The detrimental effects of hyperlipidemia on the healing of rotator cuff tears are well documented. The proposed underlying mechanisms for these effects include alterations in the extracellular matrix, inflammation, and oxidative stress, which hamper the reparative processes in the affected tendon tissues. Recent therapeutic strategies target these pathways, reflecting a growing body of research dedicated to mitigating these effects and promoting healing. This literature review aims to provide a comprehensive understanding of the pathophysiology underlying rotator cuff tears, examine the interplay between hyperlipidemia and rotator cuff tear healing, synthesize current knowledge on contributing biological mechanisms, and outline potential therapeutic interventions to optimize clinical management and treatment outcomes for patients.

Background: This study aimed to investigate changes after repeated subacromial drug injections in a rat model of normal rotator cuff. Methods: Thirty-nine male Sprague-Dawley rats were divided into groups 1 (no injection, n = 3), 2 (parecoxib, n = 18; 6 subgroups, n = 3 each; 0.5 mg/kg), and 3 (triamcinolone, n = 18; 6 subgroups, n = 3 each; 0.3 mg/kg). Groups 2 and 3 received subacromial injections 1–6 times once weekly for 6 weeks. The supraspinatus and infraspinatus tendons and muscles were used for biomechanical and histological evaluation. The subacromial bursa was used to analyze the prostaglandin E2 (PEG2) level. Results: In the biomechanical test, load-to-failure and ultimate stress decreased in groups 2 and 3 with repeated injections and the values were significantly lower in group 3 than in group 1 only at the sixth injection (p = 0.007 and p = 0.008, respectively). On the Bonar score, the cellularity, ground substance, and total score were significantly different among the 3 groups at the fifth and sixth injections (cellularity: p = 0.028 and p = 0.033, ground substance: p = 0.018 and p = 0.006, and total score: p = 0.029 and p = 0.027, respectively). The myocyte cross-sectional area of the infraspinatus muscle showed a significant difference among the 3 groups at the third and fourth injections (p = 0.031 and p = 0.020, respectively). The PEG2 level in the subacromial bursa was significantly different among the 3 groups at the third, fifth, and sixth injections (p = 0.019, p = 0.004, and p = 0.004, respectively). Conclusions In the rat model of normal rotator cuff, repeated local injections of the cyclooxygenase-2 inhibitor showed fewer negative effects on the biomechanical and histological properties of the normal tendon than triamcinolone.

The detrimental effects of hyperlipidemia on the healing of rotator cuff tears are well documented. The proposed underlying mechanisms for these effects include alterations in the extracellular matrix, inflammation, and oxidative stress, which hamper the reparative processes in the affected tendon tissues. Recent therapeutic strategies target these pathways, reflecting a growing body of research dedicated to mitigating these effects and promoting healing. This literature review aims to provide a comprehensive understanding of the pathophysiology underlying rotator cuff tears, examine the interplay between hyperlipidemia and rotator cuff tear healing, synthesize current knowledge on contributing biological mechanisms, and outline potential therapeutic interventions to optimize clinical management and treatment outcomes for patients.

Background: This study aimed to investigate changes after repeated subacromial drug injections in a rat model of normal rotator cuff. Methods: Thirty-nine male Sprague-Dawley rats were divided into groups 1 (no injection, n = 3), 2 (parecoxib, n = 18; 6 subgroups, n = 3 each; 0.5 mg/kg), and 3 (triamcinolone, n = 18; 6 subgroups, n = 3 each; 0.3 mg/kg). Groups 2 and 3 received subacromial injections 1–6 times once weekly for 6 weeks. The supraspinatus and infraspinatus tendons and muscles were used for biomechanical and histological evaluation. The subacromial bursa was used to analyze the prostaglandin E2 (PEG2) level. Results: In the biomechanical test, load-to-failure and ultimate stress decreased in groups 2 and 3 with repeated injections and the values were significantly lower in group 3 than in group 1 only at the sixth injection (p = 0.007 and p = 0.008, respectively). On the Bonar score, the cellularity, ground substance, and total score were significantly different among the 3 groups at the fifth and sixth injections (cellularity: p = 0.028 and p = 0.033, ground substance: p = 0.018 and p = 0.006, and total score: p = 0.029 and p = 0.027, respectively). The myocyte cross-sectional area of the infraspinatus muscle showed a significant difference among the 3 groups at the third and fourth injections (p = 0.031 and p = 0.020, respectively). The PEG2 level in the subacromial bursa was significantly different among the 3 groups at the third, fifth, and sixth injections (p = 0.019, p = 0.004, and p = 0.004, respectively). Conclusions In the rat model of normal rotator cuff, repeated local injections of the cyclooxygenase-2 inhibitor showed fewer negative effects on the biomechanical and histological properties of the normal tendon than triamcinolone.

