ObjectiveTo explore the feasibility of establishment of a artificial joint aseptic loosening mouse model by cobalt-chromium particles stimulation.MethodsTwenty-four 8-week-old male severe combined immunodeficient (SCID) mice were divided into experimental group (n=12) and control group (n=12). The titanium nail was inserted into the tibial medullary cavity of mouse in the two groups to simulate artificial joint prosthesis replacement. And the cobalt-chromium particles were injected into the tibial medullary cavity of mouse in experimental group. The survival of the mouse was observed after operation; the position of the titanium nail and the bone mineral density of proximal femur were observed by X-ray film, CT, and Micro-CT bone scanning; and the degree of dissolution of the bone tissue around the tibia was detected by biomechanical test and histological staining.ResultsTwo mice in experimental group died, and the rest of the mice survived until the experiment was completed. Postoperative imaging examination showed that there was no obvious displacement of titanium nails in control group, and there were new callus around the titanium nails. In experimental group, there was obvious osteolysis around the titanium nails. The bone mineral density of the proximal tibia was 91.25%±0.67%, and the maximum shear force at the tibial nail-bone interface was (5.93±0.85) N in experimental group, which were significantly lower than those in control group [102.07%±1.87% and (16.76±3.09) N] (t=5.462, P=0.041; t=3.760, P=0.046). Histological observation showed that a large number of inflammatory cells could be seen around the titanium nails in experimental group, while there was no inflammatory cells, and obvious bone tissue formation was observed in control group.ConclusionThe artificial joint aseptic loosening mouse model can be successfully established by cobalt-chromium particles stimulation.
Objective Metal wear products cause the aseptic loosening of joint prosthesis. To investigate the effect of metal ions Co2+ and Cr3+ on the osteoblast apoptosis, cell cycle distribution, and secretion of alkal ine phosphatase (ALP), and to search a method to prevent and treat aseptic loosening. Methods The mouse calvarial osteoblasts (MC3T3-E1) were cultured in vitro to 3-5 generations (5 × 105 cells/ mL) and divided into 2 groups: the experimental group and the controlgroup. The osteoblasts were cultured in α-MEM medium containing 10%FBS (the control group), and the mixed solution ofCoCl2 and CrCl3 was added after the osteoblasts cultured in α-MEM medium containing 10%FBS attached completely (the experimental group). At 12, 24, and 48 hours after culture, the osteoblast apoptosis and the cell cycle distribution were assessed by flow cytometry; and ELISA method was appl ied to detect ALP content in serum supernatant. Results At 12, 24, and 48 hours after culture, the apoptosis rates in the experimental group (13.90% ± 0.52%, 14.80% ± 0.41%, and 13.40% ± 0.26%) were significantly higher than those in the control group (8.56% ± 0.31%, 8.19% ± 0.24%, and 2.15% ± 0.11%), (P lt; 0.05); G2M (dividing phase) distribution ratio significantly decreased and G0G1 (dormancy stage) distribution ratio significantly increased when compared with those in the control group (P lt; 0.05); and the absorbency (A) values of ALP were 0.955 ± 0.052, 0.624 ± 0.041, and 0.498 ± 0.026 in the exprimental group, and were 1.664 ± 0.041, 1.986 ± 0.024, and 2.192 ± 0.041 in the control group, showing significant differences between 2 groups (P lt; 0.05). Conclusion Metal ions Co2+ and Cr3+ have a marked effect on osteoblasts cell cycle distribution, which can make most of the cells to be in dormancy stage (G0G1), up-regulate the apoptosis rate and inhibit the releasion of ALP from osteoblasts.
Objective To introduce the occurrence mechanisms, prevention, and treatment measures of prosthetic aseptic loosening. Methods The recent original articles about prosthetic aseptic loosening were extensively reviewed and analyzed. Results Prosthetic aseptic loosening was a very complex process involving many mechanical and biological aspects. The main mechanical factors included prosthetic materials, shapes and sizes, implant fixation methods (including surfacetreatments), cl inical installation, interface micromotion, stress shielding, implant wear, interface integrity, and peri prosthetic high hydraulic pressure, etc.; the main biological factors included the types and sizes of wear particles, cell-activated responses, cytokine release, enzyme activation and allergic reactions to wear particles, etc.. Many measures should be adopted to effectively prevent and treat it, including improving materials and designs of prostheses, fixation techniques, surgical techniques, and drug treatments. Conclusion Prosthetic aseptic loosening is still a troublesome compl ication after joint replacements in orthopaedics, and more attention should be paid for its effective prevention and treatment.
