Percutaneous short segment pedicle screw fixation with vertebral augmentation for the treatment of single level thoracolumbar osteoporosis fracture / 中国骨伤

<p><b>OBJECTIVE</b>To explore the safety and clinical effects of percutaneous vertebroplasty and pedicle screw fixation in treating osteoporotic thoracolumbar burst fracture.</p><p><b>METHODS</b>From April 2011 to April 2014, 32 patients with osteoporotic thoracolumbar burst fracture were treated with percutaneous vertebroplasty and pedicle screw fixation. There were 13 males and 19 females, aged in ranging from 60 to 73 years old(averaged 65.6 years). All fractures were single thoracolumbar fracture and 4 cases located on T₁₁, 9 on T₁₂, 16 on L₃; and 3 on L₂. Cobb angle, vertebral anterior compression rate, vertebral posterior compression rate, spinal canal occupying ratio were compared, visual analogue scale (VAS) and Oswestry Disability Index(ODI) were analyzed before and after operation.</p><p><b>RESULTS</b>The mean operation time was 65.7 min(ranged, 60 to 120 min) and blood loss was 25.2 ml (ranged, 20 to 50 ml). The operative incisions obtained primary healing. All patients were followed up from 12 to 48 months with an average of 20.6 months. Vertebral anterior compression rate and vertebral posterior compression rate were respectively corrected from preoperative (49.70±5.89)%, (17.36±4.11)% to (6.00±2.10)%, (5.48±1.65)% at 2 d after operation, and (6.06±1.57)%, (5.68±1.82)% at last follow up. Cobb angle and spinal canal occupying ratio were respectively corrected from preoperative (13.34±3.56)°, (22.77±5.83)% to(2.86±0.95)°, (5.02±1.93)% at 2 d after operation, and (3.04±0.94)°, (5.15±1.93)% at last follow up. VAS and ODI were respectively decreased from preoperative (6.84±0.88)points, (77.50±5.10)% to(1.94±0.72) points, (17.94±4.82)% at 2 d after operation, and (1.63±0.83) points, (15.63±5.19)% at last follow up. Cement leakage occurred in 3 cases. No internal fixation failure and intractable lower back pain were found.</p><p><b>CONCLUSIONS</b>Percutaneous vertebroplasty and pedicle screw fixation could restore vertebral body height, improve spinal canal occupying, correct kyphosis, relieve pain, improve life quality, and it is a safe and effective method in treating osteoporotic thoracolumbar burst fracture.</p>

Mid-term effect of unilateral pedicle screw fixation and transforaminal lumbar interbody fusion in the treatment of lumbar degenerative diseases / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the feasibility and the mid-term effects of unilateral pedicle screw fixation and transforaminal lumbar interbody fusion in treating lumbar degenerative diseases.</p><p><b>METHODS</b>From August 2005 to May 2010, 56 patients with lumbar degenerative diseases underwent lumbar posterolateral fusion,their clinical data were retrospective analyzed. The patients were divided into two groups (unilateral group and bilateral group) according to fixation methods,27 patients in unilateral group who were underwent unilateral pedicle screw fixation, including 18 males and 9 females with a mean age of (57.5 ± 7.1) years old (ranged from 41 to 66 years); and 29 patients in bilateral group who were treated with bilateral pedicle screw fixation (on the basis of the above, with contralateral vertebral pedicle screw fixation), including 19 males and 10 females with a mean age of (54.6 ± 5.1) years old (ranged from 43 to 68 years). The clinical data such as operation time, blood loss volume, hospitalization time and cost were compared between two groups. JOA score system was used to evaluate the neurological function. And fusion status and cage-related complication were also analyzed.</p><p><b>RESULTS</b>All patients were followed up from 36 to 60 months with an average of 45.8 months. No iatrogenic nerve, blood vessels or organs injury were found during operation. Operation time, blood loss volume, hospitalization time and cost in unilateral group were better than that of bilateral group (P < 0.05). There was no significant difference in JOA score between two groups (P > 0.05). Two patients in unilateral group developed with cage related complications, 1 case was cage displacement and 1 case was cage subsidence, while 2 patients in bilateral group developed with complications of no-fusion, and there was no significant differences between two groups (P = 0.58).</p><p><b>CONCLUSION</b>Unilateral pedicle screw fixation is a satisfactory method and can obtain good effects in treating lumbar degenerative diseases in mid-term, however, the indications should be well considered.</p>

