Aims

Clear cell sarcoma (CCS) of soft-tissue is a rare melanocytic subtype of mesenchymal malignancy. The aim of this study was to investigate the clinical and therapeutic factors associated with increased survival, stratified by clinical stage, in order to determine the optimal treatment.

Aims

There are concerns regarding complications and longevity of total elbow arthroplasty (TEA) in young patients, and the few previous publications are mainly limited to reports on linked elbow devices. We investigated the clinical outcome of unlinked TEA for patients aged less than 50 years with rheumatoid arthritis (RA).

The meniscus is a fibrocartilaginous tissue that plays an important role in controlling the complex biomechanics of the knee. Many histological and mechanical studies about meniscal attachment have been carried out, and medial meniscus (MM) root repair is recommended to prevent subsequent cartilage degeneration following MM posterior root tear. However, there are only few studies about the differences between meniscus root and horn cells. The goal of this study was to clarify the differences between these two cells.

Tissue samples were obtained from the medial knee compartments of 10 patients with osteoarthritis who underwent total knee arthroplasty. Morphology, distribution, and proliferation of MM root and horn cells, as well as gene and protein expression levels of Sry-type HMG box (SOX) 9 and type II collagen (COL2A1) were determined after cyclic tensile strain (CTS) treatment.

Horn cells had a triangular morphology, whereas root cells were fibroblast-like. The number of horn cells positive for SOX9 and COL2A1 was considerably higher than that of root cells. Although root and horn cells showed similar levels of proliferation after 48, 72, or 96 h of culture, more horn cells than root cells were lost following 2-h CTS (5% and 10% strain). SOX9 and COL2A1 mRNA expression levels were significantly enhanced in horn cells compared with those in root cells after 2- and 4-h CTS (5%) treatment.

This study demonstrates that MM root and horn cells have distinct characteristics and show different cellular phenotypes. Our results suggest that physiological tensile strain is important for activating extracellular matrix production in horn cells. Restoring physiological mechanical stress may be useful for promoting healing of the MM posterior horn.

Aims

The aim of this study was to report the mid-term clinical outcome of cemented unlinked J-alumina ceramic elbow (JACE) arthroplasties when used in patients with rheumatoid arthritis (RA).

Purpose

Injuries of the meniscal attachments can lead to meniscal extrusion. We hypothesized that the extent of lateral meniscal extrusion (LME) was associated with the severity of the lateral meniscus posterior root tear (LMPRT). This study aimed to evaluate the relationship between preoperative LME and arthroscopic findings of LMPRT in knees with anterior cruciate ligament (ACL) injury.

Background

Meniscus repair can restore the function of torn meniscus in anterior cruciate ligament (ACL)-reconstructed knees. However, few reports investigate the relationship between concurrent meniscus repair with ACL reconstruction and postoperative meniscal position. This study aimed to evaluate the size of the medial meniscus in patients who underwent ACL reconstruction and concomitant all-inside medial meniscus repair.

Background

Hyaluronan (HA) promotes extracellular matrix (ECM) production and inhibits the activity of matrix degrading enzymes in chondrocytes. The meniscus is composed of the avascular inner and vascular outer regions. Inner meniscus cells have a chondrocytic phenotype compared with outer meniscus cells. In this study, we examined the effect of HA on chondrocytic gene expression in human meniscus cells.

Introduction

CT-based navigation system in total hip arthroplasty (THA) is widely used to achieve accurate implant placement. Now, we developed our own CT-based navigation system originally, and since then we have been conducting various analysis in order to use the system more effectively. We compared the accuracy of registration with this navigation system and land mark matching type navigation system. In this study, we evaluated the influence of the surgical approach to the accuracy of registration.

Objectives

Few reports were shown about the position of the cup in total hip arthroplasty (THA) with CT-based navigation system. We use minimally invasive surgery (MIS) technique when we perform cementless THA and the correct settings of cups are sometimes difficult in MIS. So we use CT-based navigation system for put implants with correct angles and positions. We evaluated the depth of cup which was shown on intra-operative navigation system.

Object

CT-based navigation system in total hip arthroplasty(THA) is widely used to achieve accurate implant placement. However, its internal structure was a trade secret. Therefore, it was hard to analyze optimal reference points. Now, we developed our own CT-based navigation system originally, and since then we have been conducting various analyses in order to use the system more effectively. The purpose of this study was to analyze the optimal area and the number of registration points, which enables to move initial errors into the acceptable range.

Materials and Methods

We treated 60 hips in 60 patients (8 males and 52 females) with cementless THA that were performed from January 2007 to December 2009 in our hospital. 48 osteoarthritis hips, 5 rheumatoid arthritis hips and 7 idiopathic osteonecrosis hips were included. All patients were performed THA with VectorVision Hip navigation system (BrainLAB, Feldkirchen, Germany). We used AMS HA cups and PerFix stems (KYOCERA Medical co., Osaka, Japan). The mean age of surgery was 61 years old (35–79 years old). The pelvic inclination angles (PIA) were measured with anteroposterior radiographic image in accordance with the Doiguchi's method.

