Olaf Hasart

Charité Universitätsmedizin Berlin, Berlín, Berlin, Germany

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Publications (21)23.21 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The microbiological culture of sonicate fluid (SFC) of explanted endoprosthetic components has increased the rate of bacterial isolation in comparison to conventional microbiological methods. However, this creates the problem of interpreting cases of singular bacterial isolation through SFC, while all other microbiological samples remain negative. The aim of this study was to reference these singular positive SFC against, the histological classification of the periprosthetic membrane (PM), and the utilization of multiple SFC (separate sonication of individual endoprosthetic components). In this prospective study we compared the effect of multiple SFC for detection of periprosthetic joint infection (PJI) in patients with total hip revision surgery. All microbiological results were referenced against PM. Of the 102 cases there were 37 cases of PJI. Single SFC achieved the highest sensitivity of all individual parameters with 89% and a specificity of 72%. When multiple SFC were employed the sensitivity and specificity increased to 100%. There was a concordance of 86% between the PM and SFC. SFC achieved the highest sensitivity and it was possible to further improve the sensitivity and specificity when using multiple cultures. Multiple SFC and PM are beneficial to help reference singular bacterial isolations and achieve the diagnosis of PJI. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 9999:1-4, 2013.
    Journal of Orthopaedic Research 07/2013; · 2.88 Impact Factor
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    ABSTRACT: PURPOSE: The aim of this prospective study was to evaluate the diagnostic efficacy of sonicate fluid cultures (SFC) and the histological analysis of the periprosthetic membrane (PM) for the detection of periprosthetic joint infection (PJI). METHODS: The histological samples were evaluated according to the consensus classification of PM as defined by Morawietz and Krenn. All explanted endoprosthesis were subject to sonication. Additionally, a synovial aspiration and microbiological culture of tissue samples were performed for each patient. Twenty three of the 59 patients had an established PJI. RESULTS: Sonication achieved the highest sensitivity out of all diagnostic methods with 91 % and a specificity of 81 %. The PM achieved a sensitivity of 87 % and a specificity of 100 %. In three cases of PJI a pathogen was isolated solely by sonication while all other microbiological methods were negative. In seven cases there was a positive bacterial culture through sonication with negative histology. CONCLUSIONS: Our results show a high correlation between the microbiological and histological results. In our patient group sonication achieved the highest sensitivity out of all diagnostic methods and was more sensitive than conventional microbiological methods.
    International Orthopaedics 03/2013; · 2.32 Impact Factor
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    ABSTRACT: Introduction: The present feasibility study examined the use of an ultrasound-based navigation system (UNS) for reliability of measurement the positions of both the femoral and acetabular components, a prerequisite to adjust the combined anteversion with sufficient accuracy when using a femur-first approach in total hip arthroplasty. Method: Using a UNS, five investigators performed five measurements of the posterior femoral condyles and the anterior pelvic planes (APP) of two cadavers with different body mass index. Deviations in stem and acetabular anteversion resulting from varying acquisition of the respective landmarks were determined relative to the reference measures of anteversion determined in the same cadavers from computed tomography (CT) scans. Here, both a freehand and guided ultrasound measurement methods were used to acquire the posterior femoral condyles. Femoral and acetabular anteversion values were added in order to estimate the combined anteversion of the reconstructed hip. Results: Using an UNS, variations in the freehand technique for the acquisition of the posterior femoral condyles resulted in a mean error in the anteversion of the femoral component of -1.5° (SD 3.4°; -10.8° to 7.0°) while the mean error was -0.9° (SD 3.1°; -7.3° to 10.2°) when the UNS provided additional support to standardize the orientation of the UNS probe. In all cases, UNS navigation enabled to achieve combined anteversion values that fell within a clinically acceptable error range of less than ± 12.5° compared to the CT measures. Conclusion: Our investigations suggest that the anteversion of stem and cup can be measured with accuracy sufficient enough to utilize the concept of combined anteversion using UNS. Hence, the advantage of utilizing UNS's in a femur-first approach is the ability to intraoperatively compensate for deviations from the targeted anteversion of the stem (which is often difficult to control) by adjusting the acetabular anteversion in the final step of the implantation. In doing so, the placement of the components follows the concept of combined anteversion. Avoiding extreme anteversion values of combined anteversion could be an important step towards reducing post-operative complications following total hip arthroplasty (THA).