Surgical treatment of thoracolumbar fractures using reduction and short-segment pedicle screw at the fracture level with the approach through para-vertebral muscles / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the efficacy and clinical outcome of reduction and pedicle screws fixation at the fracture level with the approach through para-vertebral muscles in treating thoraeolumbar fractures.</p><p><b>METHODS</b>From January 2007 to March 2010,27 patients with thoracolumbar fractures were treated with posterior open reduction and internal fixation with the approach through para-vertebral muscles. There were 19 males and 8 females with the mean age of 36.3 years old (ranged,21 to 57). According to Magerl type, type A2 was in 5 cases, A3 in 14, B1 in 3, B2 in 5. According to Frankel classification of spinal cord injury: grade D was in 6 cases and grade E in 21 cases. X-rays and CT scans were performed after operation. Cobb angle of the injured vertebral segment,the percentage of vertebral compression,and sagittal diameter stenosis rate of the injured spinal canal were observed by radiographic data. Neurological function was evaluated by the Frankel grade.</p><p><b>RESULTS</b>All patients were followed up from 12 to 28 months with an average of 19.6 months. The percentage of vertebral compression, Cobb angle of the injured vertebral segment, spinal canal sagittal diameter stenosis rate were respectively corrected from (46.6 +/- 10.5)%, (18.3 +/- 7.2) degrees, (30.2 +/- 7.2)% to postoperative (5.2 +/- 3.7)%, (5.3 +/- 5.1) degrees, (6.3 +/- 4.2)% and (6.7 +/- 4.6)%, (7.1 +/- 3.1), (7.2 +/- 4.5)% at last follow-up. There were significant difference in above items between preoperation and postoperation (P < 0.05); and there was no significant difference in above items between postoperation and last follow-up (P > 0.05). In aspect of nerve function, 3 cases with Frankel grade D recovered to grade E.</p><p><b>CONCLUSION</b>Using reduction and short-segment pedicle screws fixation at the fracture level through para-vertebral muscles approach is an effective method in treating thoracolumbar fractures. The method has advantages of simple operation,easy establishing screw, short operative time, less blood loss, which can obtain good reduction and stable, reliable fixation after operation.</p>

Pedicle screw at the fracture level and vertebroplasty via paraspinal approach for the treatment of old thoracolumbar fractures / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the feasibility and safety of the treatment for thoracolumbar fractures with pedicle screw at the fracture level and vertebroplasty via paraspinal approach.</p><p><b>METHODS</b>From August 2007 to August 2010, 22 old patients with thoracolumbar fractures were treated with pedicle screw at the fracture level and vertebroplasty via paraspinal approach. There were 14 males and 8 females, ranging in age from 60 to 71 years (mean, 64.6 years). The time from injury to surgery varied from 1 to 4 d (mean,2.7 d). All the patients suffered from single thoracolumbar fractures and located at T11 in 2 cases, at T12 in 5 cases, at L1 in 11 cases and at L2 in 4 cases. According to the Denis fracture classification, there were 6 compression fractures and 16 burst fractures. The mean preoperative load-sharing classification of spine fractures was 5.4 score. The mean preoperative thoracolumbar injury classification and scoring was 5.2. Based on the ASIA neurologic grading system, preoperative neurological function was grade B in 2 cases,grade C in 3 cases, grade D in 7 cases and grade E in 10 cases. The neurological function, vertebral central and anterior height, kyphotic angle of the vertebral fractures by radiographs and visual analog scale were calculated pre-operatively, post-operatively and at the last follow-up.</p><p><b>RESULTS</b>Median operating time was 60.8 min (ranged from 50 to 95 min) and median blood loss was 84 ml (ranged from 50 to 130 ml). The operative incisions were healed well. The duration of follow-up averaged 21.6 months (ranged from 12 to 48 months). The anterior vertebral body height was corrected from preoperative (52.3 +/- 10.3) % to postoperative (6.1 +/- 4.2) % and (6.8 +/- 5.4) % at the last follow-up. The central vertebral body height was corrected from preoperative (38.9 +/- 11.2) % to postoperative (8.3 +/- 4.7) % and (9.4 +/- 4.5)% at the last follow-up. The Cobbs angle of the injured vertebral segment was corrected from preoperative (19.5 +/- 9.5) degrees to postoperative (4.3 +/- 4.1) degrees and (6.2 +/- 4.7) degrees at the last follow-up. The VAS scores reduced from preoperative 8.56 +/- 0.88 to post-operative 3.48 +/- 0.91 and 3.20 +/- 0.92 at the last follow-up. The postoperative neurologic function of all 22 patients improved 1 to 2 degrees except 10 patients of grade E. There were no instances of instrumentation failure and no patient had persistent postoperative back pain.</p><p><b>CONCLUSION</b>The pedicle screw at the fracture level and vertebroplasty via paraspinal approach has the advantages of less invasive and blood loss, and could prevent the development of kyphosis and offers improvement of the spinal cord function. Furthermore, it could decrease the risks of postoperative back pain and the failure of instrumentation.</p>

