The Accuracy of Cup Placement in Total Hip Arthroplasty (THA) Using an Augmented Reality-Based Navigation System.

Background AR HIP Navigation System® (AR-navi; Zimmer-Biomet, Warsaw, IN) is a portable navigation system employing augmented reality via a smartphone app, which was developed in Japan. We retrospectively analyzed the accuracy of cup placement in total hip arthroplasty (THA) using AR-navi, to investigate whether obesity is associated with an absolute value error in cup placement angle. Methods We retrospectively analyzed 45 hips in 43 patients who underwent THA using AR-navi (AR-navi group) and compared them with 45 hips in 45 patients who underwent THA using alignment rods (conventional group). Results The mean absolute error of cup placement (AR-navi group vs. conventional group) was found to be 2.60° (±2.11) in radiographic inclination (RI) for the AR-navi group and 4.61° (±3.28) for the conventional group, which indicates significant difference in the AR-navi group compared to that in the conventional group (p = 0.0036). The mean absolute error of radiographic anteversion (RA) was 3.57° (±3.36) for the AR-navi group and 3.87° (±2.97) for the conventional group (p = 0.4732). The mean absolute error of RI was 2.36° (±2.24) in the obese group and 3.16° (±2.03) in the nonobese group, and the mean absolute error of RA was 4.08° (±4.51) and 3.16° (±2.05) in the obese and nonobese groups, respectively. Conclusions Cup placement accuracy for THA using AR-navi was 2.60 ± 2.11° for RI and 3.87 ± 2.97° for RA. Compared to THA using the conventional method, the RI installation error was significantly improved with AR Navi. There was no significant difference in the mean absolute error of RI and RA among the obese and nonobese groups.

Specific pelvic shape in patients with developmental dysplasia of the hip on 3D morphometric homologous model analysis.

PURPOSE: To clarify the morphological factors of the pelvis in patients with developmental dysplasia of the hip (DDH), three-dimensional (3D) pelvic morphology was analyzed using a template-fitting technique. METHODS: Three-dimensional pelvic data of 50 patients with DDH (DDH group) and 3D pelvic data of 50 patients without obvious pelvic deformity (Normal group) were used. All patients were female. A template model was created by averaging the normal pelvises into a symmetrical and isotropic mesh. Next, 100 homologous models were generated by fitting the pelvic data of each group of patients to the template model. Principal component analysis was performed on the coordinates of each vertex (15,235 vertices) of the pelvic homologous model. In addition, a receiver-operating characteristic (ROC) curve was calculated from the sensitivity of DDH positivity for each principal component, and principal components for which the area under the curve was significantly large were extracted (p<0.05). Finally, which components of the pelvic morphology frequently seen in DDH patients are related to these extracted principal components was evaluated. RESULTS: The first, third, and sixth principal components showed significantly larger areas under the ROC curves. The morphology indicated by the first principal component was associated with a decrease in coxal inclination in both the coronal and horizontal planes. The third principal component was related to the sacral inclination in the sagittal plane. The sixth principal component was associated with narrowing of the superior part of the pelvis. CONCLUSION: The most important factor in the difference between normal and DDH pelvises was the change in the coxal angle in both the coronal and horizontal planes. That is, in the anterior and superior views, the normal pelvis is a triangle, whereas in DDH, it was more like a quadrilateral.

Time elapsed from definitive diagnosis to surgery for osteonecrosis of the femoral head: a nationwide observational study in Japan.

