Effect of inside-out meniscal repair on meniscal dimension in meniscal tear patients.

Background: It remains controversial whether meniscal repair causes meniscal extrusion. This study aimed to investigate the effect of inside-out meniscal repair on meniscal dimensions in patients with meniscal tear of the mid-body-posterior horn. Methods: This retrospective study included 75 patients who underwent meniscal repair followed by MRI within 2 weeks after surgery between 2020 and 2022. Patients with a discoid lateral meniscus, pull-out repair, concomitant osteotomy, all-inside repair only, and revision surgery were excluded. Thirty-three meniscal tear treated using an inside-out arthroscopic repair technique were included in the lateral meniscus (LM, n = 19) and medial meniscus (MM, n = 14) tear groups. Thirty-six participants with intact meniscus were included as controls. Meniscal extrusion and posterior shift were measured on coronal and sagittal MRI pre-operatively and within 2 weeks postoperatively. Results: Preoperative coronal extrusion was significantly greater in the LM tear group than in the control group (P = 0.001). Coronal extrusion and posterior shift were significantly smaller postoperatively than preoperatively in the LM tear group (P < 0.001 and, P = 0.008, respectively). Pre- and postoperative coronal extrusion in the MM tear group were not significantly different (P = 0.291). Postoperative coronal extrusion in both LM and MM tear groups were not significantly correlated with the number of sutures required for repair (LM: P = 0.765, R = -0.076, MM: P = 0.1, R = 0.497). Conclusions: The torn meniscus of the mid-body - posterior horn before surgery was extruded and shifted posteriorly in both LM and MM tears, and repair using an inside-out arthroscopic technique was effective in reducing meniscal extrusion and posteriors shift in the LM tear immediately after surgery.

First malaria in pregnancy followed in Philippine real-world setting: proof-of-concept of probabilistic record linkage between disease surveillance and hospital administrative data.

BACKGROUND: Although the Philippines targets malaria elimination by 2030, it remains to be a disease that causes considerable morbidity in provinces that report malaria. Pregnant women residing in endemic areas are a vulnerable population, because in addition to the risk of developing severe malaria, their pregnancy is not followed through, and the outcome of their pregnancy is unknown. This study determined the utility of real-world data integrated with disease surveillance data set as real-world evidence of pregnancy and delivery outcomes in areas endemic for malaria in the Philippines. METHODS: For the period of 2015 to 2019, electronic data sets of malaria surveillance data and Ospital ng Palawan hospital admission log of pregnant women residing in the four selected barangays of Rizal, Palawan were merged using probabilistic linkage. The source data for record linkage were first and last names, birth date, and address as the mutual variable. The data used for characteristics of the pregnant women from the hospital data set were admission date, discharge date, admitting and final diagnosis and body weight on admission. From the malaria surveillance data these were date of consultation, and malaria parasite species. The Levenshtein distance formula was used for a fuzzy string-matching algorithm. Chi-square test, and Mann-Whitney U test were used to compare the means of the two data sets. RESULTS: The prevalence of pregnant women admitted to the tertiary referral hospital, Ospital ng Palawan, was estimated to be 8.34/100 overall, and 11.64/100 from the four study barangays; that of malaria during pregnancy patients was 3.45/100 and 2.64/100, respectively. There was only one true-positive matched case from 238 women from the hospital and 54 women from the surveillance data sets. The overall Levenshstein score was 97.7; for non-matched cases, the mean overall score was 36.6 (35.6-37.7). The matched case was a minor who was hospitalized for severe malaria. The outcome of her pregnancy was detected from neither data set but from village-based records. CONCLUSIONS: This proof-of-concept study demonstrated that probabilistic record linkage could match real-world data in the Philippines with further validation required. The study underscored the need for more integrated and comprehensive database to monitor disease intervention impact on pregnancy and its outcome in the Philippines.

Quadriceps Tendon With Bone Autograft Has Better Stability and Magnetic Resonance Imaging Maturation Than Hamstring Tendon Autograft After Anterior Cruciate Ligament Reconstruction in Patients With Knee Hyperextension.

