Comparison of Ambulatory Quality Measures Between Shared Practice Panels and Independent Practice Panels

Objective

To assess for differences in patient care outcomes in the primary care setting for patients assigned to an independent practice panel (IPP) or a shared practice panel (SPP).

Patients and Methods

We retrospectively reviewed the electronic health records of patients of 2 Mayo Clinic family medicine primary care clinics from January 1, 2019 to December 31, 2019. Patients were assigned to either an IPP (physician or advanced practice provider [APP]) or an SPP (physician and ≥1 APP). We assessed 6 measures of quality care and compared them between IPP and SPP groups: diabetes optimal care, hypertension control, depression remission at 6 months, breast cancer screening, cervical cancer screening, and colon cancer screening.

Results

The study included 114,438 patients assigned to 140 family medicine panels during the study period: 87 IPPs and 53 SPPs. The IPP clinicians showed improved quality metrics compared with the SPP clinicians for the percentage of assigned patients achieving depression remission (16.6% vs 11.1%; P<.01). The SPP clinicians showed improved quality metrics compared with that of the IPP clinicians for the percentage of patients with cervical cancer screening (79.1% vs 74.2%; P<.01). The mean percentage of the panels achieving optimal diabetes control, hypertension control, colon cancer screening, and breast cancer screening were not significantly different between IPP and SPP panels.

Conclusion

This study shows a considerable improvement in depression remission among IPP panels and in cervical cancer screening rates among SPP panels. This information may help to inform primary care team configuration.

Outcomes of Mayo Clinic reBoot camps for postimplementation training in the electronic health record

OBJECTIVE

After a new electronic health record (EHR) was implemented at Mayo Clinic, a training program called reBoot Camp was created to enhance ongoing education in response to needs identified by physician leaders.

MATERIALS AND METHODS

A reBoot camp focused on EHR topics pertinent to ambulatory care was offered from April 2018 through June 2020. There were 37 2-day sessions and 43 1-day sessions, with 673 unique participants. To evaluate outcomes of the reBoot camp, we used survey data to study baseline, immediate, and long-term perceptions of program satisfaction and self-assessed skills with the EHR. The study was conducted among practitioners at a large ambulatory practice network based in several states. Data were collected from April 2018 through January 2021. We analyzed automatically collected metadata and scores that evaluated the amount of personalization and proficiency of use.

RESULTS

Confidence in skills increased by 13.5 points for general EHR use and was significant in 5 subdomains of use (13-18 point improvement). This degree of user confidence was maintained at the 6-month reassessment. The outcomes of configuration and proficiency scores also improved significantly.

DISCUSSION

Ongoing education regarding EHR tools is necessary to support continued use of technology. This study was novel because of the amount and breadth of data collected, diversity of user participation, and validation that improvements were maintained over time.

CONCLUSIONS

Participating in a reBoot camp significantly improved user confidence in each domain of the EHR and demonstrated use of best-practice tools. Users maintained gains at the 6-month evaluation phase.

Durability analysis of the highly effective BNT162b2 vaccine against COVID-19

COVID-19 vaccines are effective, but breakthrough infections have been increasingly reported. We conducted a test-negative case-control study to assess the durability of protection after full vaccination with BNT162b2 against polymerase chain reaction (PCR)-confirmed symptomatic SARS-CoV-2 infection, in a national medical practice from January 2021 through January 2022. We fit conditional logistic regression (CLR) models stratified on residential county and calendar time of testing to assess the association between time elapsed since vaccination and the odds of symptomatic infection or non-COVID-19 hospitalization (negative control), adjusted for several covariates. There were 5,985 symptomatic individuals with a positive test after full vaccination with BNT162b2 (cases) and 32,728 negative tests contributed by 27,753 symptomatic individuals after full vaccination (controls). The adjusted odds of symptomatic infection were higher 250 days after full vaccination versus at the date of full vaccination (Odds Ratio [OR]: 3.62, 95% CI: 2.52 to 5.20). The odds of infection were still lower 285 days after the first BNT162b2 dose as compared to 4 days after the first dose (OR: 0.50, 95% CI: 0.37 to 0.67), when immune protection approximates the unvaccinated status. Low rates of COVID-19 associated hospitalization or death in this cohort precluded analyses of these severe outcomes. The odds of non-COVID-19 associated hospitalization (negative control) decreased with time since vaccination, suggesting a possible underestimation of waning protection by this approach due to confounding factors. In summary, BNT162b2 strongly protected against symptomatic SARS-CoV-2 infection for at least 8 months after full vaccination, but the degree of protection waned significantly over this period.

