Osteoconductivity of thermal-sprayed silver-containing hydroxyapatite coating in the rat tibia.

A silver-containing hydroxyapatite (Ag-HA) coating has been developed using thermal spraying technology. We evaluated the osteoconductivity of this coating on titanium (Ti) implants in rat tibiae in relation to bacterial infection in joint replacement. At 12 weeks, the mean affinity indices of bone formation of a Ti, an HA, a 3%Ag-HA and a 50%Ag-HA coating were 97.3%, 84.9%, 81.0% and 40.5%, respectively. The mean affinity indices of bone contact of these four coatings were 18.8%, 83.7%, 77.2% and 40.5%, respectively. The indices of bone formation and bone contact around the implant of the 3%Ag-HA coating were similar to those of the HA coating, and no significant differences were found between them (bone formation, p = 0.99; bone contact, p = 0.957). However, inhibition of bone formation was observed with the 50%Ag-HA coating. These results indicate that the 3%Ag-HA coating has low toxicity and good osteoconductivity, and that the effect of silver toxicity on osteoconductivity depends on the dose.

Single injection digital block: is a transthecal injection necessary?

Three different methods of injection to obtain digital block anaesthesia were performed on 15 healthy volunteers to evaluate the success and extent of anaesthesia. We found that the traditional transthecal injection technique was inaccurate and the injected agent mainly flowed into the subcutaneous space, and did not remain within the sheath. The deep transthecal single injection kept the anaesthetic agent within the flexor tendon sheath, as intended. The duration of anaesthesia and the area anaesthetised by the subcutaneous injection and the traditional transthecal injection was similar and satisfactory. However, the anaesthetic area after the deep transthecal injection was significantly smaller than that of the other two techniques (P<0.01). A transthecal digital block offers no advantage over a simple subcutaneous digital block.

Changes in the WOMAC, EuroQol and Japanese lifestyle measurements among patients undergoing total hip arthroplasty.

OBJECTIVE: To assess changes in the health outcomes of Japanese patients before and after total hip arthroplasty (THA), and to assess the impact of THA on commonly performed postures or body positions requiring deep flexion of the hip joint such as the use of Japanese squat toilets. METHODS: Consecutive patients undergoing primary THA between July 2003 and July 2004 were eligible for the study. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the EuroQol 5D (EQ-5D) were administered at the preoperative period and two postoperative periods of 6 weeks and 6 months. The patients were also asked to rate three items regarding common activities of daily living in Japan such as squatting. Changes in scores were examined using effect size and proportion at the floor and ceiling. RESULTS: Four-hundred and fifty-one patients completed both pre- and post-THA surveys. Significant improvements in pain and physical function as measured by WOMAC and EQ-5D were evident within 6 weeks. Changes in WOMAC and EQ-5D subscale scores and scores for each item from the three time periods were highly significant (P=0.000). The effect size was 1.56 for WOMAC pain and 1.38 for physical function at 6 months. In contrast, two items (Japanese toilet and seiza) became significantly worse at the 6-week postoperative period (P=0.000) and returned to preoperative levels by the 6-month postoperative period. CONCLUSION: These results highlight the importance of evaluating culturally sensitive physical functions in addition to conventional measurements for the health outcomes of THA patients.

Development of a knee joint motion simulator to evaluate deep knee flexion of artificial knee joints.

A purpose of this study is to examine the effect that quadriceps femoris force gives to rotation angle and joint reaction force of total knee prosthesis during deep knee flexion such as a unique sitting style called 'seiza' in Japanese. For the evaluation, we developed the knee motion simulator which could bend to 180 degrees continually simulating the passive flexion performed by clinicians. A total knee prosthesis, which is a specially-devised posterior stabilized type and capable of flexion up to 180 degrees, was inserted into bone model. And this prosthesis pulled by three kinds of quadriceps femoris forces to perform parameter study. The results obtained in this study were showed the same tendency with those in the past cadaveric experiment. It is suggested that the rotation angle and joint reaction force of total knee prosthesis are affected by shape of prosthesis, a vector of quadriceps femoris force, and bony aliments during deep knee flexion.

