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An 84-year-old woman who underwent bilateral cementless total hip arthroplasty (THA) for dysplastic osteoarthritis 22 years ago was subjected to analysis. A huge soft-tissue mass was revealed in her left medial thigh. Plain radiographs of the left hip joint revealed severe osteolysis around the stem, cup, and ischium. Magnetic resonance imaging showed a 25 × 14-cm multilobulated mass with a thick-walled pseudocapsule. Two-stage surgery was performed with resection of the mass followed by a subsequent revision THA. The mass was diagnosed as a chronic expanding hematoma through gross and histologic findings. Two years after the revision THA, there was no recurrence of a hematoma. Two-stage revision THA was useful for definitive diagnosis, and good functional recovery was obtained after surgery.

Minimally invasive surgery (MIS) is among the preferred procedures for treating a number of ailments as patients benefit from fast recovery and reduced blood loss. The trade-off is that surgeons lose direct visual contact with the surgical site and have limited intra-operative imaging techniques for real-time feedback. Computer vision methods as well as segmentation and tracking of the tissues and tools in the video frames, are increasingly being adopted to MIS to alleviate such limitations. So far, most of the advances in MIS have been focused on laparoscopic applications, with scarce literature on knee arthroscopy. Here for the first time, we propose a new method for the automatic segmentation of multiple tissue structures for knee arthroscopy. The training data of 3868 images were collected from 4 cadaver experiments, 5 knees, and manually contoured by two clinicians into four classes: Femur, Anterior Cruciate Ligament (ACL), Tibia, and Meniscus. Our approach adapts the U-net and the U-net++ architectures for this segmentation task. Using the cross-validation experiment, the mean Dice similarity coefficients for Femur, Tibia, ACL, and Meniscus are 0.78, 0.50, 0.41, 0.43 using the U-net and 0.79, 0.50, 0.51, 0.48 using the U-net++. While the reported segmentation method is of great applicability in terms of contextual awareness for the surgical team, it can also be used for medical robotic applications such as SLAM and depth mapping.

A 64-year-old woman with a spontaneous fused hip sustained a left femoral neck fracture. It was revealed that her left hip joint had a long-standing spontaneous hip fusion due to end-stage osteoarthritis. Additionally, she sustained an ipsilateral femoral intertrochanteric fracture and underwent osteosynthesis using a dynamic hip screw 8 years ago. The one-stage THA was successfully treated with no major complications and good functional recovery was obtained. The hip range of motion improved remarkably at one year after surgery. The Modified Harris Hip Score improved from an estimated 70 points before fracture to 95 points at final follow-up.

Objective To evaluate the impact of spinopelvic parameters and hip contracture on change in the pelvic tilt (PT) after Total hip arthroplasty (THA). Methods One hundred patients (15 male and 85 female) who underwent THA were included in this prospective study. Radiographic data were obtained preoperatively and 1 year after THA. Radiographic parameters included sagittal anterior pelvic plane (APP), sagittal vertical axis (SVA), sacral slope (SS), pelvic inclination (PI), and lumbar lordosis angle (LL). The APP was defined as the angle between the anterior pelvic plane and the vertical plane. A positive value indicates pelvic retroversion. Postoperative changes in PT were divided into three groups: the PA group (pelvic anteversion, ΔAPP 5°), and the PT group (minimal change, ΔAPP ≤ ± 5°). The Kruskal–Wallis test and the Steel–Dwass test were used to compare the preoperative and postoperative spinopelvic parameters among the three groups. The Spearman's rank correlation coefficient was used to evaluate the correlation between ΔAPP and spinopelvic parameters. Results Minimal change in pelvic tilt was observed in 59% of patients, while pelvic anteversion was observed in 16% of patients and pelvic retroversion was observed in 25% of patients. There were no significant changes in the spinopelvic parameters, including TK, LL, SVA, LL, SS, and APP after THA. The Femoral angle (FA) was significantly decreased after THA (P

