全髋关节置换术的软组织平衡

目的探讨THA术后股骨偏心距恢复的重要性及重建方法,恢复髋关节的软组织平衡。方法对73例单侧THA术患者进行随访,手术均采用髋关节后外侧入路。X线片上测量股骨偏心距及髋外展肌的力臂,使用Cybex测量髋外展肌力量,对X线片测量数据进行统计学处理。结果股骨偏心距是否能够重建与髋最大外展肌肌力存在显著性差别(t=3.859;P=0.002);髋关节外展活动范围与股骨偏心距存在明显回归相关关系(r=0.593,P<0.001)。结论THA术中重建股骨偏心距可以增加髋外展肌的力臂,改善髋外展肌的力量,增强髋关节的稳定性。术中应选用近似解剖颈干角的股骨柄假体,适当地增加假体颈的长度。     

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。     

Optimizing femoral anteversion and offset after total hip arthroplasty, using a modular femoral neck system: an experimental study

To investigate the effectiveness of a modular femoral neck system, consisting of two neutral and four types of retroverted necks for the correction of femoral anteversion and offset in total hip arthroplasty, an experimental study was carried out, using sawbones with four different angles of femoral anteversion (16°, 34°, 47°, and 59°). With the neutral neck, reconstruction of the preoperative anteversion and offset in the normal femur was achieved. While the 15° retroverted long neck was effective for the mildly or moderately anteverted femur, this retroverted neck showed insufficient correction for the severely anteverted femur. This modular neck system proved to be useful for correction of the medial component of femoral offset in femora with anteversion of less than 47°. For patients with greater anteversion, a feature which is rarely seen in the clinical situation, femoral necks with a greater degree of retroversion may be useful. Received: September 3, 1999 / Accepted: March 29, 2000     

Navigation for total hip arthroplasty

Despite increasing advantages in biomaterials, prosthetic designs, and implant fixation, clinical outcome of total hip arthroplasty (THA) has 10% failure rate after 10 years. Component malposition is well known to be responsible for instability, impingement, excessive wear and early loosening. Computer-assisted procedures are expected to improve the accuracy of the components positioning and also the outcome of total hip replacements. We present the Amplivision. system (Amplitude, Porte-du-Grand-Lyon, Neyron, France) that has been used since October 2005 for total hip replacements at our institution. The surgical technique as well as the advantages of this system is described. The Amplivision© system allows accurate positioning of the acetabular and femoral components during THA and also the control of leg lengthening, offset and stability.     

初次人工全髋关节置换术中髋臼骨折的原因及处理

目的探讨初次行人工全髋关节置换术(total hip arthroplasty,THA)术中发生髋臼骨折的原因和处理方法。方法 2005年5月-2008年7月,9例9髋初次行THA患者术中发生髋臼骨折。男1例,女8例;年龄41～73岁,平均63.3岁。发育性髋关节发育不良4例,类风湿性关节炎2例,陈旧性股骨颈骨折1例,股骨头缺血性坏死1例,强直性脊柱炎1例。病程1～35年,平均19.5年。左髋3例,右髋6例。Harris评分为(40.4±2.9)分。患者均选择非骨水泥型假体。术中发生髋臼前壁骨折2例,后壁骨折6例,均属稳定型骨折,1例未作特殊处理,余7例给予3～4枚螺钉加强固定;后壁骨折伴后柱不全骨折1例,属不稳定型骨折,给予髋臼杯底植骨联合3枚螺钉固定。结果术后X线片检查示假体位置良好。切口均Ⅰ期愈合,无早期并发症发生。9例患者均获随访,随访时间1～4年,平均2年7个月。末次随访时Harris评分为(87.8±3.9)分,与术前比较差异有统计学意义(t=44.904,P=0.000)。X线片检查示,骨折均于术后8周达临床愈合;随访期间未发现髋臼假体周围透亮带及松动表现。结论初次行THA术前应仔细测量,术中充分显露,精细操作,避免暴力。非骨水泥型髋臼假体直径不应超过髋臼锉直径2 mm;对于骨质疏松患者,宜选用与髋臼锉直径相同的假体并用螺钉固定,或直接采用骨水泥型假体。一旦术中发生髋臼骨折,可根据骨折类型和假体稳定性选用增加螺钉固定或植骨配合多枚螺钉固定。     

