Uncemented Fixation Research Articles

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.

Clinical and radiographic outcomes of an all-polyethylene fluted central peg glenoid component, implanted utilizing an off-label, uncemented technique, at a minimum 5-year follow-up

Glenoid component loosening remains an important concern in anatomic total shoulder arthroplasty. The aim of this study was to evaluate the clinical and radiographic results of a fully uncemented all-polyethylene fluted central peg bone-ingrowth glenoid component at a minimum 5-year follow-up. Thirty-five shoulders in 31 patients (mean age, 73 years) with a mean follow-up of 100 months were retrospectively evaluated at an early and mid-term time point for Constant score (CS). Computed tomography visualized glenoid component fixation at both time points. Mean CS improved from 40 preoperatively to 66 postoperatively at latest follow-up (P < .001). A mean CS of 74 at early follow-up remained consistent with a mean CS of 66 at latest follow-up (P = .158), with only strength demonstrating a decrease over time (P < .001). An initial osseointegration rate of 81% at early follow-up decreased to 71% at latest follow-up with 74% of the shoulders demonstrating progressive radiolucent lines, resulting in a radiographic loosening rate of 31%. Of the 35 shoulders, 4 were revised (survival rate of 88%), of which 2 due to symptomatic aseptic loosening. Uncemented fixation of an all-polyethylene central peg bone-ingrowth glenoid was associated with satisfactory clinical and radiographic scores, and an acceptable revision rate at mid- to long-term follow-up. Despite initial bony osseointegration in the majority of cases, radiographic loosening over time remains a concern, potentially jeopardizing long-lasting fixation of this type of glenoid component when implanted in an off-label uncemented fashion.

Classifications in Brief: The Dorr Classification of Femoral Bone.

Classifications in Brief: The Dorr Classification of Femoral Bone.

Association Between Uncemented vs Cemented Hemiarthroplasty and Revision Surgery Among Patients With Hip Fracture

Consensus guidelines and systematic reviews have suggested that cemented fixation is more effective than uncemented fixation in hemiarthroplasty for displaced femoral neck fractures. Given that these recommendations are based on research performed outside the United States, it is uncertain whether these findings also reflect the US experience. To compare the outcomes associated with cemented vs uncemented hemiarthroplasty in a large US integrated health care system. Retrospective cohort study of 12 491 patients aged 60 years and older who underwent hemiarthroplasty treatment of a hip fracture between 2009 and 2017 at 1 of the 36 hospitals owned by Kaiser Permanente, a large US health maintenance organization. Patients were followed up until membership termination, death, or the study end date of December 31, 2017. Hemiarthroplasty (prosthetic replacement of the femoral head) fixation via bony growth into a porous-coated implant (uncemented) or with cement. The primary outcome measure was aseptic revision, defined as any reoperation performed after the index procedure involving exchange of the existing implant for reasons other than infection. Secondary outcomes were mortality (in-hospital, postdischarge, and overall), 90-day medical complications, 90-day emergency department visits, and 90-day unplanned readmissions. Among 12 491 patients in the study cohort who underwent hemiarthroplasty for hip fracture (median age, 83 years; 8660 women [69.3%]), 6042 (48.4%) had undergone uncemented fixation and 6449 (51.6%) had undergone cemented fixation, and the median length of follow-up was 3.8 years. In the multivariable regression analysis controlling for confounders, uncemented fixation was associated with a significantly higher risk of aseptic revision (cumulative incidence at 1 year after operation, 3.0% vs 1.3%; absolute difference, 1.7% [95% CI, 1.1%-2.2%]; hazard ratio [HR], 1.77 [95% CI, 1.43-2.19]; P < .001). Of the 6 prespecified secondary end points, none showed a statistically significant difference between groups, including in-hospital mortality (1.7% for uncemented fixation vs 2.0% for cemented fixation; HR, 0.94 [95% CI, 0.73-1.21]; P = .61) and overall mortality (cumulative incidence at 1 year after operation: 20.0% for uncemented fixation vs 22.8% for cemented fixation; HR, 0.95 [95% CI, 0.90-1.01]; P = .08). Among patients with hip fracture treated with hemiarthroplasty in a large US integrated health care system, uncemented fixation, compared with cemented fixation, was associated with a statistically significantly higher risk of aseptic revision. These findings suggest that US surgeons should consider cemented fixation in the hemiarthroplasty treatment of displaced femoral neck fractures in the absence of contraindications.

