Abstract

Aim

The aim of this study was to investigate the metabolomic profile of synovial fluid in periprosthetic joint infection (PJI) cases regarding a possible diagnostic approach. Also, further information about the metabolic composition of synovial fluid in PJI may point to future diagnostic and therapeutic approaches.

Aim

To improve the challenging treatment of periprosthetic joint infections (PJI), researchers are constantly developing new handling methods and strategies. In patients with PJI after total knee arthroplasty (TKA) and severe local or systemic comorbidities, a two-stage exchange using a temporary antibiotic loaded PMMA-spacer is considered gold standard. This method has undisputed advantages, however, the increased risk of biofilm formation on the spacer surface, bone defects and soft tissue contractions after a six-week spacer interval are severe limitations. Our hypothesis is that a vacuum sealed foam in combination with constant instillation of an antiseptic fluid can address these drawbacks due to a significantly reduced spacer interval.

Aim

In the diagnosis of prosthetic joint infection (PJI), many biomarkers have shown a sound performance in terms of accuracy, sensitivity and specificity. In this study we aimed to test the frequently used serum biomarkers C-reactive Protein (CRP), Fibrinogen, Leukocytes, Interleukin-6 (IL-6), Interferon alpha (IF-alpha) and Procalcitonin (PCT) regarding these qualities. Following that, the optimal multi-biomarker combination was calculated to further improve the diagnostic performance.

Aim

Bone loss is a severe problem in septic revision total knee arthroplasty (RTKA). The use of porous coated metaphyseal sleeves is a promising treatment option for extended bone defects. The currently published mid-term results remain limited and no study has been focused exclusively on septic cases. Our aim was to determine the implant survivorship (with special focus on osseointegration) and the clinical and radiological mid-term outcome of metaphyseal sleeve fixation in septic RTKA surgery (minimum follow-up of 2 years).

Aim

One of the most challenging problems in total knee arthroplasty (TKA) is periprosthetic infection. A major problem that arises in septic revision TKA (RTKA) are extended bone defects. In case of extended bone defects revision prostheses with metaphyseal sleeves are used. Only a few studies have been published on the use of metaphyseal sleeves in RTKA - none were septic exclusive. The aim of our study was to determine the implant survival, achieved osseointegration as well as the radiological mid-term outcomes of metaphyseal sleeve fixation in septic two-stage knee revision surgery.

The use of antibiotic-loaded cement has become a well-accepted method to develop high local antibiotic concentrations in orthopedic surgery. A new surgical technique has been established in our department in order to further increase the local antibiotic concentration, when implanting a prosthesis during revision surgery. By additional superficial vancomycin coating of the bone cement, high local antibiotic concentrations are generated. They should reach inhibiting and bactericidal concentrations of the respective pathogen during the first days after surgery.

The aim of this study was to state the safety of this method by analyzing postoperative serum and drain vancomycin concentrations. Attention was focused on possible systemic side effects. To determine nephrotoxicity, creatinine levels were also measured.

In total 32 revision operations (hip n=10, knee n=22) with additional superficial vancomycin coating were performed between 05/2013 and 04/2015. Procedures with removal of the prosthesis following temporary spacer implantation were excluded. In nine cases a one-stage procedure was performed, while in the others an arthroplasty or arthrodesis was performed after temporary spacer explantation. Vancomycin powder (2 grams) was added superficially to the surface of the bone cement and pressed onto manually before curing. Postoperative Vancomycin levels were measured in serum and the drain on day 1 to 5 or until the drain has been removed. In total 90 blood serum samples and 100 drain fluid samples were obtained.

The highest median vancomycin level from the drain was documented on postoperative day 1 with a value of 555.3 μg/mL (range 66.1 – 1081.8), continually decreasing until postoperative day 4. The highest value was documented on the second postoperative day with 2170.0 μg/mL. On the first postoperative day, a median serum vancomycin level of 3.35 μg/mL was present (range <2.0 – 8.5), while from postoperative day 2 to 5 a median level less than 2.0 μg/mL (range <2.0 – 7.2) was documented.

Anaphylactic reaction, red man syndrome or fever and chills were not observed after the surgical procedure. Furthermore, no subjective hearing loss was reported. Only in one case, a creatinine increase of 0.5 mg/dL from baseline value was detected. In this case the patient suffered preoperatively from a chronic kidney insufficiency.

