From the Metaphor of the Lizard's Tail to That of the Doughnut: A Case of Achilles Tendon Complete Regrowth.

Introduction: Tendon tissue turnover is a very slow process. However, some tendons show very unique regeneration capabilities. The Achilles tendon regeneration and maturation process occurs uniformly and centripetally along the entire the length of the neo-tendon. Case Report: The present case report describes a complete regeneration of the Achilles tendon in a 54-year-old patient with a reinjury to the Achilles tendon following open tenorrhaphy surgery. The regenerative process had a positive outcome despite the patient suffering, at the time, from an infection caused by Cutibacterium acnes. Conclusion: This case report is a paradigmatic example of how the Achilles tendon is able to maintain its regenerative capacity even in extremely critical biological situations such as after an infection. However, the issue concerning the biological characteristics of the regenerated tendon remains open.

Anterior cruciate ligament injury risk factors in football.

INTRODUCTION: Anterior cruciate ligament (ACL) lesion represents one of the most dramatic injuries in a football (soccer) player's career. There are many injury risk factors related to intrinsic (non-modifiable) and/or extrinsic (modifiable) factors of ACL injury. EVIDENCE ACQUISITION: Research of the studies was conducted until September 2018 without publication data limitation or language restriction on the following databases: PubMed/MEDLINE, Scopus, ISI, EXCERPTA. EVIDENCE SYNTHESIS: To date, evidence from the literature suggests that the risk of ACL injury is multifactorial and involves biomechanical, anatomical, hormonal, and neuromuscular factors. Despite this relative complexity, the mechanisms of injury are well known and rationally classified into two categories: mechanisms of injury based on contact or on non-contact with another player, with the non-contact injury mechanisms clearly prevailing over the mechanisms of contact injury. One of the most frequent biomechanical risk factors, associated with ACL non-contact injury, is represented by the valgus knee in the pivoting and cutting movements and in the landing phase after jumping. Gender-related risk factors show female populations to have a higher predisposition to ACL injury than males However, there are still some theoretical and practical aspects that need further investigation such as; genetic risks together with the role of estrogen and progesterone receptors in female populations, and the in-vivo interaction shoe-playing surface. In particular, the genetic risk factors of ACL lesion seem to be an interesting and promising field of investigation, where considerable progress has still to be made. CONCLUSIONS: This narrative review provides an insight into the risk factors of ACL injury that could be used by practitioners for preventing injury in football (soccer).