[The diagnosis and therapy of ligament injuries of the foot].
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Education, Medical, Continuing↗
Biomedical subjects
T Mittlmeier
Publications and source records attributed to T Mittlmeier.
[Gait analysis after intra-articular calcaneus fractures].
We retrospectively compared 20 patients with displaced intra-articular calcaneal fractures by clinical assessment and dynamic pedography. Eleven were treated operatively, 9 conservatively. The purpose was to identify differences in post-traumatic gait performance and to correlate the pedographic data to a clinical score to show its reliability. Twenty individuals without a history of foot injuries were used as a control group. Both groups had restricted motion in the subtalar joint, increased hindfoot and midfoot loading and decreased forefoot loading. Furthermore, they showed prolonged contact phases and an impaired ability to speed up gait during the toe-off phase. Load transfer from the hindfoot to the forefoot showed typical distribution patterns. The operatively treated group showed better functional results with fewer subjective complaints.
Adult↗
Modern gait analysis: a tool to improve shoes, insoles and the understanding of foot function.
The success of orthopedic devices such as orthotics, insoles, and special shoes is and was in most cases judged retrospectively by the long- or short-term outcome. The techniques of modern gait analysis can be used to quantitatively measure the effect of these orthopedic devices on foot function and foot loading. The different techniques of gait analysis together with their advantages and disadvantages are presented and their possibilities demonstrated with examples of applications. Pressure distribution measurements are emphasized, since this technology is the furthest developed and the easiest to use for the assessment of orthopedic devices.
Biomechanical Phenomena↗
Posterior stabilization of C2 metastases by combination of atlantoaxial screw fixation and hook plate.
A new technique for the stabilization of metastatic cervical instability of the axis and/or neighboring vertebrae at lower levels is described. By a combination of the transarticular screw fixation C1/2 (Magerl) with the hook plate technique (Magerl) (or facultatively with a 1/3 tubular or 3.5 mm dynamic compression plate) from a posterior approach, the risks and stresses on the patient of a transoral or a combined extended technique are avoided, creating a proven biomechanically stable situation. The new technique is particularly helpful in those patients with a rapid progression of their malignant disease in whom local tumor growth is not expected to compress the spinal cord, and palliative stabilization of the unstable upper cervical spine can avoid neurological deficits or alleviate pain syndromes at a minimized morbidity due to surgery. The new technique has been successfully applied in a limited clinical series of four patients with metastasis of the cervical spine, resulting in substantial improvement of the general condition and cervical pain syndrome and stability of the assemblage during the observation period (4-9 months).
Adult↗
Effects of mechanical loading on the profile of human femoral diaphyseal geometry.
In vivo bone behaviour predictions with respect to altered loading conditions, implants, and endoprostheses are highly desirable to avoid untoward effects such as implant loosening and breakage. This knowledge does not relate only to the result but also to the mechanisms of bone adaptation and bone growth. Since bone growth is assumed to be determined essentially by the loading history, the morphology of the human femoral midshaft region was analysed to extract those loading cases responsible for the actual cross-sectional geometry. This was achieved by the application of computer-aided optimization (CAO), a procedure supplementing a finite element analysis which allows for simulation of adaptive bone growth. A simulated load was applied to a cylinder, and the resulting changes in geometry were compared with the geometry of three ex vivo samples. Apparently, standard loading cases alone (axial loading, bending, torsion), or at consecutive or simultaneous application, did not yield the characteristic morphology of the femoral shaft region. Only the introduction of the adductor muscle force in various combinations with other standard loadings resulted in femoral mid-shaft geometries comparable with the ex vivo specimens.
Bone Development↗
Analysis of morphology and gait function after intraarticular calcaneal fracture.
Open reduction and internal fixation is suggested by an increasing number of investigators as preferable treatment of displaced intraarticular calcaneal fractures. Assuming that quasianatomical reduction coincides with adequate function, many surgeons rely on morphological parameters (standard radiography, computed tomography) to demonstrate the effectiveness of surgery by achieving an optimum restoration of calcaneal geometry and joint surfaces. In order to correlate morphologic parameters and functional assessment, a prospective study was performed on 45 patients after surgical treatment of intraarticular calcaneal fractures using standard radiographic and computed tomographic scores, clinical evaluation, and gait analysis (dynamic pedography). Mean follow-up time after reconstruction was 23 months (range 18-50). Although clinical evaluation and assessment of gait function corresponded well with each other, radiographic scores showed a poor to moderate correlation with functional evaluation (r = 0.29-0.62); this was probably due to the missing analysis of soft tissue parameters. The comparison of clinical results and gait parameters with the individual radiographical parameters allowed us to identify those factors, with the greatest influence seen on the functional prognosis (i.e., calcaneal width, arthrosis in the neighboring joints). Morphologic analysis after calcaneal reconstruction based on radiographic techniques cannot predict subsequent function or substitute for functional assessment. However, it does allow for practical conclusions for surgical strategy in primary osseous reconstruction or secondary corrections.
