Aims. The aim of this study was to identify the optimal lip position for total hip arthroplasties (THAs) using a lipped liner. There is a lack of consensus on the optimal position, with substantial variability in surgeon practice. Methods. A model of a THA was developed using a 20° lipped liner. Kinematic analyses included a physiological range of motion (ROM) analysis and a provocative dislocation manoeuvre analysis. ROM prior to impingement was calculated and, in impingement scenarios, the travel distance prior to dislocation was assessed. The combinations analyzed included nine
Aims. Limited implant survival due to aseptic
Aims. It is important to analyze objectively the hammering sound in
Aims. It is important to analyze objectively the hammering sound in
Aims. This study aimed to evaluate the accuracy of implant placement with robotic-arm assisted total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH). Methods. The study analyzed a consecutive series of 69 patients who underwent robotic-arm assisted THA between September 2018 and December 2019. Of these, 30 patients had DDH and were classified according to the Crowe type. Acetabular component alignment and 3D positions were measured using pre- and postoperative CT data. The absolute differences of
We have compared the survival of two hydroxyapatite (HA)-coated
Dual mobility
Aims. Dislocation remains a significant complication after total hip arthroplasty (THA), being the third leading indication for revision. We present a series of acetabular revision using a dual mobility
Aims. Pelvic reconstruction after the resection of a tumour around
the acetabulum is a challenging procedure due to the complex anatomy
and biomechanics. Several pelvic endoprostheses have been introduced,
but the rates of complication remain high. Our aim was to review
the use of a stemmed acetabular pedestal
The orientation of the acetabular component can
influence both the short- and long-term outcomes of total hip replacement
(THR). We performed a prospective, randomised, controlled trial
of two groups, comprising of 40 patients each, in order to compare
freehand introduction of the component with introduction using the transverse
acetabular ligament (TAL) as a reference for anteversion. Anteversion
and inclination were measured on pelvic radiographs. With respect to anteversion, in the freehand group 22.5% of the
components were outside the safe zone With respect to inclination, in the freehand group 37.5% of the
components were outside the safe zone The transverse acetabular ligament may be used to obtain the
appropriate anteversion when introducing the acetabular component
during THR, but not acetabular component inclination. Cite this article:
Between March 1990 and May 1991 we performed 85 primary total hip replacements in 74 patients using the Landos Atoll hydroxyapatite (HA)-coated
We reviewed the radiographs of 864 Charnley and STH (Zimmer) cemented total hip arthroplasties with a mean follow-up of seven years (maximum 16 years). Survivorship analysis was used to assess the correlation between radiographic performance and the bony containment or the coronal orientation of the acetabular
1. The unreliable results of the conventional
The Cambridge
Since wear and loosening of the ultra-high-molecular-weight polyethylene
We report a high rate of failure of the Ring polyethylene cementless
Peri-acetabular tumour resections and their subsequent
reconstruction are among the most challenging procedures in orthopaedic
oncology. Despite the fact that a number of different pelvic endoprostheses
have been introduced, rates of complication remain high and long-term
results are mostly lacking. . In this retrospective study, we aimed to evaluate the outcome
of reconstructing a peri-acetabular defect with a pedestal
We measured the proximal migration of 265 acetabular
We selected randomly a consecutive series of 162 patients requiring hip replacement to receive either a cementless, hemispherical, modular, titanium acetabular
We examined radiographic polyethylene wear in 233 cemented total hip arthroplasties (201 patients) with either a metal-backed or a non-metal-backed acetabular
We performed thermal analysis of polyethylene samples obtained from 73 new
We assessed differences in the incidence and appearance of the radiological signs of loosening of the
We report the long-term radiological results of 58 total hip arthroplasties (THA) using the Charnley offset-bore acetabular socket. Wear was measured at four sites and radiolucent lines and possible migration were recorded. Four
In laboratory tests, the ultra-high molecular weight polyethylene used for the acetabular
We reviewed 264 consecutive primary total hip replacements in 244 patients in which the Harris-Galante I porous-coated acetabular component had been used. The mean follow-up was 95 months (69 to 132). In 221 arthroplasties a 32 mm ceramic head had been used, and in the other 43 one of cobalt-chrome alloy. There were 124 women and 120 men with a mean age at operation of 56.8 years (21 to 83). Survival analysis of the acetabular components was performed using the following definitions of failure: 1) infection; 2) removal because of aseptic loosening; 3) removal for any cause; and 4) a worst-case analysis including removal of the
Failure of an acetabular
Fracture of the polyethylene acetabular
The Wroblewski golf ball acetabular
The need for supplementary screw fixation in acetabular revisions is still widely debated. We carried out 439 acetabular revisions over an eight-year period. In 171 hips with contained or small segmental defects, the Morscher press-fit
We carried out 71 primary total hip arthroplasties using porous-coated, hemispherical press-fit Duraloc ‘100 Series’
1. Prosthetic acetabular
This study presents the clinical and radiological results of 62 consecutive acetabular revisions in 58 patients, at a mean of 16.5 years follow-up (15 to 20). The Kaplan-Meier survivorship for the
Ten acetabular
The custom triflange is a patient-specific implant
for the treatment of severe bone loss in revision total hip arthroplasty
(THA). Through a process of three-dimensional modelling and prototyping,
a hydroxyapatite-coated component is created for acetabular reconstruction.