Incidence of embolic events during acetabular prosthesis insertion in total hip arthroplasty,and effect of intramedullary decompression in preventing embolism: higher risk of embolism with one-piece type prosthesis

PURPOSE: In total hip arthroplasty (THA), there is a high risk of bone marrow embolism during femoral prosthesis insertion. However, the incidence during acetabular prosthesis insertion has received less attention. The first goal of this study was to determine the incidence of bone marrow embolism associated with acetabular prosthesis insertion. The second goal was to evaluate the effects of intramedullary decompression of the acetabulum in suppressing bone marrow embolism. METHODS: To achieve the first goal, we evaluated the effects of prosthesis insertion on the incidence of bone marrow embolism, and on respiratory and cardiovascular dynamics. For the evaluation of bone marrow embolism, images obtained by transesophageal echocardiography were rated using Pitto's classification. To achieve the second goal, patients undergoing THA with a one-piece type acetabular prosthesis were divided into a control group and an acetabulum-decompression group, and the effects of insertion were analyzed in the same fashion. RESULTS: In the 150 patients in the study, bone marrow embolism was rated as grade 0 in 9, grade 1 in 46, grade 2 in 61, and grade 3 in 34 patients. Patients rated as grade 2 and 3 exhibited significant reductions in blood pressure and Pa(O) (2) 5 min after acetabular prosthesis insertion. The results of multivariate analysis suggested that the incidence of bone marrow embolism was higher for the one-piece type prosthesis than for the two-piece type. Among the 60 patients who underwent THA with a one-piece type prosthesis, the incidence of bone marrow embolism was significantly lower in the decompression group. CONCLUSION: As there are increasing indications for one-piece type acetabular prostheses in Japan, we must pay attention to the possibility of bone marrow embolism, not only during femoral prosthesis insertion but also during acetabular prosthesis insertion.     

Femoral anteversion, femoral offset, and abductor lever arm after total hip arthroplasty using a modular femoral neck system

We studied the effectiveness of a modular femoral neck system for the adjustment of femoral anteversion, femoral offset, and abductor lever arm during total hip arthroplasty (THA) using computed tomography data, and comparing findings in patients with a modular neck femoral component (116 hips) with those in patients with a cemented femoral component (23 hips). In the modular neck group, we intraoperatively evaluated various impingements using trial necks and heads, and selected the appropriate combination of modular neck and head from two types of straight neck, four types of anteverted/retroverted neck, two types of medialized/lateralized neck, and two types of varus/valgus neck. In the cement group, femoral anteversion was not changed using undersized stems, and an appropriate modular head was selected. While the 15° retroverted necks effectively corrected femora with a mean anteversion of 40.0° (range 28.8°–53.1°), the 15° anteverted necks were effective for femora with a mean anteversion of 14.2° (range, 3.3°–21.9°). Use of the straight or varus necks resulted in an average abductor lever arm value of more than 40 mm, with a mean anteversion of 26.4°. In patients with preoperative anteversion of more than 30°, postoperative anteversion was significantly smaller in the modular neck group than in the cement group (29.6 ± 4.2° vs. 35.3 ± 3.6°). This modular neck system effectively adjusted femoral anteversion and abductor lever arm in femora with various preoperative anteversion values. Received: March 21, 2001 / Accepted: August 20, 2001     

人工全髋关节置换术后髋臼假体初始不稳定原因分析及处理

目的探讨初次人工全髋关节置换术后髋臼假体初始不稳定的原因及处理方法。方法回顾性分析2003年1月-2010年6月初次人工全髋关节置换术后出现髋臼假体初始不稳定行髋臼翻修术的19例患者临床资料。男11例,女8例;年龄55～79岁,平均67.2岁。左髋9例,右髋10例。应用骨水泥型髋臼假体7例,非骨水泥型12例。初次置换术后3周～6个月行翻修术,平均4.5个月。分析髋臼假体初始不稳定的原因,比较翻修术前后髋臼假体骨覆盖率及髋关节功能Harris评分。结果髋臼假体初始不稳定与髋臼的处理、假体的选择及放置角度、骨水泥操作技术不当等有关。翻修术后l例出现坐骨神经麻痹,7周后自行恢复;1例髋臼前壁轻微骨折,3个月后骨折愈合。术后切口均Ⅰ期愈合,无关节假体周围感染、血管损伤、假体脱位、下肢深静脉血栓形成等并发症发生。术后患者均获随访,随访时间11～73个月,平均28个月。患者均未出现髋臼假体初始不稳定。髋臼假体骨覆盖率由初次置换时的67.9%±5.5%提高至翻修术后87.7%±5.2%,差异有统计学意义(t=11.592,P=0.003)。末次随访时Harris评分为(84.4±4.6)分,较术前的(56.5±9.3)分显著提高(t=11.380,P=0.005)。结论术前详细计划、选择合适的假体、妥善处理髋臼、按合理角度植入髋臼假体有助于获取良好的髋臼假体初始稳定性。     

