羟基磷灰石涂层人工髋关节应用于中青年患者的临床观察

目的：观察羟基磷灰石涂层人工髋关节应用于中青年患者的临床效果。方法：对61例64个髋使用同一种羟基磷灰石涂层人工髋关节假体的中青年患者进行临床和放射线随访观察。随访时间为24～59个月(平均40个月)。结果：最后一次随访时，病人术髋的关节功能评估均为优良，平均Harri评分93分。股骨髓腔内骨化的发生率为89％；股骨柄及髋臼骨假体界面的评估均为骨性稳定。结论：羟基磷灰石涂层的人工髋关节应用于中青年患者取得了满意的短期疗效。     

高龄患者使用羟基磷灰石广泛涂层股骨假体的中期随访

目的评价以羟基磷灰石(HA)广泛涂层假体进行初次人工髋关节置换的中期效果。方法1997年2月～1999年5月,对96例以HA广泛涂层股骨假体的初次置换患者进行临床和放射学随访研究,主要评价Harris评分、大腿疼痛和并发症,以Kaplan-Meier法评价股骨假体的使用寿命。结果60例患者获得平均8年(7～9年)随访,Harris评分从术前的平均42分提高到术后的90分,仅2例大腿疼痛。无其它并发症发生,未见假体柄周围放射学透亮线,所有假体均获得骨性稳定,并出现重新塑型。假体8年生存率达100%。结论HA广泛涂层股骨假体具有骨传导作用,可抗轴向力和抗扭转力,且手术风险低,能够获得较好的同定。     

骨水泥与非骨水泥股骨柄在初次全髋关节置换术后疗效的Meta分析

目的：系统评价骨水泥与非骨水泥股骨柄在初次全髋关节置换术后的疗效。方法计算机检索PubMed、EMBASE、OVID、Highwire、SpringerLink、ScienceDirect、Cochrane 图书馆、中国知网、中国生物医学文献数据库文献及手工检索相关文献,收集有关骨水泥与非骨水泥股骨柄在初次全髋关节置换术的随机对照试验,根据考克兰协作组织标准评价纳入试验质量,用Revman5.2软件进行Meta分析。结果纳入11篇文献,共1651例患者,骨水泥髋801例、非骨水泥髋850例。 Meta分析结果示：不限年龄和随访年限,术后翻修率骨水泥固定和非骨水泥固定差异无统计学意义[ OR＝3.20,95％CI （0.72,14.22）, P＞0.05],5年以内随访术后翻修率两种固定方式差异无统计学意义[OR＝0.41,95％CI （0.15,1.16）, P＞0.05],5年以上随访术后翻修率骨水泥固定较非水泥固定股骨柄高,差异有统计学意义[OR＝5.92,95％CI （2.68,13.07）, P＜0.01],术后大腿痛发生率骨水泥固定较非骨水泥固定低,差异有统计学意义[OR＝0.51,95％CI （0.28,0.94）, P＜0.05],术后Harris评分[MD ＝0.6,95％CI （-0.79,1.99）, P＞0.05],松动率[OR ＝1.31,95％CI （0.27,6.30）, P＞0.05]、骨折发生率[OR＝0.91,95％CI （0.3,2.7）, P＞0.05]、感染率[OR＝2.46,95％CI （0.7,8.58）, P＞0.05]、异位骨化发生率[OR＝0.91,95％CI （0.63,1.33）, P＞0.05]和脱位率[OR＝3.11,95％CI （0.6,16.10）, P＞0.05]二者差异无统计学差异。结论骨水泥与非骨水泥固定股骨柄在初次全髋关节置换术后均有满意的效果,非骨水泥固定股骨柄5年以上稳定性较骨水泥好,但术后大腿痛的发生率较骨水泥固定柄高。     

