Failed Total Hip Arthroplasty Research Articles

Stress-shielding in aseptic loosening on the 3D printed acetabular cup in hip arthroplasty: review article

The increasing number of prosthetic hip replacement surgeries and their growing indication have led to a growing interest in understanding the factors that influence their long-term success. Total hip arthroplasty (THA) failure is mainly due to aseptic loosening. More rarely septic mobilization may occur. In the first case, many variables influence the bone-implant relationship and periprosthetic bone remodeling. Stress-shielding is the most evident but not fully explained manifestation of the bone implant interaction. Recently, three-dimensional (3D) printed titanium orthopedic implants have offered new perspectives in the field of hip prosthetics, enabling the customization and production of acetabular cups with enhanced biocompatibility. This review aims to evaluate the efficacy and reliability of 3D printed acetabular cups from the perspective of aseptic failure particularly related to the stress-shielding. The most recent clinical and preclinical studies will be reviewed, exploring the benefits and challenges associated with the use of these emerging technologies. Key factors, such as biocompatibility, mechanical stability, osseointegration, and wear resistance.

Equivalent Survivorship of Total Hip Arthroplasty in Patients Who Have Inflammatory Bowel Disease

BackgroundInflammatory bowel disease (IBD) can have orthopaedic manifestations related to decreased bone mineral density and increased fracture risk. The impact of IBD-spectrum diseases, including Crohn’s disease (CD) and ulcerative colitis (UC), on the overall performance of total hip arthroplasty (THA), is not well understood. The present study sought to evaluate whether patients who have IBD were at an increased risk of THA failure compared to those who did not have IBD. MethodsThe Statewide Planning and Research Cooperative System was used to compare postoperative outcomes between patients who have IBD (CD and UC) and patients who do not have IBD from 2010 to 2020. A total of 119,094 patients were included in the study, of whom 1,165 had a diagnosis of IBD. Overall, 501 of those had CD, while 664 had UC. ResultsWhen controlling for comorbidities, patients who had CD had longer hospital length of stay (CD: 3.6 ± 2.5 versus UC: 3.4 ± 2.1 versus control: 3.2 ± 2.3 days, P < 0.001), higher rates of 90-day readmission (CD: 13.6 versus UC: 8.3 versus control: 7.7%, P < 0.001) and 1-year readmission (CD: 20.4 versus UC: 15.1 versus control: 12.8%, P < 0.001), and higher rates of 90-day emergency room visits (CD: 15.4 versus UC: 12 versus control: 11.1%, P = 0.007). There were no differences in all-cause revision or revision for periprosthetic joint infection between CD and UC compared with control patients. ConclusionsPatients who have UC had more emergency room visits and hospital readmissions following THA; however, survival analysis demonstrated that IBD patients are not at an increased risk of revision or periprosthetic joint infection after THA.

A comparison of dislocation risk between dual mobility and traditional constructs used in proximal femoral replacement

BackgroundProximal femoral replacement (PFR) is a reconstruction technique after tumor resection or for revision of failed total hip arthroplasty (THA). However, despite acceptable long-term oncologic and functional outcomes, extensive soft tissue or bone loss increases the risk for prosthetic instability. Instability may depend on the construct chosen for reconstruction, with current options including bipolar, constrained, or dual mobility implants. Clinical studies comparing patient outcomes after PFR with these three different constructs are limited. MethodsThis study retrospectively examined a single tertiary academic institution's experience with PFR over a fifteen-year period. The medical records of patients who underwent PFR for indications such as tumor and failed THA with bone loss were reviewed. Patients were stratified into cohorts based on use of bipolar, constrained, or dual mobility implants. Patient demographics, disease characteristics, perioperative data, and data on prosthetic dislocations were recorded. ANOVA and chi-square testing was performed for continuous and categorical variables, respectively. The threshold for statistical significance was set to p < 0.05. Results106 patients were identified who underwent PFR. 46 underwent PFR with bipolar prosthesis (follow-up: 20 ± 24.57 months), 42 with constrained liner (follow-up: 30.45 ± 35.32 months), and 18 with dual mobility (follow-up: 15.38 ± 15.67 months). Only BMI (p = 0.036) and smoking history (P = 0.002) differed between groups. Dislocations occurred in 4 (8.7 %) patients who underwent reconstruction with bipolar prosthesis, compared to 8 (19.0 %) with constrained liner, and 3 (16.7 %) patients with dual mobility. Mean time to dislocation was significantly longer in dual mobility patients (P = 0.009). There were no differences in instances of early dislocation between groups (P = 00.238). ConclusionWhile study numbers are low, mean time to dislocation was significantly longer with dual mobility. Additional large-scale longitudinal studies are needed to fully elucidate the differences in outcomes amongst these three treatments.

