Threaded acetabular components for primary and revision total hip arthroplasty

A clinical and radiographic review of 48 total hip arthroplasty patients with threaded acetabular components was undertaken at 24-44 months of follow-up study. Twenty-five patients had primary hip arthroplasties and 23 had revision procedures. Clinical scores revealed good to excellent results in 60% of primary and 30% of revision procedures. Radiographic analysis revealed stable acetabular components in 88% of primary and 61% of revision procedures. Potentially loose acetabular components were noted in 8% of primary and 4.3% of revision procedures and loose acetabular components in 4% of primary and 34.7% of revision procedures. The rate of acetabular component loosening was considered unacceptably high in revision cases and an area of concern in primary cases. Discretionary use of these components is advised.     

Extra-large uncemented hemispherical acetabular components for revision total hip arthroplasty

BACKGROUND: Extra-large uncemented components provide several advantages for acetabular revision, but limited information is available on the results of their use. The purpose of this study was to evaluate, at a minimum of five years, the results associated with the use of an extra-large uncemented porous-coated component for acetabular revision in the presence of bone loss. METHODS: Eighty-nine extra-large uncemented hemispherical acetabular components were used for revision after aseptic failure of a total hip arthroplasty in forty-six men and forty-three women (mean age at revision, fifty-nine years; range, thirty to eighty-three years). The revision implant (a Harris-Galante-I or II cup fixed with screws) had an outside diameter of > or = 66 mm in men and > or = 62 mm in women. Seventy-nine patients had a segmental or combined segmental and cavitary acetabular bone deficiency before the revision. Particulate bone graft was used in fifty-four hips and bulk bone graft, in nine. RESULTS: One patient died with the acetabular component intact and two patients were lost to follow-up within five years after the operation. At the time of the last follow--up, four acetabular components had been removed or revised again (two for aseptic loosening). All of the remaining patients were followed clinically for at least five years (mean, 7.2 years; range, 5.0 to 11.3 years). In the hips that were not revised again, only two sockets had definite radiographic evidence of loosening. All four of the sockets that loosened were in hips that had had combined cavitary and segmental bone loss preoperatively. In the hips that were not revised again, the mean modified Harris hip score increased from 56 points preoperatively to 83 points at the time of the most recent follow-up. The most frequent complication, dislocation of the hip, occurred in eleven patients. The probability of survival of the acetabular component at eight years was 93% (95% confidence interval, 85% to 100%) with removal for any reason as the end point, 98% (95% confidence interval, 92% to 100%) with revision for aseptic loosening as the end point, and 95% (95% confidence interval, 88% to 100%) with radiographic evidence of loosening or revision for aseptic loosening as the end point. CONCLUSIONS: This study demonstrates that extra-large uncemented components used for acetabular revision in the presence of bone loss perform very well and have a low rate of aseptic loosening at the time of intermediate-term follow-up.     

Bilobed oblong porous coated acetabular components in revision total hip arthroplasty

Thirty-eight oblong bilobed noncustom uncemented, porous-coated titanium acetabular components were used to reconstruct failed hip arthroplasties with large superior segmental acetabular bone deficiencies. No structural bone grafts were used. All patients were followed up for 2 to 5 years (mean, 3 years) after the operation. One patient (whose socket rested primarily on a structural bone graft from a previous procedure) had revision surgery for acetabular loosening. No other patients have had revision surgery or had another ipsilateral hip operation. At latest followup, 35 patients had no or mild pain and two patients had moderate pain. Two implants migrated more than 2 mm in the first year, then stabilized. On the latest radiographs, two implants had bead shedding, but there was no measurable migration or change in position. For selected patients with large superolateral acetabular bone deficiencies, this implant facilitated a complex reconstruction, provided good clinical results, and showed satisfactory stability at early to midterm followup in most patients.     

