Abstract Purpose To track the 24‐month longitudinal changes in tibiofemoral alignment characterised by passive anterior tibial subluxation (PATS) following anterior cruciate ligament reconstruction (ACLR), and to investigate associated factors. Methods Fifty‐one patients who underwent primary ACLR using hamstring tendon autografts between March 2021 and February 2022 were enrolled. Clinical and magnetic resonance imaging (MRI) evaluations were performed at baseline (within 3 days preoperatively) and at 6‐, 12‐ and 24‐month follow‐ups to examine the graft integrity and tibiofemoral alignment. Lateral PATS (L‐PATS), medial PATS (M‐PATS), global PATS (G‐PATS) and rotational PATS (R‐PATS) were measured on serial MRI. The repeated‐measures one‐way analysis of variance was applied to test the longitudinal changes in PATS. Univariable and multivariable linear regression analyses were performed to identify associations between preoperative and postoperative PATS, adjusting for a priori‐defined covariates including time from injury to surgery, tibial slopes, meniscal injuries and anterolateral ligament (ALL) abnormality. Results The graft integrity was clinically and radiographically confirmed in all patients at the 24‐month follow‐up. However, serial MRI revealed significant increases in L‐PATS, M‐PATS and G‐PATS (all p < 0.001) following the primary ACLR. The increases in L‐PATS (1.5 mm, 95%CI [0.6,2.5], p < 0.001), M‐PATS (1.2 mm, 95%CI [0.5,1.9], p < 0.001) and G‐PATS (1.4 mm, 95%CI [0.6,2.1], p < 0.001) from baseline became the most prominent at 12 months and remained stable thereafter. Strong correlations were identified between preoperative and 24‐month postoperative values for L‐PATS (β = 0.60, p < 0.001), M‐PATS (β = 0.43, p < 0.001), G‐PATS (β = 0.48, p < 0.001) and R‐PATS (β = 0.70, p < 0.001). ALL abnormality was associated with increased L‐PATS (β = 1.85, p = 0.008) and G‐PATS (β = 1.31, p = 0.009), while medial meniscal injury was associated with increased M‐PATS (β = 1.12, p = 0.036) and G‐PATS (β = 0.96, p = 0.048) measured at 24 months postoperatively. Conclusions Residual tibiofemoral malalignment characterised by increased L‐PATS, M‐PATS and G‐PATS persists following ACLR using hamstring tendon autografts. Excessive preoperative PATS, ALL abnormality and medial meniscal injury are associated with increased postoperative PATS. Level of Evidence Level IV.

ABSTRACT Objective There is a paucity of large‐scale epidemiological evidence on cartilage injuries among the Chinese population. This cross‐sectional study was designed to delineate the prevalence, distribution, and determinants of knee cartilage injuries in patients undergoing primary knee arthroscopy. Methods We retrospectively reviewed patients who underwent primary knee arthroscopy from 2017 to 2023. Intraoperative findings were used to document the location, severity, and size of cartilage defects. Mixed‐effects logistic regression models were employed to identify independent factors, accounting for bilateral procedures. Analysis of covariance was conducted to assess differences in preoperative Patient‐Reported Outcome Measures (PROMs). Results Among 25,293 arthroscopies, the overall prevalence of cartilage injury was 66.2%, and severe lesions (Outerbridge Grade III–IV) were present in 26.6%. Patellar cartilage exhibited the highest overall prevalence (39.4%), whereas the trochlea showed the highest prevalence of severe lesions (12.0%). Patella‐related disorders revealed the highest prevalence of concomitant cartilage injuries of 86.08% (severe injuries of 51.42%). Positive associations were found between overall cartilage injuries with professional athletic status (adjusted OR = 2.18, 95% CI: 1.47, 3.22, p < 0.001), higher BMI (adjusted OR = 1.05, 95% CI: 1.04, 1.06, p < 0.001), longer injury duration (adjusted OR = 1.00, 95% CI: 1.00, 1.00, p < 0.001), patella‐related disorders (adjusted OR = 3.73 vs. meniscal tear, 95% CI: 3.18, 4.37, p < 0.001), and prior musculoskeletal injury (adjusted OR = 1.31, 95% CI: 1.17, 1.47, p < 0.001). Negative associations were observed for pre‐injury regular sports participation (adjusted OR = 0.74, 95% CI: 0.65, 0.85, p < 0.001), ACL rupture (adjusted OR = 0.47 vs. meniscal tear, 95% CI: 0.43, 0.52, p < 0.001). A significant sex‐age interaction was noted. In males, older age was associated with higher prevalence of cartilage injuries, while females exhibited an even more significant increase after 50 years. For patients with isolated cartilage injuries, patient‐reported outcomes and limitations on daily activity were significantly worse than those with other intra‐articular disorders (all with p < 0.001). Conclusions Knee cartilage injury was highly prevalent in patients undergoing primary arthroscopy. Patellar and trochlear cartilage were the most frequently and most severely affected, respectively. Patella‐related disorders carried the greatest risk of concomitant cartilage damage. Several potentially modifiable factors, including regular sports participation, were associated with injury occurrence, underscoring opportunities for prevention and early intervention.

