Factors Predictive of Healing in Large Rotator Cuff Tears: Is It Possible to Predict Retear Preoperatively?

Biologic augmentation of rotator cuff repair with microfragmented autologous subacromial bursal tissue enveloped in a patch of compressed autologous long head of biceps tendon tissue: the Bio-Ravioli technique

Background

Rotator cuff repair is one of the most frequently performed procedures in orthopedic surgery. However, considering the limited healing potential of rotator cuff tendons, several augmentation strategies have evolved to enhance tendon healing. The purpose of this article was to present a new surgical technique called Bio-Ravioli.

Methods

Patients with repairable full-thickness posterosuperior rotator cuff tear and a moderate-to-high risk of healing failure were chosen as candidates for the Bio-Ravioli procedure. It is a biologic augmentation strategy to increase healing potential of arthroscopic rotator cuff repair by use of a biologic graft fixed at the bone-tendon interface. The Bio-Ravioli consists of microfragmented autologous subacromial bursal tissue enveloped in a patch of compressed autologous long head of biceps tendon tissue. The rotator cuff is then repaired to the bone and over the graft using a transosseus equivalent configuration.

Conclusion

The Bio-Ravioli technique represents an easy and reliable way to increase the healing potential at the bone-tendon interface by using autologous mesenchymal stem cells from different sources: subacromial bursa and long head of the biceps tendon.

Predictive Factors for the Healing of Rotator Cuff Repairs

INTRODUCTION

Rotator cuff tears (RCTs) are a significant cause of shoulder pain. Rotator cuff repair is common, but healing failure is frequent and the reasons for the retear are still unclear.

OBJECTIVE

This study aimed to determine if specific preoperative factors related to patients and tears affect the structural outcome after rotator cuff repair.

METHODS

This is a multivariate prognostic model study, based on prospectively collected data from a retrospective cohort. We included individuals who received arthroscopic RCT repair from January 2013 to April 2022. Evaluations were performed using magnetic resonance imaging (MRI) at 12 months postoperatively, and clinical outcomes were measured using the American Shoulder and Elbow Surgeons (ASES) scale. Statistical analysis was conducted using multivariate logistic regression.

RESULTS

The sample included 176 patients, with a retear rate of 35.2%. Male (p=0.029), smoking (p=0.026), full-thickness infraspinatus tears (p=0.007), and instability of the long head of the biceps (p=0.046) were identified as predictive factors for non-healing. Traumatic lesions (p=0.017) favored healing. All patients showed significant clinical improvement. At 24 months, patients with healed tendons had better clinical outcomes.

CONCLUSION

Male sex, smoking, full-thickness infraspinatus tears, and instability of the long head of the biceps are predictive factors for retear after rotator cuff repair. Traumatic lesions favor tendon healing.

Outcomes of initial nonoperative treatment of traumatic full-thickness rotator cuff tears

BACKGROUND

Nonsurgical management of chronic, degenerative rotator cuff tears (RCTs) can be an effective treatment strategy, but there is limited evidence to support conservative treatment of acute, traumatic RCTs. The objective of this study was to assess clinical outcomes and predictors of treatment success in patients with traumatic RCTs who elected for initial nonoperative treatment.

METHODS

Patients from a single institution were retrospectively identified using diagnostic codes for traumatic RCTs followed by confirmed initial treatment with ≥2 months of physical therapy. The exclusion criteria included surgery within 2 months of injury and greater than grade I fatty infiltration on magnetic resonance imaging. At minimum 2-year follow-up, patients were contacted by telephone to collect interval surgical history and standardized patient-reported outcomes. Physical therapy was considered to have failed in all those who underwent surgical treatment and those with satisfaction ratings of "moderately dissatisfied" or "very dissatisfied."

RESULTS

Follow-up outcomes were obtained in 40 of 49 patients (82%), with an average follow-up time of 4.2 years. Of the RCTs, 9 (22%) were small (<1 cm), 22 (54%) were medium (>1 cm to <3 cm), and 9 (22%) were large (>3 cm to <5 cm). Grade I fatty infiltration was seen on 25% of magnetic resonance imaging scans (n = 10). Rotator cuff repair was performed in 18 patients (45%) following an average of 6 months of nonoperative treatment (range, 3-12 months). Nonoperative treatment was determined to have failed in 23 of 40 patients (58%) in total. Conservative management was more likely to fail in patients with multiple tendons torn (P = .014). Tear size and retraction were not significantly different between patients who underwent surgery and those who did not. Patients who underwent surgical management had an 83% satisfaction rate at final follow-up compared with a 55% satisfaction rate for patients who did not undergo surgery (P = .054). There was no statistically significant difference in the American Shoulder and Elbow Surgeons score or visual analog scale score between these groups. Although patients who underwent surgery had a higher mean Single Alpha Numeric Evaluation score (86.3 vs. 75.1, P = .041), this difference was below the previously established minimal clinically important difference.

CONCLUSION

Nonoperative treatment remains a viable option for certain patients with traumatic RCTs; however, the results of our study demonstrate a considerable early failure rate. This study further supports historical literature demonstrating reliably successful outcomes with surgical treatment of acute, traumatic RCTs.

A composite PET-matrix patch enhances tendon regeneration and tendon-to-bone integration for bridging repair of the chronic massive rotator cuff tears in a rabbit model

In recent years, bridging repair has emerged as an effective approach for the treatment of massive rotator cuff tears (MRCTs). The objective of this study was to develop a composite patch that combines superior mechanical strength and biocompatibility and evaluate its potential for enhancing the outcomes of bridging repair for MRCTs. The composite patch, referred to as the PET-matrix patch (PM), was fabricated by immersing a plain-woven PET patch in decellularized matrix gel and utilizing the freeze-drying technique. The results demonstrated that the PM has reliable mechanical properties, with a maximum failure load of up to 480 N. The decellularized matrix sponge (DMS), present on the surface of the PM, displayed a loose and porous structure, with an average pore size of 62.51 μm and a porosity of 95.43%. In vitro experiments showed significant elongation of tenocytes on the DMS, with cells spanning across multiple pores and extending multiple protrusions as observed on SEM images. In contrast, tenocytes on the PET patch appeared smaller in size and lacked significant elongation. Additionally, the DMS facilitated the proliferation, migration and differentiation of tenocytes. In a rabbit model of chronic MRCTs, the PM group showed superior outcomes compared to the PET group at 4, 8 and 12 weeks after bridging repair. The PM group displayed significantly higher tendon maturing score, larger collagen diameter in the regenerated tendon and improved tendon-to-bone healing scores compared to the PET group (P < 0.05). Moreover, the maximum failure load of the tendon-bone complex in the PM group was significantly higher than that in the PET group (P < 0.05). In summary, the PM possesses reliable mechanical properties and excellent cytocompatibility, which can significantly improve the outcomes of bridging repair for chronic MRCTs in rabbits. Therefore, it holds great potential for clinical applications.

Clinical and Structural Outcomes of Arthroscopic Rotator Cuff Repair in Patients Over 75 Years Are Comparable to Those in Younger Patients: A Propensity Score-Matched Comparative Study

PURPOSE

To compare clinical and structural outcomes of arthroscopic rotator cuff repair (ARCR) in patients over 75 years and those under 75 years and to analyze the factors associated with retear and clinical outcomes after ARCR.

METHODS

This retrospective study reviewed patients who underwent ARCR between 2011 and 2021 with at least 2 years of follow-up. Using propensity score matching for sex, tear size, subscapularis involvement, and follow-up time, this study included 54 patients older than 75 years (group A) and 54 patients younger than 75 years (group B). Cuff integrity was evaluated using magnetic resonance imaging (MRI). Structural and clinical outcomes were compared between the 2 groups.

RESULTS

The mean improvements in external rotation (P = .030) and the American Shoulder and Elbow Surgeons (ASES) score (P = .043) were significantly higher in group A. Visual analog scales for pain and function, ASES score, and Constant score were significantly improved in both groups (all P = .001). On routine postoperative MRI at 6 months, the retear rate was 20.4% (11/54) in group A and 18.5% (10/54) in group B with no statistical difference between the 2 groups (P = .808). Factor analysis in group A showed that follow-up duration (P = .019), tear size in mediolateral dimension (P = .037), occupation ratio (P = .036), and incomplete repair (P = .034) were associated with retear, and mild glenohumeral arthritis (P = .003) and subscapularis involvement (P = .018) were associated with inferior Constant score.

CONCLUSIONS

Clinical and structural outcomes after ARCR in patients aged 75 years or older are comparable to those in patients younger than 75 years.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

Lineage tracing reveals a novel PDGFRβ+ satellite cell subset that contributes to myo-regeneration of chronically injured rotator cuff muscle

Massive rotator cuff (RC) tendon tears are associated with progressive fibro-adipogenesis and muscle atrophy that altogether cause shoulder muscle wasting. Platelet derived growth factor β (PDGFRβ) lineage cells, that co-express PDGFRα have previously been shown to directly contribute to scar formation and fat accumulation in a mouse model of irreversible tendon and nerve transection (TTDN). Conversely, PDGFRβ+ lineage cells have also been  shown to be myogenic in cultures and in other models of skeletal muscle injury. We therefore hypothesized that PDGFRβ demarcates two distinct RC residing subpopulations, fibro-adipogenic and myogenic, and aimed to elucidate the identity of the PDGFRβ myogenic precursors and evaluate their contribution, if any, to RC myo-regeneration. Lineage tracing revealed increasing contribution of PDGFRβ+ myo-progenitors to the formation of GFP+ myofibers, which were the most abundant myofiber type in regenerated muscle at 2 weeks post-TTDN. Muscle regeneration preceded muscle atrophy and both advanced from the lateral site of tendon transection to the farthest medial region. GFP+/PDGFRβ+Sca-1-lin-CXCR4+Integrin-β1+ marked a novel subset of satellite cells with confirmed myogenic properties. Further studies are warranted to identify the existence of PDGFRβ+ satellite cells in human and other mouse muscles and to define their myo-regenerative potential following acute and chronic muscle injury.

Natural History of Quantitative Fatty Infiltration and 3D Muscle Volume After Nonoperative Treatment of Symptomatic Rotator Cuff Tears: A Prospective MRI Study of 79 Patients

BACKGROUND

The severity of fatty infiltration (FI) predicts the treatment outcome of rotator cuff tears. The purpose of this investigation was to quantitatively analyze supraspinatus (SSP) muscle FI and volume at the initial presentation and after a 3-month minimum of conservative management. We hypothesized that progression of FI could be predicted with initial tear size, FI, and muscle volume.

METHODS

Seventy-nine shoulders with rotator cuff tears were prospectively enrolled, and 2 magnetic resonance imaging (MRI) scans with 6-point Dixon sequences were acquired. The fat fraction within the SSP muscle was measured on 3 sagittal slices, and the arithmetic mean was calculated (FI SSP ). Advanced FI SSP was defined as ≥8%, pathological FI SSP was defined as ≥13.5%, and relevant progression was defined as a ≥4.5% increase in FI SSP . Furthermore, muscle volume, tear location, size, and Goutallier grade were evaluated.

