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L Kinzl

Publications and source records attributed to L Kinzl.

At least 73 records · Page 4Linked to original sources

[Corrective osteotomies of the distal femur with retrograde intramedullary nail].

Deformities of the distal femur are usually corrected by supracondylar osteotomy. In the "classical" procedure the bone cut is performed with an oscillating saw, and internally fixed using a plate. This technique is hampered first by an invasive approach and second by limited corrective options in case of complex deformities. A supracondylar bone cut by focal dome osteotomy or drill osteoclasis in combination with internal fixation by retrograde intramedullary nailing (RN) might be a promising alternative procedure. 12 patients with multidimensional post-traumatic deformities of the distal femur were prospectively enrolled in a study to investigate this new minimal-invasive technique. In all patients a meticulous analysis of leg geometry was done pre- and postoperatively. Details of operative planning, osteotomy and fixation procedure are given as well as the postoperative treatment. 7 corrective osteotomies were one-step procedures, in 5 patients additional lengthening over the RN was performed using unilateral external fixation. The mean follow-up was 15 (range 7-27) months. All of the osteotomies healed in a normal expected time frame. All patients had important functional benefits. In 11 patients the goal of deformity correction was achieved. In one patient the correction in the frontal plane remained insufficient. 6 months after the completion of femoral lengthening osteomyelitis developed in one patient, probably due to a pin-track infection. The infection subsided after early removal of the RN. No further complications were observed. The presented technique is demanding concerning pre-operative planning and surgical realization but it offers a minimal-invasive and promising approach for the correction of multidimensional femoral deformities.

Adult↗

[Computer-assisted surgery: developments and prospects in 2001. Results of a workshop at Schloss Reisenburg, 23-24 November 2000].

The progress in computer assisted surgery (CAS) is influenced by new technologies in imaging as well as by the input of the users. At present, CAS procedures are established in dorsal spine instrumentation, prosthetics and long bone surgery. Present status and future of CAS was a topic of an expert meeting at the Reisensburg castle. Imaging will speed up in the future using multi-detector techniques. C-arm navigation will gain more information using the 3D technology intraoperatively. CT based navigation procedures are standard in spine and will be established in pelvic surgery. CAS in robotics at the moment means the use of robot-assistance. A new concept is the modality-based navigated surgery, which can be used at various skeletal locations. Visualization of patient data will improve using 3D semi-transparencies with real time update. In the future it will be mandatory to find algorithms to fuse the different possibilities and techniques. A new concept of surgical training is necessary to teach CAS procedures. Therefore discussion must go on to improve these systems.

Arthroplasty, Replacement, Knee↗

[Fractures involving the distal femoral epiphysis. Long-term outcome after completion of growth in primary surgical management].

During a period of 12 years (1983-1994) we operated 13 patients with fractures involving the distal epiphyseal cartilage of the femur. All patients could be followed up in clinical and radiological examination following the completion of growth. By examination no patients had any complaints. The clinical examination revealed no limitation in range of motion of the hip or knee joint compared to the other side in any of the patients. 5 patients out of 13 (38%) were found to have a correct axial alignment with no axis deviation, shortening or lengthening of the leg. The other 8 patients (62%) presented the following one- or multidimensional deformities (compared to the contralateral, uninjured femur): 2 patients had varus deformities, 5 patients had valgus deformities, the axial malalignment in the frontal plane was always less than 10 degrees in all cases. 5 patients were found to have a shortened femur (between 8 and 19 mm), while an elongation of the primarily injured femur (10 and 15 mm) was established in 2 patients. On the basis of this study, we recommend that clinical and, if necessary, radiological and/or sonographic examinations are performed following the completion of growth in all patients with injuries involving the epiphyseal plate of the distal femur.

Adolescent↗

[Evaluation of cartilage changes within the scope of second-look arthroscopy 12 months after surgical reconstruction of anterior cruciate ligament rupture].

The anterior cruciate ligament (ACL) rupture is among the most frequent injuries of the joints. Actually, there is no doubt regarding the necessity for surgical treatment. However, little is known about the progression of osteochondral damages and their distribution following reconstruction of the ACL. We treated 150 tears of the ACL either acute (median 7d) with augmented reinsertion (n = 41) and with autologous bone patella tendon graft (n = 24) or chronic (median 369d) with autologous bone patella tendon graft (n = 85). The study design was prospective. All osteochondral defects were documented in the six compartments. Second look arthroscopy and clinical examination were performed after twelve months in the course of removal of implants and possible changes of the osteochondral state were evaluated. Detoriation of osteochondral state was seen in 86 (57%) of 150 patients, while there was no statistical difference between the three groups. The time of operation had no influence on the osteochondral damage. There was a significant increase of chondral damages in the medial and retropatellar compartment after autologous bone patella tendon graft, while the changes after augmented reinsertion were diffuse. There were no significant differences in the clinical examination between the three groups regarding the Lysholm score and the functional and subjective outcome. However, postoperative instability was frequently observed (positive pivot-shift 25%, positive Lachmann test 57%). We suggest that postoperative instability should have led to the increased osteochondral damages.

