Contemporary Porous Titanium Acetabular Components for Total Hip Arthroplasty After Pelvic Radiation

BackgroundPatients undergoing primary total hip arthroplasty (THA) following pelvic radiation have historically had poor survivorship free of aseptic acetabular component loosening. However, several series have reported improved results with tantalum acetabular components. The purpose of this study is to assess implant survivorship, radiographic results, and clinical outcomes of contemporary, porous titanium acetabular components in the setting of prior pelvic radiation.MethodsWe retrospectively reviewed 33 patients (38 hips) with prior pelvic radiation between 2006 and 2016 who underwent primary THA. The mean overall pelvic radiation dose was 6300 cGy with a mean latency period to THA of 5 years. The most common acetabular component was Pinnacle (DePuy Synthes) in 76%. Eight-seven percent of cups were fixed with screws. The mean age at primary THA was 74 years, 76% were male, and the mean body mass index was 30 kg/m². Mean follow-up was 5 years.ResultsThe 10-year survivorship free of revision for aseptic loosening, free of any revision, and free of any reoperation were 100%, 89%, and 89%, respectively, when accounting for death as a competing risk. There were 3 revisions; one each for taper corrosion, recurrent dislocation, and infection. Radiographically, all cups had evidence of osteointegration and none had radiographic evidence of loosening. The mean Harris Hip Score improved from 50 to 84 postoperatively (P < .0001).ConclusionContemporary porous titanium acetabular components with supplemental screws provided excellent implant fixation in patients with prior therapeutic pelvic radiation. At 10 years, 100% of these components were free of revision for aseptic loosening and 100% were radiographically well-fixed.Level of EvidenceLevel IV, Therapeutic.     

金属骨小梁杯在髋臼翻修中的应用及随访

目的探讨设计新颖的组配式骨小梁金属杯在髋臼翻修中的早期效果。方法自2006年4月至2007年2月期间对24例髋臼假体翻修患者使用了骨小梁金属杯,共计25髋,女13例,男11例,平均年龄73．5岁。每个患者术前及术后6个月,1、2、3年,作X线拍片影像学随访,以及进行Harris髋关节（HHS）评分和（UCLA）活动评分。所有患者随访的临床及影像学资料完整。结果术后随访30—40个月（平均36个月）。Harris评分由翻修前的5～57分（平均33．6分）提高到术后的69～95分（平均92．4分）（t=3．943,P〈0．01）,UCLA评分由翻修前的2～5分（平均3．7）提高到术后的7～9分（平均8．6分）（t=3．910,P〈0．01）。影像学随访未见假体移位、下沉等不稳和松动迹象,骨小梁金属杯周围骨质向内长人。结论对于全髋置换手术（THA）中,初次用骨水泥固定的髋臼杯失败的患者,若无骨缺损,翻修时使用骨小梁金属杯可以获得良好的早期效果。     

Midterm Clinical and Radiographic Outcomes of a Contemporary Monoblock Dual-Mobility Cup in Uncemented Total Hip Arthroplasty

