Jin Yamaguchi

Biological reaction to alumina, zirconia, titanium and polyethylene particles implanted onto murine calvaria.

Periprosthetic osteolysis is a serious problem that limits long-term survival of total hip arthroplasty. Ceramics have been introduced as a joint surface material to reduce osteolysis due to wear particles. The aim of this study is to investigate the biological reaction of ceramic particles on murine calvarial bone, in comparison with polyethylene and titanium particles. Sixty CL/BL6 mice were divided into five groups according to the materials implanted onto the murine calvariae: control, Al(2)O(3), ZrO(2), high-density polyethylene (HDP) and Ti6Al4V. One week after the implantation, each calvarial tissue was dissected and the release of proinflammatory mediators (IL-1beta, IL-6, TNF-alpha) and bone resorption were assessed. The particles of HDP and Ti6Al4V induced three and two times larger osteolytic lesions than the control, respectively. The levels of IL-1beta and IL-6 were significantly elevated in the medium subcultured with the calvariae of HDP and Ti6Al4V groups. Any particle type did not increase the levels of TNF-alpha. There were no significant differences observed in the levels of proinflammatory mediators or osteolytic area among Al(2)O(3), ZrO(2) and control groups. The inflammatory response and bone resorption induced by ceramic particles were much smaller than those induced by HDP and Ti6Al4V. These biological features suggest the biocompatibility of ceramics as a joint surface material for artificial joints.

ALDH2 polymorphisms and bone mineral density in an elderly Japanese population

IntroductionOsteoporosis is a multifactorial genetic disease which greatly increases the risk of bone fracture in elderly persons.MethodsFour hundred and three recipients of a community health screening program were examined for the presence/absence of osteoporosis and 11 kinds of gene polymorphisms as a means of determining the relation between these gene polymorphisms and osteoporosis. The gene polymorphisms screened were: alcohol sensitivity-associated polymorphisms of alcohol dehydrogenase (ADH2) Arg47His, aldehyde dehydrogenase (ALDH2) Glu487Lys, smoking sensitivity-associated polymorphisms of glutathione S transferase (GST) M1, (GST)T1, NAD(P)H quinone oxidoreductase 1 (NQO1) C609T, inflammation-associated polymorphisms of interleukin-1β (IL-1B)T-31C, tumor necrosis factor α (TNF-α) T-1031C, endothelial constitutive nitric oxide synthase (ecNOS) Glu298Asp, longevity-associated polymorphism of mitochondrial DNA (mtDNA) 5178 A/C, allergy-associated polymorphism of interleukin-4 (IL-4), and immunity-associated polymorphism of CD14.ResultsA significant association was found between the ALDH2Glu478Lys gene polymorphisms and osteoporosis. In the osteoporosis group of patients, a significant difference was noted between the Lys/Lys group and the group comprising Glu/Lys and Glu/Glu groups (namely, the genotypes including Glu alleles). In the Lys/Lys group, after age, sex, BMI, smoking history and alcohol consumption history had been adjusted for, the morbidity rate was significantly elevated [odds ratio (OR): 3.33; 95% confidence interval (95% CI): 1.28–8.71; p=0.014], and the effect was even more evident in the sub-group of women with osteoporosis (OR: 4.31; 95% CI: 1.24–14.92; p=0.021).ConclusionsThe present results suggest that active prophylactic interventions such as dietary, exercise, and pharmacological therapies should be offered to non-carriers of the Glu allele (Lys/Lys).

Factors leading to osteoarthritis after eccentric rotational acetabular osteotomy.