OBJECTIVE:To investigate the midterm clinical efficacy of medial patellofemoral complex (MPFC) reconstruction for recurrent patellar dislocation with high-grade trochlear dysplasia. METHODS:A retrospective analysis was carried out among adult patients who underwent arthroscopically assisted MPFC reconstruction between January 2014 and December 2020. Dejour classification was evaluated to grade trochlear dysplasia; tibial tubercle-trochlear groove (TT-TG) distance and Insall-Salvati index were measured. Preoperative and postoperative patient-reported outcome measures (PROMs) were compared, including International Knee Documentation Committee (IKDC) score, Kujala score, Lysholm score and Tegner score. Information regarding returning-to-sport rate, re-instability events and complications was collected. Patellar tilt (PT), lateral patellar displacement (LPD) and bisect offset (BSO) ratio were measured based on axial computed tomography before and after surgery to assess the patellofemoral congruence. RESULTS:A total of 46 MPFC reconstructions in 43 patients were enrolled, including 16 male and 27 female. Mean age at surgery was (22.2±7.6) years (range: 14-44 years). Mean follow-up was (49.9±22.6) months (range: 18-102 months). The percentages of Dejour B, C and D dysplasia were 37.0% (17/46), 43.5% (20/46), and 19.6% (9/46), respectively. Mean Insall-Salvati index was 1.2±0.2 (range: 0.85-1.44), and mean TT-TG distance was (19.6±3.5) mm (range: 10.6-28.7 mm). At latest follow-up, there were significant improvements in all PROMs (P < 0.001): IKDC score, from 56.3±15.1 to 86.2±8.1; Kujala score, from 58.9±15.6 to 92.6±5.4; Lysholm score, from 63.7±15.0 to 94.0±5.7; Tegner score, from 3.1±1.4 to 4.7±1.4, and there were no significant differences in the improvements of the scores between the patients with Dejour B, C and D dysplasia. Overall, ninety percent of the patients returned to their preoperative sports level. One patient reported a postoperative subluxation, while no cases of infection, limited range of motion or patella fracture were observed. PT, LPD and BSO ratio were all significant altered (P < 0.001) after MPFC reconstruction. CONCLUSION:Arthroscopically assisted MPFC reconstruction yielded satisfactory midterm clinical results for recurrent patellar dislocation with high-grade trochlear dysplasia. No significant differences of improvements in knee function were observed among the three types of high-grade trochlear dysplasia.

