Biomechanical and histological evaluation of aspirin in rotator cuff tear rat model.

Background: Aspirin is a representative non-steroidal anti-inflammatory drug (NSAIDs) and has been commonly used for the treatment of tendinopathy in clinical practice. In this study, we aimed to evaluate the biomechanical and histological healing effects of aspirin on the healing of the tendon-to-bone interface after rotator cuff tear repair. Methods: A total of 20 male Sprague-Dawley rats were randomly divided into two groups of 10 rats each. Group-C performed repaironly, and group-aspirin treated with aspirin after tendon repair. Group-aspirin rat were intraperitoneally injected with aspirin at 10 mg/kg every 24 h for 7 days. Eight weeks after surgery, the left shoulder of each rat was used for histological analysis and the right shoulder for biomechanical analysis. Results: In the biomechanical analysis, there was no significant difference in load-to-failure (group-C: 0.61 ± 0.32 N, group-aspirin: 0.74 ± 0.91 N; p = .697) and ultimate stress (group-C: 0.05 ± 0.01 MPa, group-aspirin: 0.29 ± 0.43 MPa; p = .095). For the elongation (group-C: 222.62 ± 57.98%, group-aspirin: 194.75 ± 75.16%; p = .028), group-aspirin confirmed a lower elongation level than group-C. In the histological evaluation, the Bonar score confirmed significant differences in collagen fiber density (group-C: 1.60 ± 0.52, group-aspirin: 2.60 ± 0.52, p = .001) and vascularity (group-C: 1.00 ± 0.47, group-aspirin: 2.20 ± 0.63, p = .001) between the groups. Conclusions: Aspirin injection after rotator cuff tear repair may enhance the healing effect during the early remodeling phase of tendon healing.

Effect of electrical muscle stimulation on the improvement of deltoid muscle atrophy in a rat shoulder immobilization model.

Immobilization following trauma or surgery induces skeletal muscle atrophy, and improvement in the muscle atrophy is critical for successful clinical outcomes. The purpose of this study is to evaluate the effect of electrical muscle stimulation (EMS) on muscle atrophy. The study design is a controlled laboratory study. Eighty rats (56 to establish the deltoid muscle atrophy [DMA] model and 24 to evaluate the effect of EMS on the model) were used. DMA was induced by completely immobilizing the right shoulder of each rat by placing sutures between the scapula and humeral shaft, with the left shoulder as a control. After establishing the DMA model, rats were randomly assigned into three groups: low-frequency EMS (L-EMS, 10 Hz frequency), medium-frequency EMS (M-EMS, 50 Hz frequency), and control (eight rats per group). After 3 weeks, the deltoid muscles of each rat were harvested, alterations in gene expression and muscle cell size were evaluated, and immunohistochemical analysis was performed. DMA was most prominent 3 weeks after shoulder immobilization. Murf1 and Atrogin were significantly induced at the initial phase and gradually decreased at approximately 3 weeks; however, MyoD expressed an inverse relationship with Murf1 and Atrogin. IL6 expression was prominent at 1 week. The time point for the EMS effect evaluation was selected at 3 weeks, when the DMA was the most prominent with a change in relevant gene expression. The M-EMS group cell size was significantly larger than that of L-EMS and control group in both the immobilized and intact shoulders (all p < 0.05), without significant differences between the L-EMS and control groups. The M-EMS group showed significantly lower mRNA expressions of Murf1 and Atrogin and higher expressions of MyoD and Col1A1 than that of the control group (all p < 0.05). In immunohistochemical analysis, similar results were observed with lower Atrogin staining and higher MyoD and Col1A1 staining in the M-EMS group. DMA model was established by complete shoulder immobilization, with the most prominent muscle atrophy observed at 3 weeks. M-EMS improved DMA with changes in the expression of relevant genes. M-EMS might be a solution for strengthening atrophied skeletal muscles and facilitating rehabilitation after trauma or surgery.

Nanofiber Graft Therapy to Prevent Shoulder Stiffness and Adhesions after Rotator Cuff Tendon Repair: A Comprehensive Review.

