Impact of sex and age on the lateralisation of the tibial tubercle in normal paediatric and adolescent populations.

PURPOSE: Numerous methods have been proposed to characterise tubercle lateralisation. However, their normal values and related changes remain unclear. Accordingly, it was aimed to determine the potential sex and age effects and determined the optimal individualised method of diagnosing lateralisation of the tibial tubercle in patients with recurrent patellar dislocation (RPD). METHODS: Measurements included the tibial tubercle-trochlear groove (TT-TG) distance, tibial tubercle-posterior cruciate ligament (TT-PCL) distance and tibial tubercle lateralisation (TTL); and the proximal tibial width (PTW), trochlear width (TW) and trochlear dysplasia index (TDI), for adjustment. A two-way analysis of variance was used to determine the effect of age, sex and their interaction within the normal group. When the age effect was statistically significant, a nonlinear regression was created. Areas under the receiver-operating characteristic curve (AUCs) were calculated to assess diagnostic accuracy. RESULTS: A total of 277 normal participants (mean [SD] age, 13.5 [2.6] years; 125 [45.1%] female) and 227 patients with RPD (mean [SD] age, 13.5 [2.6] years; 161 [58.1%] female) were analysed. It was found that in the normal group, in patients aged 7-10, TT-PCL distance (p = 0.006), TTL (p = 0.007) and TT-PCL/PTW (p < 0.001) were significantly larger in females than in males. A significant sex effect was also detected on TT-TG/TW (p = 0.014). TT-TG distance, TT-PCL distance, TTL and TT-PCL/PTW (in male patients) approached an established normal adult value of 12.3 mm, 20.9 mm, 0.64 and 0.28, respectively, with increasing age (p < 0.001). The AUC was greater for TT-TG/TDI and TT-TG/TW (p ≤ 0.01) and TT-TG/TDI outperformed TT-TG/TW in patients aged 15-18 (p = 0.004). CONCLUSIONS: Tubercle lateralisation increased with age and was affected by sex, with the exception of TT-TG distance and TT-TG/TDI. TT-TG/TDI is the optimal method of diagnosing a lateralized tibial tubercle in patients with RPD. These findings assist with the evaluation of tubercle lateralisation in that they provide a proper protocol for paediatric and adolescent populations with RPD; and thus, will help determine whether medial tubercle transfer should be included among the tailored surgical procedures considered for the treatment of patients with RPD. LEVEL OF EVIDENCE: Level III.

Clinical and Radiological Outcomes After Combined ACL and MPFL Reconstruction Versus Isolated ACL Reconstruction for ACL Injury With Patellar Instability.

BACKGROUND: An anterior cruciate ligament (ACL) injury accompanied by patellar instability (PI) is a topic that has gained orthopaedic surgeons' attention recently. Untreated PI is reportedly associated with worse clinical outcomes after isolated ACL reconstruction (ACLR) in patients after an ACL injury with PI. Nevertheless, the appropriate surgical approach and its long-term therapeutic effects in these patients remain unclear. PURPOSE: (1) To compare the clinical and radiological outcomes between isolated ACLR (iACLR) and combined ACLR and medial patellofemoral ligament reconstruction (cAMR) in patients after an ACL injury with PI and (2) to explore the correlations between these 2 procedures and clinical and radiological outcomes. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 106 patients diagnosed with an ACL injury accompanied by PI between January 2016 and April 2021 were analyzed in this study. There were 34 patients excluded because of missing postoperative radiological data. Among the remaining 72 patients, 34 patients underwent iACLR, while 38 patients underwent cAMR. Demographic characteristics, intraoperative findings, and patient-reported outcomes (Lysholm score, subjective International Knee Documentation Committee score, and Tegner activity score) were prospectively collected. Patellar alignment parameters and worsening patellofemoral osteoarthritis (PFOA) features (evaluated with the modified Whole-Organ Magnetic Resonance Imaging Score) were analyzed longitudinally on magnetic resonance imaging. The Kujala score was used to evaluate the functional recovery of the patellofemoral joint, and redislocations of the patella were prospectively recorded. Finally, multivariate logistic regression analysis was used to explore the correlations between these 2 procedures and clinical (not achieving the minimal detectable change [MDC] for the Lysholm score) and radiological (worsening PFOA features) outcomes. RESULTS: The mean follow-up duration was 28.9 ± 6.2 and 27.1 ± 6.8 months for the iACLR and cAMR groups, respectively (P = .231). Significantly higher Lysholm scores (88.3 ± 9.9 vs 82.1 ± 11.1, respectively; P = .016) and subjective International Knee Documentation Committee scores (83.6 ± 11.9 vs 78.3 ± 10.2, respectively; P = .046) were detected in the cAMR group compared with the iACLR group postoperatively. The rates of return to preinjury sports were 20.6% and 44.7% in the iACLR and cAMR groups, respectively (difference, 24.1% [95% CI, 3.3%-45.0%]; P = .030). Moreover, the rates of worsening PFOA features were 44.1% and 18.4% in the iACLR and cAMR groups, respectively (difference, 25.7% [95% CI, 4.9%-46.4%]; P = .018). In addition, significantly higher Kujala scores (87.9 ± 11.3 vs 80.1 ± 12.0, respectively; P = .006), lower redislocation rates (0.0% vs 11.8%, respectively; difference, 11.8% [95% CI, 0.9%-22.6%]; P = .045), and significantly better patellar alignment were detected in the cAMR group compared with the iACLR group postoperatively. Furthermore, multivariate logistic regression analysis determined that iACLR and partial lateral meniscectomy were significantly correlated with not achieving the MDC for the Lysholm score and worsening PFOA features in our study population. CONCLUSION: In patients after an ACL injury with PI, cAMR yielded better clinical and radiological outcomes compared with iACLR, with better patellar stability and a lower proportion of worsening PFOA features. Furthermore, not achieving the MDC for the Lysholm score and worsening PFOA features were significantly correlated with iACLR and partial lateral meniscectomy. Our study suggests that cAMR may be a more appropriate procedure for patients after an ACL injury with PI, which warrants further high-level clinical evidence.

