‘Lumbar Degenerative Kyphosis’ Is Not Byword for Degenerative Sagittal Imbalance: Time to Replace a Misconception

Lumbar degenerative kyphosis (LDK) is a subgroup of the flat-back syndrome and is most commonly caused by unique life styles, such as a prolonged crouched posture during agricultural work and performing activities of daily living on the floor. Unfortunately, LDK has been used as a byword for degenerative sagittal imbalance, and this sometimes causes confusion. The aim of this review was to evaluate the exact territory of LDK, and to introduce another appropriate term for degenerative sagittal deformity. Unlike what its name suggests, LDK does not only include sagittal balance disorder of the lumbar spine and kyphosis, but also sagittal balance disorder of the whole spine and little lordosis of the lumbar spine. Moreover, this disease is closely related to the occupation of female farmers and an outdated Asian life style. These reasons necessitate a change in the nomenclature of this disorder to prevent misunderstanding. We suggest the name “primary degenerative sagittal imbalance” (PDSI), which encompasses degenerative sagittal misalignments of unknown origin in the whole spine in older-age patients, and is associated with back muscle wasting. LDK may be regarded as a subgroup of PDSI related to an occupation in agriculture. Conservative treatments such as exercise and physiotherapy are recommended as first-line treatments for patients with PDSI, and surgical treatment is considered only if conservative treatments failed. The measurement of spinopelvic parameters for sagittal balance is important prior to deformity corrective surgery. LDK can be considered a subtype of PDSI that is more likely to occur in female farmers, and hence the use of LDK as a global term for all degenerative sagittal imbalance disorders is better avoided. To avoid confusion, we recommend PDSI as a newer, more accurate diagnostic term instead of LDK.

Combined Interlaminar and Paraisthmic Approach for Co-existing Intracanal and Foraminal Lesion

OBJECTIVE: Stenosis or herniated nucleus pulposus (HNP) occupying lumbar intracanal and foraminal area is an important cause of double radicular symptoms. Using the combined interlaminar and paraisthmic approach, we performed decompression surgery in patients with co-existing intracanal and foraminal lesions. The objective of this study is to describe usefulness and outcome of combined interlaminar and paraisthmic approach surgery and to analysis the cause of poor outcome. METHODS: Between Apr 2009 and Apr 2014, 78 patients (42 males and 36 females) with intracanal and foraminal lesions were enrolled in this study. Patients with a vacuum disc, spondylolisthesis, instability or an isthmic defect on the preoperative dynamic view radiograph were excluded from this study. All patients underwent surgery through a combined approach for discectomy and decompression. The outcome of surgery was evaluated and classified into excellent, good, fair and poor. RESULTS: The results were excellent in 53 patients, good in 9, fair in 6 and poor in 10 during the follow-up. The outcome of the combined approach was excellent to fair in 87% (68 of 78) patients in our study. In the poor outcome group, three patients complained of early-onset relapsed pain (3 months). CONCLUSION: Combined approach for both intracanal and foraminal area lesions may be useful if selectively performed on patients whose facet joint is relatively intact, and that it is worthy of consideration as an alternative to fusion surgery; however, further studies are needed.

Transdural Nerve Rootlet Entrapment in the Intervertebral Disc Space through Minimal Dural Tear : Report of 4 Cases

Four patients underwent lumbar surgery. In all four patients, the dura was minimally torn during the operation. However, none exhibited signs of postoperative cerebrospinal fluid leakage. In each case, a few days after the operation, the patient suddenly experienced severe recurring pain in the leg. Repeat magnetic resonance imaging showed transdural nerve rootlets entrapped in the intervertebral disc space. On exploration, ventral dural tears and transdural nerve rootlet entrapment were confirmed. Midline durotomy, herniated rootlet repositioning, and ventral dural tear repair were performed, and patients' symptoms improved after rootlet repositioning. Even with minimal dural tearing, nerve rootlets may become entrapped, resulting in severe recurring symptoms. Therefore, the dural tear must be identified and repaired during the first operation.

