Comparison between posterolateral fusion with pedicle screw fixation and anterior interbody fusion with pedicle screw fixation in adult spondylolytic spondylolisthesis

There have been many reports regarding various operative methods for spondylolytic spondylolisthesis. However, there have been no reports regarding the comparison between posterolateral fusion (PLF) with pedicle screw fixation (PSF) and anterior lumbar interbody fusion (ALIF) with PSF. The purpose of the current study was to compare the clinical outcomes of PLF with PSF and ALIF with PSF, and to help in the selection of treatment options. Fifty-six patients with spondylolytic spondylolisthesis who underwent PLF with PSF (group 1, 35 patients) or who underwent ALIF with PSF (group 2, 21 patients) were studied. Minimum follow-up was 2 years. Demographic variables and disease state were similar for the two groups. We studied operating time, amount of blood loss, duration of hospital stay, clinical outcomes, complications, time at which fusion was complete, fusion rate, and radiological measurements. There were no significant differences between the two groups in terms of the amount of blood loss, duration of hospital stay, back pain, radiating pain, fusion rate, or complication rate. However, in group 2, the operation time and the time at which fusion became complete was longer, and in group 1 there was significant radiological reduction loss. In conclusion, PLF with PSF was just as effective as ALIF with PSF in terms of clinical outcomes, but ALIF with PSF was superior to PLF with PSF in terms of the prevention of reduction loss. Anterior support would be helpful for preventing reduction loss in cases of spondylolytic spondylolisthesis of the lumbar spine.

Recurrent lumbar disc herniation: results of operative management

STUDY DESIGN

A retrospective evaluation of 28 patients with recurrent lumbar disc herniation.

OBJECTIVES

To analyze the outcome of the revisions (repeat discectomy), the risk factors of recurrent disc herniation, and the factors that influenced the outcomes of repeat discectomy.

SUMMARY OF BACKGROUND DATA

Recurrent herniation following disc excision has been reported in 5-11% of patients. There have been many studies on recurrent disc herniation, but these studies have analyzed mixed patient populations.

METHODS

Recurrent lumbar disc herniation was defined as disc herniation at the same level, regardless of ipsilateral or contralateral herniation, with a pain-free interval greater than 6 months. Eight women and 20 men were studied. The levels of disc herniation were L4-L5 (19 cases) and L5-S1 (9 cases). Gadolinium-enhanced magnetic resonance imaging was performed in all patients. Revision surgery was performed in all patients by using conventional open discectomy. The pain-free interval, side and degree of herniation, operation time, duration of hospital stay, and clinical improvement rate were recorded.

RESULTS

The mean pain-free interval was 60.8 months. There were 21 cases of ipsilateral herniation and 7 cases of contralateral herniation. The degrees of herniation in revision were protrusion (14 cases), subligamentous extrusion (3 cases), transligamentous extrusion (8 cases), and sequestration (3 cases). The degrees of herniation in the previous discectomy were protrusion (17 cases), subligamentous extrusion (10 cases), and transligamentous extrusion (1 case). The length of surgery was significantly different (P = 0.003) between the revision surgery and the previous discectomy. There were no significant differences between revision and previous surgery in terms of hospital stay or clinical improvement rates. Age, gender, smoking, professions, traumatic events, level and degree of herniation, and pain-free interval did not affect the clinical outcomes.

CONCLUSION

Conventional open discectomy as a revision surgery for recurrent lumbar disc herniation showed satisfactory results that were comparable with those of primary discectomy. Based on the results of this study, repeat discectomy can be recommended for the management of recurrent lumbar disc herniation.

Lumbosacral scoliotic list by lumbar disc herniation

STUDY DESIGN

A prospective study of 45 patients with lumbar disc herniation and scoliotic list who had undergone conventional open discectomy.

OBJECTIVES

To determine the association between the location of the disc herniation and the direction of sciatic scoliotic list and to clarify the mechanism of sciatic scoliosis.

SUMMARY OF BACKGROUND DATA

The association between the scoliotic list and lumbar disc herniation is well known. However, there have been few studies regarding the direction of scoliotic list and the location of the disc herniation observed during surgery.

METHODS

The direction of scoliotic list, the preoperative and postoperative Cobb's angle, and the displacement of the first lumbar vertebra from the center sacral line were measured. The location, side, and degree of disc herniation were observed during surgery.

RESULTS

There was no statistically significant association observed between the location or degree of nerve root compression and the direction or degree of sciatic scoliosis. Moreover, there was no statistically significant association observed between the location or degree of nerve root compression and the displacement of the first lumbar spine from the center sacral line. However, there was a significant association between the side of the disc herniation and the direction of sciatic scoliosis. Most of the sciatic scoliotic list disappeared after surgical decompression.

