Aims

After failed acetabular fractures, total hip arthroplasty (THA) is a challenging procedure and considered the gold standard treatment. The complexity of the procedure depends on the fracture pattern and the initial fracture management. This study’s primary aim was to evaluate patient-reported outcome measures (PROMs) for patients who underwent delayed uncemented acetabular THA after acetabular fractures. The secondary aims were to assess the radiological outcome and the incidence of the associated complications in those patients.

Introduction. Total hip arthroplasty (THR) is one of the most successful procedures performed today. Uncemented acetabular components have by and large replaced cemented cups. As such, optimal fixation, bony ingrowth with longevity, and safety is highly demanded. In this study, we look at the safety and efficacy of the Stryker® Trident PSL™ acetabular component based on radiographic and clinical analysis. Materials and Methods. We looked at 860 consecutive patients between 2003 and 2007. Of these, 231 consecutive patients had a minimum 5 year follow up. All cases were for degenerative joint disease (DJD), except 2 for dysplasia, 1 for avascular necrosis (AVN), 1 femoral neck nonunion. Average Hospital for Special Surgery (HSS) hip scores at final follow up were recorded. Radiographic analysis included classification based on Delee and Charnley's zones 1–3. Osseointegration was assessed based on presence of SIRCAB (stress induced reactive cortical hypertrophy of bone), demarcation around the implant, stress shielding, presence of radial trabeculae, absence of radiolucency, type of bearing, presence of preoperative protrusion, violation of Kohler's line. EBRA software was used to assess acetabular inclination and version. Results. Of 231 hip replacements analyzed, 114 were male, 117 were female. The average age was 63 (range 33–87); height was 67.5 inches; BMI was 27; 3 patients had a preoperative diagnosis of DDH, 2 had AVN, 1 femoral neck nonunion, and 1 case of rheumatoid arthritis (RA), with the remainder of patients diagnosed with DJD. cup abduction angle was 41.7° with average of 17.4° of anteversion. Average HSS functional score was excellent at latest follow up was 34, with most patients not relying on any assistive devices; There were no revisions performed due to mechanical failures or due to failure to osseointegrate. Complications include 1 infection (0.43%); and 4 dislocations (1.73%). Osseointegration was measured by separating the acetabulum into DeLee and Charnley zones and assessed by analyzing:. a). stress induced hypertrophic reaction of cortical bone (SIHRCaB): zone 1 (75.8%), zone 2 (11.7%), zone 3 (51.9%). b). Radial trabeculae: zone 1 (94.8%), zone 2 (93.5%), zone 3 (92.6%). c). Absence of radiolucency: zone 1 (96.1%), zone 2 (97%), zone 3 (96.1%). No association of bearing surfaces to survivorship was noted as metal femoral heads were used in 72.7% of cases while a ceramic bearing was used in 25.1%. Conclusion. The Trident PSL acetabular component was examined in a large, consecutive series by a single surgeon with a minimum 5–9 year follow up. We have demonstrated excellent radiographic osseointegration at latest follow up with no mechanical failures, high survivorship, and excellent clinical outcome scores. It continues to be a reliable option for primary acetabular reconstruction

Objectives: We present the level of biological fixation and the medium-term results of the hemispherical porous coated acetabular component.

Methods: A number of 299 acetabular components type Duraloc 100 were placed to equivalent primary hip arthroplasties. The patients were 273 (26 bilateral), 218 women and 55 men with age which ranged between 22–80 years (aver. 52 yrs). We performed a press-fit technique to stabilize the cup and an acetabulum under-reaming of 2 mm. The size of the components we used was ranged between 48–56 mm. 175 cups were combined with the Elite cemented stem (hybrid), whereas 124 cups with the AML cementless stem. In every case a 10° hooded polyethylene liner was required. The postoperative protocol included early partial weight bearing for six weeks, full weight bearing after three months and follow up on the 3rd, 6th, 12th month and every year. The clinical evaluation was performed with D’ Aubigne-Postel system while the radiological evaluation according to the AAOS standards. The follow up period was ranged from 2 to 9 years (aver. 5,2 years).

