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Biomedical subjects

D Kohn

Publications and source records attributed to D Kohn.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Revision surgery after failed anterior cruciate ligament repair].

Not every reconstruction of the anterior cruciate ligament is successful. Possible reasons for failure are renewed severe trauma, inadequate fixation of the transplant, an isometric mistake, weak transplant material, an anterior cruciate ligament reconstruction performed in isolation in a complex unstable knee, or prosthetic ligaments. Revision surgery is indicated when patients complain about the recurrence of knee instability. Preoperative diagnostic procedures must include X-rays with the knee in defined positions in order to determine drill hole courses and visualize any signs of arthrosis and the patellar position. Revision surgery is hampered by disadvantageously placed drill holes, exhaustion of the supply of transplant material, secondary instabilities, gonarthrosis or a possible arthrofibrosis. During rehabilitation a variable knee position is imperative, because of the different procedures that might need to be implemented.

Anterior Cruciate Ligament↗
PubMed1992

Lack of changes in histomorphometric, bone mass, and biochemical parameters in ovariohysterectomized dogs.

A predictable animal model with skeletal remodeling characteristics similar to those of humans is needed to facilitate the understanding of the mechanism of postmenopausal osteoporosis. We have utilized the ovariohysterectomized (Ovh) dog to examine cellular and biochemical responses to estrogen depletion and PTH stimulation. Histomorphometric measurements of bone biopsies taken prior to (first biopsy) and five months after the operation (second biopsy) showed no significant differences in static and dynamic parameters. Bone mineral density of the excised vertebrae displayed the same values between the two groups six months after surgery. Between the second biopsy and sacrifice, two infusion studies were performed. A two-hour infusion of EDTA followed by a two-hour recovery period elicited a rapid response in PTH production, highly correlated to the changes in ionized calcium, but no significant difference in response was observed between Sham and Ovh groups. A short-term (24-h) infusion of 1-34 hPTH increased circulating ionized calcium and 1,25-(OH)2-D levels to a similar extent in both groups. The levels of alkaline phosphatase were constant and both groups showed a small but nonsignificant increase in osteocalcin. The lack of sizable responses in histomorphometric, bone mass, and biochemical parameters may limit the utility of dogs for the study of cancellous bone loss in ovarian-dysfunction osteoporosis.

Animals↗
PubMed1992

[The value of dynamic examination methods in instability of the shoulder joint].

We prospectively examined 25 patients with shoulder instability by clinical examination and by fluoroscopic and sonographic imaging. 14 patients were classified as recurrent, posttraumatic instabilities, 12 of these anterior and two posterior. Clinical examination revealed the direction of instability in 5 patients, fluoroscopy in 5 and sonography in 3 patients. 11 patients had non-traumatic recurrent instabilities. Of these, clinical examination and fluoroscopy demonstrated identical directions of laxity in 8. Sonography concurred with the other techniques in only three cases. We recommend manual instability testing followed by fluoroscopy for evaluation and documentation of patients with non-traumatic, recurrent shoulder instability. Posttraumatic instabilities should be diagnosed with other, static procedures.

Adolescent↗
PubMed1992

Medial meniscus replacement by a tendon autograft. Experiments in sheep.

In 20 skeletally mature female merino sheep, divided into four groups, we performed total medial meniscectomy, removal of the middle third of the patellar tendon, and tenotomy of the calcaneal tendon of the right hind leg. Group I (control) had no additional procedures. In the other three groups the medial meniscus was replaced by the middle third of the patellar tendon from the ipsilateral knee. The animals were killed at three (group II), six (group III), or 12 months (group IV) and the tendon-meniscus examined macroscopically, by light and scanning electron microscopy, and biomechanically. Remodelling of the tissue had taken place by 12 months but the failure stress and tensile modulus for the tendon-meniscus were lower than for the normal meniscus. Our evidence suggests that, in sheep, replacement of a meniscus by a tendon autograft may decrease the severity of the degenerative changes that occur after meniscectomy.

Animals↗
PubMed1991

The function of the Thomas splint. An experimental study.

A Thomas splint of traditional design was fitted with measuring devices and examined for its hip-relieving effect during varying activities. It was shown that there is no complete weight relief of the hip joint with this orthosis. In the most favourable case, 50% of the weight can be conducted via the ischial tuberosity and therefore transferred to the ground surface bypassing the hip joint. In regard to the hip joint, the Thomas splint is a device that reduces weight but does not entirely remove it. The results proved to be practically independent of the fitting of the orthosis and of the kind of activity.

Biomechanical Phenomena↗
PubMed1991

Long-term follow-up of patients aged 75 years and older admitted to an acute care hospital in Israel.

Certain biomedical and psychosocial factors may be important in predicting short-term and long-term outcomes in elderly inpatients in an acute care hospital. We prospectively studied all patients aged 75 years and older who were admitted to an acute inpatient geriatrics unit between June, 1984 and May, 1985, and we followed them for 5 years. Patients were followed by phone and/or the outpatient ambulatory service; follow-up visits occurred at 4 to 6 weeks following discharge and annually thereafter. After 5 years, 21% of the patients were alive. Apparently, age and gender were the major parameters associated with prognosis. Functional status and nutritional state (body weight, serum albumin) were also important prognostic factors. Of the geriatric syndromes, urinary incontinence seemed to be most strongly associated with a poor outcome, followed by falls and confusion. Iatrogenic conditions apparently had no such association. These findings suggest that certain demographic and clinical factors may be useful prognosticators for elderly hospitalized patients.

