The arthroscopic subacromial sling procedure is used to treat recurrent anterior shoulder instability. As an arthroscopic technique with less potential for complications, the subscapular sling with a half bundle of the peroneus longus tendon provides both dynamic and static stability. This procedure uses the half bundle of the peroneus longus tendon graft as a sling around the upper two-thirds of the subscapular tendon, with the graft attached to the anterior glenoid rim through the glenoid bone tunnel. We change the method of obtaining and fixing the graft during the subscapular sling procedure. The half bundle of the peroneus longus tendon has sufficient strength and diameter and reduces the risk of complications. The establishment of the glenoid bone tunnel can provide a more stable fixation for the graft, facilitating stable tendon-bone healing. This arthroscopic subscapular sling procedure with glenoid bone tunnel and half bundle of the peroneus longus tendon graft can be considered an alternative to existing surgical treatment options for recurrent anterior shoulder instability.

In recent years, with increasing participation of adolescents in sports activities, the incidence of posterior cruciate ligament (PCL) injuries in paediatric patients has been increasingly reported. Conventional PCL reconstruction techniques typically require drilling femoral and tibial tunnels that cross or are adjacent to the physes. In paediatric patients with open physes, this technique carries a risk of damage to the physes, growth arrest, and lower limb deformity. For patients with open physes, a PCL reconstruction technique that both avoids physeal injury and restores knee stability is of critical importance. We describe a PCL reconstruction technique in this technical note. On the femoral side, a retrograde outside-in drilling technique is employed to create the femoral tunnel distal to the physis. On the tibial side, using the meniscofemoral-like structure as a reference, a low tibial tunnel is recreated.

Posterior cruciate ligament reconstruction remains limited by graft elongation, residual posterior laxity, and the persistent mechanical challenge of the tibial killer turn. Graft augmentations are appealing because they may protect the graft during early healing and improve construct integrity. To those recent works on mesh and suture-based reinforcement, the concept is biomechanically rational, but greater initial strength does not itself establish clinical superiority. Recent literature supports augmentation as a means of reducing graft elongation and improving biomechanical stability, yet current clinical evidence has not shown a clear advantage in postoperative laxity or patient-reported outcomes, and reconstructed knees may still show abnormal biomechanics. So, mesh augmentation in posterior cruciate ligament reconstruction seems promising, but it is not yet ready to change routine practice.

Medial Meniscus Posterior Root Tears (MMPRTs) are known to accelerate medial compartment knee osteoarthritis (OA). This study aimed to evaluate the short-term clinical outcomes of arthroscopic all-suture anchor (ASA) repair combined with high tibial osteotomy (HTO) for patients with medial compartment OA and MMPRTs, offering a potential new surgical approach for this condition. This study retrospectively reviewed 36 patients undergoing arthroscopic ASA repair combined with HTO for medial compartment OA with MMPRTs at our institution between June 2022 and June 2023. All patients underwent second-look arthroscopy during hardware removal. We collected demographic data (age, sex, affected side, duration of symptoms, complications), preoperative and postoperative Tegner activity scores, Lysholm scores, International Knee Documentation Committee (IKDC) scores, and Knee injury and Osteoarthritis Outcome Scores (KOOS). Radiographic comparisons (pre- and post-op) included Kellgren–Lawrence (K–L) grading, hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), and posterior tibial slope (PTS). Medial meniscus extrusion rate (MMER) was also assessed. At second-look arthroscopy, the healing status of the medial meniscus posterior root was evaluated. Patients were subgrouped based on root healing status to examine correlations with clinical scores, MMER, K–L grade, and symptom duration. The cohort comprised 30 females (83.3

Arthroscopic techniques have gradually replaced open surgery as a routine method for treating posterior cruciate ligament tibial avulsion fractures. However, traditional arthroscopic surgery is associated with problems such as limited visualization, unstable fixation, and unsatisfactory reduction. By comparing various methods reported in the literature and integrating clinical experience, our team has developed an optimized technique to address current surgical challenges. Using dual posteromedial portals, we adopt a "single-suture" method, in which the same epidural needle and a single suture are employed to encircle the posterior cruciate ligament via the lateral aspect of the anterior cruciate ligament, with dual EndoButtons applied for fixation. This technique not only precisely avoids the meniscofemoral ligaments and anterior cruciate ligament but also eliminates the need for separating the anterior cruciate ligament and posterior cruciate ligament, thus simplifying the procedure and reducing surgical injuries in the whole fixation process. It enhances fixation stability and surgical efficiency and preserves the posterior septum to promote postoperative functional recovery.

