Infected Hip Research Articles

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

BackgroundRecently, 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. MethodsWe 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. ResultsA 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). ConclusionThe 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.

Is Extended Trochanteric Osteotomy Safe for Use in Two-stage Revision of Periprosthetic Hip Infection? A Systematic Review

AbstractSeveral clinical trials have retrospectively evaluated the role of extended trochanteric osteotomy in two-stage total hip arthroplasty (THA) revision for the management of periprosthetic joint infection of the hip. However, no systematic review of the literature has been published to date to evaluate the clinical, functional, and radiographic outcomes of extended trochanteric osteotomy (ETOs) performed as part of implant removal during a two-stage revision for the management of periprosthetic joint infection (PJI). The US National Library of Medicine (PubMed/MEDLINE), and the Cochrane Database of Systematic Reviews were queried for publications from January 1980 to April 2019 using the following keywords: “extended” AND “trochanteric” AND “osteotomy.” Six studies included in this systematic review assessed 305 cases (281 patients) of PJI treated surgically with two-stage revision combined with ETO at the first stage. The mean overall union rate of the ETO was 97%, while the overall rate of radiographic femoral stem subsidence &gt;5 mm was 5%. In addition, the overall mean infection-free rate of two-stage revision combined with ETO was 94% (288 out of 305 operated hips), while the overall complication rate requiring reoperation was 8% (26 out of 305 operated hips). Finally, there was some evidence to show that two-stage revision with ETO was associated with improved infection-free rates compared with two-stage revision without ETO. ETO seems safe and effective in patients with well-fixed femoral stems who require two-stage THA revision for the management of chronic PJI. Two-stage revision with ETO might result in improved infection-free rates compared with two-stage revision without ETO.

Staged Revision of Infected-hip Arthroplasty Using an Antibiotics-loaded Intra-articular Cement Spacer: Impact on Cemented and Cementless Stem Retention.

PurposeCurrently, standard management of a peri-prosthetic infection is a two-stage revision precedure. However, removal of well-fixed cement is technically demanding and associated with numerous potential complications. For theses reasons, two-stage revision with preservation of the original femoral stem can be considered and several previous studies have achieved successful results. While most prior studies used cemented stems, the use of cementless stems during arthroplasty has been gradually increasing; this study aims to assess the comparative effectiveness of a two-stage revision of infected hip arthroplasties at preserving cemented and cementless stems.Materials and MethodsBetween December 2001 and February 2017, Inje University Sanggye Paik Hospital treated 45 cases of deep infections following hip arthroplasty with a two stage revisional arthroplasty using antibiotics-loaded cement spacers. This approach was applied in an effort to preserve the previously implanted femoral stem. Of these 45 cases, 20 were followed-up for at least two years and included in this analysis. Perioperative clinical symptoms, radiological findings, function and complications during insertion of an antibiotics-loaded cement spacer were analyzed in this study.ResultsPeri-prothetic infections were controlled in 19 of the 20 included cases. Clinical outcomes, as assessed using the Harris hip score, Western Ontario and McMaster University score, also improved. Importantly, similarly improved outcomes were achieved for both cemented and cementless femoral stems.ConclusionIn cases of deep infection following hip arthroplasty, two-stage revision arthroplasty to preserve the previously implanted femoral stem (cemented or cementless) effectively controls infections and preserves joint function.

Cementless Total Hip Arthroplasty for Adult Patients With Sequelae From Childhood Hip Infection: A Medium-Term Follow-Up Study

BackgroundThe aim of this study is to evaluate midterm clinical and radiographic results of total hip arthroplasties (THAs) with cementless implants for adult patients with sequelae from childhood hip infection. MethodsBetween 2002 and 2016, 165 patients (165 hips) who had a hip infection during childhood were treated with THAs with cementless implants. The average duration of follow-up was 93.5 months (range 26-206). Clinical results were evaluated via the Harris Hip Score and radiographic results were analyzed with postoperative serial X-rays. ResultsThe average Harris Hip Score increased from 27 (range 8-53) before surgery to 91 (range 45-100) at the latest follow-up examination (P < .001). At the latest follow-up evaluation, 9 cementless acetabular components demonstrated partial, nonprogressive radiolucencies. No subsidence of more than 2 mm or evidence of a radiolucent line was observed around the femoral components. Intraoperative periprosthetic fractures occurred in 11 hips, including 3 acetabular fractures, 2 fractures of greater trochanter, 1 femoral shaft fracture, and 5 fractures of femoral calcar. Postoperative complications included 3 cases of periprosthetic infection, 1 episode of dislocation, 1 case of a femoral periprosthetic fracture, 5 cases of sciatic nerve injury, 1 case of femoral nerve injury, and 1 case of squeaking from a ceramic bearing surface. ConclusionCementless THA for adult patients with sequelae from childhood hip infection presents significant technical challenges and a relatively high complication rate. With meticulous surgical planning and anticipation for the key technical challenges frequently encountered, the medium-term clinical and radiographic results of THA in this setting were good with high implant survivorship and patient satisfaction.

