Periprosthetic joint infection (PJI) is a devastating complication in revision total hip arthroplasty (THA). As preoperative diagnosis can be difficult, some patients who undergo planned aseptic revision surgery might have positive intraoperative cultures and later be classified as infected. In this retrospective study we analyzed the influence of intraoperative positive cultures and possible underlying risk factors in patients undergoing planned aseptic THA revision. We retrospectively analyzed 276 cases of aseptic THA revision surgery between 2010 and 2017 who had a minimum follow-up period of 24 months. All patients underwent preoperative serum and synovial diagnostics according to the Center of Disease Control (CDC) (2010) or Musculoskeletal Infection Society (MSIS) Criteria (2011–2017) for PJI and were classified as aseptic prior to surgery. In all cases intraoperative tissue samples were taken and reviewed. Primary endpoint was defined as any complication leading to revision surgery. Secondary endpoint was explantation due to PJI or death. Revision free survival (RFS) and infection free survival (IFS) for intraoperative negative and positive cultures was calculated via Kaplan Meyer Method. Patients’ medical history was analyzed for possible risk factors for positive cultures.Aim
Method
Periprosthetic fungal infections are rare and account for 1–2% of all periprosthetic joint infections (PJI). This study aims at presenting treatment details, clinical and microbiological results in a large single centre cohort. We retrospectively identified 29 patients (9 total knee replacements (TKA) and 20 total hip replacements (THA) treated for a fungal infection between 2007 and 2019. Microbiological findings, patient demographics and complications were analysed. Statistical analysis was performed using descriptive statistics; non-parametric analysis were performed using the Mann-Whitney U-Test. Infection-free survival was determined using Kaplan-Meier analysis and differences in survival were analysed using the log-rank test. The p value was set at p<0.05 with 95% confidence intervals (95% CI) provided.Aims
Methods
Fungal prosthetic joint infections (PJIs) are rare and account for about 1% of total PJIs. Our aim was to present clinical and microbiological results in treating these patients with a two-stage approach and antifungal spacers. We retrospectively reviewed our institutional database and identified 26 patients with positive fungal cultures and positive Musculoskeletal Infection Society (MSIS) criteria for PJI who were treated between 2009 and 2017. We identified 18 patients with total hip arthroplasty (THA) and eight patients with total knee arthroplasty (TKA). The surgical and antifungal treatment, clinical and demographic patient data, complications, relapses, and survival were recorded and analyzed.Aims
Patients and Methods
The purpose of this study was to evaluate whether
the serum level of interleukin 6 (IL-6) could be used to identify the
persistence of infection after the first stage of a two-stage revision
for periprosthetic joint infection. Between 2010 and 2011, we prospectively studied 55 patients (23
men, 32 women; mean age 69.5 years; 36 to 86) with a periprosthetic
joint infection. Bacteria were identified in two intra-operative
tissue samples during re-implantation in 16 patients. These cases
were classified as representing persistent infection. To calculate a precise cut-off value which could be used in everyday
clinical practice, a 3 x 2 contingency table was constructed and
manually defined. We found that a serum IL-6 ≥ 13 pg/mL can be regarded as indicating
infection: its positive-predictive value is 90.9%. A serum IL-6 ≤ 8
pg/mL can be regarded as indicating an absence of infection: its
negative predictive value is 92.1%. The serum IL-6 level seems to be a reasonable marker for identifying
persistent infection after the first stage of a revision joint arthroplasty
and before attempting re-implantation. Cite this article:
We evaluated the clinical results and complications
after extra-articular resection of the distal femur and/or proximal
tibia and reconstruction with a tumour endoprosthesis (MUTARS) in
59 patients (mean age 33 years (11 to 74)) with malignant bone or
soft-tissue tumours. According to a Kaplan–Meier analysis, limb
survival was 76% (95% confidence interval (CI) 64.1 to 88.5) after
a mean follow-up of 4.7 years (one month to 17 years). Peri-prosthetic infection
was the most common indication for subsequent amputation (eight
patients). Survival of the prosthesis without revision was 48% (95%
CI 34.8 to 62.0) at two years and 25% (95% CI 11.1 to 39.9) at five years
post-operatively. Failure of the prosthesis was due to deep infection
in 22 patients (37%), aseptic loosening in ten patients (17%), and
peri-prosthetic fracture in six patients (10%). Wear of the bearings
made a minor revision necessary in 12 patients (20%). The mean Musculoskeletal
Tumor Society score was 23 (10 to 29). An extensor lag >
10° was
noted in ten patients (17%). These results suggest that limb salvage after extra-articular
resection with a tumour prosthesis can achieve good functional results
in most patients, although the rates of complications and subsequent
amputation are higher than in patients treated with intra-articular
resection. Cite this article:
We present the greatest study of patients with proximal fibula resection. Moreover we describe a new classification system for tumour resection of the proximal fibula independent of the tumour dignity. In 57 patients the functional and clinical outcome was evaluated. The follow up ranged between 6 months and 22.2 years (median 7.2 years). Indicationfor surgery was in 10 cases benign tumours and in 47 cases malignant tumours. In 32 patients a resection of the peroneal with resulting peroneal palsy was necessary.Aim
Method
The aim of this study was to define the treatment
criteria for patients with recurrent chondrosarcoma. We reviewed the
data of 77 patients to examine the influence of factors such as
the intention of treatment (curative/palliative), extent of surgery,
resection margins, status of disease at the time of local recurrence
and the grade of the tumour. A total of 70 patients underwent surgery
for recurrent chondrosarcoma. In seven patients surgery was not
a viable option. Metastatic disease occurred in 41 patients, appearing
synchronously with the local recurrence in 56% of cases. For patients
without metastasis at the time of local recurrence, the overall
survival at a mean follow-up after recurrence of 67 months (0 to
289) was 74% (5 of 27) compared with 19% (13 of 50) for patients
with metastasis at or before the development of the recurrence.
Neither the type/extent of surgery, site of tumour, nor the resection margins
for the recurrent tumour significantly influenced the overall survival. With limited survival for patients with metastatic disease at
the time of local recurrence (0% for patients with grade III and
de-differentiated chondrosarcoma), palliative treatment, including
local radiation therapy and debulking procedures, should be discussed
with the patients to avoid long hospitalisation and functional deficits. For
patients without metastasis at the time of local recurrence, the
overall survival of 74% justifies an aggressive approach including
wide resection margins and extensive reconstruction.
There has been a substantial increase in the
number of hip and knee prostheses implanted in recent years, with
a consequent increase in the number of revisions required. Total
femur replacement (TFR) following destruction of the entire femur,
usually after several previous revision operations, is a rare procedure
but is the only way of avoiding amputation. Intramedullary femur
replacement (IFR) with preservation of the femoral diaphysis is
a modification of TFR. Between 1999 and 2010, 27 patients with non-oncological
conditions underwent surgery in our department with either IFR (n
= 15) or TFR (n = 12) and were included in this study retrospectively.
The aim of the study was to assess the indications, complications
and outcomes of IFR and TFR in revision cases. The mean follow-up
period was 31.3 months (6 to 90). Complications developed in 37%
of cases, 33% in the IFR group and 4% in the TFR group. Despite
a trend towards a slightly better functional outcome compared with
TFR, the indication for intramedullary femur replacement should
be established on a very strict basis in view of the procedure’s
much higher complication rate.
Early and late infections are the most uneventfull complications after tumor resection and implantation of a maegaendoprosthesis. Therefore, silver-coating was introduced by our department years ago with successful reduction in infection rates. After promising results in animal and Phase exclusion of side effects in our Phase I trial, we would like to share our knowledge about latest research, especially the actual results of the Phase II study. We included the results off all implanted silver-coated Megaendoprosthesis since introduction in our department. Implantation had to be more than 12 months ago to guarantee a acceptable minimum follow up for calculation of the infection rate. Actually our infection rate lies at 3,1% (N=131) in the prevention group (no previous infection in medical history) and at 19% (N=36) in our “Highest-Risk” and previous infection group. Still no side-effects could be noticed. In one case we examined retrieved samples of three silver-coated Megaendoprosthesis. Macroscopically a leopard shaped figures could be noticed on the silver-coated surface in shiny and dark areas after being implanted in an infected region. Electron microscopy pictures show still intact surface and remaining silver with dark staining. Biofilm formation coulod not be noticed, though some few dead single bacteria could be found without any signs of proliferation or matrix production after adhesion. Signs of biofilm couldn’t be seen anywhere. Despite the discoloration silver is still intact in these areas without any loss of antibacterial properties. Blisterings or even flaking off the silver coating cannot be noticed. The thickness of the silver was not thinned in a significant way leading to a breakdown after a few years. Up to these days we have no experience in covering the whole prosthesis including the stem in human beings. Concerning osteointegration of silver-coated stems, our animal trial could not prove their effectiveness in comparison to titanium. Pull-out tests showed high significant discrepancies in osteointegration between titanium and silver coated stems in a dog model after a period of 12 months after implantation. Summarizing we recommend silver as a safe adjuvant therapy in patients undergoing endoprosthetic reconstruction after tumor resection. Intramedullary use of silver can be done only in experimental cases and needs further changes in the technical design of the coating.