Results: During the last follow up no mechanical no radiological loosening was detected. The cup was definitely incorporated to the bone substrate.

Conclusions: Eight years postoperatively the results are perfect. We believe that the hemispherical porous coated, press-fit acetabular component exhibits a satisfactory biological behaviour in primary hip replacements.

Introduction. Long-term success of the cementless acetabular component has been depends on amount of bone ingrowth around porous coated surface of the implant, which is mainly depends on primary stability, i.e. amount of micromotion at the implant-bone interface. The accurate positioning of the uncemented acetabular component and amount of interference fit (press-fit) at the rim of the acetabulum are necessary to reduce the implant-bone micromotion and that can be enhancing the bone ingrowth around the uncemented acetabular component. However, the effect of implant orientations and amount of press-fit on implant-bone micromotion around uncemented acetabular component has been relatively under investigated. The aim of the study is to identify the effect of acetabular component orientation on implant-bone relative micromotion around cementless metallic acetabular component. Materials and Method. Three-dimensional finite element (FE) model of the intact and implanted pelvises were developed using CT-scan data [1]. Five implanted pelvises model, having fixed antiversion angle (25°) and different acetabular inclination angle (30°, 35°, 40°, 45° and 50°), were generated in order to understand the effect of implant orientation on implant-bone micromotion around uncemented metallic acetabular component. The CoCrMo alloy was chosen for the implant material, having 54 mm outer diameter and 48 mm bearing diameter [1]. Heterogeneous cancellous bone material properties were assigned using CT-scan data and power law relationship [1], whereas, the cortical bone was assumed homogeneous and isotropic [1]. In the implanted pelvises models, 1 mm diametric press-fit was simulated between the rim of the implant and surrounding bone. Six nodded surface-to-surface contact elements with coefficient of friction of 0.5 were assigned at the remaining portion of the implant–bone interface [1]. Twenty-one muscle forces and hip-joint forces corresponds to peak hip-joint force of a normal walking cycle (13%) were used for the applied loading condition. Fixed constrained was prescribed at the sacroiliac joint and pubis-symphysis [1]. A submodelling technique was implemented, in order to get more accurate result around implant-bone interface [1]. Results and Discussions. The peak implant-bone sliding interfacial micromotion was observed around 75 microns around superior and supero-posterior regions of the acetabulum, whereas, micromotion was below 50 microns around other regions (area). As compared to other regions, less implant-bone micromotions were observed at the central region of the acetabulum and anterior part of the acetabulum, where micromotions were varied in the range between 5 microns to 30 microns. Although, the generated peak implant-bone sliding micromotion around the uncemented acetabulum was not vary notably due to change in inclination angle of the acetabular component, changes in patterns of implant-bone micromotions were observed and as shown [Fig.1]. Results of the present study indicated that the positioning of the uncemented acetabular component have influence on patterns of implant-bone micromotion and that might have influence on bone ingrowth and long-term success of uncemented acetabular component

Background

Radiostereometric Analysis (RSA) is an accurate measure of implant migration following total joint replacement surgery. Early implant migration predicts later loosening and implant failure, with RSA a proven short-term predictor of long-term survivorship. The proximal migration of an acetabular cup has been demonstrated to be a surrogate measure of component loosening and the associated risk of revision. RSA was used to assess migration of the R3 acetabular component which utilises an enhanced porous ingrowth surface. Migration of the R3 acetabular component was also assessed when comparing the fixation technique of the femoral stems implanted.

Here we present the results of functional outcome of 531 patients (aged from 27.6 to 88.7, mean 62.6) who have had the Trilogy (Zimmer; Warsaw IN, USA) acetabular shell implanted for 5 years or longer. All patients operated at our unit between 20/1/1992 and 31/3/2004 were included, looking at both Primary (431) and Revision (100) hip arthroplasties. All surgery was performed by the senior surgeon using the Trilogy shell and liners. The Trilogy acetabular shell was used with either an ultra-high molecular weight polyethylene liner or ceramic liner, along with a wide variety of femoral stems, mainly: Harris Pre-coat stem (183 patients, Zimmer), Versys cemented stem (102 pts, Zimmer), CADCAM (140 pts, Stanmore), and HAC Furlong (96 pts, JRI). There were a variety of other stems, including Exeter and Pro-femur. 48 patients had revision of socket only.