Aged↗
PubMed1991

[Routine ultrasound diagnosis of the shoulder. A simplified examination procedure].

With increasing use of ultrasonography at the shoulder, a confusing number of transducer positions have been recommended. At the shoulder, however, dynamic examination yields more information than fixed transducer orientations. In our examination routine, the transducer is guided across the shoulder following the shape of a triangle. Orientation is secured by palpable, bony structures. The clinically relevant parts of the rotator cuff and the long biceps tendon are investigated, first medially and laterally in a transverse projection and then longitudinally. Dynamic examination is provided by moving the transducer as well as the shoulder joint. In a time-saving examination routine, all important soft tissue structures of the shoulder are visualized.

Humans↗
PubMed1991

[The significance of the activity score in evaluating knee ligament reconstructions].

In a follow-up study of 156 patients after knee ligament reconstruction for chronic instability, the results of subjective Lysholm score grading and of Tegner activity grading were compared. The postoperative Lysholm score averaged 85 +/- 13.2 points, the activity scores 6.9 +/- 0.9 points prior to instability, 1.7 +/- 0.9 points preoperatively and 5.9 +/- 1.2 points postoperatively. 89 patients reached their preinjury activity level, the average improvement through surgery was 4.2 +/- 1.6 points. Non-active patients regularly returned to their original activity-level, competitive athletes were less likely to regain their previous activity. The subjective results of athletes and non-athletes showed no significant differences. The postoperative activity level clearly correlated to subjective grading by the patient. For scoring results after knee ligament surgery, we use the subjective Lysholm score and an activity score based on average German sports activities.

Activities of Daily Living↗
PubMed1991

Hepatic veno-occlusive disease post-bone marrow transplantation in children conditioned with busulfan and cyclophosphamide: incidence, risk factors, and clinical outcome.

We performed a retrospective analysis of the incidence, risk factors, and clinical outcome of hepatic veno-occlusive disease (VOD) in 50 children prepared for bone marrow transplantation with busulfan (16 mg/kg) and cyclophosphamide (200 mg/kg). The overall incidence of VOD was 28% (14/50). The incidence of VOD among patients transplanted for leukemia was 36% (14/39). In contrast, no patient transplanted for a genetic disease developed VOD. Neither patient age, sex, remission status, type of graft (i.e. allogeneic or autologous), past history of liver disease nor pretransplant liver function tests were associated with an increased risk of VOD. In addition, 23 of 50 patients had pretransplant samples available for antihepatitis C virus (HCV) testing; 3/23 were reactive (two of nine patients with VOD and one of 14 patients without VOD were positive for anti-HCV). We found a high incidence of pleural effusion in patients with VOD (7/14), an association that has previously not been described. VOD was manageable and resolved in all patients.

Adolescent↗
PubMed1990

[Intravenous iron-dextran in the elderly].

127 of 1000 patients treated during the first 2 years of this department's operation were found to be anemic. In 69 of them iron deficiency was diagnosed and 54 of them were treated with intravenous iron-dextran (Imferon). It had to be stopped because of adverse effects in 11 of them; 1 of them had a nonfatal anaphylactoid reaction, 4 women, 75-84 years old, are presented to demonstrate the indications for intravenous iron therapy. Oral administration is the treatment of choice in ambulatory patients. However, when as in the cases presented it fails, because of failure-to-thrive, intolerance to the oral preparation or noncompliance, intravenous iron is indicated.

Administration, Oral↗
PubMed1990

[Meniscus replacement using Hoffa's infrapatellar fat bodies--initial clinical results].

Between December 1986 and July 1988 a replacement of the absent medial meniscus was taken by means of the infrapatellar adipose body in seven patients. A replacement of the anterior cruciate ligament by means of the middle one third of the patellofemoral ligament was taken too. This operation was done for reconstruction of the synergism between the anterior cruciate ligament and the posterior horn of the medial meniscus. All patients are controlled in our special knee outpatient service. There were no complication postoperatively and on all seven patients a control arthroscopy was performed twelve months postoperatively. The subjective results are very satisfying because of the restoration of knee stability. The arthroscopic controls of the meniscal replacements, however, showed a reduction in size of the transplants after one year, the tissue was weak and not identical to that of a normal meniscus. Autologous strong tissue, e.g. quadriceps tendon, may have better presuppositions for meniscal replacement.

Adipose Tissue↗
PubMed1990

[Meniscus transplantation and anterior cruciate ligament replacement--results 2-4 years postoperative].

23 transplantations of meniscus combined with replacement of the anterior cruciate ligament were performed from May 1984 to December 1986 at the Department of Orthopaedics of the University of Munich ('Klinikum Grosshadern'). Clinical follow-ups were coupled with arthroscopic follow-ups on the average 10 months postoperatively in 19 patients with transplantation of the medial meniscus of the knee joint. In 17 cases a lyophilised meniscus was transplanted and in 6 cases a deep-freeze allogenous meniscus. There were no operation-specific complications in either group. Both the lyophilised meniscus transplants and the deep-frozen ones underwent a reduction in size during the observation period. Whereas good to excellent results were generally obtained with the deep-frozen transplants, the results seen in the lyophilised transplants were less satisfactory due to reduction in size partly down to regenerate size. The treatment results were of course positively influenced due to the contributory effect of the regained stability; in the patients with meniscus transplants the preoperative Lysholm score was 72 +/- 14 points, on the average 36 weeks postoperatively 82 +/- 15 points. However, clinical and arthroscopic findings showed that no clinically, immunologically and morphologically satisfactory meniscus replacement has become available to date.

Adult↗