BackgroundThe efficacy of contemporary monoblock dual-mobility (DM) cups to prevent dislocations in total hip arthroplasty (THA) is well reported, but there is little published data on their mid- to long-term outcomes. The authors aimed at reporting the 10-year survival of a contemporary DM cup as well as its clinical and radiographic outcomes.MethodsFrom a retrospective consecutive multicentric series of 516 patients (541 hips) that received uncemented THA between June 2007 and June 2010, 6 patients (6 hips) had cup and stem revisions, 5 patients (5 hips) had isolated stem revision, and 2 patients (2 hips) had isolated insert revision. A total of 103 patients (111 hips) died with their original implants, and 41 patients (42 hips) were lost to follow-up. This left 358 patients (375 hips) for clinical assessment at a median follow-up of 8.7 years (range, 6.8-10.5 years), including 279 patients (290 hips) with postoperative radiographs. Implant survival was calculated using the Kaplan-Meier method, and multivariable analyses were performed to determine whether clinical outcomes are associated with patient or surgical factors.ResultsThe 10-year survival considering revision for aseptic loosening as end point was 100% for the cup and 99.2% for the stem. No dislocations were observed, and radiographic assessment revealed 1 acetabular granuloma (0.3%), but no radiolucencies nor fractures. The Harris hip score improved from 49.6 ± 15.5 to 85.2 ± 14.5, and the postoperative Oxford hip score was 19.2 ± 7.6. Multivariable analyses revealed that improvement in Harris hip score increased with cup diameter (beta, 1.28; P = .039).ConclusionOur data confirmed satisfactory midterm outcomes of uncemented THA using a contemporary DM cup, with no dislocations nor cup revisions due to aseptic loosening.Level of EvidenceLevel IV, retrospective cohort study.     

Dual-mobility cups in total hip arthroplasty after femoral neck fractures: A retrospective study comparing outcomes between cemented and cementless fixation

IntroductionTotal hip arthroplasty (THA) after femoral neck fracture (FNF) is associated with an increased risk of dislocation. The goals of our study were (1) to determine dislocation and revision rates when dual-mobility cups (DMCs) are used in these patients, (2) to analyze clinical and radiographic outcomes, survivorship, complications and mortality rate, and (3) to compare results between cemented and cementless cups.Patients and methodsWe retrospectively reviewed patients with FNF treated using DMC-THA between 2011 and 2018. A minimum 2-year follow-up was required for clinical and radiographic assessment. The clinical outcome was assessed using the Harris Hip Score (HHS) and Merlé D´Aubigné-Postel score (MDP). Radiolucent lines, osteolysis and cup loosening were analyzed.ResultsWe included 105 patients (105 hips) with a mean age of 75.5 years. There were no dislocations. One patient (1.0%) underwent cup revision at 39 months for aseptic cup loosening. The mean HHS and MDP were 80.5 and 14.2 respectively at a mean follow-up of 4.1 years. A higher MDP was found in patients with cementless rather than cemented cups (15.0 vs. 13.1; p = 0.006). Four patients had radiolucent lines > 1 mm, around cemented cups. At 6.8 years, estimated cup survival was 98.2% for revision for aseptic loosening and 97.3% for revision for any reason. The mortality rates were 6.7% at 1 year and 23.8% at last follow-up.ConclusionOur findings suggest that using DMC in THA for FNF may prevent dislocation with a low revision rate. Cementless cups had a higher MDP than cemented cups.     

Porous tantalum shells and augments for acetabular cup revisions

Purpose

The purpose of this study was to evaluate early functional results of revision hip arthroplasty with pelvic bone loss revised with porous tantalum (PT) acetabular components.

Methods

Twenty-five consecutive patients (25 hips) with loose acetabular components after total hip arthroplasty with a minimum of Paprosky IIa pelvic bone loss treated with PT cups with and without modular augments were retrospectively reviewed. Clinical outcomes were assessed using Harris hip score, and Western Ontario and McMaster Universities scores. Mean follow-up was 20.5 months and no patient was lost during follow-up.

Results

The average Harris hip score, and Western Ontario and McMaster Universities scores improved from 40 and 36 preoperatively to 79 and 73 postoperatively, respectively. No statistically significant differences in functional outcome scores were found between the group with moderate (Paprosky IIa, b) and severe (Paprosky IIc or more) acetabular bone loss. At the most recent radiographic evaluation, 24 cups demonstrated no lucent lines and 1 cup had lucent lines but remained well fixed. One cup was revised for traumatic dislocation but was found well fixed at open reduction. There were no septic or aseptic failures in this series.

Conclusion

While awaiting longer-term follow-up studies, trabecular metal components show sufficient primary stability and appear suitable for revision hip arthroplasty with acetabular bone loss.     