Adult↗

[Computer assisted surgery, 2001 development and prospects. Results of a congress at Reisensburg Castle, 23-24 November 2000]].

The progress in computer assisted surgery (CAS) is influenced by new technologies in imaging as well as by the input of the users. At present, CAS procedures are established in dorsal spine instrumentation, prosthetics and long bone surgery. Present status and future of CAS was a topic of an expert meeting at the Reisensburg castle. Imaging will speed up in the future using multi-detector techniques. C-arm navigation will gain more information using the 3D technology intraoperatively. CT based navigation procedures are standard in spine and will be established in pelvic surgery. CAS in robotics at the moment means the use of robot-assistance. A new concept is the modality-based navigated surgery, which can be used at various skeletal locations. Visualization of patient data will improve using 3D semi-transparencies with real time update. In the future it will be mandatory to find algorithms to fuse the different possibilities and techniques. A new concept of surgical training is necessary to teach CAS procedures. Therefore discussion must go on to improve these systems.

Forecasting↗

Early inflammatory mediator response following isolated traumatic brain injury and other major trauma in humans.

The inflammatory response following isolated traumatic brain injury (TBI) is characterised by the release of pro- and anti-inflammatory mediators. In order to determine the important mediators regarding survival and outcome of patients with severe traumatic isolated head injuries, we performed this prospective preclinical and clinical study starting upon arrival at the site of the accident. After approval by the local ethics board committee, 94 multiple-injury patients were enrolled. Of these, 72 patients suffered from major injuries; the other 22 patients had a severe isolated brain injury and were allotted to subsets of survival or nonsurvival. Of the pro- and anti-inflammatory mediators (cytokines, arachidonic acid metabolites and soluble adhesion molecules), interleukin-6 (IL-6), IL-12 and malone dialdehyde (MDA) appeared to be of specific importance; maximum IL-6 plasma levels were eightfold higher in cases of nonsurvival than in those of survival. Patients that did not survive TBI were the only ones to express an IL-12 increase, whereas survivors and patients with other major trauma did not show any increase within the first 24 h. An early distinct decrease of MDA showed in patients who did not survive TBI, in contrast to survivor patients who exposed almost constant levels during the first 24 h.

Adult↗

Surface electromyography-verified muscular damage associated with the open dorsal approach to the lumbar spine.

The dorsal approach is increasingly preferred in the surgical treatment of vertebral fractures. However, the access and the implant's position cause muscle loss, which can lead to instability and a reduced capacity for rehabilitation. Morphological factors (bones, intervertebral discs) are typically blamed for chronic pain syndromes in the literature, while less importance is attached to functional factors (muscles). The objective of this study was therefore to investigate the isolated influence of dorsal spinal instrumentation on the back muscles by means of electromyography (EMG). A total of 32 patients with conditions after dorsal spondylodesis following the fracture of a vertebral body and 32 subjects with healthy backs were enrolled in this study. The EMG signal was recorded in three different muscle groups during isometric extension exercise. The evaluation was performed by comparing the mean rectified amplitudes of the three muscle groups in the patients and controls. The patients had significantly lower amplitudes in the multifidus muscle (MF) and significantly higher amplitudes in the iliocostal muscle (IL). Patients with severe pain were found to have lower electric muscle potentials in all investigated muscle groups than patients with mild pain. The muscle damage which was established in the multifidus muscle is compensated by increased activity in the iliocostal muscle. On the basis of anatomical considerations, the damage pattern can be identified as having been caused by surgery. It is extremely unlikely that trauma is the cause.

Adolescent↗

Augmentation of a ruptured posterior cruciate ligament provides normal knee joint stability during ligament healing.

