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Introduction: In recent years, computer-assisted surgery has made it possible to undergo surgery with a high degree of precision. This study aimed to investigate the usefulness of computer-assisted surgery for femoral trochanteric fractures using the ADAPT (ADAptive Positioning Technology) system. Methods: A total of forty patients with femoral trochanteric fracture underwent intramedullary nailing for fracture fixation: in twenty patients, the ADAPT system (ADAPT group), and in the other twenty, it was not used (control group). The operative time, intraoperative fluoroscopy time, tip apex distance (TAD), and tip to head surface distance (TSD) were measured and compared between the two groups to assess the efficiency and accuracy of the surgery. Results: The operative time was significantly shorter (P

Background: In rheumatoid arthritis, forefoot disease activity can lead to joint damage, pain, and disability during weight-bearing activities; therefore, the evaluation and control of forefoot disease activity is important. We aimed to investigate an association between the prevalence of abnormalities in the forefoot based on ultrasonography (US) and the clinical and US findings related to arthritis and identify factors related to the presence of synovitis in the forefoot of RA patients., Methods: In total, 810 metatarsophalangeal joints of 81 rheumatoid arthritis patients were examined using US. Patients were assigned to either a forefoot synovitis group (n = 22), with foot synovitis detected using US, or a non-forefoot synovitis group (n = 59). We assessed associations between clinical parameters and US finding of the hand and US finding of the metatarsophalangeal joints., Results: The following were significantly higher in forefoot synovitis group than in non-forefoot synovitis group: swollen joint count [P < 0.001]; Disease Activity Score 28 based on C-reactive protein [P < 0.05]; clinical disease activity index [P < 0.001]; and total Power Doppler score of the hand [P < 0.001]. Receiver-operating characteristic analysis for total Power Doppler scores of the hand to suggest the presence of synovitis in the metatarsophalangeal joints showed that a total Power Doppler score of the hand of ≥5 was associated with synovitis in the metatarsophalangeal joints, with a sensitivity of 68% and a specificity of 85% (odds ratio = 11.9)., Conclusion: Total Power Doppler scores of the hand had a good valuable score for suggesting the presence of synovitis in metatarsophalangeal joints of rheumatoid arthritis patients., Competing Interests: Declaration of competing interest None., (Copyright © 2020. Published by Elsevier B.V.)

Purpose: This study investigated the effect of mediolateral stability on sagittal stability in bi-cruciate stabilized total knee arthroplasty., Method: This study included 59 patients. We intraoperatively assessed the component gap with a joint distraction force of 60 N for each compartment. Immediately after surgery, sagittal stability was assessed using an arthrometer., Result: The intraoperative medial joint laxity at 30° of flexion was significantly correlated with postoperative anteroposterior translation (r = 0.276, p < 0.05)., Conclusion: This study demonstrated the effect of intraoperative mediolateral stability effect on postoperative sagittal stability. Improving medial stability may enhance postoperative sagittal stability., Competing Interests: The authors declare that they have no competing interests., (© 2020 Published by Elsevier B.V. on behalf of Professor P K Surendran Memorial Education Foundation.)

Therapeutic outcomes for septic arthritis vary greatly depending on the span of time between disease-onset and surgery. The most important factor is making an early and definitive diagnosis; however, some cases may be difficult to diagnose. We investigated presepsin, a biomarker of sepsis, to determine whether or not presepsin in synovial fluid would be useful for the diagnosis of septic arthritis. We selected 18 patients with septic arthritis including periprosthetic joint infections (SA group) and 28 patients with osteoarthritis (OA group). We measured the concentrations of synovial fluid presepsin, blood presepsin and procalcitonin (PCT) in the two groups. We compared the sensitivities and specificities of synovial fluid presepsin, blood presepsin and PCT. Synovial fluid and blood presepsin and blood PCT were all significantly higher in the SA group. Synovial fluid presepsin exhibited both 100% sensitivity and 100% specificity in the SA group, which were higher rates than those for blood presepsin and PCT. We found that synovial fluid presepsin is markedly elevated in case of septic arthritis, and therefore, it has potential as a new biomarker of septic arthritis., (Copyright © 2018 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Clinical outcomes of total hip arthroplasty for rheumatoid arthritis are reportedly worse than those of total hip arthroplasty for osteoarthritis of the hip. The authors examined pre- and postoperative factors associated with the modified Harris hip score (mHHS). Fifty-one joints of 48 rheumatoid arthritis patients who underwent total hip arthroplasty were studied retrospectively. The authors examined the correlation between preoperative rheumatoid arthritis disease activity (Disease Activity Score in 28 joints-C-reactive protein and C-reactive protein) and mHHS at 1 year after total hip arthroplasty. Furthermore, pre- and postoperative mHHS values were compared between patients with other affected joints and patients with no affected joints in the lower limbs. The mean mHHS improved to 73.5 points postoperatively from 36.4 points preoperatively. Preoperative Disease Activity Score in 28 joints-C-reactive protein and C-reactive protein values were negatively correlated with pre- and postoperative mHHS values. Preoperative mHHS was not significantly different between the affected and not affected groups; however, postoperative mHHS was significantly lower in the affected group than in the not affected group. Total hip arthroplasty showed good clinical results for rheumatoid arthritis at short-term follow-up. However, pre- and postoperative mHHS values were influenced by preoperative rheumatoid arthritis disease activity. Moreover, the presence of additional affected joints in the lower limbs preoperatively resulted in a lower postoperative mHHS. Unlike patients with osteoarthritis, patients with rheumatoid arthritis often have multiple affected joints, which may contribute to a lower mHHS. Comprehensive treatment, including surgery for the other affected joints in the lower limbs, may improve a patient's postoperative mHHS. [Orthopedics. 2018; 41(6):e772-e776.]., (Copyright 2018, SLACK Incorporated.)

