Introduction To help combat the SARS-CoV-2 (COVID-19) pandemic, elective inpatient procedures hav... more Introduction To help combat the SARS-CoV-2 (COVID-19) pandemic, elective inpatient procedures have been reduced. The authors hypothesized that a nationwide lockdown would negatively affect the postoperative outcome after total knee arthroplasty (TKA) due to reduced physiotherapy as well as restrictions in external facilities of physiotherapy and rehabilitation. Materials and methods We conducted a retrospective, comparative study including 41 patients who had undergone primary TKA during the first lockdown of the COVID-19 pandemic from March 2020 to April 2020 and a comparable control group consisting of 47 patients with a minimum follow-up of 6 months before the COVID-19 pandemic from 2019. Relevant end points were the visual analogue scale (VAS) for pain, Knee Society Function Score (KSS), Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and range of motion (ROM). Results The lockdown group had a significantly worse outcome compared ...
Background Despite numerous scientific investigations, the tribological advantages of mobile bear... more Background Despite numerous scientific investigations, the tribological advantages of mobile bearing inserts have not been sustainably confirmed or refuted for modern knee prostheses in clinical studies. The purpose of this study was to compare fixed and mobile bearing inserts in order to draw conclusions regarding clinical benefits. Methods The present prospective single center cohort study of 2 non-randomized stratified groups consisted of 67 patients. All included patients received cemented total knee arthroplasty (Attune®) due to osteoarthritis. 34 patients were treated with a mobile and 33 patients with a fixed insert. The WOMAC score and the Visual Analogue Scale was used for the subjective assessment of success, while the Knee-Society-Score was used considering the Range of Motion for the objective assessment. The subjective and the clinical scores showed improvements for both compared groups postoperatively at 2 years of minimum follow-up. Results The overall postoperative r...
Zusammenfassung Hintergrund Atypische chondrogene Tumoren (ACT) der kurzen und langen Röhrenknoch... more Zusammenfassung Hintergrund Atypische chondrogene Tumoren (ACT) der kurzen und langen Röhrenknochen, früher als Chondrosarkome G1 bezeichnet, verhalten sich lokal aggressiv, haben aber ein sehr geringes Metastasierungspotenzial. Die Abgrenzung zu benignen Enchondromen ist aus klinischer, radiologischer und histopathologischer Sicht komplex. Ziel der Arbeit Epidemiologie, Diagnostik und Therapie von ACT unter besonderer Berücksichtigung der Abgrenzung zu Enchondromen werden dargestellt. Material und Methoden Es erfolgt die Zusammenfassung der internationalen Fachliteratur zu ACT und Enchondromen. Ergebnisse Die Inzidenz von Enchondromen, und mehr noch von ACT, ist über die Jahre angestiegen, was auf häufiger werdende Diagnostik hinweist. Im Gegensatz zu Enchondromen können ACT mit Schmerzen verbunden sein und radiologische Zeichen aggressiven Wachstums, wie tiefes endosteales Scalloping, aufweisen. Die alleinige Biopsie zur Differenzierung zwischen Enchondromen und ACT ist oft nicht ...
In patients with metastatic or unresectable soft tissue and bone sarcoma of extremities and pelvi... more In patients with metastatic or unresectable soft tissue and bone sarcoma of extremities and pelvis, survival is generally poor. The aim of the current systematic review was to analyse recent publications on treatment approaches in patients with inoperable and/or metastatic sarcoma. Original articles published between 1st January 2011 and 2nd May 2020, using the search terms ‘unresectable sarcoma’, ‘inoperability AND sarcoma’, ‘inoperab* AND sarcoma’, and ‘treatment AND unresectable AND sarcoma’ in PubMed, were potentially eligible. Out of the 839 initial articles (containing 274 duplicates) obtained and 23 further articles identified by cross-reference checking, 588 were screened, of which 447 articles were removed not meeting the inclusion criteria. A further 54 articles were excluded following full-text assessment, resulting in 87 articles finally being analysed. Of the 87 articles, 38 were retrospective (43.7%), two prospective (2.3%), six phase I or I/II trials (6.9%), 22 phase ...
Purpose In many cases, the diagnosis of a periprosthetic joint infection (PJI) consisting of the ... more 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...
