Uncemented Components Research Articles

Using Porous Tantalum Uncemented Components to Manage Acetabular Defects and to Restore the Hip Center of Rotation in Revision Total Hip Arthroplasty: A Minimum Ten-Year Clinical and Radiological Study

BackgroundManaging acetabular defects and restoring the hip center of rotation in revision hip arthroplasty is considered a complex and challenging surgery. Among many existing options, porous tantalum components have shown favorable short-term (less than ten years) follow-up results. The present study aimed to describe clinical and radiographic outcomes in longer-term follow-up. MethodsBetween 2006 and 2013, 98 patients who underwent this surgical technique in our institute were clinically and radiographically reviewed. Re-revisions for aseptic loosening of the acetabular component were examined to consider the survivorship of the implant as the primary endpoint. The clinical outcome was measured using the Harris Hip Score (HHS). Radiological signs of osseointegration, radiolucency lines, acetabular stability, and position of the hip center of rotation (COR) were evaluated at the immediate postoperative and last follow-up radiographs. ResultsThe cup survivorship was 96% at a mean follow-up of 14 years (range, 10 to 17). Global survivorship was 83.6% if any reason for re-revisions was considered as an endpoint. The most frequent complications were dislocation (13.7%) and infections (12%). Overall, 13 patients died, and 17 patients were lost to follow-up. There were 73 patients available for clinical and radiographic evaluation. The mean HHS was 81 (range, 39 to 100). More than 80% of hips showed radiological evidence of osseointegration, and no change was found in COR position at last follow-up radiographs. ConclusionThe use of porous tantalum uncemented components to manage revision hip arthroplasty can be considered a favorable solution for managing acetabular defects and restoring the hip center of rotation with satisfactory clinical and radiological results in a long-term follow-up.

TOTAL HIP ARTHROPLASTY IN PAGET'S DISEASE: COMPARISON OF OUTCOMES AFTER CEMENTED VERSUS UNCEMENTED ARTHROPLASTY. A SYSTEMATIC REVIEW AND META-ANALYSIS

Paget's disease of bone (PDB) is characterised by increased bone resorption and development of an erratic bone structure that is highly fragile and susceptible to fracture. In addition, altered joint biomechanics lead to arthritis, more often in the hip and pelvis, resulting in disability and a Total hip Arthroplasty (THA) may be required. THA in PDB is associated with more complications compared to normal population. There is no consensus on the type of arthroplasty that performs better in people with PDB. To our knowledge, there is no meta-analysis in literature on this rare problem.We undertook a systematic review and meta-analysis to compare the effectiveness of cemented versus cementless THA in patients with PDB. PRISMA guidelines were followed. Search strings were generated based on Boolean operators for identification of the reference articles.31 studies were included overall. Revision rate was lower in the cementless group compared to the cemented group (chi square=4.36, p=0.04), aseptic loosening was lesser in the cementless group compared to the cemented group (chi square=4.13, p=0.04). The type of the arthroplasty did not affect the infection rate (chi square=2.51, p=0.11), pre and post op Harris Hip Score showed statistically significant difference, but there was no difference between types of arthroplastyWe conclude that THA with uncemented components is better and provided lower revision and aseptic loosening when compared to cemented groups in patients with PDB.

Automated design of bone-preserving, insertable, and shape-matching patient-specific acetabular components.

Effective treatment of large acetabular defects remains among the most challenging aspects of revision total hip arthroplasty (THA), due to the deficiency of healthy bone stock and degradation of the support columns. Generic uncemented components, which are favored in primary THA, are often unsuitable in revision cases, where the bone-implant contact may be insufficient for fixation, without significant reaming of the limited residual bone. This study presents a computational design strategy for automatically generating patient-specific implants that simultaneously maximize the bone-implant contact area, and minimize bone reaming while ensuring insertability. These components can be manufactured using the same additive manufacturing methods as porous components and may reduce cost and operating-time, compared to existing patient-specific systems. This study compares the performance of implants generated via the proposed method to optimally fitted hemispherical implants, in terms of the achievable bone-implant contact surface, and the volume of reamed bone. Computer-simulated results based on the reconstruction of a set of 15 severe pelvic defects (Paprosky 2A-3B) suggest that the patient-specific components increase bone-implant contact by 63% (median: 63%; SD: 44%; 95% CI: 52.3%-74.0%; RMSD: 42%), and reduce the volume of reamed bone stock by 97% (median: 98%; SD: 4%; 95% CI: 95.9%-97.4%; RMSD: 3.7%).

