Isolated Liner Exchange in Total Hip Arthroplasty at a Mean of 13 Years of Follow-up: Does Fixation Technique Matter?

BackgroundIsolated liner exchange is an option to address polyethylene wear after total hip arthroplasty (THA). The liner can be fixed with either the original locking mechanism or cemented into the acetabular cup. Whether the method used for liner fixation has any bearing on the outcomes in the first and second decade after surgery is still unclear.MethodsData for all patients who had undergone isolated liner exchange surgery in our institution between April 1995 and January 2015 were retrieved. Patients were classified according to the type of polyethylene liner (conventional or highly crosslinked polyethylene) and the locking mechanism used (original locking mechanism or cemented). Survivorship and revision rates were compared among different subgroups. A total of 118 isolated liner exchanges were performed and patients had a mean duration of follow-up of 13 years (range, 5 to 25).ResultsOverall estimated mean survivorship was 17 years. Use of highly crosslinked polyethylene (HXLPE) had a lower re-revision rate compared to conventional liners (10.5 versus 46.9%) (P < .001). The re-revision rate of exchanges using HXLPE was not affected by the type of fixation (original locking mechanism 11.1 versus cement 10.0%, P = .868). Conversely, using the original locking mechanism with a conventional liner had a higher re-revision rate compared to cemented conventional liners (58.3 versus 12.5%) (P = .024).ConclusionHXLPE liners should be used in insert exchange surgery whenever possible. Re-revision rate of exchanges using HXLPE was not affected by the fixation technique used. Cementing an insert into an acetabular component is associated with good survivorship at a mean of 13 years follow-up.     

Does Revision of an Acetabular Shell With Insertion of an Uncemented Constrained Liner Confer Benefit Over Cementing Into a Well-Ingrown Shell?

BackgroundDuring revision total hip arthroplasty (THA), a constrained acetabular liner (CAL) may be inserted to enhance hip stability. It is unclear, however, whether cementation of a CAL into a retained cup offers an advantage compared to revision of the acetabular cup and insertion of an uncemented CAL. The purpose of our study was to compare outcomes and survivorship between the 2 methods.MethodsWe identified a total of 177 patients who underwent revision THA with a specific CAL at our center between July 2004 and May 2019 (114 cup revisions and insertion of an uncemented CAL, 63 cementations of a CAL into a retained cup). Kaplan-Meier (KM) survival analysis was performed for implant survival free from aseptic failure of the CAL for both cohorts.ResultsThe average follow-up time was 7.2 and 7.02 years for the cemented and uncemented cohort, respectively (P = .55). Five patients (7.93%) in the cemented CAL group experienced failure of the CAL, whereas 10 patients (8.77%) in the uncemented CAL cohort experienced failure (P = .21). Kaplan-Meier (KM) survival analysis demonstrated comparable survivorship at 10 years (P = .055).ConclusionThe results of our study suggest comparable survivorship between cementing a CAL into a retained cup and inserting an uncemented CAL in a revised acetabular cup. As a result of these findings along with the benefits associated with cementing a CAL, we encourage surgeons to readily consider this option in the management of recurrent instability.     

Hybrid Fixation for Total Hip Arthroplasty Showed Improved Survival Over Cemented and Uncemented Fixation: A Single-Center Survival Analysis of 2156 Hips at 12-18 Years

BackgroundDespite increased use of uncemented and hybrid fixation, there is little evidence of their superiority over cemented implants. The aim of this study is to compare the long-term survivorship of cemented, hybrid and uncemented total hip arthroplasty (THA) at varying ages.MethodsA total of 2156 hips (1315 cemented, 324 uncemented, and 517 hybrid) were performed in a single center between 1999 and 2005 with follow-up through to 2017. Registry and local databases were used to determine revision rates and cause. Unadjusted and adjusted competing risk survival analysis was performed.ResultsThe cumulative incidence of all-cause revision at 18 years was cemented 10.9%, uncemented 8.9%, and hybrid 6.5%. Cemented fixation had a statistically significant higher risk of all-cause revision than hybrid in the adjusted model for all ages to 65 years (subhazard ratios [SHRs], 2.28-4.67) and a higher risk of revision for loosening, wear, or osteolysis at all ages (SHRs, 3.25-6.07). Uncemented fixation showed no advantage over hybrid fixation at any age, but did show advantages over cemented at younger ages (≤60 years) for all-cause revision (SHRs, 2.3-4.3).ConclusionHybrid fixation with conventional polyethylene shows an advantage over cemented hips at all ages. Uncemented THA showed improved survival over cemented only at younger ages and no advantage over hybrid THA.     

