[Efficacy of polyetheretherketone rod hybrid surgery in preventing proximal junctional failure after adult spinal deformity surgery].

Objective: To investigate the clinical outcome and preventive effect of polyetheretherketone(PEEK) rod hybrid surgery on proximal junction failure(PJF) after long-segment fusion of adult spinal deformity. Methods: A retrospective study was conducted to analyze patients with degenerative scoliosis/kyphosis who underwent long-segment decompression and fusion surgery at Department of Orthopedics, Peking University First Hospital from January 2017 to December 2021. A total of 75 patients were included in the study, including 14 males and 61 females, aged (67.2±6.8)years (range:55 to 84 years). According to the operation method chosen by the patients, the patients were divided into PEEK rod hybrid group (20 cases) and traditional titanium rod group (55 cases). The general information of the patients was collected, and the coronal and sagittal parameters of the spine were measured before operation, at 1 month after operation, and at the last follow-up. The clinical effect of surgery was judged by the visual analogue scale (VAS) and Oswestry disability index (ODI). Whether proximal junctional kyphosis (PJK) and PJF occurred during the follow-up and the time of occurrence were recorded. Comparisons between groups were performed using independent sample t test, Mann-Whitney U test, χ2 test and Fisher's exact probability method. The data before and after surgery in the same group were compared using the paired sample t test and the Wilcoxon test. Results: There were no significant differences in age, gender, body mass index, bone mineral density, distal instrumented vertebrae, surgical segments, osteotomy method, operation time, and intraoperative bleeding between the two groups (all P>0.05). The follow-up time of the PEEK rod group was shorter(M(IQR)16.5(4.8) vs. 25.0(12.0),Z=-4.230,P<0.01). There were no significant differences in coronal, sagittal parameters, VAS and ODI between the two groups before operation (all P>0.05). Postoperative coronal Cobb angle, pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis, thoracic kyphosis, sagittal vertical axis (SVA), VAS and ODI were significantly improved in both groups(all P<0.05). At the last follow-up, the SVA of the PEEK rod hybrid group was(3.74±2.40)cm, which was significantly lower than that of the titanium rod group (6.28±4.06)cm (t'=-3.318, P=0.002). At the last follow-up, the ODI of the PEEK rod hybrid group was 30.7±6.1, significantly better than the titanium rod group 39.3±17.2(t=-3.203, P=0.046). PJK occurred in 2 patients (10.0%) in the PEEK rod hybrid group, and no PJF phenomenon was observed. In the titanium rod group, 18 patients (32.7%) developed PJK, and 11 patients (20.0%) developed PJF. There was a statistically significant difference in the incidence of PJF between the PEEK rod hybrid group and the titanium rod group (P=0.031). Conclusions: PEEK rod hybrid surgery can achieve good clinical results in the treatment of adult spinal deformities. Compared with traditional titanium rod surgery, it can significantly reduce the incidence of postoperative PJF and improve the clinical function of patients.

[Anterior cervical discectomy and fusion to treat cervical spondylosis with sympathetic symptoms].

