for DEXA study in diagnosing osteoporosis.

Diagnostic Performance of a New Convolutional Neural Network Algorithm for Detecting Developmental Dysplasia of the Hip on Anteroposterior Radiographs.

ObjectiveTo evaluate the diagnostic performance of a deep learning algorithm for the automated detection of developmental dysplasia of the hip (DDH) on anteroposterior (AP) radiographs.Materials and MethodsOf 2601 hip AP radiographs, 5076 cropped unilateral hip joint images were used to construct a dataset that was further divided into training (80%), validation (10%), or test sets (10%). Three radiologists were asked to label the hip images as normal or DDH. To investigate the diagnostic performance of the deep learning algorithm, we calculated the receiver operating characteristics (ROC), precision-recall curve (PRC) plots, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) and compared them with the performance of radiologists with different levels of experience.ResultsThe area under the ROC plot generated by the deep learning algorithm and radiologists was 0.988 and 0.988–0.919, respectively. The area under the PRC plot generated by the deep learning algorithm and radiologists was 0.973 and 0.618–0.958, respectively. The sensitivity, specificity, PPV, and NPV of the proposed deep learning algorithm were 98.0, 98.1, 84.5, and 99.8%, respectively. There was no significant difference in the diagnosis of DDH by the algorithm and the radiologist with experience in pediatric radiology (p = 0.180). However, the proposed model showed higher sensitivity, specificity, and PPV, compared to the radiologist without experience in pediatric radiology (p < 0.001).ConclusionThe proposed deep learning algorithm provided an accurate diagnosis of DDH on hip radiographs, which was comparable to the diagnosis by an experienced radiologist.

Radiological Evaluation of the Relationship Between Cortical Hypertrophy and Stress Shielding After Total Hip Arthroplasty Using a Cementless Stem

BackgroundUnloading of the proximal medial femoral cortex is usually associated with an increased bone strain at the distal part of the prosthesis, which may cause distal femoral cortical hypertrophy (CH). The objective of this study was to determine the factors that may be considered a predisposition to distal femoral CH and its effect on the stress shielding (SS) or durability of the fixation of the stem. MethodsA total of 240 total hip arthroplasties were performed between January 2006 and December 2016, with all hips implanted with a Bicontact stem. The minimum follow-up period was more than 2 years, and the mean follow-up period was 7.2 years. The radiographic outcome was assessed on an anteroposterior hip radiograph. CH and SS were assessed on postoperative radiographs in the Gruen zone. We defined CH that appeared in zone 3 or 5 as ‘the focal type’ and defined CH that appeared in zones 2, 3, 4, 5, and 6 as ‘the diffuse type.’ SS followed the procedures from the Engh classification. ResultsCH was found in 72 hips (30% of the 240 hips), the focal type was found in 23 hips (9.6% of the 240 hips), and the diffuse type was found in 49 hips (20.4% of the 240 hips). SS was found in 41 hips (17.1% of 240 hips), including 32 hips with SS, which was found after the development of CH. One hip was from the focal-type CH and 31 hips were from the diffuse-type CH. SS, which is typically found in Engh classification types 1 and 2 developed in 13 hips, and SS, which is widely seen in Engh classification types 3 and 4 developed in 19 hips. All 19 hips with progressed SS were found after the diffuse-type CH had developed. In addition, among the 19 hips with progressed SS, Dorr type A was found in 0 hips, Dorr type B in 8 hips, and Dorr type C in 11 hips. ConclusionsAccording to the results of our radiological evaluation, development of the diffuse-type CH after total hip arthroplasty using Bicontact stems is one of the critical causes of the later development of SS and could be predicted to progress to SS. To prevent the development of the diffuse-type CH, the indication to choose a Bicontact stem for a Dorr type C with osteoporotic bone should be considered.

