Preservation of posterior cruciate ligament in cruciate-retaining total knee arthroplasty with a cruciate-substituting insert does not affect postoperative clinical outcomes, including Forgotten Joint Score 12.

Magnetic resonance imaging (MRI) is a reliable diagnostic tool for anterior cruciate ligament (ACL) injuries. Nonetheless, the clinical relevance of morphological changes in the posterior cruciate ligament (PCL), such as the M-shaped PCL, following ACL injuries has not been well studied. This study aimed to investigate whether the presence of M-shaped PCL was associated with meniscal and ligamentous injuries in patients with ACL injuries. From May 2018 to May 2023, a total of 281 patients diagnosed noncontact ACL injuries with arthroscopy were retrospectively reviewed. The preoperative MRI images were examined to identify the presence of M-shaped PCL. Thirty-five patients with an M-shaped PCL were included in the study group, while 70 patients with non-M-shaped PCL were matched using 1:2 ratio by age (within 2years) and sex to the control group. Key anatomical factors of the femur and tibia, including femoral notch width (NW), bicondylar width (BCW), notch width index (NWI), medial tibial depth (MTD), static anterior tibial subluxation (SATS), medial tibial slope (MTS), lateral tibial slope (LTS), as well as the status of meniscal and ligamentous injuries including medial and lateral menisci (LM), medial and lateral collateral ligaments, and anterolateral ligament (ALL) were assessed using MRI. The Spearman correlation coefficients and multivariate logistic regression were applied to analyze potential predictors of M-shaped PCL. The mean age of all patients was 34.7 ± 10.2years, and the male-to-femaleratio was 3:4 in each group. The incidence of M-shaped PCL was 12.4%. The study group demonstrated a higher proportion of ALL injuries compared to the control group (54.3% vs 31.4%, respectively; p = 0.024). In all patients, the presence of M-shaped PCL independently predicted ALL injury (p = 0.021). In the M-shaped PCL group, ALL injury was associated with NW (ρ = 0.372; p = 0.028), BCW (ρ = 0.380; p = 0.024), and SATS (ρ = 0.437; p = 0.009). Additionally, LM lesions (p = 0.041), a larger NW (p = 0.038), and SATS (p = 0.019) independently predicted ALL injury. In the non-M-shaped PCL group, LTS was correlated with ALL injury (ρ = 0.375; p = 0.001), and a larger LTS independently predicted ALL injury (p = 0.005). In patients with ACL injuries, the presence of an M-shaped PCL was associated with ALL injury. For patients with M-shaped PCL, ALL injury was associated with LM lesions, a larger NW, and SATS.

To quantify the association between posterior tibial slope (PTS) and anterior cruciate ligament (ACL) graft failure using meta-analysis. This study introduces the anatomic-lateral-posterior slope (ALPS) classification as a simple, clinically oriented, slope-based risk stratification tool. Embase, MEDLINE, Scopus and Cochrane were searched from inception through 30 August 2024 for studies comparing PTS in ACL graft failure versus control knees. Random-effects models synthesized mean differences (MDs) and adjusted odds ratios (aORs). Studies reporting slope-category data were mapped to ALPS risk bands based on standard deviations from the failure-group mean slope. Subgroup analyses and meta-regression examined imaging modality and measurement technique. Twenty-four studies (6335 knees; 1597 failures) were included. Lateral PTS was associated with higher graft-failure risk per 1° increase (aOR = 1.15; 95% confidence interval: 1.06-1.23). Failure incidence rose across ALPS categories (9% green; 16%-23% blue; 41% red and 50% black). Medial PTS differences were smaller and not consistently predictive. Heterogeneity was substantial. Time to re-injury was an independent determinant; other moderators were collinear. Increased PTS-particularly lateral slope-is associated with ACL graft failure. The ALPS classification offers a pragmatic way to communicate slope-related risk; however, given non-significant aORs in some analyses and an anomalous signal in one 'low-risk' subgroup, its predictive capability should be viewed as preliminary pending prospective validation. Level III.

