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Two-person interaction recognition has become an area of growing interest in human action recognition. The graph convolutional network (GCN) using human skeleton data has been shown to be highly effective for action recognition. Most GCN-based methods focus on recognizing an individual person’s actions on the basis of an intra-body graph. However, many of these methods do not represent the relation between two bodies, making it difficult to accurately recognize human interaction. In this work, we propose multi-stream adaptive GCN using inter- and intra-body graphs (MAGCN-IIG) as a new method of human interaction recognition. To ensure highly accurate human interaction recognition, our method cooperatively utilizes two types of graphs: an inter-body graph and an intra-body graph. The inter-body graph, which is newly introduced in this paper, connects the inter-body joints between two people as well as intra-body connections. The adaptive GCN using the inter-body graph captures the relation of joints between two people, even different types of joints located far away from each other. Further, by implementing a multi-stream architecture, our method simultaneously captures both inter-body and intra-body relations in each of two units that represent the position and motion of people. Experiments on interaction recognition using two large-scale human action datasets, NTU RGB+D and NTU RGB+D 120, showed that our method recognized human interactions more accurately than state-of-the-art methods.

Osteochondral fractures of the fingers are challenging to treat, and it is mandatory to acquire early bone union and joint surface reconstruction to obtain satisfactory outcomes. These injuries sometimes occur as open fractures with poor soft tissue condition and bone defect adjacent to osteochondral fragment. For such cases, surgical treatment can be more difficult, and vascularized bone graft (VBG) could be a useful method for joint reconstruction. Here, we report reverse-pedicled VBG based on the radiodorsal artery of the thumb for reconstructing a traumatic bone defect of the thumb. A 36-year-old man, who had ulcerative colitis and was taking immunosuppressive agents, sustained open fracture-dislocation of the thumb interphalangeal joint with a free osteochondral fragment of the proximal phalanx and 6 × 5 × 4 mm of subcondylar bone defect. We harvested 5 × 5 × 5 mm VBG at the base of the first metacarpal bone and dissected running the radiodorsal artery. The vascularized bone was grafted into the bone defect site through the subcutaneous tunnel created on the radial aspect of the proximal phalanx and fixed with a Kirschner wire. Bony union was obtained 2 months after surgery. At 7 months after the operation, the patient complained no pain, and the range of motion of the thumb interphalangeal joint was extension 0° and flexion 42°. Radiographs showed no avascular necrosis of the united fragment and osteoarthritis of the interphalangeal joint. This method could be a useful option for reconstruction of the thumb with bone defects.

Techniques for integrating different types of multiple features effectively have been actively studied in recent years. Multiset canonical correlation analysis (MCCA), which maximizes the sum of pairwise correlations of inter-view (i.e., between different features), is one of the powerful methods for integrating different types of multiple features, and various MCCA-based methods have been proposed. This work focuses on a supervised MCCA variant in order to construct a novel effective feature integration framework. In this paper, we newly propose supervised fractional-order embedding geometrical multi-view CCA (SFGMCCA). This method constructs not only the correlation structure but also two types of geometrical structures of intra-view (i.e., within each feature) and inter-view simultaneously, thereby realizing more precise feature integration. This method also supports the integration of small sample and high-dimensional data by using the fractional-order technique. We conducted experiments using four types of image datasets, i.e., MNIST, COIL-20, ETH-80 and CIFAR-10. Furthermore, we also performed an fMRI dataset containing brain signals to verify the robustness. As a result, it was confirmed that accuracy improvements using SFGMCCA were statistically significant at the significance level of 0.05 compared to those using conventional representative MCCA-based methods.

Osteitis of the fingers is a serious infection that needs early diagnosis and appropriate surgical debridement and antibiotic treatment of the infected bone. If the effects of treatments are insufficient, long-term antibiotic treatment and repeated operations could be required. In worst cases, some patients may have to undergo amputation. Recently, the usefulness of the Masquelet technique in extensive traumatic bone defects has been reported. We herein describe two cases of immunocompromised patients with purulent osteitis involving joint destruction of the finger treated by two-stage arthrodesis using the Masquelet technique. They obtained good infection control and better function of the finger than before the operation. Moreover, there was no recurrence of the infection. The Masquelet technique could be an alternative technique for osteitis with high risk of amputation.

