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Background: Intra-articular fibromembranous septum in the radiocarpal joint can cause wrist contracture after distal radial fracture, but the mechanism underlying the formation of the septum is unknown. This study examined the clinical outcomes in patients treated with arthroscopic excision of the septum and the factors associated with formation of the septum in patients with and without a septum.Methods: Fifty-three patients (22 with septum and 31 without septum) treated for intra-articular distal radial fracture with arthroscopy using a volar locking plate and secondary removal of the plate were included. Clinical outcomes and radiological assessments were analyzed.Results: In patients with a septum, the range of wrist flexion and total wrist arc before the second operation were significantly more limited than in those without a septum (p < 0.01 and p = 0.03, respectively). The improvement rate (improvement in wrist arc divided by the wrist arc of the healthy side) after arthroscopic excision of the septum and plate removal was greater in patients with a septum than in those without a septum (6.1% vs. 2.0%, p = 0.08). The significant factors affecting formation of the septum were the residual articular gap and the height of the midradial ridge on computed tomography images.Conclusions: Intra-articular fibromembranous septum after surgically treated intra-articular distal radial fracture affects limited range of motion and secondary arthroscopic excision of the septum improves the wrist range of motion. Anatomical reduction and maintenance of the articular fragment, as well as anatomical characteristics might be causes of septum formation. [ABSTRACT FROM AUTHOR]

Background: The efficacy of autologous bone grafting in repairing nonunion fractures, large bone defects and spinal instability is widely accepted. However, the cellular and molecular mechanisms underlying new bone formation in bone grafting have yet to be fully elucidated. The purpose of this study was to clarify the fate, origin and the contribution of the cells within the grafted bone. Methods: This study was designed to investigate the role and fate of cells contained in the grafted bone and their contribution to new bone formation in the graft in an animal model. Middiaphyseal cylindrical bone samples obtained from green fluorescent protein (GFP) transgenic and wild-type rats were transplanted into the back muscle of wild-type and GFP rats, respectively. The transplanted bones were evaluated by immunohistochemistry, in situ hybridization and quantitative reverse transcription polymerase chain reaction. Results: Immunohistochemical analyses showed that all the cells in the newly formed bone originated from the grafted bone, and osteoblasts were gradually replaced by host cells. Conversely, osteoclasts were immediately replaced by host cells 2 weeks after the bone graft. In addition, expression of bone morphogenetic protein (Bmp)- 4, Bmp receptors and Noggin in the grafted bone was significantly upregulated before new bone formation occurred, indicating that the grafted cells might contribute to the recruitment of mesenchymal cells into the graft bed. Conclusion: This study revealed the possible molecular mechanisms of the contribution of cells contained in grafted bone to facilitate new bone formation. [ABSTRACT FROM AUTHOR]

Background: Currently, regenerative repair of large bone defects that result from bone tumor resection or severe trauma is a challenging issue because of the limited regenerative potential of bone and treatment modalities. The aim of this study was to achieve repair of large bone defects to the original three-dimensional (3D) anatomical state by combining computer-aided technologies and local delivery of bone morphogenetic protein (BMP) in a canine model. Methods: Computed tomography (CT) images of the pelvic bone of each dog were obtained, and an imaginary spherical malignant bone tumor of 15-mm diameter was placed in the left ilium of a canine on the 3D CT image. Resection of the whole tumor with a 10-mm margin of healthy bone was planned preoperatively by using computer-aided design (CAD) software. In addition, an image of the implant to be used to fill the resulting bone defect was constructed on the computer image. A porous hydroxyapatite (HA) implant identical to the imaged bone defect was made by shaving a tetragonal porous apatite block (40 × 20 × 10 mm) with a computer-aided manufacturing system operated by using the CT-image data of the bone defect obtained from the CAD system. To resect the iliac bone as planned preoperatively on the 3D CT image, computer-aided surgery was performed using the CT data. The defect was filled with the HA implant fabricated as described and coated with a putty carrier either with BMP-2 (BMP group, n = 6) or without BMP-2 (control group, n = 6). Results: In the BMP group, new bone formation was noted around each implant on CT images at 3 weeks after surgery and was remodeled to restore the original anatomy of the ilium on serial CT images. At 12 weeks, the implant was enclosed within new bone, and histological analysis revealed bone formation on and within the implant. Little bone formation was noted in the control group. Conclusions: This new method may enable efficacious and precise regenerative repair of large bone defects without bone grafting. [ABSTRACT FROM AUTHOR]

Background: Massive frozen stocked allogeneic bone grafts are often used to reconstruct large bone defects caused by trauma or tumor resections. However, the long-term failure rate of such massive allografts was reported to be 25% because of infection, fracture, and nonunion. In this study, we evaluated the ability of a recombinant human bone morphogenetic protein (rhBMP)-2-retaining paste to promote the osteogenic potential of frozen stocked allogeneic bone grafts to repair intercalated femoral shaft defects in a rat model. Methods: After confirming the transplantation intolerance between two rat strains (Wistar and Lewis) by skin transplantation from Lewis rats to Wistar rats, an 8-mm-long bone segment was removed from the Wistar rats, and a frozen stocked allograft coated with the rhBMP-2-retaining paste from the Lewis rats was placed into the defect and subjected to intramedullary fixation with an 18-gauge injection needle pin. The allografted femurs were evaluated by radiographic, histologic, and biomechanical examinations at specified time points. Results: The results revealed successful repair of critical-size cortical bone defects by implanting frozen stocked allografts coated with the rhBMP-2-retaining synthetic biodegradable carrier paste from an immunologically intolerant host. Conclusions: This experimental study suggest that allogeneic bone grafting in combination with rhBMP-2 and its local delivery system may represent an innovative approach to the reconstruction of bone defects. [ABSTRACT FROM AUTHOR]

