PubMed Health⌕ Search

Biomedical subjects

D Kohn

Publications and source records attributed to D Kohn.

At least 109 records · Page 6Linked to original sources
PubMed1995

Arterial blood supply of the infrapatellar fat pad. Anatomy and clinical consequences.

The arterial blood supply to the infrapatellar fat pad (Hoffa's fat pad) was investigated in 12 knee joints of human cadavers. The infrapatellar fat pad is supplied by an anastomotic network which displays some striking topographic features. Its vascular blood supply protects it against necrosis, when either reconstructive operations are carried out or extensive surgical exposures of the knee are done. The blood supply to the center of the fat pad is limited. This is of practical importance for the choice of arthroscopic portals. In addition, arthroscopically verified sources of bleeding are described in 57 patients with hemarthrosis without clinically detectable instability. Rupture of the infrapatellar synovial fold can be a cause of posttraumatic hemarthrosis in rare cases. Arteries irregularly found within the fold contribute to the blood supply of the anterior aspect of the synovial membrane covering the cruciate ligaments.

Adipose Tissue↗
PubMed1995

Meniscus insertion anatomy as a basis for meniscus replacement: a morphological cadaveric study.

A morphological cadaveric study was carried out to gain exact data concerning location, shape, and size of the meniscal insertions to bone. Ninety-two knee joints were dissected (46 donors; age 18 to 58 years). Peripheral length of the menisci, including their insertion ligaments, was measured. The peripheral length was 111 +/- 14 mm for the medial and 111 +/- 10 for the lateral meniscus. The tibial insertion ligaments for the medial meniscus were fixed in areas that could be defined by bony landmarks. The posterior insertion area measured 80 +/- 10 mm2, the anterior insertion area measured 139 +/- 43 mm2. Bony tibial insertions of the lateral meniscus were less well defined. The posterior meniscofemoral ligament (Wrisberg) was found in 76% of the knees; the anterior meniscofemoral ligament (Humphry) was found in 50% of the specimens. The meniscofemoral ligaments in the right knee and the left knee of the same individual were frequently different. The anterior transverse ligament was found in 64% of the specimens. We concluded that an anatomical attachment of a medial meniscus substitute should be possible but to restore the lateral meniscus anatomically would be far more complicated.

Adult↗
PubMed1995

[Endoprosthesis and bone reaction].

Prosthetic implants cause a reaction on the part of the surrounding bone. Bone reaction can be interpreted as a dynamic response of the internal bone architecture to stress and strain. On the other hand, instability at the bone-implant interface or biological reactions to wear particles may lead to bone resorption. Standard X-ray examination has remained the most important tool for evaluation of the bone-implant relationship. Knowledge of the radiological features of bone remodelling and bone reaction is therefore a prerequisite for the orthopaedic surgeon. Based on eight case reports after prosthetic replacement of the hip, important radiological signs of bone reaction are presented. If possible a biomechanical or biological explanation is attempted. The information drawn from these cases, as well as from the current literature, suggests that after prosthetic joint replacement routine X-ray follow-up is required, even in asymptomatic patients, and that progressive osteolysis requires early operative revision, even if there are no acute clinical problems.

Aged↗
PubMed1994

Solitary skeletal lesions as primary manifestations of non-Hodgkin's lymphoma. Report of two cases and review of the literature.

Two patients with solitary skeletal lesions of the lower extremity were eventually diagnosed as having high-grade malignant B-cell non-Hodgkin's lymphoma. In both cases staging revealed no other nodal or extranodal involvement. One patient had been symptomatic for more than 2 years, presenting originally as a case of chronic synovitis. The second patient presented with slight exertional pain in his left knee of relatively recent history. In his case the initial plain X-ray showed little evidence of bony destruction, while magnetic resonance imaging revealed an extensive lesion in the left tibial plateau. Orthopedic surgeons should be aware of the differential diagnosis of primary lymphoma of bone. Early use of magnetic resonance imaging, in addition to plain X-ray and scintigraphic imaging, can be helpful in leading to an early biopsy and consequently early treatment. Magnetic resonance imaging should be regarded as the method of choice for follow-up examinations of lymphoma lesions.