Purpose This study aimed to explore the risk factors for dislocation of the long head of the biceps tendon (LHBT) and to establish and validate a nomogram prediction model. Methods A retrospective analysis was performed on the clinical data of 193 patients with rotator cuff tears who underwent MRI and CT examinations in the Department of Orthopaedics IV, The Third Hospital of Hebei Medical University, from November 2023 to November 2025. Preoperative morphological parameters of the bicipital groove, including width, length, medial wall angle, and total opening angle, were measured on CT. All data analyses were conducted using R software (version 4.5.2), with key statistical packages including glmnet (for Lasso regression analysis), rms (for nomogram construction), pROC (for ROC curve analysis), and caret (for logistic regression analysis) along with Zstats v1.0. The significance level was set at p < 0.05. To construct the LHBT dislocation prediction model and evaluate the correlation between clinical factors and postoperative recovery, multiple statistical methods were employed, including univariate analysis, Lasso regression, logistic regression, and calibration curve analysis. Results A nomogram prediction model was successfully constructed. Univariate analysis and Lasso regression identified gender, smoking history, medial wall angle of the bicipital groove, total opening angle, and width and length of the bicipital groove as key influencing factors for dislocation. Further logistic regression analysis confirmed that the medial wall angle of the bicipital groove was a significant independent predictor. Conclusions Gender, medial wall angle of the bicipital groove, total opening angle, width, and length of the bicipital groove are risk factors for LHBT dislocation, with gender and medial wall angle showing significant statistical relevance. The calibration curves for the training and validation sets confirmed that the nomogram model for predicting LHBT dislocation possesses good predictive performance and offers reference value in clinical practice.

Osteoarthritis (OA), the most common degenerative joint disease worldwide, currently lacks effective disease-modifying therapies that can halt its progression. This therapeutic challenge stems from the complexity of multiple pathological mechanisms, including chondrocyte metabolic imbalance, inflammatory responses, and extracellular matrix (ECM) degradation. In recent years, epigenetics, particularly reversible methylation modifications, has provided a new perspective for understanding OA. This review systematically analyzes the multi-dimensional methylation regulatory network in OA from a “pan-methylation” perspective. DNA methylation regulates the transcriptional activity of key genes (e.g., SOX9, MMP13) through the DNMTs/TETs enzyme system. RNA epitranscriptomic modifications (e.g., m6A, m5C, m7G methylation) precisely controls mRNA stability, translation efficiency, and splicing processes via its “Writers-Readers-Erasers” machinery (METTL3, FTO, YTHDFs, etc.), influencing autophagy, inflammation, and metabolic balance. Histone methylation (e.g., H3K27me3, H3K79me2) directly regulates catabolic gene expression by altering chromatin states. These multi-layered methylation networks collectively form a complex epigenetic regulatory system in OA. Based on these findings, targeting specific methyltransferases has shown great therapeutic potential in preclinical studies. This review not only deepens the understanding of OA pathogenesis but also provides a theoretical basis and innovative strategies for developing disease-modifying therapies targeting the methylation network. Future research should focus on joint-specific drug delivery systems and epigenetic precision therapy to promote a fundamental shift in OA treatment paradigms. The interplay between different methylation layers (DNA, RNA, histone) in OA remains poorly mapped. How these modifications coordinate to drive disease progression is a key unresolved question. Most epigenetic studies focus on chondrocytes, while the role of methylation in synovium, subchondral bone, and immune cells within the OA joint is largely unexplored, limiting a holistic view of OA as an organ-level disease. Patient stratification based on epigenetic signatures for precision OA therapy is an emerging concept. Whether methylation patterns can predict disease progression or treatment response remains an open and clinically significant question.

