Hisatake Yoshihara

MR T2 image classification in cervical compression myelopathy: predictor of surgical outcomes.

Study Design. Prospective imaging study of patients undergoing surgery for cervical compressive myelopathy. Objectives. To investigate whether the classification of increased signal intensity (ISI) on magnetic resonance imaging (MRI) in patients with cervical compressive myelopathy reflects the severity of symptoms and surgical outcome. Summary of Background Data. The association between ISI and surgical outcome in cervical myelopathy remains controversial. The degree of ISI has not been well discussed. Methods. A total of 104 patients with cervical compressive myelopathy were prospectively enrolled. All were treated with cervical expansive laminoplasty. MRI was performed in all patients before surgery. ISI of spinal cord was classified into three groups based on sagittal T2-weighted images as follows: Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). The severity of myelopathy was evaluated according to the Japanese Orthopedic Association (JOA) score for cervical myelopathy. Results. Eighty-six patients (83%) showed ISI before surgery. Patients with ISI were significantly older, and had a longer duration of disease, a lower postoperative JOA score, and a worse postoperative recovery rate of JOA score than those without ISI. Preoperative MRI showed 18 patients in Grade 0, 49 patients in Grade 1, and 37 in Grade 2. Duration of disease was the shortest in Grade 0 and longest in Grade 2. Although there was no significant difference in preoperative JOA scores among the three groups, Grade 0 patients had a higher postoperative JOA score and the best postoperative recovery, and Grade 2 had a lower postoperative JOA score and the worst postoperative recovery. Conclusion. Preoperative ISI on T2-weighted sagittal MRI was correlated with patient age, duration of disease, postoperative JOA score, and postoperative recovery rate. Patients with the greatest ISI had the worst postop erative recovery. Classification of ISI can be a predictor of surgical outcome.

Comparison of surgical outcomes between macro discectomy and micro discectomy for lumbar disc herniation: a prospective randomized study with surgery performed by the same spine surgeon.

Study Design A prospective study was conducted on the surgical procedures for lumbar disc herniation. Objective The objective of this study is to investigate the surgical outcomes of different methods when performed by the same surgeon, using a prospective study. Background Macro discectomy is widely known as a common surgical procedure for lumbar disc herniation, while microdiscectomy in place of Caspar technique (the Caspar method) and microendoscopic discectomy by a posterior approach are reported as less invasive surgical methods for this condition. However, there have not been a significant number of prospective studies conducted to compare different surgical procedures for lumbar disc herniation. Materials and Methods The target of our study was a group of 62 patients (male: 43, female: 19) who underwent surgery by macro discectomy (A group) and 57 patients (male: 33, female: 24) who underwent surgery by microdiscectomy in place of Caspar technique (B group). The mean ages at surgery were 34 (14 to 62) years and 41 (18 to 65) years respectively, and the mean duration of follow-up was 2 years and 8 months (12 months to 4 years). For all patients, the surgery was performed by 1 of the authors. The items investigated were the operation time, amount of bleeding, duration of hospitalization, amount of analgesic agent used after surgery, pre- and postoperative scores based on judgment criteria for treatment of lumbar spine disorders established by the Japanese Orthopaedic Association score, visual analog scales (VAS, 0 to 10) for lumbago before surgery and at discharge, VAS for sciatica before surgery and at discharge, perioperative complications, and cases requiring further surgery. Results There were no significant differences between the 2 surgical procedures in the frequency of use of an analgesic agent after surgery, the pre- and postoperative Japanese Orthopaedic Association scores or postoperative VAS for sciatica. Statistically significant differences were observed in the operation time, amount of bleeding, duration of hospitalization, and postoperative VAS for lumbar pain, but the differences were not large, and may not have been clinically significant. Conclusions For herniotomy for lumbar disc herniation, both macro discectomy and microdiscectomy are appropriate, as long as surgeons have mastery of the procedures.

Surgical outcome of ossification of the posterior longitudinal ligament (OPLL) of the thoracic spine : Implication of the type of ossification and surgical options

