3D-printed, bioactive ceramic scaffold with rhBMP-2 in treating critical femoral bone defects in rabbits using the induced membrane technique.

Although autogenous bone grafts are an optimal filling material for the induced membrane technique, limited availability and complications at the harvest site have created a need for alternative graft materials. We aimed to investigate the effect of an rhBMP-2-coated, 3D-printed, macro/microporous CaO-SiO2 -P2 O5 -B2 O3 bioactive ceramic scaffold in the treatment of critical femoral bone defects in rabbits using the induced membrane technique. A 15-mm segmental bone defect was made in the metadiaphyseal area of the distal femur of 14 rabbits. The defect was filled with polymethylmethacrylate cement and stabilized with a 2.0 mm locking plate. After the membrane matured for 4 weeks, the scaffold was implanted in two randomized groups: Group A (3D-printed bioceramic scaffold) and Group B (3D-printed, bioceramic scaffold with rhBMP-2). Eight weeks after implantation, the radiographic assessment showed that the healing rate of the defect was significantly higher in Group B (7/7, 100%) than in Group A (2/7, 29%). The mean volume of new bone formation around and inside the scaffold doubled in Group B compared to that in Group A. The mean static and dynamic stiffness were significantly higher in Group B. Histological examination revealed newly formed bone in both groups. Extensive cortical bone formation along the scaffold was found in Group B. Successful bone reconstruction in critical-sized bone defects could be obtained using rhBMP-2-coated, 3D-printed, macro/microporous bioactive ceramic scaffolds. This grafting material demonstrated potential as an alternative graft material in the induced membrane technique for reconstructing critical-sized bone defects.

Clinical outcome of AO/OTA type C fracture of the distal humerus using the expanded paratricipital approach and cadaveric comparison of the exposure of the paratricipital and expanded paratricipital approaches to the distal humerus.

BACKGROUND: We investigated the overall clinical outcome of the expanded paratricipital approach in complex articular fractures of the distal humerus and the effect of lack of visualization in the surgical field. In addition, we performed a cadaveric study to investigate the expansion or limitation of articular access in the expanded paratricipital approach. METHODS: Forty-one AO/OTA type 13C fracture cases treated using the expanded paratricipital approach at a single trauma center from 2013 to 2017 were enrolled in this study. We evaluated the overall clinical outcome and analyzed the effect of lack of visualization in the surgical field with the expanded paratricipital approach by comparing outcomes between 2 groups classified by the location of the main articular fracture (group 1, limited visualization; group 2, without limited visualization). The length of inaccessible and accessible articular segments were analyzed using 40 matched-pair elbows. RESULTS: The average duration of follow-up was 15.1 months. All fractures (type C1 in 11 cases, type C2 in 21, and type C3 in 9) were radiologically healed at 3.2 months after surgery. No cases required additional surgery because of implant irritation. The average Mayo Elbow Performance Score was 90.5. The mean Disabilities of the Arm, Shoulder and Hand score was 18.5. Among the 41 cases, the limited visualization group (group 1, n = 21) had a longer surgical time and higher percentage of nonanatomic reduction than group 2. Although the expanded paratricipital approach allowed more articular exposure than the conventional approach, there was still a 20mm inaccessible articular segment (30% of transepicondylar width) in cadaveric dissection. CONCLUSIONS: The expanded paratricipital approach can be used in type C1, type C2, and selective type C3 articular fractures of the distal humerus with favorable results. Relative to surgical times and achieving anatomic reduction, it is more successful in a fracture with a main articular fragment and with good visualization.

Fragment specific fixation technique using 2.7 mm VA LCP for comminuted posterior wall acetabular fractures: a novel surgical technique.

PURPOSE: The purposes of the study were to introduce surgical technique of fragment-specific fixation technique using multiple 2.7-mm variable-angle locking compression plates (VA LCPs) in comminuted posterior wall acetabular fractures and reported its clinical results. PATIENTS AND METHODS: Among the 68 patients, 23 with comminuted posterior wall factures with ≥ 3 fragments in the CT scan and no column involvement with a minimum follow-up duration of 12 months were enrolled in this study. We evaluated the clinical results after the treatment of comminuted posterior wall acetabular fractures via the fragment-specific fixation technique using 2.7-mm variable-angle locking compression plates (VA LCPs) retrospectively. RESULTS: The average duration of follow-up was 26.8 months. Anatomical reduction was achieved in eighteen patients. Imperfect reduction was achieved in five patients. 22 patients achieved fracture union and one patient underwent revision surgery owing to acute postoperative infection. There were no complications, including loss of reduction, fixative failures, sciatic nerve palsy, heterotopic ossification, and early posttraumatic arthritis among 22 patients. The average functional outcome was measured as 'very good'. CONCLUSION: Fragment-specific fixation technique using 2.7-mm VA LCPs for comminuted posterior wall acetabular fractures could be an acceptable alternative means of surgical fixation.

Miniplate Augmented Tension-Band Wiring for Comminuted Patella Fractures.

The aim of this study was to introduce various applications of miniplate augmented tension-band wiring (TBW) for comminuted patella fractures and to evaluate the clinical outcomes. Comminuted articular patella fractures were managed with anterior cortical miniplate fixation with a TBW technique from January 2014 to January 2016. The primary end point was radiographic union. Secondary end points were complications related to the procedure. Functional outcomes including range of motion were also evaluated. Thirty patients were followed up for a mean of 20 months (range, 12-28) postoperatively. The primary union rate was 96% (29 of 30 patients). Mean time to union was 3.2 months. One patient required additional surgery because of acute postoperative infection. Twenty-five patients recovered a full range of motion relative to the contralateral limb. The mean Bostman score at the last follow-up was 28.6 points (range, 26-30). In conclusion, miniplate augmented TBW is a versatile and useful technique for comminuted patella fracture fixation.

Lumbar posterolateral fusion using heparin-conjugated fibrin for sustained delivery of bone morphogenic protein-2 in a rabbit model.

We had devised a heparin-conjugated fibrin (HCF) system to deliver bone morphogenic proteins (BMPs) for a long-term period to enhance bone regeneration. In the present study, we tested the effectiveness of the delivery system for spinal fusion in a rabbit model. A total of 15 rabbits underwent posterolateral lumbar spine fusion with BMP-2 (50 µg per collagen sponge). The control group received only collagen sponges without BMP-2, another group (short-term delivery [SD] group) received collagen sponges filled with fibrin gel loaded with BMP-2, and the third group (long-term delivery [LD] group) received collagen sponges filled with HCF loaded with BMP-2. All animals were euthanized 8 weeks after surgery, and the fusion was assessed by radiographs, manual palpation, computed tomography, and mechanical testing. The fusion rate was significantly higher in the LD group using HCF than in the SD group or in the control group. Biomechanical testing showed the tensile strength was also significantly higher in the LD group using HCF than in other groups. The HCF system can provide a good option for the delivery of BMP-2 on posterolateral lumbar spine fusion.