[The German Society of Trauma Surgery celebrates its 75th anniversary this year].
Explore the source record for details and available documents.
Forecasting↗
Biomedical subjects
H J Oestern
Publications and source records attributed to H J Oestern.
[Scoring--criteria for operability].
For therapeutic recommendations three different kinds of scores are essential: 1. The severity scores for trauma; 2. Severity scores for mangled extremities; 3. Intensive care scores. The severity of polytrauma patients is measurable by the AIS, ISS, RTS, PTS and TRISS which is a combination of RTS, ISS, age, and mechanism of injury. For mangled extremities there are also different scores available: MESI (Mangled Extremity Syndrome Index) and MESS (Mangled Extremity Severity Score). The aim of these scores is to assist in the indication with regard to amputate or to save the extremity. These scoring indices can be used to evaluate the severity of a systemic inflammatory reaction syndrome with respect to multiple organ failure. All scores are dynamic values which are variable with improvement of therapy.
Amputation, Surgical↗
The morphological effects of synthetic augmentation in posterior cruciate ligament reconstruction: an experimental study in a sheep model.
The treatment of posterior cruciate ligament (PCL) injuries remains controversial. Due to various problems, PCL reconstruction has not consistently produced the knee stability desired. Biological graft tissue undergoes a remarkable healing process comprising different phases. The strength of autogenous graft material decreases soon after operation. During this early healing phase synthetic augmentation could protect the graft tissue from overloading or overstretching, supporting the tissue revitalization and remodeling process. In order to evaluate the morphological effects of the ligament augmentation device (LAD) on a free patellar tendon autograft in PCL reconstruction, a comparative study in sheep was conducted. In 24 mature sheep, the PCL was replaced with either a patellar tendon autograft alone or a patellar tendon autograft augmented by the LAD. The LAD was fixed at both ends. After the operation the animals were not immobilized. Tibial fixation was released 8 weeks postoperation. The autografts of both groups were histologically evaluated after 2, 6, 16, 26, 52, and 104 weeks. In addition to necrotic and degenerative alterations, a remarkable inflammatory reaction could be seen in the LAD-augmented autografts early postoperation. Compared with the nonaugmented autografts, tissue formation and remodeling were delayed in the augmented group. After 1 and 2 years, the morphology of the autograft tissue was similar in both the augmented and nonaugmented group and differed from that of a normal PCL. The LAD was surrounded by a chronic inflammatory reaction, and collagen fiber ingrowth into the LAD was not observed. Using transmission electron microscopy, small diameter collagen fibrils were predominant in the graft tissue of both groups. Thus, a better remodeling of the autograft tissue in the presence of the LAD could not be demonstrated in this particular study. The value of synthetic augmentation of biological grafts in PCL reconstruction seems to be questionable at present.
Animals↗
[Morphologic aspects of alloplastic augmentation in replacement of the posterior cruciate ligament. An experimental study on the sheep].
The treatment of injuries to the posterior cruciate ligament (PCL) remains controversial. Various problems have prevented PCL reconstruction from consistently producing the knee stability desired. Biological graft tissue undergoes a remarkable healing process comprising different phases. The strength of autogenous graft material decreases soon after the operation. During this early healing phase synthetic augmentation could protect the graft tissue from overloading or overstretching, supporting the tissue restoration process. In order to evaluate the morphological effects of the ligament augmentation device (LAD) on a free patellar tendon autograft in PCL reconstruction a comparative study in sheep was conducted. In 24 mature sheep the PCL was replaced with either a patellar tendon autograft alone or a patellar tendon autograft augmented by the LAD. The LAD was fixed at both ends. The animals were not immobilized after the operation. Tibial fixation was released 8 weeks after the operation. The autografts of both groups were histologically evaluated after 2, 6, 16, 26, 52 and 104 weeks. In addition to necrotic and degenerative alterations a pronounced inflammatory reaction could be seen in the LAD-augmented autografts soon after the operation. Compared with the non-augmented autograft, tissue formation and remodeling was delayed in the augmented group. After 1 and 2 years, the morphology of the autograft tissue was similar in the augmented and the non-augmented group and was different from that of a normal PCL. The LAD was surrounded by a chronic inflammatory reaction, and collagen fiber ingrowth into the LAD was not observed. Transmission electron microscopy showed that small-diameter collagen fibrils were predominant in the graft tissue of both groups. Thus, better remodeling of the autograft tissue in the presence of the LAD was not demonstrable in this particular study. The value of synthetic augmentation of biological grafts of PCL reconstruction seems to be questionable at present.