Femoral neck shaft angle in relation to the location of femoral stress fracture in young military recruits: femoral head versus femoral neck stress fracture

ObjectiveTo evaluate the influences of the femoral neck shaft angle (FNSA) on the location of the femoral stress fracture and to assess the potential differences in FNSA between fractured and normal femurs.Materials and methodsThirty-seven patients with femoral stress fractures who underwent both plain hip radiographs and MRI, from January 2016 to September 2019, were retrospectively included. Patients were classified as having either femoral head stress fracture (group A, n = 26) or femoral neck stress fracture (group B, n = 11). The FNSA was measured in anteroposterior (AP) hip radiograph. The Mann-Whitney U testing was used to compare the continuous values between the two groups. A receiver operating characteristic (ROC) analysis was used to evaluate the value of FNSA for predicting the risk of femoral stress fracture.ResultsThe FNSA was significantly higher in group A (median 135.9°, range 129.5–138.6°) than group B (median 124.3°, range 119.5–129.0°) (p < 0.001), but there were no significant differences in other clinical factors. Furthermore, the FNSA was significantly higher at the fractured femurs (median 135.9°, range 129.9–138.6°) than contralateral normal femurs (median 127.9°, range 123.8–132.1°) in the patients with unilateral femoral head stress fracture (n = 22) (p < 0.001). The ROC analysis revealed that the area under curve (AUC), sensitivity, and specificity for predicting the risk of femoral head stress fracture were 0.807, 72.7%, and 68.2%, respectively, at a FNSA cutoff of 131.0°.ConclusionFNSA was associated with the location of the femoral stress fracture. In addition, FNSA could serve as a predictive factor for the risk of femoral head stress fractures.

Automated classification of hip fractures using deep convolutional neural networks with orthopedic surgeon-level accuracy: ensemble decision-making with antero-posterior and lateral radiographs

Background and purpose — Deep-learning approaches based on convolutional neural networks (CNNs) are gaining interest in the medical imaging field. We evaluated the diagnostic performance of a CNN to discriminate femoral neck fractures, trochanteric fractures, and non-fracture using antero-posterior (AP) and lateral hip radiographs. Patients and methods — 1,703 plain hip AP radiographs and 1,220 plain hip lateral radiographs were included in the total dataset. 150 images each of the AP and lateral views were separated out and the remainder of the dataset was used for training. The CNN made the diagnosis based on: (1) AP radiographs alone, (2) lateral radiographs alone, or (3) both AP and lateral radiographs combined. The diagnostic performance of the CNN was measured by the accuracy, recall, precision, and F1 score. We further compared the CNN’s performance with that of orthopedic surgeons. Results — The average accuracy, recall, precision, and F1 score of the CNN based on both anteroposterior and lateral radiographs were 0.98, 0.98, 0.98, and 0.98, respectively. The accuracy of the CNN was comparable to, or statistically significantly better than, that of the orthopedic surgeons regardless of radiographic view used. In the CNN model, the accuracy of the diagnosis based on both views was significantly better than the lateral view alone and tended to be better than the AP view alone. Interpretation — The CNN exhibited comparable or superior performance to that of orthopedic surgeons to discriminate femoral neck fractures, trochanteric fractures, and non-fracture using both AP and lateral hip radiographs.

Predictive value of lateral soft tissue thickness for complications after total hip arthroplasty with a lateral incision

The purpose of this study was to determine the relationship between soft tissue thickness lateral to the greater trochanter, as measured on anteroposterior pelvis radiograph, and postoperative complications following primary total hip arthroplasty. A retrospective review of 1110 consecutive patients treated at a single institution from 2003 to 2011 was conducted. Postoperative complications were divided into surgical site infections, deep wound infections, noninfectious surgical complications, need for revision surgery, and medical complications. Lateral soft tissue thickness (LSTT) was measured as the horizontal distance from the most lateral point on the greater trochanter to the skin edge obtained from anteroposterior hip radiographs. Among the 1110 study patients, 19.19% had a postoperative complication, with a deep infection rate of 3.42%. Of the previously identified risk factors, increased LSTT and body mass index were both associated with surgical site infection and deep infection, and LSTT was associated with revision surgery. An LSTT value of >5 cm was predictive of surgical site infection, deep infection, and revision surgery. This easily obtainable radiographic measurement, along with clinical examination near the operative site, might prove helpful in making preoperative risk assessments.

Radiographic assessment of the cup orientation after total hip arthroplasty: a literature review.