RESULTS

Fifty-seven shoulders (72.2%) had normal FI SSP , 13 (16.5%) had advanced FI SSP , and 9 (11.4%) had pathological FI SSP at the initial MRI scan. Eleven shoulders (13.9%) showed a ≥4.5% increase in FI SSP at 19.5 ± 14.7 months, and 17 shoulders (21.5%) showed a ≥5-mm 3 loss of volume at 17.8 ± 15.3 months. Five tears (7.1%) with initially normal or advanced FI SSP turned pathological. These tears, compared with tears that were not pathological, had significantly higher initial mediolateral tear size (24.8 compared with 14.3 mm; p = 0.05), less volume (23.5 compared with 34.2 mm 3 ; p = 0.024), more FI SSP (9.6% compared with 5.6%; p = 0.026), and increased progression of FI SSP (8.6% compared with 0.5%; p < 0.001). An initial mediolateral tear size of ≥20 mm yielded a relevant FI SSP progression rate of 81.8% (odds ratio [OR], 19.0; p < 0.001). Progression rates of 72.7% were found for both initial FI SSP of ≥9.9% (OR, 17.5; p < 0.001) and an initial anteroposterior tear size of ≥17 mm (OR, 8.0; p = 0.003). Combining these parameters in a logistic regression analysis led to an area under the receiver operating characteristic curve (AUC) of 0.913. The correlation between FI SSP progression and the time between MRI scans was weak positive (ρ = 0.31).

CONCLUSIONS

Three risk factors for relevant FI progression, quantifiable on the initial MRI, were identified: ≥20-mm mediolateral tear size, ≥9.9% FI SSP , and ≥17-mm anteroposterior tear size. These thresholds were associated with a higher risk of tear progression: 19 times higher for ≥20-mm mediolateral tear size, 17.5 times higher for ≥9.9% FI SSP , and 8 times higher for ≥17-mm anteroposterior tear size. The presence of all 3 yielded a 91% chance of ≥4.5% progression of FI SSP within a mean of 19.5 months.

LEVEL OF EVIDENCE

Diagnostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Re-tear after arthroscopic rotator cuff tear surgery: risk analysis using machine learning

BACKGROUND

Postoperative rotator cuff retear after arthroscopic rotator cuff repair (ARCR) is still a major problem. Various risk factors such as age, gender, and tear size have been reported. Recently, magnetic resonance imaging-based stump classification was reported as an index of rotator cuff fragility. Although stump type 3 is reported to have a high retear rate, there are few reports on the risk of postoperative retear based on this classification. Machine learning (ML), an artificial intelligence technique, allows for more flexible predictive models than conventional statistical methods and has been applied to predict clinical outcomes. In this study, we used ML to predict postoperative retear risk after ARCR.

METHODS

The retrospective case-control study included 353 patients who underwent surgical treatment for complete rotator cuff tear using the suture-bridge technique. Patients who initially presented with retears and traumatic tears were excluded. In study participants, after the initial tear repair, rotator cuff retears were diagnosed by magnetic resonance imaging; Sugaya classification types IV and V were defined as re-tears. Age, gender, stump classification, tear size, Goutallier classification, presence of diabetes, and hyperlipidemia were used for ML parameters to predict the risk of retear. Using Python's Scikit-learn as an ML library, five different AI models (logistic regression, random forest, AdaBoost, CatBoost, LightGBM) were trained on the existing data, and the prediction models were applied to the test dataset. The performance of these ML models was measured by the area under the receiver operating characteristic curve. Additionally, key features affecting retear were evaluated.

RESULTS

The area under the receiver operating characteristic curve for logistic regression was 0.78, random forest 0.82, AdaBoost 0.78, CatBoost 0.83, and LightGBM 0.87, respectively for each model. LightGBM showed the highest score. The important factors for model prediction were age, stump classification, and tear size.

CONCLUSIONS

The ML classifier model predicted retears after ARCR with high accuracy, and the AI model showed that the most important characteristics affecting retears were age and imaging findings, including stump classification. This model may be able to predict postoperative rotator cuff retears based on clinical features.

Influence of body mass index on severity of rotator cuff tears

BACKGROUND

Research on the relationship between obesity and rotator cuff tears (RCTs) has been limited to the impact of obesity on the results of arthroscopic repair of RCTs; thus, a need for rigorous research controlling for other factors affecting RCTs is warranted, especially to better understand the impact of body mass index (BMI) on RCT severity.

METHODS

A retrospective study of admission records contained in electronic medical records pertaining to patients who were admitted for RCT repair on 1 shoulder between January 2018 and July 2022 was conducted. In total, 386 patients were included. In accordance with guidance regarding obesity from Taiwan's Ministry of Health and Welfare, patients were divided into three groups: underweight or normal weight (BMI <24.0 kg/m2), overweight (BMI 24.0-26.9 kg/m2), or obese (BMI ≥27.0 kg/m2). Magnetic resonance imaging was used to assess RCT severity in terms of four parameters: Patte stage (PS), fatty infiltration (FI), anteroposterior tear size (AP), and retraction size. Multinomial logistic regression analysis was performed on PS and FI grade data, and multiple linear regression analysis was performed on AP tear size and retraction size in order to analyze impact.

RESULTS

Our results revealed that the average age of the 386 patients was 63.41 years (SD = 9.29) and the mean BMI was 25.88 (SD = 3.72) kg/m2. We found significant differences in PS (P = .003), FI (P < .001), retraction size (P = .001), and AP tear size (P = .001) among patients who were underweight or normal weight, overweight, and obese. After controlling for other risk factors, including age, gender, RCT-prone occupation, duration of shoulder pain prior to surgery, history of shoulder injury, and tobacco use, we found that obese patients had higher severity levels in PS (B = 1.21, OR = 3.36, P = .029), FI (B = 1.38, OR = 3.96, P < .001), retraction size (β = 0.18, P = .001), and AP tear size (β = 0.18, P = .001) compared to underweight or normal weight patients.

CONCLUSIONS

Our study demonstrates that a correlation exists between BMI-measured obesity and RCT severity. We therefore suggest that adults control their weight given that maintaining a healthy weight is highly associated with better shoulder health.

When is a Reverse Shoulder Arthroplasty Indicated for a Rotator Cuff Tear?

Rotator cuff tears are the most frequent shoulder injury in patients over 50 years old. Treatment of rotator cuff tears is individualized based on the age, demands, and symptoms of the patient. Nonoperative treatment may often be effective, especially in lower-demand or elderly patients. Surgical repair is indicated after failure of nonoperative treatment or in patients whose high-demand lifestyle requires full strength and function of the shoulder. In older patients, larger tears are less likely to heal and rotator cuff repair may not reliable. In cases of failed previous rotator cuff repair, there may not be enough viable tissue for complete repair. If there is underlying arthritis, a rotator cuff repair is unlikely to resolve all symptoms, and treatment to care for the arthritis and rotator cuff tear is indicated. Reverse shoulder arthroplasty provides the surgical answer for these scenarios and is now being used for numerous indications of shoulder pathology.

Interventions used to mitigate muscle fatty degeneration following the repair of massive rotator cuff tears. A systematic review of animal studies

BACKGROUND

Muscle fatty degeneration following rotator cuff tears has been unequivocally associated with poorer functional outcomes and increased risk for retear following rotator cuff repair. Promising results have emerged from animal studies, with the implementation of various interventions for biologic inhibition of this fatty muscle degeneration. The lack of high quality randomized human evidence on this topic, increases the impact of pooled results from animal literature. The aim of the present study was to systematically review the available published literature for animal studies evaluating the ability of several interventions used to mitigate muscle fatty degeneration following the repair of massive rotator cuff tears.

PATIENTS AND METHODS

A comprehensive search was conducted on Pubmed, Scopus and Google Scholar, covering the period from conception until 16th April 2022. Datasets were stratified based on the type of intervention performed. SYRCLE risk of bias instrument was implemented for quality assessment of the included studies.

RESULTS

Rotator cuff repair augmentation with Adipose derived stem cells (ADSC's), Mesenchymal stem cells (MSC's) and Nandrolone was effective against fatty infiltration, but less effective against muscle atrophy. More beneficial effect was shown by the utilization of Beige adipose tissue - Fibroadipogenic progenitors (BAT-FAP) stimulation, using either Amibregon or BAT-FAPs transplantation. Both provided good results in mitigating muscle atrophy, fatty infiltration and fibrosis.

DISCUSSION

ADSC's, MSC's, Nandrolone and BAT-FAP stimulation may have a role in mitigating muscle fatty degeneration following rotator cuff tears. Large scale human studies are required to further elucidate their role in the clinical setting.

LEVEL OF EVIDENCE

V; systematic review of pre-clinical studies.

Defining Endogenous Mitochondrial Transfer in Muscle After Rotator Cuff Injury

BACKGROUND

Rotator cuff muscle degeneration leads to poor clinical outcomes for patients with rotator cuff tears. Fibroadipogenic progenitors (FAPs) are resident muscle stem cells with the ability to differentiate into fibroblasts as well as white and beige adipose tissue. Induction of the beige adipose phenotype in FAPs has been shown to improve muscle quality after rotator cuff tears, but the mechanisms of how FAPs exert their beneficial effects have not been fully elucidated.

PURPOSE

To study the horizontal transfer of mitochondria from FAPs to myogenic cells and examine the effects of β-agonism on this novel process.

STUDY DESIGN

Controlled laboratory study.

METHODS

In mice that had undergone a massive rotator cuff tear, single-cell RNA sequencing was performed on isolated FAPs for genes associated with mitochondrial biogenesis and transfer. Murine FAPs were isolated by fluorescence-activated cell sorting and treated with a β-agonist versus control. FAPs were stained with mitochondrial dyes and cocultured with recipient C2C12 myoblasts, and the rate of transfer was measured after 24 hours by flow cytometry. PdgfraCreERT/MitoTag mice were generated to study the effects of a rotator cuff injury on mitochondrial transfer. PdgfraCreERT/tdTomato mice were likewise generated to perform lineage tracing of PDGFRA+ cells in this injury model. Both populations of transgenic mice underwent tendon transection and denervation surgery, and MitoTag-labeled mitochondria from Pdgfra+ FAPs were visualized by fluorescent microscopy, spinning disk confocal microscopy, and 2-photon microscopy; overall mitochondrial quantity was compared between mice treated with β-agonists and dimethyl sulfoxide.

RESULTS

Single-cell RNA sequencing in mice that underwent rotator cuff tear demonstrated an association between transcriptional markers of adipogenic differentiation and genes associated with mitochondrial biogenesis. In vitro cocultures of murine FAPs with C2C12 cells revealed that treatment of cells with a β-agonist increased mitochondrial transfer compared to control conditions (17.8% ± 9.9% to 99.6% ± 0.13% P < .0001). Rotator cuff injury in PdgfraCreERT/MitoTag mice resulted in a robust increase in MitoTag signal in adjacent myofibers compared with uninjured mice. No accumulation of tdTomato signal from PDGFRA+ cells was seen in injured fibers at 6 weeks after injury, suggesting that FAPs do not fuse with injured muscle fibers but rather contribute their mitochondria.

