Cat at home? Cat scratch disease with atypical presentations and aggressive radiological findings mimicking sarcoma, a potential diagnostic pitfall.

Background and purpose - Cat scratch disease (CSD) is a self-limiting disease caused by Bartonella (B.) henselae. It is characterized by granulomatous infection, most frequently involving lymph nodes. However, it can present with atypical symptoms including musculoskeletal manifestations, posing a diagnostic challenge. We describe the prevalence and demographics of CSD cases referred to a sarcoma center, and describe the radiological, histological, and molecular findings.Patients and methods - Our cohort comprised 10 patients, median age 27 years (12-74) with clinical and radiological findings suspicious of sarcoma.Results - 7 cases involved the upper extremities, and 1 case each involved the axilla, groin, and knee. B. henselae was found in 6 cases tested using polymerase chain reaction and serology in 5 cases. 9 cases were soft tissue lesions and 1 lesion involved the bone. 1 patient had concomitant CSD with melanoma metastasis in enlarged axillary lymph nodes. On MRI, 5 soft tissue lesions were categorized as probably inflammatory. In 3 cases, with still detectable lymph node structure and absent or initial liquefaction, the differential diagnosis included lymph node metastasis. A sarcoma diagnosis was suggested in 4 cases. The MRI imaging features of the bone lesion were suspicious of a bone tumor or osteomyelitis.Interpretation - Atypical imaging findings cause a diagnostic challenge and the differential diagnosis includes malignant neoplasms (such as sarcoma or carcinoma metastasis) and other infections. The distinction between these possibilities is crucial for treatment and prognosis.

Body image, self-esteem, and quality of life in patients with primary malignant bone tumors.

BACKGROUND: Patients with primary malignant bone tumors are facing different challenges in their everyday lives due to improved treatment and prolonged survival. This raises the question whether and to what extent their quality of life, body image, and self-esteem is affected by their disease. The aim of this retrospective study was to analyze the quality of life, body image and self-esteem of patients with primary malignant bone tumors compared to a healthy control group. METHODS: A total of 56 patients (39 male, 17 female; average age 33.8 [± 14.29] years) who were treated with either osteosarcoma or Ewing-Sarcoma at the authors' institution between Jan 1989 and May 2015 were included into the study (mean follow-up: 9.1 ± 6.6] years). The control group consisted of 58 (average age 24.4 [± 3.1] years, 31 male, 27 female) healthy medical students. Standardized questionnaires were used to assess quality of life (SF-36), body image (MBSRQ) and self-esteem (RSE-scale). Student's t test were used for statistical analysis. RESULTS: Quality of life (SF-36) (in physical categories) and body image (MBSRQ) was significantly lower in patients with primary malignant bone tumors compared to healthy cohort (p < 0.001). Self-esteem was not affected i n patients and did not show any difference compared to control group (23.96 vs. 24.00). DISCUSSION: Physical categories of quality of life and body image sensation of patients with primary malignant bone tumors are worse compared healthy controls. However, self-esteem does not seem to be affected by the condition and its management. Patients can be encouraged about this at the time of diagnosis of a primary malignant bone tumor.

The accuracy of digital templating in uncemented total hip arthroplasty.