OBJECTIVES: This study documents the time elapsed from the diagnosis of osteonecrosis of the femoral head (ONFH) to surgery, exploring the factors that influence ONFH severity. DESIGN: Retrospective observational study of a nationwide database. SETTING: The Kaplan-Meier method with log-rank tests was applied to examine the period from definitive diagnosis of ONFH to surgery using any surgery as the end point. For bilateral cases, the date of the first surgery was the endpoint. PARTICIPANTS: This study included 2074 ONFH cases registered in 34 university hospitals and highly specialised hospitals of the multicentre sentinel monitoring system of the Japanese Investigation Committee between 1997 and 2018. MAIN OUTCOME MEASURE: The primary outcome was the time from diagnosis to surgery. The secondary outcome was the proportion of subjects remaining without surgery at 3, 6 and 9 months, and at 1, 2 and 5 years after diagnosis. RESULTS: The median time to surgery was 9 months (IQR 4-22 months) after diagnosis of ONFH. The time to surgery was significantly shorter in the alcohol alone group and the combined corticosteroid and alcohol group than in the corticosteroid alone group (p=0.018 and p<0.001, respectively), in early stage ONFH with no or mild joint destruction (stages II and III, p<0.001), and with joint preserving surgery (p<0.001). The proportion without surgery was 75.8% at 3 months, 59.6% at 6 months, 48.2% at 9 months, 40.5% at 1 year, 22.2% at 2 years and 8.3% at 5 years. CONCLUSION: ONFH has been considered to be an intractable disease that often requires surgical treatment, but the fact that surgery was performed in more than half of the patients within 9 months from diagnosis suggests severe disease with a significant clinical impact. TRIAL REGISTRATION NUMBER: Chiba University ID1049.

Joint instability in patients with borderline developmental dysplasia of the hip.

BACKGROUND: The treatment strategy for developmental dysplasia of the hip is determined based on the lateral center-edge angle. Nonetheless, an evaluation of joint instability may be important in determining the treatment strategy. This study classified the displacement patterns of the femoral head center during hip abduction. METHODS: Ten patients with borderline developmental dysplasia of the hip, 10 patients with developmental dysplasia of the hip, and 10 patients with normal hips were analyzed. Image matching was performed using X-ray images of hip abduction with a three-dimensional hip model. The displacement of the femoral head center and its trajectory length were measured. A cluster analysis was conducted to classify the displacement pattern of the femoral head center, and trajectory lengths were compared. FINDINGS: Displacement was classified into three patterns: medialization, hinge abduction, and centering. Patients with borderline developmental hip dysplasia exhibited all three patterns. Almost all patients with developmental dysplasia of the hip showed medialization and hinge abduction, whereas all normal patients had the centering type. The mean trajectory length indices for the medialization and hinge abduction types were significantly longer than those for the centering type (P = 0.01 and P = 0.016, respectively). INTERPRETATION: Borderline developmental dysplasia of the hip is a heterogeneous condition characterized by varying hip instability levels. Our findings suggest that uniform evaluation based on the lateral center-edge angle is inappropriate and that joint instability must be evaluated in each patient with borderline developmental dysplasia of the hip.

Patient-specific three-dimensional evaluation of interface micromotion in two different short stem designs in cementless total hip arthroplasty: a finite element analysis.

BACKGROUND: Evaluation of micromotion in various activities in daily life is essential to the assessment of the initial fixation of cementless short stems in total hip arthroplasty. This study sought to evaluate three-dimensionally the micromotion of two types of cementless short stems. METHODS: Two types of stems were used: the Fitmore stem with a rectangular cross-section (rectangular stem) and the octagonal-oval GTS stem with fins (finned stem). Finite element analysis was used to calculate the micromotion of two activities that place a heavy load on the stem (single-leg stance and stair climbing). Three values were measured: the magnitude of micromotion (mean and 95th percentile), the location of micromotion above the 95th percentile value, and the directions of the micromotion vector. RESULTS: 1. There was no significant difference in the magnitude of the micromotion between the rectangular stem and finned stem groups for single-leg stance or stair climbing. 2. In both groups, the micromotion was greatest at the proximal and distal ends. 3. The direction of the micromotion was similar in both groups; internal rotation occurred from the distal to the middle of the stem during stair climbing. CONCLUSIONS: The rectangular stem had comparable initial fixation to that of the finned stem. In both models, the micromotion was greater at the proximal and distal ends. The direction of the micromotion was not dependent on the stem shape but on the direction of the load on the artificial femoral head. These results will be important for stem selection and future stem development.

Diagnosis of prosthetic joint infection at the hip using the standard uptake value of three-phase 99mTc-hydroxymethylene diphosphonate SPECT/CT.

