Patients Undergoing Revision Total Hip Arthroplasty Research Articles

Do Intraarticular Metal Ion Levels Predict Adverse Local Tissue Reaction in Revision Total Hip Arthroplasty for Mechanically Assisted Crevice Corrosion?

Mechanically assisted crevice corrosion (MACC) is a complication that may occur in vivo at modular metal interfaces following metal-on-polyethylene (MoP) total hip arthroplasty (THA). Metal ions released in vivo may be associated with adverse local tissue reactions (ALTR). While there is no definitive value, high serum ion levels are implicated as contributors to ALTR, and various screening levels have been recommended. The purpose of this investigation was to evaluate the relationship between synovial fluid (SF) cobalt and chromium ion levels and the risk of developing ALTR. This was a retrospective cohort study of 552 patients who underwent 621 MoP primary THAs. A total of 69 patients underwent revision THA due to symptomatic primary failure with elevated serum metal ions levels. There were 28 who had preoperative serum and intraoperative SF chromium and cobalt samples. Patient demographics, surgical, and laboratory data were collected. Descriptive statistics, Mann-Whitney U, Analysis of Variance (ANOVA) tests, and linear regression analyses were performed. There were 40.6% of revisions that had preoperative serum and intraoperative SF samples. The mean time to revision was 5.7 (range, 3.8 to 7.6) years. Mean SF cobalt and chromium levels were 870.9mcg/L (range, 1.1 to 8,300.0) and 573.5mcg/L (range, 1.3 to 10,000.0). Mean serum and SF cobalt-chromium ratios were 4.0 (range, 0.9 to 7.1) and 6.4 (range, 0 to 15.1), respectively. Elevated serum cobalt levels were predictive of ALTR (P = 0.002), SF levels were not. Analysis of preoperative serum to SF cobalt-chromium ratios showed poor correlation (R2 = 0.05). There was no correlation between SF ion levels and ALTR. Also, serum and intraarticular ion levels did not correlate, and SF levels did not provide additional value over serum levels for diagnosis or prognosis of MACC. Further studies are needed to better understand the relationship between serum and SF ion levels and its relationship to ALTR.

Total Hip Arthroplasty for Osteonecrosis of the Femoral Head: A Mid-term Follow-Up in Patients From Northern India.

Osteonecrosis of femoral head (ONFH) is a disabling condition of the hip joint with multifactorial etiology and is associated with genetic predilection and exposure to certain risk factors most commonly being chronic alcohol or steroid intake. Total hip arthroplasty (THA) remains the gold standard for end-stage femoral head osteonecrosis. The outcome after the surgery is mainly affected by age, activity levels and other factors that affect the development of ONFH. Through this study we aimed to evaluate the clinical and radiological outcomes in the patients who have undergone uncemented THA for ONFH. We included 111 uncemented THA on 84 patients with ONFH done by a single surgeon in our institution. The patients were followed up postoperatively and were evaluated based on their functional outcome using Harris hip scores (HHS) and the radiological outcome by serial radiographs on every follow-up. The mean preoperative HHSwas 49.30 which showed significant improvement inthe final follow-up to96.17. The mean acetabular inclination and anteversion at final follow-up radiographs were 47.70 and 18.67 degrees respectively. Fifteen patients had complications which included post-operative surgical site infection (three), hip pain (six) and thigh pain (six). Complications like osteolysis, poly wear and femoral subsidence were recorded in a total of six patients at the final follow-up. Three patients underwent revision THA due to increased femoral subsidence, accelerated poly wear, and aseptic loosening due to osteolysis. Our current observational study, which included 84 patients and 111 hips affected by osteonecrosis of the femoral head, examined the outcomes of total hip arthroplasty using metal on ultra-high molecular weight polyethylene liners. The results showed excellent clinical and radiological outcomes at a mean follow-up period of 4.8 years, particularly in younger patients with a mean age of 37.05 years.

