Loosening Of Total Hip Arthroplasty Research Articles

Comparison of Health Care Costs Between Aseptic and Two Stage Septic Hip Revision

The number of septic and aseptic total hip arthroplasty (THA) revisions will increase, which involves a greater financial burden. We here provide a retrospective consecutive analysis of the major variable direct costs involved in revision THA for aseptic and septic failure. A total of 144 patients (30 septic, 114 aseptic) treated between January 1, 2009 and March 31, 2012 was included. The management of septic THA loosening is much more expensive than that of aseptic loosening ($14,379.8 vs. $5,487.4). This difference is mainly attributable to the two-stage exchange technique used for septic failure (hospital stay: 40.2 vs. 15.6 days) and significantly higher implant costs ($3,930.9 vs. $2,298.2). The septic implantation part is on average $3,384.6 more expensive than aseptic procedures (P < .001).

The Role of Oxidative Stress in Aseptic Loosening of Total Hip Arthroplasties

This study investigated the hypothesis that wear particle-induced oxidative stress initiates osteolysis after total hip arthroplasty (THA). Patient radiographs were scored for osteolysis and periprosthetic tissues were immunostained and imaged to quantify polyethylene wear, inflammation, and five osteoinflammatory and oxidative stress-responsive factors. These included high mobility group protein-B1 (HMGB1), cyclooxygenase-2 (COX2), inducible nitric oxide synthase (iNOS), 4-hydroxynonenal (4-HNE), and nitrotyrosine (NT). The results show wear debris correlated with inflammation, 4-HNE, NT and HMGB1, whereas inflammation only correlated with NT and HMGB1. Similar to wear debris and inflammation, osteolysis correlated with HMGB1. Additionally, osteolysis correlated with COX2 and 4-HNE, but not iNOS or NT. Understanding the involvement of oxidative stress in wear-induced osteolysis will help identify diagnostic biomarkers and therapeutic targets to prevent osteolysis after THA.

Correlation of Aspiration Results With Aseptic Loosening in Total Hip Arthroplasty

In the evaluation of patients with a persistently painful total hip arthroplasty establishing an accurate diagnosis is paramount in the selection of a successful treatment regimen. It is unknown whether synovial analysis might differentiate aseptic loosening from other causes of failure. A physiological basis exists to suggest that aseptic loosening might be a process of non-segmented leukocytes. The objective of this study was to determine if the synovial fluid differential cell count might aid in the diagnosis of aseptic loosening. A retrospective chart review of all patients who had undergone revision hip arthroplasty with pre-operative or intra-operative aspiration results was performed. Aseptic loosening was defined as gross intraoperative movement in the absence of infection. From these results Relative-Operating Characteristic (ROC) curves were created, and sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. A diagnosis of aseptic loosening was established in 76 of the 253 hips. The ROC curves indicated that lymphocyte count does have utility in the diagnosis of aseptic loosening. If an aspirate has a combination of fewer than 2500 WBCs (sensitivity 93%, specificity 42%, NPV 94%, accuracy 57%) or more than 10% lymphocytes (sensitivity 86%, specificity 42%, NPV 87%, accuracy 55%) then the sensitivity for aseptic loosening is 96%, the specificity is 33%, the NPV is 95% and the accuracy is 52%. In patients with painful total hip arthroplasties in whom infection has been excluded, aspiration data can be a useful adjunct in the diagnosis of aseptic loosening. In aspirates with neither a WBC cell count of less than 2500 nor a lymphocyte cell count of greater than 10% aseptic loosening can be effectively "ruled out" as fewer than 5% of these patients will have aseptic loosening. While non-specific, aspirate differential can be useful to "rule-out" aseptic loosening with a sensitivity and negative predictive value well exceeding that of standard radiographs.

