The effects of hyperlipidemia on rotator cuff diseases: a systematic review

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.

Risk Factors for the Development of Olecranon Bursitis-A Large-Scale Population-Based Study

Background: Olecranon bursitis (OB) involves fluid accumulation in the bursa, with common causes being trauma and preexisting conditions. Its incidence is difficult to quantify, and risk factors such as diabetes, obesity, and male gender are frequently noted. Hyperlipidemia has been linked to musculoskeletal disorders, but its role as a risk factor for OB remains unexplored. This study aimed to investigate the association between OB and hyperlipidemia, diabetes, obesity, cardiovascular disease, and statin use. Methods: A retrospective cohort study analyzed a large-scale database (2005-2020), ultimately including 10,301 patients with olecranon bursitis and 44,608 controls after applying exclusion criteria. Participants were aged 18-90 years, with BMI between 10 and 55. Key variables such as smoking, diabetes, hyperlipidemia, statin use, cardiovascular diseases (CVDs), and cerebrovascular accidents (CVAs) were analyzed. Logistic regression models were applied with stabilized inverse probability of treatment weighting (IPTW) to estimate odds ratios (ORs) for risk factors, and p-values were adjusted using the Benjamini-Hochberg method. Results: OB was significantly associated with male gender (OR: 1.406; p < 0.0001), hyperlipidemia (OR: 1.239; p < 0.0001), statin use (OR: 1.117; p = 0.0035), and smoking (OR: 1.068; p = 0.0094). Age and BMI were significant continuous variables influencing OB risk, particularly in older patients and those with elevated BMI. CVDs and diabetes were not significantly linked to OB. Hyperlipidemia increased OB risk, especially in males and individuals with higher BMI. Conclusions: Male gender, hyperlipidemia, and smoking are key risk factors for OB, with hyperlipidemia posing a notable risk in older individuals and those with higher BMI. Statin use did not significantly alter OB risk in hyperlipidemic patients. Further studies are needed to clarify the mechanisms behind these associations.

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.

Biological Markers of Musculoskeletal Pain: A Scoping Review

Background

Musculoskeletal pain (MSP) is the leading contributor to disability, limiting mobility and dexterity. As research on the determinants of MSP is evolving, biomarkers can probably play a significant role in understanding its causes and improving its clinical management. This scoping review aimed to provide an overview of the associations between biomarkers and MSP.

Methods

This study followed Arksey and O'Malley and PRISMA-ScR recommendations. Keywords related to biomarkers, association, and MSP were searched on PubMed, Embase, Cochrane, and Web of Science databases from inception to September 28th, 2023. Data were systematically retrieved from the retained articles. A narrative synthesis approach - but no quality assessment - was used to map the core themes of biological markers of MSP that emerged from this work.

Results

In total, 81 out of 25,165 identified articles were included in this scoping review. These studies were heterogeneous in many aspects. Overall, vitamin D deficiency, dyslipidemia (or hypercholesterolemia), and cytokines (high levels) were the most studied biomarkers with regards to MSP and were most often reported to be associated with non-specific MSP. Cadmium, calcium, C-reactive protein, collagen, creatinine, hormones, omega-3 fatty acids, sodium, tumor necrosis factor-alpha, and vitamin C were also reported to be associated with MSP syndromes, but the evidence on these associations was sketchier. No conclusions could be drawn as to age and sex.

Conclusions

Our findings suggest that some biomarkers are associated with specific MSP syndromes, while others would be associated with non-specific syndromes. Among all candidate markers, the evidence seems to be more consistent for vitamin D, cytokines and lipids (total cholesterol, triglycerides, low- and high-density lipoproteins). High-quality studies, stratified by age and sex, are needed to advance our understanding on biomarkers of MSP.

Inflammation and Fatty Infiltration Correlates with Rotator Cuff Muscle Atrophy in Hypercholesterolemic Yucatan Microswine

Rotator cuff injuries are the most common injuries among active and training astronauts. According to the CDC, 1 in 4 adults in the U.S. experience rotator cuff injuries, particularly affecting the supraspinatus muscle. Hypercholesterolemia, a condition characterized by high levels of LDL cholesterol, is prevalent in approximately 2 in 5 adults in the US and is a risk factor for worsened outcomes in shoulder inflammation and rotator cuff injury repairs. Chronic inflammation, a prolonged low-grade inflammatory state, can arise from conditions like hypercholesterolemia and contribute to muscle atrophy. Skeletal muscle atrophy can be caused by factors such as disuse, aging, malnutrition, and microgravity, and currently lacks approved drug therapies. Thus, gaining a comprehensive understanding of the associations between hypercholesterolemia, chronic inflammation, and skeletal muscle atrophy is imperative for developing effective strategies to manage this condition. We conducted an animal study in Yucatan miniswine to investigate the impact of a high-cholesterol diet on rotator cuff muscle. The results suggested the presence of chronic inflammation in rotator cuff muscle hypercholesterolemic swine, associated with elevated pro-inflammatory cytokines and intramuscular adipocytes, and skeletal muscle atrophy. The results also revealed upregulation of the FOXO3/TRIM63/Titin axis in a hyperlipidemic state. These findings open new perspectives for developing better treatment strategies by targeting the FOXO3/TRIM63/Titin axis to manage rotator cuff muscle atrophy in the context of hypercholesterolemia.

Lipids, lipid-lowering drugs and lateral epicondylitis of the humerus: a drug-targeted Mendelian randomization study

Background

Clinical observations indicate that blood lipids may be risk factors for lateral epicondylitis (LE) of the humerus, and lipid-lowering drugs are also used for the prevention and treatment of tendon diseases, but these lack high-quality clinical trial evidence and remain inconclusive. Mendelian randomization (MR) analyses can overcome biases in traditional observational studies and offer more accurate inference of causal relationships. Therefore, we employed this approach to investigate whether blood lipids are risk factors for LE and if lipid-lowering drugs can prevent it.

Methods

Genetic variations associated with lipid traits, including low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and total cholesterol (TC), were obtained from the UK Biobank and the Global Lipids Genetics Consortium (GLGC). Data on genetic variation in LE were sourced from FinnGen, including 24,061 patients and 275,212 controls. Subsequently, MR analyses were conducted to assess the potential correlation between lipid traits and LE. Additionally, drug-target Mendelian randomization analyses were performed on 10 drug targets relevant to LE. For those drug targets that yielded significant results, further analysis was conducted using colocalization techniques.

Results

No correlation was found between three blood lipid traits and LE. Lipoprotein lipase (LPL) enhancement is significantly associated with a decreased risk of LE (OR = 0.76, [95% CI, 0.65-0.90], p = 0.001). The expression of LPL in the blood is associated with LE and shares a single causal variant (12.07%), greatly exceeding the probability of different causal variations (1.93%), with a colocalization probability of 86.2%.

Conclusion

The three lipid traits are not risk factors for lateral epicondylitis. LPL is a potential drug target for the prevention and treatment of LE.

Effect of Preoperative Lipidemic Control on Retear Rates After Rotator Cuff Repair in Patients With Hyperlipidemia

BACKGROUND

In patients with hyperlipidemia, the risk of retear increases after rotator cuff repair (RCR). In particular, it has been reported that preoperative low-density lipoprotein cholesterol (LDL-C) level affects cuff integrity. However, there are no studies assessing whether lipidemic control affects cuff healing.

