Utility of histopathological examination in aseptic revision total hip arthroplasty: a preliminary analysis.

INTRODUCTION: The utility of a routine histopathological examination in aseptic revision total hip arthroplasty (THA) has not been well explored. We aim to describe the approach and present the results of histopathological examination, focusing on its clinical usefulness in the setting of aseptic revision THA. METHOD: We retrospectively reviewed 285 performed aseptic revision THA with available histopathological reports between 2015 and 2017 at a single institution. We described histopathological requests by the surgical team. Preoperative diagnoses, intraoperative findings, as well as histopathology and culture results were analysed. RESULTS: 13 painful THAs (4.5%) had preoperatively unknown diagnoses. In 10 of them, potential causes of pain were intraoperatively identified. Histopathology confirmed these findings in 8 THAs. 19 THAs (6.7%) revealed unexpected positive cultures (UPC). Histopathology was negative for infection in 18 of them. Among 16 consultants, 3 surgeons requested histopathology in 47% of the cases (130/285), usually to exclude infection (101/285; 35%). Documentation for tissue sample location was lacking in 51% (145/285), and for question asked by the surgeon in 47% (135/285). CONCLUSIONS: Histopathology is deemed a useful confirmatory tool in the context of ruling out infection in UPCs, and in documenting intraoperative findings in painful THAs with unknown preoperative diagnoses. Importantly, the approach to requesting histopathology should be optimised. Further large-scale studies, including cost analyses, are warranted to explore the usefulness of histopathology in routine utility.

First periprosthetic hip infection caused by Eggerthella lenta.

Periprosthetic joint infection (PJI) caused by anaerobic, Gram-positive bacilli is rare. We present here a case of an 83-year-old female patient who was admitted to our tertiary referral arthroplasty center to treat a complex PJI of her right hip joint after multiple failed surgeries. External and intraoperative cultures reveald growth of Eggerthella lenta (E. lenta). Microbiological identification was fast but in a very few samples. A successful management, comprising of radical debridement with one-stage exchange and an antibiotic treatment with multiple antibiotics, has been achieved at 24-month follow-up. To the best of our knowledge, we have provided the first case study of a hip PJI caused by E. lenta successfully treated with one-stage exchange and an adequate antibiotic treatment.

Survival analysis of one-stage exchange of infected unicompartmental knee arthroplasty: a single-center study with minimum 3 years follow-up.

PURPOSE: The rates of unicompartmental knee arthroplasty (UKA) are increasing yet little data exists regarding management of periprosthetic joint infections (PJI) after UKA, particularly utilizing one-stage revision. The aim of this study was to determine the septic and all-cause revision-free survival of UKA PJIs treated with one-stage revision, as well as functional outcomes and risk factors for failure. METHODS: A retrospective review of one-stage septic revisions with a hinged or rotating hinged implant between 2000 and 2015 at a single institution was performed. Results of 15 patients with a minimum of 3-year follow-up (mean = 93 months; range 37-217) were evaluated by means of infection control, survivorship, patient reported functional score and possible causal factors for a re-revision. Kaplan-Meier curves and Cox regression analysis were used. RESULTS: After a mean of 8 years of follow-up infection control rate was 93.3%, the survivorship free of any reoperation, including both septic and aseptic causes, was 80% at 5 years and 64.2% at ten years and average Lysholm score was 72.7 ± 21.3 (33-100). CONCLUSION: One-stage revision for PJI of UKA using a hinged knee design has excellent infection-free survival at mid to long-term follow-up. Likewise, patient reported functional outcomes are promising. However, one-third of patients required aseptic reoperation and aseptic loosening was the dominant etiology.

What Is the Impact of Automated Synovial Cell Counting on Different Aseptic Causes and Periprosthetic Conditions Associated With Revision THA?