羟基磷灰石涂层假体全髋置换术的早期疗效分析

背景：目前,在全髋置换术中,羟基磷灰石涂层人工股骨柄假体的疗效是否优于非涂层假体仍存在争论。目的：探讨采用羟基磷灰石涂层假体行全髋置换术的早期疗效。方法：2007年2月至2010年3月采用羟基磷灰石涂层假体全髋置换术300例,男157例,女143例;年龄34~73岁,平均67.1岁。分别于术后1、3、6个月、1年及之后的每年随访。术前、术后随访拍摄髋关节正侧位X线片并采用Gruen分区评价羟基磷灰石涂层股骨柄假体,采用DeLee和Charnley建议的三区间对髋臼假体进行影像学评估,对髋关节疼痛及其他髋关节功能参数采用Harris评分复查。记录患者术中、术后并发症发生率。结果：本组11例失去随访,其余289例患者随访12~48个月,平均37个月。末次随访时髋关节Harris评分89~99分,平均95.3分。6例（2.07%）患者术中扩髓时股骨干近段出现不完全性骨裂缝,5例（1.73%）术后出现髋关节脱位,2例（0.69%）出现异位骨化（BrookerⅠ级1例,Ⅱ级1例）,4例（1.38%）术后出现跛行。股骨柄内翻或外翻角均在5°范围以内,术后第6个月超过50%的羟基磷灰石涂层股骨柄假体周围可见骨内生长,术后2年90%羟基磷灰石涂层假体周围可见明显的骨生长。术后2年复查髋关节X线片示羟基磷灰石涂层假体下沉小于1mm者5髋（1.73%）,之后随访未再发现任何假体下沉。术后第3~6个月Gruen1、2、6、7区间羟基磷灰石涂层部位可见典型的点接合,网状骨质浓缩以及皮质骨骨密度增高影像。臼杯假体倾斜角在35°~55°,术后第6个月,在I区或Ⅲ区可见骨生长。依据Engh评判标准,无一例出现近端广泛性骨质溶解或末端骨质溶解及松动。结论：全髋置换术羟基磷灰石涂层能在假体与骨之间提供坚强的内固定,具有骨整合作用强、生物相容性及生物活性高、术后并发症少、抗骨质溶解等优点,但其远期疗效仍需进一步观察。     

Zweymüller非骨水泥型全髋关节置换术后5～11年随访研究

目的 评估Zweymüller非骨水泥型全髋关节置换术后5～11年疗效.方法 对1996至2002年由同一术者完成且应用Zweymüller假体的初次全髋关节置换术患者进行随访,包括临床评估和放射学评估.结果 共116例142髋符合纳入标准,61例77髋获得随访,随访时间为5～11年,平均7.3年.其中50例64髋同时获临床及放射学评估,5例6髋只获得临床评估,6例7髋只获得放射学评估,随访率为52.6%.Harris评分由术前平均46分提高至末次随访时平均93分,51髋(72.9%)术后疼痛在1个月内缓解,术后扶拐行走时间平均为2个月.X线片随访见远端骨皮质肥厚30髋(42.3%),髓内骨化33髋(46.5%),异位骨化45髋(63.4%).无一例髋臼侧出现透亮带,27髋(38.0%)股骨侧可见透亮带.7髋(9.9%)髋臼侧出现骨溶解,18髋(25.4%)股骨侧出现骨溶解.虽然无已行翻修病例,但3髋因髋臼明显松动移位需行翻修术.以翻修手术或需行翻修手术作为失败的标准,髋臼杯5～11年假体存活率为95.8%,股骨柄的存活率为100%.结论 Zweymüller假体术后5～11年随访总体疗效令人满意,但骨溶解发生率高.     

羟基磷灰石涂层股骨柄假体全髋关节置换术的中期疗效

目的 评价羟基磷灰石涂层股骨柄假体伞髋关节置换术的中期疗效.方法 2000年2月至2001年2月,采用U2钛合金羟基磷灰石涂层股骨柄假体行非骨水泥全髋关节置换术65例(70髋),男20例,女45例;年龄40～82岁,平均63岁.术前诊断:股骨颈骨折30例,髋关节骨关节炎15例,股骨头缺血性坏死9例,人工股骨头术后松动8例,类风湿髋关节炎2例,髋关节融合术后1例.分别于术后1周、3个月、6个月随访,以后每年随访1次,对髋关节功能(Harris评分)和X线片进行复查.结果 4例死于癌症,余61例(66髋)获7～8年随访,平均7.5年.末次随访时髋关节Harris评分85～100分,平均96分.3髋(4.5%)出现轻度大腿痛,无一髋需行翻修术治疗.术后1年内假体下沉小于1.5 mm者7髋,此后未再出现假体下沉.术后3～6个月在Gruen 2区和6区近段羟基磷灰石涂层部位出现典型的骨锚固征及松质骨和皮质骨密度增高影像.此后所有患者包括年龄大于70岁和Dorr C型髓腔者均无柄端周围的骨质增生或"底座征",也尤股骨近段或远段髓内骨溶解及假体松动.按Engh标准评定全部患者均获骨性固定.结论 羟基磷灰石涂层能增强股骨柄假体的初始固定,促进早期骨长入和生物学固定,阻止聚乙烯磨屑的髓内迁移和远段髓内骨溶解,用于非骨水泥全髋置换术中期疗效满意.     

