Cementless hemispheric acetabular component in total hip replacement

A series of 198 total hip arthroplasties was performed using a porous-coated, hemispheric press-fit cup. One hundred and twenty-seven cups were available for clinical and radiological examination at mean follow-up of 10.6 years. The mean age at the index procedure was 61.2 years. The mean Harris hip score at final follow-up was 89.8. Three cups were revised for aseptic loosening and two liners were changed for eccentric wear and pelvic osteolysis. Nine additional patients showed mild or suspected osteolysis. Two cups were rated "fibrous" stable. There was no correlation between additional screw fixation of the press-fit cup and osteolysis or revision.     

Alumina ceramic-on-ceramic total hip replacement with a layered acetabular component

A modular layered acetabular component (metal-polyethylene-ceramic) was developed in Japan for use in alumina ceramic-on-ceramic total hip replacement. Between May 1999 and July 2000, we performed 35 alumina ceramic-on-ceramic total hip replacements in 30 consecutive patients, using this layered component and evaluated the clinical and radiological results over a mean follow-up of 5.8 years (5 to 6.5). A total of six hips underwent revision, one for infection, two for dislocation with loosening of the acetabular component, two for alumina liner fractures and one for component dissociation with pelvic osteolysis. There were no fractures of the ceramic heads, and no loosening of the femoral or acetabular component in the unrevised hips was seen at final follow-up. Osteolysis was not observed in any of the unrevised hips. The survivorship analysis at six years after surgery was 83%. The layered acetabular component in our experience, has poor durability because of unexpected mechanical failures including alumina liner fracture and component dissociation.     

Intrapelvic protrusion of the acetabular component following total hip replacement.

Protrusion of the acetabular component into the true pelvis following total hip replacement has occurred in 5 patients, 4 with severe rheumatoid arthritis and 1 with a destructive type of degenerative hip disease. Preoperatively all hips had severe protrusio acetabuli, a markedly thin acetabular medial wall and advanced osteoporosis. Four had a McKee-Farrar prosthesis, a metal-to-metal device with high frictional torque, particularly when the contact is equatorial, and no damping capacity against marginal impingement in the extreme range of motion. In order to reduce the incidence of intrapelvic protrusion, extreme care should be given to preserve the medial bone stock of the acetabulum, more so when it is already damaged or defective. If anchoring holes are used they should be restricted to the superior ilium, pubis and ischium and should not perforate the medial wall. Once loosening is present, reoperation is indicated to avoid progressive bone reabsorption by the abrasive motion of the loosened prosthesis, that might lead to irreparable bone loss. To reduce the stress transmitted to an already weakened acetabulum, select a total prosthetic device with low friction; fix it with acrylic cement in order to distribute the stress over a large surface; carefully orient both components to avoid marginal impingement; be certain to preserve the medial wall as much as possible and if it is already defective reinforce it by bone grafting and/or wire mesh.     

Universal total hip replacement with focus on the acetabular component and the hybrid hip

One hundred sixty-one porous-coated Universal (Biomet Inc, Warsaw, IN) total hip arthroplasties were performed and studied preoperatively between July 1986 and June 1989. The study included 59 men (38 at 1-year follow-up; 21 at 2-year follow-up) and 91 women (60 at 1-year follow-up; 31 at 2-year follow-up). The average age was 62 years at 12-month follow-up and 64.7 years at 24-month follow-up (range 28 to 90 years). Three groups of patients with components were evaluated both clinically and radiographically: uncemented femoral and acetabular components (group 1); cemented femoral stems and uncemented acetabular components, ie, hybrid total hip arthroplasties (group 2); and revision total hip replacement arthroplasties (group 3). Clinical results for all groups showed Harris hip scores of 87 at 1-year follow-up and 89 at 2-year follow-up. Moderate to no limp occurred in 93% of patients at 1-year follow-up and 95% at 2-year follow-up. No ambulatory aids were used by 43% of patients at 1-year follow-up or 47% at 2-year follow-up. Both walking distance and endurance improved over time. Anthropometric analysis showed no progressive lucencies around the femoral or acetabular component in either group. A Kaplan-Meier survivorship analysis could not be used, because there was only one failure. This eliminated a comparison group for those lost to follow-up. Early clinical and radiographic results have been encouraging; however, long-term analysis is needed to accurately assess the success of this total hip arthroplasty system.     