Case-control study on the relationship between pain and knee function after the internal fixation of femoral fractures / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the relationship between pain and knee function after the internal fixation of femoral fractures.</p><p><b>METHODS</b>The clinical data of 73 patients after internal fixation on femoral fractures from June 2006 to December 2009 were retrospectively analyzed. All the patients were divided into two groups according to the degree of postoperative pain: low score group and high score group. Among the 39 patients in low score group (VAS 1 to 5 point), 25 patients were male and 14 patients were female, with a mean age of (37.5 +/- 5.3) years (ranged from 27 to 63 years ). Among 34 patients in high score group (VAS 6 to 10 point), 22 patients were male and 12 patients were female, with a mean age of (36.3 +/- 9.6) years (ranged from 29 to 62 years). The intra-articular pressure of knee and hospital for special surgery knee rating scale (HSS) were recorded and analyzed.</p><p><b>RESULTS</b>All the patients were followed up for an average duration of 24.1 months. The intra-articular pressure of knee was rising for two groups, there were significant difference for the high score group compared with the low score group at 3 days after operation (t=15.67, P=0.000) and the end time of follow up (t=5.63, P=0.000). As to knee joint function, in low score group, 21 patients got an excellent result, 4 good, 7 poor and 2 bad; in high score group, 31 patients got an excellent result, 6 good, 2 poor and no bad. The knee function of low score group was better than that of high score group.</p><p><b>CONCLUSION</b>The intra-articular pressure of knee is an important factor of the knee functional recovery, and its external symptoms of pain can be seen as an important index to forecast the prognosins of knee function in early time.</p>

Biomechanical study on thoracic spine segment fixed by pedicle screws placed with “funnel technique” / 医用生物力学

Objective To investigate mechanical properties of the thoracic spine fixed with pedicle screws that were placed using a “funnel technique”. MethodFourteen thoracic spinal segments (T6 to T10) were collected from adult cadavers. These specimens were divided into two groups, 7 in each, and fixed with pedicle screw using funnel and Magerl techniques. The displacement stiffness of the spinal segment and the pull out strength of the pedicle screw were tested for intact and fixed spinal specimens. The displacement stiffness was measured from different loading directions, including axial compression, anterior flexion, posterior extension, lateral bending and axial torsion. ResultsCompared to the intact spine segments, the displacement stiffness is significantly increased (P＜0.05) at all directions in the segments fixed with either funnel or Magerl technique; however, there is no significant difference between the groups fixed with different technique. The screw pull out strength is significantly decreased (P＜0.05) in spine segments fixed with Funnel technique compared to those fixed with Magerl technique. ConclusionsSince funnel technique removed a portion of bone from the posterior side of the vertebral pedicle, it can raise the accuracy and safety for the placement of pedicle screw. Although this technique does not affect the stiffness of fixed spinal segment, it may decrease the anchor strength of pedicle screw. Accordingly, we recommend that the funnel technique can be considered as a complement method for the fixation of vertebral fracture using pedicle screws.