    Technology and health care: official journal of the European Society for Engineering and Medicine 01/2012; 20(6):535-43. · 0.64 Impact Factor
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    ABSTRACT: This feasibility study investigated the accuracy of anterior pelvic reference plane (APP) registration and acetabular cup orientation in two cadavers with different BMIs. Five observers each registered the APP five times in the 2 cadavers (BMIs: 32 kg/m(2) and 25 kg/m(2)) using an ultrasound-based navigation system. By comparison against the CT-derived reference landmarks, the errors in determining the individual landmarks defining the APP, as well as the resulting errors in the orientation of the APP and the acetabular cup orientation were determined. Across all measurements obtained with the ultrasound navigation system, the errors in rotation and version in determining the APP were 0.5° ± 1.0° and -0.4° ± 2.0°, respectively. The cup abduction and anteversion errors determined from all measurements of the five investigators for both cadavers together were -0.1° ± 1.0° and -0.4° ± 2.7°, respectively. The data further demonstrated a high reproducibility of the measurements for the resulting cup adduction and anteversion angle. Our preliminary results confirm that ultrasound navigation is a highly accurate tool that allows a reproducible registration of the APP and thereby enables accurate and precise intraoperative determination of the acetabular cup orientation also in patients with increased BMI.
    Archives of Orthopaedic and Trauma Surgery 11/2011; 132(4):517-25. · 1.36 Impact Factor
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    ABSTRACT: The purpose of this study was to compare an ultrasound-based navigation system with an imageless navigation system with surface registration in the postoperative acetabular cup position. A prospective randomized controlled study of 2 groups of 40 patients each was performed. In the first group, cup positioning was assisted by an ultrasound-based navigation system, and in the second group, the cup was assisted by imageless navigation system with surface registration. There was significantly more outliers in the imageless navigation group. In addition, there was statistical significance in the anteversion angles and in the anteversion error between the imageless navigation and ultrasound-based navigation groups. Ultrasound-based navigation improves cup positioning in total hip arthroplasty better than an imageless navigation system by reducing the outliers, achieving a higher accuracy of anteversion.
    The Journal of arthroplasty 10/2011; 27(5):687-94. · 1.79 Impact Factor
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    ABSTRACT: The purpose of our study was to develop a simple and reproducible method for calculating post-operative acetabular cup position based upon computed tomographic images. Next, we sought to examine the reliability, objectivity and accuracy of this method. We developed a 3D CT evaluation software based upon Amira® (data visualisation, analysis and modelling software) to calculate the abduction and anteversion of the acetabular cup relative to the APP (anterior pelvic plane). To test the accuracy of the method, we constructed a special phantom pelvic model as the gold standard, in which the acetabulum was mounted at various abduction and anteversion angles that had previously been measured digitally. This phantom was then CT scanned in 12 different cup positions (30° to 50° abduction, 0° to 30° anteversion) and then evaluated using the 3D CT evaluation software. In addition, we also examined the reliability and objectivity of this method in 10 patients following implantation of a hip prosthesis, as a clinical trial. We observed an average accuracy of the 3D CT evaluation software of −0.3° (range −1.4° to 1.3°; SD 0.6°) for abduction and 0.2° (range −1.4° to 1.4°; SD 0.6°) for anteversion compared with the gold standard. Moreover, a high intra -and interindividual agreement in the resulting ICC well above 0.8 for abduction and abduction values in the phantom study and the clinical trial were observed. This study found that the 3D CT evaluation software provides high reliability, objectivity and accuracy. Thus, the 3D CT software is a method that permits very precise evaluation of the post-operative cup position independent of patient positioning or pelvic tilt.
    Technology and health care: official journal of the European Society for Engineering and Medicine 01/2011; 19(3):185-93. · 0.64 Impact Factor
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    ABSTRACT: Navigation of the cup in total hip arthroplasty is well analyzed and shows accurate results, reducing cup outliers of Lewinnek's "safe zone." With regard to the combined anteversion of cup and stem, however, a "new" safe zone with a range of 25° to 50° has been published. The aim of this study was to analyze total anteversion (cup and stem) by postoperative 3D computed tomography in isolated cup navigation cases. In 46 patients, the mean combined anteversion was 34.4° (range, 16.3°-57.3°, SD ± 9.3°) with 10 outliers. The mean cup anteversion was 19.5° (range, 11°-27°, SD ± 3.7°). Regarding Lewinnek's "safe zone" (cup only), we observed 5 outliers. An improvement of technique of stem implantation or navigation may reduce outliers of combined anteversion.
