Objective To evaluate the tensile mechanical characteristics of decalcified cortical bone matrix with different thicknesses so as to provide an experimental basis for the scaffold of tissue engineering. Methods Decalcified cortical bone matrix was prepared from fresh bovine tibia with rapid decalcification techniques. Its physical characteristics including colour, texture, and so on, were observed. Then the decalcified rate was calculated. Decalcified cortical bone matrices were radially cut into sl ices with different thicknesses along longitudinal axis and divided into 4 groups: group A (100- 300 μm), group B (300-500 μm), group C (500-700 μm), and group D (700-1 000 μm). Then the sl ice specimens of each group were characterized with tensile test and histological examination. Results General observation showed that decalcified cortical bone matrix with hydrogen peroxide treatment was ivory white with good elasticity and flexibil ity. The decalcified rate was 97.6%. The tensile strength and elastic modulus of groups B, C, and D were significantly higher than those of roup A (P lt; 0.05); there was no significant difference among groups B, C, and D (P gt; 0.05). The stiffness in 4 groups increased gradually with the increasing thickness, it was significantly lower in group A than those in groups B, C, and D (P lt; 0.05), and in groups B and C than that in group D (P lt; 0.05). While there was no significant difference in ultimate strain within 4 groups (P gt; 0.05). Histologically, intact osteon was observed in every group, with an average maximum diameter of 182 μm (range, 102- 325 μm). Conclusion The mechanical properties of decalcified cortical bone matrix might depend on the integrity of the osteons. Sl ices with thickness of 300 μm or more could maintain similar mechanical properties when decalcified cortical bone matrix is used as a scaffold for tissue engineering.
Objective It is difficult to treat chronic osteomyel itis due to the formation of the Staphylococcus aureus biofilms. Liposomal gentamicin-impregnated allogeneic cortical bone can inhibit the formation of the Staphylococcus aureusbiofilms. To explore the treatment of chronic osteomyel itis of rabbit by l iposomal gentamicin-impregnated allogeneic cortical bone. Methods The l iposomal gentamicin, l iposomal gentamicin-impregnated allogeneic cortical bone and gentamicinimpregnated allogeneic cortical bone were produced. Then the chronic Staphylococcus aureus osteomyel itis models of rabbit were made in left lower l imbs of 40 6-month-old rabbits and the right lower l imbs were used as controls. After 2 weeks, the observations of gross and X-ray were done. Four rabbits died within 10 days after the models were made and other 36 rabbits were devided into 6 groups: group A (no antibiotics), group B (intravenous injection of gentamicin), group C (intravenous injection of l i posomal gentamicin), group D (implantation of gentamicin-impregnated allogeneic cortical bone), group E (implantation of l i posomal gentamicin-impregnated allogeneic cortical bone), and group F (implantation of allogeneic cortical bone). After 2 weeks of treatment, the bacterial culture, X-ray and HE staining were done. Results The chronic Staphylococcus aureus osteomyel itis model of rabbit was made successfully. The X-ray showed dissolution of bone and periosteal reaction in groups A, B, C, and F, and no obvious dissolution of bone and periosteal reaction in groups D and E. The Norden scores were (2.5 ± 0.3), (2.1 ± 0.2), (1.5 ± 0.3), (1.5 ± 0.2), (0.9 ± 0.3), and (2.7 ± 0.3) points in groups A-F, respectively; showing significant differences between group A and groups B-E (P lt; 0.05), between groups B, E, F and other groups (P lt; 0.05). The results of blood and marrow cultures for Staphylococcus aureus were positive in groups A and F, and negative in other 4 groups; the results of bone marrow culture for Staphylococcus aureus were positive in 6 rabbits of group B, 4 rabbits of group C and 3 rabitts of group D; and the results were negative in group E. HE staining showed: in groups A and F, abscess and dead bone formed, and no new bone formation were observed; in groups B and C, different degrees of neutrophil accumulation was seen; in group D, some neutrophil accumulation occurred, and osteoprogenitor cells and osteoclasts were seen around implanted bone; and in group E, no neutrophil accumulation was observed, a lot of granulation tissues formed, and osteoprogenitor cells and osteoclasts were seen around implanted bone. Conclusion Implantation of l iposomal gentamicin-impregnated allogeneic cortical bone has remarkly better effect in treating chronic osteomyel itis than intravenous injection of l iposomal gentamicin and implantation of gentamicin-impregnated allogeneic cortical bone.
