No abstract

Background: This systematic review and meta-analysis assessed the role of nonoperative treatment and volar locking plate (VLP) fixation in elderly patients with distal radial fracture. Methods: The systematic literature review identified randomized controlled trials (RCTs) and observational studies using VLP and nonoperative treatment for distal radial fractures in the elderly. Two investigators independently extracted data and evaluated the quality of the studies. A meta-analysis was performed using RevMan version 5.3. Results: The five RCTs and six observational studies included 585 and 604 patients in the VLP and nonoperation groups, respectively. The quality of these 11 studies was moderate. Compared to nonoperation treatment, VLP did not improve the disabilities of the arm, shoulder and hand (DASH) score (weighted mean difference [WMD] = −1.67; 95% confidence interval [CI], −3.58-−0.24; P = 0.09), decrease complications (odds ratio = 1.05; 95% CI, 0.51-2.19; P = 0.89), or improve range of motion in flexion, extension, pronation, supination, and radial deviation. The VLP group had better grip strength (WMD = 10.52; 95% CI, 6.19-14.86; P < 0.0001) and radiographic assessment than the nonoperation group. Conclusions: Although insufficient, the study evidence shows that VLP does not improve DASH scores, complications, or range of motion, but it might provide better grip strength and radiographic assessment than nonoperation treatment.

High‐yielding syntheses of two novel cryptands based on bis(m‐phenylene)‐26‐crown‐8 are reported. One‐step [2+2] cyclization of methyl 3,5‐dihydroxybenzoate with tri(ethylene glycol) ditosylate under pseudo‐high‐dilution conditions gave BMP26C8 (1) in 28 % yield. Reduction of 1 with LAH, followed by deprotonation (NaH) and alkylation with propargyl bromide, afforded the dialkynated BMP26C8 (3) in high yield (two‐step 84 %). Unimolecular macrocyclization of 3 through copper(II)‐mediated Eglinton coupling generated the diacetylene‐containing cryptand 4 in 97 % yield. Pd/C‐catalyzed hydrogenation of 4 yielded the cryptand 5 (93 %). Their structures were confirmed by NMR, ESI‐MS, and X‐ray analysis. The complexation behavior of these new cryptands with paraquat was also studied, and it was found that these cryptands bind paraquat more strongly than the corresponding BMP26C8. The association constants (K1 and K2) in acetone solution were determined to be K1 = 914 M–1, K2 = 229 M–1 for complex 42·6 and K1 = 758 M–1, K2 = 190 M–1 for complex 52·6. Moreover, the two new [3]pseudorotaxane‐like complexes 42·6 and 52·6 were also obtained in the solid state, as confirmed by X‐ray analysis.