Anterior Lumbar Interbody Fusion for the Treatment of Postoperative Spondylodiscitis

Objective

To analyze the clinical courses and outcomes after anterior lumbar interbody fusion (ALIF) for the treatment of postoperative spondylodiscitis.

Methods

A total of 13 consecutive patients with postoperative spondylodiscitis treated with ALIF at our institute from January, 1994 to August, 2013 were included (92.3% male, mean age 54.5 years old). The outcome data including inflammatory markers (leukocyte count, C-reactive protein, erythrocyte sedimentation rate), the Oswestry Disability Index (ODI), the modified Visual Analogue Scale (VAS), and bony fusion rate using spine X-ray were obtained before and 6 months after ALIF.

Results

All of the cases were effectively treated with combination of systemic antibiotics and ALIF with normalization of the inflammatory markers. The mean VAS for back and leg pain before ALIF was 6.8±1.1, which improved to 3.2±2.2 at 6 months after ALIF. The mean ODI score before ALIF was 70.0±14.8, which improved to 34.2±27.0 at 6 months after ALIF. Successful bony fusion rate was 84.6% (11/13) and the remaining two patients were also asymptomatic.

Conclusion

Our results suggest that ALIF is an effective treatment option for postoperative spondylodiscitis.     

A Surgical Option for Multilevel Anterior Lumbar Interbody Fusion with Ponte Osteotomy to Achieve Optimal Lumbar Lordosis and Sagittal Balance

Objective

To document lumbar lordosis (LL) of the spine and its change during surgeries with the different height but the same angle setting of the anterior cage. Additionally, we attempted to determine if sufficient LL is achieved at different cage heights and to quantify the change in LL during multi-level anterior lumbar interbody fusion (ALIF).

Methods

The medical records and radiographs of 42 patients who underwent more than 2 level ALIFs between 2008 and 2009 were retrospectively reviewed. We evaluated 3 parameters seen on lateral whole spine radiographs : LL, pelvic incidence (PI), and sagittal vertical axis (SVA). The mean follow-up time was 28.1 months and the final follow-up radiographs of all patients were reviewed at least 2 years after surgery. Statistical analysis was performed using the paired t-tests.

Results

Lumbar lordosis had changed up to 30 degrees immediately and 2 years after surgery (preoperative mean LL, SVA : 22.45 degrees, 112.31 mm; immediate postoperative mean LL, SVA : 54.45 degrees, 37.36 mm; final follow-up mean LL, SVA : 49.56 degrees, 26.95 mm). Our goal of LL is to obtain as much PI as possible, preoperative mean PI value was 55.38±3.35. The pre-operative and two year post-surgery follow-up mean of the Japanese Orthopedic Association score were 9.2±0.6 and 13.2±0.6 (favorable outcome rate : 95%), respectively. In addition, we were able to obtain good clinical outcomes and sagittal balance with a subsidence rate of 22.7%.

Conclusion

We were able to achieve sufficient LL, such that it was similar to the PI, utilizing multi-level ALIF with the use of a tall cage with the same angle setting of the cage. We have found out that achieving sufficient lumbar lordosis and sagittal balance require an anterior lumbar cage with high angle and height.     

Minimum 2-Year Follow-Up Result of Degenerative Spinal Stenosis Treated with Interspinous U (Coflex?)

Objective

Clinical and radiological results of posterior dynamic stabilization using interspinous U (ISU, Coflex™, Paradigm Spine Inc.®, NY, USA) were analyzed in comparison with posterior lumbar interbody fusion (PLIF) in degenerative lumbar spinal stenosis (LSS).

Methods

A retrospective study was conducted for a consecutive series of 61 patients with degenerative LSS between May 2003 and December 2005. We included only the patients completed minimum 24 months follow up evaluation. Among them, 30 patients were treated with implantation of ISU after decompressive laminectomy (Group ISU) and 31 patients were treated with wide decompressive laminectomy and posterior lumbar interbody fusion (PLIF; Group PLIF). We evaluated visual analogue scale (VAS) and Oswestry Disability Index (ODI) for clinical outcomes (VAS, ODI), disc height ratio disc height (DH), disc height/vertebral body length ×100), static vertebral slip (VS) and depth of maximal radiolucent gap between ISU and spinous process) in preoperative, immediate postoperative and last follow up.