Characterization of the CT-based risk factors for concomitant patellofemoral instability in patients with anterior cruciate ligament injury.

OBJECTIVES: Underestimation of concomitant patellofemoral instability in patients with anterior cruciate ligament (ACL) injury has aroused extensive attention. However, the characteristics of the combined injury is not well recognized. Hence, we aimed to characterize the features of the combined injury, and determine the radiographic risk factors. METHODS: Fifteen radiological parameters were identified after discussion and pilot-tested. Radiographic measurements were compared using the analysis of variance model with Tukey post hoc analysis. A stepwise binomial logistic regression was performed and a nomogram model combining the significant risk factors was created. The model performance was validated by C-index, calibration plot, and decision curve. RESULTS: A total of 204 patients (mean [SD] age, 25.1 [6.7] years; 108 [52.9%] male) were included. The final model was updated through regression analysis using 4 parameters as significant risk factors: lateral femoral condyle ratio (OR (95% CI), 1.194 (1.023 to 1.409)), medial anterior tibial subluxation (mATS) (OR (95% CI), 1.234 (1.065 to 1.446)), medial posterior plateau tibial angle (mPPTA) (OR (95% CI), 1.266 (1.088 to 1.500)), and trochlear depth (OR (95% CI), 0.569 (0.397 to 0.784)). C-index for the nomogram was 0.802 (95% CI, 0.731 to 0.873) and was confirmed to be 0.784 through bootstrapping validation. Calibration plot established a good agreement between prediction and observation. Decision curve analysis showed that if threshold probability was over 10%, using the nomogram adds more benefit than either all or none scheme. CONCLUSIONS: Lateral femoral condyle ratio, mATS, mPPTA, and trochlear depth are strong adverse predictors of patellofemoral instability in patients with ACL injury. CLINICAL RELEVANCE: This study characterizes the radiological features of the combined injury. Patellofemoral instability should be noted when treating ACL injuries. KEY POINTS: • The radiological characteristics of the combined ACL injury and patellofemoral instability is not well recognized. • Lateral femoral condyle ratio, mATS, mPPTA, and trochlear depth are predominant risk factors for patellofemoral instability in patients with ACL injury. • Patellofemoral instability should be noted when treating ACL injuries.

The Value of Minimal Clinically Important Difference, Substantial Clinical Benefit, and Patient-Acceptable Symptomatic State for Commonly Used Patient-Reported Outcomes in Recurrent Patellar Instability Patients After Medial Patellofemoral Ligament Reconstruction and Tibial Tubercle Transfer.