BackgroundThe current standard of care to treat a ruptured anterior cruciate ligament (ACL) is ACL reconstruction (ACLR), which involves replacing the torn ligament with a tendon graft. The implanted tendon graft undergoes a graft-maturation process known as ligamentization. However, the synthesis of type III collagen, which is typically found in weaker scar tissue, continues at higher concentrations, and the heterogeneous composition of collagen fibers of varying diameters of native ACL is never restored. Culture-expanded ACL-derived cells reseeded to tendon graft have shown the potential for enhanced ligamentization. We performed in vitro and in vivo studies of the outcomes of ACLR with decellularized tendon grafts reseeded with ACL-derived cells combined with acellularized cruciate ligament matrix (ACLM) powder as a biological scaffold. We hypothesized that this tissue-engineered construct would enhance the graft maturation process and mechanical properties of the graft following ACLR.MethodsACL-derived cells were harvested and isolated from remnants of ruptured ACLs within 4 weeks of injury in patients who had undergone ACLR. An ACLM was prepared from human ACL and posterior cruciate ligament tissues. Forty-five Sprague Dawley rats were randomly divided into 3 groups: a standard allograft group, an ACLM powder-only injection group, and an ACL-derived cells and ACLM powder co-injection group (e.g., target group). ACL-derived cells were mixed with ACLM powder and then injected into the decellularized tendon graft before ACLR.ResultsIn vitro experiments found that combining ACLM powder and ACL-derived cells improved survival and integration of reseeded cells in the tendon extracellular matrix, resulting in the successful transplantation of ACL-derived cells. Animal ACLR experiments confirmed histologically improved structural maturation in cellularity, metaplasia, and restoration of collagen crimping in the graft reseeded with ACL-derived cells and ACLM powder. Enhanced gene expression of type I collagen resulted in superior mechanical properties of the tendon graft compared with the control groups.ConclusionImplantation of a tendon graft reseeded with culture-expanded ACL-derived cells, and ACLM powder enhanced the tendon graft’s maturation process and mechanical properties. We provide in vitro and in vivo proof-of-concept evidence supporting the efficacy of reseeding a tendon graft with ACL-derived cells combined with ACLM powder as a biological scaffold for ACL reconstruction.Graphical Supplementary InformationThe online version contains supplementary material available at 10.1186/s13287-025-04760-1.

The objective of this study was to determine the efficacy and safety of the employment of a tourniquet in the management of a posterior cruciate ligament reconstruction (PCLR) surgery. We hypothesized that PCLR without tourniquet use would reduce postoperative joint swelling and tourniquet-related complications while maintaining comparable surgical outcomes. We retrospectively reviewed 108 consecutive patients who underwent PCLR surgery between March 2016 and July 2022. Exclusion criteria included osteoarthritis, meniscus injury requiring repair, history of peripheral neuropathy, pregnancy, lumbar radiculopathy, or prior knee surgery on the affected or contralateral knee. Patients were categorized into tourniquet and non-tourniquet groups according to their surgery dates. The outcomes were evaluated by quantifying pain levels using the visual analog scale (VAS) and assessing the range of motion. Duration of operation, arthroscopic visibility, complications, consumption of analgesic, and total bleeding from suction and drainage were recorded. Of the 108 patients, 55 patients received PCLR with the tourniquet between March 2016 and October 2019, and 53 patients received PCLR without a tourniquet between November 2019 and July 2022. No significant difference was found in sex, age, or body mass index (BMI). There was no significant difference between the two groups with respect to intraoperatively arthroscopic visualization, operation time, total bleeding, pain score, consumption of analgesic, and range of motion. Both groups exhibited no instances of infection, wound complication, or venous thromboembolism (VTE). The rate of joint swelling was significantly higher in the tourniquet group than in the non-tourniquet group (p = 0.01). The tourniquet group also experienced a few instances of bruising and blister in the mid-thigh, while none occurred in the non-tourniquet group. Given the comparable outcomes in terms of arthroscopic visualization, operation time, bleeding, pain, function, and less joint swelling, we advocate discontinuing routine tourniquet use in PCL reconstruction. This approach significantly reduces swelling and local complications while maintaining surgical efficacy, aligning with modern minimally invasive principles.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-22398-0.