Activities of Daily Living↗
[Experiences with the isoelastic prosthesis in treatment of humerus metastases].
39 patients with pathological fractures of the humerus were treated by isoelastic polyacetal endoprosthesis. Ten patients received a humeral-head-prosthesis and 32 a prosthesis of the humeral-shaft. The average survival time was nine months. Three times within the first group of twelve patients fracture of the cone of the prosthesis occurred. Therefore an additional stabilization of the contact zone between bone and prosthesis by plate-osteosynthesis was performed in the following 20 operations, preventing breakage of the material. In contrast to the conventional posterior approach to the humeral-shaft we chose a ventrolateral approach between the biceps and triceps muscle. This technique is less traumatic and leads to a shorter operation time. In patients with pathological humeral fractures a conception of treatment is demonstrated which provides an immediate stability by using endoprostheses to preserve the quality of life of oncological patients.
Bone Neoplasms↗
Anterior transpedicular instrumentation of the lumbar spine: an anatomical study.
Lumbar burst fractures or massive tumorous destruction of the lumbar spine generally require a combined anterior-posterior surgical approach for adequate decompression and stabilization. Anatomical studies in 10 adult cadavers with 100 pedicle screw placements from a single strictly anterior approach showed that this new method represents a safe and promising way for stable lumbar spine instrumentation, avoiding the risks of a bilateral approach. The technique provides a stability comparable with bilateral instrumentation. Exact knowledge of the geometry of the corresponding vertebral bodies and the spinal canal by computed tomography scanning is a prerequisite for this surgical technique. First clinical applications using this technique reconfirm the experiences of the anatomical study.
Adult↗
[Method for in vivo measurement of intraosseous pressure of the patella].
During the development of degenerative joint disease (osteoarthritis, chondropathy), a diagnostic or even pathogenetic role is attributed to the phenomenon of intraosseous pressure (IOP). Owing to technical problems and a lack of systematic experimental or clinical studies on the control mechanisms of the IOP, the actual importance of this factor is still not known with certainty. Now, a measuring method that enables correct recording of the IOP and standardized on-line processing of the measured signal minimize artefact-related problems. The technique is evaluated for reliability in an in vitro model of the human patella and in a limited clinical study of the IOP in patients undergoing knee surgery for various reasons. Factors such as intra-articular effusion, joint position or changes in intra-articular soft tissue are examined for their influence of the primary signal.
Female↗
[Static and dynamic loading measurements of the post-traumatic foot].
There are several possibilities to assess loading of the foot after trauma. This paper gives an overview of the quantitative techniques presently applied for the measurement of kinetic (ground reaction forces, pressure distribution) and kinematic parameters (joint angles) during movement analysis; emphasis is placed on simple and reliable techniques (e.g., time variables of the roll-over process, pressure distribution), which are explained with examples of their clinical use. In addition, several mathematical foot models are introduced. None of the techniques mentioned has found a permanent place in the clinical environment for support of the diagnosis of trauma, the quantification of trauma, or the therapeutical decision. In other areas (e.g. biomechanics) these techniques are already established. Therefore, the experience to date in these areas should be taken into consideration by the clinicians and used for their purposes.
Biomechanical Phenomena↗
Compartment syndrome of the foot after intraarticular calcaneal fracture.
Seventeen patients with a total of 21 intraarticular calcaneal fractures were examined at up to 30 days after trauma for the development of tissue pressure in the central plantar muscle compartment. Twelve patients had a significant increase in tissue pressure with values greater than 30 mmHg because of primary fracture hematoma or interstitial fluid accumulation. This increase in pressure persisted for three to five days after trauma, so that ischemic damage to the short plantar foot muscles had to be suspected. Plantar muscle scarring and claw-toe formation were observed in seven patients with a total of 11 fractures during a mean observation period of 18 months. The plantar aponeurosis, which forms the constricting fascial envelope of the plantar muscles, is the anatomic structure responsible for the compartment syndrome that may develop after calcaneal fracture. Therefore, to avoid functional deficit, plantar compartmental pressures should be regularly measured after calcaneal fracture. Significantly increased plantar tissue pressure greater than 30 mmHg should be relieved by longitudinal incision of the plantar aponeurosis, preferably by a plantar incision as soon as the diagnosis is made.
Adolescent↗
[2-Pfeiler acetabulum fracture with central hip dislocation and ipsilateral femoral neck fracture in epileptic seizure].
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Acetabulum↗
Methods and applications of three-dimensional imaging in orthopedics.
