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Biomedical subjects

L Gotzen

Publications and source records attributed to L Gotzen.

At least 19 recordsLinked to original sources
PubMed1992

[Indications, technique and results of monosegmental dorsal spondylodesis in wedge compression fractures (grade II) of the thoracolumbar spine].

The management of wedge compression fractures of the thoracolumbar spine remains a controversial subject. Although there is an increasing tendency for operative intervention of spinal injuries, non-operative treatment of compression fracture has been the method of choice. The compression fracture is a fracture occurring during compressive forces of the anterior column due to flexion mechanisms. The more severe the compressive fracture, the more likely it will be to present, in an addition to anterior wedging, a failure of the posterior column indicating tension forces at that level. These fractures, defined as mechanically unstable and classified as compression fractures Grade II, are concentrated in the thoracolumbar region. Between June 1987 and July 1990 14 patients with compression fractures Grade II were treated posteriorly with one level internal fixation. Of the 14 patients, 9 had stabilization with plates and cerclage wire, 5 with an internal fixator. All patients received a localized fusion. In order to permit a more reliable analysis of the results of our stabilizing procedures, a comparison was made with a series of 11 cases with equivalent fractures treated non-operatively between 1986 and 1989. At clinical and radiographic follow-up evaluation, the results in the operative group were much more favourable, both subjective and objective, than in the non-operative group. We derive from these results that in thoracolumbar compression fractures Grade II, posterior one level stabilization and fusion is a recommendable surgical procedure.

Adult↗
PubMed1992

[Reconstructive interventions of the posterior cruciate ligament--experimental studies of isometric aspects. Part I: Studies of a string model].

In six intact cadaveric knees, we measured how the distance between six selected points in and around the femoral and tibial attachment area of the posterior cruciate ligament (PCL) changes with knee flexion. After complete removal of the PCL, 2-mm drill holes were made at the selected points. Each femoral point was measured against each tibial point using a heavy suture that was passed through the drill holes. The proximal end of the suture was fixed to the lateral aspect of the femur. The distal end of the suture was attached to a measuring unit. The changes in femorotibial distance were measured during flexion from 0 degrees to 110 degrees in 10 degrees steps. The tibial drill hole locations had only a minor effect on the changes in femorotibial distance. The most isometric point was located in the centre of the posterior intercondylar area. The femoral locations of the drill holes were the primary determinant of whether the distance increased, decreased or remained nearly constant. According to our results the most isometric femoral point is located at the posterosuperior margin of the anatomical PCL attachment. Using the tibial isometric point as a reference, the femoral points positioned anterior or posterior to the isometric point produced considerable changes in the femorotibial distance upon knee flexion. The anterior point led to an increase of about 7-8 mm at 110 degrees of flexion, the posterior point to a decrease of the same extent. Much smaller changes in femorotibial distance resulted from the points located superior or inferior to the femoral isometric point.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

[Reconstructive interventions of the posterior cruciate ligament--experimental studies of isometric aspects. Part II: Studies of the posterior cruciate ligament replacement model].

Isometric positioning of the posterior cruciate ligament (PCL) graft is important for successful reconstruction of the PCL-deficient knee. This study documents the relationship between graft placement and changes in intra-articular graft length during passive range of motion of the knee. In eight cadaveric knees the PCL was identified and cut. The specimens were mounted in a stabilizing rig. PCL reconstruction was performed using a 9-mm-thick synthetic cord that was passed through tunnels 10 mm in diameter. Three different femoral graft placement sites were evaluated: (1) in four specimens the tunnel was located around the femoral isometric point, (2) in two specimens the tunnel was positioned over the guide wire 5 mm anterior to the femoral isometric point, (3) in two specimens the tunnel was positioned over the guide wire 5 mm posterior to the isometric femoral point. In all knees only one tibial tunnel was created around the isometric tibial point. The location of the isometric points was described in part I of the study. The proximal end of the cord was fixed to the lateral aspect of the femur. Distally the cord was attached to a measuring unit. The knees were flexed from 0 degree to 110 degrees, and the changes in the graft distance between the femoral attachment sites were measured in 10 degrees steps. Over the entire range of motion measured the femoral tunnels positioned around the isometric point produced femorotibial distance changes of within 2 mm. The anteriorly placed tunnels produced considerable increases in femorotibial distance with knee flexion, e.g. about 8 mm at 110 degrees of flexion.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

[Sonographic diagnosis of the injured acromioclavicular joint. A standardized examination procedure].