Effectiveness of autologous fibrin tissue adhesive in reducing postoperative blood loss during total hip arthroplasty: a prospective randomised study of 100 cases.

PURPOSE: To evaluate the effectiveness of autologous fibrin tissue adhesive (auto-FTA) in reducing blood loss during cementless total hip arthroplasty (THA). METHODS: From September 2000 to August 2001, 100 patients who predonated 400 ml of autologous blood were randomised to undergo either standard treatment with auto-FTA (auto-FTA group) or standard treatment alone (control group). The volume of postoperative blood loss and the decrease in haemoglobin level were measured. All patients were followed up for 3 years to evaluate the rate of bone ingrowth and heterotopic ossification. RESULTS: The mean postoperative blood loss was 580 ml (standard deviation [SD], 240 ml) in the auto-FTA group and 810 ml (SD, 341 ml) in the control group; the difference was significant (230 ml, p<0.001). The decrease in haemoglobin concentration was 17 g/l (SD, 11 g/l) in the auto-FTA group and 22 g/l (SD, 12 g/l) in the control group. The difference was significant (5 g/l, p=0.03). The percentage of total blood loss of >1200 ml in any single patient was significantly lower in the auto-FTA group (4%) than in the control group (20%) [p=0.01]. CONCLUSION: Auto-FTA is a safe and effective means of reducing perioperative blood loss in THA.

Tumor necrosis factor-alpha cooperates with receptor activator of nuclear factor kappaB ligand in generation of osteoclasts in stromal cell-depleted rat bone marrow cell culture.

A member of the tumor necrosis factor (TNF) family, receptor activator of nuclear factor kappaB ligand (RANKL; also known as ODF, OPGL, and TRANCE), plays critical roles in osteoclast differentiation and activation in the presence of macrophage colony-stimulating factor (M-CSF). Recently, TNF-alpha has also been shown to induce the formation of multinucleated osteoclast-like cells (MNCs) in the presence of M-CSF from mouse macrophages. We demonstrated that mononuclear preosteoclast-like cells (POCs) were formed in the presence of conditioned medium of osteoblastic cells in a rat bone marrow culture depleted of stromal cells. Using this culture system, in this study we examined whether TNF-alpha affects differentiation into POCs from hematopoietic progenitor cells. Human TNF-alpha (hTNF-alpha) markedly stimulated the formation of POCs. Moreover, a concentration as low as 0.005 ng/mL of hTNF-alpha increased the level of mRNA for calcitonin receptor (CTR) and cathepsin-K of POCs. The POCs induced by hTNF-alpha formed MNCs, which showed dentine-resorbing activity after coculture with primary osteoblasts. Stimulation was observed after 24 h of treatment with hTNF-alpha only on day 1 or day 2 of the culture. After 24 h of hTNF-alpha treatment, expression of the receptor activator of nuclear factor kappaB (RANK) mRNA was markedly increased. The addition of soluble RANKL (sRANKL) to the preformed POCs efficiently induced MNCs. Interestingly, treatment of bone marrow cells with hTNF-alpha and sRANKL synergistically augmented the formation of MNCs. This formation was abolished by the addition of human osteoprotegerin (hOPG). These results suggest that cooperation of TNF-alpha and RANKL is important for osteoclastogenesis.

Osteoporosis and years since menopause.

