Rotator cuff repair: published evidence on factors associated with repair integrity and clinical outcome

Remodeling the Senescent Microenvironment for Promoting Osteoporotic Tendon-to-Bone Healing via Synergizing Senolytic Quercetin and Aligned Nanowire-Structured Hydrogels

Osteoporotic tendon-to-bone healing remains a major challenge, as cellular senescence disrupts tissue regeneration and impairs repair outcomes. Although the role of cellular senescence in rotator cuff repair is increasingly recognized, current strategies often overlook the complex pathological context, particularly the dual impacts of senescence on both bone marrow-derived mesenchymal stem cells (BMSCs) and tendon-derived stem cells (TDSCs). This gap hampers effective tendon-to-bone healing and integration, especially under osteoporotic conditions. Herein, a composite hydrogel system, quercetin-loaded aligned ultralong hydroxyapatite nanowire/gelatin-hyaluronic acid hydrogel (Que-AHNW/GH), has been developed to address these challenges. By integrating senolytic quercetin as a biological cue with highly aligned ultralong hydroxyapatite (HAP) nanowires as a topographical cue, the system remodels the senescent microenvironment, alleviating senescence in both BMSCs and TDSCs and promoting osteogenesis and tenogenesis. Que-AHNW/GH suppresses the PI3K/AKT pathway, enhances autophagy, and reduces senescence in both cell types. In vivo, Que-AHNW/GH improves bone tunnel regeneration, tendon repair, and tendon-to-bone integration in osteoporotic rats with rotator cuff injury. This system enhances biomechanical strength and gait performance and demonstrates excellent biosafety. These findings highlight the promising potential of Que-AHNW/GH as a multifunctional biomaterial for effectively promoting senescence-related tendon-to-bone healing, offering a promising solution for treating osteoporotic tendon-to-bone injuries.

A new section of shoulder magnetic resonance imaging (MRI) used to assess the fat infiltration of the rotator cuff muscles

BACKGROUND

Accurately assessing the degree of fat infiltration in the rotator cuff muscles is essential. However, in patients with massive rotator cuff tears and significant retractions, assessing fat infiltration of the rotator cuff in the traditional scapular Y-view of Shoulder MRI is not very accurate.

PURPOSE

This study aimed to evaluate the reliability and reproducibility of the suprascapular notch sagittal section (r-view) for assessing fatty infiltration in the supraspinatus and infraspinatus muscles, with comparative analysis against the Y-view assessment results.

METHODS

Magnetic resonance imaging data from 91 patients with rotator cuff tears (RTCs) were retrospectively analyzed. The patients were divided into three groups on the basis of the extent of retraction of rotator cuff tears. Fat infiltration of rotator cuff muscles was independently graded by three orthopedic surgeons via the Goutallier classification. The interclass and intraclass correlation coefficients (ICCs) were calculated to assess the consistency and repeatability of grading fat infiltration in the supraspinatus and infraspinatus using Y view and r view. The Wilcoxon rank-sum test was used to compare categorical variables of 3 groups (fat infiltration of the supraspinatus and infraspinatus graded in Y view and r view).

RESULTS

In the 3 groups of patients, regardless of the supraspinatus or the infraspinatus, the interclass coefficients of fat infiltration grade in the r view were ≥ 0.80, with excellent interobserver agreement and reliability of evaluation. The intraclass coefficients of each reader for grading fat infiltration of the supraspinatus and infraspinatus in the r view were ≥ 0.80, indicating excellent intraobserver agreement and reproducibility. In the group with the most severe rotator cuff tear retraction, there was a significant difference in the degree of fat infiltration between Y view and r view (P < 0.01).

CONCLUSION

The r view utilized in this study is a new section for assessing the fat infiltration of the supraspinatus and infraspinatus. In contrast to the conventional Y view, assessing fatty infiltration of the supraspinatus and infraspinatus muscles in the r view demonstrates better reliability and reproducibility, with less influence from tendon retraction.

LEVELS OF EVIDENCE

Level III.

The P2X7R/NLRP3 inflammasome axis suppresses enthesis regeneration through inflammatory and metabolic macrophage-stem cell cross-talk

The regeneration of the enthesis remains a formidable challenge in regenerative medicine. However, key regulators underlying unsatisfactory regeneration remain poorly understood. This study reveals that the purinergic receptor P2X7 (P2X7R)/Nod-like receptor family protein 3 (NLRP3) inflammasome axis suppresses enthesis regeneration by amplifying IL-1β-mediated inflammatory cross-talk and suppressing docosatrienoic acid (DTA) metabolic cross-talk. NLRP3 inflammasomes were activated in macrophages following enthesis injury, thereby impairing the histological and functional recovery of the injured enthesis. Single-cell RNA sequencing (scRNA-seq) indicated that Nlrp3 knockout attenuated pathological inflammation and ameliorated the detrimental effects of IL-1β signaling cross-talk. Furthermore, NLRP3 inflammasomes suppressed the secretion of anti-inflammatory cytokines (IL-10 and IL-13) and DTA. The NLRP3 inflammasome-mediated secretome reduced differentiation and migration of stem cells. Neutralizing IL-1β or replenishing docosatrienoic acid accelerated enthesis regeneration. Moreover, conditional knockout of P2rx7 in myeloid cells attenuated NLRP3 inflammasome activation and facilitated enthesis regeneration. This study demonstrates that the P2X7R/NLRP3 inflammasome axis represents a promising therapeutic target for enthesis repair.

Fatty infiltration predicts retear and functional impairment following rotator cuff repair: systematic review and meta-analysis

INTRODUCTION

Fatty infiltration (FI) in rotator cuff (RC) is detected in many patients with complete RC tears. But there remains controversy on the prognostic effects of FI in RC tears, especially for patients with moderate and severe FI. This study aims to systematically review the relationship between the severity of preoperative FI and risk of retear, and the association between preoperative FI and functional outcomes.

MATERIALS AND METHODS

We searched PubMed, Embase and Web of Science for studies on association between preoperative FI and retear or functional outcomes following complete RC repair. FI was assessed using Goutallier classification and global fatty degeneration index (GFDI). Meta-analysis was performed to determine odds ratios (ORs) for retear among patients with mild (grade 0-1), moderate (grade 2) and severe (grade 3-4) FI in RC tears. We delivered qualitative synthesis on association between FI and functional outcomes.

RESULTS

Eighteen studies with 1997 patients were included in the systematic review and ten studies were included in the meta-analysis. Patients with GFDI ≤ 1 had lower retear odds (OR = 0.08, 95%CI 0.02-0.29, p < 0.01). Moderate FI in supraspinatus muscle (SSP) was associated with higher retear odds compared with mild FI (OR = 1.95, 95%CI 1.09-3.48, p = 0.02) and severe FI was associated with more retear compared with moderate FI (OR = 3.37, 95%CI 1.08-10.53, p = 0.04). Similar effects were observed in FI in infraspinatus muscle (ISP) (moderate vs. mild: OR = 2.22, 95%CI 1.07-4.62, p = 0.03; severe vs. moderate: OR = 2.06, 95%CI 1.02-4.16, p = 0.04). The severity of FI in subscapularis muscle and teres minor muscle was not observed to be associated with the retear rates. In functional outcomes, lower grade of FI in GFDI was associated with better prognosis. FI in single muscles failed to present prognostic effects on functional outcomes.

CONCLUSIONS

The severity of FI in SSP and ISP showed effects on retear following complete RC repair. The GFDI was a compatible predictor for risk of anatomic and functional impairment.

No Short-term Clinical Benefit to Bovine Collagen Implant Augmentation in Primary Rotator Cuff Repair: A Matched Retrospective Study

BACKGROUND

Bovine bioinductive collagen implants (herein, "bovine collagen implant") can be used to augment rotator cuff repair. Concern exists that these bovine collagen implants may not yield clinical benefits and may actually increase postoperative stiffness and the need for reoperation.

QUESTIONS/PURPOSES

Among patients who underwent primary rotator cuff repair with or without a bovine collagen implant, we asked: (1) Did the proportion of patients undergoing reoperation for postoperative stiffness and inflammation differ between the bovine collagen implant and control groups? (2) Did short-term patient-reported outcomes differ between the two groups? (3) Did the proportion of patients receiving postoperative methylprednisolone prescriptions and corticosteroid injections differ between the two groups?

METHODS

We performed a retrospective, matched, comparative study of patients 18 years and older with minimum 2-year follow-up who underwent primary arthroscopic repair of partial or full-thickness rotator cuff tears diagnosed by MRI. All procedures were performed by one surgeon between February 2016 and December 2021. During the period in question, this surgeon broadly offered the bovine collagen implant to all patients who underwent rotator cuff repair and who (1) consented to xenograft use and (2) had surgery at a facility where the bovine collagen implant was available. The bovine collagen implant was used in rotator cuff tears of all sizes per the manufacturer's instructions. A total of 312 patients were considered for this study (243 control, 69 implant). Minimum 2-year clinical follow-up data were available for 83% (201 of 243) of patients in the control group and 90% (62 of 69) of patients in the bovine collagen implant group. After we applied the exclusion criteria, 163 control and 47 implant group patients remained and were eligible for matching. Propensity score matching was conducted to balance cohorts by age, gender, race (Black, White, other), ethnicity (Hispanic, non-Hispanic), health insurance status, Area Deprivation Index, BMI, American Society of Anesthesiologists physical status classification, diabetes, smoking, rotator cuff tear size, concomitant surgical procedures, preoperative American Shoulder and Elbow Surgeons (ASES) score, Subjective Shoulder Value (SSV), VAS score for pain, and shoulder ROM. We included 141 patients (47 in the implant group and 94 in the control group) after matching. Patients were categorized according to whether they received the bovine collagen implant. Before matching, the control cohort was older (mean ± SD 57 ± 10 years versus 52 ± 11 years; p = 0.004), more likely to be White (58% versus 23%; p < 0.001), with a smaller proportion of concomitant distal clavicle excisions (43% versus 21%; p = 0.003), and a smaller proportion of "other" concomitant procedures (17% versus 6%; p = 0.011) compared with the implant cohort. After matching, the cohorts were well matched in all demographic variables. The primary study outcome was reoperation for inflammation and stiffness, defined as a failure of nonoperative treatment for a minimum of 9 months, including physical therapy, NSAIDs, at least one course of oral methylprednisolone, and at least one cortisone injection (reoperations for traumatic retears were excluded). Secondary outcomes were patient-reported outcomes (SSV, ASES score, and VAS score for pain), receipt of methylprednisolone prescriptions, and receipt of corticosteroid injections. Chi-square, Fisher exact tests, and independent-samples t-tests were used to assess relationships between treatment group and study outcomes.

RESULTS

A greater proportion of patients in the bovine collagen implant group (9% [4 of 47]) underwent reoperation for inflammation and stiffness than in the control group (0% [0 of 94]; p = 0.01). At minimum 2-year follow-up, the cohorts did not differ by ASES score (mean ± SD 81 ± 24 implant versus 85 ±19 control; p = 0.24), SSV (79 ± 24 implant versus 85 ± 18 control; p = 0.30), or VAS score for pain (2.0 ± 2.9 implant versus 1.5 ± 2.3 control; p = 0.11). The cohorts did not differ in the proportion who received postoperative corticosteroid injections (15% implant versus 11% control; p = 0.46) or methylprednisolone prescriptions (49% implant versus 37% control; p = 0.18).

