颗粒骨打压植骨结合多孔非骨水泥臼杯在AAOSⅢ型髋臼大面积骨缺损翻修中的应用

背景：颗粒骨打压植骨是修复髋臼骨缺损的重要方法,对大面积髋臼骨缺损采用打压植骨结合非骨水泥臼杯重建仍然存在争议。目的：探讨同种异体颗粒骨打压植骨结合多孔非骨水泥臼杯髋臼重建术修复AAOSⅢ型髋臼大面积骨缺损的方法及近期疗效。方法：随访2005年6月至2010年4月收治的28例（28髋）AA0SⅢ型髋臼大面积骨缺损患者。男18例,女10例,年龄34-74岁,平均53．8岁。髋关节置换术后感染醐翻修9例,骨溶解及髋臼假体松动翻修19例。本组AAOSⅢ型髋臼骨缺损面积大,术中见髋臼骨缺损超过髋臼关节面的50％。全部采用同种异体颗粒骨打压植骨结合多孔非骨水泥臼杯髋臼重建术。术后定期随访,观察臼杯有无松动、植入骨与宿主骨整合情况,髋关节功能评分采用Harris评分。结果：28例均获得随访,术后随访时间为13-70个月,平均43个月。Harris评分由术前32-48分,平均41分,提高至末次随访时86-95分,平均90分。28例髋臼假体均固定牢固无松动征象,植入骨逐渐与宿主骨整合,无感染及坐骨神经损伤。结论：在获得臼杯初始稳定固定的情况下,大面积颗粒骨打压植骨（臼杯与宿主骨接触面积〈50％）结合多孔非骨水泥臼杯髋臼重建术修复AAOSⅢ型髋臼大面积骨缺损近期疗效较好,远期疗效尚待进一步随访。     

全髋关节翻修术中髋臼骨缺损的重建

目的探讨全髋关节置换术（THA）后，翻修术中髋臼骨缺损重建的方法及疗效。方法对81例（84髋）在THA翻修术中处理的髋臼骨缺损患者进行回顾性分析，根据AAOS分型法，Ⅰ型7髋，Ⅱ型56髋，Ⅲ型17髋，Ⅳ型4髋。分别采用大直径非骨水泥假体臼、非骨水泥假体臼＋松质颗粒植骨、骨水泥假体臼＋Cage＋松质颗粒植骨和骨水泥假体臼＋定制型假体＋松质颗粒植骨等方法，对不同类型骨缺损的患者进行修复。术后定期随访，采用Harris方法评估髋关节功能，根据X线片判断假体是否有松动，移植骨是否愈合。结果对本组患者进行术后随访，平均随访45个月（13～118个月）。术后Harris评分平均86．2分，较术前平均改善40．6分。2髋因脱位需进行再翻修，其余效果良好，X线片无假体松动下沉，可见移植骨一宿主骨交界处有连续性小梁骨通过。结论在THA翻修术中，大部分髋臼骨缺损可使用较大型号非骨水泥假体或加松质颗粒植骨进行修复；对于影响假体稳定性的较大缺损，使用骨水泥假体臼＋Cage＋松质颗粒植骨的方法可获得良好效果；定制型假体在处理严重髋臼骨缺损中有独特优势，具有良好的临床应用前景。     

