Endoprosthetic reconstruction following distal femur tumour resection has been widely advocated. In this paper, we present the design of an uncemented endoprosthesis system featuring a short, curved stem, with the goal of enhancing long-term survivorship and functional outcomes. This study involved patients who underwent implantation of an uncemented distal femoral endoprosthesis with a short and curved stem between 2014 and 2019. Functional outcomes were assessed using the 1993 version of the Musculoskeletal Tumour Society (MSTS-93) score. Additionally, we quantified five types of complications and assessed osseointegration radiologically. The survivorship of the endoprosthesis was evaluated according to two endpoints. A total of 134 patients with a median age of 26 years (IQR 16 to 41) were included in our study. The median follow-up time was 61 months (IQR 56 to 76), and the median functional MSTS-93 was 83% (IQR 73 to 91) postoperatively.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
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
The August 2024 Hip & Pelvis Roundup. 360. looks at: Understanding perceived leg length discrepancy post-total hip arthroplasty: the role of pelvic obliquity; Influence of
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 Birmingham Hip Resurfacing (BHR) was introduced in 1997 to address the needs of young active patients using a historically proven large-diameter metal-on-metal (MoM) bearing. A single designer surgeon’s consecutive series of 130 patients (144 hips) was previously reported at five and ten years, reporting three and ten failures, respectively. The aim of this study was to extend the follow-up of this original cohort at 25 years. The study extends the reporting on the first consecutive 144 resurfacing procedures in 130 patients for all indications. All operations were undertaken between August 1997 and May 1998. The mean age at operation was 52.1 years (SD 9.93; 17 to 76), and included 37 female patients (28.5%). Failure was defined as revision of either component for any reason. Kaplan-Meier survival analysis was performed. Routine follow-up with serum metal ion levels, radiographs, and Oxford Hip Scores (OHSs) was undertaken.Aims
Methods
Accurate diagnosis of chronic periprosthetic joint infection (PJI) presents a significant challenge for hip surgeons. Preoperative diagnosis is not always easy to establish, making the intraoperative decision-making process crucial in deciding between one- and two-stage revision total hip arthroplasty (THA). Calprotectin is a promising point-of-care novel biomarker that has displayed high accuracy in detecting PJI. We aimed to evaluate the utility of intraoperative calprotectin lateral flow immunoassay (LFI) in THA patients with suspected chronic PJI. The study included 48 THAs in 48 patients with a clinical suspicion of PJI, but who did not meet European Bone and Joint Infection Society (EBJIS) PJI criteria preoperatively, out of 105 patients undergoing revision THA at our institution for possible PJI between November 2020 and December 2022. Intraoperatively, synovial fluid calprotectin was measured with LFI. Cases with calprotectin levels ≥ 50 mg/l were considered infected and treated with two-stage revision THA; in negative cases, one-stage revision was performed. At least five tissue cultures were obtained; the implants removed were sent for sonication.Aims
Methods
Dual-mobility acetabular components (DMCs) have improved total hip arthroplasty (THA) stability in femoral neck fractures (FNFs). In osteoarthritis, the direct anterior approach (DAA) has been promoted for improving early functional results compared with the posterolateral approach (PLA). The aim of this study was to compare these two approaches in FNF using DMC-THA. A prospective continuous cohort study was conducted on patients undergoing operation for FNF using DMC by DAA or PLA. Functional outcome was evaluated using the Harris Hip Score (HHS) and Parker score at three months and one year. Perioperative complications were recorded, and radiological component positioning evaluated.Aims
Methods
Large bone defects resulting from osteolysis, fractures, osteomyelitis, or metastases pose significant challenges in acetabular reconstruction for total hip arthroplasty. This study aimed to evaluate the survival and radiological outcomes of an acetabular reconstruction technique in patients at high risk of reconstruction failure (i.e. periprosthetic joint infection (PJI), poor bone stock, immunosuppressed patients), referred to as Hip Reconstruction In Situ with Screws and Cement (HiRISC). This involves a polyethylene liner embedded in cement-filled bone defects reinforced with screws and/or plates for enhanced fixation. A retrospective chart review of 59 consecutive acetabular reconstructions was performed by four surgeons in a single institution from 18 October 2018 to 5 January 2023. Cases were classified based on the Paprosky classification, excluding type 1 cases (n = 26) and including types 2 or 3 for analysis (n = 33). Radiological loosening was evaluated by an orthopaedic surgeon who was not the operating surgeon, by comparing the immediate postoperative radiographs with the ones at latest follow-up. Mean follow-up was 557 days (SD 441; 31 to 1,707).Aims
Methods
Periprosthetic proximal femoral fractures (PFFs) are a major complication after total hip arthroplasty (THA). Health status after PFF is not specifically investigated. The aim of this study is to evaluate the health status pattern over two years after sustaining a PFF. A cohort of patients with PFF after THA was derived from the Brabant Injury Outcomes Surveillance (BIOS) study. The BIOS study, a prospective, observational, multicentre follow-up cohort study, was conducted to obtain data by questionnaires pre-injury and at one week, and one, three, six, 12, and 24 months after trauma. Primary outcome measures were the EuroQol five-dimension three-level questionnaire (EQ-5D-3L), the Health Utility Index 2 (HUI2), and the Health Utility Index 3 (HUI3). Secondary outcome measures were general measurements such as duration of hospital stay and mortality.Aims
Methods
Obtaining solid implant fixation is crucial in revision total knee arthroplasty (rTKA) to avoid aseptic loosening, a major reason for re-revision. This study aims to validate a novel grading system that quantifies implant fixation across three anatomical zones (epiphysis, metaphysis, diaphysis). Based on pre-, intra-, and postoperative assessments, the novel grading system allocates a quantitative score (0, 0.5, or 1 point) for the quality of fixation achieved in each anatomical zone. The criteria used by the algorithm to assign the score include the bone quality, the size of the bone defect, and the type of fixation used. A consecutive cohort of 245 patients undergoing rTKA from 2012 to 2018 were evaluated using the current novel scoring system and followed prospectively. In addition, 100 first-time revision cases were assessed radiologically from the original cohort and graded by three observers to evaluate the intra- and inter-rater reliability of the novel radiological grading system.Aims
Methods
Dual-mobility (DM) components are increasingly used to prevent and treat dislocation after total hip arthroplasty (THA). Intraprosthetic dissociation (IPD) is a rare complication of DM that is believed to have decreased with contemporary implants. This study aimed to report incidence, treatment, and outcomes of contemporary DM IPD. A total of 1,453 DM components were implanted at a single academic institution between January 2010 and December 2021: 695 in primary and 758 in revision THA. Of these, 49 presented with a dislocation of the large DM head and five presented with an IPD. At the time of closed reduction of the large DM dislocation, six additional IPDs occurred. The mean age was 64 years (SD 9.6), 54.5% were female (n = 6), and mean follow-up was 4.2 years (SD 1.8). Of the 11 IPDs, seven had a history of instability, five had abductor insufficiency, four had prior lumbar fusion, and two were conversions for failed fracture management.Aims