In the combined anteversion (CA) technique for total hip arthroplasty (THA) with a cementless stem, cup anteversion is strongly influenced by the native femoral anteversion. It is hypothesized that in cases with large native femoral anteversion, cup anteversion can be decreased, and anterior cup protrusion from the anterior edge of the acetabulum could occur due to the achievement of optimal CA. In this study, the accuracy of CA in THA with the CA technique using imageless navigation and the relationship between the protrusion of the anterior edge of cup and optimum CA was retrospectively evaluated. Ninety-seven patients (104 hips) who underwent primary THA by the CA technique using image-free navigation were enrolled in the study. The femoral stem was placed following the individual femoral anteversion so that the target cup anteversion could be determined following a mathematical formula (37 = femoral stem anteversion × 0.7 + cup anteversion). Results The resulting CA values effectively achieved accurate CA with 39.49 ± 5.03° postoperatively. On the other hand, anterior cup protrusion was measured by computed tomography image. A cup protrusion length of more than 3 mm was indicated for 60 cases (57.7%). All included patients were divided into two groups: Group 1 as protrusion positive and Group 2 as protrusion negative. In Group 1, preoperative femoral anteversion and postoperative stem anteversion were significantly higher, while postoperative cup anteversion was significantly lower. However, the postoperative CA value indicated no significant difference between the groups. The CA (stem-first) technique with image-free navigated THA could effectively achieve accurate CA. On the other hand, a large number of cases revealed anterior cup protrusion due to the low cup anteversion.

The purpose of the present study was to investigate the results of total hip arthroplasty (THA) using the Bicontact D stem with a minimum 10 year follow-up that focused on patients with developmental dysplasia of the hip (DDH). One hundred five patients with osteoarthritis due to DDH who underwent primary THA were included in this study. The mean final follow-up period was 12.7 ± 1.2 years (range 10–15 years). All cases were evaluated both clinically and radiographically, and Kaplan–Meier survivorship was determined as stem revision for any reason as the end point. Modified Harris hip score averaged 89.0 ± 1.1 (range 60–98) at the final follow-up. The survivorship was 99.0% (95% confidence interval 93.4–99.9%) at 15.0 years, and only one hip with a well-fixed stem required stem revision due to recurrent dislocations. Cortical hypertrophy (CH) was observed in 40 of 105 hips (38.1%), and stress shielding (SS) progressed to grade 3 or 4 in six hips (6 of 105 hips: 5.7%) during the study period. Among the six hips with progressed SS, Dorr type C proximal femoral geometry was seen in five hips. This study of 105 THAs using the Bicontact D stem that focused on DDH patients with a minimum 10 year follow-up period achieved satisfactory clinical and radiological outcomes. Dorr type C proximal femoral geometry could be considered a risk factor for progressed SS.

Background Unloading 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. Methods A 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. Results CH 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. Conclusions According 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.

Combined anteversion (CA) technique (stem-first procedure) has become generally accepted as an ideal means to achieve optimal CA value in THA. However, we hypothesized that CA technique for patients with various native femoral anteversions could pose a risk of anterior or posterior cup protrusion. In the present study, we examined whether it is possible to use the taper wedge stem to change the stem version to achieve optimal CA while avoiding cup protrusions with the cup-first procedure through minimally invasive (MIS) antero-lateral approach. Eighty-one patients underwent cup-first THA with a taper wedge stem. The acetabular cup was placed following the preoperative planning of the cup alignment to avoid anterior cup protrusions using CT-based navigation. Following the CA theory, anteversion of the taper wedge stem was changed to the target anteversion from the patient’s native femoral anteversion. The native femoral anteversion, the change in version angle of the stem, postoperative CA and the length of anterior cup protrusions were evaluated in postoperative CT measurements. The native femoral anteversion averaged 25.7° ± 8.9° (range 8°–45°). Cases with increased and decreased stem anteversion were observed in 42 hips (51.8%) and 33 hips (40.7%), respectively. The amount of increased and decreased version angles averaged 7.7° ± 4.8° (range 2°–21°) and 7.8° ± 5.1° (range 2°–20°), respectively. Postoperative CA values averaged 36.7° ± 3.4° (range 29.4°–44.2°) and anterior cup protrusion length averaged 2.0 mm ± 2.6 mm (0 ~ 8.8 mm) in axial view and 0.4 mm ± 1.0 mm (0 ~ 3.6 mm) in sagittal view. Anterior cup protrusion of more than 10 mm was not observed in any hips. This procedure can be considered as an option to achieve optimal CA anteversion while avoiding anterior cup protrusion in THA.

