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Background: We are planning a multicenter survey on coxarthrosis and acetabular dysplasia in Japan. To collect reliable data, we performed a preliminary study to elucidate the observer agreement on assessment items. Methods: We collected radiographs of hip joints in eight patients with various findings of coxarthrosis. Twelve registered orthopedic specialists evaluated them regarding the roentgenographic stage of coxarthrosis and five indexes of acetabular dysplasia (acetabular angle, center-edge angle, acetabular roof obliquity, acetabular head quotient, approximate acetabular quotient). To assess observer agreement, we calculated the value of the kappa statistic for stages and the coefficient of variation for the indexes. The same 12 specialists then assessed the coxarthritis stage on the same radiographs 1 month after the first evaluation based on our own descriptions of the roentgenographic stages. Results: For the first evaluation of the roentgenographic stage, the value of the kappa statistic was 0.448; and for the second evaluation it was 0.600. The results of the coefficient of variation for the indexes of acetabular dysplasia, ranked in ascending order, were as follows: acetabular angle, acetabular head quotient, acetabular roof obliquity, center-edge angle, approximate acetabular quotient. Conclusions: For the upcoming multicenter survey, clear descriptions of the stages of coxarthrosis and selection of appropriate indexes can be helpful for collecting dependable results. [ABSTRACT FROM AUTHOR]

A recent study reported that micro-osteoperforations (MOPs) accelerated tooth movement by activating alveolar bone remodeling. However, very little is known about the relationship between MOPs and external apical root resorption during orthodontic treatment. In this study, in order to investigate the mechanism through which MOPs accelerate tooth movement without exacerbating the progression of root resorption, we measured the volume of the resorbed root, and performed the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick-end labeling (TUNEL) method on exposed MOPs during experimental tooth movements in rats. Male Wistar rats (11 weeks old) were divided into three groups: 10 g orthodontic force (optimal force) applied to the maxillary first molar (optimal force: OF group), 50 g orthodontic force application (heavy force: HF group), and 10 g force application plus three small perforations of the cortical plate (OF + MOPs group). On days 1, 4, 7, 10, and 14 after force application, the tooth movement and root volume were investigated by micro-computed tomography. Furthermore, the number of apoptotic cells in the pressured sides of the periodontal ligament (PDL) and surrounding hard tissues were determined by TUNEL staining. The OF + MOPs group exhibited a 1.8-fold increase in tooth movement on days 7, 10, and 14 compared with the OF group. On days 14, the HF group had a higher volume of root loss than the OF and OF + MOPs groups. On the same day, the number of TUNEL-positive cells in the HF group increased at the root (cementum) site whereas that in the OF group increased at the alveolar bone site. Furthermore, the number of TUNEL-positive cells in the OF + MOPs group increased at the alveolar bone site compared with the OF group. These results suggest that MOPs accelerate orthodontic tooth movement without exacerbating the progression of root resorption.

Objectives: This study aimed to quantitatively assess maxillary central incisor roots using pre-orthodontics computed tomography (CT) texture analysis as part of a radiomics quantitative analysis., Methods: This retrospective case-control study included 16 patients with external apical root resorption (EARR) and 16 age- and sex-matched patients without EARR, after orthodontic treatment who underwent pre-orthodontics CT for jaw deformities. All patients were treated with a fixed orthodontic appliance before and after surgical orthodontic treatment. EARR was defined as root resorption ≥ 2 mm of the left and right maxillary central incisors on CT images more than 2 years after the start of orthodontic treatment. Texture features of the maxillary central incisor with and without EARR after orthodontic treatment were analyzed using the open-access software, MaZda Ver. 3.3. Ten texture features were selected using the Fisher method in MaZda from 279 original parameters, which were calculated for each of the maxillary central incisors with and without EARR. The results were tested using the Student's t test, Welch's t test, or Mann-Whitney U test., Results: Four gray-level run length matrix features and six gray-level co-occurrence matrix features displayed significant differences between both the groups (p < 0.01)., Conclusions: CT texture analysis was able to quantitatively assess maxillary central incisor roots and distinguish between maxillary central incisor roots with and without EARR. CT texture analysis may be a useful method for predicting EARR after orthodontic treatment., (© 2022. The Author(s) under exclusive licence to Japanese Society for Oral and Maxillofacial Radiology.)