Methods
There are limited long-term studies reporting on outcomes of the Zimmer Modular Revision (ZMR) stem, and concerns remain regarding failure. Our primary aim was to determine long-term survival free from all-cause revision and stem-related failure for this modular revision stem in revision total hip arthroplasty (THA). Secondary aims included evaluating radiological and functional outcomes. We retrospectively identified all patients in our institutional database who underwent revision THA using the ZMR system from January 2000 to December 2007. We included 106 patients (108 hips) with a mean follow-up of 14.5 years (2.3 to 22.3). Mean patient age was 69.2 years (37.0 to 89.4), and 51.9% were female (n = 55). Indications for index revision included aseptic loosening (73.1%), infection (16.7%), fracture (9.3%), and stem fracture (0.9%). Kaplan-Meier analysis was used to determine the all-cause and stem-related failure revision-free survival. At most recent follow-up, Oxford Hip Scores (OHS) were collected, and radiological stem stability was determined using the Engh classification.Aims
Methods
Aims. Refobacin Bone Cement R and Palacos R + G bone cement were introduced to replace the original cement Refobacin Palacos R in 2005. Both cements were assumed to behave in a biomechanically similar fashion to the original cement. The primary aim of this study was to compare the migration of a polished triple-tapered
Aims. This study reports the results of 38 total hip arthroplasties (THAs) in 33 patients aged less than 50 years, using the JRI Furlong hydroxyapatite ceramic (HAC)-coated femoral component. Methods. We describe the survival, radiological, and functional outcomes of 33 patients (38 THAs) at a mean follow-up of 27 years (25 to 32) between 1988 and 2018. Results. Of the surviving 30 patients (34 THAs), there were four periprosthetic fractures: one underwent femoral revision after 21 years, two had surgical fixation as the stem was deemed stable, and one was treated nonoperatively due to the patient’s comorbidities. The periprosthetic fracture patients showed radiological evidence of change in bone stock around the
Achieving accurate implant positioning and restoring native hip biomechanics are key surgeon-controlled technical objectives in total hip arthroplasty (THA). The primary objective of this study was to compare the reproducibility of the planned preoperative centre of hip rotation (COR) in patients undergoing robotic arm-assisted THA versus conventional THA. This prospective randomized controlled trial (RCT) included 60 patients with symptomatic hip osteoarthritis undergoing conventional THA (CO THA) versus robotic arm-assisted THA (RO THA). Patients in both arms underwent pre- and postoperative CT scans, and a patient-specific plan was created using the robotic software. The COR, combined offset, acetabular orientation, and leg length discrepancy were measured on the pre- and postoperative CT scanogram at six weeks following surgery.Aims
Methods
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. 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.Aims
Methods
Aims. The aim of this study was to evaluate the survival of a collarless, straight, hydroxyapatite-coated femoral stem in total hip arthroplasty (THA) at a minimum follow-up of 20 years. Methods. We reviewed the results of 165 THAs using the Omnifit HA system in 138 patients, performed between August 1993 and December 1999. The mean age of the patients at the time of surgery was 46 years (20 to 77). Avascular necrosis was the most common indication for THA, followed by ankylosing spondylitis and primary osteoarthritis. The mean follow-up was 22 years (20 to 31). At 20 and 25 years, 113 THAs in 91 patients and 63 THAs in 55 patients were available for review, respectively, while others died or were lost to follow-up. Kaplan-Meier analysis was performed to evaluate the survival of the stem. Radiographs were reviewed regularly, and the stability of the stem was evaluated using the Engh classification. Results. A total of seven stems (4.2%) were revised during the study period: one for aseptic loosening, three for periprosthetic fracture, two for infection, and one for recurrent dislocation. At 20 years, survival with revision of the stem for any indication and for aseptic loosening as the endpoint was 96.0% (95% confidence interval (CI) 92.6 to 99.5) and 98.4% (95% CI 96.2 to 100), respectively. At 25 years, the corresponding rates of survival were 94.5% (95% CI 89.9 to 99.3) and 98.1% (95% CI 95.7 to 99.6), respectively. There was radiological evidence of stable bony fixation in 86 stems (76.1%) and evidence of loosening in four (3.5%) at 20 years. All patients with radiological evidence of loosening were asymptomatic. Conclusion. The Omnifit HA
Professional dancers represent a unique patient population in the setting of hip arthroplasty, given the high degree of hip strength and mobility required by their profession. We sought to determine the clinical outcomes and ability to return to professional dance after total hip arthroplasty (THA) or hip resurfacing arthroplasty (HRA). Active professional dancers who underwent primary THA or HRA at a single institution with minimum one-year follow-up were included in the study. Primary outcomes included the rate of return to professional dance, three patient-reported outcome measures (PROMs) (modified Harris Hip Score (mHHS), Hip disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS-JR), and Lower Extremity Activity Scale (LEAS)), and postoperative complications.Aims
Methods
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
Modular dual-mobility (DM) articulations are increasingly used during total hip arthroplasty (THA). However, concerns remain regarding the metal liner modularity. This study aims to correlate metal artifact reduction sequence (MARS)-MRI abnormalities with serum metal ion levels in patients with DM articulations. A total of 45 patients (50 hips) with a modular DM articulation were included with mean follow-up of 3.7 years (SD 1.2). Enrolled patients with an asymptomatic, primary THA and DM articulation with over two years’ follow-up underwent MARS-MRI. Each patient had serum cobalt, chromium, and titanium levels drawn. Patient satisfaction, Oxford Hip Score, and Forgotten Joint Score-12 (FJS-12) were collected. Each MARS-MRI was independently reviewed by fellowship-trained musculoskeletal radiologists blinded to serum ion levels.Aims
Methods
Aims. The objective of this study was to compare the two-year migration and clinical outcomes of a new cementless hydroxyapatite (HA)-coated titanium acetabular shell with its previous version, which shared the same geometrical design but a different manufacturing process for applying the titanium surface. Methods. Overall, 87 patients undergoing total hip arthroplasty (THA) were randomized to either a Trident II HA or Trident HA shell, each cementless with clusterholes and HA-coating. All components were used in combination with a cemented Exeter V40
The February 2024 Hip & Pelvis Roundup360 looks at: Trial of vancomycin and cefazolin as surgical prophylaxis in arthroplasty; Is preoperative posterior femoral neck tilt a risk factor for fixation failure? Cemented versus uncemented hemiarthroplasty for displaced intracapsular fractures of the hip; Periprosthetic fractures in larger hydroxyapatite-coated stems: are collared stems a better alternative for total hip arthroplasty?; Postoperative periprosthetic fracture following hip arthroplasty with a polished taper slip versus composite beam stem; Is oral tranexamic acid as good as intravenous?; Stem design and the risk of early periprosthetic femur fractures following THA in elderly patients; Does powered femoral broaching compromise patient safety in total hip arthroplasty?