CONCLUSION

The direction of sciatic scoliosis was not observed to be associated with the location of nerve root compression, although it was related to the side of disc herniation.

Reliability of magnetic resonance imaging in detecting posterior ligament complex injury in thoracolumbar spinal fractures

STUDY DESIGN

Prospective study of 34 patients with thoracolumbar spinal fractures.

OBJECTIVES

To assess the reliability of magnetic resonance imaging (MRI) for posterior ligament complex injury in thoracolumbar spinal fractures.

SUMMARY OF BACKGROUND DATA

Some researchers have studied posterior ligament complex injury in spinal fracture using MRI. However, most did not evaluate the findings of MRI compared with the operative findings.

METHODS

Thirty-four patients with thoracolumbar spinal fracture were evaluated by palpation of the interspinous gap, plain radiography, and MRI before operation. In addition to conventional MRI sequences, a fat-suppressed T2-weighted sagittal sequence was performed. Surgery was performed by a posterior approach. During the operation, posterior ligament complex injury was carefully examined.

RESULTS

A wide interspinous gap was palpated in 14 patients and was found in 21 patients on plain radiography. Magnetic resonance imaging raised suspicion of injury to the posterior ligament complex in 30 patients. According to interpretation of MRI, injury to the supraspinous ligament was suspected in 27 patients, the interspinous ligament in 30 patients, and the ligamentum flavum in 9 patients. There were 28 supraspinous ligament injuries, 29 interspinous ligament injuries, and 7 ligamentum flavum injuries in operative findings. There was a significant relation between MRI interpretation and operative findings.

CONCLUSION

A fat-suppressed T2-weighted sagittal sequence of MRI was a highly sensitive, specific, and accurate method of evaluating posterior ligament complex injury. Based on the results of this study, a fat-suppressed T2-weighted sagittal sequence of MRIs is recommended for the accurate evaluation of posterior ligament complex injury and would be helpful in the selection of treatment options.

Unilateral versus bilateral pedicle screw fixation in lumbar spinal fusion

STUDY DESIGN

A prospective study of 87 patients who underwent unilateral or bilateral pedicle screw fixation.

OBJECTIVES

To determine whether unilateral pedicle screw fixation is comparable with bilateral fixation in one- or two-segment lumbar spinal fusion.

SUMMARY OF BACKGROUND DATA

Clinical results for unilateral variable screw placement instrumentation in isolated L4-L5 fusion have been reported to be as good as those for bilateral instrumentation. However, unilateral instrumentation may not be recommended for multilevel fusion.

METHODS

Eighty-seven patients were assigned to either unilateral (n = 47) or bilateral (n = 40) pedicle screw instrumentation groups. Two kinds of pedicle screw system (Moss Miami, DePuy, Warsaw, IN, and Steffee VSP, AcroMed, Cleveland, OH) were used. Operating time, blood loss, duration of hospital stay, clinical outcomes, fusion rates, complication rates, and medical expenses were studied and tested with independent sample t test and chi2 test.

RESULTS

There were no significant differences between the two groups in blood loss, clinically satisfactory results, fusion rate, and complication rate. There were significant differences in duration of operating time, duration of hospital stay, and medical expenses. The number of fusion segments or kinds of instrumentation did not affect the fusion rate or clinical outcomes.

CONCLUSIONS

Unilateral pedicle screw fixation was as effective as bilateral pedicle screw fixation in lumbar spinal fusion independent of the number of fusion segments (one or two segments) or pedicle screw systems. Based on the results of this study, unilateral fixation could be used in two-segment lumbar spinal fusion.

Deep vein thrombosis after major spinal surgery: incidence in an East Asian population

STUDY DESIGN

A prospective study of 313 patients who underwent major spinal surgery.

OBJECTIVES

To determine the incidence of deep vein thrombosis after major spinal surgery in an east Asian population without antithrombotic prophylaxis.

SUMMARY OF BACKGROUND DATA

Spinal surgery has been associated with few thrombotic complications (2-14%) compared with other reconstructive surgeries (20-70%). It has also been well documented that the incidence of deep vein thrombosis in east Asians (10%) is lower than in westerners (20-70%) in total joint replacements. There has been no previous report on the incidence of deep vein thrombosis after reconstructive spinal surgery in east Asians.

