Purpose:The purpose of this study was to evaluate the accuracy of femoral tunnel location, post-operative pain management, functional rehabilitation and clinical outcomes in medial patellofemoral ligament (MPFL) reconstruction using all-arthroscopic technique. Methods:Between 2020 and 2021, 160 patients with recurrent patellar dislocation undergoing MPFL reconstruction were categorized into control (traditional surgery) and study (all-arthroscopic technique) groups. Femoral tunnel accuracy was assessed via computed tomography scans, pain management, functional rehabilitation, knee range of motion and daily activities were evaluated up to 6 months post-operatively. Knee function was assessed using Kujala and Lysholm scores at post-operative 12 months. Results:Seventy-one patients in the control group and 69 patients in the study group reached the final follow-up with no demographic differences. Follow-up duration was 12.65 ± 0.68 vs 12.77 ± 0.73 months in the control and study groups (p = 0.3145). The intra-class correlation coefficient was excellent (r = 0.97). In femoral tunnels, 93.5% in the control group and 92.4% in the study group were correctly localized. In patellar tunnels, 96.1% in the control group and 96.2% in the study group were correctly localized (p > 0.9999). Post-operative strong opioid analgesics were used 25.9 ± 31.0 versus 12.0 ± 22.2 mg/day in the control and study groups (p = 0.0016). The pain score was 3.4 ± 1.1 versus 2.7 ± 1.2 in the control and study groups (p = 0.0006) during post-operative functional rehabilitation. Time to resume daily living was 8.2 ± 0.6 versus 7.6 ± 0.6 weeks in the control and study groups (p < 0.0001). Time to resume low-intensity exercise was 12.3 ± 0.6 versus 11.7 ± 0.6 weeks in the control and study groups (p < 0.0001). In the more than 1-year follow-up, no significant difference was found in the Kujala and Lysholm scores. Conclusions:The all-arthroscopic technique for MPFL reconstruction in recurrent patellar dislocation ensures precise femoral tunnel placement. It offers advantages in early post-operative pain management and functional recovery, enabling faster rehabilitation compared to traditional non-all-arthroscopic techniques. Level of Evidence:Level III.

Abstract Background: The achievement of an optimal return to sport (RTS) has remained a key goal after sports-related injuries, with the ongoing debate on the effectiveness of different surgical approaches for anterior cruciate ligament (ACL) rupture. This study aims to assess clinical outcomes and RTS across various surgical methods, such as anatomical single-bundle reconstruction (ASBR), central-axial single-bundle reconstruction (CASBR), and double-bundle reconstruction (DBR). Methods: A randomized clinical trial was conducted, comprising 191 patients who underwent ACL rupture. These patients were divided into three groups based on the ACL reconstruction techniques they received (ASBR, CASBR, DBR). Over the 2-year follow-up period, the study assessed RTS through four single-hop tests, isokinetic extension tests, and limb asymmetry indices. Postoperative graft status was determined using the signal-to-noise quotient (SNQ), while knee function was evaluated using the International Knee Documentation Committee 2000 (IKDC-2000) score, Lysholm score, Tegner score, and degree of knee laxity. A binary logistic regression model was developed to forecast the factors influencing ideal RTS. Results: DBR (67.63%) and CASBR (58.00%) exhibited higher RTS passing rates compared to ASBR (30.39%; χ 2 = 19.57, P <0.05). Quadriceps strength symmetry in the lower limbs was identified as the key determinant of RTS (χ 2 = 17.08, P <0.05). The RTS rate was influenced by SNQs of the graft’s tibial site (odds ratio: 0.544) and quadriceps strength of the reconstructed knee joint at 60°/s (odds ratio: 6.346). Notably, the DBR group showed enhanced knee stability, evidenced by superior results in the Lachman test (χ 2 = 13.49, P <0.01), objective IKDC-2000 (χ 2 = 27.02, P = 0.002), and anterior instability test (χ 2 = 9.46, P <0.01). Furthermore, DBR demonstrated superior clinical outcomes based on the Lysholm score (DBR: 89.57 ± 7.72, CASBR: 83.00 ± 12.71, ASBR: 83.21 ± 11.95; F = 10.452, P <0.01) and IKDC-2000 score (DBR: 90.95 ± 7.00, CASBR: 84.64 ± 12.68, ASBR: 83.63 ± 11.41; F = 11.78, P <0.01). Conclusion: For patients with ACL rupture, more ideal RTS rate and clinical outcomes were shown in the DBR group than in the ASBR and CASBR groups. Autograft status and quadriceps strength are postively related to RTS. Trial Registration: ClinicalTrials.gov (NCT05400460)

