Biomedical subjects

E M Keating

Publications and source records attributed to E M Keating.

At least 91 records · Page 5Linked to original sources

PubMed1991

Survivorship of cementless total knee arthroplasty without tibial plateau screw fixation.

Seventy-two cementless tricompartmental total knee arthroplasties were performed in 47 patients using a porous-coated prosthesis without screw fixation for the tibial components between 1984 and 1986. These individuals were observed at regular intervals for a minimum of three years. Their Hospital for Special Surgery pain and function scores as well as roentgenographic signs of anatomic alignment and subsidence were evaluated at six months, one year, and three years postoperatively. The roentgenographic evaluation for subsidence looked at a measurable difference in the anteroposterior roentgenograph on the medial and lateral plateaus and on the lateral roentgenograph anteriorly and posteriorly. Early postoperative interpretations have suggested pain and knee scores to be much lower than scores in the cemented prosthesis. Reassessment after three years, however, revealed no further deterioration of the noncemented prosthesis in respect to knee scores and survival analysis. Roentgenographic analysis showed no correlation between subsidence and alignment alterations, subsidence and time, or subsidence and pain. It appears that after an initial period of discomfort, the noncemented knee can achieve a functional, clinical, and roentgenographic result much better than previously anticipated. The consequences beyond this time period still remain unknown.

Aged↗

PubMed1991

The survival of total knee arthroplasty in patients with osteonecrosis of the medial condyle.

The results of total knee arthroplasty in patients with osteonecrosis of the medial femoral condyle were examined using Kaplan-Meier survival analysis. The study included 32 osteonecrotic knees with an average final follow-up examination of 3.9 years. For comparison, 63 osteoarthrotic knees with an average final follow-up examination of 4.6 years were also analyzed. The survival rates were calculated using four distinct categories of failure: (1) revision, (2) revision or radiolucency, (3) revision, radiolucency, or pain, and (4) pain. On the basis of pain relief alone, the five-year postoperative success rate was 82% for osteonecrosis (eight knees) and 90% for osteoarthrosis (27 knees), with no significant statistical difference between the two groups.

Aged↗

PubMed1990

A porous polyethylene-coated femoral component of a total hip arthroplasty.

The authors report their clinical experience with a femoral titanium stem with 3 mm of polyethylene (the outer 1.5 mm being porous) that was developed to function as a low-modulus type of prosthesis in an attempt to match the modulus of the prosthesis to the bone. The authors analyzed 223 of these stems of two different cross-sectional geometries: square (129) and round (94). Of these, 14 square and 5 round stems were subsequently replaced and all revealed only a fibrous ingrowth. Despite an average 82.4 Harris hip rating, 20% of the recipients still reported pain. For this reason the authors do not believe that the current design is adequate for the femoral component of a total hip arthroplasty.

Adolescent↗

PubMed1990

The use of a hip score for evaluation of the results of total hip arthroplasty.

Both the Harris and the Charnley hip evaluation forms were applied to 191 ingrowth-type total hip arthroplasties in an attempt to determine the effectiveness of the hip score as an indicator of success following arthroplasty. The Harris form demonstrated significantly lower pain scores than the Charnley form and, consequently, failed patients more often due to pain. However, it is important to note that 32% of the hips that failed due to pain on the Harris form did not fail due to total score. This inconsistency prompts the authors to state that when using a hip form to evaluate the performance of a prosthesis, especially one of the ingrowth type, it is important to consider not only the average total score but also the percentage of patients still experiencing significant pain.

Disability Evaluation↗

PubMed1990

Survival of cemented total hip replacements.

A Kaplan-Meier survival analysis of 240 Charnley, 149 Mueller (Depuy, Warsaw, IN), 576 Trapezoidal 28 (Zimmer, Warsaw, IN), and 100 Miami Orthopaedic Surgical Clinics (Biomet, Warsaw, IN) cemented total hip replacements with all polyethylene acetabular components, performed by the senior author (M.A.R.) should be the basis that all noncemented total hip replacements must exceed to be a reasonable alternative. Failure, ie, revision and a loose prosthesis, shows that 80%, 61%, and 63% of the Charnley, Mueller, and Trapezoidal 28, respectively, survive longer than 15 years. The Miami Orthopaedic Surgical Clinics prosthesis, which uses current cement technology, has been observed for only 8 years. Despite the fact that there are no differences noted between all four prostheses at 8 years, more time is needed to judge the usefulness of current cement technology.

Aged↗

PubMed1990

Long-term follow-up of the Indiana conservative resurfacing hip arthroplasty.

Sixty-four Indiana conservative (Depuy, Warsaw, IN) hip arthroplasties performed in 61 patients were reviewed for loosening, mechanisms of loosening, and revision rate. Mean follow-up time was 6.8 years. There were revisions in 26 hips (40.6%) with 4 hips awaiting revision, yielding a total of 30 hips (47%) defined as failures. Acetabular failure occurred in 20 hips, femoral failure in 18, and combined failure in 13. Failure of this prosthesis persists over time. There seems to be little or no place for this design in contemporary hip joint arthroplasty.