There are seven level IV studies describing the clinical results
of triflange components. The most common complications include dislocation
and infection, although the rates of implant removal are low. Clinical
results are promising given the challenging problem. We describe
the design, manufacture and implantation process and review the
clinical results, contrasting them to other methods of acetabular
reconstruction in revision THA. Cite this article:
We describe a simple, retroperitoneal approach for the removal of acetabular components that have migrated into the pelvis. The dense fibrous tissue layer which surrounds the implant protects the iliac vessels during removal of the
Between 1972 and 1990, we performed 168 primary low-friction arthroplasties in 125 patients with acetabular protrusion. Twelve hips were lost to follow-up within eight years and eight which became infected were excluded from the final study. Of the 148 hips remaining, 62 with a mild protrusion were classified as group 1, 54 with moderate or severe protrusion as group 2 and, after 1985, 32 with moderate and severe protrusion which required bone grafts as group 3. The mean follow-up was 18.3 years (3 to 24) for group 1, 17.4 years (8 to 22) for group 2 and ten years (8 to 13) for group 3. There were 31 revisions of the
One concern about the fixation of HA-coated implants is the possible disintegration of the surface, with the migration of HA granules into the joint space, producing third-body wear. We report a study of six revisions of HA-coated polyethylene RM
Laboratory wear testing of ultra high molecular weight polyethylene from 12 Charnley acetabular
The results of using the Ring uncemented polyethylene-to-metal (UPM) prosthesis in patients with protrusio acetabuli or dysplasia are reported. Fifty-four cases of protrusio were analysed and a modified method of measuring the deformity is described; after operation, remodelling of the medial wall had improved, on average, by 29.6%. For the dysplastic acetabulum the main difficulty is the lack of lateral support for the
We describe a new method for the accurate measurement of the angle of anteversion of an acetabular
In total hip replacement, orientation of the
The aims of this study were to examine the repeatability of measurements of bone mineral density (BMD) around a cemented polyethylene Charnley acetabular component using dual-energy x-ray absorptiometry and to determine the longitudinal pattern of change in BMD during the first 24 months after surgery. The precision of measurements of BMD in 19 subjects ranged from 7.7% to 10.8% between regions, using a four-region-of-interest model. A longitudinal study of 27 patients demonstrated a transient decrease in net pelvic BMD during the first 12 months, which recovered to baseline at 24 months. The BMD in the region medial to the dome of the component reduced by between 7% and 10% during the first three months, but recovered to approximately baseline values by two years. Changes in BMD in the pelvis around cemented acetabular components may be measured using dual-energy x-ray absorptiometry. Bone loss after insertion of a cemented Charnley acetabular component is small, transient and occurs mainly at the medial wall of the acetabulum. After two years, bone mass returns to baseline values, with a pattern suggesting a uniform transmission of load to the acetabulum.
We carried out a clinical and radiological review of 103 cementless primary hip arthroplasties with a tapered rectangular grit-blasted titanium press-fit femoral component and a threaded conical titanium acetabular component at a mean follow-up of 14.4 years (10.2 to 17.1). The mean Harris hip score at the last follow-up was 89.2 (32 to 100). No early loosening and no fracture of the implant were found. One patient needed revision surgery because of a late deep infection. In 11 hips (10.7%), the reason for revision was progressive wear of the polyethylene liner. Exchange of the acetabular component because of aseptic loosening without detectable liner wear was carried out in three hips (2.9%). After 15 years the survivorship with aseptic loosening as the definition for failure was 95.6% for the acetabular component and 100% for the femoral component.
Between 1995 and 1997 we undertook 40 bipolar hip arthroplasties in 35 patients with dysplastic osteoarthritis. The steep and shallow acetabulum was excavated and the bipolar socket was placed high with an adjustment of leg-length. At follow-up of between five and seven years, there were 19 excellent, 16 good and five fair results according to the scoring system of Merle d’Aubigné and Postel. The mean radiographic superior migration of the bipolar socket was 2.1 mm (0 to 10). Osteolysis was noted in three hips within three years of the operation. Abduction on weight-bearing was recorded in 24 hips and the bipolar system was found to be functioning predominantly between the inner bearing and the metal femoral head in 20.
We studied wear in the ultra-high-molecular-weight polyethylene offset bore socket in 54 hips which had had Charnley low-friction arthroplasty. At an average follow-up of 8.1 years, the mean penetration rate was 0.04 mm per year. Correlation between the depth of socket penetration and the incidence of socket migration was confirmed, but socket migration occurred with lower penetration than had been previously reported.
