Marcus Jäger - Academia.edu (original) (raw)
Papers by Marcus Jäger
Zeitschrift für Orthopädie
ABSTRACT
Zeitschrift für Orthopädie
Zeitschrift für Orthopädie
An os odontoideum is mostly diagnosed coincidentally on the basis of neurological symptoms or pai... more An os odontoideum is mostly diagnosed coincidentally on the basis of neurological symptoms or painful movement of the cervical spine. Diagnostic work-up and therapy are currently subjects of controversial discussion in the literature. Our report is about an eleven-year-old boy with an unknown os odontoideum, who developed neurological symptoms with tetraparesis after a fall from 1.5 m height. Conventional X-ray examination resulted in the diagnosis of a suspected dens fracture, MRI showed atlanto-axial instability and an os odontoideum with significant dural sack compression but no signs of acute bony or ligamentous lesion. Because of the importance concerning not only medical but also legal/insurance aspects, a possible coincidental finding of an os odontoideum versus a dens fracture must be included in the differential diagnosis. In the case of an os odontoideum without instability in children, conservative therapy is justified after due enlightenment regarding possible risks. In the event of neurological symptoms and/or persistent instability the authors advocate early surgical stabilization even in patients with little infirmity, particularly in view of the possible consequences.
Zeitschrift für Orthopädie
The autologous in vitro expansion of chondrocytes is a new method for the treatment of localized ... more The autologous in vitro expansion of chondrocytes is a new method for the treatment of localized cartilage defect zones in humans. In the past several investigators have shown the occurrence of mesenchymal stem cells (MSC) in human bone marrow, periosteum and somite mesoderm. Moreover it has been shown that these progenitor cells are able to differentiate into chondral tissue under special in vitro conditions. The following study shows current possibilities and borders of a chondrogenetic stem cell therapy. Furthermore advantages and disadvantages of different cellular biomatrix carriers are described, cartilage tissue engineering-related problems are discussed and possible solutions were pointed out. A literature investigation served for evaluation of the present clinical and experimental data. Furthermore our own cell culture experiences were considered. Until now there exists no clinical concept using the potential of MSC for cartilage tissue engineering. Reasons are the lack of biomechanical and histological stability and handling problems of the cultivated cartilage tissue, especially the difficulties to fix and secure the transplant in the cartilage defect zones in situ. The systematic investigation of biomatrices by chondrogenic progenitor cell culture systems may lead to important data for the evaluation of the chondrogenic potency biomatrices.
DMW - Deutsche Medizinische Wochenschrift
A 38-year-old man presented with acute low back pain and paraesthesia in dermatome S1. 4 hours be... more A 38-year-old man presented with acute low back pain and paraesthesia in dermatome S1. 4 hours before onset of symptoms he had finished the last of three scuba dives with a maximum depth of 30 m and a total diving time of 3 hours. No alcoholic beverages were taken during or before diving. The patient was complaining of local pain in the thoracic and lumbar spine and showed a 3/5 weakness of the big toe and impaired sensitivity in the S1 dermatome. 90 minutes later the patient developed a hemiparesis of the right side including hypaesthesia and additional meningism (stiff neck). The X-rays of the thoracic and lumbar spine in two standard planes, cerebrospinal fluid examination, a cranial spiral-computer tomographie (CCT) and laboratory investigations showed no pathologic values. Acute decompression sickness (DCS) type II. The patient received an intravenous infusion, antiinflammatory prophylaxis with dexamethasone and an immediate submission to hyperbaric oxygenation therapy. Complete recovery of neurological symptoms appeared after 4 decompression sessions in a hyperbaric chamber. In patients presenting low back pain as common symptoms the differential diagnosis needs to be worked out and DCS should be included especially if progressive neurologic deficits are present. Only emergency hyperbaric oxygen therapy can compromise a sufficient therapy of these patients.