We performed eccentric rotational acetabular osteotomy consecutively in 273 hips in 248 patients with hip dysplasia. Twenty-one patients were male and 227 were female. The average age was 37.7 years at the time of the index operation. Twenty-two hips had no osteoarthritis, 129 had early osteoarthritis, 117 had advanced osteoarthritis, and five had end-stage osteoarthritis. Twenty-six hips also were treated with concomitant intertrochanteric valgus osteotomy. Patients were followed for a minimum of 5 years after surgery. The average Harris hip score improved from 71 points preoperatively to 92 points at the final followup. Nine hips were converted to total hip arthroplasty as a result of deterioration after surgery. Kaplan-Meier survivorship analysis 15 years after the index operation indicated 97% in pre- and early stages and 87% in advanced and end stages when the end point was total hip arthroplasty. Risk factors identified by multivariate analysis for development of osteoarthritis of the hip 5 years after the index operation were body mass index (24 kg/m2 or more), concomitant valgus osteotomy, operative year between 1989 and 1992, a postoperative center-edge angle of Wiberg less than 25°, and a postoperative horizontal distance of the femoral head from the tear drop (40 mm or more).Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Eccentric Rotational Acetabular Osteotomy for Acetabular Dysplasia and Osteoarthritis: Follow-up at a Mean Duration of Twenty Years

BACKGROUND The aim of the eccentric rotational acetabular osteotomy is to correct the deficient acetabular coverage in the dysplastic hip in order to limit the development of secondary osteoarthritis. The purpose of this study was to investigate the results in patients managed with an eccentric rotational acetabular osteotomy after a mean of twenty years. METHODS The clinical and radiographic outcomes for the first 126 consecutive patients (132 hips) who underwent an eccentric rotational acetabular osteotomy at our institution were retrospectively evaluated. One hundred and twenty-four patients (130 hips) were evaluated; 117 were women (123 hips). The mean patient age was thirty-seven years (range, fifteen to fifty-nine years) at the time of surgery, and the average duration of follow-up was twenty years. Twenty-three hips in twenty-two patients were also treated with intertrochanteric valgus osteotomy at the time of the eccentric rotational acetabular osteotomy to further improve joint congruency. RESULTS The mean preoperative Harris hip score of 70 points (range, 51 to 90 points) improved to a mean of 88 points (range, 35 to 100 points) at the final follow-up. Thirty hips had a fair clinical outcome (Harris hip score, <80 points). In seventeen hips, the eccentric rotational acetabular osteotomy was converted to a total hip arthroplasty. The cumulative survivorship at fifteen years and at the final follow-up at twenty-three years was 97% and 80%, respectively. Four factors led to a poor outcome: a small (≤2.0-mm) preoperative minimum joint space, joint incongruence, simultaneous intertrochanteric valgus osteotomy, and lateral subluxation of the femoral head postoperatively. CONCLUSIONS Eccentric rotational acetabular osteotomy is an effective surgical procedure for treating symptomatic dysplastic hips before, and in the early stages of, osteoarthritis. The majority of patients maintained excellent or good native hip function at a mean of twenty years after surgery. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Accurate Acetabular Component Orientation After Total Hip Arthroplasty Using an Acetabular Alignment Guide

Between February 2005 and August 2006, we recorded acetabular component orientation in 90 patients (100 hips) who underwent primary total hip arthroplasty (THA), to determine whether using an alignment guide ensures accurate acetabular positioning. In the alignment-guide group (46 patients; 48 hips), a guide was placed on the pelvis, a Kirschner wire (K-wire) was attached to the guide, and orientation of the acetabular component was confirmed by both the surgeon and an assistant. In the control group (44 patients; 52 hips), a K-wire was not used and the angle was confirmed by the surgeon alone. Radiographic acetabular component inclination and anteversion and computed tomography anteversion were determined. There was no significant difference in mean component orientation between the 2 groups. However, the SD was significantly smaller in the alignment-guide group, showing that consistent acetabular component orientation in primary THA is highly reproducible when an acetabular alignment guide with an attached K-wire is used.

