Comparison of Short-Term Clinical Results and Radiologic Changes Between Two Different Minimally Invasive Decompressive Surgical Methods for Lumbar Canal Stenosis: Lumbar Spinous Process Splitting Laminectomy and Trans-Interspinous Lumbar Decompression.

STUDY DESIGN: A multicenter, retrospective study. OBJECTIVE: To clarify the clinical and radiological effects of removing interspinous contextures in lumbar decompression surgery for patients with lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: There have seldom been reports that have compared both clinical results and radiological changes among minimally invasive decompression methods. METHODS: Consecutive 52 patients underwent lumbar spinous process-splitting laminectomy (LSPSL), following which 50 patients underwent trans-interspinous lumbar decompression (TISLD). All patients presented with cauda equina type of lumbar spinal stenosis and underwent a minimum 1-year follow-up. The Japanese Orthopaedic Association (JOA) score and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) score were evaluated to determine the extent of daily living activities. Propensity score (PS)-matched analysis was used to match patients' age and preoperative JOA scores between the two groups. Lumbar lordosis (LL), disc height (DH), segmental range of motion (ROM), and vertebral anterior translation were measured by functional lumbar lateral x-ray, and changes between preoperative and 1-year postoperative values were evaluated. RESULTS: Twenty-nine pairs of patients were selected by PS-matching. Mean JOA scores increased from 14.4 to 23.5 (mean recovery rate was 62.3%) in the LSPSL group and from 14.0 to 23.2 (61.3%) in the TISLD group at preoperative and 1-year follow-up, respectively. There were no significant differences in clinical results and changes in LL, ROM, and vertebral anterior translation in each group. The DH at L4/5 level at 1-year after surgery revealed significant decrease in the TISLD group compared with the LSPSL group. There was a correlation between preoperative DH and DH decrease in the LSPSL group, but not in TISLD group. CONCLUSION: Removal of interspinous contextures did not influence clinical outcomes at 1 year after surgery, but it may be likely to cause disc height loss when it applied at the L4/5 level.Level of Evidence: 3.

Indications for prophylactic lumbar decompression at the L3/4 level in patients with L4/5 responsible lumbar spinal canal stenosis.

INTRODUCTION: Lumbar spinal canal stenosis (LSS) is a very common disease. When the responsible level is considered to be L4/5 despite the appearance of double-level (L3/4 and L4/5) stenosis on magnetic resonance imaging (MRI), it is difficult for spinal surgeons to decide whether prophylactic decompression should be performed at the L3/4 level. The purpose of this study was to investigate the relationship between the dural sac cross-sectional area (DCSA) at the L3/4 level and clinical symptoms in patients with double-level stenosis. METHODS: Thirty-five patients with double-level stenosis were registered in this study. All patients underwent decompression surgery at the L4/5 responsible level. The severity of patients' symptoms was evaluated by the Japanese Orthopaedic Association (JOA) score and its rate of recovery. A measurement program on MRI was used to determine the DCSA. RESULTS: The clinical course of LSS according to the JOA score recovery rate at the final follow-up revealed that the good group (≥50%) included 27 patients, and the poor group (<50%) included 8 patients. In the good group, the mean DCSA at the L3/4 level was 72.3 ± 32.1 mm2 preoperatively and 71.3 ± 29.0 mm2 at the final follow-up. In contrast, in the poor group, the mean DCSA at the L3/4 level was 49.1 ± 23.8 mm2 preoperatively and 40.6 ± 14.1 mm2 at the final follow-up. Significant differences were observed in the preoperative and final follow-up DCSAs at the L3/4 level between two groups. CONCLUSIONS: Considering the present results, prophylactic decompression surgery at the L3/4 level should be performed for patients with double-level stenosis and DCSA <50 mm2 at the L3/4 level.

The relationship between the anatomy of the nuchal ligament and postoperative axial pain after cervical laminoplasty: cadaver and clinical study.

