Aim. What is the fate of revision total joint arthroplasty, when conventional tissue sample culture (TSC) is negative and sonication fluid culture (SFC) is positive, in terms of re-revision?. Method. We prospectively analyzed explanted prosthetic materials from 211 consecutive cases of total hip and knee arthroplasty revision surgery performed on any indication during a one year period. We used a sonication apparatus and protocol that was previously described [Borens et al, 2013. J Orthop Res]. Sampling of five periprosthetic tissue biopsies was performed according to the local protocol and incubated for 5 days. In our non-interventional study design, clinicians were blinded to the results from sonication-culture, which were not used for the subsequent treatment strategy. In cases with suspected deep infection, thorough debridement was performed during revision surgery, and routine antibiotic treatment was dicloxacillin for 6–8 weeks. Patients were routinely seen in the outpatient clinic after 3 and 12 months, where clinical examination and any antibiotic treatment were documented. Minimum follow-up was 1 year. This cohort study is reported according to the STROBE guidelines. Results. Microbial findings in TSC and SFC were similar in 41/211 cases. Additional 11/211 cases were identified with positive SFC, despite negative in conventional culture. Of these, 8/11 cases with suspected prosthetic joint infection (PJI) a strategy of revision and empirical antibiotic therapy was completed. Another 3/11 cases with suspected aseptic failure, partial 1-stage revisions were performed with no subsequent antibiotic therapy. Re-revisions were necessary in 5/11 cases of expected PJI, and 2/11 of these ended up with permanent Girdlestone status. A strategy of antibiotic suppression was implemented in 1/11 case. Another 1/11 patient diseased in circulatory failure 4 days after 2nd stage operation. In 3/11 cases the painful joint prosthesis is still unsolved after 1 year, and only 1/11 case had an asymptomatic prosthesis at follow-up after 1 year. Culture results of the subsequent revisions in this small cohort shows several links to the microbiological findings in SFC. Conclusions. We identified 11/211 revisions of total joint arthroplasty, where conventional TSC was negative and SFC was positive. The fate of these cases included re-revision in 5/11. From a clinical perspective, patients with additional microbial findings by SFC had a discouraging prognosis and may represent true positive findings that have to be taken into consideration in the infection treatment

Despite the demonstrated success in revision total joint arthroplasties, the utilization of antibiotic-loaded bone cement in primary total joint arthroplasty remains controversial. Multiple studies have demonstrated several risks associated with the routine use of this technique including: allergic reactions, changing the mechanical properties of the cement, emergence of resistant bacterial strains, systemic toxicity, and the added cost. In addition, evidence shows a currently low rate of periprosthetic joint infections in primary total joint arthroplasty (around 1%) and the theoretical benefit of marginally reducing this rate by using antibiotic-cement may not necessarily justify the associated risks and the added cost. Moreover, most of the primary total hip and an increasing number of primary total knee arthroplasties are cementless, which further raises questions about the routine use of antibiotic-loaded bone cement in primary total joint arthroplasty

Background. Standard preoperative protocols in total joint arthroplasty utilize the International Normalized Ratio (INR) to determine patient coagulation profiles. However, the relevance of preoperative INR values in joint arthroplasty remains controversial. Acceptable INR cutoff values for joint replacement are inconsistent, and are often based on studies of primary arthroplasty, or even non-orthopedic procedures. This analysis examined the relationship between preoperative INR values and post-operative outcomes in revision total hip arthroplasty (rTHA). Optimal cutoff INR values correlated with specific outcomes were subsequently determined. Methods. The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) was retrospectively queried for revision total hip arthroplasty procedures performed between 2006 and 2017. Patients with a preoperative INR collected no later than 1 day prior to surgery were further stratified for analysis. INR values which correlated with specific outcomes were determined using receiver operating characteristics (ROC) curves for each outcome of interest. The optimal cutoff INR value for each outcome was then obtained using univariate and multivariate models which determined INR values that maximized both sensitivity and specificity. Results. There were a total of 11,393 patients who underwent a revision total hip arthroplasty from 2006–2017 recorded in NSQIP. Of the 2,012 patients who met inclusion and exclusion criteria, 858 had an INR < 1.0, 931 had an INR > 1.0 to 1.25, 175 had an INR > 1.25 to 1.5, and 48 patients had an INR > 1.5. Patients with progressively higher INR values had a significantly different risk of mortality within 30 days (p=0.005), bleeding requiring transfusion (p< 0.001), sepsis (p=0.002), stroke (p<0.001), failure to wean from ventilator within 48 hours (p=0.001), readmission (p=0.01), and hospital length of stay (p< 0.001). Similar results were obtained when utilizing optimal INR cutoff values. When correcting for other factors, the following poor outcomes were significantly associated with the respective INR cutoff values (Estimate, 95% CI, p value): LOS (1.67, 1.34–2.08, p <0.001), bleeding requiring transfusion (1.65, 1.30–2.09, p<0.001), sepsis (2.15, 1.11–4.17, p 0.02), and any infection (1.82, 1.01–3.29, p 0.04). Conclusions. INR values >1.65, >1.67, >1.82, and >2.15 were correlated with increased transfusion requirements, LOS, any infection, and sepsis respectively. Therefore, even subtherapeutic elevations in INR may predict poor outcomes following revision total joint replacement. Surgeons and perioperative medical specialists should consider more stringent INR goals when optimizing patients prior to revision arthroplasty. Level of Evidence. Prognostic Level IV. For any figures or tables, please contact authors directly

