OssDsign (Sweden)

Lisfranc fractures present unique challenges to surgeons due to the complex anatomy and small irregular bone structures where fracture reduction and realignment must be precise to achieve an optimal result for the patient. The choice of surgical technique, internal fixation used, and choice of bone graft (if fusion is required) are key aspects to consider for successful treatment. The following case describes a complicated Lisfranc fracture in a morbidly obese women where TMT fusion and ORIF were achieved with plate and screw fixation and a latest generation silicated calcium phosphate bone graft. The surgery resulted in complete pain relief, anatomical fracture reduction, and correction of alignment in the Lisfranc complex.

In this proof-of-concept, bone neoformation beyond the skeletal envelope is explored by using a collagen pouch (n = 6) packed with calcium phosphate (CaP) granules placed over the frontal bone in sheep (n = 3). At 13 weeks, macroscopic examination showed specimens covered by an adherent fibrinous envelope with slight vascularization. Histology revealed colonization of the implant by newly formed woven bone and fibrous connective tissue. Surface osteoblasts as well as material-filled macrophages, lymphocytes, polymorphonuclear cells and giant cells were also found in large quantities surrounding the newly formed bone tissue inside the collagen pouch. On the side facing the recipient bone, the collagen membrane had to a large extent been resorbed and bridging bone formation was clearly visible between the test article and recipient bone. On the other side facing soft tissue, the collagen pouch remained intact with a visible fibrous capsule. This study demonstrated that the use of a collagen sleeve as a container for CaP granules allows for good neoformation beyond the skeletal envelope with bridging bone formation clearly visible between the test article and recipient bone. Additionally, in this model, macrophages rather than osteoclasts appear to modulate CaP granule resorption and remodeling into new bone. This construct opens new perspectives for treatment methods that could be used for bone augmentation and restoration of cranio-maxillofacial defects and malformations.