Distribution of inorganic compositions of Japanese tap water: a nationwide survey in 2019-2024.

A nationwide survey of inorganic components of tap water all over Japan was conducted from 2019 to 2024. In this survey, 1564 tap water samples were collected, and an additional 194 tap water samples were collected from 33 other countries. The water samples were analyzed for 27 dissolved inorganic components, with a primary focus on the distribution of major and trace components, including Ca, Mg, K, Na, Cl-, NO3-, SO42-, total-hardness, Al, Fe, Cu, Mn, and Zn. The Japanese tap water hardness was 50.5 ± 30.2 (± 1σ SD) mg/L, classified as soft water according to the World Health Organization (WHO) classification. The average content of each major component in Japanese tap water tended to be lower than those in other countries. Furthermore, Piper trilinear diagrams were used to categorize Japanese tap water types. The dominating water types were the Ca-HCO3 and mixed types, which had a nationwide distribution. Japanese tap water generally complied with Japanese and WHO drinking water criteria, with only 1% (17/1564 sites) of the samples exceeding water quality standards. Observations of water quality changes for 2 years at three household faucets revealed that fluctuations in major components and trace metals (Al, Fe, Cu, Mn, and Zn) varied in different patterns. This suggests that the behavior of trace metal elements is influenced by local infrastructure, such as supply pipes, distinct from the variability in source water quality.

Post-operative Rehabilitation of Atypical Femoral Fracture in a Single Center.

OBJECTIVE: Increasing numbers of reports have described atypical femoral fracture (AFF) in patients being treated with oral bone resorption inhibitors, such as bisphosphonates. Most AFF patients undergo surgical treatment. However, there is little information about post-operative rehabilitation and patient activity levels after surgery for such fractures. Here we report the outcome of surgical treatment and postoperative rehabilitation for AFF at a single center in Japan. METHODS: We retrospectively reviewed 13 patients (14 AFFs) who underwent surgery at Nagano Matsushiro General Hospital between January 2013 and December 2016. The clinical backgrounds of the patients were evaluated. RESULTS: The patients comprised 1 man (1 AFF) and 12 women (13 AFFs). The mean age at surgery was 77.7±7.1 years (mean±SD). Before AFF occurred, 12 of the 13 patients had used bisphosphonates for osteoporosis. An intramedullary nail was inserted in all patients. Partial weight bearing was started on average 2 weeks after surgery, and full weight-bearing gait was permitted on average 3 weeks after surgery. The average time to bone union was 9.9±6.1 months, ranging from 3 to 23 months. None of the patients required additional surgical procedures, including revision surgery for pseudoarthrosis (nonunion) or delayed union. Before AFF, 12 patients walked independently, and 1 patient walked with a single cane. At the final follow-up (mean duration: 34.5±15.7 months), 8 patients could walk independently and 5 patients walked with a single cane. CONCLUSIONS: We recognized that rigid fixation for AFF supported early weight-bearing gait after surgery.

Disassembly of the inner head of a bipolar hip prosthesis.

We report an extremely rare case of inner head displacement from the stem of a bipolar hip prosthesis (BHP). An 88-year-old woman underwent BHP implantation for right femoral neck fracture. However, severe right hip joint pain occurred 12 days after surgery. A plain radiogram film revealed displacement of the inner head from the neck of the stem, accompanied by sinking of the stem. At reoperation, the inner head was disassembled from the stem, and Vancouver type A1 fracture was confirmed. Disassembly may have been caused by the pumping phenomenon or micromovement of the stem due to periprosthetic fracture. To our knowledge, this is the first report about disassembly of the BHP inner head, probably due to periprosthetic fracture.

Compact platelet-rich fibrin scaffold to improve healing of patellar tendon defects and for medial collateral ligament reconstruction.

BACKGROUND: Platelets are one of the most biocompatible and cost-effective sources of growth factors. Attention is being paid to autologous platelets and platelet-rich plasma. We developed a novel compact platelet-rich fibrin scaffold (CPFS) that was produced from blood and calcium gluconate only. The objective of this study was to investigate the potential of CPFS as a provisional scaffold in two rabbit models. METHODS: In the first rabbit model, the central half of the patellar tendon was resected bilaterally. Allogenic CPFS was attached to the defect in the right knee, while the left knee was untreated. In the other model, the medial collateral ligament was removed bilaterally. The ligament of the right knee was reconstructed with allogenic CPFS, whereas the left knee was untreated. RESULTS: After 12weeks, the ultimate failure load and stiffness were higher for the right patellar tendon than for the left patellar tendon in the former model. It was found that CPFS promoted ligament repair tissue in contrast with that on the untreated side in the latter model. The ultimate failure load of the CPFS repair tissue at 20weeks was 78% of that in healthy controls of the same age. CONCLUSIONS: CPFS enhanced the healing of tendons and ligaments. CLINICAL RELEVANCE: CPFS has the potential to accelerate healing of tendons and ligaments as a provisional bioscaffold or a material for graft augmentation.