钽金属骨小梁臼杯结合同种异体骨植骨治疗髋关节翻修术中严重骨缺损

[目的]探讨在髋关节翻修术中采用钽金属骨小梁臼杯结合同种异体骨植骨技术治疗髋臼骨缺损的临床疗效。[方法]2008年2月~2012年10月采用钽金属骨小梁臼杯结合同种异体骨植骨治疗44例(44髋)因髋臼无菌性松动或感染后二期翻修合并严重骨缺损和髋臼严重骨溶解的患者,并进行回顾性研究。男23例,女21例,平均年龄58.5岁(34~78岁)。全部患者均采用组配式钽金属臼杯结合同种异体骨植骨重建髋臼骨缺损,其中15例(34%)髋关节的臼杯宿主骨覆盖率不足70%。临床结果采用Harris髋关节评分进行评价。影像学结果依据术后系列X线片进行分析。[结果]平均随访时间53.4个月(30~84个月),Harris髋关节评分从术前平均20.3分(8~36分)提高至术后最后一次随访的83.8分(39~98分)(P0.001)。末次随访时原有3髋的臼杯周围放射性透亮带持续存在,但并无扩大趋势,无新发放射性透亮带出现。术后并发症包括坐骨神经损伤1例、大粗隆不愈合1例。未发现假体无菌性松动患者。[结论]在髋关节翻修术中采用钽金属臼杯结合同种异体骨植骨治疗髋臼骨缺损技术的中期临床和影像学结果令人满意,具有较低的并发症发生率。     

辐照深冻异体骨打压植骨在髋臼翻修中的应用

目的 研究辐照深冻异体骨用于髋臼翻修中严重骨缺损的打压植骨重建的临床效果.方法 2006年2月至2009年1月髋关节翻修术中共有20例21髋应用打压植骨技术结合金属网重建严重髋臼侧骨缺损,18例19髋获得随访.患者翻修时平均年龄为64.4岁(43～81岁).采用Paprosky分型,本组患者均有髋臼骨缺损,其中PaproskyⅡB型4髋,PaproskyⅡC型8髋,PaproskyⅢA型5髋,PaproskyⅢB型2髋.手术用金属网修复髋臼节段性缺损,采用辐照深冻同种异体颗粒骨打压植骨结合骨水泥臼杯完成髋臼翻修.患者术后定期进行影像学和临床评估,观察手术前后髋关节Harris评分变化,假体移位松动及异体骨骨整合情况,及术中、术后并发症等.术前Harris评分平均42.5分(31～56分).术前疼痛评分平均14.4分(10～20分).结果 患者平均随访时间22.4个月(12～48个月).术后Harris评分提高到88.6分(82～96分).术后疼痛评分提高至平均42.3分(40～44分).并发症:术后感染1例,经清创愈合.股神经损伤1例,术后1年随访时已恢复正常.1例患者术后出现股骨近端外侧皮质吸收,大粗隆骨折.有1例Paprosky ⅢB型患者出现金属网及髋臼杯明显移位等影像学松动表现,其余18髋的髋臼假体稳定,未发现臼杯在垂直和水平方向大于1 mm的移位,也未发现髋臼假体外展角的改变;植骨层和宿主骨床可见连续骨小梁通过、移植骨与周围骨床骨密度趋向一致等骨整合表现.结论 金属网与打压植骨及骨水泥髋臼技术联合应用能有效地完成髋臼的生物学翻修.辐照深冻异体骨用于打压植骨能与周围骨床很好的整合.     

病灶清除植骨保留髋臼假体的翻修术治疗假体周围局灶性骨溶解

目的 探讨病灶清除植骨保留髋臼假体的翻修术治疗全髋关节置换(total hip arthroplasty,THA)术后稳定固定的髋臼假体周围局灶性骨溶解的疗效.方法 2006年3月至2009年3月,THA术后髋臼假体稳定固定的假体周围局灶性骨溶解患者23例(23髋),男13例,女10例;年龄39～54岁,平均46.6岁.23例均为非骨水泥髋臼.初次THA至诊断髋臼假体周围骨溶解的时间为4.6～7.4年,平均5.5年.术前HarTis髋关节评分74分.手术经腹股沟入路,行髂骨内板开窗,清除髋臼骨溶解病灶、同种异体颗粒骨植骨;经后外侧人路更换聚乙烯内衬、股骨头假体,保留髋臼假体.翻修术后1、3、6、12个月及之后每年随访1次,以髋关节Harris评分评价临床疗效,摄X线片、CT扫描观察植骨区愈合、新发骨溶解病灶及假体移位情况.结果 16例获得随访,随访时间8～38个月,平均28个月.末次随访时Harris髋关节评分86～100分,平均93.8分.16例植骨区成骨均良好,12例植骨区完全被周围骨爬行替代,髋臼假体固定好,无髋臼假体松动及移位,无新发髋臼假体周围骨溶解,无异位骨化、脱位、深静脉血栓形成及感染等并发症.结论 清除病灶植骨、保留髋臼假体、更换聚乙烯内衬和股骨头假体的翻修术可有效减少聚乙烯磨损颗粒产生,避免骨溶解病灶进展导致的假体松动,近期随访结果良好.     