Purpose: To describe the anatomical and histological characteristics of the human MTL (meniscotibial ligament) that keeps the meniscus stable and are rarely discussed. Study design: Descriptive laboratory study. Methods: In total, six fresh-frozen adult cadaver knees were dissected, and the dissection protocol were designed by two experienced anatomy professors. The anatomical morphology of MTL was observed. The main anatomical specimens included meniscus, tibial plateau, MTL. The osteotome was used to excise the portion of the tibial plateau, which could obtain the complex including partial meniscus, MTL, and a tibial fragment. A histopathologic study was performed by two experienced pathologists. Results: Macroscopically, the MTL could be divided into two parts: medial meniscotibial ligament (MMTL)and lateral meniscotibial ligament (LMTL). The MMTL is distributed continuously, whereas the LMTL is discontinuous on the tibial plateau. The average length from the tibial attachment of the LMTL to the articular surface was 19 +/- 1.0mm (mean +/- SD). The average length from the tibial attachment of the MMTL to the articular surface was 10 +/- 1.2 mm (mean +/- SD). Microscopy of the MTL showed that the MTL is a ligamentous tissue, composed of a network of oriented collagenous fibers. Conclusions: In all knees, the MTL was inserted on the outer edge of the meniscus, attaching to the tibia below the level of articular cartilage, which was key to maintaining the rotational stability of knee and the meniscus in the physiological position on the tibial plateau. Histological analysis of this ligament demonstrated that the MTL is a veritable ligamentous structure, which is made up of collagen type I -expressing fibroblasts. Clinical relevance: This article contributes to the understanding of the anatomical and histological characteristics of the MTL. It is beneficial to promote the development of relevant surgical techniques for the MTL lesion.

Repair and preservation of the injured meniscus has become paramount in clinical practice. However, the complexities of various clinic stitching techniques for meniscus repair pose challenges for grassroots doctors. Hence, there is a compelling interest in innovative therapeutic strategies such as bioadhesives. An ideal bioadhesive must cure quickly in aqueous and blood environments, bind strongly, endure arthroscopic washing pressures, and degrade appropriately for tissue regeneration. Here, we present a tetra-poly (ethylene glycol) (PEG)-based hydrogel bioadhesive, boasting high biocompatibility, ultrafast gelation, facile injectable operation, and favorable mechanical strength. In view of the synergistic effects of chemical anchor and physical chain entanglement to tightly bind the meniscus, a seamless interface was formed between the surrounding meniscal tissues and hydrogels, enabling the longitudinal tear of the meniscus fused in situ to withstand large tensile force with the adhesive strength of 541.5 ± 31.4 kPa and arthroscopic washout resistance of 29.4 kPa. Superior to existing commercial adhesives, ours allows sutureless application and arthroscopic assistance, without requiring specialized clinical skills. This research is expected to significantly impact our understanding of meniscal healing and ultimately promote a simpler process for achieving functional and structural recovery in torn menisci.

Meniscus is a wedge-shaped fibrocartilaginous tissue, playing important roles in maintaining joint stability and function. Meniscus injuries are difficult to heal and frequently progress into structural breakdown, which then leads to osteoarthritis. Regeneration of heterogeneous tissue engineering meniscus (TEM) continues to be a scientific and translational challenge. The morphology, tissue architecture, mechanical strength, and functional applications of the cultivated TEMs have not been able to meet clinical needs, which may due to the negligent attention on the importance of microenvironment in vitro and in vivo. Herein, we combined the 3D (three-dimensional)-printed gradient porous scaffolds, spatiotemporal partition release of growth factors, and anti-inflammatory and anti-oxidant microenvironment regulation of Ac2-26 peptide to prepare a versatile meniscus composite scaffold with heterogeneous bionic structures, excellent biomechanical properties and anti-inflammatory and anti-oxidant effects. By observing the results of cell activity and differentiation, and biomechanics under anti-inflammatory and anti-oxidant microenvironments in vitro, we explored the effects of anti-inflammatory and anti-oxidant microenvironments on construction of regional and functional heterogeneous TEM via the growth process regulation, with a view to cultivating a high-quality of TEM from bench to bedside.

