Inhibitory effects of luteolin and its derivatives on osteoclast differentiation and differences in luteolin production by Capsicum annuum varieties.

Luteolin, an abundant flavonoid in the leaves of Capsicum annuum, has antioxidant activity and is, thus, a key chemical for promoting plant residue utilization, especially for the development of healthcare products. We assessed the inhibitory effect of luteolin and its glycosides on osteoclastic differentiation in human cells and found that the differentiation was effectively inhibited at noncytotoxic concentrations. We also screened 47 varieties of C. annuum for the accumulation of luteolin and apigenin to determine the prevalence of luteolin in diverse cultivars and identify varieties with high and/or selective luteolin production. The glycosides of luteolin and apigenin were found in all the tested varieties, with luteolin predominant over apigenin in most varieties. The identification and characterization of highly productive varieties of C. annuum is expected to be beneficial for the effective development of useful luteolin-based products from plant residues.

Incidence of and risk factors for deep vein thrombosis in patients undergoing osteotomies around the knee: comparative analysis of different osteotomy types.

PURPOSE: To examine the incidence of and risk factors for deep vein thrombosis (DVT) among different types of osteotomies around the knee. It was hypothesized that DVT would be detected at a substantial rate after the osteotomy, and there would be differences in the incidences among the different osteotomy procedures. METHODS: Consecutive patients who underwent knee osteotomies for varus osteoarthritis and met the inclusion criteria were included in the study. Ultrasonographic evaluation was performed to detect DVT on bilateral whole leg at 1 month before and 7 days after surgery. Statistical comparison of the demographic and clinical parameters between the patients with and without DVT as well as multivariate analysis using logistic regression was conducted to identify risk factors related to the incidence of postoperative DVT. RESULTS: The study subjects comprised 159 knees in 135 patients with medial opening wedge high tibial osteotomy (MOW-HTO), 93 knees in 78 patients with lateral closed wedge high tibial osteotomy (LCW-HTO), and 74 knees in 54 patients with double level osteotomy (DLO). In the postoperative evaluation, DVT was detected in 19 of 159 knees (11.9%) in MOW-HTO, 21 of 93 knees (22.6%) in LCW-HTO, and 5 of 74 knees (6.8%) in DLO. The incidence of DVT was significantly higher after LCW-HTO than after MOW-HTO and DLO (p < 0.01). DVT at a level above the knee was noted in one case after MOW-HTO, while DVT in the remaining cases developed at a level below the knee. No cases of symptomatic pulmonary embolism were encountered during the study period. Among the potential risk factors assessed for correlation with the incidence of DVT, LCW-HTO was identified as a significant risk factor (odds ratio: 2.54; 95% CI 1.334-4.836; p < 0.01). CONCLUSIONS: This study demonstrated that DVT occurred at a substantial rate (overall incidence of 13.8%) after osteotomy around the knee even with the use of prophylactic anticoagulant. Among the different osteotomy types, the DVT rate was significantly higher after LCW-HTO than after MOW-HTO and DLO. LEVEL OF EVIDENCE: Prospectively designed observational cohort study, Level III.

Hinge fracture in lateral closed-wedge distal femoral osteotomy in knees undergoing double-level osteotomy: assessment of postoperative change in rotational alignment using CT evaluation.

