Bone-patellar tendon-bone autograft maturation is superior to double-bundle hamstring tendon autograft maturation following anatomical anterior cruciate ligament reconstruction.

PURPOSE: The primary purpose of this study was to evaluate the second-look arthroscopic findings 1 year postoperatively and magnetic resonance imaging (MRI) findings 2 years after anterior cruciate ligament reconstruction (ACLR) using bone-patellar tendon-bone autograft (BTB) or hamstring tendon autograft (HT). Secondary purpose included clinical results from physical examination, including range of motion, Lachman test, pivot shift test, and knee anterior laxity evaluation, and the clinical score for subjective evaluations at 2 years after surgery. METHODS: Between 2015 and 2018, 75 patients with primary ACL injuries were divided into either the BTB group (n = 30) or HT group (n = 45). When using HT, an anatomical double-bundle ACLR was performed. BTB was indicated for athletes with sufficient motivation to return to sporting activity. Graft maturation on second-look arthroscopy was scored in terms of synovial coverage and revascularization. All participants underwent postoperative MRI evaluation 2 years postoperatively. The signal intensity (SI) characteristics of the reconstructed graft were evaluated using oblique axial proton density-weighted MR imaging (PDWI) perpendicular to the grafts. The signal/noise quotient (SNQ) was calculated to quantitatively determine the normalized SI. For clinical evaluation, the Lachman test, pivot shift test, KT-2000 evaluation, Lysholm score, and Knee injury and Osteoarthritis Outcome Score (KOOS) were used. RESULTS: Arthroscopic findings showed that the graft maturation score in the BTB group (3.6 ± 0.7) was significantly greater than that in the anteromedial bundle (AMB; 2.9 ± 0.2, p = 0.02) and posterolateral bundle (PLB; 2.0 ± 0.9, p = 0.001) in the HT group. The mean MRI-SNQs were as follows: BTB, 2.3 ± 0.5; AMB, 2.9 ± 0.9; and PLB, 4.1 ± 1.1. There were significant differences between BTB, AMB, and PLB (BTB and AMB: p = 0.04, BTB and PLB: p = 0.003, AMB and PLB: p = 0.03). Second-look arthroscopic maturation score and MRI-SNQ value significantly correlated for BTB, AMB, and PLB. No significant differences were detected in clinical scores. There was a significant difference (p = 0.02) in the knee laxity evaluation (BTB: 0.9 ± 1.1 mm; HT: 2.0 ± 1.9 mm). CONCLUSION: BTB maturation is superior to that of double-bundle HT based on morphological and MRI evaluations following anatomical ACLR, although no significant differences were found in clinical scores. Regarding clinical relevance, the advantages of BTB may help clinicians decide on using the autograft option for athletes with higher motivation to return to sporting activity because significant differences were observed in morphological evaluation, MRI assessment, and knee anterior laxity evaluation between BTB and double-bundle HT. LEVEL OF EVIDENCE: Level IV.

Joint effusion at 6 months is a significant predictor of joint effusion 1 year after anterior cruciate ligament reconstruction.

PURPOSE: This study aimed to assess the risk factors for prolonged joint effusion in patients undergoing double-bundle anterior cruciate ligament reconstruction (ACLR). METHODS: In total, 160 patients who underwent primary ACLR using autograft hamstring between 2015 and 2018 were retrospectively reviewed. Joint effusion was defined as any grade ≥ 2 (range, 0-3) according to the MRI Osteoarthritis Knee Score (MOAKS). Univariate and multivariate logistic regression analyses were performed. RESULTS: The median age of the patients was 25 years (range 14-68 years) at the time of the surgery; there were 89 women and 71 men. At 1 year, 46 (28.8%) patients experienced knee joint effusion, as defined by the MOAKS. Univariate analysis revealed that age, preoperative Kellgren-Lawrence (K-L) grade, and joint effusion at 6 months were significantly associated with joint effusion at 1 year. In the multivariate analysis, joint effusion at 6 months was significantly associated with joint effusion at 1 year (odds ratio, 68.0; 95% confidence interval, 22.1-209.4). No significant difference in the Lysholm scores was observed between patients with and without joint effusion at 1 year (n.s.). CONCLUSIONS: Joint effusion at 6 months was significantly associated with joint effusion 1 year after ACLR. LEVEL OF EVIDENCE: III.