BACKGROUND: Studies have suggested that automated synovial cell counting may overestimate the white blood cell (WBC) count, resulting in false positive tests when evaluating patients for the possibility of periprosthetic joint infection (PJI) after THA. However, associations between WBC counts high enough to mimic PJI in patients whose arthroplasties are not infected but rather are experiencing a variety of aseptic problems-including but not limited to metallosis, polyethylene wear, and recurrent dislocation-have not, to our knowledge, been adequately addressed. In addition, there is a lack of analyses about the polymorphonuclear percentage (PMN%) when assessed by automated analyzers in this context. QUESTIONS/PURPOSES: In the context of different indications for aseptic revision and different periprosthetic hip pathologic findings, we asked: (1) What were the synovial WBC count levels, and what proportion of values were above the 2018 International Consensus Meeting (ICM) cutoff (3000 cells/µL)? (2) What were the synovial PMN% levels, and what proportion of values were above the 2018 ICM (70%)? METHODS: We retrospectively studied the preoperative cell count analyses of synovial fluid in patients who underwent revision THA for aseptic reasons at our tertiary referral arthroplasty center between January 2015 and December 2017. We considered all revisions performed on patients during that time potentially eligible, and after prespecified exclusions were applied (exclusions mainly included 15% [197 of 1306] sporadic missing data and 12% [155 of 1306] insufficient synovial fluid obtained in the aspirate), a total of 702 patients undergoing revision THA for aseptic reasons remained for the final analysis. As far as we know, no patients underwent re-revision for PJI at a mean follow-up of 46 ± 11 months, which tends to confirm our impression that indeed these hips did not have PJI. Cell count analyses were conducted using an automated analyzer. Clinical findings, preoperative radiographs, and surgical reports--confirmed by available histologic results--were used to establish diagnoses. We evaluated these hips considering the recommendations of the 2018 ICM (WBC count of 3000 cells/µL and PMN% of 70%) to see what proportion of them would have been characterized as likely having PJI on basis of those cutoff values. The mean WBC count for the entire cohort was 2120 ± 2395 cells/µL. The mean PMN% for the entire cohort was 36% ± 22%. RESULTS: Compared with aseptic loosening and recurrent dislocation, polyethylene wear had the highest mean WBC count (3817 ± 3711 cells/µL; p < 0.001). Of the investigated periprosthetic conditions, wear-induced synovitis had the highest value (4464 ± 3620 cells/µL; p < 0.001). Considering the ICM threshold, polyethylene wear showed the highest proportion of WBC counts above 3000 cells/µL among the indications for aseptic revision (60% [25 of 42]; p < 0.001). Of the periprosthetic conditions, wear-induced synovitis showed the highest proportion beyond the ICM cutoff (60% [50 of 83]; p < 0.001). The mean PMN% for aseptic causes ranged between 28% and 44% without differences among them (p = 0.12). Patients with metallosis had the highest mean PMN% of the periprosthetic conditions investigated (45% ± 25%; p = 0.007). Regarding the ICM threshold, metallosis resulted in the largest proportion of patients with a PMN% above 70% (21% [10 of 47]; p = 0.003), and that for wear-induced synovitis was 6% (5 of 83; p = 0.42) and for osteolysis was 3% (1 of 33; p = 0.51). There were no differences among aseptic loosening, recurrent dislocation, and polyethylene wear in terms of the proportion above 70% among the aseptic revision causes. CONCLUSION: Using automated cell counting, we found that WBC counts differ widely across indications for aseptic revision THA, and a high proportion of patients who underwent revision THA for aseptic reasons had WBC counts above the commonly used threshold of 3000 cells/µL. However, the PMN% was much less affected in several common indications for aseptic revision THA, making this measure more reliable for interpreting aspiration results using an automated analyzer. Based on the data distributions we observed, manual counting techniques might be considered in particular among patients with polyethylene wear, metal-on-metal bearing surfaces, or suspected metallosis. However, an elevated WBC count alone, observed using an automated analyzer in the context of polyethylene wear, should not be considered to be strongly suggestive of PJI, since that finding occurred so commonly among patients without infection. LEVEL OF EVIDENCE: Level III, diagnostic study.