羟基磷灰石涂层股骨柄假体全髋关节置换术的中期疗效

目的 评价羟基磷灰石涂层股骨柄假体伞髋关节置换术的中期疗效.方法 2000年2月至2001年2月,采用U2钛合金羟基磷灰石涂层股骨柄假体行非骨水泥全髋关节置换术65例(70髋),男20例,女45例;年龄40～82岁,平均63岁.术前诊断:股骨颈骨折30例,髋关节骨关节炎15例,股骨头缺血性坏死9例,人工股骨头术后松动8例,类风湿髋关节炎2例,髋关节融合术后1例.分别于术后1周、3个月、6个月随访,以后每年随访1次,对髋关节功能(Harris评分)和X线片进行复查.结果 4例死于癌症,余61例(66髋)获7～8年随访,平均7.5年.末次随访时髋关节Harris评分85～100分,平均96分.3髋(4.5%)出现轻度大腿痛,无一髋需行翻修术治疗.术后1年内假体下沉小于1.5 mm者7髋,此后未再出现假体下沉.术后3～6个月在Gruen 2区和6区近段羟基磷灰石涂层部位出现典型的骨锚固征及松质骨和皮质骨密度增高影像.此后所有患者包括年龄大于70岁和Dorr C型髓腔者均无柄端周围的骨质增生或"底座征",也尤股骨近段或远段髓内骨溶解及假体松动.按Engh标准评定全部患者均获骨性固定.结论 羟基磷灰石涂层能增强股骨柄假体的初始固定,促进早期骨长入和生物学固定,阻止聚乙烯磨屑的髓内迁移和远段髓内骨溶解,用于非骨水泥全髋置换术中期疗效满意.     

258髋Corail股骨柄假体中期疗效观察

目的：探讨终末期髋关节疾病患者采用 Corail 羟基磷灰石(Hydroxyapatite,HA)全涂层股骨柄假体行全髋关节置换术(Total hip arthroplasty, THA)的中期疗效。方法：回顾性分析2011年 1 0月～2019 年 10月采用 Corail 假体行 THA 治疗 239例（258髋）髋关节终末期疾病患者的病例资料,其中男137例,女102例,年龄38~79岁,平均50.4岁。左髋117例,右髋141例。适应症包括股骨头缺血性坏死145髋（56.2%）,髋关节发育不良58髋（22.4%）,髋关节骨性关节炎36髋（14.0%）,股骨颈骨折11髋（4.3%）,类风湿关节炎8髋（3.1%）。采用 Harris 评分、疼痛视觉模拟评分（VAS）及临床并发症评估患者髋关节功能,随访X 片观察假体有无松动、螺钉有无断裂等。结果：所有患者均安全度过围手术期。术后1例患者出现肺部感染伴胸腔积液,术后6例患者术侧大腿出现了不同程度的疼痛,术后5例患者出现假体感染,术后6例患者出现脱位,术后7例患者出现小腿肌间静脉血栓,术后15例患者出现了假体下沉,未出现无菌性松动或神经血管损伤等并发症,无翻修患者,股骨柄存活率为100%。术后239例（258髋）均获随访,随访时间0.5~7年,平均5.8年,末次随访Harris评分（84.84±5.65）分、VAS评分（1.11±0.79）,所有的股骨柄都非常稳定,没有透亮线的迹象。结论：Corail HA 全涂层股骨柄假体具有持久的稳定性,术后大腿疼痛发生率较低等优点,中期疗效较好。     

