Infected Hip Research Articles

Prothèse de hanche infectée : le point de vue du chirurgien

An infected hip prosthesis is a serious complication. In addition to the various clinical presentations, the diagnosis is not always clear and the therapeutic strategies contrast conservative treatments by debridement, antibiotics, and implant retention with non-conservative treatments requiring an exchange arthroplasty. Joint aspiration confirms the diagnosis of infection and determines the germ's sensitivity that guides peri-operative antibiotic therapy. The surgical indication must be based on a pragmatic classification in order to avoid inappropriate intervention. The irrigation and debridement, attractive for his simplicity, remains recommended in case of acute infection, but it does not provide the same success rate than one-stage exchange arthroplasty, whose contraindications are increasingly more relative. In the absence of effective multidisciplinary approach or in a complex situation, the infected patient should be referred to a referral center for complex osteoarticular infection.

Partial Component–Retained 2-Stage Reconstruction in the Treatment of Infected Hip Arthroplasty

BackgroundIt is considered the gold standard treatment for infected hip arthroplasty to remove and reimplant the corresponding whole set of implant components before and after infection control, but it usually causes substantial bone loss to remove the well-fixed cup or stem, which may increase the difficulty in reconstruction. We would like to determine whether infected hip arthroplasty can be treated without removal of a well-fixed cup or stem. MethodsPatients with infected hip arthroplasty and a radiographically well-fixed, cementless cup or stem were selected. During the first surgical stage, we retained the stem or cup if these cannot be removed using a stem or cup extractor. We performed the reimplantation surgery after control of infection. ResultsFrom January 2008 to December 2016, 26 patients underwent partial component–retained 2-stage reconstruction. All the patients were free of infection with a mean follow-up time of 43.85 months. ConclusionPartial component–retained 2-stage reconstruction may be a treatment option for infected total hip arthroplasty with a well-fixed component in patients.

Extended Antibiotic Prophylaxis May Be Linked to Lower Peri-prosthetic Joint Infection Rates in High-Risk Patients: An Evidence-Based Review.

In 2018, Inabathula et al. published the results of a historical control study examining 90-day peri-prosthetic joint infection (PJI) rates at a single center before and after the institution of an extended post-operative oral antibiotic protocol for high-risk total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients. In the study, "Extended Oral Antibiotic Prophylaxis in High-Risk Patients Substantially Reduces Primary Total Hip and Knee Arthroplasty 90-Day Infection Rate" (J Bone Joint Surg Am. 2018;100[24]:2103-2109), the authors considered any one of several patient-related criteria-including diabetes, a body mass index of 35kg/m2 or higher, or active smoking-as sufficient to designate a patient "high risk" for PJI. Before the extended antibiotic therapy protocol was instituted, PJI rates for primary THA and TKA in the high-risk subgroup were 4.3% and 2.1%, respectively. After it was instituted, the respective rates dropped to 1.1% and 0.4%, comparable to those seen in the non-high-risk patients treated using standard peri-operative prophylaxis. After adjusting for patient factors, regression analysis showed that high-risk patients receiving only peri-operative antibiotics were more likely to develop PJI than high-risk patients receiving the extended antibiotic protocol. Although these results suggest possible benefits of extended antibiotic prophylaxis in arthroplasty, methodologic limitations and inadequate discussion of potential drawbacks of widespread adoption of such protocols limit the impact of the findings. Future research is warranted to more narrowly define risk factors for PJI and to demonstrate the safety and efficacy of extended antibiotics in reducing the long-term burden of PJI.