Background

CT-based navigation system in total hip arthroplasty(THA) is widely used to achieve accurate implant placement. The purpose of this study was to evaluate the influence of initial error correction according to the differences in the shape of the acetabulum, and correction accuracy associated with operation approach after localization of registration points at anterior or posterior area of the acetabulum.

Objectives

The shape of proximal femur is important for the selection of implant in total hip arthroplasty (THA). There are few reports about the shape of proximal femur. We analyzed preoperative and postoperative conditions of the proximal femurs of patients before and after total hip arthroplasty with computed tomography (CT) and evaluated the compatibility to the cementless stem.

Objectives

The setting angle of the cup is important for achieving the stability and avoiding the dislocation after total hip arthroplasty (THA). It is difficult to set the cup at correct angle in minimally invasive THA by modified Watson-Jones approach. So we use CT-based navigation system. We evaluated the accuracy of with post-operative CT data.

Introduction

Proximal humeral shaft fractures are rare injury. In such case, to the best of our knowledge, the treatment by both double-plate method and the MIPO has never been seen before in the literature. Here we report our experience and management about this method.

Introduction

In Japan, edoxaban has been used for the prevention of venous thromboembolism (VTE) after total knee arthroplasty (TKA) since June 2011. Edoxaban is an oral direct factor Xa inhibitor, expected to be more convenient for the postoperative treatment of TKA. Enoxaparin, a II and Xa inhibitor, was approved in Japan for the prevention of VTE in patients undergoing orthopedics surgery from 2008. In this study, the effect for the prevention of VTE after TKA was compared between these two drugs in Japanese patients.

Objectives

The anteversion angle of the cup is important for achieving the stability and avoiding the dislocation after total hip arthroplasty (THA). We place the component considering with the change of inclination of pelvis with its posture change. We analyzed the perioperative pelvic inclination angles with posture change and the time course.

Purpose

CentPillar GB HA stem (stryker®) is developed as the stem fitting the Japanese femur, and now there is CentPillar TMZF HA stem (stryker®) as the improvement type of the stem by coating the PureFix HA with plasma spray. We observed the factors which influenced on the stem subsidence between the two-type stems.

Purpose

Computer navigation system has been reported as a useful tool to obtain the proper alignment of lower leg and precise implantation in TKA. This system alsoãζζhas shown the accurate gap balancing which was lead to implants longevity and optimal knee function. The aim of this study was determine that the postoperative acquired deep knee flexion would be influenced by intraoperative kinematics on navigated TKA even under anesthesia.

Purpose

Accolade TMZF® has the wedged taper shape and is fixed at the middle part. We testified the short term result of Accolade® and investigated the factor of subsidence.

Objectives

Few reports were shown about the position of the cup in total hip arthroplasty (THA) with CT-based navigation system. We use minimally invasive surgery (MIS) technique when we perform cementless THA and the correct settings of cups are sometimes difficult in MIS. So we use CT-based navigation system for put implants with correct angles and positions. We evaluated the depth of cup which was shown on intra-operative navigation system.

Objectives

Many reports were shown about the angle of the cup in total hip arthroplasty (THA) with CT-based navigation system. However, there are few reports about the position of the stem. We investigated the position of the stem in navigated THA. We evaluated the position and alignment of stem which were shown on intra-operative navigation system.

Purpose

The complication of patellofemoral compartment was quite often in total knee arthroplasty. One of the impotant factors in these complications would be the femoral component rotation in TKA. To determine the rotation of the femoral component, the reference of the surgical epicondylar axis (SEA), posterior condylar axis (PCA), AP axis with three dimensional model achieved from computed tomography data were considered. There are some limitations with pre-oprerative CT-based planning such as radio exposure, cost, time and detection of the depth of cartilage. We evaluate the determination of the femoral component rotation with image-free registration method to compare with three-dimensional template system.

Biomechanical stimuli have fundamental roles in the maintenance and remodeling of ligaments including collagen gene expressions. Mechanical stretching signals are mainly transduced by cell adhesion molecules such as integrins. However, the relationships between stress-induced collagen expressions and integrin-mediated cellular behaviors are still unclear in anterior cruciate ligament cells.

