人工全髋关节置换翻修术术前假体松动的回顾性研究

目的通过对48例人工全髋关节置换翻修术术前资料的系统回顾性研究,评价采取不同固定方法的假体的临床疗效。方法笔者对行髋关节置换的48例实行了全髋翻修术,并对全部病例进行了术前X线评价及术中假体松动情况调查,并做χ2检验,判断不同假体固定方式对假体寿命的影响。结果早、中期假体松动主要为非骨水泥型假体。骨水泥固定的假体与非骨水泥固定的假体远期均存在很高的松动下沉率,以骨水泥臼的松动为多数。髋臼侧骨溶解发生率以Ⅰ区为高,股骨柄侧骨溶解发生率以股骨近端为最高。结论人工全髋关节置换术中生物性固定初期并不十分牢固。人工全髋关节置换术中骨水泥固定假体松动主要发生在远期,并且以髋臼侧骨水泥松动为主。     

解剖型非骨水泥固定股骨假体在股骨头坏死治疗中的应用

目的：总结使用解剖型非骨水泥固定股骨假体治疗晚期股骨头坏死的临床效果及经验。方法：回顾性分析了采用解剖型非骨水泥固定股骨假体对123例股骨头坏死患者，162个髋进行的人工全髋关节置换手术。对其中58例患者87个髋关节进行了平均37．6个月的随访，通过Harris评分及X线片评价临床效果。结果：Harris评分的优良率达95．3％。X线片未见有松动和假体下沉。结论：使用Ribbed解剖型非骨水泥固定假体治疗晚期股骨头坏死的短期效果满意。     

Titan型骨水泥假体柄中长期随访结果

目的观察Titan型骨水泥假体柄在初次全髋置换中的中远期结果。方法所有55例患者均进行术前术后以及临床随访功能评定,随访X线片了解假体情况,采用Harris评分系统进行临床功能评价。结果因其他疾病死亡5例,失访10例,40例得到随访。1名患者因髋臼侧松动行翻修后假体不匹配行股骨柄翻修术,股骨柄的生存率为97.5%。结论 Titan骨水泥假体因其特殊的设计取得了良好的临床效果,正确使用骨水泥技术,骨水泥固定股骨柄可以取得良好的中长期效果。     

Charnley型人工全髋置换术后10年以上随访的X线分析

目的:通过对骨水泥固定的Charnley型人工全髋置换术患者10年以上X线随访,探讨骨水泥型人工全髋的固定效果、松动及影响寿命的因素等。方法:获得10年以上随访的38例45髋作为研究对象,平均随访14.6年。X线包括术后及最后随访时髋关节正侧位片。结果:髋臼假体松动有24髋(53％),其中明显松动(definite loosening)14髋(13％),可能松动(possible loosening)10髋(22％)。臼杯磨损共35髋(78％),平均磨损率为0.123mm/年;股骨假体柄松动有12髋(27％),其中明显松动8髋(18％),可能松动4髋(9％)。假体柄周围骨溶解18髋(40％)。本组45髋中8髋(18％)行翻修术,其中4髋因髋臼假体松动单纯髋臼假体翻修,其余4例行髋臼和股骨假体全部翻修。结论:骨水泥固定的Charnley型人工全髋置换术后10年以上长期随访结果,股骨假体的固定效果较好,但髋臼假体的固定效果并不满意。聚乙烯臼杯磨损不可避免,作为人工关节材料,聚乙烯对金属的关节组合应重新考虑。采用改良的骨水泥固定方法对人工全髋假体的早期稳定性和长期寿命非常重要。从髋臼假体的固定效果来看,金属臼(metal shell)假体的非骨水泥固定效果优于聚乙烯臼的骨水泥固定效果。     