Isolated grade-III posterior cruciate ligament (PCL) injuries are defined as PCL injuries without any other ligamentous pathology that have a posterior translation of ≥12 mm compared with the contralateral knee. The aims of this study were to investigate isolated grade-III PCL injuries and to compare the clinical outcomes of 2 surgical methods. Patients with a PCL injury between 2008 and 2020 were retrospectively reviewed. Patients with an isolated grade-III PCL injury underwent either PCL reconstruction or combined PCL and posterolateral corner (PLC) reconstruction. Stress radiographs (Telos) and International Knee Documentation Committee (IKDC) subjective score, Lysholm knee score, and Tegner activity scale values were obtained preoperatively and at each follow-up. Of 448 patients with a PCL injury, 254 patients with an isolated PCL injury were identified. Sixty of the 254 patients had a grade-III posterior translation. Thirty patients were excluded due to a lack of follow-up or medical information, leaving a cohort of 30 patients. The 17 patients who underwent isolated PCL reconstruction (Group I) and the 13 patients who underwent combined PCL and PLC reconstruction (Group II) had a mean age of 36.2 years (range, 16 to 59 years) and 31.8 years (range, 16 to 58 years) (p = 0.438), respectively, with a mean follow-up of 4.9 years (range, 2 to 11.8 years) and 4.3 years (range, 2 to 10 years) (p = 0.623), respectively. In Groups I and II, posterior translation, compared with the contralateral knee, improved from 13.7 ± 1.7 mm to 7.2 ± 3.2 mm (p < 0.0001) and from 14.6 ± 2.0 to 7.1 ± 2.4 mm (p = 0.001), respectively. In Group I, the mean IKDC, Lysholm, and Tegner scores improved from 54.8 to 71.8 (p = 0.001), from 56.7 to 77.9 (p = 0.004), and from 3.8 to 5.5 (p = 0.021), respectively. In Group II, the mean IKDC, Lysholm, and Tegner scores improved from 47.1 to 69.5 (p = 0.003), from 54.2 to 77.8 (p = 0.003), and from 4.0 to 5.2 (p = 0.042), respectively. No differences were observed between the groups. Patients with an isolated grade-III PCL injury who underwent isolated PCL reconstruction showed significant improvements in subjective and objective outcomes. No significant difference was observed between patients who underwent isolated PCL reconstruction and those who underwent combined PCL and PLC reconstruction. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

MRI manifestations and associated injuries in adolescent tibial tuberosity fractures: A retrospective study.

Condylar-Stabilized Designs in Total Knee Arthroplasty: A Classification System and Review of Outcomes.

The posterior cruciate ligament (PCL) is crucial for normal knee kinematics and stability. An improved understanding of the long-term consequences of PCL injuries has led to greater focus on accurate injury diagnosis and improvements in surgical instrumentation and techniques. However, controversy remains regarding indications for surgical versus nonsurgical management, as well as optimal surgical techniques such as PCL repair versus reconstruction, single-bundle versus double-bundle reconstruction, transtibial versus tibial inlay fixation, and graft choice. Recognition of concomitant injuries and posterior tibial slope, as well as considerations in pediatric patients, warrants additional attention to ensure satisfactory outcomes. The purpose of this review was to evaluate the current state of the literature on PCL injuries and variables associated with injury decision making based on reported outcomes.