Animals↗
[Differential treatment of fractures of the distal radius].
Treatment of distal fractures of the radius has undergone considerable change during recent years. The cause for this lies primarily in the poor results of conservative treatments. In addition to osseous instability, the fractures of the radius are frequently combined with ligamentary instability as well, thereby exceeding the ability of conservative treatment. Among the many classifications, the AO classification of these fractures has proven to be the best and most widely accepted. This classification allows the recommendation of suitable procedures of treatment. The problem with inadequately healed fractures of the radius lies in the inherent unphysiological loading of the joint in the characteristic dorsal tilted position. This leads to a pathological displacement of the radius of flexion and extension and thereby to an overloading of the dorsal joint cartilage. The shortening of the radius leads to a mechanical impingement of the triangular fibrocartilagenous complex. The Kirschner wire fixation is particularly indicated in type A and type C fractures when combined with an external fixator. Of great importance here is the crossing of the K-wires, best accomplished by inserting an additional wire in a proximal to distal direction to achieve maximal mechanical stability. Biodegradable fixation devices are not yet in widespread use, as high costs and possible foreign body reactions have prevented their acceptance. The plate osteosynthesis has its domain in the treatment of volar luxation fractures (B3) and the partially articular fractures of the radius (B2). The domain of the external fixator, on the other hand, lies in the C2 and C3 fractures in combination with the K-wire osteosynthesis. Changing the mode of treatment to a plate osteosynthesis after two to three weeks allows a functional postoperative treatment. By use of a differentiated treatment regimen, the complication rate can be significantly reduced whose cause frequently lies in repeatedly attempted repositions. Nevertheless, a rupture of the tendon of the M. extensor pollicis longus takes place in a certain percentage of cases (less than 0.2%) due to the unusual vascularization of this tendon. The dystrophy of Sudeck has become a relatively rare occurrence. A connection between a compression syndrome of the median nerve and the dystrophy of Sudeck has been discussed. The differentiated management has led to a change from a purely conservative treatment to a more varied treatment of the fractures of the distal radius. In our own patients conservative treatment was carried out in 27.5%.
Bone Wires↗
The patellar tendon graft for PCL reconstruction. Morphological aspects in a sheep model.
Surgical reconstruction of the PCL has not yet gained the acceptance that ACL reconstruction has achieved. However, in selecting an autograft to restore PCL function in symptomatic posterior knee instability, the free patellar tendon autograft is commonly used at present. Knowledge of the basics in graft healing and of factors regulating this healing process are still limited. It is of interest to determine the biologic response and final morphology of a patellar tendon autograft after PCL replacement. Based on morphological studies in PCL replacement in a sheep model the patellar tendon autograft under-goes necrosis and degeneration followed by a gradual healing process comprising revitalization (i.e. revascularization and cellular proliferation), formation of extracellular matrix components and remodeling. The autograft bone pegs become osseointegrated by 6 weeks. After 2 years, the autograft tissue differs structurally from a ligament, suggesting that the autograft may never approach normal ligament characteristics. Degenerative alterations in the core region of the autograft, the widespread presence of type III collagen and fibronectin, as well as the predominance of thin collagen fibrils do not favor a ligamentization process. The understanding of the autograft healing process remains the prerequisite for a realistic assessment of the biologic PCL replacement and will be a baseline of studies with the goal of influencing the healing process and thus improving the clinical results.
Animals↗
[Comparison of various trauma score systems. An overview].
Among the more than 50 scoring systems available for quantitative evaluation of injury severity, only a few have proved effective in clinical practice. In particular, the Revised Trauma Score (RTS), referring to physiological variables, has proved effective in preclinical use and otherwise, the Injury Severity Score (ISS), referring to anatomical data. There is a tendency in the development of new scoring systems to aim at higher predictive accuracy, forfeiting practicability. The initial purpose of scoring--an early assessment of the risks--is being pushed into the background. The TRISS method, which includes the RTS, ISS, patient's age, and mechanism of injury, is regarded as the international standard. However, it has the disadvantage of a low sensitivity of 60% for blunt trauma, resulting in a high rate of unexpected deaths. Reasons for this are underestimation of head injuries, multiple injuries to one body region, and failure to take full account of the individual patient's age. The new ASCOT method, in which the ISS is replaced by the Anatomic Profile, and the age of the patient is given more consideration, hardly brings better results--in spite of quite time-consuming methods. When the scoring systems currently available are applied their specific deficiencies and limited evidence must be borne in mind. Nevertheless, they are an important scientific instrument for comparative examinations, and indispensable for quality assurance and economic analyses. To improve the predictive accuracy, biochemical parameters and chronic diseases should be considered, in addition to existing scores.
