Short‐term Follow‐up of Antibiotic‐loaded Articulating Cement Spacers in Two‐stage Revision of Infected Total Knee Arthroplasty: A Case Series

Objective

Infection of total knee arthroplasty (TKA) is a rare but devastating complication. Two‐stage revision is an effective treatment for late infected TKA. This study aimed to assess the short‐term results of two‐stage revision using articulating antibiotic‐loaded spacers.

Methods

Twenty‐five patients (10 men and 15 women) were diagnosed with late infections after TKA and treated with two‐stage revision from April 2006 to August 2010; 19 of these patients had TKA for osteoarthritis and 6 for rheumatoid arthritis. Median age was 64.9 (range, 56–83) years. In the first‐stage surgery, the prosthesis and all bone cement was removed. After thorough debridement, bone cement with vancomycin and tobramycin was put into a die cavity and made into temporary femoral and tibial spacers, respectively. In the cases of good knee range of motion, the temporary spacers were affixed to the bone surface using the same antibiotic bone cement. In the second surgery, gentamycin Refobacin Bone Cement with vancomycin was used to fix the prosthesis. After two‐stage revision, patients were followed up clinically and radiologically at 1, 3, and 6 months, and then annually. Knee Society Score (KSS), knee function score, knee pain score, and knee range of motion (ROM) were assessed.

Results

Among the group, all spacers were easily removed, and bone defect degree showed no obvious change compared with pre‐implant, 24 (96%) patients had been debrided once, and 1 patient had been debrided twice before reimplant prosthesis. Mean follow‐up was 64.2 (range, 52–89) months. There was no infection recurrence at final follow‐up. Compared with preoperative data, the KSS (66 [59, 71], 83 [80, 88] vs 46 [43, 57], P < 0.01), knee function score (43 [42, 49], 78 [73, 82] vs 32 [25, 37], P < 0.01), knee pain score (34 [33, 37], 42 [40, 45] vs 18 [16, 23], P < 0.01), and knee ROM (92° [86°, 96°], 94° [90°, 98°] vs 78° [67°, 86°], P < 0.01) were all improved during follow‐up and at final visit. Three patients experienced complications in the interval period: one case had knee dislocation, one had knee instability, and one had a chip in the femoral component of the spacer.

Conclusion

Using articulating antibiotic‐loaded spacers showed benefits for treating infected TKA in selected patients. No infection recurrence was observed during follow‐up.

     

Daptomycin‐Loaded Polymethylmethacrylate Bone Cement for Joint Arthroplasty Surgery

Antibiotic‐loaded acrylic bone cement has been frequently used as an infection prophylaxis or antibiotic‐loaded spacer in infected arthroplasty. In addition, daptomycin has been used recently against broad spectrum Gram‐positive organisms. The goal of this in vitro study is to investigate the bacteriacidal and mechanical properties of daptomycin‐incorporated polymethylmethacrylate (PMMA) bone cement and evaluate its feasibility for clinical use. Daptomycin (0.5, 1, or 2 g) was premixed with 40 g of PMMA bone cement powder before curing. The mechanical properties of the daptomycin‐loaded acrylic bone cement (DLABC) were estimated following standard guidance, and the release profile and kinetics of daptomycin from PMMA were analyzed. The antimicrobial efficacy of DLABC was determined with a zone of inhibition (ZOI) assay against Staphylococcus aureus, Staphylococcus epidermis, Enterococcus faecalis, and Enterococcus faecium, respectively. The results showed that the compressive strength, of PMMA bone cement, which was higher than 100 MPa in all groups, was sufficient according to ISO 5833 after incorporation of daptomycin. The encapsulated daptomycin was released for 2 weeks with a 9.59 ± 0.85%, 15.25 ± 0.69%, and 20.64 ± 20.33% released percentage on the first day in the low, mid, and high groups, respectively. According to the calculated release kinetics, incorporated daptomycin should be 3.3 times the original dose to double its release. Although all recipes of DLABC had a microbial inhibitory effect, the effect with a higher encapsulated amount of daptomycin was more significant. Therefore, we believe that daptomycin can be locally delivered from PMMA bone cement at the surgical site as a prophylactic or treatment for osteomyelitis against Gram‐positive organisms with intact cement function.     