Objective: Ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine produces myelopathy through anterior spinal cord compression that is usually progressive and unaffected by conservative treatment. Therefore, early decompressive surgery is imperative. However, decompression surgery of thoracic myelopathy is difficult, and the outcome is often poor. A retrospective study was conducted to investigate the surgical outcome of 21 patients with thoracic OPLL to evaluate which type of surgical approach is better and which type of thoracic OPLL results in a better surgical outcome. Methods: A total of 21 patients with thoracic OPLL (10 men and 11 women; mean age 54 years), who underwent surgical treatment at our department from March 1985 to October 2000, were included in the study. Seven patients exhibited the flat-type OPLL and underwent either anterior decompression and fusion (one patient), anterior decompression via a posterior approach (three patients), or expansive laminoplasty (three patients). Fourteen patients exhibited the beak-type OPLL and also underwent either anterior decompression and fusion (two patients), anterior decompression via a posterior approach (six patients), or expansive laminoplasty (six patients). Results: Regarding of operative time and blood loss, there were no marked differences between the two types of OPLL, regardless of the type of surgical procedure; anterior decompression and fusion and anterior decompression via a posterior approach yielded longer operative times and larger blood loss volumes than expansive laminoplasty. Concerning clinical outcome, there were five cases of neurologic deterioration. All of the five deteriorated cases were of the beak-type OPLL treated by a posterior approach. Two of these patients were treated with expansive laminoplasty. Conclusions: There were five instances of neurologic deterioration in our thoracic OPLL series, and all of them exhibited beak-type OPLL. In the beak-type OPLL, a subtle alteration in the spinal alignment during posterior decompression procedures may increase spinal cord compression, leading to the deterioration of symptoms. A potential increase in kyphosis following laminectomy should be avoided by fixation with a temporary rod. If intraoperative monitoring suggests spinal cord dysfunction, an anterior decompression procedure should be attempted as soon as possible.

The effect of autologous fibrin tissue adhesive on postoperative cerebrospinal fluid leak in spinal cord surgery: a randomized controlled trial.

Study Design. A prospective randomized study evaluating the efficacy of autologous fibrin tissue adhesive for decreasing postoperative cerebrospinal fluid (CSF) leak in spinal cord surgery. Objective. To compare postoperative CSF leak in 3 groups (i.e., autologous fibrin tissue adhesive used, commercial fibrin glue used, and no fibrin tissue adhesive used) of patients undergoing spinal surgery who needed dural incision. Summary of Background Data. Spinal cord operations, particularly when dural incision is inevitable, sometimes involve postoperative CSF leak. Because CSF leak is a serious complication, countermeasure is necessary to prevent it after dural suture. Commercial fibrin tissue adhesive was formerly used. Because the possibility of prion infection was widely noticed, commercial fibrin tissue adhesive containing animal components has been used less often. Methods. In 13 of 39 cases in which dural incision would be made, 400 mL whole blood was drawn, and autologous fibrin tissue adhesive was made of plasma. Cases were divided into 3 groups: (1) dural closure alone, (2) use of autologous fibrin tissue adhesive after dural closure, and (3) use of commercial fibrin tissue adhesive after dural closure. The primary outcome measure was determined as postoperative (3 days) volume of drainage fluid, and results were analyzed using the analysis of variance. The secondary outcome measure was general blood test, coagulation assay, and plasma fibrinogen, and these were analyzed also using the analysis of variance. Results. There was a significant difference in the primary outcome between the autologous and control groups. No complications such as infection or continuous CSF leak were observed in any case. The mean volume of drainage fluid was 586.2 mL in the group with autologous fibrin tissue adhesive and 1026.1 mL in the group without fibrin tissue adhesive. The volume of drainage fluid was significantly lower in the former group than that in the latter group. There was no statistical difference between the volumes of the group with autologous adhesive and with commercial adhesive (639.2 mL). Conclusions. We used autologous fibrin tissue adhesive as a new sealant after dural closure instead of commercial fibrin tissue adhesive. No definitive CSF leak was observed, and the volume of drainage fluid was significantly lower in the group with autologous fibrin tissue adhesive than that in the group without fibrin tissue adhesive. The use of autologous fibrin tissue adhesive was superior to that of commercial fibrin tissue adhesive in cost.

Vertebral reconstruction with biodegradable calcium phosphate cement in the treatment of osteoporotic vertebral compression fracture using instrumentation.