OBJECTIVE: To identify an augmentation technique which would provide mechanical protection for the healing posterior cruciate ligament. DESIGN: Six human knee specimens were tested in vitro for posterior knee joint stability after augmenting the cut posterior cruciate ligament by six different techniques using a resorbable double strand Polydioxanone augmentation device. BACKGROUND: A fresh isolated rupture of the posterior cruciate ligament is often treated conservatively. Results have shown that it can heal, but ligament elongations occur frequently. Therefore a method is needed to provide posterior knee joint stability during ligament healing. METHODS: The effect of different femoral augmentation insertions on posterior knee stability was tested by recording the antero-posterior (AP) position of the tibia and the augmentation force. Testing was performed during flexion--extension cycles and under posterior shear loads. RESULTS: The insertion combination that proved to stabilize the joints best consisted of one augmentation strand leading along the antero-lateral posterior cruciate ligament fibres and inserting at the distal end of the Blumensaat line and one strand leading along the posteriormedial fibres and inserting in the middle of the Blumensaat line. AP translations similar to those occurring in healthy knee joints could be achieved. CONCLUSIONS: It is possible to restore normal posterior knee joint stability by implanting a double strand augmentation device. This can help a posterior cruciate ligament to heal under non-elongated conditions.

Absorbable Implants↗

Prediction of strength of cortical bone in vitro by microcomputed tomography.

OBJECTIVE: The aim of this study was to evaluate the predictive value of bone mineral density and intracortical porosity measured by microcomputed tomography for the strength of cortical bone biopsies. DESIGN: Experimental study comparing the predictive value of bone mineral density and of intracortical porosity determined in vitro by microcomputed tomography for the mechanical properties of cortical bone cylinders. BACKGROUND: The assessment of cortical bone strength might be relevant for the prediction of fracture risk or the choice of suitable therapy strategies in orthopaedic surgery. The predictive value of cortical density for the mechanical properties is discussed controversially. The relevance of intracortical porosity measured by histomorphometry has been established, but the predictive value of porosity determined by microcomputed tomography remains to be explored. METHODS: Femoral cortical bone specimens from the mid diaphysis of 24 patients were harvested during total hip replacement procedure at the location, where a diaphyseal hole (diameter 4.5 mm) was drilled in order to reduce the intramedullary pressure. In vitro intracortical porosity and bone mineral density measurements by microcomputed tomography were compared with strength and elastic modulus assessed by a compression test transverse to the Haversian systems of the same specimens. RESULTS: Significant negative correlations were found between porosity measured by microcomputed tomography scans and yield stress, stiffness and elastic modulus (P<0.001), however, the positive correlations between bone mineral density and mechanical parameters were stronger (P<0.0001). The mechanical parameter best predicted by mineral density as well as by porosity was yield stress (r=0.72,P<0.0001;r=-0.64,P<0.001). CONCLUSIONS: Bone mineral density determined by microcomputed tomography imaging in vitro may be a potent method to predict mechanical properties of cortical bone non-destructively. The application in vivo remains to be explored.

Aged↗

Predictive value of Singh index and bone mineral density measured by quantitative computed tomography in determining the local cancellous bone quality of the proximal femur.

OBJECTIVE: The purpose of this study was to assess the predictive value of the Singh index as well as quantitative computed tomography for the in vitro local mechanical competence of the cancellous bone of the proximal femur. DESIGN: An experimental study examining the relation between mechanical properties and bone mineral density of the femoral neck determined in vitro and the clinical estimated Singh index on X-rays. BACKGROUND: Evaluation of the predictive value of the Singh index, an inexpensive and simple technique for the mechanical properties of the cancellous bone of the proximal femur. METHODS: The bone quality of the proximal femur of 34 patients undergoing total hip replacement was estimated by roentgenography using the Singh index. Bone mineral density was quantified by quantitative computed tomography using cylindrical cancellous bone biopsies harvested during the total hip replacement procedure by a new biopsy method. The mechanical properties of the bone specimens (Young's modulus, strength and maximum energy absorption E(max)) were measured by mechanical testing of the bone biopsies. RESULTS: A strong correlation of the Singh index versus material properties of cancellous bone was noted (r=0.66 for Young's modulus, r=0.73 for strength and r=0.69 for E(max), P<0.0001). The correlations of bone mineral density measured by quantitative computed tomography versus Young's modulus, strength and energy absorption E(max) were significant. Strength was predicted best (r=0.82; P<0.0001), followed by E(max) (r=0.79; P<0.0001) and Young's Modulus (r=0.73; P<0.0001). CONCLUSIONS: We conclude, that assessment of bone mineral density by quantitative computed tomography is a reliable and precise method for the estimation of cancellous bone material properties. The Singh index provides a rough estimate for the mechanical competence of the proximal femur. It is inexpensive, simply to assess and can in some cases replace the measurement of bone mineral density, notably in cases of marked decrease in bone density.

Aged↗

Predictive value of bone mineral density and morphology determined by peripheral quantitative computed tomography for cancellous bone strength of the proximal femur.