Optimal acetabular cup orientation is of substantial importance to good long-term function and low complication rates after total hip arthroplasty (THA). The radiographic anteversion (RA) and inclination (RI) angles of the cup are typically studied due to the practicability, simplicity, and ease of interpretation of their measurements. A great number of methods have been developed to date, most of which have been performed on pelvic or hip anteroposterior radiographs. However, there are primarily two influencing factors for these methods: X-ray offset and pelvic rotation. In addition, there are three types of pelvic rotations about the transverse, longitudinal, and anteroposterior axes of the body. Their effects on the RA and RI angles of the cup are interactively correlated with the position and true orientation of the cup. To date, various fitted or analytical models have been established to disclose the correlations between the X-ray offset and pelvic rotation and the RA and RI angles of the cup. Most of these models do not incorporate all the potential influencing parameters. Advanced methods for performing X-ray offset and pelvic rotation corrections are mainly performed on a single pelvic AP radiograph, two synchronized radiographs, or a two-dimensional/three-dimensional (2D-3D) registration system. Some measurement systems, originally developed for evaluating implant migration or wear, could also be used for correcting the X-ray offset and pelvic rotation simultaneously, but some drawbacks still exist with these systems. Above all, the 2D-3D registration technique might be an alternative and powerful tool for accurately measuring cup orientation. In addition to the current methods used for postoperative assessment, navigation systems and augmented reality are also used for the preoperative planning and intraoperative guidance of cup placement. With the continuing development of artificial intelligence and machine learning, these techniques could be incorporated into robot-assisted orthopaedic surgery in the future.

Dislocation after primary unilateral total hip arthroplasty: Hip geometry and risk factors (a matched cohort analysis)

Introduction/Objective. The purpose of this study was to determine if patient-related factors, such as hospitalization length and preoperative use of walking aids, and geometrical factors, measured with antero-posterior radiographs of hip, affect the risk of hip dislocation after total hip arthroplasty. Methods. A total of 36 of 433 (8.31%) patients with hip dislocation were identified in the institutional registry during a two-year period. The data for patients with and without hip dislocation were matched and compared. Results. Hip dislocation more often occurred in patients who had used walking aids before the operation compared to the ones who had not (p &lt; 0.001). Also, a difference in the number of hip dislocations was noticed between the patients who stayed longer in the hospital after THA (p &lt; 0.001). The patients with higher acetabular inclination angle (p &lt; 0.005) and height of greater trochanter (p &lt; 0.001) on radiographs had been more prone to hip dislocation. In addition to this, the ?safe-zone? was not identified in our study (p &gt; 0.005). Conclusion. Several factors which influence hip dislocation were identified in this study: patient characteristics and radiograph characteristics. Both groups of factors require attention and monitoring in future studies.

Reliability of the sourcil method of acetabular index measurement in developmental dysplasia of the hip.

PurposeThe ability to monitor and study developmental dysplasia of the hip (DDH) requires validated radiographic outcome measures. The sourcil method of acetabular index measurement (AI-S) has not yet been shown to be a reliable measure of acetabular dysplasia in a DDH population, despite its widespread use. The aims of this study were to test the reliability of the AI-S method in a DDH population, and to compare the reliability of the AI-S method with that of the classic lateral edge method (AI-L).MethodsFrom an institutional database, standardized anteroposterior hip radiographs were obtained from a cohort of 35 female patients (70 hips) at two and five years of age who had been treated nonoperatively for DDH. Three observers independently measured the acetabular index using the AI-L and AI-S methods on all 70 hips at two time points, four weeks apart.ResultsThe inter-rater reliability intraclass correlation coefficient (ICC) for the AI-L and AI-S methods was between good and excellent at 0.94 (confidence interval (CI) 0.89 to 0.96) and 0.91 (CI 0.87 to 0.94), respectively. The ICCs for intra-rater reliability for the AI-L method were excellent at 0.93 (CI 0.90 to 0.95), 0.95 (CI 0.93 to 0.97) and 0.95 (CI 0.94 to 0.97) for raters 1, 2 and 3, respectively. The ICCs for intra-rater reliability for the AI-S method were between good and excellent at 0.91 (CI 0.87 to 0.93), 0.93 (CI 0.90 to 0.95) and 0.90 (CI 0.86 to 0.93) for raters 1, 2 and 3 respectively.ConclusionBoth AI-S and AI-L methods are equally reliable radiographic measures of DDH.Level of EvidenceLevel III (diagnostic)

Performance of a Deep Learning Algorithm in Detecting Osteonecrosis of the Femoral Head on Digital Radiography: A Comparison With Assessments by Radiologists.