Background:Aberrant anterior tibial artery (AATA) is an uncommon variation of the anterior tibial artery. It is an important vascular variation that increases the risk of vascular complications in some knee surgeries (high tibial osteotomy, posterior cruciate ligament reconstruction, etc).Hypothesis:The anatomic and morphometric features of AATA remain unclear. The authors hypothesize that the posterior femoral morphology and popliteus muscle-related features may be associated with the presence of AATA.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Between December 2022 and December 2024, knee magnetic resonance imaging (MRIs) were analyzed to detect AATA. Images in which image analysis was not optimal due to artifacts, images of patients with previous surgery around the knee, and patients with vascular malformations in the lower extremity were excluded. A control group was formed through computer-assisted randomization, comprising an equal number of men and women with AATA as patients. The condylar twist angle, posterior condylar angle (PCA), posterior tibiofemoral angle, popliteus sulcus depth (PSD), and PSD/lateral condylar width (LCW) parameters were measured on the MRIs of all patients and recorded for each patient. Patients with AATA variation were scanned for the presence of MRI of the opposite knee outside the time interval determined for the study, and it was analyzed whether patients with opposite knee MRIs had bilateral AATA.Results:After applying the inclusion and exclusion criteria, 4075 knee MRIs were analyzed. A total of 78 AATA variations were detected, with a prevalence of 1.91%. The prevalence of AATA was 2.04% in women and 1.78% in men. The PCA was statistically higher in patients with AATA compared with the control group (P < .005). PSD and PSD/LCW were found to be lower in patients with AATA compared with the control group (P = .012, P = .05). The prevalence of bilateral AATA in patients with AATA variation was 48.5%.Conclusion:The prevalence of AATA was found to be 1.91%. High PCA, low PSD, and PSD/LCW are radiologic parameters associated with AATA variation. Both the popliteus musculature and posterior femoral morphometry are related to the occurrence of AATA variation.

Knee abnormalities, such as meniscus tears and ligament injuries, are common in clinical practice and pose significant diagnostic challenges. While traditional imaging techniques—X-ray, Computed Tomography (CT) scan, and Magnetic Resonance Imaging (MRI)—are vital for assessment. However, X-rays and CT scans often fail to adequately visualize soft tissue injuries, and MRIs can be costly and time-consuming. To overcome these limitations, we developed an innovative AI-driven approach that allows for the detection of soft tissue abnormalities directly from X-ray images—a capability traditionally reserved for MRI or arthroscopy. We conducted a retrospective study with 4,215 patients from two medical centers, utilizing knee X-ray images annotated by orthopedic surgeons. The YOLOv11 model automated knee localization, while five convolutional neural networks—ResNet152, DenseNet121, MobileNetV3, ShuffleNetV2, and VGG19—were adapted for multi-label classification of eight conditions: meniscus tears (MENI), anterior cruciate ligament tears (ACL), posterior cruciate ligament injuries (PCL), medial collateral ligament injuries (MCL), lateral collateral ligament injuries (LCL), joint effusion (EFFU), bone marrow edema or contusion (CONT), and soft tissue injuries (STI). Data preprocessing involved normalization and Region of Interest (ROI) extraction, with training enhanced by spatial augmentations. Performance was assessed using mean average precision (mAP), F1-scores, and area under the curve (AUC). We also developed a Windows-based PyQt application and a Flask Web application for clinical integration, incorporating explainable AI techniques (GradCAM, ScoreCAM) for interpretability. The YOLOv11 model achieved precise knee localization with a mAP@0.5 of 0.995. In classification, ResNet152 outperformed others, recording a mAP of 90.1% in internal testing and AUCs up to 0.863 (EFFU) in external testing. End-to-end performance on the external set yielded a mAP of 86.1% and F1-scores of 84.0% with ResNet152. The Windows and web applications successfully processed imaging data, aligning with MRI and arthroscopic findings in cases like ACL and meniscus tears. Explainable AI visualizations clarified model decisions, highlighting key regions for complex injuries, such as concurrent ligament and soft tissue damage, enhancing clinical trust. This AI-driven model markedly improved the precision and efficiency of knee abnormality detection through X-ray analysis. By accurately identifying multiple coexisting conditions in a single pass, it offered a scalable tool to enhance diagnostic workflows and patient outcomes, especially in resource-constrained areas.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-21895-6.