Background: The impact of titanium nitride (TiN) coating on implant components is controversial. ... more Background: The impact of titanium nitride (TiN) coating on implant components is controversial. TiN coating is proposed as having superior biomechanical properties compared to conventional cobalt-chromium (CoCr) alloy. This study compared long-term clinical data as well as meteoro-sensitivity in patients who underwent total knee arthroplasty (TKA), with either CoCr alloy or TiN coating. Methods: In this retrospective observational study, the clinically approved cemented “low contact stress” (LCS) TKA with conventional CoCr coating, was compared to un-cemented TiN-coated “advanced coated system” (ACS) TKA. Propensity score matching identified comparable patients based on their characteristics in a one-to-one ratio using the nearest-neighbor method. The final cohort comprised 260 knees in each cohort, with a mean follow-up of 10.1 ± 1.0 years for ACS patients and 14.9 ± 3.0 years for the LCS group. Physical examinations, meteoro-sensitivity, and knee scoring were assessed. Results: T...
Purpose Our aim was to assess the outcome with respect to cumulative revision rates of unicompart... more Purpose Our aim was to assess the outcome with respect to cumulative revision rates of unicompartmental knee arthroplasty (UKA) by comparing published literature and arthroplasty registry data. Our hypothesis was that there is a superior outcome of UKA described in dependent clinical studies compared to independent studies or arthroplasty registers. Methods A systematic review of all clinical studies on UKA in the past decade was conducted with the main endpoint revision rate. Revision rate was calculated as “revision per 100 component years (CY)”. The respective data were analysed with regard to a potential difference of the percentage of performed revision surgeries as described in dependent and independent clinical studies. Clinical data were further compared to arthroplasty registers in a systematic search algorithm. Results In total, 48 study cohorts fulfilled our inclusion criteria and revealed 1.11 revisions per 100 CY. This corresponds to a revision rate of 11.1% after 10 ye...
PurposeThe purpose of this study was to provide a matched cohort comparison of clinical and funct... more PurposeThe purpose of this study was to provide a matched cohort comparison of clinical and functional outcome scores, range of motion and quality of life following unicompartmental knee arthroplasty (UKA) or total knee arthroplasty (TKA). The hypothesis was that patients receiving UKA report better results than comparable patients who receive conventional TKA.MethodsClinical and functional results of 35 patients with medial end-stage osteoarthritis who had received a fixed-bearing UKA were compared with the results of 35 matched patients who had received a TKA from the same manufacturer by the same surgeon. Outcome scores were measured before surgery and at final follow-up using Tegner Activity Scale (TAS), range of motion (ROM) and Short Form 36 Health Survey (SF-36). The Knee Society Score (KSS) was assessed at final follow-up. The mean observation period was 2.3 years in both groups.ResultsThe preoperative knee scores had no statistically significant differences between the two ...
The purpose of this study was to provide comprehensive long-term data about sports activity level... more The purpose of this study was to provide comprehensive long-term data about sports activity levels in patients following total knee arthroplasty (TKA) and to determine the impact of pre-operative function, pain and specific performed sports on the results. 236 patients who have undergone TKA for severe osteoarthritis of the knee were asked to provide specific information regarding exercised types of sports before surgery and after at least 10 years following TKA. Pre- and postoperative function and pain were evaluated by the use of Tegner-, WOMAC- and VAS Score. After a mean of 14.9 years, a significant improvement regarding pain and function was observed. Pre-operative Tegner- and WOMAC scores revealed significant positive correlations with the post-operative Tegner-Score. Accordingly, a high percentage of patients (70.9%) stayed actively involved in sports. Nevertheless, the number of performing patients has decreased according to the sports impact. 71.3% continued practising low-...
The purpose of this study was to determine the concentrations of cobalt, chromium, and molybdenum... more The purpose of this study was to determine the concentrations of cobalt, chromium, and molybdenum in the serum of paediatric tumour patients after fixed hinge total knee arthroplasty. Further, these metal ion levels were compared with serum metal ion levels of patients with other orthopaedic devices such as hip and knee prostheses with metal-on-metal or metal-on-polyethylene articulation to find differences between anatomical locations, abrasion characteristics, and bearing surfaces. After an average follow-up of 108 months (range: 67 to 163) of 11 paediatric patients with fixed hinge total knee arthroplasty, the mean concentrations for Co and Cr were significantly increased while Mo was within the limits compared to the upper values from the reference laboratory. Furthermore, these serum concentrations were significantly higher compared to patients with a standard rotating hinge device (P=0.002andP<0.001) and preoperative controls(P<0.001). On the other hand, the serum levels...