PURPOSE: To identify the minimal clinically important difference (MCID), substantial clinical benefit (SCB) and patient-acceptable symptomatic state (PASS) for commonly used patient-reported outcomes (PROs) in recurrent patellar instability patients after medial patellofemoral ligament reconstruction (MPFLR) and tibial tubercle transfer (TTT), and to determine the impact of potential prognostic factors on the likelihood of achieving these values. METHODS: From April 2015 to February 2021, patients who underwent MPFLR and TTT were retrospectively reviewed. PROs included Kujala, Knee Injury and Osteoarthritis Outcome (KOOS), Lysholm, International Knee Documentation Committee (IKDC), and Tegner score. Relevant anchor questions were provided. A distribution- or anchor-based method was adopted to determine the MCID, SCB, and PASS. Minimal detectable change (MDC) was included to confirm the validity. Univariate regression analyses were conducted to determine the potential prognostic factors. RESULTS: One hundred forty-two patients were included. The MCID were 9.1 (Kujala), 11.1 (Lysholm), 0.9 (Tegner), 9.9 (IKDC), 9.0 (KOOS-Pain), 10.8 (KOOS-Symptoms), 10.0 (KOOS-Activities of Daily Living [ADL]), 17.8 (KOOS-Sports and Recreation [Sports/Rec]), and 12.7 (KOOS-Quality of Life [QoL]). The SCB were 14.5 (Kujala), 12.5 (Lysholm), 1.5 (Tegner), 14.5 (IKDC), 13.9 (KOOS-Pain), 14.3 (KOOS-Symptoms), 18.4 (KOOS-ADL), 47.5 (KOOS-Sports/Rec), and 15.0 (KOOS-QoL). The PASSs were 85.5 (Kujala), 75.5 (Lysholm), 3.5 (Tegner), 73.2 (IKDC), 87.5 (KOOS-Pain), 73.2 (KOOS-Symptoms), 92.0 (KOOS-ADL), 77.5 (KOOS-Sports/Rec), and 53.1 (KOOS-QoL). All SCBs were valid except KOOS-QoL. All MCIDs were valid at the 95% confidence interval (CI) except KOOS scores, the majority of which were valid at the 90% CI. A younger age was an independent prognostic factor of reaching PASS for Lysholm, IKDC, Tegner, and KOOS-ADL score. A higher baseline score was a negative prognostic factor for achieving MCID or SCB but had a slightly positive influence on the achievement of PASS. CONCLUSIONS: This study established the MCID, SCB, and PASS for commonly used PROs and confirmed their validity in recurrent patellar instability patients after MPFLR and TTT. Younger age and lower baseline scores were prognostic factors of achieving MCID and SCB, whereas patients with higher baseline scores were more likely to report satisfaction. LEVEL OF EVIDENCE: Level III, retrospective comparative prognostic trial.

Unraveling immunotherapeutic targets for endometriosis: a transcriptomic and single-cell analysis.

Background: Endometriosis (EMs), a common gynecological disorder, adversely affects the quality of life of females. The pathogenesis of EMs has not been elucidated and the diagnostic methods for EMs have limitations. This study aimed to identify potential molecular biomarkers for the diagnosis and treatment of EMs. Methods: Differential gene expression (DEG) and functional enrichment analyses were performed using the R language. WGCNA, Random Forest, SVM-REF and LASSO methods were used to identify core immune genes. The CIBERSORT algorithm was then used to analyse the differences in immune cell infiltration and to explore the correlation between immune cells and core genes. In addition, the extent of immune cell infiltration and the expression of immune core genes were investigated using single-cell RNA (scRNA) sequencing data. Finally, we performed molecular docking of three core genes with dienogest and goserelin to screen for potential drug targets. Results: DEGs enriched in immune response, angiogenesis and estrogen processes. CXCL12, ROBO3 and SCG2 were identified as core immune genes. RT-PCR confirmed that the expression of CXCL12 and SCG2 was significantly upregulated in 12Z cells compared to hESCs cells. ROC curves showed high diagnostic value for these genes. Abnormal immune cell distribution, particularly increased macrophages, was observed in endometriosis. CXCL12, ROBO3 and SCG2 correlated with immune cell levels. Molecular docking suggested their potential as drug targets. Conclusion: This study investigated the correlation between EMs and the immune system and identified potential immune-related biomarkers. These findings provided valuable insights for developing clinically relevant diagnostic and therapeutic strategies for EMs.

The relationship between fundamental motor skills and physical fitness in preschoolers: a short-term longitudinal study.

Purpose: Physical fitness and fundamental motor skills are two important aspects for the healthy development of preschoolers. Despite the growing interest in clarifying their relationship, the scarcity of longitudinal studies prevents us from understanding causality. Method: This study employed a cross-lagged model with two time points to investigate the bidirectional relationship between these two aspects. A total of 174 preschoolers (54.0% girls) from 3 to 6 years old (M = 3.96 ± 0.47) were surveyed, they were recruited by convenience from two kindergartens in Beijing, China, and their physical fitness (via CNPFDSM-EC) and fundamental motor skills (via TGMD-3) were tracked over a period of 6 months. Results: The findings revealed a bidirectional predictive effect. The predictive strength of flexibility was found to be lower than other physical fitness aspects, while locomotor skills demonstrated a higher predictive strength than object control skills. Conclusion: This study indicates that physical fitness and fundamental motor skills mutually enhance each other in young children, and both should be emphasized in preschool sports education.

Association Between Anterior Tibial Subluxation of Lateral Compartment and High-Grade Knee Laxity in Patients With Anterior Cruciate Ligament Deficiency.

