Lipopolysaccharide-binding protein: A valuable biomarker in the differentiation between periprosthetic joint infection and aseptic loosening?

Purpose

The pre-operative differentiation between periprosthetic joint infection (PJI) and aseptic loosening after total hip (THA) or knee (TKA) arthroplasty is essential for successful therapy and relies in part on the use of molecular markers. The objective of this study was to assess serum levels of lipopolysaccharide-binding protein (LBP) as a diagnostic tool for PJI and to compare its accuracy with standard tests.

Methods

One hundred and twenty patients presenting with a painful TKA or TKA with indication for surgical revision were included in this prospective, controlled, clinical trial at a single centre. Pre-operative blood and serum samples were collected and analysed for white blood cell (WBC) count, C-reactive protein (CRP) and LBP. The definite diagnosis of periprosthetic joint infection was determined on the basis of clinical, microbiological and histopathological examination.

Results

LBP showed significantly higher values in PJI compared with aseptic loosening (p?p?7 ng/ml. In combination with CRP, the positive predictive value for PJI was at 0.67; negative predictive value with both negative was at 0.77.

Discussion

Patients with PJI have elevated serum levels of LBP when compared with patients with aseptic loosening. The use of LBP in serum appears not to be a more accurate marker than CRP level in serum for detecting PJI. On the basis of these results, we cannot recommend the sole use of LBP for differentiating PJI and aseptic loosening following THA and TKA.     

C-reactive protein, white blood cells, and neutrophils as early predictors of postoperative complications in patients undergoing laparoscopic sleeve gastrectomy

Background

Early detection and treatment of complications after laparoscopic sleeve gastrectomy (LSG) are mandatory. This study aimed to evaluate C-reactive protein (CRP), white blood cell (WBC) count, and neutrophil (NEU) count in relation to the early diagnosis of major surgical complications after LSG.

Methods

A prospective study of 177 patients who underwent LSG during 2008–2011 was performed. Measurements of WBC, NEU, and CRP performed on postoperative days 0, 1, 3, 5, 7, 9, 11, 13, and 30 were correlated with postoperative surgical complications.

Results

Both WBC and NEU were correlated with leak or abscess on postoperative days 3, 5, 7, 9, and 11, whereas on day 1, only NEU was significantly increased. Elevated CRP was correlated with leak or abscess on all the days (p < 0.001). The parameters measured were not correlated with postoperative bleeding unless leak or abscess coexisted. According to receiver operating characteristic (ROC) analysis, CRP detected leak or abscess with remarkably higher sensitivity and specificity than WBC or NEU on all the days. Moreover, the area under the curve (AUC) of CRP was higher than the AUC of WBC or NEU, suggesting important statistical significance. On day 1, WBC and NEU achieved 77.8 and 78.3 % sensitivity, respectively, and an even lower specificity (68.4 and 52.6 %), whereas a CRP cutoff at 150 mg/l achieved 83.2 % sensitivity and 100 % specificity. On day 3, the sensitivity and specificity of CRP reached 100 % (cutoff level, 200 mg/l), and on day 5, CRP achieved 83.2 % sensitivity and 100 % specificity (cutoff level, 150 mg/l), whereas for WBC and NEU, specificity was high (>92 %), but sensitivity did not exceed 78.2 %.

Conclusion

Because CRP detected leak or abscess after LSG with remarkably higher sensitivity and specificity than WBC or NEU, CRP seems to be a more accurate market for the early detection of these complications.     

Characteristics and significance of fever during 4 weeks after primary total knee arthroplasty

Purpose

Most previous studies on postoperative fever (POF; ≥38 °C) after total knee arthroplasty (TKA) have reported findings from only the immediate postoperative days (PODs). The hypothesis of the current study is that 4 weeks of follow-up may reveal differences in the characteristics of POF and fever-related factors between a normal inflammatory response and an early acute infection-related response.

Methods

A total of 400 consecutive TKAs (314 patients) were retrospectively investigated. Patients were stratified into those who developed an early acute periprosthetic infection that required subsequent surgical treatment (STG; n = 5 TKAs) and those who did not (non-STG; n = 395 TKAs).

