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Biomedical subjects

T Mittlmeier

Publications and source records attributed to T Mittlmeier.

At least 19 recordsLinked to original sources
PubMed2007

[Indications and techniques for wrist arthroscopy].

After considering the anatomy of the wrist, the technical requirements for wrist arthroscopy are discussed. This method is used as an additional diagnostic procedure and staging procedure as well as a therapeutic technique. Complications, which are rare, most commonly involve nerve irritation, damage to cutaneous nerves and extensor tendons. Lose bodies can be removed arthroscopically, however, arthroscopically assisted fracture treatment or the removal of ganglions are uncommon. Approaches are lateral and oriented on the extensor tendons or other anatomical landmarks. Arthroscopy is especially useful by carpal instability as it offers many possibilities, not only diagnostically but also therapeutically.

Arthroscopes↗
PubMed2006

[Posttraumatic arthritis in the hind foot].

Posttraumatic arthritis of the joint components of the hind foot is typically linked with hind foot deformity and involvement of the neighbouring joint. The principal goals of any hind foot reconstruction are to achieve a quasi-anatomical reconstruction of the geometry and a stable and plantigrade foot position as a prerequisite for acceptable gait function, and an overall satisfactory result for the patient. Profound knowledge of the functions of the ankle-hind foot complex is the basis for the development of a valid therapeutic strategy. Any surgical reconstruction has to consider previous interventions, local soft tissue conditions, neurovascular status, and the components of deformity and degree of arthritic destruction at the corresponding joint levels. In general, an arthrodesis of any hind foot joint, as a key element in hind foot reconstruction, will be successful if correction of the underlying deformity is also adequately addressed.

Ankle Injuries↗
PubMed2006

[Management problems in the diagnostic work-up and treatment of pathological fracture of the proximal femur. Clinical case report].

Pathological fractures caused by primary bone tumours are rare compared with fractures evolving in response to general osteoporosis or bone metastases. Nevertheless in cases of fracture due to inadequate trauma the underlying causality has to be clarified including histological analysis prior to the operating procedure. This case report demonstrates diagnostic and therapeutic standards in cases of pathological fracture of the proximal femur caused by osteosarcoma.

Adult↗
PubMed2006

[Complex proximal humerus fractures--management with a humeral head prosthesis? Clinical and radiological results of a prospective study].

BACKGROUND: Proximal humerus fractures are one of the most common fractures in elderly patients. In the treatment of complex proximal humerus fractures, primary hemiarthroplasty is still discussed controversially. The present study was undertaken to evaluate the results of primary hemiarthroplasty in the treatment of proximal humerus fractures with a modular prosthesis (EPOCA, Fa. Argomedical, Gifhorn, Germany). MATERIAL AND METHODS: A prospective study of 24 patients with complex humerus fracture (NEER: IV/4, V/4, VI/4, and head split fracture) was performed from August 2000 to December 2002. Mean age was 75.6 years (range: 52-92); 18 patients were seen for follow-up after 0.5 and 1 year, respectively. The Constant-Murley score (max. 100 points) and the UCLA Rating System (max. 35 points) were calculated for functional assessment of the operated shoulder. RESULTS: Fifteen patients (83%) were pain free 1 year after the operation. The Constant-Murley score improved from 52 (+/-17) to 56 (+/-18) at the second follow-up after 1 year. On the contralateral side a score of 86 (+/-10) was assessed (p<0.05 vs operated side). Correspondingly, shoulder function according to the UCLA Rating System improved [25 (+/-4); 27 (+/-5)]. CONCLUSIONS: Osteoporotic bone of older patients often may not permit stable internal fixation of complex proximal humerus fractures. In these situations primary hemiarthroplasty is the treatment of choice.

Aged↗
PubMed2005

[Periprosthetic fractures after total knee joint arthroplasty].

Periprosthetic fractures of the femur, tibia and patella are being registered with increasing frequency due to the rising numbers of total knee replacements. Depending on the site of the fracture, apart from mere traumatic mechanisms, implant specific parameters and implant loosening may represent the main causes of periprosthetic fracture. Moreover, general risk factors promote the manifestation of a periprosthetic fracture. Nowadays, valid classifications are available to categorize periprosthetic fractures of the femur, tibia and patella, and to create the basis for specific decision-making in choice of treatment. Despite a wide field of treatment options, the actual functional outcome after therapy and the high rates of complications imply that an adequate analysis of the fracture etiology and the corresponding transfer into an individualized treatment concept offer the chance of functional restoration of the patient similar to the pre-fracture state.

