Diabetes mellitus impairs tendon-bone healing after rotator cuff repair

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

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

Metabolic Syndrome and Tendon Disease: A Comprehensive Review

Metabolic syndrome (MS) is a multifaceted pathological condition characterized by the atypical accumulation of various metabolic components such as central obesity or excess weight, hyperlipidemia, low-density lipoprotein (LDL), hypertension, and insulin resistance. Recently, MS has been recognized as a notable contributor to heart and circulatory diseases. In addition, with increasing research, the impact of MS on tendon repair and disease has gradually emerged. Recent studies have investigated the relationship between tendon healing and diseases such as diabetes, dyslipidemia, obesity, and other metabolic disorders. However, diabetes mellitus (DM), hypercholesterolemia, obesity, and various metabolic disorders often coexist and together constitute MS. At present, insulin resistance is considered the major pathological mechanism underlying MS, central obesity is regarded as the predominant factor responsible for it, and dyslipidemia and other metabolic diseases are known as secondary contributors to MS. This review aims to evaluate the current literature regarding the impact of various pathological conditions in MS on tendon recovery and illness, and to present a comprehensive overview of the effects of MS on tendon recovery and diseases, along with the accompanying molecular mechanisms.

What are the Factors that Impact the Outcomes of Arthroscopic Rotator Cuff Repair?

BACKGROUND

The cuff is a complex structure with many factors affecting it. How much it is affected after repair is still being investigated.

AIM

The aim of this study was to analyze the functional results of individuals who received arthroscopic rotator cuff repair and assess the various factors that could impact these outcomes.

METHODS

The study included 57 patients with a mean age of 58.8 years (range: 39-71) who underwent arthroscopic rotator cuff repair between 2013 and 2020, with a minimum of 6 months after the operation. Functional and clinical outcomes of the patients were evaluated using preoperative and postoperative scores (QDASH, ASES, and VAS). The study also analyzed how demographic factors, type and duration of the tear, comorbidities such as diabetes mellitus (DM) and hypertension (HT), and other pathologies may have affected the patients' scores.

RESULTS

The effect of the operation on the scores in rotator cuff tears was highly significant (P < 0.05). Age, gender, tear size, fatty degeneration, anchor configuration, comorbidities, and additional procedures presented variable values on postoperative scores, but were not statistically significant. The effect of DM and HT on VAS scores was statistically significant (P < 0.05).

CONCLUSION

The results of rotator cuff repair appear to be influenced by several factors, including the sex of the patient, type and duration of tear, comorbidities, and surgical procedures used. Although these factors had an effect on the scores, they were not statistically significant.

Perioperative glycemic control reduces the risk of retear in diabetic patients following arthroscopic rotator cuff repair: A meta-analysis

BACKGROUND

Previous studies have associated diabetes with reduced shoulder motion, increased pain, and higher postoperative retear risk after arthroscopic rotator cuff repair (ARCR). However, the impact of glycemic control, measured by hemoglobin A1c (HbA1c) levels, on retear and revision rates after ARCR in diabetic patients remains unclear.

METHODS

This systematic review was conducted using the PubMed, Cochrane Library, Web of Science, and Embase databases according to the preferred reporting conventions for systematic reviews and meta-analyses. Only studies that compared retears and revisions in ARCR patients with documented HbA1c levels between controlled and uncontrolled diabetes groups were included. Relevant data were extracted and analyzed using STATA software. The methodological index for nonrandomized studies was employed to assess the risk of bias in the selected studies. Additionally, heterogeneity tests and sensitivity analyses were conducted to evaluate potential heterogeneity within the samples, and publication bias was also detected.

RESULTS

Six studies (4395 patients), including five retrospective cohort studies and one case‒control study, were included. Four of these studies assessed retears involving 253 patients. Lower HbA1c levels, indicating better glycemic control, were significantly associated with reduced retear rates after ARCR in diabetic patients (P = 0.000; odds ratio = 0.242, 95 % confidence interval: 0.128-0.454; I2 = 25 %). For revision evaluations, two studies, with a total of 4142 patients, found no significant difference in rates between controlled and uncontrolled diabetes groups, and no publication bias was detected.

CONCLUSION

Following ARCR in diabetic patients, effective glycemic control significantly reduces retear rates without affecting revisions, and maintaining glycemic control in the postoperative period may contribute to rotator cuff healing.

Elevated HbA1c is not associated with reoperation following arthroscopic rotator cuff repair in patients with diabetes mellitus

BACKGROUND

Hyperglycemia is a known risk factor for tendon degeneration due to oxidative stresses from production of advanced glycosylation end products. In patients with diabetes mellitus (DM), analysis of glycated hemoglobin (HbA1c) provides a 3-month window into a patient's glucose control. No guidelines exist for ideal preoperative HbA1c and glucose control prior to arthroscopic rotator cuff repair. This study evaluated if a critical HbA1c level is associated with reoperation following arthroscopic rotator cuff repair.

METHODS

We retrospectively evaluated patients with DM who underwent primary arthroscopic rotator cuff repair from January 2014 to December 2018 at a single institution. Patients required a preoperative HbA1c within 3 months of surgery. Medical records were queried to evaluate for reoperation and identify the subsequent procedures performed. Univariate statistical analysis was performed to assess factors associated with reoperation (P < .05 considered significant). Threshold, area under the curve (AUC), analysis was performed to assess if a critical HbA1c value was associated with reoperation.

RESULTS

A total of 402 patients met inclusion criteria. Patients had an average age of 65.5 years (range 40-89) at time of surgery; 244 (60.6%) patients were male; and average body mass index was 32.96 ± 5.81. Mean HbA1c was 7.36 (range 5.2-12). Thirty-three patients (8.2%) underwent subsequent reoperation. Six patients (1.5%) underwent capsular release and lysis of adhesions, 20 patients (5.0%) underwent a revision rotator cuff surgery, combination revision rotator cuff repair and lysis of adhesions, graft-augmented revision repair, or superior capsular reconstruction, and 7 patients (1.7%) underwent revision to reverse shoulder arthroplasty (1.7%). There were no cases of reoperation for infection. On AUC analysis, no critical HbA1c value was identified to predispose to reoperation. Interestingly, elevated preoperative American Society of Anesthesiologists (ASA) physical status classification score (2.8 vs. 2.28, P = .001) was associated with a higher reoperation rate.

DISCUSSION

In patients with DM, preoperative HbA1c is not a predictive factor for surgical failure requiring reoperation. Stable glycemic control is important to a patient's overall health and may play a role in minimizing postoperative medical complications, but an elevated preoperative HbA1c should not be a strict surgical contraindication for arthroscopic rotator cuff repair. In patients with DM, an elevated ASA score is associated with an increased rate of subsequent reoperation; diabetic patients should be counseled accordingly.

Analysis of differentially expressed genes in torn rotator cuff tendon tissues in diabetic patients through RNA-sequencing

BACKGROUND

Rotator cuff tears (RCT) is a common musculoskeletal disorder in the shoulder which cause pain and functional disability. Diabetes mellitus (DM) is characterized by impaired ability of producing or responding to insulin and has been reported to act as a risk factor of the progression of rotator cuff tendinopathy and tear. Long non-coding RNAs (lncRNAs) are involved in the development of various diseases, but little is known about their potential roles involved in RCT of diabetic patients.

METHODS

RNA-Sequencing (RNA-Seq) was used in this study to profile differentially expressed lncRNAs and mRNAs in RCT samples between 3 diabetic and 3 nondiabetic patients. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis were performed to annotate the function of the differentially expressed genes (DEGs). LncRNA-mRNA co-expression network and competing endogenous RNA (ceRNA) network were constructed to elucidate the potential molecular mechanisms of DM affecting RCT.

RESULTS

In total, 505 lncRNAs and 388 mRNAs were detected to be differentially expressed in RCT samples between diabetic and nondiabetic patients. GO functional analysis indicated that related lncRNAs and mRNAs were involved in metabolic process, immune system process and others. KEGG pathway analysis indicated that related mRNAs were involved in ferroptosis, PI3K-Akt signaling pathway, Wnt signaling pathway, JAK-STAT signaling pathway and IL-17 signaling pathway and others. LncRNA-mRNA co-expression network was constructed, and ceRNA network showed the interaction of differentially expressed RNAs, comprising 5 lncRNAs, 2 mRNAs, and 142 miRNAs. TF regulation analysis revealed that STAT affected the progression of RCT by regulating the apoptosis pathway in diabetic patients.

CONCLUSIONS

We preliminarily dissected the differential expression profile of lncRNAs and mRNAs in torn rotator cuff tendon between diabetic and nondiabetic patients. And the bioinformatic analysis suggested some important RNAs and signaling pathways regarding inflammation and apoptosis were involved in diabetic RCT. Our findings offer a new perspective on the association between DM and progression of RCT.

Is preoperative elevated glycated hemoglobin (HbA1c) a risk factor for postoperative shoulder stiffness after posterior-superior rotator cuff repair?

Background

Postoperative shoulder stiffness (POSS) affects a large number of patients undergoing rotator cuff repair (RCR). Diabetes may increase the risk of POSS. Preoperative glycated hemoglobin (HbA1c) is a convenient measure of glucose control in this group. The aim of the present study was to determine a relationship between preoperative HbA1c and POSS in patients undergoing postero-superior RCR.

Methods

Two hundred fifty patients with full-thickness postero-superior rotator cuffs who underwent RCR were followed for 6 months. Pre- and post-operative external rotation with arm by the side at 3 and 6 months were measured. Patient demographics, tear characteristics, preoperative HbA1c level, and surgical details were recorded. Patients with subscapularis tears, concomitant instability, partial thickness tears, arthritis, and irreparable rotator cuff tears were excluded. Univariate and multivariate logistic regression were used to determine the association between patient characteristics and POSS at 6 months.

