OPERATIVE TREATMENT OF SPINAL DEFORMITIES IN PATIENTS WITH CEREBRAL PALSY

Surgical treatment of scoliosis on the background of cerebral palsy is carried out by the correction and polysegmental fixation of the spine and helps to improve balance the body, activate patient in a wheelchair, to prevent the subsequent progression of spinal deformity and rib cage, and improve self-care patients

Comparative analysis of results of treatment patients with severe spinal deformities using screw and a hybrid hardware

Purpose: evaluation of efficacy of operative treatment with the use of screw and hybrid metal constructions in idiopathic scoliosis associated with severe spine deformities. Material and methods: The outcomes of treatment of 34 patients aged 15 to 27 years old with severe scoliosisoperated on using screw metal constructions, were reviewed. 22 patients operated on with the use of hybrid metal constructions, made a control group. The groups were compared by the following parameters: pre- and postoperative Cobb angle, deformity mobility according to traction test, total sagittal/frontal balance, CT apical vertebra rotation, operation time, intraoperative blood loss, the number of instrumented vertebrae, and correction failure at 24-hr spondylograms. Results: Group A (screw spine fixation) demonstrated better outcomes compared to group B (combined spine fixation) in the following parameters. Postoperative correction was 48% and 41%;apical vertebra rotation decreased from 78° to 55° (30%) and from 74° to 59°(21%);total sagittal/frontal balance decreased from 39/25 mmto 14/12 mm (64/52%) and from 35/26 mm to 16/15 mm (55/43%), correspondingly. These results suggest better trunk compensation and postoperative correction in a group of patients with screw fixation. Smaller values of correction failure of the main arc as well as insignificant increase of thoracic kyphosis in the postoperative period (24 months) 3.8%/4.3% in group A compared to 6.2%/7.5% in group B testify to greater reliability and stability of ‘all screw’ metal constructions. The number of fixed elements was on average one more in a group with combined fixation (13 and 14, correspondingly)

REVISION SURGERY IN PATIENTS WITH SCOLIOSIS OPERATED WITH PLATE ENDOCORRECTORS

The authors presented 19 clinical observations of patients undergoing surgery at the primary idiopathic scoliosis using plate endocorrectors. The following characteristics were determined: the fixation of posterior elements of the spine there is no possibility of adequate derotation scoliotic vertebrae arc and require extensive fixation of the spine (Th2-L4), significantly reducing the functional activity of the patients. The lack of the fusion is accompanied by system micromotion, causes the instability of the upper pole of the metal construction and provokes the formation of a fistula. The presence of fibrous scar, and later - bone block, doesn’t allow to realize the lengthening effect during the patient’s growth and causes the development of Crankshaft-phenomenon, the correction of which requires a long, traumatic, multi-stage surgery

Thermally Stable Ln(II) and Ca(II) Bis(benzhydryl) Complexes: Excellent Precatalysts for Intermolecular Hydrophosphination of C-C Multiple Bonds

International audienceA series of Ln(II) and Ca(II) bis(alkyl) complexes with bulky benzhydryl ligands, [(p-tBu-C6H4)(2)-CH](2)M(L-n) (M = Sm, L = DME, n = 2 (1); M = Sm, Yb, Ca, L = TMEDA, n = 1 (2, 3, 4), were synthesized by the salt-metathesis reaction of MI2(THF)(n) (n = 0-2) and [(p-tBu-C6H4)(2)CH]Na--(+). In complex 1, the benzhydryl ligands are bound to the metal center in eta(2)-coordination mode. Unlike complex 1, in isomorphous complexes 3 and 4, due to the coordination unsaturation of the metal center, the both benzhydryl ligands coordinate to the metal in eta(3)-fashion. In complex 2, one ligand is eta(3)-coordinated while the second one is eta(4)-coordinated to the Sm(II) ion. Complexes 2-4 demonstrated unprecedented thermal stability: no evidence of decomposition was observed after heating their solutions in C6D6 at 100 degrees C during 72 h. Complex 1 behaves differently: thermolysis in C6D6 solution at 75 degrees C results in total decomposition in 8 h. Addition of DME promotes decomposition of 2-4 and makes it feasible at 40 degrees C. Complexes 1-4 demonstrated high catalytic activity and excellent regio- and chemoselectivities in intermolecular hydrophosphination of double and triple C-C bonds with both primary and secondary phosphines. Complexes 2 and 3 enable addition of PhPH2 toward the internal C=C bond of Z- and E-stilbenes with 100% conversion under mild conditions. Double sequential hydrophosphination of phenylacetylene with Ph2PH and PhPH2 was realized due to the application of Yb(II) complex as a catalyst

Alternative (kappa(1)-N:eta(6)-arene vs. kappa(2)-N,N) coordination of a sterically demanding amidinate ligand: are size and electronic structure of the Ln ion decisive factors?