Functional outcome was assessed by three questionnaires: the Oxford Hip Questionnaire (12 best function-60 worst), the Harris Hip Score (100 best to 0 worst), and the WOMAC Hip Score (0 best-96 worst).

Patients filled in these questionnaires at every postoperative follow-up clinic. These were compared with the pre-operative scores obtained from questionnaires which the patients completed retrospectively. Mean follow up questionnaire times were 76.5 months postoperatively for primary arthroplasties, and 70.6 months for the revision arthroplasties.

For primary arthroplasty mean scores improved from 40.8 pre-operatively to 16.4 post-operatively (Oxford), 43.9 to 92.9 (Harris), and 51.8 to 9.4 (WOMAC) (all p< 0.05). For revision arthroplasty mean scores improved from 39.1, 41.7, and 49.3 pre-operatively to 19.6, 88.0, and 12.5 (all p< 0.05).

No patients required re-operation for loosening, one patient dislocated at day 5.

We can conclude that the Trilogy acetabular component is a versatile acetabular implant which can be used with a wide range of femoral components, both in primary and revision Total Hip Arthroplasty, with successful functional outcome scores greater than 5 years after implantation.

The aim was to evaluate the polyethylene wear in an uncemented all polyethylene titanium coated acetabular cup a minimium of ten years post-operatively, and to determine the effect of supine “stress” radiographs on 3-dimensional polyethylene wear, compared with “non-stress” radiographs.

Twenty seven hips in twenty five patients were examined, and standard and stress radiographs were performed. All radiographs were analysed using Polywear 5 auto, to measure 2d, 3d, and volumetric wear. Wear measurements were performed three times to minimise error. Radiographs were analysed for osteolysis.

There were 12 males and 13 females. Eighteen patients had a diagnosis of osteoarthritis.20 patients had a ceramic head and 7 a metal head. There was no association between wear rates and age, weight, diagnosis, Harris hip score or femoral head type. There was no acetabular osteolysis. The average linear wear was 0.11 +/− 0.08 mm/yr. The stress radiographs did not influence the 2D or 3D wear measurements.

This sudy shows a similar wear rate to most published series. The stress radiographs did not influence the wear measurements. The absence of osteolysis is of interest as other uncemented cups have significant osteolysis at ten years.

Aims. Despite higher rates of revision after total hip arthroplasty (THA) being reported for uncemented stems in patients aged > 75 years, they are frequently used in this age group. Increased mortality after cemented fixation is often used as a justification, but recent data do not confirm this association. The aim of this study was to investigate the influence of the design of the stem and the type of fixation on the rate of revision and immediate postoperative mortality, focusing on the age and sex of the patients. Methods. A total of 333,144 patients with primary osteoarthritis (OA) of the hip who underwent elective THA between November 2012 and September 2022, using uncemented acetabular components without reconstruction shells, from the German arthroplasty registry were included in the study. The revision rates three years postoperatively for four types of stem (uncemented, uncemented with collar, uncemented short, and cemented) were compared within four age groups: < 60 years (Young), between 61 and 70 years (Mid-I), between 71 and 80 years (Mid-II), and aged > 80 years (Old). A noninferiority analysis was performed on the most frequently used designs of stem. Results. The design of the stem was found to have no significant influence on the rate of revision for either sex in the Young group. Uncemented collared stems had a significantly lower rate of revision compared with the other types of stem for females in the Mid-I group. There was a significantly higher rate of revision for uncemented stems in females in the Mid-II group compared with all other types of stem, while in males the rate for uncemented stems was only significantly higher than the rate for cemented stems. Cemented stems had a significantly lower revision rate compared with uncemented and short stems for both sexes in the Old cohort, as did females with collared stems. The rate of immediate postoperative mortality was similar for all types of stem in the Old age group, as were the American Society of Anesthesiologists grades. Conclusion. In patients aged > 80 years, uncemented and short stems had significantly higher revision rates compared with cemented and collared stems, especially in females. The design of the stem and type of fixation have to be analyzed in more detail than only considering cemented and uncemented fixation, in order to further improve the success of THA. Cite this article: Bone Joint J 2024;106-B(3 Supple A):130–136