Phthalocyanine that has four peripheral 2-methoxyphenyl substituents at the α-position and its Zn(II) and Cu(II) complexes were synthesized. Chemical oxidation by the Cu(II) ion and electrochemical oxidation of these metal complexes were investigated spectrophotometrically in acetonitrile. The UV-visible absorption spectra of these metal complexes and their one-electron oxidized π-cation radicals showed no concentration dependence, indicating that these species exist as monomers in solution. Kinetics of the thermal electron transfer reaction from each phthalocyanine complex to Cu 2+ and the photoinduced electron transfer reaction of the Zn(II) phthalocyanine complex with V(V) and V(IV) Schiff base complexes were studied using conventional spectrophotometric and transient absorption techniques, and the electron transfer rate constants were analysed using the Marcus cross relationship. The obtained rate constants of the electron self-exchange reaction between the parent phthalocyanine complexes and their π-cation radicals were in the order of 10 9 to 10 11 M -1 s -1 at T = 298.2 K. These large electron self-exchange rate constants are consistent with the phthalocyanine-centred redox reactions where small reorganization energies are required with little structural change during the electron transfer process.

Several novel silver(II) complexes ligating a tetra-substituted phthalocyaninate, [Ag(tbpc)] (where tbpc denotes tetra-tert-butylphthalocyaninate), [Ag(tppc)] (tppc = tetrakis(2,6-dimethylphenoxy)phthalocyaninate), [Ag(tObpc)] (tObpc = tetra-n-butoxyphthalocyaninate), and [Ag(tpySpc)] (tpySpc = tetrakis(4-pyridylthio)phthalocyaninate) have been synthesized and characterized by elemental analyses, MALDI-TOF MS, optical absorption, and magnetic circular dichroism (MCD) spectroscopy. Although all the compounds are well soluble in common organic solvents, concentration studies on their optical spectra in solutions have found that they are prone to strongly aggregate in a cofacial manner (i.e., H-aggregate). Silver(II) complexes, which are essentially non-fluorescent, are readily demetallated in the presence of appropriate reductant (e.g., I - or BH 4 - ) to liberate the corresponding macrocyclic ligand, which emits intense red fluorescence. Chemical oxidation by using NOBF 4 generates the corresponding silver(III) species., (Copyright © 2021. Published by Elsevier Inc.)

Water-soluble silver(II)-phthalocyanine complexes (AgPcs), tetrakis{4-( N -alkylpyridinium)thio}phthalocyaninato silver(II) tetrafluoroborate, [Ag(tRpySpc)](BF 4 ) 4 , (R = Me and Et), have been synthesized for the first time by quaternization of pyridyl groups of tetrakis(4-pyridylthio)phthalocyaninato silver(II) by using Meerwein reagents and characterized by ESI-MS, elemental analyses, and optical absorption spectroscopy. Although they strongly aggregate in water, the presence of appropriate surfactants, such as polyethyleneglycol-monooleyl ether ( n = approximately 50; PEG50) and sodium dodecyl sulfate, effectively disaggregates them to monomeric species. The spectral properties of the AgPcs and their aggregates in aqueous and nonaqueous solutions have been investigated by optical absorption, emission, and magnetic circular dichroism spectroscopy. These AgPcs rapidly react with thiols such as cysteine, glutathione, homocysteine, and sodium 2-sulfanylethanesulfonate (even on the order of 0.01 mM) in aqueous PEG50 solutions at room temperature to liberate the corresponding macrocyclic ligand, H 2 Pc, but not with the other amino-acid analogs without sulfhydryl groups. The molar ratio of thiol to AgPc has been determined to be 1:1. Since AgPcs are essentially nonfluorescent at room temperature, while H 2 Pcs emit intense red fluorescence, AgPcs can be a potent thiol-sensor toward bioimaging.