Adolescent↗
PubMed1994

Donor-site morbidity after harvest of a bone-tendon-bone patellar tendon autograft.

The effects of closure of the peritendineum and bone grafting of the patellar defect after harvest of the bone-tendon-bone patellar tendon autograft was investigated prospectively in two groups of 25 patients. Anterior cruciate ligament (ACL) reconstruction was performed with minimally invasive techniques either arthroscopically or via mini-arthrotomy. Patellar height, size of bony and tendon defects, and overall result were followed up for 2 years postoperatively. The results showed that closure of the peritendineum enhances healing of the patellar tendon defect and restores a normal appearance of the tendon within 2 years. We have stopped bone grafting the patellar defect with cancellous bone because of the risk of formation of painful spurs at the inferior pole of the patella which occurred in 36% of patients.

Adult↗
PubMed1994

Erythrocytes from young but not elderly donors can bind and degrade immune complex- and antibody-bound C3 in vitro.

In situ aged erythrocytes (senescent erythrocytes from young donors and both young and old erythrocytes from elderly donors) demonstrate high levels of membrane-bound C3c and C3d and elevated susceptibility to in vitro phagocytosis. In this study we demonstrate that in situ aged erythrocytes are defective in their ability to degrade C3 fragments and clear them from the erythrocyte membrane. Erythrocytes from young donors bind complement-bearing immune complexes via CR1 and become susceptible to complement-mediated erythrophagocytosis ('innocent bystander' sequestration). Erythrocytes from elderly donors are defective in their ability to bind such immune complexes, as attested by the lack of an increment in membrane-associated C3 fragments as detected by flow cytometry and lack of an increment in in vitro sequestration. Factor I (serum)-dependent cleavage of C3 fragments and release of immune complexes from the erythrocytes of young donors lead to a drop in erythrocyte-associated C3 fragments and the disappearance of the 'innocent bystander' phenomenon. Inhibition of Factor I, and thus inhibition of C3b degradation and immune complex release for the erythrocyte membrane, enhances the levels of 'innocent bystander' sequestration of erythrocytes from young donors. Erythrocytes from elderly donors are defective in the dynamic process of CR1 binding of complement-bearing immune complexes and Factor I-associated release of membrane-associated C3 fragments. A defect in the ability of all in situ aged erythrocytes to clear their membranes of C3 fragments is also demonstrated for complement bound to the erythrocyte via IgM isoagglutinins. While erythrocytes from both young and elderly donors allow for the IgM-mediated binding of complement to the erythrocyte, only young erythrocytes from young donors demonstrate degradative activity with the release of membrane-associated C3c. Erythrocytes from elderly donors demonstrate lower levels of detectable CR1 (CD35), decay accelerating factor (DAF) (CD55) and Protectin (CD59) than do erythrocytes from young donors. Time course studies determine that the defect in handling of immune complexes observed for in situ aged erythrocytes is not due to differences in the kinetics of loading or releasing of immune complexes. These findings on the refractiveness of erythrocytes of elderly donors to uptake of immune complexes and the degradation of C3 fragments may be of importance not only in the understanding of erythrocyte sequestration, but also in the physiology of immune clearance in the elderly.

Adolescent↗
PubMed1994

The role of business process reengineering in health care.

Business process reengineering (BPR) is a management philosophy capturing attention in health care. It combines some new, old, and recycled management philosophies, and, more often than not, is yielding positive results. BPR's emphasis is on the streamlining of cross-functional processes to significantly reduce time and/or cost, increase revenue, improve quality and service, and reduce risk. Therefore, it has many applications in health care. This article provides an introduction to the concept of BPR, including the definition of BPR, its origin, its champions, and factors for its success.

Cost Control↗
PubMed1994

[Assessment of vital activity in geriatric patients].

