**2. Incidence**

Weber–Cech in 1976, which distinguishes vital forms (hypertrophic and oligotro‐ phic) from non-vital forms (atrophic). In 2007 a new score classification system has been processed, which is the "Non-Union Scoring System (NUSS)," which divides patients in four big groups by score awarded based on the real non-healing risk. The NUSS represents an innovative approach to the problem because it understand the multifactorial reasons of failure, explains why in a variable percentage of cases (depending from de district affected), the healing is not obtained, even with a correct treatment and above all make possible the drafting of a therapeutic choice algo‐ rithm. Biotechnologies at our disposal are synthetic growth factors, the autologous growth factors and platelet-rich plasma, mesenchymal stem cells, and scaffolds or bone substitute. The biologic chamber represent the ideal site for bone regeneration; it is a bio-reactor in which are present all those elements at the base of the concept of diamond. The chamber needs to be aseptic, vital, mechanically stable, and sealed but selectively permeable. Thanks to the use of megaprosthesis not only in oncologic orthopaedics, but also it is now possible to avoid the amputation or long and often inconclusive treatment of lengthening or ankle arthrodesis. The new frontier in treatment of non-unions will be genetic therapy, that is, the possibility to transport to the patient those genes that con drive to the formation of good bone callus and his

**Keywords:** Tibial pilon, tibial plafond, non-union, biological chamber, biotechnolo‐

Non-union is a fracture with no healing potential without a further surgical procedure. Diagnosis of non-union can be done in case of healing failure from 6 to 9 months after the first fracture. Time is variable between fracture types, at the level of the tibial pilon diagnosis can be done only 9 months after trauma. Between long bones, tibia is the most frequently involved by this

We consider appropriate to keep the attention of the reader on the relevance that more frequent traumatic mechanism have in relationship with evolution and eventual failure of healing

As known, tibial plafond fractures are mainly caused by axial overload more than torsional

The mechanism of axial overload presupposes a major transfer of energy which leads to a more rapid deformation of the bone tissue until resistance limit is reached. The energy released at the broken point to soft tissues surrounding causes characteristics soft tissues lesions, which are present in those kinds of fractures and make the healing more complex: associated fractures, dislocation of the astragalus; vascular and nervous lesions; muscle and skin lesions

forces, that are, responsible more frequently of malleolus fractures.

gies, NUSS, megaprosthesis, stem cells, growth factor, diamond concept

maturation toward strong bone.

108 Advanced Techniques in Bone Regeneration

**1. Definition**

complication.

processes.

with comparison of enlarged edema.

The tibial pilon non-union incidence in the literature ranges between 2 [1] and 18% for Ruedi and Ovadia [2], and those results have been confirmed even by McFerran [3].

Studies of Havet in 2006 and Bacon and Wang in 2010 [4–6] report similar statistic data from which result in similar non-union rate independently from the kind of ostheosynthesis used.

After those premises and therapeutic compromises sometimes adopted in treatment of the tibial pilon fractures, it is easy to understand the data present in literature for which non-union mean rate is around 5% independently from the technique used, recognizing as main causes a significant fracture's comminution ad eventual bone loss, vascular damage, and local infection [4–7].
