RESUMEN
We report flexible [Pd(L)2 ]2+ complexes where there is self-recognition, driven by π-π interactions between electron-rich aromatic arms and the cationic regions they are tethered to. This self-recognition hampers the association of these molecules with aromatic molecular targets in solution. In one case, this complex can be reversibly converted to an 'open' [Pd2 (L)2 ]4+ macrocycle through introduction of more metal ion. This is accomplished by the ligand having two bidentate binding sites: a 2-pyridyl-1,2,3-triazole site, and a bis-1,2,3-triazole site. Due to favourable hydrogen bonding, the 2-pyridyl-1,2,3-triazole units reliably coordinate in the [Pd(L)2 ]2+ complex to control speciation: a second equivalent of Pd(II) is required to enforce coordination to bis-triazole sites and form the macrocycle. The macrocycle interacts with a molecular substrate with higher affinity. In this fashion we are able to use stoichiometry to reversibly switch between two different species and regulate guest binding.
RESUMEN
PURPOSE: To evaluate the efficacy of sacroplasty for treating sacral insufficiency fractures, including the effect on pain relief, patient function and adverse event rates in an as-treated on-label prospective data registry. MATERIALS AND METHODS: Observational data including patient reported outcomes (PROs), patient characteristics, osteoporosis treatment, fracture duration, cause of sacral fractures and image guidance used for treatment were collected for patients undergoing sacroplasty. The PROs were collected at baseline then at one, three, and at six months following the procedure. The primary outcomes were pain as measured by the Numerical Rating Scale (NRS) and function as measured by the Roland Morris Disability Questionnaire (RMDQ). Secondary outcomes included adverse events, cement leakage, new neurologic events, readmissions and death. RESULTS: The interim results for the first 102 patients included significant pain reduction with mean pain improvement scores at six months decreasing from 7.8 to 0.9 (P < .001) and significant improvement in function with mean RMDQ scores improving from 17.7 to 5.2 (P < .001). Most procedures were performed under fluoroscopy (58%). There was cement leakage in 17.7% of the subjects but only one adverse event which was a new neurologic deficit related to cement extravasation. The readmission rate was 16% mostly due to additional back pain and fractures and there were no subject deaths. CONCLUSIONS: Sacroplasty with cement augmentation for acute, subacute and chronic painful sacral insufficiency fractures caused by osteoporosis or neoplastic disorders results in highly significant improvements in pain and function with very low rate of procedural related adverse events.