Aims. Manual impaction, with a mallet and introducer, remains the standard method of installing cementless acetabular
Aims. Iliopsoas impingement occurs in 4% to 30% of patients after undergoing total hip arthroplasty (THA). Despite a relatively high incidence, there are few attempts at modelling impingement between the iliopsoas and acetabular component, and no attempts at modelling this in a representative cohort of subjects. The purpose of this study was to develop a novel computational model for quantifying the impingement between the iliopsoas and acetabular component and validate its utility in a case-controlled investigation. Methods. This was a retrospective cohort study of patients who underwent THA surgery that included 23 symptomatic patients diagnosed with iliopsoas tendonitis, and 23 patients not diagnosed with iliopsoas tendonitis. All patients received postoperative CT imaging, postoperative standing radiography, and had minimum six months’ follow-up. 3D models of each patient’s prosthetic and bony anatomy were generated, landmarked, and simulated in a novel iliopsoas impingement detection model in supine and standing pelvic positions. Logistic regression models were implemented to determine if the probability of pain could be significantly predicted. Receiver operating characteristic curves were generated to determine the model’s sensitivity, specificity, and area under the curve (AUC). Results. Highly significant differences between the symptomatic and asymptomatic cohorts were observed for iliopsoas impingement. Logistic regression models determined that the impingement values significantly predicted the probability of groin pain. The simulation had a sensitivity of 74%, specificity of 100%, and an AUC of 0.86. Conclusion. We developed a computational model that can quantify iliopsoas impingement and verified its accuracy in a case-controlled investigation. This tool has the potential to be used preoperatively, to guide decisions about optimal
Aims. Instability is a common cause of failure after total hip arthroplasty. A novel reverse total hip has been developed, with a femoral
Aims. Dislocation remains a leading cause of failure following revision total hip arthroplasty (THA). While dual-mobility (DM) bearings have been shown to mitigate this risk, options are limited when retaining or implanting an uncemented shell without modular DM options. In these circumstances, a monoblock DM cup, designed for cementing, can be cemented into an uncemented acetabular shell. The goal of this study was to describe the implant survival, complications, and radiological outcomes of this construct. Methods. We identified 64 patients (65 hips) who had a single-design cemented DM cup cemented into an uncemented acetabular shell during revision THA between 2018 and 2020 at our institution. Cups were cemented into either uncemented
Aims. Custom triflange acetabular components (CTACs) play an important role in reconstructive orthopaedic surgery, particularly in revision total hip arthroplasty (rTHA) and pelvic tumour resection procedures. Accurate CTAC positioning is essential to successful surgical outcomes. While prior studies have explored CTAC positioning in rTHA, research focusing on tumour cases and implant flange positioning precision remains limited. Additionally, the impact of intraoperative navigation on positioning accuracy warrants further investigation. This study assesses CTAC positioning accuracy in tumour resection and rTHA cases, focusing on the differences between preoperative planning and postoperative implant positions. Methods. A multicentre observational cohort study in Australia between February 2017 and March 2021 included consecutive patients undergoing acetabular reconstruction with CTACs in rTHA (Paprosky 3A/3B defects) or tumour resection (including Enneking P2 peri-acetabular area). Of 103 eligible patients (104 hips), 34 patients (35 hips) were analyzed. Results. CTAC positioning was generally accurate, with minor deviations in
Aims. This combined clinical and in vitro study aimed to determine the incidence of liner malseating in modular dual mobility (MDM) constructs in primary total hip arthroplasties (THAs) from a large volume arthroplasty centre, and determine whether malseating increases the potential for fretting and corrosion at the modular metal interface in malseated MDM constructs using a simulated corrosion chamber. Methods. For the clinical arm of the study, observers independently reviewed postoperative radiographs of 551 primary THAs using MDM constructs from a single manufacturer over a three-year period, to identify the incidence of MDM liner-shell malseating. Multivariable logistic regression analysis was performed to identify risk factors including age, sex, body mass index (BMI),
Aims. Metal-on-metal hip resurfacing (MoM-HR) has seen decreased usage due to safety and longevity concerns. Joint registries have highlighted the risks in females, smaller hips, and hip dysplasia. This study aimed to identify if reported risk factors are linked to revision in a long-term follow-up of MoM-HR performed by a non-designer surgeon. Methods. A retrospective review of consecutive MoM hip arthroplasties (MoM-HRAs) using Birmingham Hip Resurfacing was conducted. Data on procedure side, indication, implant sizes and orientation, highest blood cobalt and chromium ion concentrations, and all-cause revision were collected from local and UK National Joint Registry records. Results. A total of 243 hips (205 patients (163 male, 80 female; mean age at surgery 55.3 years (range 25.7 to 75.3)) with MoM-HRA performed between April 2003 and October 2020 were included. Mean follow-up was 11.2 years (range 0.3 to 17.8). Osteoarthritis was the most common indication (93.8%), and 13 hips (5.3%; 7M:6F) showed dysplasia (lateral centre-edge angle < 25°). Acetabular
Aims. The aim of this study was to evaluate the performance of first-generation annealed highly cross-linked polyethylene (HXLPE) in cementless total hip arthroplasty (THA). Methods. We retrospectively evaluated 29 patients (35 hips) who underwent THA between December 2000 and February 2002. The survival rate was estimated using the Kaplan-Meier method. Hip joint function was evaluated using the Japanese Orthopaedic Association (JOA) score. Two-dimensional polyethylene wear was estimated using Martell’s Hip Analysis Suite. We calculated the wear rates between years 1 and 5, 5 and 10, 10 and 15, and 15 and final follow-up. Results. The mean follow-up period was 19.1 years (SD 0.6; 17.3 to 20.1). The 19-year overall survival rate with the end point of all-cause revision was 97.0% (95% confidence interval (CI) 91 to 100). The mean JOA score improved from 43.2 (SD 10.6; 30 to 76) before surgery to 90.2 (SD 6.4; 76 to 98) at the final follow-up (p < 0.001). There was no osteolysis or loosening of the acetabular or femoral components. The overall steady-state wear rate was 0.013 mm/year (SD 0.012). There was no hip with a steady-state wear rate of > 0.1 mm/year. There was no significant difference in wear rates for each period. We found no significant correlation between the wear rate and age, body weight, BMI, or