THA翻修术中髋臼骨缺损的处理策略

目的探讨全髋关节置换术（THA）翻修术中髋臼骨缺损重建的方法及疗效。方法回顾1999年6月至2007年5月,在THA翻修术中处理的髋臼骨缺损112例（117髋）。根据Saleh KJ的改良分型法,Ⅰ型缺损14髋、Ⅱ型缺损26髋、Ⅲ型缺损47髋、Ⅵ型缺损16髋、Ⅴ型缺损14髋。分别采用大直径非骨水泥假体臼、非骨水泥假体臼＋松质颗粒植骨、骨水泥假体臼＋Cage＋松质颗粒植骨和骨水泥假体臼＋定制型假体＋松质颗粒植骨,对不同类型骨缺损进行修复。术后定期随访,采用Harris方法评估髋关节功能,根据X线片判断假体是否有松动,移植骨是否愈合。结果随访时间平均45（13～118）个月。除4髋因脱位或假体周围骨折进行再翻修外,其余效果良好。术后Harris评分平均86.2分,较术前平均改善40.6分。X线片无假体松动下沉,可见移植骨-宿主骨交界处有连续性小梁骨通过。结论在THA翻修术中,大部分髋臼骨缺损可使用较大型号非骨水泥假体或加松质颗粒植骨进行修复;对于影响假体稳定性的较大缺损,使用骨水泥假体臼＋Cage＋松质颗粒植骨的方法可获得良好效果;定制型假体在处理严重髋臼骨缺损中有具独特优势,有良好的临床应用前景。     

大量同种异体颗粒骨打压植骨结合多孔非骨水泥臼杯翻修髋臼大面积骨缺损的中期疗效

目的探讨同种异体颗粒骨打压植骨结合多孔非骨水泥臼杯髋臼翻修大面积髋臼骨缺损的技术要点,并随访其中期临床和影像学疗效。方法随访2004年9月-2009年8月之间连续收治的采用同种异体颗粒骨打压植骨联合非骨水泥多孔髋臼杯翻修髋臼骨缺损面积大于整个髋臼关节面50％的27例（27髋）患者。按AAOS分类标准均为AAOSⅢ型骨缺损。按Paprosky分类标准,PaproskyⅡ型19例（19髋）,PaproskyⅢ型8例（8髋）。髋臼假体与宿主自体骨接触面积均小于50％;其中有19例患者的髋臼杯全完与异体骨接触。评价术前、术后的Harris评分,肢体长度。在X线片上评价髋关节旋转中心、髋臼侧透亮线、以及植骨融合情况,并判断髋臼有无松动和移位。用Kaplan-Meier生存分析评价髋臼假体的6年生存率。结果患者均完成随访,平均随访时间（6．4±1．4）年（4～9年）。术前Harris评分为（14．9±4．4）分（6-34分）,最后随访时的Harris评分为（85．6±8．1）分（67～98分）,差异具有统计学意义意义（t=22．181,P〈0．01）。术前肢体短缩（14．7±5．1）mm（6～24mm）,术后肢体短缩（0．2±3．4）mm（-9～12mm）,差异具有统计学意义（t=19．223,P〈0．01）。术后髋关节旋转中心均在Renawat三角内。所有病例术后1～1．5年植入的异体骨均与宿主骨融合。无髋臼假体松动或失败。髋臼假体的6年生存率为100％（95％可信区间为0．95～1．0）。结论髋臼AAOSⅢ型、PaproskyⅡ型甚至部分Ⅲ骨缺损,只要髋臼顶及前、后柱3个方向均存在大部分的骨皮质及一定的支撑作用,即便骨缺损面积大于髋臼关节面的50％,仍可采用同种异体骨颗粒骨打压植骨结合多孔非骨水泥臼杯髋臼重建术进行修复,并可取的满意的中期疗效。     

