Does statin-treated hyperlipidemia affect rotator cuff healing or muscle fatty infiltration after rotator cuff repair?

Hyperlipidemia and Rotator Cuff Tears: Exploring Mechanisms and Effective Treatment

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.

Association of Antihypertensive and Statin Medication Usage With Postoperative Stiffness After Arthroscopic Rotator Cuff Repair: A Retrospective Cohort Study

Background

Angiotensin-converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARB), and statins may be able to modulate postoperative stiffness, a major cause of morbidity after arthroscopic rotator cuff repair (aRCR).

Purpose

To determine whether there is an association between ACEi, ARB, or statin usage and stiffness after aRCR.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients who underwent primary aRCR between January 2016 and December 2019 were categorized into 4 groups depending on the usage of ACEi (n = 45), ARB (n = 27), statins (n = 53), or none of these medications (controls; n = 113). Range of motion in flexion, abduction, internal rotation (IR), and external rotation (ER) was recorded preoperatively and at 6 weeks and 3, 6, and 12 months postoperatively. Functional outcomes were assessed with the American Shoulder and Elbow Surgeons (ASES) score, the Single Assessment Numeric Evaluation (SANE), and the Simple Shoulder Test (SST) preoperatively and at 1 and 2 years postoperatively. The groups were compared using t test or Mann-Whitney U test for continuous data and chi-square or Fisher exact test for categorical data.

Results

Preoperatively, compared with controls, the ACEi group had decreased flexion (P = .038), abduction (P = .001), ER (P = .009), and IR (P = .015); the ARB group had decreased abduction (P = .012) and IR (P = .019); and the statins group had decreased abduction (P = .015), ER (P = .008), and IR (P = .011). Postoperatively, compared with controls, the ACEi group had decreased 6-month abduction (P = .034) that resolved by 12 months and 3-month ER (P = .004) that persisted into 6 months, the ARB group had greater ER at 12 months (P = .006), and the statins group had increased 6-week abduction (P = .017) that normalized by 3 months. Patients taking ACEi had lower postoperative ASES (30 vs 58.6; P = .001) and SANE scores (28.4 vs 52.3; P = .002) at 1 year and lower SST scores at 2 years (74.7 vs 85.5; P = .002) versus controls.

Conclusion

Patients who used ACEi showed an increased risk of stiffness 6 months postoperatively and had worse SST scores at 2 years after aRCR, while those who used ARB demonstrated improved postoperative ER and IR, with no changes in functional outcomes at longer-term follow-ups.

Protocol for a systematic review and meta-analysis of the combination of ezetimibe and statins for hyperlipidemia

INTRODUCTION

Hyperlipidemia is increasingly recognized as a significant global health issue, often associated with conditions such as hypertension, diabetes, and obesity. While statins are frequently prescribed to manage lipid levels, recent studies indicate that reliance solely on statin therapy may present certain disadvantages, including prolonged treatment durations, the potential for drug resistance, and various adverse effects. Research indicates that the combination of ezetimibe and statins demonstrates a favorable therapeutic effect in the management of hyperlipidemia. However, existing studies have not consistently confirmed these benefits, and there is no current meta-analysis available. As a result, we will perform a meta-analysis to assess the effectiveness and safety of the combination of ezetimibe and statins in managing hyperlipidemia, aiming to offer evidence-based medical guidance for clinical practice.

METHODS AND ANALYSIS

The systematic review and meta-analysis will adhere to the PRISMA guidelines for systematic reviews and meta-analyses. We will search for randomized controlled trials that investigate the efficacy and safety of the combination of ezetimibe and statins in treating hyperlipidemia, based on specific criteria. The following electronic databases will be searched by two researchers for relevant records published up to October 1, 2024: Cochrane Central Register of Controlled Trials (CENTRAL) in Cochrane Library, Embase.com, Web of Science, MEDLINE (via PubMed), Wanfang China Database, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM) and Chinese Scientific Journal Database (VIP). They will also check references and relevant journals manually. Two independent reviewers will handle screening, data extraction, and quality assessment. Subgroup analysis, sensitivity analysis, and publication bias analysis will be performed to assess consistency and reliability. Review Manager 5.4 will be used for data analysis and synthesis, while the GRADE approach will be employed to evaluate the overall study's evidence quality.