Improved Patient-Reported Quality of Life and Hip Function After Cementless 1-Stage Revision of Chronic Periprosthetic Hip Joint Infection

BackgroundLimited information is available on health-related quality of life (HRQoL) and patient-reported hip function following treatment for a chronic periprosthetic hip joint infection. The purpose of this study is to evaluate changes in HRQoL and patient-reported hip function 2 years following a cementless 1-stage revision for chronic periprosthetic hip joint infection. MethodsPatients (n = 52) enrolled in a previously published clinical study on cementless 1-stage revision in chronic periprosthetic hip joint infection prospectively answered the EuroQol-5D, Short-Form Health Survey 36 (SF-36), and Oxford Hip Score preoperatively and at 3, 6, 12, and 24 months follow-up. Results were compared to age-matched and gender-matched population norm. ResultsA significant improvement in HRQoL and patient-reported hip function appeared in the first 3 months after surgery and reached a plateau after 6 months. The patients statistically reached age-matched and gender-matched population norm after 3 to 12 months follow-up on most items, except for Physical Functioning and Social Functioning on the SF-36. The largest effect sizes were found for Oxford Hip Score at 1.8 and for Role Limitation, Physical and Bodily Pain on the SF-36 at 1.5 and 1.6, respectively. ConclusionPatients treated with a cementless 1-stage revision for chronic periprosthetic hip joint infection experienced a marked increase in HRQoL and patient-reported hip function, and matched population norms on many parameters.

Hip Spacers in Two-Stage Revision for Periprosthetic Joint Infection: A Review of Literature.

Infection after total hip arthroplasty (THA) is a devastating complication with significant consequences for patients. In literature, single and two-stage revision, irrigation and debridement, Girdlestone resection arthroplasty, and arthrodesis and amputation are reported as possible treatments. Recently, two-stage revision has become popular as the gold standard treatment for chronic hip joint infections after THA. In this review, we evaluate the current literature about microbiology of periprosthetic joint infections and the use of antibiotic-loaded cement spacers. We aim to give an overview about indications, clinical results, and mechanical complications for spacers implantation, evaluating also selection criteria, pharmacokinetic properties, and systemic safety of the most frequently used antibiotics.

Одноэтапное ревизионное эндопротезирование при лечении перипротезной инфекции тазобедренного сустава

Background One-stage revision arthroplasty has currently a limited use in treatment of a periprosthetic infection despite obvious economic benefits in comparison with two-stage revisions. This operation involves the removal of all implant components, radical surgical debridement, joint irrigation, installation of a new implant, and a long course of antibiotic therapy. Purpose To evaluate the effectiveness of one-stage revision arthroplasty in the treatment of patients with periprosthetic infection of the hip joint. Material and methods Results of treatment of 14 patients with periprosthetic hip infection who underwent the procedure of a single-stage revision arthroplasty in the period from 2009 to 2018 were analyzed. The average follow-up was 2.7 years (range, 1 to 10 years). Results Twelve (86 %) out of 14 patients with periprosthetic infection of the hip joint completed one-stage treatment successfully. Two (14 %) patients developed recurrent infection and had a two-stage revision arthroplasty using an antibacterial spacer. In accordance with the Harris Hip Score scale, the functional state of the limbs at a one-years follow-up after treatment averaged 77.7 points (range, 36 to 95). Conclusions One-stage revision is quite a laborious medical procedure, for which sufficient experience of orthopedic surgeons and a specialized hospital service. This method of treatment provided suppression of infection in 86 % of our cases. Negative factors in using one-stage revision were polymicrobial infection and implant dislocation in the early postoperative period.

Two-stage revision and systemic antifungal therapy of Candida glabrata primary prosthetic hip infection successfully treated: a case report