Has the Use of Fixation Techniques in THA Changed in This Decade? The Uncemented Paradox Revisited.

Despite existing studies favoring cemented fixation for patients older than 75 years, a trend toward increased use of uncemented fixation has been described in a 2013 study that used arthroplasty registry data from 2006 to 2010. Updated summarized data are needed beyond 2010 to investigate contemporary trends in the usage of uncemented fixation, especially in patients older than 75 years, and to draw attention to a potential continuing conflict between trends in fixation choice and reported revision risk. Thus, healthcare policy and practice can change and surgeons can make better implant fixation choices. (1) Has the percentage of primary THAs performed with uncemented fixation changed since 2010? (2) Has the percentage of primary THAs performed in patients older than 75 years performed with uncemented fixation changed since 2010? (3) After stratifying by age, which fixation strategy (cemented versus uncemented and hybrid versus uncemented) is associated with the lowest risk of revision? National annual reports from hip arthroplasty registers were identified, and data were extracted from registers published in English or a Scandinavian language, with at least 3 years of reported data in the period from 2010 to 2017. These included Australia, Denmark, England-Wales, Finland, the Netherlands, New Zealand, Romania, Norway, Sweden, and Switzerland, which are all countries with high completeness rates. Data regarding rates of revisions (all causes) related to fixation methods and secondary to different age groups, were taken directly from the registers and no re-analysis was done. The risk estimates were presented as either hazard ratios, rate per 100 component years or as Kaplan-Meier estimates of revision. The age groups compared for Denmark were younger than 50, 50-59, 60-69,70-79, and older than 80 years, and for Australia, New Zealand, England-Wales, and Finland, they were younger than 55, 55-64, 65-74, and older than 75 years. No data were pooled across the registers. The current use of uncemented fixation in primary THAs varies between 24% (Sweden) and 71% (Denmark). Increasing use of uncemented fixation has been reported in Norway, Denmark, and Sweden, whereas decreasing use of uncemented fixation has been reported in England-Wales, Australia, New Zealand, and Finland. Examining the group of patients older than 75 years, we found that the use of uncemented fixation has been stable in Netherlands, Sweden, New Zealand, and England-Wales. The use of uncemented fixation is still increasing in Denmark and Australia. In Finland, the use of uncemented fixation has decreased (from 43 % to 24 %) from 2010 to 2017. When compared with uncemented fixation, the risk of revision for hips using cemented fixation was lower in patients older than 75 years for all registers surveyed, except for the oldest males in the Finnish register. In this group, no difference was found between cemented and uncemented fixation. Our findings should be used in healthcare policy as feedback on current THAs being performed so as to direct surgeons to choose the right implant fixation, especially in patients older than 75 years, thereby reducing revision risk and increasing the long-term survival of primary THAs. It appears that femoral stem fixation may be the most important revision risk factor in older patients, and future studies should examine this perspective. Level III, therapeutic study.

Uncemented fixation of a monoblock ingrowth polyethylene glenoid: early follow-up

Traditional monoblock pegged glenoid components are implanted with cement, increasing operative time and potentially violating more bone than those inserted without cement. We study the early radiographic loosening and reoperation rate following uncemented fixation of a hybrid cage monoblock polyethylene glenoid component. Between 2013 and 2015, a total of 51 shoulders underwent anatomic shoulder arthroplasty (TSA) using a hybrid ingrowth cage polyethylene glenoid component by a single surgeon, with a minimum follow-up of 2 years. In all cases, the glenoid component was placed without cement. Mean follow-up was 33 months (range, 24-57). The primary outcome was Lazarus scale-assessed radiographic loosening. Secondary outcomes included reoperation, range of motion (ROM), and patient-reported outcome measures (PROMs). Twelve glenoid components (24%) had radiolucent lines. Glenoid lines were rated grade 1, grade 2, and grade 5 (6, 4, and 2 shoulders, respectively). Six shoulders (12%) had humeral lucent lines. Two shoulders (4%) underwent reoperation, only 1 of these occurring due to isolated failure of the glenoid component. As a group, mean ROM and PROMs improved significantly compared with preoperative values and exceeded the minimal clinically important difference. Glenoid loosening remains a major concern at mid- to long-term follow-up of TSA. Placement of this hybrid cage monoblock polyethylene glenoid component in a completely uncemented fashion does not lead to early clinical loosening, after which bony ingrowth into the central cage can be expected. Uncemented fixation of this hybrid cage component appears to be a safe treatment option for patients undergoing primary TSA.