Results

The mean age of group ISU (66.2 ± 6.7 years) was 6.2 years older than the mean age of group PLIF (60.4 ± 8.1 years; p = 0.003 ). In both groups, clinical measures improved significantly than preoperative values (p < 0.001). Operation time and blood loss was significantly shorter and lower in group ISU than group PLIF (p < 0.001). In group ISU, the DH increased transiently in immediate postoperative period (15.7 ± 4.5% → 18.6 ± 5.9%), however decreased significantly in last follow up (13.8 ± 6.6%, p = 0.027). Vertebral slip (VS) of spondylolisthesis in group ISU increased during postoperative follow-up (2.3 ± 3.3 → 8.7 ± 6.2, p = 0.040). Meanwhile, the postoperatively improved DH and VS was maintained in group PLIF in last follow up.

Conclusion

According to our result, implantation of ISU after decompressive laminectomy in degenerative LSS is less invasive and provides similar clinical outcome in comparison with the instrumented fusion. However, the device has only transient effect on the postoperative restoration of disc height and reduction of slip in spondylolisthesis. Therefore, in the biomechanical standpoint, it is hard to expect that use of Interspinous U in decompressive laminectomy for degenerative LSS had long term beneficial effect.     

Changes in the Cross-Sectional Area of Multifidus and Psoas in Unilateral Sciatica Caused by Lumbar Disc Herniation

Objective

To quantitatively evaluate the asymmetry of the multifidus and psoas muscles in unilateral sciatica caused by lumbar disc herniation using magnetic resonance imaging (MRI).

Methods

Seventy-six patients who underwent open microdiscectomy for unilateral L5 radiculopathy caused by disc herniation at the L4-5 level were enrolled, of which 39 patients (51.3%) had a symptom duration of 1 month or less (group A), and 37 (48.7%) had a symptom duration of 3 months or more (group B). The cross-sectional areas (CSAs) of the multifidus and psoas muscles were measured at the mid-portion of the L4-5 disc level on axial MRI, and compared between the diseased and normal sides in each group.

Results

The mean symptom duration was 0.6±0.4 months and 5.4±2.7 months for groups A and B, respectively (p<0.001). There were no differences in the demographics between the 2 groups. There was a significant difference in the CSA of the multifidus muscle between the diseased and normal sides (p<0.01) in group B. In contrast, no significant multifidus muscle asymmetry was found in group A. The CSA of the psoas muscle was not affected by disc herniation in either group.

Conclusion

The CSA of the multifidus muscle was reduced by lumbar disc herniation when symptom duration was 3 months or more.     

A Multi-center Clinical Study of Posterior Lumbar Interbody Fusion with the Expandable Stand-alone Cage (Tyche? Cage) for Degenerative Lumbar Spinal Disorders

Objective

This multi-center clinical study was designed to determine the long-term results of patients who received a one-level posterior lumbar interbody fusion with expandable cage (Tyche® cage) for degenerative spinal diseases during the same period in each hospital.

Methods

Fifty-seven patients with low back pain who had a one-level posterior lumbar interbody fusion using a newly designed expandable cage were enrolled in this study at five centers from June 2003 to December 2004 and followed up for 24 months. Pain improvement was checked with a Visual Analogue Scale (VAS) and their disability was evaluated with the Oswestry Disability Index. Radiographs were obtained before and after surgery. At the final follow-up, dynamic stability, quality of bone fusion, interveretebral disc height, and lumbar lordosis were assessed. In some cases, a lumbar computed tomography scan was also obtained.

Results

The mean VAS score of back pain was improved from 6.44 points preoperatively to 0.44 at the final visit and the score of sciatica was reduced from 4.84 to 0.26. Also, the Oswestry Disability Index was improved from 32.62 points preoperatively to 18.25 at the final visit. The fusion rate was 92.5%. Intervertebral disc height, recorded as 9.94±2.69 mm before surgery was increased to 12.23±3.31 mm at postoperative 1 month and was stabilized at 11.43±2.23 mm on final visit. The segmental angle of lordosis was changed significantly from 3.54±3.70° before surgery to 6.37±3.97° by 24 months postoperative, and total lumbar lordosis was 20.37±11.30° preoperatively and 24.71±11.70° at 24 months postoperative.

