Aiming at the problem of scaffold degradation in bone tissue engineering, we studied the feasibility that controlls bone defect repair effect with the inhomogeneous structure of scaffold. The prediction model of bone defect repair which contains governing equations for bone formation and scaffold degradation was constructed on the basis of analyzing the process and main influence factors of bone repair in bone tissue engineering. The process of bone defect repair and bone structure after repairing can be predicted by combining the model with finite element method (FEM). Bone defect repair effects with homogenous and inhomogeneous scaffold were simulated respectively by using the above method. The simulation results illustrated that repair effect could be impacted by scaffold structure obviously and it can also be controlled via the inhomogeneous structure of scaffold with some feasibility.
Objective To investigate the short-term effectiveness of the anterior and middle columns in thoracolumbar tuberculosis reconstructed with whole autogenous spinous process-laminar bone through posterior approach. Methods The retrospective study included 78 patients with thoracolumbar tuberculosis who underwent posterior approach surgery and anterior and middle column bone graft reconstruction between January 2012 and May 2023. Based on the type of autogenous bone graft used, patients were divided into group A (whole autogenous spinous process-laminar bone graft, 38 cases) and group B (autogenous structural iliac bone graft, 40 cases). There was no significant difference of baseline data, such as age, gender, disease duration, involved segment of spinal tuberculosis, and preoperative erythrocyte sedimentation rate (ESR), C reactive protein (CRP), Oswestry disability index (ODI), visual analogue scale (VAS) score, the American Spinal Injury Association (ASIA) grade, segmental kyphotic angle, and intervertebral height between the two groups (P>0.05). The operation time, intraoperative blood loss, postoperative drainage, hospital stays, ESR, CRP, VAS score, ODI, bone fusion time, ASIA grade for neurological status valuation, postoperative complications, change of segmental kyphotic angle, change of intervertebral height were recorded and compared between the two groups. Results The operation time in group A was significantly shorter than that in group B (P<0.05); there was no significant difference in intraoperative blood loss, postoperative drainage, and hospital stays between the two groups (P>0.05). All patients in the two groups were followed up 14-110 months (mean, 64.1 months); there was no significant difference in the follow-up time between the two groups (P>0.05). The ESR, CRP, ODI, and VAS score at each time point after operation in both groups significantly improved when compared with those before operation, and further improved with the extension of time, the differences were significant (P<0.05). There was no significant difference between the two groups (P>0.05) except that the VAS score of group A was significantly better than that of group B at 3 days after operation (P<0.05). There was no significant difference in fusion time between the two groups (P>0.05). The neurological function of most patients improved after operation, and there was no significant difference in ASIA grade between the two groups at last follow-up (P>0.05). There was no significant difference in segmental kyphosis angle and intervertebral height between the two groups at each time point (P>0.05), and no significant difference in segmental kyphosis angle, intervertebral height correction and loss were found between the two groups (P>0.05). In group A, there was 1 case of incision fat liquefaction and 1 case of incision infection; in group B, there was 1 case of deep venous thrombosis, 2 cases of pleural effusion, and 10 cases of pain in bone harvesting area; in both groups, there were 2 cases of gout caused by hyperuricemia. There was a significant difference in the incidence of pain in bone harvesting area between the two groups (P<0.05), and there was no significant difference in the incidence of other complications between the two groups (P>0.05). ConclusionWhole autogenous spinous process-laminar bone grafting is equivalent to structural iliac bone graft in reconstruction of the anterior and middle columns in thoracolumbar tuberculosis through posterior approach, effectively supporting the stability of the anterior and middle columns of the spine, while resulting in shorter operation time and less postoperative pain in bone harvesting area.