Background: The effects of single-bundle and double-bundle ACL reconstruction are still controversial and patients with different anatomy may need to choose different surgery. The aim of the study was to assess the relationship between graft maturation and clinical outcomes, identify the risk factors, and compare the results after single/double-bundle ACL reconstruction. Methods: A single-surgeon series of 147 patients with a median follow-up of 149.7 months (range, 144-189 months) underwent isolated primary ACL reconstruction (SB-ACLR group: n = 74; DB-ACLR group: n = 73). Clinical outcomes included the pivot shift test, IKDC, Lysholm, and Tegner scores. Signal intensity (SI) of the graft, and bone anatomy were also assessed. Results: Significant correlations between graft SI and last clinical outcomes were shown. Lateral tibial slope (LTS) (β = 0.09) and medial tibial slope (MTS) (β = 0.09), or their sum (STS) greater than 12° (β = 1.16) were determined as the risk factors of graft SI among SB-ACLR group patients. No independent risk factor for graft SI of patients in the DB-ACLR group was observed. Compared to the other three groups, the STS > 12° group in SB-ACLR showed significant differences in the clinical outcomes. Conclusions: Late graft SI is negatively correlated with the clinical outcomes. It might be affected by specific anatomic features in patients with SB-ACLR, including medial tibial slope, lateral tibial slope, and their sum, and mediated the effect on clinical outcomes. Patients with STS > 12° may consider choosing DB-ACLR to expect better long-term knee function after surgery. Trial registration: No. IRB00006761-2011097 and NCT03984474. Level of Evidence: Retrospective Study, Level III.

Objective To investigate the relationship between the posterior tibial slope（PTS） and the gray scale, volume and cross-sectional area of anterior cruciate ligament（ACL） in healthy people. Methods A total of 212 healthy subjects（including 106 males and 106 females）, aged from 30 to 60 years old（mean, 39.3±7.3 years old）, with BMI from 17.7 to 36.3（mean, 24.3±3.3）, recruited from January 2020 to August 2020 were selected to measure the lateral and medial tibial slope and the gray scale, volume and cross-sectional area of ACL through MRI images and 3D models. The measured results were compared between the male and female subjects, and the relationships between the PTS and the gray scale, volume and cross-sectional area of ACL were analyzed. Results The lateral tibial slope of females was greater than that of males [（8.0±3.8）° vs.（6.3±4.1）°, t=-3.068, P=0.002]. The ACL volume and cross-sectional area of females were smaller than those of males [（1339.4±458.4） mm~3 vs.（1699.6±468.6） mm~3, t=5.658, P=0.000;（36.4±13.0） mm~2 vs.（45.2±14.8） mm~2, t=4.614, P=0.000]. There was no statistical difference in medial tibial slope and ACL gray scale between males and females（P＞0.05）.In male and female subjects, there was no correlation between PTS and ACL gray scale, volume and cross-sectional area（P＞0.05）. Conclusion In healthy people, PTS has no correlation with the gray scale, volume or cross-sectional area of ACL. LTS in healthy women is greater than that in healthy men.

The histone deacetylase inhibitor (HDACi) was a milestone in the treatment of refractory T-cell lymphoma. However, the beneficial effects of HDACi have not been appreciated in osteoarthritis (OA). Herein, we implemented a microcarrier system because of the outstanding advantages of controlled and sustained release, biodegradability, and biocompatibility. The poly(d,l-lactide-co-glycolide) (PLGA) microcapsules have a regulated and sustained release profile with a reduced initial burst release, which can improve the encapsulation efficiency of the Chidamide. The emulsion solvent evaporation strategy was used to encapsulate Chidamide in PLGA microcapsules. The encapsulation of Chidamide was established by UV–vis spectra and scanning electron microscopy. Additionally, the inhibition of Tnnt3 and immune stimulation by Chidamide helped to inhibit cartilage destruction and prevent articular cartilage degeneration. Based on the results, the Chidamide in PLGA microcapsules provides a transformative therapeutic strategy for the treatment of osteoarthritis patients to relieve symptoms and protect against cartilage degeneration.

Abstract Since the meniscus is an important stabilizing structure of the knee joint and has a significant role in load‐bearing and shock absorption, so the complete structural and functional reconstructions of the teared menisci should be done not only after partial meniscectomy but also post total meniscectomy. So far, animal experiments and good clinical practice have showed that TMAT after total meniscectomy has partially solved the problem of structural and functional reconstructions after total meniscectomy. However, partial meniscectomy will also lead to accelerated knee degeneration, and its proportion is much higher than that of patients with total meniscectomy. Herein, the feasibility of PMAT after partial meniscectomy was investigated for the first time by using the 40% posterior horn meniscectomy model of the medial meniscus in Beagle dogs, and also for the first time, TMAT group and the total meniscectomy group were used as control groups. Compared with the TMAT, the transcriptomics evaluation, scanning electron microscope observation, histological regeneration and structure, biomechanical property, inflammation environment, and the knee function post PMAT were more similar to that of normal meniscus was first reported. This study provides a PMAT scheme with clinical translational value for the complete structural and functional reconstruction of the patients with partial meniscectomy and fills the gap in the field of teared meniscus therapy on the basis of quite well clinical applications of the meniscus repair and the TMAT.