Objective: To assess the efficacy of posterior instrumentation and vertebral reconstruction with biodegradable calcium phosphate cement (CPC) in the treatment of osteoporotic vertebral compression fracture with neurologic deficit. Background: Vertebroplasty consists of the injection of polymethylmethacrylate (PMMA) cement into the vertebral body. While PMMA has high mechanical strength, it cures fast and thus allows only a short handling time. Other potential problems of using PMMA injection may include damage to surrounding tissues due to the high polymerization temperature or by the toxic unreacted monomer and the lack of long-term biocompatibility. Bone mineral cements such as calcium carbonate and CPCs have a longer working time and low thermal effect. They are also biodegradable while providing good mechanical strength. However, the viscosity of injectable mineral cements is high, and the infiltration of these cements into the vertebral body has been questioned. Recently, the infiltration properties of CPC have been significantly improved, making it more suitable for injection into the vertebral bodies for vertebral reconstruction. Methods: Five patients were included in this open prospective study. Inclusion criteria were delayed collapsed vertebral compression fractures responsible for severe pain and neurologic dysfunction necessitating posterior decompression surgery. Of five patients, two were male and three were female with an average age at surgery of 80.4 years (71–85 years) and an average duration of follow-up of 2.5 years (2–3.5 years). Evaluation of clinical data was based on x-ray, Japanese Orthopaedic Association (JOA) score for low back pain (full score is 29 points), and Visual Analog Scale (VAS). Results: The levels of the delayed collapsed vertebrae were T10, L1, and L2 (for one patient each) and L4 (two patients). All patients were in poor condition, for example, renal failure, heart failure, and chronic hepatitis. The average operative time was 2 hours (1 hour 36 minutes to 2 hours 16 minutes), and intraoperative bleeding was 181 mL (85–236 mL). As for clinical symptoms, preoperative JOA score averaged 17.8 points and was improved to 26 points postoperatively, while the preoperative VAS score of 8.6 points improved to 2 points postoperatively. Morphologic evaluation showed preoperative vertebral compression ratio averaged 41% and improved to 74% immediately after the operation and finally settled at 68%. Just one of five cases experienced late vertebral collapse 3 months after the operation. Conclusion: Vertebral reconstruction with biodegradable CPC in the treatment of osteoporotic vertebral compression fracture using instrumentation was a safe and useful surgical treatment.

Cervical myelopathy due to OPLL: clinical evaluation by MRI and intraoperative spinal sonography.

Background Concerning the relationship between morphology and clinical outcome, there have been many reports using computed tomography/myelography but not so many using axial magnetic resonance imaging (MRI) of the spinal cord. This is the first report to correlate axial cord image, intensity changes in MRI, and cord expansion pattern using intraoperative ultrasonography. Objective The objectives were to correlate MRI studies, axial cord images/expansion, and changes in MRI intensity to see if there is a direct prognostic significance to these changes and to determine whether preoperative axial MRI images of the spinal cord predict recovery from compressive myelopathy. Methods Posterior cervical decompressions with laminoplasty were performed in 44 patients with cervical myelopathy due to ossification of the posterior longitudinal ligament. On T2-weighted MR images, the cross-sectional shape of the cord at the level of maximal compression was categorized as boomerang, teardrop, or triangle. Additionally, with use of intraoperative ultrasonography, the expansion pattern of the cord that occurred intraoperatively was contrasted with that seen on postoperative MR images. Results Clinical recovery rates were the worst for those with triangular, intermediate for those with boomerang, and the best for those with teardrop shape. Preoperative low T1 and high T2 signals were found in most cases with triangular cord configurations. Triangular cord configurations showed the least expansion among the three categorized spinal cords. Conclusion Patients with triangular deformity of the cord have atrophy as confirmed on MR studies where there is a low T1 and high T2 signal in the cord. Poor postoperative clinical recovery correlates with the lack of postoperative cord expansion on either MR or ultrasound evaluations. Those with either teardrop or boomerang deformities demonstrate a relatively good recovery rate.

Hip-Spine Syndrome : Total Sagittal Alignment of the Spine and Clinical Symptoms in Patients With Bilateral Congenital Hip Dislocation

Study Design. The influence of the pathologic state of the hip joint on the total sagittal alignment of the spine was investigated in patients with congenital hip dislocation retrospectively Objective. The purpose of this study was to analyze the total sagittal alignment of the spine and the clinical symptoms in patients with bilateral congenital hip dislocation. Summary of Background of Data. Abnormality in the hip joint causes abnormal curvature of the sagittal alignment of the spine and induces lumbago or lower leg pain. However, there have been no reports on the influence of bilateral congenital hip dislocation on the sagittal alignment of the spine. Materials and Methods. A total of 9 patients (8 females and 1 male) were analyzed. Their average age was 57 years (range, 46–68 years). We measured the thoracic kyphosis (T1–T12), the lumbar lordosis (L1–S), the sacral inclination (SI), the femoral flexion angle (FFA), pelvic angulation (PA), and the distances from the pelvic hip axis (HA) to the C7 plumb line and from the promontorium to the C7 plumb line. To evaluate clinical symptoms, we used the Japanese Orthopedic Association (JOA) score of low back pain (full score is 29 points) and Visual Analog Scale (VAS) for lower back pain and lower leg pain, and the possible time of walking without rest. Results. The average thoracic kyphosis, lumbar lordosis, SI, and PA were 42°, −78°, 68°, and 27°, respectively. The FFA averaged 10°, leading to a duck-like posture. The distances from HA and, promontorium to the C7 plumb line averaged −2 cm and 4 cm, respectively. A posterior shift of the gravity line with respects to the hips was compensated for by lumbar hyperlordosis, which led to a posterior shift of the center of the spine. Regarding the clinical symptoms, the JOA score averaged 20 points and the VAS for lower back pain (lumbago) and lower leg pain averaged 6.4 and 3.1, respectively. The average possible walking time without rest was 20 minutes. Conclusion. The total sagittal alignment of the spine in patients with bilateral hip dislocation was compensated for by anterior angulation of the pelvis and by lumbar hyperlordosis. The main clinical symptoms were lower back pain, and not lower leg pain.