Removal of uncemented components: hope for the best, prepare for the worst-technical tips and tricks.

Removing well-fixed uncemented components can be challenging. With thoughtful surgical planning, appropriate surgical instruments, and proper surgical techniques, most implants can be removed expeditiously with little bone loss and minimal impact on the subsequent reconstruction. Preoperative planning is one of the most essential steps to remove uncemented implants. Obtaining previous surgical records, although tedious, should always be attempted preoperatively to determine if specific instruments will be required and to help anticipate which steps may need special attention. These include the presence of ceramic or metal bearings and the presence of acetabular screws or stem collars. Without proper preparation and available tools, the removal of implants can negatively impact the subsequent reconstruction and patient outcomes. We will describe techniques and practical tips for removing uncemented stems from the top (intramedullary) or transfemoral using an extended trochanteric osteotomy. We will also describe techniques and tools to remove uncemented acetabular shells efficiently. Case examples will highlight these clinical situations where careful planning is necessary and potential problems that may be encountered with the recurring theme of preparing for the worst but hoping for the best. We have also included cases such as removing well-fixed cementless collared stems, broken stems, and fully coated stems.

Change in CT-measured acetabular bone density following total hip arthroplasty: a systematic review and meta-analysis.

Assessing peri-acetabular bone quality is valuable for optimizing the outcomes of primary total hip arthroplasty (THA) as preservation of good quality bone stock likely affects implant stability. The aim of this study was to perform a meta-analysis of peri-acetabular bone mineral density (BMD) changes over time measured using quantitative computer tomography (CT) and, second, to investigate the influence of age, sex, and fixation on the change in BMD over time. A systematic search of Embase, Scopus, Web of Science, and PubMed databases identified 19 studies that measured BMD using CT following THA. The regions of interest (ROI), reporting of BMD results, and scan protocols were extracted. A meta-analysis of BMD was performed on 12 studies that reported measurements immediately postoperatively and at follow-up. The meta-analysis determined that periacetabular BMD around both cemented and uncemented components decreases over time. The amount of BMD loss increased relative to proximity of the acetabular component. There was a greater decrease in cortical BMD over time in females and cancellous BMD for young patients of any sex. Peri-acetabular BMD decreases at different rates relative to its proximity to the acetabular component. Cancellous BMD decreases more in young patients and cortical bone decreases more in females. Standardized reporting parameters and suggested ROI to measure peri-acetabular BMD are proposed, to enable comparison between implant and patient variables in the future.

Can Selected Use of Cemented and Uncemented Femoral Components in a Broad Population Produce Comparable Results Following Primary Total Hip Arthroplasty for Osteoarthritis?

BackgroundRegistry data have demonstrated lower rates of revision and periprosthetic fracture in select cohorts with cemented femoral fixation at primary total hip arthroplasty. Whether this is true of all component designs is not known. We hypothesized that selected use of ream-and-broach triple-tapered uncemented stem designs may provide comparable results to cemented stems. MethodsFrom 2000 to 2018, 5,809 primary total hip arthroplasties were performed with either a cemented (1,304) or ream-and-broach triple-tapered uncemented stem (4,505). Implant choice was at surgeon discretion. The cemented group was older, more often women, and had slightly lower body mass index. A subgroup analysis was performed on patients ≥75 years of age. Statistical weighting accounted for baseline cohort differences. ResultsAt 10 years, there was a trend toward higher all-cause revision (hazards ratio (HR) 1.6, P = .053) and higher all-cause reoperation (HR 1.6, P = .02) in the cemented fixation cohort. The cemented fixation group had fewer intraoperative periprosthetic fractures (HR 0.21, P < .001) but no difference in postoperative fractures (HR 0.99, P = .96). The same was true in patients ≥75 years. In the ≥75-years subgroup, there was no difference in revision or reoperation at 10 years. ConclusionCompared to cemented stems, the use of ream-and-broach triple-tapered uncemented stems in select patients, including those ≥75 years, was associated with more intraoperative fractures but no difference in 10-year implant survivorship. These findings are different than some registry data and suggest that specific uncemented components, implanted in selected patients by experienced surgeons, can perform as well as cemented implants in a broad patient population.