Hyperparathyroidism, which is increased parathyroid hormone (PTH) levels in the blood, could cause delayed or non-union of bone fractures. But, no study has yet demonstrated the effects of excess continuous PTH exposure, such as that seen in hyperparathyroidism, for fracture healing. Continuous human PTH 1-34 (teriparatide) infusion using an osmotic pump was performed for stabilized tibial fractures in eight-week-old male mice to determine the relative bone healing process compared with saline treatment. Radiographs and micro-computed tomography showed delayed but increased calcified callus formation in the continuous PTH 1-34 infusion group compared with the controls. Histology and quantitative histomorphometry confirmed that continuous PTH 1-34 treatment significantly increased the bone callus area at a later time point after fracture, since delayed endochondral ossification occurred. Gene expression analyses showed that PTH 1-34 resulted in sustained Col2a1 and reduced Col10a1 expression, consistent with delayed maturation of the cartilage tissue during fracture healing. In contrast, continuous PTH 1-34 infusion stimulated the expression of both Bglap and Acp5 through the healing process, in accordance with bone callus formation and remodeling. Mechanical testing showed that continuously administered PTH 1-34 increased the maximum load on Day 21 compared with control mice. We concluded that continuous PTH 1-34 infusion resulted in a delayed fracture healing process due to delayed callus cell maturation but ultimately increased biomechanical properties.

Aim: To determine the location of medial tibial plateau stress fractures and its relationship with tibial plateau morphology using magnetic resonance imaging (MRI)., Methods: A retrospective review of patients with a diagnosis of stress fracture of the medial tibial plateau was performed for a 5-year period. Fourteen patients [three female and 11 male, with an average age of 36.4 years (range, 15-50 years)], who underwent knee MRI, were included. The appearance of the tibial plateau stress fracture and the geometry of the tibial plateau were reviewed and measured on MRI., Results: Thirteen of 14 stress fractures were linear, and one of them stellated on MRI images. The location of fractures was classified into three types. Three fractures were located anteromedially (AM type), six posteromedially (PM type), and five posteriorly (P type) at the medial tibial plateau. In addition, tibial posterior slope at the medial tibial plateau tended to be larger when the fracture was located more posteriorly on MRI., Conclusion: We found that MRI showed three different localizations of medial tibial plateau stress fractures, which were associated with tibial posterior slope at the medial tibial plateau., Competing Interests: Conflict-of-interest statement: The authors have no conflicts of interest to declare.

In the photosynthetic light reactions of plants and cyanobacteria, plastocyanin (Pc) plays a crucial role as an electron carrier and shuttle protein between two membrane protein complexes: cytochrome b(6)f (cyt b(6)f) and photosystem I (PSI). The rapid turnover of Pc between cyt b(6)f and PSI enables the efficient use of light energy. In the Pc-cyt b(6)f and Pc-PSI electron transfer complexes, the electron transfer reactions are accomplished within <10(-4) s. However, the mechanisms enabling the rapid association and dissociation of Pc are still unclear because of the lack of an appropriate method to study huge complexes with short lifetimes. Here, using the transferred cross-saturation method, we investigated the residues of spinach (Spinacia oleracea) Pc in close proximity to spinach PSI and cyt b(6)f, in both the thylakoid vesicle-embedded and solubilized states. We demonstrated that the hydrophobic patch residues of Pc are in close proximity to PSI and cyt b(6)f, whereas the acidic patch residues of Pc do not form stable salt bridges with either PSI or cyt b(6)f, in the electron transfer complexes. The transient characteristics of the interactions on the acidic patch facilitate the rapid association and dissociation of Pc.