CONCLUSION

The authors have described a novel process of endogenous mitochondrial transfer that can occur within the injured rotator cuff between FAPs and myogenic cells. This process may be leveraged therapeutically with β-agonist treatment and represents an exciting target for improving translational therapies available for rotator cuff muscle degeneration.

CLINICAL RELEVANCE

Promoting endogenous mitochondrial transfer may represent a novel translational strategy to address muscle degeneration after rotator cuff tears.

Management of irreparable subscapularis tears: Current concepts

Primary repair of acute subscapularis (SSC) tears provides excellent results, but tendon retraction, muscle atrophy, fatty infiltration, and humeral head migration may render a more chronic tear irreparable. These irreparable SSC tears present a diagnostic and treatment challenge for orthopaedic surgeons. Careful physical examination and imaging evaluation can help to distinguish those with reparable versus irreparable tears, but they are still not very reliable due to the methodological limitations of current evidence. Therefore, future research using 3D and quantitative measurement techniques is necessary to better predict the irreparability of the SSC. When conservative treatment of an irreparable SSC tear fails, reversed shoulder arthroplasty has been established as the preferred treatment option for older, low-demand patients with arthropathy, providing reliable improvements in pain and function. In younger patients without significant arthropathy, musculotendinous transfers are the treatment of choice. The pectoralis major transfer is historically the most frequently performed procedure and provides improved range of motion and pain relief, but fails to adequately restore strength and shoulder function. The latissimus dorsi transfer has gained increased interest over the last few years due to its biomechanical superiority, and early clinical studies suggest improved outcomes as well. More recently, anterior capsular reconstruction has been proposed as an alternative to musculotendinous transfers, but clinical data are completely lacking. Future high-quality randomised controlled trials are necessary to reliably compare the different musculotendinous transfers and anterior capsular reconstruction.

Preoperative vitamin D supplementation is a cost-effective intervention in arthroscopic rotator cuff repair

BACKGROUND

This study investigates the potential role of preoperative 25(OH)D supplementation as a cost-effective strategy to decrease revision rotator cuff repair (RCR) rates and lower the total health care burden from patients undergoing primary arthroscopic RCR. Previous literature has emphasized the importance of vitamin D on bone health maintenance, soft tissue healing, and outcomes in RCR. Inadequate preoperative vitamin D levels may increase revision RCR rates following primary arthroscopic RCR. Although 25(OH)D deficiency is common in RCR patients, serum screening is not routinely performed.

METHODS

A cost-estimation model was developed to determine the cost-effectiveness of both preoperative selective and nonselective 25(OH)D supplementation in RCR patients in order to reduce revision RCR rates. Prevalence and surgical cost data were obtained from published literature through systematic reviews. Cost of serum 25(OH)D assay and supplementation were obtained from public-use data. Mean and lower and upper bounds of 1-year cost savings were calculated for both the selective and nonselective supplementation scenarios.

RESULTS

Preoperative 25(OH)D screening and subsequent selective 25(OH)D supplementation was calculated to result in a mean cost savings of $6,099,341 (range: -$2,993,000 to $15,191,683) per 250,000 primary arthroscopic RCR cases. Nonselective 25(OH)D supplementation of all arthroscopic RCR patients was calculated to result in a mean cost savings of $11,584,742 (range: $2,492,401-$20,677,085) per 250,000 primary arthroscopic RCR cases. Univariate adjustment projects that selective supplementation is a cost-effective strategy in clinical contexts where the cost of revision RCR exceeds $14,824.69 and prevalence of 25(OH)D deficiency exceeds 6.67%. Additionally, nonselective supplementation is a cost-effective strategy in clinical scenarios where revision RCR cost is ≥$4216.06 and prevalence of 25(OH)D deficiency is ≥1.93%.

CONCLUSIONS

This cost-predictive model promotes the role of preoperative 25(OH)D supplementation as a cost-effective mechanism to reduce revision RCR rates and lower the overall health care burden from arthroscopic RCR. Nonselective supplementation appears to be more cost-effective than selective supplementation, likely due to the lower cost of 25(OH)D supplementation compared to serum assays.

Parathyroid Hormone Inhibits Fatty Infiltration and Muscle Atrophy After Rotator Cuff Tear by Browning of Fibroadipogenic Progenitors in a Rodent Model

BACKGROUND

Progressive fatty infiltration and muscle atrophy after rotator cuff tears lead to tendon repair failure and poor outcomes. Fibro-adipogenic progenitors (FAPs) are involved in fatty infiltration and muscle homeostasis of skeletal muscle. Inducing FAP differentiation into brown adipocyte-like "beige adipocytes" suppresses fatty infiltration and muscle atrophy.

HYPOTHESIS

Parathyroid hormone (PTH) suppresses fatty infiltration and muscle atrophy after rotator cuff tears in a rat model by browning of FAPs.

STUDY DESIGN

Controlled laboratory study.

METHODS

PTH was administered subcutaneously for 4 or 8 weeks to a rotator cuff tear model in rats. After treatment, fatty infiltration of supraspinatus muscles was assessed using Oil Red O staining and muscle atrophy using wet muscle weight and muscle fiber cross-sectional area. Costaining of platelet-derived growth factor receptor α (FAP marker) and uncoupling protein 1 (browning marker) was performed to confirm FAP browning by PTH. Mouse-isolated FAPs were cultured with PTH and evaluated for browning-related gene expression and adipogenic differentiation using BODIPY staining. Myogenic differentiation of C2C12 myoblasts was evaluated using coculture of PTH-treated browning FAPs with C2C12.

RESULTS

PTH inhibited fatty infiltration after rotator cuff tear at 8 weeks. Rotator cuff wet muscle loss of PTH-treated rats was inhibited at 4 and 8 weeks. Furthermore, PTH-treated rats demonstrated larger myofiber cross-sectional area than did untreated rats at 4 and 8 weeks. Costaining indicated colocalization of platelet-derived growth factor receptor α and uncoupling protein 1 and promoted PTH-induced FAP browning. PTH increased the expression of browning-related genes in FAPs and suppressed fat droplet accumulation in vitro. Coculture with PTH-treated FAPs promoted C2C12 cell differentiation into myotubes.

CONCLUSION

PTH induced FAP-derived beige adipocytes by upregulating browning-related gene expression, and the browning effect of PTH on FAPs inhibited fatty infiltration and muscle atrophy in the rat rotator cuff tear model. PTH might have potential as a therapeutic drug for fatty infiltration and muscle atrophy after rotator cuff tears.

CLINICAL RELEVANCE

PTH may expand treatment options for rotator cuff tears by reducing fatty infiltration and muscle atrophy after rotator cuff tears by browning of FAPs.

Factors associated with healing failure after early repair of acute, trauma-related rotator cuff tears

BACKGROUND

Healing failure after rotator cuff repair is a challenging problem. Acute, trauma-related tears are considered a separate entity and are often treated surgically. The aim of this study was to identify factors associated with healing failure in previously asymptomatic patients with trauma-related rotator cuff tears treated with early arthroscopic repair.

METHODS

This study included 62 consecutively recruited patients (23% women; median age, 61 years; age range, 42-75 years) with acute symptoms in a previously asymptomatic shoulder and a magnetic resonance imaging-verified full-thickness rotator cuff tear after shoulder trauma. All patients were offered, and underwent, early arthroscopic repair, during which a biopsy specimen was harvested from the supraspinatus tendon and analyzed for signs of degeneration. Of the patients, 57 (92%) completed 1-year follow-up and underwent assessment of repair integrity on magnetic resonance images according to the Sugaya classification. Risk factors for healing failure were investigated using a causal-relation diagram where age, body mass index, tendon degeneration (Bonar score), diabetes mellitus, fatty infiltration (FI), sex, smoking, tear location regarding integrity of the rotator cable, and tear size (number of ruptured tendons and tendon retraction) were included and analyzed.

RESULTS

Healing failure at 1 year was identified in 37% of patients (n = 21). A high degree of FI of the supraspinatus muscle (P = .01), a tear location including disruption of rotator cable integrity (P = .01), and old age (P = .03) were associated with healing failure. Tendon degeneration as determined by histopathology was not associated with healing failure at 1-year follow-up (P = .63).

CONCLUSION

Older age, increased FI of the supraspinatus muscle, and a tear including disruption of the rotator cable increased the risk of healing failure after early arthroscopic repair in patients with trauma-related full-thickness rotator cuff tears.

Prediction of Retear After Arthroscopic Rotator Cuff Repair Based on Intraoperative Arthroscopic Images Using Deep Learning

BACKGROUND

It is challenging to predict retear after arthroscopic rotator cuff repair (ARCR). The usefulness of arthroscopic intraoperative images as predictors of the ARCR prognosis has not been analyzed.

PURPOSE

To evaluate the usefulness of arthroscopic images for the prediction of retear after ARCR using deep learning (DL) algorithms.

STUDY DESIGN

Cohort study (Diagnosis); Level of evidence, 2.

METHODS

In total, 1394 arthroscopic intraoperative images were retrospectively obtained from 580 patients. Repaired tendon integrity was evaluated using magnetic resonance imaging performed within 2 years after surgery. Images obtained immediately after ARCR were included. We used 3 DL architectures to predict retear based on arthroscopic images. Three pretrained DL algorithms (VGG16, DenseNet, and Xception) were used for transfer learning. Training and test sets were split into 8:2. Threefold stratified validation was used to fine-tune the hyperparameters using the training data set. The validation results of each fold were evaluated. The performance of each model in the test set was evaluated in terms of accuracy, area under the receiver operating characteristic curve (AUC), F1-score, sensitivity, and specificity.

RESULTS

In total, 1138 and 256 arthroscopic images were obtained from 514 patients and 66 patients in the nonretear and retear groups, respectively. The mean validation accuracy of each model was 83% for VGG16, 89% for Xception, and 91% for DenseNet. The accuracy for the test set was 76% for VGG16, 87% for Xception, and 91% for DenseNet. The AUC was highest for DenseNet (0.92); it was 0.83 for VGG16 and 0.91 for Xception. For the test set, the specificity and sensitivity were 0.93 and 0.84 for DenseNet, 0.89 and 0.84 for Xception, and 0.70 and 0.80 for VGG16, respectively.

CONCLUSION

The application of DL algorithms to intraoperative arthroscopic images has demonstrated a high level of accuracy in predicting retear occurrences.

Structural Musculotendinous Parameters That Predict Failed Tendon Healing After Rotator Cuff Repair

Background

Healing of the rotator cuff after repair constitutes a major clinical challenge with reported high failure rates. Identifying structural musculotendinous predictors for failed rotator cuff repair could enable improved diagnosis and management of patients with rotator cuff disease.

Purpose

To investigate structural predictors of the musculotendinous unit for failed tendon healing after rotator cuff repair.

Study Design

Cohort study; Level of evidence, 2.

Methods

Included were 116 shoulders of 115 consecutive patients with supraspinatus (SSP) tear documented on magnetic resonance imaging (MRI) who were treated with an arthroscopic rotator cuff repair. Preoperative assessment included standardized clinical and imaging (MRI) examinations. Intraoperatively, biopsies of the joint capsule, the SSP tendon, and muscle were harvested for histological assessment. At 3 and 12 months postoperatively, patients were re-examined clinically and with MRI. Structural and clinical predictors of healing were evaluated using logistic and linear regression models.