Stiffness and adhesions following rotator cuff tears (RCTs) are common complications that negatively affect surgical outcomes and impede healing, thereby increasing the risk of morbidity and failure of surgical interventions. Tissue engineering, particularly through the use of nanofiber scaffolds, has emerged as a promising regenerative medicine strategy to address these complications. This review critically assesses the efficacy and limitations of nanofiber-based methods in promoting rotator cuff (RC) regeneration and managing postrepair stiffness and adhesions. It also discusses the need for a multidisciplinary approach to advance this field and highlights important considerations for future clinical trials.

Effect of Gabapentin on Tendon-to-Bone Healing in a Rat Model of Rotator Cuff Repair.

BACKGROUND: Gabapentin is often used as an analgesic after rotator cuff repair surgery and is recommended as an additional analgesic for arthroscopic rotator cuff repairs. However, evidence of its effects on biological healing mechanisms is lacking. The objective of this study was to investigate the potential of gabapentin in improving tendon-to-bone healing after rotator cuff repair using a rat model. MATERIALS AND METHODS: A total of 20 male rats were randomly allocated to one of two groups: group 1 (repair only, n=10) or group 2 (gabapentin injection, n=10). The rats in the experimental group (group 2) were administered 80 mg/kg of gabapentin subcutaneously 30 minutes before surgery, followed by 80 mg/kg subcutaneously every 24 hours for 48 hours. We used the left shoulder of every rat, while for biomechanical analysis, we used the right shoulder. RESULTS: There was no significant difference in the load to failure, ultimate stress, or elongation between the groups. Collagen continuity, orientation, and density were better in group 2 than group 1. CONCLUSION: In a rat model of rotator cuff repair, gabapentin had a positive impact on the quality of collagen organization at the junction between the tendon and bone, while preserving the biomechanical properties. We propose the use of gabapentin as a supplementary analgesic agent for postoperative pain relief after arthroscopic rotator cuff repair; however, further studies of the effect of gabapentin on biological healing mechanisms are required. [Orthopedics. 202x;4x(x):xx-xx.].

Effect of magnetic microbeads on sustained and targeted delivery of transforming growth factor-beta-1 for rotator cuff healing in a rat rotator cuff repair model.

Structural failure is a well-established complication of rotator cuff repair procedures. To evaluate the effect of magnetic microbeads, designed for precise drug delivery via magnetic force, on sustained transforming growth factor-beta-1 (TGF-ß1) release and rotator cuff healing in a rat rotator cuff repair model. TGF-ß1 laden microbeads were prepared, and baseline in vitro experiments included the magnetization of the microbeads and TGF-ß1 release tests. In an in vivo experiment using a rat rotator cuff repair model on both shoulders, 72 rats were randomly assigned to three groups (24 per group): group A, conventional repair; group B, repair with and simple TGF-ß1 injection; and group C, repair with magnet insertion into the humeral head and TGF-ß1 laden microbead injection. Delivery of TGF-ß1 was evaluated at 1 and 7 days after the intervention using PCR, Western blot, and immunohistochemistry. At 6 weeks post-intervention, rotator cuff healing was assessed using biomechanical and histological analysis. The in vitro experiments confirmed the magnetization property of the microbeads and sustained delivery of TGF-ß1 for up to 10 days. No difference in the TGF-ß1 expression was found at day 1 in vivo. However, at day 7, group C exhibited a significantly elevated expression of TGF-ß1 in both PCR and Western blot analyses compared to groups A and B (all P < 0.05). Immunohistochemical analysis revealed a higher expression of TGF-ß1 at the repair site in group C on day 7. At 6 weeks, biomechanical analysis demonstrated a significantly higher ultimate failure load in group C than in groups A and B (P < 0.05) and greater stiffness than in group A (P = 0.045). In addition, histological analysis showed denser and more regular collagen fibers with complete continuity to the bone in group C than in groups A and B, a statistically significant difference according to the semi-quantitative scoring system (all P < 0.05). The use of the TGF-ß1 laden magnetic microbeads demonstrated sustained delivery of TGF-ß1 to the repair site, improving rotator cuff healing.