Results

At the end of 6 months, 16% (41/250) of patients had POSS. Multivariate analysis demonstrated an elevated preoperative HbA1c level was a statistically significant predictor of POSS at 6 months (odds ratio 7.04, P < .01) after posterior superior RCR. Lower preoperative external rotation (P = .02) and female sex (P < .01) were also risk factors associated with POSS. Age, hand dominance, worker's compensation claim status, etiology, and size of the tear, surgical technique, and additional treatments were not statistically significant predictors.

Conclusion

Elevated preoperative HbA1c level is associated with POSS after RCR. Measuring HbA1c preoperatively may assist clinicians to identify patients at risk of POSS. HbA1c is a modifiable parameter that could then be optimized preoperatively in order to improve outcomes.

Acidosis induces significant changes to the murine supraspinatus enthesis organic matrix

Rotator cuff pathology is a common musculoskeletal condition that disproportionately affects older adults, as well as patients with diabetes mellitus and chronic kidney disease. It is known that increased age and kidney dysfunction have been correlated to acidotic states, which may be related to the increased incidence of rotator cuff injury. In order to investigate the potential relationship between acidosis and rotator cuff composition and mechanics, this study utilizes a 14-day murine model of metabolic acidosis and examines the effects on the supraspinatus tendon-humeral head attachment complex. The elastic matrix in the enthesis exhibited significant changes beginning at day 3 of acidosis exposure. At day 3 and day 7 timepoints, there was a decrease in collagen content seen in both mineralized and unmineralized tissue as well as a decrease in mineral:matrix ratio. There is also evidence of both mineral dissolution and reprecipitation as buffering ions continually promote pH homeostasis. Mechanical properties of the tendon-to-bone attachment were studied; however, no significant changes were elicited in this 14-day model of acidosis. These findings suggest that acidosis can result in significant changes in enthesis composition over the course of 14 days; however, enthesis mechanics may be more structurally mediated rather than affected by compositional changes.

Associations of normal fasting glucose levels and of insulin resistance with degenerative rotator cuff tear : Normoglycemia and rotator cuff tear

BACKGROUND

The upper normoglycemic range has been proposed as a risk factor for degenerative rotator cuff tendon tear (RCT), and insulin resistance has been suggested as a risk factor for tendinopathy. However, no research has established their association with degenerative RCT in the general population. This study aimed to determine whether fasting glucose levels and insulin resistance are risk factors for degenerative RCT in the normoglycemic population and identify the risk range for fasting glucose.

METHODS

This study included 418 normoglycemic participants from a rural cohort. Participants completed questionnaires, physical exams, blood tests, and MRI evaluations of both shoulders. Insulin resistance was assessed using a triglyceride/high-density-lipoprotein (TG/HDL) ≥ 3.5. Logistic regression analysis was used to determine the association between fasting glucose level, TG/HDL ≥ 3.5, and other factors and degenerative RCT. The study calculated the areas under the receiver operating characteristic curve (AUC) to determine the more appropriate predicting value between the scale and categorical values of fasting glucose levels, and compared the AUCs using the DeLong method.

RESULTS

In the multivariable analyses, both scale and categorical values of fasting glucose levels, and TG/HDL ≥ 3.5 were significantly associated with degenerative RCT. Fasting glucose levels ≥ 90.5 mg/dL (OR: 3.87, 95% CI: 2.10-7.06) in scale value and 90-99 mg/dL (OR: 4.13, 95% CI: 2.87-8.12) in categorical value were significantly associated with degenerative RCT (P < .001). The AUC of the scale value of fasting glucose levels ≥ 90.5 mg/dL was 0.68. The AUC of the categorical value of fasting glucose levels of 90-99 mg/dL was 0.70. Because of the significantly larger AUC of the categorical value of fasting glucose levels of 90-99 mg/dL, those fasting glucose levels were determined to be independently associated with degenerative RCT (P < .001).

CONCLUSIONS

High fasting glucose levels within the normal range may link to increase insulin resistance and risk of degenerative RCT. Normoglycemic levels of 90-99 mg/dL and insulin resistance may be risk factors for degenerative RCT.

LEVEL OF EVIDENCE

Level III, prognostic study.

Glycolipotoxicity conferred tendinopathy through ferroptosis dictation of tendon-derived stem cells by YAP activation

Tendinopathy is a condition characterized by chronic, complex, and multidimensional pathological changes in the tendons. The etiology of tendinopathy is the combination of several factors, and diabetes mellitus (DM) is a risk factor. Increasing evidence has shown that the diabetic microenvironment plays an important role in tendinopathy. However, the mechanism causing tendinopathy in patients with DM remains unclear. Our study found that ferroptosis played an important role in tendinopathy in patients with DM. In vitro, high glucose and high fat treatment was used to simulate the DM microenvironment. Results showed that such a mechanism significantly increased ferroptosis, which was characterized by mass cell death, lipid peroxide accumulation, mitochondrial morphological changes, mitochondrial membrane potential decline, iron overload, and the activation of ferroptosis-related genes, in tendon-derived stem cells cultured in vitro. In the animal studies, db/db mice were used in the DM model, and the db mice had severe tendon injury and high ACSL4 and TfR1 expressions. These phenomena could be alleviated by the ferroptosis inhibitor ferrostatin-1. In conclusion, ferroptosis is associated with tendinopathy in patients with DM, and ferroptosis targeting may be a novel approach for treating diabetic tendinopathy. Our results can provide a new strategy for managing tendinopathy clinically in patients with DM.

Preoperative factors affecting the quality of life after arthroscopic rotator cuff repair: a prospective study

Background

Rotator cuff tears are well known to cause significant pain and disability, having a marked impact on an individual's quality of life. This prospective study aimed to analyze the various patient factors and their impact on health-related quality of life (HrQoL) post arthroscopic rotator cuff repair (RCR).

Material and Methods

We prospectively analyzed 95 patients at one year and 81 patients at two years, with complete rotator cuff tear, who underwent arthroscopic repair of the same. The 36-Item Short Form Survey (physical and mental component score), visual analog scale (pain, function), and QuickDASH questionnaires were administered to all the patients preoperatively and at one- and two-year follow-ups. Relationships between various patient factors (age, gender, side, duration of symptoms, pseudoparalysis, diabetes mellitus [DM], type, and size of tear) and outcome measures were analyzed.

Results

All outcome parameters showed significant improvement at one- and two-year follow-ups. Patient factors, such as gender, tear type (traumatic vs degenerative), and DM, affected all outcome parameters and were significant even in the regression analysis model at a 2-year follow-up. Factors such as age and symptoms duration were significant only at 1-year follow-up, with older age and patients with symptoms > 6 weeks showing more disability. Side (dominant or nondominant), tear size, and pseudoparalysis do not affect outcomes.

Conclusions

This study showed that arthroscopic RCR significantly improved HrQoL post arthroscopic RCRs. Factors independently affecting HrQoL were noted as gender, tear type, and DM. On the other hand, age, side involved, duration of symptoms, pseudoparalysis, and tear size had no independent effect on HrQoL at a two-year follow-up.

Biological approaches to the repair and regeneration of the rotator cuff tendon-bone enthesis: a literature review

Entheses are highly specialised organs connecting ligaments and tendons to bones, facilitating force transmission, and providing mechanical strengths to absorb forces encountered. Two types of entheses, fibrocartilaginous and fibrous, exist in interfaces. The gradual fibrocartilaginous type is in rotator cuff tendons and is more frequently injured due to the poor healing capacity that leads to loss of the original structural and biomechanical properties and is attributed to the high prevalence of retears. Fluctuating methodologies and outcomes of biological approaches are challenges to overcome for them to be routinely used in clinics. Therefore, stratifying the existing literature according to different categories (chronicity, extent of tear, and studied population) would effectively guide repair approaches. This literature review supports tissue engineering approaches to promote rotator cuff enthesis healing employing cells, growth factors, and scaffolds period. Outcomes suggest its promising role in animal studies as well as some clinical trials and that combination therapies are more beneficial than individualized ones. It then highlights the importance of tailoring interventions according to the tear extent, chronicity, and the population being treated. Contributing factors such as loading, deficiencies, and lifestyle habits should also be taken into consideration. Optimum results can be achieved if biological, mechanical, and environmental factors are approached. It is challenging to determine whether variations are due to the interventions themselves, the animal models, loading regimen, materials, or tear mechanisms. Future research should focus on tailoring interventions for different categories to formulate protocols, which would best guide regenerative medicine decision making.

Postoperative HbA1c Level as a Predictor of Rotator Cuff Integrity After Arthroscopic Rotator Cuff Repair in Patients With Type 2 Diabetes

Background

In patients with type 2 diabetes mellitus (DM), preoperative glycosylated hemoglobin (HbA1c) is associated with outcomes after arthroscopic rotator cuff repair (ARCR); however, the relationship between outcomes and postoperative serum glycosylated hemoglobin (HbA1c) after ARCR has not been investigated.

Purpose

To evaluate outcomes after ARCR in patients (1) with and without DM and (2) with DM according to their pre- and postoperative HbA1c levels.

Study Design

Cohort study; Level of evidence, 3.

Method

Included in this study were 148 patients without DM and 35 patients with type 2 DM who underwent ARCR between January 1, 2017, and December 31, 2019. Clinical and radiological outcomes were evaluated preoperatively and at the latest clinical follow-up. Postoperative magnetic resonance imaging was performed after 12 months. In patients with type 2 DM, HbA1c levels were evaluated preoperatively as well as 6 and 12 months postoperatively; patients with an HbA1c level of ≥7% were defined as having uncontrolled DM. Multivariate logistic regression analyses were performed to determine the factors for retears after ARCR.