Biomedizinische Technik
The Luque procedure was developed to correct the deformity without the need of bracing and mainta... more The Luque procedure was developed to correct the deformity without the need of bracing and maintaining that correction with growth. However many authors are disappointed by their results and the complications which appear in the management of infantile scoliosis with Luque trolley alone. Besides failed implants, pseudarthrosis, modest spinal growth and protuberant rods and wires, the major problem of the Luque systems is the high incidence of loss of correction by postoperative rotation. Therefore a new application technique is recommended. A standard posterior extraperiostal approach is chosen. Sublaminar titanium cables are passed at each level except the caudal lamina. Then the rods are precontoured in shape of the planed curve correction. We use a low profile titanium instrumentation with 5.0 mm diameter rods and 4.2 mm pedicle screws. In contrast to the conventional use of two antiparallel "L"-rods we recommend the use of one reversed "U"-rod securing the laminae with sublaminar titanium cables of the upper end vertebrae. For fixation of the lower spine a dual-opening pedicle screw system is used. Using a holding forceps the distal rods are introduced and fixed into the side opening of the screws then secured by sublaminar wires. In addition both single rods are stabilized by a low profile cross link bar. This technique allows to correct pelvic obliquity and a stable anchorage of two screws reduces risk of postoperatively rotation or caudal rod slippage due to gravity forces.
Journal of Orthopaedics and Traumatology
ABSTRACT
Klinische Pädiatrie
As a complication of chemotherapy/corticosteroids for the treatment of acute lymphoblastic leukem... more As a complication of chemotherapy/corticosteroids for the treatment of acute lymphoblastic leukemia (ALL) and other malignancies during childhood, avascular osteonecrosis appears in up to 30 % of the patients. Weight-bearing joints are involved in over 90 % of the cases. Total joint replacement is often necessary to restore function. Yet, endoprostheses in young patients again bare the risk of later complications and the need for several revision surgeries. In this report, joint preserving surgical strategies will be discussed. Three hips and eleven knee joints in 8 patients (4 male, 4 female) were operated on for symptomatic ON and/or osteochondral defects (OCD) after chemotherapy. Four of the patients underwent surgery in more than one joint. The average age at the time of surgery was 18 years (range 14 - 26). The procedures included retrograde drilling (core decompression), bone grafting, implantation of collagen sponges with autologous bone marrow aspirate, osteochondral autograft transplantation and transplantation of periosteal flaps. Two hip joints underwent total joint replacement. Average follow up was 25 months. After an average follow up of 2 years, all patients were satisfied with the functional results after the last follow up with pain free walking for a minimum of 60 minutes. No night pain was reported. One patient complained about intermittent periods of dysaesthesia around the bone harvest area at the iliac crest. The aim of surgery for ON and OCD after chemotherapy should be the reduction of pain and preservation of the joint to bypass the risks of joint replacement in young patients, although total joint replacement may become indicated in endstage degeneration of the involved joint.
Biomedizinische Technik
The good biomechanical and tribological properties, together with the excellent biocompatibility,... more The good biomechanical and tribological properties, together with the excellent biocompatibility, of ceramic-on-ceramic components, make them a preferential choice for total hip replacement surgery, at least in Europe. We report on a man admitted as an outpatient with painless grating in the hip one year after replacement of a ceramic femoral head, but not of the ceramic inlay. Clinical and radiological findings were indicative of a broken liner. This was confirmed during revision surgery, during which it was replaced by a polyethylene inlay; although the ceramic head appeared intact, it was replaced by a metal head. Inspection of the surface of the broken liner in the scanning electron microscope (SEM) revealed signs of material failure. We recommend careful inspection of ceramic-on-ceramic articulating components during total hip revision surgery and if there is any uncertainty, replacement of both so as to avoid premature failure.
Zeitschrift für Orthopädie
Besides general risks, reorienting periacetabular osteotomies include the risks of over- or under... more Besides general risks, reorienting periacetabular osteotomies include the risks of over- or under-correction. Therefore, intraoperative computer-assisted control of the pelvic fragment may allow for precise reorientation of the acetabulum in all planes. The advantages and problems of a computer assisted periacetabular osteotomy are demonstrated in a 19 year old female with spastic paresis and severe secondary dysplasia of the hip over a postoperative follow up period of 2 years. Because of progressive subluxation of the left femoral head with initial degenerative changes of the hip joint a pelvic triple osteotomy as described by Tönnis and an intertrochanteric derotation-varus osteotomy were performed. The intraoperative control of the acetabular position was optimized by CT based navigation. To compare and evaluate the pre- and postoperative clinical and functional outcome, X-rays, CT scans and a gait analysis were applied. The computer assisted orthopedic surgery (CAOS) technique allows for precise intraoperative control following reorientation of the acetabular fragment in all three planes. The pre- and postoperative clinical and radiological findings were compared and the result was classified as good. Although the costs and logistics for pelvic osteotomies are increased by CAOS technology, the authors favor this technique for corrective surgery of complex acetabular deformities, although individual parameters need to be considered in each patient.
