Adjacent-segment disease after L3-4 posterior lumbar interbody fusion: does L3-4 fusion have cranial adjacent-segment degeneration similar to that after L4-5 fusion?

OBJECTIVE: Posterior lumbar interbody fusion (PLIF) is a widely accepted procedure for degenerative lumbar diseases, and there have been many reports concerning adjacent-segment disease (ASD) after PLIF. In the reports of ASD in which the fusion level was limited to 1 segment, all reports describe ASD of the L3-4 segment after L4-5 PLIF. On the basis of these reports, it is thought that ASD mainly occurs at the cranial segment. However, no report has covered ASD after L3-4 PLIF. Therefore, the authors investigated ASD after L3-4 PLIF. METHODS: In conducting a retrospective case series analysis, the authors reviewed a surgical database providing details of all spine operations performed between 2006 and 2017 at a single institution. During that period, PLIF was performed to treat 632 consecutive patients with degenerative lumbar diseases. Of these patients, 71 were treated with L3-4 PLIF alone, and 67 who were monitored for at least 2 years (mean 5.8 years; follow-up rate 94%) after surgery were enrolled in this study. Radiological ASD (R-ASD), symptomatic ASD (S-ASD), and operative ASD (O-ASD) were evaluated. These types of ASD were defined as follows: R-ASD refers to radiological degeneration adjacent to the fusion segment as shown on plain radiographs; S-ASD is a symptomatic condition due to neurological deterioration at the adjacent-segment degeneration; and O-ASD refers to S-ASD requiring revision surgery. RESULTS: All patients had initial improvement of neurological symptoms after primary PLIF. R-ASD was observed in 32 (48%) of 67 patients. It occurred at the cranial segment in 12 patients and at the caudal segment in 24; R-ASD at both adjacent segments was observed in 4 patients. Thus, the occurrence of R-ASD was more significant in the caudal segment than in the cranial segment. S-ASD was observed in 10 patients (15%), occurring at the cranial segment in 3 patients and at the caudal segment in 7. O-ASD was observed in 6 patients (9%): at the cranial segment in 1 patient and at the caudal segment in 5. Thus, the rate of involvement of the caudal segment was 67% in R-ASD, 70% in S-ASD, and 83% in O-ASD. CONCLUSIONS: The incidences of R-ASD, S-ASD, and O-ASD were 48%, 15%, and 9%, respectively, after L3-4 PLIF for degenerative lumbar diseases. In contrast to ASD after L4-5 PLIF, ASD after L3-4 PLIF was more frequently observed at the caudal segment than at the cranial segment. In follow-up for patients with L3-4 PLIF, surgeons should pay attention to ASD in the caudal segment.

Risk factors for a kyphosis recurrence after short-segment temporary posterior fixation for thoracolumbar burst fractures.

Short-segment temporary posterior spinal instrumentation has been widely used to treat thoracolumbar burst fractures. However, kyphosis recurrence without hardware failure has become a concern. Therefore, we investigated risk factors for kyphosis recurrence after short-segment temporary fixation for thoracolumbar burst fractures. Our prospective multicenter study involved 76 consecutive patients with thoracolumbar burst fractures who underwent short-segment temporary posterior fixation using ligamentotaxis with Schanz screws and without fusion. Patients were divided into two groups -kyphosis recurrence and no kyphosis recurrence- according to correction loss of the kyphotic angle. Clinical and radiographic data were examined to reveal the risk factors for postoperative kyphosis recurrence. After surgery, all patients experienced fracture union. Kyphotic deformity was reduced significantly, and maintenance of the reduced vertebra was successful. However, mean 9.1° loss of correction in kyphotic angle was observed. Statistical analysis revealed that a high ratio of canal compromise before surgery, as seen on computed tomography scanning, and a large preoperative kyphotic angle influenced kyphosis recurrence. In conclusion,short-segment temporary posterior fixation yields satisfactory results regarding reduction and maintenance of fractured vertebrae. However, correction loss after implant removal is associated with a high compromised canal ratio before surgery and a large preoperative kyphotic angle.

Fusion Rate and Clinical Outcomes in Two-Level Posterior Lumbar Interbody Fusion.

