Prevalence of rotator cuff diseases in adults older than 40 years in or near Chuncheon city, Korea

Effect of polydeoxyribonucleotide and polynucleotide on rotator cuff healing and fatty infiltration in a diabetic rat model

Failure rate after chronic rotator cuff repair is considerably high. Moreover, diabetes mellitus is known as a compromising factor of rotator cuff tear. The effect of Polydeoxyribonucleotide (PDRN) and polynucleotide (PN) on tendon healing and fatty infiltration is unclear as tissue regeneration activator in diabetic state. Therefore, a diabetic rat model with chronic rotator cuff tear was made for mechanical, histologic and blood tests. In the animal study using a diabetic rat cuff repair model, the administration of PDRN and PN increased the load to failure of repaired cuffs and improved tendon healing and decreased fatty infiltration. Also, the plasma levels of vascular endothelial growth factor and fibroblast growth factor were elevated in PDRN and PN administrated groups. We concluded that PDRN and PN appear to boost tendon recovery and reduce the presence of fatty infiltration following cuff repair in diabetic state. Also, PN showed a later onset and a longer duration than PDRN associated with the mean plasma growth factors.

Combination of Superior and Posterior Capsular Release Versus Superior Capsular Release Alone in Arthroscopic Repair of Large-to-Massive Rotator Cuff Tears

Background

Superior capsular release has been used to reduce tendon tension, especially in arthroscopic repair of large-to-massive rotator cuff tears. Some clinicians have used a more extensive release of capsules in arthroscopic cuff repair for adequate reduction of torn tendons to footprints.

Purpose

To explore the effects of additional posterior capsular release for superior capsular release in arthroscopic repair of large-to-massive rotator cuff tears.

Study Design

Cohort study; Level of evidence, 3.

Methods

We compared 26 shoulders that underwent superior and posterior capsular release (group S&P) with 26 shoulders that underwent superior capsular release alone (group S) in arthroscopic repair of large-to-massive rotator cuff tears between January 23, 2013 and December 2, 2015. The visual analog scale for pain, American Shoulder and Elbow Surgeons score, Constant score, and range of motion (ROM) and muscle power were checked preoperatively and at 2 years postoperatively. Follow-up ultrasound was checked at 2 years postoperatively.

Results

In both groups, the overall mean functional outcomes improved from preoperatively to postoperatively. Patients in group S&P showed more pre- to postoperative improvement than patients in group S with regard to internal rotation ROM (mean difference, 30.0° vs 20.6°; P < .001) and internal rotation power (3.4 vs 1.8 kgf; P = .001). Patients in group S had a higher retear rate on the follow-up ultrasound than patients in group S&P, but this difference did not reach statistical significance (23.1% vs 11.5%, respectively; P = .465).

Conclusion

In the current study, patients who underwent superior and posterior capsular release in arthroscopic repair of large-to-massive rotator cuff tears had greater postoperative improvement in internal rotation ROM and power compared with patients who underwent superior capsular release alone.

Outcomes of Reverse Total Shoulder Arthroplasty for Proximal Humerus Fracture Versus Rotator Cuff Arthropathy

INTRODUCTION

Reverse total shoulder arthroplasty (RSA) is used to treat a variety of shoulder-related pathologies. This study compared medium-term clinical outcomes of less than 10-year follow-up in patients treated with RSA for proximal humerus fracture (PHF) versus rotator cuff arthropathy (RCA).

METHODS

This retrospective review was conducted at two tertiary care centers, in which self-reported clinical outcomes were assessed using four validated instruments, that is, American Shoulder and Elbow Society (ASES) score, Shoulder Pain and Disability Index (SPADI), visual analog scale (VAS), and shoulder subjective value (SSV). Statistical analyses were performed using linear or logistic regression with generalized estimating equations.

RESULTS

Of the 189 patients included in this study, 70 were treated for fracture and 119 for RCA. At a mean postoperative follow-up of 6.4 years, the means were 79.7 for ASES score, 20.8 for SPADI-Total, 0.8 for VAS, and 77.1 for SSV. After adjusting models for covariates, there was no significant difference in average SSV (P = 0.7), VAS (P = 0.7) or SPADI-Pain (P = 0.2) between PHF and RCA cohorts; however, the RCA cohort reported significantly better outcomes in ASES scores (P = 0.002), SPADI-Disability (P < 0.0001), and SPADI-Total (P = 0.0001).

DISCUSSION

Patients with RCA and PHF treated with RSA achieved similar medium-term outcomes in several domains, particularly postoperative pain levels; however, patients with PHF reported greater perceived disability. RSA is an effective pain-controlling procedure, but patients may have variable functional outcomes based on the indication for surgery.