全髋与半髋关节置换术治疗老年人股骨颈骨折结果比较

目的 比较全髋关节置换术与半髋关节置换术治疗老年人完全移位股骨颈骨折的疗效。方法 将1995～2001年在我院治疗的262例60岁以上有移位的股骨颈骨折患者分为两组，A组为全髋关节置换术，B组为人工股骨头置换术。随访12～78个月，平均37个月。结果 按Harris评分标准，A组术后优良率达到93.8％；B组术后优良率达78.4％，单极与双极股骨头置换组之间结果没有明显的差别；人工股骨头置换后有5例需行全髋翻修手术；双极人工股骨头置换中有2例发生双极之间脱位，7例出现假体周围骨溶解。结论 人工股骨头或全髋关节置换术是治疗老年股骨颈骨折的有效方法，可提高老年人的生活质量，减少并发症。全髋关节置换结果优于人工股骨头置换。     

Computer-assisted cup positioning in total hip arthroplasty: usefulness, limits and future

The basic hypothesis for computer-assisted placement of the cup in total hip arthroplasty (THA) is that navigation will improve cup positioning around the targeted values previously defined in the literature as the gold standard for cup placement and reduce the number of outliers. Reducing the outliers will theoretically reduce the number of dislocation, improve range of motion and reduce wear. We will present the surgical technique, and the results of a prospective randomized study comparing computer-assisted cup positioning with free-hand placement. Furthermore we will outline some limitations of the navigation systems in hip surgery observed during our early experience through the results of complementary anatomical and clinical studies. Finally we will discuss the potential for future development of computer-assisted THA.     

Total hip arthroplasty in acetabular fractures

Total Hip Arthroplasty (THA) is a well-accepted treatment for established hip arthritis following acetabular fractures. If a conservatively managed or operated case progresses to non-union/mal-union failing to restore the joint integrity, it may eventually develop secondary arthritis warranting a total hip arthroplasty. Also, in recent years, acute total hip arthroplasty is gaining importance in conditions where the fracture presents with pre-existing hip arthritis, is not amenable to salvage by open reduction and internal fixation, or, a poor prognosis is anticipated following fixation.There are several surgical challenges in performing total hip arthroplasty for acetabular fractures whether acute or delayed. As a separate entity elderly patients pose a distinct challenge due to osteoporosis and need stable fixation for early weight bearing alleviating the risk of any thromboembolic event, pulmonary complications and decubitus ulcer. The aim of surgery is to restore the columns for acetabular component implantation rather than anatomic fixation. Meticulous preoperative planning with radiographs and Computed Tomography (CT) scans, adequate exposure to delineate the fracture pattern, and, availability of an array of all instruments and possible implants as backup are the key points for success. Previous implants if any should be removed only if they are in the way of cup implantation or infected. Press fit uncemented modern porous metal acetabular component with multiple screw options is the preferred implant for majority of cases. However, complex fractures may require major reconstruction with revision THA implants especially when a pelvic discontinuity is present.     

Total hip arthroplasty in acetabular fractures

Total Hip Arthroplasty (THA) is a well-accepted treatment for established hip arthritis following acetabular fractures. If a conservatively managed or operated case progresses to non-union/mal-union failing to restore the joint integrity, it may eventually develop secondary arthritis warranting a total hip arthroplasty. Also, in recent years, acute total hip arthroplasty is gaining importance in conditions where the fracture presents with pre-existing hip arthritis, is not amenable to salvage by open reduction and internal fixation, or, a poor prognosis is anticipated following fixation.There are several surgical challenges in performing total hip arthroplasty for acetabular fractures whether acute or delayed. As a separate entity elderly patients pose a distinct challenge due to osteoporosis and need stable fixation for early weight bearing alleviating the risk of any thromboembolic event, pulmonary complications and decubitus ulcer. The aim of surgery is to restore the columns for acetabular component implantation rather than anatomic fixation. Meticulous preoperative planning with radiographs and Computed Tomography (CT) scans, adequate exposure to delineate the fracture pattern, and, availability of an array of all instruments and possible implants as backup are the key points for success. Previous implants if any should be removed only if they are in the way of cup implantation or infected. Press fit uncemented modern porous metal acetabular component with multiple screw options is the preferred implant for majority of cases. However, complex fractures may require major reconstruction with revision THA implants especially when a pelvic discontinuity is present.     