The AAOS clinical practice guideline for diagnosis of periprosthetic joint infection (PJI) and the MSIS definition of PJI were both “game changers” in terms of diagnosing PJI and the reporting of outcomes for research. However, the introduction of new diagnostic modalities, including biomarkers, prompted a re-look at the diagnostic criteria for PJI. Further there was a desire to develop an evidence-based, validated algorithm for the diagnosis of PJI. This multi-institutional study led by Dr. Jay Parvizi examined revision total joint arthroplasty patients from three academic institutions. For development of the algorithm, infected and aseptic cohorts were defined. PJI cases were defined using only the major criteria from the Musculoskeletal Infection Society (MSIS) definition (n=684). Aseptic cases underwent revision for a non-infective indication and did not show evidence of PJI or undergo a reoperation for any reason within 2 years (n=820). Risk factors, clinical findings, serum and synovial markers as well as intraoperative findings were assessed. A stepwise approach using random forest analysis and multivariate regression was used to generate relative weights for each of the various variables assessed at each stage to create an algorithm for diagnosing PJI using the 3 most important tests from each step. The algorithm was formally validated on a separate cohort of 422 patients, 222 who were treated with a 2-stage exchange for PJI who subsequently failed secondary to PJI within one year and 200 patients who underwent revision surgery for an aseptic diagnosis and had no evidence of PJI within two years and did not undergo a reoperation for any reason. The first step in evaluating PJI should include a physical examination to identify a sinus tract, followed by serum testing for C-reactive protein (cut-off value 1mg/dl), D-dimer (cut-off value 860ng/mL) and/or erythrocyte sedimentation rate (cut-off value 30mm/hr) in that order of importance. If at least one of these are elevated, or if there is a high clinical suspicion, joint aspiration should be performed, sending the fluid obtained for a synovial fluid white blood-cell (cut-off value 3,000 wbc/uL) or leukocyte esterase strip testing, polymorphonuclear percentage (cut-off value 80%) and culture. Alpha defensin did not show added benefit as a routine diagnostic test. Major diagnostic criteria are the same whereby the presence of a sinus tract or (2) positive cultures showing the same organism defines PJI. Special care should be taken in cases of ALTR (failed metal-on-metal bearing), crystalline deposition disease, inflammatory arthritis flares or slow growing organisms. In the rare cases where no fluid is obtained at the time of an attempted aspiration and revision surgery is not planned, then this is the rare scenario where nuclear imaging (my preference is an indium labeled white blood cell scan) or a biopsy can be performed. The updated definition of PJI demonstrated a higher sensitivity of 97.7% when compared to the MSIS criteria (79.3%) and the ICM definition (86.9%), with a similar specificity of 99.5%. However, just over 2% of patients examined do fall into the “inconclusive” category. The proposed diagnostic algorithm demonstrated a high overall sensitivity (96.9%) and specificity (99.5%)