A Comparison Study on the Change in Lumbar Lordosis When Standing, Sitting on a Chair, and Sitting on the Floor in Normal Individuals

OBJECTIVE: To compare radiographic analysis on the sagittal lumbar curve when standing, sitting on a chair, and sitting on the floor. METHODS: Thirty asymptomatic volunteers without a history of spinal pathology were recruited. The study population comprised 11 women and 19 men with a mean age of 29.8 years. An independent observer assessed whole lumbar lordosis (WL) and segmental lordosis (SL) between L1 and S1 using the Cobb's angle on lateral radiographs of the lumbar spine obtained from normal individuals when standing, sitting on a chair, and sitting on the floor. WL and SL at each segment were compared for each position. RESULTS: WL when sitting on the floor was reduced by 72.9% than the average of that in the standing position. Of the total decrease in WL, 78% occurred between L4 to S1. There were significant decreases in SL at all lumbar spinal levels, except L1-2, when sitting on the floor as compared to when standing and sitting on a chair. Changes in WL between the positions when sitting on a chair and when sitting on the floor were mostly contributed by the loss of SL at the L4-5 and L5-S1 levels. CONCLUSION: When sitting on the floor, WL is relatively low; this is mostly because of decreasing lordosis at the L4-5 and L5-S1 levels. In the case of lower lumbar fusion, hyperflexion is expected at the adjacent segment when sitting on the floor. To avoid this, sitting with a lordotic lumbar curve is important. Surgeons should remember to create sufficient lordosis when performing lower lumbar fusion surgery in patients with an oriental life style.

Clinical and Radiological Findings of Nerve Root Herniation after Discectomy of Lumbar Disc Herniation

The authors report 2 cases of nerve root herniation after discectomy of a large lumbar disc herniation caused by an unrecognized dural tear. Patients complained of the abrupt onset of radiating pain after lumbar discectomy. Magnetic resonance imaging showed cerebrospinal fluid signal in the disc space and nerve root displacement into the disc space. Symptoms improved after the herniated nerve root was repositioned. Clinical symptoms and suggestive radiologic image findings are important for early diagnosis and treatment.

Solitary Hemangioblastoma at the Filum Terminale: A Case Report and Review of Literature

Spinal hemangioblastomas at the filum terminale are rare. Only a few reports present immunohistopathological features of spinal hemangioblastomas. A 55-year-old woman presented with sustained low back pain and intermittent numbness in both lower extremities. She already had a decompressive surgery for a left L5-S1 extraforaminal lesion 7 months ago. Her incidental mass lesion had been slightly enlarged for 7 months and concordant symptoms had also been prolonged. Her tumor was removed en bloc with a unilateral hemilaminotomy and bilateral decompression technique. The patient's symptoms improved immediately after the surgery. In immunohistochemical stains, the stromal cells were positive for inhibin-alpha, neuron specific enolase (NSE), and the endothelial cells were positive for CD31, CD34, and factor VIII related antigen in confirming the diagnosis of hemangioblastoma. We report a rare case of intradural extramedullary spinal hemangioblastoma at the filum terminale. Complete en bloc resection was achieved with no morbidity. The immunohistopathological staining include inhibin-alpha confirmed an accurate diagnosis of the hemangioblastoma distinguishing from other vascular tumors.

Surgical Treatment of Benign Fibrous Histiocytoma as a Form of Intraspinal Extradural Tumor at Lumbar Spine

A benign fibrous histiocytoma (BFH) is one of the fibrohistiocytic groups of soft-tissue tumors for which spinal involvement is extremely rare. To the best of our knowledge, most spine-originating BFHs are bone tumors. We report the first case of BFH occurring in the intraspinal extradural space on the lumbar spine. A 66-year-old female presented with severe claudication symptom. The preoperative magnetic resonance images showed a huge intraspinal, extradural, thecal-sac-compressing soft-tissue tumor that extended along the right L5 root to the neural foramen. The tumor was a relatively well-marginated, inhomogeneous soft-tissue mass with some fluid-containing cystic portions that were well enhanced by the gadolinium contrast dye. After a total facectectomy, the tumor was removed completely. The patient had a good neurological recovery without complications, and no recurrence was noted at the 6-month follow-up.