Purpose To determine the thresholds for substantial clinical benefit (SCB) for patient-reported outcome measures (PROMs) and to identify potential factors associated with achieving the SCB thresholds after primary anterior cruciate ligament reconstruction (ACLR). Methods Patients who underwent primary single-bundle ACLR using hamstring tendon autografts at our institute were included. The collected PROMs included the visual analog scale for pain, Tegner Activity Scale (Tegner score), modified Lysholm Knee Scoring Scale (Lysholm score), and International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form (IKDC score). The SCB thresholds for PROM improvements and raw postoperative PROM scores were determined based on patient responses to an anchor question. Multivariable logistic regression analyses were performed to identify factors associated with achieving the SCB thresholds. Results A total of 382 patients with a minimum 4-year follow-up were included in this study. The SCB thresholds for PROM improvements and raw postoperative PROM scores were determined to be 2 and 1.5, respectively, for the visual analog scale pain score; 3 and 3.5, respectively, for the Tegner score; 24.2 and 81.5, respectively, for the Lysholm score; and 27.2 and 77.6, respectively, for the IKDC score. Male sex (P = .0050 for raw postoperative score), younger age (P = .0249 for score improvement, P = .0075 for raw postoperative score), athletes (P = .0001 for score improvement), and non-contact injury (P = .0034 for raw postoperative score) were associated with increased odds of achieving the SCB threshold for the Tegner score. Higher body mass index was associated with decreased odds of achieving the SCB thresholds for both the raw postoperative Lysholm score (P = .0009) and Lysholm score improvement (P = .0036). A longer time from injury to surgery was associated with decreased odds of achieving the SCB threshold for IKDC score improvement (P = .0006). Conclusions The SCB thresholds for PROM improvements and raw postoperative PROM scores were determined after primary ACLR. Male sex, younger age, lower body mass index, athletes, shorter time from injury to surgery, and non-contact injury were associated with increased odds of achieving the SCB thresholds. Level of Evidence Level IV, case series.

Purpose: To evaluate the clinical outcomes following arthroscopic anterior cruciate ligament (ACL) reconstruction (ACLR) in patients over 60 years and to investigate the potential impact of preoperative osteoarthritis (OA) on these outcomes. Methods: A retrospective study included ACL-injured patients over 60 years who underwent primary arthroscopic ACLR between 2010 and 2020. The Lysholm score and the International Knee Documentation Committee (IKDC) score were assessed preoperatively and at the final follow-up. The Tegner activity scale was performed to evaluate patients' activity levels. Data on return to sports, patient satisfaction, subsequent injuries and complications were collected. Preoperative radiographs were used to grade OA according to the Kellgrene-Lawrence classification. Correlation analysis between OA and clinical outcomes was performed. The rates of achieving the minimal clinically significant difference and patient-acceptable symptoms state were documented. Results: A total of 37 patients were included in this study. The mean age at surgery was 62.3 +/- 2.3 years, with a mean follow-up of 6.3 +/- 3.2 years (range: 2.1-12.4). Patients showed statistically significant (all p < 0.001) improvements in the mean IKDC (38.9 +/- 9.4-66.8 +/- 12.5), Lysholm (48.8 +/- 15.4-83.0 +/- 12.8) and Tegner (1-3) scores. Fourteen patients (37.8%) returned to sports. No correlation was observed between the degree of preoperative OA and clinical outcomes (n.s.). Conclusion: Patients over 60 years with symptomatic ACL-deficient knees could benefit from ACLR, even when mild to moderate OA is present preoperatively. Level of EvidenceLevel IV.

Abstract Background From the perspective of graft protection and early rehabilitation during the maturation and remodeling phases of graft healing, suture augmentation (SA) for anterior cruciate ligament reconstruction (ACLR) has attracted more and more attention. Study Design Retrospective study. Purpose To determine whether the additional SA affects clinical results, graft maturation and graft-bone interface healing during two years follow-up after ACLR. Methods 20 ACLRs with additional SA (ACLR-SA group) and 20 ACLRs without additional SA (ACLR group) were performed between January 2020 and December 2021 by the same surgeon and were retrospectively analyzed. Pre- and postoperative International Knee Documentation Committee (IKDC) scores, Lysholm scores, graft failure and reoperation were evaluated. The signal/noise quotient (SNQ) of autografts and the signal intensity of graft-bone interface were analyzed. All 40 patients in ACLR-SA group and ACLR group completed 2-years follow-up. Results There was no patient in the two cohorts experienced graft failure and reoperation. The postoperative IKDC and Lysholm scores have been significantly improved compared with preoperative scored in both ACLR-SA group and ACLR group, however, there was no significant difference between two groups. The SNQ of proximal graft of ACLR-SA group (14.78 ± 8.62 vs. 8.1 ± 5.5, p = 0.041) was significantly greater while the grades of graft-bone interface healing of posterior tibial was significantly lower than that of ACLR group at 1-year postoperatively (p = 0.03), respectively. There were no significant differences between the two groups of the SNQ of proximal, distal medial graft segments, and the graft-bone interface healing grades of anterior femoral, posterior femoral, anterior tibial and posterior tibial at other time points (p>0.05). Conclusions The additional SA in ACLR had no effect on IKDC scores, Lysholm scores, graft maturation and graft-bone interface healing at 2-year postoperatively. Our research does not support the routine use of SA in ACLR.