Fast and wide imaging with single-cell resolution, high signal-to-noise ratio and no optical aberration has the potential to open up new avenues of investigation in biology. However, this imaging is challenging because of the inevitable tradeoffs among those parameters. Here, we overcome the tradeoffs by combining a resonant scanning system, a large objective with low magnification and high numerical aperture, and highly sensitive large-aperture photodetectors. The result is a practically aberration-free, fast scanning high optical invariant two-photon microscopy (FASHIO-2PM) that enables calcium imaging from a large network composed of ∼16k neurons at 7.5 Hz in a 9 mm2 contiguous image plane including more than 10 sensory-motor and higher-order regions of the cerebral cortex in awake mice. Through a network analysis based on single-cell activities, we discover that the brain exhibits small-world-ness rather than scale-freeness. FASHIO-2PM will enable revealing biological dynamics by simultaneous monitoring of macroscopic activity and its composing elements.

Atraumatic acute carpal tunnel syndrome is a rare type of median nerve neuropathy caused by etiologies that increase compartment pressure in the carpal tunnel. This report describes a patient with flexor tendon abrasion as an unusual complication of distal radioulnar joint arthritis. This abrasion caused a hematoma to form in the carpal tunnel during anticoagulant treatment with apixaban, resulting in recurrent acute carpal tunnel syndrome.

In this paper, we propose a design of asynchronous communication for an industrial wireless LAN system. In our design, MAC is synchronous multi-user round-robin transmission protocol. Low overhead Packet Division Multiple Access scheme is utilized for Multi-user Downlink transmission up to 80 MHz, while Frequency Division Multiple Access is employed for the uplink transmission. The designed of PHY system is developed based on a fast and deterministic communication featuring the synchronous multi-user system. In this paper, the industrial robots are not only controlled by synchronous communication but also by asynchronous communication via our industrial WLAN (iWLAN) system. This paper presents the hardware and software cooperative design. In the verification, up to 10 motors can be controlled by our iWLAN system by asynchronous communication, and the delay of each robot measured is 188 μs on average. Besides, the time synchronization captured by oscilloscope is from 40 to 100 ns as in our target.

In this paper, we present supervised fractional-order embedding multiview canonical correlation analysis (SFEMCCA). SFEMCCA is a CCA method realizing the following three points: (1) learning noisy data with small number of samples and large number of dimensions, (2) multiview learning that can integrate three or more kinds of features, and (3) supervised learning using labels corresponding to the samples. In real data, it is necessary to deal with high dimensional noisy data with limited number of samples, and there are many cases where three or more kinds of multimodal and supervised data are treated in order to calculate more accurate projections. Therefore, SFEMCCA, which takes the above advantages (1)–(3) into account, is effective for data obtained from real environments. From experimental results, it was confirmed that accuracy improvements using SFEMCCA were statistically significant compared to the several conventional methods of supervised multiview CCA.

This paper presents a personalized preference estimation method for video recommendation. Our method not only uses deep convolutional neural network (DCNN)-based video features but also transforms them based on user's viewing behavior in order to improve accuracy of preference estimation for a video. Specifically, we adopt supervised multi-view canonical correlation analysis (sMVCCA) in order to calculate “canonical video features”, which have a maximal correlation between the following three kinds of features: a video, user's viewing behavior and user's evaluation scores for the video. By using the canonical video features, our method can estimate the user's personalized preference for a video more accurately than using only the DCNN-based video features. Experimental results show the effectiveness of our method.

This paper presents a novel method for personalized video preference estimation based on early fusion using multiple users' viewing behavior. The proposed method adopts supervised Multi-View Canonical Correlation Analysis (sMVCCA) to estimate correlation between different types of features. Specifically, we estimate optimal projections maximizing the correlation between three features of video, target user's viewing behavior and evaluation scores for video. Then novel video features (canonical video features), which reflect the target user's individual preference, are obtained by the estimated projections. Furthermore, our method computes sMVCCA-based canonical video features by using multiple users' viewing behavior and a target user's evaluation scores. This non-conventional approach using the multiple users' viewing behavior for the preference estimation of the target user is the biggest contribution of our method, and it enables early fusion of the canonical video features. Consequently, successful video recommendation that reflects the users' individual preference can be expected via the evaluation score prediction from the integrated canonical video features. Experimental results show the effectiveness of our method.

