TY - JOUR A1 - Jansen, Hendrik A1 - Heintel, Timo M. A1 - Jordan, Martin A1 - Meffert, Rainer H. A1 - Frey, Soenke P. T1 - Survived traumatic hemipelvectomy with salvage of the limb in a 14  months old toddler JF - Trauma Case Reports N2 - We report on a 14 months old toddler who sustained a traumatic hemipelvectomy by being crushed between a car and a stone wall. After stabilization in the resuscitation room he was treated operatively by laparotomy, osteosynthesis of the pelvic ring, reconstruction of the both external iliac vessels and the urethra and reposition of the testicles. After 66 days he was discharged into rehabilitation. Implants were removed after eight months. 20 months after the injury, the leg was plegic, initial radiological signs of femoral head necrosis showed up but the infant was able to walk with an orthesis and a walker. Up to our knowledge, this is the youngest patient described in the literature with a survived traumatic hemipelvectomy and salvaged limb. KW - Hemipelvectomy KW - Survival KW - Limb salvage KW - Toddler Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202207 VL - 22 ER - TY - JOUR A1 - Jordan, Martin C. A1 - Hufnagel, Lukas A1 - McDonogh, Miriam A1 - Paul, Mila M. A1 - Schmalzl, Jonas A1 - Kupczyk, Eva A1 - Jansen, Hendrik A1 - Heilig, Philipp A1 - Meffert, Rainer H. A1 - Hoelscher-Doht, Stefanie T1 - Surgical fixation of calcaneal beak fractures — biomechanical analysis of different osteosynthesis techniques JF - Frontiers in Bioengineering and Biotechnology N2 - The calcaneal beak fracture is a rare avulsion fracture of the tuber calcanei characterized by a solid bony fragment at the Achilles tendon insertion. Treatment usually requires osteosynthesis. However, lack of biomechanical understanding of the ideal fixation technique persists. A beak fracture was simulated in synthetic bones and assigned to five different groups of fixation: A) 6.5-mm partial threaded cannulated screws, B) 4.0-mm partial threaded cannulated screws, C) 5.0-mm headless cannulated compression screws, D) 2.3-mm locking plate, and E) 2.8-mm locking plate. Different traction force levels were applied through an Achilles tendon surrogate in a material-testing machine on all stabilized synthetic bones. Outcome measures were peak-to-peak displacement, total displacement, plastic deformation, stiffness, visual-fracture-line displacement, and mode of implant failure. The 2.3- and 2.8-mm plating groups showed a high drop-out rate at 100 N tension force and failed under higher tension levels of 200 N. The fracture fixation using 4.0-mm partial threaded screws showed a significantly higher repair strength and was able to withhold cyclic loading up to 300 N. The lowest peak-to-peak displacement and the highest load-to-failure and stiffness were provided by fracture fixation using 6.5-mm partial threaded cannulated screws or 5.0-mm headless cannulated compression screws. As anticipated, large 6.5-mm screw diameters provide the best biomechanical fixation. Surprisingly, the 5.0-mm headless cannulated compression screws yield reliable stability despite the absent screw head and washer. When such large screws cannot be applied, 4.0-mm screws also allow reasonable fixation strength. Plate fixation should be implemented with precaution and in combination with a restrictive postoperative motion protocol. Finally, clinical cases about the surgical application and recovery are included. KW - foot KW - ankle KW - Achilles KW - tendon KW - fracture Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-282792 SN - 2296-4185 VL - 10 ER - TY - JOUR A1 - Bauer, Maria A1 - Opitz, Anne A1 - Filser, Jörg A1 - Jansen, Hendrik A1 - Meffert, Rainer H. A1 - Germer, Christoph T. A1 - Roewer, Norbert A1 - Muellenbach, Ralf M. A1 - Kredel, Markus T1 - Perioperative redistribution of regional ventilation and pulmonary function: a prospective observational study in two cohorts of patients at risk for postoperative pulmonary complications JF - BMC Anesthesiology N2 - Background Postoperative pulmonary complications (PPCs) increase morbidity and mortality of surgical patients, duration of hospital stay and costs. Postoperative atelectasis of dorsal lung regions as a common PPC has been described before, but its clinical relevance is insufficiently examined. Pulmonary electrical impedance tomography (EIT) enables the bedside visualization of regional ventilation in real-time within a transversal section of the lung. Dorsal atelectasis or