PURPOSE: To compare the clinical outcomes of anterior cruciate ligament (ACL) reconstruction between methods using quadriceps tendon with bone (QTB) and hamstring tendon (HT) in patients with hyperextension of the knee. METHODS: The medical records of patients with knee hyperextension greater than 8° who underwent arthroscopic ACL reconstruction between October 2010 and October 2020 with follow-up for at least 2 years (median, 3 years; interquartile range [IQR], 2.0-4.6 years) were retrospectively reviewed. Side-to-side difference in anterior translation, pivot-shift test grade, Lysholm score, and graft intensity using the Howell grade on magnetic resonance imaging at final follow-up were compared between the QTB and HT groups. RESULTS: The HT and QTB groups consisted of 42 patients and 21 patients, respectively. The overall mean age was 21.5 years (range, 14-48 years), and the median Tegner Activity Scale score was 6 (range, 3-9). Postoperatively, the median side-to-side difference in anterior translation was 1.75 mm (IQR, 1-3 mm) in the HT group and 1.0 mm (IQR, 0-1.75 mm) in the QTB group (P = .01). Pivot-shift testing showed grade 0 in 74.7%, grade 1 in 18.7%, and grade 2 in 6.6% of patients in the HT group and grade 0 in 85.7% and grade 1 in 14.3% of those in the QTB group (P = .03). The median postoperative Lysholm score was 99 in both groups. Graft signal intensity showed a significant between-group difference: grade I in 52%, grade II in 36%, and grade III in 12% of patients in the HT group versus grade I in 85.7%, grade II in 9.5%, and grade III in 4.8% of those in the QTB group (P = .03). CONCLUSIONS: In patients who underwent ACL reconstruction for hyperextension of the knee, QTB yielded better clinical outcomes than HT with respect to anterior stability, rotational stability, and graft signal intensity on median 2-year follow-up magnetic resonance imaging. LEVEL OF EVIDENCE: Level III, retrospective case-control study.

Age-based comparison of meniscal dimensions between an asymptomatic complete discoid lateral meniscus and normal meniscus: MRI evaluation.

INTRODUCTION: This study aimed to evaluate the meniscal size of asymptomatic discoid lateral meniscus (DLM) and compare it with that of normal lateral meniscus (LM) and to compare changes in meniscal dimensions with age among patients with asymptomatic DLM and those with normal LM using magnetic resonance imaging (MRI). MATERIALS AND METHODS: We retrospectively reviewed the medical records, including MRI data, of patients with asymptomatic DLM (DLM group) or normal LM (control group). Width and extrusion of both DLM and normal LM and tibial length were measured and compared using mid-coronal and mid-sagittal MR images. Meniscal size and sagittal and coronal meniscal ratio according to age, as well as differences between DLM and normal menisci, were also evaluated. RESULTS: Thirty-four knees were included in the DLM group, whereas the control group comprised of 50 patients. The DLM group showed significantly less meniscal extrusion, greater coronal width, posterior capsule distance, sagittal meniscal length, and sagittal meniscal ratio than the control group (DLM: 0.1 ± 0.3 mm, 23.3 ± 2.2 mm, 5.4 ± 2.4 mm, 25.1 ± 2.8 mm, 61 ± 6%, and control: 0.4 ± 0.4 mm, 9.5 ± 2.3 mm, 2.5 ± 1.2 mm, 30.2 ± 2.6 mm, 71 ± 4%, respectively). The coronal meniscal ratio decreased with age in both the control (p = 0.001) and DLM (p = 0.037) groups. The sagittal meniscal ratio (p = 0.001) and minimum height (p = 0.04) decreased and the anterior capsule distance (p = 0.035), posterior capsule distance (p = 0.026), and entire sagittal length (p = 0.005) increased with age in the DLM group, while the distance between the meniscal inner margins (p = 0.019) increased with age in the control group. CONCLUSIONS: The meniscal ratio in the sagittal plane of the DLM group was significantly lower than that of the control group. The sagittal meniscal ratio of asymptomatic DLM decreased with age, indicating that the size of asymptomatic DLM does not change with age. LEVEL OF EVIDENCE: III: Retrospective comparative study.

Male elite soccer players have a higher incidence of accessory ossicles in the foot and ankle.

