@article{SteinertRudertSieker2014, author = {Steinert, Andre F. and Rudert, Maximilian and Sieker, Jakob T.}, title = {"Symptomatic loosening of a total knee arthroplasty caused by a tibial chondrosarcoma - a case report"}, doi = {10.1186/2193-1801-3-308}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-110341}, year = {2014}, abstract = {Premature implant loosening following total knee arthroplasty (TKA) can have several causes. In this article we report on a rare case of a 74 year old male patient suffering tibial component loosening 14 month after primary TKA. The patient did neither have any malignancies nor joint arthroplasty before. Upon clinical examination the range of motion in the diseased knee was painfully restricted to 80° of knee flexion, with the patient increasingly suffering sleeping and resting pain, and also at weight bearing. In standard radiographs, loosening of the TKA due to a large osteolysis at the tibial component was evident. Local computed tomography (CT) of the right knee revealed loosening of the tibial component due to a presumably malign bone tumor. For determination of the final diagnosis a representative biopsy of the tumor was taken by open surgery prior to the tumor resection. Histopathologic evaluation of the biopsy revealed a periprosthetic myxoid chondrosarcoma of the proximal tibia. Pre-operative staging examination included CT scans of lung and abdomen, as well as a bone scintigraphy which revealed no signs of tumor metastasis in the body. Surgical management comprised wide tumor resection and implantation of a hinged tumor knee arthroplasty with replacements of the distal femur and proximal tibia, as well as a patella tendon replacement using a synthetic ligament. Revision surgery was necessary twice due to impaired wound healing and critical soft tissue coverage, and treatment included a gastrocnemius muscle flap with skin mesh graft covering. Unfortunately long-term follow-up examinations could not be obtained, as the patient deceased due to an alveolitis during rehabilitation. In summary, the specifics of this rare case of aseptic TKA loosening, and the unusual circumstances of chondrosarcoma diagnosis and treatment are informative for those providing surgical treatment of similar cases.}, language = {en} } @article{ReichertvonRottkayRothetal.2018, author = {Reichert, Johannes C. and von Rottkay, Eberhard and Roth, Franz and Renz, Tim and Hausmann, Johannes and Kranz, Julius and Rackwitz, Lars and N{\"o}th, Ulrich and Rudert, Maximilian}, title = {A prospective randomized comparison of the minimally invasive direct anterior and the transgluteal approach for primary total hip arthroplasty}, series = {BMC Musculoskeletal Disorders}, volume = {19}, journal = {BMC Musculoskeletal Disorders}, number = {241}, doi = {10.1186/s12891-018-2133-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176072}, year = {2018}, abstract = {Background: The presented prospective randomized controlled single-centre study compares the clinical outcome up to 12 months after total hip arthroplasty using a minimally invasive single-incision direct anterior (DAA) and a direct transgluteal lateral approach. Methods: A total of 123 arthroplasties were evaluated utilizing the Harris Hip Score (HHS), the extra short musculoskeletal functional assessment questionnaire (XSFMA), the Short Form 36 (SF-36) health survey, a Stepwatch™ Activity Monitor (SAM), and a timed 25 m foot walk (T25-FW). Postoperative x-ray images after THA were reviewed to determine inclination and stem positioning. Results: At final follow-up, the XSFMA functional index scores were 10.3 (anterior) and 15.08 (lateral) while the bother index summed up to a score of 15.8 (anterior) and 21.66 (lateral) respectively, thus only differing significantly for the functional index (p = 0.040 and p = 0.056). The SF-36 physical component score (PCS) was 47.49 (anterior) and 42.91 (lateral) while the mental component score (MCS) summed up to 55.0 (anterior) and 56.23 (lateral) with a significant difference evident for the PCS (p = 0.017; p = 0.714). Patients undergoing THA through a DAA undertook a mean of 6402 cycles per day while those who had undergone THA through a transgluteal approach undertook a mean of 5340 cycles per day (p = 0.012). Furthermore, the obtained outcome for the T25-FW with 18.4 s (anterior) and 19.75 s (lateral) and the maximum walking distance (5932 m and 5125 m) differed significantly (p = 0.046 and p = 0.045). The average HHS showed no significant difference equaling 92.4 points in the anterior group and 91.43 in the lateral group (p = 0.477). The radiographic analysis revealed an average cup inclination of 38.6° (anterior) and 40.28° (lateral) without signs of migration. Conclusion: In summary, our outcomes show that after 1 year THA through the direct anterior approach results in a higher patient activity compared to THA utilizing a transgluteal lateral approach while no differences regarding hip function are evident.