BACKGROUND: Posterior lumbar interbody fusion (PLIF) has become a general surgical method for degenerative lumbar diseases. Although many reports have focused on single-level PLIF, few have focused on 2-level PLIF, and no report has covered the fusion status of 2-level PLIF. The purpose of this study is to investigate clinical outcomes and fusion for 2-level PLIF by using a combination of dynamic radiographs and multiplanar-reconstruction computed tomography scans. METHODS: This study consisted of 48 consecutive patients who underwent 2-level PLIF for degenerative lumbar diseases. We assessed surgery duration, estimated blood loss, complications, clinical outcomes as measured by the Japanese Orthopaedic Association score, lumbar sagittal alignment as measured on standing lateral radiographs, and fusion status as measured by dynamic radiographs and multiplanar-reconstruction computed tomography. Patients were examined at a follow-up point of 4.8 ± 2.2 years after surgery. Thirty-eight patients who did not undergo lumbosacral fusion comprised the lumbolumbar group, and 10 patients who underwent lumbosacral fusion comprised the lumbosacral group. RESULTS: The mean Japanese Orthopaedic Association score improved from 12.1 to 22.4 points by the final follow-up examination. Sagittal alignment also was improved. All patients had fusion in the cranial level. Seven patients had nonunion in the caudal level, and the lumbosacral group (40%) had a significantly poorer fusion rate than the lumbolumbar group (97%) did. CONCLUSIONS: Surgical outcomes of 2-level PLIF were satisfactory. The fusion rate at both levels was 85%. All nonunion was observed at the caudal level and concentrated at L5-S level in L4-5-S PLIF.

Temporary short-segment pedicle screw fixation for thoracolumbar burst fractures: comparative study with or without vertebroplasty.

BACKGROUND CONTEXT: Short-segment posterior spinal instrumentation for thoracolumbar burst fracture provides superior correction of kyphosis by an indirect reduction technique, but it has a high failure rate. PURPOSE: The purpose of the study we report here was to compare outcomes for temporary short-segment pedicle screw fixation with vertebroplasty and for such fixation without vertebroplasty. STUDY DESIGN: This is a prospective multicenter comparative study. PATIENT SAMPLE: We studied 62 consecutive patients with thoracolumbar burst fracture who underwent short-segment posterior instrumentation using ligamentotaxis with Schanz screws with or without vertebroplasty. OUTCOME MEASURES: Radiological parameters (Cobb angle on standing lateral radiographs) were used. METHODS: Implants were removed approximately 1 year after surgery. Neurologic function, kyphotic deformity, canal compromise, and fracture severity were evaluated prospectively. RESULTS: After surgery, all patients with neurologic deficit had improvement equivalent to at least one grade on the American Spinal Injury Association impairment scale and had fracture union. Kyphotic deformity was reduced significantly, and reduction of the vertebrae was maintained with and without vertebroplasty, regardless of load-sharing classification. Although no patient required additional anterior reconstruction, kyphotic change was observed at disc level mainly after implant removal with or without vertebroplasty. CONCLUSIONS: Temporary short-segment fixation yielded satisfactory results in the reduction and maintenance of fractured vertebrae with or without vertebroplasty. Kyphosis recurrence may be inevitable because adjacent discs can be injured during the original trauma.

Surgical outcomes of temporary short-segment instrumentation without augmentation for thoracolumbar burst fractures.

BACKGROUND: Short-segment posterior spinal instrumentation for thoracolumbar burst fracture provides superior correction of kyphosis by an indirect reduction technique, but it has a high failure rate. We investigated the clinical and radiological results of temporary short-segment pedicle screw fixation without augmentation performed for thoracolumbar burst fractures with the goal of avoiding treatment failure by waiting to see if anterior reconstruction was necessary. METHODS: We studied 27 consecutive patients with thoracolumbar burst fracture who underwent short-segment posterior instrumentation using ligamentotaxis with Schanz screws and without augmentation. Implants were removed approximately 1 year after surgery. Neurological function, kyphotic deformity, canal compromise, fracture severity, and back pain were evaluated prospectively. RESULTS: After surgery, all patients with neurological deficit had improvement equivalent to at least 1 grade on the American Spinal Injury Association impairment scale and had fracture union. Kyphotic deformity was reduced significantly, and maintenance of the reduced vertebra was successful even without vertebroplasty, regardless of load-sharing classification. Therefore, no patients required additional anterior reconstruction. Postoperative correction loss occurred because of disc degeneration, especially after implant removal. Ten patients had increasing back pain, and there are some correlations between the progression of kyphosis and back pain aggravation. CONCLUSION: Temporary short-segment fixation without augmentation yielded satisfactory results in reduction and maintenance of fractured vertebrae, and maintenance was independent of load-sharing classification. Kyphotic change was caused by loss of disc height mostly after implant removal. Such change might have been inevitable because adjacent endplates can be injured during the original spinal trauma. Kyphotic change after implant removal may thus be a limitation of this surgical procedure.

