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Objective: To explore clinical and radiographic effects of percutaneous pie-crusting deep medial collateral ligament release in patients with posterior horn tear of medial meniscus combined with tight medial compartment., Methods: From January 2012 to December 2016, 35 patients with medial meniscus posterior horn injury were treated with percutaneous pie crusting deep medial collateral ligament release technique, including 21 males and 14 females, aged from 21 to 55 years old with an average of (39.1±6.5) years old. Degree of meniscus extrusion were recorded before and 24 months after operation. The knee valgus stress test was performed to evaluate stability of medial collateral ligament, and compared difference between healthy and affected side. Lysholm and IKDC functional scores were compared before and 24 months after operation., Results: All patients were followed up from 27 to 60 months with an average of (36.7±6.8) months. All patients were underwent operation, the wound healed well without complications. Operative time ranged from 0.5 to 1.2 h with an average of (0.8±0.4) h. Nineteen patients were performed partial meniscectomy, 16 patients were performed repair suture. Convex of meniscus before operation was (1.5±0.7) mm, and (1.7±0.4) mm after operation;had no statistical difference( P >0.05). Lysholm score was improved from 53.4±8.8 before operation to 91.5±4.6 at 24 months after operation;IKDC score was increased from 50.7±9.2 before operation to 90.6±3.9 at 24 months after operation;there was statistically significant ( P <0.05). Valgus stress test was performed on 0 ° and 30 ° position of knee flexion in affected side and compared with ipsilateral side, all patients showed negative., Conclusion: For patients with medial meniscus tear of posterior horn combined with tight medial compartment, percutaneous pie-crusting deep medial collateralligament release could improve medial compartment space, and Knee valgus instability and meniscus extrusion are not affected.

Upon heating, polyesters decompose to small molecules and release flammable volatiles and toxic gases, primarily through chain scission of their ester linkages, and therefore exhibit poor fire-safety properties, thus restricting their applications. Reported herein is an end-group-capturing effect of (bis)oxazoline groups, generated from the thermal rearrangement of the N-(2-hydroxyphenyl)phthalimide (HPI) moiety which was incorporated into the polyester chain by copolymerization. These copolyesters, as a result, exhibit high efficiency in retarding decomposition by capturing the decomposed products, particularly for the carbonyl-terminated fragments, thus increasing the fire-safety properties, such as self-extinguishing, anti-dripping, and inhibiting heat release and smoke production. The successful application of this method in both semi-aromatic and aliphatic polyesters provide promising perspectives to designing versatile fire-safe polymers., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)