INTRODUCTION: Preoperative planning is an essential part of total hip arthroplasty (THA). It facilitates the surgical procedure, helps to provide the correct implant size and aims at restoring biomechanical conditions. In recent times, surgeons rely more and more on digital templating techniques. Although the conversion to picture archiving and communication system had many positive effects, there are still problems that have to be taken into consideration. OBJECTIVES: The core objective was to evaluate the impact of the planners' experience on the accuracy of predicting component size in digital preoperative templating of THA. In addition, the influence of overweight and obesity (according to WHO-criteria), patient's sex and component design on the accuracy of preoperative planning have been analysed. MATERIALS AND METHODS: The retrospective study included 632 consecutive patients who had primary uncemented THA. Digital templating was done using "syngo-EndoMap" software by Siemens Medical Solutions AG. Mann-Whitney U test and Kruskal-Wallis test have been used for statistical analysis. The accuracy of predicting component size has been evaluated by comparing preoperative planned sizes with implanted sizes as documented by the surgeons. The planner's experience was tested by comparing the reliability of preoperative planning done by senior surgeons or residents. The influence of BMI on predicting component size has been tested by comparing the accuracy of digital templating between different groups of BMI according to WHO-criteria. The same procedure has been done for evaluating the impact of patient´s sex and component design. RESULTS: The implant size was predicted exactly in 42% for the femoral and in 37% for the acetabular component. 87% of the femoral components and 78% of the acetabular cups were accurate within one size. Digital templating of femoral implant size was significantly more reliable when done by a senior surgeon. No difference was found for the acetabular component sizes. The BMI also had an impact on estimating the correct femoral implant size. In overweight patients, planning was significantly more inaccurate than normal weight people. Differences were seen in obese patients. However, these were not significant. Accuracy of acetabular components was not affected. The design of the prostheses and the patient's sex had no influence on predicting component size. CONCLUSIONS: Inexperience and overweight are factors that correlate with inaccuracy of preoperative digital templating in femoral components, whereas acetabular components seem to be independent of these factors.

Impact of the tibial slope on range of motion after low-contact-stress, mobile-bearing, total knee arthroplasty.

PURPOSE: The aim of this study was to analyse a possible correlation between the tibial slope and range of motion (ROM) after implantation of the low-contact-stress (LCS), mobile-bearing, total knee arthroplasty (TKA) after a minimum follow-up of ten years. METHODS: Eighty-three TKAs in 66 patients were investigated in this retrospective correlation analysis at a minimum follow up of ten years. Out of these 66 patients, 50 were women (76%) and 16 (24%) were men. The average age of these patients at the time of the examination was 76 years [standard deviation (SD) 11 years, range 37-95 years]. A lateral X-ray was taken at follow-up in order to analyse the tibial slope with respect to inter- and intra-observer agreement. ROM was measured and correlated with the tibial slope. RESULTS: The mean active ROM was 96.1° (SD 18.8) and the mean tibial slope after four measurements was 7.65° (SD 4.23), with substantial inter- and intra-observer agreement. We found no significant correlation between tibial slope and ROM in patients with a minimum follow-up of ten years [correlation 0.196 (p > 0.05) and 0.152, (p > 0.05), respectively]. CONCLUSIONS: Alteration of the tibial slope does not significantly influence ROM after implantation of the LCS TKA at a minimum follow-up of ten years. We conclude that the tibial slope is not the primary influencing factor for ROM in patients ten years after primary TKA and believe that it should not substantially be altered during surgery.

Prosthetic joint infection following total hip replacement: results of one-stage versus two-stage exchange.

PURPOSE: Prosthetic hip joint infection remains a challenging socio-economic problem. Curative treatment is usually a one- or two-stage revision surgery, but neither of these options has yet emerged as the treatment of choice. The aim of this study was to evaluate which of these methods produced superior outcomes. METHODS: A retrospective study was performed including 92 patients with deep infections after implantation of primary total hip arthroplasty (THA) who had undergone either one-stage or two-stage revision surgery at a single centre. Infections were classified according to McPherson and we evaluated the rate of persisting infection or reinfection after surgical intervention. RESULTS: The two-stage revision surgery revealed superior outcomes for the analysed infection categories compared to the one-stage procedure except for the least serious category of infections (i.e. McPherson Stage I/A/1, early postoperative infection, no systemic comorbidities, local status uncompromised). Eradication of prosthetic infection was achieved in 94.5 % (n = 52) within the group of two-stage exchange, and 56.8 % (n = 21) of patients treated with a one-stage procedure. Outcome of patients following a one-stage or a two-stage exchange was overall significantly different with p < 0.001. Further deviations between the described two procedures were noted in the subgroups following the classification described by McPherson. CONCLUSIONS: Our results indicate superiority of two-stage revision surgery in case of serious infections. The authors believe that decisions on the surgical approach for the treatment of deep prosthesis infections should be made on the basis of standardized staging systems.