The concentric all-polyethylene Exeter acetabular component in primary total hip replacement

We report the outcome of the flangeless, cemented all-polyethylene Exeter acetabular component at a mean of 14.6 years (10 to 17) after operation. Of the 263 hips in 243 patients, 122 prostheses are still in situ; 112 patients (119 hips) have died, 18 hips have been revised, and three patients (four hips) were lost to follow-up. Radiographs at the final review were available for 110 of the 122 surviving hips. There were acetabular radiolucent lines in 54 hips (49%). Two acetabular components had migrated but neither patient required revision. The Kaplan-Meier survivorship at 15 years with 61 hips at risk with revision for any cause as the endpoint was 89.9% (95% confidence interval (CI) 84.6 to 95.2) and for aseptic loosening of the acetabular component or lysis 91.7% (95% CI 86.6 to 96.8). In 210 hips with a diagnosis of primary osteoarthritis, survivorship with revision for any cause as the endpoint was 93.2% (95% CI 88.1 to 98.3), and for aseptic loosening of the acetabular component 95.0% (95% CI 90.3 to 99.7). The cemented all-polyethylene Exeter acetabular component has an excellent long-term survivorship.     

A method for improving acetabular preparation during cemented all-polyethylene acetabular component insertion during total hip arthroplasty

Long-term outcome from cemented acetabular components has been correlated with the presence of radiolucency on early postoperative radiographs. We describe a means for enhancing acetabular bed preparation to decrease blood at the bone-cement interface and to obtain better pressurization of the cement into the cancellous bone of the acetabulum during cemented acetabular component insertion.     

Survival analysis of an uncemented ceramic acetabular component in total hip replacement

Follow-up examinations of 67 implants of cement-free ceramic sockets show the need for an exact definition of failure, to warrant comparable evaluations of results. Statistical survival analysis offers the possibility of presenting both the incidence of failures and the dates of their occurrence. If only revision surgery with removal of the socket is considered to be a failure, our material shows the "survival quota" of the ceramic socket after 8 years to be 96.7% +/- 2.2%. If radiological signs of loosening are included in the evaluation of failures, the "survival quota" of the stable implants is reduced to 81.9% +/- 6.9%.     

Survival analysis of an uncemented ceramic acetabular component in total hip replacement

Summary Follow-up examinations of 67 implants of cement-free ceramic sockets show the need for an exact definition of failure, to warrant comparable evaluations of results. Statistical survival analysis offers the possibility of presenting both the incidence of failures and the dates of their occurrence. If only revision surgery with removal of the socket is considered to be a failure, our material shows the survival quota of the ceramic socket after 8 years to be 96.7% ± 2.2%. If radiological signs of loosening are included in the evaluation of failures, the survival quota of the stable implants is reduced to 81.9% ±6.9%.

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Zusammenfassung Anhand der Nachuntersuchung von 67 zementfrei implantierten keramischen Füßchenpfannen wird die Notwendigkeit der genauen Definition des Fehlschlages aufgezeigt, um dadurch eine vergleichbare Beurteilung der Ergebnisse zu gewährleisten. Die statistische Methode der Überlebenszeitanalyse bietet die Möglichkeit, sowohl die Häufigkeit der Fehlschläge als such den Zeitpunkt ihres Auftretens darzustellen. Wird ausschließlich die Reoperation mit Austausch der Pfanne als Fehlschlag bewertet, so ergibt sich im eigenen Material nach 8 Jahren eine Überlebensquote der keramischen Pfanne von 96,7% ± 2,2. Werden zusätzlich radiologische Lockerungszeichen in die Fehlschlagbeurteilung aufgenommen, so reduziert sich die Überlebensquote der stabilen Implantate auf 81,9% ± 6,9.