骨水泥填充修复骨缺损在翻修髋臼假体内侧移位松动中的疗效

目的探讨骨水泥填充修复骨缺损结合骨水泥髋臼假体在翻修髋臼假体内侧移位松动中的临床疗效。方法 2006年4月~2011年3月收治16例髋臼假体内侧移位松动患者,均采用骨水泥填充修复骨缺损结合骨水泥聚乙烯髋臼假体翻修松动的髋臼假体,对伴有股骨假体松动的患者,根据患者的骨质情况和骨缺损情况选择骨水泥翻修长柄假体(9例)、非骨水泥型广泛涂层假体(2例)或打压植骨结合骨水泥固定股骨柄假体(1例)。术后进行临床评估及X线评估。结果 16例患者术后平均随访2.6(1.5~6.2)年,未出现臼杯松动病例,Harris评分从术前的35(18~63)分提高到末次随访时的89(60~99)分。结论应用骨水泥填充修复骨缺损结合骨水泥髋臼假体翻修内侧移位松动的髋臼假体是一种有效的手术方法。     

Charnley型人工全髋置换术后10年以上随访的X线分析

目的:通过对骨水泥固定的Charnley型人工全髋置换术患者10年以上X线随访,探讨骨水泥型人工全髋的固定效果、松动及影响寿命的因素等.方法:获得10年以上随访的38例45髋作为研究对象,平均随访14.6年.X线包括术后及最后随访时髋关节正侧位片.结果:髋臼假体松动有24髋(53%),其中明显松动(definite loosening)14髋(13%),可能松动(possible loosening)10髋(22%).臼杯磨损共35髋(78%),平均磨损率为0.123mm/年;股骨假体柄松动有12髋(27%),其中明显松动8髋(18%),可能松动4髋(9%).假体柄周围骨溶解18髋(40%).本组45髋中8髋(18%)行翻修术,其中4髋因髋臼假体松动单纯髋臼假体翻修,其余4例行髋臼和股骨假体全部翻修.结论:骨水泥固定的Charnley型人工全髋置换术后10年以上长期随访结果,股骨假体的固定效果较好,但髋臼假体的固定效果并不满意.聚乙烯臼杯磨损不可避免,作为人工关节材料,聚乙烯对金属的关节组合应重新考虑.采用改良的骨水泥固定方法对人工全髋假体的早期稳定性和长期寿命非常重要.从髋臼假体的固定效果来看,金属臼(metal shell)假体的非骨水泥固定效果优于聚乙烯臼的骨水泥固定效果.     

Charnley型人工全髋置换术后10年以上随访的X线分析

目的：通过对骨水泥固定的Charnley型人工全髋置换术患者10年以X线随访，探讨骨水泥型人工全髋的固定效果、松动及影响寿命的因素等。方法：获得10年上随访的38例45髋作研究对象，平均随访14.6年。X线包括术后及最后随访时髋关节正侧位片。结果：髋臼假体松动有24髋（53％），其中明显松动（definite loosening）14髋（13％），可能松动（possible loosening）10髋（22％）。臼杯磨损共35髋（78％），平均磨损率为0.133mm/年；股骨假体柄松动有12髋（27％），其中明显松动8髋（18％），可能松动4髋（9％）。假体柄周围骨溶解18髋（40％）。本组45髋中8髋（18％）行翻修术，其中4髋因髋臼假体松动单纯髋臼假体翻修，其余4例行髋臼和股骨假体全部翻修。结论：骨水泥固定的Charnley型人工全髋置换术后10年以上长期随访结果，股骨假体的固定效果较好，但髋臼假体的固定效果并不满意。聚乙烯臼杯磨损不可避免，作为人工关节材料，聚乙烯对金属的关节组合应重新考虑。采用改良的骨水泥固定方法对人工全髋假体的早期稳定性和长期寿命非常重要。从髋臼假体的固定效果来看，金属臼（metal shell）假体的非骨水泥固定效果优于聚乙烯臼的骨水泥固定效果。     

初次全髋置换术前的假体选择

骨水泥与非骨水泥假体各有优缺点,就具体病人而言,选择何种固定类型的假体更为合适,是骨科医生在术前必须明确的问题。本文就不同固定方法的假体作一综述,希望对初次全髋置换术前的假体选择有所帮助。1骨水泥假体骨水泥股骨假体:在假体植入之前,以骨水泥充填股骨髓腔,插入股骨柄后使骨水泥均匀分布于股骨假体与股骨髓腔内壁之空隙间(约2mm),等骨水泥硬化后,股骨柄就会牢固地固定于髓腔内。因此,骨水泥固定可提供假体的即刻机械稳定,允许早期负重而不必担心早期的松动和下沉。然而采用第一代骨水泥灌注技术(手持填塞技术)的全髋关节置换,后期…     