Night pain is a particularly vexing symptom in patients with rotator cuff tear. It disturbs sleep and decreases quality of life, and there is no consensus regarding its etiology. Based on arthroscopic surgical observations of synovitis around the rotator interval or capsule surface in rotator cuff tear, we hypothesized that blood flow from the artery feeding the capsule increases blood supply to the synovium. This study aimed to investigate the relationship between blood flow and night pain using pulse Doppler ultrasonography. A series of 47 consecutive patients with rotator cuff tear was evaluated. The peak systolic velocity and resistance index of blood flow in the ascending branch of the anterior humeral circumflex artery were evaluated using pulse Doppler ultrasonography. We also investigated 20 normal shoulders in healthy volunteers. The peak systolic velocity and resistance index were compared between affected and unaffected sides in patients and between dominant and nondominant sides in controls. Anterior humeral circumflex artery peak systolic velocity and resistance index did not differ between sides in control subjects or in patients with rotator cuff tear without night pain. However, anterior humeral circumflex artery peak systolic velocity and resistance index did differ significantly between sides in patients with rotator cuff tear with night pain. This study revealed anterior humeral circumflex artery hemodynamics in patients with rotator cuff tear and normal subjects using Doppler ultrasonography. Night pain, particularly involving aching, appears to be related to the hemodynamics. These findings suggest that investigating the hemodynamics of patients with rotator cuff tear with night pain may lead to greater understanding of the etiology of this symptom.

This paper presents novel video feature-based favorite video estimation method. In the proposed method, we use three features, videos, users' viewing behavior and users' evaluation scores for these videos. In order to calculate the novel video features, Multiset Canonical Correlations Analysis (MCCA) is applied to these features to integrate the different types of features. Specifically, MCCA maximizes the sum of three kinds of correlations between three pairs of these features. Then the novel video features that represent the users' individual preference can be obtained by using the projection maximizing the three correlations. Finally, Supported Vector Ordinal Regression (SVOR) is trained by using the novel video features to estimate favorite videos. Experimental results show the effectiveness of our method.

The proximal femoral nail antirotation is a new generation of intramedullary device for the treatment of trochanteric femoral fractures, having a helical blade rather than a screw for suggested better purchase in osteoporotic bone. However, it is not free of complications. Few reports are available on postoperative perforation of the helical blade through the femoral head as a unique complication of proximal femoral nail antirotation. We report a 79-year-old woman with acetabular perforation after migration of the helical blade through the femoral head after an unstable trochanteric fracture, which was fixed with a proximal femoral nail antirotation.

A new vector control system for permanent magnet synchronous motor drives has been developed. To stabilize the current control loop in the high-rotating-speed region, a novel configuration of current controller is introduced. The unique characteristic of the proposed current controller is that the current regulator is connected to the conventional motor model in a series. By analyzing the transfer characteristics of the control, it became clear that the influence of the coupling component between the d–q axes can be deleted theoretically if the control parameters are set properly. The stability and torque response of the proposed vector control system were improved, and the effectiveness of the proposed controller was demonstrated by a time domain simulation and some experiments. In addition, the robustness of the controlling system was investigated experimentally. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(4): 61–72, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21123

Turbulence structures of high Reynolds number flow in the near-neutral atmospheric boundary layer (ABL) are investigated based on observations at Shionomisaki and Shigaraki, Japan. A Doppler sodar measured the vertical profiles of winds in the ABL. Using the integral wavelet transform for the time series of surface wind data, the pattern of a descending high-speed structure with large vertical extent (from the surface to more than 200-m level) is depicted from the Doppler sodar data. Essentially this structure is a specific type of coherent structure that has been previously shown in experiments on turbulent boundary-layer flows. Large-scale high-speed structures in the ABL are extracted using a long time scale (240 s) for the wavelet transform. The non-dimensional interval of time between structures is evaluated as 3.0–6.2 in most cases. These structures make a large contribution to downward momentum transfer in the surface layer. Quadrant analyses of the turbulent motion measured by the sonic anemometer (20-m height) suggest that the sweep motion (high-speed downward motion) plays a substantial role in the downward momentum transfer. In general, the contribution of sweep motions to the momentum flux is nearly equal to that of ejection motions (low-speed upward motions). This contribution of sweep motions is related to the large-scale high-speed structures.