Megaendoprotheses are widely used in the reconstruction of large bone defects in orthopaedic tumour surgery. The major complications (up to 36%) are periprosthetic infections. Persisting periprosthetic infections lead to secondary amputation up to 37% of the cases. One underestimated reason for persisting infections are subpopulations of S. aureus called “small colony variants” (SCVs). Aim of this study was to evaluate that silver ions might prevent or cure a periprosthetic infection caused by SCVs. For testing the antimicrobial activity of silver-coated titanium we used a technique introduced by Bechert et al. Therefore an adhesion and proliferation assay was performed with clinical isolates of S. aureus SCV (A22616/3). We tested the adhesion and proliferation properties of S aureus SCV on stainless steel (steel), Cobalt-Chrome-Molybdenum-alloy (CoCrMo), Titan-Aluminium-Vanadium-alloy (TiAlVa) and silver-coated Titan-Aluminium-Vanadium-alloy (scTiAlVa). Adhesion of S. aureus SCV is significantly reduced on scTiAlVa vs. steel (p>
0001). We could also demonstrate that the proliferation rate of scTiAlVa vs. all tested materials is significant (p>
0001) lower. We concluded that silver-coating has an effective antimicrobial activity against S. aureus SCVs. Thus silver-coated megaendoprostheses are a good prophylaxis against persisting infections caused by S. aureus SCVs.
Latest research concentrated on the coating of the stems, since they can still be the source of the infection if everything else is coated by silver already. Summarised so far, our experience in a rabbit model, a phase I Trial in humans and prelimnary results in Phase II Trials in humans showed no toxic side effects. Driven so far it seems to be sensible to extent the silver coating. So far, the coating is limited to all areas without joint movement or bone contact. An Animal trial was performed anylising the osteointegrative properties of an silver-coated stem versus an regular Titanium stem in 17 dogs. After 12 months of regular X-Ray Analysis a Pull-out test and a concentration analysis has been done. Results showed high significantly (p<
0.001) an osteointegration in 8 out of 8 titanium stems with an average pull-out force of 3764 Newton (Range 1755– 5967 Newton). Silver-coated stems showed no signs of Osteointegration in all 9 out of 9 femurs. The average pull-out force was 21 Newton (Range 0– 186 Newton). A cemented control could resist a pull out force of 350 Newton. Analysis of the silver concentration directly in the first millimeter of the bone-implant interface and the second millimeter showed highly elevated silver levels. The silver concentration in the bone-implant interface at Titanium stems ranged from 0.3 to 3502 parts per Billion (ng/g) compared to silver-coated stems ranging from 303 to 2.418.800 ppb parts per Billion (ng/g).
In summary, surgeons have to decide in the future how much silver they need in each individual case concerning intramedullary infection prophylaxis. The balance between loosening or infection should be based on long term expectations, taking into account that even after successful resection of a tumor an ongoning infection can lead to loosening of a limb or even life. Apart from intramedullary use, we recommend silver as a safe adjuvant therapy in all suited patients undergoing endoprosthetic reconstruction after tumor resection.
Chondrosarcoma are rare malignant tumors. About the biological characteristics of chondrosarcoma is little-known [ 32 cases were investigated clinically and histopathologically. The expression of vascular endothelial growth factor (VEGF), Endothelin-1, Endothelin-Receptor-A (ETR-A) and Endothelin-Receptor-B (ETR-B) were determined. All data were analyzed by Fisher’s exact test (p<
0,05). All tumors show an expression of either ET-1, ETR-A or ETR-B. Chondrosarcomas with grade (G) I are mostly expressing less than 10-% ET-1 in cells, Chondrosarcomas G II are expressing in most cases between 10–50% and nearly all Chondrosarcoms G III more than 50%. In addition ET-1-expression is correlating with the histological grading. The patients also show a significant high metastatic dissemination probability at the time when tumor samples present more than 10%-storing ET-1-cells. The intensity of ET-1-expression is correlating with VEGF, which is the most important angiogenetic factor in tumors. Chondrosarcomas are expressing ET-1, ETR-A and ETR-B. ET-1 seems to play a role in the angiogenesis of chondrosarcoma. Increased expression of ET-1 is accompanied with a high probability of metastatic dissemination. Endothelin receptor antagonists, which are used for example in prostate and breast cancer, can represent a potential therapy for chondrosarcoma [