Femoral nerve versus adductor canal block for early postoperative pain control and knee function after anterior cruciate ligament reconstruction with hamstring autografts: a prospective single-blind randomised controlled trial.

INTRODUCTION: The optimal pain management strategy for postoperative pain after anterior cruciate ligament reconstruction (ACLR) remains unclear. This study compared femoral nerve block (FNB) and adductor canal block (ACB) for pain management of early postoperative pain, knee function, and recovery of activity of daily living (ADL) after ACLR using hamstring autografts. MATERIAL AND METHODS: In this prospective, single-blind, randomised controlled trial, 64 patients aged 12-56 years who underwent anatomical double-bundle ACLR with a hamstring autograft between August 2019 and May 2020 were randomised to undergo preoperative FNB (n = 32) or ACB (n = 32). The peripheral nerve block was performed by a single experienced anaesthesiologist under ultrasound guidance. The primary outcomes were postoperative pain as evaluated using the visual analogue scale (VAS) at 3, 6, 12, 24, and 48 h postoperatively and the need for pain relief. The secondary outcome was knee function, including the recovery of range of motion, contraction of the vastus medialis, and stable walking with a double-crutch (ADL), as evaluated by blinded physical therapists. RESULTS: There were no significant differences in patient demographics between the two groups. The VAS scores, need for pain relief, knee function, and ADL did not significantly differ between the groups. CONCLUSION: FNB and ACB provided comparable outcomes related to early postoperative pain, knee function, and ADL after double-bundle ACLR using hamstring autografts. Further research is necessary to evaluate the mid- to long-term effect of each block on recovery of knee function and ADL. LEVEL OF EVIDENCE: I.

Thioredoxin regulates G6PDH activity by changing redox states of OpcA in the nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120.

Glucose 6-phosphate dehydrogenase (G6PDH) catalyzes the first reaction in the oxidative pentose phosphate pathway. In green plant chloroplasts, G6PDH is a unique redox-regulated enzyme, since it is inactivated under the reducing conditions. This regulation is accomplished using a redox-active cysteine pair, which is conserved in plant G6PDH. The inactivation of this enzyme under conditions of light must be beneficial to prevent release of CO2 from the photosynthetic carbon fixation cycle. In the filamentous, heterocyst-forming, nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120 (Anabaena 7120), G6PDH plays a pivotal role in providing reducing power for nitrogenase, and its activity is also reported to be suppressed by reduction, though Anabaena G6PDH does not conserve the critical cysteines for regulation. Based on the thorough analyses of the redox regulation mechanisms of G6PDH from Anabaena 7120 and its activator protein OpcA, we found that m-type thioredoxin regulates G6PDH activity by changing the redox states of OpcA. Mass spectrometric analysis and mutagenesis studies indicate that Cys393 and Cys399 of OpcA are responsible for the redox regulation property of this protein. Moreover, in vivo analyses of the redox states of OpcA showed that more than half of the OpcA is present as an oxidized form, even under conditions of light, when cells are cultured under the nitrogen-fixing conditions. This redox regulation of OpcA might be necessary to provide reducing power for nitrogenase by G6PDH in heterocysts even during the day.

Partial meniscectomy adversely affects return-to-sport outcome after anatomical double-bundle anterior cruciate ligament reconstruction.

