Elution of vancomycin, daptomycin, and amikacin from acrylic bone cement.

Increasing antibiotic resistance of bacteria that infect prosthetic joints has stimulated interest in the incorporation of more effective antimicrobial agents into polymethylmethacrylate (PMMA). Vancomycin and daptomycin are effective against nearly all staphylococci and streptococci, and amikacin has a broader spectrum against gram-negative bacilli than do other aminoglycosides such as gentamicin. These three antibiotics maintained bioactivity after incorporation into several commonly used preparations of PMMA and eluted readily into the surrounding medium.

Infants and atropine: a dangerous mixture.

Colic in infants is a common but short-lived problem. Many different theories and treatment for this distressing ailment have been tried over the years, yet the definitive cure remains elusive. Although the risks associated with the use of atropine and its derivatives are well known, they are still prescribed by some in the management of colic.

The effect of femoral component position on patellar tracking after total knee arthroplasty.

In a laboratory study, seven fresh anatomic knee specimens were evaluated to define the three-dimensional motions of the patella before and after total knee arthroplasty (TKA) with the AMK knee. The patella was displaced medially by an average of 4 mm and tilted medially by an average of 4 degrees after standard TKA. Medial translation or internal rotation of the femoral component further displaced and tilted the patella medially, but lateral translation or external rotation of the femoral component produced less predictable changes in patellar tracking.

The effect of continuous epidural analgesia on postoperative pain, rehabilitation, and duration of hospitalization in total knee arthroplasty.

Efficacies of three alternate methods of postoperative analgesia were studied in 156 patients who had total knee arthroplasty (TKA). Forty-two of these patients received parenteral meperidine hydrochloride or morphine (Group 1), 58 patients received periodic epidural injections of morphine (Group 2), and 56 patients received continuous epidural infusions of bupivacaine hydrochloride and Duramorph (Group 3). The postoperative course of all patients was documented in terms of the incidence and severity of pain, range of joint motion, duration of hospitalization, and occurrence of complications.

Evaluation of an electrogoniometric instrument for measurement of laxity of the knee.

Eight lower extremities from cadavera were tested for anterior-posterior laxity in two positions before and after transection of the anterior cruciate ligament. At critical points in the tests, electrogoniometric and radiographic measurements of tibiofemoral translation were compared. By direct measurement, we determined the accuracy of the radiographic method to +/- 0.

An anatomic study of subtalar instability.

Subtalar instability has been recognized as a cause of ankle symptoms. The purpose of this anatomic study is to determine the ligament damage required to produce subtalar instability, and to define a radiographic technique to demonstrate it. Ten fresh adult cadaver ankles were dissected.

Violence by psychiatric in-patients.

A register of violence incidents showed a progressive increase in in-patient violence from 1976 to 1984, followed by a slight decline to 1987. The case notes of all 137 in-patients committing assaults during 1982 were analysed and compared with those of matched controls. Violence was often repetitive.

External stabilization of the anterior cruciate ligament deficient knee during rehabilitation.

Using cadaveric specimens, we studied the effect of ACL deficiency upon anterior tibial translation during extension of the knee joint. Five knees were loaded via the quadriceps mechanism until flexion angles of 10 degrees, 25 degrees, 40 degrees, and 60 degrees were attained. At each angle, the anterior-posterior position of the tibia was documented with biplane radiography, both before and after division of the ACL.

Metatarsal osteotomy for primary metatarsalgia: radiographic and pedobarographic study.

The effect of surgical procedures for primary metatarsalgia on the load distribution and bony architecture of the forefoot is poorly understood. A prospective study was performed on 45 feet with this diagnosis treated by dorsal wedge osteotomy and compared with 29 symptom-free contralateral feet. Each foot was evaluated preoperatively and postoperatively with quantitative radiographic analysis, a pedobarographic study, and by physical examination.

The pulmonary complications of bone marrow transplantation in adults.

These discussions are selected from the weekly staff conferences in the Department of Medicine, University of California, San Francisco. Taken from transcriptions, they are prepared by Homer A. Boushey, MD, Professor of Medicine, and John G.

Time-based changes in fibroblast three-dimensional locomotory characteristics and phenotypes.

Three-dimensional locomotory trajectories have been determined for an embryonic fibroblast population and also for these cells after a 20-day period in tissue culture (C-20 cells). Differences in locomotory characteristics between these two cell populations are reported. Applying factor analysis to the distribution of angle changes between vectors in a cell's trajectory reveals the possibility that different locomotory phenotypes exist.

The anatomic basis of femoral component design.

The shape of the femoral canal is variable, much more variable, in fact, than most contemporary designs of femoral components would suggest or can accommodate. In the face of this variability, line-to-line or surface-to-surface contact is not expected between cementless implants and much of the endosteal surface. It also is apparent that changes in implant design are still needed if the normal biomechanics of the hip joint are to be restored in each patient and if component fixation is to be optimized.

Locomotory characteristics of Treponema denticola.

Locomotion of pathogenic spirochetes has been suggested as a virulence factor in their pathogenesis. Little is known of the locomotory characteristics of oral anaerobic spirochetes. We have determined the optimal conditions for motility of seven strains of Treponema denticola in menstrua of different viscosities.

Respiratory diseases in pregnancy.

Pregnant women with respiratory problems pose a special challenge. Pregnancy alters lung function and the natural history of common pulmonary disorders. Respiratory problems in pregnancy must be approached with an understanding of the unique, inter-dependent physiologic and psychological status of mother and fetus.

Simple dislocation of the elbow in the adult. Results after closed treatment.

The long-term results after treatment of simple dislocation of the elbow in fifty-two adults were evaluated with regard to limitation of motion, pain, instability, and residual neurovascular deficit. All patients were treated with traditional closed reduction, but the duration of immobilization before commencement of active motion varied. Goniometric, photographic, and radiographic data were compiled for these patients, who had an average follow-up of 34.

Arthroscopic subacromial decompression. An anatomical study.

Anterior acromioplasty as described by Neer has been an effective procedure for shoulder impingement syndrome. Recent presentations by Ellman suggest that an effective acromioplasty may be performed arthroscopically. These clinical reports have not been supported by any laboratory experience.

Analysis of cell three-dimensional locomotory vectors.

A method is presented for analysing the vectors of cells locomoting within three-dimensional collagen gels. The method detected differences in locomotory vector patterns between cells locomoting in two different gel formats. The potential of this analytical method for determining the role of the extracellular matrix in modulating cell locomotory behaviour is discussed.

Effects of 5 alpha-dihydrocorticosterone on evoked responses and long-term potentiation.

The effect of a Ring A-reduced metabolite of corticosterone, 5 alpha-dihydrocorticosterone (DHB) on long-term potentiation (LTP) in the dentate gyrus (DG) of the rat were studied in barbiturate-anaesthetised animals. It was observed that DHB significantly impairs the development of LTP, more particularly the population spike (PS) component of the evoked potential (EP) to perforant path (PP) stimulation. Nutralipid, an inert control solvent of the steroid, did not affect LTP development.