Patient-reported outcome after stemmed versus stemless total shoulder arthroplasty for glenohumeral osteoarthritis: a patient-blinded randomized clinical trial

BackgroundStemless shoulder arthroplasty systems with uncemented metaphyseal fixation have been used for glenohumeral osteoarthritis since 2004 (Hawi, et al. BMC Musculoskelet Disord 17:376, 2016). The stemless design has several theoretical advantages compared with the stemmed shoulder arthroplasty systems: restoring patients’ anatomy; preserving humeral bone stock; and few complications in component removal if the need for a revision arthroplasty arises. The purpose of the study is to compare the short-term, patient-reported outcome of stemless and stemmed total shoulder arthroplasty (TSA).Materials and methodsA randomized clinical trial will be conducted. Eighty patients with clinical and radiological signs of primary or post-traumatic glenohumeral osteoarthritis, computed tomography (CT) scan-verified adequate glenoid bone stock, and no total rupture of rotator cuff tendons verified by a magnetic resonance imaging (MRI) scan will be randomly allocated to a stemless or stemmed TSA. The primary outcome will be the Western Ontario Osteoarthritis Shoulder (WOOS) score at 12 months. Secondary outcomes are the WOOS score at three months and the Oxford Shoulder Score (OSS) and EQ-5D at 3 and 12 months. All complications, including glenoid and humeral component loosening, instability, rotator cuff tear, intraoperative and postoperative periprosthetic fracture, nerve injury, infection, deltoid injury, and symptomatic deep venous thrombosis, will be reported.DiscussionFindings will provide patients with better information about the potential benefits and harms of stemless and stemmed TSA and will assist shoulder surgeons and patients in decision-making.Trial registrationClinicaltrials.gov, NCT03877315. Registered on 13 March 2019.

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.

Influence of Fixation Methods on Prosthetic Joint Infection Following Primary Total Knee Replacement: Meta-Analysis of Observational Cohort and Randomised Intervention Studies.

The type of fixation used in primary total knee replacement (TKR) may influence the risk of prosthetic joint infection (PJI). We conducted a systematic review and meta-analysis to assess published evidence linking type of fixation (cemented, uncemented, or hybrid) with the risk of PJI following primary TKR. Randomised controlled trials (RCTs) and observational cohort studies comparing fixation methods and reporting PJI incidence following primary TKR were identified in MEDLINE, Embase, Web of Science, and Cochrane Library up until November 2018. Summary measures were relative risks (RR) with 95% confidence intervals (CIs). We identified 32 eligible articles (24 observational studies and 8 RCTs) involving 1,161,292 TKRs. In pooled analysis of observational studies, uncemented fixation was associated with a decreased overall PJI risk when compared with cemented fixation at 0.76 (0.64–0.89). Comparing antibiotic-loaded cemented fixation with plain cement, there was no significant difference in overall PJI risk at 0.95 (0.69–1.31), but PJI risk was increased in the first 6-month postoperative period to 1.65 (1.12–2.43). Limited data from RCTs showed no differences in PJI risk among the fixation types. Observational evidence suggests uncemented fixation may be associated with lower PJI risk in primary TKR when compared with cemented fixation. In the early postoperative period, antibiotic-loaded cemented fixation may be associated with increased PJI risk when compared with plain cement. This may either reflect appropriate selection of higher risk patients for the development of PJI to cemented and antibiotic-loaded cement or may reflect a lower PJI risk in uncemented TKR due to factors such as shorter operative time.