effusions might cause a ventral redistribution of ventilation. We hypothesized the existence of ventral redistribution in spontaneously breathing patients during their recovery from abdominal and peripheral surgery and that vital capacity is reduced if regional ventilation shifts to ventral lung regions. Methods This prospective observational study included 69 adult patients undergoing elective surgery with an expected intermediate or high risk for PPCs. Patients undergoing abdominal and peripheral surgery were recruited to obtain groups of equal size. Patients received general anesthesia with and without additional regional anesthesia. On the preoperative, the first and the third postoperative day, EIT was performed at rest and during spirometry (forced breathing). The center of ventilation in dorso-ventral direction (COVy) was calculated. Results Both groups received intraoperative low tidal volume ventilation. Postoperative ventral redistribution of ventilation (forced breathing COVy; preoperative: 16.5 (16.0–17.3); first day: 17.8 (16.9–18.2), p < 0.004; third day: 17.4 (16.2–18.2), p = 0.020) and decreased forced vital capacity in percentage of predicted values (FVC%predicted) (median: 93, 58, 64%, respectively) persisted after abdominal surgery. In addition, dorsal to ventral shift was associated with a decrease of the FVC%predicted on the third postoperative day (r = − 0.66; p < 0.001). A redistribution of pulmonary ventilation was not observed after peripheral surgery. FVC%predicted was only decreased on the first postoperative day (median FVC%predicted on the preoperative, first and third day: 85, 81 and 88%, respectively). In ten patients occurred pulmonary complications after abdominal surgery also in two patients after peripheral surgery. Conclusions After abdominal surgery ventral redistribution of ventilation persisted up to the third postoperative day and was associated with decreased vital capacity. The peripheral surgery group showed only minor changes in vital capacity, suggesting a role of the location of surgery for postoperative redistribution of pulmonary ventilation. KW - Electrical impedance tomography KW - General anaesthesia KW - Postoperative complications KW - Pulmonary function tests Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200730 VL - 19 ER - TY - JOUR A1 - Frey, Sönke Percy A1 - Jansen, Hendrik A1 - Doht, Stefanie A1 - Filgueira, Luis A1 - Zellweger, Rene T1 - Immunohistochemical and Molecular Characterization of the Human Periosteum JF - The Scientific World Journal N2 - Purpose. The aim of the present study was to characterize the cell of the human periosteum using immunohistological and molecular methods. Methods. Phenotypic properties and the distribution of the cells within the different layers were investigated with immunohistochemical staining techniques and RT-PCR, focussing on markers for stromal stem cells, osteoblasts, osteoclasts and immune cells. Results. Immunohistochemical results revealed that all stained cells were located in the cambium layer and that most cells were positive for vimentin. The majority of cells consisted of stromal stem cells and osteoblastic precursor cells. The density increased towards the deeper layers of the cambium. In addition, cells positive for markers of the osteoblast, chondrocyte, and osteoclast lineages were found. Interestingly, there were MHC class II-expressing immune cells suggesting the presence of dendritic cells. Using lineage-specific primer pairs RT-PCR confirmed the immunofluorescence microscopy results, supporting that human periosteum serves as a reservoir of stromal stem cells, as well as cells of the osteoblastic, and the chondroblastic lineage, osteoclasts, and dendritic cells. Conclusion. Our work elucidates the role of periosteum as a source of cells with a high regenerative capacity. Undifferentiated stromal stem cells as well as osteoblastic precursor cells are dominating in the cambium layer. A new outlook is given towards an immune response coming from the periosteum as MHC II positive immune cells were detected. KW - Medizin Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96623 ER - TY - JOUR A1 - Jordan, Martin C. A1 - Jäckle, Veronika A1 - Scheidt, Sebastian A1 - Eden, Lars A1 - Gilbert, Fabian A1 - Heintel, Timo M. A1 - Jansen, Hendrik A1 - Meffert, Rainer H. T1 - Ergebnisse nach Plattenstabilisierung der Symphysensprengung JF - Der Unfallchirurg N2 - Hintergrund Die Symphysensprengung mit entsprechender