Kerboull-type acetabular support rings (KT) and allogenic bone graft were used for severe periacetabular bone loss with primary and revision total hip arthroplasty (THA). The purpose of this case–control study is to evaluate the risk factors related to poor outcomes of surgery. Sixty patients underwent primary THA and revision THA using allogenic bone graft with KT for large acetabular deficiency. These patients were retrospectively evaluated postoperatively and followed-up by radiograph. The minimum follow-up period was 4 years and averaged 7 years. A radiological failure was defined by the following criteria: 1) substantial migration defined as change in the angle of inclination of more than 5 degrees or migration of more than 5 mm, 2) breakage of the screw or device, 3) acetabular revision due to aseptic loosening. Expected risk factors were defined as female, age >75 years, body mass index (BMI) >25%, medical history of hypertension, renal failure, liver steatosis, diabetes, hyperlipidemia, cardiac infarction, smoking, American Academy of Orthopedic Surgery (AAOS) classification III or IV, bleeding>500 mL, time of surgery >3hours, high hip center-type KT, inclination of KT >45 degrees, screw angle >25 degrees, morselized bone graft, Kawanabe's classification stage 3 or 4 and revision surgery. Nineteen hips (31.6%) revealed radiological failure according to our criteria, and revision THA was performed in 2 hips (3.3%). In the statistical analysis, morselized bone graft and high hip center-type KT were identified as factors of poor outcomes of surgery.

Combined anteversion (CA) technique (stem-first procedure) is generally accepted as the optimal technique to attain an appropriate CA value in total hip arthroplasty (THA). However, cup anteversion is strongly influenced by the native femoral anteversion. Accordingly, anterior protrusion of the cup in the acetabulum might occur. The purpose of the present study is to investigate the achievement of the optimal CA while avoiding anterior cup protrusion and examine the significance of our new CA technique with cup-first procedure in hybrid THA. Seventy-nine hybrid THAs with the cup-first procedure used a CT-based navigation system for cup positioning. In the preoperative planning, cup anteversion was aimed at approximately 20°. However, in actuality, sufficient cup coverage in the original acetabulum based on individual anatomy is given priority over cup placement based on CT-based planning to ensure adequate cup coverage. The target stem anteversion was determined following Widmer’s mathematical formula (37.3 = femoral stem anteversion × 0.7 + cup anteversion). Cemented stem was inserted according to the target stem anteversion angle. Regarding the assessment of overall alignment, the calculated Widmer’s CA values during surgery and postoperative CT evaluation were 34.1° ± 6.0° (range 20.7°–51.2°) and 35.1° ± 6.7° (range 21.6°–50.7°). There were 72 hips (91.1%) within 25°–50° of CA. Cup protrusion length averaged 2.0 mm ± 2.6 mm (0–8.8 mm) in the axial view and 0.4 mm ± 1.0 mm (0–3.6 mm) in the sagittal view. Cup protrusion length of more than 5 mm was indicated in 10 hips, and no hips observed more than 10 mm. Our new CA technique (cup-first procedure) with hybrid THA was able to achieve optimal CA value while avoiding anterior cup protrusion.

Exosomes (EXs), a type of extracellular vesicles secreted from various cells and especially cancer cells, mesenchymal cells, macrophages and other cells in the tumor microenvironment (TME), are involved in biologically malignant behaviors of cancers. Recent studies have revealed that EXs contain microRNAs on their inside and express proteins and glycolipids on their outsides, every component of which plays a role in the transmission of genetic and/or epigenetic information in cell-to-cell communications. It is also known that miRNAs are involved in the signal transduction. Thus, EXs may be useful for monitoring the TME of tumor tissues and the invasion and metastasis, processes that are associated with patient survival. Because several solid tumors secrete immune checkpoint proteins, including programmed cell death-ligand 1, the EX-mediated mechanisms are suggested to be potent targets for monitoring patients. Therefore, a companion therapeutic approach against cancer metastasis to distant organs is proposed when surgical removal of the primary tumor is performed. However, EXs and immune checkpoint mechanisms in pancreatic cancer are not fully understood, we provide an update on the recent advances in this field and evidence that EXs will be useful for maximizing patient benefit in precision medicine.