Results

Structural failure of tendon repair, which was significantly associated with poorer clinical outcome, was associated with older age (β = 1.12; 95% CI, 1.03 to 1.26; P = .03), shorter SSP tendon length (β = 0.89; 95% CI, 0.8 to 0.98; P = .02), and increased proportion of slow myosin heavy chain (MHC)-I/fast MHC-II hybrid muscle fibers (β = 1.23; 95% CI, 1.07 to 1.42; P = .004). Primary clinical outcome (12-month postoperative Constant score) was significantly less favorable for shoulders with fatty infiltration of the infraspinatus muscle (β = -4.71; 95% CI, -9.30 to -0.12; P = .044). Conversely, a high content of fast MHC-II muscle fibers (β = 0.24; 95% CI, 0.026 to 0.44; P = .028) was associated with better clinical outcome.

Conclusion

Both decreased tendon length and increased hybrid muscle fiber type were independent predictors for retear. Clinical outcome was compromised by tendon retearing and increased fatty infiltration of the infraspinatus muscle. A high content of fast MHC-II SSP muscle fibers was associated with a better clinical outcome.

Registration

NCT02123784 (ClinicalTrials.govidentifier).

Effect of Anterior Acromial Coverage on Functional and Radiological Outcomes After Arthroscopic Repair of Anteroposterior Massive Rotator Cuff Tears

BACKGROUND

Rotator cuff tear size, fatty infiltration, and scapular morphology are correlated with tendon healing and functional outcomes after arthroscopic repair; however, the association between anteroposterior acromial coverage and the clinical outcomes of anteroposterior massive rotator cuff tears (AP-MRCTs; involving all 3 tendons) remains unclear.

PURPOSE

To identify the association between AP acromial coverage and functional and radiological outcomes after arthroscopic repair of AP-MRCTs.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 98 patients who underwent arthroscopic repair of AP-MRCTs between January 2015 and December 2020 were included in the study and classified according to whether anterior acromial coverage (AAC) was anterior (46 patients; positive AAC group) or posterior (52 patients; negative AAC group) to the scapular line on true lateral shoulder radiographs. Demographic characteristics, surgical details, and functional outcomes were prospectively collected. Acromial morphological features, global tear extension (GTE), the global fatty infiltration index (GFII), tendon integrity after repair, proximal humeral migration, and glenohumeral abduction were measured and calculated on radiographs or magnetic resonance imaging scans preoperatively and at 2 years postoperatively. Multivariate logistic regression was performed to identify the independent risk factors of a rotator cuff retear.

RESULTS

The positive AAC group showed larger AAC, posterior acromial tilt, and anterior acromial slope as well as smaller posterior acromial coverage compared with the negative AAC group. Postoperatively, the American Shoulder and Elbow Surgeons score (82.5 ± 8.3 vs 77.2 ± 11.5, respectively; P = .013), active abduction (157.8°± 27.1° vs 142.7°± 39.6°, respectively; P = .048), and glenohumeral abduction (45.6°± 10.4° vs 39.7°± 14.9°, respectively; P = .041) in the positive AAC group were significantly higher than those in the negative AAC group, while the retear rate (23.9% vs 44.2%, respectively; P = .035) and proximal humeral migration (1.7 ± 1.0 vs 2.3 ± 1.2 mm, respectively; P = .006) were significantly lower in the positive AAC group than in the negative AAC group. Smaller AAC (odds ratio [OR], 0.93 [95% CI, 0.87-1.00]; P = .040), larger GTE (OR, 1.03 [95% CI, 1.01-1.06]; P = .017), and a higher GFII (OR, 3.49 [95% CI, 1.09-11.19]; P = .036) were associated with an increased risk of a rotator cuff retear.

CONCLUSION

Increased AAC was associated with a lower retear rate and better functional outcomes after arthroscopic repair of AP-MRCTs. A preliminary risk evaluation integrating GTE, the GFII, and AAC is recommended to consider the necessity of additional procedures for patients in need of arthroscopic rotator cuff repair.

Modifiable and Nonmodifiable Risk Factors Associated with the Development of Recurrent Rotator Cuff Tears

Nonoperative and operative strategies exist to manage rotator cuff pathology. Although surgical repair is successful for most patients, others may experience retear or nonhealing of the rotator cuff. Several modifiable and nonmodifiable risk factors are associated with an increased retear rate. The literature shows consistency and agreement regarding many of these risk factors, most notably, patient age, tear size, and rotator cuff muscular atrophy, whereas others remain controversial. It is important that shoulder surgeons are familiar with modifiable and nonmodifiable risk factors associated with retear, to better advise patients and optimize their chances of success following rotator cuff repair surgery.

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

BACKGROUND

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

PURPOSE

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

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

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

RESULTS

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

CONCLUSION

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

Volumetric Analysis of Subacromial Space After Superior Capsular Reconstruction for Irreparable Rotator Cuff Tears

Purpose

Subacromial volume measurement on magnetic resonance images is relatively new. It has been shown that decreased subacromial volume increases after surgical repair of full-thickness rotator cuff tears. There is no study examining subacromial volume changes after superior capsular reconstruction (SCR). The purpose of this study was to compare subacromial volume changes on magnetic resonance images (MRI) after superior capsular reconstruction performed for primary irreparable rotator cuff tears.

Methods

Patients who underwent an SCR procedure between 2017 and 2019 with a minimum 2-year postoperative follow-up were included in this retrospective study. Subacromial volume was measured on MRI using software. The preoperative and postoperative acromiohumeral distance, Constant Scores, graft thickness, and Hamada grades of the patients were evaluated.

Results

A total of 18 patients with a mean age of 59.7 years (range: 49-74 years) underwent an SCR for massive irreparable cuff tear. The mean preoperative subacromial volume was 3.54 ± 0.39 cm3 (range 2.88-4.36 cm3), which increased to 4.46 ± 0.39 cm3 (range 3.75-5.32 cm3) postoperatively (p =  < 0.001). The increase in subacromial volume and acromiohumeral distance did not correlate with Constant scores and graft thickness. We observed a significantly higher subacromial volume increase among Hamada grade 1 patients, compared to those with Hamada grade 2 (p = 0.011).

Conclusions

We observed that subacromial volume significantly increased after superior capsular reconstruction. However, the increase in subacromial volume did not correlate with clinical scores, acromiohumeral distance changes, or graft thickness.Level of evidence: Level III - Retrospective Cohort Study.

The Modified Assessment Tool Based on Scapular Y-View for Global Fatty Infiltration in the Supraspinatus Muscle: Correlation, Predictive Performance, and Reliability Analyses

BACKGROUND

The accurate evaluation of rotator cuff (RC) fatty degeneration after tears is critical for appropriate surgical decision making and prognosis. However, there is currently no reliable and practical tool to reflect the global fatty infiltration (Global-FI) throughout the 3-dimensional (3D) volumetric RC muscles.

PURPOSE

(1) To determine the correlations between 2 modified assessment tools and the Global-FI and their predictive performances and reliabilities for Global-FI prediction, and (2) to compare these predictive parameters with those of the conventional tool using a single scapular Y-view slice.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

A total of 49 patients with full-thickness RC tears scheduled to undergo arthroscopic repairs were included, and their surgical shoulders underwent 6-point Dixon magnetic resonance imaging preoperatively. The Global-FI was measured by calculating the 3D-volumetric fat fraction (FF) of the whole supraspinatus muscle through all acquired oblique sagittal slices. As a commonly used radiological landmark, the scapular Y-view was used to evaluate single-plane fatty infiltration (Y-FI) by calculating the FF in 1 slice, defined as the conventional assessment tool. Two modified assessment tools expand the analytic imaging by integrating the FFs from the scapular Y-view slice and its neighboring slices, which were calculated by averaging the FFs of these 3 slices (^meanY₃-FI) and accumulating local 3D-volumetric FFs from 3 slices (^volY₃-FI), respectively. The correlations between 3 assessment tools and the Global-FI were analyzed, and the predictive performance for Global-FI prediction using these tools was determined by goodness of fit and agreement. Moreover, the inter- and intraobserver reliabilities of these assessment tools were evaluated. Similar analyses were performed in the small-medium, large, or massive tear subgroups.

RESULTS

The Y-FI was significantly higher than the Global-FI in all cases and tear size subgroups, while the 2 modified assessment tools (^meanY₃-FI and ^volY₃-FI) did not significantly differ from the Global-FI. All assessment tools were significantly correlated with the Global-FI, but the ^meanY₃-FI and ^volY₃-FI showed stronger correlations than the Y-FI, which was also determined in different tear sizes. Moreover, the regression models of the ^meanY₃-FI and ^volY₃-FI showed superior goodness of fit to Y-FI in Global-FI prediction in all cases and subgroups, with larger coefficients of determination (R²) and smaller root mean square errors. The predicted Global-FI using the regression model of ^volY₃-FI had the best agreement with the measured Global-FI, followed by the ^meanY₃-FI, both showing smaller biases and standard deviation of the percentage difference between predicted- and measured Global-FI than the conventional Y-FI. In addition, the 2 modified assessment tools achieved better interobserver and intraobserver reliabilities than the conventional tool in all cases and subgroups.

CONCLUSION

Two modified assessment tools (^meanY₃-FI and ^volY₃-FI) were comparable with the Global-FI of the whole supraspinatus muscle, showing stronger correlations with the Global-FI and better predictive performances and reliabilities than the conventional tool (Y-FI). Moreover, the ^volY₃-FI was slightly superior to ^meanY₃-FI in the predictive performance and reliability.

Risk factors of tear progression in symptomatic small to medium-sized full-thickness rotator cuff tear: relationship between occupation ratio of supraspinatus and work level

BACKGROUND

Previous studies reported that full-thickness rotator cuff tear (FTRCT) is a risk factor for tear progression. However, there is no clear consensus on the risk factors of tear progression in FTRCT.

PURPOSE

To identify the demographic and radiologic risk factors of tear progression in small to medium FTRCTs.

METHODS

We retrospectively reviewed 81 shoulders of patients diagnosed with small or medium FTRCTs using magnetic resonance imaging (MRI) who underwent conservative treatment from January 2017 to November 2021. Various demographic factors, including patient work level and radiological factors such as atrophy of rotator cuff muscles were analyzed to evaluate their association with tear progression. Work level was divided into high (heavy manual labor), medium (manual labor with less activity), and low (sedentary work activity). The atrophy of rotator cuff muscles was calculated by occupation ratio.

RESULTS

Tear progression was observed in 48% (39/81) of patients (criterion for tear progression was medial-lateral or anterior-posterior tear length > 5 mm). In patients with tear progression, the lengths of medial-lateral and anterior-posterior tears progressed by 6 mm and 3 mm, respectively. Among the rotator cuff muscles, fatty degeneration and occupation ratio of the supraspinatus were only worsened (P = .014, P = 0.013, respectively). The mean MRI follow-up duration was 14.8 ± 9.0 months. The significant risk factors of tear progression were high work level (odds ratio [OR], 7.728; 95% CI, 1.204-49.610; P = .031), and occupation ratio of the supraspinatus muscle (OR, 0.308; 95% CI, 0.158-0.604; P = .001). The optimal cutoff value for the occupation ratio of the supraspinatus was 0.55 (sensitivity 74%, specificity 62%).