Hémi-arthroplastie de l’épaule avec tige ajustable : étude prospective multicentrique avec suivi de 10 ans

BackgroundAdjustable shoulder hemiarthroplasty (HA) allows the complex anatomy of the proximal humerus, including its centre of rotation, to be restored. However, whether better anatomical adaptation improves clinical outcomes and long-term survival remains unclear. Therefore long-term clinical and radiographic results of an eccentric adjustable hemiprosthesis were examined, focusing on the longevity and fixation of the humeral stem. HypothesisAdjustable shoulder HA enhances long-term functional outcomes and reduces complications. Materials and methodsIn this prospective multicentre study, 120 HAs were performed using a stemmed hemiprosthesis on 115 patients. The clinical and radiologic outcomes were measured at 3, 6, 12, and 24 months, and thereafter at 4, 7, and 10 years with a median follow-up period of 7.7 years (92.3 months, range 2.6–148.5 months). Revision-free survival rates were calculated up to 10 years postoperatively. ResultsThe mean Constant-Murley score increased over the first 24 months from 26.2±9.0 to 61.0±17.3 points, then levelled off until the final follow-up. Patients with humeral head necrosis had the best clinical outcomes, while patients with fracture sequelae and rheumatoid arthritis had the worst. Although radiolucent lines were more frequent after cemented fixation, lines of>2mm only occurred after uncemented fixation. Finally, five cases required secondary glenoid implantation, and survival free from stem revision was 99.0% (95% confidence interval [CI], 92.8%–99.9%) at 4 years, 97.6 (95% CI, 90.6%–99.4%) at 7 years, and 92.2% (95% CI, 81.9%–96.8%) at 10 years. DiscussionThe study showed that adjustable shoulder HA is a safe and effective treatment option for various degenerative disorders of the shoulder joint. Functional scores first increased then levelled off after 24 months. Moreover, revision-free survival compared well with previously reported values. Observed stable long-term results confirm that adjustable shoulder HA has beneficial clinical outcomes and a low complication rate.

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.

Adjustable stemmed shoulder hemiarthroplasty: Ten-year results of a prospective multicentre study

BackgroundAdjustable shoulder hemiarthroplasty (HA) allows the complex anatomy of the proximal humerus, including its centre of rotation, to be restored. However, whether better anatomical adaptation improves clinical outcomes and long-term survival remains unclear. Therefore long-term clinical and radiographic results of an eccentric adjustable hemiprosthesis were examined, focusing on the longevity and fixation of the humeral stem. HypothesisAdjustable shoulder HA enhances long-term functional outcomes and reduces complications. Materials and methodsIn this prospective multicentre study, 120 HAs were performed using a stemmed hemiprosthesis on 115 patients. The clinical and radiologic outcomes were measured at 3, 6, 12, and 24 months, and thereafter at 4, 7, and 10 years with a median follow-up period of 7.7 years (92.3 months, range 2.6–148.5 months). Revision-free survival rates were calculated up to 10 years postoperatively. ResultsThe mean Constant-Murley score increased over the first 24 months from 26.2±9.0 to 61.0±17.3 points, then levelled off until the final follow-up. Patients with humeral head necrosis had the best clinical outcomes, while patients with fracture sequelae and rheumatoid arthritis had the worst. Although radiolucent lines were more frequent after cemented fixation, lines of>2mm only occurred after uncemented fixation. Finally, five cases required secondary glenoid implantation, and survival free from stem revision was 99.0% (95% confidence interval [CI], 92.8%–99.9%) at 4 years, 97.6 (95% CI, 90.6%–99.4%) at 7 years, and 92.2% (95% CI, 81.9%–96.8%) at 10 years. DiscussionThe study showed that adjustable shoulder HA is a safe and effective treatment option for various degenerative disorders of the shoulder joint. Functional scores first increased, then levelled off after 24 months. Moreover, revision-free survival compared well with previously reported values. Observed stable long-term results confirm that adjustable shoulder HA has beneficial clinical outcomes and a low complication rate.

Operative Technique: Autologous Impaction Bone Grafting With Uncemented Corail Stem in Primary Total Hip Arthroplasty

The value of uncemented fixation using hydroxyapatite-coated femoral implants is now widely recognized, and the Corail has become a gold standard among stems in primary total hip arthroplasty. There have been some concerns over subsidence, loosening, and fracture in osteoporotic bone precluding the use of uncemented stems in patients with poor quality bone. The main issue appears to be lack of cancellous bone cushioning resulting in point loading of prosthesis against cortical bone. We describe a novel surgical technique utilizing the patient’s own femoral head as an autogenic source of cancellous bone graft, impacted into the proximal femoral metaphysis before implanting the stem, in order to improve the quality of bone envelope. This surgical technique is safe and simple to perform and may increase patient’s bone stock.

