Full-endoscopic versus microscopic unilateral laminotomy for bilateral decompression of lumbar spinal stenosis at L4-L5: comparative study.

PURPOSE: Full-endoscopic spine surgery for degenerative lumbar diseases is growing in popularity and has shown favourable outcomes. Lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD) has been used to treat lumbar spinal stenosis (LSS). However, studies comparing LE-ULBD to microscopic ULBD are lacking. This study compared the clinical efficacy and radiological outcomes between the LE-ULBD and microscopic ULBD. METHODS: The study retrospectively enrolled patients undergoing either LE-ULBD or microscopic ULBD for spinal stenosis at the L4-L5 level. The demographic data, operative details, radiological images, clinical outcomes, and complications of patients from the two groups were compared through matched-pairs analysis. The minimum follow-up duration was 24 months. RESULTS: There were 93 patients undergoing either LE-ULBD (n = 42) or microscopic ULBD (n = 51). The patient demographics were similar between the two groups. The LE-ULBD group had significantly less estimated blood loss, less analgesic use, and shorter hospitalization duration (P < .05). The endoscopic group had a significantly lower visual analog scale for back pain at all follow-up intervals compared with the microscopic group (P < .05). There were no significant differences in leg pain or Oswestry Disability Index. The cross-section area of the spinal canal was significantly wider after microscopic ULBD. There were no significant differences in post-operative degenerative changes in disc height, translational motion, or facet preservation rate. CONCLUSIONS: LE-ULBD is comparable in clinical and radiological outcomes with enhanced recovery for single-level LSS. The endoscopic approach might further minimize tissue injury and enhance post-operative recovery.

Twist technique for removal of spinal extradural arachnoid cyst: technical note.

STUDY DESIGN: We document a spinal extradual arachnoid cyst treated by twist technique. The cyst is tightly adherent to the neural tissue or the dura, and the communication stalk is little or short. OBJECTIVE: To demonstrate the effectiveness of twist technique of closure of the communication stalk for the removal of spinal extradural arachnoid cyst. The standard treatment for a spinal extradural arachnoid cyst is complete excision of the cyst, followed by obliteration of the communication stalk and repair of the dural defect. To our knowledge, twist technique of the communication stalk for removal of spinal extradural arachnoid cyst has not been reported. METHODS: A 44-year-old woman presented with a 10-year history of pain and dysesthesia, initially in the posterior neck region and extending gradually to the distal portion of the right upper extremity. Pain and dysesthesia were exaggerated when she was lying down and relieved when standing or walking. She was diagnosed with an extradural arachnid cyst ranging from spinal regions T1 to T3 using MRI. Computerized tomography myelography revealed a mass located posterior to the spinal cord. Pooling of contrast medium was observed in the lesion indicating communication with the subarachnoid space. Laminectomy of the T1-T3 region was performed, preserving the spinous processes and the facet joints. A short communication stalk was found at the proximal root sleeve of right T3. This stalk was closed using twist technique. RESULTS: The patient experienced marked reduction of pain and dysesthesia after surgery, and the headache and blurred vision completely disappeared. Five days after the operation, she was discharged home in good condition. Postoperative 1 year later, the patient had completely recovered and resumed her normal life. CONCLUSIONS: Twist technique can be seen safe and effective as another surgical option for spinal extradural arachnoid cysts containing a short stalk and dense fibrous adhesion with the dura mater.

Changes in the adjacent segment 10 years after anterior lumbar interbody fusion for low-grade isthmic spondylolisthesis.

