Injury characteristics and surgical treatment of lower lumbar vertebral burst fractures / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the feasibility of utilizing self-designed score system for lower lumbar vertebral burst fractures to select surgical approach.</p><p><b>METHODS</b>From January 2006 to December 2011, the clinical data of 56 patients with lower lumbar vertebra burst fractures who underwent surgical treatment were retrospectively analyzed. There were 42 males and 14 females with an average age of 43.1 years old (ranged, 19 to 65). Causes of injury included falling down (40 cases), traffic accidents (12 cases), and crashing injury by heavy objects(4 cases). Injury site was L3 in 37 cases, L4 in 16 cases, and L5 in 3 cases. According to the AO classification, 17 cases were type A3.1, 14 cases were type A3.2, 25 cases were type A3.3. According to Frankel grade of nerous function, 2 cases were grade B, 5 cases were grade C, 9 cases were grade D and 40 cases were grade E. Surgical methods and approaches were chosen based on the comprehensive evaluation of AO classification, condition of posterior column injury and spinal canal encroachment. Surgical methods and approaches included trans-vertebra fixation (15 cases), intra-vertebra pedicle screw fixation (21 cases), combination of anterior and posterior approaches (11 cases), one-stage posterior approaches (9 cases). Cobb angles, restorations of the affected vertebral anterior border height, and conditions of spinal canal encroachment were compared before and after surgery. Conditions of bone graft fusion and internal fixation (if bending, loosening or breakage existed) were observed. Spinal cord functions were assessed according to Frankel grade. Localized pain and working status of patients were also assessed at the last follow-up.</p><p><b>RESULTS</b>No incision infection was found and no spinal nerve symptoms improved in all of 56 patients. All patients were followed up for 12 to 60 months with a mean of 28.5 months, without internal fixation loosening or breakage. There was significant differences in Cobb angle, vertebral anterior border height and recovery of spinal canal encroachment between preoperative and postoperative instantly (P < 0.05), however, there was no significant difference between postoperative instantly and final follow-up (P > 0.05). Thirteen cases obtained fusion by trans-vertebra fixation, 20 cases obtained fusion by intra-vertebra fixation, and 20 cases were treated by the combination of anterior and posterior approaches or one-stage posterior approaches all of patients obtained fusion. Spinal nervous function recovered I to II grade, 1 case was grade C, 3 cases were grade D, 52 cases were grade E. Localized pain was assessed as P1 in 52 cases, P2 in 3 cases, and P3 in 1 case. Working status was classified into W1 in 12 cases, W2 in 39 cases, and W3 in 5 cases.</p><p><b>CONCLUSION</b>The lower lumbar vertebra and thoracolumbar junction exhibit different injury characteristics due to variations in anatomy and biomechanics. A comprehensive score of the AO classification, posterior column injury and degree of spinal canal encroachment will guide the selection of surgical method and approach for the treatment of lower lumbar vertebra burst fractures.</p>

Surgical treatment of thoracolumbar fractures using pedicle screws fixation at the level of the fracture: results for following up more than 2 years / 中国骨伤

<p><b>OBJECTIVE</b>To explore clinical efficacy of thoracolumbar fractures fixation with pedicle screws fixation at the level of the fracture and monosegment bone graft simultaneously.</p><p><b>METHODS</b>Retrospective analysis of 32 patients with thoracolumbar fractures underwent surgical procedure of pedicle screws fixation at the level of the fracture and monosegment bone graft simultaneously from January 2006 to December 2008. All the patients were followed up more than two years. There were 25 males and 7 females with an average age of 39.1 years (ranged, 25 to 60 years). According to the AO classification, type A1.3 was in 5 cases, type A3.1 in 17, type A3.3 in 8, type C1.1 in 1, and type C1.3 in 1. Load scoring was from 4 to 7 points with average of 5.8 points. The spinal cord function according to Frankel grade, grade A was in 2 cases, grade B in 2, grade C in 5, grade D in 9 and grade E in 14. Cobb angle, the height of anterior border of vertebral body, spinal canal stenosis rate were observed by X-ray films. Meanwhile, pain and work ability were evaluated by Denis scale.</p><p><b>RESULTS</b>All the patients were followed-up from 30 to 48 months (averaged, 39.2 months). No internal fixation loosening or breakage were found. Three cases occurred with floating callus and other obtained well bone fusion. Compared with preoperation, Cobb angle, the height of anterior border of vertebral body, and spinal canal stenosis rate improved obviously (P < 0.05); but Cobb angle had lost partially at the last follow-up (P > 0.05). Meanwhile, anterosuperior part of vertebral body of 25 cases existed cavity phenomenon. The nerve function of all cases recovered for 1-2 grades, except for 2 cases without change whose spinal cord function was degree A preoperatively. According to Denis scale, lower back pain scoring, P1 was in 22 cases, P2 in 7, P3 in 3; state of work scoring, W1 was in 18 cases, W2 in 8, W3 in 3, W5 in 3.</p><p><b>CONCLUSION</b>It can help to correct the kyphosis and improve low back pain in thoracolumbar fractures through pedicle screws fixation at the level of the fracture and monosegment bone graft simultaneously, but it can not improve the cavity phenomenon of injured vertebral body and avoid partially lost of Cobb angle.</p>