Peripheral quantitative computed tomography (pQCT) is an established diagnostic method for assessment of bone mineral density in the diagnosis of osteoporosis. However, the capacity of structural parameters of cancellous bone measured by high-resolution computed tomography remains to be explored. In 33 patients, bone mineral density (BMD) of the proximal femur was measured in vitro by pQCT using cylindrical biopsies from the intertrochanteric region harvested before the implantation of an artificial hip joint. By digital image analysis of CT scans, parameters derived from histomorphometry describing the microarchitecture of cancellous bone were measured. The biopsies were also loaded to failure by an uniaxial compression test to determine the biomechanical parameters, Young's modulus, strength, and maximum energy absorption (E(max)). Strong correlations were found for BMD vs. mechanical parameters (r = 0.73 for Young's modulus, r = 0.82 for strength, and r = 0.79 for E(max); p < 0.001, n = 29). The morphological parameters, bone volume per trabecular volume (BV/TV), apparent trabecular thickness (app.Tb.Th), apparent trabecular separation (app.Tb.Sp), and trabecular number (Tb.N), correlated significantly with all mechanical parameters. The combination of morphological parameters with BMD in a multivariate regression model led to an overall, but only moderate, increase in R(2) in all cases. Our data confirm the high predictive value of BMD for the mechanical competence of cancellous bone of the intertrochanteric region. However, quantification of cancellous bone structure by image analysis of CT scans may provide additional qualitative information for the analysis of bone strength.

Aged↗

Functional treatment of physeal and periphyseal injuries of the metacarpal and proximal phalangeal bones.

BACKGROUND/PURPOSE: Hand fractures are common injuries in infants. Complications are rare because of potent remodeling dimension and rapid healing of growing bone. There is limited remodeling capacity for angular and rotational deformity so displaced fractures often require open reduction and internal fixation. METHODS: The authors present a splint system for a protected reduction and mobilization program of displaced proximal phalanx and metacarpal fractures. The custom-molded 2-component thermoplastic splint allows motion of the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints. It has been developed to allow bone healing and recovery of motion at the same time. In this study, the authors evaluated the clinical and radiologic results of a series of 11 consecutive infants with displaced metacarpal fractures and 13 displaced proximal phalanx fractures who received functional treatment. RESULTS: Fracture consolidation and full active motion was achieved simultaneously in 4 weeks in 21 children; 2 infants required physiotherapy, and 1 child was lost to follow-up. No further growth abnormality was seen within a 12-month observation period. CONCLUSION: When there is no damage of soft tissue the functional mobilization program can lead to good results treating displaced physeal and periphyseal hand injuries of proximal phalanx and metacarpal fractures. J Pediatr Surg 36:611-615.

Child↗

[Reproducibility of measuring the finger joint angle with a sensory glove].

Joint angles are measured using goniometers according to the neutral-zero method. These measurements are dependent on the examiner and are thus subject to great variation. With a newly developed sensor glove, the grip patterns of the hand can be captured with a computer-assisted technique. In a comparative study involving five subjects, the joint angles during power grip around a cylindrical body and while clenching a fist were determined by nine examiners at three different times, using the conventional technique according to the neutral-zero method. In the same experimental design, the joint angles were measured with the sensor glove. As a criterion for the reproducibility of the measurements, the intraclass correlation coefficient (ICC) was calculated by means of an analysis of variance. The ICC is a value which approximates 1 if the reliability of the measurements is high. At 0.94, the ICC of the data determined with the sensor glove was markedly higher than the mean ICC for all examiners of 0.50 using the conventional method. Besides the measurement of the finger joint angles, the sensor glove allows the dynamic recording of joint movements of all finger joints during different grip patterns of the hand.

Adult↗

[Measuring grip strength of the hand with a sensor glove by gripping with submaximal and maximal strength].

Grip strength measurements with the aid of dynamometers are dependent on the cooperation and motivation of the individual examined. Recognising a simulated loss of grip is a hitherto unresolved problem. With a sensor glove developed at the Berlin University of Technology, the force distribution pattern of any form of grip can be captured via ten pressure sensors and evaluated by computer. In five subjects, the force distribution patterns at submaximum and maximum force of five different grips were determined in three successive measurements each. The data were recorded in force-time diagrams. For each act of grasping, the measurements produced a curve with near-constant measuring signals within a defined period (plateau). The difference in the plateau heights of successive grips and the structures of the individual plateaux (oscillation, standard deviation) were used as distinguishing criteria. The dynamics of the measuring signals showed statistically significant differences between grips with submaximum and maximum force (p < 0.0001).

