Tokish, John

Background: Rotator cuff tears are a common orthopaedic injury often resulting in shoulder pain and functional impairment. Despite the prevalence of rotator cuff tears, the incidence of retear after rotator cuff repair (RCR) remains high. There is growing interest in the use of structural augmentation in RCR to decrease retear rates and improve patient outcomes. Purpose: The purpose of this systematic review and meta-analysis was to compare the clinical and imaging outcomes of structural augmentation versus standard RCR in patients with full-thickness rotator cuff tears. The effectiveness of different augment subtypes was also assessed. Study Design: Meta-analysis; Level of evidence, 3. Methods: A comprehensive literature search was conducted in CENTRAL, Embase, and Medline from inception to November 13, 2024. Eligible studies included comparative trials evaluating structural augmentation in RCR for repairable full-thickness tears. Risk of bias was assessed using the Cochrane risk-of-bias tool for randomized controlled trials and the MINORS (Methodological Index for Non-randomized Studies) score for observational studies. Meta-analyses were performed via a random effects model, with subgroup analyses performed by study design and augment type. Results: Twenty-four studies (12 randomized controlled trials and 12 cohort studies) were included in this review, all of which evaluated biologic augments (xenograft, allograft, autograft). Structural augmentation significantly reduced the risk of retear by 35% as compared with standard RCR (risk ratio, 0.65; 95% CI, 0.48-0.89; P = .01). Retears were confirmed radiographically by magnetic resonance imaging or ultrasound. Subgroup analysis revealed the greatest reduction in retear rates with allograft augmentation (risk ratio, 0.34; 95% CI, 0.21-0.56). No significant differences were observed in patient-reported outcomes, including pain scores, American Shoulder and Elbow Surgeons scores, or Constant scores. Conclusion: Structural augmentation in RCR significantly reduces retear rates, particularly with allografts, but does not improve short-term patient-reported outcomes. Further research is needed to identify which patient and tear characteristics may influence the effectiveness of augmentation.

Background Research is limited investigating injuries/illness incidence among National Hockey League (NHL) players. This study sought to establish injury/illness incidence, initial versus subsequent injury risk among NHL players, and determine temporal trends of injury and illness incidence. Hypothesis Variations in injury incidence by body region, and initial versus subsequent injury would be observed among positions. Study Design Retrospective cohort study Methods Publicly available data were utilized. NHL players 18 years or older between 2007-2008 to 2018-2019 were included. Injury and illness was stratified by position and body segment. Incidence rate (IR), and initial versus subsequent injury and illness risk ratios were calculated. Temporal trends were reported. Results Nine thousand, seven-hundred and thirty four injuries and illnesses were recorded. Centers had the highest overall IR at 15.14 per 1000 athlete game exposures (AGEs) (95%CI:15.12-15.15) and were 1.4 times more likely to sustain a subsequent injury compared to other positions. The groin/hip/thigh was the most commonly injured body region with an IR of 1.14 per 1000 AGEs (95%CI:1.06-1.21), followed by the head/neck (0.72 per 1000 AGEs, 95%CI:0.66-0.78). Combined injury and illness IR peaked in 2009-2010 season at 12.01 (95%CI: 11.22-12.79). The groin/hip/thigh demonstrated peak incidence during the 2007-2008 season (2.53, 95%CI:2.17-2.90); head/neck demonstrated a peak incidence in 2010-2011 season (Overall: 1.03, 95%CI:0.81-1.26). Injuries reported as ‘lower body’ increased over time. Conclusions Positional differences were observed; centers demonstrated the highest overall IR, and subsequent injury risk. Injury by body region was similar to previous literature. Head/neck and concussion decreased over time supporting rule changes in body checking and visor wear. Clinicians should be aware that ‘lower body’ injuries increased over time; therefore, injuries to the groin/hip/thigh or knee are likely underreported. Level of Evidence Level 3

Background: Clinical trials are currently underway to investigate the efficacy of intra-articular administration of mesenchymal stromal cells (MSCs) to mitigate osteoarthritis (OA) progression in the knee. Although multiple MSC sources exist, studies have yet to determine whether differences in therapeutic efficacy exist between them. Purpose: To compare the ability of intra-articularly injected adipose-derived MSCs (AD-MSCs) and amnion-derived MSCs (AM-MSCs) to mitigate the progression of knee OA in a small animal model of spontaneous OA, as well as to compare the therapeutic potential of MSCs in hyaluronic acid (HA) and in HA only with saline (OA) controls. Study Design: Controlled laboratory study. Methods: Injections of AD-MSCs or AM-MSCs suspended in HA or HA only were performed in the rear stifle joints of 3-month-old Dunkin Hartley guinea pigs (DHGPs). Repeat injections occurred at 2 and 4 months after the initial injection in each animal. Contralateral limbs received saline injections and served as untreated controls. Subsequently, joints were analyzed for osteoarthritic changes of the cartilage and subchondral bone via histologic and biochemical analyses. To evaluate MSC retention time in the joint space, DHGPs received a single intra-articular injection of fluorescently labeled AD-MSCs or AM-MSCs, and the fluorescence intensity was longitudinally tracked via an in vivo imaging system. Results: No statistically significant differences in outcomes were found when comparing the ability of AD-MSCs and AM-MSCs to mitigate OA. However, the injection of AD-MSCs, AM-MSCs, and HA-only treatments more effectively mitigated cartilage damage compared with that of saline controls by demonstrating higher amounts of cartilage glycosaminoglycan content and improved histological proteoglycan scoring while reducing the percentage of osteophytes present. Conclusion: Intra-articular injection of AD-MSCs, AM-MSCs, or HA only was able to similarly mitigate the progression of cartilage damage and reduce the percentage of osteophytes compared with that of saline controls in the DHGP. However, this study was unable to establish the superiority of AD-MSCs versus AM-MSCs as a treatment to mitigate spontaneous OA. Clinical Relevance: MSCs demonstrate the ability to mitigate the progression of knee OA and thus may be used in a prophylactic approach to delay the need for end-stage treatment strategies.