To assess the impact of soft tissue release (STR) on radiological and clinical outcomes in functional alignment robot-assisted total knee arthroplasty (FA-TKA). This retrospective controlled study enrolled a total of 127 patients who underwent Mako robot-assisted FA-TKA. Based on whether soft tissue release was performed, patients were categorized into an STR group (n = 38) and a non-STR group (n = 89). Radiographic parameters, including the hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), and posterior tibial slope (PTS), were assessed. Knee function was evaluated using the Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) preoperatively and at 3 and 6 months postoperatively. STR was required in 50% of knees with valgus deformity and 28.9% of knees with varus deformity. Rates increased significantly with deformity severity: 0% for varus < 10°, 62.5% for varus ≥ 10°, 95.8% for varus ≥ 15°. In knees with varus deformity, 68.6% medial collateral ligament (MCL) and 94.3% posterior cruciate ligament (PCL) were most commonly released; iliotibial band (ITB) release was universal in knees with valgus deformity requiring STR. Preoperative HKA and MPTA were significantly lower, while mLDFA was higher, in the STR group compared to the non-STR group (all P < 0.05). Postoperatively, HKA remained lower in the STR group compared to the non-STR group. There were no significant differences between groups in postoperative mLDFA, MPTA, PTS, or in KSS and WOMAC scores at any time point. Notably, the magnitude of correction in HKA and MPTA was greater in the STR group. During FA-TKA, STR is commonly employed to achieve soft tissue balance in cases of severe varus (≥ 10°) or knees with valgus deformity. In knees with varus deformity, the most frequently released structures are the MCL and PCL, whereas in knees with valgus deformity, release predominantly involves the ITB. However, intraoperative STR did not significantly impact postoperative lower limb alignment or short-term clinical outcomes compared to no release. The decision to perform STR should be individualized based on the type and severity of preoperative deformity.

The role of the posterior cruciate ligament remains debated, particularly in medial pivot designs intended to functionally substitute the posterior cruciate ligament. While some manufacturers recommend posterior cruciate ligament resection, evidence regarding its biomechanical relevance in medial pivot total knee arthroplasty is limited. This in vitro study evaluated knee kinematics in seven cadaveric knees implanted with a mechanically aligned medial pivot total knee arthroplasty (GMK Sphere). Each specimen was tested dynamically (30°-130° flexion) under three conditions: native knee, medial pivot with posterior cruciate ligament retained and with posterior cruciate ligament resected. Kinematic parameters (anterior-posterior translation, tibial rotation, patellar shift and tilt) and quadriceps force were recorded using a 3D optoelectronic system in a validated dynamic knee rig. Compared to native knees, medial pivot total knee arthroplasty increased anterior tibial translation and altered tibial rotation (p < 0.001), regardless of posterior cruciate ligament status. Patellar shift showed less medialization in deep flexion with posterior cruciate ligament retention in comparison to native conditions (R2 = 0.20, p < 0.001). Quadriceps force differed from the native state but was unaffected by posterior cruciate ligament status; force patterns were primarily determined by the native knee (R² = 0.90, p < 0.001). Posterior cruciate ligament retention in medial pivot total knee arthroplasty does not significantly affect femorotibial or patellofemoral kinematics. The highly congruent medial design appears to reduce the functional importance of the posterior cruciate ligament. Therefore, intraoperative decisions regarding posterior cruciate ligament management may be made less on concerns about kinematic compromise. N/A.

