Search PubMed⌕ Search

Biomedical subjects

H G Willert

Publications and source records attributed to H G Willert.

81 records · Page 5Linked to original sources
PubMedDate not supplied

[Fixation of endoprostheses with or without cement?].

The question of anchoring endoprostheses with or without cement is approached by analysing the following parameters: Frequency of application, costs, current medical and technological development, difficulty and duration of surgical procedure, acceptance by the tissues (seen from the aspects of Biomaterials, Biomechanics and Biology) and longstanding clinical results of the respective devices. Yet the majority of these parameters did not allow a clear decision. Only the correlation between implant and tissue provided some interesting hints: Since bone cement guarantees immediate primary stability it is qualified especially for anchoring endoprostheses in patients who will put weight on their artificial joint right after the implantation. A fixation without bone cement could be favoured if new formation and preservation of bone have priority over primary stability. From this derives the following recommendation for practical purposes: Endoprosthetic components should be anchored without cement in patients younger than 70 and in revisions, while bone cement may be used in patients over the age 70.

Age Factors↗
PubMedDate not supplied

[Dimensional changes of polyethylene acetabuli in Müller's hip endoprosthesis. Report on measurement methods and their clinical significance].

The dimensional changes of hip sockets of total endoprosthesis of the Müller Type are subject of this article. Regular-anterior/posterior radiographs of the pelvis were taken to determine the orientation of the center of the prosthetic head in relation to the wire marker of the poly(ethylene) cup. Further measurements were done using casts of worn acetabular cups gained at revisional surgery. The possible errors of measurements of both methods are discussed. Both, creep and wear contribute to the dimensional changes of the hip sockets, the proportional amount of each mechanism is not known. Data from laboratory examinations suggest a relatively high rate of creep in the early time of function. With longer periods the dimensional changes are predominantly caused by wear. In the beginning of joint function our measurements show a high rate of the yearly dimensional change. The shift of the head amounted 0.5 mm per year and diminished after five years to rates of 0.15 to 0.2 mm. All dimensional changes that exceed a shift to the head of 0.2 mm per year are considered to be unfavourable and to contribute to loosening.

Hip Joint↗
PubMedDate not supplied

[The role of a bone cement filling in intralesional tumor treatment].

The article reports on the results of treatment of cystic and juxta-articular benign primary bone tumors and tumor-like lesions with a temporary bone cement plug. The mean implantation time of the cement plug was 18 months, following which the cement plug was replaced with an autologous spongiosa filling. Cases were followed up for an average of 58 months. In the patient group as a whole, a relapse rate of 5.8% was recorded (0% for Giant Cell Tumors alone). It was possible to describe the clinically functional results as "good" and "very good" in 95% of the cases. It is clear from these results that temporary plugging of large juxta-articular bone lesions is an excellent treatment method. The article goes on to describe complications in detail. Results are given in detailed tables.

Adolescent↗