CONCLUSIONS

Tear progression was observed in approximately 50% of patients with symptomatic small to medium FTRCTs. High physical work level and atrophy of the supraspinatus muscle were independent risk factors of tear progression. The risk of tear progression increases with occupation ratio of the supraspinatus muscle < 0.55 and heavy manual labor.

The 3-Dimensional Fatty Infiltration in the Overall Supraspinatus Can Be Predicted by Localized Sectional Accumulation Units: A Cross-Sectional Study in Patients with Atraumatic Small-to-Massive Rotator Cuff Tears

BACKGROUND

Fatty infiltration (FI) of the rotator cuff (RC) muscles is one of the most common risk factors for a retear following RC repair. Recent methodological developments focus on using 3-dimensional measurements of the overall FI of RC muscles instead of using single-plane-based measurements. However, the required labor-intensive segmentation and time-consuming post-processing steps need to be optimized for routine clinical use.

METHODS

We collected all 6-point Dixon magnetic resonance imaging (MRI) slices of the overall supraspinatus in 46 patients with atraumatic small-to-massive RC tears. Using emerging techniques, the overall 3-dimensional FI of the supraspinatus (overall FI, using all N slices) was assessed as the reference. Each sagittal segment of the supraspinatus was defined as a sectional accumulation unit (SAU). The localized FI in SAUs with different scales of N/3, N/6, and N/12 slices (SAU-FIs) was then calculated using piecewise accumulation by stacking neighboring slices after the overall supraspinatus had been sequentially segmented using MRI slices of the same thickness. The capacity of the SAU-FIs to predict the overall FI, and the ideal locations for prediction, were evaluated using linear regression models after the associations were examined. Goodness-of-fit of the regression models was appraised by the coefficient of determination (R 2 ) and root-mean-square error (RMSE). The agreement between the predicted and measured overall FI was assessed using Bland-Altman analysis and the standard deviation of the percent differences (sd%).

RESULTS

The localized SAU-FIs of the N/3, N/6, and N/12 SAUs generally displayed comparable distributions throughout the normalized distal-proximal long axis of the supraspinatus. The localized SAU-FIs showed substantial correspondence with the overall FI, and the highest correlations were found in the 2/3 SAU (Pearson r and Spearman ρ: 0.95, 0.98), 3/6 and 4/6 SAUs (Pearson r and Spearman ρ: 0.97), and 5/12 to 7/12 SAUs (Pearson r and Spearman ρ: 0.95 to 0.96). The strongest predictors to estimate the overall supraspinatus FI in the regression analysis were these SAU-FIs located in the middle third, which demonstrated good fits to the overall FI (all R 2 ≥ 0.90; RMSE ≤ 1.69). The best agreements between the overall FI predicted by the regression models and the measured overall FI were found in these SAUs (2/3 SAU: sd% = 4.84%; 3/6 and 4/6 SAUs: sd% = 5.14%; 5/12 to 7/12 SAUs: sd% = 6.44%).

CONCLUSIONS

Specific SAUs near the center of the supraspinatus (2/3, 3/6 and 4/6, and 5/12 to 7/12 SAUs), which displayed the best agreement between the predictions and actual measurements of overall FI values, can serve as appropriate surrogates to estimate the overall FI of the supraspinatus in small-to-massive RC tears. The potential to assess the overall FI of the supraspinatus using specific localized SAUs may improve the speed of analytical strategies for accurately assessing the overall FI of RC muscles and thus enable their routine clinical use in the future.

LEVEL OF EVIDENCE

Prognostic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Synthetic polytetrafluoroethylene patches for irreparable rotator cuff tears-how are they doing at 5 years?

BACKGROUND

Treating massive and irreparable rotator cuff tears are problematic. Several studies have reported that polytetrafluoroethylene (PTFE) patches demonstrated excellent construct integrity and positive clinical and patient outcomes. However, these studies either had small sample sizes or short follow-up periods.

PURPOSE

To determine the survivorship, efficacy, and medium-term (2-19 years) outcomes of PTFE patch repairs.

METHODS

This retrospective study used prospectively collected data to establish the medium-term outcomes of PTFE interposition patch repairs for massive rotator cuff tears that could not be repaired by the standard technique. Patients included those who met the ≥2-year follow-up criteria post repair. Standardized assessments of patient-ranked shoulder pain and function and shoulder strength and passive range of motion (ROM) were performed preoperatively and at follow-up visits. Radiographs and ultrasonography were used to evaluate repair integrity, measure proximal humeral head migration, and determine glenohumeral arthritis scores.

RESULTS

Forty-one shoulders formed the study cohort at a mean follow-up period of 5 years (range: 2-19 years). The mean age of this group was 72 (standard deviation: 10; range: 50-88) and had 14 cm² tears at surgery. Twenty-five of 41 (61%) PTFE interposition patch repairs remained intact at an average of 5 years postrepair. Thirteen patches failed at the patch-tendon junction, 1 was removed, and 2 patients underwent reverse total shoulder replacement. Patient-ranked shoulder stiffness (P < .05), frequency of pain during activity and sleep (P < .001), pain levels during overhead activity and rest (P < .001), and overall shoulder function significantly improved from bad preoperatively to fair at the mean 5-year postoperative visit (P < .001). No significant improvements were demonstrated in dynamometer-measured shoulder strength maneuvers and passive ROM. All patients demonstrated proximal humeral head migration on shoulder radiographs regardless of repair integrity (mean Upper Migration Index = 1.2). Failed repairs were associated with higher mean preoperative glenohumeral arthritis grades compared with intact repairs (grade 2 in failed repairs compared with grade 1 in intact repairs) (P < .01).

CONCLUSION

PTFE interposition patch repairs for massive and irreparable tears had good construct integrity and clinical outcomes at 2 years. These outcomes were not maintained. PTFE patch repairs often failed at the patch-tendon junction at 4 years and beyond and were ineffective in (1) preventing proximal humeral head migration, (2) stopping progression of glenohumeral arthritis, and (3) improving shoulder strength and ROM.

The quantification of muscle activities during arm elevation following reverse shoulder arthroplasty or superior capsular reconstruction for irreparable rotator cuff tears using positron emission tomography

BACKGROUND

Reverse shoulder arthroplasty (RSA) and superior capsular reconstruction (SCR) are recognized as surgical options for an irreparable rotator cuff tear. However, the postoperative changes of the muscle activity patterns remain unclear. The purpose of this study was to investigate the quantified muscle activities on shoulder elevation in patients treated with RSA or SCR using fluorine-18-labelled fluorodeoxyglucose-positron emission tomography.

METHODS

Asymptomatic shoulders that underwent RSA or SCR and those without a rotator cuff tear were analyzed as the RSA, SCR, and control groups. All subjects underwent shoulder elevation exercise, followed by a fluorine-18-labelled fluorodeoxyglucose-positron emission tomography examination. Using previously established methods to quantify the uptake of each muscle on positron emission tomography images, the standard uptake values (SUVs) for 16 portions of the deltoid, rotator cuff, and periscapular muscles were obtained to compare the muscle activity patterns among 3 groups.

RESULTS

The deltoid muscle showed the most characteristic differences according to the surgeries. The mean SUVs of the anterior, middle, and posterior deltoid were 3.3, 3.7, and 1.5 for the RSA group; 2.7, 4.2, and 1.5 for the SCR group; and 1.3, 2.0, and 0.9 for the control group, respectively. In comparison to the control group, both the RSA and SCR groups showed significantly increased SUVs at all portions of the deltoid muscle. The RSA group showed similar SUVs for the anterior and middle deltoid, whereas the SCR and control groups showed greatest SUVs at the middle deltoid. In addition, the serratus anterior, levator scapulae, and upper portion of the trapezius in the RSA group showed greater SUVs than in the control group.

CONCLUSION

The deltoid muscle showed increased activity in the RSA and SCR groups. The middle deltoid was mainly used in the SCR group, whereas the anterior and middle deltoid, as well as the upward rotator muscles of the scapula, were mainly used in the RSA group.

The relationship between preoperative Goutallier stage and retear rates following posterosuperior rotator cuff repair: a systematic review

BACKGROUND

An association between higher preoperative Goutallier stage and higher retear rates following primary rotator cuff repairs has been previously reported. However, there are few reviews which have described clear retear rates for each repaired tendon classified according to preoperative Goutallier stage. The purpose of this study was therefore to systematically review the literature on the relationship between preoperative Goutallier stage and retear rates and provide predictable retear rates following primary repair of posterosuperior rotator cuff tears.

METHODS

A systematic literature review was performed in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and checklist utilizing PubMed, MEDLINE, and Cochrane Library. English-language studies of Level I through IV evidence examining the clinical results of primarily repaired posterosuperior rotator cuff tears as a function of Goutallier stage using magnetic resonance imaging were included. The primary outcome of interest was retear rates according to preoperative Goutallier stage. As a secondary outcome, rotator cuff tears were divided into 2 subgroups (Goutallier stage 0-2 and 3-4) and retear rates were assessed between the 2 subgroups. A random effects model with binomial within-study variance was used for both outcomes.

RESULTS

Nine studies (687 shoulders) satisfied all inclusion criteria and reported sufficient data for statistical analysis. In the supraspinatus muscle group, rotator cuff muscles with preoperative Goutallier stages of 0, 1, and 2 had retear rates of 19.1%, 27.8%, and 33.5%, respectively, with no significant differences between each category. In contrast, when preoperative Goutallier stage of 3 and 4 existed, significant differences compared to Goutallier 0, 1, and 2 were observed with a retear rate of 74.1% and 78.5%, respectively. In the infraspinatus muscle group, the retear rates following rotator cuff repairs were 20.0%, 32.1%, and 35.1% in Goutallier 0, 1, and 2, respectively, with no significant differences between each category. In Goutallier 3 and 4, the rate was 76.6% and 100.0%, respectively, with significant differences compared to Goutallier 0, 1, and 2.

CONCLUSION

The results of this study have clearly demonstrated that retear rates following surgical repair of the rotator cuff increased in proportion to the preoperative Goutallier stage in both the supraspinatus and infraspinatus muscles.

Older age and higher body mass index are independent risk factors for tendon healing in small- to medium-sized rotator cuff tears

PURPOSE

Many previous research efforts have been made to identify prognostic factors for rotator cuff healing. However, majority of these studies were conducted with heterogeneous cohorts consisted of different tear characteristics. Healing properties of a rotator cuff tear may differ depending on tear characteristics such as tear size or fatty infiltration. Therefore, studies with subgroups confined by these variables may reflect more accurate results. This study aims to investigate predictive factors for rotator cuff healing in a subgroup with small- to medium-sized tears without significant fatty infiltration.