PURPOSE: Accessory ossicles are caused by the failure of the fusion of secondary ossification centres and are more likely to occur due to heavy loading during the growth period or improper treatment after injury. This study aimed to investigate the incidence of foot and ankle accessory ossicles in male professional soccer players. METHODS: This study included male professional soccer players who underwent medical checkups at our hospital between 2017 and 2023 as the soccer group. Medical checkups included radiographs of bilateral anteroposterior and oblique foot, as well as bilateral anteroposterior and lateral ankle. Male patients age-matched with the soccer group who visited our hospital undergoing anteroposterior and oblique foot or anteroposterior and lateral ankle radiography were included in the control group. The incidence of accessory ossicles was investigated and compared between the soccer and control groups. RESULTS: In this study, 276 ankles and 276 feet, as well as 121 ankles and 79 feet, were included in the soccer and control groups, respectively. The incidence of accessory ossicles in the soccer and control groups was as follows: accessory navicular 35.9%, 24% (P = .049), os peroneum 8.0%, 2.5% (P = .09); os supranaviculare 7.6%, 1.3% (P = .039); os infranaviculare 1.4%, 1.3% (P = .090); os calcaneus secundarius 4.3%, 0% (P = .059); os vesalianum 0%, 0%; os subfiblare 12.7%, 2.5% (P < .001); os subtibiale 18.1%, 2.5% (P = .001); and os trigonum 89%, 24% (P < .001). CONCLUSIONS: Male professional soccer players had a higher incidence of accessory navicular, os supranaviculare, os subfiblare, os subtibiale, and os trigonum.

Comparative analysis of discoid lateral meniscus size: a distinction between symptomatic and asymptomatic cases.

PURPOSE: This study evaluated the differences in meniscal sizes and occupancy between symptomatic and asymptomatic patients diagnosed with discoid lateral meniscus (DLM) using magnetic resonance imaging (MRI) to understand how these variations relate to the presence of symptoms and the patients' age. METHODS: A retrospective review of 98 patients with DLM was conducted, excluding those with meniscal displacement. Both the width and extrusion of DLM and the percentage of the meniscus to the tibia were measured using mid-coronal and mid-sagittal MRI and compared between symptomatic and asymptomatic DLM groups. The relationships among each parameter, meniscal size, and patient age were evaluated. Symptomatic cases were divided into those with and without horizontal tears on MRI to compare the differences in meniscal morphology. RESULTS: A total of 92 knees from 74 patients were included. Sixty-one knees required surgical intervention for symptomatic DLM, while 31 were asymptomatic and included the contralateral side of symptomatic knees. The symptomatic group exhibited larger morphological variations than the asymptomatic group. Moreover, the sagittal meniscal ratio reduced with age in the asymptomatic group (r = - 0.54, p = 0.002) but remained constant in the symptomatic group. The symptomatic cases with horizontal tears demonstrated larger meniscal dimensions and smaller posterior capsule distances than those without tears. CONCLUSION: Symptomatic patients with DLM had larger knee morphological changes than asymptomatic ones. Age affected the meniscal occupancy in the sagittal plane only in asymptomatic patients. LEVEL OF EVIDENCE: III.

Simultaneous Control of Venous Reservoir Level and Arterial Flow Rate in Cardiopulmonary Bypass With a Centrifugal Pump.

Cardiopulmonary bypass (CPB) is an indispensable technique in cardiac surgery, providing the ability to temporarily replace cardiopulmonary function and create a bloodless surgical field. Traditionally, the operation of CPB systems has depended on the expertise and experience of skilled perfusionists. In particular, simultaneously controlling the arterial and venous occluders is difficult because the blood flow rate and reservoir level both change, and failure may put the patient's life at risk. This study proposes an automatic control system with a two-degree-of-freedom model matching controller nested in an I-PD feedback controller to simultaneously regulate the blood flow rate and reservoir level. CPB operations were performed using glycerin and bovine blood as perfusate to simulate flow-up and flow-down phases. The results confirmed that the arterial blood flow rate followed the manually adjusted target venous blood flow rate, with an error of less than 5.32%, and the reservoir level was maintained, with an error of less than 3.44% from the target reservoir level. Then, we assessed the robustness of the control system against disturbances caused by venting/suction of blood. The resulting flow rate error was 5.95%, and the reservoir level error 2.02%. The accuracy of the proposed system is clinically satisfactory and within the allowable error range of 10% or less, meeting the standards set for perfusionists. Moreover, because of the system's simple configuration, consisting of a camera and notebook PC, the system can easily be integrated with general CPB equipment. This practical design enables seamless adoption in clinical settings. With these advancements, the proposed system represents a significant step towards the automation of CPB.