Aims. With increasing burden of revision hip arthroplasty (THA), one of the major challenges is the management of proximal femoral bone loss associated with previous multiple surgeries. Proximal femoral arthroplasty (PFA) has already been popularized for tumour surgeries. Our aim was to describe the outcome of using PFA in these demanding non-neoplastic cases. Methods. A retrospective review of 25 patients who underwent PFA for non-neoplastic indications between January 2009 and December 2015 was undertaken. Their clinical and radiological outcome, complication rates, and survival were recorded. All patients had the Stanmore Implant – Modular Endo-prosthetic Tumour System (METS). Results. At mean follow-up of 5.9 years, there were no periprosthetic fractures. Clearance of infection was achieved in 63.6% of cases. One hip was re-revised to pseudo arthroplasty for deep infection. Instability was noted in eight of the hips (32%), of which seven needed further surgery. Out of these eight hips with instability, five had preoperative infection. Deep infection was noted in five of the hips (20%), of which four were primarily revised for infection. One patient had aseptic loosening of the femoral component and awaits revision surgery. The Kaplan-Meier survivorship free of revision of any component for any reason was 72% (95% confidence interval (CI) 51.3% to 92.7%), and for revisions of only femoral component for any reason was 96% (95% CI 86.3% to 105.7%) at five years. Conclusion. Dislocation and infection remain the major cause for failure, particularly in patients with pre-existing infection. The use of dual mobility
Aims. Spinopelvic mobility plays an important role in functional acetabular component position following total hip arthroplasty (THA). The primary aim of this study was to determine if spinopelvic hypermobility persists or resolves following THA. Our second aim was to identify patient demographic or radiological factors associated with hypermobility and resolution of hypermobility after THA. Methods. This study investigated patients with preoperative posterior hypermobility, defined as a change in sacral slope (SS) from standing to sitting (ΔSS. stand-sit. ) ≥ 30°. Radiological spinopelvic parameters, including SS, pelvic incidence (PI), lumbar lordosis (LL), PI-LL mismatch, anterior pelvic plane tilt (APPt), and spinopelvic tilt (SPT), were measured on preoperative imaging, and at
six weeks and a minimum of
one year postoperatively. The severity of bilateral hip osteoarthritis (OA) was graded using Kellgren-Lawrence criteria. Results. A total of 136 patients were identified as having preoperative spinopelvic hypermobility. At one year after THA, 95% (129/136) of patients were no longer categorized as hypermobile on standing and sitting radiographs (ΔSS. stand-sit. < 30°). Mean ΔSS. stand-sit. decreased from 36.4° (SD 5.1°) at baseline to 21.4° (SD 6.6°) at one year (p < 0.001). Mean SS. seated. increased from baseline (11.4° (SD 8.8°)) to one year after THA by 11.5° (SD 7.4°) (p < 0.001), which correlates to an 8.5° (SD 5.5°) mean decrease in seated functional
Aims. Acetabular edge-loading was a cause of increased wear rates in metal-on-metal hip arthroplasties, ultimately contributing to their failure. Although such wear patterns have been regularly reported in retrieval analyses, this study aimed to determine their in vivo location and investigate their relationship with acetabular component positioning. Methods. 3D CT imaging was combined with a recently validated method of mapping bearing surface wear in retrieved hip implants. The asymmetrical stabilizing fins of Birmingham hip replacements (BHRs) allowed the co-registration of their acetabular wear maps and their computational models, segmented from CT scans. The in vivo location of edge-wear was measured within a standardized coordinate system, defined using the anterior pelvic plane. Results. Edge-wear was found predominantly along the superior acetabular edge in all cases, while its median location was 8° (interquartile range (IQR) -59° to 25°) within the anterosuperior quadrant. The deepest point of these scars had a median location of 16° (IQR -58° to 26°), which was statistically comparable to their centres (p = 0.496). Edge-wear was in closer proximity to the superior apex of the
Aims. In computer simulations, the shape of the range of motion (ROM) of a stem with a cylindrical neck design will be a perfect cone. However, many modern stems have rectangular/oval-shaped necks. We hypothesized that the rectangular/oval stem neck will affect the shape of the ROM and the prosthetic impingement. Methods. Total hip arthroplasty (THA) motion while standing and sitting was simulated using a MATLAB model (one stem with a cylindrical neck and one stem with a rectangular neck). The primary predictor was the geometry of the neck (cylindrical vs rectangular) and the main outcome was the shape of ROM based on the prosthetic impingement between the neck and the liner. The secondary outcome was the difference in the ROM provided by each neck geometry and the effect of the pelvic tilt on this ROM. Multiple regression was used to analyze the data. Results. The stem with a rectangular neck has increased internal and external rotation with a quatrefoil cross-section compared to a cone in a cylindrical neck. Modification of the