A collarless, proximally porous-coated type of Spongiosa Metal II hip prosthesis was used for cementless total hip arthroplasty in 52 hips, and 48 hips were followed and assessed during a mean follow-up period of 6.3 years (minimum 5 years). There were 8 hips (16.7%) that had stress shielding, and 2 hips (4.2%) that had thigh pain. In terms of stability, the stem was bony stable in 39 hips, fibrous stable in 6, and unstable in 3. The stability of the stem was significantly correlated with the stem canal filling ratio. It was suggested that the much more proximal transfer of loading stress by a collarless, proximally porous-coated stem is not suitable for the Spongiosa Metal II series because it may unacceptably reduce the stability of the stem.

A new vector control system for permanent magnet synchronous motor drives has been developed. To stabilize the current control loop in the high rotating speed region, a novel configuration of current controller is introduced.The unique characteristic of the proposed current controller is that the current regulator is connected to the conventional motor model in a series. By analyzing the transfer characteristics of the control, it became clear that the influence of the coupling component between d-q axes can be deleted theoretically if the control parameters are set properly. Stability and torque response of the proposed vector control system were improved. Effectiveness of the proposed controller was demonstrated by a time domain simulation and, some experiments.In addition, the robustness of the controlling system was investigated in some experiments.

In this study, influences of infliximab to health-related quality of life (HRQOL) and active status of RA were assessed. Between 2003 and 2006, 22 patients with rheumatoid arthritis (RA) began receiving infusion of infliximab. Of all the patients, 17 patients who were followed for at least 30 weeks (102 weeks at maximum) after the start of infliximab were included in this study. The mean age was 54.6+/-10 years. HRQOL was evaluated with use of the SF-8trade mark, which is a simple version of the Medical Outcome Study Short Form 36. As an index of active status of RA, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and rheumatoid factor (RF) were collected. CRP and ESR significantly improved at the final follow-up, but RF did not. All subscales of the SF-8 were significantly improved after the start of infliximab. However, there were three patients whose laboratory data were improved, but HRQOL was not. We should not be prepossessed only with laboratory data in treating patients with RA. We recommend that the SF-8 to evaluate HRQOL of patients with RA in busy outpatient clinics because it is both simple and convenient.

The aim of this research is to determine a design methodology for operational improvement of a restaurant by identifying the specific factors of concern to consumers that influence customer satisfaction (“Kansei factors”), quantify the level of influence of these factors and use these to construct a suitable logical model using the “QSCmix”concept, and also to verify the effectiveness of this logical model. Specifically, the logical model is constructed from a multi-variable analysis model as used in psychology and other fields. The effectiveness of the model was verified by using secondary data to identify the three elements of QSC and verify their formulation as a quantitative model, and by verifying the operational effectiveness at an actual restaurant in Japan over a fourteen month period. The results of the analysis showed that, by identifying and categorizing the factors of concern to consumers that influence customer satisfaction (satisfaction influence factor group, referred to as “Bf factors”), the factors were able to be systematized and divided into five categories by characterizing the attractiveness factors that are also “QSCmix”factors. Also, the composite equation for establishing the groupings and level of influence for the combinations of “Bf factors”for each of these influential categories (referred to as “Bfp factors”) was calculated using a satisfaction evaluation formula based on the each of the grouping “Bfp factors”for each examinee, and this established three groups of identification categories together with their levels of influence. The order of new categories that influence satisfaction (desirable “Bf factor”combinations) was determined to be, 1 st: guest service, 2nd: portion volume, 3rd: cleanliness, 4th: price affordability, 5th: taste, 6th: food presentation, 7th: ambience, 8th: membership privileges, and 9th: menu variety. A successful result in the form of an improving trend for patrons to make repeat visits and increasing monthly turnover was achieved in the restaurant for verification used to trial the “QSCmix”concept design process based on the satisfaction structure obtained from the “QSCmix”concept design identified by this research. These results demonstrate that the proposed logical model is effective as a quantitative model for the analysis of satisfaction factors and that it can be applied to “QSCmix”concept design.