Trabecular Metal Augments for Reconstruction of Acetabular Bone Defects in Revision Total Hip Replacement: Short-Term Outcomes

Abstract Background: Revision hip surgeries are increasing dramatically nowadays, and achieving hip center of rotation is challenging. Obtaining a press-fit implant and restoring the hip’s center of rotation might be difficult during the restoration of acetabular deformities during revision total hip arthroplasty (THA). Aim: The aim of the study was to evaluate the outcomes of using trabecular metal augments for reconstruction of the acetabulum in patients undergoing revision THA with short-term follow-up. Patients and Methods: This study was conducted in Benha University Hospital between April 2019 and March 2023. It is a prospective cohort study including 20 patients who are undergoing revision THA with acetabular defects. Results: The mean age of patients in this study was 59 years old. According to Paprosky classification: 45% of type 2B. The postoperative Oxford Hip Score showed marked improvement in the outcomes, the score was excellent in 55% (11 patients), good in 40% (8 patients), and fair in only 5% (1 patient) over 16 months’ mean follow-up period. Conclusion: Due to its modularity, tantalum augments are considered a valuable method in the reconstruction of acetabular defects.

Porous Metal Augments Have Comparable Outcomes to Other Constructs for Severe Acetabular Bone Loss at Mid-Term Follow-up

BackgroundAcetabular reconstruction options in the setting of severe bone loss remain limited, with few comparative studies published to date. The purpose of this study was to compare the outcomes of revision total hip arthroplasty (THA) for severe bone loss using porous metal augments to cup cage and triflange prostheses. MethodsWe reviewed a consecutive series of 180 patients who had Paprosky 3A or 3B acetabular defects and underwent revision THA. Patients treated with porous augments (n = 141) were compared with those who received cup cages or triflange constructs (n = 39). Failure of the acetabular construct was defined as undergoing acetabular revision surgery or radiographic evidence of loosening. ResultsThere was no difference in acetabular component survivorship in patients undergoing revision THA with porous augments or a cage or triflange prosthesis (92.2 versus 87.2%, P = .470) at a mean follow-up of 6.6 ± 3.4 years. Overall, survivorship free from any revision surgery was comparable between the 2 groups (78.7 versus 79.5%, P = .720). There was also no difference in dislocation (5.7 versus 10.3%, P = .309) or periprosthetic joint infection rates (7.8 versus 10.3%, P = .623). In a subgroup analysis of patients who had pelvic discontinuity (n = 47), survivorship free from any revision surgery was comparable between the 2 groups (79.5 versus 72.2%, P = .543). ConclusionsPorous metal augments in the setting of severe acetabular bone loss demonstrated excellent survivorship at intermediate-term (mean 6.6 years follow-up, even in cases of pelvic discontinuity, with comparable outcomes to cup cages and triflanges. Instability and infection remain major causes of failure in this patient population, and long-term follow-up is needed.

Intraoperative calprotectin lateral flow immunoassay can assist decision-making between one- and two-stage revision total hip arthroplasty for patients with suspected periprosthetic joint infection.

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. Calprotectin was positive (≥ 50 mg/l) in 27 cases; out of these, 25 had positive tissue cultures and/or sonication. Calprotectin was negative in 21 cases. There was one false negative case, which had positive tissue cultures. Calprotectin showed an area under the curve of 0.917, sensitivity of 96.2%, specificity of 90.9%, positive predictive value of 92.6%, negative predictive value of 95.2%, positive likelihood ratio of 10.6, and negative likelihood ratio of 0.04. Overall, 45/48 patients were correctly diagnosed and treated by our algorithm, which included intraoperative calprotectin measurement. This yielded a 93.8% concordance with postoperatively assessed EBJIS criteria. Calprotectin can be a valuable tool in facilitating the intraoperative decision-making process for cases in which chronic PJI is suspected and diagnosis cannot be established preoperatively.

The outcome of revision total hip arthroplasty for instability.