Polished taper-slip (PTS) cemented stems have an excellent clinical track record and are the most common stem type used in primary total hip arthroplasty (THA) in the UK. Due to low rates of aseptic loosening, they have largely replaced more traditional composite beam (CB) cemented stems. However, there is now emerging evidence from multiple joint registries that PTS stems are associated with higher rates of postoperative periprosthetic femoral fracture (PFF) compared to their CB stem counterparts. The risk of both intraoperative and postoperative PFF remains greater with uncemented stems compared to either of these cemented stem subtypes. PFF continues to be a devastating complication following primary THA and is associated with high complication and mortality rates. Recent efforts have focused on identifying implant-related risk factors for PFF in order to guide preventative strategies, and therefore the purpose of this article is to present the current evidence on the effect of cemented
The December 2023 Hip & Pelvis Roundup. 360. looks at: Early hip fracture surgery is safe for patients on direct oral anticoagulants; Time to return to work by occupational class after total hip or knee arthroplasty; Is there a consensus on air travel following hip and knee arthroplasty?; Predicting whether patients will achieve minimal clinically important differences following hip or knee arthroplasty; High-dose dual-antibiotic-loaded cement for hip hemiarthroplasty in the UK (WHiTE 8): a randomized controlled trial; Vitamin E – a positive thing in your poly?; Hydroxapatite-coated
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
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
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
This study aimed to investigate the risk of postoperative complications in COVID-19-positive patients undergoing common orthopaedic procedures. Using the National Surgical Quality Improvement Programme (NSQIP) database, patients who underwent common orthopaedic surgery procedures from 1 January to 31 December 2021 were extracted. Patient preoperative COVID-19 status, demographics, comorbidities, type of surgery, and postoperative complications were analyzed. Propensity score matching was conducted between COVID-19-positive and -negative patients. Multivariable regression was then performed to identify both patient and provider risk factors independently associated with the occurrence of 30-day postoperative adverse events.Aims
Methods
Aseptic loosening is the most common cause of failure following cemented total knee arthroplasty (TKA), and has been linked to poor cementation technique. We aimed to develop a consensus on the optimal technique for component cementation in TKA. A UK-based, three-round, online modified Delphi Expert Consensus Study was completed focusing on cementation technique in TKA. Experts were identified as having a minimum of five years’ consultant experience in the NHS and fulfilling any one of the following criteria: a ‘high volume’ knee arthroplasty practice (> 150 TKAs per annum) as identified from the National joint Registry of England, Wales, Northern Ireland and the Isle of Man; a senior author of at least five peer reviewed articles related to TKA in the previous five years; a surgeon who is named trainer for a post-certificate of comletion of training fellowship in TKA.Aims
Methods
Periprosthetic fractures (PPFs) following hip arthroplasty are complex injuries. This study evaluates patient demographic characteristics, management, outcomes, and risk factors associated with PPF subtypes over a decade. Using a multicentre collaborative study design, independent of registry data, we identified adults from 29 centres with PPFs around the hip between January 2010 and December 2019. Radiographs were assessed for the Unified Classification System (UCS) grade. Patient and injury characteristics, management, and outcomes were compared between UCS grades. A multinomial logistic regression was performed to estimate relative risk ratios (RRR) of variables on UCS grade.Aims
Methods
To evaluate if, for orthopaedic trainees, additional cadaveric simulation training or standard training alone yields superior radiological and clinical outcomes in patients undergoing dynamic hip screw (DHS) fixation or hemiarthroplasty for hip fracture. This was a preliminary, pragmatic, multicentre, parallel group randomized controlled trial in nine secondary and tertiary NHS hospitals in England. Researchers were blinded to group allocation. Overall, 40 trainees in the West Midlands were eligible: 33 agreed to take part and were randomized, five withdrew after randomization, 13 were allocated cadaveric training, and 15 were allocated standard training. The intervention was an additional two-day cadaveric simulation course. The control group received standard on-the-job training. Primary outcome was implant position on the postoperative radiograph: tip-apex distance (mm) (DHS) and leg length discrepancy (mm) (hemiarthroplasty). Secondary clinical outcomes were procedure time, length of hospital stay, acute postoperative complication rate, and 12-month mortality. Procedure-specific secondary outcomes were intraoperative radiation dose (for DHS) and postoperative blood transfusion requirement (hemiarthroplasty).Aims
Methods
United Classification System (UCS) B2 and B3 periprosthetic fractures in total hip arthroplasties (THAs) have been commonly managed with modular tapered stems. No study has evaluated the use of monoblock fluted tapered titanium stems for this indication. This study aimed to evaluate the effects of a monoblock stems on implant survivorship, postoperative outcomes, radiological outcomes, and osseointegration following treatment of THA UCS B2 and B3 periprosthetic fractures. A retrospective review was conducted of all patients who underwent revision THA (rTHA) for periprosthetic UCS B2 and B3 periprosthetic fracture who received a single design monoblock fluted tapered titanium stem at two large, tertiary care, academic hospitals. A total of 72 patients met inclusion and exclusion criteria (68 UCS B2, and four UCS B3 fractures). Primary outcomes of interest were radiological stem subsidence (> 5 mm), radiological osseointegration, and fracture union. Sub-analysis was also done for 46 patients with minimum one-year follow-up.Aims
Methods
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?