Influence of Frequent Corticosteroid Local Injections on the Expression of Genes and Proteins Related to Fatty Infiltration, Muscle Atrophy, Inflammation, and Fibrosis in Patients With Chronic Rotator Cuff Tears: A Pilot Study.

Background: The effect of local corticosteroid (CS) injections on rotator cuff muscles remains poorly defined, despite the significance of muscle quality as a crucial prognostic factor for patients with rotator cuff tears (RCTs). Purpose: To compare alterations in gene and protein expression patterns in the rotator cuff muscles of patients with RCTs who received frequent joint CS injections with alterations in those without a history of CS injections. Study Design: Controlled laboratory study. Methods: A total of 24 rotator cuff muscle samples with medium-sized tears from 12 patients with a frequent joint CS injection history (steroid group; 7 men and 5 women who had received ≥5 injections with at least 1 within the previous 3 months; mean age, 63.0 ± 7.2 years) and 12 age- and sex-matched control patients without a history of CS injections (no-steroid group) were acquired. Alterations in the expression of genes and proteins associated with adipogenesis, myogenesis, inflammation, and muscle fibrosis were compared between the groups using quantitative reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemistry. Statistical analysis included comparison of group means using the Mann-Whitney U test, chi-square test, or Fisher exact test and logistic regression for multivariate analysis. Results: In the steroid group, the mRNA expression levels of adipogenic CCAAT/enhancer-binding protein alpha (C/EBPα; P = .008) and muscle atrophy-related genes (atrogin; P = .019) were significantly higher, and those of myogenic differentiation 1 (MyoD; P = .035), inflammatory interleukin 6 (IL-6; P = .035), and high mobility group box 1 (P = .003) were significantly lower compared with the no-steroid group. In addition, MyoD (P = .041) and IL-6 (P = .026) expression were decreased in the steroid versus no-steroid group. Immunohistochemistry revealed increased expression of C/EBPα and atrogin and decreased expression of MyoD and IL-6 in the steroid versus no-steroid group. Conclusion: Patients with RCTs and a history of frequent CS injections exhibited an upregulation of adipogenic and muscle atrophy-related genes and proteins within the rotator cuff muscles and a downregulation in the expression of myogenic and inflammatory genes and proteins in the same muscles. Clinical Relevance: These altered gene and protein expressions by frequent local CS injections may cause poor outcomes in patients with RCTs.

Current research trends on the effect of diabetes mellitus on rotator cuff tendon healing/tendinopathy.

Rotator cuff tendon tears are a leading cause of shoulder pain. They are challenging to treat, and tendon-bone healing has a high failure rate despite successful surgery. Tendons connect the muscles and bones, which make them important for the body's overall mobility and stability. Metabolic diseases, including diabetes or high blood pressure, can affect the healing process after repair of a damaged tendon. With a global incidence of 9.3%, diabetes is considered as a significant risk factor for rotator cuff tendon healing because it causes structural, inflammatory, and vascular changes in the tendon. However, the mechanisms of how diabetes affects tendon healing remain unknown. Several factors have been suggested, including glycation product accumulation, adipokine dysregulation, increased levels of reactive oxygen species, apoptosis, inflammatory cytokines, imbalanced matrix-metalloproteinase-to-tissue-inhibitor ratio, and impaired angiogenesis and differentiation of the tendon sheath. Despite the effects of diabetes on tendon function and healing, few treatments are available to improve recovery in these patients. This review summarizes the current literature on the pathophysiological changes of the tendon in diabetes and hyperlipidemia. Preclinical and clinical evidence regarding the association between diabetes and tendon healing is presented. Moreover, current approaches to improve tendon healing in patients with diabetes are reviewed.

The Impact of Bone Marrow Stimulation on Arthroscopic Rotator Cuff Repair for Small to Large Rotator Cuff Tears: A Randomized Controlled Trial.