Objective To review the recent advances in treatment of aseptic femoral shaft nonunion. Methods The clinical studies about the treatments of aseptic femoral shaft nonunion in recent years were widely reviewed and analyzed. Results There are several surgical methods for aseptic femoral shaft nonunion. Due to uncertain clinical outcome, dynamization of nail should be carefully selected. The exchange nailing is suitable for the hypertrophic nonunion of the isthmal femoral shaft fracture. The exchange lateral plating is suitable for nonunion with obvious malformation. However, wave plate or dual plate should be chosen when the bone nonuinon is combined with the medial defect. The augmentation plating improves the success rate of nailing for femoral shaft nonunion, but it should be carefully selected for patients with obvious deformity or bone defect. Ilizarov technique is suitable for various bone nonunion, especially with complicated or large segmental bone defects. Induced membrane technique is also an important method for the treatment of bone nonunion with large bone defects. The clinical efficacy of the blocking screw remains to be supported by further evidence. Biological stimulants are mainly used for atrophic nonunion, and the clinical efficacy of them alone are still controversial. Conclusion Due to lack of comparative studies between different surgical methods, the orthopedist should choose the appropriate treatment according to the individual situations of the patient and the types of bone nonunion.
ObjectiveTo evaluate the effectiveness of locking compress plate (LCP) for the treatment of aseptic diaphyseal humeral nonunions. MethodsBetween January 2006 and January 2012, 23 patients with aseptic diaphyseal humeral nonuninons were treated with LCP and autologous iliac crest bone graft, and the clinical data were retrospectively analyzed. There were 15 males and 8 females with the average age of 42.5 years (range, 28-60 years). The fracture located at left side in 11 cases and right side in 12 cases. The mechanism of the injury was traffic accident in 15 patients, and falling from height in 8 patients. Fracture was treated by internal fixation in 20 cases and external fixation in 3 cases. And 6 patients had open fractures and other 17 had close fractures. Based on the Weber-Cech classification, 6 cases were rated as atrophic nonunions, and 17 cases as hypertrophic nonuninons. Shoulder function was evaluated by Constant-Murley score and elbow function was evaluated by Mayo score. ResultsAfter operation, 2 patients had transient radial nerve symptoms of numbness and 1 patient had superficial infection. Primary healing of incision was obtained in the other patients. All patients were followed up 22.22 months on average (range, 16-30 months). Normal range of motion of the shoulder was found in 11 cases; and limited movements of abduction, elevation, and posterior extension were observed in 12 cases. And osseous union was observed clinically and radiographically in all patients. The average union time was 16.95 weeks (range, 12-24 weeks). The average Constant-Murley score was 81.87 (range, 50-98); and shoulder function was excellent in 14 cases, good in 6, and fair in 3. And the average Mayo score was 87.78 (range, 70-96); and the result was excellent in 14 cases, good in 7, and fair in 2. ConclusionAseptic diaphyseal humeral nonunions can be successfully treated with LCP, coupled with the use of autologous iliac crest bone graft.
Objective To observe the human mononuclear cell releasing TNF-α and the activation of Caspase-3 during apoptosis after stimulated by Co2+ and Cr3+, to discuss the mechanism of artificial joint wear production metal ion on aseptic loosening. Methods CoCl2 powder and CrCl3 powder were dissolved by asepsis inject water, preparing solution for10 mg/L and 500 mg/L, respectively. Mononuclear cells were acquired from peripheral blood, 4 × 106/culture dish. According to the difference of culture solution, the cells were divided into 3 groups. Group A: mononuclear cell was culture with normal sal ine as control; group B: mononuclear cell was cultured with CoCl2 solution; group C: mononuclear cell was cultured with CrCl3 solution. The production of TNF-α was assessed by ELISA, the activation of Caspase-3 was measured by colorimetric assay and the apoptotic cell was detected by TUNEL assays at 12, 24 and 48 hours after co-cultured respectively. Results The concentration of TNF-α and the expression of Caspase-3 in groups B and C were higher than those in group A (P lt; 0.05), and reached the peak level at 24, 48 hours, respetively. The TUNEL positive cells were detected in the all groups, nucleus was pyknotic and darker-staining, cell body was crinkle and cell membrane was integrity. There were significant differences in the apoptosis rate between groups B, C and group A (P lt; 0.05). And the activation of Caspase-3 increased and had the positive correlation with the apoptosis rate (r=0.765). Conclusion Co2+ and Cr3+ ions can stimulate human mononuclear cell to release TNF-α and induce human mononuclear cell apoptosis, which result in periprosethetic osteolysis and related to activation of Caspase-3.