PURPOSE: The purposes of this study were to determine whether the partial meniscectomy combined with ACL reconstruction affect the postoperative return-to-sport and to identify if partial meniscectomy has an influence on the graft failure following an anatomical double-bundle ACL reconstruction case. METHODS: A retrospective cohort study including 426 primary double bundle ACL reconstruction cases. There were 206 males and 220 females, median age of 28.4 years, median BMI of 23.0, median preinjury Tegner score of 7.0 and median follow-up period after surgery of 24.0 months. Patients with less than 12 months of follow-up, revision surgery, multi-ligaments injury, previous contralateral knee ligaments injury and postoperative infection cases were excluded. Furthermore, patients who had meniscal repair were excluded in order to compare the outcomes between patients who had intact menisci and those who underwent partial meniscectomy. There were 227 patients with intact menisci (group A) and 199 patients with partial meniscectomy (group B). The median age was younger and the preoperative Tegner score was higher in group A. The patients in group B were subcategorized as the site of partial meniscectomy, including medial (group C), lateral (group D) and bicompartmental (group E) meniscectomy. There were 74, 94, and 31 patients in group C, D, and E, respectively. Return-to-sport (running and sport phase) and graft failure were included in our primary outcomes, and functional outcome as Lysholm knee scores was included in secondary outcome. RESULTS: The rate of return to running phase and sport phase were 91% (387/426) and 76% (303/399), the mean time taken to return to running and sport phase were 5.7 months and 11.1 months, respectively. There was significant difference in the returning to sport phase between group A and B (p = 0.01), and between group A and D/E subgroups (p = 0.007). There were fourteen graft failures (3.5%) in total. In addition, 9 and 5 graft failures in group A and B, respectively. Of the 5 graft failures in group B, 2 and 3 graft failures in group C and D, respectively. There was no significant difference of the graft failure ratio among the groups. CONCLUSION: Our study demonstrates that partial meniscectomy has an adverse effect on the return to sport phase following the anatomical double-bundle ACL reconstruction. Therefore, greater postoperative care would be needed to return to sport with partial meniscectomy in ACL reconstruction cases. On the contrary, partial meniscectomy is not considered to be the risk factor for graft failure at short-term follow-up. LEVEL OF EVIDENCE: Case-control study, Level III.

Inferior graft maturity in the PL bundle after autograft hamstring double-bundle ACL reconstruction.

PURPOSE: The purpose of this study was to evaluate the signal/noise quotient (SNQ) for graft maturation and the serial changes observed in the magnetic resonance imaging (MRI) findings after double-bundle (DB) anterior cruciate ligament (ACL) reconstruction using a hamstring tendon autograft at a minimum of 5 years after surgery. METHODS: Forty-five patients who underwent DB ACL reconstruction between 2007 and 2010 were included in this prospective study. All participants underwent postoperative MRI at 3 weeks and 3, 6, 9 and 12, 18, 24, 36, 48 and 50 months. The signal intensity (SI) characteristics of the reconstructed graft were evaluated on oblique axial proton density-weighted MR imaging (PDWI) perpendicular to the grafts. The signal/noise quotient (SNQ) was calculated to quantitatively determine the normalized SI. The SNQ of the AMB and PLB was evaluated separately. RESULTS: The mean SNQ of the AM bundle (AMB) continued to increase until 6 months after surgery (5.2 ± 1.2), and then gradually decreased and became well stabilized by 18 months (3.3 ± 0.5), after which it remained unchanged. On the other hand, the mean SNQ of the PL bundle (PLB) continued to increase until 9 months after surgery (6.2 ± 1.1), and then decreased incrementally and became well stabilized by 24 months (4.1 ± 0.5). The SI of PLB was significantly higher than that of AMB between 3 and 24 months (p = 0.04, 0.03, 0.01, 0.04, 0.02 and 0.03, respectively). CONCLUSIONS: These results indicate that at least 18 months is needed after ACL reconstruction to sufficiently restore the SI of the AMB, while at least 24 months are needed to for the PLB. The SI of the PLB was significantly higher than that of the AMB at 3-24 months after surgery, indicating that the PLB showed inferior graft maturity to the AMB until 24 months after surgery. For clinical relevance, the correct understanding of serial changes in graft maturation may potentially be used in decision-making regarding a return to sports. LEVEL OF EVIDENCE: Prospective case series, Level IV.

Characteristics of plantar pressure distribution in elite male soccer players with or without history of proximal fifth metatarsal fracture: a case-control study.

[Purpose] Studies have demonstrated a relationship between plantar pressure distribution and proximal fifth metatarsal fracture. We aimed to investigate the plantar pressure patterns of soccer players with or without a history of proximal fifth metatarsal fracture. [Participants and Methods] Fifty-one male soccer players (31 professional, 20 high-school) participated in this study (mean age, weight, and height ± SD: 21.1 ± 4.7 years, 68.8 ± 5.8 kg, and 175.4 ± 5.9 cm, respectively). Seven of them had a history of proximal fifth metatarsal fracture before this study (the fracture group) and 44 had no history of fracture (the control group). A Win-Pod (Medicapteurs) platform was used to measure foot pressure forces. The center of plantar pressure was measured during double and single-limb stances for 25 seconds. Fifth metatarsal pressure and the center of plantar pressure angle was calculated from the walking footprint. The calculated data were compared between the fracture group and the control group. [Results] Comparisons between the fracture and control groups in terms of morphology and the center of plantar pressure length showed no significant differences. However, the fifth metatarsal pressure and the center of plantar pressure angle were significantly higher in the fracture group. [Conclusion] The results of this study revealed that players with excessive loading in the lateral areas of the foot while walking have a risk of developing proximal fifth metatarsal fracture.