The Role of Computed Tomography in the Presurgical Diagnosis of Foraminal Entrapment of Lumbosacral Junction

OBJECTIVE: On the basis of preoperative computed tomography (CT) scans, we studied the change of the size of anterior primary division (APD) of the L5 spinal root in the presence of foraminal/extraforaminal entrapment of the L5 spinal root. METHODS: Two independent radiologists retrospectively reviewed the preoperative CT scans of 27 patients treated surgically and compared the sizes of the APDs on bilateral L5 spinal roots. If one side APD size was larger than the other side APD size, it was described as left or right "dominancy" and regarded this as "consensus (C)" in case that there was a consensus between the larger APD and the location of sciatica, and regarded as "non-consensus (NC)" in case that there was not a consensus. Oswestry Disability Index (ODI) scores were used for preoperative and postoperative evaluation. RESULTS: On CT scans, twenty-one (77%) of 27 patients were the consensus group (APD swelling) and 6 (22%) were a non-consensus group (APD no swelling). In 9 patients with acute foraminal disc herniations, asymmetric enlargement of the APD on L5 spinal root was detected in all cases (100%) and detected in 11 (64%) of 17 patients with stenosis. Preoperative ODI score was 75-93 (mean 83) and postoperative ODI scores were improved to 13-36 (mean 21). The mean follow-up period was 6 months (range, 3-11 months). CONCLUSION: An asymmetric enlargement of the APD on L5 spinal root on CT scans is meaningfully associated with a foraminal or extraforaminal entrapment of the L5 spinal root on the lumbosacral junction.

Mobility of Intradural Extramedullary Schwannoma at Spine : Report of Three Cases with Literature Review

Although very rare, a few cases of intradural extramedullary (IDEM) spinal tumor migration have been reported since Tomimatsu first reported a mobile schwannoma of the cervical cord in 1974. Schwannoma is a neurogenic tumor which originates from nerve sheath that it is relatively well-marginated tumor with little attachment or adhesion to surrounding tissue. Mobility of tumor in spinal canal sometimes can result in negative exploration at the expected area. We found three interesting cases in which different tumor locations observed in repeated magnetic resonance image (MRI) findings. All tumors were intradural and extramedullary schwannoma. We reviewed the literature about moving tumor in the spine through PUBMED search.

Sagittal Imbalance

Sagittal imbalance in adult population has a significant impact on health-related quality of life. Successful surgical treatment of sagittal plane deformities is crucial because it can significantly improve patient's quality of life. However, this reconstructive surgery for deformity is challenging for both patient and physician. Osteoporosis and systemic disease are important considerations in preparation of the surgery because they may be associated with the relatively high rate of complications. Therefore, careful planning of the meticulous surgical technique and vigilant postoperative follow-up may help in minimizing the occurrence of complications and optimizing the patients' out- comes.

Repeated Vertebral Body Fracture at Different Levels due to Sagittal Imbalance

The authors report a case of repeated vertebral body fracture at different levels due to sagittal imbalance resulting from long level spinal fusion after thoracic discectomy. A 69-year-old woman with severe cord compression at T9-T10-T11 due to calcified herniated discs underwent an anterior thoracotomy via the left transpleural approach followed by discectomy of T9-T10-T11. Six weeks later, she complained of severe thoracic and right flank pain after falling over. A newly developed burst fracture resulting in sagittal imbalance was detected, so the authors performed posterior fusion from T8 to L2 and pedicle screw fixation. Unfortunately, 4 months after the second ope- ration the patient revisited our hospital complaining of severe back and right leg pain. The whole spine lateral view revealed a newly developed bursting fracture of L3 and more aggravated sagittal imbalance accompanied with junctional kyphosis at the L2-L3 level. The authors performed a third operation composed of anterior lumbar inter- body fusion at the L5-S1 level and L3 closing wedge osteotomy with fixation for better sagittal balance and nerve decompression. The patient showed no evidence of postoperative neurological compromise. Her back and leg pain improved over time, and she was completely pain-free at 4 months after the surgery