METHODS

This retrospective case-control study was conducted with 94 patients with small- to medium-sized rotator cuff tears. Mean age of patients was 56.0 ± 9.0 years and mean follow-up duration was 38.3 ± 8.1 months. Post-operative magnetic resonance imaging assessment showed that there were 75 (79.8%) successfully healed repairs and 19 (20.2%) healing failures. Age, gender, hand dominancy, body mass index (BMI), smoking habit, diabetes, corticosteroid injection, baseline clinical status, duration of surgery and biceps procedure were variables evaluated as predictive factors.

RESULTS

Both study groups showed significant improvement from baseline regarding clinical outcome measures (p < 0.05). However, successfully healed patients had significantly higher post-operative functional scores and lower pain scores (p < 0.05). The univariate analysis revealed that healing was significantly affected by age (p = 0.004), BMI (p = 0.01) and diabetes (p = 0.03). In the multivariate analysis, age (p = 0.02) and BMI (p = 0.02) were found to be significant independent factors for healing. Cutoff values for oldest age and highest BMI were 63 years and 28.1 kg/m², respectively, for a successful healing according to receiver-operating characteristic curve analysis.

CONCLUSION

Healing failure after rotator cuff repair in small- to medium-sized tears is associated with poorer outcomes. Age and BMI are independent predictive factors for healing. A successful repair is more likely in patients younger than 63 years and with BMI less than 28.1 kg/m². Surgeons should consider this information during risk assessment, decision making and patient counselling.

LEVEL OF EVIDENCE

Level III.

Re-Tear Rates Following Rotator Cuff Repair Surgery

Aim Re-tears following rotator cuff repair surgery are a common occurrence. Previous studies have identified several factors that have been shown to increase the risk of re-tears. The purpose of this study was to evaluate the rate of re-tear following primary rotator cuff repair and to identify the factors that may contribute to this rate. Method The authors performed a retrospective review, looking at rotator cuff repair surgeries performed between May 2017 and July 2019 performed in a hospital by three specialist surgeons. All methods of repair were included. All patients' medical data, including imaging and operation records, were reviewed. Results A total of 148 patients were identified. Ninety-three males and 55 females with a mean age of 58 years (range 33-79 years). Thirty-four patients (23%) had post-operative imaging with either magnetic resonance imaging or ultrasound, where it was found that 20 (14%) had a confirmed re-tear. Of these patients, nine went on to have further repair surgery. The average age of the re-tear patients was 59 (age range 39-73) and 55% were female. The majority of the re-tears were from chronic rotator cuff injuries. This paper did not identify any correlation between smoking status or diabetes mellitus and re-tear rates. Conclusions This study indicates that re-tear after rotator cuff repair surgery is a common complication. The majority of studies find increasing age to be the biggest risk factor; however, this was not the case in our study which found females in their 50s to have the highest rate of re-tear. Additional research is required to understand what factors can contribute towards rotator cuff re-rupture rates.

Arthroscopic Repair Benefits Reparable Rotator Cuff Tear Patients Aged 65 Years or Older With a History of Traumatic Events

PURPOSE

To evaluate the clinical outcomes of arthroscopic rotator cuff repair at 2-year follow-up in patients aged 65 years or older with a history of traumatic events divided into groups based on symptom duration (<3 months, 3-6 months, and >6 months from injury to surgery) and to compared patient-reported outcomes among the 3 groups.

METHODS

Between 2015 and 2020, 110 patients who met the inclusion criteria were enrolled in this study; these patients were divided into 3 groups according to symptom duration: less than 3 months (group A), 3 to 6 months (group B) and more than 6 months (group C). Preoperative and 2-year postoperative clinical outcomes were compared, including American Shoulder and Elbow Surgeons, Constant-Murley, University of California, Los Angeles, Simple Shoulder Test, and visual analog scale scores; forward elevation; external rotation; and internal rotation. The minimal clinically important difference (MCID), patient acceptable symptom state, substantial clinical benefit, and maximum outcome improvement were also compared among the groups.

RESULTS

The American Shoulder and Elbow Surgeons score, as the primary outcome, improved significantly from 41.0 ± 18.5 to 85.4 ± 8.1 in group A, from 53.7 ± 14.3 to 86.3 ± 11.7 in group B, and from 49.7 ± 18.5 to 83.9 ± 11.9 in group C. All the other parameters showed statistically significant improvements at 2-year follow-up in each group (all P < .05). There was no significant difference in each parameter among the 3 groups except the visual analog scale score, which did not achieve the MCID. Overall, 86 patients (78.2%) exceeded the MCID, 87 patients (79.1%) achieved the patient acceptable symptom state, 77 patients (70.0%) achieved substantial clinical benefit, and 62 patients (56.4%) achieved maximum outcome improvement without significant differences among the 3 groups.

CONCLUSIONS

In rotator cuff tear patients aged 65 years or older with a history of traumatic events, arthroscopic rotator cuff repair significantly improves clinical outcomes at 2-year follow-up regardless of symptom duration if the tear is fully reparable.

LEVEL OF EVIDENCE

Level III, prognostic retrospective study.

Double-Row Rotator Cuff Repair Technique With Dermal Allograft Augmentation

Rotator cuff tears are common and debilitating injuries in the orthopaedic patient population. Although arthroscopic repair of the rotator cuff generally leads to satisfactory outcomes, some tears would benefit from augmentation with allograft to supplement the native tissue. This biological augmentation has been shown to decrease retear rates and can be beneficial in certain cases based on the size of the tear, amount of retraction, age of the patient, and chronicity. In this technical note, we describe a simple and effective technique for arthroscopic rotator cuff repair with biological augmentation.

Rotator Cuff Repair With Acromioplasty Is Associated With an Increased Rate of Revision and Subsequent Procedures

Purpose

To evaluate the mid-term rate of revision arthroscopic rotator cuff repair as well as ipsilateral shoulder reoperations after index rotator cuff repair performed with or without acromioplasty in the United States.

Methods

The Medicare Standard Analytic File, which encompasses the entire Medicare billing and payment data, was queried between 2005 and 2014. Patients undergoing arthroscopic rotator cuff repair were identified and stratified based on whether ipsilateral acromioplasty was concurrently performed using Current Procedural Terminology codes. Groups were matched by age, sex, year of index procedure, and Elixhauser index at a 2:1 ratio. Primary end point was defined as undergoing a repeat ipsilateral shoulder surgery related to the rotator cuff at 5 years of follow-up. Kaplan-Meier survival curves were constructed, and the 2 groups were compared using the log-rank test.

Results

After matching, 54,209 shoulders in the rotator cuff repair with acromioplasty group and 26,448 shoulders in the rotator cuff repair without acromioplasty group were identified. Shoulders undergoing concurrent acromioplasty at index rotator cuff repair had a significantly increased rate of repeat ipsilateral cuff repair at 5 years postoperatively (8.5% vs 6.8%, P < .001). Similarly, there was an increased rate of reoperation of all types to the ipsilateral shoulder in cases where concurrent acromioplasty was performed (9.6% vs 9.1%, P < .001).

Conclusions

Using a large, national database, concurrent acromioplasty at the time of rotator cuff tear was found to be associated with both an increase rate of overall subsequent procedures and revision rotator cuff repair.

Level of Evidence

III, retrospective comparative study.

Patch augmentation does not provide better clinical outcomes than arthroscopic rotator cuff repair for large to massive rotator cuff tears

PURPOSE

Patch augmentation for large and massive rotator cuff tears (LMRCTs) has been suggested as a repair strategy that can mechanically reinforce tendons and biologically enhance healing potential. The purpose of this study was to determine whether patients who underwent patch augmentation would have lower rates of retears and superior functional outcomes.

METHODS

Patients who underwent arthroscopic rotator cuff repair (ARCR) with patch augmentation (group A) were matched by age, sex, degree of retraction, and supraspinatus muscle occupation ratio to those treated with ARCR without using a patch (group B) with a minimum follow-up of 24 months. The retear (Sugaya IV or V) rates were evaluated by magnetic resonance imaging at 3 and 12 months post-surgery. The Constant- Murley Score (CMS), Korean Shoulder Score (KSS), and University of California-Los Angeles Shoulder Rating Scale (UCLA) score were retrospectively analyzed.

RESULTS

This study included 34 patients (group A, n = 17; group B, n = 17). The mean follow-up period was 46.5 ± 17.4 months. At postoperative 1-year follow-up, group B (6 patients, 35.3%) showed higher rates of retears than group A (1 patient, 5.9%), which was statistically significant (P = 0.034). However, the postoperative CMS, KSS, and UCLA scores did not differ between the two groups at 3 months, 12 months, and the final follow-up. Additionally, the clinical outcomes of patients with retear were not significantly different from those of the healed patients in both groups.

CONCLUSION

The use of an allodermal patch for LMRCT is effective in preventing retears without complications. However, the clinical outcomes of ARCR using allodermal patch augmentation were not superior to those of only ARCR.

LEVEL OF EVIDENCE

III.

Does the critical shoulder angle influence retear and functional outcome after arthroscopic rotator cuff repair? A systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to evaluate the correlation between increased critical shoulder angle (CSA) and higher retear rates and functional outcomes after arthroscopic rotator cuff repair (ARCR).

METHODS

PubMed, Embase, Web of Science, and Cochrane Library databases published before January 2022 were comprehensively searched. Two reviewers independently reviewed the titles and abstracts using the specified criteria. Studies were included if the authors clearly described the correlation between the CSA and rotator cuff repair. Data on patient characteristics, mean CSA, retear rate, and the functional score was pooled from the selected articles. A meta-analysis was performed using Review Manager (RevMan) 5.4.1 software, 2020 (Cochrane Collaboration, Copenhagen, Denmark).

RESULTS

Eleven articles involving 1449 patients from 7 countries were included. The ages of the patients ranged from 45 to 75 years. The follow-up period ranged from 6 to 96 months. The mean CSA was greater in the retear group than in the non-retear group after ARCR (mean difference 2.73°; 95% confidence interval [CI] 0.69-4.77) (p = 0.009). Three studies evaluated the association between increased CSA and the postoperative retear rate. All three studies showed a higher postoperative retear rate in patients with an increased CSA (odds ratio 5.35; 95% CI 2.02-14.15; p = 0.0007). No association was found between CSA and Constant-Murley (Constant), the University of California at Los Angeles (UCLA), or Visual Analog Scale (VAS) scores during the follow-up period of 24-96 months (p > 0.05).

CONCLUSIONS

This systematic review and meta-analysis showed that CSA correlates highly with rotator cuff retear after ARCR. In addition, the postoperative retear rate of the rotator cuff increased with increased CSA. CSA appeared to not affect worse functional outcomes in patients after ARCR.

Agreement between intraoperative and MRI assessments of rotator cuff pathology and two MRI-based assessments of supraspinatus muscle atrophy

Background

Magnetic resonance imaging (MRI)-based rotator cuff assessment is often qualitative and subjective; few studies have tried to validate such preoperative assessments. This study investigates relationships of preoperative MRI assessments made by conventional approaches to intraoperative findings of tear type, location, and size or MRI-assessed muscle occupation ratio.

Methods

Intraoperatively, surgeons assessed tear type, location, anterior-posterior (AP) width, and medial-lateral length in 102 rotator cuff repair patients. Two musculoskeletal radiologists independently assessed the preoperative MRI scans for these same parameters and supraspinatus muscle atrophy by both Warner classification and quantitative occupation ratio. Exact agreement proportions, kappa statistics, and correlation coefficients were used to quantify agreement relationships.