Point/Counterpoint: Nonarticulating vs Articulating Spacers for Resection Arthroplasty of the Knee or Hip

Two-stage exchange arthroplasty remains the gold standard for chronic total knee arthroplasty (TKA) and total hip arthroplasty infections in North America. Cement spacers impregnated with high-dose antibiotics have been successfully used in the interim period of the 2-stage exchange process. A number of spacers have been described; however, this article will focus on articulating spacers. In the presence of an intact extensor mechanism (for TKA), reasonable soft tissue envelope, and adequate bone, articulating antibiotic spacers provide several advantages. These include an infection eradication rate of approximately 90%, higher range of motion after reimplantation, and lower complication rates when compared with nonarticulating spacers. In the appropriate patient, articulating antibiotic spacers are an effective and a safe treatment for infected TKAs and total hip arthroplasties.

Spacer Design Options and Consideration for Periprosthetic Joint Infection

An articulating or nonarticulating antibiotic hip spacer can be placed following the first stage implant removal of a periprosthetic hip joint infection. Antibiotic spacers help fill in the dead space created at the time of resection and provide a high local concentration of antibiotics. Theoretical advantages of a static spacer include a higher elution of antibiotics because of the increased surface area, the ability to protect deficient bone in the proximal femur/acetabulum, and the ability to immobilize the periarticular soft tissues. Advantages of an articulating spacer include improved ambulation and easier motion for the patient, maintenance of soft tissue tension, and an easier surgical reconstruction at the time of the second stage. Additionally, an articulating antibiotic spacer may minimize the risk of dislocation following the second stage reconstruction. The choice of articulating or nonarticulating is currently one of surgeon preference yet it is advised that surgeons consider an articulating spacer for all patients except those with severe femoral/acetabular bone loss or deficient abductors.

Single-stage Surgery With Antibiotic-loaded Hydrogel Coated Implants Versus Two Stage Surgery for Secondary Prevention of Complex Chronic Periprosthetic Hip Joint Infection

Single-stage Surgery With Antibiotic-loaded Hydrogel Coated Implants Versus Two Stage Surgery for Secondary Prevention of Complex Chronic Periprosthetic Hip Joint Infection

Understanding a Rare Injury: An Observational Study of Anterior-Superior Hip Dislocations

OBJECTIVE. The goals of this study were to assess the prevalence of anterior hip dislocation and to highlight the distinctive imaging features of anterior-superior hip dislocation. MATERIALS AND METHODS. A retrospective chart review was conducted of all hip dislocations seen at one university hospital from January 2005 to January 2019. The radiology database was queried for all reports of hip or pelvis radiographs with the word "dislocation." Cases of developmental dysplasia of the hip, infection, tumor, arthroplasty, Girdlestone procedure, surgical dislocation, and prior hip surgery were excluded, leaving 237 traumatic hip dislocations. Electronic medical records of the 18 cases of anterior hip dislocation were reviewed to determine the mechanism of injury, treatment, and subsequent outcomes. RESULTS. Among 237 traumatic hip dislocations, 18 (7.6%) were anterior hip dislocations. Among the 18 were three (17%) anterior-superior dislocations and 15 (83%) anterior-inferior dislocations. All anterior-superior dislocations had poor outcomes. One patient had persistent hip pain and instability and underwent follow-up imaging. In one case, MRI performed at the time of injury and 11 months later showed tears of the superior capsule, iliofemoral ligament, and ligamentum teres. The iliofemoral ligament tear did not heal, resulting in a persistent anterior capsule defect, a finding previously associated with instability in patients who have undergone arthroscopic surgery. CONCLUSION. The incidence of anterior hip dislocation was lower than some studies have suggested. Anterior-superior hip dislocation is a rare injury in which ligamentous defects are visualized at MRI and possibly contribute to anterior hip instability and pain.