Objective: To investigate the effect of soft-tissue referenced tibial tunnel positioning based on the distal fold of the posterior capsule and the posterior compartment on the"killer turn"effect in posterior cruciate ligament (PCL) reconstruction. Methods: A retrospective analysis was conducted on the clinical data of 40 patients with PCL injury who underwent reconstruction surgery in the Department of Joint Surgery, the Third Hospital of Hebei Medical University, from July 2023 to October 2024. All patients underwent PCL reconstruction by the same surgical team. The distal fold of the posterior capsule and the posterior septum were set as reference landmarks at the tibial side. MRI was used to measure the soft-tissue and bony"killer turn"angles of 20 patients immediately postoperatively and at 6 months after the surgery, to assess the impact of soft-tissue referenced positioning and remnant-preserving PCL reconstruction on the"killer turn"effect and its dynamic changes. Graft diameters of these 20 patients were measured on MRI immediately postoperatively and at 6 months and were compared. The graft and remnant morphology and the status of the posterior capsule were evaluated too. The knee stability and functional scores [Lysholm score, Tegner activity score, International Knee Documentation Committee (IKDC) score] were assessed in the other 20 patients with 1 year of follow-up. A 30-year-old male volunteer underwent CT scanning and reconstruction to create a three-dimensional finite element model of the knee joint. Two models were established based on whether the PCL remnant was preserved or not: a soft-tissue referenced non-remnant-preserving PCL reconstruction model and a remnant-preserving PCL reconstruction model. A posterior drawer test was simulated to compare the stress conditions of the grafts in the two models. Results: A total of 40 eligible patients [including 27 males and 13 females, aged (37.2±14.9) years] were included in this study. The imaging data of these patients were included. Immediately postoperatively, the soft-tissue"killer turn"angle was 104.70°±7.95°, and the bony"killer turn"angle was 91.39°±10.21° (P<0.001). At 6 months postoperatively, the soft-tissue"killer turn"angle was 108.13°±12.01°, was comparable with the immediate postoperative value (P=0.107); and the graft diameter did not change significantly at 6 months postoperatively when compared with the immediate postoperative period [[(7.58±0.57) mm] vs (7.65±0.56) mm, P=0.167]. Ultrasound at 6 months postoperatively showed intact graft morphology and the distal fold structure of the posterior capsule. At 1 year postoperatively, the Lysholm score, Tegner activity score and IKDC score all improved significantly when compared to the preoperative values (all P<0.05). In the finite element analysis, the remnant-preserving model exhibited lower graft tension, interaction force with the tibial plateau, and frictional force compared to the non-remnant-preserving model. Conclusion: The soft-tissue referenced tibial tunnel positioning based on the distal fold of the posterior capsule and the posterior compartment for remnant-preserving PCL reconstruction can effectively reduce the"killer turn"effect, minimize graft-bone friction, and prevent graft wear and thinning.

The impact of coronal alignment on cruciate ligament forces in bicruciate-retaining total knee arthroplasty (TKA) remains unclear. We aimed to clarify in vivo cruciate ligament forces and knee kinematics among mechanically aligned (MA) and functionally aligned (FA) TKAs and normal knees. Normal, MA TKA and FA TKA knees were assessed during squatting using fluoroscopy. Tibiofemoral kinematics was measured using a two-dimensional/three-dimensional registration technique, including axial rotation, varus-valgus angle, and anteroposterior translation (APT) of the surgical epicondylar axis (SEA) and low contact points (LCPs). Ligament tensions during knee flexion were analysed in the anteromedial anterior cruciate ligament (aACL) and posterolateral anterior cruciate ligament (pACL) and anterolateral posterior cruciate ligament (aPCL) and posteromedial posterior cruciate ligament (pPCL). Both MA and FA TKA knees exhibited greater external femoral rotation and less varus alignment. Medially, MA TKA knees were positioned more anteriorly at 0° flexion. Laterally, both TKA knees were positioned more posteriorly up to 10° flexion. Medially, MA TKA knees were positioned more anteriorly at 0° flexion. Laterally, both TKA knees were positioned more posteriorly up to 10° flexion. In lateral LCPs, both TKA knees were more anteriorly positioned. aACL and pACL tensions decreased with flexion, with no significant differences between TKA and normal knees, whereas aPCL and pPCL tensions increased with flexion. Beyond 80° flexion, MA TKA knees exhibited greater aPCL tension. Beyond 90° flexion, pPCL tension was higher in MA TKA knees. PCL tension was notably higher in MA TKA knees. However, FA TKA and MA TKA demonstrated comparable kinematics and changes in ACL force. Although FA TKA more closely restored the physiological balance of the cruciate ligaments, the overall effect appeared to be limited. Level II.