In total hip arthroplasty (THA), combined anteversion (CA) is used as a parameter for assessment of overall prosthetic alignment. The purpose of this study was to comparatively examine the CA value in patients who underwent primary THA using the image-free navigation system either with a cup-first or stem-first technique. Eighty-three hips undergoing primary THA using the OrthoPilot® image-free navigation system (B. Braun-Aesculap, Tuttlingen, Germany) were included in this study. The patient population was divided into two groups depending on the procedure used: cup-first technique and stem-first technique. In the cup-first group, inclination and anteversion (AV) angles were targeted at 35–45° and 15–25°, respectively, while stem antetorsion (AT) was determined for each patient based on the amount of individual native femoral AT angle. In the stem-first group, the femur was prepared first with the target angle corresponding to the native femoral AT and the cup AV was decided considering the CA calculated with Widmer’s formula (aiming at the optimal Widmer’s CA of 37.3°). Better consistency in Widmer’s CA values was attained in the stem-first group as indicated by the smaller SD values. In the assessment of overall alignment, Widmer’s CA values were within the satisfactory range (37 ± 5°) in 41.9 and 92.3 % of the subjects in the cup-first group and the stem-first group, respectively. The stem-first technique with image-free navigated THA could effectively achieve accurate and consistent control of the CA value and thus is expected to improve the surgical outcome.

The purpose of this study was to evaluate the preoperative radiographs with cases of developmental dysplasia of the hip (DDH) leading to rotational acetabular osteotomy (RAO) or curved peri-acetabular osteotomy (CPO), and examine the frequency of femoroacetabular impingement (FAI) related bone morphology in the acetabulum and femoral head-neck junction. Twenty-four hips with hip dyaplasia who underwent CPO or RAO were included in this study. Six hips had grade 0 and eighteen hips had grade 1 OA according to the Tonnis classification. We excluded patients with moderate and severe hip osteoarthritis and major femoral head deformities. Preoperative radiograph was evaluated on sharp angle, center-edge angle, alpha angle, crossover sign and posterior wall sign. Crossover signs were revealed in 7 hips (29.2%); posterior wall signs were revealed in 16 hips (66.7%); and cam-type deformities with an alpha angle of ≥50.5˚ were observed in 19 hips (79.2%) in preoperative evaluation. As determined using the Tonnis scale, no progression of osteoarthritis was found in 16 of the 24 hips; there was a one-grade progression in 8 hips. Among the 8 hips, either positive cross-over sign or posterior sign in acetabulum, and an alpha angle of ≥50.5˚ in femur were observed in six hips with progression of osteoarthritis. The presence of cam-type deformity and acetabular retroversion in patients who underwent RAO or CPO was relatively high in preoperative radiographs, and caution should be employed during surgery in patients with DDH. There is a possibility of secondary FAI due to excessive forward coverage of the bone fragments after RAO and CPO.

In association with the growing interests in pain management, several modalities to control postoperative pain have been proposed and examined for the efficacy in the recent studies. Various modes of peripheral nerve block have been proposed and the effectiveness and safety have been examined for each of those techniques. We have described our clinical experiences, showing that continuous femoral nerve block could provide a satisfactory analgesic effect after total hip arthroplasty (THA) procedure. In this study, we compared the effectiveness and safety of continuous femoral nerve block with and without sciatic nerve blockade on pain control after THA. Forty patients scheduled for THA were included in the study and randomly divided into 2 groups. Postoperative analgesic measure was continuous femoral nerve block alone, while the identical regimen of continuous femoral nerve block was combined with sciatic nerve block. The amount of postoperative pain was evaluated in the immediate postoperative period, 6 hours, and 12 hours after surgery. Moreover, postoperative complications as well as requirement of supplemental analgesics during the initial 12 hours after surgery were reviewed in the patient record. The obtained study results showed that the supplemental sciatic nerve blockade provided no significant effect on arrival at the postoperative recovery room, while the NRS pain score was significantly reduced by the combined application of sciatic nerve blockade at 6 and 12 hours after surgery. In the investigation of postoperative analgesiarelated complications, no major complication was encountered without significant difference in complication rate between the groups.

