Kevin C. Chung

Reliability and validity testing of the Michigan Hand Outcomes Questionnaire

In this study, psychometric principles were used to develop an outcomes questionnaire capable of measuring health state domains important to patients with hand disorders. These domains were hypothesized to include (1) overall hand function, (2) activities of daily living (ADL), (3) pain, (4) work performance, (5) aesthetics, and (6) patient satisfaction with hand function. An initial pool of 100 questions was pilot-tested for clarity in 20 patients; following factor analysis, the number of questions was reduced to a 37-item Michigan Hand Outcomes Questionnaire (MHQ). The MHQ, along with the Short Form-12, a generic health status outcomes questionnaire, was then administered to 200 consecutive patients at a university-based hand surgery clinic and was subjected to reliability and validity testing. The mean time required to complete the questionnaire was 10 minutes (range, 7-20 minutes). Factor analysis supported the 6 hypothesized scales. Test-retest reliability using Spearmans correlation demonstrated substantial agreement, ranging from 0.81 for the aesthetics scale to 0.97 for the ADL scale. In testing for internal consistency, Cronbachs alphas ranged from 0.86 for the pain scale to 0.97 for the ADL scale (values >0.7 for Cronbachs alpha are considered a good internal consistency). Correlation between scales gave evidence of construct validity. In comparing similar scales in the MHQ and the Short Form-12, a moderate correlation (range, 0.54-0.79) for the ADL, work performance, and pain scales was found. In evaluating the discriminate validity of the aesthetics scale, a significant difference (p = .0012) was found between the aesthetics scores for patients with carpal tunnel syndrome and patients with rheumatoid arthritis. The MHQ is a reliable and valid instrument for measuring hand outcomes. It can be used in a clinic setting with minimal burden to patients. The questions in the MHQ have undergone rigorous psychometric testing, and the MHQ is a promising instrument for evaluation of outcomes following hand surgery.

The levels of evidence and their role in evidence-based medicine

As the name suggests, evidence-based medicine (EBM), is about finding evidence and using that evidence to make clinical decisions. A cornerstone of EBM is the hierarchical system of classifying evidence. This hierarchy is known as the levels of evidence. Physicians are encouraged to find the highest level of evidence to answer clinical questions. Several papers published in Plastic Surgery journals concerning EBM topics have touched on this subject. 1–6 Specifically, previous papers have discussed the lack of higher level evidence in PRS and need to improve the evidence published in the journal. Before that can be accomplished, it is important to understand the history behind the levels and how they should be interpreted. This paper will focus on the origin of levels of evidence, their relevance to the EBM movement and the implications for the field of plastic surgery as well as the everyday practice of plastic surgery.

Trends in the United States in the Treatment of Distal Radial Fractures in the Elderly

BACKGROUND Traditionally, distal radial fractures in the elderly have been treated nonoperatively with casting. However, since the introduction of the volar locking plating system in 2000, there has been an interest in the use of more aggressive treatment methods. The purpose of the present study was to assess changing trends in the treatment of distal radial fractures in elderly patients in the United States. METHODS We evaluated a 5% sample of Medicare data from 1996 to 1997 and a 20% sample from 1998 to 2005. Information on four treatment methods (closed treatment, percutaneous pin fixation, internal fixation, and external fixation) was extracted from the dataset. Other available data were diagnosis, physician specialty, and patient age, sex, and race. We calculated frequencies and rates to compare the utilization of different treatments over time. RESULTS Over the ten-year time period examined, the rate of internal fixation of distal radial fractures in the elderly increased fivefold, from 3% in 1996 to 16% in 2005. Closed treatment, however, remained the predominant method (used for 82% of the fractures in 1996 and 70% in 2005). Fractures in patients with an age of eighty-five years or more were significantly more likely to be treated in a closed fashion (p < 0.0001). There was a large variation among physician specialties with regard to the fixation methods that were used. Orthopaedic surgeons were significantly more likely to use closed treatment than hand surgeons were, whereas hand surgeons were significantly more likely to use internal fixation than orthopaedic surgeons were. CONCLUSIONS Since 2000, although the majority of distal radial fractures are still treated nonoperatively, there has been an increase in the use of internal fixation and a concurrent decrease in the rate of closed treatment of distal radial fractures in the elderly in the United States.

Treatment of unstable distal radial fractures with the volar locking plating system.