BACKGROUND: High-grade knee laxity and excessive anterior tibial subluxation (ATS) are correlated with poor clinical outcomes in patients with anterior cruciate ligament (ACL) deficiency and share similar risk factors; however, the association between excessive ATS and high-grade knee laxity remains unclear. PURPOSE: To identify the association between excessive ATS and high-grade knee laxity in patients with ACL deficiency and determine the possibility that ATS can predict high-grade knee laxity. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A total of 226 patients who underwent ACL reconstruction between May 2018 and March 2022 were analyzed in the present study; the high-grade group consisted of 113 patients who had a grade 3 result on the preoperative anterior drawer test, Lachman test, or pivot-shift test while under anesthesia, and the low-grade group consisted of 113 matched patients. The ATS values for medial and lateral compartments (ATSMC and ATSLC) were measured on magnetic resonance imaging while patients relaxed the quadriceps in the supine position under no anesthesia. The optimal cutoff values of ATSMC and ATSLC for high-grade knee laxity were determined using receiver operating characteristic curves. Univariate and multivariate logistic regression analyses with stratification were performed to identify the association between excessive ATS and high-grade knee laxity. RESULTS: Compared with the low-grade group, the high-grade group had a longer time from injury to surgery; higher rates of medial meniscus posterior horn tear (MMPHT), lateral meniscus posterior horn tear (LMPHT), and anterolateral ligament (ALL) abnormality; and larger lateral tibial slope, ATSMC, and ATSLC. The optimal cutoff value was 2.6 mm (sensitivity, 52.2%; specificity, 76.1%) for ATSMC and 4.5 mm (sensitivity, 67.3%; specificity, 64.6%) for ATSLC in predicting high-grade knee laxity. After adjustment for covariates, ATSLC ≥4.5 mm (odds ratio [OR], 2.94; 95% CI, 1.56-5.55; P = .001), MMPHT (OR, 2.62; 95% CI, 1.35-5.08; P = .004), LMPHT (OR, 2.39; 95% CI, 1.20-4.78; P = .014), and ALL abnormality (OR, 2.09; 95% CI, 1.13-3.89; P = .019) were associated with high-grade knee laxity. The association between excessive ATSLC and high-grade knee laxity was validated in patients with acute ACL injury as well as those with chronic ACL injury. CONCLUSION: Excessive ATSLC was associated with high-grade knee laxity in patients who had ACL deficiency, with a predictive cutoff value of 4.5 mm. This study may help surgeons estimate the degree of knee instability more accurately before anesthesia and may facilitate preliminary surgical decision-making, such as appropriate graft choices and consideration of extra-articular augmentation.

Arthroscopic Dynamic Anterior Stabilization Using Either Long Head of the Biceps or Conjoined Tendon Transfer for Anterior Shoulder Instability Results in a Similarly Low Recurrence Rate.

PURPOSE: To compare the clinical outcomes of arthroscopic dynamic anterior stabilization (DAS) between transferring the long head of the biceps (DAS-LHB) and the conjoined tendon (DAS-CT) for anterior shoulder instability with <15% glenoid bone loss. METHODS: From January 2016 to May 2019, a total of 63 patients who underwent DAS for recurrent anterior shoulder dislocation with <15% glenoid bone loss were included, comprising 33 patients in DAS-LHB group and 30 patients in DAS-CT group. Clinical outcomes were assessed preoperatively and at a minimum 3-year follow-up, including patient-reported outcomes, range of motion, and return to sports (RTS). Postoperative recurrent instability (including dislocation, subluxation, and subjective instability with a positive apprehension test), revisions and complications also were recorded. RESULTS: No significant demographic characteristics difference was detected between the DAS-LHB (26.3 ± 7.9 years) and DAS-CT groups (26.0 ± 6.7 years). At the latest follow-up, there were no significant differences between the 2 groups in functional scores: Oxford Shoulder Instability Score (14.8 ± 2.8 vs 15.2 ± 3.6), Rowe score (95.9 ± 6.5 vs 93.2 ± 10.2), visual analog scale for pain (0.8 ± 1.2 vs 0.7 ± 1.7), and American Shoulder and Elbow Surgeons (95 ± 8.8 vs 95.2 ± 9.1) (all P > .218). No significant difference was detected between groups in the rates of RTS (90.1% vs 86.7%, P = .700) and RTS at previous level (78.7% vs 73.3%, P = .258), respectively. No recurrent dislocation occurred in either group. One patient felt occasional subluxation in the DAS-LHB group, and one was positive for the apprehension test in each group. One patient presented with postoperative shoulder stiffness and underwent a secondary arthroscopic debridement in the DAS-CT group. CONCLUSIONS: Comparable rates of recurrence, complication, return to sports, and subjective shoulder function were observed between DAS-LHB and DAS-CT groups. LEVEL OF EVIDENCE: Level III, retrospective comparative therapeutic trial.

Sulcus depth, congruence angle, Wiberg index, TT-TG distance, and CDI are strong predictors of recurrent patellar dislocation.

