Tendon and Ligament Engineering

Plesiosaurians are highly derived secondarily-adapted organisms (if fishes are primarily-adapted) with a long evolutionary history, and they are closely related with basal eosauropterygians. Attempts to reconstruct soft-tissue anatomy can be complicated due to the lack of extant
closely-related species, thus various lines of evidence must be considered. This study aims to reconstruct the pectoral girdle myology of eosauropterygians. Information derived from the extant phylogenetic bracket method was not sufficient to clarify muscle attachments in the pectoral girdle of plesiosaurians. To correctly infer muscle homologies,
the extant phylogenetic bracket information had to be complemented with developmental and osteological information, and osteological transformations
had to be traced back to Permian basal neodiapsids. The
reconstructed pectoral girdle musculature presented here is, thus, significantly different from previous attempts. As in secondarily-adapted aquatic modern analogues, several muscles atrophied (e.g., pectoralis,
episternocleidomastoideus) and others specialized (e.g., coracobrachialis, clavodeltoideus) in order to attain a more influential role to the stringent conditions of subaquatic locomotion. The subcoracoscapularis, scapulodeltoideus, scapulohumeralis and supracoracoideus are inferred
to be glenohumeral stabilizers. The clavodeltoideus acted as the main protractor muscle and the coracobrachialis as a major retractor muscle, possibly in conjunction with the latissimus dorsi. Several heads of the triceps
possibly atrophied, as in whales, serving mainly as a cubital joint stabilizer. The trapezius, serratus and levator scapulae served as pectoral girdle stabilizers.

Our previous study revealed that the fibroblasts in the epiligament of medial collateral ligament of the knee joint in rats were not static cells. They synthesize type I and V collagens, whose presence in the EL may be important in understanding the ligament healing. The present study describes the morphological changes occurring in the medial collateral ligament epiligament in the rat knee joint and investigates it for the presence of type I and V collagens during the ligament healing. Twelve 8-month-old male Wistar rats were used in this study. In nine of them the medial collateral ligament of the knee joint was surgically transected and was allowed to heal spontaneously. On the eighth, sixteenth, and thirtieth day after injury, the animals were sacrificed and the ligaments were examined. The morphological changes during these periods are presented in details, as well as the distribution of type I and V collagens. This study offers a more complete description of the epiligament he...

The thin layer of connective tissue enveloping ligaments, termed the epiliga- ment is not well described. The aim of this study was to elucidate the normal morphology of the external surface of the medial collateral ligament epiligament tissue in rat knee joint. Our investigations revealed the presence of fibroblasts, fibrocytes, adipocytes, neuro-vascular bundles, and numerous multidirectional collagen fibres within the epiligament and significant differences between the ligament and its covering tissue. Moreover, we detected immunohistochemically the localization of type I and V collagens in the epiligament external surface. The observations and their literature explanations were discussed in details.

Background: In this study, we evaluated the changes which occurred in the epiligament, an enveloping tissue of the ligament, during the ligament healing. We assessed the association of epiligament elements that could be involved in ligament healing.
Methods: Thirty-two 8-month old male Wistar rats were used in this study. In twenty-four of them the lateral collateral ligament of the knee joint was surgically transected and was allowed to heal spontaneously. The evaluation of the epiligament healing included light microscopy and transmission electron microscopy.
Results: At the eight, sixteenth and thirtieth day after injury, the animals were sacrificed and the ligaments were examined. Our results revealed that on the eight and sixteenth day post-injury the epiligament tissue is not completely regenerated. Till the thirtieth day after injury the epiligament is similar to normal, but not fully restored.
Conclusion: Our study offered a more complete description of the epiligament healing process and defined its important role in ligament healing. Thus, we provided a base for new strategies in ligament treatment.