Direct repair of adolescent lumbar spondylolysis using a pedicle screw-laminar hook system by paramedian approach / 中国骨伤

<p><b>OBJECTIVE</b>To discuss the indication and clinical effect of direct repair of adolescent lumbar spondylolysis by screw-laminar hook system.</p><p><b>METHODS</b>From August 2003 to December 2008, 28 patients (13 males and 15 females,ranging in age from 15 and 26 years, averaged 21.6 years) with lumbar spondylolysis were treated with isthmic bone grafting and internal fixation with a pedicle screw-laminar hook system. Three patients had spondylolysis at L3, L4; 5 patients had spondylolysis at L4, L5; 8 patients had spondylolysis at L4; and 12 patients had spondylolysis at L5. All the patients had low back pain and lasted over 6 months. According to preoperative and postoperative plain radiograph, CT scan and Macnab criteria, the fusion rate and clinical effect of this technique were evaluated.</p><p><b>RESULTS</b>All the patients were followed up with a mean period of 14.9 months, ranging from 9 to 24 months. All the patients had bony union according to the X-rays and CT scan. According to the calculation results of Macnab criteria, 22 patients got an excellent result, 5 good and 1 fair.</p><p><b>CONCLUSION</b>The direct repair of adolescent lumbar spondylolysis with pedicle screw-laminar hook system can shorten length of operation,decrease blood loss, preserve more posterior structures of spine and avoid iatrogenic instability of spine. The postoperative immediate stability of vertebral segment is acquired and the mobility of adjacent intervertebral discs is reserved. The screw-laminar hook system for the treatment of adolescent spondylolisthesis can get satisfactory clinical results.</p>

Clinical control study in treating degenerative lumbar instability with single or double carbon fiber cages / 中国骨伤

<p><b>OBJECTIVE</b>To compare the clinical and radiologic effect in treating degenerative lumbar instability with single or double carbon fiber cages.</p><p><b>METHODS</b>From November 2005 to October 2006, 97 patients of degenerative lumbar instability were followed up more than two years. All cases underwent pedicle screw fixation. Meanwhile, 41 of them, named group A, were applied with single carbon fiber cage, with 23 males and 18 females, aged for 35-70 years, including 38 cases with single vertebral instability and 3 cases with existing L4.5 and L5S1 intervertebral instability. The other 56 cases, named group B, were treated with two carbon fiber cages, with 32 males and 24 females, aged for 33-72 years, including 53 cases with single vertebral instability and 3 cases existing L4.5 and L5S1 intervertebral instability. The clinical effect, intervertebral fusion ratio and lost intervertebral height were compared between two groups.</p><p><b>RESULTS</b>All patients were followed up for 24-35 months, with an average of 28 months. Clinical effects (including symptom, sign, daily action and bladder function) were evaluated according to JOA 29 score. In group A: the JOA score improve from 10.11 +/- 2.40 preoperative to 24.88 +/- 2.30 at final follow-up, 25 cases obtained excellent results, 12 good, 4 fair; 39 cases obtained fusion with the fusion ratio of 95.1% (39/41). In group B: the JOA score from 9.62 +/- 2.60 preoperative to 25.19 +/- 2.40 at final follow-up, 37 cases obtained excellent results, 13 good, 6 fair; 53 cases obtained fusion with the fusion ratio of 94.6% (53/56). In the 7th day after operation, the average intervertebral height in group A was (11.2 +/- 1.2) mm,and that of group B was (11.3 +/- 1.4) mm. Two years later, the average intervertebral height in group A was (11.0 +/- 1.4) mm, while that of group B was (11.1 +/- 1.4) mm. There was no significant difference between two groups in clinical effect, intervertebral fusion ratio and lost intervertebral height (P > 0.05).</p><p><b>CONCLUSION</b>Pedicle screw fixation and single or double carbon fiber cages in treating degenerative lumbar instability both can obtain satisfactory curative effect. Single carbon fiber cage has advantages such as minimally trauma, simply operation, retentively posterior column structure, cheaply price than double carbon fiber cages.</p>