Human ACL cells were harvested from ligament samples donated by patients who underwent total knee arthroplasties with informed consents. Interface cells were isolated from the 5-mm-end of ACL. Midsubstance cells were cultured from the middle part of ACL. The cells were seeded onto stretch chambers (2Ä−2 cm, 50,000 cells/chamber) and uni-axial cyclic mechanical stretch (0.5 Hz, 7%) was applied for 2 h using a ST140. RNA samples were reverse-transcripted and quantitative real-time RT-PCR analysis were performed. To inhibit the function of integrin alphaVbeta3 subunit or alpha5 in stretching experiments, anti-human integrin alphaVbeta3 and alpha5 functional blocking antibodies (alphaVbeta3: 20 mg/ml, alpha5: 4 mg/ml) were used. To investigate the cellular attachments responding to mechanical stretch, we observed the distribution of integrins and stress fibers in both ACL cells.

The shape of midsubstance cells showed spindle and fibroblastic cellular morphologies. On the other hand, the interface cells displayed chondroblastic appearances such as small and triangular morphologies. The expressions of COL1A1, COL2A1, and COL3A1 genes were detected in the tissue RNAs of interface zones. However, these expressions were decreased in cultured interface cells. In midsubstance cells, the expression of COL1A1 gene was equally detected in both tissues and cultured cells. COL3A1 gene expression was maintained in cultured midsubstance cells. These results indicated that the phenotypes of both ACL cells were changed by cultured conditions, especially in the interface cells. After mechanical stretch, the COL1A1 expression of midsubstance and interface cells were stimulated up to 6 and 14-fold levels of each non-stretched control, respectively. The COL3A1 expressions were also enhanced up to 1.8-fold level of controls by stretching treatment in both cells. Integrin alphaVbeta3 was shifted to the peripheral edge of cells by stretching treatment. In addition, mechanical stretch changed the integrin alphaVbeta3-dependent stress fiber formation in both ACL cells. The functional blocking of integrin alphaVbeta3 inhibited stretch-activated COL1A1 and COL3A1 expressions. However, the functional blocking of integrin alpha5 did not suppress the stretch-induced COL1A1 and COL3A1 expressions in both ACL cells.

Cultured interface cells loose their phenotypes in collagen gene expressions.

However, mechanical stretch reproduces the expression of COL1A1 and COL3A1 genes in cultured ACL cells. The present study demonstrated that stretch-activated collagen gene expressions depend on the integrin alphaVbeta3-mediated cellular adhesions.

ROBODOC is a well known tool for a computer assisted arthroplasty. However, the incision tends to enlarge with the system because of the restriction of range of motion. We have developed the robot system for minimally invasive arthroplasty. This report shows the accuracy of our system composed of original planning software, navigation and bone cutting robot.

We took the DICOM data of cadaver knees from computed tomography. The data were transferred to the workstation for planning. Matching points for registration and cutting planes were determined on the planning software. Cutting tool was the 6th robot which was able to recognize the locations of its apex and the cadaver knee with navigation system. We made five planes for TKA and two planes for UKA on femur. Then we made one plane on tibia. We evaluated the accuracy by measurement the location of cutting plane under navigation system and by CT data.

The registration errors of femur and tibia were less than 1.0mm about cadaver knees. The errors of cutting planes were 1.3 mm about the distal end of femur and 0.5 mm about the proximal end of tibia. The accuracies of the angles of cutting planes were 1.9 degrees and 0.8 degrees compared to the mechanical axis.

The errors of anterior and posterior plane of femur were increased compared to the distal plane. It was because the accuracy of registration were correct in axial direction but was not satisfied in rotational direction. The error was considered by the location of points which decided the rotation alignment. We will make effort to minimize the errors of registration and put it into practical use as soon as possible.

Purpose: Minimally invasive surgery (MIS) total knee arthroplasty (TKA) makes faster rehabilitation in many cases, but it was sometimes difficult to performed the precise osteotomy and place the implants correctly due to loss of view or orientation for its small exposure. The computer-assisted navigation TKA system (CAS) was reported to achieve the optimal alignment and placement. However, it had disadvantages of longer operation time and wider exposure to acquire the reference points than these of the conventional method. Now MIS technique needs the accuracy of implant placement, on the other hand, CAS needs less-invasive methods. Among CAS methods, CT-based navigation system would have the potential for MIS because it would be referred to preoperative CT images. This study examined the accuracy of the registration with CT-based navigation system and the possibility of its application for MIS.

Material and Methods: CT data were obtained from the femur and tibia of “Sawbone” (synthetic bone, Pacific Research Laboratories, Vashon, WA, USA) with a slice thickness of 1 mm. These data were transferred to Vector Vision Knee 1.5 (BrainLab Inc, Heimstettenm, Germany) and reconstructed to three-dimensional model. Two registrations were performed by a surface-matching algorithm. One is the conventional method as Vector Vision protocol; another is MIS approach which was allowed the limited area around the femoral notch and joint surface of tibia for registration. The accuracy of registration with these two methods was evaluated by Vector Vision Knee. And these registration points of these different methods were measured using a coordinate measuring machine, 3D surface scanner (Mitsutoyo, JAPAN) and were analyzed and calculated the distribution of points.