OBJECTIVE. The objective of our study was to compare the sensitivity of a deep learning (DL) algorithm with the assessments by radiologists in diagnosing osteonecrosis of the femoral head (ONFH) using digital radiography. MATERIALS AND METHODS. We performed a two-center, retrospective, noninferiority study of consecutive patients (≥ 16 years old) with a diagnosis of ONFH based on MR images. We investigated the following four datasets of unilaterally cropped hip anteroposterior radiographs: training (n = 1346), internal validation (n = 148), temporal external test (n = 148), and geographic external test (n = 250). Diagnostic performance was measured for a DL algorithm, a less experienced radiologist, and an experienced radiologist. Noninferiority analyses for sensitivity were performed for the DL algorithm and both radiologists. Subgroup analysis for precollapse and postcollapse ONFH was done. RESULTS. Overall, 1892 hips (1037 diseased and 855 normal) were included. Sensitivity and specificity for the temporal external test set were 84.8% and 91.3% for the DL algorithm, 77.6% and 100.0% for the less experienced radiologist, and 82.4% and 100.0% for the experienced radiologist. Sensitivity and specificity for the geographic external test set were 75.2% and 97.2% for the DL algorithm, 77.6% and 75.0% for the less experienced radiologist, and 78.0% and 86.1% for the experienced radiologist. The sensitivity of the DL algorithm was noninferior to that of the assessments by both radiologists. The DL algorithm was more sensitive for precollapse ONFH than the assessment by the less experienced radiologist in the temporal external test set (75.9% vs 57.4%; 95% CI of the difference, 4.5-32.8%). CONCLUSION. The sensitivity of the DL algorithm for diagnosing ONFH using digital radiography was noninferior to that of both less experienced and experienced radiologist assessments.

Subcutaneous Radiographic Measurement: A Marker to Evaluate Surgical Site Infection Risk in Elderly Hip Fracture Patients.

Objectives: Obesity is a documented comorbidity that is prevalent in the elderly population and a known predictor for surgical site infection (SSI). Body mass index is a convenient method to classify obesity, but it fails to account for fat distribution. The objective of our study was to evaluate the association between surgical site infection and a subcutaneous radiographic measurement (SRM) in elderly hip fracture patients.Materials and Methods: A retrospective case-control study was conducted to compare SRMs at the hip in patients diagnosed with surgical site infection after hip fracture surgery with patients that were not diagnosed with surgical site infection. Each case was matched to two controls. An SRM was defined as the distance from the tip of the greater trochanter to the skin following a perpendicular line to the femoral diaphysis in anteroposterior hip radiographs. Clinical diagnosis of acute surgical site infection was based on Tsukayama criteria.Results: Patients with an SRM greater than 6.27cm had a 7-fold increase in the odds of surgical site infection (OR=7.42, 95% Confidence Interval (CI)=3.01-18.28, p<0.001) compared to those with smaller measurements. The odds ratio (OR) for infection of patients with an ASA score of 3 was 15.82(95% CI=5.11-48.9, p-value<0.001)A statistically significant difference between cases and controls was also found when SRM at the hip was analyzed as a continuous variable. Patients with an infection had a 2.24cm (95% CI=1.59 - 2.90; p<0.001) greater mean SRM.Conclusion: Results of our study suggest an association between the SRM at the hip and the risk of SSI in elderly patients with surgically treated hip fractures. SRM may be a helpful tool for evaluating the risk of SSI in elderly hip fracture patients.

Impact of acetabular reaming depth on reconstruction of rotation center in primary total hip arthroplasty

PurposeTo study the impact of acetabular reaming depth on reconstruction of rotation center (RC) in unilateral primary total hip arthroplasty (UPTHA) and guide individualized preoperative design.Methods200 postoperative standard bilateral hip anteroposterior radiographs after UPTHA were included, which were collected from January, 2013 to June, 2017 in our hospital. Osteonecrosis of femoral head was the only diagnosis in this cohort. The parameters were measured on the anteropoterior radiographs by using RadiAnt DICOM viewer.ResultsThe average of the thickness of the teardrop is about 6.13 ± 1.42 mm. The parameter a (the difference value of the distance of bilateral RC and midline) was positively correlated with the parameter e (the acetabular reaming depth), and the Pearson correlation coefficient was 0.49 when P = 0.05. Furthermore, the value of parameter (e) was 8.25 mm when a2 (the distance from the center of the prosthesis femoral head to the vertical line across the midpoint of pubic symphysis) equaled a1 (the distance from RC of the healthy femoral head to the vertical line across the midpoint of pubic symphysis).ConclusionsThe reaming depth of the acetabulum could influence the reconstruction of RC during UPTHA. When the medial margin of the cup was placed about 2 mm to the lateral border of the ipsilateral teardrop (the bottom of the ovum), the rotation center would be accurately restored.

