ABSTRACT
Lumbar adjacent segment degeneration is defined as degenerative changes cranial or caudal to surgical segments.Some patients developed corresponding clinical symptoms in addition to radiological degeneration,which is called adjacent segment disease.Although many new surgical techniques emerged in recent years,the problem of adjacent segment degeneration has not really been resolved.MEDLINE/PubMed,Cochrane Controlled Trials Registry and EMBASE were comprehensively searched.All randomized or nonrandomized clinical studies of lumbar degenerative diseases treated by fusion/fixation,decompression-alone or artificial lumbar disc replacement were included.The number of cases enrolled in these studies was greater than or equal to 20 cases and the minimum age of the patients was 18 years old.Case reports,reviews or meta-analyses,papers with unobtainable text and abstract,and studies of trauma,infection,oncology and inflammatory disease were all excluded.The diagnostic criteria of adjacent segment degeneration,as well as the incidence and risk factors of adjacent segment degeneration and reoperation were reviewed.The concepts of adjacent segment degeneration in different literatures were very confusing,and radiological degeneration was often mixed in use with symptomatic degeneration.It was therefore difficult to make any conclusion due to lack of a standard.In addition,the previous studies did not fully understand the pathogenesis and risk factors of the disease,especially the effect of the index level on adjacent segments.Moreover,most of the current studies were retrospective,therefore,convincing conclusions can hardly be drawn due to lack of high-level evidence.The main reason for reoperation after lumbar fusion is adjacent segment degeneration.Therefore,the most important way to reduce the rate of reoperation is to reduce the incidence of adjacent segment degeneration.In the future,the diagnostic criteria for adjacent segment degeneration should be unified first.And it is extremely important to thoroughly understand the mechanism and risk factors of adjacent segment degeneration by comprehensive studies and clarify them through high-level evidence.
ABSTRACT
<p><b>OBJECTIVE</b>To retrospectively assess the feasibility and safety of percutaneous minimally invasive pedicle screw fixation for cervical fracture using intraoperative three-dimensional fluoroscopy-based navigation.</p><p><b>METHODS</b>Thirty patients admitted from April 2012 to May 2014 in Beijing Jishuitan Hospital with cervical fracture underwent pedicle screw fixation using intraoperative three-dimensional fluoroscopy-based navigation, with 8 patients using minimally invasive technique (CAOS-MIS group), and the other 22 patients using conventional open approach (CAOS-open group). Operative time, blood loss and postoperative neurovascular complications were recorded. Screw positions were studied by postoperative CT scan. All patients were followed up for at least 6 months. Neck visual analogue score (VAS) and American Spinal Injury Association (ASIA) classification were evaluated preoperatively and at 6-month follow-up. Independent-sample t test and Chi-Square test were used for statistical analysis.</p><p><b>RESULTS</b>Operation time was (139 ± 18) minutes and blood loss was (73 ± 40) ml in CAOS-MIS group and correspondingly (154 ± 42) minutes and (296 ± 171) ml in CAOS-open group. The blood loss in CAOS-MIS group was significantly lower than that in CAOS-open group (t = 5.695, P < 0.01). No screw-related injury to nerve or vertebral artery was observed. Thirty-four screws were placed in CAOS-MIS group with 28 screws (82.4%) classified as Grade I, meanwhile in CAOS-open group 108 screws were placed with 96 screws (88.9%) classified as Grade I. There was no statistical difference between the two groups (χ² = 0.998, P > 0.01). VAS score showed no statistical difference preoperatively (t = 0.334, P > 0.01), however statistical difference existed at 6 months follow-up (t = 4.111, P < 0.01) with (0.4 ± 0.5) in CAOS-MIS group and (1.5 ± 0.7) in CAOS-open group. There were 1 patient from class B to improve to D, 1 case from D to E in CAOS-MIS group, and 1 patient from class A to improve to B, 1 case from B to D, 2 cases from C to D, 3 cases from D to E in CAOS-open group 6 months after surgery. Cervical X-ray demonstrated fractures healed well in all cases at 6 months follow-up.</p><p><b>CONCLUSION</b>It is feasible and safe for percutaneous minimally invasive pedicle screw fixation for cervical fracture using intraoperative three-dimensional fluoroscopy-based navigation, which can also decreases the incidence of postoperative neck pain.</p>
