## 4 Discussion  
Various strategies for the treatment of tibial plateau fractures have been described in the medical literature, so far. Conservative treatment, such as traction and cast bracing, are viable approaches only in selected cases [25; 26]. However, in general, conservative treatment displays poorer outcomes in comparison to surgery, due to the prolonged immobilisation in a cast brace or hospitalization  
Figure 4: Exemplificative case, in anteroposterior RX, at 1 (a), 3 (b), and 6 (c) months follow-up respectively, well evidencing good consolidation, absence of non-union or retarded consolidation and graft good integration confirmed by progressive loss of radiolucency of the graft itself. required, which can eventually lead to joint stiffness, and further risks like pulmonary embolism and ulcers [3; 27]. Allowing a more rapid return to mobilisation and weight bearing, surgery is preferable in most cases and closed reduction and minimally invasive fixation, ORIF, and arthroplasty are all valid techniques for the treatment of tibial plateau fractures [28; 29; 30]. Moreover, in some circumstances like challenging comminuted, displaced fractures, excessive loss of bone matrix or severe depressions of articular surface, bone graft substitutes to augment metaphyseal defects are needed. Historically, cancellous bone harvested from iliac crest has been considered the gold standard for bone grafting. A comprehensive review of the literature published in 2013 by [PERSON] et al. [31] showed that AIBG was the most commonly performed procedure for bone augmentation in the management of tibial plateau fracture. However, this approach involves an additional incision to harvest the graft, which may eventually lead to infection, haematoma, neurovascular complications and fractures, overall representing a further risk exposure for the patients [9; 10; 31]. Furthermore, some variables like quantitative limitations to the bone that can be safely harvested, biological quality and structural strength of the graft are still concerning factors which led to the development of bone substitutes [16]. A vast variety of bone substitutes are available on market and currently used in clinical settings, each displaying some limitations [6; 32]. Recently, some authors have focused on investigating xenohybrid materials, which combine biological qualities of auto- and allo-grafts along with mechanical performances of synthetic scaffolds. The CXS we studied as bone graft in the treatment of tibial plateau fractures is a bovine bone-derived matrix enriched in poly(L-lactide-co-\(\varepsilon\)-caprolactone) (PLCL), in order to improve compressive strength and elasticity, and collagen fragments exposing the RGD sequence, which improve hydrophilicity, so favouring blood affinity, and enhance cells attachment [18; 19; 20]. It has been proved that its particular affinity to blood facilitates attachment by MSCs, which then differentiate in osteoblasts, leading to deposition of new bone matrix that eventually degrades and substitutes the CXS [7; 18]. This CXS has already been safely used in oral and maxillary surgery with promising results, and its biological and mechanical characteristics make it an interesting tool for orthopaedic surgery as well [18; 33]. Tegner Lysholm Knee Scoring Scale is a scoring system based on ten questions regarding function, pain and stability of the knee joint [20]. Scores \(<\)65 are considered poor; fair if comprised between 65 and 83; good when ranging from 84 to 90; excellent if \(>\)90 [34]. The mean Tegner Lysholm Knee Scoring Scale we obtained from our patients was \(89\pm 4.10\), which is considered good. IKDC 2000 is a form composed of ten sections, each one containing several questions, in which patient is questioned about subjective perception of knee function [35]. The final score is expressed in a scale from 0 to 100; mean IKDC 2000 of our patients was \(78.67\pm 3.31\), which indicates that 1 year after surgery patients were satisfied about the grade of their knee function.