Jiangtao Dong

Background: Combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries lead to anteromedial rotatory instability (AMRI), yet their in vivo biomechanics and effects on osteoarthritis (OA) severity relative to isolated injuries remain unclear. Purpose: To establish a murine AMRI model via combined ACL and MCL transection (ACLT+MCLT) and compare OA progression with isolated ACL transection (ACLT) and destabilization of the medial meniscus (DMM). Study Design: Controlled laboratory study. Methods: A total of 36 eight-week-old male C57BL/6 mice were used. Twelve underwent ex vivo biomechanical testing of anterior tibial translation (ATT) at neutral position, 15° internal rotation (IR), and 15° external rotation (ER) in ACLT+MCLT versus ACLT. The remaining 24 were randomized to the sham, ACLT, DMM, and ACLT+MCLT groups and underwent 6 weeks of treadmill running. ATT was assessed via photographic and radiographic evaluations. Gait, micro-computed tomography (CT) (osteophytes, subchondral bone plate), histology (OARSI score, cartilage thickness), and immunohistochemistry (type II collagen, Aggrecan, matrix metalloproteinase 13 [MMP13]) were analyzed. Data were compared using analysis of variance (ANOVA) with post hoc tests and repeated-measures ANOVA where appropriate. Results: ACLT+MCLT showed significantly increased ATT at 15° ER versus ACLT (photographic: 1.32 ± 0.28 vs 1.01 ± 0.33 mm; P < .05; loaded radiographic: 3.46 ± 0.78 vs 2.53 ± 0.50 mm; P < .001), confirming AMRI-like instability. After 6 weeks, ACLT+MCLT caused the most severe gait impairment, including increased stride width versus ACLT and DMM (3.46 ± 0.31 vs 2.80 ± 0.23 and 3.03 ± 0.17 cm; both P < .05) and reduced stride length versus sham and ACLT (5.05 ± 0.52 vs 6.87 ± 0.36 and 5.99 ± 0.57 cm; both P < .05). Micro-CT showed the greatest osteophyte number and subchondral bone plate thickness in ACLT+MCLT mice (15 ± 2.83 and 221 ± 36 μm, respectively; all P < .05 vs ACLT and DMM). Histologically, ACLT+MCLT had the highest OARSI score (5.75 ± 0.50) and lowest cartilage thickness (117.5 ± 15 μm). Immunohistochemistry showed reduced type II collagen and Aggrecan expression (13.80% ± 2.29% and 18.60% ± 0.92%) and increased MMP13-positive cells (77.10% ± 5.51%). Conclusion: Combined ACL and MCL injury created a valid murine AMRI model and induced more severe OA and dysfunction than isolated injury, confirming the detrimental effect of coupled rotational anterior instability. This model offers a preclinical tool for AMRI research; clinical translation requires human studies. Clinical Relevance: The established AMRI animal model simulates the complex rotatory instability of the knee after combined ACL and MCL injuries, as observed clinically. It provides a crucial preclinical tool for evaluating the efficacy of different ligament management strategies (eg, single-stage combined reconstruction vs staged treatment) in restoring joint stability and delaying OA progression. The findings suggest that in cases of significant rotatory instability, aggressive surgical intervention to restore rotational stability may be critical to protecting cartilage and improving long-term outcomes.

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.

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.

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.

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.

Medial Meniscus Posterior Root Tears (MMPRTs) are known to accelerate medial compartment knee osteoarthritis (OA). This study aimed to evaluate the short-t

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. Technique Video: video See video under supplementary data.

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. 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. 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. 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.

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.