混合型初次全髋关节置换术中骨水泥柄10年以上的随访研究

目的回顾性分析混合型初次全髋关节置换术（THA）中骨水泥柄的临床和影像学疗效及其相关影响因素。方法对1999年1月至2001年12月期间接受混合型初次THA治疗髋部疾病的患者126例（135髋）进行至少10年的随访。观察Harris评分、股骨假体位置、骨水泥壳及其周围骨质变化。假体生存率采用Kaplan-Meier方法进行分析,以无菌性松动导致翻修及单纯骨溶解病灶清除植骨术为随访终点。结果共有79例（85髋）获得10年以上随访。Harris评分由术前（44.5±18.8）分提高至末次随访时（92.1±5.6）分。截至随访终点,在Gruen 1区观察到2髋发生骨溶解,7区4髋发生骨溶解现象。共有4例（4髋）接受翻修手术,其中1例男性患者因骨溶解致髋臼假体松动,同侧股骨近端骨溶解,同期行右髋臼侧翻修及股骨侧骨溶解病灶清除植骨术。另3例因髋臼假体松动行髋臼侧翻修术,影像学及术中见股骨假体稳定。以无菌性松动为随访终点,股骨假体生存率为100%;以无菌性松动翻修、单纯骨溶解病灶清除植骨术为随访终点,股骨假体生存率为98.8%（95%可信区间,12.23~12.32）。结论混合型初次THA术中骨水泥假体的远期生存率令人满意;采用第3代骨水泥技术固定的股骨柄取得与现代非骨水泥假体柄相近的远期生存率。     

异体颗粒松质骨移植治疗髋臼杯稳定的髋臼周围骨溶解

[目的]评价异体颗粒松质骨移植治疗THA术后髋臼杯稳定的髋臼周围骨溶解的效果。[方法]自1996年4月~2000年7月,对26例髋臼杯周围骨溶解而假体稳定者行保留髋臼杯,清除病灶、异体颗粒松质骨移植术,并更换聚乙烯内衬和股骨头假体。术后平均随访5.5 a。对临床结果、骨溶解病变范围和骨移植愈合分别用Harris髋关节评分系统、放射线影像学和骨移植愈合分级系统进行评价。[结果]Harris评分由翻修术前的平均82分增加到术后平均88分;X线片示髋臼杯周围骨溶解范围正位由术前23.8 mm×24.9 mm减小到术后11.5 mm×8.2 mm,侧位由术前的11.1 mm×11.6 mm减少到术后5.3 mm×4.5 mm;异体骨愈合程度Ⅰ级12例(46%),Ⅱ级14例(54%)。[结论]保留髋臼杯、清除病灶后行异体颗粒松质骨移植术是非骨水泥髋臼杯稳定的髋臼周围骨溶解治疗的有效措施,可以保留更多的髋臼骨量,降低手术的复杂程度。     

颗粒骨打压植骨结合非骨水泥臼固定在髋臼翻修中的应用

目的 探讨颗粒骨打压植骨结合非骨水泥臼在髋臼翻修中的临床应用.方法 应用颗粒骨打压植骨结合非骨水泥臼技术重建髋臼骨缺损10例,术中使用异体颗粒骨直径4～6 mm,髋臼假体均为生物型髋臼,上2或3枚螺钉固定,内衬均为高交联聚乙烯.结果 切口均一期愈合,无感染、脱位等并发症发生.随访9～28个月,平均19.5个月,X线片上髋臼骨床、颗粒骨及假体界面未见明显透亮带存在,原骨缺损区修复良好.Harris评分术前平均38.1分,术后平均85.5分.结论 颗粒骨打压植骨结合非骨水泥臼固定方法可有效修复髋关节翻修中髋臼AAOSⅡ、Ⅲ型骨缺损,恢复骨量,并能提供良好的早期稳定性.     

