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As a simple and invasive treatment, arthroscopic medial meniscal posterior horn resections (MMPHRs) can relieve the obstructive symptoms of medial meniscus posterior root tears (MMPRTs) but with the risk of aggravating biomechanical changes of the joint. The aim of this study was to analyze dynamic simulation of the knee joint after medial meniscus posterior root tear and posterior horn resection.This study established static and dynamic models of MMPRTs and MMPHRs on the basis of the intact medial meniscus model (IMM). In the finite element analysis, the three models were subjected to 1000 N axial static load and the human walking gait load defined by the ISO14243-1 standard to evaluate the influence of MMPRTs and MMPHRs on knee joint mechanics during static standing and dynamic walking.In the static state, the load ratio of the medial and lateral compartments remained nearly constant (2:1), while in the dynamic state, the load ratio varied with the gait cycle. After MMPHRs, at 30% of the gait cycle, compared with the MMPRTs condition, the maximum von Mises stress of the lateral meniscus (LM) and the lateral tibial cartilage (LTC) were increased by 166.0% and 50.0%, respectively, while they changed by less than 5% during static analysis. The maximum von Mises stress of the medial meniscus (MM) decreased by 55.7%, and that of the medial femoral cartilage (MFC) increased by 53.5%.After MMPHRs, compared with MMPRTs, there was no significant stress increase in articular cartilage in static analysis, but there was a stress increase and concentration in both medial and lateral compartments in dynamic analysis, which may aggravate joint degeneration. Therefore, in clinical treatments, restoring the natural structure of MMPRTs is first recommended, especially for physically active patients.

The purpose of this study was to compare the long-term clinical and radiological outcomes between the immediate and delayed meniscus allograft transplantation (MAT).Nine menisci were transplanted immediately after total meniscectomy (immediate group, IM), and 10 menisci were delayed transplanted in patients with the median of 35 months (range 9-92 months) after total meniscectomy (delayed group, DE). Patient's subjective clinical outcomes including VAS, IKDC, Lysholm and Tegner scores as well as muscle strength measures were compared. Joint degeneration was evaluated by both radiographs to assess joint space width narrowing, Kellegren-Lawrence (KL) grade and MRI with T2 mapping sequences to quantitatively analyze both cartilage and meniscal allograft degeneration.The median follow-up time was 10.8 years (range 10-14 years). The IKDC (IM vs DE, 89.8 vs 80.9, n.s.) and Lysholm scores (IM vs DE, 87.7 vs 78.0, n.s.) were close in two groups, while the IM group showed slightly lower VAS (IM vs DE, 0.2 vs 1.5, p = 0.031), higher Tegner score (IM vs DE, 7 vs 3.5 p = 0.021) and better quadriceps muscle strength. The IM group had less joint space narrowing (IM vs DE, 0.35 mm vs 0.71 mm, n.s.), less KL grade progression (IM vs DE, 0.6 vs 1.7, p = 0.041) on radiographs and less chondral lesions development on MRIs (Cartilage Degeneration Index, IM vs DE, 252 vs 2038, p = 0.025). All meniscal grafts exhibited degeneration by showing grade 3 signal on MRI, and 4 (4/9) in the IM group and 8 (8/10) cases in the DE group. The T2 value of cartilage and meniscal allograft in the IM group was close to that of the healthy control and was significantly lower than that of the DE group.Compared to the conventional delayed MAT, the immediate MAT achieved better cartilage and meniscus protection in the long-term, while its superiority in patient-reported outcomes was limited.IV.