    Orthopedics 10/2010; 33(10 Suppl):48-51. · 1.05 Impact Factor
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    ABSTRACT: Revision of cup and reconstruction of original center of rotation. High primary and secondary stability. Prevention of additional bone loss. Osseous defects at the anterior-cranial, cranial and posterior-cranial rim of acetabulum. Larger cavitary, medial or oval defects (Paprosky IIb-IIIb). Segmental defects (anterior column up to half of host bone, posterior column up to one third of host bone). Infection of total hip arthroplasty. Pelvic discontinuity (Paprosky IV). Exposure of acetabulum and detection of defects. Complete removal of soft tissue from acetabulum, reaming of sclerotic bone, if necessary. Adaptation of trial augments to close an oval defect to a round defect and to reach an uncontained defect, respectively. Adaptation of trial cup. In case of sufficient stability, fixation of final augment with two or three screws in cranial bone stock. The screws should be directed to iliosacral joint. Augmentation with allogenic bone chips is possible in the region of wedge and acetabulum as well. Sealing of rough augment surface with bone cement. Implantation of cup, fixation with screws. Application of insert. Depending on bone defects, full weight bearing is possible. In cases of severe bone defects, reduction of weight bearing to 20 kg for 6 weeks is recommended. Postoperative physiotherapy is possible in most cases. Between 2005 and 2007, 38 patients with acetabular defects type IIIa und IIIb according to Paprosky underwent reconstruction using the TMT system (Trabecular Metal Technology). After 25 months, a significant functional improvement was seen in all patients. The Merle d'Aubigné Score increased from 6 points preoperatively to 13 points postoperatively, the Harris Hip Score from 29 to 78 points. Two revisions were necessary because of loosening or migration of the cup.
    Operative Orthopädie und Traumatologie 07/2010; 22(3):268-77. · 0.47 Impact Factor
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    ABSTRACT: Precise identification of bony landmarks by use of pointer based navigation systems is influenced by thickness of soft tissue. Ultrasound-based navigation systems try to overcome the problems of positional deviation associated with soft tissue. The aim of the study was to investigate the influence of the BMI and the thickness of the soft tissue on the post-operative cup position and accuracy in the application of an ultrasound-based (US CAOS) and a pointer-based navigation system (P CAOS). 82 patients received a hip replacement in minimally invasive surgery in two cohorts: US CAOS group: using ultrasound navigation (n = 39) and P CAOS group: using a pointer-based navigation (n = 43). There was a significant difference in anteversion and anteversion error between the groups. In addition, we observed a significant correlation between the thickness of the presymphysial soft tissue and the anteversion error in both groups. We also detected a significant correlation between the anteversion error and the BMI in both groups. However, the absolute error in anteversion with increasing thickness of the soft tissue layer was slighter in the ultrasound-based group compared to pointer-based navigation. The accuracy of the ultrasound-based and pointer-based navigation systems are influenced by the BMI and the thickness of the soft tissue layer above the symphysis. However, ultrasound-based navigation seems to have advantages with thicker soft tissue layers, as seen in overweight and obese patients.
    Technology and health care: official journal of the European Society for Engineering and Medicine 01/2010; 18(4-5):341-51. · 0.64 Impact Factor
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    ABSTRACT: The reorientation of the acetabular component in total hip replacement is currently carried out under consideration of the safe zone, respecting the best possible range of motion and is influenced by wear debris of different bearings. Is the preferred orientation a reconstruction of the native anatomy and are there sex-specific differences? On the basis of 168 CT datasets (72 women, 96 men) 336 native hip joints were analysed. The abduction and anteversion of the acetabulum as well as the location of the hip center were detected. As a reference the anterior pelvic plane was used. The 144 female hip joints showed a mean abduction of 53.0 degrees (SD 6.14 degrees ) and an anteversion of 24.63 degrees (SD 6.61 degrees ). The 192 male hip joints showed an abduction of 53.58 degrees (SD 6.68 degrees ) and an anteversion of 21.31 degrees (SD 6.17 degrees ). Significant differences were observed on comparison between the sexes in relation to the anteversion and the location of the hip center. Likewise, there was a significant correlation between the position of the hip center and the degree of anteversion. In total hip arthroplasty a reconstruction of the native acetabular orientation is not possible, gender specific characteristics should be considered.
