Intraoperative biologische Augmentation an Sehnen und Enthesen

Zusammenfassung: Trotz technischer Weiterentwicklung in der Sehnenrekonstruktionschirurgie besteht postoperativ nach wie vor eine relativ hohe Rerupturrate. Ein Grund dafür ist die Tatsache, dass bei der Sehnenansatz- und Sehnenheilung, bedingt durch eine limitierte Regenerationskapazität, Narbengewebe anstelle von normalem Gewebe gebildet wird. Dieses Narbengewebe ist sowohl in funktioneller als auch struktureller Sicht dem normalen Gewebe unterlegen. Mehrere Strategien zur biologischen Augmentation von Sehnen- und Sehnenansatzläsionen wurden in den letzten Jahren entwickelt und getestet. Dieser Artikel bespricht die klinische Evidenzlage bezüglich der biologischen Augmentation von Sehnen und Enthesen mittels Wachstumsfaktoren in Form von Plättchenkonzentraten, zellbasierten Therapien bzw. biologischen Sehnengraft

An Optical Method for Evaluation of Geometric Fidelity for Anatomically Shaped Tissue-Engineered Constructs

Quantification of shape fidelity of complex geometries for tissue-engineered constructs has not been thoroughly investigated. The objective of this study was to quantitatively describe geometric fidelities of various approaches to the fabrication of anatomically shaped meniscal constructs. Ovine menisci (n = 4) were imaged using magnetic resonance imaging (MRI) and microcomputed tomography (μCT). Acrylonitrile butadiene styrene plastic molds were designed from each imaging modality and three-dimensional printed on a Stratasys FDM 3000. Silastic impression molds were fabricated directly from ovine menisci. These molds were used to generate shaped constructs using 2% alginate with 2% CaSO4. Solid freeform fabrication was conducted on a custom open-architecture three-dimensional printing platform. Printed samples were made using 2% alginate with 0.75% CaSO4. Hydrogel constructs were scanned via laser triangulation distance sensor. The point cloud images were analyzed to acquire computational measurements for key points of interest (e.g., height, width, and volume). Silastic molds were within ±10% error with respect to the native tissue for seven key measurements, μCT molds for six of seven, μCT prints for four of seven, MRI molds for five of seven, and MRI prints for four of seven. This work shows the ability to generate and quantify anatomically shaped meniscal constructs of high geometric fidelity and lends insight into the relative geometric fidelities of several tissue engineering techniques

Fisioterapia após substituição artroscópica do ligamento cruzado cranial em cães: II - avaliação artroscópica e anatomopatológica Physiotherapy after arthroscopic repair of the cranial cruciate ligament in dogs: II - Arthroscopic and anatomopathological evaluations

Avaliou-se o enxerto da fascia lata na substituição artroscópica do ligamento cruzado cranial (LCC), realizou-se a caracterização histológica do enxerto e da interface enxerto-osso e avaliou-se, por meio de exames artroscópicos e anatomopatológicos, o efeito da fisioterapia pós-operatória. Foram utilizados 16 cães, sem raça definida, machos, pesando entre 19,2 e 26,3kg, submetidos à ruptura experimental do LCC e subsequente substituição artroscópica desse ligamento pelo enxerto autógeno da fascia lata. Os animais foram distribuídos em dois grupos de oito cada: no grupo I, os cães foram submetidos ao programa de fisioterapia pós-operatória e, no grupo II, à imobilização temporária do membro. Os exames artroscópicos e histológicos mostraram alterações articulares sugestivas de processo degenerativo aos 60 dias após a cirurgia, que se apresentavam mais acentuadas nos cães do grupo II. Na análise histológica do enxerto, observou-se reorganização das fibras colágenas, que ocorreu de forma mais intensa e precoce nos animais do grupo I. Houve progressiva integração das fibras colágenas na interface enxerto-osso. Conclui-se que é viável utilizar a fascia lata como substituto do LCC por cirurgia artroscópica, que o enxerto sofre processos de ligamentação e de osteointegração, e que a fisioterapia reduz a progressão das alterações degenerativas e incentiva o processo de ligamentação do enxerto.<br>The fascia lata graft in the arthroscopic reconstruction of the cranial cruciate ligament (CCL), the histological characteristics of the graft and the graft-bone interface, and the effects of postoperative physiotherapy by arthroscopic and anatomopathological exams were evaluated. Sixteen male mongrel dogs weighing from 19.2 to 26.3kg had the CCL experimentally ruptured and the stifle joint was stabilized by arthroscopical technique with fascia lata as an autogenous graft. Eight dogs were included in a postoperative physiotherapy group and the other eight in a temporary immobilization group. Arthroscopic and histological examinations showed articular lesions consistent with degenerative joint disease at 60 days after surgery, which was more severe in dogs from the temporary immobilization group. From histological studies, the graft underwent a collagenic reorganization process that was more intense and earlier in dogs from the physiotherapy group. There was a progressive establishment of collagen fiber continuity in the graft-bone interface. It can be concluded that fascia lata graft can be used to replace the CCL by arthroscopic surgery, the graft undergo a ligamentization and osteointegration process, and the postoperative physiotherapy decrease the degenerative joint disease progression and stimulate the ligamentization of the graft