PURPOSE: The purpose of this study was to examine the radiological features of hinge fracture occurring at the distal medial femoral cortex in knees undergoing biplanar lateral closed-wedge distal femoral osteotomy (LCW-DFO) in double-level osteotomy (DLO) based on pre- and postoperative CT image analyses. It was hypothesised that medial hinge fractures in LCW-DFO would occur with a similar incidence to that in high tibial osteotomy, and its occurrence would affect the clinical/radiological outcomes and induce unintended change in alignment depending on the fracture type (direction of the fracture). METHODS: A consecutive series of 36 knees (31 patients) with primary varus osteoarthritis undergoing DLO comprised the study population. The mean age at surgery was 62.0 ± 5.9 years. Presence of hinge fracture was assessed on radiographs and CT images at 1 week. The fracture type was classified depending on the direction of the fracture line: crack propagation in line with the osteotomy (type 1) and fractures extending proximally (type 2) or distally (type 3) from the tip of the wedge. Computer-assisted assessments of bony limb alignment and bony geometry were conducted on a full-length weight-bearing radiograph and CT images using image analysis software. In addition, subjective clinical results were evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS). Radiological and clinical follow-up results at 1 and 2 years were compared to the preoperative data, while comparative analysis was made between the subjects with and without a hinge fracture. RESULTS: Postoperative image examinations revealed type 1 and 2 medial femoral hinge fractures in 4 and 7 knees, while no type 3 fracture was identified in the study population. Consequently, the overall incidence of the hinge fracture was 30.6% (11 of the 36 knees). Four of those 11 fractures (36.4%) could not be detected on plain radiographs. CT image analysis for three-dimensional bony geometry showed greater increase in internal rotation of the distal bony segment (increased femoral antetorsion by 9.5° on average) after surgery compared to the knees without a hinge fracture (P = 0.01). Clinical evaluation using the KOOS at 2 years showed no significant difference between the groups with and without hinge fractures. CONCLUSION: In LCW-DFO, medial femoral hinge fractures occurred in 30.6% of the cases. Knees with type 1 hinge fracture exhibited significantly greater increase in femoral antetorsion as compared to those without hinge fracture. In this case series, postoperative weight-bearing protocol was delayed for knees with hinge fracture. Consequently, surgical results were not affected by the occurrence of hinge fracture for up to 2 years. LEVEL OF EVIDENCE: IV (case series).

Return to sports rate after opening wedge high tibial osteotomy in athletes.

PURPOSE: We hypothesized that patient treated with OWHTO who participate in high-impact sports would attain satisfactory outcome. The purpose of this study was to examine the clinical and radiological outcomes in a consecutive series of opening-wedge high tibial osteotomy (OWHTO) in highly active patients. METHODS: Seventy-seven consecutive patients who underwent OWHTO with varus osteoarthritic knees were included in the study. The mean age of the study population was 56.1 years. All patients were followed for a minimum of 2 years. Clinical and radiological evaluations were performed at 12 and 24 months after surgery. The clinical results were evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the International Knee Documentation Committee (IKDC) Subjective Score. In regards to radiological assessment, the following parameters were measured in full-length weightbearing radiographs both pre- and postoperatively; mechanical tibiofemoral angle (mTFA), mechanical lateral distal femoral angle (mLDFA), and weight bearing line (WBL) ratio. RESULTS: Fifty-eight patients (75.3%) returned to the same high-impact sports activities as before surgery, with a mean time to return of 8.7 ± 2.7 months (6-14 months). In the clinical assessments, the IKDC subjective score and KOOS both improved from the mean preoperative scores of 38.4 and 217.4 points to the mean postoperative scores of 74.5 and 421.6 points, respectively. The mean pre-symptomatic Tegner activity scale was 5.3 ± 0.6 and significantly decreased to 4.8 ± 1.2 at 2 years postoperative (p < 0.05). In the radiological evaluation, the postoperative mTFA, mMPTA, and WBL ratio values averaged 1.3° ± 2.2° valgus, 90.7° ± 2.9°, and 51.6% ± 8.4°, respectively, at 24 months after surgery. CONCLUSIONS: Clinical outcomes based on postoperative patient-reported outcome measures and rate of return to high-impact sports activities were favorable after OWHTO in patients with knee OA who desired to continue sporting activities with the Tegner activity score of ≥ 5 points. LEVEL OF EVIDENCE: Retrospective case series, IV.

Successful treatment of degenerative medial meniscal tears in well-aligned knees with fibrin clot implantation.