Reconstruction with massive bone allograft and autologous vascularised fibula combines the struct... more Reconstruction with massive bone allograft and autologous vascularised fibula combines the structural strength of the allograft and the advantages of fibula’s intrinsic blood supply. We retrospectively analysed the outcome of twelve patients (4 male, 8 female) who received reconstruction with massive bone allograft and autologous vascularised fibula after tumour resection in lower limb. Mean age was 17.8 years (range 11–31 years), with following primaries: Ewing’s sarcoma (n=6), osteosarcoma (n=4), liposarcoma grade 2 (n=1), and adamantinoma (n=1). Mean followup was 38.7 months (median 25.7 months; range 2–88 months). Seven tumours were located in the femur and five in the tibia. The mean length of bone defect was 18.7 cm (range 15–25 cm). None of the grafts had to be removed, but there occurred four fractures, four nonunions, and two infections. Two patients developed donor side complication, in form of flexion deformity of the big toe. The event-free survival rate was 51% at two-y...
Reconstruction of the distal radius following tumour resection is challenging and various techniq... more Reconstruction of the distal radius following tumour resection is challenging and various techniques are recorded. We retrospectively analysed the outcome of five patients (one male and four females) after reconstruction of the distal radius with osteoarticular allograft, following tumour resection. Mean followup was 32 months (range, 4–121). In three of the five patients the dominant limb was affected. Mean bone resection length was 6.5 centimetres (range, 5–11.5). Two grafts developed nonunion, both successfully treated with autologous bone grafting. No infection, graft fracture, or failure occurred. Mean flexion/extension was 38/60 degrees and mean pronation/supination was 77/77 degrees. The mean Mayo wrist score was 84 and the mean DASH score was 8, both representing a good functional result. Therefore we state the notion that osteoarticular allograft reconstruction of distal radius provides good to excellent functional results.
Introduction To help combat the SARS-CoV-2 (COVID-19) pandemic, elective inpatient procedures hav... more Introduction To help combat the SARS-CoV-2 (COVID-19) pandemic, elective inpatient procedures have been reduced. The authors hypothesized that a nationwide lockdown would negatively affect the postoperative outcome after total knee arthroplasty (TKA) due to reduced physiotherapy as well as restrictions in external facilities of physiotherapy and rehabilitation. Materials and methods We conducted a retrospective, comparative study including 41 patients who had undergone primary TKA during the first lockdown of the COVID-19 pandemic from March 2020 to April 2020 and a comparable control group consisting of 47 patients with a minimum follow-up of 6 months before the COVID-19 pandemic from 2019. Relevant end points were the visual analogue scale (VAS) for pain, Knee Society Function Score (KSS), Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and range of motion (ROM). Results The lockdown group had a significantly worse outcome compared ...
Background Despite numerous scientific investigations, the tribological advantages of mobile bear... more Background Despite numerous scientific investigations, the tribological advantages of mobile bearing inserts have not been sustainably confirmed or refuted for modern knee prostheses in clinical studies. The purpose of this study was to compare fixed and mobile bearing inserts in order to draw conclusions regarding clinical benefits. Methods The present prospective single center cohort study of 2 non-randomized stratified groups consisted of 67 patients. All included patients received cemented total knee arthroplasty (Attune®) due to osteoarthritis. 34 patients were treated with a mobile and 33 patients with a fixed insert. The WOMAC score and the Visual Analogue Scale was used for the subjective assessment of success, while the Knee-Society-Score was used considering the Range of Motion for the objective assessment. The subjective and the clinical scores showed improvements for both compared groups postoperatively at 2 years of minimum follow-up. Results The overall postoperative r...