We clinically and radiologically reviewed 79 uncemented PFC acetabular components inserted by our unit during a seven-year period, June 1991 to June 1998. Of these, 50 (63.3%) were primary and 29 (26.7%) were revision arthroplasties. The mean follow-up was five years (60 months), with a range of 12 to 95 months. Sixteen (20%) were excluded from the study, leaving 63 (26.7%) for review. Three (4.7%) cases were deemed to have failed (at 63, 69, 79 months), all of which were primary arthroplasties. One of them was found to be loose at revision and the other two cups had 2 mm of periacetabular radiolucency in only one zone, but had no definite evidence of loosening. The remaining 60 (95.3%) cases showed no radiological evidence of migration of any cups, and no hip had a radiolucent line in all three zones of the acetabulum. Clinical review gave a mean Harris hip score of 96.5. Fifty (79.4%) reported no pain from the hip. One case (1.6%) had undergone recent revision of the stem, at which time the cup was found to be stable. Three (4.7%) reported slight, occasional pain. Another three (4.7%) described mild pain that did not compromise their average activities and was relieved by simple analgesia. Two cases (3.2%) complained of moderate pain that placed some limitations on their activities and required regular analgesia, and one elderly patient who had an ankylosed contralateral hip and ipsilateral sciatic nerve palsy described marked pain (1.6%), and these were considered poor outcomes. In all of these cases the cups were clinically and radiologically stable. In conclusion, 81% of outcomes were excellent, painfree THRs. A further 4.75% had good and 4.75% fair results. 4.75% had poor outcomes and 4.75% of cases failed. We conclude that the PFC cup merits continued use and follow-up, and together with other uncemented cup designs, may produce benefits in the form of quality and longevity of results in total hip arthroplasty

Background

Implant stability and is an important factor for adequate bone remodelling and both are crucial in the long-term clinical survival of total hip arthroplasty (THA). Assessment of early bone remodelling on X-rays during the first 2 years post-operatively is mandatory when stepwise introduction of a new implant is performed. Regardless of fixation type (cemented or cementless), early acetabular component migration is usually the weakest link in THA, eventually leading to loosening. Over the past years, a shift towards uncemented cup designs has occurred. Besides the established hydroxyapatite (HA) coated uncemented cups which provide ongrowth of bone, new uncemented implant designs stimulating ingrowth of bone have increased in popularity. These cups initiate ingrowth of bone into the implant by their open metallic structure with peripheral pores, to obtain a mechanical interlock with the surrounding bone, thereby stabilising the prosthesis in an early stage after implantation. This retrospective study assessed bone remodelling, osseointegration and occurrence of radiolucency around a new ingrowth philosophy acetabular implant.

