Sex differences in reference values of hip acetabular measurements using computed tomography in Japanese adults and the effect of aging on the measurement parameters.

Background: It is very important to understand the acetabular morphology of the normal hip joint to assist in diagnosis and surgical planning of hip disorders. The purpose of the present study was to obtain gender-based reference values for the acetabular measurements of a normal hip using computed tomography data and investigate the effect of aging on the measurement values.

Methods: We measured acetabular parameters (center-edge angle, Sharp angle, vertical center anterior angle, acetabular anteversion) on computed tomography corrected for changing the obliquity, rotation, and tilt of the pelvis.

Supplying osteogenesis to dead bone using an osteogenic matrix cell sheet.

Purpose: To evaluate whether osteogenic matrix cell sheets can supply osteogenesis to dead bone.

Methods: Femur bone fragments (5 mm in length) were obtained from Fisher 344 rats and irradiated by a single exposure of 60 Gy to produce bones that were no longer viable. Osteogenic matrix cell sheets were created from rat bone marrow-derived stromal cells (BMSCs).

Bone regeneration with osteogenic matrix cell sheet and tricalcium phosphate: An experimental study in sheep.

Aim: To determine the effects of a cell sheet created from sheep bone marrow and tricalcium phosphate (TCP) on osteogenesis.

Methods: Bone marrow cells were harvested from a sheep and cultured in a minimal essential medium (MEM) containing ascorbic acid phosphate (AscP) and dexamethasone (Dex). After 2 wk, the formed osteogenic matrix cell sheet was lifted from the culture dish using a scraper.

Modifying oxygen tension affects bone marrow stromal cell osteogenesis for regenerative medicine.

Aim: To establish a hypoxic environment for promoting osteogenesis in rat marrow stromal cells (MSCs) using osteogenic matrix cell sheets (OMCSs).

Methods: Rat MSCs were cultured in osteogenic media under one of four varying oxygen conditions: Normoxia (21% O) for 14 d (NN), normoxia for 7 d followed by hypoxia (5% O) for 7 d (NH), hypoxia for 7 d followed by normoxia for 7 d (HN), or hypoxia for 14 d (HH). Osteogenesis was evaluated by observing changes in cell morphology and calcium deposition, and by measuring osteocalcin secretion (ELISA) and calcium content.

Maxillofacial bone regeneration with osteogenic matrix cell sheets: An experimental study in rats.

Objective: Regeneration of maxillofacial bone defects, characterized by relatively small but complicated shapes, poses a significant clinical challenge. Osteogenic matrix cell sheets (OMCSs) have osteogenic ability and good shaping properties and may be ideal graft materials. Here, we assessed whether implantation of OMCSs could be used to repair maxillofacial bone defects.

Promotion of Osteogenesis and Angiogenesis in Vascularized Tissue-Engineered Bone Using Osteogenic Matrix Cell Sheets.

Background: The regeneration of large, poorly vascularized bone defects remains a significant challenge. Although vascularized bone grafts promote osteogenesis, the required tissue harvesting causes problematic donor-site morbidity. Artificial bone substitutes are promising alternatives for regenerative medicine applications, but the incorporation of suitable cells and/or growth factors is necessary for their successful clinical application.

Nontraumatic tibial polyethylene insert cone fracture in mobile-bearing posterior-stabilized total knee arthroplasty.

A 72-year-old male patient underwent mobile-bearing posterior-stabilized total knee arthroplasty for osteoarthritis. He experienced a nontraumatic polyethylene tibial insert cone fracture 27 months after surgery. Scanning electron microscopy of the fracture surface of the tibial insert cone suggested progress of ductile breaking from the posterior toward the anterior of the cone due to repeated longitudinal bending stress, leading to fatigue breaking at the anterior side of the cone, followed by the tibial insert cone fracture at the anterior side of the cone, resulting in fracture at the base of the cone.

Utility of tricalcium phosphate and osteogenic matrix cell sheet constructs for bone defect reconstruction.

Aim: To determine the effects of transplanting osteogenic matrix cell sheets and beta-tricalcium phosphate (TCP) constructs on bone formation in bone defects.

Methods: Osteogenic matrix cell sheets were prepared from bone marrow stromal cells (BMSCs), and a porous TCP ceramic was used as a scaffold. Three experimental groups were prepared, comprised of TCP scaffolds (1) seeded with BMSCs; (2) wrapped with osteogenic matrix cell sheets; or (3) both.

The regeneration and augmentation of bone with injectable osteogenic cell sheet in a rat critical fracture healing model.

Limitations in the current treatment strategies make cases with compromised bone healing challenging clinical problems. Osteogenic cell sheets (OCSs), fabricated from rat bone marrow stromal cells (BMSCs), contain enriched osteoblasts and extracellular matrix. Here, we evaluated whether the minimally invasive percutaneous injection of OCSs without a scaffold could be used as a treatment to increase bone regeneration in a critical fracture healing model.

Osteogenesis of cryopreserved osteogenic matrix cell sheets.