Influence of positioning of the femoral tunnel for MPFL reconstruction on the isometric characteristics of grafts / 医用生物力学

Objective To explore the influence of positioning of the femoral tunnel for medial patellofemoral ligamentre (MPFL)construction on the isometric characteristics of grafts.Method Knee specimens from ten fresh frozen cadavers were used. The attachment of medial patellofemoral ligament was observed. The distance between points from the adductor tubercle, the medial femoral epicondyle, and proximal, distal and central point of the MPFL’s femoral attachment site respectively to the middle point of its patellar attachment site were measured. Changes in length were recorded while the knee was measured by angles of knee flexion (0°, 30°, 60°, 90°, and 120°). Results The length changes in every point were compared. All of the maximal length changes of its adductor tubercle: proximal points were not greater than 3 mm. There was no significant difference between the length changes of adductor tubercle and proximal points（P>0.05）. Conclusions The position of the femoral turnel for MPFL reconstruction should be located as follows: MPFL should be at the middle point of upper edge of femoral attachment site (proximal point), and the point can appropriately be shifted to adductor tubercle.

Therapeutic effects of suture anchors for the reconstruction of distal tendo achillis rupture / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the techniques and therapeutic effects of suture anchors for the reconstruction of distal tendo achillis rupture.</p><p><b>METHODS</b>The clinical data of 16 patients of distal tendo achillis rupture repaired with suture anchors from June 2005 to August 2008 were retrospectively analyzed. Among them, there were 13 males and 3 females with a mean age of 33.5 years (ranged from 17 to 46 years). The postoperative rehabilitation was conducted for every patient. The operation time, position of suture anchor and complications of the surgery were analyzed. The healing of stendo achillis and functional recovery were assessed by Arner-Lindholm standard.</p><p><b>RESULTS</b>All the patients were followed up for an average of 13.2 months. There were no complications of foreign-body reaction or re-rupture. The average operation time was 35.5 minute. There was no intraoperative injuries of blood vessels, nerves or tendons. A total of 19 suture anchors were used, and only 1 anchor was displaced. The functional recovery of tendo achillis was rated as excellent in 13 cases,good in 2 cases, bad in 1 case. All patients were satisfied with the effects on their current work and life. And no displacement of anchors was found in radiographic films.</p><p><b>CONCLUSION</b>Repairing of the distal tendo achillis rupture with suture anchors can make operation simple and quick, rigid fixation, less complications, and provide good therapeutic effects.</p>

Clinical application of "funnel technique" in planting thoracic pedicle screws / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the safety and accuracy of "funnel technique" in planting thoracic pedicle screws.</p><p><b>METHODS</b>From August 2005 to March 2008, a total of 39 patients with at least one thoracic pedicle screw in T1-T10 using "funnel technique" were retrospectively reviewed. Among the patients, 27 patients were male and 14 patients were female, with a mean age of 38.5 years (ranged from 17 to 56 years). One patient was lost follow-up, and other 1 patient was dead before follow-up. The accuracy of screw placement and the complications related to thoracic pedicle screws were analyzed by postoperative CT-scans.</p><p><b>RESULTS</b>All the patients were followed up ranging from 18 to 30 months, averaged 23.2 months. There were no vascular or viscera complications as well as iatrogenic neurologic injuries. The total number of screws was 208. There was no statistical difference between the percentage of fully contained screws at T1-T4 versus T5-T8 (P = 0.80),T5-T8 versus T9-T10 (P = 0.07), T1-T4 versus T9-T10 (P = 0.06). Twenty-seven screws (13.0%) were misplaced, 14 screws (6.7%) violated lateral cortex of pedicle, 7 screws (3.4%) medially, 5 screws (2.4%) superiorly, 1 screw (0.5%) violated lateral cortex of vertebral body. No violations occurred superiorly or anteriorly. Only 4 screws (1.9%) was a critical perforation.</p><p><b>CONCLUSION</b>The "funnel technique" is a simple, safe, accurate and cost-effective technique for pedicle screw placement. It provides even an entry-level surgeon with a safe way to identify and place thoracic pedicle screws.</p>

Isometry of grafts in PCL reconstruction under femoral tunnel shifting condition / 医用生物力学