ObjectiveTo investigate the effectiveness of simultaneous treatment of traumatic calcaneal osteomyelitis and defect deformity with near-arc bone transport by Ilizarov technique.MethodsBetween January 2014 and August 2020, 6 cases of traumatic calcaneal osteomyelitis with defect deformities were treated by simultaneous treatment of near-arc bone transport by Ilizarov technique. The patients were all male; aged from 40 to 61 years (mean, 49.3 years). The disease duration was 2-72 months, with an average of 16.1 months. All patients were traumatic calcaneal osteomyelitis, including 4 cases of falling from height, 1 case of traffic accident injury, and 1 case of crushing injury. The infection affected the talar-heel joint in 4 cases, and the talar-heel joint was fused or partially fused in 2 cases. After the external fixator was removed, the Maryland foot scoring system was used to evaluate the foot function, and the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot function scoring system was used to evaluate the ankle-hindfoot function, and were compared with the preoperative scores.ResultsAll patients were followed up 1.5-26.0 months, with an average of 16.3 months. All incisions healed by first intention, no recurrence of infection occurred, and no surgical intervention such as second-stage bone grafting and fusion was performed. Five cases of calcaneal osteomyelitis with defect deformity underwent one-stage osteotomy and slipped, 1 case of the original bone mass after debridement after infection of calcaneal fractures slipped directly. The bone sliding time was 28-62 days, with an average of 38.7 days; the sliding distance was 3.1-5.2 cm, with an average of 3.6 cm. In 1 patient, due to the short follow-up time, the calcaneal slip bone had not healed, the external fixator had not been removed (not involved in clinical scoring), but the foot shape, reexamination of X-ray films and with frame walking were satisfactory. The time with external fixator was 6-8 months, with an average of 6.5 months in the other 5 cases. After removing the external fixator, the foot returned to three-point weight-bearing, and the longitudinal arch was recovered to varying degrees, and there was no obvious varus valgus. The Maryland score after removal of the external fixator was 80.8±4.7, which was significantly higher than that before operation (33.6±4.3) (t=–35.782, P=0.000), 3 cases were excellent and 2 cases were good; the median AOFAS ankle-hindfoot score was 84, the interquartile range was (79, 86), which was significantly improved when compared with the preoperative score [the median score was 33.5, the interquartile range was (21.3, 37.5)] (Z=–2.023, P=0.043), 4 cases were excellent and 1 case was good. Among them, pain, walking distance, getting rid of walking aids, going up and down stairs, deformity, etc. were significantly improved when compared with preoperative ones. Mobility such as subtalar and hock joints were poor or disappeared.ConclusionSimultaneous treatment of traumatic calcaneal osteomyelitis and defect deformity with near-arc bone transport by Ilizarov technique can optimize the operation method, reduce the number of operations, and try to simulate the original shape of the calcaneus. It is an effective, economical, and novel treatment method.
ObjectiveTo study the effectiveness of trifocal bone transport by using monolateral rail system in the treatment of bone defects caused by post-traumatic tibial osteomyelitis.MethodsThe clinical data of 28 patients with tibial defects caused by post-traumatic osteomyelitis treated with trifocal bone transport technique by using monolateral rail system between January 2012 and June 2017 were retrospectively analyzed. There were 26 males and 2 females, aged 22-59 years (mean, 41.3 years). The causes of injury included 13 cases of traffic accident injury, 9 cases of falling from height, 4 cases of heavy object injury, and 2 cases of crushing injury. The disease duration was 4.5-17.0 months (mean, 7.1 months). The length of bone defect was 6.5-16.8 cm (mean, 10.3 cm). And the range of soft tissue defect ranged from 3.5 cm×2.0 cm to 18.0 cm×11.0 cm. The bone transporting time, external fixation time, duration of regenerate consolidation, and external fixation index were recorded, and the complications were observed. At last follow-up, the bone and functional results were evaluated according to the criteria given by Association for the Study and Application of the Method of the Ilizarov (ASAMI).ResultsAll patients were successfully followed up after removing the external fixator with an average of 35 months (range, 24-65 months). The bone transporting time was 41-136 days (mean, 60.2 days), the external fixation time was 7.5-20.0 months (mean, 13.4 months), the external fixation index was 1.1-1.9 months/cm (mean, 1.4 months/cm), the duration of regenerate consolidation was 6.0-16.5 months (mean, 10.5 months). Pin tract infection occurred in 12 cases, delayed union on docking site was occurred in 9 cases, axial deviation was observed in 2 cases, poor regenerate consolidation was presented in 1 case, and refracture on docking site after fixator removal was occurred in 1 case. There was no recurrence of infection, amputation, vascular and neurologic complications, and osteofascial compartment syndrome. At last follow-up, according to ASAMI criterion, the bone healing results were excellent in 17 cases, good in 7 cases, and fair in 4 cases, with an excellent and good rate of 85.7%; the functional results were excellent in 15 cases, good in 10 cases, and fair in 3 cases, with an excellent and good rate of 89.3%.ConclusionTrifocal bone transport by using monolateral rail system is an effective method in the treatment of bone defect caused by post-traumatic osteomyelitis which can reduce bone transport time, external fixation time, and complications.
