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 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 Lots of metal ions accumulation and over-expression of receptor activator of NF-κB l igand (RANKL) around the prosthesis could be found in revision of total hip arthroplasty. To investigate the relationship between metal ions and aseptic loosening by observing the effects of Co2+ and Cr3+ ions on the expression of RANKL and osteoprotegerin(OPG) from osteoblast. Methods Osteoblasts were cultured in vitro at the density of 1 × 105 cells/mL, and were divided into 2 groups according to different culture solutions. In control group, osteoblasts were cultured with normal medium without CoCl2 and CrCl3. In experimental group, osteoblasts were cultured with the medium including CoCl2 (10 mg/ L) and CrCl3 (150 mg/L) solutions. The RT-PCR and ELISA methods were appl ied to detect the mRNA expression of RANKL and OPG and protein level at 24 and 48 hours after co-cultured, respectively. Results RT-PCR revealed that the mRNA expression of RANKL and OPG could be found in two groups at 24 and 48 hours after co-cultured, the expression was higher in the experimental group than in control group, especially the expression of RANKL, showing significant difference (P lt; 0.05). At 24 and 48 hours after co- cultured, the ratios of RANKL mRNA to OPG mRNA in the experimental group were 0.860 and 1.232, respectively, which were significantly higher than those in the control group (0.695 and 0.688,P lt; 0.05). ELISA revealed that the protein level of RANKL and OPG in experimental group were significantly higher than those in the control group (P lt; 0.05). Conclusion Co2+ and Cr3+ can stimulate the mRNA expressions of RANKL, OPG and secretion of those protein from osteoblasts, especially increase of the RANKL, which promotes the formation and activation of osteoblasts and the generation of aseptic loosening.
Objective To investigate the effectiveness of acetabular revision using jumbo cementless cups. Methods Between May 1996 and May 2011, 35 patients (35 hips) underwent an acetabular revision with jumbo cementless cups, and the clinical data were retrospectively analyzed. There were 12 males and 23 females, with an average age of 64.8 years (range, 47-79 years). The time from hip arthroplaty to revision was 1-15 years (mean, 9.7 years). The causes for revision were aseptic loosening in 32 cases, femoral periprosthetic fracture (Vancouver type B3) in 2 cases, and low toxicity infection in 1 case. According to the classification of acetabular bony deficiencies of the American Association of Orthopedic Surgeon (AAOS), 6 cases were classified as type I, 9 cases as type II, and 20 cases as type III; according to the classification proposed by Paprosky, 5 cases were rated as type II A, 9 cases as type II B, 13 cases as type II C, and 8 cases as type III A. The primary hip arthroplasty cups had an outside diameter of 46-52 mm (mean, 49.6 mm), and the revision cups had an outside diameter of 56-68 mm (mean, 60.4 mm). Harris score was used for hip function evaluation, and X-ray films were taken for imaging evaluation. Results Healing of incision by first intention was obtained in all patients; without infection or neurovascular injury. Prosthetic dislocation was observed in 1 case at 20 days after operation, and was cured after expectant treatment. One patient died at 6 years after operation, and the other 34 patients were followed up 2-14 years (mean, 8.4 years). The Harris score was significantly increased from 46.4 ± 13.4 at preoperation to 90.4 ± 3.6 at last follow-up (t=18.76, P=0.00). The distance between acetabular rotation centre and teardrop line was significantly decreased, and the distance between acetabular rotation centre and lateral teardrop was significantly increased when compared with preoperative ones (P lt; 0.05). Only 1 patient received second revision for aseptic loosening after 10 years; no continuous radiolucent line, prosthetic dislocation, and osteolysis was found, and bony ingrowth was shown in the other patients. Conclusion Jumbo cementless cup for acetabular revision can achieve good effectiveness for having the advantages of simple operation, less bone grafts, and good recovery of the acetabular rotation centre.
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.
