Author Correction: Fibrinogen - A Practical and Cost Efficient Biomarker for Detecting Periprosthetic Joint Infection.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Combined serum biomarker analysis shows no benefit in the diagnosis of periprosthetic joint infection.

PURPOSE: In many cases, the diagnosis of a periprosthetic joint infection (PJI) consisting of the clinical appearance, laboratory tests, and other diagnostic tools remains a difficult task. Single serum biomarkers are easy to collect, are suitable for periodical assessment, and are a crucial tool in PJI diagnosis, but limited sensitivity or specificity is reported in literature. The aim of this study was to combine the best-performing single serum biomarkers into a multi-biomarker model aiming to improve the diagnostic properties. METHODS: Within a 27-month period, 124 surgical procedures (aseptic or septic revision total knee arthroplasty (TKA) or total hip arthroplasty (THA)) were prospectively included. The serum leukocyte count, C-reactive protein (CRP), interleukin-6, procalcitonin, interferon alpha, and fibrinogen were assessed 1 day prior to surgery. Logistic regression with lasso-regularization was used for the biomarkers and all their ratios. After randomly splitting the data into a training (75%) and a test set (25%), the multi-biomarker model was calculated and validated in a cross-validation approach. RESULTS: CRP (AUC 0.91, specificity 0.67, sensitivity 0.90, p value 0.03) and fibrinogen (AUC 0.93, specificity 0.73, sensitivity 0.94, p value 0.02) had the best single-biomarker performances. The multi-biomarker model including fibrinogen, CRP, the ratio of fibrinogen to CRP, and the ratio of serum thrombocytes to CRP showed a similar performance (AUC 0.95, specificity 0.91, sensitivity 0.72, p value 0.01). CONCLUSION: In this study, multiple biomarkers were tested for their diagnostic performance, with CRP and fibrinogen showing the best results regarding the AUC, accuracy, sensitivity, and specificity. It was not possible to further increase the diagnostic accuracy by combining multiple biomarkers using sophisticated statistical methods.

Fibrinogen - A Practical and Cost Efficient Biomarker for Detecting Periprosthetic Joint Infection.

The early and accurate diagnosis of periprosthetic joint infection (PJI) can be challenging. Fibrinogen plays an important role in mediating inflammation of bacterial infections and therefore could be a valuable biomarker for PJI. The purpose of this study was to investigate the sensitivity and specificity of serum levels of fibrinogen in detecting PJI, and to compare the results with the established PJI biomarkers C-reactive protein (CRP) and leukocyte count. Eighty-four patients (124 surgeries) were prospectively included. The preoperatively analyzed parameters were fibrinogen, CRP and leukocyte count. The sensitivity and specificity of the biomarkers were calculated and compared. Fibrinogen (p < 0.001), CRP (p < 0.001) and leukocyte count (p < 0.001) had a statistically significant correlation with the criteria defining the presence of PJI. For fibrinogen, the value of 519 mg/dl had a sensitivity of 0.90 and a specificity of 0.34. The CRP cut-off point of 11.00 mg/dl had a sensitivity of 0.90 and a specificity of 0.74. The leukocyte count of 5.68 G/l had a sensitivity of 0.90 and a specificity of 0.39. Our results indicated that fibrinogen is a significant biomarker for detecting a bacterial PJI. It has shown to be a cost-efficient diagnostic support with high sensitivity and specificity.

Argyria following the use of silver-coated megaprostheses: no association between the development of local argyria and elevated silver levels.

The aims of this study were to evaluate the incidence of local argyria in patients with silver-coated megaprostheses and to identify a possible association between argyria and elevated levels of silver both locally and in the blood. Between 2004 and 2011, 32 megaprostheses with silver coatings were implanted in 20 female and 12 male patients following revision arthroplasty for infection or resection of a malignant tumour, and the levels of silver locally in drains and seromas and in the blood were determined. The mean age of the patients was 46 years (10 to 81); one patient died in the immediate post-operative period and was excluded. Seven patients (23%) developed local argyria after a median of 25.7 months (interquartile range 2 to 44.5). Patients with and without local argyria had comparable levels of silver in the blood and aspiration fluids. The length of the implant did not influence the development of local argyria. Patients with clinical evidence of local argyria had no neurological symptoms and no evidence of renal or hepatic failure. Thus, we conclude that the short-term surveillance of blood silver levels in these patients is not required.

Elevated preoperative neutrophil/lymphocyte ratio is associated with poor prognosis in soft-tissue sarcoma patients.