Conclusion

There have been no special complications regarding the expandable cage during the follow-up period and the results of this study demonstrates a high fusion rate and clinical success.     

Clinical and Radiological Outcomes of Unilateral Facetectomy and Interbody Fusion Using Expandable Cages for Lumbosacral Foraminal Stenosis

Objective

Surgical treatment of lumbosacral foraminal stenosis requires an understanding of the anatomy of the lumbosacral area in individual patients. Unilateral facetectomy has been used to completely decompress entrapment of the L5 nerve root, followed in some patients by posterior lumbar interbody fusion (PLIF) with stand-alone cages.

Methods

We assessed 34 patients with lumbosacral foraminal stenosis who were treated with unilateral facetectomy and PLIF using stand-alone cages in our center from January 2004 to September 2007. All the patients underwent follow-up X-rays, including a dynamic view, at 3, 6, 12, 24 months, and computed tomography (CT) at 24 months postoperatively. Clinical outcomes were analyzed with the mean numeric rating scale (NRS), Oswestry Disability Index (ODI) and Odom''s criteria. Radiological outcomes were assessed with change of disc height, defined as the average of anterior, middle, and posterior height in plain X-rays. In addition, lumbosacral fusion was also assessed with dynamic X-ray and CT.

Results

Mean NRS score, which was 9.29 prior to surgery, was 1.5 at 18 months after surgery. The decrease in NRS was statistically significant. Excellent and good groups with regard to Odom''s criteria were 31 cases (91%) and three cases (9%) were fair. Pre-operative mean ODI of 28.4 decreased to 14.2 at post-operative 24 months. In 30 patients, a bone bridge on CT scan was identified. The change in disc height was 8.11 mm, 10.02 mm and 9.63 mm preoperatively, immediate postoperatively and at 24 months after surgery, respectively.

Conclusion

In the treatment of lumbosacral foraminal stenosis, unilateral facetectomy and interbody fusion using expandable stand-alone cages may be considered as one treatment option to maintain post-operative alignment and to obtain satisfactory clinical outcomes.     

Comparison of Percutaneous Endoscopic Lumbar Discectomy and Open Lumbar Microdiscectomy for Recurrent Disc Herniation

Objective

The purpose of this study was to compare clinical and radiological outcomes of percutaneous endoscopic lumbar discectomy (PELD) and open lumbar microdiscectomy (OLM) for recurrent disc herniation.

Methods

Fifty-four patients, who underwent surgery, either PELD (25 patients) or repeated OLM (29 patients), due to recurrent disc herniation at L4-5 level, were divided into two groups according to the surgical methods. Excluded were patients with sequestrated disc, calcified disc, severe neurological deficit, or instability. Clinical outcomes were assessed using Visual Analogue Scale (VAS) score and Oswestry Disability Index (ODI). Radiological variables were assessed using plain radiography and/or magnetic resonance imaging.

Results

Mean operating time and hospital stay were significantly shorter in PELD group (45.8 minutes and 0.9 day, respectively) than OLM group (73.8 minutes and 3.8 days, respectively) (p < 0.001). Complications occurred in 4% in PELD group and 10.3% in OLM group in the perioperative period. At a mean follow-up duration of 34.2 months, the mean improvements of back pain, leg pain, and functional improvement were 4.0, 5.5, and 40.9% for PELD group and 2.3, 5.1, and 45.0% for OLM group, respectively. Second recurrence occurred in 4% after PELD and 10.3% after OLM. Disc height did not change after PELD, but significantly decreased after OLM (p = 0.0001). Neither sagittal rotation angle nor volume of multifidus muscle changed significantly in both groups.

Conclusion

Both PELD and repeated OLM showed favorable outcomes for recurrent disc herniation, but PELD had advantages in terms of shorter operating time, hospital stay, and disc height preservation.     