Adult↗
Staging of patellar tendon autograft healing after posterior cruciate ligament reconstruction. A biomechanical and histological study in a sheep model.
The prerequisite for adequate rehabilitation after cruciate ligament reconstruction with a patellar tendon autograft is a thorough knowledge of the biologic healing processes. It is of interest to determine whether distinct phases similar to those in wound healing can be differentiated. It is also important to assess the magnitude of the biomechanical loading capacity and the duration of the healing processes. One posterior cruciate ligament in each of 48 skeletally mature sheep was replaced with a free patellar tendon autograft. Immediate rehabilitation without immobilization followed. Four phases of healing were demonstrated using the histologic condition of the autograft as a guide. The biomechanical data were correlated with the morphologic data. During the necrotic phase, a maximum of necrotic tissue was seen two weeks postoperatively. The strength of the graft is initially limited by the surgical fixation strength; however, later the intraarticular portion becomes the strength-limiting factor. During the revitalization phase, which is characterized by revascularization and proliferation of fibroblasts, and during the following phase, collagen formation, an increase in maximum stress is seen while the elastic modulus remains constant. Only in the remodeling phase is an increase in elastic modulus seen, owing to longitudinal alignment of the collagen bundles. One year after implantation, the autograft achieves approximately 50% of the material properties of the control. Even after two years, the autograft reaches only a maximum stress of 60% and an elastic modulus of 70% of the control. Ligamentization of the autograft could not be demonstrated in this study, but degeneration was seen in the core region of the graft during late remodeling.
Animals↗
The relationship of mechanical properties to morphology in patellar tendon autografts after posterior cruciate ligament replacement in sheep.
In a sheep model the posterior cruciate ligament (PCL) was replaced by a patellar tendon autograft (PTAG) using the central one-third of the ipsilateral patellar tendon (PT). The sheep were sacrificed at 16, 26, 52 and 104 weeks postoperation. The PTAG, and, as controls, the contralateral PCL and PT were harvested. These were examined using biomechanical testing as well as light and transmission electron microscopy, including immunohistological techniques. The material properties (maximum stress, elastic modulus) were compared to the morphological features. The cellular distribution, the distribution of glycosaminoglycans (GAGs), the collagen fibril diameter and the occurrence of Type III collagen were studied. Prior to transplantation, the PTAG was shown to be superior in maximum stress (57.2 +/- 5.5 MPa vs 41.3 +/- 1.9 MPa) and elastic modulus (368.8 +/- 49.3 MPa vs 172.3 +/- 14.6 MPa) to the PCL. The early decline in material properties of the PTAG (maximum stress 22% and elastic modulus 42% of the control) after free grafting paralleled a cell- and capillary-rich PTAG tissue with remnants of necrosis and a poorly organized extracellular matrix. Two years after implantation, with progressive alignment of the tissue matrix, maximum stress and elastic modulus acquired approximately 60 and 70% of the control, respectively. However, there was also an evidence of degenerative changes characterized by acellular areas, loss of the normal bundling pattern of collagen fibers and abnormal accumulation of GAGs. Ultrastructurally, there was a predominant shift to thin collagen fibrils in the PTAG compared to PCL and PT, both consisting of thick and thin collagen fibrils. Thin fibrils were demonstrated to be, in part, split thick fibrils as well as newly formed fibrils. Most of these thin fibrils revealed a positive reaction with antibodies to Type III collagen.
Animals↗
Influence of immobilization on autograft healing in the knee joint. A preliminary study in a sheep knee PCL model.