Computer vs human: Deep learning versus perceptual training for the detection of neck of femur fractures

To evaluate the accuracy of deep convolutional neural networks (DCNNs) for detecting neck of femur (NoF) fractures on radiographs, in comparison with perceptual training in medically-naïve individuals. This study extends a previous study that conducted perceptual training in medically-naïve individuals for the detection of NoF fractures on a variety of dataset sizes. The same anteroposterior hip radiograph dataset was used to train two DCNNs (AlexNet and GoogLeNet) to detect NoF fractures. For direct comparison with perceptual training results, deep learning was completed across a variety of dataset sizes (200, 320 and 640 images) with images split into training (80%) and validation (20%). An additional 160 images were used as the final test set. Multiple pre-processing and augmentation techniques were utilised. AlexNet and GoogLeNet DCNNs NoF fracture detection accuracy increased with larger training dataset sizes and mildly with augmentation. Accuracy increased from 81.9% and 88.1% to 89.4% and 94.4% for AlexNet and GoogLeNet respectively. Similarly, the test accuracy for the perceptual training in top-performing medically-naïve individuals increased from 87.6% to 90.5% when trained on 640 images compared with 200 images. Single detection tasks in radiology are commonly used in DCNN research with their results often used to make broader claims about machine learning being able to perform as well as subspecialty radiologists. This study suggests that as impressive as recognising fractures is for a DCNN, similar learning can be achieved by top-performing medically-naïve humans with less than 1 hour of perceptual training.

Do osteoarthritic subchondral bone cysts spontaneously consolidate after total hip replacement?

During total hip replacement (THR), subchondral acetabular bone cysts are either left alone or treated by filling with autologous bone graft. We hypothesized that subchondral cysts would consolidate spontaneously over time without compromising the midterm survival of the implant. We retrospectively screened the anteroposterior hip radiographs of 731 consecutive patients who underwent primary THR between January 2006 and April 2009. Patients were included in the current study if they had acetabular subchondral bone cysts visible radiographically that had been left alone during THR. 52 patients (54 hips) matched the inclusion criteria, with mean age of 66 ± 11 years at surgery, and a mean follow-up of 6.3 years (range 5-9 years). Among the 52 patients, there were 88 cysts, with 1.6 ± 0.83 cysts per patient and a mean cyst size of 9.3 ± 10 mm2 (range 0.9-57 mm2). Among the 88 cysts, 71 cysts (38 hips) had disappeared by the final follow-up, whereas 17 cysts (16 hips) were still visible. Most of these persistent cysts were located in Charnley zone I and were significantly smaller at the follow-up than before surgery (p = 0.015). Overall, most cysts decreased in size (p = 0.04). All cups survived and none showed radiological signs of loosening. After THR, most neglected subchondral cysts spontaneously consolidate or decrease in size. Larger cysts may persist without affecting the surgical outcome. No radiological signs of loosening or other adverse effects were observed when acetabular bone cysts are neglected during primary THR.

Fragility fractures of the proximal femur: review and update for radiologists.

Proximal femoral fragility fractures are common and result in significant morbidity and mortality along with a considerable socioeconomic burden. The goals of this article are to review relevant proximal femoral anatomy together with imaging, classification, and management of proximal femoral fragility fractures, and their most common complications. Imaging plays an integral role in classification, management and follow-up of proximal femoral fragility fractures. Classification of proximal femoral fragility fractures is primarily based on anteroposterior hip radiographs. Pertinent imaging features for each category of proximal femoral fractures that would guide management are: differentiating nondisplaced from displaced femoral neck fractures, distinguishing stable from unstable intertrochanteric fractures, and determining the morphology and comminution of subtrochanteric fractures. Treatment of proximal femoral fragility fractures is primarily surgical with either arthroplasty or internal fixation. Intramedullary nailing is used in the treatment of some types of proximal femoral fragility fractures and may be associated with unique complications that become evident on postoperative follow-up radiographs.