Gender-specific outcome after implantation of low-contact-stress mobile-bearing total knee arthroplasty with a minimum follow-up of ten years.

PURPOSE: The study aim was an analysis of gender-specific outcome differences after implantation of the low-contact-stress (LCS) mobile-bearing total knee arthroplasty (TKA) with a minimum follow-up of ten years. METHODS: We retrospectively analysed 138 prostheses in 108 patients (82 women and 26 men) using our hospital database and a minimum follow-up of ten years (mean 14, range 11-23). Data was extracted with respect to quality of life, clinical outcome parameters [range of motion (ROM), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, visual analogue scale (VAS), Knee Society Score (KSS), and complications. RESULTS: At follow-up, we observed no statistically significant differences in all outcome parameters between female and male patients after LCS TKA, except for VAS score, which revealed no clinical relevance due to the low difference (1.53 vs 1.03, p = 0.043). CONCLUSIONS: Ten years after implantation of the LCS TKA, gender did not influence its beneficial outcome.

[Osteosarcoma: reliability and quality of the information in the internet]. / Osteosarkom--Vertrauenswürdigkeit und Qualität der Informationen im Internet.

The World Wide Web has grown during the last years to a considerable source of medical information for experts as well as for laymen and patients. The quality of this information is subjected to some limitation linked with the structure of the Internet and the management of Internet pages. The cross- sectional study presented evaluates and compares quality and reliability of information with respect of osteosarcoma in the most common German-language Internet pages for medical information. As both, one of the most common primary malignant bone tumors and its peak of incidence at the age of childhood and youth, osteosarcoma is considered of significant importance in orthopedic oncology.

Osteolytic lesions of the calcaneus: results from a multicentre study.

PURPOSE: Tumours of the calcaneus are exceedingly rare and the correct diagnosis is often missed. X-rays are the standard clinical examination tool and therefore we wanted to discover whether X-rays alone were a sufficient diagnostic tool for these tumours. Diard's classification was applied to define whether different types of lesions were characteristically distributed in the bone and in addition we analysed whether type and/or duration of symptoms were possible indicators of malignancy. METHODS: Ninety-two patients' files (59 men and 33 women) were retrospectively reviewed. Seventy-five patients with a mean age at surgery of 28 years (range five to 78) were surgically treated. Parameters analysed were sex, age at surgery, side, type and duration of symptoms, tentative diagnosis, biopsy prior to surgery, operative procedure, recurrence rate, revision and localisation of the lesion according to Diard. For each lesion the first documented radiological diagnosis and-in cases of malignancy-Enneking's classification was applied. RESULTS: Discrepancies between the radiological and definitive histological diagnosis occurred in 38 (41 %) of 92 cases. In eight (osteosarcoma n = 5, Ewing's sarcoma n = 2, metastases n = 1) of 17 malignant cases radiological examination initially gave no evidence of malignancy, resulting in an unplanned excision ("whoops procedure") in three cases of osteosarcoma. Applying Diard's system trabecular area 6 (radiolucent area) was highly affected in 64 (80 %) of 80 investigated plain X-rays, whereas areas 1 and 5 were affected in nine (11 %) and 16 (20 %) cases only. CONCLUSIONS: In each case of an osteolytic lesion of the calcaneus a malignant tumour must be ruled out, and thus preoperative plain X-rays in two planes alone are not sufficient and should therefore be followed by magnetic resonance imaging. Applying the Diard system different types of lesions are not characteristically distributed in the bone. Increasing pain for more than ten days without previous trauma should always justify further examinations.

Artificial Bone Graft Substitutes for Curettage of Benign and Low-Grade Malignant Bone Tumors: Clinical and Radiological Experience with Cerasorb.