Photoisomerization and energy transfer in naphthalene-terminated stilbene dendrimers.

Naphthalene-terminated stilbene dendrimers, the largest stilbene dendrimers to date, underwent photoisomerization via highly efficient energy transfer from the dendron group to the core stilbene. It was also demonstrated that the energy transfer efficiency in these dendrimers may be controlled by light, utilizing trans-cis isomerization as the key photoreaction.

The Damon System and release of substance P in gingival crevicular fluid during orthodontic tooth movement in adults.

Metabolism by peptidases plays an important role in modulating the levels of biologically active neuropeptides. One of these neuropeptides, substance P (SP), a component of gingival crevicular fluid (GCF), may exponentiate the inflammatory process during orthodontic tooth movement. The aim of this study was to investigate the GCF levels of SP in patients using different bracket systems. Subjects were 10 patients (four males, six females; mean age, 25.1 ± 4.4 years) undergoing orthodontic movement (leveling) in the maxilla. Conventional brackets were placed on the left side, while the teeth on the right received self-ligating brackets. The teeth on the mandibular left side without any orthodontic attachments served as controls. GCF was sampled at 0, 1, 24, and 168 hours after initiation of treatment. Prevention of plaque-induced inflammation allowed assessment of the dynamics of mechanically stimulated SP levels in the GCF, which was determined using commercially enzyme-linked immunoabsorbent assay (ELISA) kits. GCF levels of SP for the Damon System sites were significantly lower than for the teeth with conventional brackets at 24 hours. This result indicates that the Damon System inhibited an increase in the amount of SP in the GCF. Thus, the Damon System is useful to reduce the inflammation and pain resulting from orthodontic forces.

Repair of articular cartilage and clinical outcome after osteotomy with microfracture or abrasion arthroplasty for medial gonarthrosis.

This study compared the healing of articular cartilage and the clinical outcome after osteotomy with or without marrow stimulation microfracture or abrasion arthroplasty for osteoarthritis of the knee. Patients with osteoarthritis of the medial compartment of the knee were divided into a group undergoing high tibial osteotomy alone (HTO group: 37 knees), a group undergoing osteotomy plus microfracture (MF group: 26 knees), and a group undergoing osteotomy plus abrasion arthroplasty (AA group: 51 knees). The extent of cartilage repair was compared at 1 year after surgery by arthroscopy with reference to Outerbridge's classification, while the clinical outcome was compared at 1, 3, and 5 years postoperatively. Second-look arthroscopy revealed better repair of the femoral condylar cartilage in the AA group than the HTO group (p<0.0005) or MF group (p<0.01), with no difference between the HTO and MF groups. Repair of the tibial condylar cartilage was also better in the AA group than the HTO group (p<0.005), but there was no difference between the AA and MF groups or the MF and HTO groups. There were no differences of the clinical outcome between the three groups. In conclusion, repair of articular cartilage at 1 year postoperatively was accelerated by abrasion arthroplasty, but not by microfracture. However, there was no difference of the clinical outcome within 5 years after surgery, so the clinical utility of marrow stimulation techniques was not apparent in this study.

Arthroscopic lateral meniscectomy in knees with lateral compartment osteoarthritis: a case series study.

PURPOSE: The purpose of this study was to investigate the intermediate-term postoperative results of arthroscopic surgery for lateral compartment osteoarthritis (OA) of the knee in a case series study. METHODS: In a series of 30 knees in 29 patients who underwent arthroscopic surgery for lateral compartment OA, we were able to observe 25 joints in 24 patients prospectively for the entire postoperative period. The follow-up period ranged from 1 to 13 years, with a mean of 5.5 +/- 3.7 years. The procedure in all cases comprised lateral partial meniscectomy with either abrasion arthroplasty, or debridement of the articular cartilage surface or microfracture. Of 25 cases, 13 underwent abrasion arthroplasty, 10 underwent debridement of the articular cartilage surface, and 2 underwent microfracture. Results were assessed by use of the postoperative knee score, findings of arthritic changes on plain knee radiographs, and other measurements of postoperative progress. RESULTS: Further surgery was required in 2 cases (8%) because of poor postoperative progress. In the remaining 22 patients, knee scores improved from a mean of 52.4 points preoperatively to 84.6 points postoperatively and mean function scores improved from 45.4 points to 82.6 points, with these favorable results being maintained at the last follow-up. The femoral-tibial angle decreased slightly as each year passed postoperatively. Radiologic progression of OA was seen at 3 years postoperatively in 7 patients (28%), but no progression was seen in 12 (48%). A positive correlation was seen between the preoperative femoral-tibial angle and postoperative results (R = 0.81, P < .01). CONCLUSIONS: When lateral compartment OA and lateral meniscal tears are both present, the clinical outcome of lateral meniscal resection was favorable. In patients with lateral compartment OA, therefore, an arthroscopic procedure, including meniscectomy, should be considered early. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Assessing the performance of a methyl methacrylate-based resin cement with self-etching primer for bonding orthodontic brackets.