Results

Among the 400 knees, 149 (37 %) developed POF, with most reaching a maximum temperature (MT) on POD 0. In 13 TKA patients who had POF with a peak daily temperature ≥38 °C during postoperative weeks 2–4, the causes of POF were respiratory and urinary tract infections (n = 5 for each), superficial infection (n = 2), and periprosthetic infection (n = 1). The STG and non-STG differed significantly with regard to the rate of POF (p = 0.0205) and MT (p = 0.0003), including MTs less than 38 °C, during postoperative weeks 2–4. All five STG patients had elevated C-reactive protein levels and local symptomatic findings before the additional surgery.

Conclusions

The occurrence of POF and MT along with elevated C-reactive protein and local symptomatic findings at 2–4 weeks postoperatively may indicate the need for a positive fever workup to recognize early acute periprosthetic infection.     

Histopathologische Diagnose der periprothetischen Gelenkinfektion nach Hüftgelenkersatz

Background

The distinction between aseptic and septic loosening of a total hip arthroplasty is a diagnostic challenge. Therapy and clinical success depend on the correct diagnosis. Histopathological evaluation of the periprosthetic interface membrane is one possible diagnostic parameter; detailed analysis of tissue characteristics may reflect the cause of failure. This study evaluated the diagnostic value of a published histopathological consensus classification for the periprosthetic interface membrane in the identification of periprosthetic joint infection (PJI).

Methods

Between 2004 and 2008, a prospective analysis was performed in 106 patients who had revisions because of assumed PJI. Based on clinical presentation, radiography, and haematological screening, infection was assumed, and a joint aspiration was performed. Based on these findings, a two-stage revision was performed, with intraoperative samples for culture and histological evaluation obtained. Final diagnosis of infection was based on the interpretation of the clinical presentation and the preoperative and intraoperative findings. The basis for histopathological evaluation was the consensus classification for the periprosthetic interface membrane. Sensitivity, specificity, and accuracy were calculated for each parameter.

Results

In 92 patients, a positive diagnosis of PJI could be made. Histopathology yielded the highest accuracy (0.93) in identification of PJI, identifying 86 of 92 infections (69 type II, 17 type III). In 13 of the 14 noninfected hips, histopathology correlated in 13 (93%) cases (10 type I, three type IV). The accuracies of microbiological culture, C-reactive protein, and aspiration were 0.82, 0.86, and 0.54, respectively.

Conclusion

In the diagnosis of PJI, histopathological evaluation of the periprosthetic interface membrane proved very effective. To analyse the cause of prosthesis loosening, tissue samples of the periprosthetic interface membrane should be evaluated on the basis of the consensus classification in all revision surgeries.     

Die infizierte Knieprothese

Objective

Treatment of an early total knee arthroplasty (TKA) infection with the goal of salvaging the implant.

Indications

Early postoperative infections within the first 4 weeks. The acute hemtogenous infection of the knee joint with TKA and duration of symptoms for a maximum of 4 weeks.

Contraindications

Unsuitable for anesthesia, high acute infection with sepsis and risk for bacteremia with danger to life, large soft tissue damage where plastic surgery coverage is not possible.

Surgical technique

Arthrotomy, synovectomy, inlay removal, jet lavage, instillation of polyhexanide, new inlay, drainage and infusion–aspiration–drainage if necessary, wound closure with plastic surgery if necessary.

Postoperative management

Infusion–aspiration–drainage with polyhexanide for 3 days or drainage for 3 days. Continuous passive motion (CPM) with increasing range of motion (ROM) 0–0–30°. Removal of the drain after 5 days and mobilization with increasing ROM and full weight-bearing.

Results

The success rate for the salvage procedure is about 70?%.     

Infection surveillance in transsphenoidal pituitary surgery - comparison of lipopolysaccharide-binding-protein, interleukin 6, C-reactive protein, white blood cell count, erythrocyte sedimentation rate and body temperature

Background

One of the major concerns in transsphenoidal surgery are infections because the approach to the pituitary includes a route of microbial colonization. To minimize the associated morbidity and mortality, a surveillance program is crucial to monitor for perioperative infections.

Methods

For 1 year, we analysed body temperature (BT), erythrocyte sedimentation rate (ESR), white blood cell count (WBC), C-reactive protein (CRP), interleukin 6 (IL-6) and lipopolysaccharide-binding-protein (LBP) following elective transsphenoidal pituitary surgery. Samples were collected on admission, day 1, 3 and 7 as well as 3 months postoperatively.