BackgroundOverall, fungi are estimated to cause approximately 1% of prosthetic joint infections, Candida glabrata account for less than 10% of these cases. No well-defined treatment strategy is available.Case presentationA 71-year-old Caucasian man with non-insulin-dependent diabetes was admitted for hip prosthesis revision. For the past 17 years he suffered from recurrent infection of a perianal fistula, the last episode being 1 week before admission, and was prescribed amoxicillin/clavulanate 1 g twice a day. At surgery, the synovial fluid tested positive for infection with the Synovasure® Alpha Defensin Test, and the orthopedic surgeon reported intraoperative evidence of infection. While the synovial fluid failed to grow microorganisms, seven different samples including periprosthetic tissue and the prosthesis grew Candida glabrata. Imipenem 2 g and teicoplanin 600 mg daily were administered during surgery. Also an antibiotic loaded spacer was positioned. A week later micafungin 100 mg a day was added, and after another week imipenem was replaced with ertapenem 1 g once a day. The combination of antibiotics and antifungal was administered for a total of 7 weeks, while he also underwent treatment of the perianal fistula. The reimplantation was performed after an 8-week antibiotic-free interval. Before reimplantation, his erythrocyte sedimentation rate and C-reactive protein level were normal. At reimplant surgery, several samples were collected for microbiology, before administering ertapenem 1 g, teicoplanin 600 mg and micafungin 100 mg once a day. This antimicrobial combination was continued for 15 days until the microbiologic investigations, including culture and molecular testing after sonication technique of the spacer, were reported negative for bacteria and fungi. In this patient, systemic antifungal and extensive debridement allowed for clinical and microbiologic cure.ConclusionsAlthough Candida glabrata prosthetic joint infection is a rare event, the incidence could increase in the future, and there is need for more definitive treatment protocols. Diagnosis depends on culture. Fungal etiology must always be included in the differential diagnosis of prosthetic joint infection.

What are the Factors Associated with Re-revision After One-stage Revision for Periprosthetic Joint Infection of the Hip? A Case-control Study.

Despite increased interest in one-stage revision arthroplasty for periprosthetic joint infection (PJI) of the hip, the reported infection-free proportions after the one-stage approach are still comparable to that of two-stage revision. However, we still lack studies that analyze factors associated with any re-revision after one-stage revision arthroplasty for PJI. After one-stage revision arthroplasty for PJI of the hip, what factors were associated with an increased risk of re-revision, and what factors were associated with an increased risk of reinfection? We performed a single-center retrospective case-control analysis. Patients who underwent one-stage revision arthroplasty for PJI of the hip in our hospital between 2009 and 2017, and who were subsequently re-revised due to any reason, including reinfection, were identified from our electronic medical records. A total of 121 patients who underwent repeat revision for any reason after one-stage exchange for PJI of the hip were identified. The re-revision procedures were performed after a mean of 407 days. The primary reasons for re-revision were repeated hip dislocation in 53 of 121 patients (44%), reinfection including both new and persistent infections in 40 of 121 patients (33%), and aseptic loosening in 16 patients (13%). Forty-three patients underwent another revision procedure after the re-revision procedure (43 of 121; 36%). More than 40 potential patient-, joint- and surgery-related risk factors were investigated and compared with a 1:1 matched control participants by age, sex and year of the one-stage revision. Similar to the re-revision patients, controls were treated for PJI with one-stage revision arthroplasty; however, they did not undergo subsequent revision for any reason by the latest followup examination. The mean followup of the control group was 66 months (range, 17-119 months). The mean length of hospital stay was 26 days in the re-revised group (SD, 11.6 days) compared with 22 days for the controls (SD, 6.6 days). All analyses were performed to identify factors associated with general re-revision and reinfection. The independent factors associated with repeat revision for any reason were persistent wound drainage for at least 1 week (odds ratio [OR], 7.4; 95% CI, 2.6-20.6; p < 0.001), isolation of enterococci (OR, 4.8; 95% CI, 1.4-15.7; p = 0.010), and prior surgery due to infection before the one-stage hip revision (OR, 3.6; 95% CI, 2.0-6.4; p < 0.001). The factors associated with reinfection including both new and persistent infections were prolonged wound drainage (OR, 6.9; 95% CI, 2.2-21.5; p = 0.001) and prior surgery due to infection (OR, 4.3; 95% CI, 1.9-9.5; p < 0.001). Prolonged wound drainage after the one-stage revision arthroplasty for PJI of the hip must be treated rigorously. Patients with a history of a prior surgical procedure due to hip infection should be informed about the risk of further re-revision when deciding for the one-stage exchange. In case of enterococcal isolation, surgeons may consider another treatment approach rather than the one-stage exchange. Furthermore, we recommend the use of dual mobility cups when performing the one-stage revision hip arthroplasty to reduce the risk of dislocation.Level of Evidence Level III, therapeutic study.