Periprosthetic Fractures: A Rising Tide of Hip Arthroplasty Failure Noted in the American Joint Replacement Registry and the Preventative Role of Cemented Stems

BackgroundThis investigation examined cemented femoral component use in total hip arthroplasty (THA) and its impact on the incidence of periprosthetic fractures (PPFx), a common failure mode in THA. The study leverages data from the American Joint Replacement Registry (AJRR) to assess trends in cemented femoral component usage over time, its association with PPFx rates, and compares the survivorship and 90-day complication rates between cemented and cementless femoral component THAs. MethodsPrimary THAs, captured in the AJRR, in patients aged 65 years and older from 2012 to 2021 were analyzed. Variables considered included age, sex, race, region, teaching status, year, Charlson comorbidity index, and institution bed size. Analysis compared fixation types for THA on all-cause linked revision and PPFx. Logistic regression models analyzed the odds ratios for all-cause linked revision and PPFx for any follow-up time as well as for 90-day revision. The models were adjusted for the listed variables. ResultsDuring the study period, the rate of cement utilization as a percentage of primary THAs performed and reported to the AJRR increased from 4.4 to 8.3%. The rate of THA failure from PPFx increased from 11.4 to 33.3%. When both fixation groups were compared in the univariate analysis, there was a statistically significant difference in all demographic variables (P < .001). To account for this, multivariable logistic regression models were applied. In our models, cemented stems showed a 54.4% (odds ratio: 0.456; 95% confidence interval: 0.347 to 0.599; P < .0001) and 65.8% (odds ratio: 0.342; 95% confidence interval: 0.237 to 0.493; P < .0001) lower risk of PPFx linked and PPFx early linked revision, respectively. ConclusionsPeriprosthetic fractures are becoming a leading failure mode for THAs in the AJRR. Given cemented fixation’s relative resistance to this failure mode compared to cementless fixation, we should consider increasing the utilization of this technique.

Septic complications are on the rise and aseptic loosening has decreased in total joint arthroplasty: an updated complication based analysis using worldwide arthroplasty registers.

A decade ago, a comprehensive study was conducted to investigate the reasons for revision surgeries and their respective frequencies in cases of total hip arthroplasty (THA) and total knee arthroplasty (TKA) based on a complication-based analysis of joint replacement registries. The aim of the present study was to determine whether the causes and risks of their occurrence have changed over the last ten years and to present an updated analysis. A systematic review of national arthroplasty registries from seven countries examined the causes and rates of revisions of THA and TKA. The study focused on a descriptive analysis that provided an updated overview without statistical significance values. The most common causes for revisions of THA were aseptic loosening (35.1%), deep infection (18.2%), dislocation/instability (15.9%), and periprosthetic fractures (11.4%). The most common causes for revisions of TKA were deep infection (21.6%), aseptic loosening (18.3%), instability (14.1%), and pain (10.9%). The findings of this study revealed significant shifts in the underlying causes of revision surgeries in the last decade. Notably, septic complications emerged as the predominant reason for revision of primary TKA, while they also gained prominence as a cause of failure of THA. Although aseptic loosening remains the primary cause for re-operation of THA, the relative risk has decreased for both THA and TKA.