Results

In 116 patients, all data were available. No postoperative infections occurred within the first postoperative week. BT (37.6?±?0.6, baseline 37.0?±?0.5 °C), WBC (11,366?±?2,541, baseline 6,861?±?2,123/μl), CRP (25.3?±?22.6, baseline 3.1?±?6 mg/l), IL-6 (12?±?13, baseline 2.7?±?2.6 pg/ml), and LBP (11.3?±?4.9, baseline 5.7?±?2.7 μg/ml) peaked on day 1 postoperatively (each p?=?0.001), while ESR peaked on day 3 (25?±?16, baseline 13?±?11 mm/h, p?=?0.001). BT and IL-6 normalized by day 3 and CRP by day 7, while ESR (23?±?16 mm/h, p?=?0.001), WBC (7,807?±?2,750/μl, p?=?0.001) and LBP (7.3?±?2.6 μg/ml, p?=?0.028) were still increased by day 7.

Conclusion

The present study establishes normative values for an infection surveillance following transsphenoidal pituitary surgery. CRP, a convenient and reasonable priced parameter, is affected by the procedure for the first postoperative week. IL-6 is more robust and allows a close monitoring on the expense of additional pricing. ESR, WBC and LBP are sustained affected by surgery, and do not offer any advantage. Since no infections were observed, we were unable to calculate the respective sensitivity and specificity.     

Diagnostic Value of Synovial White Blood Cell Count and Serum C-Reactive Protein for Acute Periprosthetic Joint Infection After Knee Arthroplasty

Background

The diagnosis of periprosthetic joint infection (PJI) remains difficult, particularly in acute postoperative stage. The purpose of this study was to investigate the optimal cutoff value of synovial white blood cell (WBC) count, percentage of polymorphonuclear cells, erythrocyte sedimentation rate, and C-reactive protein (CRP) for diagnosing early postoperative infection after knee joint arthroplasty.

Ergebnisse und Komplikationen der Behandlung periprothetischer Femurfrakturen mit einem winkelstabilen Plattensystem

Background

Locked plate devices offer advantages in the treatment of periprosthetic femur fractures associated with fixed total hip or total knee arthroplasty. The purpose of this study was to evaluate the early results and complications with a locked plate system (NCB-DF®).

Patients and methods

A total of 31 patients (mean age 76 years, 7 males, 24 females) with a femur fracture above a fixed total knee arthroplasty (TKA, n=12) or a total hip arthroplasty (THA, n=19) were treated with a locked plate.

Results

There were 11 complications necessitating revision: 6 implant failures, 2 in patients with a THA and 4 in patients with a TKA, 4 hematomas and 1 infection and 2 patients died. After 6 months all fractures had healed securely but a secondary correction was necessary in one patient.

Conclusion

Fixation of periprosthetic femur fractures with a locked plate system provided satisfactory results in patients with a THA, however, the relatively high implant failure rate in fractures above a stable TKA is a cause for concern.     

Diagnostik und Therapie der Luxation nach Hüfttotalprothesenimplantation

Background

Luxation following endoprosthetic hip replacement represents a frequent and severe complication and is the reason for a relevant number of hip arthroplasty revision interventions. The probability of occurrence of luxation of a total hip arthroplasty is associated with the indications, patient and operation-specific risk factors. Approximately 50 % of luxations after total hip arthroplasty occur within 3 months of the operation (early luxation).

Diagnostics

The diagnostics of luxation of total hip arthroplasty are carried out by clinical and radiological methods. The causative assignment is made by assessment of joint stability, the bony situation (e.g. loosening, periprosthetic fracture and defects) and the soft tissue (e.g. pelvitrochanterian musculature). In cases of clinical and paraclinical signs of infection and of late luxations, a joint puncture is indicated.

Therapy

Therapy decisions are made depending on the cause (e.g. implant malpositioning, pelvitrochanterian insufficiency, impingement, incongruence between head and inlay and combinations of causes). Therapy of acute total hip prosthesis luxation begins with imaging controlled repositioning carried out with the patient under adequate analgesia and sedation. Conservative therapy is carried out by immobilization with a hip joint orthesis or pelvis-leg cast for 6 weeks. Operative therapy strategies for recurrent luxation are restoration of the correct implant position and sufficient soft tissue tension. Larger hip heads, bipolar heads and tripolar cups are more commonly used due to the geometrically lower probability of dislocation (higher jumping distance). Luxation of total hip prostheses due to infection is treated according to the principles of periprosthetic infection therapy. The rate of recurrence of luxation of 30 % is high so that in cases of unsuccessful therapy treatment should best be carried out in a center for revision arthroplasty.