股骨假体周围骨密度定量测定

目的 通过双能X线骨密度仪测定不同情况下股骨假体周围的骨密度变化情况,了解骨丢失与股骨假体松动的关系。方法 分为骨水泥固定的股骨假体组、非骨水泥固定的股骨假体组、股骨假体松动组共3个组,采用LUNAR DPXL-L型双能X线骨密度仅(Lunar Corp Wisconsin,USA)及Orthopaedies软件,分析时用Gruen’s 7区法。结果 骨水泥固定的股骨假体组骨丢失为15．1%～29．3%,非骨水泥固定的股骨假体组骨丢失为13．2％～27．9%,股骨假体松动组骨丢失为25．4％～43．4%,3组均是股骨近端骨丢失明显．骨丢失主要发生在术后8年以内。结论 骨水泥固定的股骨假体和非骨水泥固定的股骨假体周周骨密度降低一样,假体松动者假体周围骨丢失明显增加。股骨近端2个以上区域骨丢失大于35％或术后8年以后突然出现明显的骨丢失,考虑有股骨假体松动存在的可能性。     

组合式螺柄人工股骨头的研制及临床应用

针对人工髋关节置换术后假体松动、下沉发生率比较高的特点,作者研制一种新型的人工股骨头,试图减少术后并发症的发生。设计出一种组合式螺纹柄结构的人工股骨头由头颈部和螺柄部组成,假体柄呈圆锥型,表面有螺纹,能与髓腔充分接触以减少应力分布。柄部有2个骨槽,能防止假体柄旋转,头颈部和柄部通过头颈部的8个定位销子和柄部的8个定位孔相连,并用一枚螺丝固定。经生物力学试验,表明该人工关节满足强刚度要求,能形成牢固的生物学固定,松动、移位比较小,经10例手术证实,均无假体松动及下沉发生。作者认为该人工股骨头能减少松动、下沉的发生率,具有应用推广价值。     

Boneloc bone-cement: experience in hip arthroplasty during a 3-year period

Polymethyl methacrylate (PMMA) bone-cement was introduced in the 1960s for fixation of total hip arthroplasty replacement components. Long-term results of cement fixation for hip and knee arthroplasty have been extremely good. Although the use of PMMA bone-cement has enabled long-term survival of joint arthroplasty implants, there has been concern about aseptic loosening. This concern led to the introduction of Boneloc bone-cement (Biomet, Warsaw, IN) in the early 1990s. It was hoped that with the improved physical and chemical characteristics of Boneloc, there would be less aseptic loosening in the long-term. A clinical trial was conducted to evaluate Boneloc bone-cement in cementing the femoral component of the Bimetric total hip arthroplasty prosthesis in 33 hips in 32 patients. On follow-up, 7 stems (24%) developed definite loosening, and 3 stems (10%) were possibly loose. Of the 7 definite loose stems, 5 (17%) were revised because of increasing pain or progressive loosening. Despite the biologic advantages of Boneloc, this study suggests that the chemicals substituted in Boneloc bone-cement led to an alteration in its mechanical properties. These properties proved to be inferior to conventional PMMA bone-cement. There is possible time-dependent deterioration of mechanical properties leading to early aseptic loosening. The conventional PMMA bone-cement has stood the test of time. Research and experimental studies should continue to improve the mechanical properties of Boneloc before further human trials.     

Resurfacing hip arthroplasty. Classification of loosening and the role of prosthesis wear particles

Operative grading of loosening and histologic examination of the periprosthetic tissues and the femoral and acetabular bone-cement interfaces were undertaken in 72 revised resurfacing hip arthroplasties. By correlating the degree of macroscopic and microscopic loosening at the bone-cement interface, a classification of the stages of loosening at the bone-cement interface was devised. Examination of the femoral bone-cement interface of solidly fixed prosthesis components has demonstrated the presence of polyethylene wear particles and a macrophage response at the interface prior to loosening. This suggests that wear particles may migrate along bone-cement interfaces that are both macroscopically and microscopically solid, and emphasizes the important role of wear particles in prosthesis loosening.     

