Biomedical subjects

L M Specht

Publications and source records attributed to L M Specht.

3 recordsLinked to original sources

PubMed2000

Pneumatic compression hemodynamics in total hip arthroplasty.

A crossover study was performed to evaluate the effect of several pneumatic compression devices and active dorsoplantar flexion in 10 patients who underwent total hip arthroplasty. Using the Acuson 128XP/10 duplex ultrasound unit with a 5-MHz linear array probe, peak venous velocity and venous volume were assessed above and below the greater saphenous vein and common femoral vein junction. A computer generated randomization table was used to determine the order of the test conditions. The pneumatic compression devices evaluated included two foot pumps, one foot and calf pump, one calf pump, and three calf and thigh pumps. Statistical analyses included analysis of variance and analysis of variance with covariance between devices and patients. The covariates tested were the baseline measurements and the order in which the devices were tested. Differences between devices relate in part to the frequency and rate of inflation and the location and type of compression. Pulsatile calf and foot and calf pneumatic compression with a rapid inflation time produced the greatest increase in peak venous velocity, whereas compression of the calf and thigh showed the greatest increase in venous volume. Because patient and nursing compliance is essential to the success of mechanical prophylaxis for thromboembolic disease, the more simple, yet efficacious, devices that are easier to apply and less cumbersome appear to have a greater likelihood of success. In the active and alert patient, active dorsoplantar flexion should be encouraged.

Arthroplasty, Replacement, Hip↗

PubMed1998

Venous haemodynamics after total knee arthroplasty: evaluation of active dorsal to plantar flexion and several mechanical compression devices.

We performed a crossover study to evaluate the haemodynamic effect of active dorsal to plantar flexion and seven pneumatic compression devices in ten patients who had a total knee arthroplasty. Using the Acuson 128XP/10 duplex ultrasound unit with a 5MHz linear array probe, we assessed the augmentation of peak venous velocity and venous volume above and below the junction of the greater saphenous and common femoral veins in order to study both the deep and superficial venous systems. The pneumatic compression devices evaluated included two foot pumps (A-V Impulse System and PlexiPulse Foot), a foot-calf pump (PlexiPulse Foot-Calf), a calf pump (VenaFlow System) and three calf-thigh pumps (SCD System, Flowtron DVT and Jobst Athrombic Pump). The devices differed in a number of ways, including the length and location of the sleeve and bladder, the frequency and duration of activation, the rate of pressure rise, and the maximum pressure achieved. A randomisation table was used to determine the order of the test conditions for each patient. The enhancement of peak venous velocity occurred primarily in the deep venous system below the level of the saphenofemoral junction. The increases in peak venous velocity were as follows: active dorsal to plantar flexion 175%; foot pumps, A-V Impulse System 29% and PlexiPulse 65%; foot-calf pump, PlexiPulse, 221%; calf pump, VenaFlow, 302% and calf-thigh pumps, Flowtron DVT 87%, SCD System 116% and Jobst Athrombic Pump 263%. All the devices augmented venous volume, the greatest effect being seen with those incorporating calf compression. The increases in ml/min were found in the deep venous system as follows: foot pumps, A-V Impulse System 9.6 and PlexiPulse Foot 16.7; foot-calf pump, PlexiPulse, 38.1; calf pump, VenaFlow, 26.2; calf-thigh pumps, Flowtron DVT 61.5, SCD System 34.7 and Jobst Athrombic Pump 82.3. Active dorsal to plantar flexion generated 8.5 ml for a single calf contraction.

Aged↗

PubMedDate not supplied

Robotics and computer-assisted orthopaedic surgery.

These are just a few representative applications of the synergistic use of computer and robotic technology assisting the orthopaedic surgeon. While the individual systems are certain to change over time, the basic principles of correlating radiographic and anatomic data through a registration process, and displaying additional instrument or implant information through smart tools and surgical navigation are certain to become an increasingly important aspect of joint arthroplasty, deformity correction, and spinal and trauma surgery. Only the orthopaedic surgeon who clearly understands the goals, applications, and limitations of these systems can decide which are appropriate for his patients, his hospital, and his practice. Determining the cost and time benefits, both before and after an obligatory "learning curve" requires a complex interaction of capital investments, time savings, and outcome research on both safety and efficacy issues. The orthopaedist who understands and applies these technologies will help his patients to achieve the best possible care. Excellent resources in the literature on this topic include the September, 1998, issue of Clinical Orthopaedics and Related Research, a symposium on "Computer-Assisted Orthopaedic Surgery: Medical Robots and Image Guided Surgery"; Guest editor, Anthony M. DiGioia, III, MD. Also, the January, 2000, issue of Operative Techniques in Orthopaedics, "Medical Robotics and Computer-Assisted Orthopaedic Surgery. Guest editors: Anthony M. DiGioia, III, M.D. and Branislav Jaramaz, Ph.D. Additional Internet based information is available from the Journal of Computer Aided Surgery (formerly: Journal of Image Guided Surgery), at http://journals.wiley.com/.

Arthroplasty, Replacement, Hip↗