Serial force plate analyses of dogs with unilateral knee instability, with or without interruption of the sensory input from the ipsilateral limb.

OBJECTIVE AND DESIGN: We characterized the mean peak vertical forces (MFz) in five groups of dogs which underwent transection of the left anterior cruciate ligament (ACLT) or sham ACLT and ipsilateral dorsal root ganglionectomy or sham-ganglionectomy, and the relationship of these forces to the severity of osteoarthritis (previously reported) 72 weeks after arthrotomy. Group I (N=7) underwent ACLT; Group II (N=8) underwent ACLT followed 52 weeks later by ganglionectomy; Group III (N=7) underwent ganglionectomy followed 2 weeks later by ACLT; Group IV (N=7) underwent sham-ganglionectomy followed 2 weeks later by ACLT; Group V (N=8) underwent ganglionectomy followed 2 weeks later by sham-ACLT. The dogs were evaluated 2, 6, 12, 24, 52 and 72 weeks after arthrotomy. RESULTS: From 6 weeks after arthrotomy until death, the left hindlimb MFz in Group V was significantly greater (P< 0.05) than that in the other four groups. The MFz of all groups which underwent ACLT decreased after arthrotomy. While the MFz of Group III (very severe OA) was about 10-20% greater than that of Groups I, II and IV (mild OA) 6 and 12 weeks after ACLT, and generally about 5-10% greater subsequently, this difference was not statistically significant. The MFz of Group II returned to pre-ganglionectomy levels, rather than to baseline levels, following ganglionectomy. CONCLUSIONS: (1) since the ipsilateral limb of dogs with ganglionectomy+sham ACLT bore normal amounts of weight throughout most of the postsurgical period, and its knee did not develop OA, one cannot argue that the knee was protected from OA because the limb was not used; (2) the fact that the MFz of dogs which underwent ACLT+ganglionectomy returned to pre-ganglionectomy levels, rather than baseline, is consistent with the hypothesis that the unstable joint was protected from accelerated breakdown by a central nervous system that was reprogrammed by sensation from the unstable limb; (3) the slightly-but consistently-greater MFz of dogs which underwent ganglionectomy+ ACLT may contribute to the acceleration of OA in this model.

Management of osteoarthritis of the knee by primary care physicians.

BACKGROUND: Most patients with osteoarthritis (OA) are treated by primary care physicians (in this article, primary care physicians are family physicians and general internists). OBJECTIVE: To describe and compare the self-reported practice patterns of family physicians and general internists for the evaluation and management of severe OA of the knee, including factors that might influence referral for total knee replacement. DESIGN, SETTING, AND PARTICIPANTS: A survey was developed and mailed to randomly selected community family physicians and general internists practicing in Indiana. MAIN OUTCOME MEASURE: Self-reported physician practice patterns regarding OA of the knee. RESULTS: Physical examination was the most common method of evaluating OA of the knee. Family physicians were more likely to examine for crepitation, joint stability, and quadriceps muscle strength than were general internists (P<.05). Patients with OA of the knee treated by family physicians were more likely to receive nonsteroidal anti-inflammatory drugs or oral corticosteroids and were less likely to receive aspirin, acetaminophen, or narcotics compared with patients treated by general internists. Six patient characteristics were rated as positive factors favoring a referral for possible total knee replacement, 8 characteristics were rated as negative, and 5 were rated as not a factor in the decision about referral. CONCLUSIONS: Results from this study suggest that additional research is needed to determine the evaluative techniques for OA of the knee that provide the most useful information for management decisions, the management techniques that maximize patient outcomes, and the criteria that should be used to select patients who would benefit most from referral for possible total knee replacement.

Racial disparity in cardiac decision making: results from patient focus groups.

BACKGROUND: While numerous studies suggest that African Americans receive fewer invasive cardiac procedures than whites, the basis for these treatment differences is not understood. METHODS: We conducted focus group sessions with patients who had received treatment in the hospital or the emergency department within the preceding 3 months for ischemic heart disease at 2 urban, university-affiliated hospitals. RESULTS: Discussions with patients identified the following factors that influenced their decision making: clarity, simplicity, and consistency of treatment recommendations; advice from friends and family about whether to accept recommendations; availability to speak with others who accepted similar recommendations; and having honest and caring physicians. African American patients identified the following additional factors that influenced their decision making: perceptions of health care discrimination; perceptions of undesirable physician behavior; faith in God to control one's destiny; and patient-physician camaraderie. CONCLUSIONS: Participants identified common issues influencing health care decision making, regardless of race. However, additional factors were expressed only by African American participants. These factors conveyed racial differences in perceptions of the health care system that may, in part, contribute to differences in health care decision making and treatment.

Revision rates after knee replacement in the United States.

OBJECTIVES: Each year approximately 100,000 Medicare patients undergo knee replacement surgery. Patients, referring physicians, and surgeons must consider a variety of factors when deciding if knee replacement is indicated. One factor in this decision process is the likelihood of revision knee replacement after the initial surgery. This study determined the chance that a revision knee replacement will occur and which factors were associated with revision. METHODS: Data on all primary and revision knee replacements that were performed on Medicare patients during the years 1985 through 1990 were obtained. The probability that a revision knee replacement occurred was modeled from data for all patients for whom 2 full years of follow-up data were available. Two strategies for linking revisions to a particular primary knee replacement for each patient were developed. Predictive models were developed for each linking strategy. ICD-9-CM codes were used to determine hospitalizations for primary knee replacement and revision knee replacement. RESULTS: More than 200,000 hospitalizations for primary knee replacements were performed, with fewer than 3% of them requiring revision within 2 years. The following factors increase the chance of revision within 2 years of primary knee replacement: (1) male gender, (2) younger age, (3) longer length of hospital stay for the primary knee replacement, (4) more diagnoses at the primary knee replacement hospitalization, (5) unspecified arthritis type, (6) surgical complications during the primary knee replacement hospitalization, and (7) primary knee replacement performed at an urban hospital. CONCLUSIONS: Revision knee replacement is uncommon. Demographic, clinical, and process factors were related to the probability of revision knee replacement.

