Looped suture properties: implications for multistranded flexor tendon repair.

Multiple-strand repair techniques are commonly used to repair cut flexor tendons to achieve initial biomechanical strength. Looped sutures achieve multiple strands with fewer passes and less technical complexity. Their biomechanical performance in comparison with an equivalent repair using a single-stranded suture is uncertain. This study examined the mechanical properties of double-stranded loops of 3-0 and 4-0 braided polyester (Ticron) and polypropylene monofilament (Prolene). Double loops were generally less than twice the strength of a single loop. Ticron and Prolene had the same strengths, but Ticron was stiffer. The 4-0 double loops had significantly higher stiffness than 3-0 single loops. Increasing the size of sutures had a larger relative effect on strength than using a double-stranded suture. However, a double-strand loop had a larger effect on increasing stiffness than using a single suture of a larger equivalent size. Looped suture repairs should be compared with standard techniques using a thicker single suture.

Performance of a knotless four-strand flexor tendon repair with a unidirectional barbed suture device: a dynamic ex vivo comparison.

With increased numbers of reports using barbed sutures for tendon repairs we felt the need to design a specific tendon repair method to draw the best utility from these materials. We split 30 sheep deep flexor tendons in two groups of 15 tendons. One group was repaired with a new four-strand barbed suture repair method without knot. The other group was repaired with a conventional four-strand cross-locked cruciate repair method (Adelaide repair) with knot. Dynamic testing (3-30 N for 250 cycles) and additional static pull to failure was performed to investigate gap formation and final failure forces. The barbed suture repair group showed higher resistance to gap formation throughout the test. Additionally final failure force was higher for the barbed suture group compared with the conventional repair group. When used appropriately, barbed suture materials could be beneficial to use in tendon surgery, especially with regard to early loading of the repair site and gap formation.

Multiple cerebral hydatid disease: case report with magnetic resonance imaging study.

A case of multiple hydatid cysts of the brain is reported. Computed tomographic and magnetic resonance imaging scanning revealed a thick and calcified pericystium. These findings allowed appropriate surgical planning, with a marked recovery of the neurological deficits and absence of relapse in the follow-up period.

Enhancement of electrooptic effects at wavelengths in the proximity of electronic resonances.

The notion is analyzed of obtaining materials with large electrooptic coefficients relative to their dielectric constants by incorporating appropriate optical transitions near the operating wavelengths. It is shown that in such cases the absorption coefficient becomes an important practical parameter of the material. Enhancement of the electrooptic effect in the vicinity of an optical transition was indeed observed in the compound Na(3)Li(CrO(4))(2)-6H(2)O. The electrooptic coefficient n(o)(3)r(22) was found to be 9.7 x 10(-8) cm/statV at nu = 1.67 x 10(4) cm(-1) and 12.2 x 10(-8) cm/statV at nu = 2.00 x 10(4) cm(-1). The absorption coefficient on the tail of the t(1) ? e transition of the chromate ion was considerably greater than what was initially estimated. This was shown to be due partially to the effects of lattice vibrations and partially to crystal imperfections. The extra absorption can in principle be eliminated, and it is concluded that the approach investigated could lead to electrooptic materials with improved characteristics.