Journal of Biomaterials Science Polymer Edition
For more than 50 years PMMA bone cements have been used in orthopaedic surgery. In this study att... more For more than 50 years PMMA bone cements have been used in orthopaedic surgery. In this study attempts were made to show whether cultured human bone marrow cells (HBMC) show an osteogenetic response resulting in new bone formation, production of extracellular matrix (ECM) and cell differentiation when they were cultured onto polymerized polymethylmethacrylate (PMMA)-hydroxyapatite (HA), conventional PMMA bone cement being taken as reference. Biocompatibility parameters were collagen-I and -II synthesis, the detection of the osteoblast markers alkaline phosphatase (ALP) and osteocalcin, the number of adherent cells and the cytodifferentiation of immunocompetent cells. Cement surface structure, HA stability in culture medium and chemical element analysis of specimens were considered. Fresh marrow cells were obtained from the human femora during hip replacement. Incubation time was up to ten weeks. We used atomic forced microscopy (AFM) and scanning electron microscopy (SEM) for cement specimen analysis. Fluorescent activated cell sorter (FACS), immunohistochemical staining. SEM and light microscopy (LM) served us to judge the cellular morphology. Products of the extracellular matrix were analyzed by protein dot blot analysis, SEM energy dispersive X-ray analysis (SEM-EDX) and Ca2+/PO(4)3- detection. HA particles increased the osteogenetic potential of PMMA bone cement regarding the cellular production of collagen, alkaline phosphatase (AP), the number of osteoblasts and the cellular differentiation pattern in vitro. Both tested cements showed good biocompatibility in a human long-term bone marrow cell-culture system.
In vivo (Athens, Greece)
Background: Stem cells derived from umbilical cord blood display mesenchymal multipotency and can... more Background: Stem cells derived from umbilical cord blood display mesenchymal multipotency and can differentiate into osteoblasts, chondroblasts and adipoblasts in vitro under defined stimuli. Although sheep have been used as experimental models for investigations on xenoreactivity after transplantation of stem cells isolated from human umbilical cord blood, the potential of ovine cord blood stem cells to differentiate has been examined to date. Materials and Methods: Mononuclear cells from the placentoms of 3 lambs were isolated via density gradient centrifugation and cultivated. After expansion up to 3 passages, the cells were stimulated to differentiate towards osteogenic (dexamethasone, ascorbic-acid-2-phosphate, ‚-glycerolphosphate), chondrogenic (TGF-‚3, insulin, transferrin, selenium, dexamethasone, ascorbic-acid-2-phosphate) and adipogenic (indomethacine, insulin, 3-isobutyl-1-methylxanthine, dexamethasone) lines for 20 days. The cells were characterized morphologically by transmission and phase contrast light microscopy during lineage-specific stimulation. Immunocytochemistry and conventional stains were used to detect lineage-typical markers: fat vacuoles and peroxisome proliferation-acitivated receptor Á2 (PPAR) served to detect adipoblasts, whereas osteopontin (OP) was used to characterize osteoblasts. A positive antibody reaction to collagen II and chondrogenic oligomeric protein (COMP) revealed the presence of chondroblasts. Results: The osteogenic line formed bone nodules, adipogenic cells developed lipid droplets and the cells of the chondrogenic line showed typical chondroblast-like morphology. Conclusion: It was demonstrated that ovine mesenchymal stem cells, derived from umbilical cord blood (sheep unrestricted somatic stem cells, S-USSCs), can be isolated via gradient density centrifugation and expanded in vitro. Under lineage-specific stimulation, S-USSCs differentiated into osteo-, chondro-and adipoblasts with typical morphological characteristics. Significant quantitative differences between the stimulated and control groups in lineage-typical immunocytochemical markers verified these findings.
Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association, 2004
Femoroacetabular impingement is often associated with reduced femoral anteversion or an osseous b... more Femoroacetabular impingement is often associated with reduced femoral anteversion or an osseous bump deformity on the femoral head-neck junction. We report prospectively on 17 patients showing an osseous bump at the anterolateral head-neck junction on radiography (22 hips) and typical signs of femoroacetabular impingement on clinical examination. Following three plans of treatment, nine patients (10 hips) underwent nonoperative treatment, and eight patients (12 hips) had surgery. In eight hips with labral defects but minor cartilage damage, the bump was surgically removed via trochanter flip osteotomy. Two hips were treated surgically through an anterior surgical approach without hip dislocation. Four hips with severe signs of osteoarthritis and significantly reduced range of motion underwent total replacement. To elucidate a local osteogenic differential potential, tissue specimens of the perilesional capsule were investigated immunohistochemically. Various antigens and protein syn...
Technology and health care: official journal of the European Society for Engineering and Medicine
The present meta-analysis illustrates relevant information about hip replacement in young patient... more The present meta-analysis illustrates relevant information about hip replacement in young patients that has been published during the past 3 decades. Based on a MedLine literature review a total of 95 studies were evaluated. Parameters for evaluation of study quality and outcome were implant survival rates (ISR),number of patients, indications, follow-up, surgical approaches and number of surgeons. Most studies consider patient numbers <50. In 33 studies one implant system was applied compared to 65 studies in which more than one system was used. Most studies include different surgical approaches. 20% of all studies contained neither the number of surgeons,nor the type of surgical approach. The overall ISR could be evaluated in 67 studies. Sufficient data about the ISR of stem and/or sockets were available in 50 papers. Most published studies analyzed inhomogeneous study populations; study variables vary as do the implants used for treatment.
Anticancer research
Background: Since the first trial of chemotherapy in patients with osteosarcoma the survival rate... more Background: Since the first trial of chemotherapy in patients with osteosarcoma the survival rate has gradually improved. For more than two decades, most osteosarcoma patients from Germany, Austria and Switzerland have been treated according to the protocols of the Cooperative Osteosarcoma Study Group (COSS). The uniform treatment concept of a high-dose polychemotherapy pre-and postoperatively improved the survival rate of these patients significantly. One severe side-effect of COSS chemotherapy is multiple osteonecrosis. Patients and Methods: In this study the osteogenic stem cell potency of three different tissue types was elucidated after COSS-96 chemotherapy (high-risk arm). Mononuclear cells were obtained from the periosteum, cartilage and bone marrow of a 17-year-old female with a chondroblastic osteosarcoma. The cells were cultivated for 4 weeks in standard medium and stimulated for osteogenic differentiation after the second passage with dexamethasone, glycerolphosphate and ascorbine acid. Two weeks later, the cell cultures were analysed with respect to cell morphology and immunochemical stainings. Results: All cells cultures showed an osteoblastic regeneration potential measured by osteocalcin (OC), osteopontin (OP) and alkaline phosphatase (ALP) expression. Compared to other donor tissues and localizations, the fibula periosteum showed siginificantly higher osteoblast rates in vitro, whereas collagen II, CD34 and CD45 were not expressed in any culture. Conclusion: The results of this study demonstrate the survival of mesenchymal progenitor cells in bone marrow during COSS-96 polychemotherapy, which allows for an osteogenic regeneration in vitro and potentially in vivo.
Der Orthopäde
Autogenous bone grafts from the iliac crest are frequently harvested for autologous bone transpla... more Autogenous bone grafts from the iliac crest are frequently harvested for autologous bone transplantation. Although an autologous bone transplant does improve the local bone healing potency, significant donor site morbidity must be considered. In this study we elucidate special bone harvesting techniques from the iliac crest and review the literature related to clinical significance of donor site morbidity. Furthermore, our own experiences are compared and discussed critically with relevant data of other investigators. The increasing number of scientific publications which focus on bone harvesting techniques and related complications in recent years indicate the high interest and relevance of this issue. There is a tendency to alternatives such as biomaterials as bone substitutes, whereas the role of growth factors and cell therapeutics in the treatment of bony defects are still being evaluated in clinical studies. Although autologous, heterotopic bone transplantation is still the gold standard in the treatment of bony defects, there is a tendency towards the application of biomaterials, stem cells, and growth factors. Conscientious observation of relevant anatomic considerations during bone harvesting procedures may help to avoid complications.