Growth and differentiation factor-7 immobilized, mechanically strong quadrol-hexamethylene diisocyanate-methacrylic anhydride polyurethane polymer for tendon repair and regeneration

Biological and mechanical cues are both vital for biomaterial aided tendon repair and regeneration. Here, we fabricated mechanically tendon-like (0 s UV) QHM polyurethane scaffolds (Q: Quadrol, H: Hexamethylene diisocyanate; M: Methacrylic anhydride) and immobilized them with Growth and differentiation factor-7 (GDF-7) to produce mechanically strong and tenogenic scaffolds. In this study, we assessed QHM polymer cytocompatibility, amenability to fibrin-coating, immobilization and persistence of GDF-7, and capability to support GDF-7-mediated tendon differentiation in vitro as well as in vivo in mouse subcutaneous and acute rat rotator cuff tendon resection models. Cytocompatibility studies showed that QHM facilitated cell attachment, proliferation, and viability. Fibrin-coating and GDF-7 retention studies showed that mechanically tendon-like 0 s UV QHM polymer could be immobilized with GDF-7 and retained the growth factor (GF) for at least 1-week ex vivo. In vitro differentiation studies showed that GDF-7 mediated bone marrow-derived human mesenchymal stem cell (hMSC) tendon-like differentiation on 0 s UV QHM. Subcutaneous implantation of GDF-7-immobilized, fibrin-coated, QHM polymer in mice for 2 weeks demonstrated de novo formation of tendon-like tissue while implantation of GDF-7-immobilized, fibrin-coated, QHM polymer in a rat acute rotator cuff resection injury model indicated tendon-like tissue formation in situ and the absence of heterotopic ossification. Together, our work demonstrates a promising synthetic scaffold with human tendon-like biomechanical attributes as well as immobilized tenogenic GDF-7 for tendon repair and regeneration. STATEMENT OF SIGNIFICANCE: Biological activity and mechanical robustness are key features required for tendon-promoting biomaterials. While synthetic biomaterials can be mechanically robust, they often lack bioactivity. To biologically augment synthetic biomaterials, numerous drug and GF delivery strategies exist but the large tissue space within the shoulder is constantly flushed with saline during arthroscopic surgery, hindering efficacious controlled release of therapeutic molecules. Here, we coated QHM polymer (which exhibits human tendon-to-bone-like biomechanical attributes) with fibrin for GF binding. Unlike conventional drug delivery strategies, our approach utilizes immobilized GFs as opposed to released GFs for sustained, localized tissue regeneration. Our data demonstrated that GF immobilization can be broadly applied to synthetic biomaterials for enhancing bioactivity, and GDF-7-immobilized QHM exhibit high clinical translational potential for tendon repair.

Prediction of Bilaterality in Patients With 1 Posterosuperior Rotator Cuff Tear

BACKGROUND

In patients with a known unilateral posterosuperior rotator cuff tear (PSRCT), the ability to predict a contralateral PSRCT may assist in earlier diagnosis and improved patient outcomes.

PURPOSE

To determine factors associated with bilateral PSRCT and their most predictive combinations using a nonhospitalized general population.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

This study involved 736 individuals (n = 1472 shoulders) drawn from a rural cohort. PSRCT was diagnosed using magnetic resonance imaging. Symptoms of the contralateral shoulder were not considered. The demographic, physical, social, metabolic, and imaging factors, as well as comorbidities, were evaluated using logistic regression analysis. Cutoff values for the significantly associated variables obtained from multivariable logistic regression analysis were calculated using the receiver operating characteristic (ROC) curve. The areas under the ROC curve (AUCs) of the combinations of significantly associated variables were compared using the DeLong method to determine the combination most predictive of bilateral PSRCT. The likelihood ratio and the posttest probability for each of the combinations were assessed.

RESULTS

Age ≥61 years, manual labor, critical shoulder angle (CSA) ≥35°, retraction degree of Patte ≥ grade 2, biceps tendon injury, and metabolic syndrome were significantly associated with bilateral PSRCT in multivariable analysis (P < .001). The 1-by-1 combination of any 4 of the 6 associated factors significantly increased the AUC of any smaller combinations of those 6 factors (P < .001). The AUCs of the 4-somes were all similar (P ≥ .383) and were not significantly increased by further addition of identified associated factors (P ≥ .422). Any combination of 4 of the 6 associated factors was highly predictive of bilateral PSRCT, each having a minimum AUC of 0.70, a likelihood ratio of >10, and a minimum posttest probability of 80%.

