No abstract

III.

Despite the tremendous efforts devoted to the structural analysis of hydrogel microspheres (microgels), many details of their structures remain unclear. Reported in this study is that thermoresponsive poly(N‐isopropyl acrylamide) (pNIPAm)‐based microgels exhibit not only the widely accepted core–shell structures, but also inhomogeneous decanano‐sized non‐thermoresponsive spherical domains within their dense cores, which was revealed by temperature‐controlled high‐speed atomic force microscopy (TC‐HS‐AFM). Based on a series of experiments, it is concluded that the non‐thermoresponsive domains are characteristic for pNIPAm microgels synthesized by precipitation polymerization, and plausible structures for microgels prepared by other polymerization techniques are proposed.

Purpose Concomitant meniscus injuries in the anterior cruciate ligament (ACL) injuries have been suggested to exacerbate rotational laxity. However, the effect is supposed to be so small, if any, that some quantitative pivot-shift measurement is needed. The purpose of this prospective study was to determine the effect of meniscus tear on rotational laxity in ACL-deficient knees by an quantitative measurement. We hypothesized that a concomitant meniscus tear, especially a lateral one, would induce greater pivot-shift. Methods Fifty-seven unilateral ACL-injured patients (26 men and 31 women, mean age: 24±10 years) were included. The pivot-shift test was performed prior to ACL reconstruction while a quantitative evaluation using an electromagnetic system to determine tibial acceleration and a clinical grading according to the IKDC were performed. Meniscus injuries were diagnosed arthroscopically, and concomitant meniscus tear was confirmed in 32 knees. Chi-squared and Mann-Whitney U tests were used to assess the difference between knees with and without meniscus tear. A subgroup analysis was subsequently performed for the medial, bilateral, and lateral meniscus-torn groups compared with the meniscus-intact group, using the chi-squared test and analysis of variance. Statistical significance was defined at p<0.05.

Compared with 3 weeks postoperatively, the articular side outlets of the femoral and tibial bone tunnels at 1 year postoperatively had enlarged slightly but statistically maintained their volume, and they had moved a little in the direction that the grafts were pulled.