Aims. The primary aim of this study is to assess the survival of the uncemented hydroxyapatite (HA) coated Trident II acetabular component as part of a hybrid total hip arthroplasty (THA) using a cemented Exeter stem. The secondary aims are to assess the complications, joint-specific function, health-related quality of life, and radiological signs of loosening of the acetabular component. Methods. A single-centre, prospective cohort study of 125 implants will be undertaken. Patients undergoing hybrid THA at the study centre will be recruited. Inclusion criteria are patients suitable for the use of the uncemented acetabular component, aged 18 to 75 years, willing and able to comply with the study protocol, and provide informed consent. Exclusion criteria includes patients not meeting study inclusion criteria, inadequate bone stock to support fixation of the prosthesis, a BMI > 40 kg/m. 2. , or THA performed for pain relief in those with severely restricted mobility. Results. Implant survival, complications, functional outcomes and radiological assessment up to ten years following index THA (one, two, five, seven, and ten years) will be performed. Functional assessment will include the Oxford Hip Score, Forgotten Joint Score, 12-Item Short Form Health Survey, EuroQol five-dimension health questionnaire, and pain and patient satisfaction. Radiological assessment with assess for acetabula lucent lines, lysis, and loosening according to DeLee and Charnley zones. Conclusion. This study is part of a stepwise introduction of a new device to orthopaedic practice, and careful monitoring of implants should be carried out as part of the Beyond Compliance principles. The results of this study will provide functional, radiological, and survival data to either support the ongoing use of the HA acetabulum or highlight potential limitations of this new implant before wide adoption. Cite this article: Bone Jt Open 2023;4(10):782–790

Abstract. Background. Optimal acetabular component position in Total Hip Arthroplasty is vital for avoiding complications such as dislocation, impingement, abductor muscle strength and range of motion. Transverse acetabular ligament (TAL) and posterior labrum have been shown to be a reliable landmark to guide optimum acetabular cup position. There have been reports of iliopsoas impingement caused by both cemented and uncemented acetabular components. Acetabular component mal-positioning and oversizing of acetabular component are associated with iliopsoas impingement. The Psoas fossa (PF) is not a well-regarded landmark to help with Acetabular Component positioning. Our aim was to assess the relationship of the TAL and PF in relation to Acetabular Component positioning. Methods. A total of 12 cadavers were implanted with the an uncemented acetabular component, their position was initially aligned to TAL. Following optimal seating of the acetabular component the distance of the rim of the shell from the PF was noted. The Acetabular component was then repositioned inside the PF to prevent exposure of the rim of the Acetabular component. This study was performed at Smith & Nephew wet lab in Watford. Results. Out of the twelve acetabular components that were implanted parallel to the TAL, all had the acetabular rim very close or outside to the psoas notch with a potential to cause iliopsoas impingement. Alteration of the acetabular component position was necessary in all cadavers to inside the PF to prevent iliopsoas impingement. It was evident that the edge of PF was not aligned with TAL. Conclusion. Optimal acetabular component position is vital to the longevity and outcome following THA. TAL provides a landmark to guide acetabular component position. We feel the PF is a better landmark to allow appropriate positioning of the acetabular component inside bone without exposure of the component rim and thus preventing iliopsoas impingement at the psoas notch. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Abstract. Optimal acetabular component position in Total Hip Arthroplasty is vital for avoiding complications such as dislocation and impingement, Transverse acetabular ligament (TAL) have been shown to be a reliable landmark to guide optimum acetabular cup position. Reports of iliopsoas impingement caused by acetabular components exist. The Psoas fossa (PF) is not a well-regarded landmark for Component positioning. Our aim was to assess the relationship of the TAL and PF in relation to Acetabular Component positioning. A total of 22 cadavers were implanted on 4 occasions with the an uncemented acetabular component. Measurements were taken between the inner edge of TAL and the base of the acetabular component and the distance between the lower end of the PF and the most medial end of TAL. The distance between the edge of the acetabular component and TAL was a mean of 1.6cm (range 1.4–18cm). The distance between the medial end of TAL and the lowest part of PF was a mean of 1.cm (range 1,3–1.8cm) It was evident that the edge of PF was not aligned with TAL. Optimal acetabular component position is vital to the longevity and outcome following THA. TAL provides a landmark to guide acetabular component position. However we feel the PF is a better landmark to allow appropriate positioning of the acetabular component inside edge of the acetabulum inside the bone without exposure of the component rim and thus preventing iliopsoas impingement at the psoas notch and resultant groin pain