Can raters consistently evaluate the content of focus groups?

Focus groups are increasingly being used to provide insights to researchers and policy makers. These data complement quantitative approaches to understanding the world. Unfortunately, quantitative and qualitative methodologies have often been viewed as antithetical, rather than complementary, strategies. While focus groups can clearly generate rich information that is unobtainable through other quantitative methods, it is important to determine the degree to which different raters can consistently extract information from transcripts. Thus, our goal was to quantify agreement in the interpretation of transcripts from patient and physician focus groups, using decision-making in ischemic heart disease as a model. We used data from focus groups with both patients and physicians that sought to identify factors affecting diagnostic and treatment decisions in ischemic heart disease. Three raters independently reviewed transcribed audiotapes from focus groups of patients with ischemic heart disease, as well as focus groups of physicians who care for these patients. We found that raters could not distinguish between major and minor factors reliably. More troubling, however, is that consistency regarding the apparently straightforward judgment as to the mere presence or absence of a factor was difficult to achieve. In particular, the three raters of each transcript failed to agree on between one third and one half of the factors. This reasonably high level of disagreement occurred despite the raters: (1) having generated the individual factors themselves based upon their reading a random sample of actual transcripts and (2) being trained in the use of rating forms (including standard definitions of themes). These data suggest that if a single rater evaluates focus group transcripts, as is commonly done, judgments may not be reproducible by other raters. Moreover, a single rater may not extract all important information contained in the transcripts.

Examination of racial differences in management of cardiovascular disease.

OBJECTIVES: We sought to identify the clinical characteristics associated with, and to investigate the impact of cohort selection criteria on, interracial use of invasive cardiac procedures and to determine survival. BACKGROUND: Although interracial differences in the use of invasive cardiac procedures have been previously reported, the underlying reasons are not known. METHODS: A retrospective cohort study was conducted at a Veterans Affairs Medical Center. Study patients were evaluated for cardiovascular disease between January 1 and December 31, 1993. RESULTS: The study included 1,406 male patients (85% white, 58% married), with a mean age of 63.4 years. African Americans were less likely than whites to undergo procedures (cardiac catheterization: odds ratio [OR] 0.37, 95% confidence interval [CI] 0.24 to 0.58; coronary angioplasty: OR 0.60, 95% CI 0.25 to 1.49; coronary bypass surgery: OR 0.22, 95% CI 0.08 to 0.63; any procedure: OR 0.32, 95% CI 0.21 to 0.50). On bivariate analysis, patients who underwent cardiac procedures were more likely to be younger, married and reside nonlocally and less likely to have severe comorbid disease; however, African Americans were less likely to be married and to reside nonlocally and more likely to have severe comorbid disease. Cohorts adjusting for referral status and specified cardiac diagnoses reduced or reversed interracial treatment differences. Thirty-day and 1-year survival rates (96% and 87.6%, respectively) were equivalent. CONCLUSIONS: Racial disparity in invasive cardiac procedure use may be partially explained by clinical differences and cohort selection bias. Despite treatment differences, survival rates were equivalent in African Americans and whites.

Outcome implications for the timing of bilateral total knee arthroplasties.

Health Care Financing Administration data from 1985 to 1990 revealed 339,152 total knee arthroplasties of which 62,730 (18.6%) were bilateral procedures (simultaneous 112,922; staged 6 weeks, 4354; staged 3 months, 4524; staged 6 months, 9829; and staged 1 year 31,401). Medicare beneficiaries undergoing bilateral procedures were an average of 73 years of age; demographics revealed that among the various simultaneous and staged groups 57% to 69% were females, 90% were white, 85% to 90% had a diagnosis of osteoarthritis, and 30% to 40% were performed in rural hospitals. Between 1985 and 1990, surgical and vascular complications ranged from 2.4% to 4% and 4.1% to 6.8%, respectively, for all types of bilateral staged and simultaneous total knee arthroplasties. All differences were statistically significant. After controlling statistically for demographic variables and diagnoses, a surrogate for case mix, it was found that individuals electing simultaneous bilateral arthroplasties experienced twice the number of intensive care days than those choosing staged procedures. Days in the intensive care unit were double when done simultaneously instead of staged (0.48 versus 0.21). Nosocomial infections were similar within groups (10% versus 13%); however, wound infections were nearly half when done simultaneously (0.5% versus 1%) versus in a staged fashion. Length of stay and cost were much less for the simultaneous procedure group who were sicker as measured by the number of diagnoses. Mortality at 30 days was highest for the simultaneous procedure group (.99%) versus staged 3 or 6 months (0.30%); however, by 2 years it was close to 4% for all groups. Staging the procedure 3 to 6 months seems to offer the fewest disadvantages, is only slightly more expensive, and has the lowest mortality rate.