Equivalent 2-year stabilization of uncemented tibial component migration despite higher early migration compared with cemented fixation: an RSA study on 360 total knee arthroplasties

Background and purpose — Thresholds of implant migration for predicting long-term successful fixation of tibial components in total knee arthroplasty have not separated cemented and uncemented fixation. We compared implant migration of cemented and uncemented components at 1 year and as the change in migration from 1 to 2 years.Patients and methods — Implant migration of 360 tibial components measured using radiostereometric analysis was compared at 1 year and as the change in migration from 1 to 2 years in 222 cemented components (3 implant designs) and 138 uncemented components (5 implant designs).Results — 1-year maximum total point motion was lower for the cemented tibial components compared with the uncemented components (median = 0.31 mm [0.03–2.98] versus 0.63 mm [0.11–5.19] respectively, p < 0.001, mixed model). The change in migration from 1 to 2 years, however, was equivalent for cemented and uncemented components (mean [SD] 0.06 mm [0.19] and 0.07 mm [0.27] mm respectively, p = 0.6, mixed model).Interpretation — These findings suggest that current thresholds of acceptable migration at 1 year may be better optimized by considering cemented and uncemented tibial components separately as higher early migration of uncemented components was not associated with decreased stability from 1 to 2 years.

Is There a Difference between Cemented and Uncemented Femoral Stem Extensions in Revision Knee Arthroplasty?

A stem is usually recommended for the femoral component in revision total knee arthroplasty (TKA) for reasons of alignment, fixation, and bone loss. However, the optimal method of fixation for the femoral component stem remains controversial. We queried the prospective revision TKA database of one surgeon and performed a clinical and radiographic evaluation of 84 knee revisions in which a femoral component stem extension was implanted. There was no established protocol for fixation of the femoral stem during this time. There were 34 knees with cemented (C) fixation and 50 with uncemented (UC) fixation. There were no significant differences in age, gender, body mass index (BMI), or Anderson's Orthopaedic Research Institute (AORI) defect between the two groups. Patients were evaluated using the classic Knee Society clinical and radiographic scores and followed for a mean of 6 years (range: 2-17 years). There was no statistically significant difference in prevalence of reoperation for loosening between cemented and uncemented stems (cemented 3.3% vs. uncemented 10%; p = 0.4). Post hoc power analysis showed that 203 knees in each group would be needed for statistical significance. With the numbers available, there was no difference in aseptic component loosening and radiographic loosening combined (one revision and two radiographic loosening, 9%, in the C group vs. five revisions and three radiographic loosening, 16%, in the UC group; p = 0.51). There was no difference between the groups in the overall rate of any reoperation. There were no differences in postoperative Knee Society pain score, change in pain score, Knee Society function score, or change in function score. Due to the numbers required, a large multicenter study will be needed to determine the optimal method of fixation of the femoral stem in revision TKA.

An Alternative Femoral Stem-bone Implantation Technique Using an Innovative Short Femoral Stem Endoprosthesis

Arthroplasty of the hip, for either arthritic changes or femoral neck fracture, is a common procedure in orthopedic surgery. Although the standard designs for implantation, either cemented or uncemented, are well described and studied, there are also alternative designs regarding the implantation of both prosthetic stem and cup. This paper aims to explore one such alternative design, using the screw-in technique. It has been described in past literature for uncemented fixation of both the cup and the stem, and the biomechanical principles of fixation are different from the classical methods, offering certain advantages that are insufficiently explored in current-day endoprosthesis. Also, we will be presenting an innovative femoral stem design, recently developed, that combines an uncemented screw-on technique with a cemented augmentation possibility, aimed to provide the practitioner with the advantages of a bone-preserving mini-stem design, combined with the innovative screw-in fixation technique and the versatility of the hybrid cemented/uncemented fixation method.

Primary stability of uncemented acetabular liner of a total hip prosthesis using an axisymmetric finite element method based on computed tomography

Primary stability has a great influence on behaviour during day-to-day activities and on the long-term success of uncemented acetabular components. Achieving this stability by pushing the acetabular bush (uncemented fixation) is a common practice today. In this paper, it was tried to establish a criterion for the success of fixing the acetabular cup by evaluating the short-term stability. The influence of the contact parameters established between the cup and the peripheral area of the acetabulum was investigated in this paper. These parameters depend on the intraoperative procedures: reaming and fixation. Reaming is considered without residual stress, but the acetabulum has been remodelled (a sphere has been adapted through an optimization algorithm). Uncemented fixation (press fit) involves a series of load impulses applied to the cup, simulating the impact strokes through the surgeon’s hammer. Finite Element Method (FEM) was used for this simulation along with a pelvis model based on computed tomography (CT) data. Consequently, there is a postoperative state of residual effort. Assessing this state of effort could lead to a good estimation of short-term stability.