     

Position of the acetabular component determines the fate of femoral head autografts in total hip replacement for acetabular dysplasia

We have reviewed 54 patients who had undergone 61 total hip replacements using bulk femoral autografts to augment a congenitally dysplastic acetabulum. There were 52 women and two men with a mean age of 42.4 years (29 to 76) at the time of the index operation. A variety of different prostheses was used: 28 (45.9%) were cemented and 33 (54.1%) uncemented. The graft technique remained unchanged throughout the series. Follow-up was at a mean of 8.3 years (3 to 20). The Hospital for Special Surgery hip score improved from a mean of 10.7 (4 to 18) pre-operatively to a mean of 35 (28 to 38) at follow-up. The position of the acetabular component was anatomical in 37 hips (60.7%), displaced less than 1 cm in 20 (32.7%) and displaced more than 1 cm in four (6.6%). Its cover was between 50% and 75% in 34 hips (55.7%) and less than 50% in 25 (41%). In two cases (3.3%), it was more than 75%. There was no graft resorption in 36 hips (59%), mild resorption in 21 (34%) and severe resorption in four (6%). Six hips (9.8%) were revised for aseptic loosening. The overall rate of loosening and revision was 14.8%. Overall survival at 8.3 years was 93.4%. The only significant factor which predicted failure was the implantation of the acetabular component more than 1 cm from the anatomical centre of rotation of the hip.     

Long-term results with the Atlas IIIp elastic cementless acetabular component in total hip replacement

Purpose

Modular cementless elastic acetabular systems have advantages over cemented and hard shell cementless acetabular systems. There are few reports on the medium-term and long-term follow up of this particular type of implant. This study describes our experience with the Atlas IIIp modular acetabular system, which is a thin shell cementless elastic acetabular implant for total hip replacement commercialized under this name in many countries.

Methods

We prospectively followed 244 patients treated with Atlas IIIp acetabular system between 2001 and 2004. Minimum ten year follow up was available for 148 hips (139 patients) from the original cohort of 263 hips (244 patients). One hundred five patients had died from unrelated causes and were excluded from the results. Post-operative and follow up radiographs of patients were assessed; and Harris hip scores were used as clinical outcome. Revision for any reason was defined as the end point for survivorship analysis.

Results

The mean pre-operative Harris hip score was 48 (S.D. 16) and the average post-operative score was 82 (S.D. 12). The mean follow up in our series was 11.5 years, ranging from ten to 13.5 years. Thirteen hips required further surgery in our cohort; of which ten cases required cup revision. The 13-years cumulative implant survival was 91.2 % and the risk of implant revision was 8.8 % at 13 years in 148 hips (139 patients). Kaplan-Meier analysis showed the implant survival rate of 95.2 % at ten years for revision for any reason and 99.4 % for aseptic loosening.

Conclusions

Our clinical experience with this acetabular cup suggests good long-term survival rates that are similar to other cups on the market. The clinical experience in this study shows long-term survival rates that are consistent, acceptable and good results achieved with a low revision rate.Level of evidence: Therapeutic III; therapeutic study.

     

Early postoperative loosening of acetabular component presenting as dislocation of total hip replacement

We report a rare case of acetabular component loosening presenting as a dislocation of the hip within 10 days of the initial surgery, which we attribute to debonding of the acetabular component. That has been reported in femoral component but not in acetabular component, though, it is theoretically possible. The revision of the acetabular component in the patient in the second operation settled the problem and the patient had normal recovery at the follow up without any further dislocations. This significant complication needs to be further highlighted in literature.     