Saucerization of complete discoid lateral meniscus is associated with change of morphology of the lateral femoral condyle and tibial plateau.

PURPOSE: To determine the effect of saucerization surgery on knee joint morphology associated with a complete discoid lateral meniscus (DLM) using magnetic resonance (MR) imaging. METHODS: This retrospective study included cases had undergone saucerization surgery for symptomatic DLM between 2007 and 2022. All cases were divided into two by age group: < 12 (U13) and > 13 (O13). The cases in the match group were randomly selected from preoperative cases in the O13 group matched with the age at the final follow-up (F/U) of cases in the U13 group. The following morphological parameters were evaluated using MR images preoperatively and at the final postoperative F/U in each group: anterior obliquity of the lateral tibial plateau (AOLTP), posterior obliquity of the lateral tibial plateau (POLTP), and the lowest point of the lateral femoral condyle (LPLFC). Each parameter was compared between the U13 preoperative (pre-OP) group and the O13 pre-OP group, the preoperative and final follow-up in the U13, and the U13 group at the final F/U and the match group preoperatively. RESULTS: A total of 77 cases were evaluated. 31 cases were in the U13 pre-OP group and 46 were in the O13 pre-OP group. With a minimal F/U of 2 years, 27 cases in the U13 group and 36 in the O13 group were included. The mean F/U period was 4.6 years in the U13 group and 3.2 years in the O13 group. 32 cases were included in the match group. In the match group, the inclination of the POLTP was significantly larger (P = 0.042) and the LPLFC was more lateral (P = 0.0034) than at the final F/U in the U13 group. CONCLUSIONS: Saucerization surgery for DLM in juvenile patients can prevent progression to the characteristic bone morphology DLM. These results could help the surgeon making the decision when the surgery would be performed for symptomatic DLM patients. LEVEL OF EVIDENCE: Retrospective comparative study; level of evidence, 3.

Evaluation of the knee joint morphology associated with a complete discoid lateral meniscus, as a function of skeletal maturity, using magnetic resonance imaging.

INTRODUCTION: A discoid lateral meniscus (DLM) is associated with increased risk for meniscal tears and progression of knee joint osteoarthritis. Our aim was to differentiate knee joint morphology between patients with and without a DLM, as a function of skeletal maturity, using magnetic (MR) imaging. MATERIALS AND METHODS: This was a retrospective analysis of MR images of the knee for 110 patients, 6-49 years of age. Of these, 62 were in the open physis group (38 with a DLM) and 48 in the closed physis group (23 with a DLM). The following morphological parameters were measured: anterior obliquity of the lateral tibial plateau (AOLTP), posterior obliquity of the lateral tibial plateau (POLTP), the lowest point of the lateral femoral condyle (LPLFC), and the posterior lateral condylar angle (PLCA). RESULTS: Regardless of skeletal maturity, a DLM was associated with a greater inclination of the POLTP, lateralization of the LPLFC, and smaller PLCA (p < 0.001 for all compared to that of the control group). In the DLM group, the inclination of the AOLTP and the POLTP were significantly smaller (p < 0.001) and the LPLFC was more lateral (p < 0.001) in the closed physis group than in the open physis group. In the control group, the inclination of the POLTP was larger (p < 0.001) and the PLCA smaller (p = 0.019) in the open than in the closed physis group. CONCLUSIONS: We identified a characteristic knee morphology among patients with a complete DLM using MR imaging, which was observed before physeal closure and persisted after skeletal maturity was attained. We also noted lateralization of the LPLFC in the presence of a DLM, with an increase in lateralization with skeletal maturation. LEVEL OF EVIDENCE: Case-control study, III.