Outcomes of Isolated Head and Liner Exchange Using Large Femoral Heads and Modern Liners in Revision Total Hip Arthroplasty

BackgroundPrevious reports on the outcomes of isolated head and liner exchange in revision total hip arthroplasty have found high rates of instability after these surgeries. Most reports have studied constructs using ≤28 mm femoral heads. The purpose of this study was to determine if modern techniques with the use of larger head sizes can improve the rate of instability after head and liner exchange.MethodsWe identified 138 hips in 132 patients who underwent isolated head and liner exchange for polyethylene wear/osteolysis (57%), acute infection (27%), metallosis (13%), or other (2%). All patients underwent revision with either 32 (23%), 36 (62%), or 40 (15%) mm diameter heads. Cross-linked polyethylene was used in all revisions. Lipped and/or offset liners were used in 104 (75%) hips. Average follow-up was 3.5 (1.0-9.1) years. Statistical analyses were performed with significance set at P < .05.ResultsRevision-free survivorship for any cause was 94.6% and for aseptic causes was 98.2% at 5 years. 11 (8%) hips experienced a complication with 7 (5%) hips requiring additional revision surgery. After revision, 4 (3%) hips experienced dislocation, 5 (4%) hips experienced infection, and 1 (1%) hip was revised for trunnionosis. No demographic or surgical factors significantly affected outcomes.ConclusionOur study shows that isolated head and liner exchange using large femoral heads and modern liners provides for better stability than previous reports. The most common complication was infection. We did not identify specific patient, surgical, or implant factors that reduced the risk of instability or other complication.     

Survival of 11,390 Continuum cups in primary total hip arthroplasty based on data from the Finnish Arthroplasty Register

Background and purpose — The use of trabecular metal (TM) cups for primary total hip arthroplasty (THA) is increasing. Some recent data suggest that the use of TM in primary THA might be associated with an increased risk of revision. We compared implant survival of Continuum acetabular cups with other commonly used uncemented cups.

Patients and methods — Data on 11,390 primary THAs with the Continuum cup and 30,372 THAs with other uncemented cups (reference group) were collected from the Finnish Arthroplasty Register. Kaplan–Meier survival estimates were calculated; the endpoint was revision for any reason, for infection, or for dislocation. Revision risks were assessed with adjusted Cox multiple regression models. A subgroup analysis on the use of neutral or elevated liners in the Continuum group was made.

Results — The 7-year survivorship of the Continuum group was 94.6% (95% CI 94.0–95.2) versus 95.6% (CI 95.3–95.8) in the reference group for revision for any reason. The risk for revision was higher in the Continuum group than in the reference group both for revision for any reason (HR 1.3 [CI 1.2–1.5)]) and for revision for dislocation (HR 1.9 [CI 1.5–2.3]). There was no difference in the rates of revision because of infection (HR 0.99 [CI 0.78–1.3]). Use of a neutral liner increased the risk for revision due to dislocation in comparison with the use of an elevated rim liner in the Continuum group (HR 1.7 [CI 1.2–2.5]).

Interpretation — THA with Continuum cups is associated with an increased risk of revision compared with other uncemented cups, mainly due to revisions because of dislocation. Our results support the use of an elevated liner when Continuum cups are used for primary THA.     