Conclusions

The search for the exact cause of total hip prosthesis luxation is extremely important. A classification is only possible when the exact cause is known and together with patient and implant-specific details the therapeutic approach can be ascertained. In revision operations the intraoperative functional diagnostics must be exactly documented. The reasons for delayed luxations could be prosthesis infections, abrasion and loosening.     

Two-stage treatment of infected total knee arthroplasty: two to thirteen year experience using an articulating preformed spacer

Purpose

Infection following knee replacement is an important cause of failure despite rigorous prophylaxis antibiotic protocols. The two-stage reimplantation procedure is considered the gold standard for treatment of subacute and chronic deep periprosthetic infections. The purpose of this study was to determine whether or not a preformed articulated spacer would allow comparable eradication of infection equal to rates reported in published studies and to see whether there is a resulting improvement in postoperative function with an acceptable quality of life, reducing postoperative pain and limiting surgical complications, thus simplifying the second stage of the procedure.

Methods

We retrospectively reviewed 50 patients with infected TKA who underwent a two-stage exchange arthroplasty using an articulating preformed spacer. The device, designed like an ultracongruent condylar knee prosthesis, is composed of acrylic cement impregnated with antibiotic, with tested and standardised mechanical properties and antibiotic content and release mechanism.

Results

The median follow-up period was seven (two to 13) years. Two-stage exchange arthroplasty was successful in controlling the infection in 92 % of patients; 64% of patients where women, and median patient age was 68 (54–80) years. Median implantation time of the preformed spacer was 16 (four to 60) weeks; 4 % of infections were delayed, and 96 % were late. Forty-six percent were caused by coagulase-negative Staphylococcus (CoNS). Mean Knee Society Score (KSS) was 35.38 (clinical) and 37.96 (function) on presentation; it improved to a mean of 72.92 (clinical) and 76.04 (function) after the first stage and to a mean of 75.38 (clinical) and 80.58 (function) at the final review. Bone loss was unchanged between stages, and range of motion remained unchanged or improved after definitive reimplantation.

Conclusion

The use of preformed articulated knee spacer during a two stage technique for infected TKA improves patient QOL between stages and increases patient compliance and cooperation, reducing social costs.     

Preoperative predictors for allogenic blood transfusion in hip and knee arthroplasty for rheumatoid arthritis

Introduction

To identify the preoperative predictors of requirement for postoperative allogenic blood transfusion following hip and knee joint arthroplasty.

Materials and methods

We analysed the retrospective data on patients with rheumatoid arthritis who had undergone either total hip or knee arthroplasty at a single university teaching hospital. Factors of age, sex, procedure type, preoperative haemoglobin, blood transfusion data, comorbidities and body mass index were investigated for association with postoperative allogenic blood after hip or knee arthroplasty.

Results

Three hundred and forty nine cases of patients with rheumatoid arthritis were reviewed. 21 % (n = 72) required allogenic blood transfusion. The only significant predictive preoperative factors associated with postoperative blood transfusion were a low preoperative haemoglobin (Hb) level (p < 0.001), procedure of total hip arthroplasty (p = 0.008), a previous history of myocardial infarction (p = 0.038) and previous allogenic blood transfusion (p = 0.03). A preoperative haemoglobin <120 g/l was associated with a tenfold increase in transfusion requirement. All patients with a preoperative Hb level <90 g/l were transfused.

Conclusions

The ability to identify those within this high-risk group who are likely to receive blood transfusion allows for an informed, appropriate and cost effective approach to blood management strategies.     

Laparoscopy versus open distal gastrectomy by expert surgeons for early gastric cancer in Japanese patients: short-term clinical outcomes of a randomized clinical trial

Background

Short-term outcomes of laparoscopy-assisted distal gastrectomy (LADG) and open DG (ODG) have been investigated in previous clinical trials, but operative techniques and concomitant treatments have evolved, and up-to-date evidence produced by expert surgeons is required to provide an accurate image of the relative efficacies of the treatments. The purpose of this study was to compare laparoscopic versus ODG with respect to specific primary and secondary short-term outcomes.

Methods

From October 2005 to February 2008, a total of 64 patients with early gastric cancer were randomly assigned to the LADG or the ODG group. One patient was excluded due to concurrent illness unrelated to the intervention, so the data from 63 patients were analyzed. The primary short-term outcome was the 4-day postoperative use of analgesics. Secondary short-term outcomes were postoperative residual pain, complications, days hospitalized, blood data, days with fever, and days to first flatus.