Results and Discussion: There was a high degree of reproducibility of the MIS approach compared with the conventional method in the femur. However, the reference points in the distal tibia were deviated 1.5 cm to medial and thus 2.39 degree in varus would be happened at the proximal tibia in both methods. Now this software should be improving to be more accurate.

Introduction Rheumatoid arthritis (RA) commonly affects the forefoot, and pain caused by the deformity of forefoot impairs the walking ability. We have performed resection arthroplasty for all metatarsal heads using modified Lelièvre procedure in affected feet. The aim of the current retrospective study was to investigate the long term results and problems of this procedure.

Patients and methods We investigated 45 feet treated by modified Lelièvre procedure in 29 women from 1985 to 2003 at our institute. Their average age at operation was 54.8 years (range 39 – 76 years). They were followed-up more than two years (26 – 203 months). Resection of all five metatarsal heads was performed for the RA forefoot which had severe deformity and persistent pain, using medial approach for first metatarsophalangeal (MTP) joint and plantar approach for lesser MTP joint. The results were evaluated by the rating scale of the American Orthopaedic Foot and Ankle Society (AOFAS), Foot Function Index (FFI), physical examination, radiographic evaluation, as well as subjective assessment using questionnaire for mental and physical disability.

Results Pain and walking ability were improved in all but 2 feet; one of which underwent additional surgical treatment. Eight out of 45 feet had recurrence of MTP joint dislocation of thumb at the final follow-up. Re-formation of callosities was seen in 69% of the patients, 50% of which were developed within 3 years after operation, and 78% within 5 years. No superficial infection or delayed wound-healing was noted in any case. Satisfactory surgical outcome was maintained for at least 2 years after operation in all cases, and deteriorated later. At an average of 96 months postoperatively, the average AOFAS forefoot score was 67.9 points. Seven cases were judged to have excellent (25%), 13 cases good (46%), 7 cases (25%) fair, and 1 case poor (4%) results. The average radio graphic hallux valgus angle was 31.3 degrees. Eventually, 70% of patients underwent total hip or knee arthroplasty.

Conclusion Resection arthroplasty of all five metatarsal heads using modified Lelièvre procedure in RA patients with pain and deformity of forefoot seemed to be an effective procedure over a long postoperative period, providing reasonable relief of symptoms. Because RA affects multiple joints including hip and knee joints, the forefoot reconstruction alone cannot sustain the improved walking ability.

In 45 patients we assessed the functional results and complications for three different reconstructive procedures after resection of primary tumors of the proximal humerus. An osteoarticular allograft was used in 11, a clavicula pro humero operation in 15 and a tumour prosthesis in 19. The glenoid was resected with the proximal humerus in 25 patients. The axillary nerve was resected in 42 patients.

The complication rate was lowest after reconstruction with a tumour prosthesis. The clavicula pro humero operation resulted in the most revisions. Cumulative survival rates for all the reconstructive procedures were similar.

At follow-up at two years the functional results for the three reconstructive procedures were the same with a mean functional rating of 79% (Musculoskeletal Tumor Society). Excision of the glenoid had no influence on the functional result.

Our findings indicate that the use of a tumour prosthesis is the most reliable limb-salvage procedure for the proximal humerus. The clavicula pro humero is an appropriate procedure if a prosthesis cannot be used.

We treated 58 patients with osteoid osteoma by CT-guided radiofrequency ablation (RF). In 16 it followed one or two unsuccessful open procedures. It was performed under general anaesthesia in 48, and spinal anaesthesia in ten. The nidus was first located by thin-cut CT (2 to 3 mm) sections. In hard bony areas a 2 mm coaxial drill system was applied. In softer areas an 11-gauge Jamshidi needle was inserted to allow the passage of a 1 mm RF probe into the centre of the nidus. RF ablation was administered at 90°C for a period of four to five minutes.

Three patients had recurrence of pain three, five and seven months after treatment, respectively, and a second percutaneous procedure was successful. Thus, the primary rate of success for all patients was 95% and the secondary rate was 100%. One minor complication was encountered.

CT-guided RF ablation is a safe, simple and effective method of treatment for osteoid osteoma.

We assessed the results of 17 limb-salvage procedures using osteoarticular allografts after wide resection of high-grade malignant bone tumours. All patients received chemotherapy. At the five-year follow-up, three patients had died from metastases. The allografts survived for five years in only seven patients all of whom had good function, ranging from 73% to 90% of normal. The allografts were removed because of fracture in seven patients and infection in one, and in all of these a second limb-salvage procedure was undertaken.

With such a low rate of survival of osteoarticular allografts, we believe that their use in the management of high-grade malignant bone tumours should, at best, be considered a temporary solution.