Morphologic Changes of L5 Root at Coronal Source Images of MR Myelography in Cases of Foraminal or Extraforaminal Compression

OBJECTIVE: Two findings easily found at coronal source images of MR myelography (MRM) were evaluated : dorsal root ganglion (DRG) swelling and running course abnormality (RCA) of L5 exiting root at foramen or extraforamen. We tried to find the sensitivity of each finding when root was compressed. METHODS: From 2004 July to 2006, one hundred and ten patients underwent one side paraspinal decompression for their L5 root foraminal or extraforaminal compression at L5-S1 level. All kinds of conservative treatments failed to improve leg symptom for several months. Before surgery, MRI, CT and MRM were done. Retrospective radiologic analysis for their preoperative MRM coronal source images was done to specify root compression sites and L5 root morphologic changes. RESULTS: DRG swelling was found in 66 (60%) of 110 patients. DRG swelling has statistically valuable meaning in foraminal root compression (chi-square test, p < 0.0001). Seventy-two (66%) in 110 patients showed abnormal alteration of running course. Abnormal running course has statistically valuable meaning in foraminal or extraforaminal root compression (chi-square test, p < 0.0001). CONCLUSION: Three-dimensional MRM provides precise thin sliced coronal images which are most close to real operative views. DRG swelling and running course abnormality of L5 exiting root are two useful findings in diagnosing L5 root compression at L5-S1 foramen or extraforamen. MRM is thought to provide additional diagnostic accuracy expecially in L5-S1 foraminal and extraforaminal area.

The Ligamentotactic Effect on a Herniated Disc at the Level Adjacent to the Anterior Lumbar Interbody Fusion : Report of Two Cases

The authors report two cases of spontaneous regression of disc herniation at the level adjacent to the anterior lumbar interbody fusion (ALIF) level. This phenomenon may be due to the increased tension on the posterior longitudinal ligament (PLL) by appropriate restoration of the disc height and lumbar lordosis, which is a mechanism similar to ligamentotaxis applied to the thoracolumbar burst fracture.

Posterior Atlantoaxial Fixation with a Combination of Pedicle Screws and a Laminar Screw in the Axis for a Unilateral High-riding Vertebral Artery

A vertebral artery (VA) injury presents a difficult problem in atlantoaxial fixation. Recent technical reports described posterior C2 fixation using bilateral, crossing C2 laminar screws. The translaminar screw technique has the advantages of producing little risk of VA injury and the unconstrained screw placement. In addition, biomechanical studies have demonstrated the potential of the translaminar screw technique to provide a firmer construct that is equivalent to methods currently used. We report the successful treatment of C1-2 instability with a left-side high-riding VA. Because of the potential risk of VA injury, we performed a posterior C1-2 fixation with a combination of pedicle screws and a laminar screw in C2. We first placed bilateral C1 lateral mass screws and a right-side C2 pedicle screw. However, placement of the left- side C2 pedicle screw was technically difficult due to a narrow isthmus and pedicle. A laminar screw was inserted instead and authors believe that this posterior C1-C2 fixation with a combination of pedicle screws and a laminar screw in C2 can be a useful alternative technique for the treatment of C1-C2 instability in the presence of a unilateral high-riding VA.