Background: Artificial bone graft substitutes (ABGS) for curettage of bone tumors are becoming increasingly popular. The aim of this retrospective analysis was to determine the efficacy of the ABGS Cerasorb (Curasan-AG, Kleinostheim, Germany), a beta-tricalcium phosphate (beta-TCP), concerning resorption profile, bone healing, and remodeling after surgery and to evaluate potential complications. Methods: Forty-three patients suffering from benign and low-grade malignant bone tumors were treated with curettage and refilling of the bony cavity using the ABGS Cerasorb between 2018 and 2021 and included in the final analysis. Clinical follow-up exams with X-rays in two planes were performed 6 weeks, 3 months, 6 months, and 1 year after surgery. Results: After a mean follow-up period of 14.6 months, radiological consolidation following curettage was observed in all patients. Total resorption was observed in 16.3% of patients; in the other 83.7%, resorption was partial. In four patients, of whom two had a tumor in the distal femur and two in the humeral diaphysis, fractures occurred within 6 weeks after primary surgery. Conclusion: In conclusion, the beta-TCP Cerasorb seems to be a reliable bone graft substitute with low complication rates and is a suitable alternative to autologous bone grafts or allografts. Nonetheless, it shows a tendency of delayed resorption. Level of Evidence: III; retrospective cohort study.

Osteoporosis in children and young adults: a late effect after chemotherapy for bone sarcoma.

BACKGROUND: Premature bone loss after childhood chemotherapy may be underestimated in patients with bone sarcoma. Methotrexate (MTX), a standard agent in osteosarcoma protocols, reportedly reduces bone mineral density (BMD). The literature, however, has reported cases of BMD reduction in patients with Ewing's sarcoma treated without MTX. Thus, it is unclear whether osteoporosis after chemotherapy relates to MTX or to other factors. QUESTIONS/PURPOSES: We therefore asked whether (1) young patients with a bone sarcoma had BMD reduction, (2) patients treated with MTX had lower BMD, and (3) other factors (eg, lactose intolerance or vitamin D deficiency) posed additional risks for low BMD. METHODS: We retrospectively reviewed 43 patients with malignancies who had dual-energy x-ray absorptiometry (DEXA) (lumbar, femoral); 18 with Ewing's sarcoma (mean age, 26 ± 8 years), and 25 with an osteosarcoma (mean age, 27 ± 10 years). The mean time since diagnosis was 8 ± 4 years in the group with Ewing's sarcoma and 7 ± 5 years in the group with osteosarcoma. At last followup we determined BMD (computing z-scores), fracture rate, and lifestyle, and performed serum analysis. RESULTS: BMD reduction was present in 58% of patients (37% had a z-score between -1 and -2 SD, 21% had a z-score less than -2 SD) in at least one measured site. Seven of the 43 patients (16%) had nontrauma or tumor-associated fractures after chemotherapy. Findings were similar in the Ewing and osteosarcoma subgroups. We found vitamin D deficiency in 38 patients (88%) and borderline elevated bone metabolism; lactose intolerance was present in 16 patients (37%). CONCLUSION: Doctors should be aware of the possibility of major bone loss after chemotherapy with a risk of pathologic fracture. Vitamin D deficiency, calcium malnutrition, and lactose intolerance may potentiate the negative effects of chemotherapy, and should be considered in long-term patient management. LEVEL OF EVIDENCE: Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Sex-related outcome differences after implantation of low-contact-stress mobile-bearing total knee arthroplasty.

PURPOSE: The aim of the study was to investigate outcome differences between female and male patients after implantation of low-contact-stress (LCS) mobile-bearing total knee prostheses at a minimum follow-up of five years with respect to clinical and radiological parameters. METHODS: We retrospectively analysed 128 prostheses in 126 patients (90 women and 34 men) using our hospital database. Data was extracted with respect to range of motion (ROM), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, the Knee Society Score (KSS) and radiolucent lines on conventional X-rays. RESULTS: At follow-up, we observed no significant differences between female and male patients after LCS total knee prostheses. Benefit after implantation of LCS total knee prostheses after five years of minimum follow-up was not significantly different between female and male patients in terms of clinical outcome or radiolucent lines. CONCLUSIONS: We found no factors in favour of gender-specific total knee prostheses.