CONCLUSION

Unilateral PSRCT, accompanied by any 4 of the variables of age ≥61 years, manual labor, CSA ≥35°, retraction degree of Patte ≥ grade 2, biceps tendon injury, and metabolic syndrome, is highly predictive of PSRCT in the other shoulder.

Clinical Outcomes of Interposition Graft Versus Superior Capsular Reconstruction in Patients With Irreparable Rotator Cuff Tears: A Systematic Review and Meta-analysis

Background:

Interposition grafting (IG), also called bridging grafting, and superior capsular reconstruction (SCR) are the most commonly used joint-preserving surgical methods for irreparable rotator cuff tears (RCTs).

Purpose:

To compare the effectiveness of IG versus SCR to treat patients with irreparable RCTs.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A literature search was performed in MEDLINE, Embase, and Scopus. Included in this review were clinical studies evaluating the effect of IG or SCR in patients with irreparable RCTs with a minimum follow-up of 1 year. Various clinical results from the studies were extracted and compared between IG and SCR, and among them, the results of the American Shoulder and Elbow Surgeons score, graft retear rate, and complication rate were included in the meta-analysis.

Results:

Of 1638 identified articles, 17 (10 studies of IG involving 321 patients and 7 studies of SCR involving 357 patients) were selected. Both surgical methods showed significantly improved clinical outcomes in all but 1 study; however, the IG group had lower pain visual analog scale score, higher Constant score, and bigger active forward flexion and internal rotation compared with the SCR group (all P < .001). The meta-analysis showed no difference in the American Shoulder and Elbow Surgeons score between groups (P = .44), but showed a significantly lower complication rate in the IG group compared with the SCR group (1.12% vs 8.37%, respectively; P < .001). The graft retear rate was not significantly different between groups (IG = 10.64% vs SCR = 12.67%; P = .79). The meta-analysis of graft type indicated no difference between groups in retear rate (autograft: 95% CI, 0.045-0.601; I² = 93.28 [IG], 91.27 [SCR]; P = .22; allograft: 95% CI, 0.041-0.216; I² = 80.39 [IG], 69.12 [SCR]; P = .64) or complication rate (autograft: 95% CI, 0.009-0.150; I² = 0 [IG], 65.89 [SCR]; P = .25; allograft: 95% CI, 0.012-0.081; I² = 0 [IG], 30.62 [SCR]; P = .09).

Conclusion:

Both IG and SCR techniques resulted in improvement in patients with irreparable RCTs. Meta-analysis showed a lower complication rate in the IG group; however, the lack of randomized studies limited our conclusions.

Effect of a Porous Suture Containing Transforming Growth Factor Beta 1 on Healing After Rotator Cuff Repair in a Rat Model

BACKGROUND

The healing failure rate after rotator cuff repair is considerably high.

PURPOSE

To evaluate the effect of a porous suture containing transforming growth factor beta 1 (TGF-β1) on the sustained release of TGF-β1 and rotator cuff healing in a rat model.

STUDY DESIGN

Controlled laboratory study.

METHODS

A porous suture was developed, and its tensile strength was measured. TGF-β1 was delivered using the porous suture, and a TGF-β1 release test and human fibroblast proliferation assay were performed. For the animal experiment, 30 rats were randomly allocated into 3 groups (n = 10 each). A bilateral supraspinatus tendon tear was made in all the rats, and repair was performed. Group 1 received repair only; group 2, repair and a single injection of TGF-β1; and group 3, repair using the porous suture containing TGF-β1. Eight weeks after repair, biomechanical and histological analyses were performed.

RESULTS

The porous suture was successfully developed with mechanical properties compatible with the conventional suture, and the sustained release of TGF-β1 from the porous suture was confirmed. In addition, the cell proliferation assay confirmed the biological safety of the porous suture. In the animal experiment, group 3 biomechanically exhibited the largest cross-sectional area and the highest ultimate failure load and ultimate stress (all P < .05). Histological examination revealed that group 3 showed significantly better collagen fiber density and tendon-to-bone maturation than did groups 1 and 2 (all P < .05).

CONCLUSION

The porous suture containing TGF-β1 could sustainedly and safely release TGF-β1, and its use during rotator cuff repair could improve rotator cuff healing, as assessed on the basis of the biomechanical and histological changes in the rat model in this study. Considering the effectiveness, safety, and convenience of the porous suture without extra effort in surgery, the findings of the present study will have a far-reaching effect on the treatment of rotator cuff tears.

CLINICAL RELEVANCE

The porous suture containing TGF-β1 might improve healing after rotator cuff repair.