Biomedical subjects

M Tanzer

Publications and source records attributed to M Tanzer.

40 records · Page 3Linked to original sources

PubMed1992

Revision of the acetabular component with an uncemented Harris-Galante porous-coated prosthesis.

One hundred and forty revisions for loosening of the acetabular component were performed in 124 patients, with the use of an uncemented Harris-Galante acetabular prosthesis. A component was considered loose if there was a change in its position or vertical or horizontal migration, or both, of four millimeters or more, as demonstrated on serial radiographs. All patients were followed prospectively for a mean of forty-one months (range, twenty-four to seventy-six months). Bone-grafting was performed at the time of the revision in 127 of the hips. Identifiable failure of fixation of the acetabular component occurred in only two hips (1 per cent), which had both severe acetabular bone loss and pelvic discontinuity. In one of these hips, fixation of the component could not be achieved during the revision, and the component subsequently migrated. No other components migrated. Only one patient had a revision of the index acetabular operation. A continuous radiolucency developed at the bone-mesh interface of five acetabular components, and in one other hip a small portion of the mesh separated. This hip was reoperated on for a problem with the femur, and the socket was found to be rigidly fixed. No other evidence of loosening was identified. All of the bone grafts united, but partial resorption of the graft occurred in thirty-nine hips. Although there were substantial osseous defects that necessitated major bone-grafting, revision with the uncemented Harris-Galante porous-coated acetabular component provided superior fixation compared with that reported in other series in which cemented acetabular components were used for revision. Of the 140 hips, eighty-nine (64 per cent) had a postoperative score of good or excellent, according to the Harris hip-rating system. Twenty-eight (70 per cent) of the forty hips that had revision of the acetabular component alone were rated as good or excellent.

Acetabulum↗

PubMed1992

The progression of femoral cortical osteolysis in association with total hip arthroplasty without cement.

Twenty hips in twenty patients had development of femoral endosteal cortical erosion after a cementless total hip replacement with the Harris-Galante porous-coated implant. Serial anteroposterior and lateral radiographs of all of the affected femora were reviewed to determine the interval between the operation and the first recognition of the osteolytic lesion or lesions, as well as to evaluate the radiographic appearance and progression of the lesions. The twenty affected hips were followed for an average of fifty-three months (range, twenty to seventy-seven months) after the operation. Osteolysis was first noted radiographically at twelve to sixty-six months (mean, thirty-nine months) postoperatively; in most patients, it occurred around the distal portion of the prosthetic stem. Twelve (60 per cent) of the femoral components were shown to be loose, as proved either radiographically or operatively. Three of these components had been judged radiographically to be stable when the endosteal erosion had first been identified, but they had subsequently migrated. The remaining eight hips had no evidence of loosening. The osteolysis was more severe in the femora in which the component was loose than in those in which it was stable. Of the fourteen patients who were followed, twelve (86 per cent) had an increase in the size of the osteolytic lesions with time, and only one patient had some radiographic evidence of healing.

Adult↗

PubMed1990

The relationship of intercondylar notch size and content to notchplasty requirement in anterior cruciate ligament surgery.

A stenotic intercondylar notch is an indication for a notchplasty at the time of ACL reconstructive surgery. However, the absence of a stenotic notch does not ensure that impingement of the ligament upon the intercondylar notch will not occur. An excessively large ligament, even in the presence of a normal intercondylar notch, will result in abrasion of the ligament on the notch. This can result in the premature failure of the reconstructed ACL. Therefore, both the notch size and notch content are important determinants in assessing whether a notchplasty is required as part of the ACL reconstructive procedure.

Adolescent↗

PubMed1989

The natural history of flexion contracture in total knee arthroplasty. A prospective study.

A prospective study was carried out to document the natural history of flexion contractures of the knee after total knee arthroplasty (TKA). Thirty-five knees in 33 patients with TKA were followed for a mean duration of 55 weeks. In no case did the surgical procedure include excessive bony resection in order to correct a flexion contracture. Standard goniometric measurements were used to determine the knee flexion contractures preoperatively and postoperatively while the patient was anesthetized and at each successive follow-up visit. All preoperative and postoperative flexion contractures were less than 30 degrees. The mean fixed flexion deformity of the entire group preoperatively was 12.9 degrees; immediately postoperatively, 14.8 degrees; and at final follow-up, 2.9 degrees. No difference was found in the amount of flexion contracture present at final follow-up evaluation with respect to age or gender. The impression that fixed flexion contractures must be corrected at the time of arthroplasty has led to the intraoperative removal of excess bone from the distal femur and/or proximal tibia. The present findings indicate that knee flexion contractures can significantly improve after TKA. There appears to be little, if any indication for excessive removal of bone in an attempt to achieve intraoperative correction.

Adult↗