Three-Dimensional Printed Silk Fibroin/Hyaluronic Acid Scaffold with Functionalized Modification Results in Excellent Mechanical Strength and Efficient Endogenous Cell Recruitment for Articular Cartilage Regeneration.

Treatment of articular cartilage remains a great challenge due to its limited self-repair capability. In tissue engineering, a scaffold with both mechanical strength and regenerative capacity has been highly desired. This study developed a double-network scaffold based on natural biomaterials of silk fibroin (SF) and methacrylated hyaluronic acid (MAHA) using three-dimensional (3D) printing technology. Structural and mechanical characteristics of the scaffold was first investigated. To enhance its ability of recruiting endogenous bone marrow mesenchymal stem cells (BMSCs), the scaffold was conjugated with a proven BMSC-specific-affinity peptide E7, and its biocompatibility and capacity of cell recruitment were assessed in vitro. Animal experiments were conducted to evaluate cartilage regeneration after transplantation of the described scaffolds. The SF/HA scaffolds exhibited a hierarchical macro-microporous structure with ideal mechanical properties, and offered a 3D spatial microenvironment for cell migration and proliferation. In vitro experiments demonstrated excellent biocompatibility of the scaffolds to support BMSCs proliferation, differentiation, and extracellular matrix production. In vivo, superior capacity of cartilage regeneration was displayed by the SF/MAHA + E7 scaffold as compared with microfracture and unconjugated SF/MAHA scaffold based on macroscopic, histologic and imaging evaluation. In conclusion, this structurally and functionally optimized SF/MAHA + E7 scaffold may provide a promising approach to repair articular cartilage lesions in situ.

Short-Term Complications of Arthroscopic Bristow or Latarjet Procedure with Screw Versus Suture-Button Fixation: A Prospective Study of 308 Consecutive Cases by a Single Surgeon.

BACKGROUND: This study aimed to investigate the short-term complications (minimum 1-year follow-up) after either an arthroscopic Bristow or Latarjet procedure for anterior shoulder instability utilizing screw or suture-button fixation. METHODS: Patients undergoing arthroscopic Bristow or Latarjet procedures between November 2016 and April 2021 were enrolled. Data were collected at baseline, 3 months, 6 months, and every year after surgery. Risks of postoperative complications and unplanned reoperations were assessed. A multivariable regression model was used to identify risk factors for complications and to determine the association of complications with patient-reported outcomes. RESULTS: A total of 412 patients (425 shoulders) undergoing arthroscopic Bristow or Latarjet procedures performed by a single surgeon between November 2016 and April 2021 were reviewed. Two hundred and ninety-nine patients (308 shoulders, 76.2% of 404 eligible) with a mean follow-up of 22.3 ± 4.2 months were included for analysis. Two hundred and sixty-nine shoulders (87.3%) underwent a Bristow procedure (165 with screw and 104 with suture-button fixation), while 39 (12.7%) underwent a Latarjet procedure (18 with screw and 21 with suture-button fixation). Eighty-two patients (83 shoulders) reported a total of 85 complications within 2 years after surgery, with an overall complication rate of 26.9%. The rates of recurrent dislocation or subluxation and infection were 1.9% and 0.6%, respectively, while a total of 4 (1.3%) of the shoulders had unplanned reoperations. The most common complications were graft-related (11.7%), followed by complications involving neurologic symptoms (10.7%). The overall, graft, and neurologic complication rates following Bristow or Latarjet procedures were 27.1% versus 25.6%, 12.3% versus 7.7%, and 10.0% versus 15.4%, respectively. Compared with the Bristow technique with screw fixation, Bristow with suture-button fixation yielded a lower risk of any complications (odds ratio [OR], 0.55; p = 0.04). Paying with rural insurance and poor sleep quality prior to surgery were associated with increased risk of any complications. CONCLUSIONS: Compared with arthroscopic Bristow procedures with screw fixation, Bristow procedures with suture-button fixation resulted in a lower overall complication risk. Both patient demographic and implant-specific factors were associated with the development of a complication. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Association of the Inlay Structure Used in the Modified Bristow Procedure With Accelerated Bone Union: Comparing the Cuistow and Modified Bristow Procedures.