In total two reinfections occurred, one after explanting a spacer with subsequent hip total endoprosthesis, the other one after a one-stage hip revision.

Superficial Vancomycin Coating of bone cement in orthopedic revision surgery represents a safe method to increase local inhibiting vancomycin concentrations.

In two-stage revision surgery of infected joint prosthesis, temporary bone cement spacers have been used for several years. By adding antibiotics to the cement, high local antibiotic concentrations that exceed the minimum inhibiting and bactericidal concentration of the respective pathogen during the first days after surgery, are achieved. Currently, aminoglycosides (e.g. gentamicin and tobramycin), as well as glycopetides (e.g vancomycin) are used as antibiotic agents and mixed into the acrylic cement. In order to increase the quantity of active antibiotic substances, we established a novel surgical technique of additional superficial vancomycin coating (SVC) of temporary bone cement spacer. The aim of this study was to analyze the safety of this method by measuring postoperative joint and serum vancomycin concentrations, as well as the creatinine levels.

We reviewed prospectively collected data on all patients, which were treated by explanting the prosthetic components, following temporary spacer implantation and SVC between 05/2013 and 04/2015 at the Department of Orthopedic Surgery, Medical University of Graz. In total 13 patients were treated by addition SVC during the study period. Before hardening, vancomycin powder (2 grams) was pressed manually onto the surface of the bone cement. Vancomycin levels were obtained from drains and blood samples on postoperative days 1 to 5. Forty-six blood serum samples and 52 drain fluid samples were available for further

On postoperative day one to five, a median serum vancomycin level of < 2.0 μg/mL was present (range <2.0 – 3.9). The highest median vancomycin level from the drain was documented on postoperative day 1 with a value of 388.0 μg/mL (range 44.4–1650.0), continually decreasing until postoperative day 4. After SVC, neither an anaphylactic reaction nor side effects such as a red man syndrome, fever and chills were observed. Furthermore, no patient complained about subjective hearing loss. No serum creatinine increase of 0.5 mg/dL from creatinine baseline value or a ≥50% increase from baseline was detected. After a median of 64 days (range 18–82), the temporary cement spacer was explanted followed by prosthesis implantation. During this time no reinfection occurred. One patient suffered from a dislocation of the spacer with a distal femur fracture and was therefore re-operated after 18 days.

Powdered vancomycin as an additional superficial coating of bone cement spacer results in much higher local antibiotic concentrations than in conventional spacers. The newly introduced method is feasible, safe and promising to enhance local inhibiting concentrations of vancomycin.

Joint replacement is a highly effective intervention to treat osteoarthritis of the hip, relieving pain and improving mobility and quality of life.(1) Periprosthetic joint infection (PJI) is a devastating complication after arthroplasty. Debridement, antibiotics and implant retention are treatment of first choice in case of early infection after total hip arthroplasty (THA).(2) In case of persisting infection, one- or two-stage revision needs to be performed.(3) The use of different kinds of spacers has been widely debated in the past years.(4)

The aim of this study was to determine which type of spacer should be used during the interval of two-stage revision of an infected THA.

A search term with Boolean operators was constructed. We extracted all information regarding study and patient characteristics and baseline clinical and laboratory findings. Data regarding type of spacer and antibiotics used, timing of second stage surgery, tissue culture results, postoperative regimen, functional outcome and patient satisfaction were extracted.

A total of twenty-six studies met our inclusion criteria and were included for data analysis. Ten studies described various preformed spacers, six studies described functional spacers and eleven studies described custom made spacers. See Table 1 for results.

Research should focus on finding the preferred type of treatment and type of spacer to combine a high success rate of infection treatment with a good functional and patient reported outcome. There is a need for a prospective study evaluating patient satisfaction and functional outcome after two-stage revision THA comparing various spacers. Secondly, research should focus on the optimal timing of the second stage procedure.

Functional spacers achieve a comparable rate of infection eradication in the treatment of periprosthetic hip joint infections as compared to preformed spacers. There is insufficient evidence concerning rehabilitation and functional outcome after two-stage revisionTHA to advocate or discourage the use of either kind of interval spacer.

Aim

Accurate and reliable patient information plays a crucial role in the multidisciplinary treatment of malignancies helping to ensure compliance of the patients and their relatives with often long-lasting and stressful treatment. The English version of the online encyclopaedia Wikipedia has been recently reported to be the prominent source of online health information. However, there is little information concerning the quality of information found in Wikipedia.