High re-revision rate following one-stage exchange for streptococcal periprosthetic joint infection of the hip.

INTRODUCTION: This study was undertaken to analyse the outcome of 1-stage exchange in the management of streptococcal periprosthetic joint infection (PJI) of the hip at a single hospital. METHODS: We identified 30 patients with a streptococcal PJI of the hip who had been treated by 1-stage exchange at our hospital between 2002 and 2017. Postoperative complications and the need for any subsequent re-revision for infection or other reasons were analysed. The Harris Hip Score (HHS) was evaluated at final follow-up. RESULTS: The mean follow-up was 8.2 years (SD 4.1). The overall re-revision rate for any reason was 53% (16/30) at a mean 5.3 years (SD 0.68 years). Re-revision for infection was 20% (6/30) at a mean 1.8 years (SD 0.74 years). All re-revisions for PJI (6/6; 100%) were for relapse of the streptococcal infection. At final follow-up, the mean HHS was 68 points (SD 20). CONCLUSIONS: The rate of re-revision after 1-stage exchange for streptococcal PJI is high. Eradication of a streptococcal PJI of the hip remains challenging. Further extensive and comparative studies between 1-and 2-stage exchange are encouraged.

Resection of the proximal femur during one-stage revision for infected hip arthroplasty : risk factors and effectiveness.

AIMS: One-stage revision hip arthroplasty for periprosthetic joint infection (PJI) has several advantages; however, resection of the proximal femur might be necessary to achieve higher success rates. We investigated the risk factors for resection and re-revisions, and assessed complications and subsequent re-revisions. METHODS: In this single-centre, case-control study, 57 patients who underwent one-stage revision arthroplasty for PJI of the hip and required resection of the proximal femur between 2009 and 2018 were identified. The control group consisted of 57 patients undergoing one-stage revision without bony resection. Logistic regression analysis was performed to identify any correlation with resection and the risk factors for re-revisions. Rates of all-causes re-revision, reinfection, and instability were compared between groups. RESULTS: Patients who required resection of the proximal femur were found to have a higher all-cause re-revision rate (29.8% vs 10.5%; p = 0.018), largely due to reinfection (15.8% vs 0%; p = 0.003), and dislocation (8.8% vs 10.5%; p = 0.762), and showed higher rate of in-hospital wound haematoma requiring aspiration or evacuation (p = 0.013), and wound revision (p = 0.008). The use of of dual mobility components/constrained liner in the resection group was higher than that of controls (94.7% vs 36.8%; p < 0.001). The presence and removal of additional metal hardware (odds ratio (OR) = 7.2), a sinus tract (OR 4), ten years' time interval between primary implantation and index infection (OR 3.3), and previous hip revision (OR 1.4) increased the risk of proximal femoral resection. A sinus tract (OR 9.2) and postoperative dislocation (OR 281.4) were associated with increased risk of subsequent re-revisions. CONCLUSION: Proximal femoral resection during one-stage revision hip arthroplasty for PJI may be required to reduce the risk of of recurrent or further infection. Patients with additional metalware needing removal or transcortical sinus tracts and chronic osteomyelitis are particularly at higher risk of needing proximal femoral excision. However, radical resection is associated with higher surgical complications and increased re-revision rates. The use of constrained acetabular liners and dual mobility components maintained an acceptable dislocation rate. These results, including identified risk factors, may aid in preoperative planning, patient consultation and consent, and intraoperative decision-making. Cite this article: Bone Joint J 2021;103-B(11):1678-1685.

Do Not Postpone Revision of Worn Conventional Liners in Ceramic-on-Polyethylene Total Hip Arthroplasty: A New Dramatic Failure.