Hip Hemiarthroplasty for Fractured Neck of Femur Revised to Total Hip Arthroplasty: Outcomes Are Influenced by Patient Age Not Articulation Options

BackgroundHip hemiarthroplasty is the most common arthroplasty option for fractured neck of femur (FNOF). Revision to total hip arthroplasty (THA) is occasionally required. This study aimed to assess the outcome of hemiarthroplasty revised to THA and to assess the impact of femoral head size, dual mobility (DM), and constrained liners.MethodsAll aseptic 1^st revisions reported to the Australian Joint Replacement Registry after hemiarthroplasty performed for FNOF when a THA was used as the revision procedure were included from September 1999 to December 2019. The primary outcome measure was the cumulative percent revision for all-causes and dislocation. The impact of prosthesis factors on revision THA was assessed: standard head THA (≤32 mm), large head THA (≥36 mm), DM, and constrained liners. Outcomes were compared using Kaplan Meyer and competing risk.ResultsThere were 96,861 hemiarthroplasties performed, with 985 revised to THA. The most common reasons for 1^st revision were loosening (49.3%), fracture (17.7%), and dislocation (11.0%). Of the hemiarthroplasty procedures revised to THA, 76 had a 2^nd revision. The most common reasons for 2^nd revision were fracture (27.6%), dislocation (26.3%), loosening (23.7%), and infection (18.4%). Femoral head size, DM, or constrained liner use did not alter the incidence of all-cause 2^nd revision. This did not change when solely looking at patients still alive. A 2^nd revision was more likely in patients aged <75 years.ConclusionThe outcome of hemiarthroplasty performed for FNOF revised to THA is influenced by patient age, not by the articulation used.     

Survivorship of Ceramic-on-Ceramic Total Hip Arthroplasty With Metal-Backed Acetabular Liners at 10 Years

BackgroundCeramic-on-ceramic bearings are becoming increasingly popular in primary total hip arthroplasty (THA). To enhance ceramic-on-ceramic liner exchange in case of revision surgery, metal-backed liner systems have been proposed. Little is known about the clinical performance of these implants. The purpose of this study is to evaluate a metal-backed liner implant system for primary THA.MethodsA total of 422 patients (with 468 consecutive THAs) were followed over a mean period of 10 years. All arthroplasties were performed with a cementless stem, a press-fit cup, and a metal-backed liner system. Surgical and clinical data, complications, and revisions were analyzed. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) before surgery and at 1 and 10 years after surgery were compared.ResultsThe overall 10-year implant survival rate was 93.8%. The survival rate was 97.0% for heads and liners, 97.5% for stem, and 99.3% for acetabular cup. The most common reason for revision was ceramic breakage (2.4%) of the third-generation (BIOLOX forte) acetabular liner. Mean WOMAC score improved significantly from 50.1 before surgery to 13.2 at 1 year after surgery. There was no difference in WOMAC scores between surgical approach and type of bearing at 1 and 10 years after surgery.ConclusionTHA using cementless stem, press-fit cup, and metal-backed liner system provides satisfactory long-term outcomes, with revision rate comparable to that with other systems available in the market. The metal-backed liner system has low risk of mal-seating. Third-generation ceramic liners should be avoided as they seem to be more prone to breakage.     

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.     

Cemented Liner Exchange With Bone Grafting Halts the Progression of Periacetabular Osteolysis

The aims of this were to examine the effect of acetabular liner exchange and intra-operative bone grafting surgery on peri-prosthetic osteolysis. Seven patients with well-fixed Harris-Galante-1 acetabular components received cemented exchange liners for worn liners associated with pre-operatively CT-quantified osteolysis. During surgery, accessible osteolytic lesions were debrided and bone-grafted. Except for one patient with recurrent dislocation and acetabular component revision, the other patients had CT scans at a median of 4 months and at approximately 4 years after surgery. None of the pre-operative lesions increased in volume during the post-operative reporting period and no new lesions were detected. These results show that cemented liner exchange surgery can halt the progression of osteolysis and that bone grafting has the potential to restore bone.     