BACKGROUND: Bone marrow stimulation (BMS), a procedure involving the creation of multiple channels in the greater tuberosity, is often performed alongside arthroscopic rotator cuff repair (ARCR). This study evaluated the effect of BMS on clinical and structural outcomes following ARCR. METHOD: This study involved 204 patients with small, medium, and large full-thickness rotator cuff tears. In all, 103 patients who underwent BMS and ARCR made up the BMS group, while the 101 patients who only had ARCR made up the control group with randomization. Clinical and functional outcomes were assessed before and at 3 months, 6 months, 1 year, and 2 years after surgery, using parameters such as range of motion, functional scores (ASES and constant score), and clinical scores (VAS). Tendon integrity was also examined postoperatively via ultrasound at 6 months and 2 years. RESULTS: There were no significant differences between the two groups concerning range of motion, functional scores (ASES score and constant score), and clinical score (VAS) during the 2-year post-surgery period (all p>0.05). Similarly, the rotator cuff retear rate, as assessed using ultrasonographic tendon integrity checks over 2 years post-surgery, did not significantly vary between the groups (all p>0.05). CONCLUSION: There were no significant disparities in functional scores and clinical outcomes between the BMS and control groups. Further, no significant differences were observed in tendon integrity post-surgery. Therefore, the inclusion or exclusion of BMS is not anticipated to influence the postoperative outcome in ARCR for patients with small, medium, or large rotator cuff tears.

Artificial intelligence- and computer-assisted navigation for shoulder surgery.

Background: Over the last few decades, shoulder surgery has undergone rapid advancements, with ongoing exploration and the development of innovative technological approaches. In the coming years, technologies such as robot-assisted surgeries, virtual reality, artificial intelligence, patient-specific instrumentation, and different innovative perioperative and preoperative planning tools will continue to fuel a revolution in the medical field, thereby pushing it toward new frontiers and unprecedented advancements. In relation to this, shoulder surgery will experience significant breakthroughs. Main body: Recent advancements and technological innovations in the field were comprehensively analyzed. We aimed to provide a detailed overview of the current landscape, emphasizing the roles of technologies. Computer-assisted surgery utilizing robotic- or image-guided technologies is widely adopted in various orthopedic specialties. The most advanced components of computer-assisted surgery are navigation and robotic systems, with functions and applications that are continuously expanding. Surgical navigation requires a visual system that presents real-time positional data on surgical instruments or implants in relation to the target bone, displayed on a computer monitor. There are three primary categories of surgical planning that utilize navigation systems. The initial category involves volumetric images, such as ultrasound echogram, computed tomography, and magnetic resonance images. The second type is based on intraoperative fluoroscopic images, and the third type incorporates kinetic information about joints or morphometric data about the target bones acquired intraoperatively. Conclusion: The rapid integration of artificial intelligence and deep learning into the medical domain has a significant and transformative influence. Numerous studies utilizing deep learning-based diagnostics in orthopedics have remarkable achievements and performance.

Tranexamic Acid Can Reduce Early Tendon Adhesions After Rotator Cuff Repair and Is Not Detrimental to Tendon-Bone Healing: A Comparative Animal Model Study.

