Early Failure of Cementless Porous Tantalum Monoblock Tibial Components

Patient selection for cementless knee arthroplasty (TKA) remains challenging. 106 consecutive TKAs performed with a cementless porous tantalum tibial component of PS-design were reviewed. Nine failures (8 male/1 female) occurred at a mean 18 months and demonstrated a characteristic failure mode of medial tibial collapse. The mean height of 72.5 inches in the failure group was greater than the 65.8 inches in the well-functioning group (P < 0.001). The mean weight of 260.4 lb in the failure group was greater than the 204.1 lb in the well-functioning group (P = 0.006). The high early failure rate occurred predominantly in tall, heavy, male patients and may be related to medial tibial overload resulting from increased flexibility of the implant in this patient type.     

Uncemented total hip arthroplasty in patients 50 years of age or younger

The results of a consecutive series of uncemented total hip arthroplasties in patients 50 years or younger are reviewed. There were 41 total hip arthroplasties in 36 patients at an average follow-up period of 5.3 years. Average patient age was 42 years at the time of implantation. Preoperative Harris hip score (HHS) averaged ; the final HHS averaged 93. Radiographic evaluation revealed that the femoral stems were all solid, with no progressive subsidence, reactive lines, or osteolysis. Twenty of the hips (49%) demonstrated evidence of polyethylene wear. There was significant acetabular osteolysis in 12 of these 20 hips. Five of the acetabular cups were definitely loose; 1 was possibly loose. Three of the patients underwent revision surgery for acetabular loosening and/or osteolysis. It is concluded from this study that the femoral stem is excellent but that the original acetabular component and polyethylene locking mechanism are poor and made even worse with the use of a titanium femoral head.     

生物型假体全髋置换术后早期负重近期效果

目的 探讨生物型全髋置换早期下床负重的可行性.方法 将56例年龄≤70岁的生物型假体全髋置换术后患者随机分成早期负重组(27例)和晚期负重组(29例),所有病例均采用小切口微创技术.早期负重组术后1周内下床拄拐自由负重,晚期负重组术后6周后下地负重,分别对两组进行术后6周和3、6、12、24个月的临床和影像学随访.髋关节功能按Harris评分,并对评分结果进行统计学分析.结果 术后6周、3个月的Harris评分早期负重组为(71.9±10.2)分、(87.6±9.4)分,晚期负重组为(60.3±9.1)分、(74.0±12.0)分,早期负重组明显高于晚期负重组(P＜0.01),Xx线最后随访时假体无松动、下沉;晚期负重组有2例患肢深静脉血栓形成.结论 在保证术中假体初始稳定性的前提下,生物型全髋置换术后可以早期下床负重;近期能明显促进患肢的功能恢复,预防下肢深静脉血栓形成.     

人工全髋置换联合髋臼造盖治疗先天性髋关节脱位

背景：以往采用单纯的人工关节置换、截骨重建等治疗成人CrownⅣ型先天性髋关节脱位的效果都不是很满意。 目的：探讨人工全髋置换联合髋臼造盖重建治疗成人CrownⅣ型先天性髋关节脱位的疗效。 方法：回顾性分析采用人工全髋置换联合髋臼造盖重建治疗23例成人CrownⅣ型先天性髋关节脱位的患者,其中男2例,女21例,年龄20-35岁,平均(24.26±3.56)岁。重建治疗后按Harrris髋关节功能标准评定术后疗效并进行统计学分析。 结果与结论：23例患者均获得随访,随访时间为12-60个月,平均(26.60±13.16)个月。采用SPSS19.0进行统计学比较后发现,手术前后髋关节功能Harrris评分差异有显著性意义(P < 0.01)。人工全髋置换联合髋臼造盖能重建髋关节正常结构,缓解疼痛,增加髋关节稳定性,是治疗成人CrownⅣ型先天性髋关节脱位的理想方法。     

Uncemented Total Hip Arthroplasty Through the Direct Anterior Approach: Analysis of a Consecutive Series of 275 Hips With a Minimum Follow-Up of 10 Years