Instability is a common indication for revision total hip arthroplasty (THA). However, even after the initial revision, some patients continue to have recurrent dislocation. The aim of this study was to assess the risk for recurrent dislocation after revision THA for instability. Between 2009 and 2019, 163 patients underwent revision THA for instability at Stanford University Medical Center. Of these, 33 (20.2%) required re-revision due to recurrent dislocation. Cox proportional hazard models, with death and re-revision surgery for periprosthetic infection as competing events, were used to analyze the risk factors, including the size and alignment of the components. Paired t-tests or Wilcoxon signed-rank tests were used to assess the outcome using the Veterans RAND 12 (VR-12) physical and VR-12 mental scores, the Harris Hip Score (HHS) pain and function, and the Hip disability and Osteoarthritis Outcome score for Joint Replacement (HOOS, JR). The median follow-up was 3.1 years (interquartile range 2.0 to 5.1). The one-year cumulative incidence of recurrent dislocation after revision was 8.7%, which increased to 18.8% at five years and 31.9% at ten years postoperatively. In multivariable analysis, a high American Society of Anesthesiologists (ASA) grade (hazard ratio (HR) 2.72 (95% confidence interval (CI) 1.13 to 6.60)), BMI between 25 and 30 kg/m2 (HR 4.31 (95% CI 1.52 to 12.27)), the use of specialized liners (HR 5.39 (95% CI 1.97 to 14.79) to 10.55 (95% CI 2.27 to 49.15)), lumbopelvic stiffness (HR 6.03 (95% CI 1.80 to 20.23)), and postoperative abductor weakness (HR 7.48 (95% CI 2.34 to 23.91)) were significant risk factors for recurrent dislocation. Increasing the size of the acetabular component by > 1 mm significantly decreased the risk of dislocation (HR 0.89 (95% CI 0.82 to 0.96)). The VR-12 physical and HHS (pain and function) scores improved significantly at mid term. Patients requiring revision THA for instability are at risk of recurrent dislocation. Higher ASA grades, being overweight, a previous lumbopelvic fusion, the use of specialized liners, and postoperative abductor weakness are significant risk factors.

Highly Porous Acetabular Cup and Augment Constructs in Complex Revision Total Hip Arthroplasty: What Predicts 10-Year Implant Survivorship?

BackgroundPorous tantalum acetabular cup and augment constructs have demonstrated favorable outcomes up to 5 years postsurgery despite severe bone loss during revision total hip arthroplasty (THA). Prior literature lacks long-term studies with substantial case numbers. This study aims to assess long-term clinical and radiographic outcomes 10 years postsurgery in patients undergoing revision THA with porous tantalum acetabular cup-augment constructs and determine factors associated with long-term survivorship. MethodsBetween 2000 and 2012, 157 revision THAs were performed in cases with major acetabular defects (mainly Paprosky type IIIA and IIIB) utilizing porous tantalum cup-augment constructs. Pelvic discontinuity was noted intraoperatively in 17 hips (11%). Postoperative radiographs were evaluated at regular intervals for implant stability and radiolucent lines. There were 49 patients who had complete radiographic follow-up at 10 years or longer postsurgery. ResultsThe 10-year survivorship free of revision of the cup-augment construct for aseptic loosening was 93%, free of any acetabular construct revision was 91%, free of any hip rerevision was 77%, and free of any reoperation was 75%. Pelvic discontinuity was associated with increased risk of reoperation (hazard ratio [HR] = 2.8), any hip rerevision (HR = 3.2), any cup-augment construct revision (HR = 11.8), and aseptic construct revision (HR = 10.0). Of unrevised cases with radiographs at 10 years, 4 hips showed radiographic loosening. Mean Harris hip scores improved from 47 preoperatively to 79 at 10 years. ConclusionsPorous tantalum acetabular cup-augment constructs used in revision THA with severe acetabular bone loss provide excellent implant survivorship at 10 years when the acetabulum is intact. Due to lower survivorship of cup-augment constructs in cases of pelvic discontinuity, additional construct fixation or stabilization methods are recommended, when a discontinuity is present. Level of EvidenceIV

Tranexamic Acid Reduces the Amount of Blood Transfused in Revision Total Hip Arthroplasty for Vancouver B2/B3 Periprosthetic Femur Fractures.