CONCLUSION

At minimum 2-year follow-up, patients undergoing primary arthroscopic rotator cuff repair with bovine collagen implant augmentation had a greater proportion of reoperation due to inflammation and stiffness compared with patients who did not receive the implant. Furthermore, the implant offered no benefit in patient-reported outcomes or need for postoperative corticosteroid injections or methylprednisolone prescriptions. Because of the lack of clinical benefit and potential increase in postoperative complications, we recommend against the use of these bovine collagen implants unless high-quality randomized controlled trials are able to demonstrate their clinical effectiveness, cost-effectiveness, and overall safety.

LEVEL OF EVIDENCE

Level III, therapeutic study.

A Quantitative Fatty Infiltration Evaluation of the Supraspinatus Muscle: Enhanced Clinical Relevance and Improved Diagnostic Value on Predicting Retear Compared With the Goutallier Classification

BACKGROUND

Preoperative assessment of fatty degeneration is important for managing rotator cuff tears. The Goutallier classification is semiquantitative and observer dependent. Discrepancies among surgeons can be prominent. A quantitative method may improve accuracy and reliability in evaluating the exact percentage of fatty infiltration (Fat%).

HYPOTHESIS/PURPOSE

This study aimed to investigate the correlation between the new quantitative method and the Goutallier classification in assessing fatty infiltration (FI) of the supraspinatus muscle and to explore the use of this method in predicting retear after rotator cuff repair. It was hypothesized that the new method would significantly correlate with the Goutallier classification and be more sensitive to retear.

STUDY DESIGN

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

METHODS

This study included 105 patients who underwent arthroscopic rotator cuff repair for large to massive tears. All patients underwent routine preoperative and 1-year postoperative magnetic resonance imaging and were divided into 2 groups according to tendon healing. Preoperative quantitative Fat% of the supraspinatus muscle was evaluated based on the signal intensity (SI) of the T1-weighted sequence. The Fat% was calculated using the following equation: SIsupraspinatus = SIfat× Fat% + SImuscle× (1 - Fat%). The correlation between the Fat% and the Goutallier grade was determined. Univariate and multivariate analyses were performed to identify the independent risk factors for retear.

RESULTS

The mean preoperative Fat% of the supraspinatus muscle was 23.77 ± 15.96. A significant correlation was found between the Fat% and the Goutallier grade of the supraspinatus muscle (R = 0.655; P < .001). The overall retear rate was 21.9%; however, functional status significantly improved regardless of cuff healing. Multivariate analysis identified the Fat% (P = .005) and the modified Patte classification (P = .003) as independent risk factors of retear. The receiver operating characteristic curves showed that the cutoff value of Fat% for predicting retear was 33.2%. Fat% >33.2% possessed superior diagnostic accuracy (79.0%), Youden index (0.513), and positive and negative predictive values (51.6% and 90.5%, respectively) compared with the Goutallier grades.

CONCLUSION

Although the quantitative method for assessing Fat% of the supraspinatus muscle significantly correlated with the Goutallier classification, the quantitative method is more clinically relevant to retear. Fat% of the supraspinatus muscle >33.2% possessed higher diagnostic value than the Goutallier grades in predicting retear.

Editorial Commentary: Early Postoperative Stiffness After Rotator Cuff Repair Is Often a Good Thing

Early postoperative stiffness after rotator cuff (RC) repair is not uncommon and can be frustrating for patients and physical therapists, as well as surgeons, as it has the potential to lengthen the recovery process, and in rare instances, can lead to additional interventions such as injections or surgery. Many risk factors for early postoperative stiffness after RC repair have been identified, including duration of immobilization and timing of rehabilitation, size of tear, preoperative stiffness, and diabetes mellitus and, according to recent research, fatty infiltration of the RC muscles. Yet, there are potential benefits to early postoperative stiffness after RC repair, as research has shown that stiffness at 6 and 12 weeks postoperatively correlates with rotator cuff integrity at 6 months postoperatively, and stiffness generally resolves. At present, I do not worry about early stiffness after RC repair and do not adjust rehabilitation or intervene at an early time point except in extreme instances. I worry more about patients with extremely good motion at early time points. Future studies must focus on discerning "good" stiffness from "bad" stiffness.

Il-6 signaling exacerbates hallmarks of chronic tendon disease by stimulating reparative fibroblasts

Tendinopathies are debilitating diseases currently increasing in prevalence and associated costs. There is a need to deepen our understanding of the underlying cell signaling pathways to unlock effective treatments. In this work, we screen cell signaling pathways in human tendinopathies and find positively enriched IL-6/JAK/STAT signaling alongside signatures of cell populations typically activated by IL-6 in other tissues. In human tendinopathic tendons, we also confirm the strong presence and co-localization of IL-6, IL-6R, and CD90, an established marker of reparative fibroblasts. To dissect the underlying causalities, we combine IL-6 knock-out mice with an explant-based assembloid model of tendon damage to successfully connect IL-6 signaling to reparative fibroblast activation and recruitment. Vice versa, we show that these reparative fibroblasts promote the development of tendinopathy hallmarks in the damaged explant upon IL-6 activation. We conclude that IL-6 activates tendon fibroblast populations which then initiate and deteriorate tendinopathy hallmarks.

Midterm Functional Outcomes After Retear of an Arthroscopic Rotator Cuff Repair: A Propensity Score-Matched Comparative Study

BACKGROUND

Studies are still limited on the isolated effect of retear after arthroscopic rotator cuff repair (ARCR) on functional outcomes after the midterm period.

PURPOSE

To assess the effect of retear at midterm follow-up after ARCR and to identify factors associated with the need for revision surgery.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective review was conducted on patients who underwent ARCR between 2014 and 2018, with a minimum 5-year follow-up. The structural integrity was evaluated using magnetic resonance imaging. After propensity score matching, 65 patients for the retear group and 65 for the healed group were included. Functional outcomes, including visual analog scale for pain and function (PVAS and FVAS) and American Shoulder and Elbow Surgeons (ASES) score, were compared between the groups at 1 year and final follow-up. Multivariate analysis was conducted on the retear group to identify factors associated with the final ASES score.

RESULTS

The mean ± SD follow-up period was 6.9 ± 1.4 years. All outcomes at the final follow-up improved as compared with the preoperative status, regardless of retear (all P < .001). In the retear group, PVAS at the final follow-up showed deterioration when compared with postoperative 1 year (P = .044). While there were no significant differences in all outcomes at 1 year postoperatively between the groups (all P > .05), the retear group demonstrated significantly worse outcomes than the healed group in scores on the PVAS (2.5 ± 1.5 vs 1.9 ± 1.5; P = .011), FVAS (7.3 ± 1.4 vs 7.8 ± 1.3; P = .020), and ASES (73.2 ± 12.7 vs 79.9 ± 15.4; P = .008) at the final follow-up. The revision rate in the retear group was 12.8%, and multivariate analysis showed that larger anteroposterior retear size (P = .017) and retear of the subscapularis (P = .047) were negatively associated with the final ASES score.

CONCLUSION

Functional outcomes after ARCR improved during midterm follow-up, regardless of retear. While the effect of retear itself on functional outcomes was minimal in the short term, it became more pronounced after the midterm period. A retear involving the subscapularis or with a larger anteroposterior size was associated with a poorer functional outcome.

Electrohydrodynamic-Printed Dual-Triphase Microfibrous Scaffolds Reshaping the Lipidomic Profile for Enthesis Healing in a Rat Rotator Cuff Repair Model

Rotator cuff injuries often result in chronic pain and functional limitations due to retears and scar formation at the enthesis. This study assess the efficacy of electrohydrodynamic-printed microfibrous dual-triphase scaffolds (DTSs), designed to optimize enthesis repair. These scaffolds, composed of polycaprolactone enhanced with nanohydroxyapatite, nano-magnesium-oxide, and kartogenin demonstrate significant biological advantages. In vitro, the scaffolds support over 95% stem cell viability and promote enhanced expression of critical markers such as tenomodulin (TNMD), sex-determining region Y-Box transcription factor 9 (SOX-9), and runt-related transcription factor 2 (RUNX-2). Enhanced expressions of tendon markers tenomodulin and scleraxis (SCX) are noted, alongside significant upregulation of chondrocyte and osteoblast markers. In vivo, these scaffolds significantly improve the biomechanical properties of the repaired enthesis, with a maximum failure load of 27.0 ± 4.2 N and ultimate stress of 5.5 ± 1.0 MPa at 6 weeks postimplantation. Lipidomic analysis indicates substantial regulation of phospholipids such as phosphatidylcholine and phosphatidylserine, highlighting the scaffold's capacity to modulate biochemical pathways critical for tissue repair and regeneration. This study underscores the potential of DTS to improve clinical outcomes in rotator cuff injury treatment by enhancing cellular differentiation, biomechanical properties, and biochemical environment, setting a foundation for personalized treatment strategies in tendon-bone repair.

Biologic Adjuvants to Rotator Cuff Repairs Induce Anti-inflammatory Macrophage 2 Polarization and Reduce Inflammatory Macrophage 1 Polarization In Vitro

PURPOSE

To examine the effect of various biologic adjuvants on the polarization of macrophages in an in vitro model for rotator cuff tears.

METHODS

Tissue was harvested from 6 patients undergoing arthroscopic rotator cuff repair. An in vitro model of the supraspinatus and subacromial bursa was created and treated with control, platelet-rich plasma (PRP), autologous activated serum (AAS), or a combination of PRP+AAS. The effect of treatment on macrophage polarization between M1 proinflammatory macrophages or M2 anti-inflammatory macrophages was measured using gene expression, protein expression, flow cytometry, and nitric oxide production.

RESULTS

Tendon and bursa treated with PRP, AAS, and PRP+AAS significantly decreased the gene expression of M1 markers interleukin (IL)-12 and tumor necrosis factor-alpha while significantly increasing the expression of M2 markers arginase, IL-10, and transforming growth factor-β (P < .05) compared with treatment with control. Enzyme-linked immunosorbent assay analysis of protein production demonstrated that, compared with control, coculture treated with PRP, AAS, and PRP+AAS significantly decreased markers of M1-macrophages (IL-6, IL-12, and tumor necrosis factor-alpha) while significantly increasing the expression of markers of M2-macrophages (arginase, IL-10, and transforming growth factor-beta) (P < .05). Flow cytometry analysis of surface markers demonstrated that compared with control, tendon and bursa treated with PRP, AAS, and PRP+AAS significantly decreased markers of M1-macrophages (CD80, CD86, CD64, CD16) while significantly increasing the expression of markers of M2-macrophages (CD163 and CD206) (P < .05). Treatment of the coculture with PRP, AAS, and PRP+AAS consistently demonstrated a decrease in nitric oxide production (P < .05) compared with control. AAS and PRP+AAS demonstrated an increased macrophage shift to M2 compared with PRP alone, whereas there was not as uniform of a shift when comparing PRP+AAS with AAS alone.

CONCLUSIONS

In an in vitro model of rotator cuff tears, the treatment of supraspinatus tendon and subacromial bursa with PRP, AAS, and PRP+AAS demonstrated an increase in markers of anti-inflammatory M2-macrophages and a concomitant decrease in markers of proinflammatory M1-macrophages. AAS and PRP+AAS contributed to a large shift to macrophage polarization to the anti-inflammatory M2 compared with PRP.