EXPECTED RESULTS

The findings of this systematic review will be shared with various stakeholders who are interested in the combination of ezetimibe and statins for hyperlipidemia. This will offer valuable insights for researchers undertaking future investigations and for clinical practitioners specializing in the treatment of hyperlipidemia.

ETHICS AND DISSEMINATION

This study is based on a secondary analysis of the literature, so ethical review approval is not required. The final report will be published in a peer-reviewed journal.

STUDY REGISTRATION

The protocol of the systematic review has been registered on Open Science Framework, with a registration DOI https://doi.org/10.17605/OSF.IO/TEVUY.

Influence of statin use on progression of postoperative fatty infiltration in the arthroscopic rotator cuff repair

PURPOSE

The purpose of this study was to determine the influence of hyperlipidemia and statin (hydroxyl-methylglutaryl-coenzyme-A reductase inhibitors) use on fatty infiltration (FI) of the rotator cuff muscle after arthroscopic rotator cuff repair (ARCR). The presence or absence of statin use and type of statins used (type 1 naturally derived statins and type 2 synthetic statins) were examined.

METHODS

This was a retrospective review of 620 cases (620 shoulders) who underwent arthroscopic rotator cuff repair. Total cholesterol (TC), low-density lipoprotein (LDL), triglycerides (TG) levels, and statin use were reviewed with the medical records. FI of the cuff muscles and repair integrity were assessed by MRI. A generalized linear model was used to analyze the progression of fatty infiltration. Repair integrity was determined according to the Sugaya classification, with types 4 and 5 as retears.

RESULTS

The mean age was 66.9 years (272, females). The overall retear rate was 16.1%. There was no significant difference in retears between statin use and non-use with a trend toward higher retear rates in the type 2 statins. FI progressed postoperatively, and multivariate regression showed that type 2 statin use was a significant risk factor (p = 0.006). Other significant risk factor were large-to-massive tear (p = 0.02) and retear (p < .0001).

CONCLUSIONS

The progression of FI after ARCR was observed. The new generation of strong statins (type 2 statins) was a significant risk factor for the progression of postoperative fatty infiltration, while neither serum lipid level (TC, LDL, and TG) was significant.

Statin Use Not Linked to Rotator Cuff Retear After Arthroscopic Rotator Cuff Repair

PURPOSE

To evaluate the risk factors, including hyperlipidemia and statin use, on rotator cuff healing after arthroscopic repair.

METHODS

A retrospective review of prospectively collected cases who underwent arthroscopic rotator cuff repair was conducted. Total cholesterol, low-density lipoprotein, triglycerides levels, and the presence or absence of statin use and type of statins used (type 1 naturally derived statins and type 2 synthetic statins) were reviewed. Repair integrity was determined according to the Sugaya classification, assessed by magnetic resonance imaging (types 4 and 5 were considered retear). Including serum lipid levels and statin use, potential risk factors for retear were tested using multivariate logistic regression.

RESULTS

Six hundred twenty cases were evaluated. The mean age was 66.9 years; 348 were male, and 272 were female. The overall retear rate was 16.1%. There was no statistically significant difference in serum lipid levels among the categories of the Sugaya classification. Multivariate logistic regression analysis showed no association between serum lipid levels and odds ratio for retear: total cholesterol (odds ratio [OR] 1.00; P = .72), low-density lipoprotein (OR 0.99; P = .44), and triglycerides (OR 1.00; P = .88). Statins did not have a statistically significant increase or decrease in odds: type 1 statin (OR 0.3; P = .061) and type 2 statin (OR 1.4; P = .26). Older age (OR 1.1; P < .0001), male sex (OR 1.8; P = .021), and large-to-massive cuff tear size (OR 3.4; P < .0001) were significant risk factors.

CONCLUSIONS

No association was found between serum lipid levels and retear after arthroscopic rotator cuff repair. Statin use was not a statistically significant factor for retears, but different trends were seen for type 1 and type 2 statins. Older age, male sex, and large to massive tears were significant risks for retears.

LEVEL OF EVIDENCE

Level III, retrospective cohort design, prognosis study.

Statin use and longitudinal changes in quantitative MRI-based biomarkers of thigh muscle quality: data from Osteoarthritis Initiative

OBJECTIVE

To assess whether changes in MRI-based measures of thigh muscle quality associated with statin use in participants with and without/at-risk of knee osteoarthritis.