Objective: Autografts or allografts are used frequently in posterior cruciate ligament (PCL) reconstruction. This study aims to assess functional results and donor-site morbidity associated with using the peroneus longus tendon (PLT) autograft in primary posterior cruciate ligament (PCL) reconstruction.Methods: This systematic review followed PRISMA guidelines. We searched the literature through multiple databases. After using predetermined eligibility criteria, seven studies published between 2019 and 2024 were included in this systematic review.All studies reported quantitative outcomes in patients who underwent isolated PCL reconstruction using PLT autografts and had a follow-up of ≥12 months... Extracted data included International Knee Documentation Committee (IKDC), Lysholm and Cincinnati scores, hop test results, thigh circumference differences, the American Orthopedic Foot and Ankle Society (AOFAS) score, and the Foot and Ankle Disability Index (FADI) scores. Results: The analysis included a total of 178 patients, with 131 males and 47 females. The average follow-up duration was 22.36 ± 3.18 months, and their mean age was 33.74 ± 6.10 years.Significant improvement was observed in all measured functional outcome scores. The average IKDC score was 82.48. The average postoperative Lysholm score was 84.44. Furthermore, the Modified Cincinnati score increased by more than 30 points, and the Hop test results revealed that limb function exceeded 91% compared to the contralateral side. Differences in thigh circumference ranged from –0.7 cm to –1.5 cm and were not considered clinically significant.The average AOFAS score was 92.34, and the FADI score averaged 94.30, indicating preservation of ankle function and minimal impairment at the donor site. Comparative studies showed that the use of PLT autografts yielded equal or superior outcomes to hamstring autografts.Conclusion: PCL reconstructions that use PLT autografts display promising efficacy, resulting in minimal donor-site morbidity and excellent functional outcomes. Future high-quality randomized studies are necessary to confirm the broad use of this technique.

To evaluate the effects of posterior cruciate ligament(PCL) resection on soft tissue elasticity and knee stability in total knee arthroplasty(TKA). Six adult cadaveric knee specimens (involving 10 knees) were included in the study. With the assistance of the robotic system(TiRobot Recon, TINAVI, Beijing), total knee arthroplasty (TKA) was performed sequentially using cruciate retaining (CR) prostheses and posterior stabilizing (PS) prostheses. Between the two surgical procedures, the femoral and tibial osteotomy surfaces were not altered;only the posterior cruciate ligament (PCL) was resected and the intercondylar fossa was treated. After installing the femoral trial component, a soft tissue balance solver was used to apply tension ranging from 30 N to 90 N in 5 N increments at 0°, 10°, and 90° of knee flexion. Meanwhile, the medial and lateral joint gaps were measured synchronously. Based on the tension-gap coupling data, the equivalent elastic coefficients of the medial and lateral soft tissue sleeves at different knee flexion angles, as well as the range of the joint line convergence angle (JLCA) under fixed varus-valgus stress, were calculated. Additionally, the gap balance status under 80 N of tension was analyzed. Self-control comparisons of each indicator were conducted before and after PCL resection to analyze the change patterns. After PCL resection, in the fully extended position (knee flexion 0°). The medial equivalent elastic coefficient was 32.2 (25.7, 63.3) N·mm-1 for the CR prosthesis and 27.7 (22.0, 51.9) N·mm-1 for the PS prosthesis, and the statistically significant difference (P=0.013). The range of JLCA was 0.41°(0.26, 0.55)° for the CR prosthesis, which was smaller than 0.75° (0.40, 0.98)° for the PS prosthesis, and the difference was statistically significant(P=0.041). At 90° of knee flexion, the medial joint gap was 10.7(10.1, 11.7) mm for the CR prosthesis, which was smaller than 12.1(10.9, 15.1) mm for the PS prosthesis, with a statistically significant difference(P=0.011). No statistically significant differences were observed in other joint gaps. PCL resection reduces the rigidity of the medial soft tissues in the fully extended knee and increases the medial joint gap in the flexed position, thereby affecting knee stability and balance. This finding suggests that PS and CR prostheses may require different morphological designs, and there should be differences in indications and osteotomy strategies between CR-TKA and PS-TKA. CR-TKA is more suitable for patients with preoperative medial soft tissue laxity.