PURPOSE: The purpose of this study was to examine the results of meniscal repair performed for symptomatic degenerative medial meniscal tears. METHODS: Twenty-four knees in 24 patients with symptomatic degenerative medial meniscal tears (mostly complex horizontal tears) who underwent isolated arthroscopic repair combined with autologous fibrin clot implantation were included in this study. The patients were followed up for a minimum of 2 years. The overall clinical outcome was evaluated using the Lysholm score, while the activity level was graded on the Tegner Activity Scale. The assessment of healing status at the repair site was based on clinical signs/symptoms and follow-up MRI examination results. In addition, the effects of the patient's clinical and radiological factors on healing of the repaired menisci were analyzed. RESULTS: The mean age of the study subjects was 47.0 ± 8.1 years with a mean follow-up period of 39.3 ± 11.6 months. The Lysholm score significantly improved after surgery (P < 0.01). During the follow-up period, meniscal repairs were deemed to have failed in 6 of the 24 knees (25%). In the analysis of factors influencing meniscal healing, varus deformity (% of mechanical axis < 30%) was identified in all knees in the repair failure group, and the presence of varus deformity was shown to be a significant risk factor correlated with repair failure, while other factors did not significantly influence the healing status. CONCLUSIONS: The short-term follow-up results showed that arthroscopic repair of degenerative medial meniscal tears combined with fibrin clot implantation attained clinical healing in 18 of 24 knees (75%) of patients, while 6 of the 24 knees (25%) of patients experienced clinical failure. The presence of varus deformity negatively affects the healing rate. In well-aligned knees, degenerative medial meniscal tears are successfully treated by isolated repair with fibrin clot implantation. LEVEL OF EVIDENCE: IV.

Green tea extracts reduce leukocyte cell-Derived chemotaxin 2 and selenoprotein P levels in the livers of C57BL/6J mice fed a high-fat diet.

Epidemiological studies suggest that green tea extracts (GTEs), including catechins such as epigallocatechin gallate and epicatechin gallate, have a beneficial effect on obesity, hyperglycemia, insulin resistance, endothelial dysfunction, and inflammation. Although several studies have shown that catechins directly modulate the cellular and molecular alterations in the liver tissue, the contributions of indirect mechanisms underlying these systemic effects of catechins remain unclear. In this study, we report that, in the C57BL/6J mouse liver, GTEs reduce high-fat diet-induced increases in the levels of hepatokines, liver-derived secretary proteins such as leukocyte cell-derived chemotaxin 2 and selenoprotein P production, which have been shown to induce systemic adverse effects, including several metabolic diseases. These findings suggest that the systemic effects of GTEs involve the regulation of hepatokine production as an indirect mechanism.

Antiviral Effect of Propylene Glycol against Envelope Viruses in Spray and Volatilized Forms.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is highly contagious and continues to spread worldwide. To avoid the spread of infection, it is important to control its transmission routes. However, as methods to prevent airborne infections are lacking, people are forced to take measures such as keeping distance from others or wearing masks. Here, we evaluate the antiviral activity of propylene glycol (PG), which is safe, odorless, and volatile. PG showed pronounced antiviral activity against the influenza virus (IAV) at concentrations above 55% in the liquid phase. Given its IAV inactivation mechanism, which involves increasing the fluidity of the viral membrane, PG is expected to have a broad effect on enveloped viruses. PG showed antiviral activity against SARS-CoV-2. We also developed a system to evaluate the antiviral effect of PG in spray and volatilized forms. PG was found to be effective against aerosol IAV in both forms; the effective PG concentration against IAV in the vapor phase was 87 ppmv (0.27 mg/L). These results demonstrate that PG is an effective means for viral inactivation in various situations for infection control. This technology is expected to control the spread of current and future infectious diseases capable of causing outbreaks and pandemics.

Persistent Hemarthrosis of the Knee after Arthroscopic Meniscal Repair.