Periprosthetic fractures around total hip arthroplasty (THA) represent a significant source of morbidity and mortality. The use of tranexamic acid (TXA) in arthroplasty is well described, yet little literature supports its role in periprosthetic femur fractures (PFFs). This study investigated the effect of preoperative TXA administration on transfusion rate and volume, length of stay, and 90-day complication rates in patients undergoing revision THA for PFF. All patients undergoing revision THA for PFF (Vancouver B2/B3) at our institution from August 2016 to June 2022 were identified. Routine TXA administration at surgical start was introduced in 2018. Patient demographics, operative time, blood product use, length of stay, and 90-day complications were collected. Patients were divided into those who received TXA preoperatively and those who did not. A total of 56 patients were included. There was no difference in age, sex, anesthetic type, fracture classification, or preoperative blood values between cohorts. TXA significantly lowered the amount of blood product required (2.3 units vs 3.2 units, P=.023). Preoperative TXA did not independently reduce length of stay; however, blood transfusion was associated with increased length of stay (7 days vs 4.7 days, P=.003). There were no differences in 90-day complications. Among patients who underwent revision THA for Vancouver B2/B3 PFF, TXA did not affect transfusion rates but did result in the use of fewer blood products without an increase in complications. We support routine use of TXA in this patient population. Future studies should assess earlier administration of TXA in the emergency department or once patients' conditions have been medically optimized. [Orthopedics. 2024;47(5):e261-e267.].

Quantification of trunnion damage in a series of intact total hip arthroplasty femoral stems previously identified to be at risk of catastrophic failure.

Corrosion at the head-neck junction of femoral stems is a rare complication of total hip arthroplasty (THA) with manifestations ranging from subclinical wear to failure. Prior studies have identified a single femoral component design with an increased propensity for catastrophic trunnion failure. The purpose of the present study was to quantify trunnion damage of this femoral component retrieved from patients undergoing revision THA for non-trunnionosis indications. 24 femoral components from a single manufacturer were identified for study inclusion. Each prosthesis underwent stereomicroscopic inspection. Corrosion and fretting scores were assigned per the Goldberg criteria to quadrants of the trunnion. Material loss was calculated based on cone angles across trunnion quadrants. This was carried out using a coordinate measuring machine that digitised each trunnion surface. Stems were compared to a series of femoral stems with the same trunnion design. 20 of the 24 (83%) trunnions demonstrated corrosion, all 24 trunnions demonstrated fretting. Corrosion scores did not statistically differ with respect to trunnion zone (p = 0.53), while fretting scores were higher in the inferior compared to the superior zones (p < 0.001). There was no significant difference in cone angles assessing material loss between stems (p = 0.25). Evidence of trunnion damage was observed in each stem retrieved for non-trunnionosis revision. Fretting occurred more frequently about the inferior quadrants. However, digitised trunnion shapes were similar between compared stems exhibiting no material loss. Therefore, it is possible that previous reports of trunnion failures for this implant are not a systemic issue, and that further investigation is required.

THE FATE OF REVISION TOTAL HIP ARTHROPLASTY FOR INSTABILITY

Instability is a common indication for revision total hip arthroplasty (THA). However, even after the initial revision, some patients continue to have recurrent dislocations. This study investigates those at risk for recurrent dislocation after revision THA for instability at a single institution.Between 2009 and 2019, 163 patients underwent revision THA for instability at a single institution. Thirty-three of these patients required re-revision THA due to recurrent dislocation. Cox proportional hazard models with death as a competing event were used to analyze risk factors, including prosthesis sizing and alignment. Paired t-tests or Wilcoxon signed rank tests were used to assess patient outcomes (Veterans RAND 12 (VR-12) physical score, VR-12 mental score, Harris Hip Score, and hip disability and osteoarthritis outcome score for joint replacement).Duration of follow-up until either re-revision or final follow-up was a mean of 45.3 ± 38.2 months. The 1-year cumulative incidence for recurrent dislocation after revision was 8.7%, which increased to 19.6% at 5 years and 32.9% at 10 years postoperatively. In the multivariable analysis, high ASA score [HR 2.71], being underweight (BMI&lt;18 kg/m2) [HR 36.26] or overweight/obese (BMI&gt;25 kg/m2) [HR 4.31], use of specialized liners [HR 5.51–10.71], lumbopelvic stiffness [HR 6.29], and postoperative abductor weakness [HR 7.20] were significant risk factors for recurrent dislocation. Increasing the cup size decreased the dislocation risk [HR 0.89]. The dual mobility construct did not affect the risk for recurrent dislocation in univariate or multivariable analyses. VR-12 physical and HHS (pain and function) scores improved postoperatively at midterm.Patients requiring revision THA for instability are at risk for recurrent dislocation. Higher ASA scores, abnormal BMI, use of special liners, lumbopelvic stiffness, and postoperative abductor weakness are significant risk factors for re-dislocation.