Articular cartilage possesses a limited capacity for self-renewal. The regenerated tissue often resembles fibrocartilage-like tissue rather than hyaline cartilage, and degeneration of the articular surface eventually occurs. The purpose of this study was to investigate the effect of basic fibroblast growth factor (bFGF) on the healing of full-thickness articular cartilage defects. bFGF (0, 10, 50, 100, 250, 500, or 1000 ng) was mixed with collagen gel and implanted into full-thickness articular cartilage defects drilled into rabbit knees. The repaired tissue was examined grossly and histologically, and was evaluated with the use of a grading scale at 4, 12, 24, and 50 weeks. At 4 weeks, treatment with 100 ng of bFGF had greatly stimulated cartilage repair both grossly and histologically in comparison with untreated defects (those filled with plain collagen gel). The average total scores on the histological grading scale were significantly better for the defects treated with bFGF than for the untreated defects. These improvements were evident as long as 50 weeks postoperatively, although slight deterioration was noted in the repaired cartilage. Immunohistochemical staining for type II collagen showed that this cartilage-specific collagen was diffusely distributed in the repaired tissue at 50 weeks. These findings suggest that bFGF may be a practical and important candidate for use in cartilage repair.

The effects of basic fibroblast growth factor (bFGF) on osteogenic differentiation in-vivo were investigated using a rat bone marrow ablation model. bFGF was infused directly into rat femora for 6 days after bone marrow ablation. The contralateral femur was infused with vehicle only and used as control. Bone formation was induced in the rat femoral cavity, and the gene expression of osteoblast markers was examined. Treatment with bFGF at 50 and 100 ng/day significantly enhanced the mRNA levels of osteopontin compared with the levels in the control leg, with increases of 25% and 24%, respectively. In contrast, bFGF infusion at 50 ng/day provoked a significant (nearly 20%) inhibition of expression for type I collagen. Infusion of bFGF at a higher dose exhibited an inhibitory tendency for bFGF action on gene expression. There were no significant changes in alkaline phosphatase and osteocalcin mRNA levels in response to any dose of bFGF. The findings presented here suggest that bFGF modulates osteogenic differentiation in-vivo and may play an important role in the process of bone remodeling.

Local and systemic expression of insulin-like growth factor-I (IGF-I) during bone formation was studied using the rat bone marrow ablation model. The temporal expression pattern of IGF-I mRNA in rat femurs was examined. The IGF-I mRNA level was enhanced rapidly after ablation reaching a level threefold greater than basal by day 3 (P < 0.01) and declined to basal or below basal level by day 5. Histological analysis showed that IGF- I immunoreactivity was predominantly associated with the mesenchymal cells at the bone/connective tissue interface and osteoblastic cells at active sites of bone formation. Serum level of IGF-I increased 50 and 130%, respectively (P < 0.005), over the basal level at days 3 and 6. We also investigated the systemic expression of IGF-I in liver and kidney. In contrast, hepatic IGF-I gene expression decreased 37 and 48%, respectively, at days 3 and 6 after marrow ablation (P < 0.001). Kidney IGF-I mRNA levels also fell 13 and 27%, respectively, at days 3 and 6 (P < 0.005). The present findings suggest that locally produced IGF-I during bone formation may not only serve as an autocrine/paracrine factor but also influence systemic expression of IGF-I in other organs., (Copyright 2001 Academic Press.)

We have isolated two novel cDNAs encoding the transforming growth factor-beta (TGF-beta) type II receptor (TGF-beta IIR), termed TGF-beta IIR alpha and TGF-beta IIR beta 1 from a human fetal liver library. They have unique nucleotide (nt) sequences, compared with the reported TGF-beta IIR sequence, at the 5' end. Southern blot analysis using probes from each clone detected the specific genomic DNA fragments. RT-PCR analysis revealed a distinct pattern of expression for each isoform. These results indicated that TGF-beta IIR has heterogeneity in the structure, and the expression of TGF-beta IIR isoforms is differentially regulated. The heterogeneity of TGF-beta IIR molecules could be derived from alternative splicing and might elicit specific TGF-beta receptor functions.