Introduction: In this case report, we report a patient with complicated with persistent hemarthrosis following arthroscopic meniscal repair. Case Presentation. A 41-year-old male patient presented with persistent swelling of the knee 6 months after arthroscopic meniscal repair and partial meniscectomy performed for lateral discoid meniscal tear. The initial surgery was performed at another hospital. Four months after the surgery, swelling of the knee was noted when he resumed running. At his initial visit to our hospital, intra-articular blood accumulation was revealed via joint aspiration. A second arthroscopic examination performed 7 months after the initial procedure showed healing of the meniscal repair site and synovial proliferation. The suture materials identified during the arthroscopy were removed. Histological examination of the resected synovial tissue showed inflammatory cell infiltration and neovascularization. In addition, a multinucleated giant cell was identified in the superficial layer. After the second arthroscopic surgery, the hemarthrosis did not recur, and the patient was able to resume running without symptom one and a half years post-surgery. Conclusion: Bleeding from the proliferated synovia at or near the periphery of the lateral meniscus was thought to be the cause of the hemarthrosis as a rare complication following arthroscopic meniscal repair.

Efficacy of intravenous tranexamic acid administration in medial opening-wedge distal tibial tuberosity osteotomy (MOWDTO) for varus knee osteoarthritis: a randomized control trial.

BACKGROUND: This randomized controlled study was undertaken to investigate the efficacy of intravenous tranexamic acid (TXA) administration in reducing perioperative blood loss in patients undergoing medial opening-wedge distal tibial tuberosity osteotomy (MOWDTO). It was hypothesized that TXA would reduce perioperative blood loss in MOWDTO. METHODS: A total of 61 knees in 59 patients who underwent MOWDTO during the study period were randomly assigned to either of the groups with intravenous TXA administration (TXA group) or without TXA administration (control group). In the TXA group, patients received 1000 mg of TXA intravenously before skin incision and 6 h after the first dose. The primary outcomes was the volume of perioperative total blood loss which calculated using the blood volume and hemoglobin (Hb) drop. The Hb drop was calculated as the difference between preoperative Hb and postoperative Hb at days 1, 3, and 7. RESULTS: The perioperative total blood loss was significantly lower in the TXA group (543 ± 219 ml vs. 880 ± 268 ml, P < 0.001). The Hb drop was significantly lower at postoperative days 1, 3 and 7 in the TXA group than in the control group (day 1: 1.28 ± 0.68 g/dl vs. 1.91 ± 0.69 g/dl, P = 0.001; day 3: 1.54 ± 0.66 g/dl vs. 2.69 ± 1.00 g/dl, P < 0.001; day 7: 1.74 ± 0.66 g/dl vs. 2.83 ± 0.91 g/dl, P < 0.001). CONCLUSION: Intravenous TXA administration in MOWDTO could reduce the perioperative blood loss. Trial registration The study was approved by the institutional review board. (Registered on 26/02/2019 Registration Number 3136). Level of Evidence Level I, randomized controlled trial.

Screening and Validation of Odorants against Influenza A Virus Using Interpretable Regression Models.

Influenza is a respiratory infection caused by the influenza virus that is prevalent worldwide. One of the most contagious variants of influenza is influenza A virus (IAV), which usually spreads in closed spaces through aerosols. Preventive measures such as novel compounds are needed that can act on viral membranes and provide a safe environment against IAV infection. In this study, we screened compounds with common fragrances that are generally used to mask unpleasant odors but can also exhibit antiviral activity against a strain of IAV. Initially, a set of 188 structurally diverse odorants were collected, and their antiviral activity was measured in vapor phase against the IAV solution. Regression models were built for the prediction of antiviral activity using this set of odorants by taking into account their structural features along with vapor pressure and partition coefficient (n-octanol/water). The models were interpreted using a feature weighting approach and Shapley Additive exPlanations to rationalize the predictions as an additional validation for virtual screening. This model was used to screen odorants from an in-house odorant data set consisting of 2020 odorants, which were later evaluated using in vitro experiments. Out of 11 odorants proposed using the final model, 8 odorants were found to exhibit antiviral activity. The feature interpretation of screened odorants suggested that they contained hydrophilic substructures, such as hydroxyl group, which might contribute to denaturation of proteins on the surface of the virus. These odorants should be explored as a preventive measure in closed spaces to decrease the risk of infections of IAV.

Optimal additional support screw position for prevention of hinge fracture in biplanar closed wedge distal femoral osteotomy.