Objective To investigate the clinical effects of repairing massive bone defects in limbs by using vascularized free fibular autograft compoundingmassive bone allografts. Methods From January 2001 to December 2003, large bone defects in 19 patients (11 men and 8 women, aging from 6 to 35 years) were repaired by vascularized free fibular transplant with a monitoringflap compounding massive deep frozen bone allografts. The length of bone defects were 12 to 25 cm (16.6 cm on average), of vascularized free fibular 15 to 28 cm (18.3 cm on average), and of massive bone allografts 11 to 24 cm (16.1 cm on average). Thelocation of massive bone defects were humerus in 1 case, femur in 9 cases and tibia in 9 cases. Results After followup of 5 to 36 onths (18.2 months on average), wounds of donor and recipient sites were healed at Ⅰstage, monitoringflaps were alive, no obvious eject reaction of massive bone allografts was observed and no complications occurred in donor limbs. The radiographic evidence showed union in 15 patients 3 months and 3 patients 8 months after operation. One case of malignant synovioma of left lower femur recurred and amputation was performed 2.5 months after surgery. Internal fixation was removed in 5 patients, and complete bone unions werefound 1 year postoperatively. No massive bone allografts was absorbed or collapsed. Conclusion With strict indication, vascularized free fibular autograft compounding massive bone allografts, as an excellent method of repairing massive bone defects in limbs, can not only accelerate bone union but also activate and changer the final results of massive bone allografts from failure.
Objective To investigate the expression levels and significance of vascular endothel ial growth factor (VEGF) and microvessel density (MVD) in rabbit radius defects repaired with allogeneic and autogenic bone. Methods Forty adult New Zealand rabbits were chosen, and 10 mm bone defect model was created in the bilateral radii of 28 experimental rabbits. The other 12 rabbits provided allogeneic bone under the standard of American Association of Tissue Bank. In the left side, allogeneic bone were used to repair bone defect (experimental group), equal capacity autogenous il iac bone was used in the right side (control group). Animals were sacrificed at 2, 4, 8, and 12 weeks postoperatively. Immunohistochemical method was used to determine the expression of VEGF, CD34 protein and MVD counting. Bone histomorphometric parameters, including percent trabecular area (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), and trabecular separation (Tb.Sp) were measured by von Kossa staining undecalcified sl ices. The relation was analyzed between VEGF and MVD, histomorphometric parameters. Results The positive signals of VEGF protein were detected in cytoplasm of vascular endothel ial cells, chondrocytes, osteoblasts, fibroblasts and osteoclasts. At 2 weeks, there was no significant difference in VEGF protein expression between experimental group and control group (P gt; 0.05); at 4 and 8 weeks, the expression of VEGF in control group was significantly higher than that in experimental group (P lt; 0.05); and at 12 weeks, there was no significant difference between two groups (P gt; 0.05). There was a positive correlation (P lt; 0.01) between VEGF expression and MVD value in two groups at 2, 4, 8, and 12 weeks postoperatively. There was no significant difference in bone histomorphometric parameters (BV/TV, Tb.Th, Tb.N, Tb.Sp) between two groups at 12 weeks postoperatively (P gt; 0.05), but there was a positive correlation between VEGF expression and parameters of BV/TV, Tb.Th, and Tb.N (P lt; 0.01); and a negative correlation between VEGF and Tb.Sp (P lt; 0.01). Conclusion VEGF can express diversity at different time and positions, and the different expressions indicated various biology significances in the process of the bone heal ing. It can coordinate growth of cartilage and bone and profit vascular reconstruction of allogeneic bone. VEGF may participate in promoting osteogenesis in the course of allogeneic bone transplantation.
Objective To investigate the effectiveness of arthroscopic autologous iliac bone grafting with double-row elastic fixation in treatment of recurrent anterior shoulder dislocation combined with massive glenoid bone defects. Methods Between January 2018 and December 2021, 16 male patients with recurrent anterior shoulder dislocation combined with massive glenoid bone defects were treated with arthroscopic autogenous iliac bone grafting and double-row elastic fixation. The patients were 14-29 years old at the time of the first dislocation, with an average age of 18.4 years. The causes of the first dislocation included falling injury in 5 cases and sports injury in 11 cases. The shoulders dislocated 4-15 times, with an average of 8.3 times. The patients were 17-37 years old at the time of admission, with an average age of 25.1 years. There were 5 left shoulders and 11 right shoulders. The preoperative instability severity index (ISIS) score of the shoulder joint was 5.8±2.1, and the Beighton score was 4.3±2.6. The University of California Los Angeles (UCLA) score, Constant score, American Shoulder and Elbow Surgeons (ASES) score, and Rowe score were used to evaluate shoulder function, and the degree of the glenoid bone defect repair was observed based on CT after operation. Results All incisions healed by first intention, and no complication such as incision infection or neurovascular injury occurred. The patients were followed up 12 months. At 12 months after operation, UCLA score, Constant score, ASES score, and Rowe score all significantly improved when compared with the scores before operation (P<0.05). CT imaging showed the degree of glenoid bone defect was significantly smaller at immediate, 6 and 12 months after operation when compared with that before operation (P<0.05), and the bone blocks healed with the scapula, and bone fusion had occurred at 12 months. ConclusionArthroscopic autologous iliac bone grafting with double-row elastic fixation is a safe treatment for recurrent anterior shoulder dislocation combined with massive glenoid bone defects, with good short-term effectiveness.