Subject(s)
Humans , Fluoroscopy , Methods , Minimally Invasive Surgical Procedures , Methods , Operative Time , Orthopedic Procedures , Methods , Pedicle Screws , Postoperative Complications , Retrospective Studies , Spinal Fractures , General Surgery , Tomography, X-Ray Computed , Treatment OutcomeABSTRACT
<p><b>BACKGROUND</b>Percutaneous pedicle screw use has a high rate of cranial facet joint violations (FVs) because of the facet joint being indirectly visualized. Computer-assisted navigation shows the anatomic structures clearly, and may help to lower the rate of FVs during pedicle screw insertion. This study used computed tomography (CT) to evaluate and compare the incidence of FVs between percutaneous and open surgeries employing computer-assisted navigation for the implantation of pedicle screw instrumentation during lumbar fusions.</p><p><b>METHODS</b>A prospective study, including 142 patients having lumbar and lumbosacral fusion, was conducted between January 2013 and April 2014. All patients had bilateral posterior pedicle screw-rod instrumentation (top-loading screws) implanted by the same group of surgeons; intraoperative 3-dimensional computer navigation was used during the procedures. All patients underwent CT examinations within 6 months postoperation. The CT scans were independently reviewed by three reviewers blinded to the technique used.</p><p><b>RESULTS</b>The cohort comprised 68 percutaneous and 74 open cases (136 and 148 superior-level pedicle screw placements, respectively). Overall, superior-level FVs occurred in 20 patients (20/142, 14.1%), involving 27 top screws (27/284, 9.5%). The percutaneous technique (7.4% of patients, 3.7% of top screws) had a significantly lower violation rate than the open procedure (20.3% of patients, 14.9% of top screws). The open group also had significantly more serious violations than did the percutaneous group. Both groups had a higher violation rate when the cranial fixation involved the L5. A 1-level open procedure had a higher violation rate than did the 2- and 3-level surgeries.</p><p><b>CONCLUSIONS</b>With computer-assisted navigation, the placement of top-loading percutaneous screws carries a lower risk of adjacent-FVs than does the open technique; when FVs occur, they tend to be less serious. Performing a single-level open lumbar fusion, or the fusion of the L5-S1 segment, requires caution to avoid cranial adjacent FVs.</p>
Subject(s)
Aged , Female , Humans , Male , Middle Aged , Lumbar Vertebrae , General Surgery , Minimally Invasive Surgical Procedures , Pedicle Screws , Prospective Studies , Zygapophyseal Joint , General SurgeryABSTRACT
<p><b>OBJECTIVE</b>To evaluate the effect of axial rotation of lumbar vertebrae on the accuracy of pedicle screw placement using the traditional method, as well as to assess the value of intraoperative three-dimensional (3D) navigation in improving the accuracy.</p><p><b>METHODS</b>Sixteen lumbar simulation models at different degrees of axial rotation (0°, 5°, 10° and 20°), with every four assigned with the same degree, were equally divided into two groups (traditional method group and intraoperative 3D navigation group). Random placement of pedicle screws was carried out, followed by CT scan postoperatively. Then the outer pedicle cortex contours were depicted from reconstructed sectional pedicle images using Photoshop. The accuracy of pedicle screw placement was evaluated by determining the interrelationship between screw trajectory and pedicle cortex (qualitative) and measuring the shortest distance from pedicle screw axis to outer cortex of the pedicle (quantitative).</p><p><b>RESULTS</b>Eighty pedicle screws were implanted respectively in each group. In traditional method group, statistical difference existed in the accuracy of pedicle screw placement at different axial rotational degrees (P < 0.05). With degrees increasing, the accuracy declined. The accuracy of intraoperative 3D navigation group was higher than traditional method group in vertebrae with axial rotation (P < 0.01). In qualitative evaluation, the accuracy of the two methods had statistical difference when the degree was 20°, and in quantitative evaluation, statistical difference existed in 5°, 10° and 20° of vertebral axial rotation.</p><p><b>CONCLUSIONS</b>Screw malposition can be caused by vertebral axial rotation in lumbar spine using traditional method. Accuracy of pedicle screw placement declines with the increase of axial rotational degrees. However, the accuracy can be improved by using intraoperative 3D navigation.</p>