Diastase kann durch eine Symphysenplatte stabilisiert werden. Fragestellung Welche Beckenverletzungen werden mit einer Symphysenplatte stabilisiert und wie ist das Outcome? Material und Methoden Retrospektive Auswertung von 64 Patienten über einen Untersuchungszeitraum von 24 Monaten. Ergebnisse Es waren 56 Patienten männlich, 8 weiblich und das mittlere Alter betrug 44 Jahre (SD ± 17). Unfälle im Straßenverkehr waren der führende Grund für die Beckenverletzung. Die Verteilung nach AO-Klassifikation zeigte sich wie folgt: 14-mal B1-, 10-mal B2-, 5‑mal B3-, 23-mal C1-, 9‑mal C2- und 3‑mal C3-Verletzungen. Die Verteilung nach Young und Burgess ergab: 9‑mal APC-I-, 18-mal APC-II-, 13-mal APC-III-, 9‑mal LC-I-, 3‑mal LC-II-, 2‑mal LC-III- und 10-mal VS-Verletzungen. Der mittlere Injury Severity Score (ISS) betrug 32 und die mittlere stationäre Verweildauer 29 Tage (pos. Korrelation p ≤ 0,001). Im Verlauf war eine radiologische Implantatlockerung bei 52 Patienten nachweisbar. Therapierelevante Komplikationen gab es in 14 Fällen. Hierbei war das Implantatversagen (n = 8) der Hauptgrund für eine operative Revision. Diskussion Obwohl die radiologische Implantatlockerung häufig beobachtet wird, ist sie nur selten Grund für einen Revisionseingriff. Kommt es hingegen zum vollständigen Implantatversagen, tritt dies meist innerhalb der ersten postoperativen Wochen auf und ist revisionsbedürftig. Eine frühzeitige Abklärung durch Röntgenbildgebung sollte bei Verdacht erfolgen. N2 - Background Separation of the pubic symphysis with corresponding diastasis can be stabilized by symphyseal plating. Objective Which pelvic injuries are stabilized with symphyseal plating and what is their outcome? Material and methods A retrospective evaluation of 64 patients who underwent symphyseal plating over a period of 24 months was conducted. Results Of the patients 56 were male and 8 female with a mean age of 44 years (SD ± 17 years). The main cause of the pelvic injuries were traffic accidents. The distribution according to the AO fracture classification was 14 × B1, 10 × B2, 5 × B3, 23 × C1, 9 × C2 and 3 × C3 injuries. The distribution according to the Young and Burgess classification showed 9 × APC I, 18 × APC II, 13 × APC III, 9 × LC I, 3 × LC II, 2 × LC III and 10 × VS injuries. The mean Injury Severity Score (ISS) was 32 (SD ± 17) and the mean inpatient stay was 29 days (SD ± 16 days; positive correlation p ≤ 0.001). Radiological implant loosening occurred in 52 patients. 14 patients required treatment for severe complications. The leading reason for revision surgery was implant failure (n = 8). Conclusion These observations suggest that radiological signs of implant loosening are commonly observed but rarely the reason for revision surgery. Complete implant failures, however; occur mainly within the first postoperative weeks and require early revision. A timely clarification by additional X-ray imaging should be carried out if this is suspected. KW - Beckenring KW - Beckenfraktur KW - AO KW - Fixation KW - Trauma KW - pelvic ring KW - pelciv fracture KW - AO KW - fixation KW - trauma Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232447 SN - 0177-5537 VL - 123 ER - TY - JOUR A1 - Jordan, Martin C. A1 - Jansen, Hendrik A1 - Meffert, Rainer H. A1 - Heintel, Timo M. T1 - Comparing porous tantalum fusion implants and iliac crest bone grafts for spondylodesis of thoracolumbar burst fractures: Prospectice Cohort study JF - Scientific Reports N2 - The aim of this study was to compare two different techniques of performing one-level spondylodesis for thoracolumbar burst fractures using either an autologous iliac crest bone graft (ICBG) or a porous tantalum fusion implant (PTFI). In a prospective nonrandomized study, 44 patients (20 women, 24 men; average age 43.1 +/- 13.2 years) suffering from severe thoracolumbar burst fractures were treated with combined anterior-posterior stabilization. An ICBG was used in 21 cases, and a PTFI was used in the other 23 cases. A two-year clinical and radiographic follow-up was carried out. There were no statistically significant differences in age, sex, localization/classification of the fracture, or visual analog scale (VAS) before injury between the two groups. All 44 patients were followed up for an average period of 533 days (range 173-1567). The sagittal spinal profile was restored by an average of 11.1 degrees (ICBG) vs. 14.3 degrees (PTFI) (monosegmental Cobb angle). Loss of correction until the last