17 parameters of vital activity (VA) were scanned in 35 female and 12 male dependent geriatric patients (mean age 81). These included mental testing, Barthel score, lung function, urinanalysis, creatinine clearance, Hb, albumin, globulin and electrolytes, skin-folds, locomotion, presence of IHD, hemodynamic state, continence, infections, WBC and lymphocyte count, pressure sores and dysphagia, 4 main templates of VA deterioration identified were: IHD, hemisyndrome (due to CVA), vegetative state (post-CVA) and senile dementia (SDAT). The IHD template was characterized by marked variations in VA, ending in death due to cardiac complications (pulmonary edema, ischemia, etc.). In the 3 other templates VA gradually deteriorated. Gradual declining VA allowed assessment of individual mortality prognosis. Assessment was by approximation of the computed exponent of the extrapolated VA curves; the longer the observation, the fewer the mistakes in assessment. Epidemiologic prognosis data of 48 dependent patients is described; mean age was about 81 years. Hospitalization mean was 853.5 +/- 601 days and for patients with dementia, 1158.6 +/- 622.7 days.

Aged↗
PubMed1994

[Transplantation of allogeneic menisci].

The increase in severe ligament injuries of the knee has led to consideration of the need for meniscal transplantation in reconstructive operations for chronic rotational instability. Transplantation of the medial meniscus was carried out in 30 sheep, which were divided up into 2 groups, each containing 15 sheep. In the first group lyophilized, y-sterilized allogeneic menisci were transplanted and these underwent complete remodelling in 48 weeks. In the other group, deep-frozen allogeneic menisci were used and these remained fully functional without remodelling. Twenty-three transplantations of the medial meniscus combined with replacement of the anterior cruciate ligament were performed from May 1984 to December 1986. Clinical follow-ups were coupled with arthroscopic follow-ups on an average of 10 months post-operatively in 19 sheep. In 17 cases a lyophilized meniscus was transplanted and in 6 cases a deep-frozen allogenous meniscus was used. There were no operation-specific complications in either group. Both the lyophilized meniscus transplants and the deep-frozen ones underwent a reduction in size during the observation period. Good-to-excellent results were generally obtained with the deep-frozen transplants; however, there is the risk of transmitting disease. The results seen in the lyophilized transplants were less satisfactory due to a reduction in size, sometimes down to the regeneration size. Taking the infrapatellar fatty pad for meniscal replacement (as suggested by Lexer), we saw only weak meniscus-like tissue after the first year postoperatively. The meniscus tendon by means of an autologous tendon for meniscus replacement may be an alternative procedure. Therefore, allogeneic meniscus transplantation for reconstruction of the knee joint cannot be recommended at present as a standard procedure.

Adult↗
PubMed1994

[Meniscus replacement].

Partial meniscectomy and meniscus reconstruction are the procedures of choice for the majority of symptomatic meniscus lesions. If total meniscectomy cannot be avoided or was already performed, there is a risk of osteoarthritis, especially in the unstable knee. Different approaches of meniscus replacement are under experimental and clinical investigation at present. Replacement by a tendon autograft, by a meniscus allograft, by a prosthesis or by a collagenous scaffold are discussed. This article is an up-date on the current situation today.

Animals↗
PubMed1994

[Meniscus insertion].

In meniscus replacement procedures anatomically correct fixation of the graft is one of the prerequisites for a successful outcome. An anatomical cadaver study was carried out to identify the insertion areas in the femur and tibia as well as the peripheral meniscus length. Ninety-two fresh knees from 46 human donors were included. The tibial insertions of the medial meniscus could be defined by bony landmarks. The peripheral length was 111 +/- 11 mm for the medial and 110 +/- 13 mm for the lateral meniscus. Wrisberg's ligament was present in 76% of all knee specimens and Humphry's ligament could be found in 50%. The correlation between the right and left knee in the same individual was poor concerning the presence of the meniscofemoral ligaments and the size of the tibial meniscal insertions to bone.

Adolescent↗