Objective To compare the short-term effectiveness of functional double-bundle anterior cruciate ligament reconstruction with internal brace (F-DBACLR+IB) by helical continuous suture fixation versus anatomical single-bundle anterior cruciate ligament reconstruction (A-SBACLR). Methods A retrospective analysis was performed on the clinical data of 66 patients who underwent anterior cruciate ligament reconstruction between January 2023 and December 2024 and met the selection criteria. Patients were divided into the A-SBACLR group (n=34) and the F-DBACLR+IB group (n=32) according to the surgical procedure. No significant intergroup difference was observed in baseline data, including gender, age, body mass index, injured side, preoperative meniscal injury status, or preoperative Tegner score, Lysholm score, International Knee Documentation Committee (IKDC) score, KT-1000 measurement, and pivot shift test grade (P>0.05). Intraoperative data including operation time, intraoperative blood loss, and complications were recorded and compared between the two groups. Functional outcomes were evaluated preoperatively and postoperatively using the Tegner score, IKDC score, Lysholm score, KT-1000 measurement, and pivot shift test grade. Results There was no significant difference in operation time, intraoperative blood loss, and graft complex diameter between the two groups (P>0.05). All patients were followed up, the follow-up duration was (22.94±4.55) months in the A-SBACLR group and (21.25±4.25) months in the F-DBACLR+IB group, with no significant difference (t=1.558, P=0.852). All incisions healed by first intention, and no complication such as knee stiffness/fibrosis or deep joint infection occurred in either group. No revision surgery was performed due to postoperative graft re-rupture in either group. Medial knee pain was reported in 7 patients in the A-SBACLR group and 6 patients in the F-DBACLR+IB group, and peripatellar numbness occurred in 6 and 5 patients, respectively; the incidences showed no significant intergroup differences (P>0.05). At last follow-up, the F-DBACLR+IB group exhibited significantly greater improvements in the Tegner score, IKDC score when compared with the A-SBACLR group (P<0.05); no significant difference was found in changes of Lysholm score, KT-1000 measurement, or pivot shift test grade between the two groups (P>0.05). Conclusion Compared with A-SBACLR, F-DBACLR+IB yields superior early postoperative recovery of sporting and effectiveness. The helical continuous suture technique provides reliable internal brace fixation for F-DBACLR.
Objective To evaluate the effect of biodegradable magnesium alloy materials in promoting tendon-bone healing during rotator cuff tear repair and to investigate their potential underlying biological mechanisms.Methods Forty-eight 8-week-old Sprague Dawley rats were taken and randomly divided into groups A, B, and C. Rotator cuff tear models were created and repaired using magnesium alloy sutures in group A and Vicryl Plus 4-0 absorbable sutures in group B, while only subcutaneous incisions and sutures were performed in group C. Organ samples of groups A and B were taken for HE staining at 1 and 2 weeks after operation to evaluate the safety of magnesium alloy, and specimens from the supraspinatus tendon and proximal humerus were harvested at 2, 4, 8, and 12 weeks after operation. The specimens were observed macroscopically at 4 and 12 weeks after operation. Biomechanical tests were performed at 4, 8, and 12 weeks to test the ultimate load and stiffness of the healing sites in groups A and B. At 2, 4, and 12 weeks, the specimens were subjected to the following tests: Micro-CT to evaluate the formation of bone tunnels in groups A and B, HE staining and Masson staining to observe the regeneration of fibrocartilage at the tendon-bone interface after decalcification and sectioning, and Goldner trichrome staining to evaluate the calcification. Immunohistochemical staining was performed to detect the expressions of angiogenic factors, including vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2), as well as osteogenic factors at the tendon-bone interface. Additionally, immunofluorescence staining was used to examine the expressions of Arginase 1 and Integrin beta-2 to assess M1 and M2 macrophage polarization at the tendon-bone interface. The role of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway in tendon-bone healing was further analyzed using real-time fluorescence quantitative PCR. Results Analysis of visceral sections revealed that magnesium ions released during the degradation of magnesium alloys did not cause significant toxic effects on organs such as the heart, liver, spleen, lungs, and kidneys, indicating good biosafety. Histological analysis further demonstrated that fibrocartilage regeneration at the tendon-bone interface in group A occurred earlier, and the amount of fibrocartilage was significantly greater compared to group B, suggesting a positive effect of magnesium alloy material on tendon-bone interface repair. Additionally, Micro-CT analysis results revealed that bone tunnel formation occurred more rapidly in group A compared to group B, further supporting the beneficial effect of magnesium alloy on bone healing. Biomechanical testing showed that the ultimate load in group A was consistently higher than in group B, and the stiffness of group A was also greater than that of group B at 4 weeks, indicating stronger tissue-carrying capacity following tendon-bone interface repair and highlighting the potential of magnesium alloy in enhancing tendon-bone healing. Immunohistochemical staining results indicated that the expressions of VEGF and BMP-2 were significantly upregulated during the early stages of healing, suggesting that magnesium alloy effectively promoted angiogenesis and bone formation, thereby accelerating the tendon-bone healing process. Immunofluorescence staining further revealed that magnesium ions exerted significant anti-inflammatory effects by regulating macrophage polarization, promoting their shift toward the M2 phenotype. Real-time fluorescence quantitative PCR results demonstrated that magnesium ions could facilitate tendon-bone healing by modulating the PI3K/AKT signaling pathway. ConclusionBiodegradable magnesium alloy material accelerated fibrocartilage regeneration and calcification at the tendon-bone interface in rat rotator cuff tear repair by regulating the PI3K/AKT signaling pathway, thereby significantly enhancing tendon-bone healing.