The short-term effect after a single injection of high-molecular-weight hyaluronic acid in patients with enthesopathies (lateral epicondylitis, patellar tendinopathy, insertional Achilles tendinopathy, and plantar fasciitis): a preliminary study.

BACKGROUND: Hyaluronic acid (HA) with a high molecular weight of 2700 kDa is approved in Japan to treat osteoarthritis of the knee, periarthritis scapulohumeralis, and knee pain associated with rheumatoid arthritis. The purpose of this preliminary study was to investigate the short-term efficacy, safety, and injectable volume of HA in the treatment of enthesopathies. METHODS: A total of 61 patients (16 with lateral epicondylitis, 14 with patellar tendinopathy, 15 with insertional Achilles tendinopathy, and 16 with plantar fasciitis) were each administered a single injection of HA (up to 2.5 ml). Efficacy and safety were assessed by comparing the visual analog scale (VAS) for pain and local symptoms before injection (baseline) and at 1 week after injection. We also investigated the injectable volume by means of the difference in syringe weight before and after injection and by the judgment of the administering investigator. RESULTS: The injection of HA resulted in a change in VAS (mean ± SD) of -2.20 ± 2.26 cm for the four sites overall and -2.55 ± 2.43 cm for lateral epicondylitis, -2.01 ± 2.16 cm for patellar tendinopathy, -1.80 ± 1.91 cm for insertional Achilles tendinopathy, and -2.38 ± 2.61 cm for plantar fasciitis. The injection of HA also improved local symptoms in each site. It was also determined that 2.5 ml of HA can be injected in each of the four sites. CONCLUSION: A single injection of HA resulted in similar improvements of pain in each of the four enthesopathies (lateral epicondylitis, patellar tendinopathy, insertional Achilles tendinopathy, and plantar fasciitis). These results suggest that HA could be clinically effective in the treatment of enthesopathies.

Abnormal Wrist Sagittal Kinematics in Gymnasts With Dorsal Wrist Pain: A New Syndrome.

BACKGROUND: The pathology of dorsal wrist pain in gymnasts without abnormal radiographic findings remains unclear. PURPOSE/HYPOTHESIS: The purpose of this study was to identify abnormal wrist sagittal kinematics in gymnasts with dorsal wrist pain. It was hypothesized that gymnasts with dorsal wrist pain would show abnormal sagittal kinematics with reversible hypermobility of the intercarpal joint. STUDY DESIGN: Controlled laboratory study. METHODS: Participants included 19 wrists in male gymnasts with dorsal wrist pain, 18 wrist in male gymnasts without wrist pain, and 20 adult men without a history of wrist pain. Magnetic resonance imaging (T2-weighted sagittal images) findings at 0°, 30°, 60°, and 90° of wrist extension were used in kinematic analysis. The angles and translations of the radiolunate, capitolunate, and third carpometacarpal joint were measured and compared between the 3 groups. RESULTS: At 90° of wrist extension, gymnasts with dorsal wrist pain had a significantly lower radiolunate joint angle (28.70°± 6.28° vs 36.19°± 7.81°; P = .020) and a significantly higher capitolunate joint angle (57.99°± 6.15° vs 50.50°± 6.98°; P = .004) and distal translation (1.17 ± 0.50 mm vs 0.46 ± 0.62 mm; P = .002) than gymnasts without dorsal wrist pain. CONCLUSION: Gymnasts with dorsal wrist pain showed abnormal wrist sagittal kinematics. These novel findings may facilitate understanding of dorsal wrist pain, which can be recognized as a new syndrome termed "gymnast's lunate dyskinesia."