PURPOSE

To evaluate the effect of preoperative lipidemic control on cuff integrity after arthroscopic RCR across cardiovascular disease risk groups in patients with hyperlipidemia.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

The authors retrospectively reviewed the charts of patients with hyperlipidemia who underwent arthroscopic double-row suture bridge RCR between 2014 and 2019. The included patients had LDL-C tested within 1 month before surgery. Magnetic resonance imaging was conducted 6 months after surgery to evaluate the integrity of the repaired cuff tendon. Patients were divided into groups of low, moderate, high, and very high risk according to the 4th Korean Dyslipidemia Guidelines. On the basis of the target LDL-C set in each risk group, patients were categorized into 2 groups: group C (controlled hyperlipidemia, less than target LDL-C) and group U (uncontrolled hyperlipidemia, target LDL-C or greater). The correlation between serum lipid profile, lipidemic control, and post-RCR integrity was evaluated.

RESULTS

A total of 148 patients were analyzed, 51 in group U and 97 in group C. The retear rate was significantly higher in group U than in group C (23/51 [45.1%] vs 18/97 [18.6%], respectively; P = .001). The proportion of group U was significantly higher in the retear group than in the healing group (56.1% vs 26.2%; P = .001). In addition, the proportions of patients with uncontrolled diabetes mellitus (DM) (19.5% vs 3.7%; P = .002) and mediolateral (2.6 ± 1.2 cm vs 1.7 ± 1.1 cm; P < .001) and anteroposterior (2.2 ± 1.1 cm vs 1.6 ± 0.8 cm; P = .003) tear sizes were significantly different between the retear and healing groups, respectively. No significant difference in serum lipid profile, including LDL-C level (119.6 ± 31.3 vs 116.7 ± 37.2; P = .650), was observed between the retear and healing groups. Multivariate regression analysis identified uncontrolled hyperlipidemia (OR, 4.005; P = .001), uncontrolled DM (OR, 5.096; P = .022), and mediolateral tear size (OR, 1.764; P = .002) as independent risk factors for retear. The 2.0-cm mediolateral size cutoff and the 3 independent risk factors had significant associations with retear.

CONCLUSION

Poor preoperative lipidemic control was significantly associated with poor healing after RCR. In addition to large mediolateral tear size, uncontrolled hyperlipidemia and DM were significant risk factors for retear. Moreover, poor lipidemic control compared with the recommended target level before surgery was more correlated with an increased retear rate than a preoperative LDL-C level.

Characteristics of Traumatic Versus Atraumatic Rotator Cuff Tears in Patients Under 50 Years of Age

BACKGROUND

 The prevalence of rotator cuff tears (RCTs) is known to be lower in younger patients compared to older patients. Recent studies in patients less than 50 years of age who sustain an RCT have focused on etiology, pathogenesis, and clinical outcomes following treatment. There are fewer studies that have focused on the demographics and clinical characteristics that may predispose this patient population to develop a tear. The purpose of this study is to evaluate the difference in risk factors for degenerative tears compared to traumatic tears in patients under 50 years of age.

METHODS

This single-center retrospective study utilized an internal registry of patients who had RCT injuries identified by the International Classification of Diseases (ICD)-10 code M75.1x and confirmed by MRI between 2018 and 2023. Patients 50 years of age or younger were included and then classified into traumatic versus atraumatic RCT etiology groups. Demographics, tear characteristics, and clinical comorbidities were compared between the cohorts. Statistical analyses included a two-sided student's t-test, Wilcoxon rank-sum test, Chi-square test, and Fisher's exact test.

RESULTS

A total of 177 patients under 50 years of age were identified. There was a higher prevalence of traumatic tears (59.9% vs. 40.1%; p = 0.008), the majority of whom identified as male (75.5% vs. 49.3%, p<0.001) when compared to the atraumatic cohort. Full-thickness tears were more likely to be traumatic (p = 0.04) and seen in patients insured by workers' compensation (p = 0.05). There was no significant difference in the age or preoperative comorbidities between the two groups.

CONCLUSIONS

Our study reveals a higher incidence of traumatic RCTs in a younger patient group. Sex, severity of tear, and workers' compensation were found to differ between traumatic and atraumatic cohorts. Further research is required to understand the interplay of these factors in younger patients' tear risk.

Novel methods to diagnose rotator cuff tear and predict post-operative Re-tear: Radiomics models

Objective

To validated a classifier to distinguish the status of rotator cuff tear and predict post-operative re-tear by utilizing magnetic resonance imaging (MRI) markers.

Methods

This retrospective study included patients with healthy rotator cuff and patients diagnosed as rotator cuff tear (RCT) by MRI. Radiomics features were identified from the pre-operative shoulder MRI and selected by using maximum relevance minimum redundancy (MRMR) methods. A radiomics model for diagnosis of RCT was constructed, based on the 3D volume of interest (VOI) of supraspinatus. Another model for the prediction of rotator re-tear after rotator cuff repair (Re-RCT) was constructed based on VOI of humerus, supraspinatus, infraspinatus and other clinical parameters.

Results

The model for diagnosing the status of RCT produced an area under the receiver operating characteristic curve (AUC) of 0.989 in the training cohort and 0.979 for the validation cohort. The radiomics model for predicting Re-RCT produced an AUC of 0.923 ± 0.017 for the training dataset and 0.790 ± 0.082 for the validation dataset. The nomogram combining radiomics features and clinical factors yielded an AUC of 0.961 ± 0.020 for the training dataset and 0.808 ± 0.081 for the validation dataset, which displayed the best performance among all models.

Conclusion

Radiomics models for the diagnosis of rotator cuff tear and prediction of post-operative Re-RCT yielded a decent prediction accuracy.

A causal association between lipid-lowering medications and rotator cuff syndrome: a drug-targeted mendelian randomization study

Background: Previous research has suggested that dyslipidemia may be a risk factor for rotator cuff syndrome (RCS), and lipid-lowering drugs may aid in its treatment, though conclusions have not been definitive. Mendelian randomization is a statistical method that explores the causal relationships between exposure factors and diseases. It overcomes the confounding issues inherent in traditional observational studies, thereby providing more reliable causal inferences. We employed this method to investigate whether hyperlipidemia is a risk factor for rotator cuff syndrome and whether lipid-lowering drugs can effectively treat this condition. Methods: Genetic variations linked to lipid traits low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), and total cholesterol (TC) were acquired from the UK Biobank and the Global Lipids Genetics Consortium (GLGC). Data on genetic variation in rotator cuff syndrome were obtained from FinnGen, including 24,061 patients and 275,212 controls. In the next step, we carried out two-sample Mendelian randomization analyses to determine whether lipid traits correlate with rotator cuff syndrome risk. Additionally, we performed drug-target Mendelian randomization (MR) analyses on 10 drug targets related to rotator cuff syndrome. For the drug targets that showed significant results, further analysis was done using Summary-data-based Mendelian Randomization (SMR) and colocalization techniques. We performed a mediation analysis to identify potential mediators between HMG-CoA reductase (HMGCR) and RCS. Results: No causative link was established between these lipid traits and rotator cuff syndrome. However, a significant association has been identified where HMGCR inhibition corresponds to a reduced risk of rotator cuff disease (OR = 0.68, [95% CI, 0.56-0.83], p = 1.510 × 10-4). Additionally, enhanced expression of HMGCR in muscle tissues is also linked to a decreased risk of rotator cuff syndrome (OR = 0.88, [95% CI, 0.76-0.99], p = 0.03). Body mass index (BMI) mediated 22.97% of the total effect of HMGCR on RCS. Conclusion: This study does not support low-density LDL-C, TG, and TC as risk factors for rotator cuff syndrome. HMGCR represents a potential pharmaceutical target for preventing and treating rotator cuff syndrome. The protective action of statins on the rotator cuff syndrome might not be associated with their lipid-lowering properties.