Objective To explore the isometry of grafts in PCL(posterior cruciate ligament)double-bundle re-construction under femoral tunnel shifting condition.Method Knee specimens from ten fresh frozen cadavers were used.PCL were divided into anterolateral bundles(ALB)and posteromedial bundles(PMB)to the inser-tion footorint.The anterior,postedor,proximal,distal and central points of the two bundles'femoral attachment site were respectivelyanchored to the middle of the PCL's tibial attachment site by the trial wires.Changes in length of the intra-articular part of the wires were recorded while the knee was flexed from 0°to 120°.Result The length changes in every point were compared.All of the maximal length changes of ALB's proximal,pos-todor points and PMB's proximal points were not greater than 2mm.No significant difference between the length changes of ALB's proximal point and posterior(P=0.864>0.05)was found.Conclusions The femo-ral tunnel for the PCL double-bundle reconstruction should be located as follows:ALB should be at the middle point of upper edge of femoral attachment site(proximal point),while PIVIB at the middle point of femoral attachment site(proximal point).

Isometry of grafts in PCL reconstruction under femoral tunnel shifting condition / 医用生物力学

Objective To explore the isometry of grafts in PCL(posterior cruciate ligament)double-bundle re-construction under femoral tunnel shifting condition.Method Knee specimens from ten fresh frozen cadavers were used.PCL were divided into anterolateral bundles(ALB)and posteromedial bundles(PMB)to the inser-tion footorint.The anterior,postedor,proximal,distal and central points of the two bundles'femoral attachment site were respectivelyanchored to the middle of the PCL's tibial attachment site by the trial wires.Changes in length of the intra-articular part of the wires were recorded while the knee was flexed from 0°to 120°.Result The length changes in every point were compared.All of the maximal length changes of ALB's proximal,pos-todor points and PMB's proximal points were not greater than 2mm.No significant difference between the length changes of ALB's proximal point and posterior(P=0.864>0.05)was found.Conclusions The femo-ral tunnel for the PCL double-bundle reconstruction should be located as follows:ALB should be at the middle point of upper edge of femoral attachment site(proximal point),while PIVIB at the middle point of femoral attachment site(proximal point).

Improved EPSTR for prevention of dislocation after total hip arthroplasty / 中国骨伤

<p><b>OBJECTIVE</b>To explore the effect of improved EPSTR on prevention of dislocation after total hip arthroplasty.</p><p><b>METHODS</b>From January 2006 to May 2007, the posterior structures were repaired using improved EPSTR in 85 cases (87 hips) of total hip arthroplasty, which involved 39 males and 46 females, with an average age of 69.5 years (range, from 62 to 85 years). Fifty-eight cases were of fresh femoral neck fracture, 25 cases were of aseptic necrosis of femoral head, 3 cases were of osteoarthritis, 1 case was of a internal fixation failure of femoral intertrochanteric fracture.</p><p><b>RESULTS</b>All 85 cases were followed up for 8-24 months (average 15 months). None of these 85 patients had posterior dislocation, external rotation contracture and greater trochanter fracture. The Harris score at the 6th month postoperatively was 89.2 +/- 4.5.</p><p><b>CONCLUSION</b>Improved EPSTR is an effective, simple and timesaving method in prevention of dislocation after total hip arthroplasty, it has clinical application value.</p>

Comparison of accuracy of pedicle screw placement in the thoracic spine using funnel technique and free hand technique / 中国骨伤

<p><b>OBJECTIVE</b>To study the accuracy the pedicle screw placement in the thoracic spine using funnel technique and free hand technique.</p><p><b>METHODS</b>Eight cadavers including 5 males and 3 females were analysed. The age ranged from 57 to 82 years (mean 68 years). Cadawers were randomly assigned to one of two instrumentation groups. In four cadavers, "funnel technique" was used for screw placement. In the remaining four cadavers,free hand technique then was used. Success of pedicle screw placement was judged by CT scan. The rate of success of two ways was compared using statistic analysis.</p><p><b>RESULTS</b>Ninety-six screws were inserted by "funnel technique" and free hand technique respectively, 84 of "funnel technique" were successful, and 73 of free hand technique were successful. Significant differences were found between two ways (P < 0.05). Chanciness tresis occurred in "funnel technique" on 2 screws and free hand technique on 9 screws. There were significant differences in rates of chanciness tresis (P < 0.05).</p><p><b>CONCLUSION</b>Funnel technique is simple, safe and cost-effective alternative to any other thchnique for pedicle screw placement in thoracic spine,funnel technique is able to reduce the chance of critical injury of nerve root and dura.</p>