Arthroplasty, Replacement, Knee↗
PubMed2005

[Clinical gait analysis].

Clinical gait analysis comprises a well defined repertoire of various methods for valid and reliable assessment. The rapid development of corresponding hardware and software has substantially decreased the efforts necessary for data processing and has promoted the clinical applicability of the procedures. The clinical question defines the amount of methodological input. Clinical gait analysis may provide diagnostic insight into the pathobiomechanics and the pathophysiology of complex gait disorders for which a profound understanding of the underlying causes is a prerequisite for adequate treatment. The methods may help in the screening of gait function following reconstructive surgery as a measure of quality control, the assessment of the severity of a gait disturbance, the evaluation of a rehabilitation process, or the quantification of the effect of orthoses, insoles or specific shoe ware. Simple procedures of gait analysis may suffice to obtain information on gait function which can not be derived by mere clinical observation and which can be incorporated into a clinical concept.

Activities of Daily Living↗
PubMed2003

Temporal profile of microvascular disturbances in rat tibial periosteum following closed soft tissue trauma.

BACKGROUND AND AIMS: Bone devascularization due to impaired periosteal perfusion following fracture with severe soft tissue trauma has been proposed to precede and underlie perturbed bone healing. The extent and temporal relationship of periosteal microcirculatory deteriorations after severe closed soft tissue injury (CSTI) are not known. We hypothesized that periosteal microcirculation is adversely affected and the manifestation of trauma-initiated microvascular impairment in periosteum is substantially prolonged following CSTI. MATERIAL AND METHODS: Using the controlled-impact injury device, we induced standardized CSTI in the tibial compartment of 35 isoflurane-anesthetized rats. Following the trauma the rats were assigned to five groups, differing in time of analysis (2 h, 24 h, 48 h, 1 and 6 weeks). Non-injured rats served as controls. Before the metaphyseal/diaphyseal periosteum was surgically exposed, intramuscular pressure within tibial compartment was measured. Using intravital fluorescence microscopy (IVM) we studied the microcirculation of the tibial periosteum. We calculated the edema index (EI) by measuring the skeletal muscle wet-to-dry weight ratio (EI = injured limb/contralateral limb). RESULTS: Microvascular deteriorations of periosteal microhemodynamics caused by isolated CSTI were reflected by persistent decrease in nutritive perfusion, markedly prolonged increase in microvascular permeability associated with increasingly sustained leukocyte rolling and adherence throughout the entire study period, mostly pronounced 48 h after the trauma. Peak level in capillary leakage coincided with the maximum leukocyte adherence, tissue pressure, and edema. Microcirculation of tibial periosteum in control rats demonstrated a homogeneous perfusion with no capillary or endothelial dysfunction. CONCLUSION: Isolated CSTI in absence of a fracture exerts long-lasting disturbances in periosteal microcirculation, suggesting a delayed temporal profile in manifestation of CSTI-induced periosteal microvascular dysfunction and inflammation. These observations may have therapeutic implications in terms of preserving periosteal integrity and considering the interaction of skeletal muscle damage and periosteal microvascular injury during management of musculoskeletal trauma.

Animals↗
PubMed2003

[Radio-radial external fixation in the treatment of distal radius fractures allows for free wrist motion].

INTRODUCTION: Joint bridging external fixation in the treatment of distal radius fractures restores radial length, whereas anatomic reduction of articular fragments is difficult. Immobilisation of the wrist joint is a further disadvantage. An extraarticular hybrid fixation of distal radius fractures was introduced that facilitates fracture reduction, safe retention and allows for free wrist movement. METHODS: 30 consecutive patients with extra- and intraarticular comminuted fractures of the distal radius were treated with an extraarticular radio-radial external fixation employing a modified Ilizarov hybrid fixation technique. The operative procedure is described in detail. A clinical and radiological evaluation was carried out on the first and seventh day as well as 6 weeks postoperatively after implant removal. RESULTS: Anatomic reduction was achieved in 24 cases (80%). On the first postoperative day dorsiflexion was 30%, palmar flexion was 51% and pronation/supination was 60%/70% of the uninjured side. Six weeks postoperatively all fractures united. Wrist motion of the affected side was more than 80% of the unaffected side. Neither extensor tendinitis nor pin loosening in the distal fragment did occur. CONCLUSION: The technique of extraarticular hybrid fixation is safe and reliable in the treatment of comminuted fractures of the distal radius. It allows for early wrist movement in the immediate postoperative period.