Aims. Pelvic tilt (PT) can significantly change the functional orientation of the acetabular component and may differ markedly between patients undergoing total hip arthroplasty (THA). Patients with stiff spines who have little change in PT are considered at high risk for instability following THA. Femoral component position also contributes to the limits of impingement-free range of motion (ROM), but has been less studied. Little is known about the impact of combined anteversion on risk of impingement with changing pelvic position. Methods. We used a virtual hip ROM (vROM) tool to investigate whether there is an ideal functional combined anteversion for reduced risk of hip impingement. We collected PT information from functional lateral radiographs (standing and sitting) and a supine CT scan, which was then input into the vROM tool. We developed a novel vROM scoring system, considering both seated flexion and standing extension manoeuvres, to quantify whether hips had limited ROM and then correlated the vROM score to component position. Results. The vast majority of THA planned with standing combined anteversion between 30° to 50° and sitting combined anteversion between 45° to 65° had a vROM score > 99%, while the majority of vROM scores less than 99% were outside of this zone. The range of PT in supine, standing, and sitting positions varied widely between patients. Patients who had little change in PT from standing to sitting positions had decreased hip vROM. Conclusion. It has been shown previously that an individual’s unique spinopelvic alignment influences functional
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. Methods. This 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. Results. Overall 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
Aims. Vitamin E-infused highly crosslinked polyethylene (VEPE) has been introduced into total hip arthroplasty (THA) with the aim of further improving the wear characteristics of moderately and highly crosslinked polyethylenes (ModXLPE and HXLPE). There are few studies analyzing the outcomes of vitamin E-infused components in cemented arthroplasty, though early acetabular component migration has been reported. The aim of this study was to measure five-year polyethylene wear and acetabular component stability of a cemented VEPE acetabular component compared with a ModXLPE cemented acetabular component. Methods. In a prospective randomized controlled trial (RCT), we assessed polyethylene wear and acetabular component stability (primary outcome) with radiostereometric analysis (RSA) in 68 patients with reverse hybrid THA at five years follow-up. Patients were randomized to either a VEPE or a ModXLPE cemented acetabular component. Results. Mean polyethylene wear in the proximal direction was 0.17 mm (SD 0.15) for the VEPE group and 0.20 mm (SD 0.09) for the ModXLPE group (p = 0.005) at five years. Annual proximal wear rates were 0.03 mm/year (VEPE) and 0.04 mm/year (ModXLPE). Total 3D wear was 0.21 mm (SD 0.26) and 0.23 mm (SD 0.10) for the VEPE and ModXLPE groups, respectively (p = 0.009). Total 3D
Aims. The aim of this prospective cohort study was to evaluate the early migration of the TriFit cementless proximally coated tapered femoral stem using radiostereometric analysis (RSA). Methods. A total of 21 patients (eight men and 13 women) undergoing primary total hip arthroplasty (THA) for osteoarthritis of the hip were recruited in this study and followed up for two years. Two patients were lost to follow-up. All patients received a TriFit stem and Trinity
Post-traumatic periprosthetic acetabular fractures are rare but serious. Few studies carried out on small cohorts have reported them in the literature. The aim of this work is to describe the specific characteristics of post-traumatic periprosthetic acetabular fractures, and the outcome of their surgical treatment in terms of function and complications. Patients with this type of fracture were identified retrospectively over a period of six years (January 2016 to December 2021). The following data were collected: demographic characteristics, date of insertion of the prosthesis, details of the intervention, date of the trauma, characteristics of the fracture, and type of treatment. Functional results were assessed with the Harris Hip Score (HHS). Data concerning complications of treatment were collected.Aims
Methods
Periprosthetic fracture and implant loosening are two of the major reasons for revision surgery of cementless implants. Optimal implant fixation with minimal bone damage is challenging in this procedure. This pilot study investigates whether vibratory implant insertion is gentler compared to consecutive single blows for acetabular component implantation in a surrogate polyurethane (PU) model. Acetabular components (cups) were implanted into 1 mm nominal under-sized cavities in PU foams (15 and 30 per cubic foot (PCF)) using a vibratory implant insertion device and an automated impaction device for single blows. The impaction force, remaining polar gap, and lever-out moment were measured and compared between the impaction methods.Aims
Methods
Pelvic discontinuity is a challenging acetabular defect without a consensus on surgical management. Cup-cage reconstruction is an increasingly used treatment strategy. The present study evaluated implant survival, clinical and radiological outcomes, and complications associated with the cup-cage construct. We included 53 cup-cage construct (51 patients) implants used for hip revision procedures for pelvic discontinuity between January 2003 and January 2022 in this retrospective review. Mean age at surgery was 71.8 years (50.0 to 92.0; SD 10.3), 43/53 (81.1%) were female, and mean follow-up was 6.4 years (0.02 to 20.0; SD 4.6). Patients were implanted with a Trabecular Metal Revision Shell with either a ZCA cage (n = 12) or a TMARS cage (n = 40, all Zimmer Biomet). Pelvic discontinuity was diagnosed on preoperative radiographs and/or intraoperatively. Kaplan-Meier survival analysis was performed, with failure defined as revision of the cup-cage reconstruction.Aims
Methods
The aim of this study was to evaluate the suitability of the tapered cone stem in total hip arthroplasty (THA) in patients with excessive femoral anteversion and after femoral osteotomy. We included patients who underwent THA using Wagner Cone due to proximal femur anatomical abnormalities between August 2014 and January 2019 at a single institution. We investigated implant survival time using the endpoint of dislocation and revision, and compared the prevalence of prosthetic impingements between the Wagner Cone, a tapered cone stem, and the Taperloc, a tapered wedge stem, through simulation. We also collected Oxford Hip Score (OHS), visual analogue scale (VAS) satisfaction, and VAS pain by postal survey in August 2023 and explored variables associated with those scores.Aims
Methods