The associations of implant and patient factors with migration of the tibial component differ by sex

Thresholds of acceptable early migration of the components in total knee arthroplasty (TKA) have traditionally ignored the effects of patient and implant factors that may influence migration. The aim of this study was to determine which of these factors are associated with overall longitudinal migration of well-fixed tibial components following TKA. Radiostereometric analysis (RSA) data over a two-year period were available for 419 successful primary TKAs (267 cemented and 152 uncemented in 257 female and 162 male patients). Longitudinal analysis of data using marginal models was performed to examine the associations of patient factors (age, sex, BMI, smoking status) and implant factors (cemented or uncemented, the size of the implant) with maximum total point motion (MTPM) migration. Analyses were also performed on subgroups based on sex and fixation. In the overall group, only fixation was significantly associated with migration (p < 0.001). For uncemented tibial components in males, smoking was significantly associated with lower migration (p = 0.030) and BMI approached significance (p = 0.061). For females with uncemented components, smoking (p = 0.081) and age (p = 0.063) approached significance and were both associated with increased migration. The small number of self-reported smokers in this study warrants cautious interpretation and further investigation. For cemented components in females, larger sizes of tibial component were significantly associated with increased migration (p = 0.004). No factors were significant for cemented components in males. The migration of uncemented tibial components was more sensitive to patient factors than cemented implants. These differences were not consistent by sex, suggesting that it may be of value to evaluate female and male patients separately following TKA. Cite this article: Bone Joint J2022;104-B(4):444-451.

Cemented versus uncemented hemiarthroplasty of hip for displaced neck of femur fractures: A prospective comparative study

Objective: To prospectively compare the functional outcome associated with cemented and uncemented hemiarthroplasty of the hip. Patients: All individuals designated for hemiarthroplasty, older than 55 years, with a displaced femoral neck fracture and the ability to walk prior to injury (48 patients) presented with a displaced femoral neck fracture. Materials and Methods: Hip hemiarthroplasty with a cemented femoral component or an uncemented component is done. Observations: Harris Hip Score was used to objectively measure functional outcomes. Results: No statistically significant differences were present in the groups’ preoperative or intraoperative characteristics, like ASA grade, operative time, anesthesia time, estimated blood loss. No difference was found in haemoglobin level or acute complication rate postoperatively. At 30-day, 60-day, and 1-year follow-ups, no clinically or statistically significant differences were found in mortality, complication rate including infections, and change in Daly. Conclusions: In treating femoral neck fractures, cemented and uncemented femoral components are associated with similar functional outcomes at 1 year. Neither of the treatment modalities has a statistically significant advantage over the other. Either can be chosen according to the surgeon’s preference, implant availability and affordability, and familiarity with the technique.

Total Knee Replacement with an Uncemented Porous Tantalum Tibia Component: A Failure Analysis.

Porous tantalum has been extensively used in orthopaedic surgery, including uncemented total knee arthroplasty (TKA). Favourable results were reported with earlier monobloc tibial components and the design evolved to modular implants. We aimed to analyse possible causes for extensive medial tibia bone loss, resulting in modular porous tantalum tibia baseplate fracture after primary TKA. Retrieved tissue samples were scanned with 3 MeV focused proton beam for Proton-Induced X-ray Emission (micro-PIXE) elemental analysis. Fractographic and microstructural analysis were performed by stereomicroscopy. A full 3D finite-element model was made for numerical analysis of stress–strain conditions of the tibial baseplate. Histological examination of tissue underneath the broken part of the tibial baseplate revealed dark-stained metal debris, which was confirmed by micro-PIXE to consist of tantalum and titanium. Fractographic analysis and tensile testing showed that the failure of the tibial baseplate fulfilled the criteria of a typical fatigue fracture. Microstructural analysis of the contact surface revealed signs of bone ingrowth in 22.5% of the surface only and was even less pronounced in the medial half of the tibial baseplate. Further studies are needed to confirm the responsibility of metal debris for an increased bone absorption leading to catastrophic tibial tray failure.