STUDY DESIGN: A cadaver and clinical study investigated the attachment of the nuchal ligament to the cervical spinous process. OBJECTIVE: To investigate the anatomical details of the attachment of the nuchal ligament to the spinous process and the relationship between the morphology of the nuchal ligament and postoperative axial pain after laminoplasty. SUMMARY OF BACKGROUND DATA: The relationship between the length of the C6 spinous process and the morphology of the nuchal ligament and occurrence of postoperative axial pain has not been elucidated. METHODS: The morphology of the nuchal ligament was investigated in 35 cadavers and 60 patients on preoperative computed tomography and magnetic resonance imaging. The lengths of the C6 and C7 spinous processes were measured, and the C6:C7 ratio (C6 spinous process length/C7 spinous process length) was calculated. The relationship between the morphology of the attachment of nuchal ligament to the C6 spinous process and the C6:C7 ratio were investigated. In addition, the effects of the anatomy of the nuchal ligament around the C6 spinous process and different procedures of surgical invasion to C6 or C7 on postoperative axial pain were investigated for 113 patients who underwent laminoplasty. RESULTS: The nuchal ligament was attached to not only the C7 spinous process, but also the C6 spinous process when the C6:C7 ratio was more than 0.8. When the nuchal ligament was attached to the C6 spinous process and to C7, postoperative axial pain after C3-C7 laminoplasty occurred more often compared with C3-C6 laminoplasty for patients without the nuchal ligament attached to the C6 spinous process. CONCLUSION: This study shows that there is an association between the individual anatomical differences of the nuchal ligament and the occurrence of postoperative axial pain after laminoplasty. Careful attention should be paid to the morphology of the attachment of the nuchal ligament to the C6 spinous process to reduce postoperative axial pain.

Simple foot tapping test as a quantitative objective assessment of cervical myelopathy.

STUDY DESIGN: A clinical and cohort study. OBJECTIVE: The first purpose of this study was to investigate the standard value of a simple foot tapping test (FTT) in a large healthy population. The second purpose was to elucidate the validity of FTT as a quantitative assessment of lower extremity motor function for cervical compressive myelopathy. SUMMARY OF BACKGROUND DATA: Several clinical performance tests have been reported as objective assessments for the severity of cervical myelopathy. The FTT is the simplest and easiest method for a quantitative analysis of lower limb motor dysfunction in the upper motor neuron diseases. However, there were few studies about the FTT in cervical myelopathy. METHODS: We recruited 252 patients who were diagnosed with cervical myelopathy and 792 healthy volunteers who participated in a health promotion project. Among the patients, 126 who underwent surgery were evaluated both before and 1 year after surgery. We performed the FTT and grip and release test and evaluated the modified Japanese Orthopaedic Association (JOA) score for cervical myelopathy. RESULTS: The mean value of FTT was 23.8 ± 7.2 in myelopathic patients, which was significantly lower than 31.7 ± 6.4 in healthy controls and decreased with age. The value of FTT significantly correlated with the lower extremity motor function of modified JOA score and the value of grip and release test. Among the patients who underwent surgery, the average value of FTT was 22.4 ± 7.0 preoperatively and improved to 28.4 ± 8.1 at 1 year postoperatively. Postoperative gain of FTT significantly correlated with the gain of JOA score. CONCLUSION: The FTT results correlated with those of other tests for cervical myelopathy, and the FTT scores were improved by surgery. The FTT is an easy and useful quantitative assessment method for lower extremity motor function in patients with cervical myelopathy, especially those who cannot walk.

Perioperative cardiopulmonary complications after cervical spine surgery in the prone position: the relationship between age and preoperative testing.