The present paper is aimed to study the effect of sand-therapy with Uyghur medicine on biomechanical properties and femoral bone volume of the femur of osteoarthritis (OA) rabbits at two different ages. In the experiments, we injected Papain through the joint space of right knees into the bodies of New Zealand rabbits (16 in the growing group, and 16 in the mature group), and established an OA model. The 16 rabbits in the mature group were divided randomly into 2 sub-groups: 8 in control group (no sand therapy), and 8 sand-therapy group. The 16 rabbits in the growing group were divided randomly into 2 groups as well: 8 in the control group (no sand therapy), and 8 in the sand-therapy group. We carried out CT scanning four times (1 day before, 13th, 27th and 41st days after the establishment of the model, respectively). After importing the CT data to MIMICS, the different volumes of each sclerotin were recorded and change of the percentage of each sclerotins in total femur bone volume were analyzed. Finally the rabbit femurs were given three-point bending test, the elastic load and the elastic deflection were obtained and the inertia of the section, the maximum bending stresses, the bending modulus of elasticity and the structural rigidity were calculated. The experimental results showed that ① Compared with 1 day before and 13th day after establishment of model at maturity, the cancellous bone volume increased and cortical bone volume decreased (P<0.05), but compared with those in the control group, the cancellous bone volume of femurs decrease and cortical bone volume increased under sand-therapy (P<0.05). Compared with those in the control group, there were no significant changes in the deflection and cross-sectional moment of inertia in the sand-therapy group (P>0.05), but the maximum bending normal stress, maximum load, elastic modulus, and structural stiffness (P<0.05) in the sand therapy group were larger than those in the control group. The study showed that sand-therapy in Uyghur medicine has benign effect on bone volume of the OA rabbit femur in two ages and the mechanical properties of the OA rabbit femur at the two ages induced by sand-therapy in Uyghur medicine have been improved.
In the present study, swine thighbone samples with different water contents were prepared through process of dehydration. The influence of water content on the biotribological behavior of the bone tissue was studied with nanoindentation test, reciprocating sliding test and impact wear test. It is shown that the water contents had significant influence on the mechanical properties and biotribological behavior of the swine thighbone samples. In this experiment condition, with decreasing water content, the hardness and elastic modulus of the swine thighbone samples increased, while the tribological properties significantly decreased. The viscoelasticity of bone tissue decreased with decreasing water content, which mainly resulted in different wear mechanisms of the bone tissue samples under applied loading.
Objective To assess the effectiveness of locking compress plate and extra cortical bone bridge fixation for treating atrophic humeral nonunion. Methods Seventeen patients with atrophic humeral nonuninon were treated with locking compress plate and extra cortical bone bridge fixation between November 2006 and June 2015. Of 17 cases, 11 were male, 6 were female, aged 24-63 years (mean, 38.2 years). Fracture located at the left side in 9 cases and at the right side in 8 cases. The mechanism of injury was traffic accident in 13 cases, falling from height in 3 cases, and heavy pound injury in 1 case. The patients underwent surgery for 1 time in 7 cases, for 2 times in 5 cases, for 3 times in 4 cases, and for 4 times in 1 case. The time from fracture to hospitalization was 10-76 months (mean, 22.6 months). The shoulder function was evaluated by Neer score, and elbow function by Mayo score. Results All incisions healed by first intention. Two cases had transient radial nerve symptoms of numbness. All patients were followed up 27.3 months on average (range, 15-60 months). Radiographic examination showed signs of bone remodeling at 6-8 weeks after operation, and formation of extra cortical bone bridge. All of them achieved bone union within 10 to 41 weeks (mean, 17.6 weeks). At last follow-up, the average Neer score was 83.36 (range, 72-96); and the shoulder function was excellent in 10 cases, good in 5, and fair in 2 with an excellent and good rate of 88.24%. And the average Mayo score was 86.52 (range, 68-100); and the elbow function was excellent in 11 cases, good in 3, and fair in 3 with an excellent and good rate of 82.35%. Conclusion The bone bridging could effectively form by extra cortical grafting technique. Atrophic humeral nonunions can be successfully treated with locking compress plate and extra cortical bone bridge fixation.
Objective To compare the effectiveness of cortical bone trajectory screw (CBTS) and conventional pedicle screw for posterior lumbar interbody fusion (PLIF) in the treatment of single segment lumbar degenerative disease. Methods Between May 2013 and May 2016, a total of 97 patients with single segment lumbar degenerative disease were treated with PLIF. Fifty-one patients were fixed with CBTS in PLIF (trajectory screw group) and 46 with pedicle screw (pedicle screw group). There was no significant difference in age, gender, body mass index, preoperative diagnosis, lesion segment, and preoperative visual analogue scale (VAS) score, Oswestry dysfunction index (ODI) between 2 groups (P>0.05). The operation time, intraoperative blood loss, postoperative drainage, bed rest time, length of hospital stay, serum creatine kinase (CK) concentration, total amount of diclofenac sodium, perioperative complications, ODI, VAS score, and interbody fusion rate were recorded and compared between 2 groups. Results All patients were followed up 12 months. The patients in trajectory screw group had a significantly less operation time, intraoperative blood loss, postoperative drainage, and serum CK concentration when compared with the patients in pedicle screw group (P<0.05). Thirty-five patients (68.6%) in trajectory screw group and 46 patients (100%) in pedicle screw group were given diclofenac sodium within 48 hours after operation, showing significant difference between 2 groups (χ2=89.334, P=0.000). There was no significant difference in the incidence of perioperative complications between trajectory screw group and pedicle screw group (3.9% vs. 8.7%, P=0.418). There was no significant difference in the VAS score, ODI, and interbody fusion rate at 12 months after operation between 2 groups (P>0.05). Conclusion For the single segment degenerative lumbar disease, the use of CBTS or conventional pedicle screw for PLIF can obtain satisfactory clinical function and interbody fusion rate. But the former has the advantages of less blood loss, less intraoperative muscle damage, less perioperative pain, shorter length of hospital stay and bed rest time.