The weight of complications: high and low BMI have disparate modes of failure in total hip arthroplasty

BackgroundBody mass index (BMI) has been shown to influence risk for revision total hip arthroplasty (rTHA), but few studies have specifically examined which causes of rTHA are most likely in different BMI classes. We hypothesized that patients in different BMI classes would undergo rTHA for disparate reasons.MethodsNinety-eight thousand six hundred seventy patients undergoing rTHA over 2006–2020 were identified in the National Inpatient Sample. Patients were classified as underweight, normal-weight, overweight/obese, or morbidly obese. Multivariable logistic regression was used to analyze the impact of BMI on rTHA for periprosthetic joint infection (PJI), dislocation, periprosthetic fracture (PPF), aseptic loosening, or mechanical complications. Analyses were adjusted for age, sex, race/ethnicity, socioeconomic status, insurance, geographic region, and comorbidities.ResultsCompared to normal-weight patients, underweight patients were 131% more likely to have a revision due to dislocation and 63% more likely due to PPF. Overweight/obese patients were 19% less likely to have a revision due to dislocation and 10% more likely due to PJI. Cause for revision in morbidly obese patients was 4s1% less likely to be due to dislocation, 8% less likely due to mechanical complications, and 90% more likely due to PJI.ConclusionsOverweight/obese and morbidly obese patients were more likely to undergo rTHA for PJI and less likely for mechanical reasons compared to normal weight patients. Underweight patients were more likely to undergo rTHA for dislocation or PPF. Understanding the differences in cause for rTHA among the BMI classes can aid in patient-specific optimization and management to reduce postoperative complications.Level of evidenceIII.

Extreme Serum Titanium Concentration Induced by Acetabular Cup Failure: Unveiling a Unique Scenario of Titanium Alloy Debris Accumulation.

The majority of contemporary total hip arthroplasty (THA) implants are constructed from Ti alloys, which are generally believed to generate fewer adverse local tissue reactions (ALTRs) compared to CoCr alloys. This study presents a case of unusual primary THA failure where a substantial release of Ti alloy debris was observed. A 52-year-old active male underwent THA after post-traumatic aseptic necrosis of the femoral head in 2006. Seventeen years after the procedure, the patient presented with groin pain and a restricted range of motion. X-rays revealed the protrusion of the alumina ceramic head through the Ti6Al4V acetabular cup. Trace element analysis indicated significantly elevated levels of serum Ti, Al, and V. CT and MRI confirmed Ti alloy cup failure and a severe ALTR. During revision surgery, it was found that the worn-out ceramic head was in direct contact with the acetabular cup, having protruded through a central hole it had created over time. No acetabular liner was found. Histological analysis of his tissue samples showed wear-induced synovitis with areas of multinucleated foreign body giant cells and the accumulation of numerous metal particles but no acute inflammatory response. Six months after the revision THA, the patient has experienced favourable outcomes. This case provides an instructive illustration for studying the consequences of the substantial release of Ti alloy debris from orthopedic implants.

Influence of offset on osseointegration in cementless total hip arthroplasty: A finite element study.

Early aseptic loosening is caused by deficient osteointegration of the femoral stem due to increased micromotions and represents a common mode of failure in uncemented total hip arthroplasty (THA). This study hypothesized that a higher femoral offset, a smaller stem size and obesity increase femoral micromotion, potentially resulting in early aseptic loosening. A finite element analysis was conducted based on computed tomography segmented model of four patients who received a THA with a triple-tapered straight stem (Size 1, 3, 6). The influence of femoral stem offset (short neck, standard, lateral), head length (S to XXL), femoral anteversion and obesity during daily activities of fast walking and stair climbing was analyzed. The micromotions for the femoral stem zones were compared to a threshold representing a value above which only partial osseointegration is expected. The minimum femoral offset configuration compared to the maximum offset configuration (short neck stem, S head vs. lateral stem, XXL head) leads to a relative mean micromotion increase of 24% for the upper stem zone. Increasing the body weight (body mass index 30-35 kg/m2 ) increases the micromotion by 20% for all stem zones. The obese population recorded threshold-exceeding micromotions for stem sizes 1 and 3 for all offset configurations during stair climbing. Higher femoral offset, a smaller stem size, and higher loading due to obesity lead to an increase in micromotion between the prosthesis and proximal femur and represent a risk configuration for impaired osseointegration of a triple-tapered straight stem, especially when these three factors are present simultaneously.