Introduction: Infections associated with prosthetic joints cause significant morbidity and account for substantial costs for health care systems. The management of prosthetic joint infections is less standardized, because of the variable clinical presentations and the lack of data from randomized, controlled trials.

We evaluated the results of surgical one stage versus two stage exchange of patients diagnosed positive for prosthetic infection following total hip replacement in correlation with a classification described by Mc Pherson.

Material and Methods: 94 patients were diagnosed positive for prosthetic joint infection following total hip replacement in the years 1995 to 2004: gender distribution was 45 male and 49 female patients. 37 patients were treated with a one stage exchange, 57 patients underwent a two step procedure. Patients were further divided into two groups following the mentioned classification described by Mc Pherson as infection type I+II and III. Further characterisation was performed following systemic host grade (A versus B+C) and local extremity grade 1 versus 2+3.

Results: 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 step exchange was overall significantly different with p< .001. Further deviations between the described two procedures were noted in the subgroups following the classification described by Mc Pherson. A benefit of patients who underwent a two step procedure was seen according the severity of the classification following Mc Pherson.

Conclusion: Eradication rate of prosthetic joint infections differs statistically significant overall and in the subgroups following Mc Pherson in dependence of the surgical procedure. For this reason the individual surgical procedure should be geared to an algorithm, following the classification described by Mc Pherson.

In animal experiments antioxidants like Resveratrol, Quercetin-dihydrate and Selen-L-Methionine cause a growth rate decrease in synovial tissue and furthermore an inhibition of pro-infiammatory factors. We investigated the effect of these antioxidants on synovial fibroblasts of Osteoarthritis (OA) patients compared to Rheumatoid Arthritis (RA) patients.

Random biopsies of synovial membrane were obtained aseptically from joints of OA and RA patients. After in vitro expansion cells were cultivated until passage three, seeded in 96 well microtiterplates and treated with 0μM, 50μM, 100μM and 200μM of Resveratrol, Quercetin-dihydrate and Selen-L-Methionin. After 24 and 48 hours incubation cell proliferation assays and apoptosis FACS analysis were performed. Additionally woundhealing assays and photographic documentation of resettlement of synovial fibroblasts was accomplished.

The results of cell proliferation assays showed a highly significant reduction as well in OA and RA cells. In OA synovial fibroblasts 200μM of Resveratrol evoked a decrease of 72,3 ±1,7% (***), 200 μM of Quercetin-dihydrate induced a reduction of 16,11 ±3% (***). 200μM of Selen-L-Methionine evoked a decrease of 27,3 ±3,8% (***). In RA cultures 200 μM of Resveratrol evoked a decrease of 77,7 ±1,8% (***), 200μM of Quercetin-dehydrate induced a reduction of 20,38 ±15,3%(**), 200μM of Seleno-L-Methionine evoked a decrease of 23,3 ±4,8%(***)(n=20). The results of photographic documentation correlated with cell experiments. Analysis with untreated and treated OA and RA synovial fibroblasts for their content of apoptotic and necrotic cells by Annexin/7AAD staining displayed only few apoptotic cells. Caspase 3, a key mediator of apoptosis, was not activated in resveratrol-treated OA and RA synovial fibroblasts.

Resveratrol, Quercetin-dihydrate and Selen-L-Methionine showed a significant growth rate decrease in OA and RA synovial fibroblasts. In OA and RA the pharmacologic treatment with these antioxidants may be a therapeutic approach. Different apoptosis assays represented only few apoptotic cells. We therefore conclude that apoptosis is not the major pathway in resveratrol-treated synovial fibroblasts.

Introduction: Giant cell tumor of bone is a semimaligne tumor which locally recurs very often but rarely metastasises. En bloc resection of the distal radius with reconstruction using a homologeous allograft, curettage with PMMA blomb, and allograft arthrodesis are established methods. The aim of the study was to evaluate the functional outcome of our patients with the DASH-Score and the Mayo Wrist Score

Materials and Methods: In the last 7 years six patients were treated at our clinic due to a giant cell tumor of the distal radius. Two patients were primary treated with an en bloc resection. The other four were primary treated with curettage and filled up with PMMA cement plomb (Phenol was used in every case). In two of these cases a secondary en bloc resection was performed for local recurrence. For evaluation of function in daily live we used the DASH Score and the MAYO wrist score.