Objective To compare the outcomes between intramedullary nail change and augmentation plating with a retained intramedullary nail for aseptic nonunion of femoral shaft fractures after femoral nailing, and to analyze the cause so as to guide the clinical application. Methods Between June 2001 and June 2011, 28 patients with aseptic nonunion of femoral shaft fractures after femoral nailing were treated with intramedullary nail change (11 patients, group A) and augmentation plating with a retained intramedullary nail (17 patients, group B), and the clinical data were analyzed retrospectively. There was no significant difference in age, gender, smoking, location of fracture, Association for the Study of Internal Fixation (AO/ASIF) classification, type of injury, associated injury, type of nonunion, and time of nonunion between 2 groups (P gt; 0.05). The patients were followed up by imaging and the clinical function at regular intervals to observe the callus growth and the recovery condition of the affected limb function, and clinical curative effectiveness was evaluated by Tohner-Wrnch standard. Results The operation time, intraoperative bleeding volume, and intraoperative erythrocyte-transported volume in group A were significantly higher than those in group B (P lt; 0.05). There was no significant difference in postoperative drainage volume and hospitalization days between 2 groups (P gt; 0.05). All the incisions healed by first intention, and no nerve and blood vessel injury occurred. All patients were followed up 18.6 months on average (range, 12-36 months). All cases obtained bone union, and time of clinical and radiological bone healing in group B was significantly shorter than those in group A (P lt; 0.05). During follow-up, no following complication occurred: deep incision infection, injuries of blood vessels and nerves, loosening and breakage of internal fixation, loss of reduction, angulated and rotational malunion. According to Tohner-Wrnch standard at last follow-up, the results were excellent in 6 cases, good in 3 cases, and poor in 2 cases, with an excellent and good rate of 81.8% in group A; the results were excellent in 12 cases, good in 5 cases, with an excellent and good rate of 100% in group B; and difference was significant between 2 groups (Z= — 2.623, P=0.021). Conclusion Augmentation plating with a retained intramedullary nail is an ideal treatment for aseptic nonunion of femoral shaft fractures after femoral nailing and can achieve satisfactory clinical outcomes because it has simpler operation, shorter operation time, less blood loss, and less trauma than intramedullary nail change.
ObjectiveTo investigate the expression changes of the receptor activator of nuclear factor-κB ligand (RANKL) in the peripheral blood of patients with aseptic loosening of the implant after total hip arthroplasty (THA) by comparing with that of patients with femoral neck fracture and to analyze the correlation between RANKL expression and aseptic loosening. MethodsBetween January 2008 and January 2013,the peripheral blood were harvested from 58 patients with aseptic loosening of the implant after THA (trial group) and 63 patients with femoral neck fracture (control group).The 2 groups were well matched,with no significant differences in age and gender (P>0.05).The expressions of the RANKL mRNA and RANKL protein were evaluated by quantitative real-time PCR and Western blot respectively.At the same time,the concentration of RANKL was also measured by ELISA. ResultsThe expression of the RANKL mRNA in the trial group was 18.30±1.09,which was significantly higher than that of control group (1.00±0.05)(t=125.390,P=0.000).The relative RANKL protein expression values in trial group and control group were 0.856±0.254 and 0.404±0.102 respectively,showing significant difference (t=13.032,P=0.000).The results of ELISA showed that the concentration of RANKL in trial group [(3.553 5±0.129 7) ng/mL] was significantly higher than that of control group [(1.912 3±0.126 2) ng/mL] (t=18.124,P=0.000). ConclusionThe high RANKL expression in peripheral blood is probably correlated with aseptic loosening of the implant in patients undergoing THA,which possibly is the prognostic factor of aseptic loosening of the implant.