Computed tomography is a commonly used technique for detecting pathological alterations in soft tissues and the skeleton. Three-dimensional images of the skeleton are very useful for planning surgical treatment and monitoring therapy, but unfortunately mental reconstruction of complex three-dimensional anatomical structures from conventional tomography is very difficult. This article describes a process by which automated analysis of the regions of interest in the computed tomographic (CT) images yields the contours of the surfaces which can be presented pseudo-three-dimensionally using Phong's lighting model and Gouraud's shading methods. Three applications in the areas of orthopedics and neurosurgery demonstrate the efficacy of the method.
Bone Diseases↗
The cruciate ligaments in knee replacement.
The cruciate ligaments were resected with their bony insertions during total knee arthroplasty carried out in 12 patients with severe rheumatoid or osteoarthritis. The ligaments were examined histologically and biomechanically, using ten specimens from healthy adults as a control. A significant difference was found in the tensile stiffness and viscoelastic properties of the ligaments between the arthritic and the control group. The ligaments in the rheumatoid knees had a distinctly inferior tensile strength compared with the osteoarthritic knees. Total knee replacement, which also replaces ligament function, should therefore be considered in severely damaged rheumatoid knees.
Arthritis, Rheumatoid↗
Characterization of UHMWPE hip cups run on joint simulators.
The density and crystallinity of UHMWPE-hip cups were investigated as a function of thickness from the inner stressed surface to the unstressed outer surface. The effects of mechanical strain and chemical reactions during simulation tests, and damage of the material due to pretreatments and storage, resulted in changes of the structure, as indicated by variations in the crystallinity. Independent of either the batch of UHMWPE supplied or the manufacturer and the type of simulator used, the individual sample-sets showed a similar characteristic curve of density versus wall thickness. Infrared spectroscopic evaluations indicated the presence of oxidative degradation, and answers the question as to which areas of the polymers are changed by aging and which compounds are newly formed. The characteristic carbonyl groups were also determined. The concentration trend of carbonyl groups versus wall thickness obtained agrees surprisingly well with the locally determined density and crystallinity trend. As these compounds are formed by reactions which produce stable oxidative degradation products and also crosslinking, we have determined the degree of cross-linking. The determination of the soluble constituents after extraction showed lower degree of crosslinking on the surface than in the middle of the material. Hence it follows that on the surfaces oxidative chain scission is prevailing, whereas in the interior mainly crosslinking is developed. These results indicate that the samples used for the simulation tests had distinct differences in characteristics. Generally the results show that wear tests in joint simulators lead to property changes in UHMWPE which differ considerably from test results previously obtained on retrieved hip cups.
Crystallization↗
[Thoracic and abdominal injuries in polytrauma].
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Abdominal Injuries↗
Arthroscopic labrum refixation for post-traumatic anterior shoulder instability: suture anchor versus transglenoid fixation technique.
SUMMARY: The aim of this retrospective study was to compare recurrence rates following transglenoid labrum refixation or fixation using the suture anchor (FASTak, Arthrex, Naples, FL) technique. Additionally, parameters that apparently influence the rate of redislocation were investigated. There were 163 patients with post-traumatic anterior shoulder instability treated with an arthroscopic labrum refixation; 108 patients (66.3%) were stabilized with the transglenoid suture technique (group I) and 55 patients (33. 7%) with the suture anchor (FASTak) technique (group II). The average follow-up was 4.5 years (range, 2.0 to 7.9 years) in group I and 3.2 years (range, 2.0 to 5.0 years) in group II. The Rowe score increased from a preoperative average of 35.0 points in group I and 35.4 points in group II to a postoperative average of 68.3 points in group I and 84.6 points in group II (P <.01). There was recurrence in 35 patients (32.4%) in group I and 9 patients (16.4%) in group II (P <.05). All incidents of redislocation occurred during the first 21 postoperative months; 58.4% of the patients (n = 63) in group I and 16.4% of the patients in group II (n = 9) had to reduce their sporting activity (P <.001). Independent of the type of surgery, there was a significant correlation of the postoperative rate of redislocation and age (P <.001), number of preoperative dislocations (P <.01), and degree of labrum lesion (P <.001). No correlation with the rate of redislocation was shown for gender, handedness, dislocation-operation interval, degree of Hill-Sachs lesion, or number of transglenoid sutures or anchors. Concerning post-traumatic anterior shoulder instability, the arthroscopic labrum reconstruction with the suture anchor (FASTak) technique was superior to the transglenoid technique but has not yet achieved the level of success obtained by open surgery. With fewer than 5 preoperative redislocations after a first traumatic shoulder dislocation, the arthroscopic treatment is recommended. In cases of more frequent preoperative dislocations, open surgery in combination with a capsular shift should be performed.
Adult↗