Partial implant retention in two-stage exchange for chronic infected total hip arthroplasty.

The efficacy of partial retention of well-fixed components during two-stage exchange for chronic total hip arthroplasty (THA) infection has remained unknown. A total of 14 patients with chronic infected THA were treated with damage control two-stage revision, including selective retention of the well-fixed femoral or acetabular component, aggressive debridement, antibiotic-laden cement spacer, antibiotic therapy, and delayed reimplantation. Indications for this treatment included chronic infected THAs with ingrown femoral or acetabular component and positive microbial growth with sensitive antibiotics. We excluded patients with acute infection; negative microbial growth; positive pathogen with high-virulence bacterial infections and multiple drug-resistant bacteria such as methicillin-resistant Staphylococcus aureus, fungi, and Mycobacterium tuberculosis; sinus formation; a prior failure for periprosthetic joint infection (PJI) treatment; and obvious bone resorption in both femoral and acetabulum side. During the study period, this represented 3.3% (14/425) of the patients treated for infected THA. Minimum follow-up was threeyears. None of the 14 patients in this series were lost to follow-up. Successful treatment was defined according to a modified Delphi-based international multidisciplinary consensus. No repeated debridement and recurrence of infection occurred during the study period; no patient need chronic antibiotic suppression. Successful treatment of chronic PJI was achieved in all patients. Despite the high peri-operative complication rate, no severe consequences were observed. The mean Harris Hip Score was 86 (range, 82-92; SD, 3.3). The selective partial implant retention two-stage revision for chronic PJI may be a treatment option in properly selected patients with low virulence bugs.

Mid-term outcomes of a partial 2-stage approach in late chronic periprosthetic hip infections.

Late chronic periprosthetic infections (LCPIs) are worrisome complications of primary hip arthroplasties. The gold standard procedure is the 2-stage revision. 1-stage exchange is gaining popularity in order to reduce the invasivity of the former technique. A partial 2-stage exchange technique, retaining fixed components, may overcome some of the drawbacks of the previous techniques, allowing a much easier reconstruction step. 28 patients with a LCPI after a primary total hip arthroplasty underwent a first removal stage: the loosened component was removed (23 cups and 5 stems) and the fixed component, with no local signs of infection, was retained. An antibiotic hand molded spacer was positioned in 16 cases. After a mean time of 8 months and a tailored antimicrobial therapy, the spacer was removed and the implant was revised. The mean follow-up was 5 years. The HHS score was 82.7. 4 cases failed (2 patients presenting a septic relapse after revision and 2 patients undergoing Girdlestone arthroplasty), achieving a survival rate of 83.4% at 5 years. 2 patients were unwilling to perform a further procedure and did not proceed to the second stage. All the other patients had no clinical, radiological, laboratory signs of septic relapse. The partial 2-stage approach seems a promising technique for LCPI in selected cases, with good infection control. It allows an easier revision by sparing the fixed components. Larger case series and longer follow-ups are needed to confirm the results and identify the limits of this approach.

Clinical and microbiological characteristics of periprosthetic hip and knee infections

Objective. To characterize periprosthetic joint infection in patients undergoing a total hip and knee joint replacement. Materials and Methods. A total of 77 patients with periprosthetic infection following hip and knee joint replacement hospitalized in Grodno City Clinical Hospital were studied over the period of 2014-2018. Wound discharge, tissue samples, and fistula’s wall swab were used for microbiological tests. The analysis of surgical treatment of patients with deep periprosthetic knee and hip joint infection has been performed. Results. Periprosthetic infection after hip joint arthroplasty was observed in 32 (41.6%) patients, and after total knee joint arthroplasty in 45 (58.4%) patients. Surgical treatment was performed in 18 (56.3%) and 32 (71.1%) patients with periprosthetic infection following total knee and hip joint replacement, respectively. A total of 10 (31.2%) of 32 cultures from patients with periprosthetic infection after total hip joint replacement and 8 (17.8%) of 45 cultures from patients with periprosthetic infection after total knee joint replacement were positive. Overall, Staphylococcus aureus was detected in 9 (50%) of 18 positive cultures. Gram-negative aerobic bacteria (Acinetobacter baumannii, Klebsiella pneumoniae Pseudomonas aeruginosa) were detected in 4⁄10 and 5⁄8 of positive cultures from patients with periprosthetic infection of hip and knee joints, respectively. Conclusions. The most common pathogens causing periprosthetic infection of hip and knee joints were S. aureus (50%) and Gram-negative bacteria. The surgical treatment was performed in 71.4% of patients with periprosthetic joint infection.

