Catastrophic Failure of a Metal-on-Metal Total Hip Arthroplasty Secondary to Metal Inlay Dissociation

Metal-on-metal bearing surfaces in total hip arthroplasty have been recently shown to have acceptable survivorship properties (J Bone Joint Surg Am. 2006;88:1183; J Bone Joint Surg Am. 2006;88:1173), and they have certain advantages and disadvantages when compared to conventional metal-on-polyethylene bearing surfaces. Like traditional metal-on-polyethylene bearings, these metal-on-metal implants may also suffer from catastrophic failure. This case report represents an unusual situation in a 57-year-old man in which dissociation of a metal inlay in a metal-on-metal total hip arthroplasty resulted in articulation of the inferior aspect of the inlay with the femoral neck, leading to femoral neck notching, extensive periprosthetic soft tissue metallosis, osteolysis, and subsequent prosthetic catastrophic failure.     

Cemented Total Hip Arthroplasty With Subtrochanteric Osteotomy in Dysplastic Hips

Background  

Total hip arthroplasty (THA) in the presence of developmental dysplasia of the hip (DDH) can be technically challenging. Restoring the anatomic center of hip rotation may require femoral osteotomy. Techniques using cementless components are widely reported but less is known about using cemented components that may be more appropriate with osteopenic bone.     

Cemented Calcar Replacement Femoral Component in Revision Hybrid Total Hip Arthroplasty

We evaluated intermediate-term to long-term survival of cemented calcar replacement femoral components in hybrid revision total hip arthroplasty. We followed up 52 hips in 50 patients for a mean of 11.4 years. Six (12%) femoral components had been revised: 2 for aseptic loosening, 2 for periprosthetic fracture, and 2 for deep infection. One additional femoral component was definitely loose. The number of previous revision operations (P = .004), preoperatively poorer femoral bone stock (P = .005), and postoperative poor cement mantle grading (P = .003) were significant factors for failure. Kaplan-Meier analysis revealed that the 15-year survival rate was 90% with mechanical failure as the end point. This technique remains a reasonable option for the first-time revision, especially for older and less active patients.     

Constrained Acetabular Liners Cemented Into Cages During Total Hip Revision Arthroplasty

The combination of acetabular bone loss and hip instability is challenging. Sixteen patients underwent revision total hip arthroplasty using constrained acetabular liners cemented into cages. The average follow-up was 28 months (range, 24-60 months). Clinical evaluation was obtained using the Harris hip score along with radiographic data. At latest follow-up, 13 patients were available for evaluation. Although the average postoperative Harris hip score was 62 points, which was better than the preoperative score of 27 points, the overall radiographic failure rate was 23%. The combination of poor acetabular bone stock and altered stresses from the increased constraint likely led to the poor outcome. We would only recommend use of a cemented, constrained acetabular liner in combination with a protrusio cage as a bail out or salvage procedure.     

同一设计的骨水泥和非骨水泥股骨假体的效果比较

观察同一设计的骨水泥和非骨水泥股骨假体的临床效果。 1 993年 1月～ 1 995年 8月 ,应用同一设计的骨水泥和非骨水泥股骨假体 ,施行 2 4 6髋全髋关节置换。骨水泥组 1 1 7髋 ,平均随访 4 5年 ;非骨水泥组 1 2 9髋 ,平均随访 4 1年。骨水泥组Merled’Aubigne评分平均 1 0 4 (5～ 1 2 ) ,优良率 88 9% ;日常行为评分平均1 9 4 (7～ 2 4 ) ,优良率 80 3 %。无一髋假体松动。非骨水泥组Merled’Aubigne评分平均 1 1 (8～ 1 2 ) ,优良率为 95 3 % ;日常行为评分平均 2 1 4 (9～ 2 4 ) ,优良率 92 2 % ,全部假体均无松动。认为同一设计的非骨水泥股骨假体的临床效果优于骨水泥股骨假体 ,两组假体均无松动     

Cemented Total Hip Arthroplasty With Transverse Subtrochanteric Shortening Osteotomy for Crowe Group IV Dislocated Hip

A consecutive series of 19 cemented total hip arthroplasties with transverse subtrochanteric shortening osteotomy was performed for Crowe group IV hip, with a mean follow-up of 38 (6-96) months. The osteotomy sites were covered with onlay grafts of the excised fragments. The conditions of the osteotomy sites were classified into 3 types according to the presence of a remaining gap and cement interposition within it. Three cases had a noticeable gap, and 2 of them showed cement interposition. All osteotomy sites became united involving the onlay grafts, with an average time to union of 4.9 (3-8) months. Our findings suggest that cemented total hip arthroplasty with subtrochanteric transverse osteotomy provides satisfactory short-term results without major complications for Crowe group IV hip.     

Failure of the Modular Neck in a Total Hip Arthroplasty

Modular femoral necks in total hip arthroplasty are promoted as giving the surgeon more options during surgery and as being safe. We report a case of fatigue fracture in the modular neck of a femoral implant 3 1/2 years after implantation. The probable design errors leading to product failure are discussed.     

