Efficacy and validity of radiofrequency neurotomy for chronic lumbar zygapophysial joint pain.

STUDY DESIGN: A prospective audit. OBJECTIVE: To establish the efficacy of lumbar medial branch neurotomy under optimum conditions. SUMMARY OF BACKGROUND DATA: Previous reports of the efficacy of lumbar medial branch neurotomy have been confounded by poor patient selection, inaccurate surgical technique, and inadequate assessment of outcome. METHODS: Fifteen patients with chronic low back pain whose pain was relieved by controlled, diagnostic medial branch blocks of the lumbar zygapophysial joints, underwent lumbar medial branch neurotomy. Before surgery, all were evaluated by visual analog scale and a variety of validated measures of pain, disability, and treatment satisfaction. Electromyography of the multifidus muscle was performed before and after surgery to ensure accuracy of the neurotomy. All outcome measures were repeated at 6 weeks, and 3, 6, and 12 months after surgery. RESULTS: Some 60% of the patients obtained at least 90% relief of pain at 12 months, and 87% obtained at least 60% relief. Relief was associated with denervation of the multifidus in those segments in which the medial branches had been coagulated. Prelesion electrical stimulation of the medial branch nerve with measurement of impedance was not associated with outcome. CONCLUSIONS: Lumbar medial branch neurotomy is an effective means of reducing pain in patients carefully selected on the basis of controlled diagnostic blocks. Adequate coagulation of the target nerves can be achieved by carefully placing the electrode in correct position as judged radiologically. Electrical stimulation before lesioning is superfluous in assuring correct placement of the electrode.

The ability of lumbar medial branch blocks to anesthetize the zygapophysial joint. A physiologic challenge.

STUDY DESIGN: Randomized, controlled, single blinded study. OBJECTIVES: To determine the physiologic effectiveness of lumbar medial branch blocks. SUMMARY OF BACKGROUND DATA: Zygapophysial joint pain can be diagnosed by anesthetization of the joint or its nerve supply (the medial branch divisions of the dorsal rami). The physiologic effectiveness of lumbar medial branch blocks has been assumed but not proven. METHODS: Eighteen asymptomatic individuals were randomly assigned to either L4-L5 or L5-S1 zygapophysial joint injections with contrast medium until capsular distention elicited pain without extracapsular contrast spread. One week later, 15 blinded individuals underwent two randomized saline or 2% lidocaine medial branch injections that correlated to the innervation of the previously injected joint. Medical branch injections were performed such that inadvertent venous uptake was avoided in 14 individuals. Thirty minutes after medial branch injections, these 14 individuals underwent repeat capsular distention of the same zygapophysial joint provoked the prior week in an attempt to elicit another painful response. RESULTS: All five control individuals who received saline medial branch injections felt pain on repeat capsular distention. Nine individuals received 2% lidocaine medial branch blocks; eight felt no pain, and one felt pain on repeat capsular distention. CONCLUSIONS: There was a significant effect of 2% lidocaine (versus saline) medial branch injections on anesthetization of the zygapophysial joint when venous uptake was avoided during these injections. When properly performed, lumbar medial branch blocks successfully inhibit pain associated with capsular distention of the lumbar zygapophysial joints at a rate of 89%.

A novel approach to preemployment worker fitness evaluations in a material-handling industry.

STUDY DESIGN: Effectiveness of a pre-employment worker fitness evaluation in a sample of grocery warehouse order selectors was studied retrospectively. Implementation of the program began in March 1990 and as of September 10, 1993, 1100 prospective employees have been tested. OBJECTIVES: Identification of prospective employees with the necessary job specific physical requirements was conducted with a standardized test protocol based on job analysis and normative data. Follow-up injury rates and costs for this department were supplied by the company for statistical analysis. SUMMARY OF BACKGROUND DATA: To establish normative data for minimum standards of job performance, a control group of current, uninjured and experienced order selectors was evaluated in respect to job requirements and isokinetic variables. In the control group, 17 variables were identified including one each from two 5-minute repetitive lifting tasks with weighted crates and 15 isokinetic trunk function and lifting variables. Prospective employees were required to successfully complete at least 15 variables for hire as an order selector. METHODS: The t-test for significance of difference between two proportions was used to compare injury rates in 1989 to those reported in 1990, 1991, 1992, and 1993. RESULTS: Statistically significant differences were found between the unimplemented comparison year of 1989 and the 4 years post-implementation. CONCLUSIONS: Preliminary data suggests that a worker fitness evaluation using the above methodology may be an effective method of reducing injuries and subsequent costs.

Planning a new library in an age of transition: the Washington University School of Medicine Library and Biomedical Communications Center.

In an era of great technological and socioeconomic changes, the Washington University School of Medicine conceptualized and built its first Library and Biomedical Communications Center in seventy-eight years. The planning process, evolution of the electronic library, and translation of functions into operating spaces are discussed. Since 1983, when the project was approved, a whole range of information technologies and services have emerged. The authors consider the kind of library that would operate in a setting where people can do their own searches, order data and materials through an electronic network, analyze and manage information, and use software to create their own publications.

Beyond the online catalog: developing an academic information system in the sciences.

The online public access catalog consists essentially of a machine-readable database with network capabilities. Like other computer-based information systems, it may be continuously enhanced by the addition of new capabilities and databases. It may also become a gateway to other information networks. This paper reports the evolution of the Bibliographic Access and Control System (BACS) of Washington University in end-user searching, current awareness services, information management, and administrative functions. Ongoing research and development and the future of the online catalog are also discussed.

BACS: evolution of an integrated library system toward information management.

The evolution of the Washington University School of Medicine BACS integrated library system toward information management functions is outlined. The creation of a machine-readable database and its extension through telecommunications have consequences that reach beyond the functions of the library as we have perceived them. It is argued that libraries are flexible institutions that, with automation, are likely to enlarge rather than to diminish.