A Morphometric Analysis of Neuroforamen in Grade I Isthmic Spondylolisthesis by Anterior Lumbar Interbody Fusion with Pedicle Screw Fixation

OBJECTIVES: The aim of this study was to evaluate the morphometric changes in neuroforamen in grade I isthmic spondylolisthesis by anterior lumbar interbody fusion (ALIF). METHODS: Fourteen patients with grade I isthmic spondylolisthesis who underwent single level ALIF with percutaneous pedicle screw fixation were enrolled. All patients underwent standing lateral radiography and magnetic resonance imaging (MRI) before surgery and at 1 week after surgery. For quantitative analysis, the foraminal height, foraminal width, epidural foraminal height, epidural foraminal width, and epidural foraminal area were evaluated at the mid-portion of 28 foramens using T2-weighted sagittal MRI. For qualitative analysis, degree of neural compression in mid-portion of 28 foramens was classified into 4 grades using T2-weighted sagittal MRI. Clinical outcomes were assessed using Visual Analogue Sale (VAS) scores for leg pain and Oswestry disability index before surgery and at 1 year after surgery. RESULTS: The affected levels were L4-5 in 10 cases and L5-S1 in 4. The mean foraminal height was increased (p<0.001), and the mean foraminal width was decreased (p=0.014) significantly after surgery. The mean epidural foraminal height (p<0.001), epidural foraminal width (p<0.001), and epidural foraminal area (p<0.001) showed a significant increase after surgery. The mean grade for neural compression was decreased significantly after surgery (p<0.001). VAS scores for leg pain (p=0.001) and Oswestry disability index (p=0.001) was decreased significantly at one year after surgery. CONCLUSION: Foraminal stenosis in grade I isthmic spondylolisthesis may effectively decompressed by ALIF with percutaneous pedicle screw fixation.

Acute Spinal Epidural Hematoma Following Unilateral Laminectomy for Bilateral Decompression

We present a case of acute spinal epidural hematoma(EDH) following unilateral laminectomy for bilateral decompression(ULBD). A 45-year-old male presented with severe multi-level spinal stenosis underwent ULBD on the left side at the L2-3 and L3-4 level. Five hours after operation, paraparesis developed along with severe bilateral buttock pain. The CT scan showed an acute spinal EDH at the L2-3 level. The acute spinal EDH was successfully decompressed after emergency decompressive surgery with performing an additional laminectomy on the contralateral side at the L2-3 level. Although ULBD is an effective minimally invasive surgical technique for treating spinal stenosis, the possibility of acute spinal EDH should be kept in mind, as happened in our case.

Anterior Lumbar Interbody Fusion with Pedicle Screw Fixation for Elderly Isthmic Spondylolisthesis

OBJECTIVE: The surgical outcome of anterior lumbar interbody fusion(ALIF) with pedicle screw fixation for elderly isthmic spondylolisthesis was analyzed. METHODS: Consecutive nineteen elderly patients (aged 65 years or more) with isthmic spondylolisthesis (Grade I or II) who underwent single level ALIF with pedicle screw fixation in 2002 were analyzed. Using clinical chart and mailed questionnaires, preoperative and postoperative Visual Analogue Scale(VAS) of back and leg pain and postoperative Macnab criteria were evaluated. RESULTS: The mean age at the time of operation was 68.4 years (range 65 to 78 years). Twelve patients underwent ALIF with percutaneous pedicle screw fixation. Seven patients underwent ALIF followed by posterior decompression and pedicle screw fixation. The postoperative complication rate was 10.5% (wound dehiscence in 1 patient and incisional hernia in 1 patient). There was no postoperative major morbidity or mortality. At a mean follow-up duration of 30.7 months (range 25 to 35 months), 93.3% (14/15) of the patients showed excellent or good outcomes in terms of Macnab criteria. The mean VAS scores of back pain and leg pain significantly decreased after surgery. CONCLUSION: ALIF with pedicle screw fixation yielded favorable results for elderly isthmic spondylolisthesis in selected cases.