Characteristics of needlestick and sharps injuries of the hands in the operating room among orthopedic surgeons in Japan.

Among the reports on needlestick and sharps injuries (NSIs), many are orthopedic-related due to the frequent use of sharp devices such as pins and wires. This study aimed to identify high-risk instruments, the most common injury sites for each instrument, and the circumstances of NSIs of the hand during orthopedic surgeries in Japan. Incidents of exposure to blood or bodily fluids among physicians during orthopedic surgeries reported to the Japan-EPINet between 2000 and 2015 were included in this study. The four most common devices were identified and the associations among years of experience, equipment users, and injured sites were analyzed. We identified 666 cases of NSIs affecting orthopedic surgeons in the operating room. The instrument most frequently responsible for NSIs was suture needles, which were involved in 265 cases (39.7%). The second most common instrument was pins/wires, which was involved in 111 cases (16.6%). NSIs of the hands of orthopedic surgeons were frequently caused by suture needles used in all surgeries, but relatively often caused by orthopedic devices. Orthopedic surgeons must be aware that they are at risk of NSIs and must take appropriate measures and always be cautious when performing surgery, regardless of their years of experience.

Associations between Depressive Symptoms, Work Environment, and Lifestyle in <40-year-old Male Orthopedic Physicians in Japan.

Introduction: Efforts are being made to reduce doctors' working hours and implement reforms in the way doctors work. This study aims to determine the associations between depressive symptoms and work environment/lifestyle among <40-year-old male orthopedic physicians in Japan. Methods: Participants were 1,343 male orthopedic physicians selected from a survey (N = 25,139) of all regular members conducted in 2019 by the Japanese Orthopaedic Association. Participants completed the Quick Inventory of Depressive Symptomatology and provided information about total working hours, number of on-call/night duties, number of patient complaints received, smoking habits, exercise habits, and sleep time. Results: Of the participants, 6.6% had depressive symptoms. Factors associated with depressive symptoms were total working hours of ≥80 h per week (80-99 h: adjusted odds ratio [AOR] = 2.06; 95% confidence interval [CI], 1.02-4.18; ≥100 h: AOR = 3.89; 95% CI, 1.92-7.88), one or more unreasonable patient demands/complaints in the previous 6 months (AOR = 1.61; 95% CI, 1.00-2.60), current smoking (AOR = 2.98), no sweat-inducing exercise sessions of ≥30 min per week in the previous month (AOR = 2.50), and an average of <6 h of sleep per night in the previous month (AOR = 2.15). Conclusions: Work factors at the main medical institution (i.e., total working hours of ≥80 h per week) were associated with depressive symptoms. In addition, associations between depressive symptoms and unhealthy living conditions, such as smoking habits, lack of exercise, and <6 h of sleep per night, were observed.

Repairing Cartilage with Processed Chondrocyte Constructs: A 6-Month Study Using a Porcine Model.

OBJECTIVE: Autologous chondrocyte implantation was the first cell-based therapy that used a tissue engineering process to repair cartilage defects. Recently improved approaches and tissue-engineered cell constructs have been developed for growing patient populations. We developed a chondrocyte construct using a collagen gel and sponge scaffold and physicochemical stimuli, implanted with a surgical adhesive. We conducted a proof-of-concept study of these improvements using a cartilage defect model in miniature swine. DESIGN: We implanted the autologous chondrocyte constructs into full-thickness chondral defects in the femoral condyle, compared those results with empty and acellular scaffold controls, and compared implantation techniques with adhesive alone and with partial adhesive with suture. Two weeks after the creation of the defects and implantation of the cellular or acellular constructs, we arthroscopically confirmed that the implanted constructs remained at the chondral defects. We evaluated the regenerated tissue macro- and microscopically 6 months after the cell constructs were implanted. The tissues were stained with Safranin-O and evaluated using Sellers' histology grading system. RESULTS: The defects implanted with processed cell constructs and acellular scaffolds were filled with chondrocyte-like round cells and with nearly normal tissue architecture that were significantly greater degree compared to empty defect control. Even with the adhesive alone and with suture alone, the cell construct was composed of the dense cartilaginous matrix that was found in the implantation using both the sutures and the adhesive. CONCLUSION: Implantation of cell constructs promoted regeneration and integration of articular cartilage at chondral defects in swine by 6 months.