Stems are a crucial part of implant stabilization in revision total knee arthroplasty. In most cases the metaphyseal bone is deficient, and stabilization in the diaphyseal cortical bone is necessary to keep the implant tightly fixed to bone and to prevent tilt and micromotion. While sleeves and cones can be effective in revision total joint arthroplasty, they are technically difficult and may lead to major bone loss in cases of loosening or infection, especially if the stem is cemented past the cone. A much more conservative method is to ream the diaphysis to the least depth possible to achieve tight circumferential fixation, and to apply porous augments to the undersurface of the tibial tray or inner surface of the femoral component to allow them to bottom out against the bone surface and apply compressive load. If a robust, strong taper, stem and component combination is used, rim contact on only one side is necessary to achieve rigid permanent fixation. Porous and non-porous stems are available. The non-porous stems should have a spline surface that engages the diaphyseal bone and achieves rigid initial fixation but does not provide long-term axillary support. In that way the porous rim-engaging surface can bear compressive load and finally unload the stem and taper junction. Correctly designed stems do not stress relieve unless they are porous-coated. In situations where metaphyseal bone is not available, porous-coated stems that link to hinge prostheses are a very important part of the armamentarium in complex revision arthroplasty. Use of stems requires experience and special technique. Slight underreaming and initial scratch fit are necessary techniques. This does not result in tight fixation every time because split of the cortex does occasionally occur. In most cases these splits do not need to be repaired, but when there is a question, an intra-operative x ray should be taken and the surgeon should be prepared to repair the fracture. Stems are an essential part of revision total knee arthroplasty. A tightly fit stem in the diaphysis is necessary for fixation when metaphyseal bone is deficient. No amount of cement pressed into the deficient metaphyseal bone will substitute for rigid stem fixation

Introduction. Despite recent advances in the diagnosis of periprosthetic joint infection(PJI), identifying the infecting organism continues to be a challenge, with up to a third of PJIs reported to have negative cultures. Current molecular techniques have thus far been unable to replace culture as the gold standard for isolation of the infecting pathogen. Next- generation sequencing(NGS) is a well-established technique for comprehensively sequencing the entire pathogen DNA in a given sample and has recently gained much attention in many fields of medicine. Our aim was to evaluate the ability of NGS in identifying the causative organism(s) in patients with PJI. Methods. After obtaining Institutional Review Board approval and informed consent for all study participants, samples were prospectively collected from 148 revision total joint arthroplasty procedures (83 knees, 65 hips). Synovial fluid, deep tissue and swabs were obtained at the time of surgery and shipped to the laboratory for NGS analysis (MicroGenDx). Deep tissue specimens were also sent to the institutional laboratory(Thomas Jefferson University Hospital) for culture. PJI was diagnosed using the Musculoskeletal Infection Society(MSIS) definition of PJI. Statistical analysis was performed using SPSS software. Results. Fifty-five revisions were considered infected; culture was positive in 40 of these (40/55, 72.7%), while NGS was positive in 47 (47/55, 85.5%). Among the positive cultures, complete concordance between NGS and culture was observed in 33 cases (33/40, 82.5%). One case was partially discordant between NGS and culture, with culture detecting three organisms as opposed to one organism on NGS. One case showed complete discordance with NGS and culture detecting different organisms. Three patients with negative NGS results had positive cultures. In another two cases culture simply reported the gross morphology of the organism but the phenotype was not identified, while NGS was able to definitively identify an organism. Among the 15 cases of culture-negative PJI, NGS was able to identify an organism in 10 cases (10/15, 66.7%). These data are summarized in Figure 1. Ninety-three revisions were considered to be aseptic; NGS exclusively identified microbes in 15 of 93 “aseptic” revisions (16.1%) and culture exclusively isolated an organism in 4 of 93 cases(5.3%). One case was positive on both NGS and culture, however the results were discordant from each other. The remaining cases (73/93, 78.5%) were both NGS and culture negative. NGS detected several organisms in most positive samples, with a greater number of organisms detected in aseptic compared to septic cases (6.8 vs. 4.0, respectively). Discussion. NGS was able to detect a pathogen in two-thirds of culture-negative cases and demonstrated a high rate of concordance with culture in culture-positive cases. The rate of false positives was low compared to earlier studies using molecular techniques. Our findings also suggest that some cases of PJI may be polymicrobial and escape detection using conventional culture. NGS may be a useful adjunct for identifying the causative organism(s) in PJI, particularly in the setting of negative cultures. Further study is required to determine the significance of isolated organisms in samples from patients who are not thought to be infected