In Fukuoka Prefecture, in south-western Japan, a regional screening program for osteoporosis was conducted from 1994 to 1995. The screening level in the bone mineral density (BMD) at the distal non-dominant radius was equal to or less than two standard deviations below age-specific mean (< or = -2.0 SD). In 1177 examinees with natural menopause (mean age: 61.4, range: 42-88), 56 of those who were screened were subsequently radiologically confirmed by orthopedic specialists to have osteoporosis (case group). They were then compared with 802 normal BMD (> or =-1.0 SD) women (reference group) with their lifestyle and reproductive characteristics. The adjusted odds ratio (OR) and its 95% confidence interval (CI) were calculated using a logistic regression model. A significant increase in the ORs for osteoporosis based on the number of years since menopause was observed for 7-13 years since menopause (OR = 2.3; 95% CI: 1.0-5.4) compared with <7 years, however, no increasing trend in risk was evident in 14+ years since menopause (OR = 1.4; 95% CI: 0.4-5.1). Thus, the elevated risk continued up to around 10 years since menopause. These findings are consistent with previous studies that reported an alternation in the calcium metabolism and bone loss related to the length of time after menopause. Both the childhood and current milk consumption were also associated with a decreased risk: ORs were 0.4 (95% CI: 0.2-0.9) and 0.5 (95% CI: 0.3-1.0), respectively.

Diagnostic criteria for non-traumatic osteonecrosis of the femoral head. A multicentre study.

Six major and seven minor diagnostic criteria have been developed by the Japanese Investigation Committee for osteonecrosis of the femoral head (ONFH). We have carried out a multicentre study to clarify these. We studied prospectively 277 hips in 222 patients, from six hospitals, who had ONFH and other hip pathology and from whom histological material was available. We identified five criteria with high specificity: 1) collapse of the femoral head without narrowing of the joint space or acetabular abnormality on radiographs, including the crescent sign; 2) demarcating sclerosis in the femoral head without narrowing or acetabular abnormality; 3) a 'cold-in-hot' appearance on the bone scan; 4) a low-intensity band on T1-weighted images (band pattern); and 5) evidence of trabecular and marrow necrosis on histological examination. With any combination of two of these criteria, the sensitivity and specificity of the diagnosis were 91% and 99%, respectively.

Assessment of subchondral bone blood flow in the rabbit femoral condyle using the laser speckle method.

The laser speckle method is a new form of flowmetry that can obtain a two-dimensional distribution of blood flow in tissue. This method is a noncontact, simple, and rapid technique that may aid in the diagnosis of osteonecrosis. We investigated whether the subchondral bone blood flow within the femoral condyles of rabbits could be measured by the laser speckle method. The hydrogen washout method was chosen as a comparison technique because of its ability to allow repetitive measurements of blood flow in various conditions in one rabbit and because of its reliability, which already has been established. We simultaneously measured the bone blood flow in 20 femoral condyles of 10 rabbits with the laser speckle and hydrogen washout methods and found a significant correlation between the blood flow levels with use of these two methods. For the clinical application of the laser speckle method, we also investigated the influence of cartilage thickness on the measurements and the depth in the bone to which blood flow could be measured with this method. A cartilage thickness of 0.2 mm did not influence the measurement of the bone blood flow, and the depth in the bone to which the laser speckle method could be used was approximately 2 mm.

Evaluation of blood flow within the subchondral bone of the femoral head: use of the laser speckle method at surgery for osteonecrosis.

The laser speckle method is a new form of tissue flowmetry that can analyze the interference pattern that appears when tissue is illuminated with a laser beam. During surgery for 100 cases of osteonecrosis of the femoral head, we measured the blood flow within the subchondral bone using this method. We compared the flow maps (two-dimensional distribution of the microcirculation) obtained this way with the necrotic area estimated by the preoperative magnetic resonance images and with the collapse seen during surgery. The laser speckle method was able to distinguish between the ischemic areas and the normal areas in 92 femoral heads, including five hips for which neither the magnetic resonance images nor the collapse observed during surgery demonstrated a distinct margin surrounding the necrotic area. We concluded that the laser speckle method is useful for defining the margin around a necrotic area.

Pronator Teres Syndrome Associated with Mononeuritis Multiplex in Polyarteritis Nodosa.