Revision Risk of Total Hip Arthroplasty With Vitamin E Doped Liners: Results From the Danish Hip Arthroplasty Register

BackgroundVitamin E-doped cross-linked polyethylene (VEPE) liners were introduced in total hip arthroplasty (THA) to reduce wear and risk of aseptic loosening and liner fracture. We report this nationwide population-based study to investigate the safety of VEPE liners for THA compared to cross-linked annealed or remelted polyethylene (XLPE).MethodsWe included THAs from The Danish Hip Arthroplasty Register from January 1, 2008 to June 30, 2019, with uncemented cup, VEPE or XLPE liner, and metal or ceramic head. The outcome was revision due to (1) polyethylene-related endpoints (aseptic loosening, granuloma, osteolysis, or liner fractures) and (2) other endpoints.ResultsA total of 110,803 THAs were assessed for eligibility and 53,842 THAs (46,645 patients) were included in the study: 5069 (9.4%) THAs with a VEPE liner and 48,773 (91.6%) with a XLPE liner. Median observation time was 5.48 (interquartile range 3.80-7.15) years for VEPE and 4.85 (interquartile range 2.68-7.76) for XLPE. VEPE had a lower risk of revision for polyethylene-related endpoints compared to XLPE (hazard ratio [HR] 0.60, 95% confidence interval 0.36-0.98) during complete follow-up. THAs with VEPE liners were associated with increased risk of any revision within the first 3 months (HR 1.62, 1.36-1.94), revision recorded as aseptic loosening within 3 months (HR 4.46, 2.26-8.80), and periprosthetic fracture within 3 months (HR 2.57, 1.98, 3.33).ConclusionVEPE liners had a lower risk of revision due to polyethylene-related endpoints, but a higher risk of all-cause revision within 3 months.     

Survivorship and Risk Factors for Re-Revision after Aseptic Revision Total Hip Arthroplasty in Patients Aged ≤55 Years

BackgroundThere is a relative paucity of literature on the outcomes after revision total hip arthroplasty (rTHA) in young patients. This study reports the survivorship and risk factors for re-revision in patients aged ≤55 years.MethodsWe identified 354 patients undergoing aseptic nononcologic rTHA at mean follow-up of 5 years after revision, with mean age of 48 years, body mass index of 28 kg/m², and 64% female. Thirty-five (10%) patients underwent at least 1 previous rTHA. The main indications for rTHA included wear/osteolysis (21%), adverse local tissue reaction (21%), recurrent instability (20%), acetabular loosening (16%), and femoral loosening (7%); and included acetabular component-only rTHA in 149 patients (42%), femoral component-only rTHA in 46 patients (13%), both component rTHA in 44 patients (12%), and head/liner exchanges in patients 115 (33%). The Kaplan-Meier method was used to measure survivorship free from re-revision THA, and multivariate regression was used to identify risk factors for re-revision THA.ResultsSixty-two patients (18%) underwent re-revision THA at the mean time of 2.5 years, most commonly for instability (37%), aseptic loosening (27%), and prosthetic joint infection (15%). The rTHA survivorship from all-cause re-revision and reoperation was 83% and 79% at 5 years, respectively. Multivariate analysis demonstrated that patients undergoing femoral component only (hazard ratio 4.8, P = .014) and head/liner exchange rTHA (hazard ratio 2.5, P = .022) as risk factors for re-revision THA.ConclusionAbout 1 in 5 patients aged ≤55 years undergoing rTHA required re-revision THA at 5 years, most commonly for instability. The highest risk group included patients undergoing head/liner exchanges and isolated femoral component revisions.     