Durability analysis of the highly effective mRNA-1273 vaccine against COVID-19

COVID-19 vaccines are effective, but breakthrough infections have been increasingly reported. We conducted a test-negative case-control study to assess the durability of protection against symptomatic infection after vaccination with mRNA-1273. We fit conditional logistic regression (CLR) models stratified on residential county and calendar date of SARS-CoV-2 PCR testing to assess the association between the time elapsed since vaccination and the odds of symptomatic infection, adjusted for several covariates. There were 2,364 symptomatic individuals who had a positive SARS-CoV-2 PCR test after full vaccination with mRNA-1273 ("cases") and 12,949 symptomatic individuals who contributed 15,087 negative tests after full vaccination ("controls"). The odds of symptomatic infection were significantly higher 250 days after full vaccination compared to the date of full vaccination (Odds Ratio [OR]: 2.47, 95% confidence interval [CI]: 1.19-5.13). The odds of non-COVID-19 associated hospitalization and non-COVID-19 pneumonia (negative control outcomes) remained relatively stable over the same time interval (Day 250 OR_{Non-COVID Hospitalization}: 0.68, 95% CI: 0.47-1.0; Day 250 OR_{Non-COVID Pneumonia}: 1.11, 95% CI: 0.24-5.2). The odds of symptomatic infection remained significantly lower almost 300 days after the first mRNA-1273 dose as compared to 4 days after the first dose, when immune protection approximates the unvaccinated state (OR: 0.26, 95% CI: 0.17-0.39). Low rates of COVID-19 associated hospitalization or death in this cohort precluded analyses of these severe outcomes. In summary, mRNA-1273 robustly protected against symptomatic SARS-CoV-2 infection at least 8 months after full vaccination, but the degree of protection waned over this time period.

Surveillance of Safety of 3 Doses of COVID-19 mRNA Vaccination Using Electronic Health Records

Importance

Recent reports on waning of COVID-19 vaccine-induced immunity have led to the approval and rollout of additional doses and booster vaccinations. Individuals at increased risk of SARS-CoV-2 infection are receiving additional vaccine doses in addition to the regimen that was tested in clinical trials. Risks and adverse event profiles associated with additional vaccine doses are currently not well understood.

Objective

To evaluate the safety of third-dose vaccination with US Food and Drug Administration (FDA)-approved COVID-19 mRNA vaccines.

Design, Setting, and Participants

This cohort study was conducted using electronic health record (EHR) data from December 2020 to October 2021 from the multistate Mayo Clinic Enterprise. Participants included all 47 999 individuals receiving 3-dose COVID-19 mRNA vaccines within the study setting who met study inclusion criteria. Participants were divided into 2 cohorts by vaccine brand administered and served as their own control groups, with no comparison made between cohorts. Data were analyzed from September through November 2021.

Exposures

Three doses of an FDA-authorized COVID-19 mRNA vaccine, BNT162b2 or mRNA-1273.

Main Outcomes and Measures

Vaccine-associated adverse events were assessed via EHR report. Adverse event risk was quantified using the percentage of study participants who reported the adverse event within 14 days after each vaccine dose and during a 14-day control period, immediately preceding the first vaccine dose.

Results

Among 47 999 individuals who received 3-dose COVID-19 mRNA vaccines, 38 094 individuals (21 835 [57.3%] women; median [IQR] age, 67.4 [52.5-76.5] years) received BNT162b2 (79.4%) and 9905 individuals (5099 [51.5%] women; median [IQR] age, 67.7 [59.5-73.9] years) received mRNA-1273 (20.6%). Reporting of severe adverse events remained low after the third vaccine dose, with rates of pericarditis (0.01%; 95% CI, 0%-0.02%), anaphylaxis (0%; 95% CI, 0%-0.01%), myocarditis (0%; 95% CI, 0%-0.01%), and cerebral venous sinus thrombosis (no individuals) consistent with results from earlier studies. Significantly more individuals reported low-severity adverse events after the third dose compared with after the second dose, including fatigue (2360 individuals [4.92%] vs 1665 individuals [3.47%]; P < .001), lymphadenopathy (1387 individuals [2.89%] vs 995 individuals [2.07%]; P < .001), nausea (1259 individuals [2.62%] vs 979 individuals [2.04%]; P < .001), headache (1185 individuals [2.47%] vs 992 individuals [2.07%]; P < .001), arthralgia (1019 individuals [2.12%] vs 816 individuals [1.70%]; P < .001), myalgia (956 individuals [1.99%] vs 784 individuals [1.63%]; P < .001), diarrhea (817 individuals [1.70%] vs 595 individuals [1.24%]; P < .001), fever (533 individuals [1.11%] vs 391 individuals [0.81%]; P < .001), vomiting (528 individuals [1.10%] vs 385 individuals [0.80%]; P < .001), and chills (224 individuals [0.47%] vs 175 individuals [0.36%]; P = .01).