Does poor spousal health negatively affect own health among elderly retired Japanese couples? A 1-year follow-up study.

BACKGROUND: We aimed to determine whether poor spousal health affected respondents' own self-rated health after 1 year among older retired Japanese couples. METHODS: Data were extracted from the nationwide population-based survey, the "Longitudinal Survey of Middle-aged and Elderly Persons", which has been conducted annually since 2005 by the Japanese Ministry of Health, Labour and Welfare. We used 2016 survey data as a baseline and 2017 data for 1-year follow-up. Baseline respondents comprised 21,916 individuals; of these, we focused on 4397 respondents who were retired, married, aged 65-70 years, and had good self-rated health. The survey included questions about respondents' own health and lifestyle, and their spouses' health status. Multivariate logistic regression analysis was used to explore the association between spousal health at baseline and respondents' own self-rated health after 1 year. RESULTS: We found that poor spousal health is associated with respondents' own self-rated poor health after 1 year. The odds ratio (OR) for worsening health was 1.67 (95% confidence interval (CI): 1.11-2.52) for men and 1.72 (95% CI: 1.25-2.37) for women when their spouse's health was "somewhat bad". The OR was 2.25 (95% CI: 1.40-3.62) for women when spousal health was "bad/very bad", compared with "somewhat good". Conversely, good spousal health was associated with a low risk of declining health for respondents after 1 year. The association for men was apparent when their spouse's health was "good" [OR: 0.69; 95% CI: 0.49-0.98], and the association for women was apparent when their spouse's health was "very good" [OR: 0.46; 95% CI: 0.24-0.90]. CONCLUSIONS: Poor spousal health is an independent factor that negatively affects own self-rated health after 1 year among retired couples in Japan aged 65-70 years.

Clinical and Radiographic Outcomes After Fixation of Chondral Fragments of the Knee in 6 Adolescents Using Autologous Bone Pegs.

BACKGROUND: Little is known regarding the optimal treatment for displaced, purely chondral fragments in the knee. PURPOSE: To report the clinical and radiographic outcomes of chondral fragment fixation in adolescents through use of autologous bone pegs. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: This retrospective, single-center study evaluated 6 patients (mean age, 12.9 years) who underwent fixation of chondral fragments (no visualized bone attached) using autologous bone pegs (mean postoperative follow-up, 5.2 years; range, 1.4-10.9 years). The causes were trauma (n = 5) and osteochondritis dissecans (n = 1). Lesions were located in the trochlear groove (lateral, n = 3; medial, n = 2) or posterior part of the lateral femoral condyle (n = 1). The mean lesion size was 3.8 cm2 (range, 0.8-9.0 cm2). Patients were evaluated via physical examination and magnetic resonance imaging (MRI) using magnetic resonance observation of cartilage repair tissue scores. RESULTS: In total, 5 patients successfully returned to sports without restrictions at a mean of 7 months (range, 6-8 months) postoperatively. At the latest follow-up, these 5 patients had full range of motion and no joint effusion. The mean magnetic resonance observation of cartilage repair tissue score was 85 (range, 70-95) at a mean duration of 3 years (range, 1-5 years). One patient experienced failure at 1.3 years postoperatively after a traumatic injury and subsequently underwent removal of the fixed fragment and a drilling procedure. CONCLUSION: In most adolescents, fixation of chondral fragments with no visualized bony portion using autologous bone pegs provided a satisfactory success rate and good healing of cartilage tissue confirmed on MRI scans.

Effects of hydrostatic pressure and deviatoric stress on human articular chondrocytes for designing neo-cartilage construct.

