Biomedical subjects

K Yamakoshi

Publications and source records attributed to K Yamakoshi.

94 records · Page 6Linked to original sources

PubMedDate not supplied

Mechanical strength of latissimus dorsi tendon transfer with Teflon felt augmentation.

Tensile properties of Teflon felt augmentation after latissimus dorsi tendon transfer to rotator cuff defect were examined in dog cadaver shoulders. Two experimental groups with latissimus dorsi tendon transfer were designed. In group 1 (right shoulders, n = 7) the tendon ends of latissimus dorsi were sutured to the greater tuberosity. In group 2 (left shoulders, n = 7) the repair was augmented with Teflon felt at the suture site. The ultimate tensile force and stiffness of each specimen in group 2 were individually compared with those in group 1. The average increases in ultimate tensile force and stiffness in group 2 were 53.8% and -3.7%, respectively. The individual value of ultimate tensile force in group 2 was significantly greater than that in group 1. These results demonstrate that augmentation at the repair site is mechanically effective latissimus dorsi tendon transfer. The augmentation procedure may provide protection during the healing period because of this and a surrounding fibrous tissue reaction.

Animals↗

PubMedDate not supplied

Restoration of tensile properties at tendon insertion to bone by a patellar tendon-tibia autograft: an experimental study with canine infraspinatus.

A free patellar tendon-tibia autograft was performed to reconstruct a tendon insertion to bone of the canine infraspinatus. In this experimental study restoration of mechanical properties at tendon insertion to bone of the patellar tendon-tibia autograft was examined on 0, 42, and 84 postoperative days. Five dogs were used for each time point. Bone union occurred in all grafts by 6 postoperative weeks. The ultimate strength at the tendon insertion to bone recovered from 255.5 N on 0 day to 264.3 N and 439.3 N on 42 and 84 postoperative days, respectively. Stiffness recovered from 141.8 KN/m on 0 day to 201.8 KN/m and 226.3 KN/mN on 42 and 84 postoperative days, respectively. Our results demonstrate that patellar tendon-tibia autograft maintains excellent mechanical properties at tendon insertion to bone in the early healing period. This result suggests that transfer or free graft of tendons with attaching bone plug has a mechanical advantage for reconstruction of the rotator cuff, which may allow the patient to institute early postoperative mobilization.

Animals↗

PubMedDate not supplied

Pulse glucometry: A new approach for noninvasive blood glucose measurement using instantaneous differential near-infrared spectrophotometry.

We describe a new optical method for noninvasive blood glucose (BGL) measurement. Optical methods are confounded by basal optical properties of tissues, especially water and other biochemical species, and by the very small glucose signal. We address these problems by using fast spectrophotometric analysis in a finger, deriving 100 transmittance spectra per second, to resolve optical spectra (900 to 1700 nm) of blood volume pulsations throughout the cardiac cycle. Difference spectra are calculated from the pulsatile signals, thereby eliminating the effects of bone, other tissues, and nonpulsatile blood. A partial least squares (PLS) model is used with the measured spectral data to predict BGL levels. Using glucose tolerance tests in 27 healthy volunteers, periodic optical measurements were made simultaneously with collection of blood samples for in vitro glucose analysis. Altogether, 603 paired data sets were obtained in all subjects and two-thirds of the data or of the subjects randomly selected were used for the PLS calibration model and the rest for the prediction. Bland-Altman and error-grid analyses of the predicted and measured BGL levels indicated clinically acceptable accuracy. We conclude that the new method, named pulse glucometry, has adequate performance for safe, noninvasive estimation of BGL.

Algorithms↗

PubMedDate not supplied

An experimental evaluation of isometric placement for extraarticular reconstructions of the anterior cruciate ligament.

We measured the changes in distance between the tibial and femoral attachment points of the extraarticular ACL substitute during knee motion. To measure the changes in distance continuously and directly, a computer-assisted experimental system was developed using an electrolyte-in-rubber transducer. We used 6 cadaveric knees to measure changes in distance of 15 combinations during a simple flexion and extension knee motion. The distance became longer with flexion in each pair of attachment locations. Although the smallest change in distance was obtained between the posterolateral site of the femoral distal metaphysis and a point posterior to the Gerdy tubercle (percent average of the maximum strain was about 12%), it was concluded that the extraarticular ACL reconstruction is not recommended from a standpoint of isometry of the substitute.

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