Streptococcus bovis Hip and Knee Periprosthetic Joint Infections: A Series of 9 Cases.

Introduction: Prosthetic joint infection (PJI) due to Streptococcus bovis group (SBG), specifically S. bovis biotype I (S. gallolyticus), is rare and associated with colorectal carcinoma. Little has been published regarding SBG PJI. We analyzed nine cases of SBG PJI at our institution, the largest series to date.Methods: The medical records of patients diagnosed with SBG PJI between 2000-2017 were reviewed. Patients were followed until death, failure, or loss to follow-up. Mean follow-up was 37 months (range 0.5-74 months).Results: Nine PJI in 8 patients with mean prosthesis age at diagnosis of 8 years (range 4 weeks-17 years) were identified. The median duration between symptom onset and treatment was 38 weeks (range 0.3 weeks-175 weeks). 8/9 had their PJI eradicated with treatment based on acuity of symptoms. Acute PJI (2) was treated with DAIR, and chronic PJI (7) was treated with 2-stage revision arthroplasty. 1 PJI with chronic PJI developed recurrent infection after initial treatment. All patients received post-operative IV antibiotics. 7/8 patients received Ceftriaxone. Three patients received lifelong oral antibiotics. 7/8 patients underwent colonoscopy. 5/7 patients were found to have polyps following PJI diagnosis with one carcinoma and two dysplastic polyps. The two patients without polyps had identifiable gastrointestinal (GI) mucosal abnormality: tooth extraction prior to symptom onset and diverticulosis on chronic anticoagulation.Conclusion: SBG PJI is typically due to hematologic seeding. Colonoscopy should be pursued for patients with SBG PJI. Surgical treatment dictated by infection acuity and 6-week course of Ceftriaxone seems sufficient to control infection.

What are patients’ preferences for revision surgery after periprosthetic joint infection? A discrete choice experiment

ObjectivesUnderstanding patients’ preferences for treatment is crucial to provision of good care and shared decisions, especially when more than one treatment option exists for a given condition. One such condition...

Decision Matrix-Guided Treatment of Infected Hip Resurfacing.

Infection can nullify the benefits of a successful hip resurfacing arthroplasty (HRA). Even with infection, it may be feasible to meet a patient's desire to retain the implant. The author reviewed records of 301 patients with infected hip resurfacing. Patients expressed their treatment preference using a decision matrix that considered treatment efficacy, consequences of treatment failure, probability of infection worsening, and treatment side effects. Patient interviews were analyzed to determine their experience with treatment. Treatment alternatives were (1) no surgery, oral antibiotics, and local incision care; (2) surgical debridement, IV antibiotics, and implant retention; (3) one-stage explantation, IV antibiotics, and reimplantation generally with conversion to total hip replacement; and (4) two-stage reimplantation with conversion to total hip replacement. Mean follow-up was 9 years (range, 2-34). Pretreatment qualitative themes found that some patients believed their early infection symptoms were not validated, leading to diagnostic delays. During treatment, themes centered on mobility and lifestyle limitations for those receiving revision surgery. Posttreatment themes were reduced function following revision compared to pretreatment function. Of the 301 patients, 199 (66%) had nonoperative care, with remission for 169 (85%); 40 (13%) had one-stage reimplantation and 36 (90%) had infection remission; 16 (5%) had two-stage reimplantation with remission in 14 (87%); and 46 (16%) had debridement and implant retention, with remission for 38 (83%). The matrix showed that patients with infected HRA preferred nonoperative care, which was successful for 85%. Qualitative themes found less patient distress with nonoperative treatment and the greatest patient distress with two-stage revision.