Long-term changes in serum silver concentrations after extremity reconstruction with silver-coated megaprostheses.

Silver-coated megaprostheses are considered to reduce infection rate following reconstruction of bone defects in tumour surgery or revision arthroplasty. However, little is known about systemic silver exposure and possible side effects. The aim of this study was to analyse serum silver concentrations in patients with silver-coated megaprostheses over a prolonged time period. Between 2004 and 2016, 46 patients (52.2% female, mean age at surgery 47.1 ± 24.2 years) received silver-coated megaprostheses for septic (n = 26) or oncological (n = 17; main implant since 2013) indications, or aseptic loosening (n = 3). Blood was drawn from all patients within the first few days following surgery (without silver ion levels) and thereafter every 6 months at the outpatient department (with silver ion levels). Inductively coupled plasma mass spectrometry was used to determine silver ion levels. Median follow-up was 47.3 months (IQR: 16.1-78.9). Overall, 29 revision surgeries became necessary in 20 patients, equivalent to a cumulative complication rate of 63.0%. Revisions were most commonly for periprosthetic joint infections (PJIs, n = 12) and instability/soft tissue problems (n = 10). Revision-free implant survival was 81.4%, 42.3% and 35.2% at one, 5 and 10 years. Incidence of local argyria was 8.7% (n = 4). Silver ion levels at two or more consecutive time points during follow-up were available for 26 patients. An increment of silver levels within the first months ("run-in") was observed, followed by an unspecific undulating course. Median initial and latest follow-up (median, 49.5 months) serum silver ion levels were 16.0 ppb (IQR: 9.1-29.1) and 7.4 ppb (IQR: 2.7-14.1), respectively. According to the multivariate mixed linear random-effects model, development of PJI was associated with significantly higher silver ion levels over time (p = 0.002), irrespective of time from surgery (p = 0.274). In the current series, a cumulative complication rate of 63.0% was observed for patients receiving silver-coated megaprostheses for septic of oncological indications. An overall unspecific course of silver ion concentration was present. Development of PJI was significantly associated with increased silver ion levels over time. Yet, no systemic complication associated to high silver levels occurred. It can be concluded that silver-coated implants constitute a safe solution for megaprosthetic reconstruction, but monitoring of silver concentrations is recommended.

Radiolucent lines in low-contact-stress mobile-bearing total knee arthroplasty: a blinded and matched case control study.

BACKGROUND: Low-contact-stress (LCS) mobile-bearing total knee arthroplasty (TKA) (Johnson & Johnson, New Brunswick, NJ; previously: DePuy, Warsawa, USA) provides excellent functional results and wear rates in long-term follow-up analyses. Radiological analysis shows radiolucent lines (RLL) appearing immediately or two years after primary implantation, indicative of poor seat. Investigations proved RLL to be more frequent in uncemented TKA, resulting in a consensus to cement the tibial plateau, but their association with clinical findings and patients discomfort and knee pain is still unknown. METHODS: 553 patients with 566 low-contact-stress (LCS) total knee prostheses were screened for continuous moderate knee pain. We compared tibial stress shielding classified by Ewald in patients suffering from pain with a matched, pain-free control group on blinded X-rays. We hypothesized a positive correlation between pain and radiolucency and higher frequency of such radiolucent lines in the most medial and most lateral zones of the tibial plateau. RESULTS: Twenty-eight patients suffered from knee pain in total. Radiolucencies were detected in 27 of these cases and in six out of 28 matched controls without knee pain. We could demonstrate a significant correlation of knee pain and radiolucencies, which appeared significantly more frequently in the outermost zones of the tibial plateau. CONCLUSION: Our findings suggest that radiolucent lines, representing poor implant seat, about the tibial plateau are associated with knee pain in LCS patients. Radiolucencies are observed more often in noncemented LCS, and cementing the tibial plateau might improve implant seat and reduce both radiolucent lines and associated knee pain.