Occupational Stress as a Possible Risk Factor for Rotator Cuff Damage - Systematic Review and Meta-analysis

PURPOSE

In September 2021, the Federal Ministry of Labour and Social Affairs in Germany (BMAS) recommended recognising rotator cuff lesions caused by occupational long-term overhead work, repetitive movements, hand-arm-vibration and carrying and lifting heavy loads as an occupational disease. To gain a more detailed understanding of the correlation between occupational risk factors and lesions of the rotator cuff, a systematic literature review was carried out to determine their influence on the development of rotator cuff disease.

MATERIAL AND METHOD

A systematic literature review was used to search in the databases PubMed, Cochrane and Web-of-Science for papers dealing with occupational shoulder load and associated shoulder disorders. The influence of overhead work, repetitive movements, hand-arm-vibrations and carrying and lifting heavy loads were examined.

RESULTS

58 studies were read in full text, of which 13 papers were included in the meta-analysis. In all risk factors, a significant association can be found with the strongest dose-response relationship in "overhead work" and "repetitive movements": overhead work: 2.23 (95% CI 1.98-2.52), repetitive movements: 2.17 (95% CI 1.92-2.46), hand-arm-vibration: 1.59 (95% CI 1.13-2.23), carrying and lifting heavy loads: 1.57 (95% CI 1.15-2.15).

CONCLUSION

Although a significant effect could be shown in our study for all the four risk factors examined, due to the low number of studies with high-quality study design and insufficient pathophysiological explanation for the development of a rotator cuff disease in these mechanical activities, no reliable correlation can currently be established.

Hyperlipidemia Induced Pathological Changes with no Effect in Biomechanical Properties in the Achilles Tendon of Young Swine

Hyperlipidemia is linked to atherosclerosis and various diseases. Its strong association with Achilles tendinopathies and xanthomas affects tendon properties through lipid deposition in tendon tissue. We examined the impact of hyperlipidemia on the biomechanical properties of the swine Achilles tendons. Swines were fed a high-cholesterol-high-fat diet to induce hyperlipidemia, and their Achilles tendons were collected and examined for biomechanical properties. The ultimate tensile strength, modulus of elasticity and viscoelastic properties did not exhibit significant differences between hyperlipidemic and control swines. H&E and pentachrome staining revealed extracellular matrix (ECM) disorganization and cellular infiltration in the hyperlipidemic swines, highlighting a marked difference between the control and hyperlipidemic groups. These results suggest hyperlipidemia in young swines alters the tendon composition and may contribute to weak biomechanical properties with time.

Mitochondrial Biogenesis as a Therapeutic Target for Rotator Cuff Tendon Tears

Rotator Cuff Injuries (RCI) are highly prevalent and characterized by shoulder pain, restricted shoulder movement, and difficulty with overhead activity, radiating pain in the deltoid muscle, and atrophy of the rotator cuff muscles. Increasing age, hand dominance, smoking, hypertension, hyperlipidemia, and obesity are common risk factors. Chronic inflammation plays a critical role in the underlying pathogenesis. RCI accounts for massive healthcare expenditure costing about $15,000 per repair, and over 4.5 million physician visits per year, however, there is still no therapeutic target to improve clinical outcomes. Mitochondrial biogenesis in response to inflammatory stimuli supports increased cellular energy requirements, cell proliferation, and differentiation. This suggests that mitochondrial biogenesis may play a role in healing RCI by serving as a protective factor against free oxygen species and promoting homeostasis within the rotator cuff. There is evidence highlighting the potential therapeutic benefits of mitochondrial biogenesis in various inflammatory diseases, but no study explored the role of mitochondrial biogenesis in rotator cuff tears. Since hypercholesterolemia is a risk factor for RCI, we investigated the effects of hypercholesterolemia on the expression of PGC-1α, a marker of mitochondrial biogenesis, in rotator cuff muscle. The findings revealed an increased gene and protein expression of inflammatory mediators and PGC-1α, suggesting enhanced inflammation and increased mitochondrial biogenesis due to hypercholesterolemia. Additional studies are warranted to further investigate the chronic effect of hyperlipidemia induced RCI to elucidate the cause of insufficient mitochondrial biogenesis unable to protect the rotator cuff and the therapeutic effect of promoting mitochondrial biogenesis.

The Effect of Hyperlipidemia as a Risk Factor on Postoperative Complications in Patients Undergoing Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To analyze the effect of hyperlipidemia (HLD) on postoperative complications in patients who underwent anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

ACDF represents the standard procedure performed for focal anterior nerve root or spinal cord compression with low complication rates. HLD is well known as a risk factor for major complications after vascular and transplant surgery, and orthopedic surgery. To date, there have been no studies on HLD as a risk factor for cervical spine surgery.

PATIENTS AND METHODS

Patients who underwent ACDF from 2010 through quarter 3 of 2020 were enrolled using the MSpine subset of the PearlDiver Patient Record Database. The patients were divided into single-level ACDF and multilevel ACDF groups. In addition, each group was divided into subgroups according to the presence or absence of HLD. The incidence of surgical and medical complications was queried using relevant International Classification of Disease and Current Procedural Terminology codes. Charlson Comorbidity Index was used as a broad measure of comorbidity. χ 2 analysis, with populations matched for age, sex, and Charlson Comorbidity Index, was performed.

RESULTS

A total of 24,936 patients who underwent single-level ACDF and 26,921 patients who underwent multilevel ACDF were included. In the multilevel ACDF group, wound complications were significantly higher in the patients with HLD. Among medical complications, myocardial infarction, renal failure, and urinary tract infection/urinary incontinence were significantly higher in the patients with HLD in both groups. Revision surgery and readmission were significantly higher in the patients with HLD who underwent multilevel ACDF.

CONCLUSIONS

In patients who underwent ACDF, several surgical and medical complications were found to be higher in patients with HLD than in patients without HLD. Preoperative serum lipid concentration levels and management of HLD should be considered during preoperative planning to prevent postoperative complications in patients undergoing ACDF.

Rotator Cuff Tendon Repair after Injury in Hyperlipidemic Swine Decreases Biomechanical Properties

Rotator cuff injury is the leading cause of shoulder pain. Hyperlipidemia is responsible in depositing lipids in tendons and reduce the healing upon injuries or tears. In this study, we created rotator cuff injury and repair models in swine and studied the changes in biomechanical properties of infraspinatus tendons in hyperlipidemic swine. The infraspinatus tendons from control group, hyperlipidemic injury and repair group of animals were collected and tested ex-vivo. The ultimate tensile strength (UTS) and modulus of elasticity increased in the tendons from the contralateral side on both the injury and repair models and were higher than the injury side. The presence of large number of fibrous tissues in the surgical site of repair and increased water content was observed in addition to the fatty infiltration which would have contributed to the decreased mechanical properties of the injured tendons following repair. Meanwhile the tendons of the contralateral side in both the injury and repair model showed adaptation to chronic load as observed in the modulus and viscoelastic properties. This is a pilot study that warrants detailed investigation in a larger sample size with longer duration following tendon injury and repair to gain better understanding on the effect of hyperlipidemia in the healing of rotator cuff tendon injury.

