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P. P. Besselaar - One of the best experts on this subject based on the ideXlab platform.

  • The results of downgrading moderate and severe slipped capital femoral epiphysis by an early Imhauser Femur Osteotomy
    Journal of Children's Orthopaedics, 2009
    Co-Authors: Melinda M. E. H. Witbreuk, M. Bolkenbaas, M. G. Mullender, I. N. Sierevelt, P. P. Besselaar
    Abstract:

    Purpose Patients with moderate and severe slipped capital femoral epiphysis (SCFE) develop osteoarthritis earlier in life in association with mechanical impingement. Methods To correct deformity and diminish impingement, we performed epiphysiodesis combined with an Imhauser intertrochanteric Osteotomy (ITO) in moderate and severe slipped capital femoral epiphysis. We downgraded the angle of the head relative to the acetabulum into an angle corresponding to a mild slip or even an anatomical position. Our hypothesis is that the avoidance of anterior impingement at an early stage can prevent the development of osteoarthritis. Results The results of 28 patients (32 hips) were evaluated. Outcome parameters were SF-36, Harris Hip Score, range of motion, Kellgren–Lawrence score, chondrolysis and avascular necrosis. After a median follow-up of 8 (range 2–25) years, the group was clinically, functionally and socially performing well. Radiologically, there was no sign of chondrolysis or avascular necrosis, and more than 80% of the patients did not show any signs of osteoarthritis. Conclusions Based on these results, we conclude that a one-stage Imhauser ITO combined with epiphysiodesis performed on patients with moderate and severe SFCE gives satisfactory results.

  • The results of downgrading moderate and severe slipped capital femoral epiphysis by an early Imhauser Femur Osteotomy
    Journal of children's orthopaedics, 2009
    Co-Authors: Melinda M. E. H. Witbreuk, M. Bolkenbaas, M. G. Mullender, I. N. Sierevelt, P. P. Besselaar
    Abstract:

    Purpose Patients with moderate and severe slipped capital femoral epiphysis (SCFE) develop osteoarthritis earlier in life in association with mechanical impingement.

Anita Ignatius - One of the best experts on this subject based on the ideXlab platform.

  • chronic psychosocial stress compromises the immune response and endochondral ossification during bone fracture healing via β ar signaling
    Proceedings of the National Academy of Sciences of the United States of America, 2019
    Co-Authors: Melanie Haffnerluntzer, Katja Prystaz, Sandra Foertsch, Verena Fischer, Miriam Tschaffon, Yvonne Modinger, Chelsea S Bahney, Ralph S Marcucio, Theodore Miclau, Anita Ignatius
    Abstract:

    Chronic psychosocial stress/trauma represents an increasing burden in our modern society and a risk factor for the development of mental disorders, including posttraumatic stress disorder (PTSD). PTSD, in turn, is highly comorbid with a plethora of inflammatory disorders and has been associated with increased bone fracture risk. Since a balanced inflammatory response after fracture is crucial for successful bone healing, we hypothesize that stress/trauma alters the inflammatory response after fracture and, consequently, compromises fracture healing. Here we show, employing the chronic subordinate colony housing (CSC) paradigm as a clinically relevant mouse model for PTSD, that mice subjected to CSC displayed increased numbers of neutrophils in the early fracture hematoma, whereas T lymphocytes and markers for cartilage-to-bone transition and angiogenesis were reduced. At late stages of fracture healing, CSC mice were characterized by decreased bending stiffness and bony bridging of the fracture callus. Strikingly, a single systemic administration of the β-adrenoreceptor (AR) blocker propranolol before Femur Osteotomy prevented bone marrow mobilization of neutrophils and invasion of neutrophils into the fracture hematoma, both seen in the early phase after fracture, as well as a compromised fracture healing in CSC mice. We conclude that chronic psychosocial stress leads to an imbalanced immune response after fracture via β-AR signaling, accompanied by disturbed fracture healing. These findings offer possibilities for clinical translation in patients suffering from PTSD and fracture.

  • Pharmacological inhibition of IL-6 trans-signaling improves compromised fracture healing after severe trauma
    Naunyn-Schmiedeberg's Archives of Pharmacology, 2018
    Co-Authors: Kathrin Kaiser, Melanie Haffner-luntzer, Katja Prystaz, Anna Vikman, Stephanie Bergdolt, Gudrun Strauss, Georg H. Waetzig, Stefan Rose-john, Anita Ignatius
    Abstract:

    Patients with multiple injuries frequently suffer bone fractures and are at high risk to develop fracture healing complications. Because of its key role both in systemic posttraumatic inflammation and fracture healing, the pleiotropic cytokine interleukin-6 (IL-6) may be involved in the pathomechanisms of trauma-induced compromised fracture healing. IL-6 signals are transmitted by two different mechanisms: classic signaling via the membrane-bound receptor (mIL-6R) and trans-signaling via its soluble form (sIL-6R). Herein, we investigated whether IL-6 classic and trans-signaling play different roles in bone regeneration after severe injury. Twelve-week-old C57BL/6J mice underwent combined Femur Osteotomy and thoracic trauma. To study the function of IL-6, either an anti-IL-6 antibody, which inhibits both IL-6 classic and trans-signaling, or a soluble glycoprotein 130 fusion protein (sgp130Fc), which selectively blocks trans-signaling, were injected 30 min and 48 h after surgery. Bone healing was assessed using cytokine analyses, flow cytometry, histology, micro-computed tomography, and biomechanical testing. Selective inhibition of IL-6 trans-signaling significantly improved the fracture healing outcome after combined injury, as confirmed by accelerated cartilage-to-bone transformation, enhanced bony bridging of the fracture gap and improved mechanical callus properties. In contrast, global IL-6 inhibition did not affect compromised fracture healing. These data suggest that classic signaling may mediate beneficial effects on bone repair after severe injury. Selective inhibition of IL-6 trans-signaling might have therapeutic potential to treat fracture healing complications in patients with concomitant injuries.

  • A COMPLEMENT ANTAGONIST IMPROVES FRACTURE HEALING AFTER SYSTEMIC INFLAMMATION INDUCED BY BLUNT CHEST TRAUMA
    2018
    Co-Authors: Stefan Recknagel, Ronny Bindl, Tim Wehner, Christian Ehrnthaller, Florian Gebhard, Markus Huber-lang, Lutz Claes, Anita Ignatius
    Abstract:

    There is evidence that fracture healing is delayed in severely injured patients. We recently demonstrated that a blunt chest trauma, which induced posttraumatic systemic inflammation, considerably impaired fracture healing in rats. Because the complement anaphylatoxin C5a is an important trigger of systemic inflammation, we tested the hypothesis, whether the impairment of fracture healing observed after a severe trauma resulted from systemically activated complement.16 male Wistar rats received a thoracic trauma and a Femur Osteotomy stabilized by an external fixator. Immediately and 12 h after the trauma, half of the animals received a C5aR-antagonist to prevent the C5a-dependent systemic inflammation. Control rats received a nonsense peptide, which does not provoke any biological effect. The animals were killed after 35 days and the calli were analyzed by three point bending testing, μCT and histomorphometry. Statistics: Mann-Whitney U test, level of significance to p

  • FRACTURE HEALING IN A MOUSE MODEL WITH SEVERE DEFECTS OF THE INNATE AND ADAPTIVE IMMUNE SYSTEM
    2018
    Co-Authors: Ronny Bindl, Stefan Recknagel, Anna E. Rapp, A. Erbacher, I. Mueller, Anita Ignatius
    Abstract:

    There is evidence that fracture healing is impaired in patients with chronic immune disorders the reasons remaining unclear so far. To further elucidate the role of the immune system in bone healing, this study investigated the hypothesis that fracture healing would be considerably disturbed in a mouse model with severe defects of the innate as well as adaptive immune system.Immune deficient Nod-scidIL2Rγnull and immune competent BALBcByJ mice were used (12 weeks, male, each n=24). The mice received a Femur Osteotomy stabilized by an external fixator and were sacrificed at d 21, 28, and 35. The calli were evaluated by three-point-bending testing, μCT and histomorphometry.The flexural rigidity of the callus did not significantly differ between both genotypes after 21 and 28 days but was significantly lower in Nod-scidIL2Rγnull mice after 35 days (31%). The maximum moment of inertia was significantly increased after 21 days (by 34%), and the callus cross section area after 21, 28 and 35 days in Nod-scidIL2R...

  • CONVERSION FROM EXTERNAL FIXATOR TO INTRAMEDULLARY NAIL CAUSED A SECOND HIT AND IMPAIRED FRACTURE HEALING IN A RAT MODEL OF SEVERE TRAUMA MODEL
    2018
    Co-Authors: Ronny Bindl, Stefan Recknagel, Tim Wehner, Christian Ehrnthaller, Florian Gebhard, Markus Huber-lang, Lutz Claes, Anita Ignatius
    Abstract:

    In polytrauma patients invasive surgeries can potentiate the posttraumatic systemic inflammation thus increasing the risk of multi organ dysfunction. Therefore, fractures are initially treated by external fixators, which later are replaced by intramedullary nails. We showed that a severe trauma impaired the healing of fractures stabilized by external fixation. Here we studied, whether the conversion to an intramedullary nail increases posttraumatic inflammation and leads to further impairment of healing.44 rats received a Femur Osteotomy stabilized by an external fixator (FixEx). Half of the rats underwent a thoracic trauma (TXT) at the same time. After 4 days the fixator was replaced by an intramedullary nail (IMN) in half of the rats of each group. The rats were killed after 40 and 47 days. C5a serum levels were measured 0, 6, 24, and 72h after the 1st as well as the 2nd surgery. The calli were evaluated by three-point-bending test, μCT and histomorphometry.The TXT significantly increased serum C5a leve...