Plasma fibrinogen may predict persistent infection before reimplantation in two-stage exchange arthroplasty for periprosthetic hip infection

BackgroundThe diagnosis of persistent infection before reimplantation in two-stage exchange arthroplasty for periprosthetic joint infection (PJI) remains challenging. Currently, several studies suggested coagulation-related markers, such as D-dimer and fibrinogen, may be promising in diagnose of PJI. The purpose of the study was to investigate the predictive values of plasma D-dimer and fibrinogen for assessment of persistent infection before reimplantation hip arthroplasty.MethodsWe retrospectively reviewed 129 hips that treated with two-stage exchange arthroplasty for PJI from 2012 to 2016 in our institution. The persistent infection before reimplantation was based on a modified Musculoskeletal Infection Society (MSIS) criteria. After exclusion, 102 hips were included in the final analysis. Receiver operating characteristic (ROC) curves were generated to determine the prognostic value of plasma D-dimer and fibrinogen in predicting persistent infection before reimplantation.ResultsThe area the under ROC curves (AUC) for fibrinogen (0.773; 95% confidential interval [CI], 0.569–0.905) was significantly higher than that of D-dimer (0.565; 95% CI, 0.329–0.777). With the calculated threshold of fibrinogen set at 3.61 g/L, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) was 87.5%, 62.8%, 16.7%, and 98.3%, respectively. With the threshold value of D-dimer set at 0.82 μg/mL, the sensitivity, specificity, PPV, and NPV was 83.3%, 41.9%, 21.7%, and 92.9%, respectively.ConclusionsIn conclusion, the current study reveals that the plasma fibrinogen may be a promising biomarker in predicting persistent infection before reimplantation. Further prospective studies with larger cohorts are needed to validate predictive values and optimal thresholds of coagulation-related markers.

Preoperative joint aspiration culture results and causative pathogens in total hip and knee prosthesis infections: mind the gap

ABSTRACT Objectives In prosthetic joint infections (PJIs), there is no consensus about the utility of the preoperative joint aspiration culture to guide antimicrobial treatment. The main objective of this retrospective study was to investigate the value of these preoperative samples to narrow immediate postoperative empirical antimicrobial treatment in patients with a knee or hip PJI. Methods Adult patients admitted for an exchange procedure between June 2007 and July 2016 for whom a preoperative joint aspiration within 6 months prior to the procedure was available and with an antibiotic-free interval before sampling, were eligible. Per PJI, taking both preoperative joint aspiration and intraoperative deep samples into account, causative pathogen(s) were assessed by the current Infectious Diseases Society of America (IDSA) guidelines. Per PJI, agreement of preoperative joint aspiration cultures corresponding to the causative pathogen(s) was investigated both on species and on Gram/fungi level. Results From the 85 PJIs, on species level, the total agreement was found in 58 (68%) PJIs. On Gram/fungi level, when preoperative joint aspiration cultures yielded exclusively Gram-positive microorganisms (n = 61), a 100% predictive value for Gram positive causing pathogens was attained. Insufficient predictive value was observed in PJIs with preoperative joint aspiration yielding Gram-negative microorganisms (n = 4), a fungus (n = 1) or with sterile results (n = 19). Conclusion In the immediate postoperative setting, the treating team might consider a broad spectrum empirical antibiotic regime, guided by the local epidemiology and susceptibility, which can be narrowed to Gram-positive coverage if preoperative joint aspiration cultures yield exclusively Gram-positive microorganisms.