Cutibacterium positive cultures in total joint arthroplasty: a comparison of the hip, knee, and shoulder.

Cutibacterium spp. (formerly Propionibacterium) is a slow growing, Gram-positive, anaerobic bacteria and is an emerging clinical entity in prosthetic joint infection (PJI). This study compares the presentation, surgical management, and post-operative antibiotic therapy of patients with positive intraoperative cultures during revision total joint arthroplasty (TJA) of the hip, knee, and shoulder. This was a retrospective cohort study of patients from 2014 to 2020 of 57 revision TJAs (27 total hip arthroplasty (THA), 17 total shoulder arthroplasty (TSA), and 13 total knee arthroplasty (TKA)) with intraoperative cultures positive for Cutibacterium at a tertiary academic centre. Patient demographics, pre-operative labs, radiographs, and aspirate results were collected. Intraoperative data was reviewed. Post-operative antibiotic therapy and repeat infections were recorded. Data was compared with univariate analyses. There was no significant difference in pre-operative lab values between the cohorts. All cohorts had >58% radiographic lucency. Revision TSA patients had significantly fewer pre-operative aspirates. Six patients undergoing revision THA, three TKA and one TSA had a repeat infection requiring further surgery. Four in the THA cohort and one in the TKA cohort with repeat infections did not receive prolonged antibiotic therapy. Cutibacterium is an infectious agent that can present in an indolent fashion after TJA. It commonly causes progressive radiographic lucency. The workup and post-operative management differs in the hip, knee, and shoulder, which is likely due to existing literature guiding physician practice. In all joints, Cutibacterium is a virulent pathogen that can cause repeat infections requiring surgical treatment.

Comparison of re-revision rate and radiological outcomes between Kerboull-type plate and metal mesh with impaction bone grafting for revision total hip arthroplasty

BackgroundThis study compared the re-revision rate and radiographic outcomes of revision total hip arthroplasty (THA) using a Kerboull-type acetabular reinforcement device (KT plate) with bulk structural allograft and metal mesh with impaction bone grafting (IBG).MethodsNinety-one hips of 81 patients underwent revision THA for American Academy of Orthopedic Surgeons (AAOS) classification type III defects from 2008 to 2018. Of these, seven hips of five patients and 15 hips of 13 patients were excluded due to insufficient follow-up information (< 24 months) and large bone defects with a vertical defect height ≥ 60 mm, respectively. The current study compared the survival and radiographic parameters of 45 hips of 41 patients using a KT plate (KT group) and 24 hips of 24 patients using a metal mesh with IBG (mesh group).ResultsEleven hips (24.4%) in the KT group and 1 hip (4.2%) in the mesh group exhibited radiological failure. Moreover, 8 hips in the KT group (17.0%) required a re-revision THA, while none of the patients in the mesh group required a re-revision. The survival rate with radiographic failure as the endpoint in the mesh group was significantly higher than that in the KT group (100% vs 86.7% at 1-year and 95.8% vs 80.0% at 5-years, respectively; p = 0.032). On multivariable analysis evaluating factors associated with radiographic failure, there were no significant associations with any radiographic measurement. Of the 11 hips with radiographic failure, 1 (11.1%), 3 (12.5%), and 7 (58.3%) hips were of Kawanabe classification stages 2, 3, and 4, respectively.ConclusionsThe findings of this study suggest that revision THA using KT plates with bulk structure allografts could provide poorer clinical outcomes than revision THA using a metal mesh with IBG. Although revision THA using KT plates with bulk structural allografts could set the true hip center, there is no association between a high hip center and clinical outcomes. The relationship between the position of the KT plate and the host bone might be considered more carefully.