Background: The purpose of this study was to examine the biomechanical significance of supplemental fixation using a positional screw in prevention of the hinge fracture in lateral closed-wedge distal femoral osteotomy (LCW-DFO) by means of a three-dimensional finite element analysis. Methods: The three-dimensional numerical knee models with LCW-DFO were developed. To assess the mechanical efficacy of the positional screw and determine its optimal position and orientation, in total, 13 screwing methods were analyzed. In the first four methods, the screw was supported by the cortical bone only on the medial surface (mono-cortical). In the other 9 models, the screw was supported by both medial and lateral cortical bones (bi-cortical). Under 1000 N of vertical force and 5 Nm of rotational torques, the highest shear stress value around the medial hinge area was adopted as an analytical parameter. Results: In mono-cortical methods, with the cancellous bone support, all methods were able to reduce the highest stress value compared to the value without the screw, while the efficacy was rather inferior when the screw was in horizontal direction. Without the cancellous bone support, however, all methods were not able to reduce the stress value. In bi-cortical methods, with the cancellous bone support, almost all screw augmentation methods were able to reduce the stress value. When screwing from the medial to the lateral, it only gets worse when going extremely posterior. Without the cancellous bone support, all methods were able to reduce the stress value. Conclusion: The mechanical efficacy of the bi-cortical method was proven regardless of the quality of the local cancellous bone.

Effect of Cross-sectional Area of the Hamstring Tendon Autograft on Failure Rate or Clinical Outcomes After Double-Bundle ACL Reconstruction: Tendon Autograft.

Background: In previous studies examining the relationship between graft size and failure rate after anterior cruciate ligament reconstruction (ACLR), graft size was determined as diameter of the bone tunnel, and graft failure was defined as revision surgery. Consequently, the correlation between graft size and postoperative recurrent instability could not be assessed. Purpose: (1) To intraoperatively measure the cross-sectional area (CSA) of the hamstring tendon (HT) autograft and compare the CSA of the autograft with the bone tunnel and (2) to assess the effect of the graft CSA on postoperative graft failure among patients who underwent double-bundle ACLR. Study Design: Case-control study; Level of evidence, 3. Methods: The study included 129 patients who underwent double-bundle ACLR using an HT autograft (mean ± SD age, 16.7 ± 1.7 years; all with a Tegner activity level ≥6). All patients had a minimum follow-up of 2 years. During surgery, the graft CSA was measured using an area micrometer, combining the anteromedial (AM) and posterolateral (PL) grafts. The total area of the bone tunnel was defined as the combined CSAs of the AM and PL tunnels as calculated by the diameter of the drill. The relationship between the CSAs of the combined HT graft and the bone tunnel was statistically compared, as was the relationship between graft CSAs and graft failure, defined as reinjury, recurrent instability manifested as quantitative laxity measurement, or revision ACLR. Results: The CSAs of the midsubstance of the combined AM and PL graft significantly correlated with those of the bone tunnels (femoral side, R 2 = 0.334, P < .0001; tibial side, R 2 = 0.421, P < .0001). As for the relationship between the graft CSA and ACLR failure, there was no significant difference in the graft CSAs between the groups with and without graft failure in any of the failure criteria (P = .188). Conclusion: The graft CSA was not a predictor of early failure after double-bundle ACLR using an HT autograft in this patient population.

Preoperative Ahlbäck radiographic classification grade significantly influences clinical outcomes of double level osteotomy for osteoarthritic knees with severe varus deformity.