Fate of cementless acetabular components retained during revision total hip arthroplasty

BACKGROUND: Removal of a well-fixed cementless acetabular component can result in increased operative time and postoperative morbidity. The objectives of this retrospective study were to determine whether retention of a well-fixed acetabular component at the time of isolated femoral revision was compatible with long-term socket survival. METHODS: The records of eighty-three consecutive patients (ninety hips) in whom a well-fixed cementless socket had been retained during revision of a femoral component were reviewed. The mean age of the patients was 48.7 years at the time of the primary arthroplasty and 54.1 years at the time of femoral revision. The radiographic analysis was based on anteroposterior radiographs and was performed by a single independent reviewer. The intraoperative criterion for stability of the socket was the absence of movement at the bone-implant interface during the application of direct pressure to the edges of the socket in four quadrants with use of a metallic pusher. RESULTS: At the time of the isolated femoral revision, no socket demonstrated a radiolucent line measuring >1 mm in any two zones and forty of the ninety hips had periacetabular osteolysis. The mean size of the osteolytic lesions was 5.71 cm(2) (range, 0.4 to 24.2 cm(2)), and twenty-eight of the forty hips underwent bone-grafting. The mean duration of follow-up was 9.7 years after the isolated femoral revision and 14.9 years after the primary arthroplasty. Five acetabular sockets were revised at a mean of 6.8 years after the femoral revision. Only one of these sockets had failed because of aseptic loosening. With revision of the acetabular component for any reason as the end point, the survival rate was 98.7% at five years and 93.5% at ten years after the femoral revision and 100% at ten years and 93.9% at fifteen years after the primary arthroplasty. No hip showed recurrence or expansion of periacetabular osteolysis. The prevalence of dislocation was 16% (fourteen of ninety). CONCLUSIONS: Revision of a stable, cementless acetabular component solely on the basis of its duration in vivo or the presence of periacetabular osteolysis does not appear to be warranted. Retention of the socket with grafting of larger periacetabular osteolytic lesions appears to be consistent with satisfactory socket longevity.     

Structural acetabular allograft in revision total hip arthroplasty

Structural allografts are a surgical option only in cases of severe bone loss. Structural allografting techniques have been developed to fill large bony defects and can be used to provide structural support and reconstitute bone stock. Superior dome allografts are utilized when 50% or more of host bone is available for contact with the ingrowth cup. In revision surgery where the allograft supports more than 50% of the reconstruction, complications are more common. Although good results are reported, implant failure and graft resorption are more commonly seen. The addition of a reconstruction ring to the reconstruction unloads some of the stress applied to the allograft. In these cases, superior results have been reported.     

Cementless acetabular reconstruction in revision total hip arthroplasty

Reconstruction of the failed acetabular component in total hip arthroplasty (THA) can be challenging. Although there are multiple reconstructive options available, a cementless acetabular component inserted with screws has been shown to have good intermediate-term results and is the reconstructive method of choice for the majority of acetabular revisions. We reviewed the results of 138 consecutive acetabular revisions done with a hemispheric, cementless acetabular component that is sintered with Ti fiber metal mesh and was inserted with line-to-line reaming and multiple screws for fixation. At a mean of 15 years, 19 acetabular components had been revised (13.8%); seven were revised for recurrent instability, six were revised for deep periprosthetic infection, five well-fixed cups were removed at the time of femoral revision, and one cup was fixed by fibrous tissue only at the time of femoral revision and was removed. One acetabular component was radiographically loose. Survivorship of the component was 81% at 15 years when revision for any reason was considered as an end point and 96% when revision for loosening or radiographic evidence of loosening was considered as a second end point. Cementless acetabular revision provides durable results at 15 years with a low rate of failure for loosening.     

A new technique for removing noncemented acetabular components in revision total hip arthroplasty

Removal of noncemented acetabular components during revision surgery can be a time-consuming technical challenge, resulting in exacerbation of defects and compromised bone stock. These factors are deleterious to reconstructive efforts and can compromise clinical results. A technique is described that can accomplish timely removal of noncemented acetabular components. The advantages of this technique include no further weakening of the remaining structural supports, minimal bone loss, avoidance of intrapelvic perforations, and reduction in operative time.     

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。     

全髋翻修术中髋臼骨缺损翻修重建

全髋关节置换术后髋臼失败的翻修重.是骨科医生面临的巨大的技术挑战.翻修时面对广泛的髋臼骨缺损,可能需要采用几种不同技术,尽可能使髋臼侧恢复到初次全髋关节置换术时的骨量.获得翻修假体初始稳定是翻修手术成功的关键.该文就全髋翻修术中髋臼骨缺损的分类、术前计划和翻修重建策略作一综述.     

