1.The Impact of Systemic Metabolic Disorders on Rotator Cuff Tears and Surgical Outcomes
Sung-Jin PARK ; Jong Pil YOON ; Seok Won CHUNG
The Journal of the Korean Orthopaedic Association 2026;61(1):38-49
Rotator cuff tears are a common musculoskeletal disorder that significantly impairs shoulder function, especially in the elderly. Traditionally, mechanical wear and age-related degeneration have been considered the leading causes. Recent studies, however, emphasize that systemic metabolic disorders, such as diabetes mellitus, obesity, and dyslipidemia, play a crucial role in the development and healing of rotator cuff disease. This narrative review comprehensively examines the biological mechanisms and clinical outcomes associated with these metabolic comorbidities in rotator cuff degeneration and surgical repair failure. Based on relevant clinical and experimental studies, this study analyzed how each metabolic disease contributes to tendon injury and impaired regeneration. Diabetes mellitus induces chronic inflammation, inhibits collagen synthesis, and impairs microvascular perfusion, hindering tendon healing. Obesity increases the mechanical load on the shoulder and promotes systemic inflammation, exacerbating fatty infiltration of muscles and delaying tissue repair. Dyslipidemia accelerates tendon degeneration through the accumulation of fat, oxidative stress, and fatty infiltration of the rotator cuff muscles. These systemic factors are associated with higher re-tear rates, delayed functional recovery, and poorer surgical outcomes. As the prevalence of metabolic syndrome increases, precise assessment and perioperative management of these metabolic disorders are essential to improve patient outcomes and develop personalized treatment strategies for rotator cuff tears.
2.Current Biological Approach to Improve Rotator Cuff Muscle Quality
Sung-Jin PARK ; Jong Pil YOON ; Seok Won CHUNG
The Journal of the Korean Orthopaedic Association 2026;61(1):22-37
Rotator cuff (RC) injuries cause degenerative changes, including muscle atrophy and fatty infiltration, which remain key pathophysiological factors limiting functional recovery and increasing the risk of re-tears even after surgical repair. In particular, these changes tend to progress to fibrofatty replacement over time, highlighting the limitations of surgery-focused treatments alone. Recent research has addressed this by increasingly focusing on biological therapeutic strategies that directly target the degenerative pathology of the RC muscle. This review article examines the current trends in preclinical and clinical research on three main biological approaches: stem cell-based tissue regeneration, modulation of pathological signaling pathways, and metabolic reprogramming strategies that restore the pathological metabolic environment. Building upon these pathophysiological foundations, this review aims to develop recent biological treatment strategies and explore their potential clinical applications.
3.Maxillary complete denture fabrication using CAD-based digital tooth arrangement in a patient with wide arch:a case report
Chaerin KIM ; Sang-Won PARK ; Hyun-Pil LIM ; Kwi-Dug YUN ; Chan PARK ; Woohyung JANG
The Journal of Korean Academy of Prosthodontics 2026;64(1):27-35
This case report describes the use of CAD-based digital tooth arrangement to overcome the limitations of conventional methods in a patient with a maxillary arch wider than the average Korean morphology. In such wide arches, average-based tooth arrangement often restricts the ability to adjust the occlusal plane and cusp positions, thereby limiting functional and esthetic reproduction.In this case, virtual tooth arrangement and occlusal analysis were performed using CAD software, and a putty index was fabricated on a 3D-printed reference model to guide the final arrangement. The fabricated maxillary cast metal complete denture and mandibular distal extension removable partial denture successfully achieved bilateral balanced occlusion, and the patient reported high satisfaction in both functional and esthetic aspects. This case highlights the clinical utility of digital tooth arrangement in atypically wide arches and suggests that CAD-assisted workflows can enhance accuracy and reproducibility in clinical prosthodontics.
4.Fabrication of removable partial denture using CAD-CAM customized artificial teeth: a case report
Seohyun KIM ; Sang-Won PARK ; Hyun-Pil LIM ; Kwi-Dug YUN ; Chan PARK ; Woohyung JANG
The Journal of Korean Academy of Prosthodontics 2026;64(1):95-103
With the advancement of digital technology, the clinical application of CAD-CAM systems in dentistry has been expanding. CAD-CAM technology is now being utilized not only for fixed dental prostheses but also in the fabrication of removable dentures. However, its use in removable partial dentures has primarily focused on fabricating metal frameworks, with insufficient research on intraoral fitness and long-term prognosis. Recently, CAD-CAM technology has enabled the fabrication of customized artificial teeth, offering several advantages such as the establishment of precise occlusal relationships, reduced laboratory time, and ease of reproduction. This case reports on a patient who presented with discomfort due to mobility of the mandibular anterior teeth and multiple missing posterior teeth. Given the patient’s economic and systemic conditions, fabrication of a mandibular removable partial denture was chosen as the treatment option.Clinical examination revealed occlusal wear and supraeruption in the maxillary dentition, resulting in an uneven occlusal plane. To achieve a more precise occlusal relationship and accurate tooth arrangement, customized artificial teeth were fabricated using CAD-CAM technology. Despite the uneven and non-ideal occlusal plane, a removable partial denture incorporating these CAD-CAM customized artificial teeth was successfully delivered, resulting in satisfactory functional and esthetic outcomes.
