Fixation and osteolysis in plasma-sprayed hemispherical cups with hybrid total hip arthroplasty

The optimal surface finish on cementless total hip arthroplasty is still a matter of debate. 145 hips in 130 patients with hybrid total hip arthroplasty using a hemispherical, titanium plasma-sprayed cup were followed for an average of 8.5 years. The average age was 63 years, and the average weight was 165 lb. Three hips were revised for polyethylene wear and synovitis/osteolysis. In all 3 cases, the acetabular component remained well fixed. Radiographically, 5 hips had femoral osteolysis, and 5 sockets had osteolysis in zone 2, with 4 in zone 1. There were no cases of progressive lucent lines, and no acetabular components were revised. Plasma-sprayed acetabular components remain durable up to 12 years. Moreover, in cases with wear particle overload and osteolysis, fixation was maintained at revision surgery.     

Five-year comparative study of highly cross-linked (crossfire) and traditional polyethylene

The purpose of this study was to compare the linear penetration rates of a highly cross-linked ultra-high-molecular-weight polyethylene to traditional polyethylene. Twenty-seven highly cross-linked components were matched to 27 traditional polyethylene components with respect to age, sex, body mass index, and activity level. Each group was followed up for a mean of approximately 6 years. Linear penetration was measured using Martell's computerized technique (J Bone Joint Surg Am 1997;79:1635). The mean total penetration was 0.283 mm (SD, 0.253) for the highly cross-linked group. The mean total penetration for the traditional polyethylene was 0.696 mm (SD, 0.402). This difference was highly significant (P < or = .001). Our experience demonstrates a 59% reduction in total penetration of highly cross-linked polyethylene when compared with traditional polyethylene at a minimum of 5 years.     

Does Use of a “Rim Cutter” Improve Quality of Cementation of the Acetabular Component of Cemented Exeter Total Hip Arthroplasty?

A randomized controlled trial was performed to assess the effect of a rim cutter device on cement mantles in modern elective total hip arthroplasty using a flanged acetabular component. Forty patients were randomized to a rim cutter (21) or control (19) group. A statistically significant improvement in cement penetration was demonstrated in zone 1 (10.1 vs 8.6 mm, P = .023), and in cement mantle thickness in zones 2 and 3 (7.8 and 6.7 mm vs 5.7 and 5.4 mm [P < .001 and P = .017]), with a reduced incidence of bottoming out of the socket (1/21 vs 8/19 [P = .007]). Cement mantle thicknesses greater than 8 mm were achieved more consistently in the rim cutter group (30% vs 2%). This technique improves cement penetration and mantle thickness in a reliable manner.     

The influence of acetabular component position on wear in total hip arthroplasty

Our experience has implicated cup inclination as an important factor in wear, whereas others have suggested that the hip center of rotation (COR) must be closely reestablished to reduce wear. We conducted a retrospective study to determine the relative importance of these 2 factors. One hundred thirty-nine total hip arthroplasties were studied after a mean follow-up of 9.2 years (range, 6-3 years). Forty-nine of 139 operated hips had a contralateral normal hip, which allowed the most accurate measurement of the influence of change in the COR. Wear was related to the inclination of the cup but not to a change in the COR. Secondarily, wear was less with a ceramic-polyethylene polyarticular surface than with metal-polyethylene. The importance of this data is related to cup implantation techniques. The hip COR can be moved superiorly and/or medially to permit cup inclination below 45 degrees with correct cup coverage.     

Surgical dislocation and periacetabular osteotomy through a posterolateral approach: a cadaveric feasibility study and initial clinical experience

Since its introduction, Bernese periacetabular osteotomy with a modified Smith-Petersen approach has become a successful strategy for the treatment of insufficient femoral head coverage in developmental dysplasia of the hip. Additionally, femoro-acetabular impingement secondary to acetabular retroversion has been effectively treated by this technique. Although the vascularity of the osteotomized acetabular fragement has not been a problem with the modified Smith-Petersen approach for the Bernese periacetabular osteotomy, little information is available on the vascularity of the periacetabular bone after an osteotomy through a posterolateral approach. Such an approach would allow for improved treatment of certain intraarticular pathologies while simultaneously providing the option of performing an acetabular osteotomy. This study was designed to determine the vascularity of the external periacetabular bone with a colored latex injection technique into the common iliac artery in 16 fresh cadavers. Additionally, in 7 injected cadavers, a periacetabular osteotomy was performed with a posterolateral approach. Our dissections demonstrated the technical feasibility of a juxta-acetabular osteotomy performed through a posterolateral approach. These dissections further demonstrated the importance of identifying and protecting the constant acetabular branch of the superior gluteal artery (present in 23 of 23 cases), which is necessary for preservation of the superior acetabular blood supply. The integrity of both the superior gluteal branch and the acetabular branch of the obturator artery were maintained in all 7 osteotomy cases. Thus, in indicated cases, a juxta-acetabular osteotomy can be safely executed and combined with a capsulotomy, femoral head dislocation, and femoral head/neck shaping procedure through a posterolateral approach.     