Bone cement

The knowledge about the bone cement is of paramount importance to all Orthopaedic surgeons. Although the bone cement had been the gold standard in the field of joint replacement surgery, its use has somewhat decreased because of the advent of press-fit implants which encourages bone in growth. The shortcomings, side effects and toxicity of the bone cement are being addressed recently. More research is needed and continues in the field of nanoparticle additives, enhanced bone–cement interface etc.     

应用抗生素骨水泥植入技术治疗第一跖趾关节痛风石并骨缺损的短期疗效研究

目的 研究对比痛风石病灶清理联合抗生素骨水泥植入技术与常规手术清除病灶在痛风石病人中的短期疗效。方法 回顾性分析2020年5月至2023年5月内蒙古科技大学包头医学院第一附属医院手足踝外科收治的40例第一跖趾关节痛风石伴骨缺损病人的临床资料,按照手术方法的不同分为观察组和对照组,每组20例,均为男性,年龄为22~82岁。观察组采用痛风石病灶清理联合抗生素骨水泥植入治疗,对照组则采用清理病灶的常规手术。比较两组白细胞（WBC）、C反应蛋白（CRP）、红细胞沉降率（ESR）、住院时间、换药次数、创面完全愈合时间。观察并记录病人入院时和随访3个月时美国足踝外科医师协会（AOFAS）评分、疼痛视觉模拟量表（VAS）评分和血尿酸（sUA）值。结果 病人术后随访时间3个月,观察组所有病人伤口均完全愈合,对照组20例病人中有7例伤口迁延不愈。观察组住院时间、换药次数、创面完全愈合时间、WBC、CRP、ESR、术后VAS评分均明显低于对照组,差异有统计学意义（P＜0.05）。对照组术后3个月AOFAS评分低于观察组,差异有统计学意义（P＜0.05）。两组术后3个月sUA值的差异无统计学意义（P＞0.05）。结论 对于第一跖趾关节痛风石并骨缺损病人,应用痛风石病灶手术清除联合抗生素骨水泥植入技术具有缩短住院时间,降低感染率,减轻病人疼痛,术后早期功能恢复快等优势,可作为严重痛风石合并骨缺损的外科治疗方法,值得推广应用。     

Effect of Bone Cement Thickness on the Risk of Scalded Skin in Joint Surgery

Objective

Bone cement releases a large amount of heat as it polymerizes. Skin burns caused by discarded bone cement are not well understood during arthroplasty. It is important to study the correlates and mechanisms of scalding and to accurately evaluate the severity of burns to guide treatment decisions.

Methods

Standardized burns were created in eight anesthetized rabbits using different thicknesses of bone cement. Bone cement was uniformly stirred to make thicknesses of 1 mm, 4 mm, 8 mm, 12 mm, 16 mm, and 20 mm and a 20 × 40 mm cuboid. Bone cement samples were then placed on the back of a rabbit, and the temperature changes were recorded with an industrial digital thermometer. One hour later, the appearance of scalded skin was observed, and the rabbits were euthanized. The scalded parts were cut to make pathological sections and stained with HE, and the differences in the depth of the scalded skin caused by different thicknesses of bone cement were observed under a light microscope.

Results

Damage caused by 1 mm-, 4 mm-, 8 mm-, 12 mm-, 16 mm-, and 20 mm-thick bone cement samples mainly involved the epidermis, the papillary dermis, the reticular dermis layer, and the full thickness of the skin and the subcutaneous tissue. The maximum temperature of 1 mm, 4 mm, 8 mm, and 12 mm bone cementation had a statistically significant difference (p < 0.001), while there was no significant difference between 12 mm, 16 mm, and 20 mm samples (p = 0.856). The time to severe scalding with bone cement at temperatures above 70°C was significantly different between different thicknesses (p < 0.001).

Conclusion

The heat released by different thicknesses of bone cement leads to different maximum temperatures and the duration of severe burns, resulting in different degrees of skin burns. Attention should be paid to discarded bone cement to prevent this potential complication in knee arthroplasty.     