The last two decades have seen remarkable technological advances in total hip arthroplasty (THA) implant design. Porous ingrowth surfaces and highly crosslinked polyethylene (HXLPE) have been expected to dramatically improve implant survivorship. The purpose of the present study was to evaluate survival of contemporary cementless acetabular components following primary THA. 16,421 primary THAs performed for osteoarthritis between 2000 and 2019 were identified from our institutional total joint registry. Patients received one of 12 contemporary cementless acetabular designs with HXLPE liners. Components were grouped based on ingrowth surface into 4 categories: porous titanium (n=10,952, mean follow-up 5 years), porous tantalum (n=1223, mean follow-up 5 years), metal mesh (n=2680, mean follow-up 6.5 years), and hydroxyapatite (HA) coated (n=1566, mean follow-up 2.4 years). Kaplan-Meier analyses were performed to assess the survivorship free of acetabular revision. A historical series of 182 Harris-Galante-1 (HG-1) acetabular components was used as reference. The 15-year survivorship free of acetabular revision was >97% for all 4 contemporary cohorts. Compared to historical control, porous titanium (HR 0.06, 95% CI 0.02–0.17, p<0.001), porous tantalum (HR 0.09, 95%CI 0.03–0.29, p<0.001), metal mesh (HR 0.11, 95%CI 0.04–0.31, p<0.001), and HA-coated (HR 0.14, 95%CI 0.04–0.48, p=0.002) ingrowth surfaces had significantly lower risk of any acetabular revision. There were 16 cases (0.1%) of acetabular aseptic loosening that occurred in 8 (0.07%) porous titanium, 5 (0.2%) metal mesh, and 3 (0.2%) HA-coated acetabular components. 7 of the 8 porous titanium aseptic loosening cases occurred in one known problematic design. There were no cases of aseptic loosening in the porous tantalum group. Modern acetabular ingrowth surfaces and HXLPE liners have improved on historical results at the mid-term. Contemporary designs have extraordinarily high revision-free survivorship, and aseptic loosening is now a rare complication. At mid-term follow-up, survivorship of contemporary uncemented acetabular components is excellent and aseptic loosening occurs in a very small minority of patients

A well-fixed uncemented acetabular component is most commonly removed for chronic infection, malposition with recurrent dislocation, and osteolysis. However, other cups may have to be removed for a broken locking mechanism, a bad “track record”, and for metal-on-metal articulation problems. Modern uncemented acetabular components are hemispheres which have 3-dimensional ingrowth patterns. Coatings include titanium or cobalt-chromium alloy beads, mesh, and now the so-called “enhanced coatings”, such as tantalum trabecular metal, various highly porous titanium metals, and 3-D printed metal coatings. These usually pose a problem for safe removal without fracture of the pelvis or creation of notable bone deficiency. Preoperative planning is essential for safe and efficient removal of these well-fixed components. Strongly consider getting the operative report, component “stickers”, and contacting the implant manufacturer for information. There should a preoperative check list of the equipment and trial implants needed, including various screwdrivers, trial liners, and a chisel system. The first step in component removal is excellent 360-degree exposure of the acetabular rim, and this can be accomplished by several approaches. Then, the acetabular polyethylene liner is removed; a liner that is cemented into a porous shell can be “reamed out” using a specific device. Following this, any central or peripheral screws are removed; broken or stripped screw heads add an additional challenge. A trial acetabular liner is placed, and an acetabular curved chisel system is used. There are two manufacturers of this type of system. Both require the known outer acetabular diameter and the inner diameter of the trial liner. With the curved chisel system and patience, well-fixed components can be safely removed, and the size of the next acetabular component to be implanted is usually 4mm larger than the one removed. There are special inserts for removal of monobloc metal shells. Remember that removal of these well-fixed components is more difficult in patients compared to models, and is just the first step of a successful acetabular revision