Isthmic Spondylolisthesis Associated with Foraminal Disc Herniation Treated by Anterior Lumbar Interbody Fusion

A 45-year-old man presented with lower back pain and pain in the right leg of 3years duration. A plain radiographic examination revealed grade I isthmic spondylolisthesis, with instability at L4-5. Computed tomography and magnetic resonance imaging demonstrated bilateral foraminal stenosis, with soft foraminal disc herniation on the right side at the L4-5 level. He underwent anterior lumbar interbody fusion(ALIF) with percutaneous posterior fixation(PF) at the L4-5 level. Without removing the posterior bony structures, removal of foraminal disc herniation and reduction of spondylolisthesis were successfully performed using ALIF with percutaneous PF. When there is no hard disc herniation or lateral recess stenosis, ALIF with percutaneous PF can be one of the treatment options for isthmic spondylolisthesis, even in the presence of foraminal disc herniation, as in our case.

The Morphometric Analysis of the Extraforamen in the Lumbosacral Spine: Magnetic Resonance Imaging and Computed Tomography Study

OBJECTIVE: The goal of this study is to establish the anatomical criteria of the normal and stenotic lumbosacral extraforaminal tunnel, and also to determine the effect of the pathologic intervertebral disc on the size of extraforaminal tunnel in the lumbosacral spine. METHODS: MRI and CT scans were reviewed and classified into two groups: (1) 40patients with normal discs at L5-S1 (Group 1) and (2) 43 patients that had undergone successful decompression surgery for extraforaminal entrapment at the lumbosacral region(Group 2). In these two groups, the following parameters were compared are compared: the distance between the disc margin and the ala (lumbosacral tunnel) on the axial MRI, and the posterior disc height at L5-S1 on the mid-sagittal MRI. RESULTS: In the group 1, the mean distance of the lumbosacral tunnel on the axial MRI was 10.1+/-2.2mm. The mean posterior disc height at L5-S1 was 7.4+/-1.7mm on the mid-sagittal MRI. In the group 2, the mean distance between the disc margin and the ala (costal process) was 1.6+/-1.3mm on the axial MRI. The average posterior disc height was 4.4+/-1.5mm on the mid-sagittal MRI. The posterior disc height and the size of the lumbosacral tunnel between the two groups were statistically different on the paired t-test (p<0.0001). However, the posterior disc height was not positively correlated with the size of the extraforaminal tunnel for group 2 (p=0.909). CONCLUSION: The extraforaminal stenosis was correlated to pathologic disc. However, the posterior disc height was not correlated to the size of the of the extraforaminal tunnel.

The Triple Entrapment Syndrome of the 5th Lumbar Spinal Nerve

OBJECTIVE: The 5th lumbar spinal nerve can be entrapped in the intraspinal zone, foraminal zone, and the extraforaminal zone simultaneously. The failure to recognize that the nerve root can be compressed in such manners may be the reason of a number of failures of surgical decompression. Here we describe a microsurgical method for the decompression of the triple entrapment of the L5 spinal nerve in 21 patients. METHODS: Clinical manifestations and surgical results of twenty-one patients treated surgically under the diagnosis of the triple entrapment of the L5 spinal nerve were reviewed retrospectively. All patients were treated by the posterior midline approach for the intraspinal entrapment and by the paraspinal approach for the foraminal and the extraforaminal entrapment. RESULTS: Pain relief was obtained in all patients immediately after surgery. The mean follow-up period after the surgery was 13 months, ranged from 6 to 24 months. The mean Numeric Rating Scale (pain score) improved from 8.9 before the surgery to 1.4 (p < 0.0001). The mean ODI scores improved from 76.2 before the surgery to 13.1 (p < 0.0001). Nineteen patients were satisfied with their result at the last follow-up examination. Neither complications related to the surgery, nor the spinal instability was detected. CONCLUSION: The triple entrapment of the 5th lumbar spinal nerve is an important pathologic entity to identify for the treatment of L5 radiculopathy. Combined medial and lateral approaches are safe, minimally invasive and it provide the complete decompression of triple entrapment of the L5 spinal nerve without causing secondary instability like after complete facetectomy.