PURPOSE: To determine the effects of topical tranexamic acid (TXA) administration on tendon adhesions, shoulder range of motion (ROM), and tendon healing in an acute rotator cuff repair rat model. METHODS: A total of 20 Sprague Dawley rats were used. Tendon adhesion, ROM, and biomechanical and histological analysis of tendon-bone healing was conducted at 3 and 6 weeks after surgery. The rats underwent rotator cuff repair surgery on both shoulders and were administered TXA via subacromial injections. The tendon adhesion was evaluated macroscopically and histologically. Biomechanical tendon healing was measured using a universal testing machine, and histological analysis was quantified by H&E, Masson's trichrome, and picrosirius red staining. RESULTS: At 3 weeks after surgery, the adhesion score was significantly lower in the TXA group (2.10 ± 0.32) than in the control group (2.70 ± 0.48) (P = .005), but there was no significant difference between the 2 groups at 6 weeks. Regarding ROM, compared with the control group, the TXA group showed significantly higher external rotation (36.35° ± 4.52° vs 28.42° ± 4.66°, P < .001) and internal rotation (45.35° ± 9.36° vs 38.94° ± 5.23°, P = .013) 3 weeks after surgery. However, at 6 weeks, there were no significant differences in external and internal rotation between the 2 groups. In the biomechanical analysis, no significant differences in gross examination (3 weeks, P = .175, 6 weeks, P = .295), load to failure (3 weeks, P = .117, 6 weeks, P = .295), or ultimate stress (3 weeks, P = .602, 6 weeks, P = .917) were noted between the 2 groups 3 and 6 weeks after surgery. In the histological analysis of tendon healing, no significant differences in the total score (3 weeks, P = .323, 6 weeks, P = .572) were found between the 2 groups 3 and 6 weeks after surgery. CONCLUSIONS: Topical TXA administration showed a beneficial effect in reducing tendon adhesions and improving ROM 3 weeks postoperatively and had no effect at 6 weeks. This suggests that additional intervention with TXA may be useful in achieving long-term improvement in shoulder stiffness. Additionally, TXA may increase tissue ground substance accumulation in the late postoperative period but does not adversely affect tendon-bone interface healing. CLINICAL RELEVANCE: The use of TXA after rotator cuff repair has no effect on tendon-bone interface healing in clinical practice and can improve shoulder stiffness in the early postoperative period. Additional research on the long-term effects is needed.

Calcium pyrophosphate crystal deposition with rotator cuff tear-A case report.

Calcium pyrophosphate dihydrate (CPPD) deposition disease is an inflammatory arthritis induced by calcium pyrophosphate (CPP) crystals and clinically it is called pseudogout. It usually deposits in articular cartilage and in periarticular soft tissues. But no cases of pseudogout in the rotator cuff without cartilage deposition or destruction have been reported so far. We present a case of a 57-year-old woman who was diagnosed as pseudogout with rotator cuff tear.

Current Research on the Influence of Statin Treatment on Rotator Cuff Healing.

Rotator cuff tears are a condition characterized by damage to the muscles and tendons that connect the scapula and humerus, which are responsible for shoulder rotation and arm lifting. Metabolic factors such as diabetes, thyroid disease, high cholesterol, vitamin D deficiency, obesity, and smoking have been associated with an increased risk of rotator cuff tears. Interestingly, patients with hyperlipidemia, a condition characterized by high levels of cholesterol and other fats in the blood, have been found to have a higher incidence of rotator cuff tears and breakdown of tendon matrix. As a result, statin therapy, which is commonly used to lower cholesterol levels in hyperlipidemia, has been explored as a potential treatment to improve clinical outcomes in rotator cuff tears. However, the results of preclinical and clinical studies on the effects of statins on tendon healing in rotator cuff tears are limited and not well-defined. Moreover, since hyperlipidemia and rotator cuff tears are more prevalent in older individuals, a literature review on the efficacy and safety of statin therapy in this population is needed.

Superior capsular reconstruction for irreparable rotator cuff tear: a review of current methods.

Irreparable massive rotator cuff tears can significantly impact daily life; and these types of tears can be difficult to repair completely, especially in younger patients who are more active and have higher functional requirements. Since its introduction by Mihata and the colleagues, superior capsular reconstruction (SCR) has gained popularity in the treatment of irreparable massive rotator cuff tears and has shown promising short-term results. A variety of studies have focused on the clinical and biomechanical outcomes of this procedure. This article reviews the biomechanics, indications for the surgical procedure, graft options, surgical technique, and rehabilitation from SCR.

Biomechanical Comparison of 1.2-mm Suture Tape, 2.0-mm Suture Tape, and 0.5-mm Suture Using Various Arthroscopic Knot Techniques.