Wear, bone density, functional outcome and survival in vitamin E-incorporated polyethylene cups in reversed hybrid total hip arthroplasty: design of a randomized controlled trial

BackgroundAseptic loosening of total hip arthroplasties is generally caused by periprosthetic bone resorption due to tissue reactions on polyethylene wear particles. In vitro testing of polyethylene cups incorporated with vitamin E shows increased wear resistance. The objective of this study is to compare vitamin E-stabilized highly cross-linked polyethylene with conventional cross-linked polyethylene in “reversed hybrid” total hip arthroplasties (cemented all-polyethylene cups combined with uncemented femoral stems). We hypothesize that the adjunction of vitamin E leads to a decrease in polyethylene wear in the long-term. We also expect changes in bone mineral density, less osteolysis, equal functional scores and increased implant survival in polyethylene cemented cups incorporated with vitamin E in the long-term.DesignA double-blinded randomized controlled trial will be conducted. Patients to be included are aged under 70, suffer from non-inflammatory degenerative joint disease of the hip and are scheduled for a primary total hip arthroplasty. The study group will receive a reversed hybrid total hip arthroplasty with a vitamin E-stabilized highly cross-linked polyethylene cemented cup. The control group will receive a reversed hybrid total hip arthroplasty with a conventional cross-linked polyethylene cemented cup. Radiological follow-up will be assessed at 6 weeks and at 1, 3, 5, 7 and 10 years postoperatively, to determine polyethylene wear and osteolysis. Patient-reported functional status (HOOS), physician-reported functional status (Harris Hip Score) and patients’ physical activity behavior (SQUASH) will also be assessed at these intervals. Acetabular bone mineral density will be assessed by dual energy X-ray absorptiometry (DEXA) at 6 weeks and at 1 year and 2 years postoperatively. Implant survival will be determined at 10 years postoperatively.DiscussionIn vitro results of vitamin E-stabilized polyethylene are promising, showing increased wear resistance. However, controlled clinical follow-up data are not available at this moment.This randomized controlled trial has been designed to determine wear, bone mineral density, functional outcome and survival in reversed hybrid total hip arthroplasty comparing cemented vitamin E-stabilized highly cross-linked polyethylene cups with cemented conventional cross-linked polyethylene cups.Trial registrationDutch Trial Registry NTR3049

CIRCUMFERENTIAL PROXIMAL FEMORAL ALLOGRAFTS IN TOTAL HIP ARTHROPLASTY REVISION SURGERY

Objective: To evaluate the clinical and radiographic results from patients who underwent femoral reconstruction secondary to loosening of total hip arthroplasty, using circumferential proximal femoral allografts and cemented implants. Methods: A retrospective study was conducted on 32 patients (33 hips) who underwent femoral reconstruction secondary to loosening of total hip arthroplasty, using circumferential proximal femoral allografts and cemented implants. Among these patients, 28 (29 hips) fulfilled all the requirements for this study. The mean follow-up was five years and two months. The clinical evaluation was done in accordance with the Harris Hip Score. Radiographically, the patients were assessed regarding reabsorption and consolidation of the allograft, migration of the greater trochanter, stability of the femoral component and heterotypic calcification. Results: The average preoperative Harris Hip Score was 32 points. At the last postoperative follow-up, the average score was 82 points. Allograft resorption of some degree was seen in nine hips (31%). Regarding consolidation, 24 cases (82.8%) showed full consolidation, three (10.3%) showed partial consolidation and two (6.9%) showed pseudarthrosis. All femoral components were stable. According to the criteria established, 27 cases (93.1%) were considered to be successful reconstructions after a mean follow-up of five years and two months. Conclusion: From the results obtained, it was concluded that use of circumferential proximal femoral allografts in selected cases of femoral reconstruction secondary to loosening of arthroplasty presented a high survival rate from the reconstruction over an average follow-up of five years and two months.