BACKGROUND: Recent data indicate that tumour microenvironment, which is influenced by inflammatory cells, has a crucial role in cancer progression and clinical outcome of patients. In the present study, we investigated the prognostic relevance of preoperative neutrophil/lymphocyte (N/L) ratio on time to tumour recurrence (TTR) and overall survival (OS) in soft-tissue sarcoma (STS) patients who underwent curative surgical resection. METHODS: In all, 260 STS patients were included in this retrospective study. Kaplan-Meier curves and multivariate Cox proportional models were calculated for TTR and OS. RESULTS: In univariate analysis, elevated N/L ratio was significantly associated with decreased TTR (hazard ratio (HR), 2.32; 95% confidence interval (CI), 1.30-4.14; P=0.005) and remained significant in the multivariate analysis (HR, 1.98; 95%CI, 1.05-3.71; P=0.035). Patients with elevated N/L ratio showed a median TTR of 77.9 months. In contrast, patients with low N/L ratio had a median TTR of 99.1 months. Regarding OS, elevated N/L ratio was also significantly associated with decreased survival in univariate analysis (HR, 2.90; 95%CI, 1.82-4.61; P=0.001) and remained significant in multivariate analysis (HR, 1.88; 95%CI, 1.14-3.12; P=0.014). CONCLUSION: In conclusion, our findings suggest that an elevated preoperative N/L ratio predicts poor clinical outcome in STS patients and may serve as a cost-effective and broadly available independent prognostic biomarker.

Observer variability in the assessment of the acromiohumeral interval using anteroposterior shoulder radiographs.

BACKGROUND: An acromiohumeral interval narrower than 6 mm measured on AP shoulder radiographs has been considered pathological and suggestive of rotator cuff tears. This prospective study was conducted to assess inter- and intraobserver variation in the radiographic assessment of the acromiohumeral interval and its critical value on routinely taken AP shoulder radiographs off-study use to evaluate the accuracy of this measurement method. METHODS: The acromiohumeral distance from the inferior anterior acromial aspect to the humeral head was measured in millimeters. Thirty blinded, anteroposterior shoulder radiographs were independently reviewed by five board-certified orthopedic shoulder surgeons at two time points in random order. RESULTS: The results of three investigators showed significant intraobserver variation. Five investigator pairs showed significant interobserver variation at both examination time points. The maximum interobserver difference for the same radiograph was 8 mm (range 0 to 8 mm). CONCLUSION: Our results indicate that the assessment of the acromiohumeral interval using non-standardized anteroposterior radiographs off-study use cannot be seen as a reproducible and reliable method of measurement.

[Clinical and radiological outcome after trapezium resection with suspension and interposition arthroplasty]. / Klinische und radiologische Ergebnisse der Resektions-Suspensions-Interpositionsarthroplastik bei Rhizarthrose.

INTRODUCTION: Trapezium resection with suspension and interposition arthroplasty of the thumb-carpometacarpal joint is a common method for treatment of severe osteoarthritis of the 1st carpometacarpal joint. METHODS: We performed a single center retrospective data analysis after trapezium resection with suspension and interposition arthroplasty of the thumb-carpometacarpal joint with emphasis on quality of life and radiological parameters 3.4 years (1.2-8.7 years) after operation in 60 patients. Pre- and postoperative pain was analysed with VAS, function was measured using the DASH score, pinch grip power with a pinchmeter. RESULTS: Subjective outcome was rated excellent in 42 cases (64.6%), good in 17 (26.2%), fair in 3 (4.6%) and 3 times (4.6%) poor. 56 patients (93.3%) would like to be operated again; 4 patients (6.7%) would deny an operation retrospectively. In the VAS pain was reduced by about 75% compared to the preoperative value. The pinch grip was increased by 46.6% compared to the preoperative value. The rate of major complications was 1.5% and of minor complications 9.2 %. CONCLUSION: Trapezium resection with suspension and interposition arthroplasty can increase the quality of life and reduce pain in patients with severe osteoarthritis of the 1st carpometacarpal joint. The rate of complications is low. Outcome assessment is possible by subjective parameters. Objective values like the range of movement or the decrease of the distance between metacarpal I and scaphoid do not correlate with outcome.

[Surgical treatment of pathologic fractures of the humerus and femur]. / Operative Versorgung von pathologischen Humerus- und Femurfrakturen.