We intravenously administered flomoxef sodium (FMOX) 120 minutes before cataract surgery, topically administered levofloxacin (LVFX) into the eyes four times at 30-minute intervals before surgery, and measured the aqueous humor concentrations of these agents to investigate their penetration into the aqueous humor and their efficacy in the prevention of postoperative endophthalmitis.Sixty-eight patients who underwent cataract surgery at the Department of Ophthalmology, Yokohama City University School of Medicine, or its affiliate, Kanazawa Hospital, Yokohama, were enrolled in this study. They received one or both of the following: 1.0 g FMOX via a 20-minute intravenous drip and LVFX ophthalmic solution applied four times at 30-minute intervals, both beginning two hours before the operation. Aqueous humor was aspirated from the anterior chamber and assayed for FMOX and LVFX concentrations using high-performance liquid chromatography (HPLC).The mean intraoperative FMOX and LVFX concentrations in the patients' aqueous humor were 1.21 +/- 0.63 microg/ml and 0.69 +/- 0.47 microg/ml, respectively. These concentrations sufficiently exceeded the MIC90 values against Staphylococcus epidermidis, S. aureus, and Propionibacterium acnes.The FMOX and LVFX concentrations in the aqueous humor sampling were adequate to kill bacteria in vitro. These drugs may have efficacy in the prevention of postoperative endophthalmitis in patients undergoing cataract surgery.

This paper describes the effect of terrain configuration on the atmospheric boundary layer for siting large wind turbines, based on data from Doppler SODAR. Prior to installing large machines, standard meteorological anemometers, to about 30 m height, are cost effective and relatively easy to install for an approximate extrapolated wind assessment. However, if accurate wind assessment is needed, the wind condition at hub height of more than 50 m should be measured directly, especially in complex terrain. The data presented in this paper were collected from a measurement site located at the coast of the Japan Sea. Comparison is made between data measured at hub-height by Doppler SODAR and the data predicted from observation of the wind condition at lower height. A significant difference is noted between the extrapolated results from lower level measurements and the results directly measured by SODAR, especially when the wind is over complex terrain. Thus it is shown that wind speed measurement at low height is not satisfactory for assessing wind accurately at rotor height, but that Doppler SODAR measurement is satisfactory.

An acoustic array antenna which has a narrow main lobe and suppressed sidelobes is studied. The directivity function formed by the multiple point sources is used to estimate the aperture of an array and the spacing between the transducer elements to make a desired beam. Then the aperture tapering based on a Chebyshev distribution and the effect of an acoustic shield are evaluated to suppress the sidelobe radiation. The total performance of the phased array system has been examined by comparison with tower instruments. The field test shows that the measured beam pattern agrees with the calculated one and the sodar-derived winds have a correlation of 0.96 and a standard deviation of differences of about 0.47–0.52 m s−1 compared with in situ measurements. These statistical values are as good as or even better than those from the previous experiment. Copyright © 1998 Royal Meteorological Society

We evaluated the clinical and radiographic results of primary total hip arthroplasty for 81 dysplastic hips (71 patients) using cementless Spongiosa Metal II cups (ESKA Implants, Lubeck, Germany). The mean follow-up period was 6.4 years (minimum 5 years), and the preoperative mean Japanese Orthopaedic Association hip score had improved from 45.2 to 87.4 points at the latest follow-up. The radiographic outcome was no aseptic loosening in all 81 hips. The hip center was located significantly more superior than in the contralateral normal hip in 45 patients, but the difference was less than 10 mm; however, there was no significant difference in the lateral position of the hip center. The use of a Spongiosa Metal II cup for dysplastic hips provided satisfactory 5- to 10-year clinical and radiographic results.