BACKGROUND:Optimal graft selection for anterior cruciate ligament (ACL) reconstruction (ACLR) remains controversial, particularly regarding tendon-to-bone incorporation and biomechanical performance among autografts, allografts, and hybrid grafts. HYPOTHESIS:Autografts demonstrate superior tendon-to-bone healing, biomechanical strength, and functional recovery compared with allografts and hybrid grafts. STUDY DESIGN:Controlled laboratory study. METHODS:A total of 84 rats underwent ACLR using autograft, allograft, or hybrid grafts (a construct combining autograft and allograft tissues) (n = 21 per group), with an intact group serving as the control group. Grafts were harvested from the peroneus longus tendon. Assessments at 1, 2, 4, and 8 weeks included histology (hematoxylin and eosin; the Masson trichrome staining; immunohistochemistry), gait analysis, micro-computed tomography, and biomechanical testing. RESULTS:Histologically, compared with allografts and hybrid grafts, autografts exhibited significantly improved synovial coverage, lower cartilage degeneration (score, autograft vs allograft vs hybrid graft: 10.80 ± 0.84 vs 3.20 ± 0.84 vs 4 ± 0.71; P < .001), improved collagen alignment, reduced inflammation, and enhanced vascularization and tenogenesis, whereas allografts and hybrid grafts exhibited distinct necrosis. Autografts exhibited superior value of bone volume per total volume (femur, autograft vs allograft vs hybrid graft: 5.40 ± 0.55 vs 2.60 ± 0.86 vs 2.69 ± 0.25; P < .001). Gait parameters, including stride length and step height, were restored to near-control levels only in the autograft group (intact control vs autograft: stride length, 3.09 ± 0.40 vs 2.96 ± 0.35; P = .899; step height, 2.67 ± 0.31 vs 2.26 ± 0.35; P = .199). Biomechanically, autografts demonstrated superior stress (autograft vs allograft: 14.86 ± 4.26 vs 2.64 ± 1.35; P < .001), stiffness (autograft vs allograft: 11.21 ± 5.55 vs 3.15 ± 1.55; P = .027), and tensile modulus (autograft vs allograft vs hybrid graft: 31.71 ± 10.35 vs 3.71 ± 1.83 vs 15.07 ± 4.51; P < .001). CONCLUSION:Autografts provided superior tendon-to-bone integration, biomechanical performance, and functional outcomes compared with allograft and hybrid grafts in a rat ACLR model. CLINICAL RELEVANCE:This preclinical study, conducted in a rat model, provides mechanistic evidence that autografts exhibit superior biological incorporation and mechanical integrity, supporting the existing clinical preference for autograft in ACLR and helping inform graft selection.