Zeitschrift für Orthopädie
ABSTRACT
Zeitschrift für Orthopädie
Zeitschrift für Orthopädie
An os odontoideum is mostly diagnosed coincidentally on the basis of neurological symptoms or pai... more An os odontoideum is mostly diagnosed coincidentally on the basis of neurological symptoms or painful movement of the cervical spine. Diagnostic work-up and therapy are currently subjects of controversial discussion in the literature. Our report is about an eleven-year-old boy with an unknown os odontoideum, who developed neurological symptoms with tetraparesis after a fall from 1.5 m height. Conventional X-ray examination resulted in the diagnosis of a suspected dens fracture, MRI showed atlanto-axial instability and an os odontoideum with significant dural sack compression but no signs of acute bony or ligamentous lesion. Because of the importance concerning not only medical but also legal/insurance aspects, a possible coincidental finding of an os odontoideum versus a dens fracture must be included in the differential diagnosis. In the case of an os odontoideum without instability in children, conservative therapy is justified after due enlightenment regarding possible risks. In the event of neurological symptoms and/or persistent instability the authors advocate early surgical stabilization even in patients with little infirmity, particularly in view of the possible consequences.
Zeitschrift für Orthopädie
The autologous in vitro expansion of chondrocytes is a new method for the treatment of localized ... more The autologous in vitro expansion of chondrocytes is a new method for the treatment of localized cartilage defect zones in humans. In the past several investigators have shown the occurrence of mesenchymal stem cells (MSC) in human bone marrow, periosteum and somite mesoderm. Moreover it has been shown that these progenitor cells are able to differentiate into chondral tissue under special in vitro conditions. The following study shows current possibilities and borders of a chondrogenetic stem cell therapy. Furthermore advantages and disadvantages of different cellular biomatrix carriers are described, cartilage tissue engineering-related problems are discussed and possible solutions were pointed out. A literature investigation served for evaluation of the present clinical and experimental data. Furthermore our own cell culture experiences were considered. Until now there exists no clinical concept using the potential of MSC for cartilage tissue engineering. Reasons are the lack of biomechanical and histological stability and handling problems of the cultivated cartilage tissue, especially the difficulties to fix and secure the transplant in the cartilage defect zones in situ. The systematic investigation of biomatrices by chondrogenic progenitor cell culture systems may lead to important data for the evaluation of the chondrogenic potency biomatrices.
DMW - Deutsche Medizinische Wochenschrift
A 38-year-old man presented with acute low back pain and paraesthesia in dermatome S1. 4 hours be... more A 38-year-old man presented with acute low back pain and paraesthesia in dermatome S1. 4 hours before onset of symptoms he had finished the last of three scuba dives with a maximum depth of 30 m and a total diving time of 3 hours. No alcoholic beverages were taken during or before diving. The patient was complaining of local pain in the thoracic and lumbar spine and showed a 3/5 weakness of the big toe and impaired sensitivity in the S1 dermatome. 90 minutes later the patient developed a hemiparesis of the right side including hypaesthesia and additional meningism (stiff neck). The X-rays of the thoracic and lumbar spine in two standard planes, cerebrospinal fluid examination, a cranial spiral-computer tomographie (CCT) and laboratory investigations showed no pathologic values. Acute decompression sickness (DCS) type II. The patient received an intravenous infusion, antiinflammatory prophylaxis with dexamethasone and an immediate submission to hyperbaric oxygenation therapy. Complete recovery of neurological symptoms appeared after 4 decompression sessions in a hyperbaric chamber. In patients presenting low back pain as common symptoms the differential diagnosis needs to be worked out and DCS should be included especially if progressive neurologic deficits are present. Only emergency hyperbaric oxygen therapy can compromise a sufficient therapy of these patients.