Purpose: Early diagnosis of attritional wear of the flexor pollicis longus (FPL) tendon is essential in preventing subsequent tendon rupture. There are currently few objective methods of assessing FPL attrition. We hypothesized that color Doppler imaging could visibly detect FPL tendon attrition, and analyzed our results.Methods: We evaluated ultrasound imaging of the contact between the FPL tendon and a volar locking plate using the real-time B-mode and Doppler waveforms of the FPL tendon using the continuous Doppler wave mode in 40 patients who underwent fixation of the distal volar locking plate for distal radius fracture. Twenty out of 40 patients underwent plate removal surgery after ultrasound evaluation. We also assessed the relationship between the Doppler waveforms and attrition of the FPL tendon in these 20 patients.Results: Based on the ultrasound findings (n = 40), we divided Doppler waveforms of the FPL tendon into three categories: type 1, spindle wave; type 2, spindle wave with spike; and type 3, spike wave. There were 23, 11, and six patients with type 1, 2, and 3 waveforms in the affected hand, respectively. There were 37 patients with type 1, three with type 2, and no patient with type 3 waveforms in the contralateral wrist. Of the 20 patients who underwent plate removal, five had type 3 waveforms. We found tendon fraying or partial tears in three of these five patients. In addition, all five patients showed changes to type 1 or 2 waveforms after plate removal. None of the other 15 patients with type 1 or 2 waveforms had any tendon injuries during plate removal.Conclusions: Spike Doppler waveform can indicate abnormal findings, and may be a useful method to predict tendon attrition, because of its visibility.Diagnostic Study: Level III evidence. [ABSTRACT FROM AUTHOR]

Background: We evaluated trigger fingers ultrasonographically and clarified differences between fingers with and without continuous locking or snapping symptoms according to the thicknesses of the A1 pulley, flexor tendon and volar plate.Methods: We evaluated 26 trigger fingers, divided into two groups: Group 1, 14 fingers with locking or snapping; and Group 2, 12 fingers without such symptoms. We also evaluated 26 contralateral fingers as controls (Control 1 and 2 groups). We compared each group to the respective control group according to thickness of the A1 pulley and volar plate, and cross-sectional area of the flexor tendon. In addition, nine fingers with locking or snapping and treated using corticosteroid injection were evaluated according to symptoms and sonographic findings 3-4 weeks after treatment.Results: Thickness of the A1 pulley and cross-sectional area of the flexor tendon were greater in both Groups 1 and 2 than in controls. Thickness of the volar plate was greater in Group 1 than in Control 1, although no significant difference was seen between Group 2 and Control 2. In Group 1, eight of the nine fingers showed an alleviation of locking or snapping symptoms with corticosteroid injection, and sonographic findings showed that thickness of the volar plate was significantly decreased with corticosteroid injection, in addition to reduced thickness of the A1 pulley.Conclusion: In addition to thickening of the A1 pulley, thickening of the volar plate may represent an important contributor to continuous snapping or locking symptoms. [ABSTRACT FROM AUTHOR]

Background: Currently, regenerative repair of large bone defects that result from bone tumor resection or severe trauma is a challenging issue because of the limited regenerative potential of bone and treatment modalities. The aim of this study was to achieve repair of large bone defects to the original three-dimensional (3D) anatomical state by combining computer-aided technologies and local delivery of bone morphogenetic protein (BMP) in a canine model. Methods: Computed tomography (CT) images of the pelvic bone of each dog were obtained, and an imaginary spherical malignant bone tumor of 15-mm diameter was placed in the left ilium of a canine on the 3D CT image. Resection of the whole tumor with a 10-mm margin of healthy bone was planned preoperatively by using computer-aided design (CAD) software. In addition, an image of the implant to be used to fill the resulting bone defect was constructed on the computer image. A porous hydroxyapatite (HA) implant identical to the imaged bone defect was made by shaving a tetragonal porous apatite block (40 × 20 × 10 mm) with a computer-aided manufacturing system operated by using the CT-image data of the bone defect obtained from the CAD system. To resect the iliac bone as planned preoperatively on the 3D CT image, computer-aided surgery was performed using the CT data. The defect was filled with the HA implant fabricated as described and coated with a putty carrier either with BMP-2 (BMP group, n = 6) or without BMP-2 (control group, n = 6). Results: In the BMP group, new bone formation was noted around each implant on CT images at 3 weeks after surgery and was remodeled to restore the original anatomy of the ilium on serial CT images. At 12 weeks, the implant was enclosed within new bone, and histological analysis revealed bone formation on and within the implant. Little bone formation was noted in the control group. Conclusions: This new method may enable efficacious and precise regenerative repair of large bone defects without bone grafting. [ABSTRACT FROM AUTHOR]