Background: The biomechanical properties of the 1.2-mm suture tape have outperformed conventional sutures in previous studies. Purpose: To compare the loop and knot security of 2 tape-type and 1 cord-type sutures using different arthroscopic knot techniques. Study Design: Controlled laboratory study. Methods: The biomechanical characteristics of the 1.2-mm tape, 2.0-mm tape, and 0.5-mm No. 2 suture were compared using 4 different knot types: 2 sliding knots (Samsung Medical Center [SMC] and Tennessee) and 2 nonsliding knots (2-throw surgeon's and 2-throw square) with 2 and 3 additional reverse half-hitches on alternating posts (RHAPs) in a closed-loop system on a materials testing device. Each configuration was tested for loop security (maximal load applied between 0 and 3 mm of displacement), knot security (ultimate failure load), and failure mode with cyclical loading (30 N load for 20 cycles at 1 cycle per sec until failure). Loop and knot security among the configurations were compared using an analysis of variance. Results: With 2 RHAPs, the 2.0-mm tape showed significantly greater loop security than the 1.2-mm tape and suture (P = .001). With 3 RHAPs, the loop security of the suture was significantly superior compared with the 1.2-mm tape (P = .010). Regarding knot security, with 2 RHAPs, the 2.0-mm tape was significantly better than the 1.2-mm tape and suture (P < .001), while with 3 RHAPs, the suture was significantly superior to the 1.2-mm tape (P = .012). Using a square knot with 2 RHAPs, the 2.0-mm tape had significantly greater loop security (P = .001) and better knot security (P = .001) to the 1.2-mm tape and suture. Using the Tennessee knot with 2 RHAPs, the 1.2-mm tape had less loop security (P = .011) and knot security (P = .005) than the suture. Using the SMC knot with 3 RHAPs, the 2.0-mm tape and suture were significantly superior in loop security (P = .001) and knot security (P < .001) to the 1.2-mm tape. There was no significant difference in the failure mode between tapes and sutures with 2 and 3 RHAPs. Conclusion: With 2 RHAPs, the 2.0-mm tape demonstrated greater resistance to suture loop displacement and better knot security compared with the 1.2-mm tape and suture. However, with 3 RHAPs, the 1.2-mm tape manifested weaker loop and knot security compared with the suture.

Metformin increases the expression of proinflammatory cytokines and inhibits supraspinatus fatty infiltration.

BACKGROUND: After a rotator cuff (RC) tendon tear, the supraspinatus (SS) inflammatory response induces fatty infiltration (FI). Metformin has the effect of regulating the initial inflammatory response of atrophic muscles. Therefore, this study aimed to investigate the effect of metformin use on modulating the expression of proinflammatory cytokines and SS FI in an acute RC tear rat model. METHODS: This study used 26 male Sprague-Dawley rats. Animals were randomly divided into two groups: The metformin group received metformin for 5 days after cutting the RC tendon, and the control group was administered only with saline after cutting the tendon. Metformin 50 mg/kg was intraperitoneally injected for 5 days. Three rats in each group were sacrificed 5 days after SS tendon rupture surgery, and 10 rats in each group were sacrificed 14 days after surgery. The SS was sampled 5 days after SS tendon tear surgery, and the expression of proinflammatory cytokines was measured by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). On day 14 after sampling, histological analysis of the SS was performed using hematoxylin and eosin, Masson's trichrome, and picrosirius red staining. RESULTS: On day 5 of surgery, the expression values of interferon gamma (increased 7.2-fold, P < .01), tumor necrosis factor alpha (increased 13-fold, P < .05), interleukin-1ß (increased 4.7-fold, P < .001), and interleukin-6 (increased 4.6-fold, P < .01) increased significantly in the metformin group compared with those in the control group. As a result of Oil Red O staining, SS FI was significantly suppressed in the metformin group compared with that in the control group (metformin group, 305 ± 50.3 µm2, P < .001; control group, 3136 ± 662.8 µm2, P < .001). In addition, the SS volume of the metformin group was not reduced compared with those of the control group, and the morphology and structure of the SS were better preserved. CONCLUSIONS: The results of this study revealed that metformin can increase the expression of proinflammatory cytokines and suppress SS fat infiltration in delayed sutures.

Types and doses of anti-adhesive agents injected into subacromial space do not have an effect on the clinical and anatomical outcomes after arthroscopic rotator cuff repair.

