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Biomedical subjects

D A Waldman

Publications and source records attributed to D A Waldman.

12 recordsLinked to original sources
PubMed2001

Patellar resurfacing in total knee arthroplasty. A prospective, randomized, double-blind study with five to seven years of follow-up.

BACKGROUND: Whether to resurface the patella during a primary total knee arthroplasty performed for the treatment of degenerative osteoarthritis remains a controversial issue. Parameters that have been suggested as being useful in guiding this decision include patient height and weight, the presence of anterior knee pain preoperatively, and the grade of chondromalacia encountered intraoperatively. The purpose of this study was to determine whether these parameters were predictive of the clinical result following total knee arthroplasty with or without patellar resurfacing. METHODS: Eighty-six patients (118 knees) undergoing primary total knee arthroplasty for the treatment of osteoarthritis were enrolled in a prospective, randomized, double-blind study. All patients received the same posterior-cruciate-sparing total knee prosthetic components. Patients were randomized to treatment with or without resurfacing of the patella. Evaluations consisted of the determination of a Knee Society clinical score, the completion of a patient satisfaction questionnaire, specific questions relating to patellofemoral symptoms, and radiographs. Sixty-seven patients (ninety-three knees) were followed for a minimum of five years (range, sixty to eighty-four months; average, 70.5 months). RESULTS: With the numbers available, there was no significant difference between the groups treated with and without resurfacing with regard to the overall Knee Society score or the pain and function subscores. Obesity, the degree of patellar chondromalacia, and the presence of preoperative anterior knee pain did not predict postoperative clinical scores or the presence of postoperative anterior knee pain. CONCLUSIONS: The occurrence of anterior knee pain could not be predicted with any clinical or radiographic parameter studied. On the basis of these results, it seems likely that postoperative anterior knee pain is related either to the component design or to the details of the surgical technique, such as component rotation, rather than to whether or not the patella is resurfaced.

Arthroplasty, Replacement, Knee↗
PubMed1997

Resurfacing of the patella in total knee arthroplasty. A prospective, randomized, double-blind study.

During a two-year period, eighty-nine patients who were scheduled to have a total knee arthroplasty for the treatment of degenerative osteoarthrosis were randomly assigned to one of two groups: resurfacing of the patella or retention of the patella. All patients received the same posterior cruciate-sparing prosthesis, and all operations were performed by, or under the direct supervision of, one of us. Three patients died in the early postoperative period. The remaining eighty-six patients (118 knees; fifty-eight that had had resurfacing of the patella and sixty that had not) formed the study group. They were followed for a mean of thirty months (range, twenty-four to forty-four months). Evaluation was performed with use of the clinical scoring system of The Knee Society, a patient-satisfaction questionnaire, specific questions regarding patellofemoral symptoms and function, and radiographs. All clinical evaluations were performed by the same research nurse, without the involvement of a physician, in a blinded manner (neither the nurse nor the patient had knowledge of whether the patella had been resurfaced). Preoperatively, the mean Knee Society score, on a scale ranging from 0 to 200 points, was 89.7 points (range, 33 to 132 points); postoperatively, this score improved to a mean of 172.7 points (range, 98 to 200 points). With the numbers available for study, we could detect no significant difference between the knees that had had patellar resurfacing and those that had not with regard to the over-all score (p = 0.63), the subscore for pain (p = 0.56), or the subscore for function (p = 0.77). We also could detect no difference between the treatment groups, with the numbers available, with regard to patient satisfaction or the responses to questions involving the function of the patellofemoral joint, including the ability to exit from an automobile, to rise from a chair, and to climb stairs. Thirty-two patients had bilateral total knee replacement with resurfacing of the patella in one knee and retention of the patella in the other. These patients expressed no clear preference for either knee. Eight (13 per cent) of the sixty knees that had not had resurfacing were painful anteriorly compared with four (7 per cent) of the fifty-eight that had; this was not a significant difference (p = 0.38), with the numbers available. The anterior pain that was noted postoperatively was predominantly of new onset; it had not been observed preoperatively in three of the four knees that had had resurfacing or in four of the eight that had not. No additional treatment options were offered to the patients who had anterior pain in the knee after resurfacing. However, six (10 per cent) of the sixty knees that had not had resurfacing had it subsequently, because of anterior pain in the knee, after the twelfth postoperative month (range, fifteen to thirty-nine months). The pain decreased in four of these knees. Thus, total knee arthroplasty with retention of the patella yielded clinical results that were comparable with those after total knee arthroplasty with patellar resurfacing, but it was associated with a 10 per cent prevalence of the need for subsequent resurfacing. The prevalence of anterior pain after total knee arthroplasty was not influenced by whether or not the patella had been resurfaced. The postoperative clinical scores, the postoperative development of anterior pain, and the need for subsequent resurfacing were not predicted by the presence of preoperative anterior pain, obesity, or the grade of chondromalacia observed intraoperatively. Because of the short duration of follow-up, these results should be considered preliminary. Additional follow-up is planned.

