Kevin L. Smith

Demographic, Belief, and Situational Factors Influencing the Decision to Utilize Emergency Medical Services Among Chest Pain Patients

BACKGROUND Empirical evidence suggests that people value emergency medical services (EMS) but that they may not use the service when experiencing chest pain. This study evaluates this phenomenon and the factors associated with the failure to use EMS during a potential cardiac event. METHODS AND RESULTS Baseline data were gathered from a randomized, controlled community trial (REACT) that was conducted in 20 US communities. A random-digit-dial survey documented bystander intentions to use EMS for cardiac symptoms in each community. An emergency department surveillance system documented the mode of transport among chest pain patients in each community and collected ancillary data, including situational factors surrounding the chest pain event. Logistic regression identified factors associated with failure to use EMS. A total of 962 community members responded to the phone survey, and data were collected on 875 chest pain emergency department arrivals. The mean proportion of community members intending to use EMS during a witnessed cardiac event was 89%; the mean proportion of patients observed using the service was 23%, with significant geographic differences (range, 10% to 48% use). After controlling for covariates, non-EMS users were more likely to try antacids/aspirin and call a doctor and were less likely to subscribe to (or participate in) an EMS prepayment plan. CONCLUSIONS The results of this study indicate that indecision, self-treatment, physician contact, and financial concerns may undermine a chest pain patients intention to use EMS.

A prospective multipractice investigation of patients with full-thickness rotator cuff tears: the importance of comorbidities, practice, and other covariables on self-assessed shoulder function and health status.

Background: Rotator cuff tears are among the most common conditions of the shoulder. One of the major difficulties in studying patients with rotator cuff tears is that the clinical expression of these tears varies widely and different practices may have substantially different patient populations. The goals of the present prospective multipractice study were to use patient self-assessment questionnaires (1) to identify some of the characteristics of patients with rotator cuff tears, other than the size of the cuff tear, that are correlated with shoulder function, and (2) to determine whether there are significant differences in these characteristics among patients from the practices of different surgeons.Methods: Ten surgeons enrolled a total of 333 patients with a full-thickness tear of the supraspinatus tendon into this prospective study. Each patient completed self-assessment questionnaires that included items regarding demographic characteristics, prior treatment, medical and social comorbidities, general health status, and shoulder function.Results: As expected, patients who had an infraspinatus tendon tear as well as a supraspinatus tendon tear had significantly worse ability to use the arm overhead compared with those who had a supraspinatus tear alone (p < 0.005). However, shoulder function and health status were correlated with patient characteristics other than the size of the rotator cuff tear. The number of shoulder functions that were performable was correlated with the subscales of the Short Form-36 and was inversely associated with medical and social comorbidities. The patients from the ten different surgeon practices showed significant differences in almost every parameter, including age, gender, method of tear documentation, tear size, prior treatment, medical and social comorbidities, general health status, and shoulder function.Conclusions: Clinical studies on the natural history of rotator cuff tears and the effectiveness of treatment must control for a wide range of variables, many of which do not pertain directly to the shoulder. Patients from the practices of different surgeons cannot be assumed to be similar with respect to these variables. Patient self-assessment questionnaires appear to offer a practical method of uniform assessment across different practices.Level of Evidence: Prognostic study, Level I-1 (prospective study). See Instructions to Authors for a complete description of levels of evidence.