微创与传统动力髋螺钉治疗老年股骨转子间骨折疗效比较的Meta分析

目的 应用Meta分析的方法评价微创与传统动力髋螺钉(DHS)治疗老年股骨转子间骨折疗效的差异.方法 计算机检索PubMed(1966年至2011年5月),EMBASE(1980年至2011年5月),Cochrane图书馆,中国期刊全文数据库(1994年至2011年5月)以及万方数据库(1993年至2011年5月),收集微创与传统DHS治疗老年股骨转子间骨折疗效比较的文献资料,比较两种方法的术后严重并发症的发生率、手术时间、手术前后血红蛋白差值、骨折愈合时间及术后髋关节Harris评分.利用RevMan5.0统计学软件进行异质性分析及Meta分析.结果 共纳入10篇微创与传统DHS治疗老年股骨转子间骨折疗效比较的文献,共769例患者.研究结果提示微创DHS组患者术后严重并发症发生率较传统DHS组低(RR=0.30,95％ CI 0.18 ～0.49,P＜0.001),手术时间较传统DHS组短(WMD=-21.47,95％ CI-31.95 ～-10.99,P＜0.001),手术前后血红蛋白差值较传统DHS组小(WMD=-1.44,95％ CI-1.98 ～-0.89,P＜0.001),骨折愈合时间较传统DHS组短(WMD=-0.74,95％ CI-1.16～-0.33,P＜0.00l),术后髋关节Harris评分较传统DHS组高(WMD=1.60,95％ CI0.68～2.53,P＜0.001).结论 与传统DHS比较,微创DHS治疗老年股骨转子间骨折具有手术时间短、术中出血量少、术后严重并发症少、骨折愈合快及术后髋关节功能恢复好等优点.     

全髋关节置换术使用羟基磷灰石涂层股骨柄假体的Meta分析

背景：越来越多的青壮年患者在接受全髋关节置换术（total hip arthroplasty,THA）中使用羟基磷灰石（hydroxyapatite,HA）涂层股骨柄假体,评价HA涂层多孔股骨柄假体的相关临床对照研究的报道并不完全一致,且样本量较少,存在一定局限性。目的：通过Meta分析评价THA使用HA涂层股骨柄假体的有效性及安全性。方法：计算机检索数据库Medline（1966年至2012年2月）、PubMed（1966年至2012年2月）、Embase（1966年至2012年2月）、Cochrane图书馆（2011年第4期）、中国生物医学光盘数据库（1978年至2012年2月）、中国生物医学文献数据库（1978年至2012年2月）和维普中文科技期刊数据库（1978年至2012年2月）,收集THA使用HA涂层股骨柄假体和多孔股骨柄假体的临床随机对照试验,提取数据进行分析,采用统计软件RevMan5.1进行Meta分析。结果：共纳入10个随机对照研究,其中试验组480例,对照组478例。Meta分析结果显示,与对照组相比,接受HA涂层股骨柄假体的患者THA术后Harris评分无统计学差异（均数差=1.49,95%置信区间[-2.32,5.31],P=0.44）,周围透光线的发生率无统计学差异（优势比=1.06,95%置信区间[0.76,1.48],P=0.74）,点焊现象发生率无统计学差异（优势比=1.09,95%置信区间[0.74,1.62],P=0.66）。结论：HA喷涂于股骨柄假体多孔表面,对于初次THA无临床益处。限于纳入文献的数量和质量,Meta分析结果尚有待于更多高质量大样本随机对照试验以予证实。     

Bone ingrowth into polymer coated porous synthetic coralline hydroxyapatite

Porous hydroxyapatite, converted hydrothermally from the calcium carbon exoskeleton of the coral genus Goniopora (CHAG), has been shown to be effective as a scaffold for bone ingrowth (2,3,5-7,9). However, the large pores in the material resulted in low compressive strengths. In a previous study, we found that microcoating the internal surfaces of CHAG with dilactic-polyactic acid (DL-PLA) improved significantly its compressive properties. The objective of this study was to determine the effect of PLA microcoating on bone ingrowth into CHAG plugs. Plugs of thick- (3:1 chloroform to DL-PLA by weight), medium- (10:1), and thin- (30:1) coated as well as uncoated CHAG were implanted transcortically in the proximal third of the diaphysis of the rabbit tibia. Specimens were harvested at 3, 12, and 24 weeks for mechanical testing and contralaterally for histological and histomorphometric assessment. At 12 weeks, uncoated CHAG plugs developed an average ultimate interface shear stress of 26.7 MPa, compared with 17 MPa for 30:1 and 8 MPa for 10:1 and 3:1 coated specimens. At 24 weeks, there were no significant differences in shear stress among any of the specimens. Histomorphometric assessments showed that the ratio of area fractions of new bone to area fractions of new bone and void space increased from 68-70% for 3:1 and 10:1 coated specimens at 3 weeks, and to 85.5-89.5% at 24 weeks. In comparison, uncoated and 30:1 specimens had area fraction ratios of about 82% at 3 weeks and 93% at 24 weeks. Histologic sections demonstrated direct apposition of new bone to both the coating and the hydroxyapatite as well as degradation of the coating.     