}, language = {en} } @article{ArnholdtKamawalHorasetal.2020, author = {Arnholdt, J{\"o}rg and Kamawal, Yama and Horas, Konstantin and Holzapfel, Boris M. and Gilbert, Fabian and Ripp, Axel and Rudert, Maximilian and Steinert, Andre F.}, title = {Accurate implant fit and leg alignment after cruciate-retaining patient-specific total knee arthroplasty}, series = {BMC Musculoskeletal Disorders}, volume = {21}, journal = {BMC Musculoskeletal Disorders}, doi = {10.1186/s12891-020-03707-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230012}, year = {2020}, abstract = {Background For improved outcomes in total knee arthroplasty (TKA) correct implant fitting and positioning are crucial. In order to facilitate a best possible implant fitting and positioning patient-specific systems have been developed. However, whether or not these systems allow for better implant fitting and positioning has yet to be elucidated. For this reason, the aim was to analyse the novel patient-specific cruciate retaining knee replacement system iTotal (TM) CR G2 that utilizes custom-made implants and instruments for its ability to facilitate accurate implant fitting and positioning including correction of the hip-knee-ankle angle (HKA). Methods We assessed radiographic results of 106 patients who were treated with the second generation of a patient-specific cruciate retaining knee arthroplasty using iTotal\(^{TM}\) CR G2 (ConforMIS Inc.) for tricompartmental knee osteoarthritis (OA) using custom-made implants and instruments. The implant fit and positioning as well as the correction of the mechanical axis (hip-knee-ankle angle, HKA) and restoration of the joint line were determined using pre- and postoperative radiographic analyses. Results On average, HKA was corrected from 174.4 degrees +/- 4.6 degrees preoperatively to 178.8 degrees +/- 2.2 degrees postoperatively and the coronal femoro-tibial angle was adjusted on average 4.4 degrees. The measured preoperative tibial slope was 5.3 degrees +/- 2.2 degrees (mean +/- SD) and the average postoperative tibial slope was 4.7 degrees +/- 1.1 degrees on lateral views. The joint line was well preserved with an average modified Insall-Salvati index of 1.66 +/- 0.16 pre- and 1.67 +/- 0.16 postoperatively. The overall accuracy of fit of implant components was decent with a measured medial overhang of more than 1 mm (1.33 mm +/- 0.32 mm) in 4 cases only. Further, a lateral overhang of more than 1 mm (1.8 mm +/- 0.63) (measured in the anterior-posterior radiographs) was observed in 11 cases, with none of the 106 patients showing femoral notching. Conclusion The patient-specific iTotal\(^{TM}\) CR G2 total knee replacement system facilitated a proper fitting and positioning of the implant components. Moreover, a good restoration of the leg axis towards neutral alignment was achieved as planned. Nonetheless, further clinical follow-up studies are necessary to validate our findings and to determine the long-term impact of using this patient- specific system.}, language = {en} } @article{RudertHolzapfelJakubietz2011, author = {Rudert, Maximilian and Holzapfel, Boris Michael and Jakubietz, Michael}, title = {Adjuvant Radiotherapy}, series = {Deutsches {\"A}rzteblatt International}, volume = {108}, journal = {Deutsches {\"A}rzteblatt International}, number = {33}, doi = {10.3238/arztebl.2011.0553a}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133571}, pages = {553}, year = {2011}, abstract = {No abstract available.}, language = {en} } @article{StratosScarlatRudert2021, author = {Stratos, Ioannis and Scarlat, Marius M. and Rudert, Maximilian}, title = {Bibliometrics of orthopaedic articles published by authors of Germanophone countries}, series = {International Orthopaedics}, volume = {45}, journal = {International Orthopaedics}, number = {5}, doi = {10.1007/s00264-021-05052-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-266343}, pages = {1121-1124}, year = {2021}, abstract = {No abstract available.