Background: The nipple is a potential source of pathogens because its lactiferous ducts act as direct conduits from the nipple–areolar complex to the breast parenchyma. Our previous studies identified breast microbiota as a factor in postoperative complications following immediate breast reconstruction using silicone implants and acellular dermal matrix. This study aimed to investigate the correlation between preoperative nipple swab microbiota and the incidence of surgical site infections (SSIs) after autologous breast reconstruction. Methods: We conducted a retrospective chart review of patients who underwent autologous breast reconstruction following total mastectomy. Preoperative nipple swab cultures were obtained. Patient demographics, surgical characteristics, and complication rates were compared between culture-positive and culture-negative groups. Microbiological data, including antibiotic‑resistance profiles, were collected. Results: Among 39 reconstructed breasts, 18 (46.9%) had positive preoperative nipple cultures. The mean duration of drain placement was significantly longer in the culture‑positive group (14.39±3.96 days) than in the culture‑negative group (12.14±2.76 days, P=0.045). Methicillin‑susceptible Staphylococcus epidermidis accounted for 55.0% of isolates. Of the four SSIs observed, three occurred in patients with positive preoperative cultures. Conclusions Although pathogen strains differed between preoperative and postoperative settings, obtaining preoperative nipple microflora cultures and determining antibiotic‑resistance profiles can guide immediate antibiotic selection for SSIs and enhance postoperative management.

Background: and Purpose The pain lateralization in cluster headache (CH) may be related to the asymmetry in the functions of the brain hemispheres. The right-sided dominance of pain in CH has been found inconsistently across studies, and so we aimed to characterize this and identify the factors influencing pain lateralization during current and previous bouts. Methods: This study enrolled 227 patients from the Korean Cluster Headache Registry between October 2018 and December 2020. We evaluated the side of pain during current and previous bouts, demographic features, and clinical characteristics, including handedness. Multivariable logistic regression analyses were performed to identify factors associated with the side of pain. Results: The 227 patients with CH included 131 (57.7%) with right-sided pain and 86 (37.9%) with left-sided pain during the current bout (p<0.001). The 189 patients with previous bouts of CH included 86.8% who consistently reported the same side of pain throughout multiple bouts (side-locked pain), with a higher prevalence of pain on the right than the left side (55.0% vs. 31.7%, p<0.001). Multivariable analyses revealed that higher age at diagnosis (odds ratio [OR]=1.045, p=0.031) and shorter CH attacks (OR=0.992, p=0.017) were associated with left-side-locked pain. However, handedness was not associated with the lateralization of leftside-locked pain. Conclusions This study has confirmed the predominance of right-sided pain throughout multiple CH bouts. We found that higher age at diagnosis and shorter CH attacks were associated with left-side-locked pain, suggesting that certain clinical factors are associated with the pain laterality. However, the underlying mechanisms linking these factors to lateralized pain remain unclear and therefore require further investigation.

The detrimental effects of hyperlipidemia on the healing of rotator cuff tears are well documented. The proposed underlying mechanisms for these effects include alterations in the extracellular matrix, inflammation, and oxidative stress, which hamper the reparative processes in the affected tendon tissues. Recent therapeutic strategies target these pathways, reflecting a growing body of research dedicated to mitigating these effects and promoting healing. This literature review aims to provide a comprehensive understanding of the pathophysiology underlying rotator cuff tears, examine the interplay between hyperlipidemia and rotator cuff tear healing, synthesize current knowledge on contributing biological mechanisms, and outline potential therapeutic interventions to optimize clinical management and treatment outcomes for patients.