Zusammenfassung Hintergrund Atypische chondrogene Tumoren (ACT) der kurzen und langen Röhrenknoch... more Zusammenfassung Hintergrund Atypische chondrogene Tumoren (ACT) der kurzen und langen Röhrenknochen, früher als Chondrosarkome G1 bezeichnet, verhalten sich lokal aggressiv, haben aber ein sehr geringes Metastasierungspotenzial. Die Abgrenzung zu benignen Enchondromen ist aus klinischer, radiologischer und histopathologischer Sicht komplex. Ziel der Arbeit Epidemiologie, Diagnostik und Therapie von ACT unter besonderer Berücksichtigung der Abgrenzung zu Enchondromen werden dargestellt. Material und Methoden Es erfolgt die Zusammenfassung der internationalen Fachliteratur zu ACT und Enchondromen. Ergebnisse Die Inzidenz von Enchondromen, und mehr noch von ACT, ist über die Jahre angestiegen, was auf häufiger werdende Diagnostik hinweist. Im Gegensatz zu Enchondromen können ACT mit Schmerzen verbunden sein und radiologische Zeichen aggressiven Wachstums, wie tiefes endosteales Scalloping, aufweisen. Die alleinige Biopsie zur Differenzierung zwischen Enchondromen und ACT ist oft nicht ...
In patients with metastatic or unresectable soft tissue and bone sarcoma of extremities and pelvi... more In patients with metastatic or unresectable soft tissue and bone sarcoma of extremities and pelvis, survival is generally poor. The aim of the current systematic review was to analyse recent publications on treatment approaches in patients with inoperable and/or metastatic sarcoma. Original articles published between 1st January 2011 and 2nd May 2020, using the search terms ‘unresectable sarcoma’, ‘inoperability AND sarcoma’, ‘inoperab* AND sarcoma’, and ‘treatment AND unresectable AND sarcoma’ in PubMed, were potentially eligible. Out of the 839 initial articles (containing 274 duplicates) obtained and 23 further articles identified by cross-reference checking, 588 were screened, of which 447 articles were removed not meeting the inclusion criteria. A further 54 articles were excluded following full-text assessment, resulting in 87 articles finally being analysed. Of the 87 articles, 38 were retrospective (43.7%), two prospective (2.3%), six phase I or I/II trials (6.9%), 22 phase ...
Purpose In many cases, the diagnosis of a periprosthetic joint infection (PJI) consisting of the ... more 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...
Background: The impact of titanium nitride (TiN) coating on implant components is controversial. ... more Background: The impact of titanium nitride (TiN) coating on implant components is controversial. TiN coating is proposed as having superior biomechanical properties compared to conventional cobalt-chromium (CoCr) alloy. This study compared long-term clinical data as well as meteoro-sensitivity in patients who underwent total knee arthroplasty (TKA), with either CoCr alloy or TiN coating. Methods: In this retrospective observational study, the clinically approved cemented “low contact stress” (LCS) TKA with conventional CoCr coating, was compared to un-cemented TiN-coated “advanced coated system” (ACS) TKA. Propensity score matching identified comparable patients based on their characteristics in a one-to-one ratio using the nearest-neighbor method. The final cohort comprised 260 knees in each cohort, with a mean follow-up of 10.1 ± 1.0 years for ACS patients and 14.9 ± 3.0 years for the LCS group. Physical examinations, meteoro-sensitivity, and knee scoring were assessed. Results: T...
Purpose Our aim was to assess the outcome with respect to cumulative revision rates of unicompart... more Purpose Our aim was to assess the outcome with respect to cumulative revision rates of unicompartmental knee arthroplasty (UKA) by comparing published literature and arthroplasty registry data. Our hypothesis was that there is a superior outcome of UKA described in dependent clinical studies compared to independent studies or arthroplasty registers. Methods A systematic review of all clinical studies on UKA in the past decade was conducted with the main endpoint revision rate. Revision rate was calculated as “revision per 100 component years (CY)”. The respective data were analysed with regard to a potential difference of the percentage of performed revision surgeries as described in dependent and independent clinical studies. Clinical data were further compared to arthroplasty registers in a systematic search algorithm. Results In total, 48 study cohorts fulfilled our inclusion criteria and revealed 1.11 revisions per 100 CY. This corresponds to a revision rate of 11.1% after 10 ye...