PURPOSE: The purpose of this study was to examine the relationship between preoperative Ahlbäck radiographic classification grade and the clinical outcomes of double level osteotomy (DLO) performed for osteoarthritic knees with severe varus deformity. METHODS: The study population comprised a consecutive series of 99 knees (68 patients) for which DLO was performed and follow-up results for a minimum of two years were available. The Ahlbäck radiographic classification system was used to determine the osteoarthritic grade. The following radiological parameters for alignment and bone geometry were measured: mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), joint-line convergence angle (JLCA), and mechanical tibiofemoral angle (mTFA). Clinical results were assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the International Knee Documentation Committee (IKDC) subjective score preoperatively and at 2 years after surgery. Difference between preoperative and postoperative measurements as well as relationship between Ahlbäck grade and radiological/clinical results were statistically assessed. RESULTS: The average age of the study participants was 60.9 ± 6.2 years and the mean follow-up period was 45.4 ± 15.2 months. Each of the radiological parameters exhibited preoperative abnormal values. Knees with Ahlbäck grade 3 and 4 osteoarthritis exhibited significantly greater JLCA and mTFA than grade 1 knees. Two years post-surgery, all radiological parameter values measured within a normal range. Clinical evaluation showed significant improvement in KOOS after surgery. Analysis of the relationship between Ahlbäck grade and clinical score showed that the 2-year postoperative KOOS scores in grade 3 and 4 osteoarthritic knees were significantly lower than grade 1 knees (with the mean 2-year KOOS scores of 350.0 ± 79.9, 317.9 ± 78.3, and 420.2 ± 42.9, respectively). CONCLUSIONS: While DLO may produce significant radiological and clinical improvement in knees with joint space obliteration, Ahlbäck grade 3 and 4 osteoarthritic knees associated with larger JLCA and mTFA showed less satisfactory clinical results compared to grade 1 knees. LEVEL OF EVIDENCE: IV case series.

Osteochondral autologous transplantation for large steroid-induced osteonecrosis lesion of the knee in a young patient yielding satisfactory results despite only partial coverage: a case report.

Osteochondral autologous transplantation (OAT) is one of the most common surgical options for osteochondral disorders of the knee. In cases where OAT is performed for steroid-induced osteonecrosis, there are several problems potentially affecting the surgical outcomes such as large chondral damage area and compromised host bone. In addition, steroid administration for a long period of time may lead to extensive lesion, which poses difficulty in obtaining sufficient donor tissue. Those factors affect the prognosis of steroid-induced osteonecrosis resulting in inferior treatment outcomes. We present a young female with a large steroid-induced osteonecrosis lesion repaired only with two osteochondral plugs harvested from the healthy area. The reported case indicates that only partial osteochondral grafting limiting to the weight-bearing area may yield satisfactory outcome when OAT is performed for large steroid-induced osteonecrosis of the knee.

Evaluation of the Anterior Cruciate Ligament Injury Risk During a Jump-Landing Task Using 3-Dimensional Kinematic Analysis Versus the Landing Error Scoring System.

Background: The Landing Error Scoring System (LESS) has been utilized on the field or in the clinic to identify patients with an increased risk for anterior cruciate ligament (ACL) injuries; however, its validity and efficacy have not been fully confirmed. Purpose: To assess the efficacy of the LESS in identifying the ACL injury risk by examining the correlation between the LESS score and motion patterns on 3-dimensional kinematic analysis. Study Design: Controlled laboratory study. Methods: The jump-landing motion was analyzed for 16 female basketball or badminton players who volunteered to participate in the study. All study participants were aged 19 or 20 years. The sequence of motion was evaluated with the LESS, while kinematic data were simultaneously acquired with a 3-dimensional motion analysis system utilizing the point cluster method. The correlation between the LESS score and knee kinematics was statistically analyzed. Results: When a LESS score ≥6 was defined to be a risk factor for ACL injuries, 7 of the 16 participants (43.8%) were found to exhibit risky motion patterns. Significant correlations were noted between the LESS score and knee valgus (r = 0.87; P < .0001) and internal tibial rotation (r = 0.57; P = .02) at landing. By contrast, a substantial variability was present in knee flexion, showing no correlation with the LESS score. Conclusion: Significant correlations were found between the LESS score and knee valgus and internal tibial rotation during a jump-landing task. Clinical Relevance: The LESS can be regarded as an effective measure to identify risky motion patterns that may increase the likelihood of ACL injuries.

Increased posterior slope and coronal inclination of the tibial joint line after opening wedge high tibial osteotomy may induce mucoid degeneration of the anterior cruciate ligament: A case report.