Purpose We create a viable, mechanically expanded autograft long head biceps tendon (LHBT) scaffold for biologically augmenting the repair of torn rotator cuffs. Methods The proximal aspect of the tenotomized LHBTs was harvested from patients during rotator cuff repair surgery and was mechanically formed into porous scaffolds using a surgical graft expander. LHBT scaffolds were evaluated for change in area, tensile properties, and tenocyte viability before and after expansion. The ability of endogenous tenocytes derived from the LHBT scaffold to promote tenogenic differentiation of human adipose‐derived mesenchymal stromal cells (ADMSCs) was also determined. Results Autograft LHBTs were successfully expanded using a modified surgical graft expander to create a porous scaffold containing viable resident tenoctyes from patients undergoing rotator cuff repair. LHBT scaffolds had significantly increased area (length: 24.91 mm [13.91, 35.90] × width: 22.69 mm [1.87, 34.50]; P = .011) compared with the native LHBT tendon (length: 27.16 mm [2.70, 33.62] × width: 6.68 mm [5.62, 7.74]). The structural properties of the autograft were altered, including the ultimate tensile strength (LHBT scaffold: .56 MPa [.06, 1.06] vs. native LHBT: 2.35 MPa [1.36, 3.33]; P = .002) and tensile modulus (LHBT scaffold: 4.72 MPa [−.80, 1.24] versus native LHBT: 37.17 MPa [24.56, 49.78]; P = .001). There was also a reduction in resident tenocyte percent viability (LHBT scaffold: 38.52% [17.94, 59.09] vs. native LHBT: 68.87% [63.67, 74.37]; P =.004). Tenocytes derived from the LHBT scaffold produced soluble signals that initiated ADMSC differentiation into an immature tenocyte‐like phenotype, as indicated by an 8.7× increase in scleraxis ( P = .040) and a 3.6× increase in collagen type III mRNA expression ( P = .050) compared with undifferentiated ADMSC controls. Conclusions The ability to produce a viable autologous scaffold from the proximal biceps tendon having dimensions, porosity, mechanical characteristics, native ECM components, and viable tenocytes that produce bioactive signals conducive to supporting the biologic augmentation of rotator cuff repair surgery has been demonstrated. Clinical Relevance This biologically active construct may help to improve the quality of healing and regeneration at the repair site of rotator cuff tears, especially those at high risk for retear.

ABSTRACT Intervertebral disc degeneration (IVDD) is a progressive condition marked by tissue destruction and inflammation. The therapeutic effector functions of mesenchymal stem cells (MSCs) makes them an attractive therapy for patients with IVDD. While several sources of MSCs exist, the optimal choice for use in the inflamed IVD remains a significant question. Adipose (AD)‐ and amnion (AM)‐derived MSCs have several advantages compared with other sources, however, no study has directly compared the impact of IVDD inflammation on their effector functions. Human MSCs were cultured in media with or without supplementation of interleukin‐1β (IL‐1β) and tumor necrosis factor‐α at concentrations reportedly produced by IVDD cells. MSC proliferation and production of pro‐ and anti‐inflammatory cytokines were quantified following 24 and 48 h of culture. Additionally, the osteogenic and chondrogenic potential of AD‐ and AM‐MSCs was characterized via histology and biochemical analysis following 28 days of culture. In inflammatory culture, AM‐MSCs produced significantly more anti‐inflammatory IL‐10 (14.47 ± 2.39 pg/ml; p = 0.004) and larger chondrogenic pellets (5.67 ± 0.26 mm 2 ; p = 0.04) with greater percent area staining positively for glycosaminoglycan (82.03 ± 3.26%; p < 0.001) compared with AD‐MSCs (0.00 ± 0.00 pg/ml; 2.76 ± 0.18 mm 2 ; 34.75 ± 2.49%; respectively). Conversely, AD‐MSCs proliferated more resulting in higher cell numbers (221,000 ± 8,021 cells; p = 0.048) and produced higher concentrations of pro‐inflammatory cytokines prostaglandin E 2 (1,118.30 ± 115.56 pg/ml; p = 0.030) and IL‐1β (185.40 ± 7.63 pg/ml; p = 0.010) compared with AM‐MSCs (109,667 ± 5,696 cells; 1,291.40 ± 78.47 pg/ml; 144.10 ± 4.57 pg/ml; respectively). AD‐MSCs produced more mineralized extracellular matrix (3.34 ± 0.05 relative absorbance units [RAU]; p < 0.001) compared with AM‐MSCs (1.08 ± 0.06 RAU). Under identical inflammatory conditions, a different effector response was observed with AM‐MSCs producing more anti‐inflammatories and demonstrating enhanced chondrogenesis compared with AD‐MSCs, which produced more pro‐inflammatory cytokines and demonstrated enhanced osteogenesis. These findings may begin to help inform researchers which MSC source may be optimal for IVD regeneration. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2445–2456, 2019