BACKGROUND: Adjacent segment degeneration is a long-term complication of arthrodesis. However, the incidence of adjacent segment degeneration varies widely depending on the patient's age and underlying disease and the fusion techniques and diagnostic methods used. QUESTIONS/PURPOSES: We determined (1) the frequency of adjacent segment degeneration and increased lordosis on imaging tests, (2) the frequency and severity of clinical sequelae of these findings, including revision surgery, and (3) the sequence of degeneration and risk factors for degeneration. METHODS: Seventy-three patients underwent anterior lumbar interbody fusion for low-grade isthmic spondylolisthesis at one institution between October 2000 and February 2002. Forty-nine (67%) of the original patients had complete radiographic and clinical followup for 10 years. CT and MRI were performed at 5 years and 10 years in all cases. The disc height, sagittal profiles, and facet and disc degeneration at adjacent levels were examined to identify radiographic and clinical adjacent segment degeneration. Mean followup was 134.2 months (range, 120-148 months). RESULTS: Cranial segment lordosis increased (from 14.8° to 18.5°; p < 0.001), while caudal segment lordosis changed little (from 16.4° to 17.3°). Radiographic and clinical adjacent segment degeneration occurred in 19 (38.8%) and six (12.2%) patients, respectively, and two patients (4.1%) underwent revision surgery. Patients with adjacent segment degeneration had more advanced preexisting facet degeneration than patients without adjacent segment degeneration (odds ratio: 18.6; 95% CI, 1.97-175.54, p = 0.01). Acceleration of disc and facet degeneration occurred in 4.1% and 10.2%, respectively. CONCLUSIONS: Adjacent segment degeneration requiring surgery is rare, although radiographic adjacent segment degeneration is common after anterior lumbar interbody fusion for isthmic spondylolisthesis. The only risk factor we found was preexisting facet degeneration of the cranial segment. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Interlaminar Endoscopic Lumbar Discectomy Using a New 8.4-mm Endoscope and Nerve Root Retractor.

STUDY DESIGN: Surgical technique. OBJECTIVE: Using an 8.4-mm endoscope and endoscopic nerve root retractor, the interlaminar endoscopic lumbar discectomy (IELD) technique is introduced for lumbosacral levels. SUMMARY OF BACKGROUND DATA: Although spine surgeons are familiar with IELD, this technique is only used for L5-S1 disk herniations and requires a wide interlaminar space. METHODS: Using an 8.4 mm-endoscope, high-speed drill, and endoscopic Kerrison punches, a nerve-root retractor facilitated the simultaneous medial retraction of the nerve root and removal of the disk fragment by the instrument's cannula. Clinical parameters such the visual analog scale scores for back and leg pain, modified Macnab criteria, and Oswestry Disability Index were analyzed. RESULTS: A total of 101 patients were enrolled. The visual analog scale scores for back and leg pain significantly decreased from 6.8±2.1 and 7.8±1.5 to 2.0±0.6 and 1.78±1.1, respectively, at the 1-year follow up (P<0.01). The Oswestry Disability Index score significantly improved from 28.6±11.7 to 7.4±2.9 (P<0.01). Ninety-nine patients (97.1%) showed good outcomes. CONCLUSIONS: A new IELD technique and instruments can overcome the drawbacks of existing IELD with adequate bone work and control of the affected nerve root.

Intraoperative Disc Prolapse During Percutaneous Endoscopic Lumbar Discectomy.

BACKGROUND: Percutaneous endoscopic lumbar discectomy (PELD) is regarded as an alternative treatment for lumbar disc herniation. Although the indication for PELD has expanded with remarkable evolution of the technique, sometimes unexpected complications have occurred during PELD. We report 3 cases of de novo disc prolapse during PELD. CASE DESCRIPTION: In 3 patients who underwent PELD for lumbar disc herniation with local anesthesia, postoperative magnetic resonance imaging demonstrated newly developed up-migrated disc herniation. Compared with their preoperative states, these patients experienced decreased intensity of both leg and back pain. There were no neurologic deficits. PELD was repeated for L1-L2 disc herniation only to relieve compression of the conus medullaris. CONCLUSIONS: Although the incidence was very low (0.3%) and the lesions were nonsymptomatic, de novo disc prolapse may be associated with an inside-out PELD technique. Discography and insertion of the obturator should be handled gently. The possibility of de novo disc prolapse should be kept in mind when performing PELD.