Quality of life following femoral osteotomy and total hip arthroplasty for nontraumatic osteonecrosis of the femoral head

BackgroundNontraumatic osteonecrosis of the femoral head (NOFH) frequently develops in active young persons. The affected femoral head collapses owing to weight-bearing, and the individual’s quality of life (QOL) can be predicted to deteriorate greatly with time. We undertook to determine the efficacy of surgery and to clarify whether patient QOL differs according to differences in the surgical method employed.MethodsWe cross-sectionally compared QOL in NOFH patients treated with femoral osteotomy, total hip arthroplasty (THA), or nonoperatively. A total of 81 cases were available for study, comprising 41 with osteotomy, 19 with THA, and 21 in the nonoperative group. The mean age was significantly higher in the THA group than in the other two groups. The Japanese Orthopaedic Association (JOA) hip score and Visual Analogue Scale (VAS) regarding hip pain were compared among the groups. These groups were also analyzed for their health-related QOL using the Short Form Health Survey (SF-36) with analysis of variance for age adjustment.ResultsThe mean JOA score was significantly lower in the nonoperative group than in the osteotomy group. The mean VAS scores showed no significant difference between any of the three groups. Regarding the subscales of SF-36, the physical functioning subscale in the nonoperative group showed a significantly lower value than was seen in the osteotomy group (P = 0.003). The physical component summary (PCS) scores were 39.4 (osteotomy group), 39.1 (THA group), and 27.8 (nonoperative group), with a significant difference between the osteotomy and nonoperative groups (P = 0.027). There was also a trend for a better PCS scores in the THA group than in the nonoperative group (P = 0.056). The mental component summary scores were 49.6 (osteotomy group), 50.3 (THA group), and 48.3 (nonoperative group), with no significant difference found among any of the three groups.ConclusionsAmong patients with NOFH, physical function impairment was a more potent factor than pain for decreasing QOL in the nonoperative group than in the surgical groups. Furthermore, osteotomy and THA were similar in regard to the evaluation of the postoperative QOL score if the indications for osteotomy were strictly applied.

Interleukin-1β gene polymorphism associated with radiographic signs of osteoarthritis of the knee

BackgroundOsteoarthritis is recognized as a noninflammatory, progressive condition, the principal cause of which is regressive changes associated with aging and which pursues a chronic course. Recently, the involvement of genetic factors has been widely reported. The purpose of this study was to identify polymorphisms at particular risk of osteoarthritis of the knee for community-living middle-aged and elderly people.MethodsFocusing on 359 participants (ages 44–56 years) of the comprehensive health examination program (CHEP), we investigated the presence/absence of radiographic osteoarthritis (ROA) of the knee, and 11 types of gene polymorphisms and their association with ROA.ResultsInterleukin-1β (IL1B) T-31C polymorphism was found to be associated with ROA. In the case of IL1B T-31C polymorphism in the ROA group, a significant difference was found between the groups combining the C/C genotype, the C/T genotype, and the T/T genotype. In particular, the genotypes with the C allele differed from the T/T genotype, with the morbidity rate being higher in the T/T group (odds ratio (OR) 2.04, 95% confidence interval (95%CI) 1.05–1.98, P = 0.036).ConclusionOur results confirm that in IL1B T-31C with the T/T genotype, the rate of ROA was significantly higher than that with the C/C and C/T genotypes. It might be possible to implement active preventative measures, such as avoidance of obesity and excessive exercise loads, for carriers of IL1B T/T.

Association of serum carotenoids, retinol, and tocopherols with radiographic knee osteoarthritis: possible risk factors in rural Japanese inhabitants