Autologous chondrocyte implantation is a promising therapy for the treatment of the articular cartilage defects. Recently, we have developed a three-dimensional chondrocyte construct manufactured with a collagen gel/sponge scaffold and cyclic hydrostatic pressure. However, the roles of various mechanical stresses, specifically hydrostatic pressure and deviatoric stress, as well as poststress loading, were unclear on metabolic function in chondrocytes. We hypothesized that hydrostatic pressure and deviatoric stresses each alter individual metabolic characteristics of chondrocytes. We embedded human articular chondrocytes within an agarose hydrogel and applied hydrostatic pressure and/or deviatoric stress individually or simultaneously for 4 days. Subsequently, we kept the cell constructs without stress for an additional 3 days. With hydrostatic pressure and/or deviatoric stress, more cells proliferated significantly than no stress (p < .05) and more cells proliferated near the inner side of the construct than the outer (p < .05). Cartilage specific aggrecan core protein and collagen type II were upregulated significantly after off-loading hydrostatic pressure alone at Day 7 (p < .05). On the other hand, these molecules were upregulated significantly immediately after deviatoric stress alone and combined with hydrostatic pressure at Day 4 (p < .05). Tissue inhibitor of metalloproteinase-2 was upregulated significantly after off-loading hydrostatic pressure alone and combined deviatoric stress at Day 7 (p < .05). Metalloproteinnase-13 was upregulated significantly with deviatoric stress at Day 4 (p < .05) and combined with hydrostatic pressure at Day 4. These results suggest that metabolic functions are regulated by the combination of hydrostatic pressure and deviatoric stress and by the timing of stress loading.

Optimization of Extracellular Matrix Synthesis and Accumulation by Human Articular Chondrocytes in 3-Dimensional Construct with Repetitive Hydrostatic Pressure.

Objective The effects of hydrostatic pressure (HP) on the matrix synthesis by human articular chondrocytes have been reported elsewhere. In order to optimize the production of extracellular matrix, we aimed to clarify the effects of repetitive HP on metabolic function by human articular chondrocytes. Design The human articular chondrocytes were expanded and embedded within a collagen gel/sponge scaffold. We incubated these constructs with and without HP followed by atmospheric pressure (AP) and repeated the second HP followed by AP over 14 days. Genomic, biochemical, and histological evaluation were performed to compare the effects of each regimen on the constructs. Results The gene expressions of collagen type II and aggrecan core protein were significantly upregulated with repetitive HP regimens compared with a single HP or AP by 14 days ( P < 0.01 or 0.05). Matrix metalloptoteinase-13 (MMP-13) in AP was upregulated significantly compared to other HP regimens at day 14 ( P < 0.01). No significant difference was observed in tissue inhibitor of metalloproteinases-II. Immunohistology demonstrated that application of HP (both repetitive and single) promoted the accumulation of specific extracellular matrix and reduced a MMP-13. A single regimen of HP followed by AP significantly increased the amount of sulfated glycosaminoglycan than that of the AP, whereas repetitive HP remained similar level of that of the AP. Conclusions Repetitive HP had a greater effect on anabolic activity by chondrocytes than a single HP regimen, which will be advantageous for producing a matrix-rich cell construct.

Transcriptional regulation of the Drosophila rfc1 gene by the DRE-DREF pathway.

The DNA replication-related element (DRE) is a common 8-bp sequence (5'-TATCGATA) found in the promoters of many DNA replication-related genes, to which DRE-binding factor (DREF) specifically binds to activate transcription. Replication factor C (RFC) is an essential five-subunit complex in DNA replication, the largest subunit being RFC140. We first identified the gene (rfc1) encoding the Drosophila RFC140 (dRFC140) protein and then isolated a mutant. The phenotypes suggested that the gene is essential for cell-cycle progression, and immunocytochemical studies also indicated a relation between its expression and the cell cycle. The rfc1 gene contains three DRE-like sequences in its 5'-flanking region, one of them perfectly matching DRE and the other two demonstrating a match in seven of eight nucleotides. These sequences were named DRE1 (-63 to -69), DRE2 (-378 to -385), and DRE3 (-1127 to -1134), respectively. Immunostaining of polytene chromosomes in third-instar larvae using anti-DREF sera detected a specific band in 82E2 of 3R chromosome, containing the rfc1 gene region. Band-mobility shift assays using Drosophila Kc cell nuclear extracts revealed that DREF binds to DRE1, -2, and -3 in vitro, and chromatin immunoprecipitation using anti-DREF IgG confirmed that this occurs in vivo. Luciferase transient expression assays in S2 cells further suggested that DREs in the rfc1 promoter are involved in transcriptional regulation of the gene. Moreover, rfc1 promoter activity was reduced by 38% in DREF double-stranded RNA-treated S2 cells. These results indicate that DREF positively regulates the rfc1 promoter.

