Functional and radiographic evaluation of the treatment of traumatic bone loss of the hand using the Masquelet technique

IF 0.308 (2017)International audienceThis study was a retrospective evaluation of 18 patients with traumatic bone loss affecting the fingers, hand and wrist who were treated using the induced-membrane technique. Sixteen men and two women, mean age 54years (27-74) presented a hand injury including bone loss. Sixteen patients were treated on an emergency basis and two following nonunion of their fractures. There were 13 cases of open fracture of the phalanx and 5 cases of metacarpal fractures. These patients were treated with debridement and the injuries were covered when necessary. To address the bone loss, the first step of the induced-membrane technique involved placing a cement spacer (polymethylmethacrylate [PMMA]) without antibiotics in the defect. During the second step, the cement spacer was removed and replaced by autologous cancellous bone graft. The graft was placed within the biological tube left empty after removal of the cement. For each patient, bone union was assessed with radiographs and/or CT scan. Failure was defined as nonunion at 1year. In 16 patients, the fractures had healed after 4months (1.5-12months) on average. Two failures were noted (one nonunion treated using a PIP prosthesis and one case of delayed union). Mobility of the fingers, evaluated using the Total Active Motion (TAM) was 145° (75°-270°). The Kapandji score reached 8 for the thumb. Grip strength reached 21kg/F and pinch strength was 5kg/F; these values were 50% of those in the healthy hand. The induced-membrane technique is simple and can be used to treat traumatic bone loss in an emergency, thus avoiding amputation and limb shortening, while preserving limb function. It provides immediate stability and allows early mobilization

Odontoblastic differentiation of dental pulp stem cells from healthy and carious teeth on an original PCL-based 3D scaffold

Aims: To isolate and characterize dental pulp stem cells (DPSCs) obtained from carious and healthy mature teeth extracted when conservative treatment was not possible or for orthodontic reasons; to evaluate the ability of DPSCs to colonize, proliferate and differentiate into functional odontoblast-like cells when cultured onto a polycaprolactone cone made by jet-spraying and prototyped into a design similar to a gutta-percha cone. Methodology: DPSCs were obtained from nine carious and 12 healthy mature teeth. Then cells were characterized by flow cytometry and submitted to multidifferentiation to confirm their multipotency. These DPSCs were then cultured on a polycaprolactone cone in an odontoblastic differentiation medium. Cell proliferation, colonization of the biomaterial and functional differentiation of cells were histologically assessed. For the characterization, a t-Student test was used to compare the two groups. Results: In all cell cultures, characterization highlighted a mesenchymal stem cell phenotype (CD105+, CD90+, CD73+, CD11b-, CD34-, CD45-, HLA-DR-). No significant differences were found between cultures obtained from carious and healthy mature teeth. DPSCs from both origins were able to differentiate into osteocytes, adipocytes and chondrocytes. Cell colonization was observed both on the surface and in the thickness of polycaprolactone cones as well as a mineralized pericellular matrix deposit composed of type I collagen, alkaline phosphatase, osteocalcin and dentin sialophosphoprotein. Conclusions: DPSCs were isolated from both carious and healthy mature teeth. They were able to colonize and proliferate within a polycaprolactone cone and could be differentiated into functional odontoblast-like cells