PURPOSE: To retrospectively investigate whether the standard uptake value (SUV) of 99mTc-bone single-photon emission computed tomography (SPECT)/CT could be useful for predicting prosthetic joint infection (PJI) at the hip. PATIENTS AND METHODS: We analyzed the cases of 37 patients with a suspected PJI at the hip who underwent 99mTc-bone SPECT/CT and surgical intervention with pathological and bacterial examinations. We divided the cases into those with and those without a causative bacterium detected in a surgical specimen, i.e., the positive bacterial culture (PBC) group (n = 17) and negative bacterial culture (NBC) group (n = 20). Cases with neutrophilic infiltration of surgical specimen comprised the positive neutrophilic infiltration (PINF) group (n = 18) and those without INF comprised the non-neutrophilic infiltration (NINF) group (n = 19). Quantitative analyses were performed using maximum SUVs and peak SUVs of blood-pool (BP) phase images (SUVmaxBP and SUVpeakBP) and late (LT)-phase images (SUVmaxLT and SUVpeakLT). RESULTS: Regarding the bacterial cultures, there were significant differences between the PBC and NBC groups in SUVmaxBP (5.26 ± 1.49 vs. 4.21 ± 1.15, respectively; p = 0.019), SUVpeakBP (4.89 ± 1.32 vs. 3.87 ± 1.06, p = 0.012), SUVmaxLT (16.10 ± 6.36 vs. 11.67 ± 4.95, p = 0.026), and SUVpeakLT (14.58 ± 5.83 vs. 10.49 ± 4.31 p = 0.036). Regarding neutrophilic infiltration, there were significant differences between the PINF and NINF groups in SUVmaxBP (5.18 ± 1.48 vs. 4.24 ± 1.19, p = 0.047) and SUVpeakBP (4.78 ± 1.32 vs. 3.92 ± 1.10, p = 0.043). CONCLUSION: An SUV analysis of 99mTc-bone SPECT/CT is a useful method to differentiate a PJI at the hip from non-infection.

The Short-term Outcomes of Physiotherapy for Patients with Acetabular Labral Tears: An Analysis according to Severity of Injury in Magnetic Resonance Imaging.

Purpose: The aim of this study was to evaluate the short-term outcome of physiotherapy in patients with acetabular labral tears and to assess the effectiveness of physiotherapy according to the severity of the labral tear. Materials and Methods: Thirty-five patients who underwent physiotherapy for treatment of symptomatic acetabular labral tears were enrolled. We evaluated the severity of the acetabular labral tears, which were classified based on the Czerny classification system using 3-T MRI. Clinical findings of microinstability and extra-articular pathologies of the hip joint were also examined. The International Hip Outcome Tool 12 (iHOT12) was use for evaluation of outcome scores pre- and post-intervention. Results: The mean iHOT12 score showed significant improvement from 44.0 to 73.6 in 4.7 months. Compared with pre-intervention scores, significantly higher post-intervention iHOT12 scores were observed for Czerny stages I and II tears (all P<0.01). However, no significant difference was observed between pre-intervention and post-intervention iHOT12 scores for stage III tears (P=0.061). In addition, seven patients (20.0%) had positive microinstability findings and 22 patients (62.9%) had findings of extra-articular pathologies. Of the 35 patients, eight patients (22.9%) underwent surgical treatment after failure of conservative management; four of these patients had Czerny stage III tears. Conclusion: The iHOT12 score of patients with acetabular labral tears was significantly improved by physiotherapy in the short-term period. Improvement of the clinical score by physiotherapy may be poor in patients with severe acetabular labral tears. Determining the severity of acetabular labral tears can be useful in determining treatment strategies.

Changes in Invasiveness and Latent Infection Rate Associated with Switching the Approach in Total Hip Replacement.

PURPOSE: Muscle-sparing approaches for total hip replacement (THR) involve learning curves. This study aimed to clarify changes in invasiveness and infection rate with changes in approach. METHODS: One surgeon changed the approach of THR from Dall's approach (Dall) to anterolateral modified Watson-Jones approach (OCM). Another changed from Dall to a direct anterior approach (DAA). Another 3 surgeons changed from posterolateral approach (PL) to OCM. Subjects were 150 cases, comprising the last 25 cases with conventional approaches and the first 25 cases with new approaches (Dall to OCM: 25 + 25; Dall to DAA: 25 + 25; PL to OCM: 25 + 25 cases). Differences in operative time, bleeding volume, hospital stay, haemoglobin (Hb), white blood cell count, lymphocyte count, creatine kinase (CK) and C-reactive protein (CRP) were investigated. RESULTS: In the change from Dall to OCM, only hospital stay decreased. In the change from Dall to DAA, hospital stay and CRP decreased, but bleeding volume increased. In the change from PL to OCM, operative time, CRP and CK decreased, but Hb also decreased. Cases with lymphocyte count <1000/µL or lymphocytes comprising <10% of total white blood cells at around day 4 after surgery were defined as latent infection cases. In these cases, operative time was longer, Hb was lower and CK was higher. CONCLUSION: Introducing muscle-sparing approaches improved many markers of invasiveness, but some items deteriorated. In the early stages of introducing a new approach, choosing cases without obesity and without high muscle volume may reduce the risk of infection.