The possibility of using ultrasound leads to an improvement and extension of the methods conventionally used for diagnostic examination of the injured acromio-clavicular (AC) joint. Periarticular soft tissues can be assessed, as well as the osseous parts making up the joint. Coraco-clavicular ligaments in particular can be visualized well, and the coraco-clavicular distance can be measured precisely. Evaluation of the ultrasound findings makes classification of the grade of severity of injury according to Tossy much easier. We examined 35 injured AC joints of all grades of severity. With two standard planes of examination--a frontal and a sagittal plane--it was possible to obtain information about the grade severity of the injury in every case. Instability of the joint is diagnosed by measuring the coraco-clavicular distance with and without weights pulling on each arm. Standard X-rays of the shoulder remain mandatory to exclude fractures. When ultrasound examination is possible, however, X-ray examination of the shoulder with weights pulling on the arms is unnecessary.

Acromioclavicular Joint↗
PubMed1991

[Technical measuring procedures for 3-dimensional movement analysis of experimentally-induced fractures of the thoracolumbar spine and initial results].

Biomechanics and motion following fractures of the thoracolumbar spine have not yet been clarified. The motion acts in 6 degrees of freedom: three rotations and three translations parallel to the system of coordinates. The problem is to measure each rotation and each translation individually. This requires a method allowing precise three-dimensional evaluation of the motion that takes place in the genesis of a spine fracture. This technique should not influence the experiment, should give exact data over a wide range of measurement and, finally, should require as little equipment as possible. To fulfil these conditions we have developed a "double cube" model. Cadaver spine units from T11 to L3 were used. T11 was blocked with T12 and L2 with L3. These blocks were used to fix the spine in a testing machine so that a wedge-compression fracture could be produced in L1. Dorsal to each of the blocks one cube was mounted, the caudal one fixed while the cranial one could be moved by the machine. In the caudal cube a right-handed cartesian system of coordinates was defined, in which the vertebrate above would move and break. This technique can be used to describe either physiological or fracture experiments or, for example, to compare stability tests for different fixation devices. It is demonstrated that precise three-dimensional description of the biomechanics of vertebral fractures is possible with little and simple equipment. The cubes in this model are easily to integrate in the experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomechanical Phenomena↗
PubMed1990

[Indication for, technic and results of reconstruction of the extensor apparatus in the treatment of patellar instability and patellar chondropathy].

Patella dislocation or subluxation is a common cause of internal derangement of the knee. Frequently they lead to lesions of the articular cartilage of the patella. More than one-hundred operative methods have been described for surgical correction of this condition and for treatment of the chondral damage, suggesting that none has been consistently successful. Long-term results of extensor mechanism reconstruction have been published by Turba et al. (26) advocating a numerical rating system with subjective and objective criteria for the follow-up control. We present our operative technique and results with extensor mechanism reconstruction in 54 cases by applying the above mentioned rating system. With a follow-up period from more than one year 39 patients were available for control. The results of proximal reconstruction (24 cases) were good and excellent in 20 cases by subjective and in 23 cases by objective evaluation. The proximal and distal reconstructions (15 cases) showed subjective 13 and objective 14 patients with good and excellent results.

Adolescent↗
PubMed1990

[Thumb replacement operation using metacarpal distraction osteotomy as a secondary intervention after thumb amputation].

After thumb amputation distal to the MCP-1 joint, good results can be achieved with lengthening of the first metacarpal bone by an external fixateur if a correct technique is applied. In all our patients the lengthened thumb was mechanically stable and sensitive, thus improving the patient's ability to use the hand to grasp. Another advantage of this procedure is the relative simplicity of the method. Furthermore, the original nerve and vascular supply can be preserved.

Amputation, Traumatic↗
PubMed1990

[Sonographic imaging of meniscus lesions. An experimental study].

There is still no general agreement on the value of ultrasonographic visualization of pathologic changes in the knee menisci. Some examiners report on large patient collectives in which it has yielded accurate diagnoses in 90% of cases. Other authors describe much higher failure rates and unreliable imaging of meniscal lesions. The aim of this experimental study was to determine how reliable the imaging of such lesions is, which of the different types can be recognized, and what their ultrasonic morphological characteristics are. To this end, the examinations were performed on isolated menisci in a waterbath to avoid artefacts that might be caused by the tissues surrounding the meniscus in situ. It was shown that all types of lesion except the transverse rupture could be visualized and localized reliably. The different types of meniscal injuries all produce the same sort of appearance on the screen: a hard, glaring reflection of sound waves. The necessity of using a 7.5-MHz sector, or curved-array transducer for the examination is emphasized.

Aged↗
PubMed1990

[The bone bank--a standardized procedure? Results of a federal survey of German surgical clinics].

An inquiry at German surgical departments about their bone bank techniques showed that 45% of clinical hospitals use allogeneic bone implants among other implants. In 1989, the year of the official survey, allogeneic bone was transplanted about 6000 times in these clinical hospitals. Despite of this high transplantation frequency important differences turn out regarding selection and testing of recipients, transplantation storage and treatment. A lot of clinical hospitals do not perform important donor examinations inspite of proven transmission risks of bacterial and viral diseases by deep frozen bone. A trend analysis shows that despite of the risk of an HIV-transmission and the resulting difficulties in the logistic of the bone bank, the transplantation frequency allogeneic bone stays constant. The official surveys prove the large range of bone bank techniques and should give rise to make efforts to take note of the recommendations for bone banking techniques.