Posterior Interspinous Fusion Device for One-Level Fusion in Degenerative Lumbar Spine Disease : Comparison with Pedicle Screw Fixation - Preliminary Report of at Least One Year Follow Up

Objective

Transpedicular screw fixation has some disadvantages such as postoperative back pain through wide muscle dissection, long operative time, and cephalad adjacent segmental degeneration (ASD). The purposes of this study are investigation and comparison of radiological and clinical results between interspinous fusion device (IFD) and pedicle screw.

Methods

From Jan. 2008 to Aug. 2009, 40 patients underwent spinal fusion with IFD combined with posterior lumbar interbody fusion (PLIF). In same study period, 36 patients underwent spinal fusion with pedicle screw fixation as control group. Dynamic lateral radiographs, visual analogue scale (VAS), and Korean version of the Oswestry disability index (K-ODI) scores were evaluated in both groups.

Results

The lumbar spine diseases in the IFD group were as followings; spinal stenosis in 26, degenerative spondylolisthesis in 12, and intervertebral disc herniation in 2. The mean follow up period was 14.24 months (range; 12 to 22 months) in the IFD group and 18.3 months (range; 12 to 28 months) in pedicle screw group. The mean VAS scores was preoperatively 7.16±2.1 and 8.03±2.3 in the IFD and pedicle screw groups, respectively, and improved postoperatively to 1.3±2.9 and 1.2±3.2 in 1-year follow ups (p<0.05). The K-ODI was decreased significantly in an equal amount in both groups one year postoperatively (p<0.05). The statistics revealed a higher incidence of ASD in pedicle screw group than the IFD group (p=0.029).

Conclusion

Posterior IFD has several advantages over the pedicle screw fixation in terms of skin incision, muscle dissection and short operative time and less intraoperative estimated blood loss. The IFD with PLIF may be a favorable technique to replace the pedicle screw fixation in selective case.     

Direct Lateral Lumbar Interbody Fusion: Clinical and Radiological Outcomes

Objective

According to the recent development of minimally invasive spinal surgery, direct lumbar interbody fusion (DLIF) was introduced as an effective option to treat lumbar degenerative diseases. However, comprehensive results of DLIF have not been reported in Korea yet. The object of this study is to summarize radiological and clinical outcomes of our DLIF experience.

Methods

We performed DLIF for 130 patients from May 2011 to June 2013. Among them, 90 patients, who could be followed up for more than 6 months, were analyzed retrospectively. Clinical outcomes were compared using visual analog scale (VAS) score and Oswestry Disability Index (ODI). Bilateral foramen areas, disc height, segmental coronal and sagittal angle, and regional sagittal angle were measured. Additionally, fusion rate was assessed.

Results

A total of 90 patients, 116 levels, were underwent DLIF. The VAS and ODI improved statistically significant after surgery. All the approaches for DLIF were done on the left side. The left and right side foramen area changed from 99.5 mm² and 102.9 mm² to 159.2 mm² and 151.2 mm² postoperatively (p<0.001). Pre- and postoperative segmental coronal and sagittal angles changed statistically significant from 4.1° and 9.9° to 1.1° and 11.1°. Fusion rates of 6 and 12 months were 60.9% and 87.8%. Complications occurred in 17 patients (18.9%). However, most of the complications were resolved within 2 months.

Conclusion

DLIF is not only effective for indirect decompression and deformity correction but also shows satisfactory mechanical stability and fusion rate.     

Unilateral Extrapedicular Vertebroplasty and Kyphoplasty in Lumbar Compression Fractures : Technique, Anatomy and Preliminary Results

Objective

A single balloon extrapedicular kyphoplasty has been introduced as one of the unilateral approaches for thoracic compression fractures; however, the unilateral extrapedicular technique in the lumbar area needs a further understanding of structures in the lumbar area. The purpose of the present study is to describe methods and pitfalls of this procedure based on the anatomy of the lumbar area and to analyze clinical outcome and complications.