PURPOSE: To characterize patellofemoral morphology, determine radiological cutoff values based on computed tomography (CT) images, and clarify predominant anatomic risk factors in young patients with recurrent patellar dislocation (RPD). METHODS: A total of 212 knees (age 23.0 ± 5.3 years, female: male = 110:102) with CT-confirmed RPD were enrolled for analysis. The control group was matched by age and sex (2:1). Patellofemoral and trochlear morphology, patellofemoral alignment, and other parameters were assessed by CT. Standardized methods were used for measurements. Receiver operating characteristic (ROC) curves and the areas under the ROC curve (AUCs) were used to assess accuracy in diagnosing RPD. The index of union (IU) was employed to identify a cutoff value for risk. A binary logistic regression model (Forward, LR) was constructed, and standardized coefficients were calculated to compare the relative strength of different predictors. Factors included in the model were employed to calculate distributions in the studied population. RESULTS: The majority of measurements showed a significant difference between the RPD and control groups when comparing mean values. The AUC value was favorable for sulcus depth and significantly better than that for other trochlear morphology parameters (P < 0.0001). Cutoff values were 0.58 for the Wiberg index, 153.3° for the sulcus angle, 3.6 mm for the sulcus depth, 1.94 for the trochlear width ratio, 16.2° for the lateral trochlear inclination, 17.2° for the patellar lateral tilt, 25.5° for the congruence angle, 1.2 for the patellar height [Caton-Deschamps index (CDI)], 6.1° for the knee rotation, and 16.4 mm for the tibial tubercle-trochlear groove (TT-TG) distance. A binary logistic regression model (χ2 = 20.826, P = 0.008) including the Wiberg index, sulcus depth, congruence angle, patellar height (CDI), and TT-TG distance was constructed for RPD (P ≤ 0.015), which showed excellent diagnostic performance, as indicated by an AUC of 0.989 (95% CI, 0.979 to 0.998). Sulcus depth showed the strongest relationship with RPD, followed by the congruence angle and Wiberg index, as indicated by the standardized coefficients - 1.43, 1.02, and 0.97, respectively. Eighty-seven percent of the RPD population had sulcus depth ≤ 3.6 mm. CONCLUSIONS: This study provides a systematic reference of cutoff values based on CT data. The combination of five anatomic risk factors (sulcus depth, congruence angle, Wiberg index, TT-TG distance, and CDI) may be an excellent predictor of RPD as initial risk assessment. Sulcus depth, as the most frequently observed anatomic risk factor, showed the best diagnostic performance among trochlear morphological parameters and the strongest relationship with RPD, followed by the congruence angle and Wiberg index. In clinical practice, the sulcus depth, congruence angle, Wiberg index, TT-TG distance, and CDI with the proposed cutoff values can be used in combination to evaluate RPD. When assessing trochlear morphology, sulcus depth is recommended as the best radiological parameter. LEVEL OF EVIDENCE: Level III.

Clinical and Radiological Outcomes in Patients With Anterior Shoulder Instability and Glenoid Bone Loss after Arthroscopic Free Bone Block Combined With Dynamic Anterior Stabilization.

BACKGROUND: As an alternative to the Latarjet procedure, the arthroscopic free bone block (FBB) procedure combined with dynamic anterior stabilization (DAS) has been recently proposed to provide both glenoid augmentation and a tendon sling effect for treating anterior shoulder instability (ASI) with glenoid bone loss. PURPOSE: To evaluate the clinical and radiological outcomes of FBB-DAS for ASI with glenoid bone loss. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients who underwent arthroscopic FBB-DAS for ASI with >15% glenoid bone loss between February 2017 and March 2020 were screened and enrolled in this study. Clinical outcome measures were assessed preoperatively and at a minimum 2-year follow-up, including recurrence, complications, shoulder functional scores, range of motion, and return to sports. Postoperative computed tomography and magnetic resonance imaging were also performed. RESULTS: Of a total of 65 patients with a mean follow-up of 46.1 ± 13.1 months, no patients experienced a recurrent dislocation or subluxation postoperatively, while 2 had a positive anterior apprehension test (3.1%). Additionally, 2 patients (3.1%) experienced complications of hematoma and shoulder stiffness, respectively. The mean visual analog scale score, American Shoulder and Elbow Surgeons score, Rowe score, and Oxford Shoulder Instability Score all improved significantly from 3.2 ± 2.4, 75.0 ± 18.9, 43.6 ± 27.3, and 33.8 ± 9.0 preoperatively to 1.3 ± 0.8, 95.1 ± 8.0, 95.5 ± 7.8, and 14.8 ± 3.5 at final follow-up, respectively (all P < .001). No difference was detected in range of motion except for 8.1° and 7.5° external rotation limitations in adduction and abduction, respectively. There were 62 patients (95.4%) who returned to sports, and 54 patients (83.1%) returned to the preinjury level. The transferred biceps tendon was intact in all 59 patients who completed radiological examination at the latest follow-up. Good bone healing was achieved in 98.3% of patients, and the glenoid bone defect decreased from 18.1% to 4.9%. Osseous and labral glenoids were significantly enlarged in width and depth on the latest magnetic resonance imaging (all P < .001). CONCLUSION: Arthroscopic FBB-DAS provided satisfactory clinical and radiological outcomes for ASI with glenoid bone loss. Despite slight external rotation restrictions, it achieved low recurrence and complication rates, excellent shoulder functional scores, a high return-to-sports rate, and favorable graft healing and remodeling.

Meniscal resection increases the risk of residual knee laxity even in patients undergoing anatomic double-bundle anterior cruciate ligament reconstruction with eight strands of hamstring autografts.