Two-Stage Treatment of Periprostetic Infection: Mid-Term Results

Purpose — to evaluate the efficiency of two-stage revision arthroplasty performed according to a standardized protocol by a multidisciplinary surgical team. Materials and Methods. 87 patients with deep periprosthetic hip and knee joint infection (PJI) were included into the prospective study. The patients were admitted to the clinic in the period from January 2012 until December 2014 and underwent two-stage revision procedure. First stage included removal of infected implant and insertion of a cemented spacer, second stage — re-implantation of a prosthesis. Results. Re-implantation of a prosthesis was performed in 89.7% (95% CI 82.8–95.4) of cases. Infection recurrence rate was 13.8% (95% CI 6.9–20.7) and 12.8% (95% CI 6.4–21.8) after the first and the second stage, respectively. Overall efficiency of two-stage procedure was 80,5% (95% CI 71.3–88.5) with a median of 4.7 year follow up. Conclusion. Rate of re-implantation, recurrent infection and newly occurred infection should be taken into consideration for evaluation of treatment efficiency. Application of single criteria for assessment of successful treatment outcomes will allow to compare various studies. Positive microbiological tests during the second stage of procedure are not a risk factor for recurrent infection but can be caused by contamination of specimens.

Early Deep Periprosthetic Hip Infection of Odontogenic Origin (Case Report)

Deep periprosthetic joint infection (PJI) is a severe complication after primary and revision hip joint arthroplasty resulting in multiple interventions on the joint. The present paper describes a rare case of early deep hip PJI of odontogenic etiology. The patient suffered from early PJI after a planned procedure of left hip joint arthroplasty. Antibacterial therapy without surgical debridement was performed in an outpatient unit which resulted in a late, on day 12th after surgery, admittance of the patient to hospital with continued administration of antibiotics. Treatment tactics was selected upon patient’s admission basing on patient complaints, medical history of the disease, clinical signs and findings of roentgenological, laboratory and bacteriological examinations. Two-stage treatment consisting of revision, removal of implant, debridement, biopsy and wound drainage by a swab was performed and followed by empiric antibacterial therapy (for 5 days). Targeted antibacterial therapy was prescribed basing on bacteriological test findings. Together with dentists the authors examined oral cavity of the patient, identified a site of chronic infection and undertook the focused treatment by dental extraction and sanitation of the oral cavity. Postoperative period after the first stage was uncomplicated. Second stage of revision (re-arthroplasty of left hip joint) was performed on week 36 of the surgical time-out with a good clinical outcome: 80 points on Harris hip score in 40 weeks after the second stage. Presented clinical case illustrates the existence of hematogenous mechanism of postoperative microorganism dissemination from the chronic infection nidus with subsequent progression of inflammation at the surgical site, including PJI. In the present case the Actinomyces odontolyticus was isolated from periprosthetic tissues and parodontal recesses which allowed the authors to suggest a highly probable cause for early PJI by Actinomyces odontolyticus translocation into periprosthetic tissues of the hip joint. However, strain sequencing is required for the complete verification. The described case confirms the need for debridement of chronic infection nidus prior to joint arthroplasty aiming at prevention of hematogenous periprosthetic infection.

Difficult-To-Treat Periprosthetic Hip Infection: Outcomes of Debridment

Purpose of the study — to compare management efficiency for difficult-to-treat periprosthetic hip joint infection (PJI) during resection arthroplasty with grafting by vastus lateralis pedicle island flap in comparison with insertion of an antimicrobial-loaded cement spacer. Material and Methods. 132 patients were included into the retrospective study who underwent treatment from 2012 until 2018 including removal of orthopaedic implant, radical surgical debridement of infection focus, resection arthroplasty with grafting by vastus lateralis pedicle island muscle flap (PMF group — 57 patients) or insertion of antibacterial-loaded cement spacer (AMS group — 75 patients). The authors examined medical histories, nature of infection process, infection agent type, laboratory data in respect of systemic inflammation, size of bone defects, follow up status and remission of PJI in the late period. Results. 89.4% of patients (n = 51) who underwent grafting by vastus lateralis pedicle island flap had a history of 3 and more prior surgical procedures in the same area. At the same time the share of such patients in the spacer group was only 38.6% (n = 29) (p0.0001) while the share of patients with two and more recurrences was 78.9% (n = 45) and 25.3% (n = 19), respectively (p0.0001). No significant variances were observed between the groups in respect of type composition of PJI microbial infection agents. The infection in a vast majority of patients in both groups was caused by microbial association: 77.2% and 72.0% in PMF and AMS groups, respectively. In the early postoperative period secondary revision of surgical site was performed in 35% and 28% of cases in PMF group (n = 20) and AMS group (n = 21), respectively, including due to recurrent infection in 15.8% and 28% of cases, respectively. Stable remission of difficult-to-treat PJI in PMF group was 96.5% and 45.3% in AMS group. Conclusion. Despite some cases that required secondary revisions in early postoperative period the resection arthroplasty in combination with pedicle muscle flap can be considered a surgery of choice for management of recurrent difficultto-treat PJI with feasible re-implantation of prosthesis against the stable remission of infection.