OBJECTIVE: To investigate the clinical effectiveness of polytheretherketone (PEEK) cages assisted anterior cervical discetomy and fusion (ACDF) to treat cervical spondylosis with sympathetic symptoms. METHODS: Retrospective analysis was undertaken for 39 patients who were diagnosed as cervical spondylosis with sympathetic symptoms and underwent ACDF with PEEK cages. Radiographs obtained before surgery, after surgery, and at the final follow-up were assessed for quality of fusion. The following criteria were used for assessing radiographic success of fusion: (1) endplate obliterated with no lucent lines; (2) obliteration of disc space by bony trabeculae; (3) less than 2°of intervertebral motion or 2 mm of motion between the spinous processes at the operated segment on flexion-extension lateral radiographs. The sympathetic symptoms including vertigo, headache, tinnitus, nausea and vomiting, heart throb, hypomnesia and gastroenterological discomfort were scored by 20-point system preoperatively, 2 months postoperatively and at the final follow-up. The recovery rate and clinical satisfaction rate were also evaluated. Surgical complications were also assessed. RESULTS: They were followed up for at least one year. The mean follow-up was 15.6 months. Radiographs of the cervical spine at the last follow-up revealed a solid fusion with no signs of a pseudoarthrosis in 36 cases. In two patients delayed union and bony fusion were achieved at the end of 9 and 11 months. Pseudoarthosis was found in 1 case but the patient had no symptoms. The score of sympathetic symptoms before surgery, 2 months after surgery and at the final follow-up were 8.4±1.0,2.2±0.3,and 2.4±0.3, respectively. There were 22 excellent cases, 15 good cases, 1 fair case and 1 bad case in terms of RR. Good to excellent results were attained in 95% of theses patients. The sympathetic symptoms improved in all the patients and the score was significantly improved after surgery. There was one patient who had cerebral spinal fluid leakage but he recovered one week after surgery. Two patients felt a mild swallowing discomfort, but it disappeared within one month after surgery. Subcutaneous hematoma occurred in one patient due to obstructed drainage. It was cleared two days after surgery. CONCLUSION: Cervical spondylosis patients with sympathetic symptoms may be managed successfully with ACDF using PEEK cages. Successful clinical results regarding symptom improvement and general satisfaction with the surgical procedure depend not only on obtaining successful decompression and radiographic fusion but also on patient selection.

[Polymethylmethacrylate augmentation of bone cement injectable cannulated pedicle screws was used to treat degenerative lumbar scoliosis with osteoporosis].

OBJECTIVE: To describe the application of polymethylmethacrylate (PMMA) augmentation of cement-injectable cannulated pedicle screws for the treatment of degenerative lumbar scoliosis with osteoporosis. METHODS: Retrospective cohort study was used to compare cement injectable cannulated pedicle screws (CICPs) group with PMMA augmentation and control group with traditional method in the correction surgery for Lenke-silva level III and level IV degenerative scoliosis cases with osteoporosis. Both groups were followed up for 1 year. The clinical results were assessed by visual analog scale (VAS) of pain on lumbar and lower limbers, Oswestry disability index (ODI) score and EuroQol-5 dimensions (EQ-5D) score. The coronal major curve Cobb angel in coronal plane and thoracic kyphosis Cobb angle, lumbar lordosis Cobb angle and sagittal vertical axis (SVA) in sagittal plane were tested in whole long spine X ray. The fusion rates were evaluated by lumbar X ray and dynamic X ray. RESULTS: In this study 34 cases were enrolled, 15 cases in CICPs group and 19 cases in control group. The general characteristics including age, gender, weight, height, BMI and BMD were without statistical difference between the two groups. There were (5.7±2.2)PMMA augmentation screws in CICPs group. The operation time, blood loss and blood transfusion were higher in CICPs group than in control group, but without statistical difference. Lumbar VAS, lower limbers VAS, ODI score and EQ-5D were all better in 1 month postoperation, 6 months postoperation and 1 year postoperation than in preoperation in both groups. lumbar VAS scores of CICPs group in 6 months postoperation (CICPs group 3.1±1.3 vs. control group 4.4±1.4, P<0.01) together with lumbar VAS scores (CICPs group 3.3±1.0 vs. control group 5.2±1.4, P<0.01), ODI scores (CICPs group 22.7±17.2 vs. control group 31.4±18.5, P<0.01) and EQ-5D in 1 year postoperation (CICPs group 2.9±2.0 vs. control group 3.5±2.5, P<0.01)were lower than those of control group. The coronal major curve Cobb angels were all lower in 1 month postoperation, 6 months postoperation and 1 year postoperation than in preoperation in both groups; thoracic kyphosis Cobb angle and lumbar lordosis Cobb angle were all higher in 1 month postoperation, 6 months postoperation and 1 year postoperation than in preoperation in both groups. The coronal major curve Cobb angel was lower in CICPs group than that in control group in 1 year postoperation (CICPs group 17.6°±6.9° vs. control group 21.2°±7.2°, P<0.01)and thoracic kyphosis Cobb angle was higher in CICPs group than that in control group in 6 months postoperation (CICPs group -33.5°±8.8 ° vs. control group -28.9°±8.3°, P<0.01) and 1 year postoperation (CICPs group -33.0°±8.1° vs. control group -26.3°±7.4°, P<0.01) together with lumbar lordosis Cobb angle were higher in CICPs group than that in control group in 1 year postoperation (CICPs group 26.4°±8.1° vs. control group 22.1°±7.3°, P<0.01). CONCLUSION: Polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws for the treatment of degenerative lumbar scoliosis with osteoporosis was effective and safe, the short-term clinical result was good.

[Polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws for the treatment of degenerative lumbar diseases with osteoporosis].

OBJECTIVE: To describe the application of polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws for the treatment of degenerative lumbar diseases with osteoporosis. METHODS: Observation group included 14 cases of degenerative lumbar diseases with osteoporosis received polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws from November 2014 to July 2015, control group included 12 cases of degenerative lumbar diseases with osteoporosis received polymethylmethacrylate augmentation with traditional pedicle screws.The operation time, blood loss, number of pedicle screws and number of augmented pedicle screws in the two groups were compared. The bone cement leakage and pulmonary bone cement embolism in the two groups were also compared. The fusion rate and pedicle screws loosening by lumbar X ray and dynamic X ray were evaluated. The clinical results were assessed by visual analog scale (VAS) of pain on lumbar and lower limbers, lumbar Japanese Orthopaedic Association scores (JOA), Prolo functional scores and Oswestry disability (ODI) scores. RESULTS: Differences of operation time and blood loss in the two groups were not statistically significant. The average number of pedicle screws was 9.9±4.7 and the average number of augmented pedicle screws was 5.9±2.6 in observation group while the average number of pedicle screws was 7.1±2.8 and the average number of augmented pedicle screws was 3.0±1.9 in control group. The ratio of augmented pedicle screws was higher in observation group than in control group (0.69±0.30 vs.0.47±0.30,P<0.05). The bone cement leakage rate was lower in observation group than in control group (5/83 vs. 12/42, P<0.01). All the cases in observation group were without leakage to the interspinal canal while one case in control group suffered from bone cement leakage to the interspinal canal with augmentation of 3 pedicle screws. The follow up period was (10.6±2.3) months in observation group and (36.5±7.2) months in control group. In final follow up, no case with non-fusion or pedicle screws loosening was found in both groups. Lumbar VAS, lower limbers VAS, lumbar JOA scores, Prolo functional scores and ODI scores were all better than pre-operation (P<0.01). CONCLUSION: Polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws for the treatment of degenerative lumbar diseases with osteoporosis was effective, with simple working processes and lower risk of bone cement leakage. The short-term clinical result was good.

[Analysis of the clinical outcomes of the over 5-year follow-up study of degenerative lumbar scoliosis treated with posterior decompression and instrumented fusion].