Aloenxerto circunferencial de fêmur proximal em cirurgias de revisão de artroplastia total de quadril

OBJETIVO: Avaliar os resultados clinicos e radiograficos de pacientes submetidos a reconstrucao femoral secundaria a afrouxamento de artroplastia total de quadril, com utilizacao de aloenxerto circunferencial de femur proximal e implante cimentado. METODOS: Foi efetuado um estudo retrospectivo com 32 pacientes (33 quadris) submetidos a reconstrucao femoral secundaria a afrouxamento de artroplastia total de quadril, com utilizacao de aloenxerto circunferencial de femur proximal e implante cimentado. Desses pacientes, 28 (29 quadris) preencheram todos os requisitos necessarios. O seguimento medio foi de cinco anos e dois meses. A avaliacao clinica foi realizada de acordo com o Harris Hip Score. Radiograficamente, os pacientes foram avaliados quanto a reabsorcao e consolidacao do aloenxerto, migracao do trocânter maior, estabilidade do componente femoral e calcificacao heterotopica. RESULTADOS: O Harris Hip Score apresentou resultado pre-operatorio medio de 32 pontos e pos-operatorio tardio de 82 pontos. Considerando-se a reabsorcao do aloenxerto, visibilizou-se nove quadris (31%) com presenca de reabsorcao em algum grau. Com relacao a consolidacao, observou-se 24 casos (82,8%) consolidados, tres (10,3%) consolidados parcialmente e dois (6,9%) com pseudoartrose. Conforme os criterios estabelecidos, consideraram-se 27 casos (93,1%) como sucesso da reconstrucao em seguimento medio de cinco anos e dois meses. CONCLUSOES: Com base nos resultados obtidos, conclui-se que a utilizacao de aloenxerto circunferencial de femur proximal em casos selecionados de reconstrucao femoral secundaria a afrouxamento de artroplastia, apresenta alto indice de sobrevida da reconstrucao em seguimento medio de cinco anos e dois meses.

Reliability of the Radiological Assessments of Radiolucency and Loosening in Total Hip Arthroplasty Using Pacs

We evaluated the reliability of three commonly used radiological assessments of total hip arthroplasty (THA) using the electronic picture archiving and communications system (PACS). Thirty-three patients were selected at random at a mean of 7.2 years after THA. The Barrack, Gruen and Hodgkinson evaluations of cementing quality, loosening/radiolucency were graded. Three observers assessed each radiograph (one consultant orthopaedic surgeon, one senior orthopaedic registrar and one senior house officer). Four weeks after the initial assessment, each radiograph was reviewed a second time. The findings indicated that the intra- and inter-observer reliability of the Barrack, Gruen and Hodgkinson methods were questionable. Inter-observer reliability using the Gruen system was poor, using the Barrack system it was moderate to good, and fair to good using the Hodgkinson assessment. Intra-observer reliability was moderate to good for Barrack assessment, poor to good using Gruen zone assessments, but good to very good for the Hodgkinson assessment. The use of Barrack, Gruen and Hodgkinson assessments to evaluate femoral and acetabular loosening should be questioned since these exhibit limited inter- and intra-observer reliability on PACS radiographs, but of the three, the Hodgkinson system is the most reliable.

Clinical report. Atypical acetabular bone loss in chronic septic total hip arthroplasty loosening

Abstract Background: When a periprosthetic infection is diagnosed, the surgical treatment is usually performed as soon as possible to avoid further bone damage or life threatening complications. There is no report on the radiographic change in patients with untreated infected total hip arthroplasty (THA) for several years. Objective: Report radiographic change in patients with untreated infected THA. Method: Two patients presented with chronic septic loosening of cemented acetabular fixation after total hip replacement at King Chulalongkorn Memorial Hospital. Both patients had mild hip pain and had been lost for follow-up until the bone destruction became very severe. Serial radiographs after the surgeries were evaluated. The Paprosky’s acetabular bone loss classification was used to classify the radiographic findings. Results: Based on the Paprosky’s classification for acetabular bone loss, there were two similar atypical radiographic findings found in both patients. These included pelvic discontinuity from extensive medial acetabular bone loss beyond the Kohler’s line, and minimal superior and inferior acetabular bone loss. Conclusion: These atypical radiographic findings were rarely observed in septic acetabular loosening patients, as infection usually causes patients to present earlier. Following the septic acetabular loosening of THA, surgical procedure should be performed before massive bone damage was demonstrated.