In metal-on-metal (MoM) hip arthroplasties and resurfacings, mechanically induced corrosion can lead to elevated serum metal ions, a local inflammatory response, and formation of pseudotumours, ultimately requiring revision. The size and diametral clearance of anatomical (ADM) and modular (MDM) dual-mobility polyethylene bearings match those of Birmingham hip MoM components. If the acetabular component is satisfactorily positioned, well integrated into the bone, and has no surface damage, this presents the opportunity for revision with exchange of the metal head for ADM/MDM polyethylene bearings without removal of the acetabular component. Between 2012 and 2020, across two centres, 94 patients underwent revision of Birmingham MoM hip arthroplasties or resurfacings. Mean age was 65.5 years (33 to 87). In 53 patients (56.4%), the acetabular component was retained and dual-mobility bearings were used (DM); in 41 (43.6%) the acetabulum was revised (AR). Patients underwent follow-up of minimum two-years (mean 4.6 (2.1 to 8.5) years).Aims
Methods
The primary objective of this study was to develop a validated classification system for assessing iatrogenic bone trauma and soft-tissue injury during total hip arthroplasty (THA). The secondary objective was to compare macroscopic bone trauma and soft-tissues injury in conventional THA (CO THA) versus robotic arm-assisted THA (RO THA) using this classification system. This study included 30 CO THAs versus 30 RO THAs performed by a single surgeon. Intraoperative photographs of the osseous acetabulum and periacetabular soft-tissues were obtained prior to implantation of the acetabular component, which were used to develop the proposed classification system. Interobserver and intraobserver variabilities of the proposed classification system were assessed.Aims
Methods
The liner design is a key determinant of the constraint of a reverse total shoulder arthroplasty (rTSA). The aim of this study was to compare the degree of constraint of rTSA liners between different implant systems. An implant company’s independent 3D shoulder arthroplasty planning software (mediCAD 3D shoulder v. 7.0, module v. 2.1.84.173.43) was used to determine the jump height of standard and constrained liners of different sizes (radius of curvature) of all available companies. The obtained parameters were used to calculate the stability ratio (degree of constraint) and angle of coverage (degree of glenosphere coverage by liner) of the different systems. Measurements were independently performed by two raters, and intraclass correlation coefficients were calculated to perform a reliability analysis. Additionally, measurements were compared with parameters provided by the companies themselves, when available, to ensure validity of the software-derived measurements.Aims
Methods
Radiostereometric analysis (RSA) is the most accurate radiological method to measure in vivo wear of highly cross-linked polyethylene (XLPE) acetabular components. We have previously reported very low wear rates for a sequentially irradiated and annealed X3 XLPE liner (Stryker Orthopaedics, USA) when used in conjunction with a 32 mm femoral heads at ten-year follow-up. Only two studies have reported the long-term wear rate of X3 liners used in conjunction with larger heads using plain radiographs which have poor sensitivity. The aim of this study was to measure the ten-year wear of thin X3 XLPE liners against larger 36 or 40 mm articulations with RSA. We prospectively reviewed 19 patients who underwent primary cementless THA with the XLPE acetabular liner (X3) and a 36 or 40 mm femoral head with a resultant liner thickness of at least 5.8 mm. RSA radiographs at one week, six months, and one, two, five, and ten years postoperatively and femoral head penetration within the acetabular component were measured with UmRSA software. Of the initial 19 patients, 12 were available at the ten-year time point.Aims
Methods
Pelvic discontinuity is a rare but increasingly common complication of total hip arthroplasty (THA). This single-centre study evaluated the performance of custom-made triflange acetabular components in acetabular reconstruction with pelvic discontinuity by determining: 1) revision and overall implant survival rates; 2) discontinuity healing rate; and 3) Harris Hip Score (HHS). Retrospectively collected data of 38 patients (39 hips) with pelvic discontinuity treated with revision THA using a custom-made triflange acetabular component were analyzed. Minimum follow-up was two years (mean 5.1 years (2 to 11)).Aims
Methods
Large acetabular bone defects encountered in revision total hip arthroplasty (THA) are challenging to restore. Metal constructs for structural support are combined with bone graft materials for restoration. Autograft is restricted due to limited volume, and allogenic grafts have downsides including cost, availability, and operative processing. Bone graft substitutes (BGS) are an attractive alternative if they can demonstrate positive remodelling. One potential product is a biphasic injectable mixture (Cerament) that combines a fast-resorbing material (calcium sulphate) with the highly osteoconductive material hydroxyapatite. This study reviews the application of this biomaterial in large acetabular defects. We performed a retrospective review at a single institution of patients undergoing revision THA by a single surgeon. We identified 49 consecutive patients with large acetabular defects where the biphasic BGS was applied, with no other products added to the BGS. After placement of metallic acetabular implants, the BGS was injected into the remaining bone defects surrounding the new implants. Patients were followed and monitored for functional outcome scores, implant fixation, radiological graft site remodelling, and revision failures.Aims
Methods
Computer-assisted 3D preoperative planning software has the potential to improve postoperative stability in total hip arthroplasty (THA). Commonly, preoperative protocols simulate two functional positions (standing and relaxed sitting) but do not consider other common positions that may increase postoperative impingement and possible dislocation. This study investigates the feasibility of simulating commonly encountered positions, and positions with an increased risk of impingement, to lower postoperative impingement risk in a CT-based 3D model. A robotic arm-assisted arthroplasty planning platform was used to investigate 11 patient positions. Data from 43 primary THAs were used for simulation. Sacral slope was retrieved from patient preoperative imaging, while angles of hip flexion/extension, hip external/internal rotation, and hip abduction/adduction for tested positions were derived from literature or estimated with a biomechanical model. The hip was placed in the described positions, and if impingement was detected by the software, inspection of the impingement type was performed.Aims