Background: The Chinese unique inlay Bristow (Cuistow) procedure is a modified Bristow surgery in which an inlay (mortise-and-tenon) structure is added to the contact surface between the coracoid tip and the glenoid. Patients who have undergone the Cuistow procedure have had satisfying clinical performance and excellent postoperative bone healing rates (96.1%). Purpose: To compare the clinical and radiographic outcomes after the arthroscopic Cuistow procedure and the arthroscopic Bristow procedure. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 91 patients who underwent either the Cuistow or Bristow procedure between January 2017 and March 2018 were selected, and 69 patients (70 shoulders; 35 in the Cuistow group and 35 in the Bristow group) were included. Clinical assessment at minimum 24 months postoperatively, including the visual analog scale for pain and instability, American Shoulder and Elbow Surgeons score, Rowe score, subjective shoulder value score, and active range of motion, was completed by independent observers and compared with values collected preoperatively. Assessment with 3-dimensional computed tomography scans was performed preoperatively; immediately after the operation; at 3, 6, and 12 months postoperatively; and at the final follow-up. Results: A total of 69 patients (70 shoulders) were included, with a mean follow-up duration of 34.41 ± 5.99 months (range, 24-50 months). Both groups saw significant improvement in visual analog scale for pain and instability, American Shoulder and Elbow Surgeons, Rowe, and subjective shoulder value scores at the final follow-up compared with the preoperative values (P < .001 for all), with no significant between-group differences on any clinical outcomes at the final follow-up. The 3-month postoperative graft union rate on computed tomography was significantly higher in the Cuistow group compared with the Bristow group (82.9% vs 51.4%, respectively, P = .003), although the graft union rate at the final follow-up was not significantly different (94.3% vs 85.7%, respectively; P = .449). Conclusion: Patients receiving the Cuistow procedure had equivalent clinical outcomes and a significantly higher bone union rate at 3 months postoperatively than those in the Bristow group. The inlay structure used in the Cuistow procedure was found to be associated with accelerated bone union.

Construction and evaluation of sarcopenia risk prediction model for patients with diabetes: a study based on the China health and retirement longitudinal study (CHARLS).

PURPOSE: Sarcopenia is a common complication of diabetes. Nevertheless, precise evaluation of sarcopenia risk among patients with diabetes is still a big challenge. The objective of this study was to develop a nomogram model which could serve as a practical tool to diagnose sarcopenia in patients with diabetes. METHODS: A total of 783 participants with diabetes from China Health and Retirement Longitudinal Study (CHARLS) 2015 were included in this study. After oversampling process, 1,000 samples were randomly divided into the training set and internal validation set. To mitigate the overfitting effect caused by oversampling, data of CHARLS 2011 were utilized as the external validation set. Least absolute shrinkage and selection operator (LASSO) regression analysis and multivariate logistic regression analysis were employed to explore predictors. Subsequently, a nomogram was developed based on the 9 selected predictors. The model was assessed by area under receiver operating characteristic (ROC) curves (AUC) for discrimination, calibration curves for calibration, and decision curve analysis (DCA) for clinical efficacy. In addition, machine learning models were constructed to enhance the robustness of our findings and evaluate the importance of the predictors. RESULTS: 9 factors were selected as predictors of sarcopenia for patients with diabetes. The nomogram model exhibited good discrimination in training, internal validation and external validation sets, with AUC of 0.808, 0.811 and 0.794. machine learning models revealed that age and hemoglobin were the most significant predictors. Calibration curves and DCA illustrated excellent calibration and clinical applicability of this model. CONCLUSION: This comprehensive nomogram presented high clinical predictability, which was a promising tool to evaluate the risk of sarcopenia in patients with diabetes.

[Research progress of Chinese unique Inlay Bristow (Cuistow surgery) using suture button fixation].

Objective: To explore the research progress of the coracoid transfer surgery using suture button fixation, particularly focusing on the technique known as Chinese unique Inlay Bristow (Cuistow surgery). Methods: Extensive literature review was conducted to summarize and analyze the utilization of suture button fixation in the Cuistow surgery, comparing its biomechanical and clinical outcomes with those of traditional screw fixation. Results: Utilizing suture button fixation in coracoid transfer surgery helps circumvent certain metal-related complications associated with traditional screw fixation. While its biomechanical stability and effectiveness have been preliminarily confirmed, debates persist regarding its graft healing rate and postoperative recurrence rate compared to traditional screw fixation. The Cuistow surgery based on the Inlay structure is a solution to improve the healing rate of graft after suture button fixation. Conclusion: Suture button fixation, as a novel approach in coracoid transfer surgery, remains to have its advantages and disadvantages compared to traditional screw fixation not entirely elucidated, underscoring the need for further in-depth clinical and fundamental research. Cuistow surgery is the Chinese experience of coracoid transfer surgery, and its biomechanical stability and clinical advantages have been preliminarily confirmed.