The reactions of [Ru 2 (O 2 CCH 3 ) 4 Cl] with 2-aminopyridine (Hamp) and 2-amino-4-methylpyridine (Hammp) afforded two novel Ru 2 complexes, [Ru 2 (amp) 4 Cl 2 ] (1) and [Ru 2 (ammp) 4 Cl 2 ] (2), respectively. Single crystal X-ray diffraction analyses revealed that 1 and 2 adopted typical paddlewheel-type structures, where the Ru 2 units are coordinated with four aminopyridinate ligands with a cis-2:2 arrangement at the equatorial positions and two chloride ligands at the axial positions. The stabilities of 1 and 2 were supported by unrestricted density functional theory (uDFT) calculations. The zero-point energies of the three structural isomers (trans-2:2, 3:1, and 4:0 arrangements) of 1 and 2 were less stable than those of the respective cis-2:2 arrangements. Temperature-dependences of the magnetic susceptibility measurements and uDFT calculations showed that the oxidation and spin states of the Ru 2 units in 1 and 2 were commonly Ru 2 6+ and triplet states, respectively. Cyclic voltammetry showed that 1 and 2 underwent one-electron reduction processes, i.e., 1/1 - and 2/2 - , at redox potentials (E 1/2 ) of -0.08 and -0.18 V vs. SCE, respectively. These results agreed well with the DFT-calculated E 1/2 values of 1 (-0.08 V vs. SCE) and 2 (-0.18 V vs. SCE) and were theoretically attributed to Ru 2 -centred (δ*(Ru 2 )) redoxes. Moreover, 1 and 2 showed unique near-infrared absorption bands at approximately 1200-1500 nm, which were theoretically attributed to the ligand-to-metal charge transfer (LMCT) with π(amp or ammp) →δ*(Ru 2 ) transition characteristics.

Introduction: The aim of this study was to investigate the mechanism of how micro-osteoperforations (MOPs) accelerate tooth movement. We focused on inflammation, cell proliferation, and apoptosis of periodontal ligament cells and performed immunostaining of MOPs exposed to tumor necrosis factor-alpha (TNF-α), proliferating cell nuclear antigen (PCNA), and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) during experimental tooth movement., Methods: Eleven-week-old male Wistar rats were divided into 2 groups: (1) 10 g of orthodontic force applied to the maxillary first molar (TM) and (2) force application plus 3 small perforations of the cortical plate (TM + MOPs). On days 1, 4, 7, 10, and 14 after force application, we investigated tooth movement and alveolar bone microstructure using microcomputed tomography (n = 5). We also determined the expression of TNF-α and PCNA in the pressure sides of periodontal ligaments via an immunohistochemical analysis. The expression of apoptotic cells was also determined by the TUNEL method., Results: The tooth movement in the TM + MOPs group was significantly greater on days 4 to 14 than in the TM group. The TM + MOPs group showed statistically significant decreases in bone volume/tissue volume ratio and bone mineral density compared with the TM group. The ratios of TNF-α positive cells in the TM + MOPs group were increased on days 1, 4. 7, and 10 compared with the TM group. The ratios of PCNA positive cells in the TM + MOPs group were increased on days 1, 4, and 7 compared with the TM group, and the ratios of TUNEL positive cells in the TM + MOPs group were increased on days 1 and 7 compared with the TM group., Conclusions: These results suggest that MOPs may accelerate tooth movement through activation of cell proliferation and apoptosis of periodontal ligament cells., (Copyright © 2018 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

An efficient approach to the synthesis of perinaphthenones via the rhodium-catalyzed dehydrative annulation of 1-naphthoic acids with internal alkynes was developed. Norbornadiene can act as an acetylene equivalent to give unsubstituted perinaphthenones at the 2- and 3-positions via dehydrative annulation followed by a retro Diels-Alder reaction.