Dual-mobility cups in revision acetabular reconstructions: Short-term outcomes in high-risk patients for instability

ObjectiveThe aim of this study was to evaluate the performance of dual-mobility (DM) cup systems for revision total hip arthroplasty (rTHA) in patients who had high risk for instability.MethodsWe prospectively followed up 34 hips of 30 patients (27 females, 3 males; mean age: 66.1 (range: 33 to 89) years) who underwent rTHA with DM cups for aseptic loosening in 23 hips, infection treatment as second or single stage in nine hips, and instability in two hips. Clinical functions of the patients were evaluated using the Harris Hip Score (HHS), and radiological migration or loosening of the DM cups were recorded. The survival of the components was calculated with the Kaplan-Meier survival analysis and failure was defined as any dislocation of the polyethylene (PE) insert, intraprosthetic dislocation (IPD), aseptic loosening of any component or total hip system revision due to any reason.ResultsThe mean duration of follow-up was 3.52 (range: 2.05 to 6.26) years. There was one dislocation of PE insert (2.9%), which was treated with closed reduction. There were two (5.8%) re-revisions for cemented DM cup due to migration. There was one PE insert and head change due to subacute infection. The mean HHS increased from 42.8 ± 6.7 (range: 34 to 60) points preoperatively to 87.3 ± 5.8 (range: 75 to 98) points postoperatively. The cumulative survival rate of the DM cup system was 91.2% (95% CI: 81.6–100%) with any revision, 94.1% (95% CI: 86.2–100%) with aseptic loosening and %97.1 (%95 CI: 91.4–100%) with dislocation as the end point at 3.5 years.ConclusionDual-mobility cups may provide good stability and represent a good option for revision acetabular reconstruction in patients who have high risk for instability.Level of evidenceLevel IV, therapeutic study.     

Low Revision Rates at More Than 10 Years for Dual-Mobility Cups Cemented Into Cages in Complex Revision Total Hip Arthroplasty

BackgroundInstability and aseptic loosening are the two main complications after revision total hip arthroplasty (rTHA). Dual-mobility (DM) cups were shown to counteract implant instability during rTHA. To our knowledge, no study evaluated the 10-year outcomes of rTHA using DM cups, cemented into a metal reinforcement ring, in cases of severe acetabular bone loss. We hypothesized that using a DM cup cemented into a metal ring is a reliable technique for rTHA at 10 years, with few revisions for acetabular loosening and/or instability.MethodsThis is a retrospective study of 77 rTHA cases with severe acetabular bone loss (Paprosky ≥ 2C) treated exclusively with a DM cup (NOVAE STICK; Serf, Décines-Charpieu, France) cemented into a cage (Kerboull cross, Burch-Schneider, or ARM rings). Clinical scores and radiological assessments were performed preoperatively and at the last follow-up. The main endpoints were revision surgery for aseptic loosening or recurring dislocation.ResultsWith a mean follow-up of 10.7 years [2.1-16.2], 3 patients were reoperated because of aseptic acetabular loosening (3.9%) at 9.6 years [7-12]. Seven patients (9.45%) dislocated their hip implant, only 1 suffered from chronic instability (1.3%). Cup survivorship was 96.1% at 10 years. No sign of progressive radiolucent lines were found and bone graft integration was satisfactory for 91% of the patients.ConclusionThe use of a DM cup cemented into a metal ring during rTHA with complex acetabular bone loss was associated with low revision rates for either acetabular loosening or chronic instability at 10 years.     

What Are the Long-term Results of Cemented Revision THA with Use of Both Acetabular and Femoral Impaction Bone Grafting in Patients Younger Than 55 Years?