Acetabular Morphology in Patients with Developmental Dysplasia of the Hip with High Dislocation.

PURPOSE: The current study aimed to investigate the morphology of the true acetabulum in developmental dysplasia of the hip (DDH) with high dislocation. A secondary was to evaluate the acetabular cup placement in patients with high dislocation who were treated with total hip arthroplasty (THA). MATERIALS AND METHODS: Using a retrospective design, 23 hips with DDH with high dislocation in patients who were treated with THA were included in this study. We measured the depth, width and thickness of the anterior and posterior walls of the original acetabulum using preoperative computed tomography images and investigated the cup size applied in these cases. RESULTS: The mean depth and width of the acetabulum was 18.4 and 16.2 mm proximal end, 18.4 and 24.3 mm in the middle, and 15.8 and 27.6 mm at the distal part. Mean thickness of the anterior and posterior walls was 10.9 and 23.9 mm at the proximal end, 10.3 and 22.2 mm in the middle, and 10.9 and 22.7 mm at the distal part. A 42-mm cup was using in one hip, a 46-mm cup in three hips, a 48-mm cup in 13 hips, and a 50-mm cup in six hips. CONCLUSION: In patients with Crowe IV DDH, the morphology of the acetabulum comprises a triangle that broadens from proximal to distal points, with a relatively thick posterior wall. Reaming the acetabulum posteriorly and inferiorly may enable the placement of a relatively larger cup to achieve stable fixation.

Successful reimplantation surgery after extraction of well-fixed cementless stems by femoral longitudinal split procedure.

BACKGROUND: Well-fixed cementless stems sometimes need to be extracted in patients with complications including periprosthetic infection, stem-neck breakage, or trunnionosis. The purpose of this study was to report the clinical outcome in patients undergoing reimplantation surgery after removal of a well-fixed porous-coated cementless stem by the femoral longitudinal split (FLS) procedure. METHODS: We conducted a retrospective study and radiographic review of 16 patients who had undergone reimplantation following the FLS procedure to remove a well-fixed stem due to periprosthetic infection, stem-neck breakage, or trunnionosis. The study group consisted of 2 men and 14 women with an average age of 68.4 years. Mean follow-up was 44.6 months. The Kaplan-Meier method was used to evaluate the longevity of the stem. RESULTS: The average operation time was 272 ± 63 minutes and intraoperative bleeding was 420 ± 170 mL. Although postoperative dislocation occurred in 5 hips and subsidence of the stem was found in 2 hips after surgery, no progressive subsidence was observed and the clinical JOA and JHEQ scores were both improved after reimplantation surgery. Reimplantation surgery with Zweymüller-type stems revealed evidence of osseointegration of the stem without femoral fracture. Kaplan-Meier survival analysis of stem revision for any reason as the end point revealed 70.0% survival at 9 years. CONCLUSIONS: In this study, we experienced some complications in patients with trunnionosis or periprosthetic infections. However, the FLS procedure is expected to confer successful clinical results without loosening of the reimplanted cementless stem, after safe extraction of well-fixed porous-coated cementless stems without fracture.

The proton pump inhibitor, lansoprazole, prevents the development of non-traumatic osteonecrosis of the femoral head: an experimental and prospective clinical trial.