Nonoperative and Operative Soft-Tissue, Cartilage, and Bony Regeneration and Orthopaedic Biologics of the Elbow and Upper Extremity: An Orthoregeneration Network Foundation Review.

Orthoregeneration is defined as a solution for orthopaedic conditions that harnesses the benefits of biology to improve healing, reduce pain, improve function, and, optimally, provide an environment for tissue regeneration. Options include drugs, surgical intervention, scaffolds, biologics as a product of cells, and physical and electromagnetic stimuli. The goal of regenerative medicine is to enhance the healing of tissue after musculoskeletal injuries as both isolated treatment and adjunct to surgical management, using novel therapies to improve recovery and outcomes. Various orthopaedic biologics (orthobiologics) have been investigated for the treatment of pathology involving the elbow and upper extremity, including the tendons (lateral epicondylitis, medial epicondylitis, biceps tendonitis, triceps tendonitis), articular cartilage (osteoarthritis, osteochondral lesions), and bone (fractures, nonunions, avascular necrosis, osteonecrosis). Promising and established treatment modalities include hyaluronic acid; botulinum toxin; corticosteroids; leukocyte-rich and leukocyte-poor platelet-rich plasma; autologous blood; bone marrow aspirate comprising mesenchymal stromal cells (alternatively termed medicinal signaling cells and frequently mesenchymal stem cells [MSCs]) and bone marrow aspirate concentrate; MSCs harvested from adipose and skin (dermis) sources; vascularized bone grafts; bone morphogenic protein scaffold made from osteoinductive and conductive ß-tricalcium phosphate and poly-ε-caprolactone with hydrogels, human MSCs, and matrix metalloproteinases; and collagen sponge. Autologous blood preparations such as autologous blood injections and platelet-rich plasma show positive outcomes for nonresponsive tendinopathy. In addition, cellular therapies such as tissue-derived tenocyte-like cells and MSCs show a promising ability to regulate degenerative processes by modulating tissue response to inflammation and preventing continuous degradation and support tissue restoration.

Proteome-Wide Mendelian Randomization and Colocalization Analysis Identify Therapeutic Targets for Knee and Hip Osteoarthritis.

Osteoarthritis (OA) is a common degenerative disease. Although some biomarkers and drug targets of OA have been discovered and employed, limitations and challenges still exist in the targeted therapy of OA. Mendelian randomization (MR) analysis has been regarded as a reliable analytic method to identify effective therapeutic targets. Thus, we aimed to identify novel therapeutic targets for OA and investigate their potential side effects based on MR analysis. In this study, two-sample MR, colocalization analysis, summary-data-based Mendelian randomization (SMR) and Mendelian randomization phenome-wide association study (MR-PheWAS) were conducted. We firstly analyzed data from 4907 plasma proteins to identify potential therapeutic targets associated with OA. In addition, blood expression quantitative trait loci (eQTLs) data sources were used to perform additional validation. A protein-protein interaction (PPI) network was also constructed to delve into the interactions among identified proteins. Then, MR-PheWASs were utilized to assess the potential side effects of core therapeutic targets. After MR analysis and FDR correction, we identified twelve proteins as potential therapeutic targets for knee OA or hip OA. Colocalization analysis and additional validation supported our findings, and PPI networks revealed the interactions among identified proteins. Finally, we identified MAPK3 (OR = 0.855, 95% CI: 0.791-0.923, p = 6.88 × 10-5) and GZMK (OR = 1.278, 95% CI: 1.131-1.444, p = 8.58 × 10-5) as the core therapeutic targets for knee OA, and ITIH1 (OR = 0.847, 95% CI: 0.784-0.915, p = 2.44 × 10-5) for hip OA. A further MR phenome-wide association study revealed the potential side effects of treatments targeting MAPK3, GZMK, and ITIH1. This comprehensive study indicates twelve plasma proteins with potential roles in knee and hip OA as therapeutic targets. This advancement holds promise for the progression of OA drug development, and paves the way for more efficacious treatments of OA.

The New Double-row Bankart Repair Recovered Shoulder Stability without Excessive Motion Limitation: A Case-Control Study with Single-row Bankart Repair.