Several different designs of hemiarthroplasty are used to treat intracapsular fractures of the proximal femur, with large variations in costs. No clinical benefit of modular over monoblock designs has been reported in the literature. Long-term data are lacking. The aim of this study was to report the ten-year implant survival of commonly used designs of hemiarthroplasty. Patients recorded by the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) between 1 September 1999 and 31 December 2020 who underwent hemiarthroplasty for the treatment of a hip fracture with the following implants were included: a cemented monoblock Exeter Trauma Stem (ETS), cemented Exeter V40 with a bipolar head, a monoblock Thompsons prosthesis (Cobalt/Chromium or Titanium), and an Exeter V40 with a Unitrax head. Overall and age-defined cumulative revision rates were compared over the ten years following surgery.Aims
Methods
Periprosthetic femoral fractures are increasing in incidence, and typically occur in frail elderly patients. They are similar to pathological fractures in many ways. The aims of treatment are the same, including 'getting it right first time' with a single operation, which allows immediate unrestricted weightbearing, with a low risk of complications, and one that avoids the creation of stress risers locally that may predispose to further peri-implant fracture. The surgical approach to these fractures, the associated soft-tissue handling, and exposure of the fracture are key elements in minimizing the high rate of complications. This annotation describes the approaches to the femur that can be used to facilitate the surgical management of peri- and interprosthetic fractures of the femur at all levels using either modern methods of fixation or revision arthroplasty. Cite this article:
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.
Instability is a common cause of failure after total hip arthroplasty. A novel reverse total hip has been developed, with a femoral cup and acetabular ball, creating enhanced mechanical stability. The purpose of this study was to assess the implant fixation using radiostereometric analysis (RSA), and the clinical safety and efficacy of this novel design. Patients with end-stage osteoarthritis were enrolled in a prospective cohort at a single centre. The cohort consisted of 11 females and 11 males with mean age of 70.6 years (SD 3.5) and BMI of 31.0 kg/m2 (SD 5.7). Implant fixation was evaluated using RSA as well as Western Ontario and McMaster Universities Osteoarthritis Index, Harris Hip Score, Oxford Hip Score, Hip disability and Osteoarthritis Outcome Score, 38-item Short Form survey, and EuroQol five-dimension health questionnaire scores at two-year follow-up. At least one acetabular screw was used in all cases. RSA markers were inserted into the innominate bone and proximal femur with imaging at six weeks (baseline) and six, 12, and 24 months. Independent-samples Aims
Methods
Using data from the Hip Fracture Evaluation with Alternatives of Total Hip Arthroplasty versus Hemiarthroplasty (HEALTH) trial, we sought to determine if a difference in functional outcomes exists between monopolar and bipolar hemiarthroplasty (HA). This study is a secondary analysis of patients aged 50 years or older with a displaced femoral neck fracture who were enrolled in the HEALTH trial and underwent monopolar and bipolar HA. Scores from the Western Ontario and McMaster University Arthritis Index (WOMAC) and 12-Item Short Form Health Survey (SF-12) Physical Component Summary (PCS) and (MCS) were compared between the two HA groups using a propensity score-weighted analysis.Aims
Methods
The Unified Classification System (UCS), or Vancouver system, is a validated and widely used classification system to guide the management of periprosthetic femoral fractures. It suggests that well-fixed stems (type B1) can be treated with fixation but that loose stems (types B2 and B3) should be revised. Determining whether a stem is loose can be difficult and some authors have questioned how to apply this classification system to polished taper slip stems which are, by definition, loose within their cement mantle. Recent evidence has challenged the common perception that revision surgery is preferable to fixation surgery for UCS-B periprosthetic fractures around cemented polished taper slip stems. Indications for fixation include an anatomically reducible fracture and cement mantle, a well-fixed femoral bone-cement interface, and a well-functioning acetabular component. However, not all type B fractures can or should be managed with fixation due to the risk of early failure. This annotation details specific fracture patterns that should not be managed with fixation alone. Cite this article:
Aims. The Exeter V40
Cementing in arthroplasty for hip fracture is associated with improved postoperative function, but may have an increased risk of early mortality compared to uncemented fixation. Quantifying this mortality risk is important in providing safe patient care. This study investigated the association between cement use in arthroplasty and mortality at 30 days and one year in patients aged 50 years and over with hip fracture. This retrospective cohort study used linked data from the Australian Hip Fracture Registry and the National Death Index. Descriptive analysis and Kaplan-Meier survival curves tested the unadjusted association of mortality between cemented and uncemented procedures. Multilevel logistic regression, adjusted for covariates, tested the association between cement use and 30-day mortality following arthroplasty. Given the known institutional variation in preference for cemented fixation, an instrumental variable analysis was also performed to minimize the effect of unknown confounders. Adjusted Cox modelling analyzed the association between cement use and mortality at 30 days and one year following surgery.Aims
Methods
The February 2023 Hip & Pelvis Roundup360 looks at: Total hip arthroplasty or internal fixation for hip fracture?; Significant deterioration in quality of life and increased frailty in patients waiting more than six months for total hip or knee arthroplasty: a cross-sectional multicentre study; Long-term cognitive trajectory after total joint arthroplasty; Costal cartilage grafting for a large osteochondral lesion of the femoral head; Foley catheters not a problem in the short term; Revision hips still a mortality burden?; How to position implants with a robotic arm; Uncemented stems in hip fracture?