The number of Americans over the age of 80 is increasing at a faster rate than that of the 65–80 population. The cohort age 85–94 years had the fastest rate of growth from 2000–2010. The number of Americans older than 95 years grew at approximately 26% during the same period. This rapid growth has been associated with an increasing incidence of osteoarthritis of the hip and knee in this population. This surge in the growth rate of the elderly population has coincided with an increasing demand for primary and revision total joint arthroplasty. Surgeons need to be prepared to perform safely and appropriately these procedures in this rapidly growing segment of the population. Surgeons need to be aware of the 1) clinical outcomes that can be expected when total joint procedures are performed in this group of patients; 2) the morbidity and mortality associated with the performance of these procedures; and 3) the relative cost effectiveness of these interventions. Clinical outcomes of TJA in this population are generally good. Pain and satisfaction scores are similar to those of younger patients. Although pre-operative pain and functional impairment scores are higher pre-operatively in elderly patients, these improve significantly following TJA. However, functional outcome scores decline noticeably after 5 years, reflecting the impact of coexistent comorbidities. The continued need for assistive devices is greater in this age group than in younger total joint patients. The risk of falls, a particular issue of concern in this age group, is reduced after total hip and knee surgery. The rate of complications, including mortality, following TJA in this age group is greater than in the 65–79-year-old group. The use of hospitalists to co-manage peri-operative care is particularly important in this age group. The increased rate of complications is associated with longer lengths of stay. However, the length of stay for this age group after primary total joint replacement is decreasing significantly; reflecting the widespread streamlining of peri-operative care that is being incentivised and implemented nationwide. The use of extended care facilities is also greater in this age group. The performance of revision TJA in this age group is particularly challenging. The rates of revision in elderly patients are anticipated to rise significantly in coming years. Although revision TJA is associated with significant pain relief and patient satisfaction, it is accompanied by mortality and complication rates that are substantially greater than those in younger age groups

Aims. The purpose of this study was to evaluate the infection-free outcome of patients underwent revision of total joint arthroplasty (TJA) for presumed aseptic causes, with positive intra-operative cultures. Patients and Methods. A retrospective cohort study was assembled with 130 patients undergoing revision knee (21 cases) or hip arthroplasty (109 cases) for presumed aseptic causes. For all patients five to seven separate intra-operative cultures were obtained and prosthesis sonication was done. Patients were diagnosed with a previously unsuspected prosthetic joint infection (PJI) if two or more cultures were. positive or a positive prosthesis sonication. Data were reviewed for demographic details, preoperative laboratory results and culture results. The endpoint was infection-free implant survival at 24 months. Results. Patients with unsuspected PJI was 16 out of 130 (12,3%). Following revision surgery, the rate of infection-free implant survival in patients with an unsuspected PJI was 68,8% (95% confidence intervals (CI) 45,6 to 92) at two years compared. with 94,7% (95% CI 90,5 to 98,9) in patients without PJI (p = 0.001). Conclusion. Around 12% of positive cultures can be expected after TJA aseptic revision surgery; in these cases, the rate of infection-free implant survival is lower than in cases without PJI

Introduction. The legacy constrained condylar knee prosthesis (LCCK, Zimmer.) is designed for primary and revision total joint arthroplasties that need additional stability due to ligament deficiency and to compensate for bone defects. In this follow-up we present our mid term results. Methods and Material. Between November 1999 and January 2006 59 patients were provided with 67 LCCK knee endoprotheses. 38 prostheses were implanted in cases of revision surgery and 29 as primary implants. The mean patient age was 76 years (range 22–93). Indications for revisions were 20 aseptic loosenings, 11 late infections, 7 instabilities (5 cases due to polyethylene wear). Indications for primary arthroplasties were 16 severe valgus and 7 severe varus deformities, 5 cases of osteoarthritis after infection and 1 posttraumatic deformity. 36 femur components (54%) and 34 tibia components (51%) were augmented. 31 stems were fixed cementless, 15 stems were cemented (6 with an intermedullary plug). We evaluated the results prospectively with a clinical inspection and x-ray. Clinical rating systems used were the Knee society, SF-36 Quality of life and Womac score. The mean follow up was 5.6 years. 42 patients were examined, 10 questioned on the telephone, 3 deceased, 12 had to be revised and 2 were lost for follow-up. Results. We had an increase in ROM from 93° to 110°. The Knee Society score improved from 40 to 75 and the function score improved from 46 to 72. The early complications included 1 peroneal lesion, 1 intraoperative fracture, 7 limitations in movement, 10 wound healing problems and 1 thrombosis. 12 revisions had to be performed. 1 septic loosening, 1 synovectomy, 4 aseptic loosenings, 3 secondary patella replacements, 1 traumatic rupture of the quadriceps muscle, 1 chondrosacroma and 1 revision performed in another clinic. 25 (80%) uncemented stems, 3 (33%) cemented stems and 1 (17%) of the stems cemented with an intramedullary plug showed radiolucencies. Conclusion. The LCCK prosthesis can be recommended as a primary implant and for revisions in cases of severe instability or severe bone loss. Due to the bad general health of the patients and preoperative situation of the knee joints the results are satisfactory. All revisions due to aseptic loosening had to be performed on LCCKs with uncemented stems