BACKGROUND: Cardiac arrest during spine surgery in the prone position is difficult to manage as poor access makes cardiopulmonary resuscitation and defibrillation difficult. Advanced age is the maximal risk factor for cardiac arrest. Therefore, we wanted to determine the relationship between age and cardiac risk factors/pre-operating tests for cervical spine surgery in the prone position. METHODS: The inclusion criteria for this study specified 88 patients scheduled should undergo cervical spine surgery in the prone position. The patients were divided into two groups: Paients in group A (50 patients) were aged 69 and under, Group B (38 patients) 70 and above. All patients responded to a medical interview about eight cardiac risk factors including past history, chest symptoms, diabetes mellitus, hypertension, hyperlipidemia, obesity, smoking, and family history. All patients underwent physical examination and 24-h Holter ECG and echocardiography performed by two cardiologists before surgery. We analyzed relationships between cardiac risk factors and ECG/echocardiography and investigated intra- and postoperative cardiovascular complications. RESULTS: Although there were no significant differences in the number of cardiac risk factors between the two groups, the frequency of hypertension was significantly greater in Group B than in Group A. The frequency of abnormal ECG and echocardiography findings especially was significantly greater in Group B than in Group A. In ECG and echocardiography, three patients in Group B who had no cardiac risk factors before surgery showed abnormal findings, and one of the three patients had the amalgamation of arrhythmia after the operation. Also, in Group B, cardiovascular complications occurred in one case during operation. CONCLUSION: These results suggested that patients aged 70 and above should undergo ECG and echocardiography examination before cervical spine surgery in the prone position whether they have cardiac risk factors or not . A prospective, randomized multi-center study with a larger patient sample is warranted to ultimately demonstrate how patients should be tested before spine surgery in the prone position.

Surgical anatomy of the nuchal muscles in the posterior cervicothoracic junction: significance of the preservation of the C7 spinous process in cervical laminoplasty.

STUDY DESIGN: An anatomic study investigated the attachment of the nuchal muscles to the spinous process. OBJECTIVE: To investigate the anatomic details of the attachment of the nuchal muscles to the spinous process, and which muscles are spared, and to what extent, when the C7 spinous process is preserved in the cervical laminoplasty. SUMMARY OF BACKGROUND DATA: In previous studies, it was reported that the incidence of postoperative axial pain was lower in C3-C6 laminoplasty than in C3-C7 laminoplasty, emphasizing the effectiveness of the former procedure where discission of the nuchal muscles that are attached to the C7 spinous process is avoided. However, there have been no detailed anatomic studies of the attachment of the nuchal muscles to the spinous process at the cervicothoracic junction. METHODS: The anatomy of the speculum rhomboideum of the trapezius, rhomboideus minor, rhomboideus major, serratus posterior superior, splenius capitis, and splenius cervicis to the spinous processes of the cervicothoracic junction were studied using 50 cadavers. RESULTS: The possibility of total discission of the speculum rhomboideum of the trapezius was 0% with C3-C6 laminoplasty and 18% with C3-C7 laminoplasty. More than 50% preservation of the speculum rhomboideum of the trapezius is possible in 72% in C3-C6 laminoplasty and 16% in C3-C7 laminoplasty. In C3-C7 laminoplasty, the possibility of partial preservation of the rhomboideus minor, serratus posterior superior, and splenius capitis at the spinous process was 0%, 66%, and 29%, respectively. The rhomboideus major in 16% and the splenius cervicis in 56% could be completely preserved without partial discission of the muscle attachment. On the other hand, in C3-C6 laminoplasty, the muscles that were spared without complete discission of the muscular attachment at the spinous process were the rhomboideus minor in 35%, the serratus posterior superior in 100% and the splenius capitis in 67%. The rhomboideus major in 76% and the splenius cervicis in 80% were completely spared without partial discission of the muscular attachment. CONCLUSION: The current study confirmed that C3-C6 laminoplasty in which the C7 spinous process is preserved reduces invasion of the nuchal muscles.

Cervical spinal motion before and after surgery in patients with Chiari malformation type I associated with syringomyelia.

OBJECT: There have been few reports about the cervical spinal motion in patients with Chiari malformation Type I (CM-I) associated with syringomyelia. To investigate this phenomenon, the relationship between the preoperative cervical range of motion (ROM) and the stage of cerebellar tonsillar descent as well as the cervical ROM before and after foramen magnum decompression (FMD) were evaluated. METHODS: Thirty patients who had CM-I associated with syringomyelia and who underwent FMD participated in the study. The ROM and lordosis angle of the cervical spine were measured on x-ray films. In addition, the relationship between preoperative degree of cerebellar tonsillar descent and the ROM between the levels of the occiput (Oc) and C2 was investigated. RESULTS: The mean flexion-extension ROM at Oc-C2 was 15.5 degrees before and 14.1 degrees after surgery, and the mean flexion-extension ROM of C2-7 was 55.1 degrees before and 52.8 degrees after surgery. The mean pre- and postoperative lordosis angles at C2-7 were 16.8 and 19.1 degrees, respectively. There was no significant difference between the values measured before and after surgery. There was no correlation between the degree of cerebellar tonsillar descent and the ROM at Oc-C2. CONCLUSIONS. Foramen magnum decompression is an excellent surgical technique that has no effect on the postoperative cervical ROM and cervical alignment.