Adult↗
PubMed2003

[Acute CRPS I (morbus sudeck) following distal radial fractures--methods for early diagnosis].

INTRODUCTION: CRPS I represents a frequent complication following distal radial fractures. Early diagnosis may prevent chronification of the disease. However posttraumatic pain, swelling and motor disturbances render the differentiation from normal fracture patients more difficult. The incidence of CRPS I in patients at risk and the diagnostic value of clinical evaluation, radiography and thermography in the early posttraumatic phase are analysed. METHODS: 158 consecutive patients with distal radial fractures were followed-up for 16 weeks after trauma. Apart from a detailed clinical examination 8 and 16 weeks after trauma, thermography and bilateral radiographs of both hands were performed. RESULTS: At the end of the observation period 18 patients (11%) were clinically identified as CRPS I. The severity of the preceding trauma and the chosen therapy did not influence the process of the disease. 16 weeks after trauma easy differentiation between normal fracture patients and CRPS I patients was possible. 8 weeks after distal radial fracture clinical evaluation showed a sensitivity of 78% and a specificity of 94%. Thermography (58%) however and bilateral radiography (33%) revealed a poor sensitivity, respectively. The specificity was high for radiography (91%) and again poor for thermography (66%), respectively. CONCLUSION: The results of the study support the importance of clinical evaluation in the early diagnosis of CRPS I. Plain radiographs facilitate the diagnosis as soon as bony changes develop.

Acute Disease↗
PubMed2003

Noninvasive analysis of conjunctival microcirculation during carotid artery surgery reveals microvascular evidence of collateral compensation and stenosis-dependent adaptation.

OBJECTIVE: Hemodynamically relevant internal carotid artery (ICA) stenosis is a major cause of ischemic stroke. Despite its long-term benefit, carotid endarterectomy may also be associated with severe neurologic deficits. Intraoperative and early recognition of ischemia in the region of the ICA may reduce this risk. To date, direct imaging and quantitative analysis of microvascular structures and function in the human ICA region have not been possible. We purposed to visualize and quantify ischemia/reperfusion-induced microcirculatory changes in the terminal vascular bed of the ICA in patients undergoing unilateral ICA endarterectomy. METHODS: Sequential analysis of the ipsilateral and contralateral conjunctival microcirculation was performed with orthogonal polarized spectral imaging in 33 patients undergoing unilateral ICA endarterectomy because of moderate or severe ICA stenosis (North American Symptomatic Carotid Endarterectomy Trial score, 75% +/- 13%), before clamping the ICA (baseline), during clamping of the external carotid artery and ICA, during reperfusion of the ICA (intraluminal shunt), during the second clamping of the ICA (shunt removal), after declamping (reperfusion) of the external carotid artery and ICA, and 15 to 20 minutes after the second ICA reperfusion. RESULTS: During ICA clamping for shunt placement, ipsilateral and contralateral conjunctival capillary perfusion was significantly decreased, but it was completely restored after reperfusion with carotid shunting. Reclamping of the ICA for shunt removal caused microvascular dysfunction, which was significantly less pronounced than that observed during the first clamping. The individual degree of ICA stenosis was inversely correlated with the ipsilateral and contralateral decrease in conjunctival functional capillary density during the first ICA clamping. CONCLUSIONS: These results suggest adaptive mechanisms of capillary perfusion with increasing stenosis and development of collateral compensatory circulation in the vascular region of the human ICA. Conjunctival orthogonal polarized spectral imaging during unilateral ICA reconstruction enables continuous noninvasive analysis of bilateral conjunctival microcirculation in the terminal region of the ICA and enables monitoring for efficient carotid shunt perfusion during and after endarterectomy.