Reverse shoulder arthroplasty for proximal humeral fracture in the elderly. Cemented or uncemented stem?

The purposes of this study were to compare functional outcomes, radiographic stem changes and complication rate in patients with proximal humeral fractures operated with cemented or uncemented RSA. Retrospective review of 68 primary RSAs in PHF, 45 cemented/23 uncemented. Functional outcomes were evaluated according to constant, ASES scales and the range of motion (ROM). Radiographic assessment was performed at a minimum of two years post-operatively. The mean follow-up cemented/uncemented was 37.8/26.5months (p = .04) and the mean age 78/80years old (p = .09). The functional outcome and range of movement were equivalent in the two groups except for the forward flexion that was significantly higher in the cemented group (p = .03). Stress shielding was seen in 30.4% of uncemented group and none in the cemented. Anatomic tuberosity healing was significantly higher with uncemented components compared with cemented components (64% vs 91%, p = .02). Cemented stems had radiolucent lines with a width of 2mm or more in three or more Gruen zones in 9% vs 0% in the uncemented group and an evident change in the stem position was present in 4% vs 0% in the non-cemented group. At mid-term follow-up, no differences in functional outcomes were detected depending on the stem fixation technique. Cemented stems, however, have a complication rate (including stem loosening) significantly higher than press-fit stems.

Anthropometric method for estimating component sizes in total hip arthroplasty.

BACKGROUNDPreoperative templating is essential in total hip arthroplasty (THA) as it not only helps to facilitate the correct implant type and size but also determines the post-operative biomechanics. Templating is also increasingly important from a medico-legal perspective and recommended in the British Orthopaedic Association Guide to Good Practice. Although templating has become increasingly digitised, there are no simple anthropometric models to predict implant sizes in the absence of digital methods.AIMTo assess the accuracy of using an easily obtainable measurement (shoe size) to predict component sizes in THA compared with digital templating.METHODSDigital radiographs from a cohort of 102 patients (40 male, 62 female) who had undergone uncemented or hybrid THA at a single centre were retrospectively templated to desired cup and stem sizes using TraumaCad®. We compared the templated size to the actual size of the implant and assessed if there was any correlation with the patient’s shoe size.RESULTSStatistically significant positive correlations were observed between: shoe size and templated cup size (ρ = 0.92, P < 0.001); shoe size with implanted cup size (ρ = 0.71, P < 0.001); shoe size and templated stem size (ρ = 0.87, P < 0.001); and shoe size with implanted stem size (ρ = 0.57, P < 0.001). Templated and implanted acetabular cup sizes were positively correlated (ρ = 0.76, P < 0.001) and were exact in 43.1% cases; 80.4% of implanted cup sizes were within 1 size (+/- 2 mm) of the template and 100% within 2 sizes (+/- 4 mm). Positive correlation was also demonstrated between templated and implanted femoral stem sizes (ρ = 0.69, P < 0.001) and were exact in 52.6% cases; 92.6% were within 1 size of the template and 98% within 2 sizes.CONCLUSIONThis study has shown there to be a significant positive correlation between shoe size and templated size. Anthropometric measurements are easily obtainable and can be used to predict uncemented component sizes in the absence of digital methods.

The association between bone mineral density and postoperative drainage volume following cruciate-substituting primary total knee arthroplasty: a cross-sectional study