BackgroundThe purpose of this study was to document complications, outcomes, and 10-year survivorship of primary total hip arthroplasty (THA) using a direct anterior approach with an uncemented, straight, hydroxyapatite-coated stem and an uncemented cup.MethodsA retrospective, consecutive series of 275 primary THAs through a direct anterior approach with traction table using Medacta Versafit cup and Quadra-H stem with a minimum of 10-year follow-up was identified. The cumulative 10-year survival of the implants was estimated using Kaplan-Meier estimator. All complications, reoperations, and failures were analyzed. Subjective and clinical outcomes (Subjective Hip Value, Western Ontario and McMaster Universities Osteoarthritis Index, and Harris Hip Score) were measured.ResultsOf 256 patients (275 hips, 143 men and 113 women) with a mean age of 63 (range, 24-85) years, 48 (19%) patients (52 hips) deceased not related to the surgery after a mean time 49 months (range, 3-118) postoperatively. At >10-year follow-up, 9 THAs were revised. The overall implant survival rate was 96.8% (95% confidence interval, 94.4-98.7) at 10 years. One cup and 1 stem were revised because of aseptic loosening. At the last follow-up, the median Subjective Hip Value was 90% (range, 20-100), the Western Ontario and McMaster Universities Osteoarthritis Index score reached a median of 0.2 points (range, 0-6.3), and the median Harris Hip Score points was 99 (range, 29-100).ConclusionPrimary THA through an anterior minimal invasive approach with the mentioned implants showed low revision rates and good to excellent clinical outcome after at least 10 years.     

Mild Coronal Stem Malalignment Does Not Negatively Impact Survivorship or Clinical Results in Uncemented Primary Total Hip Arthroplasties With Dual-Tapered Implants

BackgroundProper component positioning in total hip arthroplasty (THA) is crucial for implant fixation and hip stability. The purpose of this study is to assess if neutral coronal stem alignment (0° ± 3°) improved long-term survivorship in uncemented femoral components.MethodsBetween 2005 and 2010, 1028 primary THAs were performed with 2 contemporary dual-tapered, proximally coated uncemented stem types. Alignment was measured immediately postoperatively and at most recent follow-up. In total, 978 femoral stems (95%) were within 0° ± 3° of the neutral anatomic coronal axis, and the 50 stems (5%) outside that range were considered outliers (3.1° of valgus to 4.8° of varus). Outcomes analyzed included implant survivorship, Harris Hip Scores, and incidence of dislocation. Mean follow-up was 5 years.ResultsSurvivorship free of aseptic femoral component loosening was 99.3% and 98.2% at 5 and 8 years in the neutral group vs 100% at 5 and 8 years in the outlier group (P = .98). Survivorship free of femoral component revision for any reason was 99.1% and 97.3% at 5 and 8 years vs 100% at 5 and 8 years, respectively (P = .80). Harris Hip Scores were similar (89 in both groups; P = .84) at most recent follow-up. The incidence of mild to moderate thigh pain was also similar in both groups (6.1% vs 6%, P = .85). The incidence of dislocation was 1.5% at 8 years, and similar between both groups (P = .77).ConclusionSlight malalignment of contemporary dual-tapered uncemented THA femoral components does not appear to negatively impact survivorship or clinical outcomes, which is in contrast to cemented femoral components.Level of evidence IIICase-control study.     

Midterm Success of a Custom,Non-Fluted,Diaphyseal, Press-Fit Stem Used With a Tumor Megaprosthesis System

BackgroundHigh rates of aseptic loosening with cemented prostheses have led to increased utilization of uncemented stems in the setting of megaprosthetic reconstruction. Theoretic concerns of rotational instability resulted in early stem designs with de-rotational mechanisms such as flutes or side plates. However, these designs have their own associated complications, and mechanical data suggest they are unnecessary. The purpose of this study is to evaluate outcomes and survivorship of an unfluted diaphyseal press-fit stem in the setting of megaprosthetic reconstruction.MethodsForty-five patients (46 stems), with a minimum 3-year follow-up, underwent reconstruction using 1 of 2 fully porous coated, unfluted, press-fit stems between 2005 and 2013: revision stem with adapter to the megaprosthesis (revision stem), or custom megaprosthesis stem (custom stem). Complications were described using the Henderson classification system, and subanalyses evaluated stem-related failures and survival. Radiographic evaluation of stem fixation was determined via evidence of bone bridging, spot welding, resorption, subsidence, and pedestal formation. Four patients had early stem removal for local recurrence or infection and were thus excluded from the radiographic analyses.ResultsTwenty-eight femoral (15 revision stem, 13 custom stem) and 14 tibial (6 revision stem, 8 custom stem) stems were reviewed. Average follow-up was 81 months (range, 42-140 months). Revision for implant-related complications occurred in 7 of 41 (17%), all in revision stems (3 adapter failures, 4 polyethylene wear). At final follow-up, all stems were retained without evidence of aseptic loosening, although 7 of 41 (17%) exhibited mild stress shielding.ConclusionA non-fluted, press-fit stem used with a tumor prosthesis provided a stable bone-prosthesis interface at midterm follow-up.     