Biphasic bone graft substitute in revision total hip arthroplasty with significant acetabular bone defects

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. Mean follow-up was 39.5 months (36 to 71), with a significant improvement in post-revision function compared to preoperative function. Graft site remodelling was rated radiologically as moderate in 31 hips (63%) and strong in 12 hips (24%). There were no cases of complete graft site dissolution. No acetabular loosening was identified. None of the patients developed clinically significant heterotopic ossification. There were twelve reoperations: six patients developed post-revision infections, three experienced dislocations, two sustained periprosthetic femur fractures, and one subject had femoral component aseptic loosening. Our series reports bone defect restoration with the sole use of a biphasic injectable BGS in the periacetabular region. We did not observe significant graft dissolution. We emphasize that successful graft site remodelling requires meticulous recipient site preparation.Cite this article: Bone Jt Open2022;3(12):991-997.

Surgical Technique: Abductor Reconstruction With Gluteus Maximus and Tensor Fascia Lata in Revision Total Hip Arthroplasty.

Abductor deficiency in revision total hip arthroplasty (THA) is a common problem that can lead to pain, limping, and instability. Repair and reconstruction of the abductors is challenging, with a high rate of failure reported in the literature. The purpose of this study is to describe a simplified technique of abductor repair augmented with the transfer of gluteus maximus (Gmax) and the tensor fascia lata (TFL). We describe a novel abductor reconstruction with transfer of the anterior 30% of Gmax and the posterior 70% of TFL to the vastus lateralis origin. These transfers can be used in isolation or to augment repair of torn abductors to the greater trochanter. The technique is simple and quick to perform via a lateral approach, requiring dissection of only two muscle slips and minimal additional soft tissue dissection. We describe the use and outcomes of this technique on three patients undergoing revision THA with severe and irreparable abductor deficiency. Although these patients reported improved function after the reconstruction, there was persistence of mild to moderate limping. Abductor reconstruction with partial transfers of Gmax and TFL is a promising approach to manage abductor deficiency in revision THA. Larger series are required to determine the efficacy of this technique for restoring abductor function and improving patient reported outcomes.

Advanced quantitative 3D imaging improves the reliability of the classification of acetabular defects.

Classifying complex acetabular defects in revision total hip arthroplasty (THA) by means of conventional radiographs comes with significant limitations. Statistical shape modelling allows the virtual reconstruction of the native pelvic morphology, hereby enabling an analytic acetabular defect assessment. Our objective was to evaluate the effect of advanced imaging augmented with analytic representations of the defect on (1) intra- and inter-rater reliability, and (2) up- or downscaling of classification scores when evaluating acetabular defects in patients undergoing revision THA. The acetabular defects of 50 patients undergoing revision THA were evaluated by three independent, fellowship-trained orthopaedic surgeons. Defects were classified according to the acetabular defect classification (ADC) using four different imaging-based representations, namely, standard radiographs, CT imaging, a virtual three-dimensional (3D) model and a quantitative analytic representation of the defect based on a statistical shape model reconstruction. Intra- and inter-rater reliabilities were quantified using Fleiss' and Cohen's kappa scores, respectively. Up- and downscaling of classification scores were compared for each of the imaging-based representations and differences were tested. Overall inter-rater agreement across all imaging-based representations for the classification was fair (κ 0.29 95% CI 0.28-0.30). Inter-rater agreement was lowest for radiographs (κ 0.21 95% CI 0.19-0.22) and increased for other representations with agreement being highest when using analytic defect models (κ 0.46 95% CI 0.43-0.48). Overall intra-rater agreement was moderate (κ 0.51 95% CI 0.42-0.60). Intra-rater agreement was lowest for radiographs (κ 0.40 95% CI 0.23-0.57), and highest for ratings including analytic defect models (κ 0.64:95% CI 0.46-0.82). Virtual 3D models with quantitative analytic defect representations upscaled acetabular defect scores in comparison to standard radiographs. Using 3D CT imaging with statistical shape models doubles the intra- and inter-rater reliability and results in upscaling of acetabular defect classification when compared to standard radiographs. This method of evaluating defects will aid in planning surgical reconstruction and stimulate the development of new classification systems based on advanced imaging techniques.