Methods

Anatomical evaluation was performed with 2 human cadavers. A retrospective review of unilateral extrapedicular approaches yielded 74 vertebral levels in 55 patients that were treated with unilateral extrapedicular vertebroplasty and kyphoplasty. Radiographic assessment included the restoration rate of vertebral height and correction of kyphosis.

Results

Anatomical evaluation indicates that the safe needle entry zone of bone for the extrapedicular approach was located in the supero-lateral aspect of the junction between the pedicle and vertebral body. The unilateral extrapedicular procedure achieved adequate pain relief with a mean decreases in pain severity of 7.25±1.5 and 2.0±1.4, respectively. Complications were 1 retroperitoneal hematoma, 6 unilateral fillings and 3 epidural leak of the polymethylmethacrylate.

Conclusion

The method of a unilateral extrapedicular approach in kyphoplasty and vertebroplasty in the lumbar area might be similar to that in thoracic approach using a route via the extrapedicular space. However, different anatomical characteristics of the lumbar area should be considered.     

The Comparative Analysis of Clinical Characteristics and Surgical Results between the Upper and Lower Lumbar Disc Herniations

Objective

There are differences in the clinical characteristics and surgical results between upper (L1-2 and L2-3) and lower (L3-4, L4-5, and L5-S1) lumbar disc herniations. We conducted this study to compare the clinical features and surgical outcomes between the two types of lumbar disc herniations.

Methods

We retrospectively reviewed the clinical features of patients who underwent microdiscectomies from 2008 to 2012. We evaluated the clinical characteristics such as age, preoperative autonomic dysfunction, the presence or absence of previous lumbar surgery and fusion required during surgery. Visual Analogue Scale (VAS) scores about back pain and leg pain were evaluated preoperatively and at the final follow-up.

Results

Upper lumbar group (n=15) was significantly older than lower lumbar group (n=148). The incidence of autonomic dysfunction was significantly higher in upper lumbar group. The number of patients with a previous lumbar surgery was significantly greater in upper lumbar group. There was no statistical significance for fusion required during surgery between two groups. Both groups showed a significant decrease in the VAS scores of leg pain. VAS scores of back pain were significantly decreased in lower lumbar group. But this was not seen in upper lumbar group. Both groups showed significant improvement of Oswestry Disability Index score.

Conclusion

Upper lumbar group had different clinical characteristics from those of lower lumbar group and these include older age, a higher incidence of autonomic dysfunctions and a higher incidence of patients with previous lumbar surgery. There were no significant differences in surgical outcomes, except for back pain, between two groups.     

Lumbar Interbody Fusion Outcomes in Degenerative Lumbar Disease : Comparison of Results between Patients Over and Under 65 Years of Age

Objective

To evaluate the clinical and radiological outcomes of lumbar interbody fusion and its correlation with various factors (e.g., age, comorbidities, fusion level, bone quality) in patients over and under 65 years of age who underwent lumbar fusion surgery for degenerative lumbar disease.

Methods

One-hundred-thirty-three patients with lumbar degenerative disease underwent lumbar fusion surgery between June 2006 and June 2007 and were followed for more than one year. Forty-eight (36.1%) were older than 65 years of age (group A) and 85 (63.9%) were under 65 years of age (group B). Diagnosis, comorbidities, length of hospital stay, and perioperative complications were recorded. The analysis of clinical outcomes was based on the visual analogue scale (VAS). Radiological results were evaluated using plain radiographs. Clinical outcomes, radiological outcomes, length of hospital stay, and complication rates were analyzed in relation to lumbar fusion level, the number of comorbidities, bone mineral density (BMD), and age.

Results

The mean age of the patients was 61.2 years (range, 33-86 years) and the mean BMD was -2.2 (range, -4.8 to -2.8). The mean length of hospital stay was 15.0 days (range, 5-60 days) and the mean follow-up was 23.0 months (range, 18-30 months). Eighty-five (64.0%) patients had more than one preoperative comorbidities. Perioperative complications occurred in 27 of 133 patients (20.3%). The incidence of overall complication was 22.9% in group A, and 18.8% in group B but there was no statistical difference between the two groups. The mean VAS scores for the back and leg were significantly decreased in both groups (p < 0.05), and bony fusion was achieved in 125 of 133 patients (94.0%). There was no significant difference in bony union rates between groups A and B (91.7% in group A vs. 95.3% in group B, p = 0.398). In group A, perioperative complications were more common with the increase in fusion level (p = 0.027). Perioperative complications in both groups A (p = 0.035) and B (p = 0.044) increased with an increasing number of comorbidities.