    Technology and health care: official journal of the European Society for Engineering and Medicine 01/2010; 18(2):129-36. · 0.64 Impact Factor
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    ABSTRACT: Intraoperative landmarks are used in image-free navigation systems. The ultrasound-based navigation systems try to overcome the problems of positional deviation associated with soft tissue. Our study analyzed the accuracy of ultrasound-based navigation of cup positioning compared with postoperative 3-dimensional (3D) computed tomography scans of cup positioning. Twenty-five ultrasound-navigated total hip arthroplasties (THAs) were analyzed. The difference between the intraoperative cup orientation (navigation) and the postoperative cup position (CT) was evaluated. The average difference between intraoperative navigation and postoperative CT measurements was 2.8 degrees (SD+/-1.8 degrees ) for abduction and 2.2 degrees (SD+/-1.6 degrees ) for anteversion. Therefore, we recommend ultrasound-based navigation as an exact tool for cup positioning in THA.
    Orthopedics 10/2009; 32(10 Suppl):6-10. · 1.05 Impact Factor
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    ABSTRACT: The distinction between aseptic and septic loosening of a total hip arthroplasty is a diagnostic challenge. Therapy and clinical success depend on the correct diagnosis. Histopathological evaluation of the periprosthetic interface membrane is one possible diagnostic parameter; detailed analysis of tissue characteristics may reflect the cause of failure. This study evaluated the diagnostic value of a published histopathological consensus classification for the periprosthetic interface membrane in the identification of periprosthetic joint infection (PJI). Between 2004 and 2008, a prospective analysis was performed in 106 patients who had revisions because of assumed PJI. Based on clinical presentation, radiography, and haematological screening, infection was assumed, and a joint aspiration was performed. Based on these findings, a two-stage revision was performed, with intraoperative samples for culture and histological evaluation obtained. Final diagnosis of infection was based on the interpretation of the clinical presentation and the preoperative and intraoperative findings. The basis for histopathological evaluation was the consensus classification for the periprosthetic interface membrane. Sensitivity, specificity, and accuracy were calculated for each parameter. In 92 patients, a positive diagnosis of PJI could be made. Histopathology yielded the highest accuracy (0.93) in identification of PJI, identifying 86 of 92 infections (69 type II, 17 type III). In 13 of the 14 noninfected hips, histopathology correlated in 13 (93%) cases (10 type I, three type IV). The accuracies of microbiological culture, C-reactive protein, and aspiration were 0.82, 0.86, and 0.54, respectively. In the diagnosis of PJI, histopathological evaluation of the periprosthetic interface membrane proved very effective. To analyse the cause of prosthesis loosening, tissue samples of the periprosthetic interface membrane should be evaluated on the basis of the consensus classification in all revision surgeries.
    Der Orthopäde 09/2009; 38(11):1087-96. · 0.51 Impact Factor
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    ABSTRACT: The use of navigation techniques in primary total hip arthroplasty improves the position of endoprosthetic components, especially cup positioning. An intraoperative registration of the anterior pelvic plane is necessary to define the anteversion and inclination angles on the acetabular side. This study compares the accuracy of manual pointer palpation to ultrasound registration in navigation to determine pelvic plane registration in 60 cases of minimally invasive surgical technique. Findings show more accurate postoperative radiographic anteversion with ultrasound navigation, although both manual pointer palpation and ultrasound registration techniques show a very small standard deviation in anteversion, inclination, and leg length difference. In conclusion, we recommend navigation as a very reliable tool for the positioning of implants.