Revision of an infected total hip arthroplasty: the need for the adjustment of risk in bundled payment models for revision arthroplasty.

The aim of this study was to investigate the differences in 30-day outcomes between patients undergoing revision for an infected total hip arthroplasty (THA) compared with an aseptic revision THA. This was a retrospective review of prospectively collected data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database, between 2012 and 2017, using Current Procedural Terminology (CPT) codes for patients undergoing a revision THA (27134, 27137, 27138). International Classification of Diseases Ninth Revision/Tenth Revision (ICD-9-CM, ICD-10-CM) diagnosis codes for infection of an implant or device were used to identify patients undergoing an infected revision THA. CPT-27132 coupled with ICD-9-CM/ICD-10-CM codes for infection were used to identify patients undergoing a two-stage revision. A total of 13 556 patients were included; 1606 (11.8%) underwent a revision THA due to infection and there were 11 951 (88.2%) aseptic revisions. Patients undergoing an infected revision had a significantly greater length of stay of more than three days (p < 0.001), higher odds of any 30-day complication (p < 0.001), readmission within 30 days (p < 0.001), 30-day reoperations (p < 0.001), and discharge to a destination other than the patient's home (p < 0.001). The findings suggest the need for enhanced risk adjustment based on the indication of revision THA prior to setting prices in bundled payment models of total joint arthroplasty. This risk adjustment should be used to reduce the chance of financial disincentives in clinical practice. Cite this article: Bone Joint J 2019;101-B:547-551.

Different microbiological profiles between hip and knee prosthetic joint infections.

The study aims to analyze the demographics and microbiological profiles of hip and knee prosthetic joint infection (PJI) and to compare the microbiological differences between hip and knee PJI. We performed a retrospective study of all PJI cases between January 2006 and December 2014 at a referral medical center in Taiwan. A total of 294 PJI cases were collected: 159 were identified as hip PJI and 135 as knee PJI. The most common causative pathogen was Staphylococcus aureus (78 cases, 27%), followed by coagulase-negative staphylococci (CoNS, 42 cases, 14%). Methicillin-resistant staphylococci (MRS) accounted for 21% of all PJI cases. Fungus and mycobacterium were only involved in 12 cases (4.1%) of all PJI cases. Polymicrobial pathogens, anaerobes, and enteric gram-negative bacilli (GNB) were more likely to occur in hip joint prostheses than in knee joint prostheses (22 vs. 6 cases, p = 0.006; 11 vs. 0 cases; p = 0.002; 20 vs. 6 cases; p = 0.014, respectively). The prevalence of polymicrobial pathogens, anaerobes, and enteric GNB was higher in the prosthetic hip infection than in the prosthetic knee infection. The high prevalence of MRS, including Methicillin-resistant (MR) S. aureus and MR-CoNS in PJI, may warrant the need for empiric antibiotic therapy with broader coverage while pending the culture result of PJI. Although fungal and mycobacterial PJI cases are rare, the incidence of these infections is relatively high in Taiwan. Fungus and mycobacterium should also be taken into consideration whenever a persistent PJI case is encountered.

Efficacy evaluation of one-stage revision combined with intra-articular injection of antifungal agents in the treatment of chronic periprosthetic fungal infection