Association of Total Hip Arthroplasty Flexural Rigidity With Magnetic Resonance Imaging and Histological Findings

BackgroundModular connections in total hip arthroplasty (THA) offer surgical advantages, but can contribute to implant fretting and corrosion due to micromotion at the head–stem interface. Previous studies implicated lower flexural rigidity as a key contributing factor to THA corrosion and fretting, but none associated flexural rigidity with direct histological evaluation or magnetic resonance imaging (MRI) outcomes. The purpose of this study was to determine how implant flexural rigidity is associated with MRI imaging metrics and histopathological outcomes in patients who have a failed THA. MethodsPatients requiring revision THA surgery underwent preoperative MRIs with 3-dimensional multispectral imaging techniques to suppress metal artifacts. The MRI images were graded for adverse local tissue reactions. For each hip, trunnion flexural rigidity was measured from the retrieved femoral stem, and a periprosthetic tissue sample was retrieved and evaluated using semiquantitative histology. Generalized linear models and analyses of variance were used to assess associations between flexural rigidity and MRI and histology outcomes. ResultsA total of 106 THA stems were retrieved (46 women and 60 men, age: 68 years (range, 60 to 73 years). After adjustment for length of implantation, flexural rigidity was negatively correlated with histologic aseptic lymphocyte-dominant vasculitis-associated lesion severity (β = −26.27, P = .018), Fujishiro lymphocyte grading (β = −13.4, P = .039), perivascular lymphocyte layers (β = −17.8, P = .022), the grade of tissue organization (β = −22.5, P = .009), the presence of diffuse synovitis (β = −66.5, P = .003), and the presence of lymphoid aggregates (β = −75.9, P = .022). No association was found between MRI metrics and flexural rigidity. ConclusionsAmong these implants, decreased trunnion stiffness was associated with increased histologic features of adverse host-mediated soft tissue reactions.

Biomarkers to discriminate between aseptic loosened and stable total hip or knee arthroplasties: a systematic review.

Loosening is a major cause for failure of total hip and total knee arthroplasties (THAs/TKAs). Preemptive diagnostics of asymptomatic loosening could open strategies to prevent gross loosening. A multitude of biomarkers may discriminate between loosened and stable implants, but it is unknown which have the best performance. The present systematic review aimed to assess which biomarkers have shown the most promising results in discriminating between stable and aseptic loosened THAs and TKAs. PubMed, Embase, Web of Science, Cochrane Library, and Academic Search Premier were systematically searched up to January 2020 for studies including THA/TKA and biomarkers to assess loosening. Two reviewers independently screened records, extracted data, and assessed the risk of bias using the ICROMS tool to classify the quality of the studies. Twenty-eight (three high-quality) studies were included, reporting on a median of 48 patients (interquartile range 28-69). Serum and urine markers were evaluated in 22 and 10 studies, respectively. Tumor necrosis factor α and osteocalcin were significantly higher in loosened compared with stable implants. Urinary N-terminal telopeptide had significantly elevated levels in loosened prostheses. Several serum and urine markers were promising in discriminating between loosened and stable implants. We recommend future studies to evaluate these biomarkers in a longitudinal fashion to assess whether progression of loosening is associated with a change in these biomarkers. In particular, high-quality studies assessing the usability of these biomarkers are needed.

Polyethylene thickness does not influence aseptic revision rate with highly cross-linked liners in THA with 36-mm femoral heads.