OBJECTIVES: Bankart lesion is one of the most common lesions of the glenohumeral joint. Several double-row suture methods were reported for Bankart repair, which could provide more stability, yet more motion limitation and complications. Therefore, we introduced a new double-row Bankart repair technique, key point double-row suture which used one anchor in the medial line. The purpose of this article is to investigate the clinical outcomes of this new method and to compare it with single-row suture. METHODS: Seventy-eight patients receiving key point double-row suture or single-row suture from October 2010 to June 2014 were collected retrospectively. The basic information including gender, age, dominant arm, and number of episodes of instability was collected. Before surgery, the glenoid bone loss was measured from the CT scan. The visual analogue scale, American shoulder and elbow surgeons, the University of California at Los Angeles shoulder scale, and subjective shoulder value were valued before surgery and at the last follow-up. RESULTS: Forty-four patients (24 patients receiving single-row suture and 20 patients receiving key point double-row suture) were followed up successfully. The follow-up period was 9.2 ± 1.1 years (range, 7.8-11.4 years). At the last follow-up, no significant differences were detected for any of the clinical scores. The recurrence rate was 12.5% for the single-row group and 10% for the double-row group, respectively (p = 0.795) 14 patients (31.8%) in the single-row group and nine patients (26.5%) in the double-row group were tested for active range of motion. A statistically significant difference was found only for the internal rotation at 90° abduction (48.9° for single-row and 76.7° for key point double-row, p = 0.033). CONCLUSION: The key point double-row sutures for Bankart lesions could achieve similar long-term outcomes compared with single-row suture, and one medial anchor did not result in a limited range of motion. The low recurrence rate and previous biomechanical results also indicate the key point double-row suture is a reliable method.

Inlay structure can improve bone graft stability in the Bristow procedure.

BACKGROUND: Compared with the Latarjet procedure, the Bristow procedure has a lower screw-related complication rate but poor bone healing. A modified Inlay Bristow procedure has been reported to significantly improve the bone healing rate, but the biomechanical mechanism is unclear. The aim of this study was to evaluate the biomechanical stability of the bone graft between a modified Inlay Bristow procedure and the classic Bristow procedure. METHODS: Sixteen left scapula models (Sawbones, Composite Scapula, and fourth generation) were randomly divided into 2 groups (8:8). The bone graft in the first group was fixed with a 3.5 mm screw using the Inlay structure. The bone graft in the second group was fixed with a 3.5 mm screw via the traditional method. The maximum cyclic displacement, ultimate failure load and stiffness were evaluated biomechanically. The failure type was recorded for each model. RESULTS: Cyclic loading tests demonstrated that the maximum cyclic displacement of the Inlay procedure was significantly smaller (P = .001) than that of the classic procedure. The Inlay Bristow technique resulted in a significantly higher (P = .024) ultimate failure load than the classic Bristow technique. The stiffness of the classic group was 19.17 ± 4.01 N/mm and that of the inlay group was 22.34 ± 5.35 N/mm (P = .232). Failure was mainly due to bone graft fractures through the drill hole or glenoid bone fractures. CONCLUSION: Inlay Bristow fixation of the bone graft in a Sawbones model provides significantly stronger fixation and better time point zero stability than classic Bristow fixation, suggesting a higher likelihood of graft union.

Using a Xenogeneic Acellular Dermal Matrix Membrane to Enhance the Reparability of Bone Marrow Mesenchymal Stem Cells for Cartilage Injury.

Due to its avascular organization and low mitotic ability, articular cartilage possesses limited intrinsic regenerative capabilities. The aim of this study is to achieve one-step cartilage repair in situ via combining bone marrow stem cells (BMSCs) with a xenogeneic Acellular dermal matrix (ADM) membrane. The ADM membranes were harvested from Sprague-Dawley (SD) rats through standard decellularization procedures. The characterization of the scaffolds was measured, including the morphology and physical properties of the ADM membrane. The in vitro experiments included the cell distribution, chondrogenic matrix quantification, and viability evaluation of the scaffolds. Adult male New Zealand white rabbits were used for the in vivo evaluation. Isolated microfracture was performed in the control (MF group) in the left knee and the tested ADM group was included as an experimental group when an ADM scaffold was implanted through matching with the defect after microfracture in the right knee. At 6, 12, and 24 weeks post-surgery, the rabbits were sacrificed for further research. The ADM could adsorb water and had excellent porosity. The bone marrow stem cells (BMSCs) grew well when seeded on the ADM scaffold, demonstrating a characteristic spindle-shaped morphology. The ADM group exhibited an excellent proliferative capacity as well as the cartilaginous matrix and collagen production of the BMSCs. In the rabbit model, the ADM group showed earlier filling, more hyaline-like neo-tissue formation, and better interfacial integration between the defects and normal cartilage compared with the microfracture (MF) group at 6, 12, and 24 weeks post-surgery. In addition, neither intra-articular inflammation nor a rejection reaction was observed after the implantation of the ADM scaffold. This study provides a promising biomaterial-based strategy for cartilage repair and is worth further investigation in large animal models.