Leg length measures appear inaccurate in the early phase following total hip arthroplasty.

The aims of this study were to (1) assess reliability of leg length discrepancy (LLD) measurements at different anatomical landmarks, (2) longitudinally investigate LLD in patients within the first year following total hip arthroplasty (THA) and to (3) correlate changes in LLD with functional outcome. Ninety-nine patients with short stem THA (53.3% males, mean age: 61.0 ± 8.1 years) were prospectively included. Upright pelvic anteroposterior (a.p.) radiographs taken at 6 timepoints (preoperatively, discharge, 6, 12, 24, 52 weeks postoperatively) were used to assess LLD at 5 anatomical landmarks (iliac crest, upper sacroiliac joint, lower sacroiliac joint, tear drop figure, greater trochanter). WOMAC and Harris Hip Score (HHS) were obtained preoperatively and at 6 and 52 weeks. LLD measures significantly increased in the initial phase following THA, from discharge to 6 weeks postoperatively and remained constant thereafter. Documentation of LLDs is dependent on measurement site: LLDs varied significantly between trochanter and iliac crest to tear drop figure (p < 0.001). Functional assessments did not correlate with the occurrence of LLDs [WOMAC (p = 0.252); HHS (p = 0.798)]. Radiographic assessment of LLD following THA may not be performed early postoperatively, as measurements appear to inaccurately reflect actual LLDs at this time, potentially due incomplete leg extension and/or inhibited weight-bearing.

A technical note to prevent superficial tumor cell dissemination at fungating soft tissue tumor resection.

Dissemination of the tumor within surgical field increases the risk of local recurrences. Fungating soft tissue tumors present a special risk of contamination in the attempt to perform wide resections. We hypothesized that adequate tumor coverage at resection could prevent tumor spilling and superficial dissemination in the operation field. For this purpose we used swabs to soak secretions. Incise drapes were put over swabs to seal the tumor. Double row skin staples were placed at the edge of the adhesive drapes for lift-off-prevention. We present eight patients treated with wide resection (3 myxofibrosarcomas, 2 malignant melanomas, 1 spindle cell sarcoma, 1 basal cell carcinoma, and 1 exulcerated lipoma). No complications were observed using this technique. An intraoperative local control, confirmed histologically, was achieved in all patients. Tumor covering could help local tumor control at fungating tumor resection.

Fetal Rhabdomyoma of the upper Extremity in a 31-Year Old Patient: a Case Report.

Fetal rhabdomyomas (RM) are extremely rare benign mesenchymal tumours that occur primarily in the head and neck. This tumour exhibits immature skeletal muscle differentiation. The patients' median age is four years and surgical resection is the recommended treatment. Fetal RM of limbs are rare and not well described in the literature and if, predominantly in form of case reports. We report the second case of a fetal RM in the upper extremity in a 31-year old male patient. One should be aware of this skeletal muscle tumour and fetal RM should be considered as a differential diagnosis to its malignant counterpart rhabdomyosarcoma.

Air entrapment resembling necrotising fasciitis as a frequent incident following total hip arthroplasty.