Purpose: To identify risk factors for patients who sustain nontraumatic anterior cruciate ligament reconstruction (ACLR) failure. Methods: A retrospective analysis was performed on patients undergoing primary or revision ACLR in our institution between 2010 and 2018. Patients sustaining insidious-onset knee instability without history of trauma were identified as nontraumatic ACLR failure and assigned to the study group. The control group of subjects who showed no evidence of ACLR failure with minimum 48-month follow-up were matched in a 1:1 ratio based on age, sex, and body mass [LTPsublx], medial [MTPsublx]); notch width index (NWI); and lateral femoral condyle ratio were measured with magnetic resonance imaging or radiography. Graft tunnel position was assessed using 3-dimensional computed tomography and reported in 4 dimensions: deep-shallow ratio (DS ratio) and high-low ratio for femoral tunnel, anterior-posterior ratio and medial-lateral ratio for tibial tunnel. Interobserver and intraobserver reliability were evaluated by the intraclass correlation coefficient (ICC). Patients' demographic data, surgical factors, anatomic parameters, and tunnel placements were compared between the groups. Multivariate logistic regression and receiver operating characteristic curve analysis was used to discriminate and assess the identified risk factors. Results: A total of 52 patients who sustained nontraumatic ACLR failure were included and matched with 52 control subjects. Compared to patients with intact ACLR, those who sustained nontraumatic ACLR failure showed significantly increased LTS, LTPsublx, MTS, and deceased NWI (all P < .001). Moreover, the average tunnel position in the study group was significantly more anterior (P < .001) and superior (P = .014) at the femoral side and more lateral (P = .002) at the tibial side. Multivariate regression analysis identified LTS (odds ratio [OR] = 1.313; P = .028), DS ratio (OR = 1.091; P = .002), and NWI (OR = 0.813; P = .040) as independent predictors of nontraumatic ACLR failure. LTS appeared to be the best independent predictive factor (area under the curve [AUC] = 0.804; 95% confidence interval [CI], 0.721-0.887), followed by DS ratio (AUC = 0.803; 95% CI, 0.717-0.890), and NWI (AUC = 0.756; 95% CI, 0.664e0.847). The optimal cutoff values were 6.7 degrees for increased LTS (sensitivity = 0.615, specificity = 0.923); 37.4% for increased DS ratio (sensitivity = 0.673, specificity = 0.885); and 26.4% for decreased NWI (sensitivity = 0.827, specificity = 0.596). Intraobserver and interobserver reliability was good to excellent, with ICCs ranging from 0.754 to 0.938 for all radiographical measurements. Conclusions: Increased LTS, decreased NWI, and femoral tunnel malposition are predictive risk factors for nontraumatic ACLR failure. Level of Evidence: Level III, retrospective comparative study.

PURPOSE:To compare graft failure, nonrevision reoperation, complication, patient-reported outcome measures (PROMs) and return to sports (RTS) between patients who underwent anterior cruciate ligament reconstruction (ACLR) with and without suture augmentation (SA). METHODS:A systematic search was performed on PubMed, Cochrane, Embase and Web of Science databases from the inception of databases to 18 April 2024, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies comparing clinical outcomes of SA- and standard ACLR with a minimum 2-year follow-up were included. Data extraction and quality appraisal were performed by two researchers independently. RESULTS:Eight retrospective cohort studies were included, with a total of 408 patients receiving SA-ACLR and 443 patients receiving standard ACLR. A meta-analysis of graft failure demonstrated a 62% relative risk reduction (RR [risk ratio], 0.38 [95% confidence interval {CI}, 0.19-0.73]; p = .004) in those receiving SA-ACLR compared with standard ACLR. An age-related heterogeneity in graft failure reduction was detected in the subgroup analysis, which was more pronounced in studies with mean ages of <20 years compared with ≥20 years (p = .05; I2 = 73.9%). No significant difference was observed in nonrevision reoperation or complication rates. No clinically relevant difference was observed in PROMs. SA-ACLR was associated with a significantly higher RTS rate compared with the standard ACLR (RR, 1.12 [95% CI, 1.00-1.24]; p = .04), whereas no significant difference was observed in time to RTS. CONCLUSION:SA-ACLR is associated with a reduced graft failure rate and increased RTS rate compared with standard ACLR without additional reoperations or complications. However, confidence in the evidence is limited by substantial heterogeneity. Future studies with a higher level of evidence are warranted to validate the benefit of SA and to determine the indication for different risk populations. LEVEL OF EVIDENCE:Level III.