Conclusion

Elderly patients with comorbidities are at a high risk for complications and adverse outcomes after lumbar spine surgery. In our study, clinical outcomes, fusion rates, and perioperative complication rates in older patients were comparable with those in younger populations. The number of comorbidities and the extent of fusion level were significant factors in predicting the occurrence of postoperative complications. However, proper perioperative general supportive care with a thorough fusion strategy during the operation could improve the overall postoperative outcomes in lumbar fusion surgery for elderly patients.     

Difference of Sagittal Spinopelvic Alignments between Degenerative Spondylolisthesis and Isthmic Spondylolisthesis

Objective

The purpose of this study was to analyze the differences of spinopelvic parameters between degenerative spondylolisthesis (DSPL) and isthmic spondylolisthesis (ISPL) patients.

Methods

Thirty-four patients with DSPL and 19 patients with ISPL were included in this study. Spinopelvic parameters were evaluated on whole spine X-rays in a standing position. The following spinopelvic parameters were measured : pelvic incidence (PI), sacral slope, pelvic tilt (PT), lumbar lordosis (LL), and sagittal vertical axis from C7 plumb line (SVA). The population of patients was compared with a control population of 30 normal and asymptomatic adults.

Results

There were statistically significant differences in LL (p=0.004) and SVA (p=0.005) between the DSPL and ISPL group. The LL of DSPL (42±13°) was significantly lower than that of the control group (48±11°; p=0.029), but that of ISPL (55±6°) was significantly greater than a control group (p=0.004). The SVA of DSPL (55±49 mm) was greater than that of a control group (<40 mm), but that of ISPL (21±22 mm) was within 40 mm as that of a control group. The PT of DSPL (24±7°) and ISPL (21±7°) was significantly greater than that of a control group (11±6°; p=0.000).

Conclusion

Both symptomatic DSPL and ISPL patients had a greater PI than that of the asymptomatic control group. In conclusion, DSPL populations are likely to have global sagittal imbalance (high SVA) compared with ISPL populations because of the difference of lumbar lordosis between two groups.     

Prevalence of Disc Degeneration in Asymptomatic Korean Subjects. Part 1 : Lumbar Spine

Objective

Asymptomatic patients show high degeneration prevalence at lumbar disc in previous literatures. Unfortunately, there are few Korean data, so the authors attempted to analyze the prevalence of disc degeneration in highly selective asymptomatic Korean subjects using MRI.

Methods

We performed 3 T MRI sagittal scans from T12 to S1 on 102 asymptomatic subjects (50 men and 52 women) who visited our hospital between the ages of 14 and 82 years (mean age 46.3 years). All images were read independently by three observers (two neurosurgeons and one neuroradiologist) who were not given any information about the subjects. We classified grading for lumbar disc herniation (HN), annular fissure (AF), and nucleus degeneration (ND), using disc degeneration classification.

Results

The prevalence of HN, AF, and ND were 81.4%, 76.1%, and 75.8% respectively. Almost all levels showed an age-related proportional tendency with some exceptions.

Conclusion

In asymptomatic Korean subjects, the abnormal findings showed high prevalence of AF, ND, and extrusion. Especially in young ages, the authors found that bulging, protrusion, and AF showed high prevalence at L4/5 and L5/S1. And ND showed high prevalence at L5/S1. So, all lumbar disc degenerations are not pathologic, especially in children and adolescents.     

Clinical Significance of Radiological Stability in Reconstructed Thoracic and Lumbar Spine Following Vertebral Body Resection

Objective

Vertebral body replacement following corpectomy in thoracic or lumbar spine is performed with titanium mesh cage (TMC) containing any grafts. Radiological changes often occur on follow-up. This study investigated the relationship between the radiological stability and clinical symptoms.