Results

The retear rates after ARCR were 22.9% (8/35) and 16.9% (25/148) in patients with and without DM, respectively. The retear rates were significantly higher in the 6-month postoperative uncontrolled DM group than in the controlled DM and non-DM groups (50% vs 8.7% and 16.8%; P < .05). The odds ratio for retears in the postoperative uncontrolled DM group was 5.555 (P =0.01) compared with the non-DM group. Among the patients with DM, in the uncontrolled DM group, 6-month postoperative hyperglycemia was superior in accuracy, sensitivity, and specificity for predicting retears after ARCR than preoperative hyperglycemia (77.1% vs 62.9%, 75% vs 37.5%, and 77.8% vs 70.4%, respectively).

Conclusion

This study demonstrated the association between uncontrolled postoperative DM and an increased risk of retears compared with no DM or controlled DM. Furthermore, postoperative HbA1c values were correlated more closely with the risk of retears than preoperative HbA1c values.

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.

Review of human supraspinatus tendon mechanics. Part II: tendon healing response and characterization of tendon health

Overuse injuries of the rotator cuff, particularly of the supraspinatus tendon (SST), are highly prevalent and debilitating in work, sport, and daily activities. Despite the clinical significance of these injuries, there remains a large degree of uncertainty regarding the pathophysiology of injury, optimal methods of nonoperative and operative repair, and how to adequately assess tendon injury and healing. The tendon response to fatigue damage resulting from overuse is different from that of acute rupture and results in either an adaptive (healing) or a maladaptive (degenerative) response. Factors associated with the degenerative response include increasing age, smoking, hypercholesterolemia, biological sex (variable by tendon), diabetes mellitus, and excessive load post fatigue damage. After injury, the average healing rate of tendon is approximately 1% per day and may be significantly influenced by biologic sex (females have lower collagen synthesis rates) and excessive load after damage. Although magnetic resonance imaging (MRI) is considered the gold standard in assessing acute tears as well as tendinopathic change in the SST, ultrasonography has proven to be a valuable tool to measure tendinopathic change in real time. Ultrasonography can determine multiple mechanical and structural parameters of the SST that are altered in fatigue loading. Thus, ultrasonography may be utilized to understand how these parameters change in response to SST overuse, and may aid in determining the activity level that places the SST at greater risk of rupture.

Arthritis Severity and Medical Comorbidities Are Prognostic of Worse Outcomes Following Arthroscopic Rotator Cuff Repair in Patients With Concomitant Glenohumeral Osteoarthritis

Purpose

To assess demographic factors, comorbidities, radiographic variables, and injury patterns as potential prognostic indicators of poor functional and patient-reported outcomes following arthroscopic rotator cuff repair in patients with concomitant glenohumeral osteoarthritis.

Methods

A retrospective review of consecutive patients with glenohumeral osteoarthritis who underwent arthroscopic supraspinatus repairs between 2013 and 2018 with a minimum of 1-year follow up was performed. Demographic variables included age, tobacco use, alcohol use, diabetes, sex, hypercholesterolemia, and body mass index while injury patterns included partial- versus full-thickness tear, bicep tendon involvement, and osteoarthritis severity. Multivariate linear regression was used to identify independent predictors of visual analog pain scale (VAS), subjective shoulder value (SSV), and American Shoulder and Elbow Surgeons (ASES) score as well as active range of motion (ROM) in forward flexion (FF) and external rotation (ER). Binary logistic regression was used to identify predictors of repair failure as well as postoperative strength in FF and ER.

Results

In total, 91 patients (mean age 61.48 ± 9.4 years) were identified with an average follow up of 26.3 ± 5.7 months. Repair failures occurred in 9.9% (9/91 patients) of the total cohort. Postoperative outcomes were significantly improved with regards to visual analog pain scale, subjective shoulder value, ASES score, ROM in FF, FF strength, and external rotation strength compared with preoperative baseline. Obesity (P = .023) and diabetes (P = .010) were significant independent predictors of greater pain scores postoperatively. Obesity (P = .029) and tobacco use (P = .007) were significant predictors of lower ASES scores postoperatively. Finally, moderate-to-severe osteoarthritis was a significant risk factor for poor ROM and strength in FF postoperatively compared to mild osteoarthritis (P = .029). No variables were predictive of repair failure.

Conclusions

Tobacco use, obesity, and diabetes are associated with worse pain and patient-reported outcomes following arthroscopic rotator cuff repair in the context of glenohumeral OA. In addition, moderate-to-severe OA is associated with worse strength and forward flexion compared to those with mild OA.

Level of Evidence

Level III, retrospective cohort study.

The relationship between clinical outcomes of arthroscopic rotator cuff repair and hemoglobin A1c

Background

The clinical outcomes of diabetic patients who underwent arthroscopic rotator cuff repair have been reported. However, few studies have focused on the relationship between these clinical outcomes and postoperative hemoglobin A1c. This study compared clinical outcomes of diabetic patients with a hemoglobin A1c < 7% to those with a hemoglobin A1c ≥ 7% at 12 months post-arthroscopic rotator cuff repair.

Methods

This retrospective study involved 51 consecutive patients who underwent arthroscopic rotator cuff repair from 2015 to 2020. Approximately 26 and 25 shoulders were assigned to a Low group (hemoglobin A1c < 7%) and High group (hemoglobin A1c ≥ 7%) at 12 months postoperatively, respectively. Patients with poorly controlled diabetes were preoperatively hospitalized for perioperative diabetic control. Clinical outcomes were shoulder range-of-motion, Constant Shoulder Score, and University of California, Los Angeles Score preoperatively and at 12 months postoperatively. Complications were also evaluated.

Results

Both groups showed significant improvement in their range-of-motion, Constant Shoulder Score, and University of California, Los Angeles score at 12 months post-arthroscopic rotator cuff repair (p < 0.05) except external rotation in High group. These improvements were significantly inferior in the High group compared to the Low group (Low/High group; 167.3 ± 7.7°/159.5 ± 16.3° for forward flexion; p = 0.013, 94.9 ± 7.6/90.1 ± 9.9 points for Constant Shoulder Score; p = 0.033, 32.6 ± 3.6/30.6 ± 4.1 points for University of California, Los Angeles score, p = 0.037). Hemoglobin A1c at 12 months postoperatively was also significantly inferior in the High group (Low/High group; 6.5 ± 0.3%/7.6 ± 0.8%; p < 0.05). The rate of rotator cuff retear was not significantly different between groups (Sugaya type4; p = 0.49, type5; p = 0.322) and there were no cases of infection or shoulder stiffness in either group.

Conclusion

Diabetic patients showed improvement of their range-of-motion and function after arthroscopic rotator cuff repair; however, patients with poorly controlled diabetes had significantly inferior improvement.

Evaluating the role of subacromial impingement in rotator cuff tendinopathy: development and analysis of a novel rat model

BACKGROUND

Subacromial impingement of the rotator cuff caused by variations in acromial anatomy or altered glenohumeral kinematics leads to inflammation and degeneration of the rotator cuff, ultimately contributing to the development of tendinopathy. However, the underlying cellular and molecular changes in the impinged tendon remain poorly understood. Because the rat is an accepted model for rotator cuff studies, we have developed a rat model to study rotator cuff tendinopathy.

METHODS

Forty-four adult male Sprague-Dawley rats were allocated to one of 4 study groups: intact control group (group 1, n = 11); bilateral subacromial surgical clip placement to induce supraspinatus impingement for 2 weeks (group 2, n = 11), 4 weeks (group 3, n = 11), and 8 weeks (group 4, n = 11). Bilateral shoulder specimens were harvested for biomechanical testing, histology, and quantitative real-time polymerase chain reaction (qRT-PCR) analysis.

RESULTS

Radiography confirmed that all microvascular clips remained in stable position in the subacromial space. Gross inspection of supraspinatus tendon specimens in the impingement groups revealed changes in tendon morphology at the enthesis and midsubstance. Biomechanical evaluation demonstrated decreased supraspinatus tendon failure force and tissue stiffness at all time points compared with control tendons. Semiquantitative scoring of histologic specimens demonstrated significant, persistent tendinopathic changes over 8 weeks. qRT-PCR analysis of impinged tendon specimens demonstrated upregulation of gene expression for Col3 and Mmp14 in the impingement groups compared with control groups. In muscle samples, significant upregulation was seen in the expression of genes that are commonly associated with muscle atrophy (MuRF1 and Ube2b) and fatty infiltration (Fabp4, Pparg2, and Klf15).

CONCLUSION

This new rat subacromial impingement model creates cellular and molecular changes consistent with the development of rotator cuff tendinopathy. The results of this study may serve as a baseline for future investigation.

Rotator Cuff Repair in Upper Extremity Ambulators: An Assessment of Longitudinal Outcomes

Background

Individuals who rely on wheelchairs, walkers, and crutches for ambulation have an increased incidence of rotator cuff tears due to altered shoulder biomechanics and increased force transmission across the shoulder joint. The purpose of our study is to review our longitudinal outcomes treating upper extremity ambulators to guide patient expectations and identify risk factors for rotator cuff repair failure.

Methods

A total of fifteen patients were included after a cohort of thirty-nine patients were identified. The mean age was 54.9 years at the time of index rotator cuff repair, with each patient requiring either wheelchair, cane, walker, or crutches for ambulation. Clinical outcomes were measured (strength, range of motion, and pain scores), and patient-reported outcome scores (American Shoulder and Elbow Surgeons, Simple Shoulder Test, and University of California Los Angeles functional shoulder assessment tool) were obtained. No follow-up imaging was obtained unless indicated by a change in clinical status.