人工关节置换充填骨水泥对血液动力学的影响

目的观察人工关节置换术中充填骨水泥对血液动力学的影响。方法40例ASAⅡ～Ⅲ级行人工关节置换术的患者，观察骨水泥充填后10min内血液动力学的变化。结果充填骨水泥后10min内患者血液动力学都有显著变化（P〈0．05），个别患者血压下降严重。需升压药支持。结论人工关节置换术中充填骨水泥可致血液动力学严重波动，应引起重视。     

应用特殊髋臼钢板结合植骨技术治疗全髋翻修术中髋臼骨缺损

目的 探讨髋臼钢板结合植骨治疗髋臼骨缺损的临床效果.方法 应用髋臼钢板结合植骨治疗20例髋臼骨缺损髋臼骨缺损按AAOS分型,其中Ⅰ型2例,Ⅱ型4例,Ⅲ型14例.术前髋关节Harris评分平均37.6分,术后根据临床及X线进行评估.结果 所有患者均采用该方法重建髋臼,术后髋部顽固性疼痛1例,原因可能是髋臼周缘发生异位骨化.经服用强效止痛药物1年后好转.其余病例无并发症,平均随访3年,Harris评分平均86.4分.X线片示无一例患者的髋臼骨床、移植骨、重建钛板和聚乙烯内衬交界面出现透亮带.结论 髋臼钢板结合植骨可为假体提供坚强的初始固定,具有恢复髋关节旋转中心的作用.可有效修复髋臼骨缺损.     

人工关节置换术后并发应激性溃疡大出血(附2例报告及文献复习)

目的：探讨人工关节置换术后并发应激性溃疡大出血的预防及治疗经验。方法：1997年9月－2001年9月行人工关节置换术589例，对术后出现应激性溃疡大出血的2例临床资料进行回顾性分析并复习相关文献。结果：本组患者合并有高血压，长期服用激素和非甾体类消炎药物（NSAIDs)，1例患者抗凝治疗，人工关节置换术后并发应激性溃疡大出血的发生率为0．34％，临床表现为排柏油样大便，呕血、低血容量休克、贫血，急诊胃镜显示胃十二指肠粘膜糜烂，弥散性出血，结论：人工关节置换术后并发应激性溃疡大出血是一种严重的并发症，治疗在于有效控制出血，补充血容量，同时注意对重要脏器的保护，非手术治疗无效时，应外科手术治疗。对长期服用容易引起胃粘膜损害药物的患者，围手术期应使用抑制胃酸分泌的药物，预防应激性溃疡的发生。     

硅胶薄膜囊预防椎体后凸成形术中骨水泥渗漏的实验研究

目的探讨硅胶薄膜囊预防椎体后凸成形术中骨水泥渗漏的可能性和有效性。方法取6具甲醛固定的老年女性脊柱标本(T12～L5)制成36个单椎体,刮匙在椎体前3/4制成体积约为6ml单侧或双侧空腔,分别直接注入骨水泥和先置入壁厚100μm、200μm的硅胶薄膜囊后再注入骨水泥。结果壁厚100μm的硅胶薄膜囊包裹骨水泥可控制骨水泥在椎体内的分布,和直接注入骨水泥一样能较好地嵌入到周围骨小梁内,不形成界面。而壁厚200μm的硅胶囊虽能控制骨水泥在椎体内分布,但会在骨小梁间形成界面。结论球囊扩张椎体后凸成形术中置入壁厚100μm的硅胶薄膜囊包裹骨水泥可控制椎体内骨水泥分布,并能嵌入到骨小梁间隙,不形成界面,有效预防球囊扩张椎体后凸成形术并发症的出现。     

Analysis of the Effect of Antibiotic Bone Cement in the Treatment of Diabetic Foot Ulcer through Tibia Transverse Transport