BACKGROUND The best treatment for an inadequately reduced fracture of the distal part of the radius is not well established. We collected prospective outcomes data for patients undergoing open reduction and internal fixation of an inadequately reduced distal radial fracture with use of the volar locking plating system. METHODS Over a two-year period, 161 patients underwent open reduction and internal fixation of an inadequately reduced distal radial fracture with use of the volar locking plating system. Patients were enrolled in the present study three months after the fracture on the basis of strict entry criteria and were evaluated three, six, and twelve months after surgery. Outcome measures included radiographic parameters, grip strength, lateral pinch strength, the Jebsen-Taylor test, wrist range of motion, and the Michigan Hand Outcomes Questionnaire. RESULTS Eighty-seven patients with a distal radial fracture were enrolled. The mean age at the time of enrollment was 48.9 years. Forty percent (thirty-five) of the eighty-seven fractures were classified as AO type A, 9% (eight) were classified as type B, and 51% (forty-four) were classified as type C. Radiographic assessment showed that the plating system maintained anatomic reduction at the follow-up periods. At the time of the twelve-month follow-up, the mean grip strength on the injured side was worse than that on the contralateral side (18 compared with 21 kg; p<0.01), the mean pinch strength on the injured side was not significantly different from that on the contralateral side (8.7 compared with 8.9 kg; p=0.27), and the mean flexion of the wrist on the injured side was 86% of that on the contralateral side. All Michigan Hand Outcomes Questionnaire domains approached normal scores at six months, with small continued improvement to one year. CONCLUSIONS The volar locking plating system appears to provide effective fixation when used for the treatment of initially inadequately reduced distal radial fractures.

A Systematic Review of Outcomes and Complications of Treating Unstable Distal Radius Fractures in the Elderly

PURPOSE As the population in developed countries continues to age, the incidence of osteoporotic distal radius fractures (DRFs) will increase as well. Treatment of DRF in the elderly population is controversial. We systematically reviewed the existing literature for the management of DRFs in patients aged 60 and over with 5 common techniques: the volar locking plate system, nonbridging external fixation, bridging external fixation, percutaneous Kirschner wire fixation, and cast immobilization (CI). METHODS We reviewed articles retrieved from MEDLINE, Embase, and CINAHL Plus that met predetermined inclusion and exclusion criteria in 2 literature reviews. Outcomes of interest included wrist arc of motion, grip strength, functional outcome measurements, radiographic parameters, and the number and type of complications. We statistically analyzed the data using weighted means and proportions based on the sample size in each study. RESULTS We identified 2,039 papers and selected 21 papers fitting the inclusion criteria in the primary review of articles with a mean patient age of 60 and older. Statistically significant differences were detected for wrist arc of motion, grip strength, and Disabilities of the Arm, Shoulder, and Hand score, although these findings may not be clinically meaningful. Volar tilt and ulnar variance revealed significant differences among groups, with CI resulting in the worst radiographic outcomes. The complications were significantly different, with CI having the lowest rate of complications, whereas the volar locking plate system had significantly more major complications requiring additional surgical intervention. CONCLUSIONS This systematic review suggests that despite worse radiographic outcomes associated with CI, functional outcomes were no different from those of surgically treated groups for patients age 60 and over. Prospective comparative outcomes studies are necessary to evaluate the rate of functional recovery, cost, and outcomes associated with these 5 treatment methods.

Observational Studies: Cohort and Case-Control Studies

Summary: Observational studies constitute an important category of study designs. To address some investigative questions in plastic surgery, randomized controlled trials are not always indicated or ethical to conduct. Instead, observational studies may be the next best method of addressing these types of questions. Well-designed observational studies have been shown to provide results similar to those of randomized controlled trials, challenging the belief that observational studies are second rate. Cohort studies and case-control studies are two primary types of observational studies that aid in evaluating associations between diseases and exposures. In this review article, the authors describe these study designs and methodologic issues, and provide examples from the plastic surgery literature.

Chortle: a technology mapping program for lookup table-based field programmable gate arrays

Field Programmable Gate Arrays are new devices that combine the versatility of a Gate Array with the user-programmability of a PAL. This paper describes an algorithm for technology mapping of combinational logic into Field Programmable Gate Arrays that use lookup table memories to realize combinational functions. It is difficult to map into lookup tables using previous techniques because a single lookup table can perform a large number of logic functions, and prior approaches require each function to be instantiated separately in a library. The new algorithm, implemented in a program called Chortle uses the fact that a K-input lookup table can implement any Boolean function of K-inputs, and so does not require a library-based approach. Chortle takes advantage of this complete functionality to evaluate all possible decompositions of the input Boolean network nodes. It can determine the optimal (in area) mapping for fanout-free trees of combinational logic. In comparisons with the MIS II technology mapper, on MCNC-89 Logic Synthesis benchmarks Chortle achieves superior results in significantly less time. 1

Maternal cigarette smoking during pregnancy and the risk of having a child with cleft lip/palate.