Catastrophic failure of ceramic-on-polyethylene total hip arthroplasty is still occasionally described. We report on a new case of complete atraumatic penetration of an intact ceramic head through the titanium cup in a cementless total hip arthroplasty due to dramatic polyethylene and metal wear. We reviewed the literature for similar cases and analyzed potential risk factors. Most importantly, revision of radiologically worn liners should not be postponed, especially in young and active patients with conventional liners, because the time to dramatic failure could be shorter than expected.

What to Do When Revision Procedures Fail to Prevent Recurrent Hip Dislocation in THA? A Novel Simple Technique for Selected Patients.

Failure to achieve postoperative stability is disappointing for both surgeons and patients after revision total hip arthroplasty. In particular, when available revision options have been exhausted. We describe our modification of previously reported surgical techniques without revising any component in a high-risk female patient with persistent hip dislocation despite multiple cup revisions using different implants. To stabilize the hip through the posterolateral approach, a synthetic polyethylene tube was used. This relatively simple, modified technique may be a solution in disappointing cases with failure to achieve hip stability in revision total hip arthroplasty.

Intravenous tranexamic acid is associated with safe reduced blood loss and transfusion rate in one-stage exchange for infected hip arthroplasty.

OBJECTIVES: This study aims to investigate if the use of intravenous (IV) tranexamic acid (TXA) during one-stage exchange for periprosthetic joint infection (PJI) of the hip that necessitates an extensive debridement is associated with decreased blood loss, if the rate of blood transfusion that may lead to side effects can be lowered with IV TXA, and if there is any difference regarding the occurrence of postoperative venous thromboembolism (VTE). PATIENTS AND METHODS: We retrospectively reviewed patients who underwent one-stage exchange for PJI of the hip with perioperative IV administration of TXA (n=163; 90 males, 73 females; mean age 68±10.3; range, 25 to 90 years) between January 2015 and December 2016 and compared them to another group (n=190; 106 males, 84 females; mean age 71±10.1; range, 39 to 92 years) who underwent one-stage exchange for PJI of the hip without perioperative IV administration of TXA between January 2006 and December 2012. Blood loss, transfusion rates, amount of transfused blood, and occurrence of VTE complications were observed. RESULTS: Mean blood loss of the TXA group was significantly lower than that of the non-TXA group (2.4 L and 4.5 L, respectively; p<0.001). Patients in non-TXA group experienced significantly higher rate of blood transfusion (71.1% and 58.3%, respectively; p=0.014) and higher quantity of transfused packed red blood cells (3.2 and 1.9 units, respectively; p<0.001). There was one patient with VTE complication in each group. CONCLUSION: Even in the presence of infection, usage of IV TXA during one-stage exchange for PJI of the hip is associated with significantly lower blood loss and transfusion rates showing no higher risk of VTE events.

Preliminary clinical results of coated porous tibia cones in septic and aseptic revision knee arthroplasty.

PURPOSE: To analyze the first results of calcium-phosphate-coated porous tibia cones. METHODS: Patients treated with TrabecuLink®-CaP Cones were retrospectively recruited from January 2016 to December 2017. These custom-made cones were produced using titanium alloy Ti-6Al-4 V (Tilastan®) and using additive manufacturing with a special calcium-phosphate coating (HX®-coating). Clinical outcome was evaluated using Oxford Knee Score. For radiological evaluation of the implants, patients sent us outpatient taken radiographs. A minimum follow-up of one year was required. Lastly, we analyzed postoperative complications and revision rates. RESULTS: 52 patients with revision knee arthroplasty (RKA) were recruited for final analysis, of whom, we had 17 septic RKAs (33%) and 35 aseptic cases of RKA (67%). The bone defects were grouped into 17 AORI Type 2A (32.7%), 14 Type 2B (26.9%) and 21 Type 3 (40.4%). After a mean follow-up of 22 months (13.2-34.8; SD = ± 10), we had 4 surgical revisions (7.7%), 2 septic and 2 aseptic cases. The mean Oxford Knee Score was 28.6 points (8-47; SD = ± 10). 22 of 28 radiographs (78.6%) showed regular positioning of the cones and TKAs at a mean follow-up of 16.8 months (13.2-34.8; SD = ± 6). Three patients (10.7%) showed slight radiolucencies in the bone-cement interfaces and 3 patients (10.7%) had beginning heterotopic ossifications. CONCLUSIONS: This study shows the initial clinical results of calcium-phosphate-coated tibia cones showing a good functional outcome. Further research should focus on long-term clinical and radiological follow-up.