Results

There was a significant difference in favor of LADG for postoperative use of analgesics (P = 0.022). Unexpectedly, there was no significant difference in degree of pain in the immediate postoperative period, putatively due to the optimal use of analgesics. Of the secondary outcomes, residual pain at postoperative day 7 (P = 0.003) and days to first flatus (P = 0.001) were significantly better with LADG. Postoperative complications, number of days hospitalized, and number of days with fever were also better with LADG, but the differences were not significant. Blood data representing inflammation (WBC and CRP) showed marked differences, especially on postoperative day 7 (P = 0.0016 and P = 0.0061, respectively).

Conclusions

LADG performed by expert surgeons results in less postoperative pain accompanied by decreased surgical invasiveness and is associated with fewer postoperative inconveniences. No preliminary suggestions of changes in long-term curability were observed. LADG for early gastric cancer is a feasible and safe procedure with short-term clinical results superior to those of ODG.     

A meta-analysis of bisphosphonates for periprosthetic bone loss after total joint arthroplasty

Background

Periprosthetic bone loss, which is common after joint arthroplasty, may cause bone loosening and lead to failed prosthetic fixation. Two previous meta-analyses have confirmed the mid-term effect of bisphosphonates (BPs) in preventing bone loss after arthroplasty. To determine long-term efficacy and gender bias of BPs after joint arthroplasty, we conducted a meta-analysis based on 17 RCTs involving 781 patients to evaluate the effect of BPs.

Methods

Meta-analysis was conducted after a systematic search of Medline, Embase, the Cochrane Collaboration Central Register of Controlled Clinical Trials, CINAHL, and ISI Web of Science, and manual examination of references in selected articles and conference abstracts of key orthopedic journals. Methodological quality and abstracted relevant data were evaluated. In addition to analysis of bone mineral density (BMD), we also conducted systematic analysis of clinically relevant outcomes and bone biochemical markers.

Results

Seventeen trials involving a total of 781 patients were assessed. Significantly less periprosthetic bone loss occurred in the BP-treated group than in the control group at 6 and 12 months (p < 0.0001). This protective effect was not noted at 3 months (p = 0.11) nor from 24–72 months (p = 0.14). The efficacy of BPs in the gender balance, shorter duration, and the non-nitrogenous BPs groups was no different from that for controls. Biochemical bone markers were suppressed in the BPs group. However, clinically relevant outcomes in the BPs group and controls were similar at all times.

Conclusions

The overall moderate-quality evidence from the RCTs confirmed the significant mid-term efficacy of BPs on periprosthetic bone loss after joint arthroplasty. Long-term efficacy of BPs was not observed, and the therapy was of more benefit to women, especially postmenopausal women. To achieve better efficacy, nitrogenous BPs and long duration of treatment may be recommended.     

Modified direct anterior approach in minimally invasive hip hemiarthroplasty in a geriatric population: a feasibility study and description of the technique

Introduction

The direct anterior approach (DAA) is generally accepted method for minimal invasive arthroplasty of the hip. As good results for total hip arthroplasty are already published, there is a lack of evidence for the implantation of bipolar hip hemiarthroplasty (BHH) in elderly patients with osteoporosis after femoral neck fracture.

Materials and methods

For hip arthroplasty using a direct anterior approach (DAA) in elderly patients with femoral neck fractures, a number of modifications of the original technique are being described. The modified DAA considers in particular the co-morbidity and the bone quality of the geriatric patient population. A consecutive series of 16 hemiarthroplasties using this technique is presented. In all 16 cases, the BHH was implanted in modified DAA technique. Mobility measured by 4-item Barthel Index, pain via visual analogue scale (VAS), duration of surgery, external length of incision and blood loss were evaluated.

Results

There was no major operative complication during the procedures. The pain level decreased from 7 (preoperatively) to 0 at postoperative day 40. The Barthel Index increased from 5 at first postoperative day to 40 at day 40. Early postoperative mobilisation is efficiently accelerated. Mean operating time was 71 min; the medium skin incision length was 8 cm. The mean haemoglobin level decreased from 118 g/dl preoperatively to 101 g/dl at first postoperative day.

Conclusion

The described modifications of the DAA help to implant a BHH gently in elderly patients with increasing risk of complications like iatrogenic fractures, wound or prosthesis infections and haematoma. This will hopefully lead to a faster rehabilitation and lower mortality rate for patients with femoral neck fractures in the future.