E7 Peptide Enables BMSC Adhesion and Promotes Chondrogenic Differentiation of BMSCs Via the LncRNA H19/miR675 Axis.

Therapeutic strategies based on utilizing endogenous BMSCs have been developed for the regeneration of bone, cartilage, and ligaments. We previously found that E7 peptide (EPLQLKM) could enhance BMSC homing in bio-scaffolds and, therefore, promote cartilage regeneration. However, the profile and mechanisms of E7 peptide in cartilage regeneration remain elusive. In this study, we examined the effect of E7 peptide on the BMSC phenotype, including adhesion, viability and chondrogenic differentiation, and its underlying mechanism. The konjac glucomannan microsphere (KGM), a carrier material that is free of BMSC adhesion ability, was used as the solid base of E7 peptide to better explore the independent role of E7 peptide in BMSC behavior. The results showed that E7 peptide could support BMSC adhesion and viability in a comparable manner to RGD and promote superior chondrogenic differentiation to RGD. We examined differentially expressed genes of BMSCs induced by E7 compared to RGD. Subsequently, a real-time PCR validated the significantly upregulated expression of lncRNA H19, and the knockdown of lncRNA H19 or miR675, a downstream functional unit of H19, could significantly obscure the chondrogenic differentiation induced by E7. In conclusion, this study confirmed the independent role of E7 in the adhesion and viability of BMSCs and revealed the pro-chondrogenic effect of E7 on BMSCs via the H19/miR675 axis. These results could help establish new therapeutic strategies based on employing endogenous BMSCs for cartilage tissue regeneration.

Therapeutic Potential of Exosomes in Tendon and Tendon-Bone Healing: A Systematic Review of Preclinical Studies.

Exosomes have been proven to play a positive role in tendon and tendon-bone healing. Here, we systematically review the literature to evaluate the efficacy of exosomes in tendon and tendon-bone healing. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic and comprehensive review of the literature was performed on 21 January 2023. The electronic databases searched included Medline (through PubMed), Web of Science, Embase, Scopus, Cochrane Library and Ovid. In the end, a total of 1794 articles were systematically reviewed. Furthermore, a "snowball" search was also carried out. Finally, forty-six studies were included for analysis, with the total sample size being 1481 rats, 416 mice, 330 rabbits, 48 dogs, and 12 sheep. In these studies, exosomes promoted tendon and tendon-bone healing and displayed improved histological, biomechanical and morphological outcomes. Some studies also suggested the mechanism of exosomes in promoting tendon and tendon-bone healing, mainly through the following aspects: (1) suppressing inflammatory response and regulating macrophage polarization; (2) regulating gene expression, reshaping cell microenvironment and reconstructing extracellular matrix; (3) promoting angiogenesis. The risk of bias in the included studies was low on the whole. This systematic review provides evidence of the positive effect of exosomes on tendon and tendon-bone healing in preclinical studies. The unclear-to-low risk of bias highlights the significance of standardization of outcome reporting. It should be noted that the most suitable source, isolation methods, concentration and administration frequency of exosomes are still unknown. Additionally, few studies have used large animals as subjects. Further studies may be required on comparing the safety and efficacy of different treatment parameters in large animal models, which would be conducive to the design of clinical trials.

The Arthroscopic Bristow Procedure Is Superior to the Arthroscopic Latarjet Procedure in Return to Sports but Inferior in Graft Healing: A Comparative Study With 3.4-Year Follow-Up.

PURPOSE: To compare clinical and computed tomography outcomes between the arthroscopic Latarjet procedure and the arthroscopic Bristow procedure. METHODS: Patients who underwent arthroscopic Latarjet or Bristow procedures with at least 2 years of follow-up were retrospectively reviewed. Thirty-eight shoulders were included in the Latarjet group, and 34 were included in the Bristow group. Recurrence of dislocation, clinical scores, rate of return to sports (RTS), and computed tomography assessment findings (position of transferred coracoid, graft healing, graft absorption, and glenohumeral degenerative osteoarthritis [OA]) were obtained at final follow-up. RESULTS: No recurrent dislocation occurred in either group, and no significant differences in clinical scores were found between the 2 procedures, with a mean follow-up period of 3.4 years. The operative time in the Bristow group was significantly shorter than that in the Latarjet group (P < .001). The transferred coracoid had healed in 94.7% of the patients in the Latarjet group and 85.3% in the Bristow group at final follow-up (P = .01). No significant difference in graft absorption or the degree of glenohumeral OA was detected between the 2 groups. However, moderate to severe OA only occurred in the Latarjet group at final follow-up (4 of 38 shoulders, 10.5%). The postoperative external rotation angle and level of RTS favored the Latarjet procedure (P = .030 and P = .034, respectively). CONCLUSIONS: Both the arthroscopic Latarjet and arthroscopic Bristow procedures led to good clinical scores with no new dislocation episodes. The Bristow group showed significantly less graft healing than the Latarjet group. However, the arthroscopic Bristow procedure took less operative time and showed a lower rate of early moderate to severe glenohumeral OA, better range of motion, and a higher rate of RTS. LEVEL OF EVIDENCE: Level III, retrospective comparative therapeutic trial.