A case of pronator teres syndrome associated with mononeuritis multiplex in polyarteritis nodosa is reported. External neurolysis of the median nerve at the proximal forearm and prednisolone were effective for treatment of the disease.

Inhibition of endochondral ossification during fracture repair in experimental hypothyroid rats.

Using a rat fracture model, we investigated the effects of a decrease in serum levels of thyroid hormone on the fracture-repair process. Rats were divided into the following groups: (a) controls, (b) those treated with methimazole for the duration of the experiment, and (c) those treated with methimazole and L-thyroxine, receiving both for the same duration. Three weeks after the initiation of pharmacologic treatment, closed femoral fractures were produced. The formation of cartilage tissue in the fracture callus in all rats was not obviously different on day 7 after fracture. In the rats treated with methimazole, differentiation from proliferating to hypertrophic chondrocytes in the fracture callus was less advanced and vascular invasion was clearly inhibited on day 12. Gene expression of alkaline phosphatase and osteocalcin in the callus was significantly lower in these rats than in the controls on days 10, 12, and 14. The mechanical properties of the fracture callus were also significantly weaker in these animals than in the controls on day 21, resulting in impaired fracture repair. These results demonstrate that hypothyroidism inhibits endochondral ossification, resulting in an impaired fracture-repair process. L-thyroxine replacement in the rats treated with methimazole caused the impaired repair process to revert to normal. These results indicate that thyroid hormone is one of the critical systemic factors for fracture repair.

Induction of abundant osteoclast-like multinucleated giant cells in adjuvant arthritic rats with accompanying disordered high bone turnover.

The development of an in vivo system for investigating osteoclast differentiation is important because molecular events occurring in vivo can be observed during the differentiation of the authentic osteoclasts. In adjuvant arthritic rats, an experimental model of human rheumatoid arthritis, extensive bone resorption is observed in the distal diaphysis of the tibia. In the area of extensive bone resorption, it is always accompanied with clusters of numerous multinucleated giant cells (MGCs) as well as bone-resorbing osteoclasts. Here we characterized the morphological properties of these MGCs with the use of enzymehistochemical and immunohistochemical techniques. Extensive destruction but also a marked formation of the inner and outer bone surfaces were the predominant features in the tibiae of such arthritic rats 4 weeks after the adjuvant injection. Numerous MGCs were frequently clustered in the bone marrow spaces located apart from the bone matrices. Although the MGCs lacked ruffled borders, these cells were rich in mitochondria and vacuoles. These multinucleated cells revealed a positive reaction for tartrate-resistant acid phosphatase but a negative reaction for non-specific esterase staining. Most of these MGCs expressed the Kat 1-antigen, an immunological marker specifically expressed on the cell surface of rat osteoclasts. In a dentin resorption experiment using a cluster of MGCs excised from the bone marrow tissues of the tibial distal diaphyses of rats with adjuvant arthritis, many resorption lacunae were formed on dentin slices after a 3-day culture. These results suggest that the majority of the MGCs are osteoclasts but not macrophage polykaryons.

Macrophage inflammatory protein-1 alpha (LD78) expressed in human bone marrow: its role in regulation of hematopoiesis and osteoclast recruitment.

Human macrophage inflammatory protein-1 alpha (hMIP-1 alpha), also known as LD78, is a member of the chemokine/ intercrine family and an inhibitor of the proliferation of the hematopoietic stem cells in vitro. Using a specific monoclonal antibody, we observed significant localization of hMIP-1 alpha in eosinophilic myelocytes in human bone marrow. We further examined the expression of hMIP-1 alpha mRNA in human bone tissue by in situ hybridization. A high level of hMIP-1 alpha mRNA expression was detected in eosinophilic myelocytes in bone marrow, confirming these cells as the site of hMIP-1 alpha synthesis. hMIP-1 alpha mRNA expression was also detected in osteoblasts in the bone-remodeling sites, and osteoclasts were frequently observed in the vicinity of these osteoblasts. hMIP-1 alpha was also able to induce osteoclastogenesis on calcified matrices in the absence of any other osteotropic hormones. These results strongly suggest that hMIP-1 alpha is involved not only in the regulation of hematopoiesis but also in the modulation of bone remodeling.