A mucoid degeneration of the anterior cruciate ligament (ACL) is regarded as a degenerative change in the ligament, which is clinically presented with pain on full extension or flexion. Regarding morphological factors, it has been reported that an increased posterior tibial slope can be a cause of ACL degeneration secondary to the repetitive overload. The increase in the tibial slope is among the potential problems after medial opening wedge high tibial osteotomy (OWHTO). Especially, a large wedge opening in the correction of severe varus deformity may lead to non-physiologic bony geometry including an increased posterior tibial slope and medial tibial coronal inclination. We present a 69-year-old man had undergone OWHTO with a wedge correction angle of 12.4° for Kellegren-Lawrence grade 2, medial uni-compartmental osteoarthritis of the left knee. Evaluations of the postoperative radiographs revealed postoperative changes in radiological parameters with mechanical medial proximal tibial axis (mMPTA) from 81.3° to 94.3°, and posterior tibial slope (PTS) from 12.2° to 15.8°. Physical examination at 3 years after surgery revealed a knee extension of 0° and a limitation to knee flexion with maximum flexion of 110° and, and severe knee pain was elicited when the knee approached deep flexion. MRI revealed an increased signal intensity along the substance of the ACL and multiple cystic lesions indicative of a ganglion formation around the proximal ACL attachment site extending into the adjacent lateral femoral condyle. Microscopic examination of the resected tissues showed mucoid degeneration and mucous cysts indicative of ganglions formation within the ligament substance and the bone at the attachment site. The reported case illustrates the importance of being aware of this potential complication following OWHTO.

Investigation of the Oral Retention of Tea Catechins in Humans: An Exploratory Interventional Study.

Green tea catechin ingestion or gargling exhibit anti-viral activity against upper respiratory infection. We hypothesized that retention in the oral cavity could improve the anti-viral effects of catechins. The present study investigated the oral retention of catechins in humans and the effect of catechin beverage viscosity on oral retention. Two intervention studies with different test beverages, beverage-C (40 mL, containing 73.4 mg of catechins) and beverage-XT (40 mL, beverage-C containing 100 mg xanthan gum) were conducted in 20 healthy volunteers (mean age 38.7 years). Catechin concentrations were measured in buccal mucosa samples collected at 10 min, 40 min, and 60 min after ingesting test beverages, and the catechin variability of the tissue after intake was compared between test beverages. As a result, the mean (SEM) concentrations of EGCG were 99.9 (27.2), 58.2 (16.6), and 22.3 (5.7) ng/mg-mucosa at 10, 40, and 60 min, respectively, after ingestion of beverage-XT. Similarly, the catechin concentrations were 86.1 (20.3), 32.2 (5.3), and 27.8 (5.9) ng/mg-mucosa after ingestion of beverage-C. The total retention volume over 60 min tended to be slightly higher after ingestion of beverage-XT, though the difference was not statistically significant. Additional studies are needed to confirm the effect of xanthan gum on improving oral retention of catechins.

Mucoid degeneration of the posterior cruciate ligament in a college soccer player: a case report.

BACKGROUND: To the best of our knowledge, arthroscopic treatment for symptomatic mucoid degeneration of the posterior cruciate ligament in young athletes has not been reported before. CASE PRESENTATION: An 18-year-old Asian male college soccer player presented with a 3-month history of right knee pain without episodes of trauma. Despite conservative treatment over the preceding 3 months, his symptoms persisted. Physical examination of the right knee revealed full range of motion, though posterior knee pain was induced when the knee approached full flexion. On ligament examination, posterior sagging and Lachman test were negative, and no clinical finding indicative of ligament insufficiency was noted. Magnetic resonance imaging showed a diffusely thickened posterior cruciate ligament with increased signal intensity on the T2-weighted sequence. A few intact fibers were observed with continuous margin from origin to insertion. Based on the patient's history and the magnetic resonance imaging findings, we suspected mucoid degeneration of the posterior cruciate ligament as the cause of the patient's symptoms. Since conservative treatment had failed to relieve the symptoms, arthroscopic treatment was indicated. Arthroscopic examination revealed yellowish crumbly tissues along the thickened posterior cruciate ligament. Tension and bulk of the posterior cruciate ligament were well preserved. Curettage of degenerative tissue and decompression of the posterior cruciate ligament resulted in symptom relief without instability of the knee joint. The patient returned to play at 3 months. At 12 months, postoperative magnetic resonance imaging showed no evidence of recurrence and indicated that the remaining posterior cruciate ligament was thicker than before the surgery. At 2 years follow-up, the patient remained asymptomatic and could play soccer at the same level as before the onset of pain. CONCLUSIONS: Arthroscopic decompression of the posterior cruciate ligament may relieve knee pain and facilitate early return to play with good functional results.