Bone tissue regeneration and blood vessel formation are inseparable. How to realize the vascularization of bone repair scaffolds is an urgent problem in bone tissue engineering. The growth and development, mineralization maturity, reconstruction and remodeling, and tissue regeneration of bone are all based on forming an excellent vascularization network. In recent years, more and more researchers have used hydrogels to carry different cells, cytokines, metal ions and small molecules for in vitro vascularization and application in bone regeneration. Based on this background, this article reviews the hydrogel-based vascularization strategies in bone tissue engineering.
Objective To analyze the short-term effectiveness and safety of personalized three-dimensional (3D) printed customized prostheses in severe Paprosky type Ⅲ acetabular bone defects. Methods A retrospective analysis was conducted on 8 patients with severe Paprosky type Ⅲ acetabular bone defects and met the selection criteria between January 2023 and June 2024. There were 3 males and 5 females, with an average age of 64.6 years ranged from 56 to 73 years. All primary replacement prostheses were non-cemented, including 1 ceramic-ceramic interface, 1 ceramic-polyethylene interface, and 6 metal-polyethylene interfaces. The time from the primary replacement to the revision was 4 days to 18 years. The reasons for revision were aseptic loosening in 5 cases, revision after exclusion in 2 cases, and repeated dislocation in 1 case. The preoperative Harris score was 39.5±3.7 and the visual analogue scale (VAS) score was 7.1±0.8. The operation time, intraoperative blood loss, hospital stay, and complications were recorded. The hip function was evaluated by Harris score, and the degree of pain was evaluated by VAS score. The acetabular cup abduction angle, anteversion angle, rotational center height, greater trochanter height, and femoral offset were measured on X-ray film. Results The operation time was 95-223 minutes, with an average of 151.13 minutes. The intraoperative blood loss was 600-3 500 mL, with an average of 1 250.00 mL. The hospital stay was 13-20 days, with an average of 16.88 days. All 8 patients were followed up 2-12 months, with an average of 6.4 months. One patient had poor wound healing after operation, which healed well after active symptomatic treatment. One patient had lower limb intermuscular vein thrombosis, but no thrombosis was found at last follow-up. No serious complications such as aseptic loosening, infection, dislocation, and periprosthetic fracture occurred during the follow-up. At last follow-up, the Harris score was 72.0±6.2 and the VAS score was 1.8±0.7, which were significantly different from those before operation (t=−12.011, P<0.001; t=16.595, P<0.001). On the second day after operation, the acetabular cup abduction angle ranged from 40° to 49°, with an average of 44.18°, and the acetabular cup anteversion angle ranged from 19° to 26°, with an average of 21.36°, which were within the “Lewinneck safety zone”. There was no significant difference in the rotational center height, greater trochanter height, and femoral offset between the healthy side and the affected side (P>0.05). ConclusionThe use of personalized 3D printed customized prostheses for the reconstruction of severe Paprosky type Ⅲ acetabular bone defects can alleviate pain and enhances hip joint function, and have good postoperative prosthesis position, without serious complications and have good safety.
Objective To study and prepare a new kind of bone graft, which has osteogenesis, local anti-infective function and low immunogenicity. Methods Gentamicin-impregnated bone was prepared bymeans of ultrasonic and vacuum, the release of gentamicin in vivo was measured by inhibition bacteria. Ten healthy male adult sheep were made animal infection models of thigh bone or humerus defect of 6 mm×6 mm×20 mm at size, and the defect was inoculated into 1 ml 5×1010CFU/ml Staphylococcus aureus. The animals were randomly divided into the experimental group (n=5, the bone graft with gentamicin was implanted) and the control group (n=5, the bone graft without gentamincin). Macroscopic, WBC count, radiological, and histological investigations were carried out to evaluate the antiinfective and osteosis capability. Results The concentrations of gentamicin were 46.1 μg/ml in bone allograft and 17.3 μg/ml in muscles after 1 day. The concentrations of gentamicin exceeding the minimum inhibitory concentration lastedfor 14 days in vivo. WBC in the control group was higher than that in the experimental group. In the control group, 1 case died owing to septemia 3 weeks afteroperation. The implanted bones were wrapped in pus 4 and 6 weeks, and the defects were filled with fibre tissue 8 and 10 weeks after operation. In the experimental group, 1 case was infected, the others had a good concrescence. The bone allografts began to integrate with adjacent bone after 4-8 weeks and integrate well after 12 weeks. The X-ray and histological observation showed that new bone formed and took the place of bone allograft. Conclusion The gentamicinimpregnated bone allograft was of a good sustained release feature in vivo, local antiinfection and osteogenesis. It might be an ideal bone grafting material for bone defects with infection.