Results

Within our cohort, 14 of 15 (93%) presented with supraspinatus tears, 7 of 15 (47%) with infraspinatus tears, and only 3 of 15 (20%) with subscapularis pathology. Additionally, the rates of concurrent biceps pathology or acromioclavicular joint pathology were significant at 53% and 73%, respectively. Only one patient in our cohort experienced known failure of cuff repair, despite longitudinal follow-up at an average of 97 months following surgery, however, routine follow-up imaging was not obtained. There were statistically significant improvements in visual analog scale pain scores, forward flexion ROM and strength, and abduction ROM. Additionally, statistically significant improvements were noted in all patient-reported outcome scores measured.

Conclusion

Despite the apparent risks associated in rotator cuff repair in upper extremity ambulators, these patients demonstrate clinically significant improvements following surgery. Appreciating additional pathology beyond the rotator cuff is important in formulating a treatment plan.

Descriptive transcriptome analysis of tendon derived fibroblasts following in-vitro exposure to advanced glycation end products

BACKGROUND

Tendon pathologies affect a large portion of people with diabetes. This high rate of tendon pain, injury, and disease appears to manifest independent of well-controlled HbA1c and fasting blood glucose. Advanced glycation end products (AGEs) are elevated in the serum of those with diabetes. In vitro, AGEs severely impact tendon fibroblast proliferation and mitochondrial function. However, the extent that AGEs impact the tendon cell transcriptome has not been evaluated.

OBJECTIVE

The purpose of this study was to investigate transcriptome-wide changes that occur to tendon-derived fibroblasts following treatment with AGEs. We propose to complete a descriptive approach to pathway profiling to broaden our mechanistic understanding of cell signaling events that may contribute to the development of tendon pathology.

METHODS

Rat Achilles tendon fibroblasts were treated with glycolaldehyde-derived AGEs (200μg/ml) for 48 hours in normal glucose (5.5mM) conditions. In addition, total RNA was isolated, and the PolyA+ library was sequenced.

RESULTS

We demonstrate that tendon fibroblasts treated with 200μg/ml of AGEs differentially express 2,159 gene targets compared to fibroblasts treated with an equal amount of BSA-Control. Additionally, we report in a descriptive and ranked fashion 21 implicated cell-signaling pathways.

CONCLUSION

Our findings suggest that AGEs disrupt the tendon fibroblast transcriptome on a large scale and that these pathways may contribute to the development and progression of diabetic tendinopathy. Specifically, pathways related to cell cycle progression and extracellular matrix remodeling were affected in our data set and may play a contributing role in the development of diabetic tendon complications.

Quercetin treatment protects the Achilles tendons of rats from oxidative stress induced by hyperglycemia

Background

Quercetin, a flavonoid abundantly in vegetables and fruits, exerts antioxidant and anti-inflammatory effects. We investigated the protective effects of quercetin against oxidative stress in the Achilles tendons of diabetic rats.

Methods

Cells were collected from the Achilles tendons of Sprague–Dawley rats and cultured under four conditions: regular glucose (RG) without quercetin (Quer-), RG with quercetin (Quer +), high-glucose (HG) Quer-, and HG Quer + . The expression of genes related to NADPH oxidase (NOX) and inflammation, reactive oxygen species accumulation, and apoptosis rates was analyzed. Additionally, diabetic rats were divided into two groups and subjected to quercetin (group Q) or no quercetin (group C) treatment. Histological evaluation and expression analysis of relevant genes in the Achilles tendon were performed.

Results

In rat tendon-derived cells, the expression of Nox1, Nox4, and Il6; reactive oxygen species accumulation; and apoptosis rates were significantly decreased by quercetin treatment in the HG group. The collagen fiber arrangement was significantly disorganized in the diabetic rat Achilles tendons in group C compared with that in group Q. The mRNA and protein expression levels of NOX1 and NOX4 were significantly decreased upon quercetin treatment. Furthermore, the expression of Il6, type III collagen, Mmp2, and Timp2 was significantly decreased, whereas that of type I collagen was significantly increased in group Q compared with that in group C.

Conclusions

Quercetin treatment decreases NOX expression and thus exerts antioxidant and anti-inflammatory effects in the Achilles tendons of diabetic rats. Quercetin treatment may be effective against diabetic tendinopathy.

Comparison of the Characteristics of Rotator Cuff Tissue in a Diabetic Rat Model

This study evaluated the biomechanical and histologic characteristics of the rotator cuff tendon and muscle tissue with rat models with diabetes mellitus (DM) (group 1) and 30 male rats without DM (group 2). We conducted a time zero study without any additional procedures or external variables at 9 weeks after induction of the diabetic rat model. Thereafter, quantitative evaluation of advanced glycation end products (AGEs) was accomplished via enzyme-linked immunosorbent assay and immunohistochemistry (IHC). Fatty infiltration was investigated with Oil Red O staining, and the peroxisome proliferator activated receptor-gamma (PPAR-gamma) value was studied with IHC. Grossly, the supraspinatus tendons of the group 1 rats were more friable and discolored (yellowish) than those of group 2. In the biomechanical analysis, group 1 rats showed significantly inferior ultimate failure load (P=.001) and ultimate stress (P=.02). Group 1 was significantly inferior to group 2 in terms of total histologic scoring (P<.001). Mean AGE levels were significantly higher in group 1 (P<.001), as determined by IHC. In evaluating fatty infiltration, the degree of Oil Red O staining was significantly higher in group 1 (P<.001), but there was no significant difference in PPAR-gamma value between the 2 groups (P=.14). The intact rotator cuffs of rats with DM were associated with inferior biomechanics in association with AGE accumulation and increased fatty infiltration, as confirmed by histologic examination The hyperglycemic state caused by DM is associated with rotator cuff tendon degeneration. [Orthopedics. 2022;45(3):e154-e161.].

How Long Does It Take to Achieve Clinically Significant Outcomes After Isolated Biceps Tenodesis?

Background:

Clinically significant outcomes (CSOs) connect patient-reported outcome measures data to patient-perceived benefit. Although investigators have established threshold values for various CSOs, the timeline to achieve these outcomes after isolated biceps tenodesis (BT) has yet to be defined.

Purpose:

To define the time-dependent nature of minimal clinically important difference (MCID), substantial clinical benefit (SCB), and Patient Acceptable Symptom State (PASS) achievement after isolated BT.

Study Design:

Case series; Level of evidence, 4.

Methods:

The American Shoulder and Elbow Surgeons score (ASES), the Single Assessment Numeric Evaluation, and the Constant-Murley score (CMS) were administered preoperatively and at 6 and 12 months postoperatively to patients undergoing isolated BT between 2014 and 2018 at our institution. Cumulative probabilities for achieving MCID, SCB, and PASS were calculated using Kaplan-Meier survival analysis. Weibull parametric regression evaluated the hazard ratios (HRs) of achieving earlier MCID, SCB, and PASS.

Results:

Overall cohort (N = 190) achievement rates ranged between 77.8% and 83.2% for MCID, between 42.2% and 80.2% for SCB, and between 59.7% and 62.9% for PASS. Median achievement time was 5.3 to 6.1 months for MCID, 5.9 to 6.4 months for SCB, and 6.07 to 6.1 months for PASS. Multivariate Weibull parametric regression identified older age, male sex, higher body mass index, preoperative thyroid disease, smoking history, and higher preoperative CMS as predictors of delayed CSO achievement (HR, 1.01-6.41), whereas normal tendon on arthroscopy, defined as absence of tenosynovitis or tendon tear on arthroscopy, predicted earlier CSO achievement (HR, 0.19-0.46). Location of tenodesis and worker compensation status did not significantly predict the time to achieve CSOs on multivariate analysis.

Conclusion:

After isolated BT, patients can expect to attain CSO by 13 months postoperatively, with most patients achieving this between 5 and 8 months. Patients tend to take longer to achieve PASS than MCID and SCB.

A Hyperglycemic Microenvironment Inhibits Tendon-to-Bone Healing through the let-7b-5p/CFTR Pathway

Background

Tendon-to-bone healing is a difficult process in treatment of rotator cuff tear (RCT). In addition, diabetes is an important risk factor for poor tendon-to-bone healing. Therefore, we investigated the specific mechanisms through which diabetes affects tendon-to-bone healing by regulating the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR).

Methods

Tendon-derived stem cells (TDSCs) were extracted from rats after which their proliferative capacities were evaluated by the MTT assay. The expression levels of CFTR and tendon-related markers were determined by qRT-PCR. Then, bioinformatics analyses and dual luciferase reporter gene assays were used to identify miRNAs with the ability to bind CFTR mRNA. Finally, CFTR was overexpressed in TDSCs to validate the specific mechanisms through which the high glucose microenvironment inhibits tendon-to-bone healing.

Results

The high glucose microenvironment downregulated mRNA expression levels of tendon-related markers and CFTR in TDSCs cultured with different glucose concentrations. Additionally, bioinformatics analyses revealed that let-7b-5p may be regulated by the high glucose microenvironment and can regulate CFTR levels. Moreover, a dual luciferase reporter gene assay was used to confirm that let-7b-5p targets and binds CFTR mRNA. Additional experiments also confirmed that overexpressed CFTR effectively reversed the negative effects of the hyperglycaemic microenvironment and upregulation of let-7b-5p on TDSC proliferation and differentiation. These findings imply that the hyperglycemic microenvironment inhibits CFTR transcription and, consequently, proliferation and differentiation of TDSCs in vitro by upregulating let-7b-5p.

Conclusions

A hyperglycemic microenvironment inhibits TDSC proliferation in vitro via the let-7b-5p/CFTR pathway, and this is a potential mechanism in diabetes-induced poor tendon-to-bone healing.

Evaluating the role of type 2 diabetes mellitus in rotator cuff tendinopathy: Development and analysis of a novel rat model

OBJECTIVE

To establish and validate an intact rotator cuff rat model for exploring the pathophysiological effects of type 2 diabetes on the rotator cuff tendon in vivo.