Most somatic cells secrete vesicles called exosomes, which contain a variety of biomolecules. Recent research indicates that macrophage-derived exosomes are strongly correlated with tumors, infectious diseases, chronic inflammation, and tissue fibrosis. Therefore, the purpose of this review is to delve into the mechanisms of pathological states and how macrophage-derived exosomes react to them. We also discuss the biological effects of exosomes and how they affect disease. In addition, we have examined the possible uses of exosomes in illness treatment, highlighting both the benefits and drawbacks of these applications.

Background Pyogenic liver abscess (PLA) is a common visceral infectious disease, its associated thrombocytopenia has been rarely studied clinically. Objective To discuss the epidemiological and clinical characteristics as well as risk factors of thrombocytopenia secondary to PLA. Methods All 161 patients hospitalized for PLA in Peking University People's Hospital from January 2011 to December 2020 were recruited. Patient data were collected, including general demographics〔age, gender, body mass index (BMI) , symptoms (fever, abdominal pain, nausea, vomiting) , and past medical history information (hypertension, diabetes, coronary heart disease, hepatobiliary disease, and cancer) , auxiliary examination results, including white blood cell count, absolute neutrophil count, absolute lymphocyte count (ALC) , absolute monocyte count, hemoglobin, C-reactive protein (CRP) , procalcitonin (PCT) , alanine aminotransferase (ALT) , aspartate aminotransferase (AST) , total bilirubin (TBiL) , blood urea nitrogen (BUN) , serum creatinine (Scr) , albumin (ALB) , prothrombin time (PT) , activated partial thromboplastin time, fibrinogen, D-Dimer, platelet count (PLT) 〕, imaging examination results (abdominal CT or ultrasonographic findings of liver abscesses) , pathogenic examination results (blood culture, prevalence of cultured Klebsiella pneumoniae) and complications and prognosis. The above-mentioned data were compared between group with decreased PLT (n=21) and group without decreased PLT (n=140) divided by the prevalence of PLT less than 100×109/L. The risk factors of thrombocytopenia were analyzed by multivariate Logistic regression analysis. Results The mean BMI in PLT reduction group was statistically significant higher than that in non-PLT reduction group (P<0.05) . PLT reduction group had much lower mean levels of ALC and ALB, PT, and much higher mean levels of CRP, PCT, ALT, AST, TBiL, BUN, Scr and D-Dimer than non-PLT reduction group (P<0.05) . Furthermore, PLT reduction group had significantly higher prevalence of concomitant pneumonia, brain abscess and ICU admission (P<0.05) . ALB〔OR=0.255, 95%CI (0.074, 0.877) 〕and PT〔OR=0.282, 95%CI (0.085, 0.941) 〕were influencing factors for thrombocytopenia in PLA (P<0.05) . Conclusion ALB and PT are the influencing factors of thrombocytopenia in PLA patients. PLT levels should be closely monitored in PLA patients, especially those with reduced ALB and decreased PT.

