Fascia Lata

From the histological point of view, fascia lata is a dense connective tissue. Although extracellular matrix is certainly the most predominant fascia's feature, there are also several cell populations encountered within this structure. The aim of this study was to describe the existence and characteristics of fascia lata cell populations viewed through a transmission electron microscope. Special emphasis was placed on telocytes as a particular interstitial cell type, recently discovered in a wide variety of tissues and organs such as the heart, skeletal muscles, skin, gastrointestinal tract, uterus and urinary system. The conducted study confirmed the existence of a telocyte population in fascia lata samples. Those cells fulfil main morphological criteria of telocytes, namely, the presence of very long, thin cell processes (telopodes) extending from a relatively small cell body. Aside from telocytes, we have found fibroblasts, mast cells and cells with features of myofibroblastic differentiation. This is the first time it has been shown that telocytes exist in human fascia. Currently, the exact role of those cells within the fascia is unknown and definitely deserves further attention. One can speculate that fascia lata telocytes likewise telocytes in other organs may be involved in regeneration, homeostasis and intracellular signalling.

BackgroundFascia lata augmentation of massive rotator cuff tears has shown good clinical results. However, its biological effect during the early healing process is not clearly understood. The purpose of the study was to evaluate the biological efficacy of fascia lata augmentation during the early healing process of rotator cuff tears using a rabbit rotator cuff defect model.MethodsThe infraspinatus tendon was resected from the greater tuberosity of a rabbit to create a rotator cuff tear. The tendon edge was directly sutured to the humeral head. The rotator cuff repaired site was augmented with a fascia lata autograft (augmentation group, group A). The rotator cuff defect in the contralateral shoulder was repaired without augmentation (reattachment group, group R). A group with intact rotator cuff was set as the control group. Histological examinations and mechanical analysis were conducted 4 and 8 weeks postoperatively.ResultsIn the HE staining, the tendon maturing score of group A was higher than that of group R at 4 weeks postoperatively. In the safranin O staining, proteoglycan staining at the repaired enthesis in group A at 4 weeks postoperatively was stronger than that in group R. Picrosirius red staining showed that type III and type I collagen in group A was more strongly expressed than that in group R at 4 weeks postoperatively. The ultimate failure load of the infraspinatus tendon-humeral head complex in group A was statistically higher than that in group R at 4 weeks postoperatively. The ultimate failure load of group A was similar to that of the control group.ConclusionThe biological and mechanical contribution of fascia lata augmentation for massive rotator cuff tears was analyzed in this study. Type III collagen was reported to be expressed during the tendon healing process. Although the biological action similar to natural ligament healing occurred around the fascia lata grafts, type III collagen was gradually replaced by type I collagen as the tissue matured. Our results suggest that fascia lata augmentation could stimulate biological healing and provide initial fixation strength of the repaired rotator cuff.

The iliotibial band (ITB) is a suitable scaffold for anterior cruciate ligament (ACL) reconstruction, providing a sufficient mechanical resistance to loading. Hence, ITB-derived fibroblasts attract interest for ligament tissue engineering but have so far not been characterized. This present study aimed at characterizing ITB fibroblasts before, during, and after emigration from cadaveric ITB explants to decipher the emigration behavior and to utilize their migratory capacity for seeding biomaterials. ITB and, for comparison, ACL tissues were assessed for the content of alpha smooth muscle actin (αSMA) expressing fibroblasts and degeneration. The cell survival and αSMA expression were monitored in explants used for cell isolation, monolayer, self-assembled ITB spheroids, and spheroids seeded in polyglycolic acid (PGA) scaffolds. The protein expression profile of targets typically expressed by ligamentocytes (collagen types I-III, elastin, lubricin, decorin, aggrecan, fibronectin, tenascin C, CD44, β1-integrins, vimentin, F-actin, αSMA, and vascular endothelial growth factor A [VEGFA]) was compared between ITB and ACL fibroblasts. A donor- and age-dependent differing percentage of αSMA positive cells could be detected, which was similar in ITB and ACL tissues despite the grade of degeneration being significantly higher in the ACL due to harvesting them from OA knees. ITB fibroblasts survived for several months in an explant culture, continuously forming monolayers with VEGFA and an increased αSMA expression. They shared their expression profile with ACL fibroblasts. αSMA decreased during the monolayer to spheroid/scaffold transition. Using self-assembled spheroids, the migratory capacity of reversible myofibroblastic ITB cells can be utilized for colonizing biomaterials for ACL tissue engineering and to support ligament healing.

BackgroundAdequate peri-implant soft tissue thickness and keratinized mucosa width are crucial for implant health and aesthetics. Autogenous subepithelial connective tissue grafts (CTG) are the gold-standard for augmenting thin biotypes, but they require a second surgical site. This trial evaluated whether a human fascia lata allograft (FLA) or platelet-rich fibrin (PRF) membrane could comparably enhance peri-implant soft tissue phenotype and serve as less invasive alternatives of CTG.MethodsForty-five patients with a thin gingival phenotype (≤ 1 mm thickness) requiring upper anterior implant were randomly assigned to receive soft tissue augmentation with either (1) FLA allograft, (2) PRF membrane, or (3) CTG (control). Interventions were applied concurrently with implant placement in a standardized manner. Gingival thickness (GT) and keratinized tissue width (KTW) were measured at baseline and 6 months using transgingival probing and clinical indices. Labial bone thickness was assessed by cone-beam CT at implant placement and 6 months.ResultsForty-five enrolled patients completed the study. All treatment modalities showed improvements in gingival and bone parameters, with the connective tissue graft consistently demonstrating the greatest gains. The median keratinized tissue width increased to 4.00 mm in the Connective Tissue Graft group, slightly higher than the Fascial Lata Allograft and Platelet-Rich Fibrin groups (3.75 mm). Gingival thickness showed significant increases in all groups, with the Connective Tissue Graft reaching 2.15 mm, followed by Fascia Lata Allograft (1.80 mm) and Platelet-Rich Fibrin (1.55 mm). Labial bone thickness also increased, with the Connective Tissue Graft achieving the highest mean value of 2.300 mm, and after 6 months, significant gains were observed in both this group (p = 0.032) and in the Platelet-Rich Fibrin group (p = 0.044), while Fascia Lata Allograft showed a smaller, non-significant increase.ConclusionsBoth fascia lata allograft (FLA) and PRF improved peri-implant soft tissue parameters, however the connective tissue graft (CTG) remains the gold standard for achieving the greatest thickness and best aesthetic results. FLA is a promising alternative that avoids a second surgical site with comparable outcomes, whereas PRF offers faster healing but lacks the volume necessary for significant tissue modification.