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. CONCLUSION Biodegradable 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.
Animals ; Rotator Cuff Injuries/metabolism* ; Rats, Sprague-Dawley ; Signal Transduction ; Wound Healing/drug effects* ; Alloys/pharmacology* ; Rats ; Proto-Oncogene Proteins c-akt/metabolism* ; Rotator Cuff/metabolism* ; Macrophages/metabolism* ; Magnesium/pharmacology* ; Phosphatidylinositol 3-Kinases/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Male ; Biocompatible Materials ; Bone Morphogenetic Protein 2/metabolism*

OBJECTIVE: To explore early clinical efficacy and advantages of Huoxue Fang's directional dialysis combined with extracorporeal shock wave in treating rotator cuff injury. METHODS: A retrospective analysis was performed for 42 patients with rotator cuff injury admitted from September 2020 to December 2022, and they were divided into shock wave group and directed dialysis group according to different treatment methods. There were 20 patients in shock wave group, including 12 males and 8 females; aged from 47 to 68 years old with an average of (63.2±3.3) years old;the course of disease ranged from 2 to 6 weeks with an average of (3.1±1.4) weeks;10 patients with gradeⅠand 10 patients with gradeⅡaccording to Ellman classification;non-steroidal drugs and extracorporeal shock wave therapy were performed. There were 22 patients in directed dialysis group, including 16 males and 6 females;aged from 44 to 67 years old with an average of (61.0±2.3) years old;the course of disease ranged from 2 to 8 weeks with average of (3.3±1.3) weeks;12 patients with gradeⅠand 10 patients with gradeⅡaccording to Ellman classification;with Huoxue prescription directed transdrug therapy based on shock wave group. Visual analogue scale (VAS), University of California at Los Angeles (UCLA) and range of motion (ROM) were compared between two groups before treatment, 1 and 6 months after treatment;changes of tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1) and interleukin-6 (IL-6) between two groups were detected and compared. The complications between two groups were compared. RESULTS: All patients were followed up, shockwave group followed up for 6 to 8 months with an average of (7.1±1.9) months, 6 to 8 months with an average of (7.2±1.8) months in directed dialysis group, with no statistical significance between two groups (P>0.05). At 1 and 6 months after treatment, VAS in directed dialysis group were (3.85±0.99), (1.24±0.75), which were lower than that in shock wave group (4.91±0.89), (1.81±0.84) (P<0.05). UCLA scores in directed dialysis group (25.25±2.34), (32.71±2.33) were higher than those in shock wave group (21.67±3.38) °, (29.11±3.01) °(P<0.05). Forward bending (139.15±20.39) °, (150.14±20.55) °, external rotation (63.46±16.62) °, (73.35±13.82) °, internal rotation (46.99±2.93) °, (58.24±2.10) ° in directed dialysis group were better than those in shock wave group (130.61±22.27) °, (141.28±19.47) °, external rotation (57.36±17.53) °, (68.12±13.64) °, internal rotation (41.21±3.10) °, (49.16±3.21) ° (P<0.05). At 1 and 6 months after treatment, TNF-α, IL-1 and IL-6 in directed dialysis group were (2.12±0.49), (2.06±0.55), (0.69±0.26) μg·L-1;(1.27±0.25), (1.14±0.23), (0.37±0.11) μg·L-1, which were lower than those in shock wave group (2.87±0. 51), (2.67±0.48), (0.92±0.21) μg·L-1, (1.88 ± 0.26), (1.36±0.27), (0.45±0.09) μg·L-1(P<0.05). At the latest follow-up, 8 patients got excellent result, 10 good and 2 poor in shock wave group;10 patients excellent, 10 good, and 2 poor in directed dialysis group;there was no significant difference between two groups (P>0.05). There were no complications such as skin allergy, subcutaneous hemorrhage, ecchymosis, vascular and nerve injury occurred in both groups. CONCLUSION For the treatment of rotator cuff injury, Huoxue prescription combined with extracorporeal shock wave is effective, which could not only release the local adhesion tissue, improve local blood circulation, accelerate absorption of inflammatory exudate of the local soft tissue, and promote recovery of the diseased muscle bond and ligament. It could also effectively relieve shoulder pain, improve shoulder motion, restore shoulder function, improve patients' quality of life.
Humans ; Male ; Female ; Middle Aged ; Aged ; Extracorporeal Shockwave Therapy ; Retrospective Studies ; Rotator Cuff Injuries/physiopathology* ; Adult ; Drugs, Chinese Herbal/administration & dosage* ; Combined Modality Therapy ; Interleukin-6/metabolism*