Spectral (optical absorption and emission) properties of three amphoteric phosphorous(V)-phthalocyanine derivatives, [P(Pc)(O)OH], where Pc=tetra(tert-butyl)phthalocyaninate (tbpc), tetrakis(2',6'-dimethylphenoxy)phthalocyaninate (tppc), and octakis(4'-tert-butylphenoxy)phthalocyaninate (obppc), have been investigated in ethanolic solutions. Spectral changes upon protonation/deprotonation (the reaction sites have been determined to be their axial ligands by magnetic circular dichroism study) are drastic and rapid. All the initial ([P(Pc)(O)OH]), protonated ([P(Pc)(OH) 2 ] + ), and deprotonated ([P(Pc)(O) 2 ] - ) species are possessed with sufficient brightness (defined as the product of their molar extinction coefficient, ε (inM -1 cm -1 ), and fluorescence quantum yield, Φ F ) in bio-imaging window (650-900nm). For example, spectral characteristics of the tbpc derivatives have been determined as follows: ε=1.65×10 5 (absorption maximum 676nm) and Φ F =0.80 (emission maximum 686nm) for [P(tbpc)(O)(OH)] while ε=1.45×10 5 (697nm) and Φ F =0.27 (714nm) for [P(tbpc)(OH) 2 ] + , and ε=2.25×10 5 (662nm) and Φ F =0.90 (667nm) for [P(tbpc)(O) 2 ] - . Emission of tppc and obppc derivatives behave in essentially the same manner irrespective of nature of the peripheral substituents and hence Φ F values are greater with increasing emission peak wavenumbers in line with the "energy gap law". These characteristics make these compounds promising candidates as chemical probes for deep-tissue bio-imaging., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: We investigated the rate of conversion to total hip arthroplasty by twenty years and radiographic findings at a minimum of twenty years after rotational acetabular osteotomy., Methods: Between June 1986 and August 1991, we performed 172 rotational acetabular osteotomies in 168 patients with acetabular dysplasia. Of those, ninety-three hips (ninety-one patients), including twenty-three hips with pre-osteoarthritis, twenty-nine with initial osteoarthritis, and forty-one with advanced osteoarthritis, had clinical and radiographic findings available. The mean age of the patients was 32.4 years (range, twelve to forty-nine years). The duration of follow-up was a mean of twenty-three years (range, twenty to twenty-seven years) for seventy-six hips, excluding hips that underwent conversion to total hip arthroplasty., Results: Conversion to total hip arthroplasty by twenty years after surgery was performed in one hip (4%) with pre-osteoarthritis, two hips (7%) with initial osteoarthritis, and fourteen hips (34%) with advanced osteoarthritis. The hips with advanced osteoarthritis had a significantly higher rate of conversion to total hip arthroplasty than hips in the other stages did (p = 0.0005). At the latest follow-up or at conversion to total hip arthroplasty, the disease stage had not progressed in seventeen hips (74%) with pre-osteoarthritis, nineteen (66%) with initial osteoarthritis, and twenty-six (63%) with advanced osteoarthritis., Conclusions: The progression of osteoarthritis after rotational acetabular osteotomy was not detected for at least twenty years in most hips with either pre-osteoarthritis or initial osteoarthritis in this cohort. Rotational acetabular osteotomy may delay conversion to total hip arthroplasty in advanced osteoarthritis., Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence., (Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.)

Introduction: Femoral component revisions with extensively porous-coated stems have shown promising clinical results, although there are still concerns over stress-shielding., Materials and Methods: We retrospectively reviewed data for 18 patients undergoing femoral component revisions with extensively porous-coated stems with high stiffness. The average length of follow-up was 10 years (range 6-13.7 years)., Results: Radiographic evidence of a bone-ingrown stem was present in 94 % of the hips, and stable fibrous fixation was present in only one hip, but no hips were considered unstable. There was mild stress-shielding in 15 hips, moderate stress-shielding in one hip, and severe stress-shielding in two hips. In one of the latter two hips, stress-shielding was progressive even 8 years after revision surgery. In 12 (92 %) of the 13 hips in which bypass fixation for diaphyseal cortical defects was used, there was good remodeling., Conclusions: We suggest that femoral component revision using extensive porous-coated stems is a useful option that may allow for healing of diaphyseal cortical defects.