}, language = {en} } @article{SeilerEbertRudertetal.2022, author = {Seiler, Jonas and Ebert, Regina and Rudert, Maximilian and Herrmann, Marietta and Leich, Ellen and Weißenberger, Manuela and Horas, Konstantin}, title = {Bone metastases of diverse primary origin frequently express the VDR (vitamin D receptor) and CYP24A1}, series = {Journal of Clinical Medicine}, volume = {11}, journal = {Journal of Clinical Medicine}, number = {21}, issn = {2077-0383}, doi = {10.3390/jcm11216537}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-297377}, year = {2022}, abstract = {Active vitamin D (1,25(OH)2D3) is known to exert direct anti-cancer actions on various malignant tissues through binding to the vitamin D receptor (VDR). These effects have been demonstrated in breast, prostate, renal and thyroid cancers, which all have a high propensity to metastasise to bone. In addition, there is evidence that vitamin D catabolism via 24-hydroxylase (CYP24A1) is altered in tumour cells, thus, reducing local active vitamin D levels in cancer cells. The aim of this study was to assess VDR and CYP24A1 expression in various types of bone metastases by using immunohistochemistry. Overall, a high total VDR protein expression was detected in 59\% of cases (39/66). There was a non-significant trend of high-grade tumours towards the low nuclear VDR expression (p = 0.07). Notably, patients with further distant metastases had a reduced nuclear VDR expression (p = 0.03). Furthermore, a high CYP24A1 expression was detected in 59\% (39/66) of bone metastases. There was a significant positive correlation between nuclear VDR and CYP24A1 expression (p = 0.001). Collectively, the VDR and CYP24A1 were widely expressed in a multitude of bone metastases, pointing to a potential role of vitamin D signalling in cancer progression. This is of high clinical relevance, as vitamin D deficiency is frequent in patients with bone metastases.}, language = {en} } @article{BoelchBarthelGoebeletal.2015, author = {Boelch, Sebastian Philipp and Barthel, Thomas and Goebel, Sascha and Rudert, Maximilian and Plumhoff, Piet}, title = {Calcinosis universalis - a rare case with classical presentation}, series = {Case Reports in Orthopedics}, volume = {2015}, journal = {Case Reports in Orthopedics}, doi = {10.1155/2015/505420}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126300}, pages = {505420}, year = {2015}, abstract = {Juvenile Dermatomyositis (JDM) is a rare autoimmune disease in children and adolescents. In these patients calcinosis might be the most characteristic symptom. However there are only few reported cases of intramuscular calcinosis in Dermatomyositis. We report a case of calcinosis universalis (CU) of the elbow in JDM successfully treated with broaching. The patient, a 24-year-old woman, suffered from a long history of JDM. On examination she presented with a fistula lateral to the olecranon and pain of the right elbow joint. Plain X-rays displayed a diffuse pattern of multiple periarticular, subcutaneous, and intramuscular calcifications. The patient underwent surgery for histological and microbiological sampling as well as broaching. Intraoperatively sinus formation and subfascial hard calcium deposition were found. Due to the risk of collateral tissue damage, incomplete broaching was performed. A local infection with Staphylococcus was diagnosed and treated with antibiotics. On six-week and 30-month follow-up the patient was free of pain and had very good function. Calcifications on standard radiographs had almost resolved entirely. This case report gives a summary on calcinosis in Dermatomyositis and adds a new case of recalcitrant CU to the literature. Broaching surgery proved to be a reliable treatment option in symptomatic calcinosis.}, language = {en} } @article{HolzapfelChhayaMelchelsetal.2013, author = {Holzapfel, Boris Michael and Chhaya, Mohit Prashant and Melchels, Ferry Petrus Wilhelmus and Holzapfel, Nina Pauline and Prodinger, Peter Michael and von Eisenhart-Rothe, R{\"u}diger and Griensven, Martijn van and Schantz, Jan-Thorsten and Rudert, Maximilian and Hutmacher, Dietmar Werner}, title = {Can Bone Tissue Engineering Contribute to Therapy Concepts after Resection of Musculoskeletal Sarcoma?}, series = {Sarcoma}, volume = {2013}, journal = {Sarcoma}, number = {Article ID 153640}, doi = {10.1155/2013/153640}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132465}, pages = {10 p.}, year = {2013}, abstract = {Resection of musculoskeletal sarcoma can result in large bone defects where regeneration is needed in a quantity far beyond the normal potential of self-healing. In many cases, these defects exhibit a limited intrinsic regenerative potential due to an adjuvant therapeutic regimen, seroma, or infection. Therefore, reconstruction of these defects is still one of the most demanding procedures in orthopaedic surgery. The constraints of common treatment strategies have triggered a need for new therapeutic concepts to design and engineer unparalleled structural and functioning bone grafts. To satisfy the need for long-term repair and good clinical outcome, a paradigm shift is needed from methods to replace tissues with inert medical devices to more biological approaches that focus on the repair and reconstruction of tissue structure and function. It is within this context that the field of bone tissue engineering can offer solutions to be implemented into surgical therapy concepts after resection of bone and soft tissue sarcoma. In this paper we will discuss the implementation of tissue engineering concepts into the clinical field of orthopaedic oncology.