To reduce the risk of dislocation, larger head size can be used in total hip arthroplasty (THA). However, larger head size leads to thinner acetabular liners. With conventional polyethylene, thickness of >8 mm has been advocated to reduce stress and wear rate of the polyethylene. Modern polyethylene has become more wear-resistant. In this study, we investigated if the thickness of sequentially cross-linked polyethylene (XLPE) liners is associated with failure of THA in the medium term. 3654 THAs were included (2009-2016), in which THA was performed with a XLPE liner in combination with a 36-mm femoral head. Patient and surgical characteristics were collected. We compared implant survival of THA with thin liners (<7.9 mm) and thick liners (⩾7.9 mm) with a Kaplan Meier survival analysis at 5 years, median follow-up and 10 years of follow-up with and point aseptic loosening and performed a multivariate analysis to estimate hazard ratios (HR). Median follow-up was 7.7 years (IQR 5.6-9.8). In total, 179 revision procedures were performed, where 82 revisions (46%) were performed for aseptic loosening. The survival rate at 5 years, median and 10 years of follow-up showed no statistically significant difference in implant survival. The survival rate at 10 years follow-up was for thin liners 97.1% (95% CI, 96.3-97.9) and for thick liners 98.2% (95% CI, 97.4-99.0) in the aseptic loosening group (chi-square 2.55; p = 0.11).The adjusted HR for thick liners (⩾7.9 mm) was 0.65 (95% CI, 0.38-1.08) compared with the thin liners (<7.9 mm), which was not significantly different. From this single-centre retrospective study it appears that thinner polyethylene liners are well tolerated when using second-generation highly cross-linked polyethylene. Thickness of the XLPE liners did not influence the risk of aseptic loosening of the implants in the medium term.

Updates on Biomaterials Used in Total Hip Arthroplasty (THA).

One of the most popular and effective orthopedic surgical interventions for treating a variety of hip diseases is total hip arthroplasty. Despite being a radical procedure that involves replacing bone and cartilaginous surfaces with biomaterials, it produces excellent outcomes that significantly increase the patient's quality of life. Patient factors and surgical technique, as well as biomaterials, play a role in prosthetic survival, with aseptic loosening (one of the most common causes of total hip arthroplasty failure) being linked to the quality of biomaterials utilized. Over the years, various biomaterials have been developed to limit the amount of wear particles generated over time by friction between the prosthetic head (metal alloys or ceramic) and the insert fixed in the acetabular component (polyethylene or ceramic). An ideal biomaterial must be biocompatible, have a low coefficient of friction, be corrosion resistant, and have great mechanical power. Comprehensive knowledge regarding what causes hip arthroplasty failure, as well as improvements in biomaterial quality and surgical technique, will influence the survivability of the prosthetic implant. The purpose of this article was to assess the benefits and drawbacks of various biomaterial and friction couples used in total hip arthroplasties by reviewing the scientific literature published over the last 10 years.

Impact of previous lumbar spine surgery on total hip arthroplasty and vice versa: How long should we be concerned about mechanical failure?

This registry study aims to assess the prevalence and demographic characteristics of patients with lumbar spine (LS) surgical procedures who undergo total hip arthroplasty (THA), to compare the long-term survival and causes of failure of THA in patients who previously underwent LS fusion and non-fusion surgical procedures, and to evaluate the risk of undergoing a revision LS surgery after THA. Patients who underwent LS surgery followed by THA were identified by cross-referencing data from the Orthopedic Prosthetic Implants Registry and the Regional Hospital Discharge Database. Three groups of THA patients were identified: patients who underwent previous lumbar surgery with fusion (LS fusion-THA), without fusion (LS non-fusion-THA), and a control group with only THA (No LS surgery-THA). Demographic data, THA survival, number and causes of failure, and data on revision procedures on THA and LS were collected. Of the total of 79,984 THA, 2.2% of patients had a history of LS procedures. THA only patients showed better results, while patients in the LS fusion-THA group had worse implant survival at 5-year follow-up. In the LS fusion-THA and LS non-fusion-THA, mechanical THA failures were more frequent in the first two years after implantation. There were no differences between groups regarding the risk of undergoing LS revision surgery. LS surgery negatively affects THA survivorship. In patients who previously underwent LS fusion and non-fusion surgical procedures, most THA failure occurs in the first two years after implant. The study contributes to the understanding of the relationship between the hip and the LS and provides useful guidance for clinical practice.