Osteolysis in cemented versus cementless acetabular components

A prospective, randomized, double-blind, clinical trial comparing cemented with cementless total hip arthroplasty was performed to compare the prevalence and pattern of acetabular osteolysis. Both groups were similar before surgery. Acetabular components were metal-backed, titanium implants. Twenty-eight-millimeter modular femoral heads with titanium femoral stems were used. At a minimum 2-year and mean 4-year follow-up period (range, 2–6 years), 224 patients had clinical and radiographic data available. There was no significant difference in the prevalence of acetabular osteolysis between cemented (5%) and cementless (9%) fixation. With or without cement, the use of a titanium femoral head led to osteolysis within a relatively short period after surgery in almost all of the cases, although this was not significant. The pattern of acetabular osteolysis was different. Progressive osteolysis occurred predominantly in acetabular zone 1 in the cemented group and zone 2 in the cementless group. Cementless fixation of acetabular components has been advocated in an attempt to minimize osteolysis that may occur in cemented total hip arthroplasty. This study found no difference in the prevalence of acetabular osteolysis between the two groups.     

Radiographically Undetectable Periprosthetic Osteolysis With ASR Implants : The Implication of Blood Metal Ions

Patients with ASR implants (resurfacing and large-diameter (XL) metal-on-metal (MoM) total hip arthroplasty), even if asymptomatic and with a stable prosthesis, may present extremely high blood metal ion levels. We report on a consecutive series of fourteen ASR revisions, focusing on osteolysis and their radiographic correspondence and their correlation with blood metal ion levels. At revision, seven hips revealed severe periacetabular osteolysis which was radiographically undetectable in six and asymptomatic in five. Seven hips with no acetabular osteolysis had significantly lower serum Cr and Co ion concentrations (respectively 25.2, 41.1 μg/l) compared to the seven hips with severe acetabular bone loss (respectively 70.1, 147.0 μg/l). Elevated blood metal ion levels should be considered as a warning of undetectable and ongoing periprosthetic osteolysis in asymptomatic patients with ASR prosthesis.     

Hylamer vs Conventional Polyethylene in Primary Total Hip Arthroplasty: A Long-Term Case-Control Study of Wear Rates and Osteolysis

The long-term results of Hylamer implants have not been reported previously. Clinical and radiographic results of a consecutive series of 43 patients (45 hips) who had primary total hip arthroplasty using Hylamer liners were compared with those of 37 patients (43 hips) who had conventional liners after 10-year follow-up. The linear wear rates for Hylamer and conventional polyethylene acetabular liners were 0.21 and 0.20 mm/y, respectively. The number of pelvic osteolytic lesions and their size detected on plain radiographs were significantly greater for Hylamer liners. Seven Hylamer hips were revised or are pending revision for osteolysis (16%) compared with 1 control hip. Close radiographic surveillance of patients who have Hylamer liners and evidence of osteolysis found on plain radiographs is warranted.     

Osteolysis of the pelvis: evaluation and treatment

Osteolysis of the pelvis is a common and well-recognized complication associated with total hip arthroplasty. The diagnosis and treatment of osteolysis of the pelvis is a challenging and controversial problem. Osteolysis of the pelvis often is asymptomatic and does not present with symptoms until considerable bone loss and loosening of the acetabular socket occur. Radiographs are the most common way to detect and monitor osteolysis around an implant. However, lesions viewed radiographically usually are underestimations of the lesions found intraoperatively. Moreover, some advocate computed tomography scanning to evaluate these lesions. The indications for treatment of osteolysis with cemented acetabular components are defined more clearly than with a cementless component. If the cemented or cementless acetabular component is loose, then revision is necessary. However, it is less clear when to intervene surgically with a well-fixed cup with osteolysis. Many early reports advocated the removal of a well-fixed socket during revision surgery for osteolysis and polyethylene wear. However, the removal of a well-fixed socket has the potential for significant damage and loss of the surrounding bone resulting in loss of integrity of a column or pelvic discontinuity, which may compromise placing another acetabular component. Recently, a new treatment strategy of retaining a well-fixed socket, exchanging the liner, and grafting lesions has proven successful. Without the removal of the acetabular shell, different techniques are needed to graft the osteolytic lesions. Osteolysis is a difficult problem; however, with radiographic surveillance to monitor patients for lesions, proper indications, and good surgical techniques, the treatment of osteolysis of the pelvis can result in a well-functioning total hip arthroplasty.     