Letter to the Editor: Aseptic Loosening of Total Hip Arthroplasty: Infection Always Should be Ruled Out

We welcome the study by Parvizi et al. [3] published in the May edition of the journal and the attention it draws to the misdiagnosis of aseptic loosening which may occur if infection is not rigorously excluded. This supports the work of other authors, who have confirmed infection in as much as 13% of cases of presumed aseptic loosening [2]. The methodology of the study however poses some questions. First, the distinction between patients with infection and without infection must be questioned as a large proportion of patients deemed to be correctly diagnosed as having aseptic loosening did not have specimens sent for culture. In patients who did have specimens sent, a minimum of three intraoperative specimens were cultured but this number has been shown to be inadequate [1]. Sending less than five intraoperative specimens is especially likely to be insensitive for the low virulence organisms which are most likely to masquerade as aseptic loosening. There is also the likelihood that a proportion of the patients assigned to Group 1 (prosthetic joint infection) on the grounds of definite prosthetic joint infection at the time of subsequent rerevision actually had infection after their revision surgery rather than representing falsely diagnosed aseptic loosening. Also, in patients assigned to Group 1 on the basis of positive cultures, the number of tissues required to be positive for a diagnosis of infection is not stated. It is recognized that positive cultures from one tissue specimen are likely to represent contamination, again emphasizing the need to send an adequate number of specimens [1]. After arrival at the laboratory, the microbiologic processing of the specimens is not detailed. Variations in processing technique are recognized to greatly impact on the sensitivity and specificity of orthopaedic tissue culture. Correctly diagnosing prosthetic joint infection is a team effort requiring an appropriate number of correctly taken specimens to be rapidly transported to a microbiology laboratory. The specimens need to be processed correctly, avoiding contamination but optimizing the potential for growth of any pathogenic organisms. Important in this regard are the use of broth cultures (and their subsequent terminal subculture at the end of prolonged incubation) in addition to direct cultures and prolongation of incubation to detect slow-growing low virulence organisms [4]. Finally, the organisms grown need to be identified correctly, their significance interpreted, and an appropriate management plan formulated between surgeon and microbiologist. Ideally patients with possible prosthetic joint infections should be under the care of a surgeon with a specialist interest in the field and the diagnostic process facilitated by the use of a microbiology laboratory and reporting microbiologist specializing in orthopaedic infections. By adopting this approach the number of incorrect diagnoses of aseptic loosening can be minimized.

Reply to Letter to the Editor: Aseptic Loosening of Total Hip Arthroplasty: Infection Always Should be Ruled Out

We thank Dr. Partridge and his colleagues for their letter. They commented, ”…the distinction between patients with infection and without infection must be questioned as a large proportion of patients deemed to be correctly diagnosed as having aseptic loosening did not have specimens sent for culture.” As we explained [4], before institution of a standard protocol, some patients with aseptic loosening may not have been adequately investigated to rule out periprosthetic joint infection (PJI). The latter explains why intraoperative culture specimens were not sent for some patients. Although their point is valid, it does not detract from the message of the paper. At worst, sending culture specimens for the aseptic cases might have increased the number of “misdiagnosed” aseptic cases adding strength to the message of the article. However, the number of optimal culture specimens is not known. In the recent AAOS Guidelines for Diagnosis of PJI for which a comprehensive literature search was done, Della Valle et al. were not able to address this issue based on evidence [3]. Dr. Partridge and his colleagues also commented, “There is also the likelihood that a proportion of the patients assigned to Group 1 (prosthetic joint infection) on the grounds of definite prosthetic joint infection at the time of subsequent rerevision actually had infection after their revision surgery rather than representing falsely diagnosed aseptic loosening.” We were cognizant regarding the possibility that some of the subsequent infections might have been de novo PJIs and not missed aseptic cases, as we stated in our article. Although plausible, the latter is unlikely as these patients did have abnormal serology, and in some cases synovial cell count, at the time of their index revision. There currently are no definite diagnostic criteria for PJI [1]. We are unaware of any validated criteria specifying the number of culture specimens required to be positive for the case to qualify as PJI, nor is there a definite criterion that specifies the importance of isolation of organisms from broth. Diagnosis of PJI is based on a combination of criteria that may need to be varied on an individual basis. As reported previously, in as much as 7% of PJI cases one is not able to isolate the infecting organism (culture negative cases) [2]. Thus, reliance on isolation of an organism (positive culture) is not accepted as the gold standard for diagnosis of PJI. We disagree with the last comment in the third paragraph that isolation of an organism from a single culture represents contamination. For example, for a patient with abnormal serology and abnormal synovial cell count parameters in whom an organism is isolated from a single culture–even broth, would the latter result not be considered significant? Within the confines of manuscript length, we discussed the details pertinent to transport and processing of culture specimens. We recognize that variations in processing culture specimens might have existed but also acknowledge that this is not unique to this cohort or our institution. We agree that management of patients with PJI requires a team effort. As a center that treats approximately 300 patients with PJI per year, we rely on the expertise of our colleagues from infectious disease, microbiology, pharmacy, rehabilitation, and other disciplines to optimize the care of these patients.