The life expectancy of patients with malignant tumours and the incidence of osseous metastases have increased over the last decades. Operations for skeletal metastases of the extremities represent the most frequent surgery in orthopaedic oncology. The purpose of this study was to evaluate and compare the different operative treatment options for patients with pathologic fractures of the humerus and femur in terms of complications, postoperative recovery, and survival.From 2000 to 2005, 109 patients were surgically treated for pathologic fractures of the humerus (n=19) or femur (n=90). The study group consisted of 60 women and 43 men, with a mean age of 67 years (13-88). Breast carcinoma (36%) was the most common primary tumour, followed by kidney (17%) and bronchial (16%) carcinoma. Of all patients, 75 (73%) had numerous skeletal metastases, and 38 (37%) had visceral metastases.Wide or marginal resection was performed in seven fractures of the humerus and 14 fractures of the femur; intralesional resection was done in seven humeral and 73 femoral fractures; and stabilisation alone was done in five fractures of the humerus and three fractures of the femur. The median survival time for all patients was 6 months (0-102). The survival rate at 1 year was 25% (25% for both humeral and femoral fractures), 15% at 2 years (17% for humeral and 15% for femoral fractures), and 8% at 3 years (16% for humeral and 7% for femoral fractures). The overall complication rate was 11%, and revision surgeries were performed in seven patients (6.4%). The majority of patients (n=65; 60%), especially those with fractures close to the articular joint, were successfully treated with endoprosthetic replacement. Patients with fractures stabilised by intramedullary nails had shorter operating times, a shorter hospital stay, and fewer complications than patients treated with plating systems. Therefore, we recommend intralesional resection of the metastasis and stabilisation with intramedullary devices, supported by bone cement, as the treatment of choice for pathologic fractures of the diaphysis and metaphysis of the humerus and femur. Wide resection should be reserved for selected cases, such as solitary bone metastasis of kidney carcinoma.

[Evaluation of macroamputations of the upper extremity in the management of primary malignant bone and soft-tissue tumours using the DASH score]. / Evaluation von Makroamputationen der oberen Extremität bei primär malignen Knochen- und Weichteiltumoren mittels DASH-Score.

PURPOSE/BACKGROUND: The purpose of this retrospective analysis was to identify patients with macroamputations of the upper extremity due to malignant bone or soft-tissue tumours at a single institution. The German DASH score (Disability of Arm, Shoulder, Hand) was obtained in order to measure how patients manage their daily activities. PATIENTS AND METHODS: Between 1998 and 2005, 1652 patients were operated due to a bone or soft-tissue tumour, 370 of these due to a malignant one (22 %). The tumour was localised in the lower extremity or in the pelvis in 246 cases, in the trunk in 38 and in the upper extremity in 86 cases. These 86 primary malignant tumours comprised 22 bone and 64 soft tissue tumours. Amputations had to be performed in the lower extremity in 14 % (35/246) and in the upper extremity in 7 % (6/86). Six patients with macroamputations of the upper extremity were identified and in five of these the DASH score was obtained. RESULTS: The mean DASH score for the module 1 (disability/symptom) was 75.1 points ([sum of responses - 30]/1.2), for module 2 (work) 92.4 ([sum of responses - 4]/0.16), and for module 3 (sports/performing arts) 90 points ([sum of responses - 4]/0.16). Only two patients worked again and only one played an instrument. CONCLUSION: Despite neo-/adjuvant therapeutic options and modified reconstructive procedures 7 % of patients with malignant bone or soft tissue tumours of the upper extremity had to undergo an amputation. The DASH score is an appropriate instrument to measure the disability after upper limb amputation due to tumour.

[A case of a tumorsimulating expansion caused by anabolic androgen steroids in body building]. / Steroid-Doping im Bodybuilding - Ursache für eine tumorsimulierende Expansion.

Despite intensive information on possible side effects and complications of performance-enhancing substances in sports, the use of AAS (anabolic androgen steroids) is far common. Particularly in sports like bodybuilding or weight lifting AAS are used for setting up muscle mass and increasing muscle power. We present the case of a 27 year old bodybuilder, who was transferred due to suspected malignant expansion of the upper limb to a department of orthopaedic surgery, not knowing that the patient had injected AAS. At biopsy the tumor was found to be an abscess formation, that had to be treated surgically with curettage. The microbiological analysis detected an infection with Pseudomonas fluorescens and Erwinia species. Erwinia species are associated with plants, Pseudomonas fluorescens is found in feces, sewage and soil. It is obvious, that the infection is caused by an inappropriate injection of AAS or by the contamination of the injected substances.