Background The number of hemodialysis patients has been progressively increasing in our country. On the other hand, chronic hip arthropathy associated with long-term hemodialysis is a devastating problems affecting patients' quality of life. In our previous study, we proposed a classification system for radiological abnormalities seen in hemodialysis-related hip lesions. The purpose of the study was to propose the surgical strategy for hip disorders caused by long-term hemodialysis. Methods Patients with a history of hemodialysis for more than 10 years, 191 hip lesions in 165 consecutive patients who visited our institute due to hip symptoms. Various abnormalities were identified in 116 out of 191 hips. A retrospective assessment of the patient record and radiographs was performed for the included subjects examining the natural course of the disease process as well as the results of surgical treatment. Results Seventy-six hip lesions (69.0%) were conservatively managed at the time of the initial visit. Surgeries were performed for 75 hips (64.7%) during the study period. Among those, surgical treatment was indicated for 40 hips at the time of the initial visit. On the other hand, surgeries were performed for 35 hips during the subsequent follow-up period due to progression of the disease process. Conclusions Based on the analysis of our surgical experiences by the retrospective chart review, we have established a flowchart of the treatment strategy for chronic hip arthropathy in long-term hemodialysis patients. Study design This study is retrospective clinical study.

Major vascular injury is one of the most devastating complications in total hip arthroplasty (THA). Risk for intraoperative vascular injury is increased when the normal vascular anatomy is distorted by previous surgery or dislocation with displacement. Therefore, an appreciation of the vascular anatomy in relation to the anticipated surgical field is critical to avoid this complication during preoperative assessment for a complicated THA.Preoperative three-dimensional (3D) CT angiography was performed for 24 complicated THAs when altered vascular anatomy around the acetabulum was suspected. When assessing the CT images, the presence of apparent proliferation of vessels close to the original acetabulum as well as a distance of10 mm from the artery to the acetabulum was deemed a potential risk factor for intraoperative vascular injury. Additionally, the relationships of clinical characteristics and the presence of these risk factors were analyzed to identify the patient population at risk.The incidence of proliferation of collateral vessels was higher in patient groups with proximal femoral migration of 5 cm or more and multiple previous surgeries prior to the index THA. Moreover, in three ankylosed hips, lateral deviation of the main vascular trunk with an artery-acetabulum distance of10 mm was identified in all cases.Preoperative 3D-CT angiography in cases of complicated THA revealed altered vascular anatomy which may increase the risk for intraoperative vascular injuries. Patient characteristics related to the risk for this complication were marked proximal femoral migration, multiple previous surgeries, and hip ankylosis. Preoperative image examination of the vascular anatomy is thought to help reduce the risk of inadvertent vascular injury in these complicated THA cases.

Synovial osteochondromatosis of the hip is a rare condition, and the surgical treatment approach for this condition requires complete removal of loose bodies combined with synovectomy. While these, procedures are generally accepted as the optimal treatment method, this is still controversial topic. Recent studies have reported that open surgical procedures remain acceptable for synovial osteochondromatosis of the hip. These procedures include the dislocation of the femoral head, and complications such as femoral head necrosis and bursitis or great trochanter non-union due to trochanteric osteotomy have been reported. The present study reports a modified technique for surgical dislocation through a Z-shaped capsular incision without trochanteric flip osteotomy for the treatment of synovial osteochondromatosis of the hip.