Introduction: Rotational acetabular osteotomy (RAO) has been used successfully in patients with developmental dysplasia of the hip (DDH). However, some patients are forced to undergo total hip arthroplasty (THA) because of the progression of osteoarthritis. We evaluated the effect of previous RAO on the outcome of THA performed for degenerative arthritis secondary to DDH, comparing outcomes for patients with THA and prior RAO versus outcomes for patients with THA and no prior RAO., Materials and Methods: At an average follow-up point of 8.2 years (range 7-11 years), we compared outcomes in dysplastic hips for 22 hips (group R) in patients who underwent THA after successful RAO with outcomes for a well-matched control group of 30 hips in patients who underwent primary THA (group C) during the same period., Results: Both groups had similar midterm results. No acetabular or femoral components exhibited loosening or revision in either group. Harris hip scores (HHSs) at the most recent follow-up had not been compromised by RAO, and there were no significant differences in intraoperative blood loss and operative time between the two groups. Although there was a tendency toward superolateral placement of the acetabular component in group R, there were no significant differences in the mean steady-state linear and volumetric wear rates between the two groups. There were no infections, dislocations, intraoperative fractures, damaged nerves, or deep vein thromboses in either group., Conclusions: Our midterm results demonstrated that RAO does not lead to higher revision rates, compromised HHSs, or shortened survivorship in eventual THA for DDH.

Aims: The aim of this study was to evaluate clinical outcomes using the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ)., Methods: 100 consecutive patients at 6 months after total hip arthroplasty (THA) were evaluated., Results: The improvement rate for the pain subscale was significantly higher than that for the movement and mental subscales. Preoperative scores on the JHEQ movement and mental subscales were positively correlated to scores on the same subscales at 6 months after surgery., Conclusion: We conclude that the most predictable aspect of THA is pain relief and preoperative hip-joint ROM and mental status influence 6-month postoperative outcomes.

Zirconia femoral heads were introduced for total hip arthroplasty (THA) with the expectation of lower polyethylene (PE) wear and better clinical results. Because several studies reported poor survivorship of yttria-stabilized zirconia-PE THA, we investigated a new-generation yttria-stabilized zirconia head (diameter, 26 mm) manufactured by NGK Spark Plug. We retrieved six zirconia heads at revision THA after they had been in place for a mean of 8.6 years and measured their surface roughness and mean monoclinic content. Although their mean monoclinic content was higher than that of the unused head, surface roughness in the implanted heads was as low as that of the unused head, indicating that wear reduction may be possible with the selection of a suitable zirconia femoral head.

Anatomic femoral components are optimized for primary osteoarthritis, and few long-term results for their use are available for developmental dysplasia of the hip (DDH). We reviewed 135 uncemented total hip arthroplasties in which an anatomic femoral component was used in 106 patients with DDH, excluding femurs with neck-shaft angles of >160° and femurs with anteversion of >50°. The mean age of patients at surgery was 49.4 years (range, 33-66 years), and the mean duration of follow-up was 13.5 years (range, 10-18 years). No osteoporotic femurs were included in our study group. Despite 18 acetabular revisions, no femoral component was removed for any reason. No femoral loosening was seen at the final follow-up examination. An anatomic femoral component with circumferential porous coating can produce good clinical and radiologic findings in young patients with good bone quality who have DDH without excessive femoral deformity., (© 2013.)

We previously reported the results of wear comparison at a minimum of 5 years between highly cross-linked polyethylene (HXLPE) and conventional polyethylene (PE) against a zirconia femoral head. We now report the mean wear at 10 years for 52 patients (56 hips) of the original cohort of 61 patients (65 hips) who had undergone primary total hip arthroplasty at our hospital between November 1999 and August 2000. The mean steady-state linear wear rate of HXLPE was 0.045 mm/y, compared with 0.080 mm/y for conventional PE (P=.0003). The incidence of osteolysis was 25% in the conventional PE group compared with 0% in the HXLPE group. Our study demonstrated that the steady-state wear rate for HXLPE remains significantly lower than that for conventional PE against a zirconia femoral head at a mean of 10 years after implantation., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Introduction: There is controversy about which is more suitable for determining correct socket position in patients with severe bone deficiency of the acetabular roof because of developmental dysplasia of the hip (DDH): the anatomic centre of hip rotation or a high centre. 
, Method: We evaluated the relationship, in 200 hips, between the centre of rotation and presence of the Trendelenburg sign to determine the upper limit of cup position from the standpoint of hip-abductor strength. 
, Results: Of the 200 hips, 20 (10%) showed a positive Trendelenburg sign. There were no statistically significant differences between parameters (the centre of rotation, femoral offset, abductor lever arm) regarding the presence of the Trendelenburg sign except for age at surgery. Patients with a positive Trendelenburg sign were significantly older (64.1 ± 9.4 years) than those with a negative Trendelenburg sign (58.8 ± 7.7 years) (P = 0.01).
, Conclusions: Our findings indicate that a high centre of hip rotation of up to approximately 30 mm from the inter-teardrop line is a feasible option for patients with DDH from the standpoint of hip-abductor strength if stems are used that allow the restoration of femoral offset and the abductor lever arm.

