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Biomedical subjects

L L Higgins

Publications and source records attributed to L L Higgins.

11 recordsLinked to original sources

A new method of trochanteric fixation after osteotomy in revision total hip arthroplasty with a calcar replacement femoral component.

Two series of cementless revision hip arthroplasties, using a transtrochanteric approach and an identical calcar replacement femoral prosthesis, were compared to ascertain the rate of trochanteric union and device problems. The failed implants removed at the time of revision were short-stemmed cemented or cementless designs in comparable patient populations. Eighteen patients had a traditional wiring fixation with a 72% union rate, and 111 patients had a bolt-and-plate fixation device, when it became available, that transfixed the trochanter to the lateral side of the femur through the proximal femoral component. The rate of union here was 94%. Of 111 bolt-and-plate devices, 13 (11.7%) were radiographically loose, although asymptomatic with a united osteotomy. Two bolts of the first-generation design broke, with 1 needing removal. Two bolt-and-plate devices disassembled, with 1 needing removal.

Adult↗

A titanium cementless calcar replacement prosthesis in revision surgery of the femur: 13-year experience.

From January 1987 through December 2000, 1,179 cementless calcar prostheses were implanted at the Texas Center for Joint Replacement. The prosthesis is titanium, has proximal circumferential plasma-spray coating, and is designed for proximal bone loading. The average follow-up for the entire series was 6.2 years, and the projected stem survivorship at 13 years is 95.2%. There have been 9 stem revisions for loosening. When mechanical loosening alone is evaluated, the projected stem survivorship is 99%. There have been 56 revisions in the entire series. Prosthetic survivorship for the entire patient population is projected at 93.6% at 13 years. There have been no cases of distal lysis or late loosening. None of the prostheses are classified as loose at this time, and none are classified as stable fibrous fixation.

Adolescent↗

The AGC total knee prosthesis at average 11 years.

A retrospective study of a series of 126 consecutive primary cemented total knee replacements using the AGC prosthesis is reported. Sixty-two knees were available for long-term review with an average clinical follow-up of 11.4 years (range, 8.4-13.6 years). The survivorship was 95%, defining the endpoint as revision of all components for any reason except sepsis. The average knee flexion was 110.9 degrees. The average Knee Society score was 91, and the average Knee Society Functional score was 67. There was no finding of tibial polyethylene failure, wear debris-generated osteolysis, or tibial or femoral loosening. Seven metal-backed patellae developed wear-through at an average of 80.4 months (7 of 126 for a 5.5% failure rate), with 3 (2.3%) resulting in complete revision. The authors continue to use the AGC prosthesis with an all-polyethylene patella. Compared with historical controls, the AGC has comparable survivorship.

Biomechanical Phenomena↗

Surgical closing in total knee arthroplasty. A series followup.

The benefits of closing the surgical wound of a primary and revision total knee prosthesis with the knee in full flexion are examined. A previous study showed that surgically closing the primary knee arthroplasty with the knee in full flexion produced significantly more postoperative flexion at 6 months: 114.7 degrees compared with 108.1 degrees. Of 108 selected sequential primary knee arthroplasties, the first 52 knees were closed surgically with the leg in full knee extension, and the second 56 knees were closed in 90 degrees to 110 degrees flexion, depending on the available motion of the joint. The patients in each group were matched closely in age, weight, height, gender, and surgical technique. At all followup intervals, the flexion measurements were significantly better in the flexion closure group. At 1 year, the flexion group had 117.9 degrees and the extension group had 112.9 degrees flexion. The revision series also was a selected sequential series with 13 knees in each closure group. In the revision case, the 1-year findings were similar, with significantly more knee flexion in the flexion closure group (118.7 degrees compared with 112.7 degrees). In matched groups, flexion closure in primary and revision knee replacements significantly increased total range of motion, as seen at the 1-year followup.

Aged↗

Surgical closing in primary total knee arthroplasties: flexion versus extension.

One hundred eight consecutive patients with primary osteoarthritis of the knee undergoing primary arthroplasty were compared retrospectively to determine whether surgical closure of the entire wound in flexion has any effect on range of motion postoperatively over a period of up to 6 months. The knees of the first 52 patients were surgically closed in extension. In the second group of 56 patients, the knees were closed in 90 degrees to 110 degrees flexion depending on the available motion of the joint. Although the patients were not randomized, the groups were closely matched in age, weight, height, and gender. Preoperative and postoperative patellar heights were similar in both groups. The patients were started on a continuous passive motion device in the recovery room. At all intervals the flexion measurements were significantly better in the flexion closure group. By 6 months the flexion closure group had surpassed their preoperative measurements, whereas the extension closure group had not yet achieved this goal. The flexion group required less home physical therapy than the extension group. Closing the knee in flexion permits the patients to regain knee motion faster with less effort, thereby saving money and enhancing patient satisfaction.

Aged↗

A human endothelial cell membrane protein that binds Staphylococcus aureus in vitro.

We have investigated S. aureus adherence to human endothelial cells utilizing an in vitro model. Staphylococcus binding to confluent endothelial cell monolayers was saturable in both dose and time response studies suggesting that the binding interaction was specific. We have developed a technique, based on the pH dependent affinity of iminobiotin for streptavidin, for the isolation of an endothelial cell membrane component that binds S. aureus, in vitro. A 50-kD membrane component was isolated and purified using this approach. This component was trypsin sensitive, periodate insensitive, and did not label with [3H]glucosamine. [35S]Methionine and [125I]iodine labeling confirmed that the protein was synthesized by and expressed on the endothelial cell surface. Functional binding studies demonstrated that staphylococci, but not endothelial cells, bound to the protein when immobilized on microtiter wells. Preincubation of staphylococci with the purified protein significantly (P less than 0.001) reduced staphylococcal binding to cultured endothelial cells. The capacity of S. aureus to colonize and invade endovascular surfaces may in part be a consequence of staphylococcal interaction with this endothelial cell membrane protein.

Bacterial Adhesion↗

Staphylococcus aureus--human endothelial cell interactions.

Staphylococcus aureus is an invasive pathogen capable of causing life-threatening disease. A major component of this pathogen's virulence is its ability to invade normal endovascular tissue. We examined the interaction of S. aureus with cultured human endothelial cells and with human and rabbit endovascular tissue. Our ultrastructural study demonstrated a sequence of steps which occurred with staphylococcal invasion of human endothelial cells; adhesion, endocytosis, and intracellular replication. Ultimately, this resulted in cell disruption and death. Cytochemical staining of lysosomes demonstrated lysosomal fusion with both viable and killed intracellular bacteria without evidence of staphylococcal degradation. Quantitative studies using an in vitro infection assay demonstrated comparable rates of adhesion by viable and ultraviolet-killed bacteria, phagocytosis at a slower rate, and intracellular replication. The present study demonstrates an active role for the endothelial cell in the development and spread of endovascular staphylococcal infections. It also supports the use of this in vitro tissue culture system as a model for the study of bacterial invasion of the endothelium.

Animals↗