METHODS

Three hundred thirteen patients who underwent major spinal surgery were evaluated prospectively. All patients were examined with duplex ultrasonography assessments of both lower extremities. No specific antithrombotic prophylaxis were used in any patients before or after surgery.

RESULTS

There were four patients with positive findings of deep vein thrombosis on duplex ultrasonography, and there was only one with clinically symptomatic deep vein thrombosis. The overall incidence of thrombotic complications was 1.3%, and the incidence of symptomatic deep vein thrombosis was 0.3%.

CONCLUSION

Considering the low rate of deep vein thrombosis, routine screening and prophylaxis for deep vein thrombosis appears unwarranted in east Asians before or after major spinal surgery.

Clinical and radiological differences between traumatic and idiopathic coccygodynia

Several reports of coccygodynia have been confined to the causes, the methods of treatment, and the methods of radiological examination. As far as we know, there has been no previous study about the objective measurement of the coccyx. The purpose of this study was to find the possible cause of idiopathic coccygodynia by comparing the clinical and radiological differences between traumatic and idiopathic coccygodynia by innovative objective clinical and radiological measurements. Thirty-two patients with coccygodynia were evaluated retrospectively. We divided the patients into two groups. Group 1 consisted of 19 patients with traumatic coccygodynia and group 2 consisted of 13 patients with idiopathic coccygodynia. We reviewed medical records and checked age, sex distribution, symptoms, and treatment outcome in each group. We also reviewed coccyx AP and lateral views of plain radiological film and measured the number of coccyx segments and the intercoccygeal angle in each group. The intercoccygeal angle devised by the authors was defined as the angle between the first and last segment of the coccyx. We also checked the intercoccygeal angle in a normal control group, which consisted of 18 women and 2 men, to observe the reference value of the intercoccygeal angle. The outcome of treatment was assessed by a visual analogue scale based on the pain score. Statistical analysis was done with Mann-Whitney U test and Chi-square test. Group 1 consisted of 1 male and 18 female patients, while group 2 consisted of 2 male and 11 female patients. There were no statistically significant differences between the traumatic and idiopathic coccygodynia groups in terms of age (38.7 years versus 36.5 years), male/female sex ratio (1/18 versus 2/11), and the number of coccyx segments (2.9 versus 2.7). There were significant differences between the traumatic and idiopathic coccygodynia groups in terms of the pain score (pain on sitting: 82 versus 47, pain on defecation: 39 versus 87), the intercoccygeal angle (47.9 degree versus 72.2 degrees), and the satisfactory outcome of conservative treatment (47.4% versus 92.3%). The reference value of the intercoccygeal angle in the normal control group was 52.3 degrees, which was significantly different from that of the idiopathic group. In conclusion, the intercoccygeal angle of the idiopathic coccygodynia group was greater than that of the traumatic group and normal control group. Based on the results of this study, the increased intercoccygeal angle can be considered a possible cause of idiopathic coccygodynia. The intercoccygeal angle was a useful radiological measurement to evaluate the forward angulation deformity of the coccyx.

The role of transitional vertebrae in spondylolysis and spondylolytic spondylolisthesis

Transitional lumbar vertebrae include lumbarization and sacralization of the lumbosacral region. This study was performed to evaluate the relationship of transitional vertebra to spondylolytic spondylolisthesis such as the incidence and degree of slippage and to ascertain the clinical relevance for treatment. The study included 182 cases with 33 cases (18.1%) of transitional vertebra, 12 cases of lumbarization, and 21 cases of sacralization. The remaining 149 cases constituted the control group. The degree of the anterior slippage of the vertebral body was measured by Meyerding's grading and the percentage of the anterior slippage was measured by Taillard's method. In the patients with lumbarization and the isthmic defects in the fourth lumbar spine, the average slip of L4 was 14.5%. While patients with sacralization and the isthmic defects in L4, the average slip of L4 was 19.3%. The average slip of L4 was 11.4% in the control group. In patients with lumbarization and the isthmic defects in the fifth lumbar vertebra, the average slip of L5 was 12.5%. While in patients with sacralization and the isthmic defects in L5, the average slip of the L5 vertebra was 9.5%. The average slip of L5 was 16.2% in the control group. The patients with sacralization and the isthmic defects in L4 showed more anterior slippage than the patients with the isthmic defect in L4 without transitional vertebrae. The patients with sacralization and the isthmic defects in L5 showed less anterior slippage than the patients with isthmic defects in L5 without transitional vertebrae. From this it can be concluded that more aggressive treatment is recommended in the patients with sacralization and isthmic defects in L4, whereas more conservative treatment is recommended in the patients with sacralization and the isthmic defects in L5.