Introduction. Aseptic loosening is a major cause of revision of total joint arthroplasty (TJA). Although crosslinked Ultra-high molecular weight polyethylene (UHMWPE) have improved wear resistance, residual radicals remaining in the material have a possibility to increase bio-reactivity of particles [2]. In this study, we attempt to evaluate the effects of irradiation and residual radicals on bio-reactivity of the material with a new method called the inverse culture method [1]. Material and methods. UHMWPE particles (10µm diameter in average, Mitsui chemicals Co., LTD) along with irradiated particles (RAD, 300kGy electron irradiation) and particles annealed after the irradiation (RAD+ANN, 100°C 72 hours) are co-incubated with mouse macrophage cell line RAW264 using the inverse culture method. The amount of TNF-α was measured with ELISA. Results and discussion. The amount of TNF-α released by macrophages reacting with virgin UHMWPE, RAD and RAD+ANN is shown in Figure 1. The horizontal axis represents the total surface area of the particles. The coefficient of determination and inclination of the approximate curve are calculated to analyze the result. The coefficient of determination suggested that cytokines released from macrophage is dose-dependent to the surface area of polyethylene particles, which was consistent with the result of our former study[1]. We use the inclination of the approximation curve in Figure 1 as an index to evaluate the bio-reactivity. The values of the index of virgin, RAD and RAD+ANN were 21×10. -4. gLm. -2. , 100×10. -4. gLm. -2. and 59×10. -4. gLm. -2. The inclination of the approximation line of RAD is significantly larger than that of virgin (test for the difference of regression line angle). These suggest that the irradiation to UHMWPE particles increases their bio-reactivity possibly due to radicals. The increased reactivity cannot be eliminated by annealing (100°C 72 hours) completely. Conclusion. Although electron irradiation increases the bio-reactivity of UHMWPE particles, annealing after the irradiation can decrease it, but cannot restore to original reactivity. For any figures or tables, please contact authors directly

Background. Two-stage revision is considered the gold standard for treatment of knee prosthetic joint infections. Current guidelines for selecting the most appropriate procedure to eradicate knee prosthetic joint infections are based upon the duration of symptoms, the condition of the implant and soft tissue evaluated during surgery and the infecting organism. A more robust tool to identify candidates for two-stage revision and who are at high risk for treatment failure might improve preoperative risk assessment and increase a surgeon's index of suspicion, resulting in closer monitoring, optimization of risk factors for failure and more aggressive management of those patients who are predicted to fail. Methods. Charts from 3,809 revision total joint arthroplasties were reviewed. Demographic data, clinical data and disease follow-up on 314 patients with infected total knee arthroplasty treated with two-stage revision were collected. Univariate analyses were performed to determine which variables were independently associated with failure of the procedure to eradicate the prosthetic joint infections. Cox regression was used to construct a model predicting the probability of treatment failure and the results were used to generate a nomogram which was internally validated using bootstrapping. Results. 209 (66.6%) cases experienced reinfection at an average of 429 days (range, 9 to 3,886) following the two-stage revision. Univariate analysis identified multiple variables independently associated with reinfection including: a longer duration of symptoms (p<0.001), a longer time from the index total knee arthroplasty (p=0.003), a higher number of previous surgeries in the same joint (p<0.001), an elevated C-reactive protein (p=0.005), an elevated erythrocyte sedimentation rate (p=0.006), a low hemoglobin (p=0.001), a previous infection in the same joint (p<0.001), diabetes (p<0.001), and heart disease (p=0.006). Among 1,000 bootstrap samples, the bias corrected receiver operating characteristic for the nomogram was 0.77. Conclusions. Preoperative knowledge of the probability that a treatment strategy will eradicate a patient's prosthetic joint infection may improve risk assessment and allow adequate time for consideration of alternative therapies