Nationwide survey of bone grafting performed from 1980 through 1989 in Japan.

Nationwide surveys were conducted in 1985 and 1989 on the status of bone grafting performed in Japan. At the first survey, questionnaires were sent to 527 hospitals, with 218 responding. Of 26,800 bone grafts performed, 96.4% were autografts, and the remaining 3.6% were allografts and xenografts. Most allografts were bone chip grafts (85%), followed by massive bone grafts excluding osteoarticular grafts (14%). Osteoarticular allografts and whole bone allografts composed only 0.4% and 0.5% of the total, respectively. At the second survey, questionnaires were sent to 2053 hospitals, with 967 responding. The use of synthetic bone substitutes and bone grafts was investigated in the second survey. Of 87,994 bone grafts performed, 94.3% were autografts, 3.2% were synthetic bone substitutes, 1.9% were banked bone allografts, 0.4% were fresh allografts, and 0.2% were xenografts. Most of all grafts were bone chip grafts (57.1%), followed by massive bone grafts excluding osteoarticular grafts (40.3%). Osteoarticular grafts and whole bone grafts accounted for only 0.3% and 2.3% of the totals, respectively. Although the number of patients requiring bone grafts increased yearly, bone allografts were not widely used in Japan.

Osteoclasts in normal and adjuvant arthritis bone tissues express the mRNA for both type I and II interleukin-1 receptors.

Osteoclasts are known to play a crucial role in both physiologic and pathologic bone resorption. Moreover, it is generally agreed that IL-1 has powerful effects on osteoclastic bone resorption, although the precise cellular sites and mechanisms by which IL-1 mediates osteoclastic bone resorption remain unclear. In particular, it is still controversial whether osteoclasts can respond to IL-1 directly. The expression of mRNA for type I IL-1 receptor (IL-1RI) and type II IL-1 receptor (IL-1RII) in osteoclasts was investigated in normal and inflammatory bone tissues by in situ hybridization to determine whether osteoclasts are the target cells for IL-1 and to elucidate the mechanism by which IL-1 induces osteoclastic bone resorption. For this study, normal tibiae were obtained from newborn, young, and adult mice and rats, and inflammatory bone tissues with bone destruction were obtained from adjuvant arthritis rat models. The results showed that (a) both IL-1 receptors (IL-1RI and -II) mRNA were expressed by osteoclasts in all tissue sections of normal tibiae; (b) at the stage of the adjuvant arthritis studied, the IL-1RI mRNA was the most predominant message in osteoclasts present in the area with serious cartilage and bone destruction, whereas the expression level of IL-1RII mRNA in these osteoclasts was weak; and (c) both IL-1RI and -II mRNA were expressed by osteoblasts, as well as by osteocytes localized in the osteoid. In addition, these messages were also expressed by chondrocytes, but the signals were not detected in the chondrocytes in the zones of hypertrophy and provisional calcification. Our present study demonstrates for the first time that mouse and rat osteoclasts express IL-1RI and -II mRNA, which suggest that a primary effect of IL-1 on osteoclasts may be one of the mechanisms by which IL-1 mediates normal bone remodeling and pathologic bone resorption in chronic inflammatory diseases.

Effect of IL-10 on collagen-induced arthritis in mice.