Objective: To investigate the clinical effect of one-stage revision combined with intra-articular injection of antifungal agents in the treatment of chronic periprosthetic fungal infection. Methods: A retrospective analysis of 11 patients(4 hips, 7 knees) admitted with chronic periprosthetic fungal infection at Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University from January 2004 to April 2016.There were males and females with an age of 67 years (range:47-77 years). Each patient underwent single-stage revision including aggressive soft-tissue debridement. Liquid samples and tissue samples were immediately sent to the microbiology laboratory for drug sensitivity testing and histological analysis. Removed the infected components and cement thoroughly, pouring powdered vancomycin into the medullary cavity and direct intra-articular injection of fungussensitive antibiotics. The patients with infected hips received an uncemented prosthesis and 0.5 g of gentamicin loaded commercial cement was received by the patients with infected knee.After that, a new prosthesis was implanted.Long-term combination therapy of antibacterial agents and antifungal agents were given after operation. Recurrence of infection and clinical outcomes were evaluated. The follow-up period was 5 years (range: 2-12 years). Results: One patient died of acute heart failure on the eighth postoperative day.Three infection cases were recurred.Eight cases had satisfactory outcomes and required no additional surgical or medical treatment for recurrence of infection. The Harris hip score assessed preoperatively and at latest follow-up was increased from 39.25±5.12 to 79.50±4.79, the difference was statistically significant (t=-11.356, P=0.001).The Hospital for Special Surgery knee score was improved from preoperative 46.25±5.61 to final follow-up 80.50±5.06, and the difference was statistically significant (t=-9.930, P=0.002). Conclusion: Treatment of chronic fungal periprosthetic joint infection with single-stage revision can be fairly effective for achieving acceptable functional outcomes.

Recurrent postoperative delirium in spinocerebellar ataxia type 2: a case report

BackgroundPostoperative delirium is a relatively uncommon condition in middle aged patients, but very widespread in patients with psychiatric and neurological diseases undergoing general anesthesia. Few studies are currently available in the literature on the perioperative anesthesiological management of patients suffering from spinocerebellar ataxia.Case presentationA 58-year-old Caucasian woman affected by spinocerebellar ataxia type 2 underwent total hip arthroplasty for advanced osteoarthritis. One month later, debridement, antibiotics, and implant retention was performed for periprosthetic hip infection. Both times she underwent general anesthesia and developed an early postoperative delirium treated successfully with chlorpromazine.ConclusionsThis case report highlights the need to correctly manage patients at high risk of developing postoperative delirium, especially if suffering from degenerative neurological diseases. On the other hand, further studies will be needed in order to evaluate if spinocerebellar ataxia is an independent risk factor for the development of this acute and transient pathological condition.

Biarticular total femoral spacer for complete bone loss in periprosthetic joint infection. A technical modification

BackgroundThe management of complete bone defects in hip and knee periprosthetic infection is still a real surgical challenge. Material and methodsWe present a technical modification for performing a biarticular total femoral spacer with a femoral nail without the need to approach the proximal tibia. ResultsThree patients were operated with this technique. There was no intraoperative complication. The infection was resolved in all patients operated at final follow-up. All patients improved their previous functional situation and could walk with different aids. ConclusionsThis technical modification is an alternative for cases where it is necessary to resect the complete femur, but it is not necessary to approach the tibia.

Association between Allogeneic Blood Transfusion and Wound Infection after Total Hip or Knee Arthroplasty: A Retrospective Case-Control Study.

Background: To assess using a retrospective case control study, whether patients undergoing primary, elective total hip or knee arthroplasty who receive blood transfusion have a higher rate of post-operative infection compared to those who do not.Materials and Methods: Data on elective primary total hip or knee arthroplasty patients, including patient characteristics, co-morbidities, type and duration of surgery, blood transfusion, deep and superficial infection was extracted from the Alberta Bone and Joint Health Institute (ABJHI). Logistic regression analysis was used to compare deep infection and superficial infection in blood-transfused and non-transfused cohorts.Results: Of the 27892 patients identified, 3098 (11.1%) received blood transfusion (TKA 9.7%; THA 13.1%). Overall, the rate of superficial infection (SI) was 0.5% and deep infection (DI) was 1.1%. The infection rates in the transfused cohort were SI 1.0% and DI 1.6%, and in the non-transfused cohort were SI 0.5% and DI 1.0%. The transfused cohort had an increased risk of superficial infection (adjusted odds ratio (OR) 1.9 [95% CI 1.2-2.9, p-value 0.005]) as well as deep infection (adjusted OR 1.6 [95% CI 1.1-2.2, p-value 0.008]).Conclusion: The odds of superficial and deep wound infection are significantly increased in primary, elective total hip and knee arthroplasty patients who receive blood transfusion compared to those who did not. This study can potentially help in reducing periprosthetic hip or knee infections.