Bone density adjacent to press-fit acetabular components. A prospective analysis with quantitative computed tomography

BACKGROUND: The status of periprosthetic bone stock is an important concern when revision total hip arthroplasty is undertaken. Remodeling of periprosthetic femoral bone after total hip arthroplasty has been studied extensively, and the phenomenon of femoral stress-shielding has been well characterized. Finite element analysis and computer-simulated remodeling theory have predicted that retroacetabular bone-mineral density decreases after total hip arthroplasty; however, remodeling of periprosthetic pelvic bone in this setting has yet to be well defined. This study was conducted to evaluate the short-term natural history of periacetabular bone-mineral density following primary total hip arthroplasty. METHODS: Periacetabular bone-mineral density was studied prospectively in a group of twenty-six patients who underwent primary hybrid total hip arthroplasty for the treatment of advanced osteoarthritis. Density within the central part of the ilium (directly cephalad to a press-fit acetabular component) was assessed with serial quantitative computed tomography. Baseline density was measured within the first five days following the total hip arthroplasty. Ipsilateral density measurements were repeated at an average of 1.28 years postoperatively. Density values at corresponding levels of the contralateral ilium were obtained at both time-points in all patients to serve as internal controls. RESULTS: Bone-mineral density decreased significantly (p< or =0.001) between the two time-points on the side of the operation. The mean absolute magnitude of the interval density reduction (75 mg/cc) was greatest immediately adjacent to the implant (p<0.001), but it was also significantly reduced (by 35 mg/cc) at a distance of 10 mm cephalad to the implant (p = 0.001). Relative declines in mean density ranged from 33% to 20% of the baseline values. No focal bone resorption (osteolysis) was detected at the time of this short-term follow-up study. With the numbers available, no significant interval alteration in bone-mineral density was found on the untreated (internal control) side (p> or =0.07). CONCLUSIONS: We suggest that the observed decline in bone-mineral density represents a remodeling response to an altered stress pattern within the pelvis that was induced by the presence of the acetabular implant. This finding corroborates the predictions of finite element analysis and computer-simulated remodeling theory. It remains to be seen whether this trend of atrophy of retroacetabular bone stock will continue with longer follow-up or will ultimately affect the long-term stability of press-fit acetabular components.     

Outcome and Risk Factors Associated with Failures of Isolated Bearing Exchange for Osteolysis in Well-Fixed Cementless Total Hip Arthroplasty

BackgroundIt is often challenging to decide whether to revise only the bearing or femoral acetabular component in the setting of progressive osteolysis without component loosening in revision total hip arthroplasty (THA). In this study, we aimed to (1) compare the survivorship of isolated bearing exchange and single/both component revision for patients with periprosthetic osteolysis without component loosening, and (2) identify potential risk factors associated with failures of isolated bearing exchange.MethodsA total of 228 consecutive cases of revision THA for progressive osteolysis without component loosening was evaluated in 2 groups: (1) 124 component revision and (2) 104 isolated bearing exchange. The primary outcome was survival, with failure defined as repeat revision or reoperation for any reason. Patient risk factors, such as demographics and medical comorbidities, were also analyzed.ResultsThere was no significant difference in survivorship between the component revision group and the bearing exchange group at 10 years (85% vs 82%; P = .89). There was no progression of osteolysis on radiographs at last follow-up for patients with isolated bearing change. Univariate regression modeling demonstrated that renal disease was associated with failure of isolated bearing exchange after revision THA.ConclusionThis study demonstrated that isolated bearing exchange is associated with similar outcomes compared with component revision for aseptic osteolysis without loosening, demonstrating that isolated bearing exchange is a viable option for selected patients with osteolysis in the setting of well-fixed THA components. This provides clinically useful information for surgeons in the surgical treatment of THA patients with wear and osteolysis without component loosening.     