METHODS

A total of 45 adult male rats were randomly divided into a control group (n = 9) and type 2 diabetes group (n=36). The rats were sacrificed at 2 weeks (T2DM-2w group, n=9), 4 weeks (T2DM-4w group, n=9), 8 weeks (T2DM-8w group, n=9), and 12 weeks (T2DM-12w group, n=9) after successful modeling of type 2 diabetes. Bilateral shoulder samples were collected for gross observation and measurement, protein expression(enzyme-linked immunosorbent assay,ELISA), histological evaluation, biomechanical testing, and gene expression (real-time quantitative polymerase chain reaction, qRT-PCR).

RESULTS

Protein expression showed that the expression of IL-6 and Advanced glycation end products (AGEs)in serum increased in type 2 diabetic group compared with the non-diabetic group. Histologically, collagen fibers in rotator cuff tendons of type 2 diabetic rats were disorganized, ruptured, and with scar hyperplasia, neovascularization, and extracellular matrix disturbances, while Bonar score showed significant and continuously aggravated tendinopathy over 12 weeks. The biomechanical evaluation showed that the ultimate load of rotator cuff tendons in type 2 diabetic rats gradually decreased, and the ultimate load was negatively correlated with AGEs content. Gene expression analysis showed increased expression of genes associated with matrix remodeling (COL-1A1), tendon development (TNC), and fatty infiltration (FABP4) in tendon specimens from the type 2 diabetic group.

CONCLUSION

Persistent type 2 diabetes is associated with the rupture of collagen fiber structure, disturbance in the extracellular matrix, and biomechanical decline of the rotator cuff tendon. The establishment of this new rat model of rotator cuff tendinopathy provides a valuable research basis for studying the cellular and molecular mechanisms of diabetes-induced rotator cuff tendinopathy.

Risk factors affecting rotator cuff retear after arthroscopic repair: a meta-analysis and systematic review

BACKGROUND

Retear after arthroscopic rotator cuff repair (ARCR) consistently challenges medical staff and patients, and the incidence of retear after surgery is 10%-94%. The purpose of this study was to identify the risk factors that cause retear after ARCR and provide theoretical guidance for clinical intervention to reduce the occurrence of postoperative rotator cuff retear.

METHODS

The protocol for this meta-analysis was registered with PROSPERO (CRD42021225088). PubMed, Web of Science, and Embase were searched for observational studies on risk factors for rotator cuff retear after arthroscopic repair. Meta-analytical methods were used to determine the odds ratio or weighted mean difference of potential risk factors related to postoperative rotator cuff retear. Stata 15.1 was used to quantitatively evaluate the publication bias of the statistical results.

RESULTS

Fourteen studies from 6 countries with a total of 5693 patients were included. The meta-analysis revealed that the risk factors for retear after rotator cuff repair were age, body mass index, diabetes, subscapularis and infraspinatus fatty infiltration, symptom duration, bone mineral density, tear length, tear width, tear size area, amount of retraction, critical shoulder angle, acromiohumeral interval, distance from the musculotendinous junction to the glenoid, operative duration, biceps procedure, and postoperative University of California Los Angeles shoulder score.

CONCLUSION

These findings can help clinical medical staff identify patients who are prone to retear early after arthroscopic repair and develop targeted prevention and treatment strategies for modifiable risk factors, which are of great significance for reducing the occurrence of rotator cuff retear after ARCR.

Patients with diabetes mellitus experience poorer outcomes after arthroscopic rotator cuff repair

Hypothesis

The purpose of this study was to identify potential differences using validated clinical outcome instruments between patients with and without diabetes mellitus (DM) after arthroscopic rotator cuff repair (RCR).

Methods

Six-hundred eighty-four patients (32 with and 652 without DM) who underwent arthroscopic RCR were prospectively followed using the visual analog pain scale, Simple Shoulder Test, Single Assessment Numeric Evaluation, American Shoulder and Elbow Surgeons score, and Veterans RAND 12-item Health Survey (mental and physical component scores) preoperatively and at 3, 6, 12, and 24 months postoperatively.

Results

Patients with DM experienced significantly more pain (P = .0172) and had lower Simple Shoulder Test (P = .0458) and American Shoulder and Elbow Surgeons (P = .0200) scores than patients without DM 6 months after surgery. Although differences between groups are seen at other postoperative time points, none are statistically significant.

They also exhibited lower self-rated mental health status at 12 months (P = .0034) and 24 months (P = .0077), as well as lower self-rated physical health status at 12 months (P = .0223) and 24 months (P = .0077). Changes in scores from preoperatively to postoperatively were not different for patients with DM vs. without DM.

Conclusion

Patients with DM experience significantly more pain, exhibit significantly poorer shoulder function, and report persistently diminished mental and physical health status compared with their counterparts without DM after undergoing arthroscopic RCR. Although these differences did not reach the minimal clinically important difference, orthopedic surgeons should be cognizant of DM as an outcome-modifying variable when selecting, counseling, and treating patients with rotator cuff tears. Glycemic control should be scrutinized and optimized during the perioperative medical evaluation and ultimately factored into the surgical risk profile and prognosis.

Distinct Gene Expression Profile in Patients With Poor Postoperative Outcomes After Rotator Cuff Repair: A Case-Control Study

BACKGROUND

Impaired healing after rotator cuff repair is a major concern, with retear rates as high as 94%. A method to predict whether patients are likely to experience poor surgical outcomes would change clinical practice. While various patient factors, such as age and tear size, have been linked to poor functional outcomes, it is currently very challenging to predict outcomes before surgery.

PURPOSE

To evaluate gene expression differences in tissue collected during surgery between patients who ultimately went on to have good outcomes and those who experienced a retear, in an effort to determine if surgical outcomes can be predicted.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Rotator cuff tissue was collected at the time of surgery from 140 patients. Patients were tracked for a minimum of 6 months to identify those with good or poor outcomes, using clinical functional scores and follow-up magnetic resonance imaging to confirm failure to heal or retear. Gene expression differences between 8 patients with poor outcomes and 28 patients with good outcomes were assessed using a multiplex gene expression analysis via NanoString and a custom-curated panel of 145 genes related to various stages of rotator cuff healing.

RESULTS

Although significant differences in the expression of individual genes were not observed, gene set enrichment analysis highlighted major differences in gene sets. Patients who had poor healing outcomes showed greater expression of gene sets related to extracellular matrix production (P < .0001) and cellular biosynthetic pathways (P < .001), while patients who had good healing outcomes showed greater expression of genes associated with the proinflammatory (M1) macrophage phenotype (P < .05).

CONCLUSION

These results suggest that a more proinflammatory, fibrotic environment before repair may play a role in poor healing outcome. With validation in a larger cohort, these results may ultimately lead to diagnostic methods to preoperatively predict those at risk for poor surgical outcomes.

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.

[Analysis of the effect of asymptomatic hyperuricemia on the effectiveness after arthroscopic rotator cuff repair]

Objective

To investigate the effect of asymptomatic hyperuricemia on the effectiveness of arthroscopic rotator cuff repair.

Methods

The clinical data of 80 patients who underwent arthroscopic rotator cuff repair and met the selection criteria between March 2018 and December 2019 were retrospectively analyzed. According to the serum uric acid level, the patients were divided into hyperuric acid group (46 cases, the serum uric acid level was more than 417 μmol/L in males and was more than 357 μmol/L in females) and normal group (34 cases, serum uric acid level was lower than the above standard). There was no significant difference in gender, age, side, body mass index, blood glucose level, total cholesterol level, rotator cuff tear size, and preoperative shoulder motion, visual analogue scale (VAS) score, University of California-Los Angeles (UCLA) score, Constant score, American Shoulder and Elbow Surgeons (ASES) score, and other general data between the two groups ( P>0.05). The range of motion of abduction, forward flexion, and external rotation at 90° abduction were recorded and compared between the two groups before operation and at last follow-up; the improvement of shoulder pain was evaluated by VAS score; the improvement of shoulder function was evaluated by UCLA score, Constant score, and ASES score; and the shoulder joint MRI grade was evaluated according to Sugaya evaluation criteria.

Results

All patients were followed up 9-16 months, with an average of 11.9 months; there was no significant difference in the follow-up time between the two groups ( t=0.968, P=0.336). There were 2 cases of retear in the hyperuric acid group (including 1 case of severe tear) and 1 case of light retear in the normal group. The remaining patients in the two groups had no early-related complications. At last follow-up, the range of motion of the shoulder joints (abduction, forward flexion, external rotation at 90° abduction), VAS score, UCLA score, Constant score, and ASES score of the two groups were significantly improved when compared with preoperative ones ( P<0.05); the above indicators in the normal group were significantly better than those in the hyperuric acid group ( P<0.05). The MRI grade of the shoulder joint in the normal group was significantly better than that in the hyperuric acid group ( Z=-2.000, P=0.045).

Conclusion

Compared with patients with normal serum uric acid level, asymptomatic hyperuricemia can lead to worse recovery after arthroscopic rotator cuff repair in patients with rotator cuff tears.

Diabetes is an independent risk factor for infection after non-arthroplasty shoulder surgery: a national database study

OBJECTIVES

Diabetes has been associated with poor healing and prior literature has shown worse functional outcomes in diabetic patients undergoing both open and arthroscopic shoulder surgery. However, the effects of diabetes on perioperative complications for patients undergoing non-arthroplasty type shoulder procedures are not well defined. The purpose of this study was to analyze the effects of diabetes on 30-day complications following non-arthroplasty shoulder surgery.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program was used to identify patients who underwent open and arthroscopic shoulder procedures (excluding arthroplasty) from 2011 to 2018. Diabetic patients were identified and compared to a non-diabetic cohort. Demographic data and postoperative complications within 30 days were analyzed. Multivariable regression was used to determine the effect of diabetes on shoulder surgery.