To compare the long-term clinical and radiological results of meniscal allograft transplantation (MAT) for discoid lateral meniscus (DLM) patients with MAT for non-discoid lateral meniscus patients and meniscectomy (ME) for DLM patients and, thus, to determine whether DLM patients are suitable candidates for MAT.Eight MAT cases in DLM patients were identified (discoid MAT group), six MAT cases in non-discoid lateral meniscus patients (non-discoid MAT group) and ten total meniscectomy cases in DLM patients (discoid ME group) were matched as controls. Subjective evaluations, postoperative radiography and magnetic resonance imaging (MRI) were conducted at 5 years and 10-14 years, respectively. Joint degeneration was evaluated by the Kellgren-Lawrance (KL) grade and joint space width (JSW). MRI with T2 mapping sequences was used to quantitatively evaluate degeneration of the joint cartilage and shrinkage of the allografts. Student's t test was used to compare quantitative variables and the Mann‒Whitney U test was used to compare categorical variables.There was no difference in Lysholm, IKDC, Tegner or VAS scores amongst the discoid MAT, non-discoid MAT and discoid ME groups at the final follow-up. No revision surgery was performed in any MAT patient. The JSW narrowing in the discoid MAT group was better than that in the discoid ME group (0.8 ± 0.4 mm vs. 2.1 ± 1.3 mm, p = 0.012) and worse than that in the non-discoid MAT group (0.1 ± 0.1 mm, p = 0.003). The KL progression of the discoid MAT group was less than that of the discoid ME group (1.3 ± 0.7 vs. 2.3 ± 0.9, p = 0.034). The discoid ME group had worse cartilage lesion progression than the discoid MAT and non-discoid MAT groups. The allograft width of the DLM patients shrank more than that of the non-discoid patients at the meniscus midbody (3.6 ± 0.9 mm vs. 6.2 ± 1.9 mm, p = 0.015).Compared to meniscectomy, MAT achieved similar long-term symptom relief and superior chondroprotection in discoid meniscus patients. Despite more graft shrinkage, the outcomes of MAT in discoid meniscus patients were comparable to those in non-discoid meniscus patients. Therefore, DLM patients may be suitable candidates for MAT procedures.Level III.

Lateral meniscal posterior root tears are defined as tears of meniscus within 9 mm from the bony root attachment. Unrepaired root tears significantly compromise the biomechanical functions of the meniscus, resulting in early and accelerated osteoarthritis. Several authors have described various techniques to reattach the posterior root of the lateral meniscus, and decent short-term results have been observed. Although most previous techniques are capable of repairing radial root tears, difficulties are encountered when repairing oblique type IV tears. In this technique note, the author describes an efficient side-to-side repair technique using the FAST-FIX system, which is practical in repairing the type IV tears of the lateral meniscus. This technique includes certain sequence of the stitches and skills of controlling the root remnant, which makes it easy to penetrate the meniscus and to achieve anatomic repair.

Background: The long-term chondroprotective effect of meniscal allograft transplant (MAT) and its superiority over meniscectomy have rarely been reported. Hypothesis: MAT would reduce osteoarthritis (OA) progression when compared with the meniscus-deficient knee. Graft extrusion distance would strongly affect the chondroprotective effect of the MAT. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 17 knees receiving MAT were followed up as the MAT group. The MAT group was further divided into the nonextrusion subgroup (n = 9) and the extrusion subgroup (n = 8) according to 3-mm extrusion on the magnetic resonance imaging (MRI) coronal section. A further 26 consecutive patients receiving meniscectomy in the same period were followed up as the ME group. The healthy control group consisted of healthy contralateral legs chosen from the MAT and ME groups (n = 27). Joint space width (JSW) narrowing was measured on radiographs. Three-dimensional MRI with a T2 mapping sequence was used to quantitatively analyze cartilage degeneration and meniscal allograft extrusion in 5 directions (0°, 45°, 90°, 135°, and 180°). The cartilage degeneration index (CDI) was calculated according to the size and degree of the chondral lesions on MRI scans. The correlation between the CDI increase and the extrusion distance was analyzed. Results: The mean follow-up time was 11.3 years (range, 10-14 years). The MAT group had moderate superiority in chondral protection with less JSW narrowing (0.58 ± 0.66 mm) and CDI increase (1132 ± 1589) compared with the ME group (JSW narrowing: 1.26 ± 1.13 mm, P = .025; CDI increase: 2182 ± 1958, P = .079). The JSW narrowing (0.71 ± 0.80 mm; P = .186) and CDI increase (2004 ± 1965; P = .830) of the extrusion subgroup were close to those of the ME group, demonstrating that a 3-mm extrusion led to complete loss of the meniscal chondroprotective effect. The nonextrusion group had significantly less JSW narrowing (0.48 ± 0.48 mm; P = .042) and CDI increase (358 ± 249; P = .011) than the ME group. The JSW narrowing of the healthy control group was 0.22 ± 0.27 mm. The cartilage T2 values of the extrusion subgroup were similar to those of the ME group, with more OA features, whereas the T2 values of the nonextrusion subgroup were closer to those of the healthy control group. The extrusion distance in the 90° direction ( P = .002) and the follow-up time ( P = .019) significantly affected the CDI increase in the multivariate regression model. The average extrusion distance in the 45°, 90°, and 135° directions better predicted chondroprotection compared with the other individual directions. Conclusion: MAT had moderate advantages in chondroprotection compared with meniscectomy in the long term. Graft extrusion distance strongly affected the chondroprotective effect of MAT. The chondroprotective effect of the nonextruded meniscal allograft was close to that of the native meniscus, whereas the allografts with an extrusion >3 mm completely lost their function after meniscectomy.