BackgroundThe prevalence of osteoporosis in patients who undergo a primary total knee arthroplasty (TKA) is increasing. Low bone mineral density (BMD) is related to unfavorable outcomes following TKA such as migration of uncemented tibial components. Postoperative blood loss in TKA is an important complication. Non-modifying predicting factors for postoperative blood loss in patients undergoing primary TKA need further elucidation. Studies on the association between BMD and blood loss after TKA are limited. We aimed to demonstrate the relationship between BMD and postoperative drainage volume following primary TKA.MethodsA cross-sectional study was conducted between January 2014 and August 2020. A total of 119 primary varus osteoarthritis knees with BMD results were included in the study. Patients with secondary causes of osteoporosis were excluded.ResultsThe median postoperative drainage volume of participants in the normal total hip BMD group and the normal trochanter BMD group was higher than that of patients in the low total hip BMD group and the low trochanter BMD group (285.0 ml vs 230.0 ml, P = 0.003; 282.5 ml vs 240.0 ml, P = 0.013, respectively). Multivariate regression analyses showed that operative time, spinal anesthesia, and normal total hip BMD status were significant predictive factors associated with increased postoperative drainage volume (P = 0.014, 0.022, and 0.013, respectively). No association was identified between the lumbar spine BMD status and postoperative drainage volume.ConclusionsThe relationship between BMD and postoperative blood loss in primary TKA was identified in this study. Normal total hip BMD was found to be associated with an increased postoperative drainage volume after primary TKA compared with low BMD.

Anatomical pelvic loading of a monoblock polyethylene acetabular component.

Uncemented metal acetabular components show good osseointegration, but material stiffness causes stress shielding and retroacetabular bone loss. Cemented monoblock polyethylene components load more physiologically; however, the cement bone interface can suffer fibrous encapsulation and loosening. It was hypothesized that an uncemented titanium-sintered monoblock polyethylene component may offer the optimum combination of osseointegration and anatomical loading. A total of 38 patients were prospectively enrolled and received an uncemented monoblock polyethylene acetabular (pressfit) component. This single cohort was then retrospectively compared with previously reported randomized cohorts of cemented monoblock (cemented) and trabecular metal (trabecular) acetabular implants. The primary outcome measure was periprosthetic bone density using dual-energy x-ray absorptiometry over two years. Secondary outcomes included radiological and clinical analysis. Although there were differences in the number of males and females in each group, no significant sex bias was noted (p = 0.080). Furthermore, there was no significant difference in age (p = 0.910) or baseline lumbar bone mineral density (BMD) (p = 0.998) found between any of the groups (pressfit, cemented, or trabecular). The pressfit implant initially behaved like the trabecular component with an immediate fall in BMD in the inferior and medial regions, with preserved BMD laterally, suggesting lateral rim loading. However, the pressfit component subsequently showed a reversal in BMD medially with recovery back towards baseline, and a continued rise in lateral BMD. This would suggest that the pressfit component begins to reload the medial bone over time, more akin to the cemented component. Analysis of postoperative radiographs revealed no pressfit component subsidence or movement up to two years postoperatively (100% interobserver reliability). Medial defects seen immediately postoperatively in five cases had completely resolved by two years in four patients. Initially, the uncemented monoblock component behaved similarly to the rigid trabecular metal component with lateral rim loading; however, over two years this changed to more closely resemble the loading pattern of a cemented polyethylene component with increasing medial pelvic loading. This indicates that the uncemented monoblock acetabular component may result in optimized fixation and preservation of retroacetabular bone stock. Cite this article: Bone Joint J2021;103-B(5):872-880.

Uncemented total hip arthroplasty can be used safely in the elderly population.

Aims“Get It Right First Time” (GIRFT) and NHS England’s Best Practice Tariff (BPT) have published directives advising that patients over the ages of 65 (GIRFT) and 69 years (BPT) receiving total hip arthroplasty (THA) should receive cemented implants and have brought in financial penalties if this policy is not observed. Despite this, worldwide, uncemented component use has increased, a situation described as a ‘paradox’. GIRFT and BPT do, however, acknowledge more data are required to support this edict with current policies based on the National Joint Registry survivorship and implant costs.MethodsThis study compares THA outcomes for over 1,000 uncemented Corail/Pinnacle constructs used in all age groups/patient frailty, under one surgeon, with identical pre- and postoperative pathways over a nine-year period with mean follow-up of five years and two months (range: nine months to nine years and nine months). Implant information, survivorship, and regular postoperative Oxford Hip Scores (OHS) were collected and two comparisons undertaken: a comparison of those aged over 65 years with those 65 and under and a second comparison of those aged 70 years and over with those aged under 70.ResultsOverall revision rate was 1.3% (13/1,004). A greater number of revisions were undertaken in those aged over 65 years, but numbers were small and did not reach significance. The majority of revisions were implant-independent. Single component analysis revealed a 99.9% and 99.6% survival for the uncemented cup and femoral component, respectively. Mean patient-reported outcome measures (PROMs) improvement for all ages outperformed the national PROMs and a significantly greater proportion of those aged over 65/69 years reached and maintained a meaningful improvement in their OHS earlier than their younger counterparts (p < 0.05/0.01 respectively).ConclusionThis study confirms that this uncemented THA system can be used safely and effectively in patient groups aged over 65 years and those over 69 years, with low complication and revision rates.Cite this article: Bone Jt Open 2021;2(5):293–300.