RESULTS

We identified 99,970 patients who underwent shoulder surgery in our cohort and 13.9% (13,857 patients) of these patients were diabetics. Within the diabetic cohort, 4,394 (31.7%) were insulin dependent. Diabetics were more likely to be older, female, and have a higher body mass index (P < 0.01). Diabetics had a higher rate of associated medial comorbidities (P < 0.05). Diabetics were less likely to be smokers and on average had shorter surgeries (P < 0.05). Univariate analysis showed that diabetes was associated with increased risk for infectious and other major and minor complications; however, multivariate regression revealed that diabetes was only independently associated with infection (OR 1.33, P = 0.38).

CONCLUSION

While diabetes is associated with increased likelihood of infection following shoulder surgery, absent commonly associated comorbidities, they are not at increased risk for other 30-day postoperative complications.

Clinical results of arthroscopic rotator cuff repair in diabetic and non-diabetic patients

BACKGROUND

Although the clinical outcomes of arthroscopic rotator cuff repair (ARCR) have been reported, few studies have focused on diabetic patients. We investigated and compared the clinical results of ARCR in patients with and without diabetes.

METHODS

This retrospective study involved 195 consecutive patients who underwent ARCR from 2015 to 2018 in our hospital. Twenty-seven and 168 shoulders were assigned to diabetes and non-diabetes groups, respectively. Diabetic patients with poor control were preoperatively hospitalized for perioperative diabetic control. We evaluated range of motion (ROM), Japanese Orthopaedic Association shoulder (JOA) score, Constant Shoulder Score, and University of California, Los Angeles (UCLA) score preoperatively and at 6 months and 1 year post-ARCR. Rates of rotator cuff retear 1 year post-ARCR and preoperative and postoperative stiff shoulder were also evaluated. We compared the results between groups and analyzed them statistically. A p-value of <0.05 was considered statistically significant.

RESULTS

Preoperative ROM, JOA score, Constant Shoulder Score and UCLA scores showed significant improvement at post-ARCR in both groups (p < 0.05). On comparing the groups, although preoperative JOA score and Constant Shoulder Score were significantly lower in diabetes group than in non-diabetes group (diabetic/non-diabetic group; 60.0/65.3 for JOA score; p = 0.003, 59.7/64.2 for Constant Shoulder Score; p = 0.003), there was no significant difference postoperatively (6 months post-ARCR; 88.0/89.7 for JOA score; p = 0.783, 88.1/88.6 for Constant Shoulder Score; p = 0.597, 1 year post-ARCR; 96.7/95.4 for JOA score; p = 0.238, 96.6/95.4 for Constant Shoulder Score; p = 0.248). Furthermore, preoperative and postoperative stiff shoulder and retear rates were not significantly different between groups (p = 0.152, p = 0.344, p = 0.347, and p = 0.563, respectively).

CONCLUSION

Diabetic patients showed comparable clinical results with non-diabetic patients post-ARCR. Perioperative diabetic control may be recommended for preoperatively uncontrolled diabetic patients.

Effect of Smoking on Postoperative Function and Quality of Life After Full Thickness Arthroscopic Rotator Cuff Repair: A Retrospective Analysis

PURPOSE

The effect of smoking on preoperative and postoperative outcome scores as well as quality of life measurements after arthroscopic rotator cuff repair (ARCR) has not been fully understood, and studies regarding this are lacking in the literature. This study aimed to evaluate the effect of smoking on function and quality of life after ARCR.

METHODS

Two-hundred patients who underwent full-thickness ARCR with a minimum 1-year follow-up period were included and evaluated retrospectively. The patients were divided into two groups: smokers (Group 1, 59 patients) and nonsmokers (Group 2, 141 patients). Pre- and postoperative Constant Murley (CM) scores, American Shoulder and Elbow Surgeons (ASES) scores, visual analogue scale scores (VASs), and Short-Form 36 health survey (SF-36) scores were used to evaluate functional and quality of life outcomes. The correlation between the smoking amount (pack-years) and outcomes was evaluated.

RESULTS

A total of 200 patients included into study (90 male and 110 female) with mean age of 62.68 ± 3.98. There was no statistically significant difference between the two groups regarding preoperative scores, except in the ASES score (P = 0.021 ) Additionally, there was a statistically significant difference between the groups regarding postoperative CM score, ASES score, and VAS, and in physical functioning and role limitations due to physical health domains of the SF-36 (P = 0.029, P = 0.038, P = 0.021 and P = 0.020, respectively). There were small to moderate negative correlations between amount of smoking and preoperative physical functioning, role limitations from emotional problems, energy/fatigue, emotional well-being, and pain domains of the SF-36. However, there were moderate to strong negative correlations between amount of smoking and postoperative SF-36 domains.

CONCLUSION

Preoperative and postoperative functional outcome scores, and quality of life measurements are negatively affected from smoking. As the amount of smoking increases, postoperative results are negatively affected.

LEVEL OF EVIDENCE

3.

Arthroscopic Repair of Medium to Large Rotator Cuff Tears With a Triple-Loaded Medially Based Single-Row Technique Augmented With Marrow Vents

PURPOSE

The primary purpose of this study was to evaluate the repair integrity on magnetic resonance imaging (MRI), and secondarily, clinical outcomes, of medium to large (2-4 cm) rotator cuff tears treated using an arthroscopic triple-loaded medially based single-row repair technique augmented laterally with bone marrow vents.

METHODS

This is a retrospective outcomes study of patients with full-thickness medium to large (2-4 cm) rotator cuff tears repaired by 4 surgeons at a single institution over a 2-year period with a minimum of 24 months' follow-up. A single-row repair with tension-minimizing medially based triple-loaded anchors and laterally placed bone marrow vents was used. Patients completed a satisfaction and pain survey, the Western Ontario Rotator Cuff index questionnaire, and a Short Form-36 version 2 survey to evaluate clinical outcomes. MRI was obtained at a minimum of 24 months follow-up to assess repair integrity.

RESULTS

A total of 64 males and 27 females with a mean age of 59.7 (range, 34-82) were included. The mean tear size was 2.6 cm in anteroposterior dimension, treated with a mean of 2.2 anchors. Eighty-three of 91 shoulders (91%) reported being completely satisfied with their result. The median Western Ontario Rotator Cuff score was 95.2% of normal, with a significant difference found between those with an intact repair and those with a full-thickness recurrent defect (median, 95.9% vs. 73.8%; P = .003). Postoperative MRI obtained at a median of 32 months (range, 24-48) demonstrated an intact repair in 84 of 91 shoulders (92%), with failure defined as a full-thickness defect of the tendon.

CONCLUSIONS

Arthroscopic repair of medium to large rotator cuff tears using triple-loaded medially based single-row repair augmented with marrow vents resulted in a 92% healing rate by MRI and excellent patient-reported outcomes LEVEL OF EVIDENCE: Level IV, retrospective case series.

Understanding cellular and molecular mechanisms of pathogenesis of diabetic tendinopathy

There is accumulating evidence of an increased incidence of tendon disorders in people with diabetes mellitus. Diabetic tendinopathy is an important cause of chronic pain, restricted activity, and even tendon rupture in individuals. Tenocytes and tendon stem/progenitor cells (TSPCs) are the dominant cellular components associated with tendon homeostasis, maintenance, remodeling, and repair. Some previous studies have shown alterations in tenocytes and TSPCs in high glucose or diabetic conditions that might cause structural and functional variations in diabetic tendons and even accelerate the development and progression of diabetic tendinopathy. In this review, the biomechanical properties and histopathological changes in diabetic tendons are described. Then, the cellular and molecular alterations in both tenocytes and TSPCs are summarized, and the underlying mechanisms involved are also analyzed. A better understanding of the underlying cellular and molecular pathogenesis of diabetic tendinopathy would provide new insight for the exploration and development of effective therapeutics.

Patients With Diabetes Mellitus Have a Higher Risk of Tendon Retear After Arthroscopic Rotator Cuff Repair: A Meta-analysis

Background

Retear of a repaired rotator cuff tendon is a major issue for shoulder surgeons. It is possible that diabetes mellitus (DM) is associated with a greater risk of tendon retear after arthroscopic rotator cuff repair.

Purpose

To determine whether patients with DM have a higher tendon retear risk after arthroscopic rotator cuff repair.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using the Web of Science, PubMed, and Embase databases. Inclusion criteria were articles written in the English language that included patients undergoing arthroscopic rotator cuff repair surgeries, reported the numbers of patients with and those without DM, and reported the number of rotator cuff retears. Data relevant to this study were extracted and statistically analyzed. Random-effects models were used to generate pooled odds ratio estimates and CIs.

Results

A total of 160 studies were identified from the initial search, and 5 of them met the inclusion criteria. A total of 1065 patients (207 patients with DM and 858 patients without DM) were included. The pooled results showed that the patients in the DM group had a significantly higher tendon retear risk than did those in the non-DM group (relative risk, 2.25; 95% CI, 1.14-4.45; P = .02).

Conclusion

Patients with DM have a 2.25 times higher risk of tendon retear after arthroscopic rotator cuff repair compared with patients without DM.

Assessment of Tendon Retraction in Large to Massive Rotator Cuff Tears: A Modified Patte Classification Based on 2 Coronal Sections on Preoperative Magnetic Resonance Imaging With Higher Specificity on Predicting Reparability

PURPOSE

To propose a modified Patte classification (evaluating tendon retraction on 2 coronal sections) and analyze whether this classification was better at predicting irreparability and retear of large to massive rotator cuff tears (RCTs).