Early failure of revision total hip arthroplasty with cemented precoated femoral components: comparison with uncemented components at 2 to 8 years

This is a retrospective analysis of 2 methods of fixation of the femoral component in 86 consecutive revision arthroplasties, for which all clinical and radiographic data were recorded prospectively. There were 56 cemented revisions using precoated femoral components followed for 2 to 8 years (mean, 4 years) and 30 uncemented, proximally porous-coated femoral revisions followed for 2 to 6 years (mean, 4 years). Of the 56 cemented hips, 31 (55%) had a good or excellent clinical result. Rerevision has been performed in 10 hips, and revision of 3 loose femoral components is pending (23%). Radiographic review of 56 femoral components showed that 16 (29%) had probable or definite loosening. Of 30 cementless hips, 24 (80%) had a good or excellent clinical result. There was radiographic bone ingrowth in 22 of 30 hips (73%). Seven hips (23%) had nonprogressive subsidence, and 3 hips (10%) had progressive subsidence or loosening. Rerevision has been performed in only 2 hips (7%). The high rate of loosening (29%) and rerevision (23%) at a mean follow-up of only 4 years suggests that a precoated femoral component may place increased stress at the already damaged bone-cement interface.     

Outcomes of Long Tapered Hydroxyapatite-Coated Stems in Revision Total Hip Arthroplasty

The purpose of this study was to evaluate the outcome of femoral component revisions using a long tapered HA coated femoral revision stem. Between 2001 and 2008, 55 femoral component revisions were performed using this stem. Forty-one patients were available for follow up evaluation at average of 59 months. The clinical results were evaluated using the HHS and serial radiographs were evaluated for loosening. The mean HHS was 71 (range 22–100). Three hips required revision of KAR stem (1 aseptic loosening, 1 infection, 1 limb length discrepancy). Only one prosthesis demonstrated radiographic evidence of subsidence. Our study suggests that long tapered HA coated revision femoral components can provide stable fixation and in-growth in cases where there is good proximal femoral bone stock and favorable canal geometry.     

Aseptic loosening after total hip arthroplasty. Incidence, clinical significance, and etiology

Three hundred forty-one consecutive Charnley total hip arthroplasties were reviewed after a 3-10-year follow-up period to correlate the radiographic signs of aseptic loosening to clinical outcome, femoral cementing technique, and epidemiologic patient characteristics. High-grade femoral demarcation at the bone-cement interface (75-100%) correlated with a significantly higher incidence of unsatisfactory follow-up clinical scores. The incidence of high-grade femoral bone-cement demarcation and the associated radiographic signs of aseptic loosening had a direct correlation with the quality of the femoral cementing technique (P less than .01). Trochanter nonunion or trochanter separation demonstrated a highly significant correlation with high-grade femoral bone-cement demarcation (P less than .001). Patients having secondary total hip arthroplasty for failed cup arthroplasty or endoprosthesis had a higher rate of unsatisfactory pain and function scores, compared with those having arthroplasties performed after failed internal fixation. Male patients or patients with a high activity level demonstrated a twofold greater incidence of high-grade femoral demarcation (P less than .05). Patient weight by itself did not demonstrate any effect on radiographic outcome.     

Critical radiological analysis after Austin Moore hemiarthroplasty

The aim of this study is to investigate the causes of prosthesis loosening in patients treated with Austin Moore hemiarthroplasty (AMA). The clinical and radiological outcomes were documented in a quantitative manner after 7 years follow-up of 144 patients. At the time of final follow-up, 52 patients had died and 48 patients were lost to follow-up, leaving a total of 44 patients for analysis. Immediate post-operative X-rays were studied for the initial alignment of prosthesis, the fit of the prosthesis and the degree of osteoporosis. X-rays on latest follow-up were studied for evidence of loosening. All patients were assessed clinically with the hip score of hospital for special surgery. It was found that hip pain was significantly related to subsidence and pivoting of the prosthesis (P = 0.014 and 0.035, respectively). Significant increase in subsidence was noted if the stem of prosthesis was not fitting well within the shaft of femur (P = 0.006). When the patient was younger than 73 years old at the time of operation, there was more subsidence of the prosthesis at the final follow-up (P = 0.001). It was concluded that the fill of AMA within the shaft of femur should be greater than 70% to avoid early loosening. Relatively younger patients with acute fracture of the neck of femur should be treated by methods other than cementless AMA.     