BackgroundSecondary hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening disease of immune hyperactivation that arises in the context of infectious, inflammatory, or neoplastic triggers. The aim of this study was to establish a predictive model for the timely differential diagnosis of the original disease resulting in HLH by validating clinical and laboratory findings to further improve the efficacy of therapeutics for HLH.MethodsWe retrospectively enrolled 175 secondary HLH patients in this study, including 92 patients with hematologic disease and 83 patients with rheumatic disease. The medical records of all identified patients were retrospectively reviewed and used to generate the predictive model. We also developed an early risk score using multivariate analysis weighted points proportional to the β regression coefficient values and calculated its sensitivity and specificity for the diagnosis of the original disease resulting in HLH.ResultsThe multivariate logistic analysis revealed that lower levels of hemoglobin and platelets (PLT), lower levels of ferritin, splenomegaly and Epstein−Barr virus (EBV) positivity were associated with hematologic disease, but young age and female sex were associated with rheumatic disease. The risk factors for HLH secondary to rheumatic diseases were female sex [OR 4.434 (95% CI, 1.889-10.407), P =0.001], younger age [OR 6.773 (95% CI, 2.706-16.952), P<0.001], higher PLT level [OR 6.674 (95% CI, 2.838-15.694), P<0.001], higher ferritin level [OR 5.269 (95% CI, 1.995-13.920), P =0.001], and EBV negativity [OR 27.656 (95% CI, 4.499-169.996), P<0.001]. The risk score included assessments of female sex, age, PLT count, ferritin level and EBV negativity, which can be used to predict HLH secondary to rheumatic diseases with an AUC of 0.844 (95% CI, 0.836~0.932).ConclusionThe established predictive model was designed to help clinicians diagnose the original disease resulting in secondary HLH during routine practice, which might be improve prognosis by enabling the timely treatment of the underlying disease.

目的:总结外侧半月板前角-前体部损伤的临床分型及相应手术策略并评估治疗效果.方法:回顾性分析2020年1月至2020年12月收治的87例外侧半月板前角-前体部损伤患者病例资料,总结撕裂类型和手术策略,根据术前和末次随访的国际膝关节评分委员会(IKDC)评分和Lysholm膝关节评分评估治疗效果.结果:前角-前体部损伤占所有外侧半月板损伤的10.8％.依据撕裂类型将外侧半月板前角-前体部损伤分为5型,其中Ⅰ型为复合撕裂,表现为水平撕裂合并某一层垂直撕裂,并根据垂直撕裂的部位分为Ⅰa、Ⅰb、Ⅰc三种亚型;Ⅱ型为水平撕裂;Ⅲ型为垂直撕裂,并根据移位情况和形态分为Ⅲa、Ⅲb、Ⅲc三种亚型;Ⅳ型为松散型,发生在前角;Ⅴ型为缺失型,半月板前角-前体部消磨殆尽.对于常规手术入路无法处理的Ⅰb型和Ⅱ型损伤,附加外下入路进行操作并视情况进行Outside-in缝合.87例患者均获得随访,平均随访25.1±5.7月(19～31月).末次随访时IKDC评分和Lysholm评分均显著高于术前(分别为64.5±7.4 vs 84.3±6.9和73.3±5.1 vs 90.1±5.0,均P<0.05).结论:基于不同分型采取相应手术策略是治疗外侧半月板前角-前体部损伤的有效方法.

内侧半月板桶柄样撕裂(bucket handle tear,BHT)临床常见,损伤范围较大并严重影响膝关节功能,主要继发于前交叉韧带(anterior cruciate ligament,ACL)断裂或ACL重建术后膝关节前后松弛和旋转不稳定.ACL早期重建、正确放置胫骨隧道位置,或联合前外侧结构增强控制膝关节旋转不稳定,有利于降低内侧半月板BHT的发生.内侧半月板BHT最优治疗方法尚有争议,应根据损伤症状、部位、范围、类型和病程选择不同治疗方式,包括支具固定、理疗、富血小板血浆注射、运动疗法等保守治疗,以及半月板修整、修复等手术治疗,但疗效尚缺乏高质量临床证据.内侧半月板BHT通常发生在有血供区域,具有一定愈合能力,随着修复技术的进步及半月板保留策略的倡导,BHT修复在临床中的应用越来越多.本文综述内侧半月板桶柄样撕裂损伤机制和治疗研究进展,为临床决策和康复理念更新提供参考.

