The fixation of articular fractures, with many small osteochondral fragments, is a challenging unmet need where a bone adhesive would be a useful adjunct to standard treatments. Whilst there are no such adhesives in current clinical use, preclinical animal models have demonstrated good healing of bone in unloaded models using an adhesive based on phosphoserine modified calcium phosphate cement (PM-CPC). An ex-vivo human bone core model has shown that this adhesive bonds freshly harvested human bone. To confirm this adhesive is capable of supporting loaded osteochondral fragments a porcine model has been developed initially ex-vivo on the path to an in-vivo study. In this model bone cores, harvested from the medial knee condyle, are glued in place with the adhesive. In-vivo adjacent pairs of bone cores would be replaced with adhesive and a control with conventional pin fixation respectively. As osteochondral bone fragments have both bone and cartilage components, this suggested a dual adhesive strategy in which components designed for each tissue type are used. This concept has been explored in an ex-vivo porcine pilot study presented herewith. At the subchondral bone level, the PM-CPC was used. At the cartilage level, a second adhesive, a methacrylated phosphoserine containing hyaluronic acid (MePHa) hydrogel designed specifically for soft tissues was applied. This is a challenging model as both adhesives have to be used simultaneously in a wet field. The pilot showed that once the subchondral component is glued in place, the PM-CPC adhesive intruding into the cartilage gap can be removed before applying the cartilage adhesive. This enabled the MePHa adhesive to be injected between the cut cartilage edges and subsequently light-cured. This two-stage gluing method is demanding and an in-vivo pilot is necessary to perfect and prove the operative technique. Acknowledgements: The human bone core project was partially financed by Innovation Fund of Västra Götaland Region, Sweden. The MePHa hydrogel work was supported by a Swiss National Fund grant # CR23I3_159301

Advancements in treating distal humerus fractures. We will review and discuss approaches to the elbow to treat different types of fractures. We will discuss the role of soft tissue structures and how they affect elbow function. During this session, we will review the latest techniques for treating the complex articular fractures of the distal humerus to include capitellar and trochlear fractures. Techniques presented will address fixation, reconstruction, and salvaging of complex distal humerus fractures

Introduction and Objective. Joint malleolar fractures have been estimated around 9% of all fractures. They are characterized by different both early and late complications. Among the latter, arthrofibrosis and early secondary arthrosis represent the two most common ones. Moreover, these two complications could be considered related to each other. Their real cause is still under investigation, even if residual post-operative hematoma and acute post-traumatic synovitis appear to be the most accredited. Supporting this hypothesis, joint debridement and the evacuation of the post-operative hematoma could represent a possible solution. The aim of this prospective study is to evaluate the role of arthroscopic lavage and debridement during internal fixation in order to prevent late joint complications. Materials and Methods. Sixty consecutive patients who reported dislocated articular ankle fractures with surgical indication of open reduction and internal fixation (ORIF) have been included in this study. 27 patients underwent ORIF surgery associated with arthroscopic washout and debridement, while 33 patients, representing the control group, underwent just internal reduction and osteosynthesis. Patients with pure dislocations, non-articular fractures, polytrauma, previous local trauma, metabolic and connective pathologies were excluded. Follow-up was performed at 40 days (T1), 3 (T2) and 6 months (T3) after trauma for all patients. If necessary, some have been re-evaluated 12 months after the trauma. Efficacy of the treatment was evaluated through the VAS scale, Maryland scale, search for local complications such as dehiscence or infections, and finally radiographic evaluation. T-Student was estimated in order to individuate statistical significance. Results. VAS scale showed higher values for the case group than the control group with mean values of 2.7 and 4.2 at T1 and 2.1 and 3.8 at T2, respectively. At 6 months follow-up, the VAS values resulted similar with 2.6 for the case group and 2.8 for the control group. The same projections were found for the Maryland scale, with values of 61.5 and 40.7 at T1, 80.8 and 68.0 at T2 and 87.8 and 85.0 with no significant differences at T3 respectively. No significant differences were detected for complications or radiographic evaluation. Conclusions. Our study has shown significance differences in terms of pain and time for recovery only in the very short term follow up. Although our study, due to the specific limits, cannot be considered diriment, on the basis of the data, we could hypothesize that the aforementioned hypothesis may remain valid for the non-acute hematoma or that the cause of the arthrofibrosis should be sought somewhere else. However, evidence is low, and further research is needed

Post-traumatic arthritis is a frequent consequence of articular fracture. The mechanisms leading to its development after such injuries have not been clearly delineated. A potential contributing factor is decreased viability of the articular chondrocytes. The object of this study was to characterise the regional variation in the viability of chondrocytes following joint trauma. A total of 29 osteochondral fragments from traumatic injuries to joints that could not be used in articular reconstruction were analysed for cell viability using the fluorescence live/dead assay and for apoptosis employing the TUNEL assay, and compared with cadaver control fragments. Chondrocyte death and apoptosis were significantly greater along the edge of the fracture and in the superficial zone of the osteochondral fragments. The middle and deep zones demonstrated significantly higher viability of the chondrocytes. These findings indicate the presence of both necrotic and apoptotic chondrocytes after joint injury and may provide further insight into the role of chondrocyte death in post-traumatic arthritis