ObjectiveTo explore the efficacy of antibiotic bone cement (ABC) combined with the modified tibial transverse transport (mTTT) on the treatment of severe diabetic foot with infection.MethodsA retrospective cohort study was conducted of 243 patients with TEXAS grade 3/4 stage D diabetic foot ulcers from December 2016 to December 2019. A total of 115 patients treated with mTTT were classified as the mTTT group (78 male and 37 female, mean age: 70.4 ± 6 years) and 128 patients who were treated with ABC combined with mTTT were in the ABC + mTTT group (89 male and 39 female, mean age: 68.9 ± 8 years). Follow‐up records during treatment and 6 months after surgery were collected, including the time required for white blood cells (WBC) and C‐reactive protein (CRP) to return to normal range, wound healing time, pain visual analog scale (VAS), ankle‐brachial index (ABI), foot skin temperature, transcutaneous oxygen pressure measurement (TcPO₂), complications, and other indicators. Normally distributed data were compared using the independent sample t‐test, non‐normally distributed data were analyzed by one‐way ANOVA analysis of variance.ResultsThere were 128 cases in the ABC + mTTT group (89 male and 39 female, mean age: 68.9 ± 8 years) treated with ABC and mTTT, and 115 cases in the TTT group (78 male and 37 female, mean age: 70.4 ± 6 years) treated with mTTT alone. The time required for WBC and CRP to return to the normal range and wound healing time in the ABC + mTTT group were significantly shorter than those in the mTTT group (12.9 ± 4.6 vs. 22.6 ± 1.6 days, t = 3.979, p < 0.001; 25.3 ± 1.3 vs. 31.3 ± 2.3 days, t = 4.261, p = 0.001; 11.9 ± 3.8 vs. 15.9 ± 3.9 days, t = 4.539, p < 0.001). There were no significant intergroup differences in the foot skin temperature, VAS score, ABI, and TcPO₂ (t = 0.349, 0.542, 0.765, 0.693 while all p > 0.05).ConclusionAlthough the application of ABC with mTTT for treatment of diabetic foot ulcers did not affect the wound healing time and ankle blood supply in the mid‐term, it could control ulcer infection faster and accelerate wound healing.     

Bioactivity of Ceftazidime and Fluconazole Included in Polymethyl Methacrylate Bone Cement for Use in Arthroplasty

Background

The microorganisms that most frequently cause prosthetic joint infection are methicillin-resistant Staphylococcus aureus and gram-negative aerobic bacillus. Studies have documented the efficacy of mixing antibiotics with polymethyl methacrylate, but that of antifungal drugs has not received much attention. The objective of this in vitro study was to characterize the elution profile and bioactivity of ceftazidime and fluconazole when incorporated into bone cement in proportions intended for prophylaxis and treatment of bone infections.

Effect of Antibiotic-Impregnated Bone Cement in Primary Total Knee Arthroplasty

BackgroundThe purpose of this study is to evaluate the effect of commercially available antibiotic-impregnated bone cement (AIBC) on (1) prosthetic joint infections (PJIs) and (2) surgical site infections (SSIs) after primary total knee arthroplasty (TKA).MethodsA review of primary TKAs between 2014 and 2017 from an institutional database was conducted. This identified 12,541 cases which were separated into AIBC (n = 4337) and non-AIBC (8,164) cohorts. Medical records were reviewed for PJIs and SSIs (mean 2-year postoperative period). Infection rates between the cohorts were compared with univariate analyses followed by subanalysis of high risk patients (defined as having 2 or more of the following characteristics: >65 years, body mass index >40, or Charlson Comorbidity Index score >3). To control for confounders, multivariate analyses were performed with regression models adjusted for age, gender, body mass index, comorbidities, year, operative times, and lengths of stay.ResultsOn univariate analysis, PJI rates were higher in the AIBC cohort (1.0%) compared to the non-AIBC cohort (0.5%, P < .001). Subanalysis of the high risk patients also showed that PJI rates were higher in the AIBC cohort (1.9% vs 0.6%, P < .01). After adjusting for potential confounders, no significant associations between PJIs and AIBC use were found (odds ratio 1.4, 95% confidence interval 0.9-2.3, P = .133). Similarly, no significant differences in SSI rates were observed between the AIBC (2.9%) and non-AIBC cohorts (2.4%, P = .060) and no significant associations between SSIs and AIBC were found with multivariate analysis (odds ratio 1.0, 95% confidence interval CI 0.8-1.3, P = .948).ConclusionThis study found that there was no clinically or statistically significant decrease in infection rates with AIBC in primary TKAs.     

Quantification of the Effect of Vertical Bone Resection of the Medial Proximal Tibia for Achieving Soft Tissue Balancing in Total Knee Arthroplasty

Background

Degenerative osteoarthritis of the knee usually shows arthritic change in the medial tibiofemoral joint with severe varus deformity. In total knee arthroplasty (TKA), the medial release technique is often used for achieving mediolateral balancing. But, in a more severe varus knee, there are more difficult technical problems. Bony resection of the medial proximal tibia (MPT) as an alternative technique for achieving soft tissue balancing was assessed in terms of its effectiveness and possibility of quantification.

Methods

TKAs were performed in 78 knees (60 patients) with vertical bone resection of the MPT for soft tissue balancing from September 2011 to March 2013. During operation, the medial and lateral gaps were measured before and after the bony resection technique. First, the correlation between the measured thickness of the resected bone and the change in medial and lateral gaps was analyzed. Second, the possibility of quantification of each parameter was evaluated by linear regression and the coefficient ratio was obtained.