BACKGROUND: An effective prevention strategy for osteonecrosis of the femoral head (ONFH) has yet to be established. We previously reported that the innate immune system via the toll-like receptor (TLR) response induced by corticosteroids leads to the development of ONFH and that repression of IRF7 activity by an inhibitor could interfere with the development of ONFH while maintaining the therapeutic effect of the corticosteroids. OBJECTIVE: In the present study, we hypothesize that lansoprazole has the potential to suppress IRF7 activity and prevent corticosteroid-induced ONFH in rats. Furthermore, we conducted a preliminary clinical trial to prevent corticosteroid-induced ONFH in autoimmune disease patients. METHODS: Male Wistar rats were randomly divided into four groups. On Day 1, each rat was injected with TLR4 ligand (LPS) or TLR7 ligand (imiquimod), followed by methylprednisolone with or without lansoprazole on Day 2. They were killed at 1 or 14 days after the last injection.We prospectively recruited 30 patients requiring primary high-dose corticosteroid treatment for immune diseases. All patients were administered lansoprazole, starting the night before corticosteroid treatment began. MRI was performed before corticosteroid treatment, and at 4, 12 and 24 weeks afterward. RESULTS: In rats, co-treatment of lansoprazole with corticosteroids significantly repressed both IRF7 activity and the development of ONFH. Moreover, in the human patients, the incidence of ONFH was significantly decreased from 53.4 to 13.3%. CONCLUSIONS: Although the present study is preliminary, the results show that co-treatment of lansoprazole with corticosteroids prevents ONFH development. Lansoprazole may be both safe and effective in preventing osteonecrosis of the femoral head in patients needing corticosteroid treatment.

Denosumab prevents periprosthetic bone mineral density loss in the tibial metaphysis in total knee arthroplasty.

BACKGROUND: Periprosthetic bone quality is one of the most important factors preventing early prosthesis migration and long-term failure. Although denosumab, which binds to the receptor activator of nuclear factor kappa-B ligand (RANKL), has been linked with periprosthetic bone mineral density (BMD), the effectiveness of denosumab against bone loss remains unclear. We hypothesized that denosumab treatment after total knee arthroplasty (TKA) could prevent periprosthetic bone resorption. METHODS: In this prospective cohort study, 28 patients with primary knee osteoarthritis were divided into two groups: denosumab (denosumab and vitamin D) and control (vitamin D only) groups. All patients underwent TKA with the same implant model and received medication after surgery. We used dual-energy X-ray absorptiometry to measure periprosthetic BMD after TKA. RESULTS: In the control group, the BMD of the proximal medial tibia decreased drastically at 12 months after TKA (-19.7%). Denosumab treatment significantly preserved this BMD loss (0.7%). The linear regression analysis revealed that denosumab intervention had the highest significantly positive relationship with BMD. CONCLUSIONS: Our results indicate that denosumab treatment significantly reduces periprosthetic BMD loss, even at the early stages after TKA. This therapeutic strategy may facilitate early stable fixation of the prosthesis which, in turn, may help to prevent early implant migration and reduce the need for revision surgery.

Functional Adaptation of the Fibrocartilage and Bony Trabeculae at the Attachment Sites of the Anterior Cruciate Ligament.

The direct insertion of an enthesis is composed of uncalcified fibrocartilage (FC) and calcified FC, believed to function as buffers for multidirectional forces applied to the ligament. This study was performed to investigate the relationship between the FC thickness and bony trabecular orientation of the anterior cruciate ligament (ACL) on both the femoral and tibial sides. Six cadavers were examined (age at death: 73-92 years). Both femoral and tibial insertions of the ACL were harvested and used to make 0.5 mm interval semi-serial sections. Microdigital images were taken and used to measure the maximum thickness of both the uncalcified FC and Calcified FC. Two-dimensional discrete Fourier analysis was also performed to determine the orientation angle and orientation intensity of bony trabeculae directly under the FC. The mean thicknesses of the uncalcified FC at the femoral and tibial insertions were 0.98 mm and 0.49 mm, respectively. The mean thicknesses of the calcified FC were 0.47 mm and 0.38 mm, respectively. There was a significant difference in the uncalcified FC thickness, but not in the calcified FC thickness. The bony trabeculae showed a prominent orientation parallel to the ACL fiber on both sides, but it was more intense on the tibial side than on the femoral side. The trabecular orientation was prominent in the proximal-posterior part of the femoral side and in the anteromedial part of the tibial side, suggesting that mechanical stress is greater in these parts. The dominant bony trabecular angle was 69.0° on the femoral side and 59.8° on the tibial side when the tidemark was set at 0°. These findings suggest that the femoral side receives multidirectional stresses, while relatively unidirectional stress is loaded on the tibial side. Furthermore, stress is considered to be greater in the proximal-posterior part of the femoral insertion and in the anteromedial part of the tibial insertion. At the time of ACL reconstruction, attention should be paid to assign a robust portion of the graft to the posterior part of the femoral insertion and anteromedial part of the tibial insertion. Clin. Anat., 33:988-996, 2020. © 2019 Wiley Periodicals, Inc.

