Factors affecting the onset and progression of rotator cuff tears in the general population

A Comparison of Functional Outcomes in Rotator Cuff Repairs Using Adjunctive Bone Marrow Aspirate Concentrate vs. Bone Marrow Aspirate Concentrate With Platelet-Rich Plasma: A Systematic Review and Meta-Analysis

Regenerative medicine, specifically bone marrow aspirate concentrate (BMAC) and platelet-rich plasma (PRP), has become a novel adjunct that orthopedic surgeons have started to use with surgical rotator cuff repairs (RCR). Thus, we are conducting this systematic review to determine if either RCRs with BMAC alone or with BMAC and PRP result in superior functional outcomes. We conducted a comprehensive search using five databases including PubMed, Web of Science, Embase, Scopus, and Cochrane. After duplicates were removed, 1205 studies were screened by title and abstract using Rayyan, resulting in three included studies (one BMAC with PRP and two BMAC only). Only studies that reported functional outcomes using the American Shoulder and Elbow Surgeons Shoulder Score and the University of California Los Angeles Shoulder Score were included. Changes in assessment scores from baseline to follow-up evaluation were quantified using the effect size and used in the meta-analysis for each group. Interpretation of treatment efficacy was represented using Cohen's d. The effect size of BMAC with PRP (Cohen's d = 2.19) was not significantly different (p = 0.76) from that of BMAC alone (Cohen's d = 2.35). Between-group differences in functional outcomes were Cohen's d = 0.16, which was not significant. Given the lack of superiority and the small sample size, more research is required before a conclusion can be drawn as to the benefits of combining PRP with BMAC for RCR. If functional outcomes are the same, using BMAC alone as an adjunct may be optimal to reduce resources used and cost. Future studies should be conducted with a larger pool as our primary limitation is that only three studies were included.

A Modified Mason-Allen Suture Enhancement Technique (Sunglasses Loop) for Single-Row Repair of Medium-to-Large Rotator Cuffs

We propose a single-row repair method for medium-to-large rotator cuff rotator cuff tears using a modified Mason-Allen suture enhancement technique (sunglasses loop), which uses high-tensile modified Mason-Allen sutures to close the medial rotator cuff tissues to form a sunglasses loop, resets the rotator cuff tissues via traction with the high-tensile suture, repairs the rotator cuff in a single row with triple-loaded suture anchor (anchor with 3 high-strength sutures), and finally employs an outer row of staples to secure the suture to the lateral aspect of the greater tuberosity, preventing the tendon from pulling out. This method uses a special sunglasses-shaped suture loop, which produces an increase in holding power and a reduction in tension relative to other single-row repair techniques and reduces the rate of rotator cuff retear.

Arthroscopy Technique: Repair of Musculotendinous Junction Rotator Cuff Tears in the Shoulder Using a Dynamic Convergence Suture Bridge Technique

Musculotendinous junction (MTJ) rotator cuff tears in the shoulder are rare injuries in which the tendon fails medial to its tuberosity attachment. There is difficulty in striking a balance between restoring the length-tension relationship of the tendon while avoiding high suture tension at the repair site. In view of the rare incidences of these tears, there is a paucity of literature on their repair techniques. We seek to share our surgical technique in addressing type A MTJ tears-where the medial muscular tear margin is short but remains adequate for suture bridge repair, whereas the lateral tendon remains on the footprint. We used mattress sutures from the medial row of anchors, threaded through the lateral tendon stump, then passed medially to engage the medial stump, before being fixed to a lateral row in a knotless fashion. Pulling on this pair of sutures will thus bring into closer apposition of both medial and lateral tear margins in a dynamic convergence pattern. Our surgical technique is a safe and effective method of repairing type A MTJ tear that confers improved biological and biomechanical advantage via the formation of a dynamic convergence suture bridging technique in addition to a double-row repair construct.