CLINICAL RELEVANCE

The mechanism of biologic adjuvant effects on the rotator cuff remains poorly understood. This study suggests that they may contribute to polarization of macrophages for their proinflammatory (M1) state to the anti-inflammatory (M2) state.

A visual marker for early atrophy of the supraspinatus muscle on conventional MRI: introduction of the blackbird sign

OBJECTIVES

The aim of this study was to introduce the blackbird sign as a fast, qualitative measure of early supraspinatus (SSP) muscle atrophy and to correlate the sign with quantitatively assessed muscle volume and intramuscular fat fraction (FF) in patients with full-thickness SSP tears.

MATERIALS AND METHODS

The blackbird sign describes the asymmetric pattern of early SSP atrophy: on sagittal MR images, the supero-posterior contour of the muscle becomes concave, resembling the shape of a blackbird. MRIs of patients with full-thickness SSP tears were retrospectively reviewed for the presence of the blackbird and tangent signs. Patients were then divided into group 1: negative tangent sign and negative blackbird sign (n = 67), group 2: negative tangent sign and positive blackbird sign (n = 31), and group 3: positive tangent sign (n = 32). A 2-point Dixon sequence was acquired in all patients from which quantitative FF and muscle volumes were calculated.

RESULTS

In total 130 patients (mean age 67 ± 11 years) were included. Mean SSP volume was significantly smaller in group 3 (15.8 ± 8.1 cm3) compared to group 2 (23.9 ± 7.0 cm3, p = 0.01) and group 1 (29.7 ± 9.1 cm3, p < 0.01). Significantly lower muscle volumes were also found in group 2 compared to group 1 (p = 0.02), confirming that the blackbird sign is able to identify early SSP atrophy. Mean FF in the SSP was significantly higher in group 3 (18.5 ± 4.4%) compared to group 2 (10.9 ± 4.7%, p < 0.01) and group 1 (6.1 ± 2.6%, p < 0.01).

CONCLUSION

Visual assessment of early muscle atrophy of the SSP is feasible and reproducible using the blackbird sign, allowing the diagnosis of early SSP atrophy.

CLINICAL RELEVANCE STATEMENT

In routine clinical practice, the blackbird sign may be a useful tool for assessing early muscle degeneration before the risk of postoperative rotator cuff re-tears increases with progressive muscle atrophy and fatty infiltration.

KEY POINTS

Quantitative measurements of rotator cuff injuries require time, limiting clinical practicality. The proposed blackbird sign is able to identify early SSP atrophy. Reader agreement for the blackbird sign was substantial, demonstrating reproducibility and ease of implementation in the clinical routine.

Single slice MR image estimation of 3D supraspinatus intramuscular fatty infiltration in older adults: relevance for clinical practice and research

OBJECTIVE

(1) To compare older adults stratified by supraspinatus tendon tear status (STT status)-no tear (Intact), partial-thickness (PT) tear, full-thickness (FT) tear-by 3D Dixon fat fraction (3D-FF); 2D fat fraction (2D-FF); and 2D Goutallier grade (2D-GG) at the Y-shaped view, and 1.4 cm and 2.8 cm medial to the Y-shaped view. Stratified by STT status to determine (2) correlation of 3D-FF with 2D-FF and 2D-GG and (3) inter-rater reliability at and medial to the Y-shaped view.

MATERIALS AND METHODS

Forty-five volunteers ≥ 60 years recruited prospectively received shoulder MRI. 3D-FF and 2D-FF were measured on 6-point-Dixon MRI by three trainees. Goutallier grade was assessed on T1-weighted MRI by three fellowship-trained diagnostic radiologists. Descriptive, reliability, and correlation analyses were performed.

RESULTS

Groups showed no difference in age. The FT group showed higher (p < 0.05) mean 3D-FF (14.09% ± 10.99%), mean 2D-FF (1.4 cm medial to Y-shaped view, 14.91% ± 12.11%; 2.8 cm medial to Y-shaped view, 13.32% ± 9.48%), and mean 2D-GG (Y-shaped view, 1.71 ± 0.78; 1.4 cm medial to Y-shaped view, 1.71 ± 0.69; 2.8 cm medial to Y-shaped view, 1.71 ± 0.72), relative to Intact/PT groups. 3D-FF showed strong correlation with 2D-FF among all groups/all analyses (rho, 0.80-0.98; p < 0.001). 3D-FF showed strong correlation with 2D-GG for all FT group analyses (rho, 0.85-0.91; p < 0.05). 3D-FF showed moderate-to-strong correlation considering all Intact/PT group analyses (rho, 0.51-0.79; p < 0.50). Dixon fat fraction showed excellent reliability for all groups (≥ 0.884, intraclass correlation coefficient). Goutallier grade showed excellent reliability for FT group (0.771, weighted Fleiss's kappa) but poor (0.294) and fair (0.502) for Intact and PT groups, respectively.

CONCLUSION

Single slice MR image estimation of 3D supraspinatus intramuscular fatty infiltration has merit for continued use in clinical populations requiring potential rotator-cuff-repair surgery. However, Dixon fat fraction should be prioritized for use in research over Goutallier grade due to superior reliability.

Rotator Cuff Footprint Medialization: Indications and Technique

When attempting to repair a large, retracted rotator cuff tear, the orthopaedic surgeon can use several techniques such as capsular release and interval slides that can aid in achieving a low-tension repair and thus allow the best environment for healing. One less commonly used strategy is medialization of the greater and lesser tuberosity anatomic rotator cuff footprint. Previous studies have shown that increased tension across the bone-tendon interface decreases healing rates. Medialization effectively decreases the repair tension by reducing the distance from the tendon to its insertion point. As a result, we commonly apply some degree of footprint medialization even for repair of some small- or medium-sized tears if intraoperative assessment shows that reapproximation of the rotator cuff tissue to the anatomic footprint may lead to excessive tension. The purpose of this article is to share our indications and to describe our technique for medialization of the rotator cuff footprint insertion.

Overexpression of PRDM16 improves muscle function after rotator cuff tears

BACKGROUND

Muscle atrophy, fibrosis, and fatty infiltration are commonly seen in rotator cuff tears (RCTs), which are critical factors that directly determine the clinical outcomes for patients with this injury. Therefore, improving muscle quality after RCT is crucial in improving the clinical outcome of tendon repair. In recent years, it has been discovered that adults have functional beige/brown adipose tissue (BAT) that can secrete batokines to promote muscle growth. PRDM16, a PR-domain-containing protein, was discovered with the ability to determine the brown fat cell fate and stimulate its development. Thus, the goal of this study was to discover the role of PRDM16 in improving muscle function after massive tendon tears using a transgenic mouse model with an elevated level of PRDM16 expression.

METHODS

Transgenic aP2-driven PRDM16-overexpressing mice and C57BL/6J mice underwent unilateral supraspinatus (SS) tendon transection and suprascapular nerve transection (TTDN) as described previously (n = 8 in each group). DigiGait was performed to evaluate forelimb function at 6 weeks post the TTDN injury. Bilateral SS muscles, interscapular brown fat, epididymal white fat, and inguinal beige fat were harvested for analysis. The expression of PRDM16 in adipose tissue was detected by Western blot. Masson Trichrome staining was conducted to evaluate the muscle fibrosis, and Oil Red O staining was used to determine the fat infiltration. Muscle fiber type was determined by major histocompatibility complex (MHC) expression via immunostaining. All data were presented in the form of mean ± standard deviation. t test and 2-way analysis of variance was performed to determine a statistically significant difference between groups. Significance was considered when P < .05.

RESULTS

Western blot data showed an increased expression of PRDM16 protein in both white and brown fat in PRDM16-overexpressing mice compared with wild-type (WT) mice. Even though PRDM16 overexpression had no effect on increasing muscle weight, it significantly improved the forelimbs function with longer brake, stance, and stride time and larger stride length and paw area in mice after RCT. Additionally, PRDM16-overexpressing mice showed no difference in the amount of fibrosis when compared to WT mice; however, they had a significantly reduced area of fatty infiltration. These mice also exhibited abundant MHC-IIx fiber percentage in the supraspinatus muscle after TTDN.

CONCLUSION

Overexpression of PRDM16 significantly improved muscle function and reduced fatty infiltration after rotator cuff tears. Promoting BAT activity is beneficial in improving rotator cuff muscle quality and shoulder function after RCT.

Platelet-Rich Plasma for Arthroscopic Rotator Cuff Repair: A 3-Arm Randomized Controlled Trial

BACKGROUND

Although there has been some amount of research into the use of platelet-rich plasma (PRP) after arthroscopic rotator cuff repair, most studies have not fully demonstrated its benefits. In addition, PRP formulations containing different concentrations of leukocytes have not been directly compared for rotator cuff repair.

PURPOSE/HYPOTHESIS

The purpose of this article was to determine whether arthroscopic rotator cuff repair combined with PRP injection, either leukocyte-rich PRP (LR-PRP) or leukocyte-poor PRP (LP-PRP), is superior to the control. The null hypothesis was that the addition of any PRP formulation would not result in outcomes superior to the control group.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Patients with full-thickness rotator cuff tears who underwent arthroscopic repair were assessed for eligibility. The included patients were randomized to 3 treatment groups: the LR-PRP, LP-PRP, and standard-care control groups. After the rotator cuff suture was fixed firmly, different groups of liquid PRP preparations prepared by centrifugation were injected into the tendon-to-bone interface. The functional outcomes were assessed using the University of California, Los Angeles (UCLA) score, the Constant score, the American Shoulder and Elbow Surgeons (ASES) score, the visual analog scale for pain during sleep and activity, and active range of motion at 3, 6, and 12 months after surgery. In addition, the visual analog scale score was obtained at weeks 2 and 6. Postoperative structural integrity was assessed by magnetic resonance imaging at 12 months using the Sugaya classification. Type III was considered partial retear, and types IV and V were considered complete retears. The safety of surgery was compared by the incidence of complications. The main analyses were performed in accordance with the intention-to-treat principle.

RESULTS

Of 150 patients initially randomized, the functional outcomes in 142 (46 LR-PRP, 47 LP-PRP, 49 control) and the structural integrity in 133 (40 LR-PRP, 46 LP-PRP, 47 control) were analyzed. There was no significant difference in the primary outcome of the UCLA score among the 3 groups (P = .169). The trends in functional outcomes and range of motion were similar for the 3 groups, with no significant differences among the groups at 12 months. However, within 6 months after surgery, the ASES score was better in the LR-PRP group than in the control group (3 months: 85.8 ± 4.1 vs 81.6 ± 8.7; P = .011; 6 months: 90.0 ± 5.4 vs 86.2 ± 6.8; P = .003). At 12 months after surgery, the overall retear rate, including partial and complete retears, was 8%. There were no significant differences in the rates of overall retear (P = .755) or complete retear (P = .633) among the 3 groups. The only surgical complication was postoperative stiffness, which occurred in 3% of patients, and the incidence did not significantly differ among the groups (P = .790).

CONCLUSION

The study did not reveal that shoulders treated with the LR-PRP or LP-PRP formulations had any superior functional or structural outcomes at 12 months compared with those of the control group. However, LR-PRP may offer better ASES scores than the control group up to 6 months after surgery, and its clinical benefit remains to be proven.

REGISTRATION

ChiCTR2100045039 (Chinese Clinical Trial Register).