A novel antimony-phthalocyanine, [Sb(H(3)tsppc)(OH)(2)], where H(3)tsppc denotes monodeprotonated tetrakis{(2',6'-dimethyl-4'-sulfonic acid)phenoxyl}phthalocyaninate, has been synthesized through sulfonation of [Sb(tppc)(OH)(2)](+) (tppc denotes tetrakis{(2',6'-dimethyl)phenoxyl}phthalocyaninate) in concentrated sulfuric acid. This compound is highly soluble in water (ca. 4 × 10(-2) M) without surfactant or alcohol. Moreover, it has been found free from aggregation in water up to almost 10(-4) M, unlike its copper and metal-free analogues, and show an intense optical absorption and emission band in optical therapeutical window (700-800 nm). The axial hydroxyl groups play a crucial role in disaggregation of the antimony derivative in water., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Three amphiphilic antimony(V)-phthalocyanines have been synthesized by treating [Sb(R(4)Pc)(OH)(2)](+) salts in concentrated H(2)SO(4) and isolated as zwitter ions, [Sb(R(4)Pc)(SO(4)H)(SO(4))], where R(4)Pc denotes tetra-substituted phthalocyaninate; R(4)Pc=pc (R=H), tbpc (R=(t)Bu), and tObpc (R=O(n)Bu). Their solubility (R=tbpc>pc >>tObpc in H(2)O (much improved by the presence of surfactant or alcohol) while tbpc>tObpc >>pc in CH(2)Cl(2)) and aggregation behaviors are highly sensitive to the nature of the peripheral substituents. The pc and tbpc derivatives form well-behaved J-aggregates in aqueous media in the presence of surfactant or alcohol., (Copyright © 2012 Elsevier Inc. All rights reserved.)

There is sometimes uncertainty concerning the correct socket position prior to total hip arthroplasty (THA). We conducted a study to determine the hip centre in Japanese women in order to define the true anatomical position of the acetabulum. The study involved 200 consecutive female patients in whom the contralateral hip joint was normal or was prearthritic and who underwent unilateral THA. The 'normal' group comprised 100 hip joints with no acetabular hip dysplasia, and the prearthritis group comprised 100 hip joints with Crowe type I dysplasia. The length of a perpendicular line drawn under the teardrop (interteardrop line) connecting both inferior edges of the teardrop with the centre of the femoral head was recorded as the vertical distance, and the distance from the intersection of the perpendicular line and interteardrop line up to the teardrop was recorded as the horizontal distance. We measured these distances on the femoral head of the side that did not undergo THA. The mean vertical distances in the 'normal' and prearthritis groups were 14.6 ± 2.8 mm and 16.8 ± 2.7 mm, respectively, and the mean horizontal distances were 30.2 ± 2.8 mm and 32.5 ± 2.7 mm, respectively. We therefore determined the mean centre of the hips to lie at a vertical distance of 11 to 22 mm and a horizontal distance of 27 to 38 mm. These values can serve as a useful index for socket positioning in THA.