To observe the effect of different dosage of curcumin on expression of MMP-2 and MMP-9 in the tissue of cystiform in air-pouch mouse models after the injection of polyethylene wear particles, and to investigate its mechanism of intervening inflammatory response induced by wear particles. Methods Seventy-two kunming strain mice were used to establ ish air-pouch animal models by referring to the method of Yang et al. and injecting 3 mL suspension of ultrahigh molecular weight polyethylene wear particles (concentration 1 × 108 cells/mL) into dorsal cyst cavity. Then the animals were randomized into 3 groups (n=24 per group): group A (control group), 0.6 mL/day normal sal ine by gavage; group B(low-dosage experimental group), 0.6 mL/day curcumin solution at a concentration of 1.6 mg/mL by gavage; group C (highdosage experimental group), 0.6 mL/day curcumin solution at a concentration of 3.2 mg/mL by gavage. General condition of the animals was observed after operation. The mice were killed 3, 7 and 14 days after operation (8 mice per group at a time), the tissue of cystiform was harvested to receive gross, histology and immunohistochemistry observation, as well as RT-PCR and Western blot detection. Results All mice survived till the end of experiment. White cystiform tissue was evident on the back of mice subcutaneously in each group. For diameter of the cyst cavity at each time point, group A was obviously greater than groups B and C, and group C was significantly less than group B. Microscope observation showed that inflammatory response in group A was ber than that of groups B and C, and group C was obviously less than group B at 7 and 14 days. There was a significant difference between groups B and C and group A in terms of MMP-2 and MMP-9 expression at 7 and 14 days after curcumin del ivery (P lt; 0.05), and no significant differences were evident at 3 days (P gt; 0.05). There was no significant difference between group B and group C in MMP-2 expression at 7 days after curcumin del ivery (P gt; 0.05), and significant difference was evident at 14 days (P lt; 0.05). There was significant difference bewteen group B and group C in MMP-9 expression at 7 and 14 days after curcumin del ivery (P lt; 0.05). Nuclear translocation of NF-κB P65 was inhibited remarkably after curcumin del ivery,and there were significant differences among three groups at 7 and 14 days (P lt; 0.05), and no significant differences were evident at 3 days (P gt; 0.05). Conclusion Ultra-high molecular weight polyethylene wear particles can stimulate expression of MMP-2 and MMP-9 in cystiform tissue. Curcumin can restrain expression of MMP-2 and MMP-9 in cystiform tissue of air-pouch animal models, and expression of MMP-2 and MMP-9 may be regulated by the activation of NF-κB.
Objective To explore the effectiveness of additional anti-rotation steel plate assisted intramedullary nail technology in treatment of aseptic femoral non-union patients. Methods A retrospective analysis was conducted on 21 patients with aseptic femoral non-union who admitted between September 2020 and October 2024 and treated with additional anti-rotation steel plate assisted intramedullary nail technology. There were 17 males and 4 females, aged 25-67 years (mean, 44 years). There were 19 cases of femoral anterograde intramedullary nail fixation, 1 case of femoral retrograde intramedullary nail fixation, and 1 case of steel plate fixation with fatigue fracture. There were 9 cases of hypertrophic non-union and 12 cases of atrophic non-union. All patients had varying degrees of fracture end atrophy/sclerosis. Among them, 20 patients who were fixed with intramedullary nails underwent removal of soft tissue and hardened bone at the fracture end, and cortical treatment resulted in the appearance of “chili sign” at the fracture end. Iliac bone grafting and anti-rotation steel plate fixation were performed. One patient with steel plate fixation was removed the steel palte and fixed with a retrograde intramedullary nail, while the hardened bone at the fracture end was removed, iliac bone grafting and anti-rotation steel plate fixation were performed. Postoperative follow-up observation included the incision healing, maximum knee flexion range of motion, bone healing, length of lower limbs, and subjective satisfaction. The lower extremity functional scale (LEFS) score was used to evaluate the lower limb function. Results All incisions healed by first intention. All patients were followed up 7-26 months (mean, 15.5 months). At last follow-up, the femoral fracture healed with the obvious callus formation at the fracture end; the maximum knee flexion range of motion was 95°-127° (mean, 112.67°). The LEFS score increased from 29.9±6.7 before operation to 75.9±3.0 at last follow-up, and the difference was significant (t=−29.622, P<0.001). Except for 1 patient who underwent intramedullary nail dynamic treatment before operation and had a lower limb shortening of about 0.9 cm, the other patients had bilateral lower limbs of equal length. All patients had no postoperative infections, mal-union of fractures, deep vein thrombosis, joint stiffness, or other complications. Conclusion The use of additional anti-rotation steel plate assisted intramedullary nail technology in the treatment of aseptic femoral non-union not only overcomes the drawbacks of insufficient stability at the fracture end of intramedullary nails, but also overcomes the shortcomings of biased fixation with steel plates. It has the advantages of minimal trauma, effective maintenance of fracture stability, and ideal postoperative functional recovery, making it an effective treatment for aseptic femoral non-union.