PurposeThe purpose of this study was to provide a matched cohort comparison of clinical and funct... more PurposeThe purpose of this study was to provide a matched cohort comparison of clinical and functional outcome scores, range of motion and quality of life following unicompartmental knee arthroplasty (UKA) or total knee arthroplasty (TKA). The hypothesis was that patients receiving UKA report better results than comparable patients who receive conventional TKA.MethodsClinical and functional results of 35 patients with medial end-stage osteoarthritis who had received a fixed-bearing UKA were compared with the results of 35 matched patients who had received a TKA from the same manufacturer by the same surgeon. Outcome scores were measured before surgery and at final follow-up using Tegner Activity Scale (TAS), range of motion (ROM) and Short Form 36 Health Survey (SF-36). The Knee Society Score (KSS) was assessed at final follow-up. The mean observation period was 2.3 years in both groups.ResultsThe preoperative knee scores had no statistically significant differences between the two ...
The purpose of this study was to provide comprehensive long-term data about sports activity level... more The purpose of this study was to provide comprehensive long-term data about sports activity levels in patients following total knee arthroplasty (TKA) and to determine the impact of pre-operative function, pain and specific performed sports on the results. 236 patients who have undergone TKA for severe osteoarthritis of the knee were asked to provide specific information regarding exercised types of sports before surgery and after at least 10 years following TKA. Pre- and postoperative function and pain were evaluated by the use of Tegner-, WOMAC- and VAS Score. After a mean of 14.9 years, a significant improvement regarding pain and function was observed. Pre-operative Tegner- and WOMAC scores revealed significant positive correlations with the post-operative Tegner-Score. Accordingly, a high percentage of patients (70.9%) stayed actively involved in sports. Nevertheless, the number of performing patients has decreased according to the sports impact. 71.3% continued practising low-...
The purpose of this study was to determine the concentrations of cobalt, chromium, and molybdenum... more The purpose of this study was to determine the concentrations of cobalt, chromium, and molybdenum in the serum of paediatric tumour patients after fixed hinge total knee arthroplasty. Further, these metal ion levels were compared with serum metal ion levels of patients with other orthopaedic devices such as hip and knee prostheses with metal-on-metal or metal-on-polyethylene articulation to find differences between anatomical locations, abrasion characteristics, and bearing surfaces. After an average follow-up of 108 months (range: 67 to 163) of 11 paediatric patients with fixed hinge total knee arthroplasty, the mean concentrations for Co and Cr were significantly increased while Mo was within the limits compared to the upper values from the reference laboratory. Furthermore, these serum concentrations were significantly higher compared to patients with a standard rotating hinge device (P=0.002andP<0.001) and preoperative controls(P<0.001). On the other hand, the serum levels...
Reconstruction with massive bone allograft and autologous vascularised fibula combines the struct... more Reconstruction with massive bone allograft and autologous vascularised fibula combines the structural strength of the allograft and the advantages of fibula’s intrinsic blood supply. We retrospectively analysed the outcome of twelve patients (4 male, 8 female) who received reconstruction with massive bone allograft and autologous vascularised fibula after tumour resection in lower limb. Mean age was 17.8 years (range 11–31 years), with following primaries: Ewing’s sarcoma (n=6), osteosarcoma (n=4), liposarcoma grade 2 (n=1), and adamantinoma (n=1). Mean followup was 38.7 months (median 25.7 months; range 2–88 months). Seven tumours were located in the femur and five in the tibia. The mean length of bone defect was 18.7 cm (range 15–25 cm). None of the grafts had to be removed, but there occurred four fractures, four nonunions, and two infections. Two patients developed donor side complication, in form of flexion deformity of the big toe. The event-free survival rate was 51% at two-y...
Reconstruction of the distal radius following tumour resection is challenging and various techniq... more Reconstruction of the distal radius following tumour resection is challenging and various techniques are recorded. We retrospectively analysed the outcome of five patients (one male and four females) after reconstruction of the distal radius with osteoarticular allograft, following tumour resection. Mean followup was 32 months (range, 4–121). In three of the five patients the dominant limb was affected. Mean bone resection length was 6.5 centimetres (range, 5–11.5). Two grafts developed nonunion, both successfully treated with autologous bone grafting. No infection, graft fracture, or failure occurred. Mean flexion/extension was 38/60 degrees and mean pronation/supination was 77/77 degrees. The mean Mayo wrist score was 84 and the mean DASH score was 8, both representing a good functional result. Therefore we state the notion that osteoarticular allograft reconstruction of distal radius provides good to excellent functional results.
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