Purpose To explore an optimal drilling depth and direction for osteochondral lesions of the talus based on a 3-dimensional vascular microarchitecture model constructed with micro–computed tomography (microCT). Methods Twelve tali were perfused with the contrast agent and then scanned with microCT. The talar dome was divided into 9 zones, and the vessel densities were measured at the subchondral depths of 0 to 5 mm, 5 to 10 mm and 10 to 15 mm in each zone. The anterolateral (AL) and posterolateral (PL) approaches of retrograde drilling were simulated and the vascular compromising effect was evaluated. Results The vessel density of the 0- to 5-mm depth was lower than that of the 5- to 10-mm (P = .001) and 10- to 15-mm (P = .007) depths, but no significant difference was found between the 5- to 10-mm and 10- to 15-mm depths (P > .9999). The vessel density in the 5- to 10-mm depth of medial talar dome was similar to that of the adjacent zones (P = .05). Vessel density in the 5- to 10-mm depth around the lateral talar dome was higher in the anterior and medial side. The anterolateral approach disturbed the main intraosseous vessels from the tarsal canal–tarsal sinus, causing extensive vascular compromise in the talus neck and body, whereas the posterolateral approach disturbed only the vessels near the tunnel. Conclusions The vessel density changed greatly from the subchondral 0- to 5-mm to the 5- to 10-mm depth. The vessel densities of the 5- to 10-mm depth around the medial talar dome were similar, whereas the anterior and medial side of the lateral talar dome was better vascularized. The posterolateral approach caused less vascular damage than the anterolateral approach. Clinical Relevance The anterograde drilling depth was preferable to the subchondral 5- to 10-mm depth. There was no preferred drilling direction for the osteochondral lesion in the medial talar dome, whereas it is preferable to drill anteriorly or medially in the lateral dome. The posterolateral approach might be a safer alternative for retrograde drilling.

Background: There is much room for improvement and optimization of meniscal allograft survivorship. Purpose: To understand prognostic factors for survivorship using evidence-based selection criteria in order to identify patients who would best benefit from meniscal allograft transplant (MAT). Study Design: Systematic review; Level of evidence, 4. Methods: We conducted this systematic review to analyze prognostic factors for survivorship of MAT. The Cochrane Central Register, PubMed publisher, Embase.com , and Web of Science databases were searched through August 8, 2019. Included studies entailed patients of any age who received MAT with a reported association between prognostic factors and survivorship of the allograft. Two reviewers independently screened all titles and abstracts for eligibility, extracted the data, assessed the risk of bias using the Newcastle-Ottawa Scale, and performed a best-evidence synthesis. Results: The review included 18 studies with a total of 1920 patients. The mean follow-up time was 6.0 years (range, 2.1-11.2 years). A total of 20 prognostic factors were identified and shown to be associated with survivorship of MAT. Strong evidence was found that severe cartilage damage was associated with poor survivorship. Strong evidence was also found showing that sex, knee compartment, surgical side, concomitant anterior cruciate ligament (ACL) reconstruction, and concomitant osteotomy for malalignment had no effect on survivorship. Moderate evidence was found that body mass index (Conclusion: Severe cartilage damage decreases the survivorship of MAT. Concomitant ACL reconstruction and osteotomy showed no relationship to survivorship. Many determinants showed conflicting and limited evidence. Older age may be of interest and should be further studied.

Objective In the present study, we aimed to establish a novel score to predict long-term mortality of non-ST-segment elevation acute coronary syndrome (NSTE-ACS) patients who underwent percutaneous coronary intervention (PCI). Methods A total of 2,174 NSTE-ACS patients from the CORFCHD-ZZ study were enrolled as the derivation cohort. The validation cohort including 1,808 NSTE-ACS patients were from the CORFCHD-PCI study. Receiver operating characteristic analysis and area under the curve (AUC) evaluation were used to select the candidate variables. The model performance was validated internally and externally. The primary outcome was cardiac mortality (CM). We also explored the model performance for all-cause mortality (ACM). Results Initially, 28 risk factors were selected and ranked according to their AUC values. Finally, we selected age, N-terminal pro-B-type natriuretic peptide, and creatinine to develop a novel prediction model named “ABC” model. The ABC model had a high discriminatory ability for both CM (C-index: 0.774, p Conclusion In the present study, we developed and validated a novel model to predict mortality in patients with NSTE-ACS who underwent PCI. This model can be used as a credible tool for risk assessment and management of NSTE-ACS after PCI.