Results: The mean bone resection length was 5,25cm (5–6 cm).

All four patients treated with en bloc resection (primary or secondary) had no recurrence but in two out of that cases a re-operation was necessary because of non union.

At a mean follow up from 27 months (4–95) there were no recurrences or metastases at all

The flexion/extension of the wrist in currettaged radius was 60° and 80° compared with 38° and 68° in reconstructed radius. The pronation/suppination was 90°/90° in the currettaged ones versus 77°/77° in the allograft replaced ones.

The functional outcome evaluated with Mayo Wrist Score and DASH score showed an exellent outcome for both groups (84/7,7 Allograft < -> 85/10 Currettage)

Discussion: Functional outcome of distal radius resection reconstruction using an allograft is highly satisfactory compared with the literature, however we experienced a high risk for pseudoarthrosis. For prevention of non union simultan bone grafting at the index operation could be advisable.

The functional outcome proof no disadvantages in daily life and daily work compared to curettage. Thus allograft reconstruction of the distal radius represents a valuable alternative to arthrodesis.

Background: Desmoplastic fibroma (DF) of bone is a very infrequent non-metastasizing osseous tumour with local aggressive appearance. The tendency of local recurrence in published cases is high.

Case reports: We present the clinical and radiological data of a male (35 years) and a female (37years) patient suffering from desmoplastic fibroma. Although in literature spinal lesions are severity rare, in our database two lesions located in the spine (C6 and L4) were identified. The first disturbances have been variable: The lesion in C6 was an accidental finding due to a control examination of a thyroid-ca, whereas the relapse-tumour of the L4 induced lumbago and hypaesthesia of the left heel.

Due to the importance of the thyroid treatment it was decided to control the lesion in C6 in close intervals. The lumbar tumour was initially treated outside and the first relapse was marginal resected at our department 11 years after the first diagnosis. The bone alterations appeared radiographically lytic and cystic.

Discussion: The spine is an unusual location of desmoplastic fibroma which arises in 56% at the long tubular bones followed by the mandible. To our knowledge only a few cases are reported to be located in the spine. DF located spinal, is a very untypical tumour and initial symptoms can be very unequal. Due to this dissimilar symptoms and variable histological appearance the diagnosis can be tricky. At least marginal resection should be achieved because intraleasional resected lesions show a local recurrence of 43%.

Introduction: Rotating hinge knee prostheses are designed to provide a stable knee reconstruction when the intrinsic soft-tissue stability of the knee had been lost as a result of tumor resection, multiple knee replacements, trauma or surgical reconstruction. Instability is the main risk factor for implant’s dislocation. We performed a biomechanical analysis to establish the association between design of the central rotational stem (length and taper) and the implant’s stability, using a self constructed biomechanical apparatus on a test bench in the laboratory.

Materials and Methods: The lengths and tapers of the central rotational stem of three different rotating hinge knee implants (LPS/M.B.T. (DePuy)-cylindrical, length: 46mm, taper: 0°; S-ROM Noiles (DePuy) -conical, length: 46mm, taper: 5°; GMRS (Howmedica) -cylindrical, length: 47mm, taper: 0°) were measured using a self-constructed biomechanical testing device. The degree of tilting of the central rotational stem within the vertical post-in channel by extending the distraction was measured as well the maximum amount of distraction before the stem’s dislocation.

Results: The GMRS implant design was superior to the LPS/M.B.T. and the S-ROM Noiles implant design concerning stability and maximum amount of distraction before dislocation (38 vs. 27 vs. 26 mm). The GMRS system had a steep rising distraction-angular displacement curve until the dislocation at 38mm occurred while the laxity curve of S-ROM Noiles showed a poor increasement. Besides early high laxity it required only 26mm of distraction to dislocate.

Conclusions: Our conclusion is that rotating hinge prostheses with a short and markedly tapered central rotational stem have the highest instability/angular laxity at any given amount of distraction. Such knee prostheses should be used with caution in patients after excessive soft tissue resection. A long and cylindrical central rotational stem seems to prevent early instability and implant’s dislocation.

Giant cell tumor of the distal radius is associated with a high local recurrence rate. En bloc resection of the distal radius and reconstruction using osteoarticular allograft, curettage with PMMA blomb, and allograft arthrodesis are established methods. The aim of the study was to evaluate the functional outcome of our patients with the DASH-Score and the Mayo Wrist score.