Osteolysis in patients with a metal-on-metal hip arthroplasty

Background: Despite design and manufacturing improvements in contemporary metal‐on‐metal hip replacements, the problem of wear particles persists. The local and systemic biological consequences of this ionic debris have been the subject of much investigation and it has become clear that cell‐mediated delayed‐type hypersensitivity reactions are a discrete mode of osteolysis in susceptible patients. Methods: We have carried out a consecutive series of 125 primary hip replacements using the Metasul (Zimmer, Warsaw, IN, USA) bearing couple. The radiographs, periprosthetic tissue and retrieved implants of patients undergoing revision for osteolysis were analysed. Results: Three patients underwent revision procedures during a follow‐up period of 3–9 years. Histological analysis showed a perivascular lymphocytic infiltrate of the pseudocapsule. Infection was excluded in each patient, there was no implant loosening and no evidence of impingement between trunion and acetabular component. Conclusion: We report a prevalence of 2.6% of patients displaying femoral osteolysis associated with characteristic clinical and histological findings.     

Serum interleukin 8 levels correlate with synovial fluid levels in patients with aseptic loosening of hip prosthesis

Levels of inflammatory cytokines (tumor necrosis factor alpha, interleukin [IL] 6, and IL-8) in serum from patients with osteolysis on radiographs after hip arthroplasty [osteolysis(+), n = 28], patients without osteolysis after hip arthroplasty [osteolysis(-), n = 24], and nonoperated healthy subjects [controls, n = 20] were determined. In addition, cytokine levels in synovial fluid from patients undergoing revision total hip arthroplasty (n = 14) for loosening were measured and compared with each other and with the area of osteolysis on radiographs. Serum IL-6 and IL-8 levels were significantly higher in the osteolysis(+) group than in the osteolysis(-) or the control groups. Furthermore, a significant correlation was found between the serum and synovial fluid IL-8 levels and between synovial fluid IL-8 levels and the area of osteolysis in patients undergoing revision total hip arthroplasty. Therefore, serum IL-8 levels could be a useful periprosthetic osteolysis marker.     

Magnetic resonance imaging after total hip arthroplasty: evaluation of periprosthetic soft tissue

BACKGROUND: The evaluation of periprosthetic osteolysis in patients who have had a total hip arthroplasty is challenging, and traditional imaging techniques, including magnetic resonance imaging and computerized tomography, are limited by metallic artifact. The purpose of the present study was to investigate the use of modified magnetic resonance imaging techniques involving commercially available software to visualize periprosthetic soft tissues, to define the bone-implant interface, and to detect the location and extent of osteolysis. METHODS: Twenty-eight hips in twenty-seven patients were examined to assess the extent of osteolysis (nineteen hips), enigmatic pain (five), heterotopic ossification (two), suspected tumor (one), or femoral nerve palsy (one). The results were correlated with conventional radiographic findings as well as with intraoperative findings (when available). RESULTS: Magnetic resonance imaging demonstrated the bone-implant interface and the surrounding soft-tissue envelope in all hips. Radiographs consistently underestimated the extent and location of acetabular osteolysis when compared with magnetic resonance imaging. Magnetic resonance imaging also disclosed radiographically occult extraosseous soft-tissue deposits that were similar in signal intensity to areas of osteolysis, demonstrated the relationship of these deposits to adjacent neurovascular structures, and allowed further visualization of hypertrophic synovial deposits that accompanied the bone resorption in twenty-five of the twenty-eight hips. CONCLUSIONS: Magnetic resonance imaging is effective for the assessment of the periprosthetic soft tissues in patients who have had a total hip arthroplasty. While not indicated for every patient who has pain at the site of an arthroplasty, these techniques can be effective for the evaluation of the surrounding soft-tissue envelope as well as intracapsular synovial deposits and are more effective than radiographs for the detection and evaluation of osteolysis, thus aiding in clinical management.