Surgical outcomes in adult patients with syringomyelia associated with Chiari malformation type I: the relationship between scoliosis and neurological findings.

OBJECT: The clinical characteristics of pediatric scoliosis associated with syringomyelia have been reported in previous studies, but scoliosis associated with syringomyelia in adults is rarely treated, and there is a paucity of detailed studies. In the present study of adult syringomyelia associated with Chiari malformation Type I, the authors investigated the relationships among the syrinx, scoliosis, and neurological data. METHODS: The population was composed of 27 patients (> or = 20 years of age) who underwent foramen magnum decompression for the treatment of syringomyelia. The patients were divided into two groups: those with scoliosis of 10 degrees or more (Group A) and those without scoliosis (Group B). The authors assessed the length of the syrinx, duration of morbidity, and clinical status before and after surgery based on the Japanese Orthopaedic Association (JOA) Scale. There were 15 cases in Group A and 12 in Group B. The mean length of the syrinx was 12.8 vertebral bodies (VBs) in Group A and 7.2 VBs in Group B. The mean duration of morbidity was 14.2 years in Group A and 6.8 years in Group B. The mean preoperative JOA score was 10.1 in Group A and 14.4 in Group B, whereas the mean postoperative JOA scores were 11.9 and 15.8, respectively. There were significant differences between Groups A and B in length of the syrinx, duration of morbidity, and pre- and postoperative JOA scores. CONCLUSIONS: In patients with syringomyelia and scoliosis the syringes spanned a greater number of VBs, the duration of morbidity was greater, neurological dysfunction was more severe, and surgical results were poorer. Scoliosis could be a predicting factor of the prognosis in patients with syringomyelia and Chiari malformation Type I.

Postoperative changes at the lower end of cervical laminoplasty: for preservation of the C7 spinous process in laminoplasty.

INTRODUCTION: C3-C7 laminoplasty has been the standard treatment for cervical myelopathy, although several recent reports described C3-C6 laminoplasty for preserving the muscles inserting in C7 and reducing postoperative axial symptoms. However, postoperative changes at C6/C7 of the lower end of C3-C6 laminoplasty, especially regarding a possibility of postoperative spinal canal narrowing have not been measured. The purpose of this study was to clarify postoperative changes at the lower end of laminoplasty. METHODS: Pre and postoperative spinal dura diameter at the lower end of conventional C3-C7 laminoplasty using MRI, and the related factors for spinal dura diameter and the causes of postoperative dura narrowing were investigated. RESULTS: At the last follow-up after C3-C7 laminoplasty, dura diameter at C7/T1 was significantly wider after operation than before operation, and postoperative narrowing of dura diameter, which was found in 20% of patients, was a maximum amount of one millimeter. No pre and postoperative factor significantly correlated with dura diameter at C7/T1. The causes of postoperative narrowing at the lower end of laminoplasty were disc protrusion and/or posterior scar, or segmental angulation of the spinal cord. CONCLUSION: In conclusion, the presence of preoperative subarachnoid space over one millimeter at C6/C7 may be able to be one of the radiological indications for C3-C6 laminoplasty.

Inadvertent C2-C3 union after C1-C2 posterior fusion in adults.