Intraoperative acetabular fracture is a rare complication of primary total hip arthroplasty (THA), typically occurring during impaction of the cementless acetabular component. Here we report an unusual case of pelvic discontinuity caused by overreaming of the acetabulum during primary THA. Restoration of posterior columnar continuity was achieved with an autologous fibular graft and a reconstruction plate. Wall defects and cavitary defects were reconstructed with metal mesh and femoral head allograft, followed by placement and fixation of a Kerboull-type acetabular reinforcement device. Previous reports of acetabular fracture during THA have indicated that it has a relatively good prognosis without extensive treatment. However, to our knowledge, there has been no report of pelvic discontinuity necessitating acetabular reconstruction surgery as an intraoperative complication of primary THA.

Young athletes who employ overhead arm movements frequently develop shoulder pain caused by muscle tightness or scapula dysfunction1-3. Generally, they are instructed to perform a stretching and muscle-conditioning regimen1,3, but refractory pain without muscle tightness sometimes persists. In such cases, magnetic resonance imaging (MRI) should be used to look for other lesions, and occasionally a cystic lesion may be identified. Cysts located near the labrum, referred to as paralabral cysts or labral cysts, may cause shoulder pain or suprascapular nerve palsy4,5. To our knowledge, there have been no previous reports of ganglion cysts that were located below the coracoacromial ligament as being the cause of shoulder impingement syndrome in athletes. We report the presence of such a cyst in a patient who had the typical symptoms of shoulder impingement syndrome. For diagnostic imaging, we carried out radiographs, MRI, ultrasonography, and cystographic three-dimensional computed tomography (CT) examinations. Ultrasonography was particularly helpful for understanding the movement of the ganglion, while shoulder-dynamic and cystographic three-dimensional CT was very useful for identifying the location of the stalk and estimating the size of the cyst. Our patient was informed that data concerning the case would be submitted for publication, and he consented. A twenty-one-year-old male, right-hand-dominant volleyball player developed pain in the anterior aspect of the right shoulder when spiking the ball. The pain had persisted for more than a year as of the time that the patient presented to our institution, but there was no history of trauma. Physical examination revealed tenderness on compression of the area over the coracoacromial ligament. The examination findings did not suggest shoulder instability, and the patient had no limitation of motion in the shoulder. There was no evidence of local heat, a mass, muscle weakness, or …

It is challenging to reconstruct normal hip motion after a high hip dislocation. Although total hip arthroplasty (THA) with shortening osteotomy is a solution for high hip dislocation, osteotomy nonunion is a major complication. To improve the rate of osteotomy union, subtrochanteric transverse shortening osteotomy was performed using a modular-type stem, S-ROM, that can be fixed to both the proximal and distal parts of the femur individually with a stepped proximal sleeve and polished distal flutes with fins, respectively. The stem can facilitate union of the osteotomy by maintaining rigid rotational stability and generating compression pressure between bone parts of the femur even in simple transverse osteotomy. Moreover, transverse osteotomy is technically simple and minimizes the damage of the periosteum at the osteotomy. In our series, this procedure was performed on 6 hips in 6 patients with high hip dislocation. The mean follow-up period was 8.1 years. Osteotomy union was achieved in all patients for a mean of 8.8 weeks. This procedure is a good option for surgical treatment of high hip dislocation.

Bacille Calmette-Guérin osteomyelitis in infants is a known complication of Bacille Calmette-Guérin vaccination. Treatment consists of antituberculosis chemotherapy after biopsy/curettage; however, in cases of Bacille Calmette-Guérin osteomyelitis extending to the growth plate and epiphysis, the extent and time of surgical treatment such as curettage/biopsy is unknown because of bone growth disturbances. This article presents a case of an infant with this type of Bacille Calmette-Guérin osteomyelitis at the proximal tibia. A metaanalytic review was performed for possible risk factors of its recurrence. In our patient, primary curettage of partial lesion, excluding the part extending to the growth plate and epiphysis, failed, and recurettage of the extended lesion involving the growth plate and epiphysis was required for its eradication, resulting in bone growth disturbance. In the metaanalysis, 7 literatures reporting 14 cases of Bacille Calmette-Guérin osteomyelitis extending to the growth plate and epiphysis were included. Although statistical analysis showed no significant risk factors associated with the recurrence, these cases showed high recurrence rate in approximately 55.6%, requiring reoperation. Generally, the smaller damage to the growth plate can minimize bone growth disturbance. Taken together, it is suggested that Bacille Calmette-Guérin osteomyelitis extending to the growth plate and epiphysis is associated with high recurrence rate, and early curettage of the entire lesion should be performed to eradicate it and avoid resulting complications.