Uncemented or cemented femoral components work equally well in total knee arthroplasty.

To study the pattern of migration and clinical results up to 10years of uncemented versus cemented fixation of the femoral component in total knee arthroplasty. Randomized controlled trial was conducted of 41 patients (23 women, 18 men) under the age of 60years using radiostereometric analysis. About two-thirds of the cemented implants and half of the uncemented implants stabilized between 2 and 10years, while the remainder displayed a small annual increase of maximum total point motion of 0.09-0.10mm/year. At 10years there were no statistically significant differences in migration or clinical results between the groups. Uncemented fixation with titanium fiber mesh coating of the femoral component in total knee arthroplasty works equally as well as cemented fixation up to 10years. An annual migration of 0.1mm seems compatible with excellent long-term performance. I.

Clinical application of uncemented distal stem fixation for revising femoral prosthesis of hip arthroplasty in elderly patients

Objective To evaluate the effectiveness of uncemented distal stem fixation for elderly patients needing revision of femoral prosthesis of hip arthroplasty. Methods From July 2005 to January 2013, 22 patients(12 males and 10 females)aged from 70 to 85 years(average: 76 years old)with aseptic loosening of the femoral stem undergone revision via uncemented distal stem fixation were enrolled into this study.Of all patients, 10 had revision on the right side and 12 on the left side; 11 patients received artificial replacement of the femoral head; 9 had total hip replacements; 2 had femoral fractures.According to the Paprosky classification system, 2 cases were type I, 12 were type Ⅱ, 6 were type ⅢA, and 2 were type ⅢB.Femoral stems for revision included MP(Link)and Solution(Depuy). The Harris score, clinical and radiological results were retrospectively analyzed. Results All patients were followed up for 48 to 78 months(mean: 61 months). The average Harris score increased from 38(25-46)to 87(76-94). All prostheses were initially stable, and no infection, dislocation or complication like deep venous thrombosis was observed after revision.All patients were able to walk without assistance; two of them had minor claudication; radiographs after surgery showed well-positioned implants with increased bone density and thickness around the prosthesis and without loosening or subsidence. Conclusions Reliable axial and anti-rotational stability can be achieved by using uncemented distal stem fixation, with good short-and medium-term clinical results for revision in elderly patients with less severe bone defects than those in Paprosky Ⅳ. Key words: Hip joint; Revision; Femur

Total Hip Arthroplasty in Young Patients in The Netherlands: Trend Analysis of >19,000 Primary Hip Replacements in the Dutch Arthroplasty Register

BackgroundTotal hip arthroplasty (THA) is one of the most successful interventions in medical care. Because of shifting trends in THA and failure rates being higher in younger patients, we aimed to assess trends in implant fixation, bearing type, head diameter, and surgical approach in patients younger than 55 years in the Netherlands using data from the Dutch Arthroplasty Register. MethodsTrends in the method of implant fixation, bearing type, head diameter, and surgical approach were analyzed over year of surgery (2007-2016) and over age groups (<25, 25-29, 30-34, 35-39, 40-44, 45-49, and 50-54 years). ResultsBetween 2007 and 2016, a total of 19,915 primary THAs were performed in patients <55 years. Osteoarthritis was the most prevalent diagnosis (66.1%). Uncemented fixation was used in 79.5% of all performed THAs. The use of 32-mm head diameters increased (from 32.6% in 2007 to 50.1% in 2016), where an increasing trend toward the use of ceramic-on-polyethylene as most frequently used bearing type was present (from 37.5% in 2007 to 53.8% in 2016). The posterolateral surgical approach was the most frequently used approach; however, the anterior approach is used increasingly (0.1% in 2007 to 21.1% in 2016). Ceramic-on-polyethylene bearing surfaces, 32-mm head diameters, and the anterior approach were most commonly used in patients between 50 and 54 years. ConclusionThere was a clear preference for uncemented fixation in young patients. In head diameter, bearing type, and surgical approach, clear trends were visible. Characteristics of THA in young patients were subject to changing perspectives.