The aim of this study was to compare open reduction and internal fixation (ORIF) with revision surgery for the surgical management of Unified Classification System (UCS) type B periprosthetic femoral fractures around cemented polished taper-slip femoral components following primary total hip arthroplasty (THA). Data were collected for patients admitted to five UK centres. The primary outcome measure was the two-year reoperation rate. Secondary outcomes were time to surgery, transfusion requirements, critical care requirements, length of stay, two-year local complication rates, six-month systemic complication rates, and mortality rates. Comparisons were made by the form of treatment (ORIF vs revision) and UCS type (B1 vs B2/B3). Kaplan-Meier survival analysis was performed with two-year reoperation for any reason as the endpoint.Aims
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Arthroplasty surgery of the knee and hip is performed in two to three million patients annually. Periprosthetic joint infections occur in 4% of these patients. Debridement, antibiotics, and implant retention (DAIR) surgery aimed at cleaning the infected prosthesis often fails, subsequently requiring invasive revision of the complete prosthetic reconstruction. Infection-specific imaging may help to guide DAIR. In this study, we evaluated a bacteria-specific hybrid tracer (99mTc-UBI29-41-Cy5) and its ability to visualize the bacterial load on femoral implants using clinical-grade image guidance methods.
99mTc-UBI29-41-Cy5 specificity for Aims
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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. 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).Aims
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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
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The aims of this study were to determine the incidence and factors for developing periprosthetic joint infection (PJI) following hemiarthroplasty (HA) for hip fracture, and to evaluate treatment outcome and identify factors associated with treatment outcome. A retrospective review was performed of consecutive patients treated for HA PJI at a tertiary referral centre with a mean 4.5 years’ follow-up (1.6 weeks to 12.9 years). Surgeries performed included debridement, antibiotics, and implant retention (DAIR) and single-stage revision. The effect of different factors on developing infection and treatment outcome was determined.Aims
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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?
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
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Our objective was describing an algorithm to identify and prevent vascular injury in patients with intrapelvic components. Patients were defined as at risk to vascular injuries when components or cement migrated 5 mm or more beyond the ilioischial line in any of the pelvic incidences (anteroposterior and Judet view). In those patients, a serial investigation was initiated by a CT angiography, followed by a vascular surgeon evaluation. The investigation proceeded if necessary. The main goal was to assure a safe tissue plane between the hardware and the vessels.Aims
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Aims. Although CT is considered the benchmark to measure femoral version, 3D biplanar radiography (hipEOS) has recently emerged as a possible alternative with reduced exposure to ionizing radiation and shorter examination time. The aim of our study was to evaluate
Aims. The aim of this study was to examine the implant accuracy of custom-made partial pelvis replacements (PPRs) in revision total hip arthroplasty (rTHA). Custom-made implants offer an option to achieve a reconstruction in cases with severe acetabular bone loss. By analyzing implant deviation in CT and radiograph imaging and correlating early clinical complications, we aimed to optimize the usage of custom-made implants. Methods. A consecutive series of 45 (2014 to 2019) PPRs for Paprosky III defects at rTHA were analyzed comparing the preoperative planning CT scans used to manufacture the implants with postoperative CT scans and radiographs. The anteversion (AV), inclination (IC), deviation from the preoperatively planned implant position, and deviation of the centre of rotation (COR) were explored. Early postoperative complications were recorded, and factors for malpositioning were sought. The mean follow-up was 30 months (SD 19; 6 to 74), with four patients lost to follow-up. Results. Mean CT defined discrepancy (Δ) between planned and achieved AV and IC was 4.5° (SD 3°; 0° to 12°) and 4° (SD 3.5°; 1° to 12°), respectively. Malpositioning (Δ > 10°) occurred in five hips (10.6%). Native COR reconstruction was planned in 42 cases (93%), and the mean 3D deviation vector was 15.5 mm (SD 8.5; 4 to 35). There was no significant influence in malpositioning found for
We aim to explore the potential technologies for monitoring and assessment of patients undergoing arthroplasty by examining selected literature focusing on the technology currently available and reflecting on possible future development and application. The reviewed literature indicates a large variety of different hardware and software, widely available and used in a limited manner, to assess patients’ performance. There are extensive opportunities to enhance and integrate the systems which are already in existence to develop patient-specific pathways for rehabilitation. Cite this article:
Dislocation of the hip remains a major complication after periacetabular tumour resection and endoprosthetic reconstruction. The position of the acetabular component is an important modifiable factor for surgeons in determining the risk of postoperative dislocation. We investigated the significance of horizontal, vertical, and sagittal displacement of the hip centre of rotation (COR) on postoperative dislocation using a CT-based 3D model, as well as other potential risk factors for dislocation. A total of 122 patients who underwent reconstruction following resection of periacetabular tumour between January 2011 and January 2020 were studied. The risk factors for dislocation were investigated with univariate and multivariate logistic regression analysis on patient-specific, resection-specific, and reconstruction-specific variables.Aims
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Despite multiple trials and case series on hip hemiarthroplasty designs, guidance is still lacking on which implant to use. One particularly deficient area is long-term outcomes. We present over 1,000 consecutive cemented Thompson’s hemiarthroplasties over a ten-year period, recording all accessible patient and implant outcomes. Patient identifiers for a consecutive cohort treated between 1 January 2003 and 31 December 2011 were linked to radiographs, surgical notes, clinic letters, and mortality data from a national dataset. This allowed charting of their postoperative course, complications, readmissions, returns to theatre, revisions, and deaths. We also identified all postoperative attendances at the Emergency and Outpatient Departments, and recorded any subsequent skeletal injuries.Aims
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The aim of this study is to report the long-term outcomes of instrumented femoral revisions with impaction allograft bone grafting (IBG) using the X-change femoral revision system at 30 years after introduction of the technique. We updated the outcomes of our previous study, based on 208 consecutive revisions using IBG and the X-change femoral revision system in combination with a cemented polished stem, performed in our tertiary care institute between 1991 and 2007. Kaplan-Meier survival analyses were used to determine the survival rate of the revisions with endpoint revision for any reason and aseptic loosening. Secondary outcomes were radiological loosening and patient-reported outcome measures.Aims