Management of acetabular bone loss in revision total hip arthroplasty

Most acetabular revisions can be managed with a hemispherical component with screw fixation. Areas of segmental bone loss that preclude acetabular component stability may be managed with structural allograft or second-generation porous metal augments. Acetabular cages have a limited application but can be a useful tool in the management of massive bone loss and pelvic discontinuity.     

Extensile anterior column acetabular reconstruction in revision total hip arthroplasty

The extensile triradiate approach, with anterior-column plate reconstruction using structural allografts, was used in 12 cases. Pelvic discontinuity requiring posterior-plate application was present in eight of these cases. Allograft reconstructions seemed to be radiographically incorporated by approximately 8 months postoperatively and all discontinuities united. The results were excellent in four cases, good in two cases, fair in three cases, and poor in three cases. Two cups were revised for loosening. Deep sepsis resulted in graft and component removal in two cases. At reexploration, discontinuity and allografts were noted to be healed in these cases.     

Trabecular metal acetabular components in primary total hip arthroplasty

Background and purpose — Trabecular metal (TM) cups have demonstrated favorable results in acetabular revision and their use in primary total hip arthroplasty (THA) is increasing. Some evidence show that TM cups might decrease periprosthetic infection (PPI) incidence. We compared the survivorship of TM cups with that of other uncemented cups in primary THA, and evaluated whether the use of TM cups is associated with a lower risk of PPI.

Patients and methods — 10,113 primary THAs with TM cup and 85,596 THAs with other uncemented cups from 2 high-quality national arthroplasty registries were included. The mean follow-up times were 3.0 years for the TM cups and 3.8 years for the other uncemented cups.

Results — The overall survivorship up to 8 years for TM cups and other uncemented cups was 94.4% and 96.2%, respectively (p = < 0.001). Adjusting for relevant covariates in a Cox regression model the TM cups had a persistently higher revision risk than other uncemented cups (HR =1.5, 95% CI 1.4–1.7, p = < 0.001). There was a slightly higher, though not statistically significant, revision rate for PPI in the TM group (1.2, 95% CI 1.0–1.6, p = 0.09).

Interpretation — Risk of revision for any reason was higher for the TM cup than for other uncemented cups in primary THA. In contrast to our hypothesis, there was no evidence that the revision rate for PPI was lower in the TM cup patients. Regardless of the promising early and mid-term results for TM cups in hip revision arthroplasty, we would like to sound a note of caution on the increasing use of the TM design, especially in uncomplicated primary THAs, where uncemented titanium cups are considered to provide a reliable outcome.     

Aortic thrombosis after acetabular revision of a total hip arthroplasty

In the case described, infrarenal aortic thrombosis occurred after acetabular component revision in an 86-year-old man with recurrent dislocation of a total hip arthroplasty. Early diagnosis and prompt emergency vascular bypass operation were successful in restoring flow to the extremity, although the dislocation recurred. The literature is reviewed, and judicious steps for the avoidance of this serious complication are discussed.     

人工全髋关节翻修术中髋臼骨缺损的分类和重建

人工全髋关节置换术作为一项逐渐成熟的技术,已经被越来越多的骨科医师所熟知和开展,但随之也使髋关节翻修术患者增多。翻修的原因主要包括假体的无菌性松动、不稳、周围骨折、内衬磨损等,而髋臼骨缺损和髋臼假体的选择一直困扰着广大医师。本文总结了人工全髋关节翻修术中髋臼骨缺损的分类和重建,比较各种分类法的优缺点,在此基础上有多种植骨方式及髋臼假体的选择来重建髋臼,阐述了植骨的材料来源、植骨方式、复杂髋臼骨缺损的重建以及假体固定方式的选择,为临床医生处理各种髋臼骨缺损提供依据,以期更精准地指导临床个体化治疗。     

Use of constrained acetabular liners in total hip arthroplasty

The use of constrained acetabular liners is indicated when soft-tissue tensioning techniques such as femoral neck lengthening, component repositioning, and use of lateralized acetabular liner are ineffective. It is most commonly used as a salvage procedure in revision situations. However, a locking acetabular insert may be used for primary THAs in patients with joint or soft-tissue laxity, neuromuscular disease, or intraoperative instability. In addition to the described commercially available liners, several manufacturers will provide customized components on request.     

