UNASSIGNED: Extracorporeal shock wave therapy (ESWT) promotes tissue healing by modulating inflammation, which has implications for meniscal tear healing in the avascular zone.
UNASSIGNED: To evaluate the effects of a single dose of radial ESWT on the healing process and inflammation of the meniscus and knee joints after meniscal tears in the avascular zone.
UNASSIGNED: Controlled laboratory study.
UNASSIGNED: Avascular tears were induced in the medial meniscus (MM) of 72 Sprague-Dawley rats. One week postoperatively, the rats received a single session of radial ESWT with a Power+ handpiece (ESWT group; n = 36) or with a fake handpiece (sham-ESWT group; n = 36). The rats were then euthanized at 2, 4, or 8 weeks postoperatively. The MMs were harvested for analysis of healing (hematoxylin-eosin, safranin O-Fast Green, and collagen type 2 staining) and inflammation (interleukin [IL]-1β and IL-6 staining). Lateral menisci and synovia were obtained to evaluate knee joint inflammation (enzyme-linked immunosorbent assay of IL-1β and IL-6). Cartilage degeneration was assessed in the femurs and tibial plateaus using safranin O-Fast Green staining.
UNASSIGNED: The ESWT group showed significantly better meniscal healing scores than the sham-ESWT group at 4 (P = .0066) and 8 (P = .0050) weeks postoperatively. The IL-1β level was significantly higher in the sham-ESWT group than in the ESWT group at 2 (MM: P = .0009; knee joint: P = .0160) and 8 (MM: P = .0399; knee joint: P = .0001) weeks. The IL-6 level was significantly lower in the sham-ESWT group than in the ESWT group at 2 (knee joint: P = .0184) and 4 (knee joint: P = .0247) weeks but higher at 8 weeks (MM: P = .0169; knee joint: P = .0038). The sham group had significantly higher osteoarthritis scores than the ESWT group at 4 (tibial plateau: P = .0157) and 8 (femur: P = .0048; tibial plateau: P = .0359) weeks.
UNASSIGNED: A single dose of radial ESWT promoted meniscal tear healing in the avascular zone, modulated inflammatory factors in the menisci and knee joints in rats, and alleviated cartilage degeneration.
UNASSIGNED: Radial ESWT can be considered a potential option for improving meniscal tear healing in the avascular zone because of its ability to modulate inflammation.

Unlike the adult meniscus, the fetal meniscus possesses robust healing capacity. The dense and stiff matrix of the adult meniscus provides a biophysical barrier for cell migration, which is not present in the fetal meniscus. Inspired by developmental characteristics, modifying the matrix of the adult meniscus into a fetal-like, loose and soft microenvironment holds opportunity to facilitate repair, especially in the avascular zone.
Modifying the dense and stiff matrix of the adult meniscus into a fetal-like, loose and soft microenvironment could enhance cell migration to the tear interface and subsequent robust healing capacity.
Controlled laboratory study.
Fresh porcine menisci were treated with hyaluronidase or collagenase. The density and arrangement of collagen fibers were assessed. The degradation of proteoglycans and collagen was evaluated histologically. Cell migration within the meniscus or the infiltration of exogenous cells into the meniscus was examined. Dendritic silica nanoparticles with relatively large pores were used to encapsulate hyaluronidase for rapid release. Mesoporous silica nanoparticles with relatively small pores were used to encapsulate transforming growth factor-beta 3 (TGF-β3) for slow release. A total of 24 mature male rabbits were included. A longitudinal vertical tear (0.5 cm in length) was prepared in the avascular zone of the medial meniscus. The tear was repaired with suture, repaired with suture in addition to blank silica nanoparticles, or repaired with suture in addition to silica nanoparticles releasing hyaluronidase and TGF-β3. Animals were sacrificed at 12 months postoperatively. Meniscal repair was evaluated macroscopically and histologically.
The gaps between collagen bundles increased after hyaluronidase treatment, while collagenase treatment resulted in collagen disruption. Proteoglycans degraded after hyaluronidase treatment in a dose-dependent manner, but collagen integrity was maintained. Hyaluronidase treatment enhanced the migration and infiltration of cells within meniscal tissue. Last, the application of fibrin gel and the delivery system of silica nanoparticles encapsulating hyaluronidase and TGF-β3 enhanced meniscal repair responses in an orthotopic longitudinal vertical tear model.
The gradient release of hyaluronidase and TGF-β3 removed biophysical barriers for cell migration, creating a fetal-like, loose and soft microenvironment, and enhanced the fibrochondrogenic phenotype of reparative cells, facilitating the synthesis of matrix and tissue integration.
Modifying the adult matrix into a fetal-like, loose and soft microenvironment via the local gradient release of hyaluronidase and TGF-β3 enhanced the healing capacity of the meniscus.

OBJECTIVE: To analyze the influence factors of the area of superficial plexus foveal avascular zone (FAZ) and related indexes of fovea measured with optical coherence tomography angiography (OCT-A) in normal subjects.
METHODS: This was a cross-sectional study from November 2020 to May 2021 in the Inner Mongolia Autonomous Region, China. Each subject received related eye examination. The correlation between all the factors and superficial plexus FAZ were analyzed under univariable and multivariable linear regression analysis.
RESULTS: Finally, 239 subjects with sufficient data were recruited in the study, including 108 males and 131 females, aged 27.41±4.63 years. The area of superficial plexus FAZ was 0.33±0.16 mm2. In the univariate regression, gender (β = 41.702, 95%CI: 9.152 to 74.253, P = 0.012), drinking (β = -66.074, 95%CI: -99.197 to -32.951, P = 0.001) and axial length (β = -15.874, 95%CI: -29.562 to -2.185, P = 0.023) were associated with superficial plexus FAZ area. In multivariate regression analysis results, drinking (β = -42.410, 95%CI = -79.388 to -5.432, P = 0.025) was significantly correlated with superficial plexus FAZ area.
CONCLUSIONS: The area of superficial plexus FAZ was not affected by age, gender, systematical and biochemical indicators, but related to the status of drinking.