人工全髋关节置换治疗髋臼内陷症的早期疗效

目的探讨人工全髋关节置换治疗髋臼内陷症的方法及早期疗效。方法 2006年1月-2010年2月,收治髋臼内陷症16例16髋。男6例,女10例;年龄39～72岁,平均56.5岁。病程1年6个月～35年,中位病程6.4年。左髋7例,右髋9例。原发性3例,继发性13例。髋关节Harris评分为(49.5±5.5)分。髋臼内陷按Dunlop等的诊断标准分度:轻度3例,中度9例,重度4例。患者均行人工全髋关节置换,髋臼重建时采用植骨及非骨水泥型髋臼假体恢复患髋股骨偏心距及髋臼旋转中心。结果术后16例切口均Ⅰ期愈合,无感染及下肢深静脉血栓形成等并发症发生。患者均获随访,随访时间12～62个月,平均37个月。末次随访时,髋关节Harris评分为(90.5±4.5)分,与术前比较差异有统计学意义(t=49.578,P=0.000)。X线片显示假体位置良好,无松动、下沉,植骨与髋臼融合,无髋臼再次内陷。结论人工全髋关节置换治疗髋臼内陷时,采用植骨及非骨水泥型髋臼假体恢复患髋股骨偏心距及髋臼旋转中心,可获满意早期疗效。     

重建股骨偏心距对人工全髋关节置换术后骨盆稳定性的影响

目的 探讨人工全髋关节置换术后股骨偏心距对行走过程中骨盆稳定性的影响.方法 2000年1月-2005年12月,29例患者行单侧人工全髋关节置换术.男10例,女19例;年龄33～75岁,平均64.3岁.左髋15例,右髋14例.随访时间5～10年,平均7.7年.末次随访时Harris评分为90～100分,平均97分.末次随...     

Effect of screw fixation on acetabular component alignment change in total hip arthroplasty

Purpose

The use of screws can enhance immediate cup fixation, but the influence of screw insertion on cup position has not previously been measured. The purpose of this study was to quantitatively evaluate the effect of intra-operative screw fixation on acetabular component alignment that has been inserted with the use of a navigation system.

Methods

We used a navigation system to measure cup alignment at the time of press-fit and after screw fixation in 144 hips undergoing total hip arthroplasty. We also compared those findings with factors measured from postoperative radiographs.

Results

The mean intra-operative change of cup position was 1.78° for inclination and 1.81° for anteversion. The intra-operative change of anteversion correlated with the number of screws. The intra-operative change of inclination also correlated with medial hip centre.

Conclusion

The insertion of screws can induce changes in cup alignment, especially when multiple screws are used or if a more medial hip centre is required for rigid acetabular fixation.     

Cost-effectiveness of cemented versus cementless total hip arthroplasty. A Markov decision analysis based on implant cost

Background Probabilistic decision analysis is a means of reflecting the uncertainty parameter in models and of presenting it in a comprehensible manner to decision-makers. Materials and methods A cost-effectiveness model was constructed to compare the cementless and cemented total hip prostheses implanted at our department in terms of lifetime costs and quality-adjusted life-years (QALY). Revision rates were obtained from the Orthopaedic Prosthesis Register of the Laboratory of Medical Technology, Istituti Ortopedici Rizzoli, Bologna, Italy. Results The risk of early revision (at 5 years of follow-up) for cementless and cemented prostheses was 1.6% and 1.4%, respectively, resulting in equal QALY for the two implant types. Analysis of mean cost and QALY indicated that use of either implant is not associated with cost savings. Discussion Management with cementless or cemented total hip prostheses in a theoretical cohort of 70-year-old patients with fracture of the femoral neck or arthritis involving the hip is not significantly different according to the probabilistic results from the model.     