Results

Agreement between MRI readers’ and surgeons’ observations of tear status averaged 93% with κ = 0.38, and that of tear location averaged 77% with κ = 0.50. Concordance correlations of MRI and intraoperative measures of anterior-posterior and medial-lateral tear length averaged 0.59 and 0.56 across readers, respectively. Despite excellent interrater agreement on Warner classification (exact agreement proportion 0.91) and occupation ratio (concordance correlation 0.93) separately, correlations between these 2 measures were −0.54 and −0.64 for the 2 readers, respectively. Patients with Warner grade 0 had occupation ratios ranging from 0.5 to 1.5.

Conclusion

Correlations of preoperative MRI tear dimensions and muscle atrophy assessed by conventional approaches with intraoperatively measured tear dimensions and quantitative occupation ratio, respectively, were only fair. Since tear size and muscle atrophy are known strong predictors of outcomes following rotator cuff repair that may influence treatment decisions, surgeons need to be aware of the limitations of MRI methods. Continued development and validation of quantitative preoperative imaging methods to accurately assess these parameters are needed to improve surgical planning and prognosis.

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

Background

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

Methods

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

Results

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

Conclusion

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

Rotator cuff repair protected with subacromial balloon spacer shows a low rate of non-healing

PURPOSE

The purpose of this study was to evaluate clinical outcomes and tendon integrity on magnetic resonance imaging (MRI) of chronic posterosuperior rotator cuff tears treated with single-row tensionless repair and subacromial balloon spacer as protection with a minimum follow-up of 2 years. The hypothesis of this study was that this procedure would have acceptable clinical outcomes and tendon-healing rate without increased complications.

METHODS

This is a retrospective study of patients with chronic posterosuperior rotator cuff tears repaired with a single-row technique protected with a subacromial balloon device. Patients were followed up for a minimum of 2 years. Clinical outcomes were evaluated with American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) and Numerical Rating Scale (NRS) for pain. MRI study was obtained likewise after at least 2 years to assess tendon-healing rate. Statistical comparison was performed between pre-operative and at least 2-year clinical and imaging follow-up.

RESULTS

Thirty-two patients were included in the study with a mean follow-up of 27 ± 7 (range 24-48). The mean age of this cohort was 58 ± 6 (range 41-66) including 15 males and 17 females. The tear size was on average 2.3 cm (range 2-4) and a mean of 2.1 triple-loaded anchors were used (range 2-3). The ASES score significantly increased from a mean of 39 ± 12 points to a mean of 89 ± 12 at the final follow-up (P < 0.001). Similarly, pain significantly reduced from a mean pre-operative NRS of 6.8 ± 1.4 to 0.8 ± 1.5 at the final follow-up (P < 0.001). MRI scans showed that repair occurred in 26 patients (81.3%). Significant higher ASES score was reached at final follow-up in patients with a "healed" (Sugaya I-III) tendon when compared to patients with an evidence of tendon discontinuity on MRI study (Sugaya IV-V), 93 ± 9 and 74 ± 13, respectively (P < 0.001).

CONCLUSIONS

Arthroscopic repair of chronic posterosuperior rotator cuff tears using a single-row tensionless repair and subacromial spacer as protection resulted in an 81.3% of tendon integrity at a mean follow-up of 27 months. Clinical outcomes and pain scores significantly improved without severe complications reported after a minimum follow-up of 2 years.

LEVEL OF EVIDENCE

III.

Comparing Sex-Specific Outcomes After Rotator Cuff Repair: A Meta-analysis

Background

Rotator cuff repair (RCR) is a well-studied procedure. However, the impact of patient sex on outcomes after RCR has not been well studied.

Purpose

To conduct a systematic review and meta-analysis of sex-based differences in outcomes after RCR and to record what proportion of studies examined this as a primary or secondary purpose.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review was performed using multiple databases according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies were included if they were written in English, performed on humans, consisted of patients who underwent RCR, evaluated at least 1 of the selected outcomes based on patient sex, and had statistical analysis available for their sex-based claim. Excluded were case reports, review studies, systematic reviews, cadaveric studies, and studies that did not report at least 1 sex-specific outcome or included certain other injuries associated with a rotator cuff injury.

Results

Of 9998 studies screened and 1283 full-text studies reviewed, 11 (0.11%) studies with 2860 patients (1549 male and 1329 female) were included for quantitative analysis. None of these 11 studies examined the impact of patient sex on outcomes after RCR as a primary outcome. Postoperative Constant-Murley scores were analyzed for 7 studies. Male patients had a postoperative Constant-Murley score of 76.77 ± 15.94, while female patients had a postoperative Constant-Murley score of 69.88 ± 17.02. The random-effects model showed that male patients had significantly higher scores than female patients, with a mean difference of 7.33 (95% CI, 5.21-9.46; P < .0001). Analysis of retear rates in 5 studies indicated that there was no difference in the retear rate between sexes (odds ratio, 0.91 [95% CI, 0.49-1.67]).

Conclusion

Female patients had lower postoperative Constant-Murley scores compared with male patients, but there was no difference in the retear rate. However, these results were based on an analysis of only 11 studies. The paucity of studies examining the impact of sex suggests that more research is needed on the impact of patient sex on outcomes after RCR.

Clinical effect of arthroscopic long head of biceps transfer and tenodesis on irreparable rotator cuff tear

Objective

To explore the clinical effect of arthroscopic long head of biceps transfer and tenodesis for on irreparable rotator cuff tear.

Methods

A total of 18 patients with irreparable rotator cuff tear who were treated in the Dongfang Hospital Affiliated to Tongji University School of Medicine from April 2018 to March 2020 were included in this study. They all underwent arthroscopic long head of biceps transfer and tenodesis. Shoulder joint motions (forward flexion, abduction, and external rotation angle) and magnetic resonance imaging (MRI) were performed. Moreover, visual analogue scale (VAS) and university of California Los Angeles (UCLA) score were conducted during follow-up.

Results

Preoperative symptoms lasted from 3 to 16 months, with an average duration of 10 months. All patients healed in the first stage without obvious complications were included. All patients were followed up for 4 to 14 months after the surgery, with an average duration of 11.1 months. The range of shoulder joint motions, including forward flexion (80.52° ± 31.19° vs. 149.47° ± 28.36°), abduction (65.13° ± 37.59° vs. 152.46° ± 28.64°) and lateral rotation (30.17° ± 15.15° vs. 71.49° ± 11.42°) was significantly improved after operation (P < 0.05). The VAS score was notably decreased after operation (8.46 ± 0.80 vs. 1.55 ± 0.70), but the UCLA score was markedly increased (15.27 ± 2.89 vs. 31.17 ± 2.36). MRI imaging showed that 15 patients had good tissue healing, with a healing rate of 83.3% (15/18).

Conclusion

Arthroscopy of the biceps long head tendon transposition can significantly relieve pain in patients with large rotator cuff tears, improve joint mobility, and restore joint function.

Monitoring Rotator Cuff Muscle Fatty Infiltration Progression by Magnetic Resonance Imaging T1 Mapping: Correlation With Direct Evaluation Findings in Rats

BACKGROUND

Monitoring the fatty infiltration (FI) process in rotator cuff muscles is of value in establishing a treatment plan and predicting the postoperative prognosis. Quantitative T1 mapping shows promise for evaluating muscle degeneration, while its validity in monitoring rotator cuff muscle FI progression needs further investigation.

PURPOSE

To determine the validity of T1 mapping in monitoring FI progression of rotator cuff muscles.

STUDY DESIGN

Controlled laboratory study.

METHODS

Sprague-Dawley rats (N = 108) underwent left supraspinatus (SS) and infraspinatus (IS) tenotomy only (TT), suprascapular nerve transection only (NT), or SS and IS tenotomy plus suprascapular nerve transection (TT+NT). Sham surgery on the right shoulder served as the control. The magnetic resonance imaging examination included T1 mapping performed at 12, 16, and 20 weeks postoperation. SS and IS muscles were harvested to quantitatively evaluate FI via direct evaluation (triglyceride quantification assay and histological analysis) at the same predetermined intervals. The correlation of the imaging data with direct evaluation of rotator cuff muscles was analyzed.

RESULTS

T1 values were significantly lower in left SS and IS muscles at 12, 16, and 20 weeks postoperation as compared with those on the right side. T1 values of the left SS and IS muscles were continuously decreased in all groups. The TT+NT group had a greater decrease in T1 value than did the TT and NT groups. Triglyceride quantification assay and histological analysis demonstrated significant and progressive FI of the left SS and IS muscles in the 3 groups. The most serious FI changes were observed in the TT+NT group. T1 values were also well correlated with triglyceride contents and area fractions of fat.

CONCLUSION

T1 mapping can be an effective imaging modality for sensitive and quantitative monitoring of FI progression in rotator cuff muscles.

CLINICAL RELEVANCE

The findings of this study provide a tool for researchers to noninvasively and quantitatively monitor the process of muscle degeneration, contributing to the evaluation of surgical indication and postoperative prognosis.

Better Short-Term Outcomes After Rotator Cuff Repair in Studies With Poorer Mean Shoulder Scores and Predominantly Small to Medium-Sized Tears at Baseline: A Systematic Review and Meta-analysis

PURPOSE

To perform a meta-analysis to explore factors associated with clinical and structural short-term outcomes in randomized and nonrandomized prospective studies of rotator cuff repair.

METHODS

Medline, clinicaltrials.gov, and Mendeley were searched for literature published from January 2000 to December 2020 to identify randomized controlled trials (RCT) and nonrandomized prospective cohort studies (PCS) describing the outcome of surgical repair of full-thickness rotator cuff tears. Study quality was assessed by two independent reviewers. We calculated standardized mean difference (SMD) from baseline to follow-up in each trial arm, preferably at 12 months follow-up. Between-study heterogeneity of outcomes, small-study effects and rates of retear were assessed. Meta-regression was performed to estimate associations between prespecified variables and clinical and structural outcomes.

RESULTS

Outcomes in 64 RCT and 19 PCS trial arms were analyzed. Median age was 59 years. There was substantial between-study heterogeneity in clinical outcomes (SMD range: .42 to 6.44; I² = 93% in RCT, 88% in PCS) and summary estimates were not calculated. On the basis of multivariate analysis, better clinical outcome was associated with lower (worse) mean outcome value at baseline, smaller tear size, and lower proportion of large-massive tears (R² = 56 and 44%, respectively). Overall retear rate at median 13-month follow-up was 19.9% (interquartile range: 10-30). Higher mean age together with larger tear size and higher proportion of large-massive tears were associated with increased retear rates (R² = 33% and 58%, respectively). Clinical outcome was not significantly related to rate of retear.

CONCLUSIONS

Studies with lower mean outcome values at baseline and predominantly small- to medium-sized tears reported better clinical outcomes. Studies with higher mean age and a predominance of large-massive tears had significantly increased retear rates, but retear rates were not associated with clinical outcome.