Conclusions and Relevance

This study found that although third-dose vaccination against SARS-CoV-2 infection was associated with increased reporting of low-severity adverse events, risk of severe adverse events remained comparable with risk associated with the standard 2-dose regime. These findings suggest the safety of third vaccination doses in individuals who were eligible for booster vaccination at the time of this study.

Comparative effectiveness of mRNA-1273 and BNT162b2 against symptomatic SARS-CoV-2 infection

BACKGROUND

mRNA coronavirus disease 2019 (COVID-19) vaccines are safe and effective, but increasing reports of breakthrough infections highlight the need to vigilantly monitor and compare the effectiveness of these vaccines.

METHODS

We retrospectively compared protection against symptomatic infection conferred by mRNA-1273 and BNT162b2 at Mayo Clinic sites from December 2020 to September 2021. We used a test-negative case-control design to estimate vaccine effectiveness (VE) and to compare the odds of symptomatic infection after full vaccination with mRNA-1273 versus BNT162b2, while adjusting for age, sex, race, ethnicity, geography, comorbidities, and calendar time of vaccination and testing.

FINDINGS

Both vaccines were highly effective over the study duration (VEmRNA-1273: 84.1%, 95% confidence interval [CI]: 81.6%-86.2%; VEBNT162b2: 75.6%, 95% CI: 72.2%-78.7%), but their effectiveness was reduced during July-September (VEmRNA-1273: 75.6%, 95% CI: 70.1%-80%; VEBNT162b2: 63.5%, 95% CI: 55.8%-69.9%) as compared to December-May (VEmRNA-1273: 93.7%, 95% CI: 90.4%-95.9%; VEBNT162b2: 85.7%, 95% CI: 81.4%-88.9%). Adjusted for demographic characteristics, clinical comorbidities, time of vaccination, and time of testing, the odds of experiencing a symptomatic breakthrough infection were lower after full vaccination with mRNA-1273 than with BNT162b2 (odds ratio: 0.60; 95% CI: 0.55-0.67).

CONCLUSIONS

Both mRNA-1273 and BNT162b2 strongly protect against symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. It is imperative to continue monitoring and comparing available vaccines over time and with respect to emerging variants to inform public and global health decisions.

FUNDING

This study was funded by nference.

Outcomes of COVID-19 With the Mayo Clinic Model of Care and Research

OBJECTIVE

To report the Mayo Clinic experience with coronavirus disease 2019 (COVID-19) related to patient outcomes.

METHODS

We conducted a retrospective chart review of patients with COVID-19 diagnosed between March 1, 2020, and July 31, 2020, at any of the Mayo Clinic sites. We abstracted pertinent comorbid conditions such as age, sex, body mass index, Charlson Comorbidity Index variables, and treatments received. Factors associated with hospitalization and mortality were assessed in univariate and multivariate models.

RESULTS

A total of 7891 patients with confirmed COVID-19 infection with research authorization on file received care across the Mayo Clinic sites during the study period. Of these, 7217 patients were adults 18 years or older who were analyzed further. A total of 897 (11.4%) patients required hospitalization, and 354 (4.9%) received care in the intensive care unit (ICU). All hospitalized patients were reviewed by a COVID-19 Treatment Review Panel, and 77.5% (695 of 897) of inpatients received a COVID-19-directed therapy. Overall mortality was 1.2% (94 of 7891), with 7.1% (64 of 897) mortality in hospitalized patients and 11.3% (40 of 354) in patients requiring ICU care.

CONCLUSION

Mayo Clinic outcomes of patients with COVID-19 infection in the ICU, hospital, and community compare favorably with those reported nationally. This likely reflects the impact of interprofessional multidisciplinary team evaluation, effective leveraging of clinical trials and available treatments, deployment of remote monitoring tools, and maintenance of adequate operating capacity to not require surge adjustments. These best practices can help guide other health care systems with the continuing response to the COVID-19 pandemic.