Bone Transplantation↗
PubMed1990

[Monolateral external compression arthrodesis of the upper ankle joint].

A new method of compression-arthrodesis of the ankle joint using monolateral external fixation is introduced. After bimalleolar incision and resection of the tibio-talar joint-surfaces, compression fixation was achieved by the Monofixateur placed ventromedially. The lateral malleolus was used as a bar-chip fixed with two screws. Between 1985 and 1988 this operation was performed on ten patients, mostly because of posttraumatic joint destruction. On the average the hospital stay was 17 days. Walking with crutches was allowed on the third postop. day with partial weight bearing after one week. Two patients developed a pin-tract infection with one of them needing operative revision. Except in a case of primary arthrodesis done in a severely open talus dislocation fracture bony fusion was achieved between 8 to 12 weeks postoperatively. Eight patients were followed up after an average of 2.5 years. Four patients were completely painfree and showed an almost normal gait. Four patients were able to walk 2 to 3 hours without serious complains. Five patients classified the result as good, two as fair and one as poor. In the poor result the distal Schanz-screws had partially penetrated the subtalar joint with consecutive joint deterioration. The tarsal mobility had a mean value of 23 degrees. The length of the operated leg was on the average one cm shorter. Due to the favourable results we recommend monolateral external compression-arthrodesis as a useful procedure.

Adolescent↗
PubMed1990

[Ilizarov's distraction osteogenesis using the mono-fixator system and initial clinical experiences with the injured lower leg].

Distraction osteogenesis, as developed by Ilizarov, allows the limbs to be lengthened and intercalary defects to be filled by bone transport without the use of bone grafts. In five patients with traumatic sequelae (fractures of the lower leg), unilateral dynamic mono_fixation and a special distraction apparatus were used for application of the Ilizarov technique. With the distraction device, gradual distraction of the osteotomy surfaces (1/3 mm in three steps per day) is easy for the patients to perform. In three cases distraction osteogenesis was used to correct shortening of the lower leg and in two cases for bridging a tibial defect due to an infection in the plate osteosynthesis. In all cases, the course of treatment and bone healing were uneventful. Based on our first clinical experiences, we believe that mono_fixation provides appropriate stability and the distraction apparatus permits appropriate bone transportation for successful distraction osteogenesis in the tibia.

Adolescent↗
PubMed1989

[Pseudarthroses of the fibula following fracture of the lower leg].

There are few reports in the literature on nonunion of the fibula following simultaneous fracture of the tibia and fibula. They apparently develop in cases where when only the tibia is stabilized and early functional treatment follows. Six patients suffering from painful nonunion of the fibula were treated in our trauma center from 1985 to 1987. Primary fixation was achieved with a plate in three cases, external fixation in two, and a Küntscher nail in one case. Because of infection, the nail was replaced by external fixation after 2 weeks. After healing of the tibia, the patients developed pain during normal use, and there was local tenderness, edema, and paresthesia. In all cases the X-ray films showed hypertrophic nonunion of the fibula. Four patients were treated with plate osteosynthesis of the fibula, which alleviated the problems. From our retrospective data we conclude that in primary therapy of lower leg fractures, plate fixation of the fibula should also be included in cases where the fractures are located in the distal half of the lower leg and show signs if instability due to displacement, oblique fracture forms, and multiple fragments.

Adult↗
PubMed1989

[Treatment of isolated medial ligament lesions of the knee joint].

In all, 52 patients have been treated in our clinic for isolated medial ligament tears during the time from Jan. 1985 to July 1988. There were 47 patients with a 1+ or 2+ and 5 patients with a 3+ instability in 30 degrees knee flexion. 42 patients with 1+ or 2+ instability received a nonoperative treatment in a fiberglass cast brace with metal hinges at the level of the knee over a period of 3-4 weeks, followed by an intensive rehabilitation program. 33 were followed for an average of 19 months, showing in 82% good and excellent results. Our retrospective study confirms previous reports of successful nonoperative management of isolated grade III MCL injury with 1+ or 2+ instability. The 5 patients with 3+ instability underwent an operative treatment.

Adolescent↗
PubMed1987

[Meniscus and cartilage damage].

It is well accepted that those meniscus lesions causing an internal derangement of the knee joint lead to chondromalacia. An operation is necessary to prevent progressive condylar cartilage damage. Menisci with minor traumatic tears and mild degeneration protect the joint surface. A removal is rarely indicated. The complete meniscectomy leads to a degenerative arthrosis and should be avoided. Partial meniscus removal minimizes subsequent degenerative changes.

Biomechanical Phenomena↗