METHODS

This retrospective cohort study used data from the Osteoarthritis Initiative study. Statin users and non-users were matched for relevant covariates using 1:1 propensity-score matching. Participants were further stratified according to baseline radiographic knee osteoarthritis status. We used a validated deep-learning method for thigh muscle MRI segmentation and calculation of muscle quality biomarkers at baseline, 2nd, and 4th visits. Mean difference and 95% confidence intervals (CI) in longitudinal 4-year measurements of muscle quality biomarkers, including cross-sectional area, intramuscular adipose tissue, contractile percent, and knee extensors and flexors maximum and specific contractile force (force/muscle area) were the outcomes of interest.

RESULTS

After matching, 3772 thighs of 1910 participants were included (1886 thighs of statin-users: 1886 of non-users; age: 62 ± 9 years (average ± standard deviation), range: 45-79; female/male: 1). During 4 years, statin use was associated with a slight decrease in muscle quality, indicated by decreased knee extension maximum (mean-difference, 95% CI: - 1.85 N/year, - 3.23 to - 0.47) and specific contractile force (- 0.04 N/cm2/year, - 0.07 to - 0.01), decreased thigh muscle contractile percent (- 0.03%/year, - 0.06 to - 0.01), and increased thigh intramuscular adipose tissue (3.06 mm2/year, 0.53 to 5.59). Stratified analyses showed decreased muscle quality only in participants without/at-risk of knee osteoarthritis but not those with established knee osteoarthritis.

CONCLUSIONS

Statin use is associated with a slight decrease in MRI-based measures of thigh muscle quality over 4 years. However, considering statins' substantial cardiovascular benefits, these slight muscle changes may be relatively less important in overall patient care.

Dyslipidaemia is associated with Cutibacterium acnes hip and knee prosthetic joint infection

PURPOSE

Optimization of medical factors including diabetes and obesity is a cornerstone in the prevention of prosthetic joint infection (PJI). Dyslipidaemia is another component of metabolic syndrome which has not been thoroughly investigated as an individual, modifiable risk factor. This study examined the association of dyslipidaemia with PJI caused by the lipophilic microbe Cutibacterium acnes (C. acnes).

METHODS

A retrospective chart review examined patients with positive C. acnes culture at hip or knee arthroplasty explantation. A control group with methicillin-sensitive Staphylococcus aureus (MSSA) positive cultures at explantation was matched for age, sex, and surgical site, as well as a second control group with no infection. A total of 80 patients were included, 16 with C. acnes, 32 with MSSA, and 32 with no infection. All patients had a lipid panel performed within one year of surgery. Lipid values and categories were compared using multinomial logistic regressions.

RESULTS

High or borderline triglycerides (TG) (relative risk ratio (RRR) = 0.13; P = 0.013) and low high-density lipoprotein (HDL) (RRR = 0.13; P = 0.025) were significantly associated with C. acnes PJI compared to MSSA-PJI. High or borderline TG (RRR = 0.21; P = 0.041) and low HDL (RRR = 0.17; P = 0.043) were also associated with a greater probability of C. acnes infection compared to no infection.

CONCLUSIONS

The presence of elevated TG and low HDL were both associated at a statistically significant level with C. acnes hip or knee PJI compared to controls with either MSSA PJI or no infection. This may represent a specific risk factor for C. acnes PJI that is modifiable.

Dyslipidemia may impact initial recovery following arthroscopic rotator cuff repair: a retrospective study

BACKGROUND

The current literature shows that dyslipidemia can lead to a higher incidence of rotator cuff tears (RCTs) and an increased retear rate after repair. We aimed to evaluate the influence of preoperative dyslipidemia on postoperative pain, patient-reported outcomes (PROs), active range of motion (ROM), and structural integrity.