PURPOSE: To compare the midterm clinical outcomes of different meniscal surgeries in patients undergoing anatomic double-bundle anterior cruciate ligament reconstruction (DB-ACLR) with eight strands of hamstring (HT8) autografts and explore the potential predictive risk factors for residual knee laxity. METHODS: From 2010 to 2017, a total of 410 patients who underwent anatomic trans-tibial DB-ACLR with HT8 autografts (169 patients without meniscal surgery, 105 patients with meniscal repair, and 136 patients with meniscal resection) were included in this study. The equivalent graft diameter was introduced to make the total graft size of DB-ACLR comparable with that of single-bundle ACLR and calculated as the square root of the quadratic sum of the diameter for each bundle. Residual laxity was defined as excessive anterior tibial translation or residual pivot shift at any follow-up visit, while graft rupture was confirmed by second-look arthroscopy or magnetic resonance imaging. RESULTS: The mean follow-up period was 8.3 ± 2.2 years. The mean equivalent graft diameter was 9.9 ± 0.7 mm. Graft rupture was confirmed in 16 (3.9%) patients, while residual laxity was detected in 72 (17.6%) patients (34 [25.0%] in the meniscal resection group vs. 22 [13.0%] in the no meniscal surgery group, p = 0.021). In the multivariate logistic regression analysis, high-grade preoperative knee laxity (odds ratio OR 2.04, p = 0.020), equivalent graft diameter < 9 mm (OR 3.31 compared with 9-10 mm, p = 0.012; OR 3.28 compared with ≥ 10 mm, p = 0.019), and meniscal resection (OR 1.94 compared with no meniscal surgery, p = 0.045) were associated with residual laxity. CONCLUSION: During a midterm follow-up, meniscal resection increased the risk of residual knee laxity even in patients undergoing anatomic DB-ACLR with HT8 autografts. Increasing the hamstring graft diameter and preserving the menisci are important strategies for ACLR to restore knee stability. LEVEL OF EVIDENCE: Level III.

Patellar shift ratio (PSR) is the optimal measurement for characterising lateral patellar shift and a reliable predictor of recurrent patellar dislocation.

PURPOSE: To propose a new measurement, the patellar shift ratio (PSR), for characterising lateral patellar shift; to determine its diagnostic accuracy in predicting recurrent patellar dislocation (RPD); and to identify the effect of patellar tilt and morphology on shift measurements. METHODS: Variables including the PSR, bisect offset (BSO), BSO adjusted by trigonometric analysis, linear patellar displacement (LPD) distance and congruence angle were measured on axial computed tomography (CT). Furthermore, PSR was classified into grades determined by the threshold generated by receiver operating characteristic (ROC) curves. Youden's index was used to identify the ideal threshold on the curve. The area under the ROC curve (AUC) values and likelihood ratios were calculated to assess diagnostic performance in predicting RPD. Correlation analysis was conducted to identify the effects of lateral tilt and the Wiberg index on lateral shift. Intra- and interobserver reliability were evaluated using the intraclass correlation coefficient. RESULTS: The study included 54 RPD patients and 54 controls matched by sex and age. The threshold for PSR was 24.3% (sensitivity, 96.30%; specificity, 85.19%). AUCs were categorised as excellent for all protocols (P < 0.001). The positive likelihood ratio of the PSR for predicting RPD was 6.50. PSR was categorised in terms of lateral trochlear quadrants consisting of 25% increments. Lateral patellar tilt showed a strong positive correlation with BSO (P < 0.001); moderate correlations with PSR, LPD distance and adjusted BSO (P ≤ 0.001); and a weak correlation with congruence angle (P = 0.034). The Wiberg index presented a positive moderate correlation with BSO (P < 0.001), while no correlation was found with PSR, LPD distance, or congruence angle (n.s.). All parameters showed good repeatability (intraobserver) and reproducibility (interobserver). CONCLUSIONS: The PSR showed excellent diagnostic performance as indicated by likelihood ratios, measurement accuracy (being relatively resistant to the effects of tilt and the Wiberg index), and intra- and interobserver reliability. The optimal PSR threshold for predicting RPD risk was 24.3%, and the grade of PSR (normal, 1-4) was also a reliable and easily calculated predictor of RPD. This quantifying method to characterise lateral patellar shift is an alternative useful method for clinical assessments of RPD patients and for research on patellofemoral congruence. LEVEL OF EVIDENCE: Level III.

Precursors and formation pathways of furfural in sugarcane juice during thermal treatment.

As a potent aromatic compound, furfural may have adverse effects on sugarcane juice quality. In this study, simplified sugarcane juice models containing glucose, fructose and amino acids were used to explore the potential precursors and formation pathways of furfural. The changes of precursors and intermediates involved in furfural formation were quantified. The results indicated that fructose contributed more to furfural formation than glucose. Serine was the main amino acid precursor for furfural formation. Furfural could be generated through 3 pathways in sugarcane juice: 1) Streaker reaction of serine, 2) caramelization of glucose and fructose via 3-deoxyglucosone, 3) formed from reducing sugars (glucose or fructose) and serine via N-(1-Deoxy-d-fructos-1-yl)-l-serine intermediate, which further converted to 3-deoxyglucosone. At the first 10 min, furfural was mainly produced through the caramelization of fructose. Subsequently, furfural was produced in the above three ways. Furfural was more effectively formed by caramelization than Maillard reaction in sugarcane juice.