Adult↗

PubMed1990

Survival of a cemented porous-coated prosthesis.

Porous-surfaced femoral components were approved by the United States Food and Drug Administration for implantation with polymethyl methacrylate cement in total hip arthroplasty. The ability of porous coating to prevent loosening of prostheses in vivo has not been reported in the literature previously. This study compared the radiographic and clinical success of two structurally similar prosthetic designs, one of which incorporates a porous coat. Kaplan-Meier survival analysis showed no significant difference between the components (P greater than .05) when failure is defined as revision alone, radiolucency alone, or the combination of revision and radiolucency.

Aged↗

PubMed1990

Roentgenographic evaluation of a conical threaded acetabular cup.

A radiographic analysis was done of 83 primary hip arthroplasties performed in 70 patients. The arthroplasty consisted of a truncated acetabular cup and a cemented titanium femoral stem. The patients were evaluated at an average of 3.3 years postoperatively (range 2 to 5 years). Using the method of DeLee and Charnley, the acetabulum was divided into three zones. Specific attention was focused on the percentage of fill in the threads of zones 1 and 3 and the measurement of radiolucency in zone 2. Over time, a large percentage of the acetabulae showed both a decrease in bone fill in zone 3 and an increase in radiolucency in zone 2. By the third postoperative year, 16% (11 of 70) of the acetabulae had migrated. Although all the hips had been rated good or excellent on the Charnley hip score, ie, receiving a 5 or better, 11 had migrated and 3 had been revised, indicating an unacceptable failure rate of the acetabular component.

Acetabulum↗

PubMed1990

A radiographic analysis of a straight-stemmed uncemented femoral component and hemispheric porous-coated acetabular component in total hip arthroplasty.

A radiographic examination of 91 uncemented hemispheric titanium alloy acetabular components and 85 straight-stemmed titanium alloy femoral components was performed. Analysis included zonal radionuclides, migration, bone changes, and fit. Correlation of these parameters were made. Acetabular radiolucencies were common in zone 3 but none were progressive; also, they were unrelated to number and position of screws. Two acetabuli were considered to demonstrate loosening. Femoral changes of calcar atrophy, distal cortical hypertrophy, and distal femoral capping were independent of bone type and distal fit. One component subsided. Proximal radiolucency occurred in three patients, all on the lateral surface. Bony changes around the prostheses were statistically not related to bone type.

Adult↗

PubMed1990

A radiographic and histological analysis of 17 retrieved ultrahigh-molecular-weight polyethylene porous-coated femoral stems.

Radiographic and histological and evaluation for failure of 17 retrieved implants was performed. The implants consisted of a titanium stem with a 3-mm ultrahigh-molecular-weight polyethylene coating and an outer 1.5-mm ultrahigh-molecular-weight polyethylene fiber layer. Particular attention was paid to osteolysis, subsidence, debris, and foreign body reaction. Radiographic analysis showed subsidence (14 of 17), osteolytic lesions (9 of 14), and unique posterior medial exostoses (8 of 14). Histological analysis showed no significant evidence of acrylic bone cement either as debris or reactive tissue. There was an intense foreign body reaction directly related to the amount and size of polyethylene debris.

Adult↗

PubMed1990

Review of the all-polyethylene tibial component in total knee arthroplasty. A minimum seven-year follow-up period.

A retrospective analysis of 144 total knee arthroplasties was performed between 1975 and 1981 with a minimum follow-up period of seven years. A posterior cruciate condylar prosthesis was used in each procedure. Patients were followed clinically and roentgenographically, and a set of statistical variables was established based on elevation in joint line, tibial component angular alignment, overall limb alignment, and position of the tibial component on anteroposterior and lateral roentgenograms. Review of the study group found that the Hospital for Special Surgery knee scores improved from a preoperative score of 55 to a postoperative score of 88, with 94.5% having good or excellent results. The mean postoperative range of motion was 106 degrees with a mean extension of -0.3 degrees. Radiolucencies developed in 41% of the knees with 5% of the knees having progressive radiolucencies. Eight knees were considered failures based on clinical and roentgenographic evaluations. Factors found to significantly affect the formation of radiolucent lines included a shift of the tibial component medially by greater than 4 mm, a varus tilt of the tibial component greater than 2 degrees, and the diagnosis of rheumatoid arthritis. The only variable associated with aseptic loosening was an elevation of the joint line by greater than 8 mm.

Adult↗

PubMed1990

Structures at risk from medially placed acetabular screws.

The anatomical structures adjacent to fourteen acetabula were studied to identify structures that are at risk from acetabular screws. There were six embalmed acetabula, four acetabula from two fresh autopsy specimens, and four acetabula that were studied during two gynecological operations. Models were constructed to show where these screws can penetrate. Medially placed screws either penetrated or came dangerously close to the external iliac vein; the obturator artery, nerve, and vein; and tributaries of the internal iliac vein. To avoid injury to the medial vascular structures, screws should not be placed in the anterosuperior quadrant of the acetabulum.

Acetabulum↗

PubMed1990

Metal-backed acetabular cups in total hip arthroplasty.