In the last 7 years six patients were treated at our department due to a giant cell tumor of the distal radius. Two patients were primary treated with an en bloc resection. The other four were primary treated with curettage packing of the defect with polymethylmethacrylate. In two of these cases a secondary en bloc resection was performed for local recurrence. For evaluation of function in daily live we used the DASH score and the MAYO wrist score.

The mean bone resection length was 5,25cm (5–6 cm).All four patients treated with en bloc resection (primary or secondary) had no recurrence but in two out of that cases a re-operation was necessary because of non union.

At a mean follow up from 27 months (4–95) there were no recurrences or metastases at all.

The flexion/extension of the wrist in currettaged radius was 60°/80° compared with 38°/68° in reconstructed radius. The pronation/suppination was 90°/90° in the currettaged ones versus 77°/77° in the allograft replaced ones.

The functional outcome evaluated with Mayo Wrist Score and DASH score showed an excellent outcome for both groups (84/7,7 Allograft < -> 85/10 Currettage)

Functional outcome of distal radius resection reconstruction using an allograft is highly satisfactory compared with the literature, however we experienced a high risk for pseudoarthrosis. For prevention of non union simultaneous bone grafting at the index operation could be advisable.

Thus allograft reconstruction of the distal radius represents a valuable alternative to arthrodesis.

Whereas thermography has already been used as an assessment of disease activity in some kinds of inflammatory arthritis, it is a new method for objektive pain evaluation in patients with joint prosthesis. To our knowledge, no study has tested the correlation between increase of temperature and anterior knee pain with total knee prosthesis yet.

Thirteen patients were included in this study who suffered from anterior knee pain of the retinaculum patellae with total knee prosthesis. The patients were asked to walk 3 km before entering a room which was cooled down to 20 degrees Celsius. A black 1 cm times 4.5 cm square stripe was attached on the diameter of the patella and the patients rested for 20 minutes to cool down before thermographic fotos were taken from 90 degrees, 45 degrees, frontal medial and lateral. The evaluation of temperature difference of each side was performed by marking a 1cm times 2cm square field rectangular around the black stripe and comparing it with a reference point of the same size 3 cm distal of the field. The patients were compared with thirteen others, not suffering from anterior knee pain. Statistical analysis was performed using a t- test and a p value < 0.05 was considered to be significant.

The temperature differences between the rectangular field and the reference point increased significantly on the medial (p= 0.00037) or lateral (p= 0.000002) pain side of the knee. The thirteen knees with knee pain had significantly higher temperature differences between medial and lateral temperature differences, than the knees without knee pain.

We demonstrate a significant correlation between anterior knee pain and an increase of superficial skin temperature around the retinaculum patellae. To our knowledge, this is the first report of an objective assessment of pain of the retinaculum patellae with total knee prosthesis.

In several countries fine needle aspiration (FNA) biopsy of soft tissue tumours is regarded as a standard procedure. However, various problems using FNA compared to core needle biopsy have been reported. Less cell amount, blood and other non tumour tissue aspirated and cells torn out of their environment lead to problems in histological diagnose. The aim of this study was to measure the number of cells harvested by two new needle systems (THYROSAMPLER®) in comparison with the conventional fine needle system (C-FNA). The innovation of the new system is aeration after aspiration by a valve, so that undesired aspiration of blood, debris, and cells from outside the tumour during withdrawal of the needle is minimized.

In a blinded setting, 45 punctures from fresh pig thyroid glands were made and analysed – 15 for each needle (C-FNA, single-needle with air valve T-ONE and multi needle system with air valve T-THREE). The aspirated cell material was evacuated into 10ml cell-culture liquid and calculated according to the manufacturer’s recommendations for the CASY cell counter (CASY® technology, Reutlingen).

With each system, 15 punctures each were aspirated and the cells counted. With the T-ONE System the amount of vital cells was 688%, the amount of total cells 521% higher then using the C-FNA system. With the T-THREE System the amount of vital cells was 901%, the amount of total cells 798% higher then using the C-FNA system.

The mean difference between C-FNA and T-ONE was significant regarding total number of cells (p=0.030) as well as number of vital cells (p=0.032).

The needle systems with the air-valve led to a significantly higher cell amount in needle aspiration biopsy. According to the requirement of cytological diagnosis of soft tissue sarcomas more cell volume could be harvested, which is a well-defined benefit.