Bone Marrow-Derived Fibrin Clots Stimulate Healing of a Knee Meniscal Defect in a Rabbit Model.

PURPOSE: To determine the in vivo effectiveness of bone marrow aspirate-derived (BMA) fibrin clots for avascular meniscal defect healing in a rabbit model. METHODS: In 42 Japanese white rabbits, a 2.0-mm cylindrical defect was introduced into the avascular zone of the anterior part of the medial meniscus in the bilateral knees. The rabbits were grouped according to implantation of a BMA fibrin clot (BMA group) or a peripheral blood (PB)-derived clot (PB group) into the defect and nonimplantation (control group). Macroscopic and histological assessments were performed using a scoring system at 4 and 12 weeks after surgery. At 12 weeks after surgery, compressive stress was analyzed biomechanically. RESULTS: The meniscal score in the BMA group (12.1) was greater than that in the PB group (5.5; P = .031) and control group (4.4; P = .013) at 4 weeks. The meniscal score in the BMA group (13.1) was greater than that in the control group (6.4; BMA = 13.1; P = .0046) at 12 weeks. In the biomechanical analysis, the BMA group demonstrated significantly higher compressive strength than the PB group (6.6 MPa) (BMA = 15.4 MPa; P = .0201) and control group (3.6 MPa; BMA = 15.4 MPa; P = .007). CONCLUSIONS: Implantation of BMA fibrin clots into the meniscal defect of the avascular zone in a rabbit model improved the meniscal score at 4 weeks and strengthened the reparative meniscal tissue at 12 weeks compared with the implantation of PB fibrin clots. CLINICAL RELEVANCE: Healing in the avascular zone of the meniscus can be problematic. Approaches to improving this healing response have had variable results. This study provides additional information that may help improve the outcomes in patients with these injuries.

Intrameniscal degeneration and meniscotibial ligament loosening are associated factors with meniscal extrusion of symptomatic discoid lateral meniscus.

PURPOSE: This study aimed to compare the amount of extrusion of the discoid lateral meniscus (DLM), which was symptomatic and required surgery, with normal meniscuses and asymptomatic DLMs and examine factors associated with the extrusion of symptomatic DLM. METHODS: Medical records of participants with DLM or normal lateral meniscus (LM) were retrospectively reviewed using magnetic resonance imaging (MRI). DLM cases were divided into symptomatic and asymptomatic groups. The midbody meniscal extrusion was measured using mid-coronal MRI. The association between meniscal extrusion and MRI findings, including the meniscofemoral ligament, meniscotibial ligament (MTL), intrameniscal signal intensity of the peripheral rim, meniscal shift, and skeletal maturity, was evaluated. RESULTS: Eighty-six knees with DLM (63 symptomatic) were included. The control group included 31 patients. The symptomatic group showed significantly greater meniscal extrusion (mean ± standard deviation symptomatic DLM: 1.0 ± 1.1 mm, asymptomatic DLM: 0.1 ± 0.4 mm, and normal LM: 0.3 ± 0.6 mm, P < 0.001) and had a significantly higher incidence of MTL loosening (P = 0.02) and intrameniscal signal (P < 0.001) than the other two groups. In the symptomatic group, multivariable linear regression analysis showed that MTL loosening [ß = 1.45, 95% confidence interval (CI) 1.03-1.86, P < 0.001] and intrameniscal signal (ß = 0.49, 95% CI 0.09-0.90, P = 0.002) were independent associated factors. CONCLUSIONS: LM extrusion was significantly more common in patients with symptomatic DLM than in those with asymptomatic DLM or a normal LM. MTL loosening and intrameniscal high-signal intensity on MRI were independently associated with meniscal extrusion. These findings help explain the pathogenesis and diagnosis of symptomatic DLM. LEVEL OF EVIDENCE: III.

The Potential of Using an Autogenous Tendon Graft by Injecting Bone Marrow Aspirate in a Rabbit Meniscectomy Model.