To develop a simple and effective method for evaluating the femoral tunnel position using the apex of the deep cartilage (ADC) as the landmark. A total of 52 patients who underwent arthroscopic ACL reconstruction were recruited between June and September 2021. The femoral tunnel was placed on the central point of the anteromedial footprint with an accessory anteromedial and a high anterolateral portal. Then, the length from the ADC to the shallow cartilage margin (L1) and to the center of the femoral tunnel (l1), as well as the center to the low cartilage margin (H1, intraoperative height), was measured under arthroscopy and on postoperative CT scans (L2, l2 and H2). Moreover, intraoperative and postoperative cartilage ratios were equivalent to l1/L1 and l2/L2, respectively. Linear regression, Pearson correlation and Bland–Altman analysis were performed to evaluate the consistency between these two measurements of cartilage ratio (l/L) and height (H). The mean age at the time of surgery was 28.7 years; 42 patients were male, and 17 patients were hurt in the left knee among 52 patients. The intraoperative cartilage ratio was 0.37 ± 0.04, and the height was 8.1 ± 1.1 mm with almost perfect inter-observer reproducibility. After the surgery, the cartilage ratio and height were measured as 0.39 ± 0.04 and 8.2 ± 1.3 mm on 3D–CT, respectively, with almost perfect intra- and inter-observer reproducibility. Significant positive correlations and linear regression were detected in the cartilage ratio (r = 0.844, p < 0.001), and height (r = 0.926, p < 0.001) intraoperatively and postoperatively. The Bland–Altman plot also showed excellent consistency between arthroscopy and 3D–CT. The ADC is a good landmark in the assessment of femoral tunnel position, with excellent consistency between intraoperative arthroscopic measurements and postoperative 3D–CT. ClinicalTrials.gov Identifier: NCT04937517. Level III.

Medial meniscal posterior root tear (MMPRTs) is a common lesion of the knee joint, and repair surgery is a well-established treatment option. However, patients with obvious varus alignment are at an increased risk for MMPRT and can suffer from a greater degree of medial meniscus extrusion, which leads to the development of osteoarthritis following repair. The efficacy of high tibial osteotomy (HTO) as a means of correcting this malformation, and its potential benefits for MMPRT repair, remains unclear. To explore whether HTO influenced the outcome of MMPRT repair in clinical scores and radiological findings. Systematic review. According to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) guidelines, we searched PubMed, Embase, Web of Science, and the Cochrane Library databases for studies reporting the outcomes of MMPRT repair and extracted data about characteristics of patients, clinical functional scores and radiologic outcomes. One reviewer extracted the data and 2 reviewers assessed the risk of bias and performed a synthesis of the evidence. Articles were eligible if they reported the results of MMPRT repair with exact mechanical axis (registered in the International Prospective Register of Systematic Reviews, CRD42021292057). Fifteen studies with 625 cases of high methodological quality were identified. Eleven studies were assigned to the MMPRT repair group (M) with 478 cases performing MMPRT repair only, and others belonged to the MMPRT repair and HTO group (M and T) performing HTO and MMPRT repair. Most of the studies had significantly improved clinical outcome scores, especially in M groups. And the radiologic outcomes showed that the osteoarthritis deteriorated in both groups with similar degree in about 2-year follow-up. HTO is a useful supplement in treating MMPRT patients with severe osteoarthritis and the clinical and radiological outcomes were similar with MMPRT repair alone. Which would be better for patients’ prognosis generally, performing MMPRT repair alone or a combination of HTO and MMPRT repair, was still controversial. We suggested taking K-L grade into account. Large-scale randomized control studies were called for in the future to help make better clinical decisions. III

PURPOSE:To investigate the association between lateral femoral condyle ratio (LFCR) measured by magnetic resonance imaging (MRI) and anterior cruciate ligament (ACL) rerupture after anatomic ACL reconstruction (ACLR) and to compare the diagnostic accuracy between MRI and radiograph measurements. METHODS:A retrospective review was conducted on patients who underwent anatomic ACLR in our institution between 2015 and 2018. Patients who experienced rerupture after ACLR were identified and matched 1:1 with control patients who showed no evidence of graft failure during a minimum 48-month follow-up. The matching criteria included age, sex, and body mass index. LFCR was measured on MRI scans and radiographs of the affected limb. Patients' characteristics, surgical features, and anatomic measurements were compared between groups. Conditional logistic regression was performed to investigate whether MRI-measured LFCR is a risk factor for ACL rerupture. The optimal cutoff value was determined by receiver operating characteristic curves (ROC). Delong's test was performed to compare the diagnostic accuracy between MRI and radiograph measurements. RESULTS:A total of 72 patients who sustained ACL rerupture were included and matched with 72 control subjects. Compared to patients with intact ACLR, those who sustained ACL rerupture showed a significant increase in LFCR on MRI scans (63.38% ± 2.26% [95% CI, 62.84%-63.91%] vs 61.10% ± 2.19% [95% CI, 60.59%-61.61%], P < .001). An MRI-measured LFCR >62.18% was set as the cutoff point to discern patients at a higher risk of graft failure after anatomic ACLR, with sensitivity and specificity of 75.0% and 70.8%, respectively. MRI-measured LFCR demonstrated superior diagnostic accuracy during ROC curve analysis, achieving a higher area under the curve compared to radiograph-measured LFCR (0.783 ± 0.051 vs 0.668 ± 0.060, P = .041). CONCLUSIONS:The study found that MRI-measured LFCR was associated with ACL rerupture. A cutoff value of 62.18% was determined, which can help identify patients at a higher risk of rerupture. LEVEL OF EVIDENCE:Level III, retrospective comparative study.