METHODS

A retrospective study was performed. Imaging evaluation including tendon retraction, fatty infiltration, the acromiohumeral distance (AHD), and the tangent sign was performed using magnetic resonance imaging. The modified Patte classification was used to assess tendon retraction. Intraobserver and interobserver reliability was analyzed by calculating intraclass correlation coefficients. Factors affecting irreparability and retear were analyzed using both univariate and multivariate analyses. Sensitivity and specificity of tendon retraction to predict irreparability and retear were calculated.

RESULTS

A total of 121 shoulders with large to massive RCTs underwent arthroscopic rotator cuff repairs. The modified Patte classification system had excellent interobserver and intraobserver reliability. Several factors were associated with reparability and retear in the univariate analysis. However, in binary logistic regression analysis, the only factors affecting reparability were AHD less than 0.4 cm (P = .007) and modified Patte stage III tendon retraction (P = .023). Low-grade repair quality (P = .001) and modified Patte stage III tendon retraction (P = .031) were independent factors for retear. Modified Patte stage III had a high specificity for predicting irreparability (93.58%) and retear (98.78%), whereas the specificity of original Patte stage III was 76.15% and 84.15%, respectively.

CONCLUSIONS

For large to massive RCT repairs, modified Patte stage III tendon retraction with evaluation of 2 coronal cuts reveals higher specificity on predicting tendon irreparability and postoperative retear. An AHD less than 0.4 cm on magnetic resonance imaging and modified Patte stage III tendon retraction were independent risk factors for irreparability. Low-grade repair quality and modified Patte stage III tendon retraction were independent risk factors for postoperative retear.

LEVEL OF EVIDENCE

Level III, case-control study.

Shoulder range of movement in the general population: age and gender stratified normative data using a community-based cohort

Background

An understanding of the average range of movement of the shoulder that is normally achievable is an important part of treatment for shoulder disorders. The average range of active shoulder flexion, abduction and external rotation was measured in a population cohort aged 20 years and over without shoulder pain and/or stiffness in order to provide normative shoulder range data.

Methods

Cross-sectional analysis using participants in a community-based longitudinal cohort study. There have been three stages of data collection – Stage 1 (1999–2003), Stage 2 (2004–2006) and Stage 3 (2008–2010). Each stage has consisted a of broad ranging computer assisted telephone interview, a self-complete questionnaire and a clinic assessment. Participants in this study are those who undertook assessments in Stage 2. The main outcome measures were active shoulder range of movement (flexion, abduction and external rotation) measured as part of the clinic assessment using a Plurimeter V inclinometer. Mean values were determined and analyses to examine differences between groups (sex and age) were undertaken using non-parametric tests.

Results

There were 2404 participants (51.5% male), mean age 45.8 years (SD 17.3, range 20–91). The average range of active right shoulder flexion was 161.5° for males and 158.5° for females, and active right shoulder abduction was 151.5° and 149.7° for males and females respectively. Shoulder range of movement declined with age, with mean right active shoulder flexion decreasing by 43° in males and 40.6° in females and right active shoulder abduction by 39.5° and 36.9° respectively. External rotation range also declined, particularly among females.

Conclusion

To our knowledge this is the largest community-based study providing normative data for active shoulder range of movement. This information can be used to set realistic goals for both clinical practice and clinical trials.

Clinical and Structural Outcomes After Rotator Cuff Repair in Patients With Diabetes: A Meta-analysis

Background:

The impact of diabetes on clinical and structural outcomes after rotator cuff repair remains controversial.

Purpose/Hypothesis:

The purpose of this study was to compare clinical outcomes and retear rates after rotator cuff repair in patients with and without diabetes. Our hypotheses were that adequate control of diabetes would decrease the retear rate after rotator cuff repair and that patients with diabetes would have worse clinical outcomes.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

The PubMed, Embase, and Cochrane Library databases were searched for studies comparing outcomes in patients with and without diabetes after full-thickness rotator cuff repair. Clinical outcome analysis included the Constant score, the American Shoulder and Elbow Surgeons (ASES) score, and the University of California–Los Angeles shoulder rating scale; we compared preoperative, postoperative, and change in functional scores from baseline to final follow-up among the included studies. The pooled relative risk was calculated using a random-effects model for retear rates. Clinical outcomes were also pooled using a random-effects model.

Results:

Overall, 10 studies were included. Compared with patients without diabetes, patients with diabetes had a worse preoperative ASES score (P = .009) as well as worse postoperative Constant score (final follow-up range, 9-103 months; P = .0003). However, there was no significant difference in the absolute mean change in clinical outcomes between patients with and without diabetes. Diabetes was associated with a higher retear rate (19.3% in patients without diabetes vs 28.2% in patients with diabetes; P < .0001). The retear rate according to the severity of sustained hyperglycemia in the subgroup analysis was 14.6% in patients without diabetes, versus 22.7% in patients with well-controlled diabetes (<7.0% of preoperative serum HbA1c level; P = .12) and 40.0% in patients with uncontrolled diabetes (HbA1c level ≥7.0%; P < .00001).

Conclusion:

This meta-analysis suggests that diabetes mellitus is associated with an increased risk of retears after rotator cuff repair, and improved blood glucose control may reduce the risk of retears in patients with diabetes mellitus. Although effective glycemic control was associated with a decreased risk of retears in patients with diabetes, we could not prove causation because of potential bias and confounding in the included studies.

The Effect of Patient Characteristics and Comorbidities on the Rate of Revision Rotator Cuff Repair

PURPOSE

To describe the national rates of failed primary rotator cuff repair (RCR) requiring revision repair, using numerous patient characteristics previously defined in orthopaedic literature, including smoking history, diabetes mellitus (DM), hyperlipidemia (HLD), vitamin D deficiency, and osteoporosis to determine which factors independently affect the success of primary RCR.

METHODS

A combined public and private national insurance database was searched from 2007 to 2016 for all patients who underwent RCR. Current Procedural Terminology codes were used to identify RCRs. Laterality modifiers for the primary surgery were used to identify subsequent revision RCRs. All patients who did not have a linked laterality modifier for the RCR Current Procedural Terminology code were excluded from the study. Basic demographics were recorded. International Classification of Diseases Ninth Revision codes were used to identify patient characteristics including Charlson Comorbidity Index, smoking status, DM, obesity, HLD, vitamin D deficiency, and osteoporosis. Patient age categorized as <60, 60-69, 70-74, or 75+ years old. Dichotomous data were analyzed with χ² testing. Multivariable logistic regression was used to characterize independent associations with revision RCR.

RESULTS

Included in the study were 41,467 patients (41,844 shoulders, 52.7% male patients) who underwent primary arthroscopic RCR. Of all arthroscopic RCRs, 3072 patients (3463 shoulders, 53.5% male patients) underwent revision RCR (8.38%). In both primary and revision RCR, patients age 60 to 69 years were most prevalent, accounting for 38.4% and 37.6% of the cohorts, respectively. The average time from primary RCR to revision was 414.9 days (median 214.0 days). Increasing age and male sex (odds ratio [OR] 1.10, P = .019, 95% confidence interval [CI] 1.02-1.19) were significantly predictive of revision RCR. Of the remaining patient characteristics, smoking most strongly predicted revision RCR (OR 1.36, P < .001, CI 1.23-1.49). Obesity (OR 1.32, P < .001, CI 1.21-1.43), hyperlipidemia (OR 1.09, P = .032, CI 1.01-1.18), and vitamin D deficiency (OR 1.18, P < .001, CI 1.08-1.28) also increased risk of revision RCR significantly. DM was found to be protective against revision surgery (OR 0.84, P < .001, CI 0.76-0.92). Overall comorbidity burden as measured by the Charlson Comorbidity Index was not predictive of revision RCR.

CONCLUSIONS

Smoking, obesity, vitamin D deficiency, and HLD are shown to be independent risk factors for failure of primary RCR requiring revision RCR. However, despite the suggestions of previous studies, DM, osteoporosis, and overall comorbidity burden did not demonstrate independent associations in this study.

LEVEL OF EVIDENCE

IV, Case Series.

Osteoprotegerin/bone morphogenetic protein 2 combining with collagen sponges on tendon-bone healing in rabbits

INTRODUCTION

The aim was to investigate the effect of collagen sponges (CS) as a delivery device for osteoprotegerin (OPG)/bone morphogenetic protein 2 (BMP-2) and support matrix on the tendon-bone healing after anterior crusicate ligament (ACL) reconstruction in modeled rabbits.

MATERIALS AND METHODS

Sixty New Zealand white rabbits were randomly divided into four groups based on treatments they received at the tendon-bone interface after left knee ACL reconstruction: the control group, OPG/BMP-2, CS, and OPG/BMP-2/CS combination. At 4, 8 and 12 weeks post-surgery, five rabbits from each group were euthanized to examine the tendon-bone healing. Levels of OPG and BMP-2 in synovial fluid, the bone tunnel enlargement value, the histomorphological typing of tendon-bone interface, and the bone tunnel area of the tendon-bone interface were compared among different treatments.

RESULTS

The OPG/BMP-2/CS combination treatment group had the highest levels of OPG and BMP-2 in synovial fluid (both P < 0.05), the greatest number of Sharpey-like collagen fibers at all test points (P < 0.05), the most fibrocartilage enthesis on week 12, the greatest bone tunnel area (P < 0.05), and the greatest decrease in bone tunnel enlargement on week 12 (P < 0.05). Histomorphological typing of tendon-bone interface of all groups showed changes varying from tendon-bone separation to firm healing, and the change was most significant in the OPG/BMP-2/CS combination treatment group.

CONCLUSION

CS treatment alone serves as a fixing support, and CS combining with growth factors OPG/BMP-2 ensures slow and stable release of OPG/BMP-2, significantly improves the tendon-bone healing in the rabbit ACL model.