Background: Moore et al. recently described five radiological signs (absence of radiolucent line, zone 2 osteo-penia, superolateral buttress, inferomedial buttress and radial trabeculae) for predicting osseointegration of porous coated uncemented acetabular components in the long term. The positive predictive value for a stable fixation was 96.9% when three or more signs were present. 83% of the cups with one or no signs were unstable. Aim: To evaluate the prevalence of these signs in clinically well functioning uncemented acetabular components in the short term and to evaluate whether there is a difference acetabular components with different modulus of elasticity. Materials and methods: The preoperative, immediate postoperative and the latest (minimum 2 years) radiographs of 196 hip replacements with 2 different acetabular components: a 2.9 mm, thin, flexible, macro textured titanium component (Allofit, Zimmer) and a 4 mm thick, stiff, titanium plasma sprayed chrome-cobalt component (Durom, Zimmer) were reviewed by two independent observers searching for the five osseointegration signs. The observers also looked for conventional signs of loosening including: continuous radiolucency of more than 2 mm, component migration of more than 3 mm, component rotation, or the presence of broken screws. Results: 95 Allofit components and 101 Durom components were available for evaluation. None of the hips were considered loose according to conventional criteria and were well functioning. Out of the new osseointegration signs, at least one sign was present in 100 % of the cases, two signs or more in 30%, three signs or more in 5% and four signs in 1%. There was no difference between the two types of cups. In addition, superolateral buttress and zone 2 osteopenia were also present in preoperative/immediate postoperative radiographs in 8% and 4% of respectively. Conclusion: Apart from absence of radiolucency, very few of the five osseointegration signs were present at short term follow-up of two very different well functioning uncemented acetabular components designs. We conclude they are not useful in evaluation of unce-mented acetabular components at a follow up of 2–5 years. Further study at mid-term follow-up might reveal whether the bony adaptive changes occur with time

Highly crosslinked polyethylene (XLPE) was introduced to decrease peri-prosthetic osteolysis related to polyethylene wear, a major reason for revision of total hip arthroplasty. There are few reports of wear and osteolysis at 10 years post-operatively. We asked the following questions: (1) What are the linear and volumetric wear rates of one remelted XLPE at 10–14 years using the Martell method? (2) What is the relationship between volumetric wear, femoral head size, and osteolysis? (3) What is the incidence of osteolysis using conventional radiographs with Judet views and the Martell method?. Methods We evaluated a previously reported cohort of 84 hips (72 patients) with one design of an uncemented acetabular component and one electron-beam irradiated, remelted XLPE at a mean follow-up of 11 years (range 10 to 14 years). Measurements of linear and volumetric wear were performed in one experienced laboratory by the Martell method and standard radiographs, with additional Judet views, were used to detect peri-prosthetic osteolysis. Statistical analysis of wear and osteolysis compared to head size was performed. Results The mean linear wear rate by the first-to-last method was 0.024 mm/year (median, 0.010 mm/year) and the mean volumetric wear rate by this method was 12.2 mm. 3. /year (median, 3.6 mm. 3. /year). We found no association between femoral head size and linear wear rate. However, there was a significant relationship between femoral head size and volumetric wear rates, with 36/40 mm femoral heads having significantly higher volumetric wear (p=0.02). Small osteolytic lesions were noted in 12 hips (14%), but there was no association with head size, acetabular component position, or linear or volumetric wear rates. Conclusion This uncemented acetabular component and this particular remelted XLPE had low rates of linear and volumetric wear. Small osteolytic lesions were noted at 10 to 14 years, but were not related to femoral head size, linear or volumetric wear rates

This study evaluates forty-four consecutive autopsy specimens of the senior author’s own patients in attempt to locate and measure periacetabular bone defects and correlate this information with their communication pathways with the joint space. The purpose of this study was to evaluate autopsy retrieved hemipelves of previously well-functioning total hip arthroplasties (THAs) with computed tomography (CT) to better understand patterns of osteolysis around modular uncemented acetabular components. Forty-four hemipelves containing titanium porous-coated modular acetabular components were retrieved at autopsy, imaged with CT, and analyzed to determine the location and volume of osteolytic lesions. The mean age of the patients at the time of surgery was seventy years. The mean time in situ for the implants was eight years. A total of forty-six osteolytic lesions were identified in twenty-eight of the forty-four cases (64%). Thirty-one of forty-six lesions (67%) had one or more apparent communications with the joint space. We identified four types of communication pathways between osteolytic lesions and the joint space: around the rim, through a central dome hole, in association with a screw or screw hole, or around a non-ingrown interface. The mean volume of lesions that had a clear communication pathway was significantly larger than those lesions that did not have a clear communication pathway (p=0.012). Thirteen of the fifteen lesions that did not have a clear communication with the joint space represented bone defects that had existed prior to total hip arthroplasty. Osteolysis was commonly observed at early time intervals around modular uncemented acetabular components. The communication with the joint space is important for developing osteolysis, as well as in the detection of true osteolytic lesions