Adult↗

[Results of basal joint arthrosis treatment--comparison of Epping ligament reconstruction with trapeziectomy alone].

Objective of this study is to compare clinical and radiological results of two different methods of treatment for trapeziometacarpal osteoarthrosis of the thumb. Eighteen patients received operative treatment. An operation according to Epping was performed in eleven cases (collective I), while nine cases were treated with a trapeziectomy only (collective II). The mean follow-up of the first collective was 40 months and 15 months for the second one. The results of the two patient groups were subjected to statistical comparison in a retrospective study. This revealed no significant differences with regard to active range of motion, power, and subjective symptoms, classified according to the Buck-Gramcko score. With a mean of 49 points for the first and 50 points for the second collective, both achieved very good results. However, the mean operating time was significantly shorter in the patients treated with a trapeziectomy only, while the mean distance between the base of the first metacarpal bone and the scaphoid bone was significantly greater in this group. This is surely due to the shorter follow-up of the patients who underwent trapeziectomy only, since further proximalisation has to be expected. We were able to demonstrate that both methods yield equally good results, and hence the simpler technique of trapeziectomy alone should be given preference, at least in the standard situation of a patient, whose intermetacarpal ligaments offer sufficient stability after trapeziectomy.

Carpal Bones↗

[Incidence of complications of the screw osteosynthesis of odontoid process fractures].

In this retrospective clinical study the incidence of complications in 58 consecutive, with anterior screw fixation stabilized patients after fractures of the odontoid process is evaluated. In 51 patients the fracture has been defined as type II according to Anderson, in 6 patients an oblique type II fracture was present and one patient showed a cephalad type III fracture. Preoperatively, in only 19 % of the patients (n = 11) no dislocation of the dens occurred. 32 patients were treated with single screw osteosynthesis, in 26 patients two screws were implanted. Significant complications with clinical relevance were registered in 14 patients (24 %), in 10 cases (17 %) an operative reintervention was required. Intraoperatively, in one patient a rupture of the carotid artery while winding around the motor drill occurred and in another case a complete malplacement of the screw posteriorly to the odontoid process was observed. A clearly excentric positioning of the implant was evaluated in 5 patients with a consecutive high rate of implant migration (n = 3). Two patients died perioperatively not related to the cervical injury. Postoperatively, one patient with a wound infection due to an iatrogenic perforation of the esophagus required reoperation as well as 4 patients with instability because of implant migration. Patients beyond the age of 65 years (n = 3) were significantly overrepresented in that group. In one case, the secondary intervention was caused by a pseudarthrosis of the dens axis. Complications without any relevance to the clinical and functional long term result were fusions in malposition of the odontoid process in 14 patients (24 %) and 10 (17 %) marginal screw perforations laterally. Differences in the use of one or two screws have not been observed in this study, although the investigations showed a tendency between marginal lateral screw perforations and double screw osteosynthesis and an increasing number of complications in the geriatric cohort.

Adolescent↗

Reduced serum total reductive capacity in lethal severe trauma.

BACKGROUND: Risk assessment is a prerequisite for effective treatment and triage in severe injury. A novel substrate-based assay to measure total reductive capacity (TORC) in serum was used to stratify risk of lethal outcome in severe trauma in a clinical trial. METHODS: Serum of patients with severe trauma (Injury Severity Score > 19) was obtained at the accident site, at admission, and at regular intervals thereafter. TORC was determined and correlated to outcome. The TORC assay uses thiol-labeled arachidonic acid as substrate from which free thiols are released by reductive amino acids and the specific activity of phospholipase A2. Free thiols are coupled to monochrombimone, and the resulting fluorescence is proportional to TORC. RESULTS: Eighteen patients with lethal severe trauma and 16 patients who survived were studied. Injury Severity Scores (lethal, 33 (29--43); survival, 31 (25--42); p = NS) and Polytrauma Scores (lethal, 25 [18--32]; survival, 26 [23--31], p = NS) were not significantly different. At the accident site, patients with a lethal course had significantly lower TORC than nonlethal cases (59.2 +/- 5.1 ng/mL vs. 89.5 +/- 6.7 ng/mL; p < 0.001). Values at admission were similar (lethal, 51.2 +/- 7 ng/mL; survival, 73.8 +/- 9 ng/mL; p < 0.01). At the accident site and at admission, TORC < 82.3 ng/mL was prognostic of lethal outcome (sensitivity, 88%; specificity, 65%/73% and 69%, respectively, for admission). CONCLUSION: Serum reductive potential at the site of accident or at admission allows the stratification of trauma patients with respect to lethal outcome in severe trauma when severity scores fail to do so.

Adolescent↗