BACKGROUND: Selenoprotein S (SelS) is a novel selenoprotein encoded by the SelS gene on chromosome 15q26.3. SelS is associated with the development of diabetes, dyslipidemia and macrovascular complications. However, the relationship between genetic polymorphisms of SelS and coronary artery disease (CAD) remains unclear. METHODS: In the present study, we genotyped four single nucleotide polymorphisms (rs117613208, rs117512970, rs986500879, rs542989868) of SelS gene using direct sequencing method in a case-control study (576 CAD cases and 452 control subjects). Furthermore, we developed a predictive model using SelS genetic variation and clinical variables to predict risk of CAD. RESULTS: We found that rs117613208 T allele was more frequent in the CAD cases than that in the controls. Logistic regression analysis suggested after adjustment of other confounders, the difference remained significant between the two groups [odds ratio (OR) =2.107, 95% confidence interval (CI): 1.239–3.583, P

Background Achilles sleeve avulsion usually occurs from pre-existing insertional Achilles tendinopathy, leaving a calcific spur at the insertional site. The purpose of this study was to introduce a new technique using the spur base on the insertional site to drill the suture tunnel to repair Achilles sleeve avulsion. Methods In total, 11 patients diagnosed with Achilles sleeve avulsion underwent this new surgical technique and were followed for a mean time of 40 months. Clinical outcomes were measured using the visual analog scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) score, Victorian Institute of Sports Assessment-Achilles (VISA-A) score, Tegner score, and time taken to return to activities. Preoperative and postoperative MRI, the ability to perform heel rise, and complications were also evaluated. Results All cases (11/11) had insertional Achilles tendinopathy with calcific spur formation on the tendon’s insertion. At final follow-up, the average VAS score improved from 5.3 to 0.1, AOFAS score improved from 44.8 to 97.9, VISA-A score improved from 23.6 to 96.6, and Tegner score improved from 0.9 to 4.9. Tendinopathy symptoms were eliminated. Patients returned to daily activities, work, and sports 3.5 months, 2.8 months, and 12.3months after operation, respectively. Patients took an average of 18.1 weeks after operation to perform the single heel rise test. No severe complications such as infection and rerupture were observed. Conclusion Our new transosseous suture technique is a promising alternative option in treating Achilles sleeve avulsion. More cases and longer follow up are needed in order to find the best reconstructive option for this pathology. Levels of evidence Level IV

Background Peripheral blood (PB) is a potential source of chondrogenic progenitor cells that can be used for cartilage repair and regeneration. However, the cell types, isolation and implantation methods, seeding dosage, ultimate therapeutic effect, and in vivo safety remain unclear. Methods PubMed, Embase, and the Web of Science databases were systematically searched for relevant reports published from January 1990 to December 2019. Original articles that used PB as a source of stem cells to repair cartilage in vivo were selected for analysis. Results A total of 18 studies were included. Eight human studies used autologous nonculture-expanded PB-derived stem cells (PBSCs) as seed cells with the blood cell separation isolation method, and 10 animal studies used autologous, allogenic or xenogeneic culture-expanded PB-derived mesenchymal stem cells (PB-MSCs), or nonculture-expanded PBSCs as seed cells. Four human and three animal studies surgically implanted cells, while the remaining studies implanted cells by single or repeated intra-articular injections. 121 of 130 patients (in 8 human clinical studies), and 230 of 278 animals (in 6 veterinary clinical studies) using PBSCs for cartilage repair achieved significant clinical improvement. All reviewed articles indicated that using PB as a source of seed cells enhances cartilage repair in vivo without serious adverse events. Conclusion Autologous nonculture-expanded PBSCs are currently the most commonly used cells among all stem cell types derived from PB. Allogeneic, autologous, and xenogeneic PB-MSCs are more widely used in animal studies and are potential seed cell types for future applications. Improving the mobilization and purification technology, and shortening the culture cycle of culture-expanded PB-MSCs will obviously promote the researchers' interest. The use of PBSCs for cartilage repair and regeneration in vivo are safe. PBSCs considerably warrant further investigations due to their superiority and safety in clinical settings and positive effects despite limited evidence in humans.