SAT-511 Refractory Hypercalcemia Secondary to Antibiotic Eluting Calcium Sulphate Beads

Hypercalcemia secondary to placement of antibiotic eluting calcium sulphate beads is rare. We present the case of a 58 year old Caucasian woman who presented with altered mental status, septic shock and respiratory failure. Labs showed hypercalcemia. History revealed placement of antibiotic-eluting calcium sulphate beads after removal of her infected left prosthetic hip joint two days before presentation. She had no known history of calcium, parathyroid disorders, fractures or kidney stones. Total serum calcium was elevated to 12.2 mg/dl (Ref 8.4-10.2 mg/dl) on admission with peak levels two days later at 15.7mg/dl. Her intact PTH was < 10.0 pg/ml (Ref 15-65.0 pg/ml); 1,25 Dihydroxy Vitamin D was 8.9 pg/ml (Ref 18-78.0 pg/ml) and 25 Hydroxy Vitamin D was 13 pg/ml (Ref 30-80 pg/ml) thus ruling out primary hyperparathyroidism, granulomatous disease or Vitamin D toxicity as etiology. Multiple myeloma work up was negative and was on no medications known to cause hypercalcemia. She received 8 doses of calcitonin (4 units/kg) but due to her worsening kidney function (< 30 ml/min), she could not receive a bisphosphonate. She became volume overloaded and required dialysis which corrected her hypercalcemia and renal function. She received 8 days of continuous renal replacement therapy followed by 2 sessions of hemodialysis which improved her serum calcium levels and renal function to normal range. Mental status also improved with improvement in her calcium levels. Duration of elevated calcium levels was 5 days. After dialysis was stopped, her calcium level and creatinine remained normal. In this case, hypercalcemia was attributed to antibiotic-eluting calcium sulphate beads. This case represents a rare etiology of hypercalcemia. On review of the literature, very few cases have been reported in humans. The first report to describe hypercalcemia following placement of calcium sulphate beads in humans was a case series consisting of 15 patients. Out of these patients, 3 developed hypercalcemia, one of which developed symptoms and required treatment with intravenous fluids and bisphosphonates.1 Another case reported a woman who suffered seizures due to a calcium leak into her cerebrospinal fluid after placement of calcium sulphate beads into her lumbar spine, however her serum calcium levels remained normal. 2 This case is one of a few reported in the literature of symptomatic hypercalcemia that occurred after placement of calcium sulphate beads. Further work is needed to understand those at risk of hypercalcemia from these agents. 1. Kallala R, Haddad FS. Hypercalcaemia following the use of antibiotic-eluting absorbable calcium sulphate beads in revision arthroplasty for infection. The bone & joint journal. 2015;97-b(9):1237-1241. 2. Smith I. Convulsions and Coma Associated with Iatrogenically Elevated CSF Calcium Levels Post Spinal Surgery: A Case Report. Crit Care Resusc. 2005;7(3):173-176.