METHODS

A cohort of 111 patients who underwent arthroscopic RCT repair between January 2021 and July 2022, and whose complete preoperative serum lipid data were available within one week prior to surgery was retrospectively reviewed. Dyslipidemia was defined as the presence of an increase or decrease in at least one blood lipid profile (triglycerides, total cholesterol, low-density lipoprotein, high-density lipoprotein, or non-high-density lipoprotein). There were 43 patients in the dyslipidemia group and 68 in the ortholiposis group. Patient evaluations, including pain score, PROs, and ROMs, were conducted preoperatively; at 3 and 6 months postoperatively; and at the last follow-up. Structural integrity was assessed by magnetic resonance imaging (MRI) 6 months after surgery if possible, and Sugaya type 4 or 5 was considered a retear. Propensity score matching (PSM) was used to reduce bias.

RESULTS

The RCT size, surgical technique, preoperative pain status, PROs, and active ROM were comparable between patients with dyslipidemia and those with ortholiposis. Three months after surgery, patients in the dyslipidemia group had worse average PROs (Constant score: P = 0.001; ASES score: P = 0.012; UCLA score: P = 0.015), forward flexion (P = 0.012), and internal rotation (P = 0.001) than patients in the ortholiposis group did. The difference between the two groups persisted after PSM but disappeared at the sixth month after surgery. No significant differences in pain score, PROs, or active ROMs were detected between the dyslipidemia and ortholiposis groups after a mean follow-up of 24 months. Of the 72 patients who underwent MRI, 4 retears (5.6%) were found, and all were in the ortholiposis group. There was no difference in the rate of retears between the two groups (P = 0.291) or with (P = 0.495) PSM.

CONCLUSIONS

In conclusion, we found that perioperative dyslipidemia may impact initial recovery within the first 3 months following arthroscopic rotator cuff repair but may have no effect on pain, PROs, or active ROMs at a mean 2-year follow-up or rotator cuff integrity at 6 months postoperatively. Trail registration Retrospectively registered.

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.

Progress in studying the impact of hyperlipidemia and statins on rotator cuff injury and repair

This review delves into the intersection of two prevalent conditions, hyperlipidemia and rotator cuff injuries, both of which bear substantial healthcare burdens. Our investigation begins with an exploration of rotator cuff injuries, common musculoskeletal disorders that severely impair shoulder functionality and quality of life. These injuries are notably pervasive among sports enthusiasts and the older adult, with an incidence rate estimated at 5-10% in the general population. Despite their widespread occurrence and the diverse, multifactorial etiological factors, effective treatment strategies remain elusive. We then examine hyperlipidemia, a metabolic disorder affecting approximately 40% of the global adult population. Characterized by elevated levels of cholesterol and triglycerides, hyperlipidemia can precipitate severe cardiovascular complications and presents a significant socioeconomic burden. Although current management strategies encompass lifestyle modifications and pharmacological interventions, the condition remains a formidable health challenge. Central to this review is the exploration of a potential association between hyperlipidemia and rotator cuff injuries. We aim to synthesize the current understanding of hyperlipidemia's role in the pathophysiology of rotator cuff injuries, thereby offering fresh insights into their common etiological underpinnings, potential therapeutic targets, and drugs, such as Statins. The influence of other lipid-lowering therapeutics on tendon health is also considered, and further research into the molecular pathways and potential therapeutic benefits of these drugs is required. This pursuit aligns with broader efforts to enhance patient outcomes, minimize healthcare burdens, and contribute to the global understanding of these prevalent conditions.

Pathological alterations in the expression status of rotator cuff tendon matrix components in hyperlipidemia

Hyperlipidemia is an important risk factor in the development and progression of tendon pathology, however its role in aggravating rotator cuff tendon injury (RCTI) is largely unknown. We aimed to assess the expression status of key extracellular matrix (ECM) components in the tendon tissues and tenocytes under hyperlipidemia. Shoulder rotator cuff (RC) tendon tissues harvested from the swine model of hyperlipidemia displayed alterations in histomorphometry and the expression status of major ECM component proteins including COL-I, COL-III, COL-IV, COL-V, COL-VI, MMP2, and MMP9. Similarly, the LDL- and oxLDL-challenged tenocytes displayed altered expression of the same proteins at both transcriptional and translational levels. In addition, the lipid uptake and cellular reactive oxygen radicals predominated in the lipid-challenged tenocytes compared to the control. Overall, the LDL-treated cells displayed predominant pathological alterations compared to the ox-LDL-treated cells. Further understanding regarding the underlying molecular mechanisms driving the tendon matrisome alteration and subsequent aggravated RCTI pathology in hyperlipidemia could open novel translational avenues in the management of RCTI.