Purpose:To identify bone morphological risk factors and injury patterns of medial structural injuries in patients with anteromedial rotatory instability (AMRI) after anterior cruciate ligament (ACL) injury. Methods:This comparative study analyzed patients' data between August 2024 and June 2025. ACL-deficient patients with combined injury of ligaments other than the medial collateral ligament or knee fracture were excluded. Patients aged 16 to 55 who were diagnosed with ACL rupture on magnetic resonance imaging and Kellgren-Lawrence grade < II on radiograph were included. All ACL injury patients were divided into 2 groups based on physical examination under anesthesia: 58 patients with a positive anterior drawer and Slocum test under anesthesia served as the AMRI group; 25 patients with a positive anterior drawer test but negative Slocum test under anesthesia served as the isolated ACL injury group (nonanteromedial rotatory instability [NAMRI] group). Preoperative magnetic resonance imaging was used to characterize bone morphological factors, including lateral femoral condyle ratio, medial femoral condyle width (MFCW), notch width, notch width index, coronal tibial slope, medial tibial depth, medial tibial posterior slope, and lateral tibial posterior slope. Medial structural injuries (superficial medial collateral ligament, deep medial collateral ligament [dMCL], and anteromedial retinaculum [AMR]) were assessed via ultrasound and magnetic resonance imaging. All patients did not experience postoperative infections or other surgical complications during at least 3 months of follow-up. During data analysis, t-tests were used to compare the differences between the mean values of various factors, 1-way analysis of variance was used to test the influence of each factor, and receiver operating characteristic (ROC) curves were used to test the predictive performance of MFCW. Results:The comparative study included 141 patients who were divided into 3 groups: AMRI (n = 58), ACL-injured patients without AMRI (NAMRI, n = 25), and isolated meniscus tear patients (control, n = 58). The AMRI group exhibited significantly smaller MFCW (AMRI: 6.72 ± 0.55 vs control: 7.35 ± 0.51, P < .001) and notch width (AMRI: 1.79 ± 0.29 vs control: 2.01 ± 0.37, P = .001), whereas significantly larger lateral femoral condyle ratio (AMRI: 0.672 ± 0.039 vs control: 0.644 ± 0.043, P = .001), medial tibial depth (AMRI: 0.36 ± 0.07 vs control: 0.31 ± 0.06, P < .001), and lateral tibial posterior slope (AMRI: 8.5 ± 2.6 vs control: 6.4 ± 2.9, P < .001) relative to the control group. The NAMRI group also showed significant differences, including larger lateral femoral condyle ratio (NAMRI: 0.668 ± 0.035 vs control: 0.644 ± 0.043, P = .048), lateral tibial posterior slope (NAMRI: 8.1 ± 2.3 vs control: 6.4 ± 2.9, P = .027), and medial tibial depth (NAMRI: 0.36 ± 0.08 vs control: 0.31 ± 0.06, P = .004) and smaller MFCW (NAMRI: 7.03 ± 0.37 vs control: 7.35 ± 0.51, P = .018), notch width (NAMRI: 1.73 ± 0.24 vs control: 2.01 ± 0.37, P = .001), and notch width index (NAMRI: 0.248 ± 0.035 vs control: 0.273 ± 0.044, P = .018) when compared with the control group. Critically, the AMRI group exhibited a smaller MFCW (NAMRI: 7.03 ± 0.37 vs AMRI: 6.72 ± 0.55, P = .033) relative to the NAMRI group, which represented a key factor in controlling anteromedial rotatory stability. Ultrasonography revealed a high prevalence of dMCL (89.7%) and AMR (63.8%) injuries in the AMRI group, and the combined injury of dMCL and AMR had the most frequent injury pattern. In addition, the ROC curve showed that MFCW showed a higher area under the ROC curve value in AMRI when compared with the control and NAMRI groups, respectively (area under the ROC curve: 0.791 AMRI vs control; 0.655 AMRI vs NAMRI). Conclusions:A smaller MFCW is associated with AMRI in patients with dMCL and AMR injuries compared with NAMRI patients. The injury pattern in AMRI is predominantly characterized by combined lesions of the ACL and dMCL + AMR. Level of Evidence:Level IV, retrospective comparative case series.

Treating patients with irreparable massive rotator cuff tears, particularly those with loss of external rotation and active elevation function, has always been a challenging clinical problem. Latissimus dorsi transfer has shown long-term clinical reliability, especially as a preferred surgical option for relatively young patients. However, isolated tendon transfer appears insufficient to restore the range of motion in patients with bidirectional deficits. There are various surgical techniques using the long head of the biceps tendon to mimic superior capsular reconstruction, among which dynamic biceps rerouting is a superior capsular reconstruction with more tension that can reconstruct the balance of vertical pairs acting on the shoulder. Latissimus dorsi transfer combined with dynamic biceps rerouting can compensate for the bidirectional functional deficiencies of the rotator cuff and minimize the risk of latissimus dorsi tendon rupture and related complications.