High Rate of Reinfection With New Bacteria Following One-Stage Exchange for Enterococcal Periprosthetic Infection of the Knee: A Single-Center Study.

BACKGROUND: A wide range of success rates following the surgical management of enterococcal periprosthetic joint infection (PJI) with a tendency toward worse outcomes have been reported. However, the role of 1-stage exchange remains under-investigated. Therefore, we aimed to evaluate our results after the 1-stage knee exchange for enterococcal PJI. METHODS: Forty patients were retrospectively included between 2002 and 2017 with a mean follow-up of survivors of 80 months (range 22-172; standard deviation [SD] = 5). Polymicrobial infections occurred in 45% (18/40) of patients. Patients' characteristics, joint-related data, and antibiotic therapy were recorded. Rates of enterococcal infection relapse, reinfection with new microorganisms, and re-revision for any reason were determined. Bivariate analysis was conducted to identify risk factors of infection recurrence. RESULTS: Revision surgery was required in 22 cases (55%) with a mean time to revision surgery of 27 months (range 1-78; SD = 25). Indications for aseptic revisions (18%) included aseptic loosening (10%), periprosthetic fracture (5%), and patellar instability (3%). The most common cause of re-revision was a subsequent PJI (15/22; 68%) after a mean time of 22 months (range 1-77; SD = 24). Overall infection recurrence rate was 37.5% (15/40), substantially due to entirely non-enterococcal infections (9/15; 60%). Infection relapse with Enterococci occurred in 4 cases (10%) within 16 months postoperatively. Older patients (P = .05) and male gender (P = .05) were associated with a higher risk of infection recurrence. CONCLUSION: Overcoming the Enterococci using the 1-stage exchange for knee PJI is achievable but the rate of reinfection due to new microorganisms is high . However, the overall infection recurrence rate is comparable to other treatment approaches.

How reliable is the next generation of multiplex-PCR for diagnosing prosthetic joint infection compared to the MSIS criteria? Still missing the ideal test.

INTRODUCTION: Identification of the pathogen in case of a periprosthetic joint infection (PJI) remains 1 of the greatest challenges in septic surgery. Rapid germ identification enables timely, specific, antimicrobial therapy. The first multiplex PCR (polymerase chain reaction) generation (Unyvero-i60) enables germ detection within 5 hours with a sensitivity of 78.8% and a specificity of 100%. The aim of this study is to investigate the performance of the new generation of cartridges (Unyvero-ITI) of multiplex PCR in the case of a PJI. METHODS: In a prospective study, intraoperatively aspirated synovial fluid from 97 patients with aseptic or septic hip or knee revision surgery (49 aseptic, 48 septic) was examined with the multiplex PCR system (Unyvero-ITI) and the results were compared with the MSIS criteria. In addition, the time until the microbiological result was obtained in the event of a germ detection was documented. RESULTS: The multiplex PCR showed a germ detection with a sensitivity of 85.1% and a specificity of 98.0%. In 7 cases a false negative result was found and in one patient a false positive result was found. The general accuracy of this test procedure was 91.8%. The detection of germs was carried out within 5 hours with the multiplex PCR compared to 4.9 days in conventional microbiological diagnostics. CONCLUSIONS: The new generation of multiplex-PCR was able to improve germ detection. The possibility of prompt detection of germs offers the option of faster, targeted antimicrobial therapy. This diagnostic tool offers significant advantages, particularly in the context of an acute periprosthetic infection.