Cost-effectiveness of microdiscectomy versus endoscopic discectomy for lumbar disc herniation.

BACKGROUND CONTEXT: Microdiscectomy is a standard technique for the surgical treatment of lumbar disc herniation (LDH). Endoscopic discectomy (ED) is another surgical option that has become popular owing to reports of shorter hospitalization and earlier return to work. No study has evaluated health care costs associated with lumbar discectomy techniques and compared cost-effectiveness. PURPOSE: To assess the cost-effectiveness of four surgical techniques for LDH: microdiscectomy (MD), transforaminal endoscopic lumbar discectomy (TELD), interlaminar endoscopic lumbar discectomy (IELD), and unilateral biportal endoscopic discectomy (UBED). STUDY DESIGN AND SETTING: Retrospective analysis. PATIENT SAMPLE: Patients who underwent either MD or ED for primary LDH with 1-year follow-up between the ages of 20 and 60 years old. OUTCOME MEASURES: Incremental cost-effectiveness ratio (ICER). METHODS: Five hundred sixty-five patients aged 20-60 years who underwent treatment using one of the four surgical techniques with at least 1-year follow-up were reviewed. Health care costs were defined as the sum of direct and indirect costs. The former included the covered and uncovered costs of the National Health Insurance from operation to 1-year follow-up; indirect costs included costs incurred by work loss. Direct and indirect costs were evaluated separately. ICER was determined using cost/quality-adjusted life year (QALY). Health care costs and ICER were compared statistically among the four surgical groups. Cost-effectiveness was compared statistically between MD and ED. RESULTS: One hundred fifty-seven patients who underwent TELD, 132 for IELD, 140 for UBED, and 136 for MD were enrolled. The direct costs of TELD, IELD, UBED, and MD were $3,452.2±1,211.5, $3,907.3±895.3, $4,049.2±1,134.6, and $4,302.1±1,028.9, respectively (p<.01). The indirect costs of TELD, IELD, UBED, and MD were $574.5±495.9, $587.8±488.3, $647.4±455.6, and $759.7±491.7, respectively (p<.01). The 1-year QALY gains were 0.208 for TELD, 0.211 for IELD, 0.194 for UBED, and 0.186 for MD. ICER (costs/QALY) was the highest for MD ($34,840.4±25,477.9, p<.01). Compared with MD, ED saved an additional net of $8,064 per QALY (p<.01). There was no significant difference in the ICERs among the three endoscopic techniques. CONCLUSIONS: ED was more cost-effective compared with MD at 1-year follow up.

Comparison of Surgical Invasiveness Between Microdiscectomy and 3 Different Endoscopic Discectomy Techniques for Lumbar Disc Herniation.

OBJECTIVE: Muscle injury is inevitable during surgical exposure of the spine. This study compared paraspinal muscle injury after 4 surgical techniques: microdiscectomy (MD), percutaneous endoscopic lumbar discectomy (PELD), percutaneous endoscopic interlaminar discectomy (PEID), unilateral biportal endoscopic discectomy (UBED). METHODS: Eighty patients who underwent MD, PELD, PEID, and UBED were prospectively observed. Creatine phosphokinase (CPK) and C-reactive protein levels were measured on admission and postoperative days 1, 3, 5, and 7. CPK ratio was calculated as CPK on postoperative day 1/CPK on admission. Cross-sectional area of the high-intensity lesion in the paraspinal muscle was measured on magnetic resonance imaging after surgery. Operative time and hospital stay duration were also examined. Clinical outcome was evaluated using the visual analog scale for back and leg pain. RESULTS: MD group had the highest CPK levels on postoperative days 1 and 3 and CPK ratio (P < 0.01, P = 0.02, P = 0.04). Serial C-reactive protein levels were highest in MD group (P < 0.01). PELD and PEID groups had lower C-reactive protein level on postoperative day 1 than UBED group. MD group had largest cross-sectional area (P < 0.01). Cross-sectional area was larger in UBED group than in PELD and PEID groups (P < 0.01). Operative time and hospital stay duration were shortest in PELD group (P < 0.01, P < 0.01). MD group had significantly higher visual analog scale scores for back pain on postoperative days 1 and 3 than the other groups (P < 0.01, P = 0.02). CONCLUSIONS: PELD is the least invasive spinal surgical technique.