A 12-year-old boy with a history of decreased vision and photophobia since he was 1 year old. Comprehensive clinical and molecular approaches were applied to evaluate his condition by which a detailed ophthalmological examination revealed bilateral isolated foveal hypoplasia with the absence of the avascular zone. Novel homozygous aryl hydrocarbon receptor (AHR) splice site mutation NM_001621.4: c.899_908 + 15del (p.?) was identified and segregated within the family members.
This case represents the first report of autosomal recessive isolated foveal hypoplasia without infantile nystagmus in the literature and the second reported AHR mutation with autosomal recessive isolated foveal hypoplasia post the original cloning paper. Our identified novel splice site AHR mutation supports the pathogenicity of the AHR gene and expands its phenotypic spectrum.

Injuries to menisci are the most common disease among knee joint-related morbidities and cover a widespread population ranging from children and the general population to the old and athletes. Repair of the injuries in the meniscal avascular zone remains a significant challenge due to the limited intrinsic healing capacity compared to the peripheral vascularized zone. The current surgical strategies for avascular zone injuries remain insufficient to prevent the development of cartilage degeneration and the ultimate emergence of osteoarthritis (OA). Due to the drawbacks of current surgical methods, the research interest has been transferred toward facilitating meniscal avascular zone repair, where it is expected to maintain meniscal tissue integrity, prevent secondary cartilage degeneration and improve knee joint function, which is consistent with the current prevailing management idea to maintain the integrity of meniscal tissue whenever possible. Biological augmentations have emerged as an alternative to current surgical methods for meniscal avascular zone repair. However, understanding the specific biological mechanisms that affect meniscal avascular zone repair is critical for the development of novel and comprehensive biological augmentations. For this reason, this review firstly summarized the current surgical techniques, including meniscectomies and meniscal substitution. We then discuss the state-of-the-art biological mechanisms, including vascularization, inflammation, extracellular matrix degradation and cellular component that were associated with meniscal avascular zone healing and the advances in therapeutic strategies. Finally, perspectives for the future biological augmentations for meniscal avascular zone injuries will be given.

OBJECTIVE: Horizontal cleavage tears of the meniscus (HCTs) are primarily degenerative in nature, and, however, can be the result of trauma. Such tears account for 12-35% of all tear patterns and can be treated by partial meniscectomy or arthroscopic repair. The purpose of this review was to systematically assess the outcomes and complications for patients undergoing the surgical treatment of HCTs.
METHODS: This review has been conducted according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-analyses. The electronic databases PubMed, MEDLINE, and EMBASE were searched from data inception to December 30, 2018 for articles addressing the surgical treatment of HCTs. The Methodological Index for Non-randomized Studies was used to assess study quality. Data are presented descriptively.
RESULTS: Overall, 23 studies were identified, comprising of 702 patients (708 knees) with a mean age of 36.6 ± 9.9 years and a mean follow-up of 33.6 ± 19.6 months. The majority of patients were treated with a partial meniscectomy (59.0%), followed by repair (32.8%) and total meniscectomy (8.2%). Both meniscectomy and repair patients had improvements which surpassed minimal clinically important differences with regard to clinical (e.g. pain, function, daily living) and radiographic outcomes. The overall complication rate was 5.1%, primarily involving patients undergoing meniscal repair (12.9% of all knees undergoing a repair).
CONCLUSIONS: Although meniscal repair theoretically may provide improvement in biomechanical loading, patients undergoing repair had higher complication rates than those undergoing partial meniscectomy. Clinicians should consider the available implants in determining which tear patterns to repair and future studies with long-term follow-up are needed to investigate complications (e.g. secondary meniscal procedures) as well as the potential for delay in the development of osteoarthritis.
METHODS: Level IV.

OBJECTIVE: In this study, we sought to investigate the effect of different amounts of Bone Marrow-Derived Mesenchymal Stem Cells (BMSCs), obtained by different BMSCs, on the healing of avascular zone meniscal defects.
BACKGROUND: Treating avascular zone meniscal injuries has gained popularity. BMSCs contribute to the healing of avascular zone meniscal defects. The amount of BMSCs derived from different bone marrow stimulation techniques (BMSTs) varies, which could affect the therapeutic efficacy of this treatment.
METHODS: Fifty-four skeletally mature female New Zealand White rabbits were used after local ethical committee approval. A full thickness, 1.5 mm diameter defect was produced in the inner two-thirds of the anterior portion of the medial meniscus avascular zone using a biopsy punch. Animals were enrolled into three different groups according to BMST (0.8 mm, 1.5 mm, and 4 mm). Medial menisci were harvested and prepared for histomorphometric, histologic and immune-histologic analyses.
RESULTS: Larger bridging tissues across the defect were detected in the 1.5-mm and 4-mm groups at 4 weeks (p < 0.05). The best quality score at the 1-,4- and 12-week endpoints was in 0.8 mm, 4 mm and 0.8 mm, 1.5 mm, respectively (p 0.05)CONCLUSION: The largest amount of BMSCs did not correlate with best quality and largest quantity of bridging tissue at the avascular zone in meniscal defects (Tab. 3, Fig. 4, Ref. 30).