Andreas B. Imhoff - One of the best experts on this subject based on the ideXlab platform.

  • Osseous valgus alignment and posteromedial ligament complex deficiency lead to increased ACL graft forces
    Knee Surgery Sports Traumatology Arthroscopy, 2020
    Co-Authors: Julian Mehl, Alexander Otto, Cameron Kia, Matthew Murphy, E. Obopilwe, Florian B. Imhoff, Matthias J. Feucht, Andreas B. Imhoff, Robert A. Arciero, Knut Beitzel
    Abstract:

    Purpose To biomechanically investigate the influence of osseous valgus alignment, with and without deficiency of the posteromedial ligament complex (PMC), on ACL-graft forces under axial load. Methods ACL reconstruction was performed on ten cadaveric knee joints. A lateral distal Femur Osteotomy was then done to adjust for three different alignment conditions according to the position, where the axial weight bearing line (WBL) dissected the tibial plateau (% from medial to lateral): 50%, 85% and 115%. Each alignment was tested with the PMC intact, deficient and reconstructed. Axial loads of 400 N were applied in 15° of knee flexion and changes of ACL-graft forces and dynamic valgus angle (DVA) were recorded. Results In the PMC intact state, lateralization of the WBL to 85% and to 115% led to significantly increased ACL graft forces (85%: p  = 0.010; 115%: p  

  • Nonunion and delayed union in lateral open wedge distal femoral osteotomies—a legitimate concern?
    International Orthopaedics, 2018
    Co-Authors: Franz Liska, Florian B. Imhoff, Andreas Voss, Lukas Willinger, Andreas B. Imhoff
    Abstract:

    Introduction Due to a supposed high rate of nonunions in lateral open wedge distal Femur Osteotomy (LOWDFO), the medial closing wedge technique has been favoured for a long time. The aim of this study was to report the occurrence of delayed- and nonunions following LOWDFO. We hypothesized that the occurrence of nonunions needing revision surgery is comparable to medial closing osteotomies. Methods Forty-one patients were treated with LOWDFO with a minimum follow-up of 12 months. Parameters such as age, gender, body mass index, valgus angle, the heights of the opening wedge, as well as the type of Osteotomy (biplane vs single plane) were collected. Delayed union and nonunion were evaluated on radiographs along with clinical symptoms. Results The study group consisted of 21 females and 20 males, with a median age of 37 years at the time of surgery. Removal of hardware was performed in 63% after 1.3 years (0.6–2.1 years). The median preoperative valgus angle was 6.1° valgus (range 2–15.5°). The heights of the opening wedge ranged from 2 to 12 mm (mean 5.3 mm). Hinge fracture of the medial cortex was seen in 39%. Three patients had a delayed union, and one patient had a nonunion requiring revision surgery. Conclusion LOWDFO is a safe alternative to MCWDFO. Although radiolucency of the Osteotomy gap can be evident on radiographs even after 12 months, this does not reflect the clinical finding. The nonunion rate is proven to be low and comparable with the nonunion rates of MCWDFOs as well as open wedge HTOs.

  • Nonunion and delayed union in lateral open wedge distal femoral osteotomies-a legitimate concern?
    International orthopaedics, 2017
    Co-Authors: Franz Liska, Florian B. Imhoff, Andreas Voss, Lukas Willinger, Andreas B. Imhoff
    Abstract:

    Due to a supposed high rate of nonunions in lateral open wedge distal Femur Osteotomy (LOWDFO), the medial closing wedge technique has been favoured for a long time. The aim of this study was to report the occurrence of delayed- and nonunions following LOWDFO. We hypothesized that the occurrence of nonunions needing revision surgery is comparable to medial closing osteotomies. Forty-one patients were treated with LOWDFO with a minimum follow-up of 12 months. Parameters such as age, gender, body mass index, valgus angle, the heights of the opening wedge, as well as the type of Osteotomy (biplane vs single plane) were collected. Delayed union and nonunion were evaluated on radiographs along with clinical symptoms. The study group consisted of 21 females and 20 males, with a median age of 37 years at the time of surgery. Removal of hardware was performed in 63% after 1.3 years (0.6–2.1 years). The median preoperative valgus angle was 6.1° valgus (range 2–15.5°). The heights of the opening wedge ranged from 2 to 12 mm (mean 5.3 mm). Hinge fracture of the medial cortex was seen in 39%. Three patients had a delayed union, and one patient had a nonunion requiring revision surgery. LOWDFO is a safe alternative to MCWDFO. Although radiolucency of the Osteotomy gap can be evident on radiographs even after 12 months, this does not reflect the clinical finding. The nonunion rate is proven to be low and comparable with the nonunion rates of MCWDFOs as well as open wedge HTOs.