BACKGROUND:The Meyers-McKeever two-dimensional classification has been widely used in diagnosing and treating posterior cruciate ligament avulsion fractures since its introduction in 1959. However, because of image overlap and obscuration on knee radiographs, the type of avulsion fracture injury is often not identified, which can lead to misdiagnosis. CT has a higher overall confidence in size assessment, displacement, and degree of comminution of the posterior cruciate ligament avulsion fracture block compared with X-ray. Therefore, this study aims to propose a new classification system based on CT for posterior cruciate ligament avulsion fractures. METHODS:This multicenter study evaluated 523 patients with posterior cruciate ligament avulsion fractures admitted between July 2018 and July 2023 at nine medical centers. The new CT-based classification system, the Dong classification system, includes 2 major types and 7 subtypes. Furthermore, the inter- and intra-observer reliability of this classification system were compared to the Meyers - McKeever classification system by 4 observers (Kappa coefficient, K-value) to assess the reproducibility of the Dong-classification system for posterior cruciate ligament avulsion fractures. RESULTS:A total of 446 patients were eligible for inclusion criteria; 29 patients (6%) could not be classified through the Meyers - McKeever classification system, but all the cases were classifiable through the Dong classification system. The most common type of posterior cruciate ligament avulsion fracture is Type Ic, with 176 cases, accounting for 40%, followed by Type Ib, with 141 cases, accounting for 32%. Non-displaced fractures, including Type Ia and Type IIa, totaled 55 cases, representing 12%. The Meyers-McKeever classification had a mean K-value of 0.593 for inter-observer reliability and a mean K-value of 0.896 for intra-observer reliability. However, the Dong classification had a mean K-value of 0.768 for inter-observer reliability and 0.910 for intra-observer reliability. CONCLUSION:The CT-based 3D Dong classification is the first proposed 3D CT classification of posterior cruciate ligament avulsion fractures, which helps analyze the type of avulsion fracture and whether it is combined with a tibial plateau fracture from a 3D level. This classification shows higher inter- and intra-observer reliability than the Meyers - McKeever classification and can be used as a complement to the Meyers - McKeever and Schatzker classifications.

PURPOSE:The purpose of this study was to investigate whether meniscal injury and bony factors can predict high-grade pivot shift (HPS). METHODS:This study retrospectively reviewed patients who underwent reconstruction surgery for anterior cruciate ligament (ACL) rupture. According to the grading of the pivot-shift test under anaesthesia preoperatively, patients were allocated into the HPS group and low-grade pivot shift (LPS) group. Baseline demographic and clinical characteristics, including meniscal injury location and type, were systematically documented. Anterior tibial translation (ATT) was quantified via side-to-side difference (SSD) measurements using a Ligs digital arthrometer. Radiographic assessments included posterior tibial slope (PTS) and lateral femoral condyle ratio (LFCR). Coronal tibial slope (CTS), intercondylar notch width (NW), and femoral condylar width (FCW) were evaluated using magnetic resonance imaging (MRI). RESULTS:A total of 123 patients (77 males and 46 females, average age of 33.6 ± 12.7years) were included. Compared with the LPS group, the HPS group had a higher incidence of longitudinal tear of the medial meniscus posterior horn (MMPHL), smaller NW and FCW, larger PTS and CTS. Univariate and multivariate logistic analysis results revealed that MMPHL, NW, and PTS were significantly independent predictive factors for HPS. The cut-off value for PTS prediction of HPS was 12.3° (sensitivity 57.4%; specificity 69.1%) and that for NW prediction of HPS was 1.9 cm (sensitivity 83.8%; specificity 43.6%). CONCLUSIONS:MMPHL, smaller NW, and larger PTS were predictive factors for HPS in ACL rupture patients, with cut-off values of 1.9 cm (for NW) and 12.3° (for PTS).These findings help clinicians to timely identify patients at high risk of HPS preoperatively and better formulate surgical strategies. LEVEL OF EVIDENCE:Level IV.