Characterizing the Functional Improvement After Total Shoulder Arthroplasty for Osteoarthritis

Background: Both shoulder surgeons and patients who are considering total shoulder arthroplasty are interested in the anticipated improvement in shoulder comfort and function after the procedure. The purpose of the present study was to characterize shoulder-specific functional gains in relation to preoperative shoulder function and to present this information in a way that can be easily communicated to patients who are considering this surgery.Methods: We analyzed the preoperative and follow-up shoulder function in patients managed with total shoulder arthroplasty for the treatment of primary glenohumeral osteoarthritis. Functional self-assessments were available for 102 (80%) of 128 shoulders after thirty to sixty months of follow-up. Outcome was assessed with respect to the change in the number of shoulder functions that were performable, the change in shoulder function as a percentage of the preoperative functional deficit, and the change in the ability to perform specific shoulder functions.Results: The average number of shoulder functions that were performable improved from four of twelve preoperatively to nine of twelve postoperatively (p < 0.01). Function improved in ninety-six shoulders (94%). The number of functions that were performable at the time of follow-up was positively associated with preoperative shoulder function (p < 0.05): the better the preoperative function, the better the follow-up function. The improvement in function was greatest for shoulders with less preoperative function (p < 0.01). On the average, patients regained approximately two-thirds of the functions that had been absent preoperatively. Significant improvement was noted in eleven of the twelve shoulder functions that were examined (p < 0.01). The chance of regaining a function that had been absent before surgery was 73%, whereas the chance of losing a function that had been present before surgery was 6%. Older men tended to have greater functional improvement than younger men.Conclusion: Total shoulder arthroplasty for the treatment of primary glenohumeral osteoarthritis significantly improves shoulder function. Postoperative function is related to preoperative function. The improvement that was observed in this clinical series can be conveyed to patients most simply by stating that, after surgery, shoulders typically regained approximately two-thirds of the functions that had been absent preoperatively.

The effects of the child and adolescent trial for cardiovascular health intervention on psychosocial determinants of cardiovascular disease risk behavior among third-grade students.

Purpose. The Child and Adolescent Trial for Cardiovascular Health is a multi-site study of a school-based intervention designed to reduce or prevent the development of risk factors for cardiovascular disease. The goal was to change (or prevent) related risk behaviors and the psychosocial variables that theoretically influence those behaviors. Design. A nested design was used in which schools served as the primary unit of analysis. Twenty-four schools participated at each of four sites (Austin, San Diego, Minneapolis, and New Orleans). Each site had 10 control and 14 intervention schools. Setting and Subject. Ninety-six schools (with more than 6000 students) in the four sites were randomized to three treatment conditions: control, school-based interventions, and school-plus-family interventions. The sample included approximately equal numbers of males and females and was 67.5% white, 13.9% African-American, 13.9% Hispanic, and 4.7% other. Measures. The psychosocial determinants measured included improvements in dietary knowledge, intentions, self-efficacy, usual behavior, perceived social reinforcement for healthy food choices, and perceived reinforcement and self-efficacy for physical activity. Results. The findings indicated significant improvements in all the psychosocial determinants measured (p < .0001). The results revealed a greater impact in the school-plus-family intervention schools for two determinants, usual dietary behavior and intentions to eat heart-healthy foods. Conclusions. These findings support theory-based interventions for changing selected psychosocial determinants of cardiovascular disease risk behavior among children.

Self-assessment questionnaires document substantial variability in the clinical expression of rotator cuff tears.

The goal of this investigation was to document the variability in the clinical expression of full-thickness rotator cuff tears with practical and standardized patient self-assessment tools. One-hundred twenty-three consecutive patients with full-thickness cuff tears diagnosed by standard cuff-imaging methods (sonography, arthrography, or magnetic resonance imagery) assessed their own shoulder function and health status with the Simple Shoulder Test and the Short Form 36, respectively. As a group, these patients were substantially compromised in their ability to perform the functions of the Simple Shoulder Test and in the Short Form 36 scales of physical role, physical function, and comfort. As individuals, however, their self-assessments varied widely. The standard deviations were often greater than 50% of the mean and the range of responses often covered the entire scale from the minimum possible score to the maximum possible score. These results show the importance of documenting the clinical expression of cuff tears in patients at initial evaluation and when treatment is being considered. The results also show the practicality of standardized self-assessment questionnaires in such documentation.