Effects of Percutaneous Sacroplasty on Pain and Mobility in Sacral Insufficiency Fracture.

OBJECTIVE: Sacral insufficiency fracture (SIF) contributes to severe low back pain. Prolonged immobilization resulting from SIF can cause significant complications in the elderly. Sacroplasty, a treatment similar to vertebroplasty, has recently been introduced for providing pain relief in SIF. The purpose of this study is to investigate the clinical short-term effects of percutaneous sacroplasty on pain and mobility in SIF. METHODS: This study is conducted prospectively with data collection. Sixteen patients (3 men and 13 women) with a mean age of 77.5 years (58 to 91) underwent sacroplasty. Patients reported visual analogue scale (VAS; 0-10) and Oswestry disability index (ODI; 0-100%) scores. VAS and ODI scores were collected preoperatively and again at one day, one month, and three months postoperatively. Questionnaires measuring six activities of daily living (ADLs) including ambulating, performing housework, dressing, bathing, transferring from chair, and transferring from bed were collected. Ability to perform ADLs were reported preoperatively and again at three months postoperatively. RESULTS: The mean preoperative VAS score (mean±SD) of 7.5±0.8 was significantly reduced to 4.1±1.6, 3.3±1.0, and 3.2±1.2 postoperatively at one day, one month, and three months, respectively (p<0.01). The mean ODI score (%) also significantly improved from 59±14 preoperatively to 15.5±8.2 postoperatively at one month and 14.8±8.8 at three months (p<0.01). All ADL scores significantly improved at three months postoperatively (p<0.01). CONCLUSION: Percutaneous sacroplasty alleviates pain quickly and improves mobility and quality of life in patients treated for SIF.

Usefulness of Percutaneous Endoscopic Lumbar Foraminoplasty for Lumbar Disc Herniation.

OBJECTIVE: Endoscopic foraminoplasty facilitates engagement of the working cannula via the intervertebral foramen, allowing cannula access near a herniated disc (HD) for successful application of percutaneous endoscopic lumbar discectomy (PELD). The purpose of this study was to evaluate the efficacy of foraminoplasty for HD and propose applicable situations for foraminoplasty in PELD. METHODS: A retrospective review of consecutive patients who underwent PELD was performed. Patients were divided into a foraminoplasty group (FG) and nonforaminoplasty group (NFG). Group differences in disc location and radiologic parameters, such as disc height (DH), foraminal width, lamina angle, facet angle, superior articular process thickness, and iliac height, were evaluated. Clinical outcomes were assessed using a visual analog scale for back and leg pain. RESULTS: There were 136 patients (36 FG and 100 NFG) were. The FG had a significantly smaller DH and higher prevalence of high-grade down migration, downward sequestration, and recurrent HD compared with the NFG. For HDs at the L5-S1 level, the FG had a significantly greater iliac crest height and smaller DH and foraminal width compared with the NFG. For central HDs, the FG had a wider lamina angle and smaller DH compared with the NFG. Improvements in back and leg pain were similar in the 2 groups. CONCLUSIONS: Percutaneous endoscopic lumbar foraminoplasty may be effective for small DH, migration, sequestration, recurrent HD, HD in L5-S1 with a high iliac crest, and central HD with a wide lamina angle.

A Strategy of Percutaneous Endoscopic Lumbar Discectomy for Migrated Disc Herniation.