Preoperative Nutrition Impacts Retear Rate After Arthroscopic Rotator Cuff Repair

BACKGROUND

A rotator cuff retear following arthroscopic rotator cuff repair (ARCR) is a concern in older patients. However, only a few of its risk factors are amenable to preoperative intervention. We aimed to elucidate the relationship between preoperative nutritional status and rotator cuff retears after ARCR.

METHODS

This single-center retrospective study included patients aged ≥65 years with rotator cuff tears who underwent ARCR. The Geriatric Nutritional Risk Index (GNRI) was used to assess preoperative nutritional status. Data collection encompassed patient demographics, clinical assessments, and surgical specifics. Patients were divided into healed and retear groups based on 2-year post-ARCR magnetic resonance imaging results. Logistic regression analysis was conducted to adjust for confounding factors and detect independent risk factors for retears. The GNRI cutoff value for retear prediction was determined by a stratum-specific likelihood ratio; clinical outcomes were compared based on the cutoff values obtained.

RESULTS

Overall, 143 patients were included. The retear rate was 20.3%. The albumin level, GNRI, postoperative shoulder strength of abduction and external rotation, and postoperative Japanese Orthopaedic Association and Constant scores in the retear group were significantly lower than those in the healed group. The logistic regression analysis showed that low risk of morbidity and mortality (compared with no risk) based on the GNRI (odds ratio [OR], 3.39) and medial-lateral tear size per mm (OR = 1.10) were independent risk factors for a retear 2 years after ARCR. Stratum-specific likelihood ratio analysis identified data-driven strata as GNRI < 103, 103 ≤ GNRI < 109, and GNRI ≥ 109. Univariate analysis showed that patients with GNRI < 103 had a significantly higher retear risk than those with 103 ≤ GNRI < 109 and those with GNRI ≥ 109. Logistic regression analysis showed that GNRI < 103 compared with 103 ≤ GNRI < 109 (OR = 3.88) and GNRI < 103 compared with GNRI ≥ 109 (OR = 5.62), along with the medial-lateral tear size per mm (OR = 1.10), were independent risk factors for a retear at 2 years after ARCR.

CONCLUSIONS

When assessing the risk of a retear after ARCR, GNRI ≥ 103 may indicate good preoperative nutritional status. However, more data are essential to ascertain the importance of this finding.

LEVEL OF EVIDENCE

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

Risk factors for healing failure after arthroscopic rotator cuff repair in small to medium-sized tears: a retrospective cohort study

Objectives

To identify risk factors for tendon healing failure following arthroscopic rotator cuff repair (ARCR) in patients with small to medium-sized rotator cuff tears (RCTs).

Methods

A retrospective study was conducted on 320 patients with RCTs who underwent arthroscopic repair between June 2018 and June 2021. All patients had at least 2 years of postoperative follow-up, with MRI scans at the final assessment. Based on MRI results, patients were categorized into the healing success group (Group A: types I-III) or the healing failure group (Group B: types IV-V). Variables associated with rotator cuff healing, including patient characteristics, baseline symptoms, imaging data, and surgery-related factors, were analyzed using univariate and multivariate logistic regression.

Results

Healing failure occurred in 54 of the 320 patients (16.9%). Functional status improved significantly across all patients (P < 0.05), irrespective of healing outcomes. Multifactorial analysis identified smoking (OR = 1.931, P = 0.028), diabetes (OR = 3.517, P = 0.038), lower bone mineral density (BMD) (OR = 1.551, P = 0.018), higher fatty infiltration (FI) (OR = 4.025, P = 0.009), and smaller acromiohumeral distance (AHD) (OR = 2.546, P = 0.006) as independent risk factors for healing failure.

Conclusions

Smoking, diabetes, lower BMD, higher FI, and smaller AHD are independent risk factors for healing failure following ARCR.

Re-tear following rotator cuff repair: Do functional outcomes predict success?

Purpose

The purpose of this study is to compare functional outcomes between patients who were found to have a retear on ultrasound versus those with an intact repair following arthroscopic rotator cuff repair.

Methods

Retrospective cohort study comparing functional outcomes of 84 patients who underwent arthroscopic rotator cuff repair and were found to have a retear versus those who did not experience a retear. Functional outcomes included American Shoulder and Elbow Surgeons (ASES) score, Simple Shoulder Test, strength and active range of motion (AROM) assessed preoperatively and postoperatively at 3 and 6 months.

Results

Patients without a retear by 6 months demonstrated greater improvements in internal rotation at 3 months (2.3° of mean change, p = 0.0356), as well as greater improvements in external rotation range of motion (8.8° of mean change, p = 0.0210) between 3 and 6 months as compared to those patients who did experience a retear. Both groups showed decreased pain scores and increased ASES scores at all points postoperatively.

Conclusions

Our study found statistically significant improvements in internal rotation at 3 months, and external rotation between 3 and 6 months in the non-retear group. No differences in functional outcomes existed between at final follow-up.

Biologic Augmentation of Rotator Cuff Repair: Current Concepts Review

Rotator cuff tears are common in an aging population. Thus far, primary repairs have shown high re-tear rates suggesting the need for improved healing modalities. Current augmentations of rotator cuff repairs include synthetic and biological scaffolds, surgical bone marrow venting, and infusing the repair with a variety of stem cells and growth factors aimed at restoring the native cellular structure and function of the repaired tissue. This current concepts review discusses the anatomy, physical presentation, diagnosis, and treatment of rotator cuff tears; biological adjuvants for rotator cuff repairs; and the current literature on outcomes after biologically augmented rotator cuff repairs. [Orthopedics. 202x;4x(x):xx-xx.].

Comparison of mediolateral (V-shaped) vs. anteroposterior dominant rotator cuff tears: the anteroposterior tear width contributes more to postoperative retears than mediolateral length when the tear size area is similar

BACKGROUND

Tear size is a significant prognostic factor following rotator cuff repair. However, no study has investigated which dimension of the tear, the mediolateral (ML) or anteroposterior (AP), more significantly influences the outcome when the product of the 2 dimensions, the tear size area, is similar.

METHODS

A retrospective cohort study was conducted with patients who underwent arthroscopic full-thickness rotator cuff tear (FTRCT) repair. Two contrasting groups were derived from preoperative tear dimensions. The ML dominant (MLD) group consisted of 45 FTRCTs with the ML tear dimension at least 1.5 times larger than the AP, and retraction exceeding the humeral head apex. The AP dominant (APD) group included 35 FTRCTs with an inverse proportion of the dimensions and retraction short of the humeral head apex. Demographic data, preoperative and postoperative magnetic resonance imaging, clinical scores, and strength were compared between the groups.

RESULTS

The mean follow-up was 26.7 and 32.2 months in the MLD and APD groups, respectively. The tear size in area (MLD vs. APD, 521.0 vs. 523.4 mm2, P = .960) and the discrepancy between ML and AP dimensions (2.0 vs. 1.9, P = .597) were similar. However, the MLD group demonstrated significant female predominance (P = .003), dominant arm involvement (P = .007), a higher incidence of pathologic subacromial spurs (P = .016), narrower acromiohumeral distance (P < .001), shorter residual tendon (P < .001), and advanced supraspinatus muscle atrophy (P = .005). Other baseline parameters were comparable between the groups. At the 1-year postoperative magnetic resonance imaging, the MLD group demonstrated a significantly lower retear rate (4.4% vs. 31.4%, P = .001). Nevertheless, clinical scores and strength at the last follow-up did not significantly differ.

CONCLUSION

In a similar tear size area, the greater AP width contributes more than the ML length in causing a retear. Female predominance, dominant arm involvement, subacromial spurs, shorter residual tendon, and supraspinatus muscle atrophy were more demonstrated in MLD tears. Surgeons should be aware that healing may be poor in APD tears despite less retraction.

Early intervention of extracorporeal shockwave therapy sustained positive long-term effect on rotator cuff healing: A randomized controlled trial with 3-year follow-up

Background

The long-term effects of extracorporeal shockwave therapy (ESWT) on rotator cuff repair are unknown.

Objectives

To investigate the functional outcomes and structural changes of ESWT at 3-year follow-up after rotator cuff repair.

Methods

A randomized clinical trial was conducted, including patients who underwent rotator cuff repair. The patients were assigned to two groups based on whether they underwent radial ESWT 3 months postoperatively. The ESWT Group received 5 weeks of rehabilitation and ESWT weekly, whereas the CONTROL Group received only rehabilitation. Visual analog scale (VAS) pain score and functional scores were analyzed at 3 months (baseline), 6 months, and 3 years follow-up. In addition, MRI and ultrasonography were used to assess tendon maturation, integrity, tendon quality, acromiohumeral distance (AHD), and muscle fatty infiltration.

Results

Finally, 32 participants completed all the assessments. At the final follow-up, 2 patients in the ESWT Group (16.5 %) versus one patient in the CONTROL Group (6.25 %) had rotator cuff failure (P = 0.176). The ESWT treatment showed similar clinical outcomes in VAS-pain score, functional scores, tendon quality, AHD, and muscle fatty infiltration versus the CONTROL Group (Ps > 0.05). MRI analysis indicated improved tendon healing after ESWT treatment at both 6-month (P = 0.036) and 3-year follow-up (P = 0.028).

Conclusion

Early intervention with radial ESWT sustained long-term effects on the healing of the repaired rotator cuff and similar functional outcomes at long-term follow-up compared with standard rehabilitation.

M2 Macrophage-Derived Exosomes Promote Tendon-to-Bone Healing by Alleviating Cellular Senescence in Aged Rats

PURPOSE

To explore the potential of M2 macrophage-derived exosomes (M2-Exos) in enhancing tendon-to-bone healing in aged rats by mitigating cellular senescence of bone marrow-derived stem cells (BMSCs).

METHODS

In vitro, the effects of M2-Exos on alleviating cellular senescence and improving chondrogenic potential of senescent BMSCs were evaluated. Rats (24 young and 48 aged) with chronic rotator cuff tear (RCT) were repaired and assigned into 3 groups: young group (young rats injected with fibrin at the enthesis), aged group (aged rats injected with fibrin at the enthesis), and aged + M2-Exos group (aged rats injected with fibrin containing M2-Exos at the enthesis). At 6 and 12 weeks after repair, enthesis regeneration was evaluated. Proteomic analysis was conducted to explore the mechanism through which M2-Exos mitigated cellular senescence.

RESULTS

In senescent BMSCs treated with M2-Exos, there was a reduction in senescence biomarkers including senescence-associated β-galactosidase, p53, p21, and senescence-associated secretory phenotype (P < .001). M2-Exos also enhanced chondrogenic potential of senescent BMSCs, reflected in greater Bern score (P < .001) and increased expression of Sox9 (P = .013), Col2a1 (P < .001), and Acan (P < .001). Histologically, aged rats treated with M2-Exos demonstrated significantly greater histologic scores (P < .001 at both 6 and 12 weeks) and increased fibrocartilage regeneration at the enthesis. Biomechanically, these rats exhibited greater failure load, stiffness, and stress (all P < .001) at 12 weeks. Mechanistically, proteomic analysis suggested that M2-Exos might alleviate cellular senescence by potentially regulating DNA replication and repair.

CONCLUSIONS

M2-Exos can significantly alleviate BMSC senescence and thereby enhance tendon-to-bone healing in an aged rat RCT model.