The correlation of comorbidity with function of the shoulder and health status of patients who have glenohumeral degenerative joint disease

We studied the effect of comorbidities on function of the shoulder and health status in a group of eighty-five consecutive patients who had glenohumeral degenerative joint disease of sufficient severity to meet one surgeons criteria for the performance of shoulder arthroplasty. A questionnaire was used to identify the comorbidities, such as other diseases, social factors, or a work-related injury, for each patient. The number of functions on the Simple Shoulder Test that the patient could perform had a significant negative correlation with the number of comorbidities (r = -0.32, intercept = 4.6 per cent, slope = -0.6, and p = 0.0031). Each parameter on the Short Form-36 (except for physical role function) had a significant negative correlation with the number of comorbidities (p < 0.05). This negative relationship was strongest for general health perception (r = -0.42) and vitality (r = -0.35). We concluded that the number of comorbidities has a quantitative effect on function of the shoulder. In the evaluation of the functional status of patients and the effectiveness of treatment, the effects of comorbidity must be controlled. The results of the present study demonstrate that the scores on the Short Form-36 are quantitatively related to the number of comorbidities. The six parameters that are unrelated to function of the shoulder (physical function, social function, emotional role function, mental health, vitality, and general health perception) may provide a practical way to integrate the effects of all potential comorbidities on individual patients. Future clinical research will be strengthened by efforts to measure the impact of comorbidities and by strategies to control for their effects.

TOTAL SHOULDER ARTHROPLASTY VERSUS HEMIARTHROPLASTY: Current Trends*

Currently, a debate exists regarding the indications for hemiarthroplasty and total shoulder arthroplasty. A number of factors are important in making this decision. The article discusses some of the variables related to choosing the appropriate procedure for every patient. The authors also discuss their approach to various arthritic conditions of the shoulder, the rationale behind their approach, and their results. Future work will be necessary before more definitive recommendations can be made, and they may well be different for each individual surgeon.

Simple Home Program for Frozen Shoulder to Improve Patients' Assessment of Shoulder Function and Health Status

Background: The purpose of this investigation was to test the hypothesis that a simple home program can improve the self-assessed shoulder function and health status of a group of patients with frozen shoulders. Methods: A case series using a one-group pretest, posttest design analyzing 41 patients from a single orthopedic practice who had a frozen shoulder were included in this study. The patients completed the Simple Shoulder Test (SST) and the Medical Outcomes Study Short-Form Health Survey (SF-36) questionniare at the time of initial consultation, had treatment consisting of education regarding frozen shoulder and home stretching instructions, and were asked to complete the same questionnaires mailed every 6 months. Initial results were compared with previously published control values to establish level of impairment, and follow-up results were compared with the initial results to determine the extent of improvement. Results: Patients initially had serious deficits in the 12 shoulder functions inventoried by the SST and were also compromised in their general health status as reflected by the SF-36 scores. At follow-up, 4 of 10 SST functions were improved (P < 0.001). The SF-36 health status scores of physical function, comfort, and physical role function were also improved (P < 0.001). Conclusion: These data suggest that this home program for frozen shoulder can lead to improved self-assessed shoulder function and health status in patients similar to those in the study population.

Posteroinferior glenoplasty can change glenoid shape and increase the mechanical stability of the shoulder