Adaptation, Physiological↗
PubMed2003

Small volume hypertonic hydroxyethyl starch reduces acute microvascular dysfunction after closed soft-tissue trauma.

A major pathway of closed soft-tissue injury is failure of microvascular perfusion combined with a persistently enhanced inflammatory response. We therefore tested the hypothesis that hypertonic hydroxyethyl starch (HS/HES) effectively restores microcirculation and reduces leukocyte adherence after closed soft-tissue injury. We induced closed soft-tissue injury in the hindlimbs of 14 male isoflurane-anaesthetised rats. Seven traumatised animals received 7.5% sodium chloride-6% HS/HES and seven isovolaemic 0.9% saline (NS). Six non-injured animals did not receive any additional fluid and acted as a control group. The microcirculation of the extensor digitorum longus muscle (EDL) was quantitatively analysed two hours after trauma using intravital microscopy and laser Doppler flowmetry, i.e. erythrocyte flux. Oedema was assessed by the wet-to-dry-weight ratio of the EDL. In NS-treated animals closed soft-tissue injury resulted in massive reduction of functional capillary density (FCD) and a marked increase in microvascular permeability and leukocyte-endothelial cell interaction as compared with the control group. By contrast, HS/HES was effective in restoring the FCD to 94% of values found in the control group. In addition, leukocyte rolling decreased almost to control levels and leukocyte adherence was found to be reduced by approximately 50%. Erythrocyte flux in NS-treated animals decreased to 90 +/- 8% (mean SEM), whereas values in the HS/HES group significantly increased to 137 +/- 3% compared with the baseline flux. Oedema in the HS/HES group (1.06 +/- 0.02) was significantly decreased compared with the NS-group (1.12 +/- 0.01). HS/HES effectively restores nutritive perfusion, decreases leukocyte adherence, improves endothelial integrity and attenuates oedema, thereby restricting tissue damage evolving secondary to closed soft-tissue injury. It appears to be an effective intervention, supporting nutritional blood flow by reducing trauma-induced microvascular dysfunction.

Acute Disease↗
PubMed2002

Late neurological deterioration 30 years following conservative treatment of a lower cervical spine fracture--a case report.

A today 44 years old man suffered from a compression and subluxation fracture of C 4 and C 5 vertebral body during a swimming accident in 1971. The primary therapy was conservative and the patient was rehabilitated. Since 1997 the patient showed a slowly progressive right hemiparesis with signs of cervical myelopathy. The diagnostic procedures revealed a severe deformity of the cervical spine with myelon compression. We performed an operation with replacement of C4 and C5 and dorsal stabilization at the same time. This very impressive case shows the risk of a late and slowly onset of myelopathic deterioration while latent bony instability persist post traumatic. The authors think in agreement with the actual literature that the early operative stabilization of instable fractures of the lower cervical spine is inevitable. According to the grade of neurological and bony damage the operation should not be performed later than 8-12 hours after injury.

Adult↗
PubMed2001

Biomechanical comparison of cervical spine interbody fusion cages.