    Orthopedics 11/2008; 31(10 Suppl 1). · 1.05 Impact Factor
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    ABSTRACT: The correct diagnosis of a prosthetic joint infection (PJI) is crucial for adequate surgical treatment. The detection may be a challenge since presentation and preoperative tests are not always obvious and precise. This prospective study was performed to evaluate a variety of pre- and intraoperative investigations. Furthermore a detailed evaluation of concordance of each preoperative diagnosis was performed, together with a final diagnosis to assess the accuracy of the pre-operative assumption of PJI. Between 01/2005 and 02/2007, a prospective analysis was performed in 50 patients, who had a two stage revision because of assumed PJI. Based on clinical presentation, radiography, haematological screening, or early failure, infection was assumed and a joint aspiration was performed. Depending upon these findings, a two stage revision was performed, with intra-operative samples for culture and histological evaluation obtained. Final diagnosis of infection was based upon the interpretation of the clinical presentation and the pre- and intraoperative findings. In 37 patients a positive diagnosis of PJI could be made definitely. The histopathology yielded the highest accuracy (0.94) in identification of PJI and identified 35 of 37 infections (sensitivity 0.94, specificity 0.94, positive-/negative predictive value 0.97/0.86). Intra-operative cultures revealed sensitivities, specificities, positive-/negative predictive values and accuracy of 0.78, 0.92, 0.96, 0.63 and 0.82. These values for blood screening tests were 0.95, 0.62, 0.88, 0.80, and 0.86 respectively for the level of C-reactive protein, and 0.14, 0.92, 0.83, 0.29 and, 0.34 respectively for the white blood-cell count. The results of aspiration were 0.57, 0.5, 0.78, 0.29, and 0.54. The detection of PJI is still a challenge in clinical practice. The histopathological evaluation emerges as a highly practical diagnostic tool in detection of PJI. Furthermore, we found a discrepancy between the pre-operative suspicion of PJI and the final post-operative diagnosis, resulting in a slight uncertainty in whether loosening is due to bacterial infection or not. The variation in accuracy of the single tests may influence the detection of PJI. Level of Evidence: Diagnostic Level I.
    Journal of Orthopaedic Surgery and Research 01/2008; 3:31. · 1.01 Impact Factor
  • K Labs, O Hasart, C Perka
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    ABSTRACT: Revision surgery after failed anterior cruciate ligament reconstructions has increased tremendously. Reasons for revisions are persistent loss of motion, recurrent joint laxity, a painful knee or joint infections. In a retrospective study with a mean follow-up of 35.2 months 82 patients were examined after revision surgery. Time interval between primary and revision surgery, causes of revisions and treatment modalities were evaluated and compared to subjective, clinical and radiological parameters. In all cases a clinical improvement could be achieved. But results after revision operations are inferior to first reconstructions. The mean Tegner score improved after revision surgery from 2.4 to 4.6 points. The mean Lysholm score increased after secondary surgery from 54 to 76 points. The overall IKDC results of follow-up showed category A - 35.4 %, B - 39 %, C - 13.4 % and D - 12.2 % of the patients. A distinction between patients with preoperative isolated loss of motion and patients with isolated joint laxity seems useful. Revision operations with an improvement of joint mobility showed a higher subjective satisfaction, a lower rate of joint instability and better overall IKDC result compared to those with a high grade of preoperative joint laxity. Better results could be also achieved for early revision compared to late revisions and also for autologous grafts compared to alloplastic revision plasty. Transplant retaining procedures are only possible in selected cases and showed no clinical benefit compared to second revision of cruciate replacements. As a result of this study we conclude that early revision operation and the use of an autologous graft can be recommended but the surgeon has to be prepared to encounter many demanding technical problems.