Revision indications for medial unicompartmental knee arthroplasty: a systematic review.

Unicompartmental knee arthroplasty (UKA) has advantages over total knee arthroplasty including fewer complications and faster recovery; however, UKAs also have higher revision rates. Understanding reasons for UKA failure may, therefore, allow for optimized clinical outcomes. We aimed to identify failure modes for medial UKAs, and to examine differences by implant bearing, cement use and time. A systematic review was conducted by searching MedLine, EMBASE, CINAHL and Cochrane databases from 2000 to 2020. Studies were selected if they included ≥ 250 participants, ≥ 10 failures and reported all failure modes of medial UKA performed for osteoarthritis (OA). A total of 24 cohort and 2 registry-based studies (levels II and III) were selected. The most common failure modes were aseptic loosening (24%) and OA progression (30%). Earliest failures (< 6months) were due to infection (40%), bearing dislocation (20%), and fracture (20%); mid-term failures (> 2years to 5years) were due to OA progression (33%), aseptic loosening (17%) and pain (21%); and late-term (> 10years) failures were mostly due to OA progression (56%). Rates of failure from wear were higher with fixed-bearing prostheses (5% cf. 0.3%), whereas rates of bearing dislocations were higher with mobile-bearing prostheses (14% cf. 0%). With cemented components, there was a high rate of failure due to aseptic loosening (27%), which was reduced with uncemented components (4%). UKA failure modes differ depending on implant design, cement use and time from surgery. There should be careful consideration of implant options and patient selection for UKA.

A prospective study on cancer risk after total hip replacements for 41,402 patients linked to the Cancer registry of Norway

BackgroundConcerns have been raised that implants used in total hip replacements (THR) could lead to increased cancer risk. Several different materials, metals and fixation techniques are used in joint prostheses and different types of articulation can cause an increased invasion of particles or ions into the human body.MethodsPatients with THR registered in the Norwegian Arthroplasty Register during 1987–2009 were linked to the Cancer registry of Norway. Patients with THR due to osteoarthritis, under the age of 75 at time of surgery, were included. Standardized incidence ratios (SIR) were applied to compare cancer risk for THR patients to the general population. Types of THR were divided into cemented (both components), uncemented (both components), and hybrid (cemented femoral and uncemented acetabular components). To account for selection mechanisms, time dependent covariates were applied in Cox-regression, adjusting for cancer risk the first 10 years after surgery. The analyses were adjusted for age, gender and if the patient had additional THR-surgery in the same or the opposite hip. The study follows the STROBE guidelines.ResultsComparing patients with THR to the general population in Norway we found no differences in cancer risk. The overall SIR for the THR-patients after 10 years follow-up was 1.02 (95% CI: 0.97–1.07). For cemented THR, the SIR after 10 years follow-up was 0.99 (95% CI: 0.94–1.05), for uncemented, 1.16 (95% CI: 1.02–1.30), and for hybrid 1.12 (95% CI: 0.91–1.33). Adjusted Cox analyses showed that patients with uncemented THRs had an elevated risk for cancer (hazard ratio: HR = 1.24, 95% CI: 1.05–1.46, p = 0.009) when compared to patients with cemented THRs after 10 years follow-up. Stratified by gender the increased risk was only present for men. The risk for patients with hybrid THRs was not significantly increased (HR = 1.07, 95% CI: 0.85–1.35, p = 0.55) compared to patients with cemented THRs.ConclusionsTHR patients had no increased risk for cancer compared to the general population. We found, however, that receiving an uncemented THR was associated with a small increased risk for cancer compared to cemented THR in males, but that this may be prone to unmeasured confounding.

