Advances on treatment of periprosthetic infection and antibiotic delivery system after total hip arthroplasty / 中国骨伤

Periprosthetic infection after hip replacement is a clinical catastrophic disease, which often leads to the failure of the prosthesis. It needs the combination of systemic antibiotics to cure the infection, which brings huge burden to doctors and patients. There are strict indications for debridement and one-stage revision of the prosthesis, and few cases meet the requirements. The second revision is still the gold standard for the treatment of periprosthetic infection. It is suitable for all infection conditions and has a high success rate. On the second phase of renovation, the antibiotic sustained release system plays a key role, and the carrier of antibiotic sustained-release system is the focus of current research, including classic bone cement and absorbable biomaterials. Bone cement has strong mechanical strength, but the antibiotic release shows a sharp decline trend; the absorbable biomaterials can continuously release antibiotics with high concentration, but the mechanical strength is poor, so it could not use alone. The combination of bone cement and absorbable biomaterials will be an ideal antibiotic carrier. PMMA is the most commonly used antibiotic carrier, but the antibiotic release concentration is decreased sharply after 24 hours. It will be difficult to control the infection and increase the risk of bacterial resistance if it is lower than the minimum inhibitory concentration. The biodegradable materials can release antibiotics completely, with long release time and high concentration, but low mechanical strength. Antibiotic spacer plays an important role in the control of infection. In the future, how to further extend the antibiotic release time of antibiotic sustained-release system, increase the amount of antibiotic release and maintain the mechanical strength of the material will be studied.

Procalcitonin as a sensitive index of chronic infection after artificial joint replacement:a retrospective analysis / 中国骨伤

OBJECTIVE@#To study the predictive value of procalcitonin as a serum biomarker in diagnosis of late periprosthetic joint infection(PJI) for providing theoretical reference basis for diagnosis of PJI.@*METHODS@#A total of 77 cases were retrospective included from January 2015 to December 2017 for revision of total hip arthroplasty and total knee arthroplasty, according to the diagnostic criteria of Musculoskeletal Infection Society(MISI). All cases were divided into infection group and non-infection group. Infection group included 21 cases, 7 cases for male and 14 cases for female, with an average age of (60.70±8.75) years old (ranged 43 to 75 years old). Non-infection group 56 included cases, 24 cases for male and 32 cases for female, with an average age (64.40±12.14) years old (ranged 43 to 85 years old). Concentration of preoperative serum procalcitonin was examined and the chi-square test was used to compare positive rate between the two groups.@*RESULTS@#Two cases in the infection group had positive serum procalcitonin, 0.06 ng/L and 0.10 ng/L respectively, with the positive rate of 9.52%; 4 cases in non-infected group had positive serum procalcitonin, 0.05 ng/L, 0.06 ng/L, 0.06 ng/L, 0.16 ng/L respectively, with the positive rate of 7.14%. No statistically significant difference was observed between the two groups (=0.662).@*CONCLUSIONS@#Most of PJI were low toxicity infection with little systemic inflammatory response, so the concentration of serum procalcitonin was normal or slightly higher level, had little clinical significance for diagnosis of PJI. But the cases of this retrospective study are not enough, more cases are needed for further study.

Experimental study of directional differentiation of bone mesenchymal stem cells (BMSCs) to osteoblasts guided by serum containing cistanche deserticola / 中国骨伤

<p><b>OBJECTIVE</b>To study directional differentiation of BMSCs guided by Desert living Cistanche (Herba Cistanches) which invigorates the kidney.</p><p><b>METHODS</b>Primary BMSCs were obtained by whole bone marrow culture and subcultured to the fourth generation by trypsin digestion, and than inoculated into two six-well plates at 5 x 10(6) cells per milliliter, all the plates were divided into three groups as blank group, Dexamethasone (DXM) group and Herba Cistanches group, three wells in each group, medium were changed at day 2. The blank group were changed with L-DMEM containing 10% FBS. The DXM group were changed with medium containing 10 mmol/L beta-sodium glycerophosphate, 0.1 micromol/L DXM and 50 mg/L vitamin C. The Herba Cistanches group were changed with medium containing 10% blood serum containing Herba Cistanches and L-DMEM. One of the six-well plates was stained by alkaline phosphatase (AKP) at the tenth day,the other one was stained by alizarin Bordeaux at the twentieth day.</p><p><b>RESULTS</b>At the tenth day DXM group and Herba Cistanches group were ALKP stained positive; from the 12th day,white calcium nodus could be seen at the surface of the wells; which alizarin stained positive by the twentyth day.</p><p><b>CONCLUSION</b>The medium containing Herba Cistanches can guide BMSCs to differentiate into osteoblast, which promises a favorable prospect for the treatment of osteoporosis and bone fracture disunion.</p>