    Zentralblatt für Chirurgie 11/2002; 127(10):861-7. · 0.69 Impact Factor
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    ABSTRACT: Low-grade bone infection represents a serious clinical problem. Diagnostic options are often insufficient, yet the therapeutic implications of proven disease are important, especially in patients with prosthetic joint replacement. Technetium-99m labelled monoclonal anti-NCA-90 granulocyte antibody Fab' fragment (MN3 Fab') has been shown to be useful in bone and joint infection, but there are no data specifically referring to low-grade bone infection. We therefore analysed 38 scans in 30 consecutive patients (age range, 30-85 years; median age, 62 years) referred for suspected low-grade bone infection. There were 17 patients (21 scans) with total hip arthroplasty (THA), six with total knee arthroplasty (TKA), three who had undergone hip or knee surgery for trauma and five (seven scans) with resected hips and no endoprostheses (Girdlestone situations); one of these five patients had been investigated before with THA in situ and another prior to surgery for low-grade coxitis. There were no patients with rheumatoid arthritis as the underlying disease. Results were verified by means of bacteriological cultures, histopathological findings and/or follow-up and compared with the respective Zimmerli scores, which were used for clinical assessment of inflammatory activity. In one patient, the final diagnosis could not be established. One, 5 and 24 h after intravenous injection of up to 1.1 GBq of MN3 Fab', whole-body and planar scans were performed using a dual-head gamma camera. Scans were analysed visually and semiquantitatively adopting an arbitrary score ranging from 0 to 3. There were 13 true positive, 14 true negative and 10 false positive outcomes, yielding an overall sensitivity of 100%, an overall specificity of 58%, an accuracy of 73% and positive and negative predictive values of 57% and 100%, respectively. In patients with THA or TKA, accuracy was 81% and 80%, respectively, while it dropped to 43% in patients with Girdlestone situations owing to a high proportion of false positive findings (4/7) in this subgroup. Scintigraphic score was 1 in all of the false positive and in 11/13 true positive findings. The two remaining true positive findings displayed scintigraphic scores of 2 and 3, respectively. Scintigraphic and Zimmerli scores were loosely correlated (Spearman rho=0.38, P<0.05). Infection was excluded in 22/24 investigations with Zimmerli scores of <6. In this group, there were 13 scintigraphically true negative, nine false positive outcomes, and just two true positive outcomes. In 11/12 investigations with Zimmerli scores of 6 or 7, infection was verified and scintigraphic outcome was accordingly true positive, while the remaining patient was true negative. In conclusion, MN3 Fab' scintigraphy proved to be highly sensitive but not specific in diagnosing low-grade infections of the hip and knee regions in patients with previous joint surgery. The method seems reliable in excluding but not in proving the presence of infection. MN3 Fab' scintigraphy should not be applied in patients with Girdlestone situations. Assessment of infection using the Zimmerli score was more reliable than MN3 Fab' scintigraphy in this group of patients without rheumatoid arthritis as the underlying disease. Considering results from the literature concerning leucocyte scintigraphy, MN3 Fab' scintigraphy may be clinically useful in evaluating low-grade bone infection in THA and TKA patients with Zimmerli scores above 5 and concomitant rheumatoid arthritis or other inflammatory diseases.
    European journal of nuclear medicine and molecular imaging 05/2002; 29(4):547-51. · 5.11 Impact Factor
  • Zeitschrift Fur Orthopadie Und Ihre Grenzgebiete - Z ORTHOP GRENZGEB. 01/2002; 140(3):323-327.
  • K. Labs, O. Hasart, C. Perka
    Zentralblatt Fur Chirurgie - ZBL CHIR. 01/2002; 127(10):861-867.
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    ABSTRACT: In total hip arthroplasty, an optimal cup orientation is essential to avoid dislocations. Computer assisted systems provide the surgeon with the intra-operative cup orientation. However, these systems rely on the palpation of the anterior pelvic plane, and are thereby prone to the palpation error of this plane. As this error is directly linked to the soft tissue overlying the pelvic landmarks, we developed a navigated ultrasound system to acquire the anterior pelvic plane. 5 operators acquired 5 times the anterior pelvic plane of 2 female cadavers. After a learning curve, the acquisition of the plane took approximately 90 seconds. Compared to the anterior pelvic plane measured on the CT-scan, the mean rotation error was less than 0.5°, with a standard deviation of less than 1.2°. The mean version error was -1.2°, and the standard deviation remained below 1.9°. Our results confirm that navigated ultrasound is a very accurate tool to acquire the anterior pelvic plane and thereby allow an accurate navigation of total hip arthroplasty.
