RESUMEN
Through literature method,expert consultation method,K-means algorithm and empirical analysis method,the paper analyzes the methods for evaluation on the layout of first-aid sites,discusses the indexes for scientific evaluation on the rationality of layout of first-aid sites,conducts visualized and practical calculation based on the first-aid related data of Wuhan city in 2015,verifies the rationality and operability of the evaluation indexes,and provides reference for overall allocation of first-aid resources and rational layout of first-aid sites.
RESUMEN
BACKGROUND: The traditional posterior lumbar interbody fusion (PLIF) technique usually involves implantation of two cages through a bilateral approach and bilateral laminectomy, which requires bilateral transpedicle screw fixation. The procedure itself has several negative impacts. Therefore, a modified PLIF procedure that includes insertion of a unilateral cage through the symptomatic side with supplementary unilateral pedicle screws has been conducted. MATERIALS AND METHODS: Thirty-one patients with unilateral radiculopathy who were diagnosed with spinal stenosis along with degenerative disc disease and a herniated intervertebral disc with lumbar instability underwent a unilateral PLIF using a single cage and unilateral pedicle screws. The postoperative clinical evaluation was based on the visual analogue scale (VAS) and the Oswestry Disability Index (ODI) for back pain and leg pain at multiple time points following the surgery. Radiological assessments were performed with lateral plain radiographs taken preoperation, immediately postoperation, 1, 2, 3 and 6 months postoperation and at the most recent follow-up. RESULTS: The patients all underwent a single-level fusion, and the mean duration for the surgeries was 94 min. The mean haemorrhage volume was 250 ml, and no blood transfusion was required for any of the cases. Twelve months postoperatively, all patients had achieved an Excellent or Good outcome (Excellent in 28 patients and Good in 3). The mean pain score was 6.8 prior to surgery and decreased to 2.3 at the 3-month postoperative examination. No significant complications or neurological deterioration occurred. None of the 31 patients appeared to have any fusion failure. No broken screw, screw loosening, significant cage migration or subsidence was observed in any of the cases. A mean increase in the intervertebral disc height of 3.14 mm from the preoperative measurement to the most recent follow-up examination was determined to be statistically significant (p = 0.05). CONCLUSIONS: Conducting PLIF using the diagonal insertion of a single cage with supplemental unilateral transpedicular screw instrumentation enables sufficient decompression and solid interbody fusion to be achieved with minimal invasion of the posterior spinal elements. This technique is a more clinically secure, straightforward and cost-effective way to perform PLIF.
Asunto(s)
Desplazamiento del Disco Intervertebral/cirugía , Vértebras Lumbares/cirugía , Tornillos Pediculares , Fusión Vertebral/métodos , Estenosis Espinal/cirugía , Anciano , Femenino , Humanos , Desplazamiento del Disco Intervertebral/diagnóstico por imagen , Vértebras Lumbares/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Radiculopatía/diagnóstico por imagen , Radiculopatía/cirugía , Radiografía , Estudios Retrospectivos , Fusión Vertebral/instrumentación , Estenosis Espinal/diagnóstico por imagenRESUMEN
BACKGROUND:Operative approaches of lumbar interbody fusion include anterior (ALIF),posterior (PLIF) and transforaminal lumbar interbody fusion (TLIF).The resected structures and cage implantation sites are different,and the initial stability of lumbar spine is varied.OBJECTIVE:To compare the initial stability of lumbar spine following ALIF,PLIF or TLIF in combination with bilateral pedicle screw fixation.DESIGN:Comparative observation.MATERIALS:Fifteen samples of fresh calf lumbar spine were used.METHODS:Models ofALIE PLIF and TLIF were simulated.After examination as normal group,the samples were randomly divided into three groups (n=5).Besides anterior,posterior and transforaminal lumbar interbody fusion include anterior,bilateral pedicle screw fixation was performed.MAIN OUTCOME MEASURES:Biomechanical characteristics of the lumbar spine before and after ALIF,PLIF or TLIF in combination with bilateral pedicle screw fixation.RESULTS:Following three approaches of lumbar interbody fusion,the stability of lumbar spine was significantly reduced,which was enhanced after bilateral pedicle screw fixation (torsion indexes were also increased).In addition,rigidity of the lumbar spine was enhanced.The stability indexes of lumbar spine following TLIF were significantly greater than the other approaches,indicating the initial stability of TLIF was the best.The rigidity,stress,and swain of lumbar spine following PLIF were greater than ALIE but torsion indexes were smaller than ALIE CONCLUSION:The stability of lumbar spine following lumbar interbody fusion was significantly reduced compared with normal sample.But bilateral pedicle screw fixation greatly increases the stability.Among three types of lumbar interbody fusion,the initial stability of lumbar spine following TLIF is the best.
RESUMEN
BACKGROUND:Transforaminal lumbar interbody fusion(TLIF)can be applied in any lumbar segment,and retain integrity of lateral vertebral plate and zygapophysiai joints.However,few studies have been conducted about the biomechanical performance.OBJECTIVE:To explore the stability of lumbar intervertebral segment following TLIF appHed bilateral and unilateral transpedicular screws fixation.DESIGN,TIME AND SETTING:Biomechanical test was performed at the Institute of Biomechanics,Shanghai University and Nantong University between August 2005 and April 2006.MATERIALS:Twenty samples of fresh one-month-old calf lumbar vertebra.METHODS:Twenty samples of calf lumbar vertebra underwent TLIF alone,TLIF in combination with bilateral or unilateral transpedicular screws fixation.Biomechanical test was performed on spinal three dimensional motion testing machine.MAIN OUTCOME MEASURES:Stress,displacement.strain and torsion angle were recorded.RESULTS:After TLIF without fixation.no obvious changes were found in mean stress and strain,but the axes stiffness and rotational stiffness were significantly decreased,indicating TLIF could produce immediate lumbar stability.After TLIF with unilateral or bilateral transpedicular screws fixation,the lumbar stability was significantly enhanced compared with TLIF alone,especially bilateral transpedicular screws fixadon.Although the lumbar stability following unilateral transpedicular screws fixation was inferior to bilateral fixation,it was still greatly enhanced,even bxceeded normal sample,indicating TLIF with unilateral transpedicular screws fixation could produce enough initiallumbar stability.CONCLUSION:TLIF alone cannot support sufficient initial stability,but TLIF with bilateral and unilateral transpedicular screws fixation can enhance lumbar initial stability.