Patella-Posterior Turning Point of the Distal Femur Distance Is a Potential Indicator for Diagnosing Patella Alta in Recurrent Patellar Dislocation Population.

PURPOSE: To introduce a simple patellar height measurement method (patella-posterior turning point of the distal femur [P-PTP] Distance) independent of patellar anatomy with standardized patient position, and tested the reliability, validity, and diagnostic accuracy compared with commonly used ratios in knee extension. METHODS: We retrospectively reviewed 418 computed tomography (CT) images of the knee joint in a group of patients who were diagnosed recurrent patellar dislocation (RPD). With the three-dimensional (3D) CT reconstructed knee, patellar height was qualitatively assessed by the patellar engagement with the femoral trochlea in terminal knee extension to divide RPD population into case (patella alta) and control group. With digitally reconstructed lateral radiographs, patellar height was measured with P-PTP distance (perpendicular distances between the distal edge of patella articular surface and posterior turning point of distal femur), and four commonly used ratios: Caton-Deschamps index, Modified Insall-Salvati index, Blackburne-Peel index, and Insall-Salvati index. An unpaired t-test was conducted to determine significant differences between groups. Correlation coefficient, intra- and inter-observer reliability, receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were also calculated. RESULTS: 198 knee images (198 patients) were included for final evaluation. Patella alta was present in 72 knees (36.3%) with RPD. The effect size was relatively large between the case and control group for P-PTP distance (d = -1.619; 95% CI, -1.948 to -1.286). P-PTP distance correlated moderately to strongly with four commonly used ratios (P < .001). Intraobserver and interobserver reliability was good for P-PTP distance. The AUC of the ROC curve was categorized as excellent for P-PTP distance, better than other measurements (P < .001), and the cutoff value was 4.2 mm with the highest sensitivity (86.11%) and specificity (84.92%). CONCLUSIONS: The measurement method, P-PTP distance, showed good intra-observer and inter-observer reliability, well correlated with commonly used ratios, and presented best diagnostic accuracy among commonly used ratios for predicting RPD. P-PTP distance might be a potential indicator for identifying patella alta in RPD patients when supine and knee extended. CLINICAL RELEVANCE: The measurement reported in this study may help in advancing clinical evaluation of patella alta, providing an alternative and simple method to measure patellar height. Standing or weight-bearing plain lateral radiographs obtained from the routine practice should be further assessed in the next step to further validate the method.

Corrigendum: Advances in regenerative sports medicine research.

[This corrects the article DOI: 10.3389/fbioe.2022.908751.].

Glenoid Track Width Is Smaller Under Dynamic Conditions: An In Vivo Dual-Fluoroscopy Imaging Study.

BACKGROUND: The glenoid track concept has been widely used to assess the risk of instability due to bipolar bone loss. The glenoid track width was commonly used as 83% of the glenoid width to determine if a lesion was on-track or off-track. However, the value was obtained under static conditions, and it may not be able to reflect the actual mechanism of traumatic dislocation during motion. PURPOSE: To compare the glenoid track width under dynamic and static conditions using a dual-fluoroscopic imaging system. STUDY DESIGN: Controlled laboratory study. METHODS: In total, 40 shoulders of 20 healthy volunteers were examined for both dynamic and static tests within a dual-fluoroscopic imaging system at 5 different arm positions: 30°, 60°, 90°, 120°, and 150° of abduction, keeping the shoulder at 90° of external rotation. The participants performed a fast horizontal arm backswing for dynamic tests while keeping their arm in maximum horizontal extension for static tests. Computed tomography scans were used to create 3-dimensional models of the humerus and scapula for 2-dimensional to 3-dimensional image registration. Magnetic resonance imaging scans were obtained to delineate the medial margin of the rotator cuff insertion. The glenoid track width was measured as the distance from the anterior rim of the glenoid to the medial margin of the rotator cuff insertion and compared between static and dynamic conditions. RESULTS: The mean glenoid track widths at 30°, 60°, 90°, 120°, and 150° of abduction were significantly smaller under dynamic conditions (88%, 81%, 72%, 69%, and 68% of the glenoid width) than those under static conditions (101%, 92%, 84%, 78%, and 77% of the glenoid width) (all P < .001). The glenoid track width significantly decreased with the increasing abduction angles in the range of 30° to 120° under static conditions (all P < .003) and 30° to 90° under dynamic conditions (all P < .001). CONCLUSION: A smaller dynamic-based value should be considered for the glenoid track width when distinguishing on-track/off-track lesions. Clinical evidence is needed to establish the superiority of the dynamic-based value over the static-based value as an indicator for augmentation procedures. CLINICAL RELEVANCE: Some off-track lesions might be misclassified as on-track lesions when the original commonly used static-based value of 83% is used as the glenoid track width.