联合前倾角技术在成人发育性髋关节发育不良全髋关节置换术中的应用

目的探讨联合前倾角技术在成人发育性髋关节发育不良全髋关节置换术中应用的可行性及临床价值。方法回顾性分析自2016-09—2018-06采用联合前倾角技术行全髋关节置换术治疗的31例(36髋)成人发育性髋关节发育不良,比较手术前后髋臼前倾角、股骨前倾角、联合前倾角及髋关节功能Harris评分。结果31例均获得12个月以上随访。术后骨盆正位及髋关节侧位X线片显示假体位置及对应关系良好,无假体松动、下沉,无脱位表现。末次随访时所有患者步态均明显改善,髋部疼痛均消失,仅2例轻度跛行。术后髋臼前倾角、股骨前倾角、联合前倾角较术前明显减小,末次随访时髋关节功能Harris评分较术前明显增加,差异有统计学意义(P<0.05)。结论联合前倾角技术应用于成人发育性髋关节发育不良全髋关节置换术对于指导合适假体的选择、设计以及确定合适的髋臼前倾角、股骨柄前倾角具有重要意义,良好的联合前倾角能够有效预防术后假体脱位的发生。     

Pitfalls in the use of acetabular reinforcement rings in total hip revision

Introduction: For the reconstruction of acetabular bone defects different types of acetabular reinforcement rings are being used. In clinical practice, these implants showed to some extent good long-term results. In the present work pitfalls and complications after the implantation of acetabular reinforcement rings as well as possible solutions are being discussed. Material and methods: In the first case recurrent dislocation was caused by the malposition of the acetabular component with an impingement of the protruding bone cement and the anterior edge of the acetabular ring as well as muscle insufficiency as a result of the shortening of the leg length. The second case revealed an impingement of the iliopsoas tendon due to a protruding acetabular reinforcement ring. During revision, bone cement was used to smoothen the protruding anterior edge of the acetabular reconstruction ring in order to obtain a relieved sliding of the tendon. Furthermore, we report on the case of a delayed neuropathy of the sciatic nerve after reconstruction of the acetabulum with an acetabular reinforcement ring. Results: Intraoperatively an impingement of the sciatic nerve at the protruding dorsal edge of the acetabular reinforcement ring and the surrounding scar tissue was found. In a further case an aseptic loosening of an acetabular reinforcement ring caused the formation of an excessive granuloma with a large intrapelvic portion. The granuloma led to persisting senso-motoric deficits of the femoral nerve. In summary, based on these clinical cases possible pitfalls, associated with the use of acetabular reinforcement rings, are shown. The mal-positioning and the intra-operative re-shaping of the implant by the surgeon are pointed out as the substantial factors for the occurrence of an impingement phenomenon and total hip instability. Furthermore, in case of an adequate orientation of the cemented polyethylene insert an improper position of the acetabular ring which results in protruding edges has to be considered as a cause of a prosthetic impingement. Conclusion: The cases presented emphasize the necessity of prevention of such pitfalls intra-operatively as well as accurate analysis of implant failures. Furthermore, they suggest explicit preoperative planning before deciding on the strategy of revision surgery of acetabular reinforcement rings.No benefits or funds were received for this work.     

Influencing factors for the increased stem version compared to the native femur in cementless total hip arthroplasty

Purpose

Stem version is not always equivalent to femoral neck version (native version) in cementless total hip arthroplasty (THA). We therefore examined the discrepancy of version between the native femoral neck and stem using pre- and postoperative computed tomography (CT), the level of the femur where the canal version most closely fit the stem version, and the factors influencing version discrepancy between the native femoral neck and stem.

Methods

A total of 122 hips in 122 patients who underwent primary THA using a metaphyseal-fit stem through the postero-lateral approach were included. Pre- and postoperative CT images were utilized to measure native and stem version, and the version of the femoral canal at four levels relative to the lesser trochanter.

Results

The mean native and stem versions were 28.1 ± 11.0° and 38.0 ± 11.2°, respectively, revealing increased stem version with a mean difference of 9.8° (p < 0.0001). A total of 84 hips (68.9 %) revealed an increase in version greater than 5°. Femoral canal version at the level of the lesser trochanter most closely approximated that of stem version. Among the factors analysed, both univariate and multivariate analysis showed that greater degrees of native version and anterior stem tilt significantly reduced the version discrepancy between the native femoral neck and stem version.

Conclusions

Since a cementless stem has little version adjustability in the femoral canal, these findings are useful for surgeons in preoperative planning and to achieve proper component placement in THA.