Restoration of proximal periprosthetic bone loss by denosumab in cementless total hip arthroplasty.

Denosumab contributed to the restoration of proximal periprosthetic bone loss around the femoral stem that were measured using a DEXA, especially in zone 7, at 1 year after cementless THA in elderly osteoporotic patients. INTRODUCTION: Although bone quality is an important issue in elderly osteoporotic patients who underwent total hip arthroplasty (THA) with a cementless stem, periprosthetic bone mineral density (BMD) in the proximal femur has been reported to be decreased by 15-40% postoperatively. Some authors have examined the use of several types of bisphosphonates to prevent decreases in BMD in the proximal femur after cementless THA; however, few reports have demonstrated success in restoring BMD in the proximal medial femoral bone, such as zone 7. METHODS: We conducted prospective study comparing patients who underwent cementless THA administered with denosumab (10 patients) and without denosumab (10 patients). BMD around the femoral stem were measured using a DEXA immediately after surgery, and at 6 months and at 1 year after surgery. No difference was found between the two groups referred to the patient's demographic data. RESULTS: We found that denosumab displayed definitive effects in increasing the % change in periprosthetic BMD at zone 7 by an average of 7.3% in patients with cementless THA, compared to control group who were given only vitamin D. CONCLUSION: Denosumab is one of a number of anti-osteoporotic agents to have a definitive effect on the restoration of proximal periprosthetic bone loss, especially in zone 7, after cementless THA. Denosumab contributed to the restoration of decreased periprosthetic BMD to normal levels. As the decrease in BMD in the proximal femur after THA is considered to be apparent at 6-12 months after surgery, it is believed that prevention of the deterioration of bone quality is important in the proximal femur immediately after cementless THA for elderly female patients with osteoporosis.

Quality of life of patients with osteonecrosis of the femoral head: a multicentre study.

PURPOSE: Quality-of-life (QOL) assessments in patients with osteonecrosis of the femoral head (ONFH) have rarely been reported. This multicentre study aimed to elucidate the relationship between disease severity, including necrotic lesion type and radiological staging, and QOL, as well as between patients' characteristics and QOL. METHODS: Two hundred seventy-four patients with ONFH (108 females, 166 males; median age, 46 years) were asked to complete self-assessment QOL questionnaires including the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire, Oxford Hip Score, and SF-12v2. RESULTS: Patients with large necrotic lesion type or collapsed ONFH had low QOL scores. Among patients with non-collapsed lesions, patients with alcohol-associated ONFH had lower QOL scores than those with steroid-associated ONFH, those with bilateral ONFH had lower mental scores, and male patients had worse social condition scores. Among patients with collapsed lesions, middle-aged patients exhibited lower mental QOL, and a strong correlation was observed between social activity and mental health. CONCLUSION: Collapsed ONFH was associated with low QOL scores. Among patients with non-collapsed lesions, alcohol-associated ONFH, bilateral disease, and male sex were linked to low QOL scores.

Chondrosarcoma mimicking MRI of the osteonecrosis of the femoral head: a case report.

A 25-year-old female visited our hospital with an 8-year history of arthralgia in the right hip joint. Plain radiography of the hip revealed a well-demarcated radiolucent lesion with a thin sclerotic rim in the epiphysis of the femoral head. T 1 weighted MRI revealed the demarcation line of a low-signal-intensity band in the femoral head. We were aware that this band did not split the signal of adipose tissue in the bone marrow. In cases of osteonecrosis, we usually find a low-signal-intensity band splitting the signal of normal bone marrow. However, we could not see such a low-signal-intensity band in this case. Therefore, we decided to perform other studies. Contrast-enhanced T 1 weighted MRI showed remarkable enhancement in the segment proximal to the low-signal-intensity band, indicating that this lesion might have blood perfusion. We decided to perform a bone biopsy to clarify the diagnosis. Histopathological examination of the biopsy specimen revealed chondrosarcoma. We found that contrast-enhanced MRI plays an important role to rule out osteonecrosis of the femoral head.