Atypical acetabular bone loss in chronic septic total hip arthroplasty loosening

Background: When a periprosthetic infection is diagnosed, the surgical treatment is usually performed as soon as possible to avoid further bone damage or life threatening complications. There is no report on the radiographic change in patients with untreated infected total hip arthroplasty (THA) for several years. Objective: Report radiographic change in patients with untreated infected THA. Method: Two patients presented with chronic septic loosening of cemented acetabular fixation after total hip replacement at King Chulalongkorn Memorial Hospital. Both patients had mild hip pain and had been lost for follow-up until the bone destruction became very severe. Serial radiographs after the surgeries were evaluated. The Paprosky’s acetabular bone loss classification was used to classify the radiographic findings. Results: Based on the Paprosky’s classification for acetabular bone loss, there were two similar atypical radiographic findings found in both patients. These included pelvic discontinuity from extensive medial acetabular bone loss beyond the Kohler’s line, and minimal superior and inferior acetabular bone loss. Conclusion: These atypical radiographic findings were rarely observed in septic acetabular loosening patients, as infection usually causes patients to present earlier. Following the septic acetabular loosening of THA, surgical procedure should be performed before massive bone damage was demonstrated. Keywords: Acetabular loosening, atypical, cemented fixation, radiographic finding, septic, total hip replacement

Aseptic Loosening of Total Hip Arthroplasty: Infection Always Should be Ruled Out

It is believed that some cases of aseptic failure of THA may be attributable to occult infections. However, it is unclear whether preoperative erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are more likely elevated in these patients than those without overt infection. We asked whether some patients with aseptic THA failures have abnormal serologic indicators of periprosthetic joint infection (PJI) at the time of revision, namely ESR and/or CRP. Three hundred twenty-three revision THAs for aseptic loosening from 2004 to 2007 were retrospectively evaluated. We categorized all cases into two groups: (1) those with overt PJI (n = 14) plus patients who had a positive intraoperative culture during the index revision (n = 13) and (2) those who did not require rerevision (n = 276) or required surgery for noninfected causes (n = 20). Mean and frequency of abnormal ESR and CRP were compared between the two groups. The minimum followup was 11 months (average, 35 months; range, 11-54 months). The mean and frequency of abnormal CRP in first group (n = 27) at 2.1 mg/dL and 48% respectively, were greater than those of the uninfected (n = 296) at 1.2 mg/dL and 27%, respectively. However, there were no differences between two groups regarding mean or frequency of abnormal ESR. Some patients with presumed aseptic loosening may have abnormal serologic indicators of PJI that either have escaped diagnosis or were not adequately investigated. All patients undergoing revision THA should have ESR and CRP measured preoperatively and those with abnormal CRP should have additional evaluations to rule out or confirm PJI.