Bone marrow aspirate (BMA) is an excellent source of cells and growth factors and has been used successfully for bone, cartilage, and soft-tissue healing. This study aimed to investigate the histological and biomechanical properties of autogenous tendon graft by injecting BMA and its protective effect against degenerative changes in a rabbit model of meniscal defects. Adult white rabbits were divided into untreated, tendon, and tendon + BMA groups, and meniscal defects were created in the knees. The tendon graft and articular cartilage status were evaluated by macroscopic and histological analysis at 4, 12, and 24 weeks postoperatively among the three groups. The tendon graft in the tendon and tendon + BMA groups were used for biomechanical evaluation at 4, 12, and 24 weeks postoperatively. The meniscal covering ratio in the tendon + BMA group was better than that in the tendon and untreated groups at 12 and 24 weeks postoperatively. The matrix around the central portion of cells in the tendon + BMA group was positively stained by safranin O and toluidine blue staining with metachromasia at 24 weeks. The histological score of the tendon graft in the tendon + BMA group was significantly higher than that in the untreated and tendon groups at 12 and 24 weeks postoperatively. In the tendon + BMA group, cartilage erosion was not shown at 4 weeks, developed slowly, and was better preserved at 12 and 24 weeks compared to the untreated and tendon groups. Histological scores for the articular cartilage were significantly better in the tendon + BMA group at 24 weeks. The compressive stress on the tendon graft in the tendon + BMA group was significantly higher than that in the tendon group at 12 weeks postoperatively. Transplantation of autogenous tendon grafts by injecting BMA improved the histologic score of the regenerated meniscal tissue and was more effective than the tendon and untreated group for preventing cartilage degeneration in a rabbit model of massive meniscal defects.

Public Interest and Accessibility of Telehealth in Japan: Retrospective Analysis Using Google Trends and National Surveillance.

BACKGROUND: Recently, the use of telehealth for patient treatment under the COVID-19 pandemic has gained interest around the world. As a result, many infodemiology and infoveillance studies using web-based sources such as Google Trends were reported, focusing on the first wave of the COVID-19 pandemic. Although public interest in telehealth has increased in many countries during this time, the long-term interest has remained unknown among people living in Japan. Moreover, various mobile telehealth apps have become available for remote areas in the COVID-19 era, but the accessibility of these apps in epidemic versus nonepidemic regions is unknown. OBJECTIVE: We aimed to investigate the public interest in telehealth during the first pandemic wave and after the wave in the first part of this study, and the accessibility of medical institutions using telehealth in the epidemic and nonepidemic regions, in the second part. METHODS: We examined and compared the first wave and after the wave with regards to severe cases, number of deaths, relative search volume (RSV) of telehealth and COVID-19, and the correlation between RSV and COVID-19 cases, using open sources such as Google Trends and the Japanese Ministry of Health, Labour and Welfare (JMHLW) data. The weekly mean and the week-over-week change rates of RSV and COVID-19 cases were used to examine the correlation coefficients. In the second part, the prevalence of COVID-19 cases, severe cases, number of deaths, and the telehealth accessibility rate were compared between epidemic regions and nonepidemic regions, using the JMHLW data. We also examined the regional correlation between telehealth accessibility and the prevalence of COVID-19 cases. RESULTS: Among the 83 weeks with 5 pandemic waves, the overall mean for the RSV of telehealth and COVID-19 was 11.3 (95% CI 8.0-14.6) and 30.7 (95% CI 27.2-34.2), respectively. The proportion of severe cases (26.54% vs 18.16%; P<.001), deaths (5.33% vs 0.99%; P<.001), RSV of telehealth (mean 33.1, 95% CI 16.2-50.0 vs mean 7.3, 95% CI 6.7-8.0; P<.001), and RSV of COVID-19 (mean 52.1, 95% CI 38.3-65.9 vs mean 26.3, 95% CI 24.4-29.2; P<.001) was significantly higher in the first wave compared to after the wave. In the correlation analysis, the public interest in telehealth was 0.899 in the first wave and -0.300 overall. In Japan, the accessibility of telehealth using mobile apps was significantly higher in epidemic regions compared to nonepidemic regions in both hospitals (3.8% vs 2.0%; P=.004) and general clinics (5.2% vs 3.1%; P<.001). In the regional correlation analysis, telehealth accessibility using mobile apps was 0.497 in hospitals and 0.629 in general clinics. CONCLUSIONS: Although there was no long-term correlation between the public interest in telehealth and COVID-19, there was a regional correlation between mobile telehealth app accessibility in Japan, especially for general clinics. We also revealed that epidemic regions had higher mobile telehealth app accessibility. Further studies about the actual use of telehealth and its effect after the COVID-19 pandemic are necessary.