INTRODUCTION: Some authors pointed out that there were more than a few patients with inadvertent C2-C3 union after C1-C2 posterior fusion, although few detailed studies of C2-C3 union have been reported. The purpose of this study was to clarify whether C2-C3 union accelerated adjacent C3-C4 disc degeneration after C1-C2 posterior fusion and to investigate the related factors for C2-C3 union. METHODS: Sixteen patients with rheumatoid arthritis (RA group) (4 males, 12 females, mean age 60 years, mean follow-up period 4 years and 3 months) and fifteen patients without RA (non-RA group) (11 males, 4 females, mean 52 years, mean follow-up period 3 years and 10 months) who underwent C1-C2 posterior fusion were radiologically assessed. The C2-C3 union was defined as trabecular bone formation at C2-C3 interlamina in lateral radiograph. C3-C4 disc height was measured to evaluate the disc degeneration. RESULTS: C2-C3 union rate was 56% and 60% in RA group and non-RA group, respectively. In RA group, postoperative C3-C4 disc height was lower (Student's t-test, P = 0.029) and the decrease rate of C3-C4 disc height was higher (Student's t-test, P = 0.015) in patients with C2-C3 union than in patients without C2-C3 union. In non-RA group, the age at operation was older (Student's t-test, P = 0.0007), and the C1-C2 fusion angle (Student's t-test, P = 0.012) was smaller in patients with C2-C3 union than in patients without C2-C3 union. CONCLUSIONS: C2-C3 union after C1-C2 posterior fusion occurred in more than half of both groups. Inadvertent C2-C3 union should be considered a radiological complication and a potential risk factor due to acceleration of C3-C4 disc degeneration in RA.

Axial symptoms after cervical laminoplasty with C3 laminectomy compared with conventional C3-C7 laminoplasty: a modified laminoplasty preserving the semispinalis cervicis inserted into axis.

STUDY DESIGN: Results of C4-C7 laminoplasty with C3 laminectomy and C3-C7 laminoplasty were compared. OBJECTIVES: To clarify prospectively whether the modified laminoplasty preserving the semispinalis cervicis inserted into C2 could reduce the axial symptoms compared with conventional laminoplasty reattaching the muscle to C2. SUMMARY OF BACKGROUND DATA: Intraoperative damage of the semispinalis cervicis is relevant to the development of axial symptoms after laminoplasty. In C3-C7 laminoplasty, however, it is difficult to preserve the muscle insertion into C2 while opening the C3 lamina. METHODS: The axial symptoms of 40 patients (Group A) with C4-C7 laminoplasty with C3 laminectomy were compared with those of 16 patients (Group B) with C3-C7 laminoplasty. The cross-sectional areas of the cervical posterior muscles were measured on magnetic resonance images. RESULTS: The number of patients with no postoperative axial symptoms increased (P = 0.035) from 19% to 52.5%, and the number of patients whose symptoms worsened after surgery decreased (P = 0.020) from 50% to 17.5%. The average atrophy rate of cross-sectional area was smaller (P < 0.001) in Group A (2.4%) than in Group B (10.8%). CONCLUSIONS: This method was less invasive to the cervical posterior muscles than C3-C7 laminoplasty. This is an effective procedure for preventing postoperative axial symptoms.

Anatomic study of the semispinalis cervicis for reattachment during laminoplasty.

Some patients who had cervical laminoplasty with subsequent substantial loss of cervical lordosis have shown failed healing of a repaired semispinalis cervicis. We also have identified some patients in whom it is difficult to repair the C2 spinous process during laminoplasty. We therefore quantitatively analyzed the morphologic features of the C2 insertion of the semispinalis cervicis and obtained data relevant to the repair of the muscle. In 24 cadavers, the width and height of the semispinalis cervicis insertion in C2 and the length and opening angle of the C2 spinous process were measured. We observed considerable individual variations in the morphologic features of the C2 spinous process and the C2 insertion of the semispinalis cervicis. The opening angle of the C2 spinous process was smaller in males than in females. In most of the cases, the width of the insertion was narrower than the width of the spinous process spacers that commonly are used in laminoplasty. Preoperative prediction of the morphologic features of insertion at the original site is possible by measuring the opening angle of the C2 spinous process using three-dimensional computed tomography because the muscle insertion correlated with the angle of the C2 spinous process. This information may be useful in reattaching the semispinalis cervicis during cervical laminoplasty.