Metal backing for the acetabular component of a total hip replacement, initially designed to allow replacement of the polyethylene liner, has since been universally accepted as a means of decreasing peak stresses at the interfaces of bone and cement. We studied the results of 238 total hip replacements that had been performed between 1980 and 1983 and that differed only in that 138 of the acetabular components had a metal backing and 100 were made of polyethylene only. Kaplan-Meier survival analysis, with three different modes of failure (radiolucency, loosening, and revision), showed a significant increase in the rate of failure of the metal-backed acetabular cup compared with the all-polyethylene cup: radiolucency, 39 compared with 23 per cent (p less than 0.0001); loosening, 4 compared with 2 per cent (p less than 0.0001); and revision, 6 compared with 2 per cent (p less than 0.0034). It was concluded that metal backing cannot be recommended for a cemented acetabular component of a total hip-replacement system.

Acetabulum↗

PubMed1989

Long-term survival analysis of the posterior cruciate condylar total knee arthroplasty. A 10-year evaluation.

Long-term survivorship analysis was applied to 394 cruciate condylar type total knee arthroplasties. Clinical and radiographic parameters were evaluated. Failure was defined in three separate survival curves as revision, radiographic loosening, and a pain rating of 20 or less on the HSS knee score scale. Survival at 10 years, using only revision or recommended revision as the criterion for failure, was 94.7%. With the addition of the other two criteria, survival fell to 81% at 10 years. The posterior cruciate condylar knee survival is comparable to that of the total condylar knee when using comparable definitions of failure.

Adult↗

PubMed1989

Urinary tract catheterization protocols following total joint arthroplasty.

Six hundred one consecutive total joint arthroplasty patients were divided into three groups using three different catheterization protocols. Each group was evaluated for preoperative and postoperative urinary tract infections, number of catheterizations, and number of subsequent urinary tract manipulations. Group 1 (165 patients) was treated with "as needed" intermittent catheterization. One hundred six of these patients (64%) required a minimum of one catheterization with a total of 265 (mean 2.4 per patient) catheterizations. One post-operative urinary tract infection was recorded. Group 2 (295 patients) was treated with in-and-out catheterization on one occasion followed by anchoring of a closed drainage system if needed. One hundred eighty-one patients (61%) required catheterization, 124 (69%) of these patients required anchoring of a closed system. Two (0.69%) of these patients developed postoperative urinary tract infections. Group 3 (140 patients) were treated with intraoperative sterile anchoring of a closed drainage system which was maintained for 48 hours or less. Ten patients required in-and-out catheterizations (maximum one per patient) after system discontinuance. No urinary tract infections developed. Using Fisher's Exact test, no statistical difference in infection rates was found between the three groups. The group 3 protocol was felt to offer several patient conveniences.

Adult↗

PubMed1989

Early clinical results of the TTAP acetabular cup.

One hundred seventy-five threaded titanium alloy prostheses (TTAP) acetabular cups and 125 cemented cups were evaluated clinically and radiographically at 1 to 3 years postoperatively. The series was statistically different in that there were more women in the cemented group than in the non-cemented group (P less than .001). The cemented group was also older than the threaded group (P less than .001). Pain, ambulation, function, range of motion, and roentgenograms were evaluated in all patients. There were no significant differences in the clinical function of the two groups, but there were fewer radiolucencies in the radiographic analysis of the TTAP group. This may be an artificial difference, since two TTAP acetabular cups were removed for loosening, but none of the cemented cups were removed.

Acetabulum↗

PubMed1989

Vancomycin prophylaxis and elective total joint arthroplasty.

A series of 201 consecutive patients treated with unilateral or bilateral total joint arthroplasty were given a single-dose prophylactic antibiotic regimen consisting of 1 g vancomycin infused over 1 hour on the morning of surgery and 80 g gentamicin given upon arrival in the operating room. Bactericidal blood levels were maintained during and for 24 hours after surgery. Elevated serum creatinine levels developed postsurgically in 8 patients but returned to normal. No serious hypersensitivity reactions occurred; minor reactions responded to antihistamine therapy. No postoperative infections were reported. Cost of administration compared favorably with 24- and 48-hour regimens employing cephalosporins. The investigators concluded that a combined single dose vancomycin/gentamicin regimen is a safe, effective, and cost efficient method of orthopedic implant prophylaxis.

Adult↗

PubMed1989

Orthopedic research: an overview of data entry, database management, and statistical analysis.

An orthopedic practitioner can facilitate clinical research and analyze quality assurance data with a minor investment in a personal computer, an optical scanner, and two software packages, namely a database manager and a statistics program. One of the most time-consuming stages in the research process includes entering patient chart data, editing and manipulating the data (database management), and analyzing the data (statistical analysis). This can be automated to a large extent with the above mentioned equipment. This article focuses on the steps involved in organizing an orthopedic office for research. The steps include choosing a method of data entry, choosing and implementing a database package, and choosing and implementing a statistics package. This discussion is followed by a practical review of basic statistics applicable to orthopedic research. Several simple and advanced tests are described and examples are given for each.

Biometry↗