Obstructive sleep apnoea syndrome in morbidly obese children with tibia vara

Morbid obesity and its association with obstructive sleep apnoea syndrome have been increasingly recognised in children. Orthopaedic surgeons are often the primary medical contact for older children with tibia vara, which has long been associated with obesity, but are unfamiliar with the evaluation and treatment of sleep apnoea in children. We reviewed all children with tibia vara treated surgically at one of our institutions over a period of five years. Thirty-seven patients were identified; 18 were nine years of age or older and 13 of these (72%) had morbid obesity and a history of snoring. Eleven children were diagnosed as having sleep apnoea on polysomnography. The incidence of this syndrome in the 18 children aged nine years or older with tibia vara, was 61%. All these patients required pre-operative non-invasive positive-pressure ventilation; tonsillectomy and adenoidectomy were necessary in five (45%). No peri-operative complications related to the airway occurred. There is a high incidence of sleep apnoea in morbidly obese patients with tibia vara. These patients should be screened for snoring and, if present, should be further evaluated for sleep apnoea before corrective surgery is undertaken.

Limit on the electron electric dipole moment in gadolinium-iron garnet

A new method for the detection of the electron electric dipole moment (EDM) using a solid is described. The method involves the measurement of a voltage induced across the solid by the alignment of the sample's magnetic dipoles in an applied magnetic field, H. A first application of the method to GdIG has resulted in a limit on the electron EDM of 5 x 10(-24)e cm, which is a factor of 40 below the limit obtained from the only previous solid-state EDM experiment. The result is limited by the imperfect discrimination of an unexpectedly large voltage that is even upon the reversal of the sample magnetization.

Retrosternal displacement after physeal fracture of the medial clavicle in children treatment by open reduction and internal fixation

Retrosternal displacement of the medial aspect of the clavicle after physeal fracture is rare. We treated six patients with this injury between 1995 and 1998, all as an emergency in order to avoid complications associated with compression of adjacent mediastinal structures. Attempted closed reduction was undertaken, but all required open reduction and internal fixation using a wire suture. There were no associated complications. Five were reviewed clinically and radiologically at a minimum of one year after operation. All had regained full use of the affected arm without pain and had resumed their preinjury level of activity including sports. Follow-up radiographs showed union in the anatomical position in all patients. We recommend attempted closed reduction in the operating room, followed, if necessary, by open reduction. Internal fixation after open reduction gives stable fixation with minimal morbidity.

Evaluation of the efficacy of pelvic shielding in preadolescent girls

SUMMARY

A standing anteroposterior pelvic radiograph with gonadal shielding is used as a screening tool for all patients evaluated for intoeing at our institution. Sixty-two normal consecutive screening pelvic radiographs obtained in 61 female patients between the ages of 4 and 6 years were evaluated. Radiographs were evaluated for the adequacy to assess the hips as well as the protection afforded the ovaries from radiation exposure. Radiographs were judged to be inadequate because the shield covered essential landmarks in at least one hip in eight radiographs (13%). Five radiographs (8%) covered >50% of the area of both ovaries, and only one radiograph covered >75% of the area of both ovaries. Standard techniques of positioning gonadal shields in preadolescent girls are inadequate and provide minimal protection with a high rate of interference with vital landmarks. We no longer advocate using gonadal shields on initial screening radiographs of preadolescent girls.

Pin site care during external fixation in children: results of a nihilistic approach

We prospectively followed 27 consecutive children with tibial circular external fixators applied between July 1, 1995, and June 30, 1997. A simple pin care system with no physical pin cleansing except that provided by daily showers was used. Children with inflamed or infected pin sites were placed on an oral antibiotic (cephalexin) for 10 days. Pin sites were graded according to the system of Dahl et al. on a 0 to 5 scale. A total of 4,473 observations was made. Patients developed 178 pin tract infections (4.0% per observation), with 151 (85%) grade 1 and 27 (15%) grade 2 infections. No pin was removed because of infection. Diaphyseal half pin sites were less commonly infected (1.6%) than periarticular wire or half pin sites (4.5%). We recommend only showering without other physical pin cleaning procedures in children undergoing external fixation procedures.