To compare the values and the relationship of tibial tubercle lateralization measurements between computerized tomography (CT) and magnetic resonance imaging (MRI). Sixty patients with patellar dislocation who underwent both CT and MRI of the same knee joint from November 2021 to February 2022 were included in our study. The intraclass correlation coefficient (ICC) and Bland–Altman analysis were performed to evaluate the reliability of tibial tubercle–trochlear groove (TT–TG), tibial tubercle–Roman arch (TT–RA), and tibial tubercle–posterior cruciate ligament (TT–PCL) distance measurements. The values of CT and MRI measurements using the same bony landmarks were compared for the difference. Pearson correlation analysis and linear regression analysis were performed to assess the correlation between CT and MRI measurements. Finally, the estimated values obtained from the regression equation were compared with the actual values obtained from the radiological measurement to evaluate the accuracy of the equations. A total of 60 patients with patellar dislocation who underwent both CT and MRI of the same knee joint were included in this study. The included measurements showed excellent agreement with ICCs > 0.9. TT–TG distance measured on CT (19.5 ± 5.1 mm) had a mean of 7.1 mm higher than that on MRI (12.4 ± 4.7 mm) (P < 0.001). The mean value of TT–RA distance was 22.5 ± 3.7 mm on CT and 16.7 ± 4.9 mm on MRI (P < 0.001), showing a mean difference of 5.8 mm. The values of TT–TG distance measured by CT and MRI were significantly correlated (R = 0.5, P < 0.001). The values of TT–RA distance between these two modalities showed a better correlation than that of TT–TG distance (R = 0.6, P < 0.001). The interchange values of TT–TG distance and TT–RA distance between CT and MRI can be obtained using regression equations (TT–TG distance: y = 0.6x + 12.3; TT–RA distance: y = 0.5x + 14.4). The values of tibial tubercle lateralization measured by MRI may be underestimated compared with those measured by CT. Although the values measured on CT and MRI are not equivalent, the value in the other modality can be estimated. Therefore, an additional CT scan for tibial tubercle lateralization evaluation may not be necessary. Level II.

局灶性关节软骨缺损在运动医学领域较为常见,通常导致关节疼痛和功能障碍,由于软骨无血管、缺乏内源性修复细胞的特点,其自愈能力有限,若不及时治疗最终将发展为骨关节炎.手术一直是临床治疗关节软骨缺损的主要手段,按照外科修复技术主要分为姑息性手术、修复性手术、重建性手术和软骨替代性手术等四大类.本文主要就近年来有关以上不同外科手段治疗局灶性软骨缺损的适应证、优势、局限性及远期疗效等方面的进展情况进行综述.

Background: Tendon-bone healing is an important factor in determining the success of ligament reconstruction. With the development of biomaterials science, the tissue engineering scaffold plays an extremely important role in tendon-bone healing and bone tissue engineering. Materials and Methods: Electronic databases (PubMed, Embase, and the Web of Science) were systematically searched for relevant and qualitative studies published from 1 January 1990 to 31 December 2019. Only original articles that met eligibility criteria and evaluated the use of issue engineering scaffold especially biomaterials in tendon bone healing in vivo were selected for analysis. Results: The search strategy identified 506 articles, and 27 studies were included for full review including two human trials and 25 animal studies. Fifteen studies only used biomaterials like PLGA, collage, PCL, PLA, and PET as scaffolds to repair the tendon-bone defect, on this basis, the rest of the 11 studies using biological interventions like cells or cell factors to enhance the healing. The adverse events hardly ever occurred, and the tendon bone healing with tissue engineering scaffold was effective and superior, which could be enhanced by biological interventions. Conclusion: Although a number of tissue engineering scaffolds have been developed and applied in tendon bone healing, the researches are mainly focused on animal models which are with limitations in clinical application. Since the efficacy and safety of tissue engineering scaffold has been proved, and can be enhanced by biological interventions, substantial clinical trials remain to be done, continued progress in overcoming current tissue engineering challenges should allow for successful clinical practice.

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.

The authors have requested that this preprint be withdrawn due to erroneous posting.