Results

A significant correlation was identified between alteration in the medial gap change in extension and the measured thickness of the vertically resected MPT (r = 0.695, p = 0.000). In the medial gap change in flexion, there was no statistical significance (r = 0.214, p = 0.059). When the MPT was resected at an average thickness of 8.25 ± 1.92 mm, the medial gap in extension was increased by 2.94 ± 0.87 mm. In simple linear regression, it was predictable that MPT resection at a thickness of 2.80 mm was required to increase the medial gap by 1.00 mm in knee extension.

Conclusions

The method of bone resection of the MPT can be considered effective with a predictable result for achieving soft tissue balancing in terms of quantification during TKA.     

The effects of clindamycin on human osteoblasts in vitro

Introduction Clindamycin is an antibiotic frequently used in different local application forms for the treatment of prosthetic joint infections, chronic osteomyelitis or as infection prophylaxis in bone cement. No information is available regarding its direct effects on bone cells, although very high local effective antibiotic concentrations can be achieved. Materials and methods We cultured pooled osteoblasts, previously derived from human trabecular bone specimens of four healthy donors, with different concentrations of clindamycin (0–500 μg/ml) for 24, 48 and 72 h. Cell proliferation (MTT), cytotoxicity [lactate dehydrogenase (LDH)-activity], cell metabolism [alkaline phosphatase (ALP)-activity] and extracellular matrix calcification (Alizarin staining) were assessed after antibiotic treatment. Results Proliferation significantly decreased in a dose-dependent manner and reached 3.5% of control samples at 500 μg/ml at 72 h. LDH-activity was unaffected at lower concentrations but significantly increased at 500 μg/ml at 48 and 72 h. ALP-activity significantly increased at 10 μg/ml at 24 and 48 h and then decreased in a time- and dose-dependent manner. Calcification increased at 10 and 25 μg/ml, while it decreased or no calcification was found at concentrations of 50 μg/ml and above. Conclusion We could demonstrate that clindamycin at lower concentrations stimulated the cell metabolism of human osteoblasts and that higher clindamycin levels of 500 μg/ml had cytotoxic effects. The observed effects of high clindamycin levels on human osteoblasts highlight a potential alteration of bone metabolism in vivo and have to be taken into account in local antibiotic administration, e.g., in clindamycin-impregnated bone cement, where such high antibiotic concentrations can be achieved.     

Combined Wear Behavior and Long‐Term Implant‐Bone Fixation of Total Knee Replacement: A Novel In Vitro Set‐up

The success of a total knee replacement (TKR) strongly depends on the prosthetic design; this includes on one hand the best choice of the bearing materials to minimize wear, on the other hand a good orientation of the prosthetic components with respect to the loading directions. The aim of this study was to investigate the feasibility of a new experimental setup combining two fundamental aspects for the long‐term success of knee implants: wear and micromotions. A novel procedure was used to simulate working conditions as close as possible to in vivo ones and to measure implant‐bone micromotion, by means of fixing the femoral component of the prosthesis to the distal part of a synthetic femur to be tested through a knee simulator. Gravimetric wear of the tibial specimens was assessed at regular intervals. Implant‐bone inducible micromotions and permanent migrations were measured at three locations throughout the test. Wear patterns on tibial specimens were characterized through a standardized protocol based on digital image analysis; fatigue damage in the cement was quantified. Some initial conditioning was noticed both in the wear process and microcracking distribution within the cement mantle. Similarity in wear tracks observed on tibial inserts and other retrieval studies, coupled with clinically consistent migration patterns for TKR, supports the efficacy of the new in vitro method presented.     

Bone Morphogenetic Protein‐2 and Vascular Endothelial Growth Factor in Bone Tissue Regeneration: New Insight and Perspectives

The study of bone tissue regeneration in orthopaedic diseases has stimulated great interest among bone tissue engineering specialists and orthopaedic surgeons. Combinations of biomaterials, growth factors and stem cells for repairing bone have been much studied and researched, yet remain a challenge for both scientists and clinicians pursuing regenerative medicine. The purpose of this review was to elucidate the role of sequential release of bone morphogenetic protein‐2 and vascular endothelial growth factor in producing better outcomes in the field of bone tissue regeneration.