Methods

The subjects of this study were 28 patients who underwent corpectomy on the thoracic or lumbar spine. Their medical records and radiological data were retrospectively analyzed. There were 23 cases of tumor, 2 cases of trauma, and 3 cases of infection. During operation, spinal reconstruction was done with TMC and additional screw fixation. We measured TMC settlement in sagittal plane and spinal angular change in coronal and sagittal plane at postoperative one month and last follow-up. Pain score was also checked. We investigated the correlation between radiologic change and pain status. Whether factors, such as the kind of graft material, surgical approach, and fusion can affect the radiological stability or not was analyzed as well.

Results

Mean follow-up was 23.6 months. During follow-up, 2.08±1.65° and 6.96±2.08° of angular change was observed in coronal and sagittal plane, respectively. A mean of cage settlement was 4.02±2.83 mm. Pain aggravation was observed in 4 cases. However, no significant relationship was found between spinal angular change and pain status (p=0.518, 0.458). Cage settlement was seen not to be related with pain status, either (p=0.644). No factors were found to affect the radiological stability.

Conclusion

TMC settlement and spinal angular change were often observed in reconstructed spine. However, these changes did not always cause postoperative axial pain.     

Clinical outcomes of percutaneous endoscopic surgery for lumbar discal cyst

Objective

Discal cyst is rare and causes indistinguishable symptoms from lumbar disc herniation. The clinical manifestations and pathological features of discal cyst have not yet been completely known. Discal cyst has been treated with surgery or with direct intervention such as computed tomography (CT) guided aspiration and steroid injection. The purpose of this study is to evaluate the safety and efficacy of the percutaneous endoscopic surgery for lumbar discal cyst over at least 6 months follow-up.

Methods

All 8 cases of discal cyst with radiculopathy were treated by percutaneous endoscopic surgery by transforaminal approach. The involved levels include L5-S1 in 1 patient, L3-4 in 2, and L4-5 in 5. The preoperative magnetic resonance imaging and 3-dimensional CT with discogram images in all cases showed a connection between the cyst and the involved intervertebral disc. Over a 6-months period, self-reported measures were assessed using an outcome questionaire that incorporated total back-related medical resource utilization and improvement of leg pain [visual analogue scale (VAS) and Macnab''s criteria].

Results

All 8 patients underwent endoscopic excision of the cyst with additional partial discectomy. Seven patients obtained immediate relief of symptoms after removal of the cyst by endoscopic approach. There were no recurrent lesions during follow-up period. The mean preoperative VAS for leg pain was 8.25±0.5. At the last examination followed longer than 6 month, the mean VAS for leg pain was 2.25±2.21. According to MacNab'' criteria, 4 patients (50%) had excellent results, 3 patients (37.5%) had good results; thus, satisfactory results were achieved in 7 patients (87.5%). However, one case had unsatisfactory result with persistent leg pain and another paresthesia.

Conclusion

The radicular symptoms were remarkably improved in most patients immediately after percutaneous endoscopic cystectomy by transforaminal approach.     

Postoperative Flat Back: Contribution of Posterior Accessed Lumbar Interbody Fusion and Spinopelvic Parameters

Objective

Posterior accessed lumbar interbody fusion (PALIF) has a clear objective to restore disc height and spinal alignment but surgeons may occasionally face the converse situation and lose lumbar lordosis. We analyzed retrospective data for factors contributing to a postoperative flat back.

Methods

A total of 105 patients who underwent PALIF for spondylolisthesis and stenosis were enrolled. The patients were divided according to surgical type [posterior lumbar inter body fusion (PLIF) vs. unilateral transforaminal lumbar interbody fusion (TLIF)], number of levels (single vs. multiple), and diagnosis (spondylolisthesis vs. stenosis). We measured perioperative index level lordosis, lumbar lordosis, pelvic tilt, sacral slope, pelvic incidence, and disc height in standing lateral radiographs. The change and variance in each parameter and comparative group were analyzed with the paired and Student t-test (p<0.05), correlation coefficient, and regression analysis.