Melinda M. E. H. Witbreuk - One of the best experts on this subject based on the ideXlab platform.

  • The results of downgrading moderate and severe slipped capital femoral epiphysis by an early Imhauser Femur Osteotomy
    Journal of Children's Orthopaedics, 2009
    Co-Authors: Melinda M. E. H. Witbreuk, M. Bolkenbaas, M. G. Mullender, I. N. Sierevelt, P. P. Besselaar
    Abstract:

    Purpose Patients with moderate and severe slipped capital femoral epiphysis (SCFE) develop osteoarthritis earlier in life in association with mechanical impingement. Methods To correct deformity and diminish impingement, we performed epiphysiodesis combined with an Imhauser intertrochanteric Osteotomy (ITO) in moderate and severe slipped capital femoral epiphysis. We downgraded the angle of the head relative to the acetabulum into an angle corresponding to a mild slip or even an anatomical position. Our hypothesis is that the avoidance of anterior impingement at an early stage can prevent the development of osteoarthritis. Results The results of 28 patients (32 hips) were evaluated. Outcome parameters were SF-36, Harris Hip Score, range of motion, Kellgren–Lawrence score, chondrolysis and avascular necrosis. After a median follow-up of 8 (range 2–25) years, the group was clinically, functionally and socially performing well. Radiologically, there was no sign of chondrolysis or avascular necrosis, and more than 80% of the patients did not show any signs of osteoarthritis. Conclusions Based on these results, we conclude that a one-stage Imhauser ITO combined with epiphysiodesis performed on patients with moderate and severe SFCE gives satisfactory results.

  • The results of downgrading moderate and severe slipped capital femoral epiphysis by an early Imhauser Femur Osteotomy
    Journal of children's orthopaedics, 2009
    Co-Authors: Melinda M. E. H. Witbreuk, M. Bolkenbaas, M. G. Mullender, I. N. Sierevelt, P. P. Besselaar
    Abstract:

    Purpose Patients with moderate and severe slipped capital femoral epiphysis (SCFE) develop osteoarthritis earlier in life in association with mechanical impingement.

M. Bolkenbaas - One of the best experts on this subject based on the ideXlab platform.

  • The results of downgrading moderate and severe slipped capital femoral epiphysis by an early Imhauser Femur Osteotomy
    Journal of Children's Orthopaedics, 2009
    Co-Authors: Melinda M. E. H. Witbreuk, M. Bolkenbaas, M. G. Mullender, I. N. Sierevelt, P. P. Besselaar
    Abstract:

    Purpose Patients with moderate and severe slipped capital femoral epiphysis (SCFE) develop osteoarthritis earlier in life in association with mechanical impingement. Methods To correct deformity and diminish impingement, we performed epiphysiodesis combined with an Imhauser intertrochanteric Osteotomy (ITO) in moderate and severe slipped capital femoral epiphysis. We downgraded the angle of the head relative to the acetabulum into an angle corresponding to a mild slip or even an anatomical position. Our hypothesis is that the avoidance of anterior impingement at an early stage can prevent the development of osteoarthritis. Results The results of 28 patients (32 hips) were evaluated. Outcome parameters were SF-36, Harris Hip Score, range of motion, Kellgren–Lawrence score, chondrolysis and avascular necrosis. After a median follow-up of 8 (range 2–25) years, the group was clinically, functionally and socially performing well. Radiologically, there was no sign of chondrolysis or avascular necrosis, and more than 80% of the patients did not show any signs of osteoarthritis. Conclusions Based on these results, we conclude that a one-stage Imhauser ITO combined with epiphysiodesis performed on patients with moderate and severe SFCE gives satisfactory results.

  • The results of downgrading moderate and severe slipped capital femoral epiphysis by an early Imhauser Femur Osteotomy
    Journal of children's orthopaedics, 2009
    Co-Authors: Melinda M. E. H. Witbreuk, M. Bolkenbaas, M. G. Mullender, I. N. Sierevelt, P. P. Besselaar
    Abstract:

    Purpose Patients with moderate and severe slipped capital femoral epiphysis (SCFE) develop osteoarthritis earlier in life in association with mechanical impingement.