Background: Quadriceps weakness is a common barrier to effective rehabilitation after anterior cruciate ligament (ACL) surgery. Neuromuscular electrical stimulation (NMES)—the application of electrical currents to induce muscle contraction—has been used as part of the postoperative rehabilitation regimen. Purpose: To investigate the effects of NMES on the recovery of quadriceps strength and knee function after ACL surgery. Study Design: Systematic review; Level of evidence, 1. Methods: A search was conducted in the Web of Science, Embase, Cochrane Library, and PubMed databases between inception and August 2023 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included were randomized controlled trials of patients undergoing NMES as postoperative rehabilitation after ACL reconstruction or repair, with standard physical therapy as the control intervention. The quality of the included studies was assessed according to the Cochrane Collaboration risk-of-bias tool. Lower limb function was assessed qualitatively, and standardized mean differences (SMDs) in muscle strength and Lysholm scores were analyzed quantitatively and pooled using a random-effects model. Results: Eleven studies (N = 202 patients) met our inclusion criteria. The meta-analysis of muscle strength values, which included 9 studies, showed that patients who underwent physical rehabilitation with adjunctive NMES had better recovery and improvement in quadriceps muscle strength compared with standard physical therapy at both short- and long-term follow-ups (≤6 weeks: SMD, 0.53 [95% CI, 0.27-0.79] vs >6 weeks: SMD, 0.59 [95% CI, 0.18-0.99]; p < 0.001). Moreover, subgroup analyses showed that earlier physical rehabilitation with the assistance of NMES resulted in better muscle strength recovery (≤1 week: SMD, 1.48 [95% CI, 0.80-2.17] vs >1 week: SMD, 0.44 [95% CI, 0.21-0.67]; p < 0.001). The meta-analysis of Lysholm scores, which included 3 studies, did not indicate any significant differences between the assisted NMES and control groups. Conclusion: Our study demonstrated that in both short- and long-term follow-up studies, postoperative rehabilitation with NMES after ACL surgery significantly increased quadriceps muscle strength compared with standard rehabilitation alone.

Objectives:This study aimed to evaluate the effectiveness of medial meniscus posterior root tear (MMPRT) repair during open-wedge high tibial osteotomy (OWHTO) by investigating MMPRT healing and clinical outcomes. It also aimed to explore the impact of lower limb alignment correction on MMPRT healing in unrepaired cases. Methods:A total of 157 patients (68 males and 89 females) were included, with an average age of 57.0 ± 6.66 years and an average postoperative follow-up duration of 22.1 ± 2.92 months, who underwent OWHTO followed by second-look arthroscopy. Patients were divided into two groups: the OWHTO with MMPRT repair group (n = 82) and the OWHTO-only group (n = 75). Each group was further divided into Fujisawa subgroup and neutral subgroups to assess the healing of MMPRT and clinical outcomes. Results:The overall MMPRT healing outcomes in the OWHTO with MMPRT repair group were similar to the OWHTO-only group. Cartilage damage showed no intergroup differences. Functional improvements were equivalent between groups. Subgroup analyses revealed differential outcomes: Fujisawa subgroup exhibits superior healing in isolated OWHTO, but not in combined procedures. Conclusion:Mid-term clinical outcomes were comparable between OWHTO combined with MMPRT pull-out repair and isolated OWHTO. For patients undergoing isolated OWHTO, mechanical axis correction targeting the Fujisawa point is significantly more conducive to MMPRT healing than neutral alignment. Consider prioritizing MMPRT repair for young patients or those with high activity demands. When MMPRT repair is not performed, it is recommended to target the correction of knee alignment to the Fujisawa point.

Compared with anterior cruciate ligament reconstruction, posterior cruciate ligament (PCL) reconstruction has a higher failure rate and revision rate, which is associated with multiple factors such as graft option, fixation method, postoperative rehabilitation, and management of concomitant injuries. Among them, “killer turn” is a key factor in the failure of PCL reconstruction. Although there are various techniques for PCL reconstruction, the ideal surgery remains controversial. Combined with our clinical experience, ultrasound-assisted positioning is used to locate the tibial tunnel with the distal posterior capsule reflection and the posterior septum as reference to safely achieve anatomic remnant preservation and PCL reconstruction. This technique not only preserves the integrity of the posterior septum but also minimizes the impact of the “killer turn” on the graft by keeping the tibial tract as low as possible and effectively improves the success rate of PCL reconstruction.