Cryopreservation of tissue engineered bone (TEB), whilst maintaining its osteogenic ability, is imperative for large-scale clinical application. We previously reported a novel cell transplantation method, in which bone-marrow-derived mesenchymal stem cells (BMSCs) were cultured to confluence and differentiated down the osteogenic lineage to form osteogenic matrix cell sheets (OMCS). OMCS have high alkaline phosphatase (ALP) activity and osteocalcin (OC) contents and can be easily used for producing TEB.

A pilot project for the Japan arthroplasty register.

Background: National arthroplasty registers are valuable tools for reporting on an updated epidemiologic survey of arthroplasties and for evaluating the performance of implants and operative procedures through the early identification of failure risk factors. More than ten registers have been launched globally, but no national register has been reported in Asia.

Methods: In February 2006, a pilot project of the Japan Arthroplasty Register (JAR) for total hip arthroplasty (THA) and total knee arthroplasty/unicompartmental knee arthroplasty (TKA/UKA) was launched by the Japanese Orthopaedic Association (JOA).

Secretory osteocalcin as a nondestructive osteogenic marker of tissue-engineered bone.

Background And Purpose: The constructs of mesenchymal stem cells and ceramics form bone tissue after implantation. Therefore, the constructs can include cultured bone (tissue-engineered bone) as bone grafts. However, the selection of constructs, prior to implantation, with high osteogenic potential is still difficult.

Cell sheet injection as a technique of osteogenic supply.

We previously reported a new cell transplantation method utilizing injections of mesenchymal stem cell (MSC) sheets that have osteogenic potential. After subcutaneous transplantation without any scaffold, the sheet demonstrated in vivo bone formation. In the present study, we transplanted such sheets by injection into implanted ceramics and assessed whether the injectable MSC sheets could stimulate osteogenic integration of the ceramics.

Differences in highly cross-linked polyethylene wear between zirconia and cobalt-chromium femoral heads in Japanese patients: a prospective, randomized study.

The purpose of this study was to compare highly cross-linked polyethylene wear between the zirconia head and the cobalt-chromium head in Japanese patients. A prospective, randomized study was performed to evaluate the outcomes in 32 hips that had zirconia heads and in 30 hips that had cobalt-chromium heads. The mean follow-up periods of both groups were same (5 years).

In vivo osteogenic capability of human mesenchymal cells cultured on hydroxyapatite and on beta-tricalcium phosphate.

The aim of the current study was to examine in vitro osteogenic capability and in vivo bone formation of mesenchymal stromal cells (MSCs) on two kinds of calcium phosphate ceramics. MSCs derived from human bone marrow were seeded on either hydroxyapatite (HA) ceramic or beta-tricalcium phosphate (beta-TCP) ceramic and then cultured in a medium supplemented with a donor's serum, vitamin C, beta-glycerophosphate, and dexamethasone. The culture revealed the expression of alkaline phosphatase activity, indicating the osteogenic differentiation of the MSCs on the ceramics (fabrication of tissue-engineered construct).

Inorganic antimicrobial coating for titanium alloy and its effect on bacteria.

Background: For orthopedic implants, infection is a serious problem. Therefore, we considered an implant with antimicrobial ability can prevent infection. We tried to coat a titanium alloy surface with Novaron, a commercially available inorganic antimicrobial.

Chondral injuries of the ankle with recurrent lateral instability: an arthroscopic study.

Background: Prolonged lateral instability of the ankle after ligament injury has been believed to be a major cause of osteoarthritis of the ankle, yet the rate of development of osteoarthritis of the ankle is relatively low. Clarifying the relationship between patient factors and chondral damage of the ankle with prolonged instability is essential to identify the important risk factors underlying osteoarthritis of the ankle.

Methods: Arthroscopic examination was performed to assess the condition of the articular cartilage in a series of patients with prolonged lateral instability of the ankle.

Vascularized scapular grafting for treatment of osteonecrosis of the humeral head.

Eight dissections in four embalmed cadavers were performed to investigate the possibility of vascularized scapular grafting for osteonecrosis of the humeral head. When the angular branch was used as the nutrient vessel, the mean length of the vascular pedicle was 12.4 cm, which was sufficient for transferring the scapula into the humeral head.

Computed tomography-based custom-made stem for dysplastic hips in Japanese patients.

We investigated 55 hips of 53 patients with dysplastic hips. Individual computed tomography data were used in the manufacturing of cementless custom-made stems made of Ti-6Al-4V. The proximal one third was coated using porous coating covered with hydroxyapatite coating.

[Regenerative medicine for bone and joint].

There are the methods made various regenerative tissue from embryonic stem cell and tissue stem cell for regenerative medicine. We have performed the basic studies to product the regenerative bone and cartilage with mesenchymal stem cell included in bone marrow. Based on the results, we have cultured patient's bone marrow in cell processing center after approval of our ethic committee and placed the regenerative bone and cartilage on scaffolds and total prostheses.

Treatment of intraosseous ganglia and bone cysts of the carpal bones with injectable calcium phosphate bone cement.

This article documents the outcome of treatment of intraosseous ganglia and simple bone cysts of the carpal bones by curettage and injectable calcium phosphate bone cement (CPC) grafting. The patients consisted of five men and three women. One had a cystic lesion in the scaphoid, one in the hamate, and five in the lunate.