Questions over the usefulness of a self-etching primer with resin adhesive in the bonding of orthodontic brackets remain unsolved. The purpose of this study was to determine the effects of using Multibond, a new methyl methacrylate (MMA)-based resin cement with self-etching primer, on the shear bond strength of orthodontic brackets compared with Superbond C&B, which is a well-known MMA-based resin cement containing phosphoric acid etching. Metal or plastic brackets were bonded to etched or self-etching primed bovine teeth using Superbond C&B or Multibond. The shear bond strengths were measured after immersion in water at 37 degrees C for 24 hours. Data were analyzed by two-way analysis of variance and Scheffe's test. The surface appearances of the teeth after phosphoric acid etching or self-etching priming were observed by field-emission scanning electron microscopy (FE-SEM). Metal brackets bonded with Multibond had a significantly lower shear bond strength than metal brackets bonded with Superbond C&B. No significant differences in shear bond strength were observed between Multibond and Superbond C&B when plastic brackets were bonded to the enamel. The shear bond strength of metal brackets bonded with Multibond was comparable with that of plastic brackets bonded with Superbond C&B. Adhesive remnant index score showed a tendency of more residual resin cement remaining on the teeth when metal brackets were bonded with Multibond. FE-SEM observation revealed less dissolution of the enamel surface resulting from treatment with Multibond self-etching primer as compared with phosphoric acid. Thus, the Multibond system may be a candidate for bonding orthodontic brackets with the advantage of minimizing enamel loss.

Three cases of pseudogout complicated with unicondylar knee arthroplasty.

Pseudogout is an uncommon complication of arthroplasty, so it is important to distinguish pseudogout from infection. We experienced three patients with the acute onset of pseudogout after unicondylar knee arthroplasty (UKA). Treatment with nonsteroidal anti-inflammatory drugs (NSAID) and cooling improved the symptoms of all three patients, and there have been no further episodes. Because there is a large area uncovered by the UKA prosthesis, it is necessary to keep in mind the possibility of pseudogout affecting the operated knee.

Fixation of the NexGen HA-TCP-coated cementless, screwless total knee arthroplasty: comparison with conventional cementless total knee arthroplasty of the same type.

We performed a 12-month prospective study on 59 patients (92 knees) who underwent NexGen (Zimmer Inc, Warsaw, IN) cruciate-retaining total knee arthroplasty. In the control group, uncoated components were fixed using screws, whereas the hydroxyapatite-tricalcium phosphate (HA-TCP) group underwent screwless fixation of coated components. At 12 months postoperatively, there was a radiographic clear zone around the femoral and tibial components of 56.5% and 32.6% of the knees in the control group. The HA-TCP group showed a clear zone at the medial aspect of the tibial component in only 1 knee. These results suggested that HA-TCP-coated articular components show good initial fixation without using screws. The NexGen coated knee arthroplasty may be useful for solving the problems of cementless fixation.

A comparison of the healing potential of fibrillated cartilage versus eburnated bone in osteoarthritic knees after high tibial osteotomy: An arthroscopic study with 1-year follow-up.

PURPOSE: To determine the healing potential of fibrillated cartilage in osteoarthritic (OA) knees when the mechanical condition is corrected. TYPE OF STUDY: Prospective study. METHODS: Subjects were patients treated with high tibial osteotomy alone for medial-compartment OA knees. They were divided into 2 groups on the basis of the Outerbridge classification; group A consisted of 37 grade IV knees (eburnation group), and group B consisted of 36 grade III knees (fibrillation group). Twelve months after surgery, the repair of joint cartilage was evaluated for arthroscopic finding and histology. RESULTS: Arthroscopic examination of the femoral joint surface showed that, in group A, 9 knees (24%) were grade II, 14 (38%) were grade III, and 14 (38%) were grade IV; in group B, 3 knees (9%) were grade II, 30 (91%) were grade III, and none were grade IV. On the other hand, examination of the tibial joint surface showed that, in group A, 5 knees (16%) were grade II, 15 (47%) were grade III, and 12 (37%) were grade IV; in group B, 3 knees (9%) were grade II, 28 (80%) were grade III, and 5 (11%) were grade IV. Thus, the incidence of cartilage repair was significantly higher in group A than in group B on both femoral (P <.01) and tibial (P <.05) joint surface. Histologic findings showed most of the nonrepaired joint surface of fibrillated cartilage appeared to be hyaline cartilage, but repair tissues of eburnated bone were mainly fibrocartilage. CONCLUSIONS: The repair of fibrillated cartilage was not promoted, but its degeneration was prevented by correction of the mechanical status. Our results show that fibrillated cartilage in OA knees has little potential for repair even though the mechanical status is corrected.