STUDY DESIGN: An in vitro biomechanical study of cervical spine interbody fusion cages using a sheep model was conducted. OBJECTIVES: To evaluate the biomechanical effects of cervical spine interbody fusion cages, and to compare three different cage design groups. SUMMARY AND BACKGROUND DATA: Recently, there has been a rapid increase in the use of cervical spine interbody fusion cages as an adjunct to spondylodesis. These cages can be classified into three design groups: screw, box, or cylinder designs. Although several comparative biomechanical studies of lumbar interbody fusion cages are available, biomechanical data for cervical spine constructs are lacking. Additionally, only limited data are available concerning comparative evaluation of different cage designs. METHODS: In this study, 80 sheep cervical spines (C2-C5) were tested in flexion, extension, axial rotation, and lateral bending with a nondestructive stiffness method using a nonconstrained testing apparatus. Three-dimensional displacement was measured using an optical measurement system (Qualysis). Complete discectomy (C3-C4) was performed. Cervical spine interbody fusion cages were implanted according to manufacturers' information. Eight spines in each of the the following groups were tested: intact, autologous iliac bone graft, two titanium screws (Novus CTTi; Sofamor Danek, Koln, Germany), two titanium screws (BAK-C 8 mm; Sulzer Orthopedics, Baar, Switzerland), one titanium screw (BAK-C 12 mm; Sulzer Orthopedics), carbon box (Novus CSRC; Sofamor Danek), titanium box (Syncage; Synthes, Bochum, Germany), titanium mesh cylinder (Harms; DePuy Acromed, Sulzbach, Germany), titanium cylinder (MSD; Ulrich, Ulm, Germany), and titanium cylinder (Kaden; BiometMerck, Berlin, Germany). The mean apparent stiffness values were calculated from the corresponding load-displacement curves. Additionally, cage volume and volume-related stiffness was determined. RESULTS: After cervical spine interbody fusion cage implantation, flexion stiffness increased, as compared with that of the intact motion segment. On the contrary, rotation stiffness decreased after implantation of a cervical spine interbody fusion cage, except for the Novus CSRC, Syncage, and Kaden-Cage. If two screws were inserted (Novus CTTi and BAK-C 8 mm), there was no significant difference in flexion stiffness between screw and cylinder design groups. If one screw was inserted (BAK-C 12 mm), flexion stiffness was higher for cylinder designs (P < 0.05). Extension and bending stiffness were always higher with cylinder designs (P < 0.05). Volume-related stiffness for flexion extension and bending was highest for the Harms cage (P < 0.05). There was no difference for rotation volume-related stiffness between Harms and Syncage. CONCLUSIONS: The biomechanical results indicate that design variations in screw and cylinder design groups are of little importance. In this study, however, cages with a cylinder design were able to control extension and bending more effectively than cages with a screw design.

Animals↗
PubMed2001

Comparison between sheep and human cervical spines: an anatomic, radiographic, bone mineral density, and biomechanical study.

STUDY DESIGN: The quantitative anatomic, radiographic, computerized tomographic, and biomechanical data of sheep and human cervical spines were evaluated. OBJECTIVES: To compare the anatomic, radiographic, computerized tomographic, and biomechanical data of human and sheep cervical spines to determine whether the sheep spine is a suitable model for human spine research. SUMMARY OF BACKGROUND DATA: Sheep spines have been used in several in vivo and in vitro experiments. Quantitative data of the normal sheep cervical spine are lacking, yet these data are crucial to discussion about the results of such animal studies. METHODS: In this study, 20 fresh adult female Merino sheep cervical spines and 20 fresh human cadaver cervical spines were evaluated anatomically, radiographically, computerized tomographically, and biomechanically. Three linear and two angular parameters were evaluated on four digital radiographic views: anteroposterior, right lateral in neutral position, flexion, and extension. Quantitative computed tomography scans at the center of each vertebral body and 3 mm below both endplates were analyzed for bone mineral density measurements. Biomechanical testing was performed in flexion, extension, axial rotation, and lateral bending by a nondestructive stiffness method using a nonconstrained testing apparatus. Range of motion and stiffness of each motion segment were calculated. Additionally, 10 linear anatomic parameters of each vertebra were measured using a digital ruler. RESULTS: Anterior and mean disc space height in the sheep cervical spine increased constantly from C2-C3 to C6-C7, whereas middle disc space height decreased and posterior disc space height remained unchanged. Anterior and mean disc space height were significantly higher in sheep. In both sheep and human cervical spines, intervertebral angles were not significantly different. Standard deviations of bone mineral density in the human cervical spine were fourfold higher than in the sheep cervical spine, yet no significant differences were found in bone mineral density values between the two species. Range of motion differed significantly between the two species except in flexion-extension of C3-C4, C5-C6, axial rotation of C2-C3, and lateral bending of C2-C3, C3-C4, and C4-C5. Stiffness also was significantly different except in flexion-extension of C2-C3, C4-C5, C5-C6, and lateral bending of C2-C3, C3-C4, and C4-C5. Anatomic evaluation showed no difference in upper endplate parameters for C4 and C5. CONCLUSIONS: Although several differences were found between human and sheep cervical spines, the small intergroup standard deviations and the good comparability with the human spine encourage the use of the sheep cervical spine as a model for cervical spine research. On the basis of the quantitative data obtained in this study, the sheep motion segment C3-C4 seemed to be the most reliable model for the corresponding human motion segment.

Adult↗