Incidence of low-grade infection in aseptic loosening of total hip arthroplasty

Purpose We investigated the hypothesis that many total hip arthroplasty revisions that are classified as aseptic are in fact low-grade infections missed with routine diagnostics.Methods In 7 Dutch hospitals, 176 consecutive patients with the preoperative diagnosis of aseptic loosening of their total hip arthroplasty were enrolled. During surgery, between 14 and 20 tissue samples were obtained for culture, pathology, and broad-range 16S rRNA PCR with reverse line blot hybridization. Patients were classified as either not being infected, suspected of having infection, or infected according to strict, predefined criteria. Each patient had a follow-up visit after 1 year.Results 7 patients were classified as infected, 4 of whom were not identified by routine culture. 15 additional patients were suspected of having infection. 20 of these 22 patients received a cemented prosthesis, fixated with antibiotic-loaded bone cement. All 22 patients received prophylactic systemic antibiotics. 7 of them reported complaints one year after surgery, but only one showed signs of early loosening. However, additional surgery was not performed in any of the patients.Interpretation Although the proportions were not as high as previously reported in the literature, between 4% and 13% of patients with the preoperative diagnosis of aseptic loosening were infected. However, as thorough debridement was performed during surgery and prophylactic antibiotics were used, the diagnosis of infection did not have any obvious clinical consequences, as most patients performed well at the 1-year follow-up. Whether this observation has implications for long-term implant survival remains to be seen.

Correlation of Technetium-99m Scintigraphy, Progressive Acetabular Osteolysis and Acetabular Component Loosening in Total Hip Arthroplasty

In total hip arthroplasty (THA) Technetium scintigraphy can help to diagnose a loose implant by detecting elevated osteoblastic activity. It has been used for timing the revision of cemented implants. In uncemented cups progressive radiological acetabular osteolysis can be present before loosening accurs, but it is probably unwise to await cup loosening before embarking on revision. We explored the possible relationship between such osteolysis and positive findings on technetium scintigraphy, to see if the technique could predict the need for revision. Between 1990 and 1996 500 hydroxyapatite-coated hip prostheses were implanted (follow-up range: 9-15 years), and technetium scintigraphy and plain radiography were performed annually postoperatively. 32 cups were revised for progressive acetabular osteolysis. We compared the introperative findings at revision with the pre-operative scintigraphic and radiographic results. The sensitivity and specificity for diagnosing progressive acetabular osteolysis by technetium scintigraphy were 34% and 0% respectively. The sensitivity and specificity of the technique for detecting loosening were 38% and 73% respectively. The sensitivity and specificity of technetium scintigraphy for detection of a either loosening or progressive acetabular osteolysis are worse than reported for plain radiography. Despite negative scintigraphy, there may be progressive bone loss at a critical level. Scintigraphy has no additional value to plain radiography as a reliable indicator for timing cup revision in the process of progressive acetabular osteolysis.

Aseptic Loosening of Total Hip Arthroplasty: Are They All Truly Aseptic?

Microorganisms can simply live in glycocalyx-enclosed biofilms that are adherent to surfaces of implanted prostheses without presenting with florid clinical signs of infection. The detection of infection in these circumstances still presents a challenge. Differentiation between aseptic loosening and failures attributable to periprosthetic joint infection (PJI) is critical, so that proper intervention can be implemented. The aim of our study was to determine if patients with failure for aseptic loosening are properly evaluated for infection prior to revision surgery. Patients developing infection after revision for an aseptic failure were evaluated in detail to assess the accuracy of diagnosis of aseptic failure.

Potential role of tartrate‐resistant acid phosphatase 5b (TRACP 5b) as a surrogate marker of late loosening in patients with total hip arthroplasty: A cohort study

In a cohort study, the role of the active tartrate-resistant acid phosphatase (TRACP 5b), a marker of bone-resorbing osteoclasts, for the assessment of loosening after total hip arthroplasty (THA), was analyzed, as well as its correlation with osteolysis and multinucleated cell appearance in the retrievals. Eighty THA patients, who went consecutively to the orthopedic department, were asked to participate, and 54 accepted and were enrolled in the study. Finally, 46 subjects were analyzed, clinical-radiographic evaluation was considered the gold standard, serum TRACP 5b was blindly measured, and a cut-off was obtained, by performing a ROC Curve. Based on the gold standard, patients were split by 19 stable and 27 loosened subjects, and results were matched. TRACP 5b was significantly higher in loosened patients than in stable ones (p < 0.001). A good specificity (89.5%), positive predictive value (90.0%), and likelihood ratio (6.33) were calculated, that provided strong evidence of loosening with TRACP 5b levels higher than the cut-off. Moreover, TRACP 5b and osteolysis (Fisher's exact test, p = 0.03) were found significantly correlated. TRACP 5b has been proven a reliable marker, specifically related to resorbing-multinucleated cells, to ascertain late loosening in THA, and could support standard procedures, if confirmed by performing prospective studies.