Hyperlipidemia Lowers the Biomechanical Properties of Rotator Cuff Tendon

Infraspinatus tendon is the most affected tendon of the rotator cuff, being an important posterior component of the shoulder joint. Hyperlipidemia is a predisposing factor in the progression of rotator cuff tears and retear. We studied the effect of hyperlipidemia on the biomechanical properties of rotator cuff tendons. The infraspinatus tendon of the rotator cuff from hyperlipidemic swine were collected and tested for ultimate tensile strength (UTS) and modulus of elasticity. Dynamic mechanical analysis was performed to examine viscoelastic properties. The findings revealed no significant difference in UTS but had significantly lower modulus of elasticity in the infraspinatus tendon of the hyperlipidemic group compared to the control group. Moreover, differences in the dynamic modulus, storage modulus, and loss modulus were not statistically significant between the hyperlipidemic and control swine. There was no difference in water content between the groups but the hyperlipidemic group had fatty infiltration aiding the initial decrease in mechanical properties. These findings suggest an association between fat deposition and early changes in the biomechanical properties of the tendons in the shoulder rotator cuff in hyperlipidemic state.

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.

Minimum 5-Year Clinical Outcomes of Arthroscopically Repaired Massive Rotator Cuff Tears: Effect of Age on Clinical Outcomes

BACKGROUND

Massive rotator cuff tears (MRCTs) can be challenging to treat, and the efficacy of repair of MRCTs in older patients has been debated.

PURPOSE

To report minimum 5-year outcomes after primary arthroscopic rotator cuff repair of MRCT and determine whether age affects outcomes.

STUDY DESIGN

Case series; Level of evidence 4.

METHODS

The study included consecutive patients with MRCTs who were treated with arthroscopic rotator cuff repair by a single surgeon between February 2006 and October 2016. MRCTs were defined as ≥2 affected tendons with tendon retraction to the glenoid rim and/or a minimum exposed greater tuberosity of ≥67. Patient-reported outcome (PRO) data collected preoperatively and at a minimum of 5 years included the American Shoulder and Elbow Surgeons (ASES) score; Single Assessment Numeric Evaluation (SANE) score; the shortened version of the Disabilities of the Arm, Shoulder and Hand score (QuickDASH); the 12-Item Short Form Health Survey (SF-12) Physical Component Summary (PCS); and patient satisfaction. Surgical failure was defined as subsequent revision rotator cuff surgery or conversion to reverse total shoulder arthroplasty. Regression analysis was performed to determine whether age had an effect on clinical outcomes.

RESULTS

A total of 53 shoulders in 51 patients (mean age, 59.7 years; range, 39.6-73.8 years; 34 male, 19 female) met inclusion criteria with a mean follow-up of 8.1 years (range, 5.0-12.1 years). Three shoulders (5.7%) failed at 2.4, 6.0, and 7.1 years. Minimum 5-year follow-up was obtained in 45 of the remaining 50 shoulders (90%). Mean PROs improved as follows: ASES from 58.8 to 96.9 (P < .001), SANE from 60.5 to 88.5 (P < .001), QuickDASH from 34.2 to 6.8 (P < .001), and SF-12 PCS from 41.1 to 52.2 (P < .001). Patient satisfaction was a median of 10 (on a scale of 1-10). Age was not associated with any PRO measures postoperatively (P > .05).

CONCLUSION

This study demonstrated significantly improved clinical scores, decreased pain, and increased return to activity for patients with MRCT at midterm follow-up (mean, 8.1 years; range, 5.0-12.1 years). In this patient cohort, no association was found between age and clinical outcomes.

Outcomes and Survivorship 5 Years After Arthroscopic Rotator Cuff Repair in Active Patients 70 Years and Older

Background

Rotator cuff tears are common in the elderly population and are associated with increased pain, decreased function, and decreased enjoyment of recreational activities.

Purpose

To evaluate clinical outcomes at a minimum of 5 years after arthroscopic repair of full-thickness rotator cuff tears in recreational athletes aged ≥70 years at the time of surgery.

Study Design

Case series; Level of evidence, 4.

Methods

Included were recreational athletes aged ≥70 years who underwent arthroscopic rotator cuff repair (RCR) from December 2005 to January 2016. Patient and surgery characteristics were collected prospectively and retrospectively reviewed. Patient-reported outcome (PRO) scores utilized were the American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), the shortened version of Disabilities of the Arm, Shoulder and Hand score (QuickDASH), 12-Item Short Form Health survey (SF-12) questionnaire (Physical Component Summary and Mental Component Summary), and patient satisfaction. Kaplan Meier survivorship analysis was performed, with failure defined as revision RCR or retear on magnetic resonance imaging (MRI).

Results

Overall, 71 shoulders (n = 67 patients [44 men, 23 women]; mean age, 73.4 years [range, 70.1-81.3 years]) were included in this study. Follow-up data was obtained for 65 of the 69 available shoulders (94%) at a mean of 7.8 years (range, 5-15.3 years). Mean age at follow-up was 81.2 years (range, 75.7-91.0). One RCR was revised after a traumatic accident, and another had a symptomatic, MRI-confirmed retear. One patient had lysis of adhesions for stiffness 3 months postoperatively. All PRO scores improved from pre- to postoperatively-ASES, from 55.3 to 93.6; SANE, from 62 to 89.6; QuickDASH, from 32.9 to 7.3; and SF-12 Physical Component Summary, from 43.3 to 53 (P < .001 for all)-and the median satisfaction score was 10 out of 10. Postoperatively, 63% of the patients returned to their original fitness program and 33% of patients modified their recreational activity. Survivorship analysis showed a 98% survival rate at 5 years and a 92% rate at 10 years.

Conclusion

Sustained improvement in function, reduced pain, and return to activities was seen after arthroscopic RCR in active patients ≥70 years old. Despite one-third of patients modifying their recreational activity, the cohort reported high levels of satisfaction and general health.

Developing a machine learning algorithm to predict probability of retear and functional outcomes in patients undergoing rotator cuff repair surgery: protocol for a retrospective, multicentre study

INTRODUCTION

The effectiveness of rotator cuff tear repair surgery is influenced by multiple patient-related, pathology-centred and technical factors, which is thought to contribute to the reported retear rates between 17% and 94%. Adequate patient selection is thought to be essential in reaching satisfactory results. However, no clear consensus has been reached on which factors are most predictive of successful surgery. A clinical decision tool that encompassed all aspects is still to be made. Artificial intelligence (AI) and machine learning algorithms use complex self-learning models that can be used to make patient-specific decision-making tools. The aim of this study is to develop and train an algorithm that can be used as an online available clinical prediction tool, to predict the risk of retear in patients undergoing rotator cuff repair.

METHODS AND ANALYSIS

This is a retrospective, multicentre, cohort study using pooled individual patient data from multiple studies of patients who have undergone rotator cuff repair and were evaluated by advanced imaging for healing at a minimum of 6 months after surgery. This study consists of two parts. Part one: collecting all potential factors that might influence retear risks from retrospective multicentre data, aiming to include more than 1000 patients worldwide. Part two: combining all influencing factors into a model that can clinically be used as a prediction tool using machine learning.

ETHICS AND DISSEMINATION

For safe multicentre data exchange and analysis, our Machine Learning Consortium adheres to the WHO regulation 'Policy on Use and Sharing of Data Collected by WHO in Member States Outside the Context of Public Health Emergencies'. The study results will be disseminated through publication in a peer-reviewed journal. Institutional Review Board approval does not apply to the current study protocol.

