The 8-plate versus physeal stapling for temporary hemiepiphyseodesis correcting genu valgum and genu varum: a retrospective analysis of thirty five patients.

PURPOSE: In skeletally immature patients, treatment of malalignment about the knee is possible by performing temporary hemi-epiphyseodesis. Following the well-established procedure of physeal stapling, the 8-plate was introduced as a new device. The purpose of this study was to compare physeal stapling with 8-plate hemi-epiphyseodesis. We focused on evaluating deformity correction, complication rate and duration of the procedures. METHODS: We retrospectively analysed 35 patients (61 extremities, age 2.9-16.0 years) who were treated by temporary hemi-epiphyseodesis about the knee for correction of genu varum or genu valgum by using Blount staples (32 extremities) or the 8-plate (29 extremities). Plain radiographs were analysed at the time of operation and at hardware removal that included measurement of mechanical axis deviation, mechanical lateral distal femoral angle and mechanical medial proximal tibial angle. Time until hardware removal, operation time and complications were recorded. RESULTS: A statistically significant improvement of all radiographic measurements could be achieved with comparable results in both groups. Complications were similar in both groups with no relevant differences in amount and severity. In the 8-plate group, however, the surgical time was significantly shorter by an average of ten minutes for implantation and 12 minutes for explantation. CONCLUSIONS: Both Blount stapling and the 8-plate technique are methods for correction of genu varum and valgum deformity in skeletally immature patients; however, a shorter operating time for implantation and explantation was noted for the 8-plate technique.

Bone marrow concentrate: a novel strategy for bone defect treatment.

BACKGROUND: Although strong efforts have been made over the last decade to introduce stem cell and tissue engineering treatment strategies to the field of orthopaedics, only few clinical applications are currently available. MATERIALS AND METHODS: The clinical outcomes of ten patients with volumetric bone deficiencies treated with mesenchymal stem cells and bone marrow aspirate are presented in this case series. Results were evaluated with radiographs. In addition to the in vivo data, we also presented in vitro data of BMC cultivated onto a porous collagen I scaffold and the technique of bone marrow aspiration via a commercially available system. RESULTS: Our results demonstrated that there is a rationale for a clinical application of BMC / bone aspirate in the treatment of osseous defects. The intraoperative harvest procedure is a safe method and does not significantly prolong the time of surgery. In addition, MSC isolated from the aspirate was able to adhere and proliferate onto a collagen scaffold in significant numbers after a 15 min incubation period. These cells were then able to allow osteogenic differentiation in vitro without any osteogenic stimuli. CONCLUSIONS: The local application of BMC / bone aspirate in the treatment of bone deficiencies may be a promising alternative to autogenous bone grafting and help reduce donor site morbidity.

Ovine cord blood accommodates multipotent mesenchymal progenitor cells.

BACKGROUND: Stem cells derived from umbilical cord blood display mesenchymal multipotency and can differentiate into osteoblasts, chondroblasts and adipoblasts in vitro under defined stimuli. Although sheep have been used as experimental models for investigations on xenoreactivity after transplantation of stem cells isolated from human umbilical cord blood, the potential of ovine cord blood stem cells to differentiate has been examined to date. MATERIALS AND METHODS: Mononuclear cells from the placentoms of 3 lambs were isolated via density gradient centrifugation and cultivated. After expansion up to 3 passages, the cells were stimulated to differentiate towards osteogenic (dexamethasone, ascorbic-acid-2-phosphate, beta-glycerolphosphate), chondrogenic (TGF-beta3, insulin, transferrin, selenium, dexamethasone, ascorbic-acid-2-phosphate) and adipogenic (indomethacine, insulin, 3-isobutyl-1-methylxanthine, dexamethasone) lines for 20 days. The cells were characterized morphologically by transmission and phase contrast light microscopy during lineage-specific stimulation. Immunocytochemistry and conventional stains were used to detect lineage-typical markers: fat vacuoles and peroxisome proliferation-acitivated receptor gamma2 (PPAR) served to detect adipoblasts, whereas osteopontin (OP) was used to characterize osteoblasts. A positive antibody reaction to collagen II and chondrogenic oligomeric protein (COMP) revealed the presence of chondroblasts. RESULTS: The osteogenic line formed bone nodules, adipogenic cells developed lipid droplets and the cells of the chondrogenic line showed typical chondroblast-like morphology. CONCLUSION: It was demonstrated that ovine mesenchymal stem cells, derived from umbilical cord blood (sheep unrestricted somatic stem cells, S-USSCs), can be isolated via gradient density centrifugation and expanded in vitro. Under lineage-specific stimulation, S-USSCs differentiated into osteo-, chondro- and adipoblasts with typical morphological characteristics. Significant quantitative differences between the stimulated and control groups in lineage-typical immunocytochemical markers verified these findings.