Migration of cemented stem and restrictor after total hip arthroplasty: a radiostereometry study of 25 patients with Lubinus SP II stem

The aim of this study was to investigate the migration pattern of the Lubinus SP II prosthesis stem. Migration at the stem-cement and at the bone-cement interface was assessed. Twenty-five patients were studied by radiostereometry during a period of 2 years. The migration of the head, of 2 points on the collar, of the stem tip, and also of the cement restrictor, was measured. The collar and the head were found stable at 2 years' follow-up, whereas an anterior migration occurred at the stem tip (median, 0.3 mm; 25th percentile, 0.04 mm; 75th percentile, 1.27 mm). Virtually no subsidence or axial rotation of the stems was observed. An anterior migration of the restrictor marker was also observed, compatible with a rigid sagittal plane rotation of the stem and of the cement mantle about the collar. Therefore, stem tip migration occurred at the bone-cement interface. Key words: total hip arthroplasty, anatomic stem, radiostereometry, subsidence, bone-cement interface.     

A study of implant failure in the Wagner resurfacing arthroplasty

Using clinical, radiographic, and pathological data, we investigated eighteen cases of early aseptic failure of an implant in patients who had undergone reconstruction of the hip with a Wagner resurfacing prosthesis. Sixteen patients required revision for loosening of the acetabular component, with eight of them also demonstrating loosening of the femoral component. One patient had loosening of the femoral component without failure of the acetabular component, and one patient sustained a femoral neck fracture that was associated with osteonecrosis. Six of the patients with loosening of the acetabular component had an associated significant loss of acetabular bone stock. Loosening was associated with the development of a membrane at the bone-cement interface in all patients. Histological examination of the membrane demonstrated a marked foreign-body response to wear products from the arthroplasty. Bone resorption appeared active at the bone-membrane interface. We concluded that the acetabular component of the Wagner prosthesis is prone to early loosening and that the early loosening is potentiated by a foreign-body response to debris resulting from arthroplastic wear.     

Wagner resurfacing arthroplasty of the canine hip

Twelve surface replacement arthroplasties were performed on the hips of ten mongrel dogs using scaled-down replicas of the Wagner prosthesis. The contralateral hips and two further animals served as nonoperated controls. Animals were killed 5 months postoperatively. Clinical, radiological, histological and fluorochrome-labelling studies were employed to assess the bony and soft tissue reaction to resurfacing arthroplasty. There was no clinical or radiographic evidence of prosthetic loosening. Histological examination disclosed a thick foreign body and chronic inflammatory membrane containing acrylic cement and polyethylene wear particles at the bone-cement interface of both components. Generally, the bone marrow and trabecula were viable. There was evidence of increased bony remodelling and new bone formation in the subchondral area. The similarity between the above findings and those of aseptic component loosening in man suggests a mechanism whereby wear debris initiate a biological foreign body reaction culminating in component loosening.     

Wear of the acetabular socket: Comparison of polyacetat and polyethylene

Frictional characteristics of polyacetal (Delrin®) sockets and of ultra-high molecular weight polyethylene sockets retrieved in revision after aseptic loosening were compared with measurements of friction in new sockets. Friction in retrieved polyacetal sockets was twice as great as in retrieved polyethylene sockets. We also found that frictional characteristics of polyacetal changed as the material aged in vivo. In contrast, friction in polyethylene sockets remained fairly constant, even though most of them contained bone-cement particles. Friction in polyacetal sockets may be important for the relatively high incidence of socket loosening of the Christiansen prosthesis.

Measurements of wear of the polyacetal sockets showed a mean annual dimensional change of 240 mm³, four times greater than that reported for the Charnley polyethylene acetabular prosthesis.