The influence of immobilization on patellar tendon autograft healing was investigated in 12 sheep with replaced posterior cruciate ligaments of the knee (PCLs). In one group achillotomy immobilized the operated knee joint. In another group initial reduced weight-bearing was obtained by hanging the sheep in a special trapeze. In the third group no protection at all was given to the operated knee. The sheep in this group went within 8 weeks from partial use of the operated leg to unrestricted weightbearing and mobility. Biomechanical testing 16 weeks after the operation demonstrated a considerable decrease in the maximum force, ligament stiffness, and strain values in the achillotomy group, as well as an increase in posterior laxity. The best data were observed in the no-protection group. This study demonstrates the negative effect of immobilization on autograft healing in a sheep PCL model. Even early in the healing process tissue may be extremely sensitive to stress and strain.
Animals↗
[Compartment syndrome. Definition, etiology, pathophysiology].
A compartment syndrome is a condition in which increased pressure a confined fascial space causes decreased capillary blood flow and tissue function below a level necessary for viability. There are a variety of possible etiologies, such as increased compartment content (hematoma, edema, exertion, intoxication) and decreased compartment size (constrictive dressings and casts, closure of fascial defects). The pathophysiology of compartment syndrome is based on the arteriovenous gradient theory. The high pressure within the compartment leads to a decrease in the arteriovenous gradient, to a lowering of tissue PO2 and finally to a metabolic deficit. The tolerance of increased pressure by nerve and muscle is defined by the relationship of mean arterial pressure to tissue pressure and not by absolute tissue pressure.
Compartment Syndromes↗
[Age, activity and strength of knee ligaments].
The cruciate ligaments of older persons are thought to have diminished biomechanical properties. On the other hand, joint immobilization also leads to similar functional losses in ligaments. It can be difficult to differentiate between these factors in older and immobile persons. The anterior and posterior cruciate ligaments of six younger (average age 30 years) and six older (average age 64.7 years) donors with similar levels of activity were subjected to biomechanical testing. Each sample had to meet the following conditions: appropriate age, no chronic vascular and cardiopulmonary disease found on autopsy, no signs of osteoarthrosis and no knee injuries. The material properties of maximum stress (e.g. ACL: young/old 24/21N/mm2), elastic modulus (e.g. ACL: young/old 144/129 MPa), and strain (e.g. ACL: young/old 25/28%), did not differ significantly (p less than 0.05). This indicates that older persons who are active do not necessarily show functional losses in the cruciate ligaments. Other data found in the literature can be ascribed to immobilization influences. In this data many of the older test persons had chronic vascular insufficiency, cardiopulmonary disease or malignancies.
Aged↗
Ultrastructural changes of the patellar tendon as a cruciate ligament substitute (one year and two year results).
In four black-faced sheep, the posterior cruciate ligament was replaced with a free autogenous patellar tendon transplant. Tissue samples from the transplants were investigated by light and electron microscopy 1 year and 2 years after surgery. The normal contralateral posterior cruciate ligament and the normal contralateral patellar tendon were used as controls. The structural differences concerned cells, collagen fibrils, elastic tissue and proteoglycans. Most of the cells of the contralateral patellar tendon were spindle-shaped, whereas those of the transplant were frequently chondroid. In the central region of the transplant as well as in the area far from the bone, cell degenerations, and occasionally hypo- or even acellular zones were found. Measurements of the diameter of collagen fibrils in both contralateral patellar tendon and posterior cruciate ligament showed a more or less pronounced bimodal distribution. A unimodal distribution with mainly thin fibrils (20-60 nm) was demonstrated in the transplant tissue which also revealed some morphological alterations of the collagen fibrils. Thin elastic fibers (microfibrils and amorphous material) were randomly scattered among the collagen fibrils of the control samples, bundles of microfibrils (without amorphous material) characterized the transplant. Staining with Alcian blue in the presence of 0.3 M MgCl2 demonstrated a close relationship between proteoglycans and collagen fibrils as well as elastic components in patellar tendon. This arrangement was lost in the transplant where abundant proteoglycans were revealed which, however, composed a tight irregular network between the collagen fibrils. The results serve as a baseline for understanding the impaired biochemical properties of a free autogenous patellar tendon transplant.
Animals↗
[Corrective osteotomy of malunited distal radius fractures].