Quinolone Ear Drops and Achilles Tendon Rupture

BACKGROUND

Delayed eardrum healing has been observed in the ear opposite to the ear treated with otic quinolones (OQ) in rats. Case reports describe tendinopathies after OQ treatment, suggesting adverse systemic effects.

METHODS

We studied patients aged 19 to 64 years with diagnosis of otitis externa or media in private insurance between 2005 and 2015. We compared OQ treatment against otic neomycin, oral amoxicillin, or azithromycin. Outcomes included Achilles tendon rupture (ATR), Achilles tendinitis (AT), and all-type tendon rupture (ATTR). We applied an active comparator, new-user design with 1-year look-back and ceased follow-up at initiation of systemic steroids or oral quinolones, external injury, hospitalization, and after 35 days. We used trimmed stabilized inverse probability of treatment weights to balance comparison groups in a survival framework. Negative outcomes (clavicle fractures or sports injuries) were examined to rule out differences from varied physical activity (unmeasured confounding).

RESULTS

We examined 1 501 009 treated otitis episodes. Hazard ratios (HR) for OQ exposure associated with ATR were 4.49 (95% confidence interval [CI], 1.83-11.02), AT 1.04 (95% CI, 0.73-1.50), and ATTR 1.71 (95% CI, 1.21-2.41). Weighted risk differences (RD) per 100 000 episodes for OQ exposure were ATR 7.80 (95% CI, 0.72-14.89), AT 1.01 (95% CI, -12.80 to 14.81), and ATTR 18.57 (95% CI, 3.60-33.53). Corresponding HRs for clavicle fractures and sports injuries were HR,1.71 (95% CI, 0.55-5.27) and HR,1.45 (95% CI, 0.64-3.30), suggesting limited residual confounding.

CONCLUSIONS

OQ exposure may lead to systemic consequences. Clinicians should consider this potential risk and counsel patients accordingly. Risk factors and mechanisms for this rare, adverse effect deserve further evaluation. Mechanistic and other clinical studies are warranted to corroborate this finding.

Rotator Cuff Health, Pathology, and Repair in the Perspective of Hyperlipidemia

Rotator Cuff Injuries (RCI) are prevalent cause of shoulder pain affecting over 20% of the population in the USA. Surgical repair of the torn rotator cuff helps in relieving the pressure on the rotator cuff tendon and from symptoms, however tendon-to-bone healing after rotator cuff surgery still has a high failure rate. Hyperlipidemia has been strongly associated with RCI although the cellular and molecular mechanisms are largely unknown. The focus of this critical review is to further explore the role of hyperlipidemia in RCI and rotator cuff tissue repair to determine its implication as a risk factor for tears, repair, and retears. A literature review was conducted to elucidate the role of hyperlipidemia as an inflammatory mediator and catalyst for structural instability within the shoulder. The results from various studies were critically reviewed to summarize the relationship between hyperlipidemia and rotator cuff pathology. Hyperlipidemia induces LDL-particle entrapment within the dense regular collagen of rotator cuff tendons resulting in foam cell aggregation and macrophage recruitment. Subsequent inflammatory pathways including the JAK2/STAT3 pathway and NLRP3 inflammasome pathway led to persistent inflammation and Extracellular Matrix (ECM) degradation within the rotator cuff. While arthroscopic repair remains the most common treatment modality, nonsurgical treatment including statins, vitamin D, and targeting miRNA are also of therapeutic benefit. Hyperlipidemia interferes with arthroscopic repairs by inducing inflammation and stiffness within tendons and increases the risk of retears. Most notably, targeting underlying mechanisms influencing inflammation has large therapeutic value as a novel treatment strategy for the management of rotator cuff pathology.

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.

Risk Factor Analysis for Predicting the Onset of Rotator Cuff Calcific Tendinitis Based on Artificial Intelligence

Background

Symptomatic rotator cuff calcific tendinitis (RCCT) is a common shoulder disorder, and approaches combined with artificial intelligence greatly facilitate the development of clinical practice. Current scarce knowledge of the onset suggests that clinicians may need to explore this disease thoroughly.

Methods

Clinical data were retrospectively collected from subjects diagnosed with RCCT at our institution within the period 2008 to 2020. A standardized questionnaire related to shoulder symptoms was completed in all cases, and standardized radiographs of both shoulders were extracted using a human-computer interactive electronic medical system (EMS) to clarify the clinical diagnosis of symptomatic RCCT. Based on the exclusion of asymptomatic subjects, risk factors in the baseline characteristics significantly associated with the onset of symptomatic RCCT were assessed via stepwise logistic regression analysis.

Results

Of the 1,967 consecutive subjects referred to our academic institution for shoulder discomfort, 237 were diagnosed with symptomatic RCCT (12.05%). The proportion of women and the prevalence of clinical comorbidities were significantly higher in the RCCT cohort than those in the non-RCCT cohort. Stepwise logistic regression analysis confirmed that female gender, hyperlipidemia, diabetes mellitus, and hypothyroidism were independent risk factors for the entire cohort. Stratified by gender, the study found a partial overlap of risk factors contributing to morbidity in men and women. Diagnosis of hyperlipidemia, diabetes mellitus, and hypothyroidism in male cases and diabetes mellitus in female cases were significantly associated with symptomatic RCCT.

Conclusion

Independent predictors of symptomatic RCCT are female, hyperlipidemia, diabetes mellitus, and hypothyroidism. Men diagnosed with hyperlipidemia, diabetes mellitus, and hypothyroidism are at high risk for symptomatic RCCT, while more medical attention is required for women with diabetes mellitus. Artificial intelligence offers pioneering innovations in the diagnosis and treatment of musculoskeletal disorders, and careful assessment through individualized risk stratification can help predict onset and targeted early stage treatment.

Inflammatory mechanisms linking obesity and tendinopathy

Chronic tendinopathy is a debilitating tendon disorder with disappointing treatment outcomes. This review focuses on the potential roles of chronic low-grade inflammation in promoting tendinopathy in obesity. A systematic literature search was performed to identify all clinical studies supporting the actions of obesity-associated inflammatory mediators in the development of tendinopathy. The mechanisms of obesity-induced chronic inflammation in adipose tissue are firstly reviewed. Common inflammatory mediators potentially linking obesity and the development of tendinopathy, and their association with mechanical overuse, are discussed, along with pre-clinical evidences and a systematic literature search on clinical studies. The potential contribution of local adipose tissues in the promotion of inflammation, pain and tendon degeneration is then discussed. The future research directions are proposed.

Translational potential statement

Better understanding of the roles of obesity-associated inflammatory mediators on tendons will clarify the pathophysiological drivers of tendinopathy in patients with obesity and identify possible treatment targets. Further studies on the mechanisms of obesity-induced chronic inflammation on tendon are a promising direction for the treatment of tendinopathy.

Cervical Spine Pathology Increases the Risk of Rotator Cuff Tear: A Population-Based Cohort Study

Background:

Patients with cervical radiculopathy typically present with shoulder pain and weakness; these symptoms are similar to those of rotator cuff disease. Studies investigating cervical spine pathology (CSP) as an independent risk factor for rotator cuff tear (RCT) are lacking in the literature.