OBJECTIVE: To explore pro-oxidative state of rotator cuff tissue and expression levels of Beclin-1 and mam-malian target of rapamycin(mTOR) in patients with acute and chronic rotator cuff injury, and then analyzed relationship between rotator cuff injury and oxidative stress and autophagy. METHODS: Forty patients with rotator cuff injury were seleceted from July 2019 to December 2020, and divided into male chronic injury group, male acute injury group, female chronic injury group, and female acute injury group, 10 patients in each group. All patients were performed rotator cuff repair under arthroscopy. The sample of tendon at the rotator cuff injury site of the patient was taken during operation, and total reactive oxygen species (ROS) and superoxide dismutase(SOD) were detected by detection kit;expression of Beclin-1 and mTOR mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR), and Western-blot was applied to detect protein expression of Beclin-1 and p-mTOR/mTOR. RESULTS: There were no significant difference in expression of ROS, SOD, Beclin-1mRNA and mTOR mRNA between male and female chronic injury groups, and between male and female acute injury groups (P>0.05); ROS, SOD and Beclin-1mRNA in male chronic injury group were higher than those in male chronic injury group, while mTOR mRNAand protein decreased (P<0.05);ROS, SOD and Beclin-1 mRNA in female chronic injury group were up-regulated compared with female acute injury group, while mTOR mRNA was down-regulated (P<0.05). CONCLUSION Chronic rotator cuff injury is more likely to stimulate the pro-oxidation state of rotator cuff tissue than acute rotator cuff injury, which could up-regulating expression of autophagy factor Beclin-1 and down-regulating expression of mTOR. Therefore, patients with chronic rotator cuff injury may have higher levels of oxidative stress and autophagy.
Female ; Humans ; Male ; Beclin-1/metabolism* ; Reactive Oxygen Species/metabolism* ; RNA, Messenger/metabolism* ; Rotator Cuff/surgery* ; Rotator Cuff Injuries/surgery* ; Superoxide Dismutase/metabolism* ; TOR Serine-Threonine Kinases/metabolism*

OBJECTIVESTo establish the animal model of acute rotator cuff tear in rabbits, and study the effect of timing of surgical repair on healing of tendon-bone interface, formation and distribution of collagens in the supraspinatus tendon insertion and biomechanical properties of supraspinatus.

METHODSSupraspinatus tenotomy was performed in the right shoulder of 90 skeletally matured male New Zealand white rabbits to establish the animal model of acute rotator cuff tear. The rabbits were randomly divided into 3 groups : group of early repair, repaired at 1 week after tenotomy; group of late repair, repaired at 4 weeks after tenotomy; and group without repair, used as control. At 2 weeks, 4 weeks and 8 weeks after repair, healing of tendon-bone interface was observed by HE staining. Collagens were observed by Sirius Red F 3B (SR) in saturated carbazotic acid staining. The areas of type I and III collagens were measured by using imaging analysis software and the ratio of type I and III collagens were calculated. Failure loads of supraspinatus on both sides were measured. The percentage of failure loads of the surgical side was calculated and contralateral supraspinatus were uninjured.

RESULTSThere was no obvious fatty infiltration and muscle atrophy in supraspinatus in all groups. At 8 weeks, the formation of a new enthesis of supraspinatus in groups of early and late repair were observed. In groups of early and late repair, the ratio of areas of type I and III collagens at 8 weeks (2.02 ± 0.77 and 2.06 ± 0.58) was larger than that at 2 weeks (1.10 ± 0.24 and 1.14 ± 0.50, t = 3.082, 3.655, P < 0.01). At 2, 4 and 8 weeks, the percentages of failure loads of the surgical side and uninjured contralateral supraspinatus in group of early repair(38% ± 11%, 66% ± 7%, 89% ± 4%) and group of late repair (41% ± 16%, 63% ± 7%, 89% ± 9%) were both higher than that in group without repair (14% ± 6%, 32% ± 4%, 56% ± 12%); the differences were all statistically significant (group of early repair: t = 3.311, 8.549, 5.719; group of late repair: t = 3.713, 8.063, 6.044; P < 0.01). The percentage of failure loads of the surgical side and uninjured contralateral supraspinatus at 8 weeks was higher than those at 4 weeks (t = 3.878 - 4.613, P < 0.01) and 2 weeks (t = 7.158 - 10.024, P < 0.01) in all groups.

CONCLUSIONSSurgical repair within 4 weeks of acute rotator cuff tear lead to formation of a new enthesis of supraspinatus, improvement of both ratio of type I collagen in the supraspinatus tendon insertion and biomechanical properties of supraspinatus.

Animals ; Biomechanical Phenomena ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Disease Models, Animal ; Male ; Rabbits ; Rotator Cuff ; pathology ; surgery ; Rotator Cuff Injuries ; Time Factors

Biologic augmentation could promote rotator cuff tendon healing and improve the mechanical properties as well as reduce postoperative adhesion. Biologic augmentations play a vital role in rotator cuff repair and healing. However, most of the studies were performed on animals and clinical outcomes were short-term follow-up. The therapeutic effects should be assessed in multicenter prospective trials.
Animals ; Humans ; Intercellular Signaling Peptides and Proteins ; metabolism ; therapeutic use ; Rotator Cuff ; metabolism ; pathology ; transplantation ; Rotator Cuff Injuries ; Transplantation ; Wound Healing