BackgroundThe consumption of antioxidant nutrients may influence the development and progression of osteoarthritis (OA). To determine the association between serum antioxidants and radiographic knee osteoarthritis, we undertook a cross-sectional investigation in a community-based study in Japan.MethodsA total of 562 subjects (224 male, 338 female) ≥40 years of age were enrolled in the Comprehensive Health Examination Program (CHEP, Yakumo Study) from 2003 to 2005. Subjects were categorized to the OA group (n = 140) if either knee was graded as Kellgren-Lawrence (K-L) grade ≥2. The no-OA group was defined as showing radiographic findings of K-L 0 or 1 in either knee (n = 422). The serum levels of retinol, β-/γ-tocopherols, α-tocopherol, zeaxanthin/lutein, canthaxanthin, cryptoxanthin, lycopene, α-carotene, and β-carotene were measured by high-performance liquid chromatography. The values of these antioxidants were divided into tertiles, and a logistic regression analysis was performed to analyze the association between them and radiographic knee OA, adjusting for potential confounders.ResultsLogistic regression analysis showed that compared to the lowest tertile of β-/γ-tocopherols the adjusted odds ratio (OR) was 0.52 [95% confidence interval (CI) 0.29–0.93] in the highest tertile; it also indicated a linear trend across tertiles. Furthermore, the adjusted OR was significantly decreased only in the middle tertile of α-tocopherol (OR 0.51, 95% CI 0.29–0.90). We reevaluated any independent association for these tocopherols after adjustment by entering them into the model simultaneously. The significance of β-/γ-tocopherols was maintained. In contrast, no associations were found with any carotenoids or retinol.ConclusionsHigh serum values of β-/γ-tocopherols were found to be significantly associated with a low OR for radiographic knee osteoarthritis. The decreasing risk with a high serum value of β-/γ-tocopherols may support the possible protective effects against knee OA.

Gender difference does not affect the outcomes of eccentric rotational acetabular osteotomy used in hip dysplasia

Introduction Various types of periacetabular osteotomies have been proposed to treat acetabular dysplasia for young and active patients. Acetabular dysplasia is prevalent in women and rare in men, therefore few reports exist concerning periacetabular osteotomy of male patients. The purpose of this study is to clarify the gender differences in surgical techniques, radiographic and clinical outcomes. Materials and methods Between 1989 and 2007, we performed 530 eccentric rotational acetabular osteotomies and followed them annually for more than five years. Thirty-six male patients were investigated. As a control group, 72 female patients were matched for age and preoperative stage of osteoarthritis at the time of surgery. We evaluated operative time and blood loss, radiographic parameters, Harris Hip Score (HHS) and survival rate. We investigated the clinical and radiographic differences between men and women. Results The mean operative time was 148 min in males and 135 min in females. The bleeding during surgery was 445 g in males and 351 g in females. HHS improved 94.1 points in males and 93.5 points in women postoperatively. The mean CE angle improved 31.7° in males and 35.1° in females. The mean AHI was 90.8% in males and 94.1% in females postoperatively. The survival rate of male patients were 92.8% and that of female patients were 98.1%. Conclusions The mean operative time and the blood loss were not significantly different between male and female patients. Postoperative CE angle tended to be smaller in male than female patients. The survival rate was not significantly different between males and females. Gender difference did not affect the clinical outcomes of ERAO in patients with hip dysplasia.

Low signal intensity area by magnetic resonance imaging that disappeared after a curved intertrochanteric varus osteotomy for traumatic osteonecrosis of the femoral head

Joint-preserving treatment is recommended for young and active patients, including core decompression, vascularized or nonvascularized bone grafting from the fi bula or ilium, varus femoral osteotomy, and a transtrochanteric rotational osteotomy. Total hip replacement or hemiarthroplasty are usually selected for older patients or patients with severely collapsed hips. The longevity of total hip arthroplasty is not satisfactory for young and active people. As a result, we have been performing joint-preserving osteotomies and bone grafting for these patients. The purpose of the femoral osteotomy is not to treat the necrotic lesion but to move the lesion to the non-weight-bearing area. Therefore, complete healing of the necrotic lesion would not be expected. However, complete disappearance of the low signal intensity might be observed in a few patients. A case of complete disappearance of the low signal intensity area by magnetic resonance imaging (MRI) after a curved intertrochanteric varus osteotomy for traumatic osteonecrosis of the femoral head is herein reported.