Arthroscopy has gradually become the routine method to treat posterior cruciate ligament tibial insertion avulsion. However, arthroscopic surgery possesses the advantages of being minimally invasive, having a good appearance, and having no need for revision surgery for internal fixation. Compared with open surgery, it is limited by disadvantages such as unstable fixation, unsatisfactory reduction, and fracture fragment displacement. After comparing the various methods proposed in the literature, the ''suture bridge'' technique, which is commonly used for rotator cuff treatment, is used for repair of posterior cruciate ligament tibial insertion avulsion in combination with the double posterior medial arthroscopic portals, is applied by our team. This surgical technique enables the even distribution of sutures above the fracture fragment, reduces the possibility of suture displacement, and enables excellent reduction under arthroscopy while fully preserving the posterior septum.

To compare the biomechanical properties of the graft during PCL reconstruction by three-dimensional finite element analysis of the PCL trans-tibial reconstruction technique with three different tibial bony channel exit positioning points, to determine which method of positioning is better able to avoid wear and tear between the graft and bony channel, and to reduce the failure rate of the PCL reconstruction. This is a study limited to computational simulation and based on data from a single anatomical model. Thirty-year-old male volunteers were selected. A three-dimensional knee joint model consisting of the distal femur, the proximal tibiofibula and the posterior cruciate ligament was established based on CT scanning and three-dimensional reconstruction of the left knee joint. According to the different positioning points of the tibial tunnel exit, the PCL model of tibial side PCL anatomical region center point reconstruction, the PCL model of Fanelli suggested point (i.e., 10 mm below and 5 mm lateral to the PCL anatomical point) reconstruction, and the PCL model of tibial side posterior posterior joint capsule distal anticompromise and posterior mediastinum reference positioning point (i.e., 5 mm above the posterior capsule distal retropubic, 5 mm medial to the posterior mediastinum) reconstruction were established (respectively designated as Model 1, Model 2, and Model 3). The diameter of the entire graft was set uniformly at 7 mm. With the knee flexed at 90° and the midpoint of the line connecting the medial and lateral apexes of the tibial intercondylar ridge as the reference point, a standardized backward thrust displacement of 5 mm was applied to simulate a posterior knee drawer test with all proximal femoral degrees of freedom constrained. The model overall Mises stress, tibial plateau Mises stress, PCL Mises stress, PCL contact Cpress stress, PCL contact stress and PCL contact effective area were measured. Simulated posterior drawer tests demonstrated that Model 3 exhibited a substantial reduction in PCL contact Cpress stress (22.57 MPa) compared to Model 1 (32.93 MPa) and Model 2 (29.86 MPa). Additionally, the ratio of contact force (277.48 N) to effective graft-tibial contact area (50.19 mm²), representing the contact force per unit area, was also the lowest in Model 3 compared to Model 1 (213.88 N/17.65 mm²) and Model 2 (470.77 N/63.75 mm²). These findings indicate that Model 3 significantly reduced frictional loads between the graft and tibia, highlighting its biomechanical optimization potential. Further analysis revealed that Model 3 also displayed the lowest tibial plateau Mises stress (48.80 MPa). However, its PCL tensile stress (69.71 MPa) was significantly higher than that of Model 1 (41.03 MPa) and Model 2 (40.90 MPa), suggesting that while Model 3 minimizes friction dependency, it primarily transfers loads through graft tension. Compared with the anatomic regional center point and Fanelli point reconstruction PCL, the grafts of the soft tissue reference tibial localization reconstruction PCL method were subjected to greater tensile forces, but they had significantly lower friction with the tibia and were able to reduce contact wear with the tibia. This can enhance long-term patient outcomes. Our study offers crucial biomechanical evidence for optimizing tunnel positioning in PCL reconstruction, propelling the advancement of surgical techniques.