International audienceThe amine elimination reaction of equimolar amounts of ansa-bis(amidine) C6H4-1,2-{NC(tBu)NH(2,6-iPr(2)C(6)H(3))}(2) ((LH)-H-1) and [(Me3Si)(2)N](2)Yb(THF)(2) affords a bis(amidinate) Yb-II complex [C6H4-1,2-{NC(tBu)N(2,6-iPr(2)C(6)H(3))}(2)]Yb(THF) (1) in 68% yield. Complex 1 features a rather rare eta(1)-amido:eta(6)-arene coordination of both amidinate fragments to the Yb-II ion, resulting in the formation of a bent bis(arene) structure. Oxidation of 1 by I-2 regardless of the molar ratio of reagents (2 : 1 or 1 : 1) leads to the formation of the Yb-III species [{(2,6-iPr(2)C(6)H(3))NC(tBu)NH}-C6H4-1,2-{NC(tBu)N(2,6-iPr(2)C(6)H(3))}]YbI2(THF)(2) (2) in which only one amidinate fragment is coordinated to the ytterbium ion in kappa(2)-N,N '-chelating coordination mode, while the second NCN fragment is protonated in the course of the reaction and is not bound to the metal ion. The outcome of the salt metathesis reaction of LaCl3 with lithium amidinates [C6H4-1,2-{NC(tBu)N(2,6-R2C6H3)}(2)Li-2] (R = Me, iPr) is proven to be strongly affected by the substituent 2,6-R2C6H3 on the amidinate nitrogens. When R = iPr, the salt metathesis reaction occurs smoothly and results in the formation of an ate-chloro-amidinate complex [C6H4-1,2-{NC(tBu)N(2,6-iPr(2)C(6)H(3))}(2)]La(mu(2)-Cl)Li(THF)(mu(2)-Cl)(2)Li(THF)(2) (3) in which the La-III ion is coordinated by both amidinate fragments in a "classic" kappa(2)-N,N '-chelating fashion. In the case of R = Me, the reaction requires prolonged heating for completion. Moreover, the salt metathesis reaction is accompanied by the fragmentation of the ligand and affords a trinuclear chloro-amidinate complex [C6H4-1,2-{NC(tBu)N(2,6-Me2C6H3)}(2)]La{[(tBu)C(N-2,6-Me2C6H3)(2)]La(THF)}(2)(mu(2)-Cl)(4)(mu(3)-Cl)(2) (4) containing one dianionic ansa-bis(amidinate) and two monoanionic [(tBu)C(N-2,6-Me2C6H3)(2)] amidinate fragments. DFT calculations are conducted to determine the factor that governs this change in coordination mode and, in particular, the effect of the metal oxidation state

Chloro and Alkyl Rare-Earth Complexes Supported by <i>ansa</i>-Bis(amidinate) Ligands with a Rigid <i>o</i>‑Phenylene Linker. Ligand Steric Bulk: A Means of Stabilization or Destabilization?

<i>ansa</i>-Bis­(amidinate) ligands with a rigid <i>o</i>-phenylene linker, C₆H₄-1,2-{NC­(<i>t</i>Bu)­N­(2,6-R₂C₆H₃)­H}₂ (R = Me (<b>1</b>), <i>i</i>Pr (<b>2</b>)), were successfully employed for the synthesis of rare-earth chloro and alkyl species. The reaction of dilithium derivatives of <b>1</b> and <b>2</b> with LnCl₃ (Ln = Y, Lu) afforded the monomeric bis­(amidinate) chloro lanthanide complexes [C₆H₄-1,2-{NC­(<i>t</i>Bu)­N­(2,6-R₂C₆H₃)}₂]­Y­(THF)­(μ-Cl)₂Li­(THF)₂ (R = Me (<b>3</b>), <i>i</i>Pr (<b>5</b>)) and [C₆H₄-1,2-{NC­(<i>t</i>Bu)­N­(2,6-Me₂C₆H₃)}₂]­LuCl­(THF)₂ (<b>4</b>). Bis­(amidinate) ligands in complexes <b>3</b> and <b>4</b> are coordinated to the metal atoms in a tetradentate fashion, while the bulkier ligand in <b>5</b> is tridentate. The alkane elimination reactions of <b>1</b> and <b>2</b> with equimolar amounts of (Me₃SiCH₂)₃Ln­(THF)₂ (Ln = Y, Lu) allowed us to obtain the monoalkyl complexes [C₆H₄-1,2-{NC­(<i>t</i>Bu)­N­(2,6-R₂C₆H₃)}₂]­Ln­(CH₂SiMe₃)­(THF)_<i>n</i> (Ln = Y, R = Me, <i>n</i> = 1 (<b>6</b>); Ln = Lu, R = Me, <i>n</i> = 1 (<b>7</b>); Ln = Y, R = <i>i</i>Pr, <i>n</i> = 2 (<b>8</b>)). The kinetics of thermal decomposition of complexes <b>6</b>–<b>8</b> were measured, and for <b>6</b> the activation energy was obtained from the temperature dependence of the rate constants (<i>E</i>_a = 67.0 ± 1.3 kJ/mol). Complexes <b>6</b> and <b>7</b> turned out to be inert toward H₂ and PhSiH₃. Surprisingly, complex <b>8</b> was inert toward H₂ and PhSiH₃ but rapidly cleaved C–O bonds of DME. The reaction resulted in the formation of the methoxy complex {[C₆H₄-1,2-{NC­(<i>t</i>Bu)­N­(2,6-<i>i</i>Pr₂C₆H₃)}₂]­Y­(μ₂-OMe)]}₂(μ₂-DME) (<b>9</b>) and methyl vinyl ether