Elevated HbA1c is not a risk factor for wound complications following total joint arthroplasty: a prospective study.

BACKGROUND: Controversies exist regarding the association of elevated serum glycated haemoglobin (HbA1c) levels and postoperative surgical site infection (SSI) or prosthetic joint infection (PJI) in the setting of total hip and knee arthroplasty (THA and TKA). The purpose of the current study was to determine the prevalence of unknown and uncontrolled diabetes mellitus (DM) in a consecutive series and to investigate the association between postoperative wound complications or SSI/PJI and elevated HbA1c in patients undergoing TJA. METHODS: In this prospective single-centre study, HbA1c was determined for patients undergoing elective primary, aseptic or septic revision THA and TKA, between September 2017 and March 2018. Prevalence of DM, unknown and uncontrolled diabetes were reported. Occurrence of 90-day wound healing disorders (WHD) as well as SSI or PJI were observed. Considering the HbA1c threshold ⩾6.5%, a comparative analysis between patients with and without WHD and SSI or PJI for the whole study cohort, as well as for each arthroplasty group, was performed. Receiver operating characteristic (ROC) curves were developed to quantify the predictive power of HbA1c with regard to WHD and infection complications. A total of 1488 patients were included for final analysis. There were 1127 primary THA and TKA (75.7%), 272 aseptic revisions (18.3%) and 89 septic revisions (6.0%). The known diabetic patients constituted 9.9% of the whole study cohort. RESULTS: The majority had uncontrolled DM (67%). Prevalence of unknown DM was 11.1%. The results reveal the prevalence for the German population and might be different in other regions. A total of 57 patients (3.7%) experienced postoperative wound or infectious complications. PJI occurred in only 5 patients (0.03%). There was no significant difference between patients with HbA1c <6.5% and patients with HbA1c ⩾6.5% (p = 0.092). CONCLUSIONS: We demonstrated that prevalence of unknown and uncontrolled DM in patients undergoing TJA is increasing, however; routine preoperative determination of the HbA1c value to prevent possible postoperative wound or infectious complications remains debatable. Larger studies investigating the optimal HbA1c level, as well as other predictors are required.

Improved treatment strategies can result in better outcomes following one-stage exchange surgery for MRSA periprosthetic joint infection.

Introduction. Periprosthetic joint infections caused by methicillin-resistant Staphylococcus aureus (MRSA-PJIs) are rare, with only a few studies reporting the treatment outcomes and even fewer reporting outcomes with one-stage exchange.Aim. This study aims to analyse the outcomes of one-stage exchange in the management of MRSA-PJIs.Methodology. Patients with MRSA-PJI of the hip and knee, who were treated with a one-stage exchange between 2001 and 2018 were enrolled in this study. The final cohort comprised of 29 patients, which included 23 hips and six knees. The mean follow-up was 5.3 years (1-9 years). Reinfection and complications rates after the one-stage exchange were analysed.Results. Overall infection control could be achieved in 93.1 % (27 out of 29 patients). The overall revision rate was 31.0% (9 patients), with three patients requiring an in-hospital revision (10.3 %). Six patients had to be revised after hospital discharge (20.7 %). Of the two reinfections, one had a growth of MRSA while the other was of methicillin-sensitive Staphyloccocus epidermidis.Conclusion. One-stage exchange surgery using current techniques could improve surgical outcomes with excellent results in the management of MRSA-PJIs.

The 2018 International Consensus Meeting Minor Criteria for Chronic Hip and Knee Periprosthetic Joint Infection: Validation From a Single Center.