BackgroundThe increasing number of THAs in younger patients will inevitably result in an increase of revision procedures. However, there is little evidence about the outcome of revision procedures in this patient group. Therefore, we updated a previous study conducted 5 years ago about the outcome of revision procedures in patients younger than 55 years.Questions/purposesWe sought to provide a concise update on the previously reported (1) long-term failure rate as defined by repeat revision, (2) clinical outcome as defined by the Oxford Hip score and the Harris Hip score, and (3) radiographic outcome of cemented revision THA performed with impaction bone grafting on both the acetabular and femoral sides in one surgery in patients younger than 55 years old.MethodsBetween 1991 and 2007, we performed 86 complete THA revisions in patients younger than 55 years. In 38% (33 of 86) of revisions, bone impaction grafting was used on both the acetabular and femoral side because of acetabular and femoral bone stock loss. Mean age at time of revision was 46 ± 8 years. No patient was lost to follow-up, but six patients died during follow-up, including three since 2015. Still, the hips of all 33 patients were included in analysis at a mean of 17 ± 5 years. Failure was calculated using competing risk analysis. For clinical outcome, we assessed the Harris Hip score and the Oxford Hip score from our longitudinally maintained institutional database. Radiographic analysis was performed to evaluate radiographic loosening, defined as radiolucencies ≥ 2 mm in all zones or ≥ 5 mm migration for both components. The acetabular component was also considered loose with tilting ≥ 5°ResultsThe 15-year failure rate of revision THA was 27% (95% CI 13 to 44) for re-revision of any component for any reason and 10% (95% CI 3 to 25) for re-revision of any component for aseptic loosening. The mean Harris Hip score increased from 55 ± 18 preoperatively to 74 ± 22 at latest follow-up. Eight cups were considered radiographically loose, seven of which were re-revised. No stems were considered radiographically loose. Failure rate with endpoint radiographic loosening at 15 years was 23% (95% CI 10 to 39).ConclusionWe found that impaction bone grafting with a cemented cup and a cemented stem is a valuable biological revision technique that results in a stable and durable solution, after one or even multiple previous revision THAs. Although current implants may prove sufficient in most cases, they do not promote bone stock preservation. We believe that in young patients with bone stock loss, impaction bone grafting can be used as long as the defect can be contained adequately with a metal mesh and viable bone bed is available for revascularization.Level of EvidenceLevel IV, therapeutic study.     

Midterm Outcomes After Reconstruction of Superolateral Acetabular Defects Using Flying Buttress Porous Tantalum Augments During Revision Total Hip Arthroplasty

BackgroundPorous tantalum augments are versatile tools in reconstructing complex acetabular defects during revision total hip arthroplasty (THA). This study examines the clinical and radiographic outcomes of porous tantalum augments placed in the type I (flying buttress) configuration at two to 17-year follow-up in the largest cohort to-date in the literature.MethodsWe retrospectively analyzed 59 consecutive revision THAs involving the use of flying buttress augments between 2003 and 2018. The mean patient age and follow-up duration were 63.9 ± 11.6 years (range, 35-87) and 8 years (range, 2-17), respectively. The Oxford hip score was used to assess clinical outcome. The modified Moore classification was used to assess acetabular augment and shell osseointegration. Kaplan-Meier survival analysis with 95% confidence interval (CI) was used to assess implant survivorship.ResultsThe mean Oxford hip score improved from 15.9 ± 6.2 preoperatively to 35.0 ± 6.5 at a mean follow-up of eight years (P < .0001). Radiographic assessment using the modified Moore classification demonstrated five signs of osseointegration in 49 hips (83.1%), four signs in six hips (10.2%), three signs in one hip (1.7%), and one sign in one hip (1.7%). Kaplan-Meier analysis demonstrated ten-year survivorship of 88.9% (95% CI 74.4-95.4) with all-cause revision as end point and 94.3% (95% CI 83.1-98.2) with revision for acetabular aseptic loosening as end point.ConclusionTreatment of superolateral acetabular defects during revision THA using porous tantalum augments placed in the type I (flying buttress) configuration provides excellent implant survivorship and favorable clinical outcomes at mid-term follow-up.Level of EvidenceTherapeutic Level IV.     