Surgical Management of Discoid Lateral Meniscus With Anterior Peripheral Instability: Retaining an Adequate Residual Meniscus Volume.

Discoid lateral meniscus (DLM) presents with differing pathoanatomy and may exhibit various types of tears. The treatment strategy is based on the presence and location of instability as a result of deficient capsular attachment. Recently, meniscal stabilization after saucerization has been recommended for DLM to preserve the meniscus shape, prevent extrusion, and mitigate against the progression of osteoarthritis. In addition to stabilization, the resection volume is important to prevent osteoarthritic changes. Although there was no tear and no displacement of the lateral meniscus on magnetic resonance imaging, some DLMs were found to have tears and peripheral instability during arthroscopy. Therefore, the assessment of peripheral instability during surgery is very important to achieve a desirable clinical outcome. This Technical Note describes an arthroscopic technique for anterior peripheral stabilization of the DLM, in which we highlight the surgical procedure for repair of the anterior horn, reassess the instability around the popliteal hiatus after the anterior horn is repaired, and the stabilization of the posterior horn, if necessary.

ACL Graft Matching: Cadaveric Comparison of Microscopic Anatomy of Quadriceps and Patellar Tendon Grafts and the Femoral ACL Insertion Site.

BACKGROUND: The optimal graft choice between the bone-patellar tendon-bone (BPTB) and the quadriceps tendon remains controversial. Studies evaluating the microscopic anatomy of the quadriceps tendon-patellar bone (QTB) and BPTB grafts for anterior cruciate ligament (ACL) reconstruction are currently lacking. HYPOTHESIS: The relationship between post-ACL reconstruction graft bending angle (GBA) and the angle corresponding to the GBA (cGBA) would indicate that the BPTB can bend more than the QTB at the femoral tunnel aperture. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty paired human cadaveric knees fixed at <10° of knee joint flexion (mean age, 82.5 years) underwent histological sectioning and staining with Masson trichrome and toluidine blue. The femoral ACL insertion, QTB graft, and BPTB graft were microscopically analyzed. The width of the direct insertion, thickness of the uncalcified fibrocartilage and calcified fibrocartilage, ligament attachment angle, and cGBA for each group were measured. Eighteen patients who underwent ACL reconstruction with QTB or BPTB autograft were included for the evaluation of GBA using computed tomography images at 1 week postoperatively. RESULTS: The mean insertion widths of the femoral ACL, QTB, and BPTB were 7.81, 9.07, and 6.54 mm, respectively. The QTB was 16% wider than the ACL, while the BPTB was 16% narrower than the ACL. The mean insertion thicknesses of the femoral ACL, QTB, and BPTB were 0.53, 0.94, and 0.38 mm, respectively. The QTB was 77% thicker than the ACL (P < .001), while the BPTB was 28% thinner than the ACL (P = .017). The mean ligament attachment angles of the femoral ACL, QTB, and BPTB were 20.3°, 30.2°, and 33.3°, respectively, and the QTB and the BPTB were 49% and 64% larger, respectively, than the ACL. The mean cGBAs of the femoral ACL, QTB, and BPTB were 33.9°, 35.1°, and 12.3°, respectively. The BPTB was 64% smaller than the ACL, while there was no significant difference between the QTB and the ACL. The mean GBA was 57.7°. CONCLUSION: The insertion width and thickness were significantly greater and smaller in the QTB and BPTB grafts, respectively, than in the ACL. The relationship between GBA after ACL reconstruction and cGBA in knee extension indicates that at the femoral tunnel aperture, the BPTB can bend more than the QTB. CLINICAL RELEVANCE: QTB graft may allow more anatomic ACL reconstruction to be performed.

Room-Temperature Reversible Chemisorption of Carbon Monoxide on Nickel(0) Complexes.