BACKGROUND: Recently, a revised definition of the minor criteria scoring system for diagnosing periprosthetic joint infection (PJI) was developed by the second International Consensus Meeting on musculoskeletal infection. The new system combines preoperative and intraoperative findings, reportedly achieving high sensitivity and specificity. We aimed to validate the modified scoring system at a high-volume center. METHODS: We retrospectively reviewed patients who underwent a revision total hip or knee arthroplasty at our institution from May 2015 to August 2018. Serum C-reactive protein, synovial white blood cell count and polymorphonuclear percentage, leukocyte esterase test, alpha-defensin, microbiological and histologic results, and documented existence of sinus tract and intraoperative purulence were available for all patients. Cases with at least 1 major criterion were considered as infected. Using the new minor criteria, a score of ≥6 reflects PJI, while a score <3 can be considered as noninfected. Sensitivity, specificity, mean accuracy (ACC), positive predictive value (PPV), and negative predictive value (NPV) were analyzed. RESULTS: A total of 345 cases were included. A cutoff score of ≥6 points had the following diagnostic performance: area under the curve (AUC) = 0.90; ACC = 0.88; sensitivity = 0.96; specificity = 0.84; PPV = 0.70; NPV = 0.98. Diagnostic performance was better for the hip (AUC = 0.92; ACC = 0.90; sensitivity = 0.96; specificity = 0.86; PPV = 0.81; NPV = 0.98) than the knee (AUC = 0.89; ACC = 0.85; sensitivity = 0.95; specificity = 0.83; PPV = 0.59; NPV = 0.98). CONCLUSION: The modified scoring system proposed by the 2018 International Consensus Meeting in diagnosing PJI showed high sensitivity and a good performance, especially as rule-out diagnostic criteria. The cutoff level seems to be different between the hip and knee. Further validation studies considering the acknowledged limitations are recommended.

Do patients with von Willebrand disease exhibit higher blood loss and revision rates in hip and knee arthroplasty? A case-control study.

BACKGROUND: The aim of the study was to compare the perioperative blood loss, need for transfusion and one-year revision rates in patients undergoing hip and knee arthroplasty who also have a diagnosis of von Willebrand disease (VWD) with a matched control group. METHODS: A retrospective single-centre case-control study was conducted. Fifty-eight patients with VWD and 116 controls (1:2 match) who were operated for primary or revision hip and knee arthroplasty at our hospital were included. Blood loss, haemoglobin (Hb)-drop, need for blood transfusion, intraoperative complications and revision rates within one year were noted in all cases. Outcome measures for subgroups of the primary hip, primary knee, revision hip and revision knee procedures, were also analysed. RESULTS: The mean perioperative Hb-drop was 3.47 (±1.27) g/dL and blood loss was 293 (±97) ml for the VWD group while Hb-drop was 2.85 (±1.21) g/dL and blood loss was 232 (±105) mL for the control group (P < .001). There were no significant increased transfusion rates (P = .264) and revision rates in the VWD group (P = .634). Patients having primary hip surgery had significantly higher Hb-drop (3.68 ± 1.25 g/dL vs 2.62 ± 1.19 g/dL; P = .003), higher blood loss (293 vs 203 mL; P = .002) and increased need for a transfusion (21% vs 2.6%; P = .038) compared to the controls. No outcome measure was found to be significantly different for primary and revision knee surgery. CONCLUSIONS: The results of this study suggest that patients with VWD undergoing primary or revision total hip and knee arthroplasty have higher levels of blood loss than the control cohort. Perioperative protective measures including meticulous surgical techniques should be considered.

Distal non-traumatic fracture of the cementless MP stem: A case report and review of previous reported cases.

Modular hip stems offer many advantages in revision arthroplasty. However, the region of modularity is prone to failure. Fracture of the non-cemented fluted tapered titanium Modular Prosthesis (MP) stem is relatively rare. We present here a case of a distal non-traumatic fracture of the MP stem and review the previously reported cases. A 53-years old, relatively active, male patient with a body mass index (BMI) of 37 kg/m2 had a fracture of the non-cemented MP stem on the left side after five years without complaints. The BMI was 45 at the time of implantation of the MP stem. His weight was significantly reduced, but the stem failed and fractured at an atypical site, quite distal to the modular junction. The broken stem with a relatively small diameter had been exchanged to a larger one. Fracture of the non-cemented fluted proximally-modular distally-tapered titanium MP stem might occur after years. Even in cases of good bone quality of the proximal femur, patient BMI and activity level should be considered when selecting the stem diameter. Furthermore, proximal bone loss of the femur should be considered as a potential cause of failure.