The Natural History of Radiolucencies Following Uncemented Total Knee Arthroplasty at 9 Years

BackgroundAseptic loosening remains a common cause of failure in total knee arthroplasty (TKA). There is an increased interest in using uncemented TKA to reduce this complication. Radiolucencies (RLs) following uncemented TKA can be concerning. We report on the 9-year history of RLs in patients with uncemented TKA.MethodsTwenty-one patients (26 knees) were treated with a cruciate-retaining fully porous coated femur/tibia and cemented patella. At final follow-up, 17 patients (22 knees) were available for review. Average follow-up was 9.6 years, average age was 59.1, and average body mass index was 34.1. X-rays were taken at 6 weeks, 1 year, and at final follow-up. RLs were measured using the Knee Society scoring system and read by two separate surgeons.ResultsAt 6 weeks, we identified RL in all patients on both the tibia and femur. The majority were beneath the tibial tray and femoral chamfer. At 1 year, 4 femurs and 4 tibias showed new RLs (<2 mm) in similar zones. Eighteen femurs and 18 tibias showed fewer or no change in RLs. At final follow-up, no new tibia or femur developed a new RL. In total, 9 of the 22 tibias and 17 of the 22 femurs had remaining RLs, all less than 2 mm and none were progressive or new. Knee Society Score averaged 92.5 (6 weeks), 95.1 (1 year), and 97.3 (final).ConclusionRLs are common following uncemented TKA. Many resolve by 1 year. There does not appear to be any association between the presence of RLs and long-term follow-up function in this group of patients.     

全膝关节置换术中骨水泥假体与非骨水泥假体生存率比较的系统评价

[目的]系统评价全膝关节置换术中应用骨水泥固定假体与非骨水泥固定假体的生存疗效,为临床治疗提供参考.[方法]全面搜索国内外关于全膝关节置换术中应用骨水泥固定假体和非骨水泥固定假体的临床对照研究资料,按照既定的纳入、排除标准,核定检出符合评价标准的文献,提取所需研究数据,采用RevMan 5.0.18软件进行Meta分析.[结果]纳入临床对照研究12篇,共计3 244膝全膝关节置换术,骨水泥固定假体组和非骨水泥固定假体组分别为1 877膝和1 367膝,假体生存率分别为96.7%和93.0%,荟萃分析加权后OR=2.58,95%CI(1.76,3.78),P＜0.05.亚组分析结果显示,不论是小于等于5年组还是大于5年组,均是骨水泥固定假体生存率高于非骨水泥假体生存率.[结论]全膝关节置换术中假体应用骨水泥固定与非骨水泥固定相比,术后假体生存率高,但二者间的比较仍需大规模多中心的RCT来进一步研究.     

骨水泥与非骨水泥固定型半髋关节置换术治疗老年人移位型股骨颈骨折的系统评价

目的:系统评价骨水泥与非骨水泥固定型半髋关节置换术治疗老年人移位型股骨颈骨折的疗效与安全性。方法:按照Cochrane系统评价的方法,计算机检索MEDLINE(1966年10月-2011年7月),EMBASE(1966年10月-2011年7月),Cochrane图书馆(2011年第三期)、CBM(截止2011年7月),CNK(I截止2011年7月);并采用手工检索等方法收集会议文献。收集所有骨水泥固定型与非骨水泥固定型半髋关节置换术治疗老年人(>60岁)移位型股骨颈骨折的随机对照试验,筛选出符合纳入标准的文献,进行严格的质量评价,利用RevMan 5.0软件对纳入研究结果进行Meta分析。结果:经全面检索筛查后,最终纳入7个RCT,共1032例。Meta分析结果显示:骨水泥固定型与非骨水泥固定型半髋关节置换术比较,骨水泥固定型半髋关节置换术能降低术后大腿疼痛发生率[RR=0.51,95%C(I 0.31,0.81),P=0.005],提高术后病人活动能力[RR=1.35,95%C(I 1.01,1.79),P=0.04]。结论:与非骨水泥固定型半髋关节置换术相比,骨水泥固定组治疗移位型股骨颈骨折可明显降低术后患者大腿疼痛发生率,提高病人术后的活动能力,因此在老年人发生移位型股骨颈骨折时,应该首先考虑使用骨水泥固定型半髋关节置换术。