Biomedizinische Technik
The Luque procedure was developed to correct the deformity without the need of bracing and mainta... more The Luque procedure was developed to correct the deformity without the need of bracing and maintaining that correction with growth. However many authors are disappointed by their results and the complications which appear in the management of infantile scoliosis with Luque trolley alone. Besides failed implants, pseudarthrosis, modest spinal growth and protuberant rods and wires, the major problem of the Luque systems is the high incidence of loss of correction by postoperative rotation. Therefore a new application technique is recommended. A standard posterior extraperiostal approach is chosen. Sublaminar titanium cables are passed at each level except the caudal lamina. Then the rods are precontoured in shape of the planed curve correction. We use a low profile titanium instrumentation with 5.0 mm diameter rods and 4.2 mm pedicle screws. In contrast to the conventional use of two antiparallel "L"-rods we recommend the use of one reversed "U"-rod securing the laminae with sublaminar titanium cables of the upper end vertebrae. For fixation of the lower spine a dual-opening pedicle screw system is used. Using a holding forceps the distal rods are introduced and fixed into the side opening of the screws then secured by sublaminar wires. In addition both single rods are stabilized by a low profile cross link bar. This technique allows to correct pelvic obliquity and a stable anchorage of two screws reduces risk of postoperatively rotation or caudal rod slippage due to gravity forces.
Journal of Orthopaedics and Traumatology
ABSTRACT
Klinische Pädiatrie
As a complication of chemotherapy/corticosteroids for the treatment of acute lymphoblastic leukem... more As a complication of chemotherapy/corticosteroids for the treatment of acute lymphoblastic leukemia (ALL) and other malignancies during childhood, avascular osteonecrosis appears in up to 30 % of the patients. Weight-bearing joints are involved in over 90 % of the cases. Total joint replacement is often necessary to restore function. Yet, endoprostheses in young patients again bare the risk of later complications and the need for several revision surgeries. In this report, joint preserving surgical strategies will be discussed. Three hips and eleven knee joints in 8 patients (4 male, 4 female) were operated on for symptomatic ON and/or osteochondral defects (OCD) after chemotherapy. Four of the patients underwent surgery in more than one joint. The average age at the time of surgery was 18 years (range 14 - 26). The procedures included retrograde drilling (core decompression), bone grafting, implantation of collagen sponges with autologous bone marrow aspirate, osteochondral autograft transplantation and transplantation of periosteal flaps. Two hip joints underwent total joint replacement. Average follow up was 25 months. After an average follow up of 2 years, all patients were satisfied with the functional results after the last follow up with pain free walking for a minimum of 60 minutes. No night pain was reported. One patient complained about intermittent periods of dysaesthesia around the bone harvest area at the iliac crest. The aim of surgery for ON and OCD after chemotherapy should be the reduction of pain and preservation of the joint to bypass the risks of joint replacement in young patients, although total joint replacement may become indicated in endstage degeneration of the involved joint.
Biomedizinische Technik
The good biomechanical and tribological properties, together with the excellent biocompatibility,... more The good biomechanical and tribological properties, together with the excellent biocompatibility, of ceramic-on-ceramic components, make them a preferential choice for total hip replacement surgery, at least in Europe. We report on a man admitted as an outpatient with painless grating in the hip one year after replacement of a ceramic femoral head, but not of the ceramic inlay. Clinical and radiological findings were indicative of a broken liner. This was confirmed during revision surgery, during which it was replaced by a polyethylene inlay; although the ceramic head appeared intact, it was replaced by a metal head. Inspection of the surface of the broken liner in the scanning electron microscope (SEM) revealed signs of material failure. We recommend careful inspection of ceramic-on-ceramic articulating components during total hip revision surgery and if there is any uncertainty, replacement of both so as to avoid premature failure.
Zeitschrift für Orthopädie
Besides general risks, reorienting periacetabular osteotomies include the risks of over- or under... more Besides general risks, reorienting periacetabular osteotomies include the risks of over- or under-correction. Therefore, intraoperative computer-assisted control of the pelvic fragment may allow for precise reorientation of the acetabulum in all planes. The advantages and problems of a computer assisted periacetabular osteotomy are demonstrated in a 19 year old female with spastic paresis and severe secondary dysplasia of the hip over a postoperative follow up period of 2 years. Because of progressive subluxation of the left femoral head with initial degenerative changes of the hip joint a pelvic triple osteotomy as described by Tönnis and an intertrochanteric derotation-varus osteotomy were performed. The intraoperative control of the acetabular position was optimized by CT based navigation. To compare and evaluate the pre- and postoperative clinical and functional outcome, X-rays, CT scans and a gait analysis were applied. The computer assisted orthopedic surgery (CAOS) technique allows for precise intraoperative control following reorientation of the acetabular fragment in all three planes. The pre- and postoperative clinical and radiological findings were compared and the result was classified as good. Although the costs and logistics for pelvic osteotomies are increased by CAOS technology, the authors favor this technique for corrective surgery of complex acetabular deformities, although individual parameters need to be considered in each patient.