In the present study, we aimed to characterize gut microbiome and develop a gut microbiome-based diagnostic model in patients with coronary artery disease (CAD). Prospectively, we collected 309 fecal samples from Central China and Northwest China and carried out the sequencing of the V3-V4 regions of the 16S rRNA gene. The gut microbiome was characterized, and microbial biomarkers were identified in 152 CAD patients and 105 healthy controls (Xinjiang cohort, n = 257). Using the biomarkers, we constructed a diagnostic model and validated it externally in 34 CAD patients and 18 healthy controls (Zhengzhou cohort, n = 52). Fecal microbial diversity was increased in CAD patients compared to that in healthy controls (P = 0.021). Phylum Bacteroidetes was increased in CAD patients versus healthy controls (P = 0.001). Correspondingly, 48 microbial markers were identified through a 10-fold cross-validation on a random forest model, and an area under the curve (AUC) of 87.7% (95% CI: 0.832 to 0.916, P < 0.001) was achieved in the Xinjiang cohort (development cohort, n = 257). Notably, an AUC of 90.4% (95% CI: 0.848 to 0.928, P < 0.001) was achieved using combined analysis of gut microbial markers and clinical variables. This model provided a robust tool for the prediction of CAD. It could be widely employed to complement the clinical assessment and prevention of CAD.

The blood supply of the patella is highly related to patellofemoral complications in total knee arthroplasty. The purpose of this study was to determine (1) the dominant blood supply for the patella and (2) the anatomic characteristics of the extraosseous and intraosseous vascularity of the patella.In 13 fresh cadaveric knees, the femoral arteries were cannulated and perfused with a lead-based contrast agent. Patellae were harvested and scanned with a micro-computed-tomography scanner. The three-dimensional microarchitecture of the vascularity was reconstructed and evaluated. For the volumetric analysis, the vessel densities of the anterior, central and subchondral sides were compared.A well-anastomosed prepatellar vascular network was found to cover the anterior surface of the patella, with main arteries from multiple directions, yielding 18.8 ± 3.1 (standard deviation) intraosseous branches into the patella. Along the intraosseous branches of the prepatellar vascular network, vessel density decreased (P 0.001) by 0.54 ± 0.29% on the anterior side, 0.40 ± 0.24% on the central side and 0.23 ± 0.19% on the subchondral side. Arteries in the infrapatellar fat pad produced 5.1 ± 1.8 intraosseous branches, mainly located in the distal apex. Almost no arteries penetrated into the patella from the quadriceps tendon, patellar ligament or medial/lateral retinaculum.The prepatellar vascular network is the dominant blood supply. Close exposure and extensive dissection around the patella should be avoided to preserve the prepatellar vascular network. The infrapatellar fat pad was recommended to be preserved when a lateral reticulum release was performed.

Background: Osteochondral lesions (OCLs) and bony impingement are common secondary lesions of chronic lateral ankle instability (CLAI), but the risk factors that predict OCLs and bony impingement are unknown. Purpose: To analyze the risk factors for the development of OCLs and osteophytes in patients with CLAI. Study Design: Case-control study; Level of evidence, 3. Methods: Patients diagnosed with CLAI at our institution from June 2007 to May 2018 were enrolled. The assessed potential risk factors were age, sex, postinjury duration, body mass index, injury side, and ligament injury type (isolated anterior talofibular ligament [ATFL] injury, isolated calcaneofibular ligament [CFL] injury, or concomitant ATFL and CFL injuries). Univariate and multivariate logistic regression analyses were performed to evaluate the association between these factors and the presence of OCLs and osteophytes. Results: A total of 1169 patients with CLAI were included; 436 patients (37%) had OCLs and 334 (31%) had osteophytes. The presence of OCLs was significantly associated with the presence of osteophytes ( P < .001). Male sex and older age were significantly associated with the presence of OCLs in the medial and lateral talus. A postinjury duration of 5 years or longer was significantly associated with the presence of OCLs in the medial talus (odds ratio [OR], 1.532; 95% CI, 1.023-2.293; P = .038) but not in the lateral talus. ATFL and CFL injuries were both significantly associated with the presence of lateral OCLs. Risk factors for the presence of osteophytes were male sex, older age, postinjury duration 5 years or longer, and CFL injury. Patients with concomitant ATFL and CFL injuries were significantly more likely to have osteophytes than were patients with single-ligament injuries ( P = .018). Conclusion: Risk factors for OCLs and osteophytes were postinjury duration of 5 years or longer, older age, and male sex. ATFL injury was associated with the presence of lateral OCLs, whereas CFL injury was associated with the presence of lateral OCLs and osteophytes. Patients with these risk factors should be closely monitored and treated to reduce the incidence of ankle arthritis.