OBJECTIVE: Percutaneous endoscopic lumbar discectomy (PELD) with remarkable advancements has led to successful results comparable with open discectomy; however, its application in herniated disc (HD) with migration is still challenging and technically demanding. The purpose of this study is to propose various strategies for PELD according to HD with migration. METHODS: A retrospective review was performed on 434 consecutive patients who had undergone PELD. HD with migration was classified into 4 zones: low-grade up/down and high-grade up/down based on the extent and direction of migration. Clinical outcomes were assessed by visual analogue scale score for back and leg pain, Oswestry Disability Index, and modified Macnab criteria. Endoscopic approaches and techniques were analyzed depending on HD with migration. RESULTS: A total of 149 patients underwent PELD for HD with migration. There were 93 low-grade down HD patients, 13 high-grade down, 11 low-grade up, and 32 high-grade up. High-grade up HDs were removed with the outside or outside-in techniques from L1-2 to L4-5. High-grade down HDs were removed via the outside technique with additional foraminoplasty. Low-grade up/down HDs with disc space continuity were removed with the inside-out technique. Meanwhile, at the L5-S1 level, interlaminar PELD was used to treat high-grade up/down HD with migration. The mean visual analogue scale score for back pain, leg pain, and Oswestry Disability Index were significantly improved after PELD. Favorable outcome was achieved in 90.6% of cases. CONCLUSIONS: An appropriate strategy for PELD is important for successful removal of HD considering the extent of migration and direction.

Does pre-existing L5-S1 degeneration affect outcomes after isolated L4-5 fusion for spondylolisthesis?

BACKGROUND: Concerns have been raised regarding residual symptoms of caudal segment (L5-S1) degeneration that may affect clinical outcomes or require additional surgery after isolated L4-5 fusion, especially if there is pre-existing L5-S1 degeneration. This study aimed to evaluate the L5-S1 segment after minimally invasive lumbar interbody fusion at the L4-5 segment, as well as the influence of pre-existing L5-S1 degeneration on radiologic and clinical outcomes. METHODS: This retrospective study evaluated patients with isthmic spondylolisthesis and degenerative spondylolisthesis who underwent mini-open anterior lumbar interbody fusion with percutaneous pedicle screw fixation (PSF) or minimally invasive transforaminal interbody fusion with PSF at the L4-5 segment. The minimum follow-up period was 7 years, and radiographic evaluations were conducted via magnetic resonance imaging, computed tomography, and plain radiography at the 5-year follow-up. Clinical outcomes were assessed using the Visual Analog Score, Oswestry Disability Index, and surgical satisfaction rate. Patients were divided into two groups, those with and without pre-existing L5-S1 degeneration, and their final outcomes and incidence of radiographic and clinical adjacent segment disease (ASD) were compared. RESULTS: Among 70 patients who underwent the procedures at our institution, 12 (17.1%) were lost to follow-up. Therefore, this study evaluated 58 patients, with a mean follow-up period of 9.4 ± 2.1 years. Among these patients, 22 patients had pre-existing L5-S1 degeneration, while 36 patients did not have pre-existing L5-S1 segmental degeneration. There were no significant differences in the clinical outcomes at the final follow-up when the two groups were compared. However, radiographic ASD at L5-S1 occurred in seven patients (12.1%), clinical ASD at L5-S1 occurred in three patients (5.2%), and one patient (1.7%) required surgery. In the group with pre-existing degeneration, L5-S1 degeneration was radiographically accelerated in four patients (18.2%) and clinical ASD developed in one patient (4.5%). In the group without pre-existing degeneration, L5-S1 degeneration was radiographically accelerated in three patients (8.3%) and clinical ASD developed in two patients (5.7%). There were no differences in the incidence of ASD when we compared the two groups. CONCLUSIONS: Pre-existing L5-S1 degeneration does not affect clinical and radiographical outcomes after isolated L4-5 fusion.