Methods
Precise implant positioning, tailored to individual spinopelvic biomechanics and phenotype, is paramount for stability in total hip arthroplasty (THA). Despite a few studies on instability prediction, there is a notable gap in research utilizing artificial intelligence (AI). The objective of our pilot study was to evaluate the feasibility of developing an AI algorithm tailored to individual spinopelvic mechanics and patient phenotype for predicting impingement. This international, multicentre prospective cohort study across two centres encompassed 157 adults undergoing primary robotic arm-assisted THA. Impingement during specific flexion and extension stances was identified using the virtual range of motion (ROM) tool of the robotic software. The primary AI model, the Light Gradient-Boosting Machine (LGBM), used tabular data to predict impingement presence, direction (flexion or extension), and type. A secondary model integrating tabular data with plain anteroposterior pelvis radiographs was evaluated to assess for any potential enhancement in prediction accuracy.Aims
Methods
Osteolysis remains a common reason for revision
after total hip arthroplasty (THA). For osteolysis associated with loose
cups, revision is indicated. For osteolysis around a well-fixed
cup, the decision is more controversial. The data available data
support retention of the cupwith lesional treatment, working through
screw holes and access channels for debridement and grafting. The
choice of graft material to fill defects, if any, remains controversial. Several
studies demonstrate good survivorship with
The August 2023 Hip & Pelvis Roundup360 looks at: Using machine learning to predict venous thromboembolism and major bleeding events following total joint arthroplasty; Antibiotic length in revision total hip arthroplasty; Preoperative colonization and worse outcomes; Short stem cemented total hip arthroplasty; What are the outcomes of one- versus two-stage revisions in the UK?; To cement or not to cement? The best approach in hemiarthroplasty; Similar re-revisions in cemented and cementless femoral revisions for periprosthetic femoral fractures in total hip arthroplasty; Are hip precautions still needed?
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. 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/m2, or THA performed for pain relief in those with severely restricted mobility.Aims
Methods
Spinopelvic characteristics influence the hip’s biomechanical behaviour. However, to date there is little knowledge defining what ‘normal’ spinopelvic characteristics are. This study aims to determine how static spinopelvic characteristics change with age and ethnicity among asymptomatic, healthy individuals. This systematic review followed the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines to identify English studies, including ≥ 18-year-old participants, without evidence of hip or spine pathology or a history of previous surgery or interventional treatment, documenting lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI). From a total of 2,543 articles retrieved after the initial database search, 61 articles were eventually selected for data extraction.Aims
Methods
The October 2023 Sports Roundup360 looks at: Extensor mechanism disruption in the treatment of dislocated and multiligament knee injuries; Treatment of knee osteoarthritis with injection of stem cells; Corticosteroid injection plus exercise or exercise alone as adjuvants for patients with plantar fasciitis?; Generalized joint hypermobility and a second ACL injury?; The VISA-A ((sedentary) questionnaire for Achilles tendinopathy?.
Navigation devices are designed to improve a surgeon’s accuracy in positioning the acetabular and femoral components in total hip arthroplasty (THA). The purpose of this study was to both evaluate the accuracy of an optical computer-assisted surgery (CAS) navigation system and determine whether preoperative spinopelvic mobility (categorized as hypermobile, normal, or stiff) increased the risk of acetabular component placement error. A total of 356 patients undergoing primary THA were prospectively enrolled from November 2016 to March 2018. Clinically relevant error using the CAS system was defined as a difference of > 5° between CAS and 3D radiological reconstruction measurements for acetabular component inclination and anteversion. Univariate and multiple logistic regression analyses were conducted to determine whether hypermobile (Aims
Methods
The June 2023 Hip & Pelvis Roundup360 looks at: Machine learning to identify surgical candidates for hip and knee arthroplasty: a viable option?; Poor outcome after debridement and implant retention; Can you cement polyethylene liners into well-fixed acetabular shells in hip revision?; Revision stem in primary arthroplasties: the Exeter 44/0 125 mm stem; Depression and anxiety: could they be linked to infection?; Does where you live affect your outcomes after hip and knee arthroplasties?; Racial disparities in outcomes after total hip arthroplasty and total knee arthroplasty are substantially mediated by socioeconomic disadvantage both in black and white patients.
The October 2023 Hip & Pelvis Roundup360 looks at: Femoroacetabular impingement syndrome at ten years – how do athletes do?; Venous thromboembolism in patients following total joint replacement: are transfusions to blame?; What changes in pelvic sagittal tilt occur 20 years after total hip arthroplasty?; Can stratified care in hip arthroscopy predict successful and unsuccessful outcomes?; Hip replacement into your nineties; Can large language models help with follow-up?; The most taxing of revisions – proximal femoral replacement for periprosthetic joint infection – what’s the benefit of dual mobility?
The December 2022 Hip & Pelvis Roundup360 looks at: Fix and replace: simultaneous fracture fixation and hip arthroplasty for acetabular fractures in older patients; Is the revision rate for femoral neck fracture lower for total hip arthroplasty than for hemiarthroplasty?; Femoral periprosthetic fractures: data from the COMPOSE cohort study; Dual-mobility cups and fracture of the femur; What’s the deal with outcomes for hip and knee arthroplasty outcomes internationally?; Osteochondral lesions of the femoral head: is costal cartilage the answer?