Journal of Biomaterials Science Polymer Edition
For more than 50 years PMMA bone cements have been used in orthopaedic surgery. In this study att... more For more than 50 years PMMA bone cements have been used in orthopaedic surgery. In this study attempts were made to show whether cultured human bone marrow cells (HBMC) show an osteogenetic response resulting in new bone formation, production of extracellular matrix (ECM) and cell differentiation when they were cultured onto polymerized polymethylmethacrylate (PMMA)-hydroxyapatite (HA), conventional PMMA bone cement being taken as reference. Biocompatibility parameters were collagen-I and -II synthesis, the detection of the osteoblast markers alkaline phosphatase (ALP) and osteocalcin, the number of adherent cells and the cytodifferentiation of immunocompetent cells. Cement surface structure, HA stability in culture medium and chemical element analysis of specimens were considered. Fresh marrow cells were obtained from the human femora during hip replacement. Incubation time was up to ten weeks. We used atomic forced microscopy (AFM) and scanning electron microscopy (SEM) for cement specimen analysis. Fluorescent activated cell sorter (FACS), immunohistochemical staining. SEM and light microscopy (LM) served us to judge the cellular morphology. Products of the extracellular matrix were analyzed by protein dot blot analysis, SEM energy dispersive X-ray analysis (SEM-EDX) and Ca2+/PO(4)3- detection. HA particles increased the osteogenetic potential of PMMA bone cement regarding the cellular production of collagen, alkaline phosphatase (AP), the number of osteoblasts and the cellular differentiation pattern in vitro. Both tested cements showed good biocompatibility in a human long-term bone marrow cell-culture system.
In vivo (Athens, Greece)
Background: Stem cells derived from umbilical cord blood display mesenchymal multipotency and can... more Background: Stem cells derived from umbilical cord blood display mesenchymal multipotency and can differentiate into osteoblasts, chondroblasts and adipoblasts in vitro under defined stimuli. Although sheep have been used as experimental models for investigations on xenoreactivity after transplantation of stem cells isolated from human umbilical cord blood, the potential of ovine cord blood stem cells to differentiate has been examined to date. Materials and Methods: Mononuclear cells from the placentoms of 3 lambs were isolated via density gradient centrifugation and cultivated. After expansion up to 3 passages, the cells were stimulated to differentiate towards osteogenic (dexamethasone, ascorbic-acid-2-phosphate, ‚-glycerolphosphate), chondrogenic (TGF-‚3, insulin, transferrin, selenium, dexamethasone, ascorbic-acid-2-phosphate) and adipogenic (indomethacine, insulin, 3-isobutyl-1-methylxanthine, dexamethasone) lines for 20 days. The cells were characterized morphologically by transmission and phase contrast light microscopy during lineage-specific stimulation. Immunocytochemistry and conventional stains were used to detect lineage-typical markers: fat vacuoles and peroxisome proliferation-acitivated receptor Á2 (PPAR) served to detect adipoblasts, whereas osteopontin (OP) was used to characterize osteoblasts. A positive antibody reaction to collagen II and chondrogenic oligomeric protein (COMP) revealed the presence of chondroblasts. Results: The osteogenic line formed bone nodules, adipogenic cells developed lipid droplets and the cells of the chondrogenic line showed typical chondroblast-like morphology. Conclusion: It was demonstrated that ovine mesenchymal stem cells, derived from umbilical cord blood (sheep unrestricted somatic stem cells, S-USSCs), can be isolated via gradient density centrifugation and expanded in vitro. Under lineage-specific stimulation, S-USSCs differentiated into osteo-, chondro-and adipoblasts with typical morphological characteristics. Significant quantitative differences between the stimulated and control groups in lineage-typical immunocytochemical markers verified these findings.
Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association, 2004
Femoroacetabular impingement is often associated with reduced femoral anteversion or an osseous b... more Femoroacetabular impingement is often associated with reduced femoral anteversion or an osseous bump deformity on the femoral head-neck junction. We report prospectively on 17 patients showing an osseous bump at the anterolateral head-neck junction on radiography (22 hips) and typical signs of femoroacetabular impingement on clinical examination. Following three plans of treatment, nine patients (10 hips) underwent nonoperative treatment, and eight patients (12 hips) had surgery. In eight hips with labral defects but minor cartilage damage, the bump was surgically removed via trochanter flip osteotomy. Two hips were treated surgically through an anterior surgical approach without hip dislocation. Four hips with severe signs of osteoarthritis and significantly reduced range of motion underwent total replacement. To elucidate a local osteogenic differential potential, tissue specimens of the perilesional capsule were investigated immunohistochemically. Various antigens and protein syn...
Technology and health care: official journal of the European Society for Engineering and Medicine
The present meta-analysis illustrates relevant information about hip replacement in young patient... more The present meta-analysis illustrates relevant information about hip replacement in young patients that has been published during the past 3 decades. Based on a MedLine literature review a total of 95 studies were evaluated. Parameters for evaluation of study quality and outcome were implant survival rates (ISR),number of patients, indications, follow-up, surgical approaches and number of surgeons. Most studies consider patient numbers <50. In 33 studies one implant system was applied compared to 65 studies in which more than one system was used. Most studies include different surgical approaches. 20% of all studies contained neither the number of surgeons,nor the type of surgical approach. The overall ISR could be evaluated in 67 studies. Sufficient data about the ISR of stem and/or sockets were available in 50 papers. Most published studies analyzed inhomogeneous study populations; study variables vary as do the implants used for treatment.
Anticancer research
Background: Since the first trial of chemotherapy in patients with osteosarcoma the survival rate... more Background: Since the first trial of chemotherapy in patients with osteosarcoma the survival rate has gradually improved. For more than two decades, most osteosarcoma patients from Germany, Austria and Switzerland have been treated according to the protocols of the Cooperative Osteosarcoma Study Group (COSS). The uniform treatment concept of a high-dose polychemotherapy pre-and postoperatively improved the survival rate of these patients significantly. One severe side-effect of COSS chemotherapy is multiple osteonecrosis. Patients and Methods: In this study the osteogenic stem cell potency of three different tissue types was elucidated after COSS-96 chemotherapy (high-risk arm). Mononuclear cells were obtained from the periosteum, cartilage and bone marrow of a 17-year-old female with a chondroblastic osteosarcoma. The cells were cultivated for 4 weeks in standard medium and stimulated for osteogenic differentiation after the second passage with dexamethasone, glycerolphosphate and ascorbine acid. Two weeks later, the cell cultures were analysed with respect to cell morphology and immunochemical stainings. Results: All cells cultures showed an osteoblastic regeneration potential measured by osteocalcin (OC), osteopontin (OP) and alkaline phosphatase (ALP) expression. Compared to other donor tissues and localizations, the fibula periosteum showed siginificantly higher osteoblast rates in vitro, whereas collagen II, CD34 and CD45 were not expressed in any culture. Conclusion: The results of this study demonstrate the survival of mesenchymal progenitor cells in bone marrow during COSS-96 polychemotherapy, which allows for an osteogenic regeneration in vitro and potentially in vivo.
Der Orthopäde
Autogenous bone grafts from the iliac crest are frequently harvested for autologous bone transpla... more Autogenous bone grafts from the iliac crest are frequently harvested for autologous bone transplantation. Although an autologous bone transplant does improve the local bone healing potency, significant donor site morbidity must be considered. In this study we elucidate special bone harvesting techniques from the iliac crest and review the literature related to clinical significance of donor site morbidity. Furthermore, our own experiences are compared and discussed critically with relevant data of other investigators. The increasing number of scientific publications which focus on bone harvesting techniques and related complications in recent years indicate the high interest and relevance of this issue. There is a tendency to alternatives such as biomaterials as bone substitutes, whereas the role of growth factors and cell therapeutics in the treatment of bony defects are still being evaluated in clinical studies. Although autologous, heterotopic bone transplantation is still the gold standard in the treatment of bony defects, there is a tendency towards the application of biomaterials, stem cells, and growth factors. Conscientious observation of relevant anatomic considerations during bone harvesting procedures may help to avoid complications.