MANAGING THE COST OF ADVANCING TECHNOLOGIES

Advances in total hip and knee replacement technologies have heretofore been largely driven by corporate marketing hype with each seeming advancement accompanied by a cost increase often out in front of peer-reviewed reports documenting their efficacy or not.As example, consider the growing use of ceramic femoral heads in primary total hip arthroplasty (THA). The question to consider is “Can an upcharge of $350 for a ceramic femoral head in primary THA be justified?” The answer to this question lies in an appreciation of whether the technology modifies the potential for costly revision arthroplasty procedures.Peer-Reviewed Laboratory &amp; Clinical Review - According to the 2022 Australian National Joint Replacement Registry, the four leading causes of primary THA failure requiring revision are: 1.) infection, 2.) dislocation/instability, 3.) periprosthetic fracture and 4.) loosening, which constitute 87.5% of the reported reasons for revision.Focusing on these failure modes, hip simulator findings report that ceramic femoral heads dramatically reduce wear debris generation, decreasing the potential for osteolytic response leading to loosening. Further, ceramic materials enable the utilization of larger head sizes, avoiding the potential for dislocation. The overall mid- to long-term survival rate reported in the peer-reviewed, clinical literature for these bearings has exceeded 95% with virtually no osteolysis.Also, could bearing surface choice influence periprosthetic joint infection (PJI)? A study on a total of more than 10,500 primary THA procedures reported a confirmed PJI incidence of 2.4% for cobalt-chrome and 1.6% for ceramic femoral heads, suggesting that the employ of a ceramic bearing surface may also play a role in decreasing the potential for infection.Review of the clinical data available for ceramic bearings justifies that it is better to “pay me now than to pay orders of magnitude later”, if in fact a revision THA can be avoided, significantly reducing the overall financial burden to the healthcare system.

EXPERIENCE OF THE 150 MM LUBINUS SP II FEMORAL STEM IN A UK CENTRE: EXCELLENT SURVIVORSHIP, LOW DISLOCATION, AND NEGLIGIBLE PERIPROSTHETIC FRACTURE RATES UP TO 15 YEARS FOLLOWING PRIMARY TOTAL HIP ARTHROPLASTY

The Lubinus SP II is an anatomical femoral stem with high survivorship levels notably described in the Swedish Arthroplasty Register. As the clinical and economic burden of revision total hip arthroplasty (THA) and periprosthetic fracture (PPF) continues to increase, it has been suggested that use of anatomical stems may facilitate more uniform cement mantles and improve implant survival. The primary aim of this study was to determine the long-term survivorship and PPF rate of the Lubinus SP II 150mm stem in a single UK centre.Between January 2007 and April 2012, 1000 consecutive THAs were performed using the Lubinus SP II femoral stem in our institution. Patient demographics and operative details were collected in a prospective arthroplasty database. Patient records and national radiographic archives were then reviewed at a mean of 12.3 years (SD 1.3) following surgery to identify occurrence of subsequent revision surgery, dislocation or periprosthetic fracture.Mean patient age at surgery was 69.3 years (SD 10.1, 24–93 years). There were 634 women (63%). Osteoarthritis was the operative indication in 974 patients (97%). There were 13 revisions in total (4 for recurrent dislocation, 3 for infection, 6 for acetabular loosening) and 16 dislocations (1.6%). Stem survivorship at 10 years was 99.6% (95 % confidence interval [CI], 99.5%–99.7%) and at 15 years was 98.8% (98.7%–98.9%). The 15-year stem survival for aseptic loosening was 100%. Analysis of all cause THA failure demonstrated a survivorship of 99.1% (99.0%–99.3%) at 10 years and 98.2% (98.1%–98.3%) at 15 years. There were 4 periprosthetic fractures in total (0.4%) at mean 12.3 year follow-up.The Lubinus SP II stem demonstrated excellent survivorship, low dislocation rates and negligible PPF rates up to 15 years following primary THA. Use of anatomical stems such as the Lubinus SPII would appear to be a wise clinical and economic investment for patients and healthcare systems alike.