Maternal cigarette smoking during pregnancy as a risk factor for having a child with cleft lip/palate has been suggested by several epidemiologic studies. However, most of these studies contained small sample sizes, and a clear association between these two factors could not be established. The U.S. Natality database from 1996 and a case-control study design were used to investigate the association between maternal smoking during pregnancy and having a child with cleft lip/palate. The records of 3,891,494 live births from the 1996 U.S. Natality database were extracted to obtain cleft lip/palate cases and random controls. The National Center for Health Statistics collects maternal and newborn demographic and medical data from the birth certificates of all 50 states. New York (excluding New York City), California, Indiana, and South Dakota did not collect smoking data, and the data from these states were excluded from the analysis. A total of 2207 live births with cleft lip/palate cases were identified, and 4414 controls (1:2 ratio) were randomly selected (using the SAS program) from live births with no congenital defects. Odds ratios and 95 percent confidence intervals were determined from logistic regression models, adjusting for confounding variables, including maternal demographic and medical risk factors. A significant association was found between any amount of maternal cigarette use during pregnancy and having a child with cleft lip/palate [unadjusted odds ratio 1.55 (1.36, 1.76), p < 0.001]. Univariate analysis showed that maternal education level, age, race, and maternal medical conditions (diabetes and pregnancy-associated hypertension) were potential confounders. After adjusting for these confounders, the odds ratio remained significant [Mantel-Haenszel odds ratio 1.34 (1.16, 1.54), p < 0.001]. To determine the dose response of cigarette smoking during pregnancy, the cigarette consumption per day was divided into four groups: none, 1 to 10, 11 to 20, and 21 or more. A dose-response relationship was found when comparing each smoking category with the no smoking reference group: 1.50 (1.28, 1.76), 1.55 (1.23, 1.95), and 1.78 (1.22, 2.59), respectively. This means that increased cigarette smoking during pregnancy resulted in increased odds of having a child with cleft lip/palate. This is the largest study to date to test the association between maternal cigarette smoking during pregnancy and having a newborn with cleft lip/palate. The significant trend in the dose-response relationship strongly suggests the association of smoking tobacco and this common congenital deformity. These results emphasize the public health risks associated with smoking during pregnancy. To prevent this devastating craniofacial anomaly, educational initiatives should be considered that will alert expectant mothers to the association between smoking during pregnancy and the occurrence of cleft lip/palate.

The epidemiology of distal radius fractures

Distal radius fractures are one of the most common types of fractures. Although the pediatric and elderly populations are at greatest risk for this injury, distal radius fractures still have a significant impact on the health and well-being of young adults. Data from the past 40 years have documented a trend toward an overall increase in the prevalence of this injury in both the pediatric and elderly populations. Understanding the epidemiology of this fracture is an important step toward the improvement of treatment strategies and the development of preventive measures with which to target this debilitating injury.

Risk of melanoma arising in large congenital melanocytic nevi: A systematic review

Large congenital melanocytic nevi are cutaneous lesions regarded by many as premalignant; estimates of malignancy incidence range from 0 to 42 percent. Given the often complex and extensive nature of large congenital melanocytic nevi resection and reconstruction, the risk of malignant transformation is a crucial factor that surgeons and families must weigh when deciding whether or not to excise the lesion. The authors conducted a systematic analysis of data from the existing literature to critically evaluate the published studies and to establish a crude incidence rate for the risk of malignant melanoma transformation in large congenital melanocytic nevi. After a comprehensive literature search, they analyzed data from eight studies (containing a total of 432 large congenital melanocytic nevi patients) of sufficient scientific quality. Twelve patients (2.8 percent) in this sample developed cutaneous malignant melanoma during the reported follow-up periods. Using a subset of this data and comparing the incidence rates to those of the Surveillance, Epidemiology, and End Results population-based database using a standardized morbidity ratio, the authors found that the large congenital melanocytic nevi patients had an increased risk of melanoma (standardized morbidity ratio, 2599; 95 percent confidence interval, 844 to 6064) compared with the general population. Regarding treatment before developing melanoma in the 12 patients, 50 percent were observed before diagnosis, 17 percent had partial excision, 8.3 percent had dermabrasion, 8.3 percent had a chemical peel, and 17 percent did not have any treatment information. These combined data are clinically useful when consulting with the parents of children with large congenital melanocytic nevi and in the management of older patients with existing lesions. This study shows that there is a significantly increased risk of melanoma in large congenital melanocytic nevi patients. The data also reveal the need for a standardized definition of large congenital melanocytic nevi and a long-term, prospective outcomes study to determine the true lifetime risk of melanoma in patients with and without surgical excision.