[Research progress in biomechanics of Bristow-Latarjet procedure for anterior shoulder dislocation].

Objective: To review the research progress of the biomechanical study of the Bristow-Latarjet procedure for anterior shoulder dislocation. Methods: The related biomechanical literature of Bristow-Latarjet procedure for anterior shoulder dislocation was extensively reviewed and summarized. Results: The current literature suggests that when performing Bristow-Latarjet procedure, care should be taken to fix the bone block edge flush with the glenoid in the sagittal plane in the direction where the rupture of the joint capsule occurs. If traditional screw fixation is used, a double-cortical screw fixation should be applied, while details such as screw material have less influence on the biomechanical characteristics. Cortical button fixation is slightly inferior to screws in terms of biomechanical performance. The most frequent site of postoperative bone resorption is the proximal-medial part of the bone block, and the cause of bone resorption at this site may be related to the stress shielding caused by the screw. Conclusion: There is no detailed standardized guidance for bone block fixation. The optimal clinical treatment plan for different degrees of injury, the factors influencing postoperative bone healing and remodeling, and the postoperative osteoarticular surface pressure still need to be further clarified by high-quality biomechanical studies.

Previously failed Bankart repair and the duration from first dislocation to surgery were the risk factors associated with the level of return to sports after coracoid transfer.

PURPOSE: This study aims to determine the rate of different levels of return to sports (RTS) in athletes undergoing the modified arthroscopic Bristow procedure and the factors associated with the level of RTS. METHODS: The study was performed retrospectively on patients with traumatic anterior shoulder instability who underwent the modified arthroscopic Bristow procedure with a minimum follow-up of 2 years. The RTS rate, the level of return and the timing of return were assessed. Additionally, factors such as preoperative basic information, clinical outcomes, graft position, graft healing and graft absorption were analysed to investigate their correlation with the level of RTS. Multivariate regression models were used to evaluate the factors affecting the level of RTS. RESULTS: In total, this study included 182 shoulders of 177 athletes undergoing the modified arthroscopic Bristow procedure. Of these patients, 142 (78.0%) shoulders of 137 athletes were enrolled, with a mean of 3.3-year follow-up. At the final follow-up, 134 (94.4%) shoulders were able to RTS, 123 (86.6%) shoulders were able to RTS to the pre-injury level, 52 (36.6%) shoulders could be completely "forgotten" without any psychological barrier during exercise. The multivariate logistic regression analysis identified the variable associated with RTS at the pre-injury level as previously failed arthroscopic Bankart repair (p < 0.001). As for the "forgetting" operated shoulder, the duration from first dislocation to surgery was a significant independent predictor (p = 0.034). CONCLUSION: Although a large majority of athletes were able to RTS at the pre-injury level after the modified arthroscopic Bristow procedure, about two-thirds of the athletes felt difference in shoulders on both sides and could not completely "forget" the operated shoulder during exercise. Previously failed Bankart repair and the duration from first dislocation to surgery were the risk factors associated with the level of RTS after the modified arthroscopic Bristow procedure. LEVEL OF EVIDENCE: IV.

Earlier and More Severe Cartilage Degeneration Occurs After Meniscal Tears in Juvenile Rabbits Compared with Adults.