Double-level osteotomy for severe varus osteoarthritic knees can prevent change in leg length and restore physiological joint geometry.

BACKGROUND: It is unclear whether double-level osteotomy (DLO) combining closed-wedge osteotomy in the distal femur and open-wedge osteotomy in the proximal tibia deformity can prevent change in leg length and excessive coronal inclination of the tibial articular surface in surgical correction of the severe varus knee. The purpose of this study was to examine the postoperative change in leg length as well as radiological and clinical outcomes following DLO compared with the results obtained from knees undergoing isolated open-wedge high tibial osteotomy (OW-HTO). METHODS: In cases of severe varus knee deformity (hip-knee-ankle angle (HKA) > 10°) 29 patients undergoing DLO and 35 patients undergoing OW-HTO were included. If the predicted mechanical medial proximal tibial angle (mMPTA) was 95° or greater or the wedge size was 15 mm or greater in the surgical simulation, then DLO was considered as the surgical of option. In cases where these criteria were not met, OW-HTO was selected. All patients were followed up for a minimum of 2 years. RESULTS: The changes in the length of the whole leg in the DLO and OW-HTO groups averaged 2.3 ±â€¯4.8 mm and 9.3 ±â€¯7.2 mm, respectively (P < 0.001). mMPTA of more than 95° was found in no knee in the DLO group. CONCLUSIONS: This study showed that DLO could avoid leg length change and non-physiologic joint lines when performed in patients with varus HKA > 10°, and the predicted mMPTA was 95° or greater or the wedge size was 15 mm or greater in the surgical simulation.

Cartilage repair examined by second-look arthroscopy following double-level osteotomy performed for osteoarthritic knees with severe varus deformity.

BACKGROUND: The purpose of this study was to examine the status of cartilage repair by second-look arthroscopy following double-level osteotomy (DLO) performed for osteoarthritic knees with severe varus deformity. METHODS: Forty-seven consecutive knees in 33 patients who underwent DLO were included in the study. The surgical technique used was a minimally invasive DLO procedure combining lateral closed-wedge distal femoral and medial open-wedge high tibial osteotomies. In the second-look arthroscopic evaluation, the following grading system proposed by Koshino was adopted: Stage A, no repair; stage B, pink fibrous tissue with or without partial coverage with white fibrocartilage; and stage C, total coverage with cartilage. The findings corresponding to stage B or C were considered as repaired. Arthroscopic assessment was performed for each compartment. Clinical outcomes were evaluated using the validated outcome measures. RESULTS: The mean age at surgery was 62.8 ± 6.2 years (range: 45-75 years), and the mean time period from DLO to second-look arthroscopy was 17.1 ± 5.0 months (range: 12-33 months). Cartilage repair to some extent was identified in over 90% of the medial femoral and tibial condyles, and 12.8% of the patellar facet. As for clinical scores, both Knee Injury and Osteoarthritis Outcome Score (KOOS) and the International Knee Documentation Committee Subjective Knee Form (IKDC) subjective scores significantly improved after surgery (P < 0.01). CONCLUSIONS: Evaluation of the present study subjects showed that DLO could induce cartilage repair in the majority of the affected femoral and tibial articular surfaces with significant clinical improvement. In the patellar facet, however, cartilage repair could be identified in only 12.8% of cases.