Acetabular revision surgery with the LOR cup: three to 8 years' follow-up

A retrospective review was conducted to evaluate the mid-term results of the Längsovalen Revisionspfanne oblong revision cup. From July 1995 to March 2000, 41 acetabular revision surgeries were performed for aseptic loosening of the acetabular cup. The acetabular defects were classified as type 2A to 3B, according to Paprosky's criteria. Morselized bone grafts were used in 19 cases (45.2%) to fill cavitary defects. The mean postoperative follow-up was 63.5 months (range, 40-99 months). Clinical assessment at follow-up showed a significantly improved mean Harris Hip Score from 46 points preoperatively to 82.2 points postoperatively, whereas the x-ray examination did not show any sign of loosening of the cups. Data analysis showed that significantly better results were correlated with restoring the hip rotation center and reducing leg length discrepancy.     

Total hip arthroplasty using hydroxyapatite-coated cementless cup for rapidly destructive coxarthrosis: Minimum 10-year follow-up

BackgroundPerforming total hip arthroplasty (THA) as early as possible is recommended for rapidly destructive coxarthrosis (RDC) as it causes pain that becomes progressively more severe. However, acetabular bone loss remains an issue in THA. Special devices, such as a Kerboull-type plate, may be used for acetabular bone defects, but the procedure is highly invasive and often the patients are elderly, further complicating matters. We retrospectively investigated the clinical and radiographic results of THA using conventional hydroxyapatite-coated cementless cup in RDC.MethodsA total of 32 patients (35 hips) with RDC were enrolled in the study with a minimum 10-year follow-up. All THAs were performed using conventional hydroxyapatite-coated cementless cup. All patients were evaluated clinically according to the Harris hip score (HHS). Acetabular bone deficiency was classified according to the American Academy of Orthopaedic Surgeons (AAOS) classification.ResultsEleven hips (31%) were AAOS type III, and none were type IV. Total HHS significantly improved from 36.5 to 79.4 (p < 0.01). Two cups exhibited loosening. The overall implant-associated survival rate after 10 years was 91.4%.ConclusionsClinical results of THA using conventional cementless implants for patients with RDC were acceptable. Thus, THA using conventional cementless implant is an effective and safe surgery for patients with RDC, minimizing surgical stress.     

A new technique for diagnosis of acetabular cup loosening using computed tomography: Preliminary experience in 10 patients

Background and purpose?Considerable migration of the acetabular cup is required for diagnosis of loosening by conventional radiography. We have developed a new clinically applicable method for assessment of cup loosening using computed tomography (CT).

Patients and methods?10 patients scheduled for revision hip replacement due to suspected wear or loosening were scanned twice with CT under torsion loading of the prosthesis. Two independent examiners assessed each patient with respect to motion of the acetabular cup relative to the pelvis using CT volume registration. The CT measurements were compared to findings at revision surgery.

Results?The method was applicable in 8 of the 10 patients. 1 patient had a severe tremor. In 1 patient, surgery revealed that the hip was ankylotic due to massive ectopic bone formation. This left 8 patients that could be evaluated. 4 cups were loose at surgery, and 3 of these cups could be seen to be mobile by CT. 4 cups that were stable on revision were accurately diagnosed as not being mobile by CT. Movements of less than 1 millimeter between bone and prosthesis could not be distinguished from errors in CT acquisition and volume registration. There was good agreement between the two observers.

Interpretation?Movement of loose acetabular cups during torsion loading could be detected using CT volume registration. It was sensitive to cup movement in 3 out of 4 cases of loose cups. The method was specific and yielded no false positive results.     