CLINICAL RELEVANCE

This study suggests the potential utility of M2-Exos as a therapy for RCT in the older population.

Circadian Rhythm-Regulated ADSC-Derived sEVs and a Triphasic Microneedle Delivery System to Enhance Tendon-to-Bone Healing

Modulating the inflammatory microenvironment to reconstruct the fibrocartilaginous layer while promoting tendon repair is crucial for enhancing tendon-to-bone healing in rotator cuff repair (RCR), a persistent challenge in orthopedics. Small extracellular vesicles (sEVs) hold significant potential to modulate inflammation, yet the efficient production of highly bioactive sEVs remains a substantial barrier to their clinical application. Moreover, achieving minimally invasive local delivery of sEVs to the tendon-to-bone interface presents significant technical difficulties. Herein, the circadian rhythm of adipose-derived stem cells is modulated to increase the yield and enhance the inflammatory regulatory capacity of sEVs. Circadian rhythm-regulated sEVs (CR-sEVs) enhance the cyclic adenosine monophosphate signaling pathway in macrophage (Mφ) via platelet factor 4 delivery, thereby inhibiting Mφ M1 polarization. Subsequently, a triphasic microneedle (MN) scaffold with a tip, stem, and base is designed for the local delivery of CR-sEVs (CR-sEVs/MN) at the tendon-to-bone junction, incorporating tendon-derived decellularized extracellular matrix in the base to facilitate tendon repair. CR-sEVs/MN mitigates inflammation, promotes fibrocartilage regeneration, and enhances tendon healing, thereby improving biomechanical strength and shoulder joint function in a rat RCR model. Combining CR-sEVs with this triphasic microneedle delivery system presents a promising strategy for enhancing tendon-to-bone healing in clinical settings.

Should I prescribe exercise to a patient with an immobilized shoulder? An electromyographic study in patients with unilateral shoulder pain and healthy volunteers

Background

There is limited evidence about exercise performance during postoperative immobilization. This study aimed to quantify the muscle activity in the immobilized shoulder girdle in an abduction and neutral rotation position during a battery of contralateral activities and ipsilateral exercises of the upper limb in healthy volunteers and patients with unilateral shoulder pain (USP).

Methods

Thirty participants were included and grouped as without (N = 17) or with USP (N = 13). Muscle activity (percentage of maximum voluntary isometric contraction (%MVIC)) of the serratus anterior (SA), upper trapezius (UT), lower trapezius (LT) and infraspinatus muscles was assessed during five contralateral activities (during comfortable speed, fast speed and comfortable speed with additional load) and seven ipsilateral exercises.

Results

No differences in % MVIC were found between healthy volunteers and patients with USP on immobilized upper limb exercises and with the contralateral shoulder girdle. General muscle activity was low (<15% MVIC) to moderate (21-40% MVIC). This similarity was maintained at different speeds and with additional load. Adapted lawnmower exercise showed a favorable UT/LT activation ratio.

Conclusion

The study results support the use of all evaluated shoulder exercises, as they have shown low muscle activity, which is important for early rehabilitation phases.

Ultrasound and patient-reported outcomes of rotator cuff repair with new acellular human allograft at 6 months and 1 year post surgery

Background

Determine the effect of a novel acellular cannulated dermal allograft on tendon-to-bone healing, retear rates, and clinical outcomes over a 12-month period.

Methods

This was a single surgeon prospective nonrandomized case series. Patients with medium sized full-thickness superior and posterosuperior rotator cuff tears, as confirmed by magnetic resonance imaging, were consented. Patients were excluded if they had fatty atrophy indicative of Goutallier grade III or IV. The allograft is a cannulated rectangular prism that has a 5-year shelf life, does not require prehydration, and does not need to be trimmed to size. Outcome metrics included ultrasound assessment at 1-year as well as 6-month patient-reported outcomes (PROs) scores.

Results

31 patients consented and enrolled in this consecutive cohort series. 9 patients were excluded, and statistical analysis was performed on the remaining 22 patients. There were 9 females and 13 males. The average age was 59.27 ± 7.48 year old. The average supraspinatus short axis measurement in males was 0.56 ± 0.12 cm and 0.52 ± 0.09 cm in females (P = .44). The average supraspinatus long axis measurement in males was 0.61 ± 0.18 cm and 0.55 ± 0.14 cm in females (P = .46). The average infraspinatus short axis measurement in males was 0.48 ± 0.10 cm and 0.50 ± 0.13 in females (P = .74). The average infraspinatus long axis measurement in males was 0.44 ± 0.12 cm and 0.43 ± 0.08 cm in females (P = .84). Of the 19 patients who completed baseline and 6-month PRO's, 17 achieved the minimal clinical important difference for American Shoulder and Elbow Surgeons and Patient-Reported Outcomes Measurement Information SystemUE 7a. Retear occurred in 2 cases. The remaining 20 cases have all demonstrated healing or fully healed repairs at their most recent clinical visits with no additional cases of retears.

Conclusion

This study is the first to report the results of a novel acellular dermal allograft for rotator cuff repair augmentation. Satisfactory PRO measures and robust tendon healing at 1 year, as measured by ultrasound, demonstrate the utility of a cannulated human acellular dermal allograft as a viable biologic augmentation device for rotator cuff repair.

Superior capsular reconstruction with the long head of the biceps tendon achieves excellent clinical results and low rotator cuff rerupture rates one year after cuff repair surgery

PURPOSE

To analyze the clinical one-year evolution of healed and rerupture lesions in patients who received a rotator cuff repair plus Superior Capsular Reconstruction (SCR) with the long head of the biceps (LHB). Moreover, to compare this evolution between men and women.

METHODS

A pilot study was conducted on patients who underwent a rotator cuff repair plus SCR with LHB between February 2021 and June 2022. All patients completed pre-operative and one-year post-operative evaluations for tendon type of tear and tendon integrity using Magnetic Resonance Imaging (MRI)after one year of the surgery. Besides, functionality was evaluated with the American Shoulder and Elbow Surgeons (ASES) score; the visual analog scale for pain (VAS); and the Constant score.

RESULTS

A total of 38 patients completed the one-year final evaluation, they presented an increased functionality score to 83 and 86 in Constant and ASES scales (p < .001), respectively. Besides, 84% of the patients presented a healed cuff, while rerupture occurred in 16% of the patients. There were differences between the healed and rerupture patients in the total Constant score, with a remarkable increase in the strength subscale, almost double for patients with healed cuff (p < .001); in the same way, daily life activity score, and balance subscale increased, while pain score decreased in the healed cuff group (p < .05). There was no difference in functionality between men and women (p > .05). Besides, almost all patients achieved the MCID in both ASES and Constant total scores, irrespectively of the healing group.

CONCLUSION

The cuff repair using SCR with the LHB achieved a low percentage of rerupture and a functional improvement after one year of follow-up. Patients who healed the lesion presented more strength and better performance in daily life activities than those with cuff repurture. Thus, SCR + LHB procedure can be considered an efficient technique for rotator cuff repair surgery for both men and women. Although a comparison with a control group is needed to confirm these findings.

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.

The Subscapularis Healing Index: A New Scoring System for Predicting Subscapularis Healing After Arthroscopic Repair

BACKGROUND

Previous research has emphasized the effect of prognostic factors on arthroscopic rotator cuff repair (ARCR) success, but a specific focus on subscapularis (SSC) tendon repair healing is lacking.

PURPOSE

To identify prognostic factors for SSC healing after ARCR and develop the Subscapularis Healing Index (SSC-HI) by incorporating these factors.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

This was a retrospective study using prospectively maintained data collected from patients with isolated or combined SSC tears who underwent ARCR between 2011 and 2021 at a single institution with a minimum 2-year follow-up. Functional outcomes were assessed using the American Shoulder and Elbow Surgeons (ASES) score, Subjective Shoulder Value (SSV), and visual analog scale (VAS) pain scale. SSC tendon healing was evaluated via ultrasound at the final follow-up. Multivariate logistic regression analysis was performed to determine the factors affecting SSC healing, and based on these factors, the SSC-HI, which ranges from 0 to 15 points, was developed using odds ratios (ORs).

RESULTS

Among 1018 ARCR patients, 931 met the inclusion criteria; 279 returned voluntarily for postoperative SSC ultrasound assessment. The overall healing failure rate was 10.8% (30/279). Risk factors for healing failure included female sex (P = .008; OR, 3.119), body mass index (BMI) ≥30 (P = .053; OR, 2.323), supraspinatus fatty infiltration ≥3 (P = .033; OR, 3.211), lower SSC fatty infiltration ≥2 (P = .037; OR, 3.608), and Lafosse classification ≥3 (P = .007; OR, 3.224). A 15-point scoring system comprised the following: 3 points for female sex, 2 points for BMI ≥30, 3 points for supraspinatus fatty infiltration ≥3, 4 points for lower SSC fatty infiltration ≥2, and 3 points for Lafosse classification ≥3. Patients with ≤4 points had a 4% healing failure rate, while those with ≥9 points had a 55% rate of healing failure. Patients with a healed SSC reported significantly higher ASES (healed SSC: ΔASES, 44.7; unhealed SSC: ΔASES, 29; P < .01) and SSV (healed SSC: ΔSSV, 52.9; unhealed SSC: ΔSSV, 27.5; P < .01) and lower VAS (healed SSC: ΔVAS, -4.2; unhealed SSC: ΔVAS, -3; P < .01) scores compared with those with an unhealed SSC.

CONCLUSION

The SSC-HI scoring system integrates clinical and radiological factors to predict SSC healing after surgical repair. Successful SSC healing was found to be associated with enhanced functional outcomes, underscoring the clinical relevance of SSC healing prediction in the management of these tears.

Editorial Commentary: Bioinductive Collagen Implants Reduce Rotator Cuff Retear, yet Cost-Effectiveness and Improvement in Clinical Outcomes Are Unclear

The estimated health care costs of failed arthroscopic rotator cuff retears (RCRs) performed in the United States represent a huge economic burden of greater than $400 million per 2-year period. Unfortunately, retear rates do not appear to have improved significantly since the 1980s, despite advances in surgical technology and the biomechanics of repair. The failure of these advances to translate into improved clinical results suggests that the limiting step in reducing retear rates is biology rather than the biomechanics of repair. Bioinductive collagen implants (BCIs) are an emerging and potentially useful option for biological augmentation. Recent meta-analysis of preclinical and clinical studies demonstrates that biological augmentation significantly lowers the risk of retear. Retrieval studies from human RCR subjects who underwent treatment with BCI demonstrate cellular incorporation, tissue formation, and maturation, providing a logical basis for a reduction in retear rates as well as small increases in tendon thickness at the footprint. Although BCIs show potential as a possible game-changing solution for reducing failure rates of RCR, concerns remain regarding cost-effectiveness analyses and demonstration of functional outcome improvement.

Biomechanical comparison of suture bridge rotator cuff repair with and without dermal allograft pledgets

BACKGROUND

One method to augment rotator cuff repair is to pass dermal allograft pledgets along the sutures that bridge from the medial to the lateral row. It remains unclear whether this augmentation method alters repair biomechanics.