This study aims to determine the efficacy of anterior cruciate ligament reconstruction (ACLR) using autograft combined with or without ligament augmentation. A computerized search of the databases was conducted, including PubMed, Web of Science, Embase, Scopus and the Cochrane Library. Only prospective or retrospective comparative studies with a minimum 2-year follow-up were considered for inclusion. Two independent reviewers performed data extraction and methodological quality assessment. A Mantel–Haenszel analysis was used for the pooling of results. Sensitivity analysis was performed to maintain the stability of results. The egger test was applied to assess the publication bias. Fourteen studies were included. The total cohort was 1353 patients (non-augmented group: 763 patients; augmented group: 590 patients). There were three Randomized Controlled Trials (RCTs, Level I), six retrospective comparative studies (Level III) and five case–control studies (Level III). The follow-up rate was ≥ 88

The aim of this retrospective cohort study was to investigate whether the apex of the deep cartilage (ADC) could help surgeons position the femoral tunnel accurately in remnant-preserving anterior cruciate ligament (ACL) reconstruction (ACLR). In the current retrospective cohort study, a total of 134 patients who underwent ACLR between 2016 and 2020 were included. The femoral tunnel position was located using ADC as the landmark. The patients were divided into two groups: the remnant-preserving group (RP group, n = 68) underwent remnant-preserving ACLR, and the nonremnant group (NRP group, n = 66) underwent traditional ACLR with remnant removal. Postoperatively, the femoral tunnel position was evaluated on 3D-CT. The length from the ADC to the shallow cartilage margin (L) and to the centre of the femoral tunnel (l) and the length from the centre of the femoral tunnel to a low cartilage ratio in the direction from high to low (H) were measured. The l/L values of the RP and NRP groups were both 0.4 ± 0.1 after rounding (n.s.), and the H values were 9.3 ± 1.6 mm and 9.3 ± 1.7 mm, respectively (n.s.). There was no significant difference in l/L or H between the two groups. The estimation plot also showed high consistency of H and l/L of the two groups. The inter- and intraobserver reliability of I, L, l/L, and H were almost perfect. The apex of the deep cartilage is a good landmark for positioning the femoral tunnel in remnant-preserving ACL reconstruction. Level III.

Osteoarthritis (OA) is characterized by progressive cartilage degeneration with increasing prevalence and unsatisfactory treatment efficacy. Exosomes derived from mesenchymal stem cells play an important role in alleviating OA by promoting cartilage regeneration, inhibiting synovial inflammation and mediating subchondral bone remodeling without the risk of immune rejection and tumorigenesis. However, low yield, weak activity, inefficient targeting ability and unpredictable side effects of natural exosomes have limited their clinical application. At present, various approaches have been applied in exosome engineering to regulate their production and function, such as pretreatment of parental cells, drug loading, genetic engineering and surface modification. Biomaterials have also been proved to facilitate efficient delivery of exosomes and enhance treatment effectiveness. Here, we summarize the current understanding of the biogenesis, isolation and characterization of natural exosomes, and focus on the large-scale production and preparation of engineered exosomes, as well as their therapeutic potential in OA, thus providing novel insights into exploring advanced MSC-derived exosome-based cell-free therapy for the treatment of OA.