A randomized trial of hydroxyapatite coated prostheses in total hip arthroplasty

In a prospective randomized trial, 62 consecutive primary cementless total hip arthroplasties in 55 patients were performed by one surgeon using either hydroxyapatite coated (35 hips) or nonhydroxyapatite coated femoral prostheses (27 hips). The dual tapered femoral stem had a Ti-6AI-4V plasma sprayed circumferential proximal porous coat applied to the proximal 1/3 of the stem. The middle 1/3 had a roughened blasted textured surface, and the distal 1/3 had a smooth surface. The hydroxyapatite coated femoral stems had an additional hydroxyapatite coating applied to the proximal porous coat with use of an air plasma process. The patients in the two groups were not significantly different regarding age (48.2 +/- 9.0 years hydroxyapatite group, 50.4 +/- 8.7 years control group), gender, Charnley class, or length of followup (4.4 +/- 0.7 years hydroxyapatite group, 4.9 +/- 1.0 years control group). Forty-nine patients (54 hips) were available for clinical followup, and 45 patients (50 hips) had radiographic followup. A minimum 3-year followup was recorded. To date, there have been no femoral prostheses failures. No femoral implant has migrated or subsided. Radiographically, the hydroxyapatite coated stems showed trends toward increased distal stem related cortical hypertrophy, increased cancellous condensation and less endosteal cavitation. Two nonhydroxyapatite coated stems had distal endosteal cavitation, whereas no hydroxyapatite coated stems did. There were two cases of acetabular osteolysis (revision in one) and two cases of acetabular cup migration (nonrevised), all occurring in the control group. The overall revision rate was 4%. There was no difference in Harris hip scores at 6 months (80.6 +/- 13.0 points hydroxyapatite group, 83.8 +/- 12.4 points control group) or at last followup (85.6 +/- 15.4 points hydroxyapatite group, 89.7 +/- 13.4 control group). The Harris hip pain scores also were not significantly different at 6 months or at last followup. Multiple linear regression analysis controlling for age, gender, and length of followup revealed no significant predictors of Harris hip or pain scores. The results of this study at an average of 4.6 years do not indicate a significant clinical advantage to the use of hydroxyapatite coated femoral prostheses in primary cementless total hip arthroplasty when judged by the criteria of Harris hip scores and femoral stem survivorship.     

Partially hydroxyapatite coated bipolar hemiarthroplasty: a prospective study of 107 patients

A 1 year, prospective study to assess results using a partially hydroxyapatite coated, bipolar hemiarthroplasty to manage displaced, subcapital neck of femur fractures in the elderly was undertaken at our district general hospital. The functional and radiological outcomes were assessed then compared and contrasted with those of previous studies. This study suggests that use of the Corin CtiII hemiarthroplasty for displaced, subcapital; fractured neck of femur gives good functional results, comparable with those of other prostheses for hemiarthroplasty. The study also highlighted the need for a smaller stem size, which the manufacturer has since implemented.     

Mid-term results of a new cementless hydroxyapatite coated anatomic unicompartmental knee arthroplasty

Introduction

We report the mid term results of a cement less HA coated unicompartmental knee prosthesis.

Material and methods

One hundred and fifty-nine Unicompartmental knee arthroplasties were done between 1995 and 2000 with ALPINA^® UNI, a cementless HA coated anatomic prosthesis. One hundred and twenty knees were available for the mid-term follow-up at a mean of 6.5 years.