Hemangioma of the rib showing a relatively high 18F-FDG uptake: a case report with a literature review.

Hemangioma of the rib is a rare benign tumor that is often difficult to distinguish from malignant bone tumors. Rib hemangioma often shows bony disruption with a slight cortical disruption, extraosseous lesion, and expanded bone on computed tomography (CT). We report the case of a 68-year-old man with atypical rib hemangioma with a slight cortical disruption and no expanded bone. The tumor showed relatively high 18FDG-uptake on positron emission tomography (PET)/CT. Rib hemangioma often shows higher 18FDG-uptake. PET/CT may not provide useful information for distinguishing rib hemangioma from a malignant tumor. Close observation without surgical resection may be feasible if the tumor is diagnosed as a rib hemangioma by biopsy.

Three-dimensional orientation of the acetabulum.

This study was designed specifically to determine the normal acetabular orientation and femoral head covering, and whether these are affected by age or sex. Computed tomographic images of normal Japanese hip joints were used (males 60, females 60; mean age 48.3 years, range 15-79 years). Male and female age profiles were matched. The reconstructed 3-D pelvic images were aligned in the anatomical pelvic coordinate system. The acetabular orientation angles and femoral covering angles were measured in the sagittal, coronal, and horizontal planes. In the sagittal plane, the acetabular orientation angle was operative anteversion (O-av), and the femoral covering angles were the anterior and posterior center-edge angles (ACE and PCE). In the coronal plane, they were the Sharp angle (SA) and the lateral center-edge angle (LCE). In the horizontal plane, they were anatomical anteversion (A-av) and the anterior and posterior sector angles (ASA and PSA). The O-av, SA, and A-av were smaller in the male than the female acetabulum (P < 0.01). SA in both males and females was inversely correlated with age (P < 0.01). Both male PCE and PSA were significantly smaller than those of females, while male ASA was larger than female ASA (P < 0.05). The male acetabulum is directed further outward and downward than the female one. However, this does not indicate that the male acetabulum covers the femoral head more, because there is no significant sex difference in the LCE. Femoral coverage is more posteriorly biased in females than in males owing to pelvic inclination. Clin. Anat. 30:753-760, 2017. © 2017Wiley Periodicals, Inc.

Soleal vein dilatation assessed by ultrasonography is an independent predictor for deep vein thrombosis after major orthopedic surgery.

BACKGROUND: Deep vein thrombosis (DVT) develops after major orthopedic surgery despite the current use of prophylaxis. DVT frequently develops in the soleal vein (SV) and might develop easily at the site of SV dilatation because of blood flow stasis. However, whether preoperative SV dilatation detected by ultrasonography predicts DVT after major orthopedic surgery remains unknown. OBJECTIVE: We examined whether SV dilatation detected by preoperative ultrasonography predicts DVT after major orthopedic surgery. METHODS: Ultrasonography was performed preoperatively and postoperatively in 243 patients with orthopedic diseases (mean age of 67±13 years, 77% women) who underwent total hip arthroplasty (THA, n=180) or total knee arthroplasty (TKA, n=63). Presence of DVT was diagnosed by ultrasonography and SV diameter ≥10mm was defined as SV dilatation. Patients with preoperative DVT were excluded. RESULTS: Sixty-nine patients (28%) developed postoperative DVT. SV dilatation was found in 24 patients (10%), and 16 (67%) of those patients had postoperative DVT. Multivariate logistic regression analysis showed that female gender [odds ratio (OR): 4.09, p=0.004], TKA (OR: 2.52, p=0.011), and SV dilatation (OR: 6.67, p<0.001), but not presence of comorbidities, medications, or plasma d-dimer value, independently predict postoperative DVT. Subgroup analyses according to the operation site showed that female gender (OR: 3.27, p=0.043) and SV dilatation (OR: 3.72, p=0.022) were independent predictors of postoperative DVT in the THA group. SV dilatation (OR: 12.0, p=0.027) was an independent predictor of postoperative DVT also in the TKA group. CONCLUSIONS: In addition to gender and TKA, SV dilatation detected by ultrasonography is an independent predictor of DVT after major orthopedic surgery. Determination of SV diameter by ultrasonography before major orthopedic surgery is useful for assessing the risk of postoperative DVT.