Adult↗
PubMed1994

Variations in cognitive, perceptual, and psychomotor abilities across the working life span: examining the effects of race, sex, experience, education, and occupational type.

Cognitive, perceptual, and psychomotor abilities were examined across the working life span for different racial groups, taking into consideration sex, job experience, education, and occupational type. Data included scores on all subtests of the General Aptitude Test Battery for White, Black, and Hispanic employees. Age and sex generally accounted for a relatively small percentage of the variance in ability test scores when experience, education, and occupational type were controlled. Race accounted for a substantial amount of variance in test performance, even after controlling for education, experience, occupational type, and age. Findings are discussed in terms of the potential for specific experiences and continuing education to affect the maintenance of abilities at later points in the life span for all racial groups.

Adolescent↗
PubMed1993

A simple way to make traction pins safer.

Prevention of inadvertent injuries to patients and hospital staff becomes more important than ever in today's hospital environment. The sharp ends of traction pins, a previous hazard, can be made safe using materials easily found throughout the hospital. Our method uses items that are easily replaced and easy to apply.

Bone Nails↗
PubMed1990

An examination of age and cognitive test performance across job complexity and occupational types.

In this study, job complexity and occupational type were examined as potential moderators of the relationship between age and cognitive ability. Data included general, verbal, and numerical ability scores for 21,646 individuals in the General Aptitude Test Battery (GATB) data base. These individuals comprised 102 unique samples and 10 major occupational groups. Differences in the relationship between age and cognitive ability test scores were observed across occupational types but not for different levels of job complexity. Findings were discussed in terms of a need for research that examines specific life and work experiences and how such experiences may influence an individual's cognitive abilities across the life span.

Adolescent↗
PubMed1990

Improve performance by appraisal.

An effective performance appraisal system will not only evaluate employees' ability and motivation, but also opportunity--those elements in the work system which contribute to performance. The authors explain how this approach works.

Employee Performance Appraisal↗
PubMed1989

Ratings of managerial skill requirements: comparison of age- and job-related factors.

This article examines how individual characteristics (age, experience) and organizational characteristics (department, level) influence the skill requirements rated as being important for managerial jobs. One hundred ninety-seven managerial employees completed a survey composed of 20 skill dimensions pertinent to supervisory positions in the mining industry. Organizational level and departmental affiliation were correlated with job skill importance ratings. Ratings of skill importance were also correlated with the age of the person being rated, years of experience, and the age of the rater. As predicted, correlations with ratee age varied across different skill dimensions. This study has implications for fair employment practices to the degree that raters base evaluations of a job on the age of incumbents vs. job relevant characteristics.

Administrative Personnel↗
PubMedDate not supplied

Personnel aptitude test scores as a function of age, education and job type.

A battery of personnel aptitude tests were administered and correlated with age for individuals working in skilled and unskilled jobs at a surface coal mining operation. Relationships between age and several measures of cognitive ability were significantly different when computed for skilled versus unskilled employees. Specifically, decreases in cognitive test performance with increasing age were more pronounced for unskilled workers. The partialling out of education had relatively little impact on relationships found between age and cognitive test performance for both skilled and unskilled workers.

Adult↗