Introduction: The results of isolated acetabular revision performed in 35 patients (36 hips) were monitored from 3 to 10 years. All femoral components were well fixed and not removed or revised during index surgery., Method: All revision acetabular implants were cementless, using a porous-coated hemispheric cup with or without bone graft. There were no cases of femoral component radiographic or clinical failure. For some cases, we performed bone grafting to focal osteolysis of the proximal femur around the cementless stem., Results: Bone incorporation occurred in 12 hips (overall 14). The mean pre- and postoperative Harris Hip Scores were 49 and 80, respectively. The findings suggest that isolated acetabular revision using a cementless porous-coated hemispheric cup can be performed without removing or revising a stable, well-fixed, uncemented femoral component if there is no concern about dislocation., Conclusion: We demonstrated that isolated acetabular revision is feasible and that grafting to the osteolytic femoral defects is a worthwhile procedure to restore bone stock.

Background: We conducted a nationwide epidemiologic study regarding hip osteoarthritis (OA) in Japan, and a previous report found these patients to be unique in comparison to Caucasians. This report focused on the data regarding each hip joint, and the involvement of acetabular dysplasia with hip OA was analyzed., Methods: Seven hundred twenty OA hips were examined. Sixty-five joints with osteonecrosis of the femoral head and 215 non-OA contralateral joints of the unilateral patients were examined as controls. The revised system of stage classification for hip OA of the Japanese Orthopedic Association (JOA) was used according to the reproducibility in order to ensure reliable data from the multiple institutions. The acetabular dysplasia indexes were also chosen according to the reproducibility and measured in the radiograph of bilateral hip joints. The clinical score was assessed using the JOA scoring system. The relative risk of the grade of acetabular dysplasia indexes for hip OA was calculated as the odds ratio and the 95% confidence interval., Results: The stage of the OA joints deteriorated with increasing age. The clinical scores also decreased. The grade of the acetabular dysplasia indexes of the OA joints was significantly higher than that of the control joints. Each index of acetabular dysplasia demonstrated significantly increased odds ratios for hip OA. Among the OA joints, the deterioration of the OA stage was found to be significantly associated with an increasing grade of acetabular dysplasia. The odds ratio for OA deterioration in the acetabular dysplasia index was also obtained. The joints of females tended to have a higher grade and prevalence of acetabular dysplasia than those of males., Conclusions: These findings confirmed a high prevalence of acetabular dysplasia in hip OA joints in Japan. Acetabular dysplasia was one of the most important factors associated with hip OA.

Highly cross-linked polyethylene (HXLPE) was developed to reduce wear of articular bearing surface in total hip arthroplasty patients. Several studies have shown reduced wear of HXLPE compared with conventional polyethylene; however, these studies had used HXLPE in combination with a Co-Cr metal head. The purpose of this study was to compare the 5-year in vivo wear of HXLPE with that of conventional PE using a zirconia femoral head. Forty-five hips with a Trilogy HXLPE (Zimmer, Warsaw, Ind) were matched and compared with a control group of 20 conventional Trilogy PE hips. The 2-dimensional linear wear rate was significantly less in the HXLPE group between 1 and 5 years postoperation (P < .001). The results show that HXLPE reduces short-term polyethylene wear against not only a Co-Cr head but also a zirconia head., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: We focused on vitamins with marked antioxidant potency to see whether their use might prevent the development of steroid-induced osteonecrosis., Methods: Fifteen Japanese white rabbits weighing about 3.5 kg were injected once into the right gluteal muscle with methylpred-nisolone (MPSL) 40 mg/kg (S group). In addition, 10 other rabbits received consecutive daily intravenous injections of vitamin E 50 mg/kg, starting from the day of MPSL administration (E group). All animals were killed 2 weeks after MPSL administration, and femurs were extracted and stained with H&E. Blood levels of reduced glutathione (GSH) were also measured., Results: In the S group the osteonecrosis development rate was 93%, in contrast to 0% in the E group (P < 0.01). Also, GSH levels in the S group abruptly decreased from the first day after MPSL administration, whereas in the E group, the decline in GSH levels was significantly suppressed on days 1 and 3 after MPSL administration (P< 0.05)., Conclusions: Vitamin E administration significantly inhibited steroid-induced oxidative stress. The results of this study suggest that the administration of vitamin E may be a novel and simple method to prevent the development of steroid-induced osteonecrosis.