Accuracy of Computed Tomography–Guided Joint Aspiration and Computed Tomography Findings for Prediction of Infected Hip Prosthesis

BackgroundInfection after total hip arthroplasty remains a diagnostic challenge. We assessed the accuracy of computed tomography (CT)-guided joint aspiration combined with CT findings for prediction of septic hip prosthesis before revision surgery. MethodsA total of 96 patients (64.6% men; mean age, 68 years) scheduled for elective revision surgery due to suspicion of infection after total hip arthroplasty underwent CT-guided joint aspiration. Volume and microbiological cultures of aspirated fluid and salient findings on CT scans, including periprosthetic soft-tissue mass, malpositioning of the prosthesis, periprosthetic osteolysis, reactive enlarged lymph nodes, and heterotopic ossification, were assessed by a blinded radiologist. ResultsSeptic hip prosthesis was shown on revision surgery in 35 patients (36.4%), with Staphylococcus epidermidis isolated in 54.3% of cases. Culture of the aspirated fluid yielded the same microorganism in 24 patients (68.6%). The accuracy of preoperative CT-guided joint aspiration was 86.5%. High volume (>1 mL) of aspirated fluid was recorded in 32 patients (33.3%). In the multivariate analysis, high volume on CT aspiration, accumulation of soft tissue exceeding the joint margin, osteolysis without bone insufflation, and enlarged iliac lymph nodes were significant predictors of infected hip prosthesis. Similar results were obtained after adjustment of the model by the presence of aggressive granulomatosis. ConclusionPreoperative CT-guided joint aspiration is accurate to diagnose septic hip prosthesis based on CT imaging findings and volume and bacterial culture of the aspirated fluid. Enlarged iliac lymph nodes emerged as a strong predictor of infection.

Similar Risk of Re-Revision in Patients after One- or Two-Stage Surgical Revision of Infected Total Hip Arthroplasty: An Analysis of Revisions in the Swedish Hip Arthroplasty Register 1979–2015

Late chronic infection is a devastating complication after total hip arthroplasty (THA) and is often treated with surgery. The one-stage surgical procedure is believed to be the more advantageous from a patient and cost perspective, but there is no consensus on whether the one- or two-stage procedure is the better option. We analysed the risk for re-revision in infected primary THAs repaired with either the one- or two-stage method. Data was obtained from the Swedish Hip Arthroplasty Register and the study groups were patients who had undergone a one-stage (n = 404) or two-stage (n = 1250) revision due to infection. Risk of re-revision was analysed using Kaplan–Meier analysis with log-rank test and Cox regression analysis. The cumulative survival rate was similar in the two groups at 15 years after surgery (p = 0.1). Adjusting for covariates, the risk for re-revision due to all causes did not differ between patients who were operated on with the one- or two-stage procedure (Hazard Ratio (HR) = 0.9, 95% Confidence Interval (C.I.) = 0.7–1.2, p = 0.5). The risk for re-revision due to infection (HR = 0.7, 95% C.I. = 0.4–1.1, p = 0.2) and aseptic loosening (HR = 1.2, 95% C.I. = 0.8–1.8, p = 0.5) was similar. This study could not determine whether the one-stage method was inferior in cases when the performing surgeons chose to use the one-stage method.

Periprosthetic hip infection: current concepts

Periprosthetic joint infection (PJI) following total hip arthroplasty (THA) is a devastating problem for surgeons, but worse for the patients involved. If diagnosed early, prompt intervention and treatment can vastly improve outcomes. Increased risk of PJI relates to decreased ability to fend off disease, along with modifiable and non-modifiable risk factors. PJI occurs due to either surgical site contamination, local spread or spread from a distant infection elsewhere in the body. Gram-positive organisms remain the most common causative microbes. Patients with PJI can present with a range of symptoms, from florid sepsis to decreased performance in a well-functioning joint. Here, the array of diagnostic tests available are used, and these are the focus of this article. The Second International Consensus Meeting on Musculoskeletal Infection 2018 advocated a scoring system for pre- and intraoperative non-microbiological tests. It highlights the importance of using multiple tests in tandem when faced with a failing arthroplasty or prosthesis, but with no organism cultured. Treatment options range from traditional two-stage revision surgery, through to single-stage surgery and antibiotic suppression. Treatment plans must be patient-specific, but all are significant undertakings. Therefore, the role of prevention must continue to be at the forefront of any arthroplasty surgeon's mind.