The malunion of the distal radius may result in shortening, radial impaction, volar angulation, dorsal displacement or rotatory deformity. For restoration, the anatomy and kinematics of the distal radioulnar joint and the triangular fibrocartilaginous complex (TFCC) are of importance. This nonunion consists of the articular disk, a meniscus homologue, the ulnar collateral ligament, and the dorsal and palmar radioulnar ligaments. Malunion of the distal radioulnar joint leads to an increase in loading on the individual parts, as well as pain and a decrease in supination and pronation. Osteotomy is indicated if the angulation of the malunion is more than 20 degrees in the frontal or sagittal plane. Corrective osteotomy requires detailed preoperative planning with calculation of the correct position in all planes. The most common operation that has proved to be effective is osteotomy of the radius, insertion of a trapezoidal bone graft in place, and internal fixation with a dorsal or volar plate.
Elbow Joint↗
[Healing phases in autogenous posterior cruciate ligament replacement. A decision aid for after-care. A biomechanical and histologic study].
In a sheep model for reconstruction of the posterior cruciate ligament using the central one-third of the autogenous patellar tendon and immediate mobilization, the incorporation course was studied biomechanically, histomorphometrically and radiographically at eight different points in time up to 1 year after surgery. Four different phases of autograft healing were demonstrated on the basis of the histological events. The biomechanical data were correlated with the morphological findings. Phase 1--necrosis--was characterized by a maximum of necrotic autograft tissue 2 weeks postoperatively. Initially, graft strength was determined by the surgical fixation strength. During phase 2--revitalization--the autograft showed cellular proliferation and revascularization, starting from the periphery. The autograft was determined to be weakest during this phase. Phase 3--collagen formation--revealed a marked increase in newly formed collagen tissue between weeks 12 and 16. A significant increase in maximum load and stress was measured. In phase 4--remodeling--the longest phase, the collagen tissue appeared more compact and less cellular. The fiber bundles were arranged more longitudinally. However, the biomechanical properties remained clearly below that of a normal posterior cruciate ligament.
Animals↗
Biological aspects of long-term failure of autografts after cruciate ligament replacement.
The alterations of the ultrastructure of the posterior cruciate ligament autograft of patellar tendon origin were examined in a sheep model 1 year after surgery. The ultrastructure was also compared with that of the normal contralateral posterior cruciate ligament and patellar tendon. The most striking finding was the unimodal distribution of the collagen fibrils, with a predominance of loosely packed thin fibrils in the central portion of the autograft. The results suggested that the remodeled autograft tissue became highly organized but never exhibited the ultrastructural features of a ligament. This could be responsible for the decreased biomechanical properties and the long-term failure of a patellar tendon autograft.
Animals↗
Healing at graft fixation site under functional conditions in posterior cruciate ligament reconstruction. A morphological study in sheep.
The incorporation course at the fixation sites of a free patellar tendon graft used in posterior cruciate ligament reconstruction was examined in eight adult sheep. After surgery the sheep were functionally treated without any protection of the operated legs. Two, 6, 12, 16, and 26 weeks after surgery the sheep were killed and the character of biological attachment to bone at fixation sites was evaluated using macroradiography, high-resolution radiography, and routine histology. After 6 weeks good osseous incorporation of the bone pegs of free patellar tendon grafts could be demonstrated at the desired position.
Animals↗
[Distal radius fracture].
The treatment of fractures of the distal radius is in a state of flux, because the results of conservative treatment have so far been unsatisfactory in 20%-30% of cases. Instability resulting from dorsal compression, damaged ligaments (60%) and the presence of débris in the area of the metaphysis means that, while reduction is easy, retention is frequently difficult to achieve. Such fractures are reduced by using the ball of the little finger for extension while the ball of the thumb is positioned under the proximal fragment to provide support. A plaster cast based on the principle of three-point fixation is applied to immobilize the fractured part. The simplest surgical technique for unstable fractures of the distal radius is internal fixation with crossed Kirschner wires. For Smith's fractures [41], and especially those of type II (Thomas [44]), internal fixation with plates fixed to the volar bone surface is the procedure of choice. Comminuted fractures of the metaphysis and a tendency to shortening should be immobilized by external fixation. Early filling of the defect with cancellous bone leads to more rapid consolidation. In our own clinic we treated 409 cases of fracture of the distal radius in 2 years. The procedures applied were: conservative treatment in 39.6% of cases; internal fixation with wires in 55%; internal fixation with plates in 3.7%; and stabilization by means of external fixation in 1.7%.
Fracture Fixation, Internal↗