The pathology of oxidative stress-induced autophagy in a chronic rotator cuff enthesis tear

Partial-thickness rotator cuff tears (PTRCTs) are often found in daily orthopedic practice, with most of the tears occurring in middle-aged patients. An anaerobic process and imbalanced oxygenation have been observed in PTRCTs, resulting in oxidative stress. Studies have shown the roles of oxidative stress in autophagy and the potential of unregulated mechanisms causing disturbance in soft tissue healing. This article aims to review literature works and summarize the potential pathology of oxidative stress and unregulated autophagy in the rotator cuff enthesis correlated with chronicity. We collected and reviewed the literature using appropriate keywords, in addition to the manually retrieved literature. Autophagy is a normal mechanism of tissue repair or conversion to energy needed for the repair of rotator cuff tears. However, excessive mechanisms will degenerate the tendon, resulting in an abnormal state. Chronic overloading of the enthesis in PTRCTs and the hypovascular nature of the proximal tendon insertion will lead to hypoxia. The hypoxia state results in oxidative stress. An autophagy mechanism is induced in hypoxia via hypoxia-inducible factors (HIFs) 1/Bcl-2 adenovirus E1B 19-kDa interacting protein (BNIP) 3, releasing beclin-1, which results in autophagy induction. Reactive oxygen species (ROS) accumulation would induce autophagy as the regulator of cell oxidation. Oxidative stress will also remove the mammalian target of rapamycin (mTOR) from the induction complex, causing phosphorylation and initiating autophagy. Hypoxia and endoplasmic reticulum (ER) stress would initiate unfolded protein response (UPR) through protein kinase RNA-like ER kinase (PERK) and activate transcription factor 4, which induces autophagy. Oxidative stress occurring in the hypovascularized chronic rotator cuff tear due to hypoxia and ROS accumulation would result in unregulated autophagy directly or autophagy mediated by HIF-1, mTOR, and UPR. These mechanisms would disrupt enthesis healing.

Risk factors for shoulder osteoarthritis with rotator cuff tear in the elderly general population

HYPOTHESIS AND/OR BACKGROUND

The relationship between shoulder osteoarthritis (OA) and rotator cuff tear (RCT) is unclear. We hypothesized that there is a difference between the pathogenesis of OA complicating RCT and that of RCT complicating OA. In this study, our primary objective was to determine the prevalence of shoulder OA without RCT, RCT without OA, and OA with RCT in the general older population. Our secondary objective was to identify risk factors for the association with OA+RCT in shoulder OA alone or RCT alone, respectively.

METHODS

We enrolled patients from the public health checkup conducted in Gunma prefecture (Japan) in 2014. Subjects' shoulder pain at rest, during motion, and at night was evaluated using a questionnaire. Moreover, active and passive range of motions (ROMs) in flexion, abduction, and external rotation were measured. For RCT parameters, we evaluated as no tear, partial-thickness supraspinatus (SSP) tear, full-thickness SSP tear, and SSP-infraspinatus tears. For further analysis, the shoulders were divided into three groups according to the presence of RCT and/or OA: OA, RCT, and OA + RCT groups. Risk factors for OA + RCT were identified in a logistic regression analysis.

RESULTS

Overall, 944 of 1148 shoulders were eligible for inclusion. The prevalence rates of shoulder OA, RCT, and OA + RCT were 5.8%, 21.1%, and 4.2%, respectively. Furthermore, 650 shoulders were excluded, and 55, 199, and 40 shoulders had OA, RCT, and OA + RCT, respectively. There were significant differences for age, ROM of active external rotation, strength of abduction, external rotation, and morphology of the rotator tears. However, there were no significant differences for pain visual analog scale score, passive ROM, Simple Shoulder Test, and grades of OA. Older age decreased active ROM in external rotation, and the presence of both subscapularis and SSP-infraspinatus tears was a risk factor for the association of OA with an RCT shoulder. Older age, weaker power in external rotation, and affected dominant side were risk factors for the association of RCT with an OA shoulder.

DISCUSSION AND/OR CONCLUSION

This study is the first to report risk factors by considering both shoulder OA and RCT in the general population. Our findings will be useful for the treatment and management of OA and RCT as well as for the prevention of these conditions in the older adults.