Fixation Method and Subsequent Revision Rates for Elective Primary Hip Arthroplasty in People Aged 70 Years and Older: Analysis of National Administrative Data Sets by the UK Getting It Right First Time Program

BackgroundWe aimed to understand the role of fixation method in predicting subsequent revision rates in people aged 70 years and older undergoing elective primary total hip arthroplasty (THA) within the UK National Health Service (NHS).MethodsData on elective primary THAs conducted in people aged 70 years and older between April 1, 2012, and March 31, 2018, and subsequent revisions conducted up to March 31, 2019, were extracted from the Hospital Episodes Statistics database for all NHS procedures in England. A flexible parametric competing risks model was used to identify the role of fixation method in predicting revision and adjust for age, sex, frailty, year of surgery, and all-cause mortality.ResultsData were available for 190,656 procedures. Crude revision rates at 1-7 years follow-up in those who had cemented, hybrid/reverse hybrid, and uncemented fixation were 1.8%, 1.8%, and 2.3%, respectively. There was a high level of variation between NHS trusts in the proportionate use of fixation method. The differences in the hazard of revision between uncemented and cemented fixation (hazard ratio, 1.238 [95% confidence interval, 1.148-1.336]) and hybrid/reverse hybrid fixation (hazard ratio, 1.184 [95% confidence interval, 1.082-1.297]) were both significant. In secondary analysis, there was evidence that revision rates in trusts where uncemented fixation predominated were not significantly lower for uncemented fixation compared to all other fixation methods.ConclusionsRevision rates were significantly higher for elective primary THA in people aged 70 years and older who have uncemented fixation, compared to those who had cemented and hybrid/reverse hybrid fixation.     

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.     

Excellent Long-Term Survival Rate of Polished,Tapered, Cemented Stems in Patients Aged 35 Years or Younger With Avascular Necrosis or Inflammatory Arthritis of the Hip

BackgroundTotal hip arthroplasty (THA) for avascular necrosis (AVN) or inflammatory arthritis (IA) comes with a relatively high risk of aseptic stem loosening, especially in young patients. There are limited long-term data on the survivorship of polished, tapered, cemented stems in this population. We therefore performed a single-center retrospective study investigating the survival of this particular stem type in young patients with AVN or IA.MethodsAll patients aged ≤35 years who had received a THA for AVN or IA operated on by the senior author between 1990 and 2010 at the University Hospitals Leuven were identified. In total, 85 THAs in 62 patients were included. Primary endpoint was revision of the femoral component for aseptic loosening. Secondary endpoints were revision of the acetabular component for aseptic loosening, revision for other reasons, and the presence of radiolucencies around the components.ResultsThe mean follow-up for the entire cohort was 18.0 ± 5.3 years (range 8.0-28.9). Taking revision for aseptic loosening as endpoint, the survival of cemented stems was 100% after 15 years and 95.1% after 20 years. Survival of uncemented cups (91.3%) was significantly better than survival of cemented cups (50.3%) after 20 years of follow-up for aseptic loosening. Taking revision for any reason as endpoint, the survival of THAs with uncemented and cemented cups was 90% and 43.1% at 20 years respectively. Radiolucencies developed in the cement mantles around 11 of the 81 nonrevised stems, mainly in zones 1 and 7.ConclusionIn this cohort of young patients with high-risk profiles for aseptic stem loosening, polished, tapered, cemented stems showed excellent long-term survival rates and they therefore remain a viable alternative to uncemented stem designs.     

Prior Instability is Strongly Associated With Dislocation After Isolated Head and Liner Exchange

BackgroundIsolated head and liner exchange is an appealing alternative to a more extensive revision total hip arthroplasty in patients who have well-fixed components. Despite efforts to increase femoral offset and restore soft tissue tensioning, limited component revision may be associated with higher rates of postoperative instability.MethodsThis retrospective analysis assessed 209 patients who had a head and liner exchange conducted at a large academic medical center between 2011 and 2019 and had >2 years of follow-up. Functional cup positioning within the Lewinnek safe zone was assessed on postoperative weight-bearing radiographs. Included patients were 56% women, had a mean age of 64 years (range, 24-89) and a mean body mass index of 28.8 kg/m² (range, 18.2-46.7). The most common indications for surgery included acetabular liner wear in 86 hips (41%), instability in 40 hips (19%), and infection in 36 hips (17%).ResultsTwenty-eight hips (13%) had a dislocation within 2 years after surgery. The best-fit model predicting postoperative dislocation included a history of dislocation (adjusted-odds ratio [adj-OR] 5.67, 95% CI 2.39-14.09, P < .001), age (adj-OR 1.04 per 1-year increase, 95% CI 0.99-1.08, P = .10), and body mass index (adj-OR 0.90 per 1-kg/m² increase, 95% CI 0.80-0.99, P = .046).ConclusionIn a large cohort of patients who had isolated head and liner exchange, patients who had prior instability had 7-fold elevated odds of postoperative dislocation. This risk remains significant after controlling for cup positioning outside the Lewinnek safe zone, liner type, head size, neck length, soft tissue compromise, neuromuscular disease, and dual mobility constructs.Level of EvidenceIII, retrospective cohort study.     