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The aim of this study was to compare the cost-effectiveness of cemented hemiarthroplasty (HA) versus hydroxyapatite-coated uncemented HA for the treatment of displaced intracapsular hip fractures in older adults. A within-trial economic evaluation was conducted based on data collected from the World Hip Trauma Evaluation 5 (WHiTE 5) multicentre randomized controlled trial in the UK. Resource use was measured over 12 months post-randomization using trial case report forms and participant-completed questionnaires. Cost-effectiveness was reported in terms of incremental cost per quality-adjusted life year (QALY) gained from the NHS and personal social service perspective. Methodological uncertainty was addressed using sensitivity analysis, while decision uncertainty was represented graphically using confidence ellipses and cost-effectiveness acceptability curves.Aims
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The aim of this study was to describe the management and associated outcomes of patients sustaining a femoral hip periprosthetic fracture (PPF) in the UK population. This was a multicentre retrospective cohort study including adult patients who presented to 27 NHS hospitals with 539 new PPFs between 1 January 2018 and 31 December 2018. Data collected included: management strategy (operative and nonoperative), length of stay, discharge destination, and details of post-treatment outcomes (reoperation, readmission, and 30-day and 12-month mortality). Descriptive analysis by fracture type was performed, and predictors of PPF management and outcomes were assessed using mixed-effects logistic regression.Aims
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This study reports the ten-year wear rates, incidence of osteolysis, clinical outcomes, and complications of a multicentre randomized controlled trial comparing oxidized zirconium (OxZr) versus cobalt-chrome (CoCr) femoral heads with ultra-high molecular weight polyethylene (UHMWPE) and highly cross-linked polyethylene (XLPE) liners in total hip arthroplasty (THA). Patients undergoing primary THA were recruited from four institutions and prospectively allocated to the following treatment groups: Group A, CoCr femoral head with XLPE liner; Group B, OxZr femoral head with XLPE liner; and Group C, OxZr femoral head with UHMWPE liner. All study patients and assessors recording outcomes were blinded to the treatment groups. The outcomes of 262 study patients were analyzed at ten years’ follow-up.Aims
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Aims. BoneMaster is a thin electrochemically applied hydroxyapatite (HA) coating for orthopaedic implants that is quickly resorbed during osseointegration. Early stabilization is a surrogacy marker of good survival of
Periprosthetic hip fractures (PPFs) after total hip arthroplasty are difficult to treat. Therefore, it is important to identify modifiable risk factors such as stem selection to reduce the occurrence of PPFs. This study aimed to clarify differences in fracture torque, surface strain, and fracture type analysis between three different types of cemented stems. We conducted biomechanical testing of bone analogues using six cemented stems of three different types: collarless polished tapered (CPT) stem, Versys Advocate (Versys) stem, and Charnley-Marcel-Kerboull (CMK) stem. Experienced surgeons implanted each of these types of stems into six bone analogues, and the analogues were compressed and internally rotated until failure. Torque to fracture and fracture type were recorded. We also measured surface strain distribution using triaxial rosettes.Aims
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The aim of this modified Delphi process was to create a structured Revision Hip Complexity Classification (RHCC) which can be used as a tool to help direct multidisciplinary team (MDT) discussions of complex cases in local or regional revision networks. The RHCC was developed with the help of a steering group and an invitation through the British Hip Society (BHS) to members to apply, forming an expert panel of 35. We ran a mixed-method modified Delphi process (three rounds of questionnaires and one virtual meeting). Round 1 consisted of identifying the factors that govern the decision-making and complexities, with weighting given to factors considered most important by experts. Participants were asked to identify classification systems where relevant. Rounds 2 and 3 focused on grouping each factor into H1, H2, or H3, creating a hierarchy of complexity. This was followed by a virtual meeting in an attempt to achieve consensus on the factors which had not achieved consensus in preceding rounds.Aims
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Adult patients with history of childhood infection pose a surgical challenge for total hip arthroplasty (THA) due to distorted bony anatomy, soft-tissue contractures, risk of reinfection, and relatively younger age. Therefore, the purpose of the present study was to determine clinical outcome, reinfection rate, and complications in patients with septic sequelae after THA. A retrospective analysis was conducted of 91 cementless THAs (57 male and 34 female) performed between 2008 and 2017 in patients who had history of hip infection during childhood. Clinical outcome was measured using Harris Hip Score (HHS) and Modified Merle d’Aubigne and Postel (MAP) score, and quality of life (QOL) using 12-Item Short Form Health Survey Questionnaire (SF-12) components: Physical Component Score (PCS) and Mental Component Score (MCS); limb length discrepancy (LLD) and radiological assessment of the prosthesis was performed at the latest follow-up. Reinfection and revision surgery after THA for any reason was documented.Aims
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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. 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).Aims
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Aims. Hip arthroplasty aims to accurately recreate joint biomechanics. Considerable attention has been paid to vertical and horizontal offset, but femoral head centre in the anteroposterior (AP) plane has received little attention. This study investigates the accuracy of restoration of joint centre of rotation in the AP plane. Methods. Postoperative CT scans of 40 patients who underwent unilateral uncemented total hip arthroplasty were analyzed. Anteroposterior offset (APO) and femoral anteversion were measured on both the operated and non-operated sides. Sagittal tilt of the
A recent report from France suggested an association between the use of cobalt-chrome (CoCr) femoral heads in total hip arthroplasties (THAs) and an increased risk of dilated cardiomyopathy and heart failure. CoCr is a commonly used material in orthopaedic implants. If the reported association is causal, the consequences would be significant given the millions of joint arthroplasties and other orthopaedic procedures in which CoCr is used annually. We examined whether CoCr-containing THAs were associated with an increased risk of all-cause mortality, heart outcomes, cancer, and neurodegenerative disorders in a large national database. Data from the National Joint Registry was linked to NHS English hospital inpatient episodes for 374,359 primary THAs with up to 14.5 years' follow-up. We excluded any patients with bilateral THAs, knee arthroplasties, indications other than osteoarthritis, aged under 55 years, and diagnosis of one or more outcome of interest before THA. Implants were grouped as either containing CoCr or not containing CoCr. The association between implant construct and the risk of all-cause mortality and incident heart failure, cancer, and neurodegenerative disorders was examined.Aims