Differences in levels of inflammatory mediators in meniscal and synovial tissue of patients with meniscal lesions.

BACKGROUND: Meniscal injuries are a risk factor for osteoarthritis (OA). While a mechanical pathway between meniscal injury and OA has been described, the biological effects of inflammation on this pathway have yet to be clarified. The aim of our study was to compare levels of specific inflammatory mediators, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and nerve growth factor (NGF), in injured and uninjured meniscal tissue and related knee joint synovium. METHODS: Tissue samples were obtained from 19 patients, 31.1 ± 13.6 years old, who underwent arthroscopic partial meniscectomy. For analysis, tissue samples were categorized into the following groups: injured meniscal site (IM), non-injured meniscal site (NIM), synovium 'nearest' the lesion (NS), and synovium from the opposite knee compartment, 'farthest' synovium (FS). Levels of inflammatory mediators were determined using enzyme-linked immunosorbent assay and between-group differences (IM and NIM; NS and FS) were evaluated using the Wilcoxon signed-rank test. The association between pre-operative pain score and the level of each inflammatory mediator was evaluated using Spearman's correlation. RESULTS: Higher levels of TNF-α and IL-6 were identified in the IM tissue, compared to NIM (p <0.05). IL-6 levels were also higher in the NS compared to the FS (p <0.05). There was no correlation between pre-operative pain score and level of each inflammatory mediator. CONCLUSIONS: Our outcomes confirm a local increase in inflammatory mediator levels, in both meniscal and synovial tissue, which could contribute to development of OA. Management of these biological effects of meniscal injury might be warranted.

Arthroscopic osseous Bankart repair for chronic recurrent traumatic anterior glenohumeral instability.

BACKGROUND: A chronic osseous Bankart lesion has traditionally been treated with soft-tissue repair and/or open bone-grafting for a large glenoid defect. We developed an arthroscopic method of osseous reconstruction of the glenoid without bone-grafting. The purpose of this study was to evaluate the postoperative outcomes of our technique for chronic recurrent traumatic anterior glenohumeral instability. METHODS: A consecutive series of forty-two shoulders in forty-one patients with chronic recurrent traumatic glenohumeral instability underwent an arthroscopic osseous Bankart repair. All shoulders were evaluated preoperatively with three-dimensionally reconstructed computed tomography, which confirmed an osseous fragment at the anteroinferior portion of the glenoid. The average bone loss in the glenoid was 24.8% (range, 11.4% to 38.6%), and the average fragment size was 9.2% (range, 2.1% to 20.9%) of the glenoid fossa. In all shoulders, a displaced osseous fragment, firmly attached to the labroligamentous complex, was separated from the glenoid neck before reduction and fixation in the optimal position with use of suture anchors. All patients were assessed with use of the scoring systems of Rowe et al. and the University of California at Los Angeles preoperatively and at the final evaluation. RESULTS: The mean duration of follow-up was thirty-four months. At that time, thirty-nine of the forty-two shoulders were rated as having a good or excellent result. The mean Rowe score improved from 33.6 points preoperatively to 94.3 points postoperatively (p < 0.01). The mean score on the University of California at Los Angeles system improved from 20.5 points preoperatively to 33.6 points at the final evaluation (p < 0.01). The average passive external rotation was 75 degrees with the arm at the side and 93 degrees with the arm at 90 degrees of abduction. Two patients had a reinjury. Eventually, thirty-five of thirty-seven patients who were active participants in sports returned to the sport they had played before the injury. CONCLUSIONS: Arthroscopic osseous Bankart repair with use of suture anchors yields a successful outcome even in shoulders with a chronic large glenoid defect.

Arthroscopic repair of glenoid fractures using suture anchors.

Anterior glenoid fractures associated with glenohumeral instability are normally treated with open fixation of the fragment. However, recent technical development enables this procedure to be performed under arthroscopic control using screws or even suture anchors if the fragment is small enough. We developed a unique method of stabilizing a larger fragment with suture anchors and the use of a clear imaging method of three-dimensional computed tomography (3D-CT) with the humeral head eliminated, preoperatively and postoperatively. In the present article, we report a detailed method of arthroscopic stabilization for a consecutive series of 8 patients, with an average of 27% bone loss (fragment size) against the lower part of the circular glenoid portion, using suture anchors.