Despite Improved Survivorship of Uncemented Fixation in Total Knee Arthroplasty for Osteoarthritis,Cemented Fixation Remains the Gold Standard: An Analysis of a National Joint Registry

BackgroundTotal knee arthroplasty (TKA) numbers are increasing worldwide. While cement fixation for both femoral and tibial components is commonly used, alternatives include hybrid and uncemented TKAs. This study aimed to evaluate survivorship, revision rates, and patient-reported outcomes for cemented, hybrid, and uncemented TKAs using New Zealand Joint Registry (NZJR) data.MethodsNZJR data relating to all TKAs performed during the 19 years up to the end of December 2017 were analyzed. Outcomes were assessed using prosthesis survivorship data (including reasons for revision) and Oxford scores at 6 months, 5 years, and 10 years postoperatively.ResultsA total 96,519 primary TKAs were performed during the period examined. Most (91.5%) were fully cemented with 4.8% hybrid and 3.7% uncemented. Mean Oxford scores at 6 months were highest in cemented and lowest in uncemented TKAs (P < .001). However, this was not clinically significant. There was no difference at 5 or 10 years. Ten-year survival rates were 97%, 94.5%, and 95.8% for cemented, uncemented, and hybrid TKAs, respectively. Revision rates were 0.47, 0.74, and 0.52 per 100 component years for cemented, uncemented, and hybrid prostheses, respectively. The revision rate for uncemented prostheses compared with cemented was higher (P < .001). When stratified by age group, there were differences in survival rates between cemented and uncemented groups (P = .001) and hybrid and uncemented groups (P = .038) in patients aged <55 years; between cemented and uncemented groups in those aged 55-64 years (P = .031); and between cemented and hybrid groups in those aged >75 years (P = .004).ConclusionUncemented TKAs had similar patient-reported outcomes but higher revision rates and worse survivorship compared with hybrid or fully cemented TKAs.     

Total hip arthroplasty for primary osteoarthrosis in younger patients in the Finnish arthroplasty register. 4,661 primary replacements followed for 0-22 years

BACKGROUND: Many studies have found a higher risk of revision after hip arthroplasty in younger patients. We evaluated the population-based survival of total hip arthroplasty (THA) in patients under 55 years of age and the factors affecting survival. METHODS: The Finnish Arthroplasty Register was established in 1980, and 74,492 primary THAs were entered into the register between 1980 and 2001. 4,661 of these were evaluated, all of which had been performed for primary osteoarthrosis on patients under 55 years of age. RESULTS: Proximally circumferentially porous-coated uncemented stems implanted between 1991 and 2001 had a 10-year survival rate of 99 (95% CI 98.5-99.6)% with aseptic loosening as endpoint. The risk of stem revision due to aseptic loosening was higher in cemented stems than in proximally porous-coated (RR 5.5, p < 0.001) or HA-coated (RR 6.6, p = 0.01) uncemented stems implanted during the same period. According to Cox regression analysis of cups implanted 1991-2001, the risk of revision for all-polyethylene cemented cups was 3.0 times as high as that for press-fit porous-coated uncemented cups with aseptic loosening as endpoint (p = 0.01). However, when the endpoint was defined as any revision (including exchange of liner), there was no longer any difference between these two concepts, the 10-year survival rates being 94 (92.1-95.5)% for press-fit porous-coated uncemented cups and 93 (88.5-97.6)% for all-polyethylene cemented cups (p = 0.9). INTERPRETATION: Modern uncemented stems seem to have better resistance to aseptic loosening than cemented stems in younger patients. Thus, for younger patients, uncemented proximally circumferentially porous- and HA-coated stems are the implants of choice. Press-fit porous- and HA-coated uncemented cups may have better endurance against aseptic loosening than cemented cups in younger patients. However, when all revisions (including exchange of liner) are taken into account, the survival of modern uncemented cups is no better than that of all-poly cemented cups.     