}, language = {en} } @article{HeinzMellerLuetkensetal.2022, author = {Heinz, Tizian and Meller, Felix and Luetkens, Karsten Sebastian and Horas, Konstantin and Sch{\"a}fer, Thomas and Rudert, Maximilian and Reppenhagen, Stephan and Weißenberger, Manuel}, title = {Can the MRI based AMADEUS score accurately assess pre-surgery chondral defect severity according to the ICRS arthroscopic classification system?}, series = {Journal of Experimental Orthopaedics}, volume = {9}, journal = {Journal of Experimental Orthopaedics}, number = {1}, issn = {2197-1153}, doi = {10.1186/s40634-022-00511-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300781}, year = {2022}, abstract = {Purpose The AMADEUS (Area Measurement And DEpth and Underlying Structures) scoring and grading system has been proposed for the MRI based evaluation of untreated focal chondral defects around the knee. The clinical practicability, its correlation with arthroscopically assessed grading systems (ICRS - International Cartilage Repair Society) and thereby its clinical value in terms of decision making and guiding prognosis was yet to determine. Methods From 2008 to 2019 a total of 89 individuals were indicated for high tibial valgus osteotomy (HTO) due to tibial varus deformity and concomitant chondral defects of the medial compartment of the knee. All patients received a preoperative MRI (1.5 Tesla or 3.0 Tesla) and pre-osteotomy diagnostic arthroscopy. Chondral defects of the medial compartment were scored and graded with the MRI based AMADEUS by three independent raters and compared to arthroscopic defect grading by the ICRS system. Interrater and intrarater reliability as well as correlation analysis with the ICRS classification system were assessed. Results Intraclass correlation coefficients for the various subscores of the AMADEUS showed an overall good to excellent interrater agreement (min: 0.26, max: 0.80). Intrarater agreement turned out to be substantially inferior (min: 0.08, max: 0.53). Spearman correlation revealed an overall moderate correlative association of the AMADEUS subscores with the ICRS classification system, apart from the defect area subscore. Sensitivity of the AMADEUS to accurately identify defect severity according to the ICRS was 0.7 (0.69 for 3.0 Tesla MRI, 0.67 for 1.5 Tesla MRI). The mean AMADEUS grade was 2.60 ± 0.81 and the mean ICRS score 2.90 ± 0.63. Conclusions Overall, the AMADEUS with all its subscores shows moderate correlation with the arthroscopic chondral grading system according to ICRS. This suggests that chondral defect grading by means of the MRI based AMADEUS is well capable of influencing and guiding treatment decisions. Interrater reliability shows overall good agreement.}, language = {en} } @article{KamawalSteinertHolzapfeletal.2016, author = {Kamawal, Yama and Steinert, Andre F and Holzapfel, Boris M and Rudert, Maximilian and Barthel, Thomas}, title = {Case report - calcification of the medial collateral ligament of the knee with simultaneous calcifying tendinitis of the rotator cuff}, series = {BMC Muscoskeletal Disorders}, volume = {17}, journal = {BMC Muscoskeletal Disorders}, number = {283}, doi = {10.1186/s12891-016-1147-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147669}, year = {2016}, abstract = {Calcification of the medial collateral ligament (MCL) of the knee is a very rare disease. We report on a case of a patient with a calcifying lesion within the MCL and simultaneous calcifying tendinitis of the rotator cuff in both shoulders. Case presentation: Calcification of the MCL was diagnosed both via x-ray and magnetic resonance imaging (MRI) and was successfully treated surgically. Calcifying tendinitis of the rotator cuff was successfully treated applying conservative methods. Conclusion: This is the first case report of a patient suffering from both a calcifying lesion within the medial collateral ligament and calcifying tendinitis of the rotator cuff in both shoulders. Clinical symptoms, radio-morphological characteristics and macroscopic features were very similar and therefore it can be postulated that the underlying pathophysiology is the same in both diseases. Our experience suggests that magnetic resonance imaging and x-ray are invaluable tools for the diagnosis of this inflammatory calcifying disease of the ligament, and that surgical repair provides a good outcome if conservative treatment fails. It seems that calcification of the MCL is more likely to require surgery than calcifying tendinitis of the rotator cuff. However, the exact reason for this remains unclear to date.}, language = {en} }