METHODS

This was a controlled laboratory study. After an a priori power analysis, 9 pairs of rotator cuffs underwent double-row suture bridge rotator cuff repair, half randomized to augmentation with dermal allograft pledgets passed along the suture bridge sutures. Repairs were then mounted on a material testing system and loaded cyclically 500 cycles to measure applied force and displacement. Repairs then underwent ultimate failure testing, and stiffness, ultimate failure force, and ultimate failure displacement were measured. Paired t tests were performed to compare between groups.

RESULTS

There were no differences between groups in construct gapping with cyclic loading after 500 cycles (P = .885). There were no differences between the augmented and control groups in yield force (103.5 ± 5.0 vs. 101.4 ± 5.9 N, respectively, P = .183), stiffness (94.2 ± 13.9 vs. 90.9 ± 13.8, P = .585), or ultimate failure force (255.3 ± 65.8 vs. 285.3 ± 83.2, P = .315). There were no differences between groups in failure modes, with most specimens failing by cuff tissue tearing within or medial to the construct.

CONCLUSION

The addition of dermal allograft pledgets does not positively or negatively influence the time-zero biomechanical characteristics of double-row suture bridge rotator cuff repair.

Heated Tobacco Products Have Detrimental Effects on Rotator Cuff Healing, Similar to Conventional Cigarettes

BACKGROUND

Cigarette smoking impairs rotator cuff healing, but no study, to our knowledge, has focused on the association between heated tobacco products and rotator cuff tears.

METHODS

This study retrospectively investigated 1,133 patients who underwent arthroscopic repair of symptomatic rotator cuff tears between March 2011 and April 2021. Patients were grouped on the basis of their smoking patterns as nonsmokers, cigarette smokers, and heated tobacco smokers. Propensity score matching was used to reduce selection bias, and 45 subjects were selected from each group via 1:1:1 matching. Functional scores and active range of motion were compared among the 3 groups preoperatively and at a 2-year follow-up. Postoperative magnetic resonance imaging was performed 6 months after the surgical procedure to assess structural integrity.

RESULTS

Except for sex, similar baseline characteristics were achieved after propensity score matching. There were no differences in the clinical scores or range of motion between the matched groups either preoperatively or at the 2-year follow-up. However, the retear rate for the matched nonsmoker group was significantly lower (8.9%) than those for the matched cigarette smoker group (31.1%) and the heated tobacco smoker group (28.9%) (p = 0.022). Multivariable logistic regression analysis revealed that the retear rates were 3.403 times higher for the cigarette smoker group and 3.397 times higher for the heated tobacco smoker group than that for the nonsmoker group.

CONCLUSIONS

Heated tobacco users, like conventional cigarette smokers, have worse clinical outcomes with respect to rotator cuff healing than nonsmokers. Regardless of the type of cigarette, abstinence from smoking is necessary for patients undergoing rotator cuff repair surgery.

LEVEL OF EVIDENCE

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

Comparison of 3 Different Surgical Techniques for Rotator Cuff Repair in a Rabbit Model: Direct Suture, Inlay Suture, and Polyether Ether Ketone (PEEK) Suture Anchor

BACKGROUND

Rotator cuff tears have been repaired using the transosseous method for decades. The direct suture (DS) technique has been widely used for rotator cuff tears; however, the retear rate is relatively high. Suture anchors are now used frequently for rotator cuff repair (RCR) in accordance with recent developments in materials. However, polyether ether ketone (PEEK) may still cause complications such as the formation of cysts and osteophytes. Some studies have developed the inlay suture (IS) technique for RCR.

PURPOSE/HYPOTHESIS

To compare how 3 different surgical techniques-namely, the DS, IS, and PEEK suture anchor (PSA)-affect tendon-bone healing after RCR. We hypothesized that the IS technique would lead to better tendon-to-bone healing and that the repaired structure would be similar to the normal enthesis.

STUDY DESIGN

Controlled laboratory study.

METHODS

Acute infraspinatus tendon tears were created in 36 six-month-old male rabbits, which were divided into 3 groups based on the technique used for RCR: DS, IS, and PSA. Animals were euthanized at 6 and 12 weeks postoperatively and underwent a histological assessment and imaging. The expression of related proteins was demonstrated by immunohistochemistry and immunofluorescence staining. Mechanical properties were evaluated by biomechanical testing.

RESULTS

At 12 weeks, regeneration of the enthesis was observed in the 3 groups. However, the DS group showed a lower type I collagen content than the PSA and IS groups, which was similar to the results for scleraxis. The DS group displayed a significantly inferior type II collagen expression and proteoglycan deposition after safranin O/fast green and sirius red staining. With regard to runt-related transcription factor 2 and alkaline phosphatase, the IS group showed upregulated expression levels compared with the other 2 groups.

CONCLUSION

Compared with the DS technique, the PSA and IS techniques contributed to the improved maturation of tendons and fibrocartilage regeneration, while the IS technique particularly promoted osteogenesis at the enthesis.

CLINICAL RELEVANCE

The IS and PSA techniques may be more beneficial for tendon-bone healing after RCR.

Are Lower Passive Anterior Elevation and External Rotation at 6 Weeks Postoperatively Associated With Healing of Isolated Arthroscopic Supraspinatus Repairs?

BACKGROUND

Despite advancements in surgical technique, failure of tendon healing remains a common problem after arthroscopic rotator cuff repair (ARCR).

PURPOSE/HYPOTHESIS

The purpose of this study was to examine the relationship between range of motion (ROM) recovery and healing after ARCR. It was hypothesized that an early loss of ROM would be associated with tendon healing.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

This was a retrospective comparative study of primary ARCR of isolated full-thickness supraspinatus (SSN) tendon tears. Cases were retrieved from a prospective rotator cuff repair database and divided into 2 groups based on healing (healed/nonhealed). A standardized clinical evaluation was performed before and at 6 weeks, 3 months, and 6 months after surgery. Collected data included passive and active ROM, visual analog scale for pain, and Constant score. Healing was assessed by ultrasound at 6 months.

RESULTS

Of 1397 eligible ARCRs, 1207 were included. The healing rate was 86.7%. Age was higher in the nonhealed group (57.8 ± 7.9 years vs 61.6 ± 8.8 years; P < .001). Patients with healed repairs had a larger decrease in passive anterior elevation (AE) from the preoperative to the 6-week postoperative visit (-31°± 28° vs -18°± 26°; P < .001), followed by a more substantial increase throughout the remaining follow-up period (32°± 23° vs 18°± 21°; P < .001). At 6 months postoperatively, there was no difference in AE between groups (159°± 17° vs 161°± 14°; P > .999). External rotation elbow at side (ER1) and internal rotation hand in the back (IR1) followed similar courses of recovery. Passive and active ROM had a strong positive correlation at each follow-up. Age (odds ratio [OR], 1.79; 95% CI, 1.45-2.23; P < .001) and 6-week passive AE (OR, 1.33; 95% CI, 1.20-1.48; P < .001) and ER1 (OR, 1.15; 95% CI, 1.03-1.29; P = .017) were predictors for nonhealing.

CONCLUSION

Lower passive AE and ER1 at 6 weeks postoperatively and younger age are associated with healing after ARCR of isolated SSN tendon tears. At 6 months postoperatively, there were no differences in ROM, regardless of tendon healing.

Clinical and Radiologic Outcomes of Arthroscopic Rotator Cuff Repair in Medial Bursal-Side Fosbury Flop Tears Compared With Tendinous Avulsion Lesions

Purpose

To determine the clinical and radiologic outcomes after surgical repair of medial bursal-side Fosbury flop rotator cuff tears compared with traditional avulsion of tendinous attachments lesions.

Methods

A retrospective cohort study was performed. All patients who had undergone arthroscopic posterosuperior repair were recruited. Patients with previous shoulder rotator cuff surgery were excluded. Recruited patients were divided into 2 groups: one presenting Fosbury flop tears and the other presenting with standard avulsion lesions. Preoperative demographics such as age, gender, and arm dominance were recorded. Range of motion (ROM), visual analog scale (VAS) for pain and satisfaction, Constant score, Single Alpha-Numeric Evaluation score, and American Shoulder and Elbow Surgeons score were evaluated at 3 points in time: preoperatively, and at 6 months and minimum 1-year postoperatively. The healing of repaired cuffs was evaluated by ultrasound at 6 months.

Results

Two hundred thirty-six patients were recruited, with 27 (11.4%) Fosbury flop tears and 209 (88.6%) tendon avulsions. Although there was no significant difference in gender or arm dominance between the groups, Fosbury flop tears had significantly older patients (P < .05) with a mean age 61.6 years (standard deviation 9.0), compared with tendon avulsions with a mean age of 56.1 years (standard deviation 9.1). There was no significant difference in tendon retraction between the groups. Both groups demonstrated significant improvement in ROM, visual analog scale, American Shoulder and Elbow Surgeons, Single Alpha-Numeric Evaluation, and Constant score postoperatively at 6 months and minimum 1 year. The groups demonstrated no significant difference in the ROM and clinical scores. There was a nonsignificant difference in re-tear rate of 7.4% (2/27) in Fosbury flop tears compared with 2.8% (6/209) in tendon avulsions (P = .361).

Conclusions

Arthroscopic rotator cuff repair of medial bursal side Fosbury Flop rotator cuff tears results in favorable clinical and radiologic outcomes at 4 years after surgery. These outcomes are comparable with surgically repaired avulsion lesions, with an acceptable retear rate after arthroscopic repair.

Level of Evidence

Level III, retrospective comparative prognostic trial.

Editorial Commentary: Artificial Intelligence Analysis of Biomedical, Large, Clinical Registry Data Using Machine Learning Requires Tens of Thousands of Subjects and a Focus on Substantial Clinical Benefit: Minimal Clinically Important Difference Is too Low a Bar

As the field of arthroscopic hip preservation surgery grows, large high-quality registries represent a foundational study design for establishing whether hip arthroscopy is effective for patients with femoroacetabular impingement syndrome (FAIS). Original research publications from experienced high-volume surgeons tell us "Can it work". A registry tells us "Does it work?". The ability of preservation to truly preserve the joint, delay the arthritis process, and reduce the risk of arthroplasty requires long-term follow-up. A geographic registry can follow this. The registry represents the "real world", a heterogeneous set of variables pertaining to the doctor, patient, intervention, and outcome. The vast array of factors that can be analyzed before, during, and after surgery makes machine learning an ideal technique for analysis of large quantities of data. A global hip preservation surgery registry is a desirable and achievable goal. In order to optimally predict outcome of hip arthroscopy, given the known large number of patient- and hip-specific factors that influence outcomes, a deep learning model with tens of thousands of subjects for this medium-scale task would be needed. Measures of clinical relevance need to include more than just MCID (minimal clinically important difference), which is the lowest bar minimal threshold. Patient expectations often far exceed MCID-requiring other metrics like SCB (substantial clinical benefit), PASS (patient acceptable symptom state), and MOI (maximal outcome improvement). Registries should include validated, reliable, and responsive patient-reported outcome scores (e.g., International Hip Outcome Tool [iHOT-12]) with measures of clinical relevance and expectations assessed routinely. The United Kingdom's NAHR (Non-Arthroplasty Hip Registry) and Denmark's DHAR (Danish Hip Arthroscopy Registry) are the two largest geography-based registries in current hip preservation research both with 11 years of patient enrollment.

Impact of obesity on outcomes of rotator cuff repair: A systematic review and meta-analysis

BACKGROUND

To synthesize the existing evidence on the association between obesity and rotator cuff repair outcomes such as pain, shoulder function, range of motion, and complications.