In the present study we investigated the effect of a potent anti-inflammatory cytokine, interleukin (IL)-10, on the development of collagen-induced arthritis (CIA) in mice. Each DBA1/J mouse was immunized with 200 micrograms of native collagen and followed by booster injections at 3 weeks. rmIL-10 was injected i.p. daily at a dose of 100 ng/mouse. Mice were divided into four groups according to the administration period of rmIL-10. As a result, a 48-day course of IL-10 treatment significantly suppressed the severity of arthritis. Among the 4 groups, the most pronounced suppression was observed in the group in which IL-10 was given from day 0 to 21. On the other hand, there were no significant differences in the serum IgG anti-type II collagen (CII) titers between the four groups. Moreover, the production of cytokines (IL-6 and tumor necrosis factor-alpha (TNF-alpha)) and other mediators (prostaglandin E2 (PGE2) and nitric oxide (NO)) by peritoneal macrophages seemed to show no clear correlation with the severity of arthritis in mice. These results raise the possibility that IL-10 might be a useful agent for suppressing the progression and the development of CIA in mice.

Experimental osteochondritis dissecans--the role of cartilage canals in chondral fractures of young rabbits.

Skeletal immature rabbits were used to study the pathogenesis of Osteochondritis Dissecans (OCD). Both histological studies and a radiographical examination were utilized after sagittal and coronal surgical chondral fractures were made in the femoral condyles cartilage. Serial microangiographies were performed in rabbits between 0 and 84 days after the chondral fractures were made. Analyses of the histology and microradiography findings suggest in either a coronal or sagittal direction, that avascular lesions like an experimental OCD occur as a sequence of chondral injury. A fracture in a wide pedicle of a stable cartilaginous flap with abundant cartilage canals heals in the usual way. However, a fracture in an unstable fragment with a small isthmus devoid of cartilage canals and of nutritious vessels, probably doesn't heal completely and a fragment closely resembling OCD is instead formed. An experimental OCD depends on the slender hinge of the flap and on the lack of stability in a rabbit's non-ossified epiphyseal cartilage. The damage to the cartilage canals and the rupture of vessels in the canals by a chondral fracture and the disturbance in the revascularization in the healing process by abnormal mechanical forces are thus most likely considered to be the main factor for OCD production.

Administration of growth hormone modulates the gene expression of basic fibroblast growth factor in rat costal cartilage, both in vivo and in vitro.

We examined the effect of growth hormone on local growth factor mRNA expression in male Sprague-Dawley rats. Repetitive systemic administration of growth hormone (0.4 IU every 4 h) increased the expression of IGF-I mRNA up to 2.8-fold in costal cartilage tissue compared with controls. Basic FGF (bFGF) mRNA expression gradually increased up to 15.5-fold compared with pre-injection samples, where the mRNA expression was 5.3-times greater than vehicle-injected controls. TGF-beta mRNA showed little changes. Moreover, one microgram/ml of growth hormone enhanced the expression of bFGF mRNA in costal chondrocytes in culture. We conclude that growth hormone increased the local expression of bFGF, as well as that of IGF-I, in cartilage, and suggest that bFGF is directly regulated by growth hormone within a local area.

[Recombinant human erythropoietin (KRN5702) therapy for autologous blood transfusion in patients with rheumatoid arthritis undergoing joint replacement surgery--a multicenter phase II clinical trial].

In order to evaluate the effect of recombinant human erythropoietin (rHuEPO) on autologous blood transfusion in patients with rheumatoid arthritis (RA), we performed a phase II clinical trial in 65 RA patients undergoing elective surgery. rHuEPO was administered subcutaneously once a week and after observing erythropoiesis, autologous blood was collected. Fifty-seven of the 58 patients who completed treatment responded to rHuEPO and could donate more than 400 ml of autologous blood. Among them, 23 out of 28 patients undergoing total hip arthroplasty, 27 out of 28 undergoing total knee arthroplasty and 1 out of 1 undergoing spinal surgery did not need homologous blood transfusion perioperatively. During rHuEPO treatment, no significant changes of clinical parameters of RA activity were observed. Two patients discontinued the treatment because of mild and transient side effects. These results indicate that subcutaneous rHuEPO is safe and effective in eliminate the need for homologous blood transfusion, even in anemic RA patients undergoing elective orthopedic surgery.