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Femoral cement-in-cement revision is a well described technique to reduce morbidity and complications in hip revision surgery. Traditional techniques for septic revision of hip arthroplasty necessitate removal of all bone cement from the femur. In our two centres, we have been using a cement-in-cement technique, leaving the distal femoral bone cement in selected patients for septic hip revision surgery, both for single and the first of two-stage revision procedures. A prerequisite for adoption of this technique is that the surgeon considers the cement mantle to be intimately fixed to bone without an intervening membrane between cement and host bone. We aim to report our experience for this technique. We have analyzed patients undergoing this cement-in-cement technique for femoral revision in infection, and present a consecutive series of 89 patients. Follow-up was undertaken at a mean of 56.5 months (24.0 to 134.7) for the surviving cases.Aims
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Although the short stem concept in hip arthroplasty procedure shows acceptable clinical performance, we sometimes get unexplainable radiological findings. The aim of this retrospective study was to evaluate changes of radiological findings up to three years postoperatively, and to assess any potential contributing factors on such radiological change in a Japanese population. This is a retrospective radiological study conducted in Japan. Radiological assessment was done in accordance with predetermined radiological review protocol. A total of 241 hips were included in the study and 118 hips (49.0%) revealed radiological change from immediately after surgery to one year postoperatively; these 118 hips were eligible for further analyses. Each investigator screened whether either radiolucent lines (RLLs), cortical hypertrophy (CH), or atrophy (AT) appeared or not on the one-year radiograph. Further, three-year radiographs of eligible cases were reviewed to determine changes such as, disappeared (D), improved (I), stable (S), and progression (P). Additionally, bone condensation (BC) was assessed on the three-year radiograph.Aims
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Artificial intelligence and machine-learning analytics have gained extensive popularity in recent years due to their clinically relevant applications. A wide range of proof-of-concept studies have demonstrated the ability of these analyses to personalize risk prediction, detect implant specifics from imaging, and monitor and assess patient movement and recovery. Though these applications are exciting and could potentially influence practice, it is imperative to understand when these analyses are indicated and where the data are derived from, prior to investing resources and confidence into the results and conclusions. In this article, we review the current benefits and potential limitations of machine-learning for the orthopaedic surgeon with a specific emphasis on data quality.
There is evidence that morbidly obese patients have more intra- and postoperative complications and poorer outcomes when undergoing total hip arthroplasty (THA) with the direct anterior approach (DAA). The aim of this study was to determine the efficacy of DAA for THA, and compare the complications and outcomes of morbidly obese patients with nonobese patients. Morbidly obese patients (n = 86), with BMI ≥ 40 kg/m2 who underwent DAA THA at our institution between September 2010 and December 2017, were matched to 172 patients with BMI < 30 kg/m2. Data regarding demographics, set-up and operating time, blood loss, radiological assessment, Harris Hip Score (HHS), International Hip Outcome Tool (12-items), reoperation rate, and complications at two years postoperatively were retrospectively analyzed.Aims
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Aims. Highly polished stems with force-closed design have shown satisfactory clinical results despite being related to relatively high early migration. It has been suggested that the minimal thickness of cement mantles surrounding the
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. 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.Aims
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Femoral bone preparation using compaction technique has been shown to preserve bone and improve implant fixation in animal models. No long-term clinical outcomes are available. There are no significant long-term differences between compaction and broaching techniques for primary total hip arthroplasty (THA) in terms of migration, clinical, and radiological outcomes. A total of 28 patients received one-stage bilateral primary THA with cementless femoral stems (56 hips). They were randomized to compaction on one femur and broaching on the contralateral femur. Overall, 13 patients were lost to the ten-year follow-up leaving 30 hips to be evaluated in terms of stem migration (using radiostereometry), radiological changes, Harris Hip Score, Oxford Hip Score, and complications.Aims
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This study investigates head-neck taper corrosion with varying head size in a novel hip simulator instrumented to measure corrosion related electrical activity under torsional loads. In all, six 28 mm and six 36 mm titanium stem-cobalt chrome head pairs with polyethylene sockets were tested in a novel instrumented hip simulator. Samples were tested using simulated gait data with incremental increasing loads to determine corrosion onset load and electrochemical activity. Half of each head size group were then cycled with simulated gait and the other half with gait compression only. Damage was measured by area and maximum linear wear depth.Aims
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One-stage revision hip arthroplasty for periprosthetic joint infection (PJI) has several advantages; however, resection of the proximal femur might be necessary to achieve higher success rates. We investigated the risk factors for resection and re-revisions, and assessed complications and subsequent re-revisions. In this single-centre, case-control study, 57 patients who underwent one-stage revision arthroplasty for PJI of the hip and required resection of the proximal femur between 2009 and 2018 were identified. The control group consisted of 57 patients undergoing one-stage revision without bony resection. Logistic regression analysis was performed to identify any correlation with resection and the risk factors for re-revisions. Rates of all-causes re-revision, reinfection, and instability were compared between groups.Aims
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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). 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 cup alignment and 3D position were compared between DDH and non-DDH patients. Moreover, these differences were analyzed in relation to the severity of DDH. The discrepancy of leg length and combined offset compared with contralateral hip were measured.Aims
Methods
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. 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.Aims