Surgical outcomes for painless drop foot due to degenerative lumbar disorders.

STUDY DESIGN: Twenty patients presenting with painless drop foot who had undergone lumbar spine surgery for degenerative lumbar diseases were included in this retrospective study. OBJECTIVE: This study aims to investigate which causative factors and patient symptoms significantly affected surgical outcome. SUMMARY OF BACKGROUND DATA: Drop foot is a neuromuscular condition that results in dorsiflexion palsy of the ankle. Patients with drop foot often complain of leg pain. Rarely, patients experience painless drop foot due to lumbar degenerative disease. For these patients, the only purpose of surgery is to improve the palsy; this makes it difficult to determine whether surgical intervention is indicated. No studies have focused on the results of surgical treatment for painless drop foot caused by degenerative lumbar diseases. METHODS: Preoperative strength of the tibialis anterior and duration of palsy were recorded and considered with surgical outcome. RESULTS: Sixty-five percent of patients recovered from drop foot after surgery. Drop foot was caused mainly by impairment of the L5 nerve root. Patients with a longer duration of palsy had poorer results. CONCLUSIONS: Duration of palsy had the greatest effect on recovery. As the only goal of this surgery is improvement in the strength of the tibialis anterior, caution must be exercised when considering surgery for patients with longstanding palsy.

Primary amyloidoma in epidural and paravertebral space of the lumbar spine.

BACKGROUND CONTEXT: Localized amyloid deposits result in a mass, that is, so-called amyloidoma; it has been reported in every anatomic site, although systemic amyloid deposition is much more common. However, primary lumbar epidural amyloidoma without bony involvement is extremely rare. To the best of our knowledge, only one case has been reported previously. PURPOSE: To report and review the clinical presentations, imaging studies, and treatment of epidural and paravertebral amyloidoma. STUDY DESIGN: A case report and review of the literature. METHODS: Lumbar epidural and paravertebral amyloidoma in a 75-year-old man with neurologic compromise is presented. Laminectomy with mass resection was performed. RESULTS: After surgery, almost complete neurologic improvement was observed. Histologically, definite diagnosis was obtained only after the specific staining of tissue. No sign of local recurrence was evident 1 year after surgery. CONCLUSIONS: Primary amyloidoma, although rare, should be included in the differential diagnosis of epidural mass of the spine. Diagnosis before surgery is difficult as there were no characteristic findings in clinical and imaging studies. Special histologic technique and stains are useful to make a definite diagnosis.

Incidence of postoperative symptomatic epidural hematoma in spinal decompression surgery.

OBJECT: Neurological deterioration due to spinal epidural hematoma (SEH) is a rare but significant complication of spinal surgery. The frequency of hematoma evacuation after spinal surgery is reportedly 0.1%-3%. The objective of this study was to investigate the symptomatology of SEH and the frequency of evacuation for each surgical procedure after spinal decompression surgery. METHODS: This is a retrospective study of 26 patients who underwent SEH evacuation after spinal decompression surgery between 1986 and 2005. During this period, 6356 spinal decompression surgeries were performed. The factors studied were the frequency of SEH evacuation for each surgical procedure, symptoms, time to SEH evacuation, comorbidities, and neurological recovery. RESULTS: The frequency of SEH evacuation was 0.41% (26 of 6356) for all operations. The frequency for each surgical procedure was 0% (0 of 1568) in standard lumbar discectomy, 0.50% (8 of 1614) in lumbar laminectomy, 0.67% (8 of 1191) in posterior lumbar interbody fusion, 4.46% (5 of 112) in thoracic laminectomy, 0.44% (4 of 910) in cervical laminoplasty, and 0.21% (1 of 466) in cervical anterior spinal fusion. Nine patients had comorbidities involving hemorrhage. Spinal epidural hematoma evacuation was performed between 4 hours and 8 days after the initial operation. Whereas severe paralysis was observed within 24 hours in most patients undergoing cervical and/or thoracic surgery, half of the patients undergoing lumbar surgery had symptoms of SEH such as leg pain or bladder dysfunction after suction drain removal. The shorter the period to evacuation, the better were the results of neurological recovery. CONCLUSIONS: Postoperative SEH was most frequent after thoracic laminectomy. In cervical and thoracic surgeries, symptoms of SEH were noted within 24 hours, mostly severe paralysis, and almost half of the lumbar surgery patients had symptoms after suction drain removal.