Various fixation techniques, including screws and suture-based methods, are used for posterior cruciate ligament (PCL) avulsion fractures. This study compared the biomechanical effects of different suture configurations in simulated PCL avulsion fractures. Twenty cadaveric knees were assigned to four fixation groups: antegrade screw (A), 1 suture tape with 2 tunnels (B), 2 suture tapes with 2 tunnels (C), and 2 suture tapes with 3 tunnels (D). Biomechanical testing included cyclic loading and load-to-failure tests, with elongation, stiffness, yield load, and failure modes recorded. No significant differences were found between groups (p > 0.05). Mean elongation ranged from 10.1 ± 2.9 mm (B) to 21.9 ± 15.9 mm (D), while mean yield load varied from 375.6 ± 110.9 N (C) to 428.6 ± 197.6 N (B). Fragment breakage was common in Groups A and D, while suture cut-through occurred in Groups B and C. Across all groups, bone mineral density (BMD) significantly correlated with yield load (r = 0.511, p = 0.021) and elongation (r = -0.553, p = 0.0110.Suture-based techniques provided comparable biomechanical performance to screws, and increasing suture tapes or tunnels did not enhance fixation strength. Bone quality should be considered when planning fixation and rehabilitation.

To summarize the research progress on knee laxity of biomechanics and prevention and treatment after posterior cruciate ligament (PCL) reconstruction. The domestic and international literature on the prevention and treatment of knee laxity after PCL reconstruction in recent years was extensively reviewed and analyzed. Different degrees of knee laxity often occur after PCL reconstruction, which can lead to poor prognosis in patients. The causes are associated with a variety of factors, including abnormal graft remodeling (such as differences in healing time and biomechanics among different types of grafts), tunnel position deviation (such as graft wear caused by the "killer turn" effect), and mechanical factors in postoperative rehabilitation (such as improper early weight-bearing and range of motion). These factors may promote graft elongation, increase early posterior tibial translation, and thereby induce knee laxity. While PCL reconstruction improves knee stability, it is crucial to focus on and prevent postoperative knee laxity. However, current surgical methods are limited by factors such as graft characteristics, surgical technique flaws, and rehabilitation protocols, and thus can not fully correct the issue of abnormal postoperative laxity. Surgical techniques and treatment strategies still need further improvement and optimization to enhance patients' postoperative outcomes and quality of life.

This study developed a new surgical robot for cruciate ligament reconstruction and compared its accuracy of bone tunnel placement with traditional surgical methods in combined posterior cruciate ligament (PCL) and anterior cruciate ligament (ACL) reconstruction. 8 human cadaver knees were used for robot-assisted combined PCL and ACL reconstruction, and three-dimensional (3D) computed tomography (CT) was performed after operation to confirm the bone tunnel information. Postoperative 3D CT images of eight patients completed by the same operator with conventional techniques were also acquired. The operation time, bone tunnel position and length were measured and compared between robotic and conventional surgery. Regarding the tunnel position, there was no significant difference between the planned and actual tunnels in robotic surgery and the anatomical site of the cruciate ligament (P > 0.05). However, there are significant differences between robotic and conventional surgery (P < 0.001). Compared with traditional surgery, the robotic surgery demonstrated higher accuracy in the drilling of the cruciate ligament tunnel. Regarding the length of the cruciate ligament tunnel, no statistically significant discrepancy was observed between the actual and planned tunnels (P > 0.05), with a maximum error of less than 2mm. The robot was able to accurately control the length of the cruciate ligament tunnel. The robots can be used to assist in combined ACL and PCL reconstruction with higher accuracy than traditional surgery. It is a potentially powerful tool to enhance cruciate ligament reconstruction surgery.