5.CBCT–IOS superimposition for integrated tissue analysis and emergence profile transfer from the provisional to the definitive prostheses in anterior esthetic restoration: case report
Chei HYUN ; Chan PARK ; Sang-Won PARK ; Hyun-Pil LIM ; Kwi-Dug YUN ; Woohyung JANG
The Journal of Korean Academy of Prosthodontics 2026;64(1):46-56
The integration of cone beam computed tomography (CBCT) and intraoral scanner (IOS) data through superimposition enables comprehensive evaluation of hard and soft tissue anatomy. While this technique has demonstrated clinical efficacy for implant and orthognathic surgery planning, its implementation in prosthetic treatment design and diagnosis remains limited. Through precise registration of CBCT and IOS data sets, clinicians can quantitatively assess alveolar bone dimensions, interproximal bone levels, and soft tissue biotype. This information enables establishment of patient-specific design criteria for prosthetic contours and interproximal contact areas. Additionally, this integrated approach facilitates evaluation of midline discrepancies, jaw asymmetries, and available restorative space for long-span fixed dental prostheses. Furthermore, the immediate gingival displacement that occurs following removal of the provisional prostheses necessitates standardized protocols for precise transfer of the subgingival emergence profile established by provisional prostheses to definitive prostheses. This clinical report describes CBCT-IOS superimposition-based digital analysis for anterior esthetic restorations, with successful transfer of subgingival emergence profile from the provisional to the definitive prostheses.
6.Anterior esthetic implant-supported fixed prostheses with customized PEEK healing abutments: a case report
Min-Jung SON ; Sang-Won PARK ; Hyun-Pil LIM ; Kwi-Dug YUN ; Chan PARK ; Woohyung JANG
The Journal of Korean Academy of Prosthodontics 2026;64(1):36-45
This case report describes a customized PEEK healing abutment fabricated using CAD-CAM technology to ensure the aesthetics of an anterior implant prosthesis.A 3-dimensional surgical guide was designed and printed to plan the ideal placement of implant, and the healing abutment was designed by CAD software to ensure the appropriate peri-gingival tissue at that location. The CAD-CAM Ti-base PEEK abutment was tightened right after the installation of implant fixture. After approximately 2 ‒ 3 months of observation, soft tissue healing and implant fixture stability were confirmed. The intraoral scanning before removing a healing abutment, after removing it which is for sub-gingival tissue, and with scan body were performed separately for the final prosthesis and all scan files were superimposed to design and fabricate the final prosthesis to ensure both aesthetic and functional performance. The final prosthesis fit comfortably without compressing the surrounding soft tissue, and the patient was functionally and esthetically satisfied with the outcome.
7.Adjusted Global Antiphospholipid Syndrome Score Is Associated with End-Stage Kidney Disease in Patients with ANCA-Associated Vasculitis:A Single-Centre Pilot Study
Pil Gyu PARK ; Hyun Joon CHOI ; Yong-Beom PARK ; Sang-Won LEE
Yonsei Medical Journal 2025;66(6):337-345
Purpose:
The adjusted Global Antiphospholipid Syndrome (APS) Score (aGAPSS) was developed for assessing the probability of thrombotic events in APS patients. This study investigated whether the aGAPSS at diagnosis was associated with poor outcomes during follow-up in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).
Materials and Methods:
This study included 170 AAV patients who had the results of APS-related antibodies at diagnosis but were not diagnosed with APS. All-cause mortality, end-stage kidney disease (ESKD), cerebrovascular accident, and acute coronary syndrome were considered poor AAV outcomes. The aGAPSS comprises five items, with 5, 4, 4, 3, and 1 points assigned to anticardiolipin antibodies, anti-β2-glycoprotein 1 antibodies, lupus anticoagulants, hyperlipidaemia, and arterial hypertension at AAV diagnosis, respectively.
Results:
The median age of the 170 patients [93 microscopic polyangiitis (MPA), 44 granulomatosis with polyangiitis (GPA), and 33 eosinophilic GPA (EGPA)] was 63.0 years. The optimal cut-off of the aGAPSS at diagnosis for ESKD during follow-up was set as two using the receiver operating characteristic curve. AAV patients with an aGAPSS ≥2 at diagnosis exhibited a significantly reduced ESKD-free survival rate compared to those with an aGAPSS <2 at diagnosis (p=0.045). Additionally, MPA and GPA patients, excluding EGPA patients for whom the median aGAPSS at diagnosis was close to 0, also showed similar patterns to the results among the 170 patients with AAV (p=0.021).
Conclusion
This study is the first to demonstrate that the aGAPSS at diagnosis was significantly associated with ESKD during follow-up in AAV patients without APS.
8.Hyperlipidemia and Rotator Cuff Tears: Exploring Mechanisms and Effective Treatment
Kang-San LEE ; Sung-Jin PARK ; Dong-Hyun KIM ; Seok Won CHUNG ; Jun-Young KIM ; Chul-Hyun CHO ; Jong Pil YOON
Clinics in Orthopedic Surgery 2025;17(2):187-193
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.
9.A Comparative Study on the Effects of Repeated Subacromial Injections of Parecoxib and Triamcinolone in a Rat Model of Normal Rotator Cuff
Jong Pil YOON ; Dong Hyun KIM ; Sung-Jin PARK ; Yoon Seong CHOI ; Hyun Joo LEE ; Seok Won CHUNG ; Kang-San LEE ; Jeoung Wook LEE
Clinics in Orthopedic Surgery 2025;17(2):291-299
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.
10.Hyperlipidemia and Rotator Cuff Tears: Exploring Mechanisms and Effective Treatment
Kang-San LEE ; Sung-Jin PARK ; Dong-Hyun KIM ; Seok Won CHUNG ; Jun-Young KIM ; Chul-Hyun CHO ; Jong Pil YOON
Clinics in Orthopedic Surgery 2025;17(2):187-193
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.

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