A Comparison of the Validity and Reliability of Established Bone Stock Loss Classification Systems and the Proposal of a Novel Classification System

The classification and management of aseptic loosening of total hip arthroplasty remains a distinct challenge to the modern orthopaedic surgeon. The aim of this study was to assess the inter-observer and intra-observer reliability of commonly used classification systems for the assessment of bone stock loss in revision hip surgery. Radiographs of 23 femoral and 32 acetabular components in 30 patients were assessed using the Paprosky, AAOS and Endo-Klinik classification systems. A novel classification system was introduced and also used to assess the radiographs. Assessment was undertaken by 3 surgeons on 2 separate occasions and the inter- and intra- observer reliability calculated. The novel classification system showed a good to very good intra-observer reliability for both femoral and acetabular components (0.77-1.0; p<0.001), performing better than the other systems assessed. The novel femoral system demonstrated moderate to good inter-observer agreement (0.46-0.73), performing as well as the Paprosky (0.63-0.80) and AAOS (0.63-0.68) femoral systems. The novel acetabular system demonstrated fair to moderate inter-observer reliability (0.35-0.51) performing better than the AAOS acetabular classification (0.07-0.10) and as well as the Paprosky acetabular classification system (0.59-0.60). We propose this novel system as an alternative method for assessing bone stock loss in revision hip surgery.

Can Preoperative Radiographic Markers be Used to Predict Loosening of Total Hip Arthroplasties?

Can Preoperative Radiographic Markers be Used to Predict Loosening of Total Hip Arthroplasties?

Reallocation of Foundation Programme Doctors From Teams to Wards Reduces Mortality From Proximal Femoral Fracture

Reallocation of Foundation Programme Doctors From Teams to Wards Reduces Mortality From Proximal Femoral Fracture

Over-expression of receptor activator of nuclear factor-κB ligand (RANKL), inflammatory cytokines, and chemokines in periprosthetic osteolysis of loosened total hip arthroplasty

Loosening of total hip arthroplasty (THA) caused by periprosthetic osteolysis induced by ultra-high molecular weight polyethylene (UHMWPE) particles is a major clinical problem. We investigated whether there are differences between loosened THA patients and primary THA patients in (1) receptor activator of nuclear factor-κB ligand (RANKL) expression on periprosthetic bone marrow cells; (2) RANKL levels, osteoprotegerin (OPG)/RANKL ratios, the levels of inflammatory cytokines and chemokines in synovial fluid. We used flow cytometric analysis to detect RANKL expression on periprosthetic bone marrow cells. We used enzyme-linked immunoassay and multiplex microsphere-based immunoassay to measure RANKL, OPG, cytokines, and chemokines in synovial fluid. We found loosened THA patients had higher RANKL expression on osteoblastic stromal cells, higher levels of RANKL, interleukin (IL)-6, IL-8, IL-10, interferon-γ-inducible protein (IP)-10, monocyte chemoattractant protein (MCP)-1, monokine induced by interferon-γ (MIG), and lower OPG/RANKL ratios in synovial fluid than primary THA patients. There was positive correlation between the levels of IL-6, IL-8, IL-10, IP-10, MCP-1, or MIG and RANKL levels in synovial fluid or RANKL expression on osteoblastic stromal cells. These suggest that UHMWPE particles induce over-expression of RANKL, IL-6, IL-8, IP-10, MCP-1, and MIG in human periprosthetic microenvironment. This results in periprosthetic osteolysis and loosening of THA.