Objective To explore the feasibility and effectiveness of maintaining the reduction of unstable intertrochanteric fractures by Kirschner wire-fixation-cortical bone technique. Methods Forty patients with intertrochanteric fracture [AO/Orthopaedic Trauma Association (AO/OTA) type 31-A2.2] admitted between May 2015 and January 2017 and requiring closed reduction and proximal femoral nail antirotation (PFNA) were randomly divided into trial group (intraoperative Kirschner wire-fixation-cortical bone technique group, 20 cases) and control group (conventional treatment group, 20 cases). There was no significant difference in general data of gender, age, side, body mass index, cause of injury, time from injury to operation between the two groups (P>0.05). The operation time, intraoperative blood loss, and intraoperative fluoroscopy times of the two groups were recorded; the reduction quality of fracture was observed according to the corresponding relationship between medial and anterior cortex (positive, neutral, and negative support) of intraoperative fluoroscopy proposed by ZHANG Shimin, and the stability of internal fixation and fracture healing were observed; Harris score was used to evaluate the recovery of hip function at 12 months after operation. Results In the trial group, 6 cases (30%) had 2 Kirschner wires implanted less than 4 times, 7 cases (35%) had 5-8 times, and 7 cases (35%) had 9 times or more. There was no significant difference in operation time and intraoperative blood loss between the two groups (P>0.05), but the blood transfusion volume and intraoperative fluoroscopy times in the trial group were significantly less than those in the control group (P<0.05). Both groups were followed up 13-21 months, with an average of 17 months. There was no complications such as wound infection, deep venous thrombosis of lower extremities, refracture, and internal fixation-related complications. The quality of intraoperative reduction in the trial group was significantly better than that in the control group (Z=–2.794, P=0.024). The Harris score of the trial group was significantly better than that of the control group at 12 months after operation (t=2.98, P=0.01). Conclusion The use of Kirschner wire-fixation-cortical bone technique during intertrochanteric fracture closed reduction and PFNA internal fixation surgery can effectively maintain the reduction effect, reduce the number of fluoroscopy, improve the reduction quality, reduce allogeneic blood input, obtain better hip function, and do not increase the operation time and intraoperative blood loss.
ObjectiveTo compare the safety and accuracy of manual and robot-assisted cortical bone trajectory (CBT) screws fixation in the treatment of lumbar degenerative diseases with osteoporosis.MethodsThe clinical data of 58 cases of lumbar degenerative disease with osteoporosis treated by CBT screw fixation between February 2017 and February 2019 were analyzed retrospectively. Among them, 29 cases were fixed with CBT screws assisted by robot (group A), 29 cases were fixed with CBT screws by hand (group B). There was no significant difference between the two groups in terms of gender, age, body mass index, lesion type, T-value of bone mineral density, and operative segment (P>0.05), with comparability. The accuracy of implant was evaluated by Kaito’s grading method, and the invasion of CBT screw to the superior articular process was evaluated by Babu’s method.ResultsThe operation time and intraoperative blood loss in group A were significantly less than those in group B (t=−8.921, P=0.000; t=−14.101, P=0.000). One hundred and sixteen CBT screws were implanted in the two groups. At 3 days after operation, according to the Kaito’s grading method, the accuracy of implant in group A was 108 screws of grade 0, 6 of grade 1, and 2 of grade 2; and in group B was 86 screws of grade 0, 12 of grade 1, and 18 of grade 2; the difference was significant (Z=4.007, P=0.000). There were 114 accepted screws (98.3%) in group A and 98 (84.5%) in group B, the difference was significant (χ2=8.309, P=0.009). At 3 days after operation, according to Babu’s method, there were 85 screws in grade 0, 3 in grade 1, and 2 in grade 2 in group A; and in group B, there were 91 screws in grade 0, 16 in grade 1, 5 in grade 2, and 4 in grade 3; the difference was significant (Z=7.943, P=0.000). No serious injury of spinal cord, nerve, and blood vessel was found in the two groups. One patient in group A had delayed cerebrospinal fluid leakage, and 2 patients in group B had mild anemia. Both groups were followed up 10-14 months (mean, 11.6 months). The neurological symptoms were improved, and no screw loosening or fracture was found during the follow-up.ConclusionCompared with manual implantation of CBT screw, robot-assisted spinal implant has higher accuracy, lower incidence of invasion of superior articular process, and strong holding power of CBT screw, which can be applied to the treatment of lumbar degenerative diseases with osteoporosis.