Relationship of Missed Statin Therapy and 10-Year Atherosclerotic Cardiovascular Disease Risk Score to Retear Rate After Arthroscopic Rotator Cuff Repair

BACKGROUND

There is no practical consensus on managing cholesterol in patients with rotator cuff repair despite hyperlipidemia and statin therapy being well-known factors in rotator cuff healing. The 10-year atherosclerotic cardiovascular disease (ASCVD) risk score is a commonly used guideline to determine statin administration for hyperlipidemia.

PURPOSE

To identify the relationship between retear and preoperative factors, including 10-year ASCVD risk score and statin administration status, and to compare clinical outcomes and retear rates between patients who are taking and not taking statins.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

This study enrolled 182 patients with a symptomatic full-thickness rotator cuff tear who underwent arthroscopic repair. Serum lipid profile, 10-year ASCVD risk score, statin eligibility, and statin administration status were assessed. Patients were categorized into 2 groups based on magnetic resonance imaging to evaluate cuff integrity at postoperative 6 months: a healed group and a retear group. Radiographic and intraoperative factors related to retear were analyzed. Multiple regression analysis was performed to evaluate factors related to rotator cuff retear. For the subgroup analysis, patients eligible for statin therapy were divided into 2 subgroups according to administration status.

RESULTS

There were 149 (81.9%) patients in the healed group and 33 (18.1%) in the retear group. In the multiple regression analysis, missed statin therapy, 10-year ASCVD risk score, and fatty infiltration of the infraspinatus muscle were the independent factors related to retear. The cutoff value for 10-year ASCVD risk score was 11.85%, with a sensitivity of 0.75 and a specificity of 0.62. In the subgroup analysis of 104 patients eligible for statin therapy, 66 (63.5%; group 1) received statin therapy and 38 (36.5%; group 2) missed it. Group 2 showed a significantly higher retear rate than group 1 (36.8% vs 13.6%; P = .006).

CONCLUSION

Missed statin therapy, 10-year ASCVD risk score, and fatty infiltration of the infraspinatus were the independent factors associated with rotator cuff retear. Patients who missed statin therapy showed a higher retear rate than patients receiving statin therapy. Optimal statin therapy for patients who undergo arthroscopic rotator cuff repair might improve repair integrity.

Increased HbA1c Levels in Diabetics During the Postoperative 3-6 Months After Rotator Cuff Repair Correlated With Increased Retear Rates

PURPOSE

To evaluate whether glycemic control affects the integrity of the repaired rotator cuff during the postoperative healing period after arthroscopic double-row suture bridge rotator cuff repair (RCR) METHODS: We retrospectively reviewed patients with diabetes mellitus (DM) who underwent arthroscopic double-row suture bridge RCR at our institution between March 2016 and November 2019. We included the patients who evaluated for serum glycosylated hemoglobin (HbA1c) levels within 1 month before and 3-6 months after surgery. Magnetic resonance imaging was conducted 6 months after surgery to evaluate the integrity of the repaired cuff tendon. Patients were categorized into two groups based on comparison between preoperative and postoperative HbA1c values: Group I (increased postoperative HbA1c) and Group D (same or decreased postoperative HbA1c). The correlation between preoperative/postoperative HbA1c, HbA1c increase/same or decrease (during the healing period), and post-RCR integrity was evaluated, including various demographic and radiologic factors.

RESULTS

A total of 103 patients were analyzed, group I was 47, and group D was 56, respectively. The retear rate of 51.1% (24/47) in Group I was significantly higher than 14.3% (8/56) in Group D (P < .001). HbA1c levels measured 3-6 months after surgery (mean: 6.9; 95% CI: 6.6-7.3 vs mean: 6.5; 95% CI: 6.3-6.7, P = .034), and the proportion of group I and group D were significantly different (75%/25% vs 32.4%/67.6%, P < .001) between the retear and healing groups. Multivariable logistic regression analysis identified increased HbA1c as an independent risk factor for retear (odds ratio: 5.402; 95% CI: 2.072-14.086; P < .001).

CONCLUSIONS

The glycemic control within 3-6 months after surgery when the healing process of the tendon was in progress had a significant effect on retear rate. In particular, the retear rate was higher when the HbA1c level increased at postoperative 3-6 months compared to before surgery.