Minimal Clinically Important Difference (MCID) at One Year Postoperatively in Aseptic Revision Total Hip Arthroplasty

BackgroundOutcomes after aseptic revision total hip arthroplasty (THA) are variable, and it is unknown whether the indication for aseptic revision THA influences postoperative clinical improvement. The minimal clinically important difference (MCID) assesses if changes in patient-reported outcome measure result in meaningful clinical benefit to patients. The purpose of this study was to quantify the 1-year postoperative MCID for aseptic revision THA and to assess the percentage of patients achieving the MCID for each revision diagnosis. MethodsA prospective, single-institution registry of revision total joint arthroplasties was used. Retrospective review of 413 first-time aseptic revision THAs was performed. Demographics, revision diagnosis, preoperative Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS Jr.), and 1-year postoperative HOOS Jr. were recorded. The MCID for the HOOS Jr. at one year postoperatively was calculated for each revision diagnosis using a distribution-based method. The percentage of patients exceeding the MCID with each diagnosis was determined. ResultsThere were 9 aseptic revision diagnoses, all with n ≥ 5. The 3 most common revision diagnosis were aseptic loosening (n = 114), dislocation or instability (n = 103), and polyethylene wear or osteolysis (n = 73). The MCID for all the aseptic revision THAs was 10.9. Seven of the nine revision diagnoses achieved the MCID. The highest percentage of patients achieving the MCID was for aseptic loosening (84.2%) and implant fracture (81.3%), whereas lowest was for adverse local tissue reaction (35.3%) and implant recall (20.0%). ConclusionThe one-year revision THA MCID is 10.9 for the HOOS Jr. There is variability in the percentage of patients achieving the MCID based on diagnosis. Our data can be used to counsel patients undergoing revision THA for noninfectious etiologies.

Evaluation of Direct Anterior Approach for Revision Total Hip Arthroplasty: A Systematic Review.

The direct anterior approach (DAA) is an established approach for total hip arthroplasty (THA) but has been sparingly tried for revisions. The purpose of this study was to examine the available literature in order to consolidate information available on revision THA using the DAA. A PubMed, Embase, and Scopus search was performed using relevant keywords. Studies reporting on patients undergoing revision THA using DAA were included for analysis. In a review of the literature, nine studies matched the pre-decided inclusion criteria with 319 hip joints undergoing revision THA. Mean follow-up of all included studies was 34 months. The indications of revision after primary THA in decreasing order were aseptic loosening (53%), prosthetic joint infection (20.7%), peri-prosthetic fracture (16.9%), dislocation (7.2%), psoas impingement (1.9%), polyethylene wear (1.2%), pain (0.6%), and instability (0.3%). Of the 319 revisions evaluated, 107 underwent a stem revision, 142 underwent cup revision, 49 underwent a combined revision, and 21 underwent isolated liner/head change. A statistically significant improvement in functional score (P<0.05) was observed for all studies reporting on functional outcomes. A low complication rate (51/319, 16.0%), which includes dislocation (12), infection (12), loosening of the acetabular shell (5), peri-prosthetic fractures (6), haematoma (4), and transient nerve palsy (6), was reported. Based on available level III-IV evidence, DAA appears to be a reliable alternative for revision of the failed hip arthroplasty with acceptable complication rates. Evidence of a higher quality is needed to further characterize its role in revision scenarios.

Intraoperative measurement of acetabular component position using imageless navigation during revision total hip arthroplasty

Background:Acetabular component malposition is a major cause of dislocation following total hip arthroplasty (THA). Intellijoint HIP is an imageless navigation tool that has been shown to provide accurate intraoperative measurement of cup position during primary THA without substantially increasing operative time. However, its accuracy in revision THA has not been evaluated. This study therefore aims to assess the accuracy of Intellijoint HIP in measuring cup inclination and anteversion in comparison with computed tomography (CT) during revision THA.Methods:Intellijoint HIP was used to measure the position of the preexisting cup in 53 consecutive patients undergoing revision THA between December 2018 and February 2020. Two authors blinded to the intraoperative navigation measurements also independently measured cup position using preoperative CT according to Murray’s radiographic definitions. Pearson correlation coefficients with 95% confidence intervals (CIs), paired t tests and Bland–Altman plots were used to assess agreement between navigation- and CT-measured cup position. Statistical analysis was performed using GraphPad Prism, with p values less than 0.05 indicating statistical significance.Results:There was excellent agreement between navigation and CT measurements for both cup inclination (r = 0.89, 95% CI 0.81–0.93) and anteversion (r = 0.93, 95% CI 0.88–0.96), with the mean absolute difference being 5.2º (standard deviation [SD] 4.0º) for inclination and 4.8º (SD 5.4º) for anteversion. The navigation measurement was within 10º of the radiographic measurement in 47 of 53 (88.7%) cases for inclination and 46 of 53 (86.8%) cases for anteversion.Conclusion:Imageless navigation demonstrated excellent correlation and agreement with CT measurements for both inclination and anteversion over a wide range of acetabular component positions.