The treatment of recurrent posterior glenohumeral instability remains an unsolved clinical problem. Although various types of capsulorraphy have been advocated, outcome studies indicate that it is difficult to achieve a balance between stability and mobility. Alterations of the bony glenoid for posterior instability have been proposed, but are not well understood from a mechanical perspective. This investigation had 2 purposes: (1) to determine in a cadaver model if posteroinferior glenoplasty can change the shape of the glenoid, and (2) to determine if altering the shape of the glenoid can increase the mechanical stability of the glenohumeral joint. We determined the effective glenoid shape in 7 normal cadaver glenoids by tracking the path of the center of the humeral head as it was translated across the glenoid face in 8 different directions. These determinations enabled us to calculate the maximum effective slope of the glenoid in each direction. We then determined the mechanical stability of the glenoids in each of the 8 directions by measuring the tangential force required to dislocate the shoulder under a 50-N compressive load. The ratio of the dislocating force to the compressive load was defined as the stability ratio. All measurements were repeated after a standardized posteroinferior glenoplasty was performed. Posteroinferior glenoplasty increased the posteroinferior glenoid depth from 3.8 +/- 0.6 mm to 7.0 +/- 1.8 mm and shifted the center of the humeral head an average of 2.2 mm anteriorly and 1.8 mm superiorly. These changes in dimension could be directly visualized as an immediate mechanical consequence of the glenoplasty procedure, particularly because of the insertion of the bone wedge. Glenoplasty increased the posteroinferior glenoid slope from 0.55 +/- 0.07 to 0.83 +/- 0.12 and increased the posteroinferior stability ratio from 0.47 +/- 0.10 to 0.81 +/- 0.17. This is a more than 70% increase in the tangential force that can be resisted before dislocation. The increase can be quantitatively understood as a direct mechanical consequence of the altered shape of the glenoid concavity. These numbers indicate that, in this cadaveric model, posteroinferior glenoplasty results in defined changes in the effective glenoid shape and in the mechanical stability of the glenohumeral joint. However, this study does not establish the role of this procedure in the clinical management of posterior glenohumeral instability.

Optimizing the Glenoid Contribution to the Stability of a Humeral Hemiarthroplasty without a Prosthetic Glenoid

BACKGROUND In a shoulder requiring arthroplasty, if the glenoid is flat or biconcave, the surgeon can restore the desired glenoid stability by using a glenoid prosthesis with a known surface geometry or by modifying the surface of the glenoid to a geometry that provides the desired glenoid stability. This study tested the hypotheses that (1) the stability provided by the glenoid is reduced by the removal of the articular cartilage; (2) the stability contributed by the glenoid is compromised by loss of its articular cartilage, and this lost stability can be restored by spherical reaming along the glenoid centerline; and (3) the stability of a reamed glenoid is comparable with that of a native glenoid and with that of a polyethylene glenoid with similar surface geometry; and (4) the glenoid stability can be predicted from the glenoid surface geometry. METHODS The stability provided by the glenoid in a given direction can be characterized by the maximal angle that the humeral joint reaction force can make with the glenoid centerline before the humeral head dislocates; this quantity is defined as the balance stability angle in the specified direction. The balance stability angles were both calculated and measured in eight different directions for an unused polyethylene glenoid component and eleven cadaveric glenoids in four different states: (1) native without the capsule or the rotator cuff, (2) denuded of cartilage and labrum, (3) after reaming the glenoid surface around the glenoid centerline with use of a spherical reamer with a radius of 25 mm, and (4) after reaming around the glenoid centerline with use of a spherical reamer with a radius of 22.5 mm. RESULTS The calculated and measured balance stability angles for each direction in each glenoid were strongly correlated. Denuding the glenoids of the articular cartilage reduced the glenoid contribution to stability, especially in the posterior direction. Reaming the glenoid restored the stability to values comparable with those of the normal glenoid. For example, the average calculated balance stability angle (and standard deviation) in the posterior direction for all eleven glenoids was 24 degrees for the native glenoids, 14 degrees for the denuded glenoids, 25 degrees for the glenoids reamed to a radius of 25 mm, and 33 degrees for the glenoids reamed to a radius of 22.5 mm. The values for the glenoids reamed to 25 mm (25 degrees ) were similar to those of a polyethylene glenoid of the same radius of curvature. For glenoids reamed to 22.5 mm, the average difference between the actual balance stability angle and that predicted from the glenoid geometry was 3.4 degrees +/- 2.4 degrees. CONCLUSIONS The glenoid contribution to shoulder stability was decreased by the removal of cartilage and labrum and was restored by spherical reaming to a level similar to resurfacing the glenoid with a polyethylene component.