Chemisorption on organometallic-based adsorbents is crucial for the controlled separation and long-term storage of gaseous molecules. The formation of covalent bonds between the metal centers in the adsorbents and the targeted gases affects the desorption efficiency, especially when the oxidation state of the metal is low. Herein, we report a pressure-responsive nickel(0)-based system that is able to reversibly chemisorb carbon monoxide (CO) at room temperature. The use of N-heterocyclic carbene ligands with hemi-labile N-phosphine oxide substituents facilitates both the adsorption and desorption of CO on nickel(0) via ligand substitution. Ionic liquids were used as the reaction medium to enhance the desorption rate and establish a reusable system. These results showcase a way for the sustainable chemisorption of CO using a zero-valent transition-metal complex.

Comparison of new and old all-inside suture devices in meniscal cyst formation rates after meniscal repair.

PURPOSE: We compared the magnetic resonance imaging (MRI)-confirmed cyst formation rate after meniscal tear repair using a new all-inside suture device (N group) versus the older all-inside suture device (O group). METHODS: Between October 2008 and July 2017, 94 consecutive menisci of 89 patients were diagnosed with meniscal tears and underwent arthroscopic meniscal repair using the all-inside suture device. Five of these patients were lost to follow-up within 12 months and were excluded from the study. The remaining 89 menisci were followed up for at least 12 months and were included in this retrospective cohort study. Older all-inside suture devices (FasT-Fix, Ultra FasT-Fix) were used until December 2012, while the new all-inside suture device (FasT-Fix 360) was used from January 2013 onwards. Meniscal cysts were detected on T2-weighted fat-suppressed MRI at 12 months postoperatively. Multiple logistic regression analysis was used to identify demographic and clinical factors associated with the use of the new all-inside suture device and cyst formation. RESULTS: In total, 36 and 53 menisci were included in the N and O groups, respectively. The incidence of meniscal cysts was significantly greater in the O group (14 out of 53, 26.4%) than in the N group (two out of 36, 5.56%) (P = 0.012). Two patients in the O group had symptomatic cysts that required removal. Multivariate logistic analyses showed that the cyst formation risk significantly decreased after using the new all-inside suture device than the older all-inside suture devices (odds ratio = 0.139; P = 0.04). CONCLUSIONS: The MRI-confirmed cyst formation rate after meniscal tear repair was significantly lower using the new than the older all-inside suture devices, indicating that the use of a low-profile device may decrease the cyst formation rate.

Autologous Platelet-Rich Fibrin Membrane to Augment Healing of Microfracture Has Better Macroscopic and Histologic Grades Compared With Microfracture Alone on Chondral Defects in a Rabbit Model.

PURPOSE: To determine the in vivo effectiveness of a single-stage surgical procedure that combines microfracture and an autologous platelet-rich fibrin (PRF) membrane for cartilage repair in a rabbit model. METHODS: Cartilage defects were created in the trochlear groove of the knees of adult white rabbits. Defects were divided into 2 treatment groups: microfracture only (control group) and microfracture covered by a PRF membrane (PRF group). To evaluate the repair cartilage, assessments were performed at 4, 12, and 24 weeks postoperatively using the International Cartilage Repair Society (ICRS) macroscopic scoring system and modified Wakitani histologic grading system. RESULTS: The mean ICRS macroscopic scores in the control and PRF groups were 4.1 and 5.8, respectively, at 4 weeks (P = .0623); 6.3 and 9.8, respectively, at 12 weeks (P = .006); and 6.5 and 10.3, respectively, at 24 weeks (P = .010). The mean modified Wakitani scores in the control and PRF groups were 4.0 and 3.9, respectively, at 4 weeks (P > .999); 5.3 and 10.4, respectively, at 12 weeks (P = .006); and 2.6 and 7.4, respectively, at 24 weeks (P = .012). CONCLUSIONS: The ICRS macroscopic scores and modified Wakitani scores showed that a single-stage surgical procedure combining microfracture and a PRF membrane was more effective than surgery with only microfracture for promoting cartilage repair. CLINICAL RELEVANCE: A single-stage surgical procedure combining microfracture and an autologous PRF membrane is a potentially beneficial treatment method for cartilage defects that does not require using any xenocollagen membrane.