OBJECTIVE: To compare the severity of cartilage degeneration after meniscal tears between juvenile and adult rabbits. DESIGN: This study included 20 juvenile rabbits (2 weeks after birth) and 20 adult rabbits (6 months after birth). Meniscal tears were prepared in the anterior horn of medial menisci of right knees. Rabbits were sacrificed at 1, 3, 6, and 12 weeks postoperatively. Cartilage degenerations in the medial femoral condyle and medial tibial plateau were evaluated macroscopically and histologically. The semiquantitative assessment of cartilage degeneration was graded by macroscopic Outerbridge scoring system and histological Osteoarthritis Research Society International (OARSI) scoring system. RESULTS: In juvenile rabbits, the morphologically intact cartilage and normal extracellular matrix architecture were observed at the first week postoperatively. Mild uneven cartilage surface and toluidine blue depletion in the medial femoral condyle were observed on histological assessment at 3 weeks postoperatively. The worsened cartilage deterioration demonstrating chondral fibrillation, prominent cell death, and glycosaminoglycan (GAG) release was observed at 6 and 12 weeks postoperatively. In adult rabbits, only mild cartilage degeneration was observed in the medial femoral condyle at 12 weeks postoperatively. The outcomes of Outerbridge and OARSI scores were consistent with the aforementioned findings in juvenile and adult rabbits. CONCLUSIONS: Our study validated that earlier and more severe cartilage degenerations were observed in juvenile rabbits after meniscal tears compared with adult rabbits. Moreover, the post-tear cartilage degeneration demonstrated regional specificity corresponded to the tear position. However, caution is warranted when extrapolating results of animal models to humans.

Osteointegration of PLLA/ß-TCP Biocomposite Anchors Used in Coracoid Transfer Procedures for Shoulder Instability: Quantitative Computed Tomography With a Minimum 2-Year Follow-up.

Background: Biocomposite anchors have been a popular choice for use in coracoid transfer procedures for shoulder instability and are hypothesized to allow bone ingrowth. Purpose: To quantitatively evaluate the osteointegration of 85% PLLA/15% ß-TCP biocomposite anchors used in the coracoid transfer procedure for shoulder instability. Study Design: Case series; Level of evidence, 4. Methods: We performed a retrospective case series of abstracted data from the records of 74 patients who underwent coracoid transfer procedures with biocomposite anchors. Computed tomography was performed at 24 months postoperatively. A total of 4 researchers independently reviewed the computed tomography images. The density (in Hounsfield unit [HU] values) of the anchor tunnels, glenoid, and subscapularis was assessed, and osteointegration of the anchor tunnels was evaluated with HU values, the quantitative ossification quality score (QOQS), and tunnel widening. Results: Included were 74 patients (58 male, 16 female), involving 76 shoulders and 124 biocomposite anchors. At ≥24-month follow-up, 72 of 124 (58.06%) anchor tunnels were classified as QOQS type 1, including 12 completely ossified tunnels and 60 almost completely ossified tunnels. Some degree of ossification (QOQS types 1-3) was observed in 118 (95.16%) anchor tunnels. Overall, 3 anchor tunnels were enlarged (QOQS type 5). The mean HU value of the anchor tunnels was 339.75, which was significantly higher than the preoperative HU value of the glenoid vault (262.19). Among the 124 anchor tunnels, 79 had HU values higher than their glenoid HU values, and 45 had lower HU values than their glenoid HU values. In the comparison of tunnel HU values at 12 versus ≥24 months, the HU value at ≥24 months was significantly higher. A total of 20 anchor tunnels widened. Conclusion: Among 124 anchor tunnels, 95.16% showed ossification, 58.06% were completely or nearly completely ossified, and 3 were enlarged. The HU value of the anchor tunnel increased over time.

A lipid metabolite lipidomics assay for prediction and severity evaluation of rotator cuff injury.