Results

The mean IKS improved from 87.1 ± 22.1 points preoperatively to 168.2 ± 26.1 at the latest follow-up (P < 0.001). Ninety-four percent of the knees were rated good and excellent. The mean knee flexion has significantly improved from 120° preoperatively to 126° at the latest follow-up (P < 0.001). Ten knees were revised: three for degeneration of osteoarthritis in the opposite compartment of the knee, four for polyethylene insert fracture, one for severe polyethylene wear and two for tibial component loosening. When revision for any reason was defined as the end point, the 5-year Kaplan–Meier survival rate was 95.7% (95% confidence interval, 90.1–98.2%) and when revision due to implant mechanical failure (excluding degeneration of osteoarthritis in the opposite compartment of the knee) was defined as the end point, the 5-year survival rate was 96.6% (95% confidence interval, 91.2–98.7%).

Conclusion

This study confirms the reliability of HA coated unicompartimental knee replacement. With careful indications it seems to be a good alternative to osteotomy of total arthroplasty.     

羟基磷灰石喷涂型椎间植入物与皮质骨界面的结合特性

目的 观察在生理负荷下羟基磷灰石表面喷涂型椎间植入物的界面介导皮质骨长入形成骨性结合的特性。方法 建立直立动物椎间植入物-椎体皮质骨界面研究动物模型，制作猕猴型椎间植入物12个，金刚砂磨面（对照组）4个、羟基磷灰石表面喷涂（观察组）8个。取4只成年猕猴，分别在其L2，3L3，4和L4，5椎间隙随机放置2个羟基磷灰石喷涂及1个金刚砂磨面植入物。于术后3、6、12、24、40周行X线摄片，40周非脱钙骨切片行骨界面形态计量学分析及组织学观察。结果 术后第3天全部动物恢复站立，行走，步态正常。观察期间植入物无松动及移位。术后40周观察组骨界面主要以部分矿化的类骨质及钙化良好的成熟骨组织充填，单位视野成骨细胞和骨细胞数明显增多（t=16．983，P=0．000），矿化骨组织百分含量高于对照组（t=5．001，P=0．000）。羟基磷灰石涂层无碎裂及剥脱，与骨组织界面密合。结论 羟基磷灰石与椎体皮质骨具有良好的组织相容性，在体内性质稳定，在椎间压应力生理负荷下，较金刚砂磨面能更好地介导椎体皮质骨组织长入骨界面，形成骨性结合。     

Adsorstion of Selected Biochemicals onto coated and Uncoated Charcoal

Creatinine, glutethimide and pentobarbital isotherms and preliminary kinetic data have been obtained in vitro on coated and uncoated charcoal from two commercially available hemoperfusion devices (B-D Hemodetoxifier and Gambro-Adsorba 300C). The uptake characteristics of these devices were examined in both buffer and plasma environments at physiological conditions (pH:7.4; temperature:37^oC), using radiolabelled solutes. Equilibrium adsorption data were analyzed by both Freundlich and Langmuir isotherm equations and isotherm constants determined. For both drugs, buffer and plasma data were well correlated by a Langmuir isotherm (r>0.99) while creatinine data were fitted better by the Freundlich equation (r>0.99). For all solutes, the amount adsorbed was lower in plasma (after correction for protein-binding) due to reversible competitive inhibition. However, charcoal capacity remained high enough for both coated and uncoated charcoals to enable satisfactory clinical hemoperfusion to be performed. Kinetic data were reduced assuming a homogeneous model of intraparticle diffusion. Calculated charcoal diffusivities were 0.3–3.8×10^--⁸ cm²/sec, with plasma values four to six times lower than corresponding values for buffer. Charcoal diffusivities were about two orders of magnitude lower than corresponding effective diffusivities through Cuprophan, indicating that the mass transfer resistance of the charcoal coating is inconsequential under conditions of intraparticle diffusion control. It was also deduced that the commonly observed decrease in clearance as a function of time during clinical charcoal hemoperfusion is mainly a consequence of diffusive rather than site-availability limitations.     