PURPOSE: Joint stiffness after arthroscopic rotator cuff repair is a major concern for orthopaedic surgeons. Various antiadhesive agents are commonly administered after rotator cuff repair for its prevention. This study aimed to compare the outcomes among patients injected with different types and amounts of anti-adhesive agents after rotator cuff repair. It was hypothesized that the outcomes might differ depending on the use of the anti-adhesive agent and its type and dose. METHODS: A total of 267 patients who underwent arthroscopic rotator cuff repair with or without subacromial injection of anti-adhesive agents were enrolled. The first group (group A; 51 patients) were injected with 3 mL of poloxamer/sodium alginate-based anti-adhesive agent. The second group (group B; 93 patients) were injected with 3 mL of sodium hyaluronate-based anti-adhesive agent. The third group (group C; 82 patients) were injected with 1.5 mL of sodium hyaluronate-based anti-adhesive agent. Finally, the last group (group D; 41 patients) who did not use anti-adhesive agents served as the control. The range of motion (ROM) and pain VAS scores were measured preoperatively and at 5 weeks, 3 months, 6 months, and 1 year postoperatively. Functional outcomes were evaluated using American Shoulder and Elbow Surgeons and Constant scores, whereas cuff integrity was assessed via MRI or ultrasonography at least 6 months postoperatively. RESULTS: All ROM measurements, pain VAS scores, and functional scores were significantly improved regardless of the use, type, and dose of the anti-adhesive agents. In addition shoulder ROM and rotator cuff healing did not significantly differ among the groups (all n.s.). CONCLUSIONS: No significant differences were found in the clinical and anatomical outcomes according to the type and dose of the anti-adhesive agents subacromially injected after rotator cuff repair. LEVEL OF EVIDENCE: III.

Influence of Vitamin D Deficiency on the Expression of Genes and Proteins in Patients With Medium Rotator Cuff Tears.

BACKGROUND: Whether vitamin D deficiency is related to rotator cuff muscle and tendon physiology is controversial. PURPOSE: To assess the relationship between vitamin D deficiency and various gene expression patterns in patients with rotator cuff tears. STUDY DESIGN: Controlled laboratory study. METHODS: During arthroscopic surgery, samples from the supraspinatus muscle, deltoid muscle, and supraspinatus tendon were acquired from 12 patients with vitamin D deficiency (serum 25-hydroxyvitamin D concentration <20 ng/dL) and 12 patients with sufficient vitamin D levels (control group, serum 25-hydroxyvitamin D concentration ≥30 ng/dL) who were matched for age, sex, and tear size. Alterations in the expression of genes and proteins associated with myogenesis, muscle atrophy, adipogenesis, inflammation, and apoptosis, as well as in vitamin D receptor expression, were assessed using quantitative reverse transcription polymerase chain reaction, Western blotting, and immunohistochemistry and were compared between the 2 groups. RESULTS: Vitamin D receptor gene expression in the deltoid muscle was significantly lower in the vitamin D deficiency group than in the control group (P = .043). Additionally, in the deltoid muscle, myoDgene expression levels were lower and atrogin levels were higher in the vitamin D deficiency group than in the control group (P = .034 and P = .011, respectively). However, in the supraspinatus muscle, no differences were observed between groups in the expression of myogenesis- or atrophy-related genes (all P > .05). The expression of inflammation-related genes (interleukin (IL)-1ß and IL-6) was significantly higher in the vitamin D deficiency group, in both the deltoid and supraspinatus muscles (all P < .05). The supraspinatus tendon tissue did not show any significant differences in any gene expression evaluated (all P > .05). A correlation between gene and protein expression was observed for atrogin and IL-1ß in the deltoid muscle (P = .019 and P = .037, respectively) and for IL-6 in the supraspinatus muscle (P = .044). CONCLUSION: Vitamin D deficiency was not associated with the expression of myogenesis-related or muscle atrophy-related genes in the supraspinatus muscle of patients with rotator cuff tears, unlike in the deltoid muscle; rather, vitamin D deficiency was associated with increased proinflammatory cytokine expression. CLINICAL RELEVANCE: In patients with rotator cuff tears, vitamin D deficiency was observed to be associated with increased levels of proinflammatory cytokines in the rotator cuff muscles, without significant changes in gene expression related to myogenesis or muscle atrophy.