Importance of the Algorithm for Diagnosis of Late Deep Periprosthetic Hip Infection

Relevance. Late deep periprosthetic infection (PJI) of the hip joint is a serious complication after arthroplasty which takes the lead among the world reasons for revision. Accurate diagnostics allows to achieve good results and select a proper treatment tactics. Purpose of the study — to evaluate the efficiency of diagnostics algorithm for late deep PJI and impact of the microbial landscape on the risk of infection recurrence. Materials and methods. The authors evaluated two groups of patients who underwent revision in the period from 2002 to 2014 and from 2015 to 2018. The first (retrospective) group included 144 patients who were not diagnosed for late deep PJI. The second (prospective) group included 157 patients who underwent detailed diagnostics for late deep PJI based on the algorithm including the analysis of x-rays, pelvic CT, triple evaluation of ESR and CRP, puncturing of affected joint and microbiology examination. The authors assessed the microbial landscape in 51 patients with late deep hip PJI. Results. In the first group 12 patients (8.3%) underwent sanation and spacer insertion during first stage of treatment, 46 patients (59.7%) after revision demonstrated positive intraoperative cultures confirming septic etiology of implant loosening, 19 patients (24.67%) had no flora growth, and no intraoperative microbiological examination was done for remaining 67 patients (46.52%). In the second group after detailed diagnostics 51 patients (32.4%) underwent removal of prosthesis and spacer insertion in the first stage, other 13 patients (8.2%) featured flora growth after revision, remaining 93 patients (59.2%) had no flora growth after revision. Recurrent PJI was observed in 21 patients (14.5%) in the first group, and in 10 patients (6.3%) in the second group. In the second group recurrent PJI was reported in 40% of patients due to microbial associations, in 30% — due to MRSA, in 20% — due to culture negative bacteria and in 10% — due to S. aureus. Conclusion. Triple examination allows to obtain an accurate diagnosis and isolate the pathogen for deep PJI. Application of such diagnostics algorithm allows to reduce 2.1 times the risk of recurrent deep PJI and to scale down 4 times the detection of type IV infection by Coventry–Tsukayama classification.

Diagnosis of Shoulder Arthroplasty Infection: New Tests on the Horizon.

Periprosthetic shoulder infection (PSI), although less common than prosthetic hip and knee infections, continues to be a devastating complication of shoulder arthroplasty. Unlike its counterparts in the hip and knee, infection with nonsuppurative bacteria is more common than infection with more virulent bacteria in periprosthetic shoulder infection. The diagnosis of PSI can be challenging because the traditional clinical and laboratory findings are not always present. The authors present a narrative review of the current methods used in the diagnosis of PSI, as well as recently developed tests that may hold promise for the diagnosis of PSI. [Orthopedics. 2020; 43(2):76-82.].

Complications of Resection Arthroplasty in Two-Stage Revision for the Treatment of Periprosthetic Hip Joint Infection.

Little data is available regarding complications associated with resection arthroplasty in the treatment of hip periprosthetic joint infection (PJI). We assessed complications during and after two-stage revision using resection arthroplasty. In this retrospective study, 93 patients undergoing resection arthroplasty for hip PJI were included. Patients were assigned to a prosthesis-free interval of ≤10 weeks (group 1; 49 patients) or >10 weeks (group 2; 44 patients). The complication rates between groups were compared using the chi-squared test. The revision-free and infection-free survival was estimated using a Kaplan–Meier survival analysis. Seventy-one patients (76%) experienced at least one local complication (overall 146 complications). Common complications were blood loss during reimplantation (n = 25) or during explantation (n = 23), persistent infection (n = 16), leg length discrepancy (n = 13) and reinfection (n = 9). Patients in group 1 experienced less complications after reimplantation (p = 0.012). With increasing severity of acetabular bone defects, higher incidence of complications (p = 0.008), periprosthetic bone fractures (p = 0.05) and blood loss (p = 0.039) was observed. The infection-free survival rate at 24 months was 93.9% in group 1 and 85.9% in group 2. The indication for resection arthroplasty needs to be evaluated carefully, considering the high rate of complications and reduced mobility, particularly if longer prosthesis-free intervals are used.