A randomized prospective study comparing migration of hydroxyapatite and non-hydroxyapatite coated glenoid components using radiostereometric analysis

BackgroundPrimary shoulder arthroplasty can significantly improve quality of life; however, the glenoid baseplate remains the most common component to loosen, which may result in implant failure and subsequent revision surgery. Radiostereometric analysis (RSA) is considered the gold standard for accurate measurement of micro-motion between implant and bone. The aims of this study were to compare migration of the Lima SMR porous titanium hydroxyapatite (HA) coated and non-hydroxyapatite (non-HA) coated glenoid components through a prospective, randomized 2-arm trial using RSA, whilst also comparing clinical and functional outcomes.MethodsTwenty patients were randomized into 2 equal (HA and non-HA coated) groups with all patients undergoing primary anatomic shoulder arthroplasty, at which time tantalum beads were also inserted. RSA imaging was performed immediately postoperatively, then at 3, 6, 12, and 24 months postprocedure. These images were digitized and analyzed using model-based RSA software. All patients completed Oxford Shoulder Score (OSS), American Shoulder and Elbow Surgeons (ASES) score, Constant Score (CS) and Visual Analogue Scale (VAS) pain scores pre-and postoperatively at the aforementioned time points. Unpaired t-tests were used for clinical outcome data; Mann-Whitney U tests were used for RSA data. Significance levels were set at P < .05.ResultsMean age for the HA group was 72.3 years; 69.5 years for the non-HA group. Mean follow-up for both groups was above 36 months. No significant differences in glenoid migration were observed at each of the postoperative time points; the only exception being at 12 months (non-HA group displaying significantly greater rotation in the z-axis). The HA group displayed fractionally more translation in the x- and z-axes at all time points (not significant). Rotation in the z-axis was marginally greater at all postoperative time points in the non-HA group. Median total migration values revealed greater motion for the non-HA group at 3, 6, and 12 months (not significant). All clinical outcome measures improved significantly within each group; no statistical differences were observed between the groups for any outcome measure. One patient in each group underwent revision surgery to reverse shoulder arthroplasty due to unexplained pain (HA group) and cuff failure (non-HA group) only. Radiolucent lines were noted in 2 patients who are still under follow-up.ConclusionThis study has revealed promising early results of both HA coated and non-HA coated implants, however, hydroxyapatite coating of glenoid components does not significantly improve outcome scores nor provide extra stability compared to non-hydroxyapatite coated implants at 2 years postprocedure.Level of evidenceLevel II; Randomized Controlled Trial     

Fracture of hydroxyapatite coated prostheses: a report of two cases of stem failure in hip hemiarthroplasty

Hydroxyapatite (HA)-coated implants for hemiarthroplasty for fractures of the femoral neck offer the advantages of stable and permanent fixation. Since April 1994, we have treated 562 patients using the JRI Furlong HA-coated hemiarthroplasty system at the Worthing and Southlands Hospitals. Fracture of the fully-HA-coated stainless steel stem was seen in two patients. To our knowledge, this complication has not been reported in the literature. In both cases, the stem was well bonded distally and was loose proximally. The possible causes of stem fracture in these two cases could be related to stress shielding and the use of stainless steel implants. In addition, the junction between the wide proximal and narrow distal part might have served as a weak spot. We would advise surgeons to be aware of the complication of stem failure while using an HA-coated implant for hemiarthroplasty for femoral neck fracture in an active patient.     

Osseointegration of polyethylene implants coated with titanium and biomimetically or electrochemically deposited hydroxyapatite in a rabbit model

Purpose

The aim of this study was to evaluate the osseointegration of a new coating directly deposited on PE at room temperature.

Methods

Thirty-six (36) male New Zealand rabbits were randomly assigned to receive one out of three types of implants: two tested implants, i.e. PE implant coated with TiPVD and biomimetic HA (biomimetic), PE implant coated with TiPVD and electrolytic HA (electrolytic), and positive control made of massive microrough titanium coated with plasma sprayed HA (TiHAPS). Osseointegration was evaluated by histomorphometry (bone tissue in contact [BIC]), mineralized bone area [MBA]) and mechanical testing (push-out test, interfacial shear strength [ISS]) at six and 12 weeks in the distal femurs.

Results

For BIC there were no differences between the groups at six (p = 0.98) and 12 weeks (p = 0.13). For MBA, no statistically significant difference was measured between groups at six (p = 0.52) and 12 weeks (p = 0.57). At six weeks, interfacial shear strength (ISS) was significantly higher (p = 0.01) for TiHAPs implants compared to biomimetic and electrolytic implants. This difference was not significant at 12 weeks (p = 0.92).

Conclusion

The osseointegration of biomimetic and electrolytic implants was equivalent to a positive control at 12 weeks.