ObjectiveTo observe the vascularity in periprosthetic tissues of aseptic loosening after total hip arthroplasty (THA) and to explore the relationship between expression of vascularity and osteolysis. MethodsBetween October 2009 and June 2012, interface tissues were obtained from 22 patients (22 hips) who underwent revision of THA because of prosthetic aseptic loosening, including 12 males and 10 females with the age range of 53-81 years and prosthesis survival range of 6-14 years. The interface tissues were divided into osteolysis group and non-osteolysis group based on preoperative X-ray findings and intraoperative observation. The synovial tissues were harvested from another 8 patients (3 males and 5 females, aged 58-72 years) with osteoarthritis undergoing THA as control group. HE stainging was used to observe the histological character, and low-wear or high-wear was identified according to metal or polyethylene particles amount in osteolysis group. The CD34 immunohistochemical staining was used to mark the blood vessels. Microvessel density and microvessel index were calculated with the use of image analysis software. ResultsHistological observation showed that wear particles and numerous macrophages/multinucleated giant cells accumulated in the membrane of osteolysis group, while many fibroblasts and synovial cells existed in non-osteolysis group. The microvessels density and microvessel index were significantly lower in non-osteolysis group than those in osteolysis group and control group (P＜0.05), and there was no significant difference in microvessel density and microvessel index between osteolysis group and control group (P>0.05). There were less microvessel density and microvessel index in heavy-loaded metal or polyethylene wear particles areas than those in low-loaded metal or polyethylene wear particles areas (P＜0.05), and there was no significant difference in microvessel index and microvessel index between low-wear group and high-wear group for either polyethylene or metal particles (P>0.05). ConclusionThe phagocytosis of macrophage in periprosthetic tissues need vicinal microvessels formation and blood supply to some extent. Vascular injury and decreased blood supply at the implant-bone interface seem to be one of the reasons for insufficient implant osseointegration and aseptic loosening.
To assess the rel iabil ity of diabetic cutaneous ulcer surface area (DCUSA) measurement usingdigital planimetry method (A) and transparency tracing method (B). Methods Images of diabetic cutaneous ulcers from35 inpatients with diabetic skin ulcers from September 2005 to April 2007 were taken by a digital camera once a week or twice a week over a period of 12 weeks, resulting in 305 photographs; the ulcers were traced on a grid with acetate wound tracings, simultaneously. A total of 305 pairs of DCUSA which were calculated respectively throughout digital camera combined with Image J medical imaging software and transparency tracing with grid sheet by two independent observers sequentially were obtained. The intraclass correlation coefficients (ICCs, one-way random effect model) was used as an indicator of chancecorrected agreement to estimate the relative rel iabil ity for the interobserver data. Multiple l inear regression analysis was also used to measure the relationship of these two methods. Results DCUSA obtained from method A and obtained from method B was (4.84 ± 7.73) cm2 and (5.03 ± 7.89) cm2, respectively; no significant difference was found (P gt; 0.05). ICCs was high (ICCs=0.949 for method B and 0.965 for method A), indicating that the relative rel iabil ity for the interobserver was excellent. The method A were highly correlated with measurements obtained from method B (r = 0.957, P lt; 0.05). Conclusion The digital planimetry method described in this study represents a simple, practical, without any wound damage and contamination, and inexpensive technique to accurately evaluate the areas of diabetic cutaneous ulcers. The photographic technique combined with Image J medical imaging software should be considered for wound measurement.
Objective Aseptic loosening of prosthesis is associated with peri prosthetical osteolysis caused by osteoclast activation. Receptor activator of nuclear factor kappa B (NF-κB) l igand (RANKL)/receptor activator of NF-κB (RANK) signalpathway is fundamental in osteoclast activation. To determine whether RANKL antibody can inhibit inflammatory osteolysis in a osteolysis model of mouse. Methods Sixty female BALB/c mice (aged 8-10 weeks, weighing 18-20 g) were selected. The skull bone piece was harvested from 20 mice as the donor of bone graft; the subcutaneous air pouches (2 cm × 2 cm) models were established on the back of the other 40 mice and the skull bone piece was inserted into the air pouches. The 40 mice were equally divided into groups A (negative control group), B (positive control group), C (low-dose RANKL antibody group), and D (high-dose RANKL antibody group). At 1 day after bone graft, 0.5 mL PBS was injected into the pouch of group A, 0.5 mL PBS containing titanium particle into groups B, C, and D. At 2 days before the titanium particle was injected, RANKL antibody (0.1 mL) were injected into the pouch of group C (50 μg/mL) and group D (500 μg/mL), respectively every day for 2 days, and 0.1 mL PBS into groups A and B. At 14 days after bone implantation, the pouchmembranes containing implanted bone were harvested for gross observation and histological analyse. Results All mice survived to the end of experiment, and incisions healed well. The gross observation showed that inflammatory responses, exudation, and vascular proliferation were obvious in group B, and were inconspicuous in groups A, C, and D. The histological analysis showed that significantly more infiltration of inflammatory cells, more obvious bone resorption, more bone collagen loss, and more positive staining area were observed in group B than in groups A, C, and D. There were significant differences in inflammatory cell number, pouch membrane thickness, bone collagen loss, and osteoclast content between group B and groups A, C, and D (P lt; 0.05). Conclusion RANKL antibody can directly blockRANKL/RANK signal pathway, which is an efficient therapy to inhibit bone absorption associated with implant wearing particles.