Salvage Options for the Failed Total Hip Arthroplasty (THA)

AbstractTotal hip arthroplasty (THA) has been referred to as the operation of the century given its success and predictable improvement in quality of life. With the increase in number of THAs performed every year, there is a concomitant rise in the incidence of revision and re-revision surgeries. Failure of THA and revision hip arthroplasty may occur due to a variety of reasons, often in older patients with multiple comorbidities. Revision procedures in this setting are associated with worse outcomes as they are often complicated by limited bone stock and poor soft tissue and bone quality, making reconstruction more challenging. The purpose of this review is to discuss modern techniques for limb salvage following failed THA in the setting of significant bone loss. These include proximal femur replacement, total femur replacement, hip resection arthroplasty, and hip disarticulation.

Combining deep learning and machine learning for the automatic identification of hip prosthesis failure: Development, validation and explainability analysis

AimRevision hip arthroplasty has a less favorable outcome than primary total hip arthroplasty and an understanding of the timing of total hip arthroplasty failure may be helpful. The aim of this study is to develop a combined deep learning (DL) and machine learning (ML) approach to automatically detect hip prosthetic failure from conventional plain radiographs. MethodsTwo cohorts of patients (of 280 and 352 patients) were included in the study, for model development and validation, respectively. The analysis was based on one antero-posterior and one lateral radiographic view obtained from each patient during routine post-surgery follow-up. After pre-processing, three images were obtained: the original image, the acetabulum image and the stem image. These images were analyzed through convolutional neural networks aiming to predict prosthesis failure. Deep features of the three images were extracted for each model and two feature-based pipelines were developed: one utilizing only the features of the original image (original image pipeline) and the other concatenating the features of the three images (3-image pipeline). The obtained features were either used directly or reduced through principal component analysis. Both support vector machine (SVM) and random forest (RF) classifiers were considered for each pipeline. ResultsThe SVM applied to the 3-image pipeline provided the best performance, with an accuracy of 0.958 ± 0.006 in the internal validation and an F1-score of 0.874 in the external validation set. The explainability analysis, besides identifying the features of the complete original images as the major contributor, highlighted the role of the acetabulum and stem images on the prediction. ConclusionsThis study demonstrated the potentialities of the developed DL-ML procedure based on plain radiographs in the detection of the failure of the hip prosthesis.

Ceramic-on-Ceramic Total Hip Arthroplasty for Avascular Necrosis: 13-Year Average Follow-Up of Patients Under 50 Years Old

AbstractThe long-term survival of ceramic-on-ceramic bearings in young, active patients with osteonecrosis undergoing total hip arthroplasty (THA) is unknown. A previously published study demonstrated a high activity level in these young patients at 5-year follow-up, and this is a second follow-up report on this previously reported series. The purpose of this study is to determine whether high activity level is associated with ceramic-on-ceramic THA failure at long-term follow-up. This is a retrospective review of a single-surgeon consecutive series of index cases performed between 2003 and 2010. Inclusion criteria were ceramic-on-ceramic THA articulations in patients younger than 50 with a diagnosis of osteonecrosis. Mean follow-up was 12.5 years (range 9–17). Data were collected by survey via mail, telephone, e-mail, and social media. Preoperative and postoperative Western Ontario and McMaster University (WOMAC) Arthritis Index and University of California at Los Angeles (UCLA) activity scores were collected. Student t-tests were used as appropriate. There were 97 patients in this series. Mean age at THA was 36 (range 14–50). Since the prior report, four more patients have been confirmed deceased, and four more have been lost to follow-up. We confirmed that six patients were deceased and 42 were otherwise lost to follow-up. The response rate was 54%. The vast majority of patients were highly active at latest follow-up (73% with UCLA scores between 7 and 10). UCLA scores (1–10 scale) improved from a preoperative mean of 3.4 to postoperative 7.1 (p &lt; 0.001). WOMAC scores (1–100 scale) increased from preoperative mean of 38.7 to postoperative 86.1 (p &lt; 0.001). At latest follow-up, four patients had undergone revision surgery. There were no ceramic component failures. One patient underwent early revision for femoral component loosening, one was revised for chronic pain at another institution. Since the prior report there have been two additional revisions; one patient was revised for instability at 5-year postop, and one patient was revised for periprosthetic fracture at 10 years. Despite additional loss to follow-up and lack of clinical and radiographic measures, this survey study suggests that at long-term follow-up ceramic bearings accommodate high activity level with excellent component survivorship (93%) in young patients undergoing THA.