In combination with pain and elevated inflammatory parameters that are frequently observed following elective total hip arthroplasty (THA), air entrapment on radiographic images could be indicative of necrotising fasciitis. The aim of the present study was to analyse presence/extent of air entrapment following THA, and to correlate radiological with clinical findings. One-hundred patients undergoing short-stem elective THA (ANA NOVA Alpha Proxy-system) were prospectively included. Patients received pre- and postoperative x-rays (day 1 + discharge) of the affected hip, together with a CT-scan of the lower extremity (discharge). C-reactive-protein-(CRP), leukocyte, haemoglobin-, creatinine-, glucose-, sodium-levels - and based on these the LRINEC score- as well as pain-scores (numeral-rating-scale, NRS) at postoperative days 1, 3 and 5 were documented. Air entrapment was visible in 98% of x-rays taken postoperatively and in 93% of CT-scans at discharge. Leukocyte-levels significantly decreased from postoperative day 1 to 5. CRP-levels had a peak at the 3rd postoperative day (p < 0.001). On discharge-x-rays of patients with low body-mass-indexes, air entrapment was significantly more often visible (p = 0.040). Neither implant-related nor laboratory parameters, LRINEC- or NRS-scores significantly correlated with presence/extent of air entrapment (p > 0.05). Considering the high rate of air entrapment following elective THA postoperatively and at discharge, suspicion of an infection with gas-producing bacteria may only be raised in case of persistent inflammatory parameters, deteriorating general condition and signs of local infection.

Surgery for metachronous metastasis of soft tissue sarcoma - A magnitude of benefit analysis using propensity score methods.

INTRODUCTION: Metastasectomy is hypothesised to improve OS in metastatic STS, but evidence in favour of this approach derives from non-controlled single-arm cohorts affected by selection bias. The objective was to quantify the effect of metastasectomy vs. non-surgical management on overall survival (OS) in patients with metachronous metastases from extremity- and trunk soft tissue sarcoma (STS). MATERIALS AND METHODS: From a population of 1578 STS patients, 135 patients who underwent surgery for localised STS at two European centres between 1998 and 2015 and developed metachronous STS metastases were included. Propensity score analyses with inverse-probability-of-treatment-weights (IPTW) and landmark analyses were performed to control for selection and immortal time bias, respectively. RESULTS: OS was significantly longer in the 68 patients undergoing metastasectomy than in the 67 patients who were treated non-invasively for their metastasis (10-year OS: 23% vs. 4%; hazard ratio (HR) = 0.34, 95% CI: 0.22-0.53, p < 0.0001). This association prevailed after IPTW-weighting of the data to control for the higher prevalence of favourable prognostic factors in the surgery group (adjusted 10-year OS: 17% vs. 3%, log-rank p < 0.0001; HR = 0.33, 95% CI: 0.20-0.52, p < 0.0001). Five-year OS estimates were 27.8% in patients who had and 14.5% in patients who had not undergone metastasectomy within the first 3 months after diagnosis of a metastasis (p < 0.0001). CONCLUSION: In this observational bi-centre study, metastasectomy was associated with prolonged survival in patients with metachronous STS metastases. In the absence of randomized studies, our results indicate that metastasectomy should be considered as an important treatment option for metachronous STS metastases.

Impact of preoperative antithrombotic therapy on blood management after implantation of primary total knee arthroplasty.

Red blood cell concentrates (RCC) substitution after total knee arthroplasty (TKA) is correlated with multifold of complications and an independent predictor for higher postoperative mortality. TKA is mainly performed in elderly patients with pre-existing polymorbidity, often requiring permanent preoperative antithrombotic therapy (PAT). The aim of this retrospective analysis was to investigate the impact of demand for PAT on inpatient blood management in patients undergoing TKA. In this study 200 patients were retrospectively evaluated after TKA for differences between PAT and non-PAT regarding demographic parameters, preoperative ASA score > 2, duration of operation, pre-, and intraoperative hemoglobin level, and postoperative parameters including amount of wound drainage, RCC requirement, and inpatient time. In a multivariate logistic regression analysis the independent influences of PAT, demographic parameters, ASA score > 2, and duration of the operation on RCC demand following TKA were analyzed. Patients with PAT were significantly older, more often had an ASA > 2 at surgery, needed a higher number of RCCs units and more frequently and had lower perioperative hemoglobin levels. Multivariate logistic regression revealed PAT was an independent predictor for RCC requirement. PAT patients are more likely to require RCC following TKA and should be accurately monitored with respect to postoperative blood loss.