Management of intraoperative acetabular fracture in primary total hip arthroplasty

BackgroundIntraoperative acetabular fracture(IAF) is a rare complication of primary total hip arthroplasty(THA). The previous reports have lacked a sufficiently large number of subjects to allow for an analysis of the causes and appropriate treatment of this problem.MethodsBetween 2015 to 2018, 4888 primary THA were enrolled. We retrospectively reviewed the records in our Total Joint Registry Database and found that 24 patients (24 hips) had sustained intraoperative acetabular fractures. Twenty-four patients(16 females and 8males)were all treated with a posterolateral approach using uncemented components. Twenty patients(83.3%)underwent supplemental screw fixation, of which 2 patients were treated with steel plate fixation. Two patients’ femoral heads were used as a graft. In 4 patients(16.7%), the acetabular components were judged to be stable despite the fracture and no additional treatment was performed. All patients were evaluated clinically with Harris Hip Scores (HHS) and radiographically with serial X-rays which follow up for a mean period of 34.0 ± 12.6 months. We evaluated the anatomic locations, causes, treatments, and outcome of the fractures to study the treatment method and effect of intraoperative acetabular fracture during operation.ResultsThe fracture rate associated with uncemented components was 0.49%. In 17(70.8%) of these patients, the fracture was noted during the impaction of the real acetabular component. Six patients(25%)with Ankylosing Spondylitis had fractures, 4 in the anterior wall, and 1 in the anterior column, because the patient with hip joint fusion needs a to pre-osteotomy before the dislocation. The HHS score increased from 30.8 ± 9.7 preoperatively to 90.2 ± 4.2 postoperatively. All the latest x-ray showed that the fracture did not move, and there is no translucent line formed in the acetabular cup bone interface.ConclusionIntraoperative acetabular fractures are rare complications of THA, and most commonly occur during the implantation of the acetabular components. It is necessary to prevent the occurrence of fractures as much as possible even if the fractures are found during the operation. It should be noted that patients with ankylosing spondylitis involving hip joints during THA surgery must be careful to prevent IAFs during dislocation and pre-osteotomy.

Highly Porous Tantalum Acetabular Components Without Ancillary Screws Have Similar Migration to Porous Titanium Acetabular Components With Screws at 2 Years: A Randomized Controlled Trial

BackgroundIt is proposed that highly porous coatings on acetabular components, such as a porous tantalum coating, provide adequate fixation without ancillary screw fixation in primary total hip arthroplasty (THA). However, tantalum acetabular components have been associated with higher rates of revision than other uncemented components in national registries. The aim of this randomized controlled trial is to determine whether the early migration of a solid-backed tantalum acetabular component was no greater than that of a titanium acetabular component with ancillary screw fixation that has proven good clinical results. MethodsSixty-six patients aged 40 to 64 years, with osteoarthritis and Charnley grade A or B activity grade and who underwent primary THA, were recruited into the trial. Patients were randomized intraoperatively to receive either the tantalum or titanium acetabular component. All patients received the same cemented polished tapered femoral stem, 28-mm cobalt-chromium femoral head, and highly cross-linked polyethylene liner. Acetabular component migration was measured using radiostereometric analysis at 4-6 days postoperatively and at 6 weeks, 3 months, 1 and 2 years following THA. ResultsThe mean proximal migration at 2 years for the tantalum cohort was 0.17 mm (95% confidence interval, 0.09-0.24) which was no greater than that of the titanium cohort which was 0.19 mm (0.07-0.32). Harris hip scores and functional activity scores were similar between groups. ConclusionThese results demonstrate that early stability can be achieved without ancillary screw fixation through the use of a highly porous high friction coating on a solid-backed modular acetabular component. Level of EvidenceLevel I.

Classifications in Brief: The Dorr Classification of Femoral Bone.

Classifications in Brief: The Dorr Classification of Femoral Bone.

CORR Insights®: What Is the Long-term (27- to 32-year) Survivorship of an Uncemented Tapered Titanium Femoral Component and Survival in Patients Younger Than 50 Years?

CORR Insights®: What Is the Long-term (27- to 32-year) Survivorship of an Uncemented Tapered Titanium Femoral Component and Survival in Patients Younger Than 50 Years?