Removal of well-fixed, cementless, acetabular components in revision hip arthroplasty

Removal of well-fixed, cementless, acetabular components during revision arthroplasty remains a challenging problem. Further damage to host bone may limit options for reconstruction and compromise the long-term result of the revision operation. We report the results of 31 hips with well-fixed, cementless sockets which were removed using a new cup extraction system. In all hips the socket was removed without difficulty and with minimal further bone loss.     

Reliability of acetabular bone defect classification systems in revision total hip arthroplasty

Three classifications for assessment of acetabular bone loss were evaluated for their reliability. The 3 systems assessed were the system described by Gross, the system described by Paprosky, and the classification of the American Academy of Orthopaedic Surgeons. In this study, we assessed their reliability based on the preoperative radiographs alone. Intraobserver agreement was measured by evaluating the classifications by the 3 innovators, 3 reconstructive orthopaedic surgeons, and 3 residents. Interobserver agreement was assessed among the reconstructive surgeons and the residents. The unweighted kappa statistic was used to establish levels of agreement. The innovators had better intraobserver agreement than the other 2 groups. Their agreement was only in the moderate range, however. For the noninnovators, intraobserver and interobserver agreement generally was poor for all 3 classifications assessed. Our results indicate that these classifications do not provide statistically reliable information for preoperative assessment of acetabular bone stock loss.     

Cementless total hip arthroplasty with structural allograft for massive acetabular defect in hip revision

Objective： To study retrospectively 20 hip revison patients treated by cementless total hip arthroplasty with structural allograft. Methods： Twenty patients suffering from aseptic loosening of an uncemented cup complicated by a large defect underwent cementless total hip arthroplasty with structural allograft and were followed up for at least 5 years. Clinical results were evaluated by Harris score and leg length measurements. Radiographic analysis included implants migration, graft absorbance, osteolysis and liner wear. Results： No cup loosening or graft reabsorption was found at final follow-up. Clinical improvements in pain and functional status were demonstrated during the follow-up period. The mean Harris hip scores improved from 29 preoperatively （range 20-41） to 81 postoperatively （range 73-89）. Conclusion： Our study shows that cementless total hip arthroplasty with allograft is a good way for massive defect in aeetabular bone stock.     

保留髋臼杯更换聚乙烯衬垫在全髋关节翻修术中的应用

目的 探讨保留髋臼杯更换聚乙烯衬垫在全髋关节翻修术中的作用.方法 1995年4月至2007年12月,80例(93髋)接受保留髋臼杯更换聚乙烯衬垫手术.男41例,女39例;年龄27～82岁,平均53.3岁.初次置换与更换衬垫手术间隔0.3～18.4年,平均10.9年.翻修原因:聚乙烯磨损及骨溶解78髋,聚乙烯接近完全磨损但无骨溶解5髋,聚乙烯磨损及股骨柄假体松动4髋,复发性关节脱位3髋,感染1髋,假体周围骨折1髋,衬垫脱位1髋.翻修衬垫采用高交联聚乙烯60髋、普通聚乙烯33髋,以骨水泥固定47髋、原锁定机制固定46髋.结果 随访5～15年,平均7年.术前Harris髋关节评分(86.0±16.9)分,终末随访时(89.4±11.6)分.并发症包括脱位10髋,感染2髋,假体周围骨折1髋,衬垫脱落1髋.10髋再次翻修:髋臼杯翻修5髋,普通聚乙烯磨损2髋,感染2髋,衬垫脱落1髋.普通聚乙烯组新发骨溶解12髋.以假体松动为终点,十年生存率骨水泥固定组100％、原锁定机制固定组84.8％;以再次翻修为终点,十年生存率分别为90.4％和65.0％.结论 以骨水泥或原锁定机制固定翻修衬垫均安全有效.高交联聚乙烯耐磨性较好,能降低骨溶解风险,假体存活率更高.