Zoledronic Acid Substantially Improves Bone Microarchitecture and Biomechanical Properties After Rotator Cuff Repair in a Rodent Chronic Defect Model

BACKGROUND

Bone mineral density at the humeral head is reduced in patients with chronic rotator cuff tears. Bone loss in the humeral head is associated with repair failure after rotator cuff reconstruction. Bisphosphonates (eg, zoledronic acid) increase bone mineral density.

HYPOTHESIS

Zoledronic acid improves bone mineral density of the humeral head and biomechanical properties of the enthesis after reconstruction of chronic rotator cuff tears in rats.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 32 male Sprague-Dawley rats underwent unilateral (left) supraspinatus tenotomy with delayed transosseous rotator cuff reconstruction after 3 weeks. All rats were sacrificed 8 weeks after rotator cuff repair. Animals were randomly assigned to 1 of 2 groups. At 1 day after rotator cuff reconstruction, the intervention group was treated with a single subcutaneous dose of zoledronic acid at 100 µg/kg bodyweight, and the control group received 1 mL of subcutaneous saline solution. In 12 animals of each group, micro-computed tomography scans of both shoulders were performed as well as biomechanical testing of the supraspinatus enthesis of both sides. In 4 animals of each group, histological analyses were conducted.

RESULTS

In the intervention group, bone volume fraction (bone volume/total volume [BV/TV]) of the operated side was higher at the lateral humeral head (P = .005) and the medial humeral head (P = .010) compared with the control group. Trabecular number on the operated side was higher at the lateral humeral head (P = .004) and the medial humeral head (P = .001) in the intervention group. Maximum load to failure rates on the operated side were higher in the intervention group (P < .001). Cortical thickness positively correlated with higher maximum load to failure rates in the intervention group (r = 0.69; P = .026). Histological assessment revealed increased bone formation in the intervention group.

CONCLUSION

Single-dose therapy of zoledronic acid provided an improvement of bone microarchitecture at the humeral head as well as an increase of maximum load to failure rates after transosseous reconstruction of chronic rotator cuff lesions in rats.

CLINICAL RELEVANCE

Zoledronic acid improves bone microarchitecture as well as biomechanical properties after reconstruction of chronic rotator cuff tears in rodents. These results need to be verified in clinical investigations.

The effect of age on risk of retear after rotator cuff repair: a systematic review and meta-analysis

Hypothesis

The purpose of this study was to perform a systematic review and meta-analysis to determine the effect of age on rotator cuff repair failure. The hypothesis of this study was that increased patient age would lead to a higher rate of retears and/or repair failures after rotator cuff repair.

Methods

We conducted a systematic review and meta-analysis of level I and II studies evaluating patients undergoing rotator cuff repair that also included an imaging assessment of the structural integrity of the repair. Univariate and multivariate meta-regression was performed to assess the dependence of the retear rate on the mean age of the cohort, imaging modality, time to imaging, and publication year.

Results

The meta-regression included 38 studies with a total of 3072 patients. Significant heterogeneity in retear rates was found among the studies (Q = 209.53, I² = 82.34, P < .001). By use of a random-effects model, the retear rate point estimate was 22.1% (95% confidence interval [CI], 18.6%-26.0%). On univariate analysis, type of imaging modality did not significantly influence the retear rate (P = .188). On univariate analysis, mean age (odds ratio [OR], 1.05 [95% CI, 1.01-1.09]; P = .027) and mean time to imaging (OR, 1.04 [95% CI, 1.01-1.08]; P = .006) were associated with the retear rate. Publication year (OR, 0.94 [95% CI, 0.88-1.01]; P = .083) demonstrated a trend toward significance. On multivariate analysis, increased age was associated with a 5%/yr increased odds of retear (OR, 1.05 [95% CI, 1.01-1.08]; P = .025). The risk of retear doubled from 15% at age 50 years to >30% at age 70 years. Time to imaging demonstrated a trend toward increased odds of retear (OR, 1.03 [95% CI, 1.00-1.07]; P = .056). Publication year was not associated with the retear rate on multivariate analysis (OR, 0.96 [95% CI, 0.90-1.02]; P = .195).

Conclusion

The risk of retear after rotator cuff repair is associated with increased age and doubles between the ages of 50 and 70 years.

Diabetic patients are almost twice as likely to experience complications from arthroscopic rotator cuff repair

AIMS

Large population-based studies have demonstrated increased prevalence of rotator cuff disease amongst diabetics. Recent studies have suggested comparable clinical outcomes from rotator cuff repair despite suggestions of increased complication rates amongst diabetics. However, there is a relative paucity of studies considering the effect of diabetes upon complication rate. We aim to report and quantify the effect of diabetes on complication rates following arthroscopic rotator cuff repair.

MATERIALS AND METHODS

A retrospective review of a consecutive series of patients undergoing arthroscopic rotator cuff repair between January 2011 and December 2014 was performed. Diabetic status and complication data defined as infection, frozen shoulder, re-tear or re-operation were collected and interrogated.

RESULTS

A total of 462 patients were included at median follow-up of 5.6 years. Diabetics were significantly more likely to experience frozen shoulder (15.8% vs. 4.4%, p = 0.001), re-tear (26.3% vs. 15.6%, p = 0.042) or at least one complication following surgery (35.1% vs. 22.7%, p = 0.041) compared to non-diabetics. These equated to odds ratios of 4.03, 1.94 and 1.84, respectively.

CONCLUSIONS

Diabetic patients are almost twice as likely to experience complications following arthroscopic rotator cuff repair, including double the risk of repair failure and more than four times the risk of frozen shoulder.

The effect of diabetes on functional outcomes among individuals with distal radial fractures

STUDY DESIGN

Prospective cohort study.

INTRODUCTION

Diabetes is reported to adversely affect outcomes; however, its effect on distal radial fractures (DRF) is not well examined.

PURPOSE OF THE STUDY

This study investigated the effect of diabetes on pain, hand function, physical health status, grip strength, and wrist and forearm range of motion among patients with DRF.

METHODS

A total of 479 patients with DRF were classified into patients with and without diabetes based on self-report. Patient-Rated Wrist Evaluation assessed pain and hand function. The Short Form-12 assessed physical health status. Both questionnaires examined DRF recovery at baseline, 3 month, and 1 year.

RESULTS

There was a significant improvement in Patient-Rated Wrist Evaluation scores over time (69 [19] to 25 [22]; 76 [15] to 20 [20] for patients with and without diabetes respectively, P < .01) with a significant interaction between time and diabetes (P < .01), indicating that patients with diabetes recovered more slowly than the rest of the cohort. There was an improvement over time on physical status (36 [12] to 45 [12]; 39 [9] to 50 [9], P < .01), grip strength (16 [7] to 24 [10]; 15 [9] to 24 [10], P < .01), and range of motion (flexion [42 {14} to 49 {15}; 43 {15} to 54 {14}, P < .01], extension [45 {11} to 52 {11}; 46 {13} to 53 {12}, P < .01], pronation [73 {10} to 77 {9}; 73 {11} to 78 {9}, P < .01], and supination [58 {17} to 65 {14}; 61 {17} to 70 {12}, P < .01]) for patients with and without diabetes, respectively. Patients with diabetes did not differ significantly in these secondary outcomes compared to the rest of the cohort.

DISCUSSION AND CONCLUSION

Although individuals with diabetes had good outcomes, their recovery was slower than the rest of the cohort. This may be due to the adverse effect of hyperglycemia on bone tissues and small blood vessels. Future studies are required to assess how severity and duration of diabetes affect outcomes after DRF.

The role of biologic agents in the management of common shoulder pathologies: current state and future directions

The field of orthopedic surgery has seen a rapid increase in the use of various biologic agents for the treatment of common musculoskeletal injuries. Most biologic agents attempt to harness or mimic naturally occurring growth factors, cytokines, and anti-inflammatory mediators to improve tissue healing and recovery. The most commonly used biologic agents are platelet-rich plasma and cells derived from bone marrow aspirate and adipose tissue. These agents have become increasingly popular despite a relative dearth of clinical data to support their use. Much confusion exists among patients and physicians in determining the role of these agents in treating common shoulder pathologies, such as glenohumeral osteoarthritis, rotator cuff tears, and tendinopathy. This article reviews the basic science and clinical evidence for the most commonly used biologic agents in the management of common shoulder pathology.

Advanced Glycation End-Products Suppress Mitochondrial Function and Proliferative Capacity of Achilles Tendon-Derived Fibroblasts

Debilitating cases of tendon pain and degeneration affect the majority of diabetic individuals. The high rate of tendon degeneration persists even when glucose levels are well controlled, suggesting that other mechanisms may drive tendon degeneration in diabetic patients. The purpose of this study was to investigate the impact of advanced glycation end-products on tendon fibroblasts to further our mechanistic understanding of the development and progression of diabetic tendinopathy. We proposed that advanced glycation end-products would induce limitations to mitochondrial function and proliferative capacity in tendon-derived fibroblasts, restricting their ability to maintain biosynthesis of tendon extracellular matrix. Using an in-vitro cell culture system, rat Achilles tendon fibroblasts were treated with glycolaldehyde-derived advanced glycation end-products (0, 50, 100, and 200 μg/ml) for 48 hours in normal glucose (5.5 mM) and high glucose (25 mM) conditions. We demonstrate that tendon fibroblasts treated with advanced glycation end-products display reduced ATP production, electron transport efficiency, and proliferative capacity. These impairments were coupled with alterations in mitochondrial DNA content and expression of genes associated with extracellular matrix remodeling, mitochondrial energy metabolism, and apoptosis. Our findings suggest that advanced glycation end-products disrupt tendon fibroblast homeostasis and may be involved in the development and progression of diabetic tendinopathy.