Background. Reduced dislocation rates using lipped polyethylene (PE) liners in modular uncemented acetabular components has been shown, yet there may be increased wear because of impingement, which may lead to aseptic loosening. We used New Zealand Joint Registry (NZJR) data to compare survival rates, revision rates for dislocation and aseptic loosening between lipped and neutral liners. Methods. 31,247 primary THAs using the four commonly used uncemented modular cups were identified (January 1, 1999 to December 31, 2018). The lipped liner group comprised 49% males vs 42% in the neutral group (p < 0.001); 96% had OA vs 95% in the neutral group (p < 0.001). There was no difference in other patient characteristics. Mean follow-up was 5.1 years (SD 3.9); longest follow-up 19.3 years. Kaplan Meier survival rates were compared (20,240 lipped and 11,007 neutral PE liners). Highly cross-linked PE was used in 99% of lipped liner cups vs 85% of neutral liner cups. Associated hazard ratios were calculated using a Cox regression analysis. Results. KM survival at 10 years for lipped PE liners was 96% for lipped (95%CI 95.4%-96.2%) and 95% for neutral liners (95%CI 94.7%-95.9%). Controlling for age, gender approach, head size, image guidance, the all-cause revision risk was greater for neutral liner (HR 1.17 [95% CI 1.06 to 1.36]; p = 0.032). There was a higher risk of revision for dislocation in those with neutral liners (HR 1.84 [95%CI 1.41–2.41]; p < 0.001) but no difference in the revision rate for aseptic acetabular loosening (HR 0.85 [95%CI 0.52–1.38]; p = 0.511). Conclusions. Using lipped PE liners is not associated with a higher rate of aseptic loosening in patients who undergo primary THA. Lipped PE liners are associated with lower rates of dislocation and lower all-cause revision rates without any increased association with revision rates for wear and aseptic loosening

Currently available uncemented acetabular components appear to provide very reliable fixation for at least 10 years. However, these cups have been associated with a significant incidence of polyethylene wear. Osteolysis associated with this wear is emerging as the most significant problem in total hip replacement surgery. The purpose of this presentation is to describe the rationale for reducing polyethylene wear through the use of an uncemented acetabular component made of a polyethylene/ Tantalum (Trabecular Metal) composite and to describe the initial clinical experience with this cup. Clinical and radiographic data were prospectively collected on the first 125 consecutively performed total hip replacements in which a tantalum (Trabecular Metal), monoblock acetabular component was used. Minimum follow-up was 24 to 46 months. Sixty three percent of the patients were female. Mean age was 61. The diagnoses were: OA-74%; AVN-12%; RA-10%; other-4%. 50% of the hips had cemented femoral components. 20% of the patients were Charnley Class 1, 30% Charnley Class 2, and 50% Charnley Class 3. At most recent follow-up, all patients were pain free (Ave. pain score pre-op.- 6.7, post-op.-1.4). No patient’s function was limited by hip function (Ave. Harris hip score pre-op.-38, post-op.-92). All hips had radiographic findings consistent with bone-ingrowth. Gaps in zone 2 were seen in 10% of hips, but filled in by one year. The rate of polyethylene wear as measured by the Martel technique was less than 0.07mm/year in the first two years. There were three complications in the group: 2 dislocations which re. The early experience with the monoblock, tantalum cup indicates that initial fixation is secure, even without screws, and that initial polyethylene wear is very low