External fixation of femoral shaft fractures in children: enhanced stability with the use of an auxiliary pin

From 1989 through 1994, we used a monolateral external fixator (Orthofix) to treat 39 femur fractures in 37 patients. The average age of the patients was 9.5 years (range, 5+11 to 18+8 years); 38 fractures were closed, and one was a grade I (Gustillo-Anderson classification) open fracture. Twenty-two fractures were treated by using the standard Orthofix pin configuration with two or three pins held in the pin clamps both above and below the fracture. We treated the remaining 16 fractures identically, except for the addition of an auxiliary pin, which was secured to the body of the fixator by using wire and methylmethacrylate. All patients were followed up to union and fixator removal at a mean of 97 days after fixator placement (range, 50-175 days). Thirty-one (84%) patients were followed up for 1 year after injury. Six of 22 femurs without an auxiliary pin required remanipulation for loss of reduction. Only one of 16 femurs treated with an auxiliary pin required remanipulation. Four of 22 femurs without an auxiliary pin went on to malunion. No femur with an auxiliary pin went on to malunion.

Fate of the psoas muscle after open reduction for developmental dislocation of the hip (DDH)

We evaluated the anatomic and functional consequences of psoas lengthening during operative intervention for developmental dislocation of the hip (DDH). Possible anatomic changes were assessed by magnetic resonance imaging (MRI), and functional assessment included strength determination by an isokinetic dynamometer and gait analysis. Six girls and one boy, ranging in age from 15 to 20 months, had operative reduction of a unilateral DDH. One closed and six open reductions (three anteromedial and three anterolateral approaches) were performed. Follow-up ranged from 4 years 0 months to 9 years 2 months. The cross-sectional area determined by MRI of the lengthened psoas muscles was markedly reduced for all of the six open-reduction patients (three moderate and three severe). Atrophy of the iliacus muscle also was apparent by MRI in five of the six open-reduction patients. Maximum flexion torque, as determined by the isokinetic dynamometer, was diminished on the DDH side for the three patients whose hips were reduced open through the anteromedial approach. Average hip-flexion torque over the entire range of motion was decreased for both anteromedial and anterolateral groups on the operated-on side. Lengthening of the psoas tendon during open reduction of a DDH is associated with considerable atrophy of the psoas muscle.

Knee pain as the initial symptom of slipped capital femoral epiphysis: an analysis of initial presentation and treatment

A retrospective review was performed of 106 patients to determine the effect of knee pain as the initial complaint of slipped capital femoral epiphysis (SCFE). Sixteen (15%) patients had a primary complaint of distal thigh or knee pain or both at initial presentation to our institution or to a referring physician. Ninety (85%) patients described primarily hip, groin, or proximal thigh discomfort. Of the 106 patients with SCFE, 65 patients received no operative treatment before being evaluated at our institution and were the subject of the remainder of the study. Of these, 15 (23%) patients had distal thigh or knee pain or both as their chief complaint (group I), and 50 (77%) patients had hip, groin, or proximal thigh pain (group II). There was no difference between the groups with respect to age, gender, or slip stability. Group I patients were more likely to receive a misdiagnosis (p < 0.05) and undergo unnecessary or uninformative radiographs (p < 0.05). Additionally, patients in group I were found to have slips of greater radiographic severity (p < 0.05). Although not statistically significant, there was a trend for group I patients to experience a longer delay to diagnosis and to require a proximal femoral osteotomy as treatment for their slips. We conclude that isolated distal thigh or knee pain or both is a common presentation of SCFE. Furthermore, this symptom complex, when compared with the more classic presentation of SCFE, leads to higher rates of unnecessary radiographs, misdiagnoses, and severe slips, potentially increasing long-term morbidity.

Differences between ECG and pulse when measuring heart rate and reactivity under two physical and two psychological stressors

To test the level of agreement of heart rate and reactivity to stressor tasks as measured via noninvasive ECG and pulse, 38 healthy subjects underwent four stressor tasks: mental arithmetic, reaction time, cold pressor, and bicycling. Data on resting and stressor heart rate were collected via ECG and photoplethysmography, and heart rate reactivity was calculated via five methods noted in the wider literature. Results indicated that, although resting heart rate values did not differ significantly across the two instruments, there were some significant differences in heart rate during certain periods of mental and physical stress reactivity. Calculation of heart rate reactivity revealed that there were few significant differences between data from the two measures but that the tasks themselves produced markedly different patterns of reactivity, questioning assumptions underlying comparison of reactivity data under different stress tasks. Implications for the assessment of reactivity are discussed.