OBJECTIVE: To evaluate the over 5-year follow-up clinical outcomes of degenerative lumbar scoliosis treated with operation of decompression and fusion, and the effectiveness and risks factors about revision surgery cases. METHODS: A total of 47 cases of diagnosis of degenerative lumbar scoliosis treated with posterior decompression and instrument fusion recorded from Jun. 2003 to Jun. 2008 were analyzed. Lumbar Japanese Orthopedic Association (JOA) score and visual analogue score (VAS) were applied to evaluate the improvement of the clinical effect after surgery treatment, and the clinical effect and reasons of revising operation were recorded and analyzed. RESULTS: All the 47 patients had finished the over 5-year followed-up time with an average time of (8.2±3.6) years (range from 5.2 years to 12.5 years). The patient's mean age was (67.0±9.6) years and the age of patient range from 56 years to 81 years. There were 10 patients who underwent revision surgery since primary operation, in whom 8 cases because of proximal failure of internal fixation and the other 2 cases because of distal failure of fusion segment. The average clinical improvement excellent rate was 83.3% after 5 years since primary operation of 37 cases while the average fine rate of revision operation was 67.6%. CONCLUSION: In the over 5-year follow-up, there was a better clinical outcome of degenerative lumbar scoliosis treated with posterior decompression and instrumented fusion, which had a certain rate of revision operation and had a worse effect of clinical results compared with primary operation. The risks of revision surgery included the poor bone quality of patients, with fusion to L1 at proximal terminal and the fusion end to S1 at distal terminal.

[Clinical research of percutaneous vertebroplasty or percutaneous kyphoplasty for treating osteoporotic vertebral compression fractures induced by glucocorticosteroid].

OBJECTIVE: To investigate the clinical characteristics of vertebral compression fracture (VCF) in glucocorticosteroid-induced osteoporosis (GIOP) and risk of vertebral refracture after percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP). METHODS: In the study, 570 cases who received PVP or PKP as treatments of VCF from January 2010 to December 2013 were retrospective reviewed, of which 42 were GIOP and 21 were followed up as GIOP group, and the other 528 were primary osteoporosis and 391 were followed up, of which 84 were selected as Control group based on age and gender. The fracture location, ratio of single segment fracture and multiple segments fracture in the two groups were compared. In the final follow up, the reoperation rates for vertebral refractures by the Kaplan-Meier method in the two groups were compared. RESULTS: The follow up periods were (24.0± 13.1) months in GIOP group and (25.8±14.4) months in control group(P>0.05). In GIOP group, there were 11 cases with one-segment fracture, 2 with two-segments fracture, 3 with three-segments fracture, 2 with four-segments fracture, 2 with five-segments fracture and 1 with eight-segments fracture. In Control group, there were 67 cases with one-segment fracture, 12 with two-segments fracture, 3 with three-segment fracture, and 2 with four-segments fracture. The ratio of single segment fracture in GIOP group was significantly lower than that in Control group(52.4% vs. 79.8%,P=0.01). There were 50 fracture segments in GIOP group and 109 fracture segments in Control group. The ratios of fracture segments located in thoracic segments(T1-T10), thoracolumbar segments(T11-L1)and lumbar segments(L2-L5)were 18%, 46% and 36% in GIOP group and 11.9%, 58.7% and 29.4% in Control group (P>0.05). The refracture rate in GIOP group was higher than that in control group (23.8% vs. 6.0%). The survival rate was lower in GIOP group than that in control group (P<0.01). CONCLUSION: The predilection site of VCF was similar in GIOP and primary osteoporosis (thoracolumbar segments> thoracic segments> lumbar segments). The risk of multiple segments VCF was higher in GIOP than in primary osteoporosis. The risk of vertebral refractures after PVP or PKP was higher in GIOP than in primary osteoporosis.

New chiral catalysts for reduction of ketones.

The condensation of o-(diphenylphosphino)benzaldehyde and various chiral diamine gives a series of diimino-diphosphine tetradentate ligands, which are reduced with excess NaBH4 in refluxing ethanol to afford the corresponding diaminodiphosphine ligands in good yield. The reactivity of these ligands toward trans-RuCl2(DMSO)4 and [Rh(COD)Cl]2 had been investigated and a number of chiral Ru(II) and Rh(I) complexes with the PNNP-type ligands were synthesized and characterized by microanalysis and IR, NMR spectroscopic methods. The chiral Ru(II) and Rh(I) complexes have proved to be excellent catalyst precursors for the asymmetric transfer hydrogenation of aromatic ketones, leading to optically active alcohols in up to 97% ee.