Purpose:

To investigate the risk of RCT among patients with CSP who have undergone cervical diskectomy (CD) and to determine whether CD reduces this risk.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

The authors queried the Taiwan National Health Insurance Research Database for patients diagnosed with CSP between 2004 and 2008 and followed up until the end of 2010. A control cohort comprised patients without CSP who were age- and sex-matched in a 4-to-1 ratio with patients with CSP through propensity score matching. A Cox multivariate proportional hazards model was applied to analyze the risk factors for RCT. After adjustment for confounders, the authors calculated the hazard ratio (HR) and adjusted HR (aHR) between the study and control cohorts. The effects of CD on the risk of RCT were also analyzed.

Results:

The study included 3245 patients and 12,980 matched controls. A higher RCT incidence rate was found in the CSP cohort, with an aHR of 1.52 (95% CI, 1.22-1.89; P < .001). Patients with CSP who underwent CD had a risk of RCT similar to that of the controls, with an aHR of 1.65 (95% CI, 0.90-3.03; P > .05).

Conclusion:

Patients with CSP had a 1.52-fold higher risk of RCT than healthy controls. Patients with CSP with CD did not have a high risk of RCT, possibly indicating a protective effect of diskectomy against RCT.

Dyslipidemia Is Associated With Increased Risk of Achilles Tendon Disorders in Underweight Individuals to a Greater Extent Than Obese Individuals: A Nationwide, Population-Based, Longitudinal Cohort Study

BACKGROUND

The association between dyslipidemia and Achilles tendinopathy (AT) or Achilles tendon rupture (ATR) remains controversial, although some studies have examined this topic.

PURPOSE

To evaluate the correlation of dyslipidemia and the risk of AT or ATR, and its association with body mass index (BMI), by assessing data from a nationwide population-based cohort.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

We used the National Health Insurance database, which includes the entire population of the Republic of Korea, to evaluate participants in the National Health Screening Program between January 2009 and December 2010. Participants diagnosed with AT or ATR before December 31, 2017, were selected. The variables assessed were age, sex, frequency of high-intensity exercise per week, BMI, waist circumference, systolic blood pressure, and levels of low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and fasting blood glucose. Multivariate Cox proportional hazards regression was used for data analysis.

RESULTS

A total of 16,830,532 participants were included. Of these, 125,814 and 31,424 participants developed AT and ATR, respectively. A higher level of LDL-C was associated with an increased risk of AT (adjusted hazard ratio [HR], 1.16) and ATR (adjusted HR, 1.18). A slightly increased risk of AT was observed in participants with higher TG levels (adjusted HR, 1.03), whereas higher HDL-C level was associated with a slight risk reduction for AT (adjusted HR, 0.95). However, no significant association was observed between higher TG or HDL-C levels and ATR. In the underweight group (BMI <18.5 kg/m2), a higher LDL-C level was associated with an increased risk of AT and ATR by 37% and 116%, respectively, compared with lower LDL-C. Higher LDL-C level was associated with an increased risk of AT and ATR by 10% and 16%, respectively, in the obese group (BMI ≥25 kg/m2).

CONCLUSION

Dyslipidemia was related to the development of AT and ATR. The association of higher LDL-C levels with AT and ATR risk was more pronounced in underweight than in overweight and obese individuals.

Use of biologics in rotator cuff disorders: Current concept review

Poor tendon to bone healing following rotator cuff repair has led to the continued interest and investigation into biological augmentation. The biology of tendinopathy is not fully understood and consequently the availability of disease modifying therapeutic targets is limited. A ceiling of benefit has been reached by mechanical optimisation of rotator cuff repair and thus, in order to improve healing rates, a biological solution is required. This review focuses on the strategies to biologically augment rotator cuff disorders with an emphasis on rotator cuff repair. Leucocyte rich platelet rich plasma has been shown to improve healing rates without clinically relevant improvements in outcome scores. Similarly, improved healing rates have also been reported with bone marrow stimulation and in long-term follow-up with bone marrow concentrate. Extracellular matrix (ECM) and synthetic scaffolds can increase healing through mechanical and or biological augmentation. A potential third category of scaffold is bio-inductive and has no mechanical support. Studies involving various scaffolds have shown promising results for augmentation of large to massive tears and is likely to be most beneficial when tendon quality is poor, however level I evidence is limited.

Does diabetes mellitus predispose to both rotator cuff surgery and subsequent failure?

Background

Diabetes mellitus (DM) may be associated with the etiology of rotator cuff disease; however, its effect on healing after surgical rotator cuff repair (RCR) is not well characterized. The purposes of this study are to analyze the association between DM and surgical RCR, the association between DM and revision RCR after RCR, and the association between DM and the cost of RCR.

Methods

A retrospective analysis of claims data of privately and publicly insured subjects from the Truven Health MarketScan database from 2008 to 2017 was conducted, collecting RCR cases and controls matched for age, sex, year of RCR, and first and last year in the database. Multivariable logistic regression models were used to compare DM incidence within the RCR and control groups after adjusting for all matching variables plus region, insurance plan type, tobacco use, and Charlson comorbidity index (CCI). Cox proportional hazard models were used to compare rates of revision RCR between DM and non-DM groups after adjusting for patient age, sex, year of RCR, plan type, and CCI. Generalized estimating equations were used to analyze RCR cost, and exponentiated regression coefficients were reported to represent cost ratios.

Results

The full analysis cohort consisted of 292,666 RCR cases and matched controls. The adjusted odds of having RCR surgery in diabetic patients was 48% higher (odds ratio = 1.48 [95% confidence interval {CI} 1.46 to 1.51], P < .001) than nondiabetics. DM was not significantly associated with revision RCR after RCR when adjusting for age, sex, region, plan type, tobacco use, year of RCR, and CCI (hazard ratio = 1.03, 95% CI 0.99 to 1.07, P = .17). Diabetes was associated with a higher cost of RCR by 3% (ratio = 1.03, 95% CI 1.02 to 1.03, P < .001).

Conclusions

Diabetic patients are at a higher risk of undergoing RCR surgery; however, there is no association between DM and subsequent rotator cuff revision surgery.

Hyperlipidemia Is a Risk Factor of Adhesive Capsulitis: Real-World Evidence Using the Taiwanese National Health Insurance Research Database

Background:

Patients with adhesive capsulitis are evaluated for pain and progressive contracture of the glenohumeral joint. Whether endocrine, immune, or inflammatory processes are involved in its definite pathogenesis is still under debate. Some cross-sectional studies with a small sample size have noted that hyperlipidemia is a possible risk factor for frozen shoulders.

Purpose/Hypothesis:

The purpose was to conduct a longitudinal population-based study to investigate the risk of adhesive capsulitis among patients with hyperlipidemia. It was hypothesized that patients with hyperlipidemia would have a higher risk of adhesive capsulitis and that the use of statin drugs could reduce the rate.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Using data from the National Health Insurance Research Database (NHIRD) of Taiwan, the authors obtained the records of patients with hyperlipidemia who received a diagnosis between 2004 and 2005 and were followed up until the end of 2010. The control cohort comprised age- and sex-matched patients without hyperlipidemia. Propensity score matching was performed for the other comorbidities. A Cox multivariate proportional hazards model was applied to analyze the risk factors of adhesive capsulitis. The hazard ratio (HR) and adjusted HR were estimated between the study and control cohorts after adjustment for confounders. The effects of statin use on adhesive capsulitis risk were also analyzed.