Modular dual-mobility cups using ceramic liners: an original solution for selected indications?

Dual mobility (DM) has been shown to improve stability both in primary and revision total hip arthroplasty (THA) and is increasingly used in patients at high risk of dislocation and in the treatment of THA instability. The introduction of modular liners has helped to overcome some of the limitations of monoblock DM cups. In this context, the use of a ceramic liner would avoid the conventional cobalt-chromium liner in the titanium shell, which can be problematic in some situations. The aim of this paper is to report the outcomes of a consecutive series of patients undergoing revision THA using a modular DM cup with a ceramic liner instead of the conventional metal one, and to clarify the rationale for this currently "off-label" use. This is a retrospective series of patients who received this new DM bearing in a single institution. Patients were followed up clinically and radiologically at 1 month, 3 months, 6 months and yearly thereafter. 5 patients received the ceramic liner in the study period (2014-2019). The indications were instability or high risk of dislocation in ceramic liner fracture and ARMD with soft tissue damage after MoM THA. The mean age at surgery was 74 (63-82) years, the mean follow-up was 36 (12-72) months. No dislocation occurred, and no adverse events related to the implant were recorded. The use of a ceramic liner in a modular DM cup offers several advantages in selected patients, and the results of our cohort are encouraging. However, caution is needed in introducing this new bearing because knowledge is currently limited. Further studies on a larger number of patients and with longer follow-ups are needed to confirm these findings and before widespread use of the device.

A cost-effectiveness assessment of dual-mobility bearings in revision hip arthroplasty.

AimsThe rate of dislocation when traditional single bearing implants are used in revision total hip arthroplasty (THA) has been reported to be between 8% and 10%. The use of dual mobility bearings can reduce this risk to between 0.5% and 2%. Dual mobility bearings are more expensive, and it is not clear if the additional clinical benefits constitute value for money for the payers. We aimed to estimate the cost-effectiveness of dual mobility compared with single bearings for patients undergoing revision THA.MethodsWe developed a Markov model to estimate the expected cost and benefits of dual mobility compared with single bearing implants in patients undergoing revision THA. The rates of revision and further revision were calculated from the National Joint Registry of England and Wales, while rates of transition from one health state to another were estimated from the literature, and the data were stratified by sex and age. Implant and healthcare costs were estimated from local procurement prices and national tariffs. Quality-adjusted life-years (QALYs) were calculated using published utility estimates for patients undergoing THA.ResultsAt a minimum five-year follow-up, the use of dual mobility was cost-effective with an estimated incremental cost-effectiveness ratio (ICER) of between £3,006 and £18,745/QALY for patients aged < 55 years and between 64 and 75 years, respectively. For those aged > 75 years dual mobility was only cost-effective if the timeline was beyond seven years. The use of dual mobility bearings was cost-saving for patients aged < 75 years and cost-effective for those aged > 75 years if the time horizon was beyond ten years.ConclusionThe use of dual mobility bearings is cost-effective compared with single bearings in patients undergoing revision THA. The younger the patient is, the more likely it is that a dual mobility bearing can be more cost-effective and even cost-saving. The results are affected by the time horizon and cost of bearings for those aged > 75 years. For patients aged > 75 years, the surgeon must decide whether the use of a dual mobility bearing is a viable economic and clinical option.Cite this article: Bone Joint J 2020;102-B(9):1128–1135.