Background: This study aimed to investigate changes after repeated subacromial drug injections in a rat model of normal rotator cuff. Methods: Thirty-nine male Sprague-Dawley rats were divided into groups 1 (no injection, n = 3), 2 (parecoxib, n = 18; 6 subgroups, n = 3 each; 0.5 mg/kg), and 3 (triamcinolone, n = 18; 6 subgroups, n = 3 each; 0.3 mg/kg). Groups 2 and 3 received subacromial injections 1–6 times once weekly for 6 weeks. The supraspinatus and infraspinatus tendons and muscles were used for biomechanical and histological evaluation. The subacromial bursa was used to analyze the prostaglandin E2 (PEG2) level. Results: In the biomechanical test, load-to-failure and ultimate stress decreased in groups 2 and 3 with repeated injections and the values were significantly lower in group 3 than in group 1 only at the sixth injection (p = 0.007 and p = 0.008, respectively). On the Bonar score, the cellularity, ground substance, and total score were significantly different among the 3 groups at the fifth and sixth injections (cellularity: p = 0.028 and p = 0.033, ground substance: p = 0.018 and p = 0.006, and total score: p = 0.029 and p = 0.027, respectively). The myocyte cross-sectional area of the infraspinatus muscle showed a significant difference among the 3 groups at the third and fourth injections (p = 0.031 and p = 0.020, respectively). The PEG2 level in the subacromial bursa was significantly different among the 3 groups at the third, fifth, and sixth injections (p = 0.019, p = 0.004, and p = 0.004, respectively). Conclusions In the rat model of normal rotator cuff, repeated local injections of the cyclooxygenase-2 inhibitor showed fewer negative effects on the biomechanical and histological properties of the normal tendon than triamcinolone.

Background: The nipple is a potential source of pathogens because its lactiferous ducts act as direct conduits from the nipple–areolar complex to the breast parenchyma. Our previous studies identified breast microbiota as a factor in postoperative complications following immediate breast reconstruction using silicone implants and acellular dermal matrix. This study aimed to investigate the correlation between preoperative nipple swab microbiota and the incidence of surgical site infections (SSIs) after autologous breast reconstruction. Methods: We conducted a retrospective chart review of patients who underwent autologous breast reconstruction following total mastectomy. Preoperative nipple swab cultures were obtained. Patient demographics, surgical characteristics, and complication rates were compared between culture-positive and culture-negative groups. Microbiological data, including antibiotic‑resistance profiles, were collected. Results: Among 39 reconstructed breasts, 18 (46.9%) had positive preoperative nipple cultures. The mean duration of drain placement was significantly longer in the culture‑positive group (14.39±3.96 days) than in the culture‑negative group (12.14±2.76 days, P=0.045). Methicillin‑susceptible Staphylococcus epidermidis accounted for 55.0% of isolates. Of the four SSIs observed, three occurred in patients with positive preoperative cultures. Conclusions Although pathogen strains differed between preoperative and postoperative settings, obtaining preoperative nipple microflora cultures and determining antibiotic‑resistance profiles can guide immediate antibiotic selection for SSIs and enhance postoperative management.

Background: and Purpose The pain lateralization in cluster headache (CH) may be related to the asymmetry in the functions of the brain hemispheres. The right-sided dominance of pain in CH has been found inconsistently across studies, and so we aimed to characterize this and identify the factors influencing pain lateralization during current and previous bouts. Methods: This study enrolled 227 patients from the Korean Cluster Headache Registry between October 2018 and December 2020. We evaluated the side of pain during current and previous bouts, demographic features, and clinical characteristics, including handedness. Multivariable logistic regression analyses were performed to identify factors associated with the side of pain. Results: The 227 patients with CH included 131 (57.7%) with right-sided pain and 86 (37.9%) with left-sided pain during the current bout (p<0.001). The 189 patients with previous bouts of CH included 86.8% who consistently reported the same side of pain throughout multiple bouts (side-locked pain), with a higher prevalence of pain on the right than the left side (55.0% vs. 31.7%, p<0.001). Multivariable analyses revealed that higher age at diagnosis (odds ratio [OR]=1.045, p=0.031) and shorter CH attacks (OR=0.992, p=0.017) were associated with left-side-locked pain. However, handedness was not associated with the lateralization of leftside-locked pain. Conclusions This study has confirmed the predominance of right-sided pain throughout multiple CH bouts. We found that higher age at diagnosis and shorter CH attacks were associated with left-side-locked pain, suggesting that certain clinical factors are associated with the pain laterality. However, the underlying mechanisms linking these factors to lateralized pain remain unclear and therefore require further investigation.