Midterm Results After Tantalum Cones in 1-Stage Knee Exchange for Periprosthetic Joint Infection: A Single-Center Study.

BACKGROUND: The use of tantalum cones to reconstruct extensive bone defects in revision total knee arthroplasty has been established. We aimed to evaluate the midterm results after 1-stage knee exchange for periprosthetic joint infection using tantalum cones. METHODS: Seventy-two patients (mean age, 70 ± 8.2 years) treated with a 1-stage exchange for infected total knee arthroplasty using porous tantalum cones, between 2011 and 2016, were retrospectively included. Either rotating or pure hinge system in combination with femoral and/or tibial cones was used. Survivorship analysis (septic and aseptic) was performed. Prospectively, functional outcome was assessed at a mean follow-up of 49.9 ± 18.8 months (range, 24-88). RESULTS: A total of 15 patients (21%) were rerevised, 8 (11.1%) for infection and 7 (10%) for aseptic loosening, requiring cone exchange in 12 patients (17%). Cone-related survival free from any revision was 83% ± 3.8 standard deviation (95% confidence interval, 74-90), and infection-free survival was 89% ± 4.2 standard deviation (95% confidence interval, 76-93). No significant correlation was reported between the types of prosthesis used (P = .8) or implanted cones and failure (P = .6). History of a previous septic revision increased the risk of cone revision after the index surgery (P < .001). Preoperative Hospital for Special Surgery knee score improved from 47 ± 16 (range, 14-87) to 60 ± 17 (range, 24-84) points at the latest follow-up. CONCLUSION: First study reports on outcomes of the 1-stage exchange using tantalum cones for knee periprosthetic joint infection with additional severe bone loss. Midterm cone-related and infection-free survival offered good results and provided reasonable functional outcomes.

Clinical Survivorship of Aseptic Revision Total Knee Arthroplasty Using Hinged Knees and Tantalum Cones at Minimum 10-Year Follow-Up.

BACKGROUND: The reconstruction of severe bone loss utilizing porous tantalum cones in patients undergoing revision total knee arthroplasty (TKA) has been established in the last years. However, reports on a long-term follow-up to assess the durability of such implants when combined with hinged knee designs are lacking. The current study aimed to evaluate the results of a previous study cohort at a minimum follow-up of 10 years. METHODS: A retrospective review was performed. The initial study cohort comprised of 38 patients who underwent aseptic revision TKA between 2007 and 2009 at a single institution. After exclusion of the deceased patients and patients who were lost to follow-up, 25 patients with hinged knees and 32 cones implanted were included with a minimum follow-up of 10 years (mean = 126.5 months, range 120-142, standard deviation [SD] = 5.92). Survivorship was determined, and re-revisions were observed. Functional Knee Society Score was assessed. RESULTS: After a minimum of 10 years, 24 of 32 cones (75%) had survived without any exchange in 18 patients. Reasons for cone revision included aseptic loosening (5/32 cones; 15.6%) and periprosthetic joint infection (3/32 cones; 9.4%). In 4 of the five revisions due to aseptic loosening, pure hinged knees had been implanted. The mean functional Knee Society Score of the survivors was 69.6 points (range 10-100, SD = 30.85), and the average flexion ability of the knee was 92° (range 30°-120°, SD = 22.09). CONCLUSION: Porous tantalum cones in revision TKA exhibited no favorable but reasonable long-term durability. Rotating-hinge designs should be used whenever possible to reduce the risk of aseptic loosening. Further comparative long-term analyses with other techniques or implants could inform us about the best treatment method.