Over the past 40 years information from large institutional total joint registries have aided in patient clinical care and follow-up efforts, have helped drive improvements in clinical practice, and have been a powerful tool for generating research studies on large well documented populations of patients. Still, these efforts are limited in that they are expensive, usually reflect a single institutional experience, and results can be biased by the larger volumes or experience at the typically large academic centers which have such registries in place. National registry efforts in other countries including Scandinavia, Australia, and the UK have resulted in improved outcomes and a decreased number of revision procedures by a combination of early identification and withdrawal of poorly performing implants, altered surgical techniques, implant choices and behaviors by surgeons, changes in practices by hospitals, and modification in requirements and incentives by payors and regulatory agencies. The American Joint Replacement Registry (AJRR) is a collaborative multi-stakeholder, independent, not-for-profit 501 c3 organisation established in 2009 for data collection and quality improvement initiatives relating to total hip and knee arthroplasty. AJRR is a national registry effort with the goal of enrolling more than 90% of the over 5,000 hospitals performing nearly 1 million hip and knee arthroplasties each year in the US. AJRR is supported by contributions from the American Academy of Orthopedic Surgeons (AAOS), the American Association of Hip and Knee Surgeons (AAHKS), the Hip Society, the Knee Society, Health Insurers, Medical Device Manufacturers, and individual orthopaedic surgeons via designated contributions through the Orthopedic Research and Education Foundation (OREF). The overarching goal of AJRR is to improve arthroplasty care for patients through the collection and sharing of data on all primary and revision total joint replacement procedures in the U.S. The mission of the registry is to enhance patient safety, and improve the value of arthroplasty care. This will be accomplished by providing national benchmarks for implant, surgeon and hospital performance which serves to modify behaviors thereby decreasing the revision burden, improving outcomes and reducing costs. From the time of incorporation in 2009 up to October 2013 the AJRR has secured the participation of 218 hospitals in 47 different states in the formal enrollment process, and have level one data submission from more than 100 institutions on over 63,000 hip and knee procedures. In addition to publicly available annual reports, confidential specific individual reports for hospitals, surgeons and manufacturers will be available by subscription with an option for future confidential online direct data queries by an individual or entity regarding their own individual performance compared to national benchmark values. In summary, registry studies have provided a rich source of information for improving arthroplasty care over the past four decades, with the emergence and increasing interaction of national registries a major factor in current efforts to increase both the quality and value of the health care of entire populations. The development, support and continued expansion of a national registry in the US must remain a central focus if we wish to improve as much as possible the arthroplasty care provided to all patients in our country

Peri-prosthetic osteolysis and subsequent aseptic loosening is the most common reason for revising total hip replacements. Wear particles originating from the prosthetic components interact with multiple cell types in the peri-prosthetic region resulting in an inflammatory process that ultimately leads to peri-prosthetic bone loss. These cells include macrophages, osteoclasts, osteoblasts and fibroblasts. The majority of research in peri-prosthetic osteolysis has concentrated on the role played by osteoclasts and macrophages. The purpose of this review is to assess the role of the osteoblast in peri-prosthetic osteolysis.

In peri-prosthetic osteolysis, wear particles may affect osteoblasts and contribute to the osteolytic process by two mechanisms. First, particles and metallic ions have been shown to inhibit the osteoblast in terms of its ability to secrete mineralised bone matrix, by reducing calcium deposition, alkaline phosphatase activity and its ability to proliferate. Secondly, particles and metallic ions have been shown to stimulate osteoblasts to produce pro inflammatory mediators in vitro. In vivo, these mediators have the potential to attract pro-inflammatory cells to the peri-prosthetic area and stimulate osteoclasts to absorb bone. Further research is needed to fully define the role of the osteoblast in peri-prosthetic osteolysis and to explore its potential role as a therapeutic target in this condition.

Cite this article: Bone Joint J 2013;95-B:1021–5.