Results:

The NHIRD records of 28,748 patients and 114,992 propensity score–matched controls were evaluated. A higher incidence rate of adhesive capsulitis was revealed in the hyperlipidemia cohort, with a crude HR of 1.70 (95% CI, 1.61-1.79; P < .001) and adjusted HR of 1.50 (95% CI, 1.41-1.59; P < .001). Patients with hyperlipidemia who used a statin still had higher crude and adjusted HRs compared with controls. Statin use did not exert protective effects on patients with hyperlipidemia.

Conclusion:

Patients with hyperlipidemia had a 1.5-fold higher risk of adhesive capsulitis than did healthy controls. Statin use did not provide protection against adhesive capsulitis in patients with hyperlipidemia.

Rotator Cuff Retears

» Regardless of recent advances in rotator cuff repair techniques, the rate of unhealed or recurrent rotator cuff tears remains high, with most recurrent rotator cuff tears occurring within the first 6 months after surgery. » Factors that can negatively affect tendon healing include older age, greater tear size, tendon retraction, and fatty infiltration. However, several clinical features that are often underestimated, including osteoporosis, diabetes, smoking, and hyperlipidemia, have proven to have an important influence on rotator cuff healing. » Recent meta-analyses that evaluated studies with Level-I and Level-II evidence have shown an overall increase in retear rates after single-row repair compared with double-row repair. However, to our knowledge, there are no Level-I clinical studies comparing different double-row configurations and, to date, no double-row repair technique has proven to be superior to the others. » The influence of postoperative rotator cuff healing on clinical outcomes is controversial. Although clinical differences may not be apparent in the short term, healed tendons have had better functional outcomes and greater strength in the midterm. » In general, a period of immobilization for 2 to 4 weeks, depending on tear size, is recommended. Graded supervised rehabilitation has proven to facilitate tendon healing without associated stiffness compared with early unprotected range of motion.

Interactive associations of sex and hyperlipidemia with calcific tendinitis of the shoulder in Taiwanese adults

Calcific tendinitis (CT) of the shoulder is a painful disorder usually identified in individuals aged 40 and 60 years. The estimated global prevalence of CT is 2.7% to 36%. We examined the association of hyperlipidemia and sex with CT of the shoulder using Taiwan Biobank (TWB) and the National Health Insurance Research Database (NHIRD).Data were available for 9903 TWB participants who were recruited between 2008 and 2015. We used multiple logistic regression analysis to estimate the odds ratios (OR) and 95% confidence intervals (CI) for CT of the shoulder.Overall, 1564 women, and 1491 men were identified with hyperlipidemia. Women, compared to men, had higher odds of CT of the shoulder (OR, 1.53; 95% CI, 1.08-2.16). Hyperlipidemia, compared to no hyperlipidemia, was associated with an increased risk of CT (OR, 1.40; 95% CI, 1.02-1.93). The test for interaction was significant for sex and hyperlipidemia (P = .006). After stratification, the odds ratio for CT was 1.95 (95% CI, 1.30-2.92) in women and 0.82 (95% CI, 0.48-1.39) in men, respectively. Compared to men with no hyperlipidemia, the odds ratio was 0.86 (95% CI, 0.53-1.38) for men with hyperlipidemia and 2.00 (95% CI, 1.29-3.10) for women with hyperlipidemia.Importantly, our findings indicated that the risk for CT of the shoulder was higher among Taiwanese women with hyperlipidemia. However, CT risk among their male counterparts with hyperlipidemia was not significant.

Effects of a Thermosensitive Antiadhesive Agent on Single-Row Arthroscopic Rotator Cuff Repair

BACKGROUND

Postoperative stiffness after rotator cuff repair is a common complication that can lead to poor outcomes and patient discomfort. The application of an antiadhesive agent at the time of repair recently became an option for clinicians, but little information is available on its effects.

PURPOSE

To evaluate and compare retear rates, the incidence of postoperative stiffness, and the clinical outcomes of patients who underwent cuff repair with or without the application of an antiadhesive agent.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Among 296 patients who underwent arthroscopic rotator cuff repair surgery, we compared the outcomes of those injected with a thermosensitive gel antiadhesive agent into the subacromial space (112 cases) versus noninjected controls (184 cases). Retear rates in the 2 groups were determined by magnetic resonance imaging at 1 year after surgery. Shoulder joint range of motion and functional scores were evaluated serially.

RESULTS

The rate of retear was significantly lower in the injection group (20/112 cases; 17.9%) than the control group (53/184 cases; 28.8%) (P = .034). Postoperative stiffness was not significantly different between the 2 groups (P = .710). Among the data regarding range of motion, only forward flexion at 6 months after surgery showed superior results in the injection group. Functional scores showed conflicting results: The control group had better visual analog scale scores for pain (injection vs control: 2.17 vs 1.68 at 6 months; 1.82 vs 1.28 at 12 months), American Shoulder and Elbow Surgeons scores (79.89 vs 89.64 at 12 months), and simple shoulder test scores (8.70 vs 10.06 at 12 months), whereas the injection group had better Constant-Murley scores (injection vs control: 59.49 vs 55.60 at 3 months; 77.35 vs 71.98 at 6 months; 87.28 vs 81.56 at 12 months).

CONCLUSION

The tendon healing rate was significantly higher in the group receiving an antiadhesive agent than in the control group. No intergroup difference was seen in the occurrence of postoperative stiffness. However, the pain-related functional score showed inferior results in the injection group at 12 months. The biological action of antiadhesive agents in rotator cuff repair should be further evaluated.

Effectiveness of isometric exercise in the management of tendinopathy: a systematic review and meta-analysis of randomised trials

Objective

To systematically review and critically appraise the literature on the effectiveness of isometric exercise in comparison with other treatment strategies or no treatment in tendinopathy.

Design

A systematic review and meta-analysis of randomised controlled trials.

Data sources

Electronic searches of Medline, Cumulative Index to Nursing and Allied Health Literature, EMBASE and Cochrane were undertaken from inception to May 2020.

Methods

Overall quality of each study was determined based on a combined assessment of internal validity, external validity and precision. For each outcome measure, level of evidence was rated based on the system by van Tulder et al.

Results

Ten studies were identified and included in the review, including participants with patellar (n=4), rotator cuff (n=2), lateral elbow (n=2), Achilles (n=1) and gluteal (n=1) tendinopathies. Three were of good and seven were of poor overall quality. Based on limited evidence (level 3), isometric exercise was not superior to isotonic exercise for chronic tendinopathy either immediately following treatment or in the short term (≤12 weeks) for any of the investigated outcome measures. Additionally, for acute rotator cuff tendinopathy, isometric exercise appears to be no more effective than ice therapy in the short term (limited evidence; level 3).

Summary

Isometric exercise does not appear to be superior to isotonic exercise in the management of chronic tendinopathy. The response to isometric exercise is variable both within and across tendinopathy populations. Isometric exercise can be used as part of a progressive loading programme as it may be beneficial for selected individuals.

PROSPERO registration number

CRD42019147179.

Dyslipidemia With Perioperative Statin Usage Is Not Associated With Poorer 24-Month Functional Outcomes After Arthroscopic Rotator Cuff Surgery

BACKGROUND

Current literature suggests a higher rate of rotator cuff disease development in patients with dyslipidemia (DL). Moderate to high levels of DL are associated with higher rates of retear and revision surgery after arthroscopic rotator cuff repair. Statins protect against development of rotator cuff disease and mitigate the need for rotator cuff repair.