METHODS

We searched PubMed, EMBASE, and Scopus databases for relevant observational studies (cohort and case-control) and randomized controlled trials (RCTs). The target population in the included studies comprised adults who had undergone rotator cuff repair procedures. The outcomes of interest were functional outcomes (such as range of motion), pain scores, patient-reported outcome measures, and complication rates (such as re-repair and readmission rates). We applied random-effects models and calculated pooled effect sizes reported as standardized mean differences (SMDs) or relative risks (RRs) with 95% confidence intervals.

RESULTS

We analysed data from 11 studies. In most, the follow-up periods ranged from 12 to 60 months. Obese individuals experienced greater pain (SMD 0.30; 95% CI, 0.10, 0.50) and lower shoulder function (SMD -0.33; 95% CI, -0.54, -0.12) than other individuals in the long-term post-operative follow-up. Obese individuals also had higher risks of complications (RR 1.48; 95% CI, 1.11, 1.98) and readmission (RR 1.35; 95% CI, 1.27, 1.43), but a similar likelihood of re-repair (RR, 1.27; 95% CI, 0.82, 1.95) than non-obese/normal BMI individuals. While the forward flexion and external rotation functions were comparable, obese individuals displayed less internal rotation function than other individuals (SMD -0.59; 95% CI, -0.87, -0.30).

CONCLUSION

Obesity was associated with unfavourable outcomes after rotator cuff surgery, including increased pain, reduced shoulder function, high risks of complications, and readmission. These findings emphasize the importance of addressing obesity-related factors to improve post-operative outcomes.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Differences in Clinical Outcomes Between Patients With Retear After Supraspinatus Tendon Repair and Those With Intact Repair at 5-Year Follow-up

BACKGROUND

It is well known that rotator cuff repair is associated with an overall retear rate of 21% to 26%. However, a cuff retear may not necessarily be associated with poor clinical outcomes.

HYPOTHESIS

There would be no difference in clinical outcomes between patients with a cuff retear and those with an intact repair at a midterm follow-up of 5 years.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective study was conducted involving patients who received arthroscopic complete repair of the supraspinatus tendon between January 2009 and December 2017. Patients who did not have a postoperative magnetic resonance imaging (MRI) scan or who had a follow-up of <5 years were excluded. Clinical outcomes, including the visual analog scale (VAS) score, American Shoulder and Elbow Surgeons (ASES) score, and active forward flexion (FF) of the involved shoulder were assessed at the 2-year and 5-year follow-up points.

RESULTS

The study group included 105 patients with a mean follow-up of 85 months. MRI scans were performed at a mean of 20 months. Fourteen full-thickness cuff retears and 91 intact repairs were identified using postoperative MRI scans. Significant improvement in VAS score, ASES score, and FF were found between the preoperative assessment and the 2 designated follow-up points (2 years and 5 years) in both the cuff retear and the intact repair groups (P < .001). The VAS and ASES scores at the 2-year follow-up for the intact repair group were 1.8 ± 2.0 and 80.7 ± 18.1, respectively. The corresponding values for the retear group were 2.3 ± 2.2 and 71.9 ± 19.5, respectively. No significant difference was found between the 2 groups in the VAS and ASES scores at the 2-year follow-up. However, patients with an intact repair had a better VAS score (1.4 ± 1.8; P = .049) and ASES score (81.7 ± 17; P = .019) than those with a cuff retear at the 5-year assessment (3.0 ± 2.8 and 67.1 ± 22.9, respectively). In the intact repair group, 91% of patients achieved the minimal clinically important difference for the 5-year VAS score, compared with 54% in the cuff retear group (P < .001). The corresponding values for the 5-year ASES score were 80% and 54%, respectively (P = .044). FF measurements at the 5-year follow-up in patients with intact repair and those with a cuff retear were 161°± 23° and 144°± 37°, respectively (P = .059). Continuous improvement in VAS score and FF between the 2-year and 5-year follow-up was observed in the intact repair group (P = .005 and P = .04, respectively).

CONCLUSION

The patients with an intact repair had better VAS and ASES scores compared with those who had a cuff retear at a midterm follow-up of 5 years. Between the 2-year and the 5-year follow-up, some further improvement was observed in the VAS score and FF in the intact repair group.

Effects of adipose-derived cell supplementation on tendon-bone healing in a rat model of chronic rotator cuff tear with suprascapular nerve injury

OBJECTIVE

To investigate the effect of adipose-derived cells (ADCs) on tendon-bone healing in a rat model of chronic rotator cuff tear (RCT) with suprascapular nerve (SN) injury.

METHODS

Adult rats underwent right shoulder surgery whereby the supraspinatus was detached, and SN injury was induced. ADCs were cultured from the animals' abdominal fat. At 6 weeks post-surgery, the animals underwent surgical tendon repair; the ADC (+ve) group (n = 18) received an ADC injection, and the ADC (-ve) group (n = 18) received a saline injection. Shoulders were harvested at 10, 14, and 18 weeks and underwent histological, fluorescent, and biomechanical analyses.

RESULTS

In the ADC (+ve) group, a firm enthesis, including dense mature fibrocartilage and well-aligned cells, were observed in the bone-tendon junction and fatty infiltration was less than in the ADC (-ve) group. Mean maximum stress and linear stiffness was greater in the ADC (+ve) compared with the ADC (-ve) group at 18 weeks.

CONCLUSION

ADC supplementation showed a positive effect on tendon-bone healing in a rat model of chronic RCT with accompanying SN injury. Therefore, ADC injection may possibly accelerate recovery in massive RCT injuries.

Dermal Allograft Augmentation for Large and Massive Rotator Cuff Tears and Revisions: A Case Series

Introduction Arthroscopic advancements have notably improved rotator cuff repair, yet the healing of tendons and retear risks still pose significant challenges, especially with massive and large tears. These larger tears have shown a quadruple increase in retear rate when the tear size grows from 1-3 cm. The prevalent cause of failure, particularly in tears with fatty degeneration, is suture tearing. As such, techniques that enhance tendon healing are pivotal due to their correlation with improved functional outcomes. Dermal allograft augmentation (DAA) is one method that has demonstrated improvements in rotator cuff repair biomechanics, as well as the promotion of vascularization and neotendon formation. This study evaluates the efficacy of DAA in the postoperative healing of large and massive rotator cuff tears, assessed through patient-reported outcomes and functional range of motion. Methods This retrospective study reviewed a single surgeon's database, selecting patients who underwent arthroscopic surgery for full-thickness rotator cuff tears measuring at least 3 cm, or those with maximum stage II fatty infiltration of the supraspinatus or infraspinatus muscle on MRI. We used three validated patient-reported outcome (PRO) measures, American Shoulder and Elbow Surgeon Score (ASES), Single Assessment Numeric Evaluation (SANE), and Simple Shoulder Test (SST), alongside a range of motion metrics, external rotation (ER), and forward flexion (FF). These were recorded pre-operatively and, at minimum, one year post-operatively, with a standard student t-test employed for comparative analysis. Results Out of 18 total patients, the average age was 61 years, and 83% were male. The cause of injury was mostly traumatic in nature (n=11), with the remainder being chronic (n=7). All three PROs (n=11) demonstrated a statistically significant increase in score including ASES (p=0.003), SANE (p=0.004), and SST (p=0.039). External rotation also significantly improved pre- to post-operative function (46 vs 58, p=0.049). Three patients (17%) suffered from a retear within three months of their rotator cuff repair. Two patients (11%) required a reverse shoulder arthroplasty within a year. Conclusion Our study demonstrated that DAA in rotator cuff repair yielded notable functional and clinical advancements, with a moderately low retear rate as confirmed by ultrasound. These outcomes suggest that DAA is a promising intervention for large and historically difficult rotator cuff tears, offering significant implications for future treatment protocols.

Characterizing the Myoarchitecture of the Supraspinatus and Infraspinatus Muscles With MRI Using Diffusion Tensor Imaging

BACKGROUND

The societal cost of shoulder disabilities in our aging society keeps rising. Providing biomarkers of early changes in the microstructure of rotator cuff (RC) muscles might improve surgical planning. Elevation angle (E1A) and pennation angle (PA) assessed by ultrasound change with RC tears. Furthermore, ultrasounds lack repeatability.

PURPOSE

To propose a repeatable framework to quantify the myocyte angulation in RC muscles.

STUDY TYPE

Prospective.

SUBJECTS

Six asymptomatic healthy volunteers (1 female aged 30 years; 5 males, mean age 35 years, range 25-49 years), who underwent three repositioned scanning sessions (10 minutes apart) of the right infraspinatus muscle (ISPM) and supraspinatus muscle (SSPM).

FIELD STRENGTH/SEQUENCE

3-T, T1-weighted and diffusion tensor imaging (DTI; 12 gradient encoding directions, b-values of 500 and 800 s/mm2 ).

ASSESSMENT

Each voxel was binned in percentage of depth defined by the shortest distance in the antero-posterior direction (manual delineation), i.e. the radial axis. A second order polynomial fit for PA across the muscle depth was used, while E1A described a sigmoid across depth: E 1 A sig = E 1 A range × sigmf 1 : 100 % depth , - EA 1 grad   ,   E 1 A asym + E 1 A shift .

STATISTICAL TESTS

Repeatability was assessed with the nonparametric Wilcoxon's rank-sum test for paired comparisons across repeated scans in each volunteer for each anatomical muscle region and across repeated measures of the radial axis. A P-value <0.05 was considered statistically significant.

RESULTS

In the ISPM, E1A was constantly negative, became helicoidal, then mainly positive across the antero-posterior depth, respective at the caudal, central and cranial regions. In the SSPM, posterior myocytes ran more parallel to the intramuscular tendon ( PA ≈ 0 ° ), while anterior myocytes inserted with a pennation angle ( PA ≈ - 20 ° ). E1A and PA were repeatable in each volunteer (error < 10%). Intra-repeatability of the radial axis was achieved (error < 5%).

DATA CONCLUSION

ElA and PA in the proposed framework of the ISPM and SSPM are repeatable with DTI. Variations of myocyte angulation in the ISPM and SSPM can be quantified across volunteers.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 2.

Longitudinal Changes in Overall 3D Supraspinatus Muscle Volume and Intramuscular Fatty Infiltration After Arthroscopic Rotator Cuff Repair

BACKGROUND

There is considerable debate regarding the longitudinal changes in overall rotator cuff (RC) muscle atrophy and intramuscular fatty infiltration (FI) following RC repair. We analyzed the longitudinal changes in overall 3D supraspinatus muscle volume and intramuscular FI (3D FI) to determine the effect of tear size and repair integrity on 3D muscle volume and intramuscular FI.

METHODS

Forty-seven patients who underwent arthroscopic RC repair and had 6-point Dixon shoulder magnetic resonance imaging (MRI) preoperatively and 3 and 12 months postoperatively were enrolled. The 3D supraspinatus muscle volume and intramuscular FI were calculated at the 3 time points, and their changes over time were evaluated in the entire cohort as well as according to tear size and repair integrity. The agreement of the difference between time points among the patients was assessed by Bland-Altman analysis.