Predicting the Objective and Subjective Clinical Outcomes of Anterior Cruciate Ligament Reconstruction: A Machine Learning Analysis of 432 Patients.

BACKGROUND: Sports levels, baseline patient-reported outcome measures (PROMs), and surgical procedures are correlated with the outcomes of anterior cruciate ligament reconstruction (ACLR). Machine learning may be superior to conventional statistical methods in making repeatable and accurate predictions. PURPOSE: To identify the best-performing machine learning models for predicting the objective and subjective clinical outcomes of ACLR and to determine the most important predictors. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A total of 432 patients who underwent anatomic double-bundle ACLR with hamstring tendon autograft between January 2010 and February 2019 were included in the machine learning analysis. A total of 15 predictive variables and 6 outcome variables were selected to validate the logistic regression, Gaussian naïve Bayes machine, random forest, Extreme Gradient Boosting (XGBoost), isotonically calibrated XGBoost, and sigmoid calibrated XGBoost models. For each clinical outcome, the best-performing model was determined using the area under the receiver operating characteristic curve (AUC), whereas the importance and direction of each predictive variable were demonstrated in a Shapley Additive Explanations summary plot. RESULTS: The AUC and accuracy of the best-performing model, respectively, were 0.944 (excellent) and 98.6% for graft failure; 0.920 (excellent) and 91.4% for residual laxity; 0.930 (excellent) and 91.0% for failure to achieve the minimal clinically important difference (MCID) of the Lysholm score; 0.942 (excellent) and 95.1% for failure to achieve the MCID of the International Knee Documentation Committee (IKDC) score; 0.773 (fair) and 70.5% for return to preinjury sports; and 0.777 (fair) and 69.2% for return to pivoting sports. Medial meniscal resection, participation in competitive sports, and steep posterior tibial slope were top predictors of graft failure, whereas high-grade preoperative knee laxity, long follow-up period, and participation in competitive sports were top predictors of residual laxity. High preoperative Lysholm and IKDC scores were highly predictive of not achieving the MCIDs of PROMs. Young age, male sex, high preoperative IKDC score, and large graft diameter were important predictors of return to preinjury or pivoting sports. CONCLUSION: Machine learning analysis can provide reliable predictions for the objective and subjective clinical outcomes (graft failure, residual laxity, PROMs, and return to sports) of ACLR. Patient-specific evaluation and decision making are recommended before and after surgery.

Glenoid Bone Loss Determination: Validity and Reliability of the Constellation Technique Versus the Sagittal Best Fit Circle Technique.

Objective: To propose a new method for glenoid bone loss measurement, the constellation technique (CST); determine its reliability and accuracy; and compare the validity of CST with that of the conventional technique (CVT) and standard measurements for ratio calculation. Materials and Methods: Sixty shoulders with intact glenoids and no glenohumeral instability and arthritis underwent CT scans. Simulated osteotomies were conducted on the 3D models of glenoids at two cutting locations, expressed as clock face times (2:30-4:20; 1:30-5:00). Two experienced surgeons compared three methods for glenoid bone loss measurement; CVT (best-fit circle), CST ('5S' steps), and standard measurement. Eight undergraduates remeasured five randomly chosen shoulders with moderate to severe bone loss. Intraclass correlation coefficients (ICCs) were calculated for raters. Results: With a defect range between 2:30 and 4:20, all 60 glenoids demonstrated minimal bone loss (< 15%); while between 1:30 and 5:00, 42 shoulders were with moderate bone loss (15-20%), and 18 shoulders with severe bone loss (≥ 20%). For experienced raters, no significant differences were noted between protocos for all categories of bone loss (p ≥ 0.051), with good inter- and intraobserver reliability indicated by ICC. For novice raters, post hoc Tukey analysis found that CST was more accurate in one patient with a standard mean bone loss of 23.2% ± 1.9% compared with CVT. Conclusion: The CST turned the key step of glenoid defect evaluation from deciding an en face view to determining the glenoid inferior rim. The protocol is simple, accurate, and reproducible, especially for novice raters.

Advances in Regenerative Sports Medicine Research.

Regenerative sports medicine aims to address sports and aging-related conditions in the locomotor system using techniques that induce tissue regeneration. It also involves the treatment of meniscus and ligament injuries in the knee, Achilles' tendon ruptures, rotator cuff tears, and cartilage and bone defects in various joints, as well as the regeneration of tendon-bone and cartilage-bone interfaces. There has been considerable progress in this field in recent years, resulting in promising steps toward the development of improved treatments as well as the identification of conundrums that require further targeted research. In this review the regeneration techniques currently considered optimal for each area of regenerative sports medicine have been reviewed and the time required for feasible clinical translation has been assessed. This review also provides insights into the direction of future efforts to minimize the gap between basic research and clinical applications.