Oxidized zirconium (OxZi) and highly cross-linked polyethylene (HXLPE) were developed to minimize wear and risk of osteolysis in total hip arthroplasty (THA). However, retrieval studies have shown that scratched femoral heads may lead to runaway wear, and few reports of long-term results have been published. The purpose of this investigation is to report minimum ten-year wear rates and clinical outcomes of THA with OxZi femoral heads on HXLPE, and to compare them with a retrospective control group of cobalt chrome (CoCr) or ceramic heads on HXLPE. From 2003 to 2006, 108 THAs were performed on 96 patients using an OxZi head with a HXLPE liner with minimum ten-year follow-up. Harris Hip Scores (HHS) were collected preoperatively and at the most recent follow-up (mean 13.3 years). Linear and volumetric liner wear was measured on radiographs of 85 hips with a minimum ten-year follow-up (mean 14.5 years). This was compared to a retrospective control group of 45 THAs using ceramic or CoCr heads from October 1999 to February 2005, with a minimum of ten years’ follow-up.Aims
Methods
The aims of this study were to determine the success of a reconstruction algorithm used in major acetabular bone loss, and to further define the indications for custom-made implants in major acetabular bone loss. We reviewed a consecutive series of Paprosky type III acetabular defects treated according to a reconstruction algorithm. IIIA defects were planned to use a superior augment and hemispherical acetabular component. IIIB defects were planned to receive either a hemispherical acetabular component plus augments, a cup-cage reconstruction, or a custom-made implant. We used national digital health records and registry reports to identify any reoperation or re-revision procedure and Oxford Hip Score (OHS) for patient-reported outcomes. Implant survival was determined via Kaplan-Meier analysis.Aims
Methods
The aim of this study was to report the long-term follow-up of cemented short Exeter femoral components when used in primary total hip arthroplasty (THA). We included all primary 394 THAs with a cemented short Exeter femoral component (≤ 125 mm) used in our tertiary referral centre between October 1993 and December 2021. A total of 83 patients (21%) were male. The median age of the patients at the time of surgery was 42 years (interquartile range (IQR) 30 to 55). The main indication for THA was a childhood hip disease (202; 51%). The median follow-up was 6.7 years (IQR 3.1 to 11.0). Kaplan-Meier survival analyses were performed to determine the rates of survival with femoral revision for any indication, for septic loosening, for fracture of the femoral component and for aseptic loosening as endpoints. The indications for revision were evaluated. Fractures of the femoral component were described in detail.Aims
Methods
Contemporary outcomes of primary total hip arthroplasties (THAs) with highly cross-linked polyethylene (HXLPE) liners in patients with inflammatory arthritis have not been well studied. This study examined the implant survivorship, complications, radiological results, and clinical outcomes of THA in patients with inflammatory arthritis. We identified 418 hips (350 patients) with a primary diagnosis of inflammatory arthritis who underwent primary THA with HXLPE liners from January 2000 to December 2017. Of these hips, 68% had rheumatoid arthritis (n = 286), 13% ankylosing spondylitis (n = 53), 7% juvenile rheumatoid arthritis (n = 29), 6% psoriatic arthritis (n = 24), 5% systemic lupus erythematosus (n = 23), and 1% scleroderma (n = 3). Mean age was 58 years (SD 14.8), 66.3% were female (n = 277), and mean BMI was 29 kg/m2 (SD 7). Uncemented femoral components were used in 77% of cases (n = 320). Uncemented acetabular components were used in all patients. Competing risk analysis was used accounting for death. Mean follow-up was 4.5 years (2 to 18).Aims
Methods
Mechanical impingement of the iliopsoas (IP) tendon accounts for 2% to 6% of persistent postoperative pain after total hip arthroplasty (THA). The most common initiator is anterior acetabular component protrusion, where the anterior margin is not covered by anterior acetabular wall. A CT scan can be used to identify and measure this overhang; however, no threshold exists for determining symptomatic anterior IP impingement due to overhang. A case-control study was conducted in which CT scan measurements were used to define a threshold that differentiates patients with IP impingement from asymptomatic patients after THA. We analyzed the CT scans of 622 patients (758 THAs) between May 2011 and May 2020. From this population, we identified 136 patients with symptoms suggestive of IP impingement. Among them, six were subsequently excluded: three because the diagnosis was refuted intraoperatively, and three because they had another obvious cause of impingement, leaving 130 hips (130 patients) in the study (impingement) group. They were matched to a control group of 138 asymptomatic hips (138 patients) after THA. The anterior acetabular component overhang was measured on an axial CT slice based on anatomical landmarks (orthogonal to the pelvic axis).Aims
Methods
The primary aim of this trial was to compare the subsidence of two similar hydroxyapatite-coated titanium femoral components from different manufacturers. Secondary aims were to compare rotational migration (anteversion/retroversion and varus/valgus tilt) and patient-reported outcome measures between both femoral components. Patients were randomized to receive one of the two femoral components (Avenir or Corail) during their primary total hip arthroplasty between August 2018 and September 2020. Radiostereometric analysis examinations at six, 12, and 24 months were used to assess the migration of each implanted femoral component compared to a baseline assessment. Patient-reported outcome measures were also recorded for these same timepoints. Overall, 50 patients were enrolled (62% male (n = 31), with a mean age of 65.7 years (SD 7.3), and mean BMI of 30.2 kg/m2 (SD 5.2)).Aims
Methods