LEVEL OF EVIDENCE

Level II, meta-analysis of level I and II studies.

Arthroscopic debridement for management of massive, irreparable rotator cuff tears: a systematic review of outcomes

Background

Surgical management of massive irreparable rotator cuff tears remains controversial. Arthroscopic debridement (AD) has shown promising results especially in the population older than 65 years; however, there is no consensus on the benefits of various AD procedures. The aim of this systematic review was to evaluate the functional midterm to long-term outcomes in patients treated with AD in combination with subacromial decompression, biceps tenotomy, tuberoplasty, or bursectomy, without repair of the rotator cuff tear.

Methods

A comprehensive search was performed in PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Cochrane databases for studies reporting clinical outcomes of AD of massive rotator cuff tears. Quality was determined using the Methodological Index for Nonrandomized Studies (MINORS) criteria by two independent reviewers. Pooled frequency-weighted means and standard deviations were calculated for patient-reported outcomes.

Results

Sixteen articles containing 643 patients and 662 shoulders met the eligibility criteria. The mean age at the time of surgery was 65.9 ± 4.4 years with a mean follow-up period of 46.5 ± 27.3 months. There was notable clinically significant improvement across all patient-reported outcome scores postoperatively: Constant 70.4 ± 8.9 (P value = .06), University of California, Los Angeles ultrasonography 26.7 ± 5.2 (P value = .001), American Shoulder and Elbow Surgeons score 71.7 ± 2.1 (P value = .12), Disabilities of the Arm, Shoulder, and Hand score 35.3, and visual analog score 1.7 ± 0.9. Forty-nine patients (7%) required reoperation, which most commonly was a reverse total shoulder arthroplasty for the development of rotator cuff arthropathy.

Conclusion

Arthroscopic debridement with a combination of subacromial decompression, tuberoplasty, subacromial bursectomy, and biceps tenotomy, for treatment of massive irreparable rotator cuff tears, produces good functional outcomes and improvement in pain at mid to long term follow up for the low-demand population greater than 65 years of age looking for pain relief over substantial increase in function.

Role of Delay Between Injury and Surgery on the Outcomes of Rotator Cuff Repair: A Systematic Review and Meta-analysis

BACKGROUND

Outcomes of rotator cuff repair (RCR) are influenced by several well-described factors, but the role of delay from injury to surgery on the outcomes is not clear.

PURPOSE

To assess the role of delay to surgery on the outcomes of RCR in the literature.

STUDY DESIGN

Systematic review with meta-analysis; Level of evidence, 4.

METHODS

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. All studies assessing outcomes after RCR-either retear rates or patient-reported outcome measures (PROMs)-and reporting delay to surgery were identified through June 2021 in PubMed, Embase, and Cochrane. Inclusion criteria consisted of traumatic injuries, mean age <65 years, minimum 6-month follow-up, and assessment of retear rates with radiologic examination or reporting of PROMs. Random-effect models were used to assess outcomes, reported in odds ratio (OR) or mean difference (MD) with 95% CIs.

RESULTS

A total of 8118 patients were included from 33 studies, with a mean age of 59 years (range, 53-64) and mean follow-up of 3.0 years (range, 0.5-8.2), among whom 53% were male and 74% had dominant-side injury. Patients undergoing surgery >3 months after injury did not have significantly higher retear rates (OR, 1.1 [95% CI, 0.5 to 3.1]; P = .700), lower Constant-Murley score (MD, -6.2 [95% CI, -16.4 to 4.1]; P = .240), or lower ASES score (American Shoulder and Elbow Surgeons; MD, -12.9 [95% CI, -26.0 to -0.2]; P = .050) compared with those having surgery within 3 months. Similarly, delaying surgery for 6 months did not result in higher retear rates (OR, 1.7 [95% CI, 0.8 to 3.7]; P = .190) or lower PROMs. Delaying surgery for 1 year, however, led to an increased likelihood of retear when compared with <1 year (OR, 2.9 [95% CI, 2.1 to 4.0]; P < .001), and this was similar for the 2-year cutoff (OR, 5.9 [95% CI, 1.1 to 32.1]; P = .040). It was also noted that patients with an intact cuff at follow-up had a mean 3.9 months' shorter time from injury to surgery than patients with retear (95% CI, 1.0-6.8 months; P = .009).

CONCLUSION

This systematic review with meta-analysis found that delaying rotator cuff surgery for 3 to 6 months did not lead to higher retear rates or inferior PROMs as compared with undergoing earlier surgery. However, delaying surgery for ≥1 year clearly resulted in higher retear rates after RCR. This study is limited by relying on retrospective studies, and larger prospective studies are needed to confirm these findings.

REGISTRATION

CRD42021240720 (PROSPERO).

Does the Interval Slide Procedure Reduce Supraspinatus Tendon Repair Tension?: A Biomechanical Cadaveric Study

Background

The benefits of the interval slide (IS) procedure in retracted rotator cuff tears remain controversial.

Purpose

The purpose was to evaluate the effect of the IS procedure on repair tension (RT). It was hypothesized that the IS procedure (anterior IS [AIS], posterior IS [PIS], and intra-articular capsular release [CR]) would reduce the RT of a supraspinatus tendon.

Study Design

Controlled laboratory study.

Methods

A total of 31 Thiel-embalmed human cadaveric shoulders (mean age, 74 years; range, 68-84 years) were tested. Full-thickness supraspinatus tendon tears were created, and 1 cm of tendon was resected to simulate a retracted defect. Shoulders were randomized into intervention (n = 16) and control (n = 15) groups. In all shoulders, the load during tendon reduction to footprint was measured, an endpoint was defined as maximum tendon lateralization before 50 N was reached, and the RT (load during lateralization to endpoint) of the native tendon (t₁) was evaluated. In the intervention group, AIS (t₂), PIS (t₃), and CR (t₄) were performed in order, with RT measurement after each step. In the control group, RT was assessed at the same time points without the intervention.

Results

A complete reduction of the tendon was not achieved in any of the shoulders. Mean maximum lateralization was 6.7 ± 1.30 mm, with no significant differences between groups. In the intervention group, the overall IS procedure reduced RT about 47.0% (t₁ vs t₄: 38.7 ± 3.9 vs 20.5 ± 12.3 N; P < .001). AIS reduced RT significantly (t₁ vs t₂: 38.7 ± 3.9 vs 27.4 ± 10.5 N; P < .001), whereas subsequent PIS (t₂ vs t₃: 27.4 ± 10.5 vs 23.2 ± 12.4 N; P = .27) and CR (t₃ vs t₄: 23.2 ± 12.4 vs 20.5 ± 12.3 N; P = .655) did not additionally reduce tension. Comparison between groups at t₄ revealed a reduction of RT of about 47.8% (control vs intervention: 39.3 ± 4.0 vs 20.5 ± 12.3 N; P < .001).

Conclusion

The IS procedure reduces RT of the supraspinatus tendon in human cadaveric shoulders. However, performing PIS and CR subsequent to AIS does not reduce tension additionally.

Clinical Relevance

These findings provide surgeons with a biomechanical rationale regarding the efficacy of the IS procedure.

Rotator Cuff Tear Size Regulates Fibroadipogenic Progenitor Number and Gene Expression Profile in the Supraspinatus Independent of Patient Age

BACKGROUND

Fatty infiltration of rotator cuff muscle is a limiting factor in the success of repairs. Fibroadipogenic progenitors (FAPs) are a population of stem cells within the rotator cuff that can differentiate into white adipocytes, fibroblasts, and beige adipocytes. The effects of patient age and rotator cuff tendon tear size on the number, differentiation patterns, and gene expression profiles of FAPs have not yet been analyzed.

PURPOSE

To determine if patient age and rotator cuff tear size independently regulate FAP number, differentiation patterns, and gene expression profiles.

STUDY DESIGN

Controlled laboratory study.

METHODS

Supraspinatus muscle samples were collected from 26 patients between the ages of 42 and 76 years with partial- or full-thickness rotator cuff tears. FAPs were quantified using fluorescence-activated cell sorting. Gene expression analysis was performed across a custom 96-gene panel using NanoString. In vitro differentiation assays of FAPs were conducted using adipogenic, fibrogenic, and beige-inducing (amibegron-treated) media, and quantitative polymerase chain reaction was used to assess gene expression differences between adipogenic and amibegron media conditions. Multivariable linear regressions were performed using Stata to independently analyze the effects of age and rotator cuff tear size on FAP number, differentiation, and gene expression.

RESULTS

Increasing age and tear size were independently correlated with increased FAP number (β_age = 0.21, P = .03; β_{tear size} = 3.86, P = .05). There was no clear association between age and gene expression of freshly sorted FAPs. Under adipogenic and fibrogenic media conditions, increasing age and tear size were independently associated with increased adipogenic and fibrogenic differentiation of FAPs. Under amibegron treatment conditions, age positively correlated with increased beige differentiation (β = 1.03; P < .0001), while increasing tear size showed a trend toward decreased beige differentiation (β = -4.87; P = .1). When gene expression patterns between adipogenic and amibegron media conditions were compared, larger tear size strongly inhibited beige gene expression, while advanced age did not.

CONCLUSION

Patient age and rotator cuff tear size independently regulated FAP number, differentiation, and gene expression. Age and tear size were positively correlated with increased FAP number and fibrogenic/adipogenic differentiation. Advancing patient age did not limit FAP beige differentiation and gene expression, while increasing rotator cuff tear size strongly inhibited these processes.

Relationship between preoperative size of rotator cuff tears measured using radial-slice magnetic resonance images and postoperative rotator cuff integrity: a prospective case-control study

Background

Magnetic resonance imaging (MRI) is useful for diagnosing shoulder diseases preoperatively. However, preoperative risk factors for retears have not been previously reported using a radial-slice MRI. Here, we investigated the relationship between the preoperative tear area of the rotator cuff evaluated using radial-slice MRI and the postoperative rotator cuff integrity. Our hypothesis is that larger tear area of the rotator cuff measured using radial-slice MRI would be associated with increased retear rates.

Methods

From June 2010 to October 2015, we treated 102 consecutive patients who underwent shoulder arthroscopy for reparable rotator cuff tears. The patient demographics, medical comorbidities, radiologic factors, tear size, fatty infiltration, muscle atrophy measured using oblique coronal and oblique sagittal MRI, and the tear area calculated using radial-slice MRI were assessed to compare the intact and retear groups in univariate and multivariate logistic regression analyses. The cutoff values of the independent factors were obtained using the receiver operating characteristic curve.

Results

Retears occurred in 15 of 102 (14.7%) patients. In the univariate analysis, significant differences were found between the two groups for tear size, fatty infiltration of the supraspinatus and infraspinatus, muscle atrophy, and tear area. In the multivariate analysis, the tear area was the independent factor that significantly affected the rate of retear. A tear area of 6.3 cm² was the strongest predictor of retear with an area under the curve of 0.965, sensitivity of 86.7%, and specificity of 96.6%.

Conclusion

The tear area was the independent factor that most significantly affected the rate of retear and showed excellent accuracy with a cutoff value of 6.3 cm². Radial-slice MRI may be a valuable diagnostic tool for assessing the postoperative rotator cuff integrity.