LEVEL OF EVIDENCE

Retrospective case-control comparative study, Level III.

Dyslipidemia is associated with risk for rotator cuff repair failure: a systematic review and meta-analysis

Background

Lipid deposition secondary to dyslipidemia (DLD) is shown to have a significant impact on tendon pathology, including tendon elasticity, fatty infiltration, and healing properties. Rotator cuff repair is a common procedure, susceptible to influence from many tear-related and patient-related characteristics. The purpose of this study was to determine the relationship between DLD and rotator cuff repair outcomes with analysis of retear risk and function.

Methods

PubMed, Embase, and SPORTDiscus were searched for all English-language, peer-reviewed studies between 2000 and the present, which analyzed relationships between patient-related factors and outcomes of rotator cuff repair. Studies that explicitly examined the effect of DLD on rotator cuff repair outcomes were chosen for inclusion. Included studies were assessed for methodological quality, and data were extracted for meta-analysis.

Results

Of the 3087 titles, 424 were screened by abstract, and 67 were reviewed in full. Inclusion criteria were met by 11 studies. Of these studies, 5 studies assessed retear, 2 studies measured function, 3 studies reported both retear and function, and 1 study evaluated the risk of retear necessitating a revision surgery. The studies report no significant difference in functional outcomes. Meta-analysis revealed that DLD patients had a significantly higher risk of retear after primary rotator cuff repair (odds ratio 1.32, 95% confidence interval 1.06-1.64).

Conclusion

DLD leads to an increased risk of retear after rotator cuff repair, although function appears to be unimpaired. DLD should be considered among other risk factors when counseling patients regarding expected rotator cuff repair outcomes.

Biochemical Markers of Aging (Advanced Glycation End Products) and Degeneration Are Increased in Type 3 Rotator Cuff Tendon Stumps With Increased Signal Intensity Changes on MRI

BACKGROUND

Advanced glycation end products (AGEs) are end products of protein glycation that bind to the receptor for AGEs (RAGE) and activate nicotinamide adenine dinucleotide phosphate oxidase (NOX), resulting in increased oxidative stress and rotator cuff fragility. Stump classification using the signal intensity ratio of the tendon rupture site to the deltoid muscle in the coronal view of T2-weighted fat-suppressed magnetic resonance imaging (MRI) scans is an indicator of clinical outcomes after rotator cuff repair surgery. Comparing the signal intensities of the deltoid (D) and rotator cuff tears (C), Ishitani et al. classified C/D <0.8 as type 1, 0.8 to 1.3 as type 2, and >1.3 as type 3.

HYPOTHESIS/PURPOSE

It was hypothesized that the oxidative stress and collagen degeneration that occur in the rotator cuff due to accumulation of AGEs can be assessed on MRI scans (stump classification). Therefore, this study aimed to compare AGE-related factors in the rotator cuff tear site tissues based on stump classification.

STUDY DESIGN

Descriptive laboratory study.

METHODS

The authors included 30 patients (11 with type 1, 9 with type 2, and 10 with type 3; mean age, 62.3 years) who underwent surgery for complete rotator cuff tears at our hospital. Tendon tissue was harvested from the torn rotator cuff site during surgery for tissue and cell evaluation.

RESULTS

There was no significant difference in the mean age according to stump classification. The number of patients with diabetes was significantly larger in type 3 than in the other types (P < .05). Tissue evaluation showed significantly higher expression of AGE and RAGE staining in type 3 than in the other types (~6.7-fold; P < .01). Cell evaluation showed that the expression rates of reactive oxygen species and apoptosis were significantly higher in type 3 than in the other types (~4.3-fold; P < .01). Gene expression by real-time polymerase chain reaction showed significantly higher RAGE (~5.1-fold), NOX (~5.3-fold), and IL (~3.0-fold) in type 3 than in the other types (P < .05).

CONCLUSION

Stump classification type 3 exhibited the highest accumulation of AGEs and the highest oxidative stress and apoptosis, suggesting a high degree of degeneration and inflammation. Imaging based on stump classification reflects the degeneration and fragility of the torn rotator cuff site.

CLINICAL RELEVANCE

This study provides evidence of a relationship between stump classification, which reflects rotator cuff fragility on MRI, and pathologies related to advanced glycation end products.