Goal attainment scaling as a measure of clinically important change in nursing-home patients

OBJECTIVES

To assess the feasibility, validity and responsiveness of an individualized measure--goal attainment scaling-in long-term care.

DESIGN

Prospective descriptive study.

SETTING

One academic and three community-based long-term care facilities.

SUBJECTS

53 nursing-home patients seen in consultation between July 1996 and June 1997.

INTERVENTION

Specialized geriatric medicine consultation.

MAIN OUTCOME MEASURES

Effect size and relative efficiency of the Barthel index, hierarchical assessment of balance and mobility, global deterioration scale, axis 8 (behaviour) of the brief cognitive rating scale, cumulative illness rating scale and the goal attainment scale.

RESULTS

Mean goal attainment scale at follow-up was 46+/-7. The goal attainment scale was the most responsive measure, with an effect size of 1.29 and a relative efficiency of 53.7. The goal attainment scale did not correlate well with the other measures (-0.22 to 0.17).

CONCLUSION

Goal attainment scaling is a feasible and responsive measure in long-term care. Although fewer problems in nursing-home patients than elderly inpatients are susceptible to intervention, clinically important goals can be achieved in this population.

Surgical treatment of congenital dislocation of the patella

Eleven patients with 17 involved knees were surgically treated for congenital dislocation of the patella between 1978 and 1993. Ten patients with 13 involved knees followed up for a minimum of 2 years postoperatively composed the study group. Six patients had both involved knees operatively treated. In four patients, congenital dislocation of the patella was associated with a recognizable syndrome. All patients had fixed, painful lateral dislocation of the patella that could not be reduced. The average age at presentation was 7 years and 9 months (range, 2 months to 15 years). All patients underwent an extensive procedure including lateral release and advancement of the vastus medialis obliquus. Skeletally immature children underwent medial transfer of the entire patellar tendon. Skeletally mature patients underwent medial transfer of the tibial tubercle. Ten patients with 13 involved knees were followed up for > or = 2 years. Mean follow-up was 5.1 years (range, 1-17.5). At last follow-up, all patients reported a marked increase in activity tolerance and relief of pain. Average extension lag improved from 15 degrees before to 2 degrees after surgery. One superficial wound infection occurred; no patient developed a deep infection. One peroneal neurapraxia occurred but resolved with observation. Redislocation of the patella occurred in the immediate postoperative period in one patient. Operative treatment of congenital dislocation of the patella can predictably improve knee function when all aspects of the complex pathologic anatomy are addressed.

The effect of unilateral varus rotational osteotomy with or without pelvic osteotomy on the contralateral hip in patients with perinatal static encephalopathy

Forty-eight patients with perinatal static encephalopathy were treated with unilateral varus rotational femoral osteotomy for hip subluxation. Twenty-one of the 48 also had concomitant pelvic osteotomy. Twenty-seven of the patients were nonambulators. Bilateral soft-tissue releases had been performed previously in 20 patients. At the time of varus rotational osteotomy, the mean age was 8 years, 11 months. The indication for a varus rotational osteotomy was femoral head subluxation or dislocation in all cases. The preoperative center-edge angle ranged from -8 degrees to 18 degrees (mean, 4 degrees), and on the contralateral side, the center-edge angle ranged from 0 degree to 32 degrees (mean, 19 degrees). The center-edge angle on the operative side at follow-up averaged 25 degrees (-10 degrees to 78 degrees), an improvement of 21 degrees, and on the contralateral side averaged 27 degrees (range, 9 degrees-40 degrees), an improvement of 8 degrees. Forty-seven patients have had no subsequent surgery on the contralateral hip. One patient had a varus rotational osteotomy on the contralateral hip 5 years postoperatively; however, this hip was subluxated at the time of the index procedure. Twelve patients have had no surgery at any time on the contralateral side. None of these patients had deterioration of the contralateral hip. Surgery on one hip should not, in itself, be an indication for surgery on the contralateral concentrically reduced hip with adequate abduction in patients with acetabular dysplasia secondary to perinatal static encephalopathy.