Long-Term Outcomes of Cementing Highly Cross-Linked Polyethylene Liners Into Well-Fixed Acetabular Shells in Revision Total Hip Arthroplasty

BackgroundCementing a new liner into a secure, well-positioned metallic shell can be a less-invasive strategy in revision total hip arthroplasty (THA). This study aimed to report the mean 14-year outcomes of cementing highly cross-linked polyethylene (XLPE) liners into well-fixed acetabular shells in revision THAs.MethodsThis study reviewed a single-surgeon series of cementing XLPE liners into well-fixed acetabular components. Of the 52 hips (51 patients) evaluated, 48 hips (47 patients) that satisfied a minimum follow-up of 10 years were included. The Harris Hip score was used for clinical evaluation. Final hip radiographs were used to determine the extent of acetabular osteolysis and stability of the components. The mean age at index operation was 53 years (range, 32 to 72). The mean follow-up duration was 14 years (range, 10 to 18).ResultsThe mean Harris Hip score improved from 58 points (range, 23-81) preoperatively to 91 points (range, 45-100) at the final evaluation (P < .001). A total of 3 acetabular rerevisions were performed, all for aseptic loosening of the outer shell. One postoperative dislocation occurred, but it was successfully treated with a closed reduction. Final radiographs showed a significant reduction in acetabular osteolysis (P < .001). Implant survivorship free from any rerevision was 93.3% (95% confidence interval, 85.9-100%) at 14 years.ConclusionCementing an XLPE liner into a well-fixed acetabular shell in revision THA demonstrated excellent clinical and radiographic outcomes at a mean of 14 years postoperatively. This technique could be a safe and durable option in the absence of XLPE liners compatible with preimplanted shells.     

Risk Factors for Dislocation and Re-revision After First-Time Revision Total Hip Arthroplasty due to Recurrent Dislocation – A Study From the Danish Hip Arthroplasty Register

BackgroundPersistent instability after hip revision is a serious problem. Our aim was to analyze surgical and patient-related risk factors for both a new dislocation and re-revision after first-time hip revision due to dislocation.MethodsWe included patients with a primary THA due to osteoarthritis and a first-time revision due to dislocation registered in the Danish Hip Arthroplasty Register (DHR) from 1996 to 2016. We identified dislocations in the Danish National Patient Register and re-revisions in the DHR. Risk factors were analyzed by a multivariable regression analysis adjusting for the competing risk of death. Results are presented as subdistribution hazard ratios (sHR).ResultsWe identified 1678 first-time revisions due to dislocation. Of these, 22.4% had a new dislocation. 19.8% were re-revised for any reason. With new dislocations treated by closed reduction as the endpoint, the sHR was 0.36 (95% CI, 0.27-0.48) for those who had a constrained liner (CL) during revision and 0.21 (0.08-0.58) for dual mobility cups (DMC), thereby lowering the risk of dislocation compared to regular liners. Changing only the head/liner increased the risk of dislocation (sHR = 2.65; 2.05-3.42) compared to full cup revisions. The protective effect of CLs and DMCs on dislocations vanished when re-revisions became the endpoint. The head/liner exchange was still found inferior compared to cup revision (sHR = 1.73; 1.34-2.23).ConclusionPatients revised with DMCs and CLs were associated with a lower risk of dislocation after a first-time revision but not re-revision, whereas only changing the head/liner was associated with a higher risk of dislocation and re-revision of any cause compared to cup revision.