Periprosthetic Bone Remodeling Using a Triple-Taper Polished Cemented Stem in Total Hip Arthroplasty

The triple-taper cemented femoral stem was developed to promote proximal femoral and calcar loading to minimize periprosthetic bone loss and aseptic loosening. Periprosthetic changes in bone mineral density in Gruen zones 1 to 7 were analyzed in 103 patients over a 2-year period using dual x-ray absorptiometry. There was a statistically significant decrease in bone mineral density in all Gruen zones, but was most marked in zones 1 and 7. Periprosthetic bone density was reduced significantly in the first 3 to 9 months, after which recovery of bone density occurred. Greater calcar bone loss was seen in women, patients with a low preoperative bone density, and patients with poor postoperative mobility. Age at surgery did not effect calcar bone loss.     

Outpatient Total Hip Arthroplasty

Patients younger than 65 years were studied to determine what percentage of patients would enroll in a study of outpatient total hip arthroplasty, its safety, and benefits of the program. Of 192 eligible patients, 69 (36%) enrolled, and 53 (77%) of these went home the same day of surgery. Of 53, 44 maintained a diary for the first 3, weeks and 52 completed a satisfaction questionnaire at 6 weeks. Patients were followed for 6 months for occurrence of complications. There were no medical readmissions. Of 52 patients who completed a 6 week questionnaire, 50 (96%) were satisfied with the decision to have outpatient total hip arthroplasty. There were no objective physical benefits identified. This study reports the distribution of acceptance and completion of same day discharge for patients with total hip arthroplasty in a metropolitan population. It confirms safety in selected patients.     

Can Arthroplasty Stem Influence Outcome: A Randomized Controlled Trial of Stem Length in Cemented Total Hip Arthroplasty

BackgroundThe primary aim was to assess whether a short (125 millimeter (mm)) stem offered an equivalent hip-specific function compared to the standard (150 mm) stem when used for cemented total hip arthroplasty. Secondary aims were to evaluate health-related quality of life, patient satisfaction, stem height and alignment, as well as radiographic loosenings and complications between the two stems.MethodsA prospective twin-center double-blind randomized control trial was conducted. During a 15-month period, 220 patients undergoing total hip arthroplasty were randomized to either a standard (n = 110) or a short (n = 110) stem. There were no significant (P ≥ .065) differences in preoperative variables between the groups. Functional outcomes and radiographic assessment were undertaken at a mean of 1 and 2 years.ResultsThere were no differences (P = .428) in hip-specific function according to the mean Oxford hip scores at 1 year (primary endpoint) or at 2 years (P = .622) between the groups. The short stem group had greater varus angulation (0.9 degrees, P = .003) when compared to the standard group and were more likely (odds ratio 2.42, P = .002) to have varus stem alignment beyond one standard deviation from the mean. There were no significant (P ≥ .083) differences in the forgotten joint scores, EuroQol-5-Dimension, EuroQol-visual analogue scale, short form 12, patient satisfaction, complications, stem height, or radiolucent zones at 1 or 2 years between the groups.ConclusionThe cemented short stem used in this study had equivalent hip-specific function, health-related quality of life, and patient satisfaction when compared to the standard stem at mean 2 years post operation. However, the short stem was associated with a greater rate of varus malalignment, which may influence future implant survival.     

使用与不用骨水泥固定人工膝关节置换术后疗效的比较

探讨使用与不用骨水泥固定氧化铝陶瓷制NCU型TKA术后的疗效。1989～1995年,为了治疗晚期骨性关节病及类风湿病,共施行NCU型TKA68例103个关节。对获得平均随访5年8个月的65例99个关节的以胫骨假体为中心的临床评价及X线计测的结果进行了比较性分析。临床评价方法是以JOA膝关节评价基准为标准,X线的评价方法是将术前、术后、最终调查时的正侧位X线照片数字化后输入电子计算机利用电脑软件系统进行了计测与评价。65例99个关节TKA术后经随访5年以上的结果表明NCU型TKA术后获得了比较良好的疗效。术后并发症7％,再手术率5％,不用骨水泥组疗效劣于使用骨水泥固定组,两组间的疼痛评分及透亮线出现率的差异均有显著性统计学意义。     

Prospective Randomized Trial Comparing Alumina Ceramic-on-Ceramic With Ceramic-On-Conventional Polyethylene Bearings in Total Hip Arthroplasty

This prospective randomized study aims to compare the outcome between an alumina ceramic-on-ceramic (CC) articulation with a ceramic on ultra-high-molecular-weight polyethylene articulation (CP). Fifty-six hips in 55 patients with mean age 42.2 (range, 19-56) each received uncemented components, a 28-mm alumina head with randomization of acetabular liner. Mean St Michael's outcome score for each group with up to 10 years follow-up (median, 8 years; range, 1-10) was 22.8 and 22.9, respectively (P = .819). Wear was identified in all but 1 CP replacement, but only 12 of the 23 CC. Mean wear in the CP group was 0.11 mm/y and 0.02 mm/yr in the CC group (P < .001). Other than significantly greater wear in the polyethylene group, there was no significant difference in midterm outcome between the 2 groups.