Intramedullary fixation of unstable both-bone forearm fractures in children

A retrospective study was performed to evaluate the results of intramedullary fixation used in the management of unstable, diaphyseal both-bone forearm fractures in skeletally immature patients. Twenty-five patients with 25 fractures were identified whose fracture management included only intramedullary fixation. Galeazzi, Monteggia, radial head, and distal metaphyseal fractures were excluded from this analysis. Mean age at fracture was 10 + 8 years. There were 15 closed and 10 open fractures (eight grade I and two grade II). Smooth Kirschner wires or Rush rods were used for fixation. Average length of immobilization was 8 + 2 weeks; 6 + 2 in a long-arm cast and 2 + 0 weeks in a short-arm cast. All 25 regained normal elbow motion, with 17 regaining full forearm rotation. Eight patients had an average loss of 13 degrees of supination and 9 degrees of pronation. There were four minor and two major complications (one rod migration and one delayed union). No infections, malunions, or synostoses occurred in this patient group. Using the grading scheme adapted by Price there were 21 excellent results (84%), four good (16%), and no fair or poor results. In our experience, intramedullary fixation of the unstable both-bone forearm fractures is a safe, effective, and user-friendly technique when alignment jeopardizes fracture position at union and eventual forearm motion.

Distortion compensation and elimination in holographic reconstruction

We discuss the quantitative location of objects from holographic images when the reconstruction wavelength differs from the recording wavelength. The holographic image equations are interpreted in a way that clarifies the meaning of stereo pairs of holographic images and indicates how backprojection methods can be used in holography to locate objects. Alternative methods involving the production of distortion-free regions in the holographic image field during reconstruction, the use of self-calibrating objects in the object field during recording, and triangulation can be used to locate objects.

Pemberton pelvic osteotomy and varus rotational osteotomy in the treatment of acetabular dysplasia in patients who have static encephalopathy

Forty-four patients (fifty-two hips) who had static encephalopathy and acetabular dysplasia were managed with a Pemberton osteotomy as part of a comprehensive operative approach. Thirty-three patients had quadriplegia and were unable to walk; the remaining eleven patients had diplegia and could walk. The age at the time of the operation ranged from four years and five months to sixteen years and five months, as an open triradiate cartilage is a prerequisite for the Pemberton procedure. Concomitant operative procedures included a varus rotational osteotomy in fifty of the involved hips, a soft-tissue release in thirty-seven hips, and an open reduction in thirteen hips. The mean center-edge angle preoperatively was -11 degrees (range, -80 to 17 degrees), which improved to a mean of 27 degrees (range, 5 to 62 degrees) at the time of the latest follow-up. The mean duration of follow-up was four years (range, two years to eight years and eight months). At the time of writing, none of the hips had redislocated but one hip had subluxated. Eight of the hips had been painful preoperatively, but none of these was painful at the time of the most recent follow-up. One patient who had not had pain in the hip preoperatively had pain at the time of the follow-up evaluation. There were no complications attributable to posterior uncovering of the hip. The age of the patient at the time of the operation had no discernible effect on the result.

Racial misclassification of American Indians: its effect on injury rates in Oregon, 1989 through 1990

OBJECTIVES

We assessed the extent to which injury rates among American Indians in Oregon are underestimated owing to misclassification of race in a surveillance system.

METHODS

The Oregon Injury Registry, a population-based surveillance system, was linked with the Indian Health Service patient registration file from Oregon, and injury rates for American Indians were calculated before and after correcting for racial misclassification.

RESULTS

In 1989 and 1990, 301 persons in the Oregon registry were coded as American Indian. An additional 89 injured persons who were coded as a race other than American Indian in the registry were listed as American Indian in the Indian Health Service records. The age-adjusted annual injury rate for health service-registered American Indians was 6.9/1000, 68% higher than the rate calculated before data linkage. American Indian ancestry, female sex, and residence in metropolitan counties were associated with a higher likelihood of concordant racial classification in both data sets.

CONCLUSION

Injury rates among American Indians in an Oregon surveillance system are substantially underestimated owing to racial misclassification. Linkage of disease registries and vital records with Indian Health Service records in other states may improve health-related data regarding American Indians.

Closed intramedullary femoral osteotomy. Shortening and derotation procedures

Closed osteotomy and nailing were performed on 37 patients for leg-length inequality or rotational deformities. Shortening operations were performed in 31 patients, derotation in six. Preoperatively, the leg-length discrepancy ranged from 2 to 6.6 cm. All femoral shortenings resulted in correction to less than 1 cm. Preoperatively, rotational deformities averaged 58 degrees; all were corrected to within 5 degrees of normal. Follow-up observation averaged 3.3 years. There were no nonunions or infections. All patients regained preoperative joint range of motion (ROM). Thirteen patients were Cybex tested one year or more postoperatively; all had quadriceps and hamstring strength equal to or greater than the contralateral leg, except for two patients who had suffered additional trauma to the shortened femur. Closed femoral osteotomy is an effective, safe, and reproducible means to obtain lower limb length correction in patients with leg-length inequality or rotational abnormality.