PURPOSE

We aimed to investigate the influence of DL and statin use on postoperative functional outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Between 2010 and 2016, 266 patients underwent arthroscopic double-row rotator cuff repair for atraumatic full-thickness tears. Evaluation was conducted preoperatively and at 3, 6, 12, and 24 months postoperatively. Three functional outcome measures were used (Constant Shoulder Score [CSS], Oxford Shoulder Score [OXF], and University of California, Los Angeles, Shoulder Rating Scale [UCLASS]), as well as a visual analog scale (VAS) for pain. DL and non-DL were classified through screening of health and assessment of lipid levels within 6 months of surgery (triglycerides, total cholesterol, low-density lipoprotein, and high-density lipoprotein). Patients with DL were divided into statin users and nonusers. Types and dosages of statins were recorded, and intensity and equivalency charts were employed for standardization. Mann-Whitney U test and Pearson chi-square test were used for analysis. Generalized estimating equations and linear mixed models were used to examine the influence of DL and statin dosage, respectively on percentage change of postoperative outcome scores.

RESULTS

Increased age was associated with a higher incidence of DL (P < .001), and 86% of the DL group was taking statins. The DL group also exhibited poorer scores preoperatively (CSS, P = .001; OXF, P = .032). No significant difference in scores was elicited between the DL and non-DL groups at 24 months. However, patients with DL experienced greater percentage improvement of CSS and OXF from preoperative baseline than did patients without DL (P = .008 and P = .034, respectively) at 24 months. There was no significant difference in 24-month functional outcomes between statin users and nonusers. No statistically significant change of CSS; OXF; UCLASS; or VAS was noted with increasing statin doses at 24 months.

CONCLUSION

Patients with DL with perioperative statin usage did not have poorer 24-month functional outcomes after arthroscopic rotator cuff surgery compared with those in patients without DL.

Factors Related to Symptomatic Failed Rotator Cuff Repair Leading to Revision Surgeries After Primary Arthroscopic Surgery

PURPOSE

To evaluate the clinical characteristics of patients with symptomatic failed rotator cuff repair who required revision surgeries and to identify clinical and radiologic factors related to the need for revision surgery.

METHODS

Ninety-eight patients who were diagnosed with rotator cuff retear within 2 years after primary arthroscopic surgery were included. Patients were divided into 2 groups: patients who underwent revision surgery within 2 years postoperatively (44 patients, group I) and patients who did not require additional treatment due to minimal discomfort during the same period (54 patients, group II). Demographic and radiographic factors related to cuff healing were analyzed. Univariate and multivariate analyses were performed to evaluate factors related to revision surgery.

RESULTS

Group I showed significantly inferior clinical outcomes at the time of revision compared to group II (American Shoulder and Elbow Surgeons score; 54.0 ± 12.1 vs 86.5 ± 12.2, Constant score; 65.2 ± 10.8 vs 84.0 ± 11.4, P < .001). Total cholesterol level (210.2 ± 40.0 vs 189.7 ± 39.1, P = .012), low-density lipoprotein level (130.7 ± 28.7 vs 115.5 ± 26.9, P = .008), and fatty infiltration of the infraspinatus (20.5% vs 3.7%, P = .011) were significantly greater in group I than in group II. On postoperative magnetic resonance imaging, retear of the infraspinatus tendon occurred significantly more frequently in group I (81.8%) than in group II (37.0%, P < .001). In group I, relative changes in anteroposterior (AP) (19.2 ± 37.8) and mediolateral retear size (29.6 ± 90.7) were significantly greater than in group II (AP; -39.5 ± 19.2, mediolateral; -29.2 ± 26.8, P < .001). Relative change in AP retear size was the most powerful independent predictor of symptomatic failed rotator cuff repair (odds ratio 1.19, confidence interval 1.08-1.31, P < .001).

CONCLUSIONS

Preoperative serum total cholesterol level, low-density lipoprotein levels, and fatty infiltration of the infraspinatus were significantly related to symptomatic failed rotator cuff repair. Relative change in AP retear size was the most powerful independent predictor of symptomatic failed rotator cuff repair.

LEVEL OF EVIDENCE

Level III, Case-control study.

Seven Key Themes in Physical Therapy Advice for Patients Living With Subacromial Shoulder Pain: A Scoping Review

OBJECTIVE

To systematically scope the reported advice and education in physical therapy management of patients with subacromial shoulder pain, and to define key themes of the advice and education.

DESIGN

Scoping review.

LITERATURE SEARCH

We searched MEDLINE, Scopus, Web of Science, and CINAHL, with publication dates from 2007 to September 2019.

STUDY SELECTION CRITERIA

We included quantitative and qualitative research that reported on physical therapy interventions for subacromial shoulder pain.

DATA SYNTHESIS

We performed a qualitative synthesis that identified items included in patient advice and education.

RESULTS

Of 89 original studies included, there were 61 randomized controlled trials; 5 prospective studies; 16 nonrandomized observational intervention studies or case series; and 7 surveys, audits of physical therapy patient records, and focus groups with physical therapists. We identified 7 key themes for advice and education: exercise intensity and pain response, activity modification advice, posture advice, pain self-management advice, pathoanatomical and diagnosis information, behavioral approaches, and pain biology advice.

CONCLUSION

While advice focused predominantly on the local tissue pathology model, 10% of studies included information about pain neuroscience education, psychosocial factors, motor imagery, or behavior change. J Orthop Sports Phys Ther 2020;50(6):285-293. doi:10.2519/jospt.2020.9152.

Partial thickness rotator cuff tears: Patient demographics and surgical trends within a large insurance database

Introduction

Partial thickness rotator cuff tears (PTRCT) are a common injury reported in 13-32% of the population, yet most of the current literature focuses on full thickness rotator cuff tears. Therefore, the purpose of this study was to analyze trends among patients with PTRCT including: (1) demographics; (2) comorbidities; (3) cost of care; (4) setting of initial diagnosis; and (5) change in incidence of PTRCT or surgical approach over time.

Methods

A Medicare patient-population consisting of 44 million lives was retrospectively analyzed from 2007 to 2017 using International Classification of Disease, 9th Revision (ICD-9) codes. Patients were identified for PTRCT using ICD-9 code: 726.13. The query yielded a total of 44,978 patients all of which had been previously diagnosed with PTRCT. Primary trends analyzed included: demographics, comorbidities, cost of care, initial setting of diagnosis, and change in incidence of PTRCT or surgical approach over time.

Results

PTRCTs and surgical repair of PTRCTs were most common in patients ages 65 to 69 and least common in patients who were 85 and older. Incidence of PTRCT was greater in females (54.12%) than males (45.88%). Comorbidities found within the population included hypertension, hyperlipidemia, diabetes mellitus, tobacco use, obesity, rheumatoid arthritis, and osteoarthritis of the shoulder. The average cost per episode of care totaled $9,923.26. PTRCTs were most commonly diagnosed in patients who resided in assisted living facilities (n = 27,106), making up 60% of the patient population. Reported incidence of PTRCT has increased substantially along with the surgical repair of PTRCT.

Conclusion

Reported cases of PTRCT and its surgical repair have both increased substantially over time. Approximately 11.70% of patients with PTRCT undergo either open or arthroscopic procedure as a means of surgical repair. With the growing popularity of arthroscopic procedures for rotator cuff repair, further investigation should be performed to analyze trends and risk factors for PTRCT, a seemingly underrepresented orthopedic condition.