Objective: Rotator cuff injury can be caused by local inflammation and fibrosis of musculotendinous cuff. Hypercholesterolemia can lead to physiological changes of rotator cuff that resemble rotator cuff injury. However, the relationship between lipid metabolism and rotator cuff injury and its potential pathological mechanism remain unclear. Herein, we aimed to investigate the correlation between the plasma lipidome, rotator cuff injury, and successive fatty infiltration pathology, and hoped to identify biomarkers for predicting higher risk or higher severity rotator cuff injury by assessing metabolic perturbations and dyslipidemia using lipidomics. Methods: We quantitatively analyzed 60 lipids species of seven lipids classes and subclasses from 66 subjects using lipidomics. Subjects were divided into four groups: (1) normal rotator cuff with normal clinical routine serum lipid test results (NN group = 13); (2) normal rotator cuff with abnormal clinical routine serum lipid test results (NA group = 10); (3) rotator cuff tear with normal routine serum lipid test results (RN group = 30); (4) rotator cuff tear with abnormal routine serum lipid test results (RA group = 13). Independent-sample t-tests and Kruskal-Wallis tests were used to compare lipid metabolite levels in serum between different groups in patients with rotator cuff tears. The orthogonal partial least squares-discriminant analysis (OPLS-DA) model was used to verify the ability of five lysophosphatidylcholines (LPCs) to distinguish rotator cuff injuries. In the rotator cuff tear group, magnetic resonance imaging (MRI) was used to classify fatty infiltration according to Goutallier's classification. Kruskal-Wallis tests were used to analyze molecular differences between high-grade (grade 3-4) and low-grade (grade 0-2) fatty infiltration groups. Receiver operator characteristic (ROC) curves were drawn for each diagnostic method via different metabolites. The area under the curve (AUC), cutoff, specificity, sensitivity, and accuracy of each diagnostic criterion were calculated. Results: Our results showed that some rotator cuff injury patients yielded unique lipidomic profiles. Based on Kruskal-Wallis tests, our results showed significant differences in three lipid molecules, 17:1 Lyso PI, 18:0-22:6 PE, and 18:3 (Cis) PC, among all four groups independent of clinical blood lipid levels. Also, independent of clinical blood lipid levels, two lipid molecules, 22:0 Lyso PC and 24:0 Lyso PC, were significantly different between the two groups based on Independent sample t-tests. Kruskal-Wallis test results showed that in the rotator cuff tear group, two metabolites (24:0 SM and 16:0 ceramide) differed between high-grade and low-grade fatty infiltration. The AUC values for 22:0 Lyso PC, 24:0 Lyso PC, 18:0-22:6 PE, 24:0 SM, and 16:0 ceramide were 0.6036, 0.6757, 0.6712, 0.8333, and 0.8981, respectively. Conclusion: The results provide insight into how the metabolic mechanisms associated with dyslipidemia impact rotator cuff diseases. Five lipid molecules, 17:1 Lyso PI, 18:0-22:6 PE, 18:3 (Cis) PC, 22:0 Lyso PC, and 24:0 Lyso PC, were closely related to rotator cuff tear based on two statistical analysis methods, independent of clinical routine serum lipid test results, which indicates that lipidomics assays are more sensitive than conventional lipid tests, and more suitable for studying rotator cuff lipid metabolism. In addition, two lipid metabolites, 24:0 SM and 16:0 ceramide, are potentially useful for predicting fatty infiltration severity. Further research with a larger number of samples is needed to verify whether these two metabolites can serve as potential markers of severe fatty infiltration. The findings illuminate how metabolic mechanisms associated with dyslipidemia affect rotator cuff disease.

The transplantation of particulated juvenile allograft cartilage and synovium for the repair of meniscal defect in a lapine model.

Background: Synovium has been confirmed to be the primary contributor to meniscal repair. Particulated Juvenile Allograft Cartilage (PJAC) has demonstrated promising clinical effect on repairing cartilage. The synergistic effect of synovium and PJAC transplant on meniscal fibrocartilaginous repair is unclear. We hypothesize that the transplantation of synovium and PJAC synergistically facilitates meniscal regeneration and the donor cells within graft tissues still survive in the regenerated tissue at the last follow up (16 weeks postoperatively). Methods: The study included 24 mature female rabbits, which were randomly divided into experimental and control groups. A cylindrical full-thickness defect measuring 2.0 â€‹mm was prepared in the avascular portion of the anterior horn of medial meniscus in both knees. The synovium and PJAC transplant were harvested from juvenile male rabbits (2 months after birth). The experimental group received synovium and PJAC transplant encapsulated with fibrin gel. The control groups received synovium transplant encapsulated with fibrin gel, pure fibrin gel and nothing. The macroscopic, imageological and histological evaluations of repaired tissue were performed at 8 weeks and 16 weeks postoperatively. The in situ hybridization (ISH) of male-specific sex-determining region Y-linked (SRY) gene was performed to detect the transplanted cells. Results: The regenerated tissue in experimental group showed superior structural integrity, superficial smoothness, and marginal integration compared to control groups at 8 weeks or 16 weeks postoperatively. More meniscus-like fibrochondrocytes filled the repaired tissue in the experimental group, and the matrix surrounding these cell clusters demonstrated strongly positive safranin O and type 2 collagen immunohistochemistry staining. By SRY gene ISH, the positive SRY signal of experimental group could be detected at 8 weeks (75.72%, median) and 16 weeks (48.69%, median). The expression of SOX9 in experimental group was the most robust, with median positive rates of 65.52% at 8 weeks and 67.55% at 16 weeks. Conclusion: The transplantation of synovium and PJAC synergistically facilitates meniscal regeneration. The donor cells survive for at least 16 weeks in the recipient. The translational potential of this article: This study highlighted the positive effect of PJAC and synovium transplant on meniscal repair. We also clarified the potential repair mechanisms reflected by the survival of donor cells and upregulated expression of meniscal fibrochondrocytes related genes. Thus, based on our study, further clinical experiments are needed to investigate synovium and PJAC transplant as a possible treatment to meniscal defects.