Monolithic Dual Mobility Cup Total Hip Arthroplasty Has High Complication Rates With Surgical Fixation in Elderly With Femur Neck Fracture

BackgroundThis study is prospectively conducted to evaluate surgical complications of monolithic dual mobility cup total hip arthroplasty (THA) in elderly patients with fractured neck of the femur.MethodsNinety-seven patients (97 hips) with displaced femoral neck fracture who gave informed consent for participation were prospectively enrolled. Their mean age was 76.6 years (range, 60-95 years), and the mean bone mineral density T-score of neck of the femur was −2.8 (range, −1.2 to −5.5). All patients underwent THA with monolithic dual mobility cup, and computed tomography scans were obtained to evaluate radiographic parameters including anteversion, inclination, and loosening of acetabular cups, and periprosthetic acetabular fractures.ResultsWith regard to cup orientation, mean inclination angle was 40.2° (range, 23.5°-63°) and mean anteversion was 32.6° (range, 7°-66.2°). The proportion of surgical outliers was 10.3% (10/97) in inclination and 35.1% (34/97) in anteversion. Early cup loosening within 2 weeks was detected in 2 hips. Periprosthetic acetabular fractures were identified in 6 hips (6/97, 6.2%). Of the 6 fractures, 5 nondisplaced fractures were healed with conservative management, but 1 fracture with displacement eventually led to cup loosening and the patient underwent revision surgery. Reoperation rate of the monolithic dual mobility cup was 4.1% (4/97).ConclusionThe use of the monolithic dual mobility was associated with improper cup fixation and periprosthetic acetabular fractures in the elderly with poor bone stock, although the dual mobility cup lowered the risk of early dislocation after THA.     

Revision total hip arthroplasty in juvenile chronic arthritis: 17 revisions in 11 patients followed for 4–12 years

Background Revision total hip arthroplasty (THA) in patients with juvenile chronic arthritis (JCA) is complicated by the young age of the patient, poor bone stock and small physical proportions. We report the complications and outcome of a prospective series of 17 revision THAs in Charnley class C JCA patients.

Methods 15 acetabular components and 10 femoral components were revised. 13 cementless cups, 2 reconstruction/roof rings and cemented cups, and 4 cemented and 6 cementless femoral stems were implanted. 2 proximal femoral allografts and 1 strut allograft were used. Age at revision was 32 (21–53) years. Follow-up averaged 7 (4–12) years.

Results 2 patients with cemented femoral stems developed loosening, osteolysis and fracture. Both were successfully revised to long-stem cementless implants with strut/proximal femoral allografts. 1 loose, worn cementless cup with osteolysis was revised. 1 patient with a peri-operative infection and late acetabular fracture had a loose, non-revised cementless cup. 1 case of sciatic nerve palsy occurred after revision using a reconstruction ring. 1 late infection necessitated resection arthroplasty. Harris hip scores improved from 53 (34–85) to 76 (47–96).

Interpretation Revision THA in JCA has a substantial complication rate, even in experienced hands. The problem of obtaining long-term stable fixation, osteolysis, and replenishment of lost bone stock are major difficulties.     

Evaluation of a porous tantalum uncemented acetabular cup in revision total hip arthroplasty: clinical and radiological results of 60 hips

Long-term survival of the acetabular component in revision total hip arthroplasty (THA) is determined by initial implant stability and bone ingrowth. Highly porous Trabecular Metal (TM, Zimmer, Inc, Warsaw, Ind) facilitates ingrowth and may be an ideal material for revision THA. The outcome and survivorship of a TM, nonmodular, uncemented acetabular cup were assessed in 60 consecutive patients undergoing revision THA (mean follow-up, 42 months; range, 14-68 months). Most (55/60) acetabular cups were implanted without screw fixation. Mean Harris Hips Scores improved from 74.8 preoperatively to 94.4 at last follow-up. Serial radiographs demonstrated excellent bone apposition and bone graft incorporation. Complications were limited to 7 cases of dislocation and 1 revision for aseptic loosening. The TM acetabular cup appears suitable for use in revision THA and warrants further study.