follow-up tended to be higher in the patients treated with ICBG than in those treated with PTFI (mean: 2.8 degrees vs. 1.6 degrees). Furthermore, significantly better restoration of the sagittal profile was obtained with the PTFI than with the iliac bone graft at the long-term follow-up (mean: ICBG 7.8 degrees, PTFI 12.3 degrees; p < 0.005). Short-segment posterior instrumentation combined with anterior one-level spondylodesis using either an ICBG or a PTFI resulted in sufficient correction of posttraumatic segmental kyphosis. PTFI might be a good alternative for autologous bone grafting and prevent donor site morbidities. KW - fracture repair KW - musculoskeletal system Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-261706 VL - 11 IS - 1 ER - TY - JOUR A1 - Jordan, Martin C. A1 - Hoelscher-Doht, Stefanie A1 - Fehske, Kai A1 - Gilbert, Fabian A1 - Jansen, Hendrik A1 - Meffert, Rainer H. T1 - Bunnell or cross-lock Bunnell suture for tendon repair? Defining the biomechanical role of suture pretension JF - Journal of Orthopaedic Surgery and Research N2 - Background Suture pretension during tendon repair is supposed to increase the resistance to gap formation. However, its effects on the Bunnell suture technique are unknown. The purpose of this study was to determine the biomechanical effects of suture pretension on the Bunnell and cross-lock Bunnell techniques for tendon repair. Methods Eighty porcine hindlimb tendons were randomly assigned to four different tendon repair groups: those repaired with or without suture pretension using either a simple Bunnell or cross-lock Bunnell technique. Pretension was applied as a 10 % shortening of the sutured tendon. After measuring the cross-sectional diameter at the repair site, static and cyclic biomechanical tests were conducted to evaluate the initial and 5-mm gap formation forces, elongation during cyclic loading, maximum tensile strength, and mode of failure. The suture failure mechanism was also separately assessed fluoroscopically in two tendons that were repaired with steel wire. Results Suture pretension was accompanied by a 10 to 15 % increase in the tendon diameter at the repair site. Therefore, suture pretension with the Bunnell and cross-lock Bunnell repair techniques noticeably increased the resistance to initial gap formation and 5-mm gap formation. The tension-free cross-lock Bunnell repair demonstrated more resistance to initial and 5-mm gap formation, less elongation, and higher maximum tensile strength than the tension-free Bunnell repair technique. The only difference between the tensioned cross-lock Bunnell and tensioned Bunnell techniques was a larger resistance to 5-mm gap formation with the cross-lock Bunnell technique. Use of the simple instead of cross-lock suture configuration led to failure by suture cut out, as demonstrated fluoroscopically. Conclusion Based on these results, suture pretension decreases gapping and elongation after tendon repair, and those effects are stronger when using a cross-lock, rather than a regular Bunnell suture. However, pretension causes an unfavorable increase in the tendon diameter at the repair site, which may adversely affect wound healing. KW - suture KW - cross-lock KW - Bunnell KW - achilles KW - pretension KW - tendon Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126262 VL - 10 IS - 192 ER - TY - JOUR A1 - Jordan, Martin C. A1 - Bittrich, Leonie A. A1 - Fehske, Kai A1 - Meffert, Rainer H. A1 - Jansen, Hendrik T1 - A rare case of Hoffa fracture combined with lateral patellar dislocation JF - Trauma Case Reports N2 - The coronal unicondylar fracture of the distal femur (AO 33-B3) is a rare intraarticular injury within the weight bearing area of the knee, initially described by Albert Hoffa in 1904. We report an unusual combination of a Hoffa fracture with lateral patellar dislocation in a young adult. Our patient sustained the injury by a sudden twist of his leg during sports. He presented clinically with knee swelling, dislocation of the patella, and localized tenderness; unable to bare weight. After plane radiograph confirmed the injury, manual reduction of the patella was done by hyperextension of the knee and medialward pressure. Afterwards, a CT scan and MRI were conducted. The injury was surgically treated with lag-screws, locking-plate and MPFL-reconstruction. KW - dislocation KW - femur KW - fracture KW - Hoffa KW - MPFL KW - patella Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158315 VL - 9 ER -