The double-mobility acetabular component in revision total hip replacement: the United Kingdom experience

We present our experience with a double-mobility acetabular component in 155 consecutive revision total hip replacements in 149 patients undertaken between 2005 and 2009, with particular emphasis on the incidence of further dislocation. The mean age of the patients was 77 years (42 to 89) with 59 males and 90 females. In all, five patients died and seven were lost to follow-up. Indications for revision were aseptic loosening in 113 hips, recurrent instability in 29, peri-prosthetic fracture in 11 and sepsis in two. The mean follow-up was 42 months (18 to 68). Three hips (2%) in three patients dislocated within six weeks of surgery; one of these dislocated again after one year. All three were managed successfully with closed reduction. Two of the three dislocations occurred in patients who had undergone revision for recurrent dislocation. All three were found at revision to have abductor deficiency. There were no dislocations in those revised for either aseptic loosening or sepsis. These results demonstrate a good mid-term outcome for this component. In the 29?patients revised for instability, only two had a further dislocation, both of which were managed by closed reduction.     

Bone grafting in total hip replacement for acetabular protrusion

Total hip replacement combined with acetabuloplasty was performed in 43 hips in 40 patients with protrusion secondary to arthrosis, rheumatoid arthritis or trauma. Depending on the acetabular defect, the acetabuloplasty encompassed reinforcement of the medial wall with bone grafts, vitallium meshes, protrusion rings and cups. The clinical and radiographic results were uniformly good on average 2 years postoperatively. All grafts appeared to be united and incorporated, without evidence of resorption. The only patient suffering from pain had radiographic signs of progressive varus migration of the femoral component.     

Bone grafting in total hip replacement for acetabular protrusion

Total hip replacement combined with acetabuloplasty was performed in 43 hips in 40 patients with protrusion secondary to arthrosis, rheumatoid arthritis or trauma. Depending on the acetabular defect, the acetabuloplasty encompassed reinforcement of the medial wall with bone grafts, vitallium meshes, protrusio rings and cups. The clinical and radiographic results were uniformly good on average 2 years postoperatively. All grafts appeared to be united and incorporated, without evidence of resorption. The only patient suffering from pain had radiographic signs of progressive varus migration of the femoral component.     

The angle-bore acetabular component and dislocation after revision of a failed total hip replacement

We reviewed 1039 revision total hip replacements where an angle-bore acetabular component was used. After a mean follow-up of nine years (0 to 20.6), the incidence of revision for dislocation was 2.1% (22 revisions), a success rate of 97.9%. In 974 revisions, where the indication was other than dislocation, the success rate was 98.5%. Of the 65 revisions for dislocation, 58 (89.2%) were successful after the first revision and a further five after the second revision, an overall success of 96.9%. Two patients elected to have their implants removed. Dislocation after revision of failed total hip replacement is a complex issue. There is often no single cause and no simple solution. The angle-bore acetabular component, in combination with a 22.225-mm diameter femoral head, offers a high level of success.     

髋关节发育不良患者全髋关节置换术的髋臼中心化

目的 探讨采用全髋关节置换术(THA)治疗髋关节发育不良继发骨关节炎术中髋臼杯假体放置的方法及其对手术疗效的影响。方法 对38例(44髋)于1989年9月至2003年4月接受全髋人工关节置换术的髋关节发育不良继发骨关节炎患者进行了随访。其中男14例,女24例,平均年龄51．2岁(29～80岁),平均随访36．4个月(8～168个月)。按Crowe方法进行分类：Ⅰ型12髋,Ⅱ型24髋,Ⅲ型7髋,Ⅳ型1髋。测量泪滴与髋旋转中心的水平距离并与术后测量结果比较。结果 髋臼杯假体中心化放置者24髋,未加深髋臼者20髋。术后两组Harris评分分别为90．2分、86．3分。结论 对于多数髋关节发育不良患者在行THA时,术中加深髋臼而将髋旋转中心内移和下移,可使髋臼杯假体置于中心化位置得到牢固固定及满意的骨覆盖,术后获得良好的临床疗效。