Returning to golf after rotator cuff repair.

Background: The prevalence of rotator cuff repair is increasing; however, no study has assessed patients who have returned to golf activity after arthroscopic rotator cuff repair. Methods: The subjects of the survey were 633 patients who were at least two years postoperative after rotator cuff repair from January 2005 to December 2017. From August 2019 to October 2019, survey responses were collected via an online questionnaire or phone calls and a total of 197 patients were reviewed retrospectively to study about returning to golf after rotator cuff repair. The detailed survey included 12 questions specific to the patient's golf career, performance, time of return to play, and symptoms related to golf activity. Depending on the size of the rotator cuff tear, each question was statistically analyzed to determine whether there were differences in the time of return to golf, uncomfortable symptoms when golfing, and distance of the driving. Results: Of the 197 patients who underwent arthroscopic rotator cuff repair, there were 145 patients (73.6%) returned to golf. In the analysis results of 145 patients, the longer the golf career, the greater the chance of returning to golf. Sixty (30.5%) people returned to golf at 1 year after surgery. Twenty-one patients (10.7%) improved and 46 patients (23.4%) maintained their driving distance, whereas 78 patients (39.6%) had a worse driving distance after surgery. Ten patients (5.1%) improved and 97 patients (49.2%) maintained their golf score, but 38 patients (19.3%) had worse golf scores after surgery. Symptoms when playing golf were reported in the order of no symptoms (62.1%), a limited range of motion (13.1%), muscle weakness (11.1%), and anxious about their operated shoulder (10.3 %). Men were 6.9 times more likely to return to golf than women (odds ratio, 6.9; 95% confidence interval, 3.2-14.8). The younger the age and the shorter the time since surgery, the higher the golfing return rate. The rate of returning to golf was high in the group of patients with good tissue quality during surgery (odds ratio, 3.9; 95% confidence interval, 0.01-2.6). Conclusion: The golfing return rate after arthroscopic rotator cuff repair was higher than expected (73.6%) and most players returned at 1 year after surgery. Especially, in the case of young males, their golf scores were maintained or improved and they were able to return to golf earlier after surgery. Better tissue quality in the intraoperative torn tendon was associated with a greater chance of returning to golf.

Automated 3-dimensional MRI segmentation for the posterosuperior rotator cuff tear lesion using deep learning algorithm.

INTRODUCTION: Rotator cuff tear (RCT) is a challenging and common musculoskeletal disease. Magnetic resonance imaging (MRI) is a commonly used diagnostic modality for RCT, but the interpretation of the results is tedious and has some reliability issues. In this study, we aimed to evaluate the accuracy and efficacy of the 3-dimensional (3D) MRI segmentation for RCT using a deep learning algorithm. METHODS: A 3D U-Net convolutional neural network (CNN) was developed to detect, segment, and visualize RCT lesions in 3D, using MRI data from 303 patients with RCTs. The RCT lesions were labeled by two shoulder specialists in the entire MR image using in-house developed software. The MRI-based 3D U-Net CNN was trained after the augmentation of a training dataset and tested using randomly selected test data (training: validation: test data ratio was 6:2:2). The segmented RCT lesion was visualized in a three-dimensional reconstructed image, and the performance of the 3D U-Net CNN was evaluated using the Dice coefficient, sensitivity, specificity, precision, F1-score, and Youden index. RESULTS: A deep learning algorithm using a 3D U-Net CNN successfully detected, segmented, and visualized the area of RCT in 3D. The model's performance reached a 94.3% of Dice coefficient score, 97.1% of sensitivity, 95.0% of specificity, 84.9% of precision, 90.5% of F1-score, and Youden index of 91.8%. CONCLUSION: The proposed model for 3D segmentation of RCT lesions using MRI data showed overall high accuracy and successful 3D visualization. Further studies are necessary to determine the feasibility of its clinical application and whether its use could improve care and outcomes.