Rationale Total hip arthroplasty (THA) concomitant with subtrochanteric femoral shortening osteotomy for Crowe type IV dysplastic hip has been reported. However, the combination of subtrochanteric femoral osteotomy and revision THA has only been mentioned in one case report. Patient concerns A 67-year-old female had a history of congenital dislocation of both hips. Diagnoses Right hip was diagnosed the aseptic loosening of THA with extremely high replacement of the acetabular component. Interventions Revision THA concomitant with subtrochanteric femoral shortening osteotomy using a cement stem was performed. Before the revision surgery, primary THA with subtrochanteric shortening osteotomy was performed on the opposite side. Regarding leg length, the actual leg length of the affected side was 9 mm longer, and the subjective leg length discrepancy was 45 mm shorter in the affected limb due to pelvic obliquity. Subtrochanteric osteotomy was performed with an amount of osteotomy equal to the amount of distal translation of the hip center to the original acetabulum. Outcomes As a result, pelvic obliquity improved, and the subjective leg length discrepancy disappeared after revision surgery. Lessons The combination of subtrochanteric femoral shortening osteotomy with revision THA resulted in a satisfactory outcome.

Implant positioning is one of the critical factors that influences postoperative outcome of total hip arthroplasty (THA). Malpositioning of the implant may lead to an increased risk of postoperative complications such as prosthetic impingement, dislocation, restricted range of motion, polyethylene wear, and loosening. In 2012, the intraoperative use of smartphone technology in THA for improved accuracy of acetabular cup placement was reported. The purpose of this study was to examine the accuracy of an iPhone/iPad-guided technique in positioning the acetabular cup in THA compared with the reference values obtained from the image-free navigation system in a cadaveric experiment. Five hips of 5 embalmed whole-body cadavers were used in the study. Seven orthopedic surgeons (4 residents and 3 senior hip surgeons) participated in the study. All of the surgeons examined each of the 5 hips 3 times. The target angle was 38°/19° for operative inclination/anteversion angles, which corresponded to radiographic inclination/anteversion angles of 40°/15°. The simultaneous assessment using the navigation system showed mean±SD radiographic alignment angles of 39.4°±2.6° and 16.4°±2.6° for inclination and anteversion, respectively. Assessment of cup positioning based on Lewinnek's safe zone criteria showed all of the procedures (n=105) achieved acceptable alignment within the safe zone. A comparison of the performances by resident and senior hip surgeons showed no significant difference between the groups ( P =.74 for inclination and P =.81 for anteversion). The iPhone/iPad technique examined in this study could achieve acceptable performance in determining cup alignment in THA regardless of the surgeon's expertise. [ Orthopedics. 2016; 39(4):e621–e626.]

A 53-year-old woman was admitted with severe subarachnoid hemorrhage due to rupture of an aneurysm associated with atypical intracranial fibromuscular dysplasia (FMD). Angiography demonstrated the aneurysm and very irregular form of the left internal carotid artery (ICA), the right ICA, and right proximal middle cerebral artery (MCA). Other arteries showed signs of atherosclerosis. The aneurysm was treated by embolization, but she subsequently died of shock of unknown cause. Detailed examination of serial angiograms detected enlargement of the aneurysm and progression of the irregular appearance of the ICA. FMD is a non-inflammatory and non-atheromatous arteriopathy that commonly affects the cervical ICA and sometimes the intracranial ICA. The association with saccular aneurysm is widely known and the prevalence of incidental aneurysms is higher than that in the general population. The common "string of beads" finding is easily distinguished from other vascular diseases, but non-specific findings such as "tubular stenosis" and "diverticular-like outpouching" are harder to differentiate. FMD is associated with various complications and appropriate periodic follow-up examination is required. Detailed analysis of serial angiograms may facilitate diagnosis of this condition.

A 47-year-old man underwent ceramic cup arthroplasty when he was 22 years old. Revision total hip arthroplasty was performed 25 years later because of limited range of motion without implant loosening. Histologic examination revealed that the femoral head and ceramic implant were well fixed through a thin fibrous membrane. The energy-dispersive X-ray analysis indicated that calcium and phosphorus were detected in the same peak pattern as cancellous bone in the bone-ceramic interface.