Background Medial Meniscus Posterior Root Tears (MMPRTs) are known to accelerate medial compartment knee osteoarthritis (OA). This study aimed to evaluate the short-term clinical outcomes of arthroscopic all-suture anchor (ASA) repair combined with high tibial osteotomy (HTO) for patients with medial compartment OA and MMPRTs, offering a potential new surgical approach for this condition. Methods This study retrospectively reviewed patients undergoing arthroscopic ASA repair combined with HTO for medial compartment OA with MMPRTs at our institution between June 2022 and June 2023. All patients underwent second-look arthroscopy during hardware removal. We collected demographic data (age, sex, affected side, duration of symptoms, complications), preoperative and postoperative Tegner activity scores, Lysholm scores, International Knee Documentation Committee (IKDC) scores, and Knee injury and Osteoarthritis Outcome Scores (KOOS). Radiographic comparisons (pre- and post-op) included Kellgren-Lawrence (K-L) grading, hip-knee-ankle angle (HKA), medial proximal tibial angle (mPTA), joint line convergence angle (JLCA), and posterior tibial slope (PTS). Medial meniscus extrusion rate (MMER) was also assessed. At second-look arthroscopy, the healing status of the medial meniscus posterior root was evaluated. Patients were subgrouped based on root healing status to examine correlations with clinical scores, MMER, K-L grade, and symptom duration. Results The cohort comprised 30 females (83.3%) and 6 males (16.7%), with a mean age of 59 years. Mean follow-up was 24.8 ± 2.4 months. Significant improvements were observed in all final scores: Lysholm (46.58 ± 16.04 to 79.08 ± 14.29), IKDC (37.08 ± 14.57 to 65.81 ± 12.33), KOOS (116.50 ± 26.13 to 65.89 ± 15.50), and Tegner (1.00 ± 1.27 to 2.33 ± 1.15) (all P < 0.001). Subgroup analysis revealed no significant differences between healed and non-healed groups regarding Lysholm, IKDC, KOOS, Tegner scores, symptom duration, or K-L grade. No complications (infection, nonunion, neurovascular issues) occurred by final follow-up. Conclusion Arthroscopic ASA repair combined with HTO significantly improves short-term clinical outcomes in patients with medial compartment OA and MMPRTs. Crucially, the healing status of the medial meniscus posterior root showed no correlation with these short-term clinical outcomes and did not influence the clinical presentation after HTO.

Hip arthroscopy is an established treatment for femoroacetabular impingement syndrome, with demonstrated long-term efficacy. However, the deep-seated anatomy of the hip joint and its complex periarticular structures pose significant challenges for achieving safe capsulotomy and adequate intra-articular exposure. We describe a technique using the greater trochanter as an anatomical reference point to perform an outside-in, distal-to-proximal longitudinal capsulotomy under postless traction.

Purpose: Patients undergoing arthroscopic hip surgery (AHS) require good analgesia and early rehabilitation after surgery, and there is no consensus on the optimal nerve block. We aimed to compare the efficacy of the pericapsular nerve group (PENG) block with lateral femoral cutaneous nerve (LFCN) block compared to fascia iliaca compartment block (FICB) in patients with AHS. Patients and Methods: A total of 80 patients receiving AHS under general anesthesia were randomized to receive either FICB (group F) or PENG block in combination with LFCN block (group P). The primary outcomes were the rate of quadriceps weakness after block on the afflicted side, as well as muscle strength grading and pain score after block, and the quality of recovery on the second postoperative day. Results: Compared with group F, group P had a lower incidence of quadriceps weakness 48 h after block (76.9% vs 28.2%, P < 0.001), and had less impact on muscle strength grade and lower static pain score at 6, 12, 18, 24, 36, and 48 h after block (P < 0.001), and a lower dynamic pain score at 6 and 12 h after block in group P ( p < 0.05). The quality of recovery on the second postoperative day improved ( p < 0.05). Conclusion: In comparison to FICB, PENG block in combination with LFCN block can affect less quadriceps muscle strength and reduce the use of postoperative analgesics, which is beneficial for the postoperative recovery of AHS patients.