RESULTS

In the cohort as a whole, there were no significant longitudinal changes in the 3D supraspinatus volume (19.65 ± 7.26 to 19.48 ± 7.46 cm 3 , p = 0.911) or 3D FI (17.18% ± 8.85% to 17.30% ± 9.18%, p = 0.977) from preoperatively to the final 12-month time point, overall and in the tear size and repair integrity subgroups. The 3D supraspinatus volume was significantly decreased at 3 months (17.39 ± 6.12 cm 3 , p < 0.001) but then increased again by 12 months (p < 0.001), reaching a value similar to the preoperative level. The 3D FI had a small increase at 3 months (18.18% ± 9.65%, p = 0.097) but subsequently decreased slightly again (p = 0.211), such that there were no significant longitudinal changes. The differences in the 3D supraspinatus volume and FI between these time points showed high agreement among patients.

CONCLUSIONS

The overall 3D supraspinatus volume and 3D FI showed no longitudinal change between the preoperative baseline and the 12-month follow-up after arthroscopic RC repair. Tear size and repair integrity had no impact on the longitudinal patterns of muscle volume and intramuscular FI changes. The 3D supraspinatus volume decreased during the first 3 months but recovered to baseline at 12 months postoperatively; 3D FI was relatively stable throughout the 12 months of follow-up after repair.

LEVEL OF EVIDENCE

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

Artificial Intelligence Aids Detection of Rotator Cuff Pathology: A Systematic Review

PURPOSE

To determine the model performance of artificial intelligence (AI) in detecting rotator cuff pathology using different imaging modalities and to compare capability with physicians in clinical scenarios.

METHODS

The review followed the PRISMA guidelines and was registered on PROSPERO. The criteria were as follows: 1) studies on the application of AI in detecting rotator cuff pathology using medical images, and 2) studies on smart devices for assisting in diagnosis were excluded. The following data were extracted and recorded: statistical characteristics, input features, AI algorithms used, sample sizes of training and testing sets, and model performance. The data extracted from the included studies were narratively reviewed.

RESULTS

A total of 14 articles, comprising 23,119 patients, met the inclusion and exclusion criteria. The pooled mean age of the patients was 56.7 years, and the female rate was 56.1%. The area under the curve (AUC) of the algorithmic model to detect rotator cuff pathology from ultrasound images, MRI images, and radiographic series ranged from 0.789 to 0.950, 0.844 to 0.943, and 0.820 to 0.830, respectively. Notably, 1 of the studies reported that AI models based on ultrasound images demonstrated a diagnostic performance similar to that of radiologists. Another comparative study demonstrated that AI models using MRI images exhibited greater accuracy and specificity compared to orthopedic surgeons in the diagnosis of rotator cuff pathology, albeit not in sensitivity.

CONCLUSIONS

The detection of rotator cuff pathology has been significantly aided by the exceptional performance of AI models. In particular, these models are equally adept as musculoskeletal radiologists in using ultrasound to diagnose rotator cuff pathology. Furthermore, AI models exhibit statistically superior levels of accuracy and specificity when using MRI to diagnose rotator cuff pathology, albeit with no marked difference in sensitivity, in comparison to orthopaedic surgeons.

LEVEL OF EVIDENCE

Level III, systematic review of Level III studies.

Revision rotator cuff repair: can a Sugaya III tendon considered to be healed or not

BACKGROUND

Sugaya et al described a classification system to assess postoperative rotator cuff tendon healing. Although Sugaya I and II tendons can be considered as healed and Sugaya type IV and V can be considered as retorn, the exact status of Sugaya III tendons remains unclear. The objective of this study was to evaluate the impact of Sugaya III tendons on postoperative functional scores in a population of patients undergoing revision rotator cuff repair.

METHODS

We retrospectively studied the records of all patients who underwent revision rotator cuff repair in one of 12 different institutions between July 2001 and December 2020. A total of 203 shoulders were included (59% males, mean age: 51 ± 8 years old, mean follow-up 11.5 years [range: 2-28.8 yr]). Fifty-four patients (61% males, mean age 52 ± 6 years old, mean follow-up 14.1 years [range: 10.4-28.8 yr]) had a follow-up ≥10 years (mean 14.1 years [range: 10.4-28.8 yr]) and were included in a long-term follow-up subgroup analysis. Structural integrity of the repaired tendon was evaluated on magnetic resonance imaging at last follow-up. Functional scores, acromiohumeral index (AHI), and progression of fatty infiltration and of osteoarthritis were compared according to Sugaya type.

RESULTS

Mean Constant score and mean strength were significantly higher in Sugaya I and II tendons than in Sugaya III (P = .021 and .003) and Sugaya IV and V tendons (P = .07 and .038), but did not differ between Sugaya III and Sugaya IV and V tendons. Mean Subjective Shoulder Value, pain, AHI were significantly higher and fatty infiltration and progression in the Hamada classification were significantly lower in Sugaya I and II tendons and in Sugaya III than in Sugaya IV and V tendons (P < .05), but did not differ between Sugaya I and II and Sugaya III tendons. Similar characteristics could also be observed in the long-term follow-up subgroup.

CONCLUSION

Sugaya III tendons after revision rotator cuff repair do not allow restoration of strength thereby impacting the Constant score. However, there seems to be a protective effect of Sugaya III tendons with regard to pain, progression of proximal migration of the humeral head, osteoarthritis, and fatty infiltration, which seems to last at long-term follow-up.

Subacromial Balloon Spacer Does Not Reduce the Retear Rate for Massive Rotator Cuff Tears: A Comparative Study

PURPOSE

To determine whether a subacromial spacer decreases the recurrent rotator cuff tear rate in arthroscopically managed massive rotator cuff tears (MRCTs) with 1 year of follow-up.

METHODS

We selected all patients who met the following criteria: (1) an MRCT excluding Collin type A, (2) Goutallier stage equal or less than 2, and (3) complete arthroscopic repair of the MRCT. Patients were allocated into 2 groups: A (without subacromial spacer) or B (with subacromial spacer) for a prospective evaluation 1 year after surgery. The primary outcome was the retear rate, determined with magnetic resonance imaging (MRI) according to the classification of Sugaya. Secondary outcome measures were the functional outcomes using visual analog score, Shoulder Subjective Value, and Constant-Murley Score. Preoperative rotator cuff characteristics such as number of tendons involved and the tear retraction also were evaluated. Patient-related data such as sex, age, laterality, history of smoking, and diabetes mellitus were analyzed.

RESULTS

In total, 31 patients were included in group A and 33 in group B. Preoperatively, only 2 differences were found between both groups: a significant (but not clinical) greater Constant score in group A (P = .034) and a slightly greater retraction of the supraspinatus in group B (P = .0025). The overall retear rate between the 2 groups was similar regarding the number of patients (P = .746) and the total number of tendons involved in the recurrent tear (P = .112). At 1-year follow-up, no differences were found in VAS (P = .397), SSV (P = .309), and Constant score (P = .105).

CONCLUSIONS

In reparable massive rotator cuff tears (excluding Collin type A), the augmentation of repair with a subacromial spacer did not significantly reduce the number of patients with recurrent rotator cuff tears identified by MRI. It was also ineffective in reducing the number of re-ruptured tendons in these patients. No patient-reported or clinically significant findings were noted in Constant, SSV, and VAS scores at 1-year postoperative follow-up. Patients with MRI findings of a healed rotator cuff (Sugaya 1-3) had better clinical outcomes compared with those without.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Decellularized biological matrices for the repair of rotator cuff lesions: a systematic review of preclinical in vivo studies

Background: Rotator cuff tears (RCTs), resulting from degeneration or trauma of the shoulder tendons, are one of the main causes of shoulder pain. In particular, massive RCTs represent 40% of all injuries, require surgical treatment, and are characterized by poor clinical outcomes and a high rate of failure. In recent years, the use of biological decellularized patches for augmentation procedures has received great interest owing to their excellent self-integration properties, improving healing and, thus, presenting an innovative therapeutic option. However, the findings from clinical studies have emerged with conflicting viewpoints regarding the benefits of this procedure, as an excessive tension load might compromise the integrity of the tendon-to-bone connection when the patch exhibits low elasticity or insufficient strength. This could prevent the healing process, leading to unpredictable results in clinical practice. Methods: This systematic review was conducted following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines across three databases (PubMed, Scopus, and Web of Knowledge) to underline the results obtained in preclinical studies involving animal models of RCT surgeries that utilized the biological decellularized matrix augmentation technique in the last 5 years. Results: Thirteen articles were included after the screening, and the SYRCLE tools were applied to assess the risk of bias in in vivo studies. Open-surgery techniques were conducted to create tendon defects or detachment in different animal models: rat (31%), rabbit (46%), dog (15%), and sheep (8%). Patches decellularized with non-standardized protocols were used in 77% of studies, while commercially available matrices were used in 15%. Of the studies, 31% used allogenic patches, 61% used xenogenic patches, and 8% utilized both xenogenic and autologous patches. Conclusion: Overall, this review provides a comprehensive overview of the use of acellular patches and their effective therapeutic potential in rotator cuff (RC) repair at the preclinical level with the aim of expanding the strategies and matrices available for surgeons. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023468716.

The Gluteus-Score-7 Predicts the Likelihood of Both Clinical Success and Failure Following Surgical Repair of the Hip Gluteus Medius and/or Minimus

PURPOSE

To identify patient preoperative history, examination, and imaging characteristics that increase the risk of postoperative failure of gluteus medius/minimus repair, and to develop a decision-making aid predictive of clinical outcomes for patients undergoing gluteus medius/minimus repair.

METHODS

Patients from 2012 to 2020 at a single institution undergoing gluteus medius/minimus repair with minimum 2-year follow-up were identified. MRIs were graded according to the "three-grade" classification system: grade 1: partial-thickness tear, grade 2: full-thickness tears with <2 cm of retraction, grade 3: full-thickness tears with ≥2 cm retraction. Failure was defined as undergoing revision within 2 years postoperatively or not achieving both a cohort-calculated minimal clinically important difference (MCID) and responding "no" to patient acceptable symptom state (PASS). Inversely, success was defined as reaching both an MCID and responding "yes" to PASS. Predictors of failure were verified on logistic regression and a predictive scoring model, the Gluteus-Score-7, was generated to guide treatment-decision making.

RESULTS

In total, 30 of 142 patients (21.1%) were clinical failures at mean ± SD follow-up of 27.0 ± 5.2 months. Preoperative smoking (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.0-8.4; P = .041), lower back pain (OR, 2.8; 95% CI, 1.1-7.3; P = .038), presence of a limp or Trendelenburg gait (OR, 3.8; 95% CI, 1.5-10.2; P = .006), history of psychiatric diagnosis (OR, 3.7; 95% CI, 1.3-10.8; P = .014), and increased MRI classification grades (P ≤ .042) were independent predictors of failure. The Gluteus-Score-7 was generated with each history/examination predictor assigned 1 point and MRI classes assigned corresponding 1-3 points (min 1, max 7 score). A score of ≥4/7 points was associated with risk of failure and a score ≤2/7 points was associated with clinical success.

CONCLUSIONS

Independent risk factors for revision or not achieving either MCID or PASS after gluteus medius and/or minimus tendon repair include smoking, preoperative lower back pain, psychiatric history, Trendelenburg gait, and full-thickness tears, especially tears with ≥2 cm retraction. The Gluteus-Score-7 tool incorporating these factors can identify patients at risk of both surgical treatment failure and success, which may be useful for clinical decision-making.

LEVEL OF EVIDENCE

Level IV, prognostic case series.