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Aims. We aimed to evaluate the long-term outcome of highly cross-linked polyethylene (HXLPE) cemented acetabular components and assess whether any radiolucent lines (RLLs) which arose were progressive. Methods. We retrospectively reviewed 170 patients who underwent 187 total hip arthroplasties at two hospitals with a minimum follow-up of ten years. All interventions were performed using the same combination of HXLPE cemented acetabular components with
This aim of this study was to assess the reliability and validity of the Unified Classification System (UCS) for postoperative periprosthetic femoral fractures (PFFs) around cemented polished taper-slip (PTS) stems. Radiographs of 71 patients with a PFF admitted consecutively at two centres between 25 February 2012 and 19 May 2020 were collated by an independent investigator. Six observers (three hip consultants and three trainees) were familiarized with the UCS. Each PFF was classified on two separate occasions, with a mean time between assessments of 22.7 days (16 to 29). Interobserver reliability for more than two observers was assessed using percentage agreement and Fleiss’ kappa statistic. Intraobserver reliability between two observers was calculated with Cohen kappa statistic. Validity was tested on surgically managed UCS type B PFFs where stem stability was documented in operation notes (n = 50). Validity was assessed using percentage agreement and Cohen kappa statistic between radiological assessment and intraoperative findings. Kappa statistics were interpreted using Landis and Koch criteria. All six observers were blinded to operation notes and postoperative radiographs.Aims
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This study evaluates risk factors influencing fracture characteristics for postoperative periprosthetic femoral fractures (PFFs) around cemented stems in total hip arthroplasty. Data were collected for PFF patients admitted to eight UK centres between 25 May 2006 and 1 March 2020. Radiographs were assessed for Unified Classification System (UCS) grade and AO/OTA type. Statistical comparisons investigated relationships by age, gender, and stem fixation philosophy (polished taper-slip (PTS) vs composite beam (CB)). The effect of multiple variables was estimated using multinomial logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs). Surgical treatment (revision vs fixation) was compared by UCS grade and AO/OTA type.Aims
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Aims. The aim of this study was to radiologically evaluate the quality of cement mantle and alignment achieved with a polished tapered cemented
Highly cross-linked polyethylene (HXLPE) has greatly improved the durability of total hip arthroplasty (THA) in young patients because of its improved wear characteristics. Few studies have followed this population into the second decade, and therefore the purpose of this investigation was to evaluate the clinical outcome for THA patients 50 years of age and younger at a minimum of 15 years postoperatively. The second purpose was to evaluate the radiological findings secondary to wear or mechanical failure of the implant. Between October 1999 and December 2005, 105 THAs were performed in 95 patients (53 female, 42 male) aged 50 years and younger (mean 42 years (20 to 50)). There were 87 patients (96 hips) that were followed for a minimum of 15 years (mean 17.3 years (15 to 21)) for analysis. Posterior approach was used with cementless fixation with a median head size of 28 mm. HXLPE was the acetabular bearing for all hips. Radiographs were evaluated for polyethylene wear, radiolucent lines, and osteolysis.Aims
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There is a paucity of long-term studies analyzing risk factors for failure after single-stage revision for periprosthetic joint infection (PJI) following total hip arthroplasty (THA). We report the mid- to long-term septic and non-septic failure rate of single-stage revision for PJI after THA. We retrospectively reviewed 88 cases which met the Musculoskeletal Infection Society (MSIS) criteria for PJI. Mean follow-up was seven years (1 to 14). Septic failure was diagnosed with a Delphi-based consensus definition. Any reoperation for mechanical causes in the absence of evidence of infection was considered as non-septic failure. A competing risk regression model was used to evaluate factors associated with septic and non-septic failures. A Kaplan-Meier estimate was used to analyze mortality.Aims
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To achieve the functional benefits of the direct anterior (DA) approach and the fixation benefits of cemented replacement, this study combined the two techniques posing the following questions: does the limited access of the DA approach adversely affect the cement technique?; and does such a cementing technique reduce the incidence of cementless complications? A consecutive series of 341 patients (360 hips) receiving the DA approach between 2016 and 2018 were reviewed. There were 203 cementless stems and 157 cemented stems. Mean age was 75 years (70 to 86) in the cementless group and 76 years (52 to 94) in the cemented group, with 239 (70%) females in the whole series. Femoral complications were compared between the two groups. Mean follow-up was 1.5 years (0.1 to 4.4) for patients in the cementless group and 1.3 years (0.0 to 3.9) for patients in the cemented group.Aims
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Cement-in-cement revision of the femoral component represents a widely practised technique for a variety of indications in revision total hip arthroplasty. In this study, we compare the clinical and radiological outcomes of two polished tapered femoral components. From our prospectively collated database, we identified all patients undergoing cement-in-cement revision from January 2005 to January 2013 who had a minimum of two years' follow-up. All cases were performed by the senior author using either an Exeter short revision stem or the C-Stem AMT high offset No. 1 prosthesis. Patients were followed-up annually with clinical and radiological assessment.Aims
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Use of the direct anterior approach (DAA) for total hip arthroplasty (THA) has increased in recent years due to proposed benefits, including a lower risk of dislocation and improved early functional recovery. This study investigates the dislocation rate in a non-selective, consecutive cohort undergoing THA via the DAA without any exclusion or bias in patient selection based on habitus, deformity, age, sex, or fixation method. We retrospectively reviewed all patients undergoing THA via the DAA between 2011 and 2017 at our institution. Primary outcome was dislocation at minimum two-year follow-up. Patients were stratified by demographic details and risk factors for dislocation, and an in-depth analysis of dislocations was performed.Aims
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Aims. Dual mobility (DM) implants have been shown to reduce the dislocation rate after total hip arthroplasty (THA), but there remain concerns about the use of cobalt chrome liners inserted into titanium shells. The aim of this study was to assess the clinical outcomes, metal ion levels, and periprosthetic femoral bone mineral density (BMD) at mid-term follow-up in young, active patients receiving a modular DM THA. Methods. This was a prospective study involving patients aged < 65 years, with a BMI of < 35 kg/m. 2. , and University of California, Los Angeles activity score of > 6 who underwent primary THA with a modular cobalt chrome acetabular liner, highly cross-linked polyethylene mobile bearing, and a cementless titanium