Results

A significant perioperative reduction was observed in index-level lordosis following TLIF at the single level and in patients with spondylolisthesis (p=0.002, p=0.005). Pelvic tilt and sacral slope were significantly restored following PLIF multilevel surgery (p=0.009, p=0.003). Sacral slope variance was highly sensitive to perioperative variance of index level lordosis in high sacral sloped pelvis. Perioperative variance of index level lordosis was positively correlated with disc height variance (R²=0.286, p=0.0005).

Conclusion

Unilateral TLIF has the potential to cause postoperative flat back. PLIF is more reliable than unilateral TLIF to restore spinopelvic parameters following multilevel surgery and spondylolisthesis. A high sacral sloped pelvis is more vulnerable to PALIF in terms of a postoperative flat back.     

Minimally Invasive Transforaminal Lumbar Interbody Fusion Using a Single Interbody Cage and a Tubular Retraction System : Technical Tips, and Perioperative, Radiologic and Clinical Outcomes

Objective

A minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) has recently been introduced. However, MIS TLIF is a technically challenging procedure. The authors performed retrospective analysis about MIS TLIF using a single interbody cage.

Methods

Twenty-eight consecutive patients were treated by MIS TLIF. Of these 28 patients, 20 patients were included in this retrospective study. Perioperative, clinical, and radiologic outcomes were assessed. Clinical outcomes were assessed using Oswestry Disability Index (ODI) and Visual Analogue Scores (VAS). Fusion rates and cross-sections of operated spinal canals were assessed by CT.

Results

Twelve patients underwent MIS TLIF at one segment and 8 patients at two segments (L3/4: 4, L4/5: 17, L5/S1: 7). Operation time for a single segment was 131.7 min and for two segment was 201.4 min, and corresponding blood losses were 208.3 mL and 481.2 mL, respectively. ODI and VAS scores were significantly improved at 6 months postop (ODI from 30.32 to 15. 54, VAS from 7.80 to 2.20, p = 0.001). Twenty-two segments (78.6%) achieved grade I fusion, 4 segments (14.3%) achieved grade II, 2 segments (7.1%) achieved grade III and 0 segments achieved grade IV at 12 months. Postoperatively at 12 months, spinal canal cross sectional areas at disc spaces significantly increased from 157.5 to 294.3 mm² (p = 0.012).

Conclusion

MIS TLIF achieved good clinical outcomes and high fusion rates. Our findings show that MIS TLIF performed with a single interbody cage and a tubular retractor system can be used as a standard MIS TLIF technique.     

Comparative Study of Posterior Lumbar Interbody Fusion via Unilateral and Bilateral Approaches in Patients with Unilateral Leg Symptoms

Objective

We investigated the clinical and radiological advantages of unilateral laminectomy in posterior lumbar interbody fusion (PLIF) procedure comparing with bilateral laminectomy, under the same procedural condition including bilateral instrumentation and insertion of two cages, in patients with degenerative lumbar disease with unilateral leg symptoms.

Methods

We retrospectively reviewed 124 consecutive cases of PLIF via unilateral or bilateral approach between January 2006 and April 2010. In 80 cases (bilateral group), two cages were inserted via bilateral laminectomy, and in 44 cases (unilateral group), via unilateral laminectomy. The average follow-up duration was 29.5 months. The clinical outcomes were evaluated with the Visual Analogue Scale (VAS) and the Oswestry disability index (ODI). The fusion rates and disc space heights were determined by dynamic standing radiographs and/or computed tomography. Operative times, intra-operative and post-operative blood losses and hospitalization periods were also evaluated.

Results

In clinical evaluation, the VAS and ODI scores showed excellent outcomes in both groups. There were no significant differences in term of fusion rate, but the perioperative blood loss and the operative time of the unilateral group were lower than that of the bilateral group.

Conclusion

Unilateral laminectomy can minimize the operative time and perioperative blood loss in PLIF procedure. However, the different preoperative disc height between two groups is a limitation of this study. Despite this limitation, solid fusion and satisfactory symptomatic improvement could be achieved uniquely by our surgical method. This surgical method can be an alternative surgical technique in patients with unilateral leg pain.