前后位X线片上髋臼杯前倾角测量

目的　证实RitenPradhan提出的髋臼杯前倾角测量方法的可靠性和可行性。方法　在标本上行人工全髋臼杯的多个角度前倾角的前后位X线摄片 ,将测量、计算的结果与实际角度进行比较 ,对实际人工全髋置换患者的臼杯前倾角进行测量和计算 ,并分析其与临床症状的关系。结果　经统计学处理 ,测量角度与实际角度两组差异无显著性 (P >0 0 5 ) ;应用中发现前倾角 0°～ 33° ,平均2 1° ,1例前倾角测量值为 0° ,术后出现脱位 ,2例在术后随访中发现前倾角有明显变化 ,髋臼杯松动。结论　该方法理论依据充分 ,测量工具普通 ,计算方法简单 ,结果误差小 ,临床中可预测人工髋关节稳定性、诊断髋臼杯松动和指导临床操作 ,是一种可靠、可行和实用的诊断方法     

Current attitudes to total hip replacement in younger patients: a comparison of two nations

Introduction: Orthopaedic surgeons performing total hip replacements (THR) today are faced with a vast array of options. Inspired by a recent UK study, we wanted to determine the current trend in prosthesis choice, fixation and bearing surfaces used in ‘young’ Australian patients, and to compare this trend to the UK. Methods: A questionnaire identical to that used in the UK study was posted to all current members of the Australian Orthopaedic Association and returned questionnaires were directly compared to the UK results on a percentage‐of‐responses basis. Results: Two hundred and forty‐six valid responses were received. The number of THR reported to be performed by these respondents (15 789) was equivalent to the estimated number of prostheses sold here during the same period (15 624). The UK results showed a predominant use of Charnley and Exeter femoral prostheses, an all‐polyethylene acetabular component, and cement fixation of both the acetabular and femoral components for both their older and younger patients. In younger patients, Australian surgeons favoured uncemented fixation techniques for the femur (57%vs 23%), and especially the acetabulum (85%vs 32%). There was a higher percentage use of modular design (95%vs 67%) and a very high use of ceramic as a bearing surface, 49% (vs 25%) using it for the femoral head, and 21% (vs 2%) employing a ceramic‐on‐ceramic bearing combination. Discussion: Despite being privy to the same published papers, the THR prosthesis and fixation preferences of UK and Australian orthopaedic surgeons are markedly different. This may be because of interpretation of papers, peers, personal experience, patient assessment, budgets, institutions, theories, fashions, differences in autonomy and advertising.     

53例髋臼骨折治疗体会

目的探讨影响髋臼骨折疗效的因素。方法总结2002年-2006年对53例髋臼骨折患者。均按Letournel和Iudet的髋臼骨折分类法进行分型，2例保守治疗51例手术治疗；根据不同骨折类型，选取不同的手术入路进行骨折复位，采用专用器械及骨盆重建钢板和螺丝钉对骨折进行复位和固定。结果随访26例，失访27例平均随访时间为40．5个月（4—60个月）。随访26例根据改良的Merle d’Aubigne和Postel的髋臼骨折临床结果评分标准，优2例，良15例，一般5例，差4例，优良率为65．4％。51例术后根据Matta影像学评分，解剖复位27例，复位满意20例，复位不满意4例。无1例死亡、感染及不愈合。随访中股骨头坏死2例，创伤性关节炎4例。结论术前正确分析骨折移位和类型、选择适当的手术径路、适时手术解剖复位、术者的经验以及对合并损伤的积极治疗是提高髋臼骨折治疗效果的重要保证。     

髋关节后脱位伴后壁骨折的治疗

目的：探讨提高髋关节后脱位伴后壁骨折疗效的方法。方法：回顾总结15例髋关节后脱位伴后壁骨折的治疗过程。12例切开复位内固定,3例侧方牵引。结果：手术病例中优10例,良2例,无一例坐骨神经损伤、感染等．3例非手术病例结果优。结论：对于髋关节后脱位伴后壁骨折的治疗应在急诊手法复位的基础上根据骨折类型、骨折块情况结合全身情况综合考虑治疗方法。II型以上应采用简单、有效的“生物学”内固定;术前应及时完善辅助检查,避免过多搬动相反复检查。     

改进Zahradnicek手术治疗先天性髋脱位疗效观察

目的 :探讨先天性髋脱位治疗优化方法 ,减少并发症。方法 :自 1 986～ 1 998年应用改进Zahradnicek手术治疗先天性髋脱位 1 0 3例、1 36个关节 ,用特制的小儿髋臼钻有限切削臼软骨 ,重建髋臼孤形结构 ,恢复其头臼同心圆关系 ,同时矫正前倾角至 5°～ 1 0°,颈干角至1 2 0° ,用专用的 1 2 0°鹅颈钢板固定。结果 :术后疗效评定 :优 76髋 ,为 5 3% ,良 45髋 ,为 33% ,可 9髋 ,为 6 6 % ,差 6髋 ,为 4 4% ,优良率占 89%。结论 :此种手术在一次手术中使股骨头、髋臼、股骨颈及股骨干恢复或接近恢复正常解剖和功能的方法