We describe a case of successful revision total hip arthroplasty for a Vancouver type B3 periprosthetic femoral fracture with extensive bone stock deficiency and osteoporotic diaphyseal bone. The femur was reconstructed with an allograft-cemented stem composite using a telescoping technique and a drainage hole for surplus cement. This procedure facilitated stable stem fixation to the host femur without cement interference and bony fusion between the allograft and host bone, as revealed by bone scintigraphy. This technique provides a surgical option for a severe periprosthetic femoral fracture in which the femoral diaphyseal bone is too osteoporotic to support the fixation of an allograft-cementless stem composite.

Infection of a hip prosthesis is one of the most severe complications encountered in orthopedic practice. Two-stage reconstruction using an antibiotic-impregnated cement spacer has become a popular procedure for the treatment of this condition. However, there are some disadvantages with the use of antibiotic-loaded cement, including low biocompatibility, a very low release ratio, and the possibility of thermal damage to the antibiotic. We have developed an effective drug delivery system for osteomyelitis in which porous hydroxyapatite (HA) blocks are loaded with an antibiotic by the vacuum method. We report here a modification of this delivery system applied for the first stage of two-stage reconstruction surgery against infected hip prosthesis. Eight consecutive patients who developed hip prosthesis infection underwent two-stage revision total hip arthroplasty (THA) using antibiotic-loaded porous HA blocks prepared by the vacuum method. Thorough debridement and insertion of antibiotic-loaded HA blocks was performed in the first stage, followed by conversion to THA after eradication of infection in the second stage. The mean interval between the stages was 16.8 weeks. There were no complications related to the use of the antibiotic-loaded HA blocks. The patients were followed up for an average of 49 months with no evidence of recurrent infection. The mean Japanese Orthopedic Association hip score improved from 45.1 before surgery to 79.6 at the latest follow-up. This simple approach utilizing antibiotic-impregnated HA blocks prepared by the vacuum method is considered to be effective for treatment of hip prosthesis infection.

Morcellized bone grafting was performed to significant acetabular deficiency in 35 hips of 29 patients in cementless total hip arthroplasty (THA). Bridging trabeculation across the graft–host interface, remodeling of the graft, and trabecular reorientation were observed at 4 weeks, 3.7 months, and 10.7 months postoperatively, respectively. These remodeling processes were observed in all cases. Morcellized bone grafting for acetabular deficiency in cementless THA stock, which is necessary to make the cup stable, revealed encouraging early trabecular reorientation and recovery of acetabular bone even in cases in which structural bone grafting is needed.

A 58-year-old woman suffered spontaneous recurrent hemarthrosis of the knee. In the clinical course, pigmented villonodular synovitis was mostly suspected, but in arthroscopic surgery the lateral meniscus appeared to be upturned and stuck into the lateral pouch with the meniscal ganglion cyst. It was suggested that meniscal tear with meniscal ganglion cyst was related with recurrent hemarthrosis. Generally, both the meniscal ganglion cysts and spontaneous recurrent hemarthrosis are highly rare conditions. In this case, we speculated that a negligible power could induce the meniscal tear with recurrent hemarthrosis in the particular situation in which the meniscal ganglion cyst existed. In other words, the meniscal ganglion cyst might basically and physically relate with hemorrhagic condition. Arthroscopically, the meniscal ganglion cyst was removed together with the anterior segment of the lateral meniscus. Recurrent hemarthrosis was treated successfully by resection of the meniscus.

This paper presents a newly developed type of submerged directional wave meter having the capability to measure water surface elevation and multiple current velocity components. These components are determined from Doppler frequency shifts using the complex covariance method. The developed system was demonstrated to be capable of successfully obtaining directional wave data, as well as adequately estimating directional wave spectra.