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    ABSTRACT: HintergrundDie Unterscheidung zwischen aseptischer und septischer Hüftendoprothesenlockerung ist für therapeutisches Vorgehen und Erfolgsaussicht von grundlegender Bedeutung und erweist sich häufig als diagnostische Herausforderung. Ein wesentlicher Diagnoseparameter ist die histopathologische Klassifikation periprothetischer Lockerungsmembranen. Anhand charakteristischer Gewebestrukturen können Rückschlüsse über Lockerungsursachen gestellt werden. Ziel dieser Arbeit ist es, mit Hilfe der Konsensusklassifikation den Stellenwert der histopathologischen Gewebeuntersuchung in der Identifizierung von Hüftendoprotheseninfektionen zu untersuchen und nach Möglichkeit als ein Standardverfahren zu etablieren. MethodenEs wurden 106Patienten mit hochgradigem präoperativen Verdacht einer Hüftendoprotheseninfektion einer Revisionsoperation unterzogen. Die Verdachtsdiagnose wurde anhand von anamnestischen, klinischen und radiologischen Auffälligkeiten sowie nach Laboruntersuchungen und Hüftpunktion erhoben. Eine definitive Diagnose ist nach Hinzuziehung eines intraoperativen Keimnachweises und einer histopathologischen Evaluierung entsprechend der Klassifikation der periprothetischen Membranen gestellt worden. Sensitivität, Spezifität und Genauigkeit wurden anschließend für jeden Untersuchungsparameter berechnet. ErgebnisseBei 92 der 106Patienten lag nachweislich eine Hüftendoprotheseninfektion vor, wobei in 86 (93,5%) Fällen die Histopathologie korrelierte (69-mal TypII, 17-mal TypIII). Bei den 14 nichtinfizierten Fällen korrelierte der histopathologische Befund in 13Fällen (93%; 10-mal TypI, 3-mal TypIV). Die Sensitivität lag bei 0,94, die Spezifität bei 0,93 und die Genauigkeit bei 0,93. Mikrobiologischer Keimnachweis und das C-reaktive Protein erwiesen sich ebenfalls als valide Parameter. Klinische radiologische Auffälligkeiten als auch die Hüftpunktion waren weniger sensitiv. Häufigste Erreger waren KNS (n=27) und Staphylococcus aureus (n=21). SchlussfolgerungDie histopathologische Begutachtung erweist sich als ein hervorragender Parameter in der Diagnose der periprothetischen Gelenkinfektion und sollte aufgrund hoher Genauigkeit standardmäßig bei jeder Revisionsoperation hinzugezogen werden. Bei allen Gewebeeinsendungen sollte zur Frage einer infektiös bedingten Entzündung Stellung genommen werden und eine Zuordnung der periprothetischen Membran entsprechend der Konsensusklassifikation erfolgen. BackgroundThe distinction between aseptic and septic loosening of a total hip arthroplasty is a diagnostic challenge. Therapy and clinical success depend on the correct diagnosis. Histopathological evaluation of the periprosthetic interface membrane is one possible diagnostic parameter; detailed analysis of tissue characteristics may reflect the cause of failure. This study evaluated the diagnostic value of a published histopathological consensus classification for the periprosthetic interface membrane in the identification of periprosthetic joint infection (PJI). MethodsBetween 2004 and 2008, a prospective analysis was performed in 106patients who had revisions because of assumed PJI. Based on clinical presentation, radiography, and haematological screening, infection was assumed, and a joint aspiration was performed. Based on these findings, a two-stage revision was performed, with intraoperative samples for culture and histological evaluation obtained. Final diagnosis of infection was based on the interpretation of the clinical presentation and the preoperative and intraoperative findings. The basis for histopathological evaluation was the consensus classification for the periprosthetic interface membrane. Sensitivity, specificity, and accuracy were calculated for each parameter. ResultsIn 92 patients, a positive diagnosis of PJI could be made. Histopathology yielded the highest accuracy (0.93) in identification of PJI, identifying 86 of 92 infections (69type II, 17 typeIII). In 13 of the 14 noninfected hips, histopathology correlated in 13 (93%) cases (10typeI, three typeIV). The accuracies of microbiological culture, C-reactive protein, and aspiration were 0.82, 0.86, and 0.54, respectively. ConclusionIn the diagnosis of PJI, histopathological evaluation of the periprosthetic interface membrane proved very effective. To analyse the cause of prosthesis loosening, tissue samples of the periprosthetic interface membrane should be evaluated on the basis of the consensus classification in all revision surgeries.
    Der Orthopäde 38(11):1087-1096. · 0.51 Impact Factor

Publication Stats

91 Citations
23.21 Total Impact Points

Institutions

  • 2008–2011
    • Charité Universitätsmedizin Berlin
      • • Center of Space Medicine Berlin (ZWMB)
      • • Medical Department, Division of Rheumatology and Clinical Immunology
      Berlín, Berlin, Germany
  • 2002
    • Humboldt-Universität zu Berlin
      • Department of Psychology
      Berlin, Land Berlin, Germany