Effects of bone ingrowth on the strength and non-invasive assessment of a coralline hydroxyapatite material

The dependence of strength on the amount of bone growth into a hydroxyapatite material made from coral was investigated. Block and granular forms of the material were implanted into cortical and trabecular regions of the skeletons of 16 dogs. The results were examined after 4, 8, 12 and 16 wk, with four dogs in each experimental group. When implanted into cortical bone, the bending strength of the implant material was found to be highly correlated with the amount of pore space which had become occupied by bone (r = 0.92, P less than 0.005 for the block form; r = 0.84, P less than 0.005 for the granular form). Multiple regression analysis showed that six histomorphometric measures of ingrowth accounted for 96% of the variability in bending strength of the block material, and there were no significant differences between block and granular forms of the material. On the other hand, when implanted into trabecular bone, the block form of the material achieved greater compressive strength than the granular form. While both strength and ingrowth increased with time, there were poor correlations between these two variables. Finally, when the material is implanted into trabecular bone, it becomes stronger in compression than the surrounding bone; when implanted in cortical bone, linear modelling suggests that resorption and replacement of the implant would be required to approximate the bending strength of the surrounding bone.

Compression-plate fixation of acute fractures of the diaphyses of the radius and ulna

A retrospective study was done of eighty-seven patients who had 129 diaphyseal fractures of either the radius or the ulna, or both, and who were treated with fixation using an AO dynamic-compression plate. Open fractures were internally fixed primarily, and both comminuted and open fractures routinely had bone-grafting. Ninety-eight per cent of the fractures united, and 92 per cent of the patients achieved an excellent or satisfactory functional result. The rate of infection was 2.3 per cent. Refracture occurred after removal of a 4.5-millimeter dynamic-compression plate in two patients, but there were no refractures after removal of a 3.5-millimeter plate. The 3.5-millimeter-plate system gave excellent results in patients who had a fracture of the forearm, and it minimized the risk of refracture. Our results demonstrated that immediate plate fixation of an open fracture of the forearm, with a low rate of complications, is possible.

Agricultural chemical use and congenital cleft lip and/or palate

A case-control study utilizing vital records and ecologic, surrogate exposure measures was conducted in Iowa and Michigan. The study hypothesis anticipated an excess risk of clefts among fetuses exposed during the peak agricultural chemical use period (April through November) coincident with their first trimester of gestation. To examine this hypothesis, multiple regression techniques were used to aid identification of potential confounders; additional analyses, stratified on the potential confounders, were performed using two chemical exposure indices. The major findings of these analyses suggest: (1) an agricultural chemical effect (using the multiple exposure index) controlling for season of conception; (2) no independent effect of season of conception (thus the null hypothesis is not rejected); and (3) little chemical/season interaction. These results imply that if exposures to agricultural chemicals are, in fact, risk factors for clefts, an expanded model that accounts for multiple pesticidal exposures may be more sensitive than consideration of season of exposure, as originally hypothesized.

Epidemiological insights on malnutrition: some resurrected, others restructured, a few retired

In its modern sense, epidemiology has progressed from a classical concern of causality as expressed within biological limits to recognition that a variety of social factors have proportionate significance in the origin and behavior of human nutritional disorders. Basically an analytical process, nutritional epidemiology has grown to include, among objectives for prevention and control, a synthesis of plans for intervention; the monitoring of action programs introduced; and again a parallel analytic mission to evaluate such accomplishments as programs bring forth. Nutritional epidemiology, so employed, becomes a general scientific discipline, widely purposed and incorporating objectives beyond public health: measures concerned with social welfare, economic growth, political stability, and behavioral compatibility with fellow humans and other living things. Specifically, nutritional epidemiology comprises a branch of knowledge utilizing human ecology to solve problems in three broad dimensions--a defined causality, a prescribed intervention (planning, operations) and an evaluation of results, concurrently made and terminally. The groundwork is medical ecology, the approach holistic. A population of pregnant mothers and their newborn children is accorded first priority among fields of interest, past any single disease entity or technical method of control. Community programs enlarge from that base.