Survivorship and Etiologies of Failure in Single-stage Revision Arthroplasty for Periprosthetic Joint Infection: A Meta-analysis

Single-stage revision arthroplasty for periprosthetic joint infection (PJI) may yield comparable infection-free survivorship with two-stage revision arthroplasty. It is unclear if the most common mode of failure of single-stage revision arthroplasty is infection or aseptic loosening. In this meta-analysis, we sought to (1) determine survivorship and (2) compare rates of different etiologies of failure of single-stage revision total hip arthroplasty (THA) and total knee arthroplasty (TKA). Preferred Reporting Items for Systematic Review and Meta-analyses guidelines search was done using search terms for "single stage revision," "exchange arthroplasty," "periprosthetic infection," "PJI," and "single stage." Patient demographics such as age, body mass index, and mean follow-up time were recorded. Overall survivorship and rates of revision surgery were aggregated using a random-effects model. Comparison of septic and aseptic loosening rates was done by risk difference and associated 95% confidence interval (CI) calculation. Twenty-four studies were identified with 2,062 and 147 single-stage revision THA and TKA procedures performed between 1984 and 2019, respectively. The weighted mean follow-up and age were 69.8 months and 66.3 years, respectively, with 55% men overall. The all-cause revision surgery rate was 11.1% and 11.8% for THA and TKA, respectively. The revision surgery rate secondary to infection and aseptic loosening and associated 95% CI for the risk difference for THA and TKA was 5.5% and 3.3% (-1.7% to 5.0%), and 3% and 8.8% (-11.4% to 2.3%), respectively. Revision surgeries due to instability and fracture combined and mortality rate were both less than 3%. Single-stage revision THA and TKA for PJI demonstrated overall high rates of survivorship, low mortality, and revision surgeries secondary to infection and aseptic loosening to be equivalent. Aseptic loosening after single-stage revision TKA might be higher than in primary TKA. As implant survivorship from infection improves in PJI, surgeons should be aware of aseptic loosening as an equally common mode of failure.

Persistent Chronic Periprosthetic Joint Infection Treated with Three-Stage Revision Hip Arthroplasty: A Case Report

Background: Periprosthetic Joint Infection (PJI) is a dreadful complication of primary Total Hip Arthroplasty (THA). Following revision THA, up to 17% of revision THA can be complicated with PJI. Three-stage revision should only be done if simple debridement fails to treat PJI. Here we present a rare case of persistent PJI, treated with three-stage revision and bone grafting.Case Report: A thirty-seven-year-old female patient came with a chief complaint of hip pain four months ago. Four years ago, the patient had a right column femur fracture and was treated with THA. One year afterward, the implant was infected, and the hip was debrided. One year later, the infection symptom recurred, and three-stage revision hip arthroplasty was planned with one year delay for each stage: removal of the implant, replacement of spacer, and reimplantation. The acetabular bone was augmented using autograft from the iliac wing during reimplantation. After reimplantation, the pain subsides, and the patient can walk normally again.Discussion: Previous studies have found various risk factors that might contribute to the failure of two-stage revision arthroplasty. The infecting bacteria is one of the major risk factors, and therefore appropriate antibiotic is important. Augmentation of bone graft can also supplement acetabular bone loss during failed THA as it helps as a scaffold for bone healing.Conclusion: Three-stage revision hip arthroplasty after PJI using bone graft for augmentation is possible with a good result.