Subaxial sagittal alignment and adjacent-segment degeneration after atlantoaxial fixation performed using C-1 lateral mass and C-2 pedicle screws or transarticular screws

OBJECT The purpose of this study was to evaluate the effect of a fixed atlantoaxial angle on subaxial sagittal alignment, and that of atlantoaxial fixation on adjacent-segment motion and degeneration. METHODS The authors retrospectively reviewed 65 patients in whom atlantoaxial instability was treated with atlantoaxial fixation by C-1 lateral mass and C-2 pedicle screw fixation (30 patients, Goel-Harms [GH] group) or a combination of transarticular screw fixation and posterior wiring (35 patients, Magerl-Brooks [MB] group). Angles of Oc–C1, C1–2, C2–3, and C2–7 were determined based on an upright lateral radiograph in flexion, neutral, and extension positions. The range of motion (ROM) at Oc–C1 and C2–3 was also determined. All patients were examined before and 2 years after surgery. RESULTS The mean preoperative atlantoaxial angles in the GH and MB groups were 20.9 ± 8.3° and 18.3 ± 7.2°, respectively, and the mean postoperative atlantoaxial angles in the same groups were 23.5 ± 5.6° and 29.7 ± 6.3°, respectively, with a statistically significant difference between the 2 groups (p < 0.05). The mean preoperative angles of C2–7 in the GH and MB groups were 15.4 ± 7.8° and 13.7 ± 9.5°, respectively, and after surgery, the angles were 11.8 ± 12° and 2.48 ± 12°, respectively, with a statistically significant difference between the 2 groups (p < 0.05). The postoperative angle of C1–2 showed a negative correlation with the extent of change observed in the C2–7 angle pre- and postoperatively in each of these 2 surgical procedures. The Oc–C1 ROM increased after surgery in both groups, but the difference was not statistically significant (p = 0.38). The C2–3 ROM decreased after surgery in both groups, and the difference was statistically significant (p < 0.05). CONCLUSIONS Atlantoaxial fixation in a hyperlordotic position produced kyphotic sagittal alignment after surgery in both GH and MB groups. Reduction of the atlantoaxial joint can be easily achieved through screw fixation at an optimal angle, thereby ameliorating the risk for subsequent subaxial kyphosis. Degeneration of lower adjacent segments appeared to be less with this procedure compared with using a combination of transarticular screw fixation and posterior wiring.

Association of gene polymorphisms with intervertebral disc degeneration and vertebral osteophyte formation.

Study Design. Cross-sectional cohort study of elderly people. Objectives. To examine the factors influencing osteophyte formation without lumbar disc degeneration and to estimate the implications of osteophytes from the viewpoint of low back pain and gene polymorphisms. Summary of Background Data. The degenerative changes that occur in the intervertebral discs are the point of departure of osteophyte formation. Several studies on factors associated with genetic susceptibility to spinal osteophyte formation, such as VDR and TGF-β1. However, there are no detailed studies concerning osteophytes not accompanied with disc degeneration. Methods. A total of 387 elderly persons were recruited, and disc degeneration and osteophyte formation were evaluated. The cases with osteophyte formation were classified into 3 groups: osteophyte formation with disc height narrowing (n = 217), osteophyte formation without disc height narrowing (n = 99), and control group defined as the cases without osteophyte formation (n = 71). Twelve genotypes were characterized. Correlations between these degenerative factors and the polymorphisms were analyzed. Results. The prevalence of low back pain was significantly greater in the group of osteophyte formation with disc height narrowing than the other 2 groups. In the polymorphism of alcohol dehydrogenase (ADH2), prevalence of osteophyte formation without disc height narrowing was less in His/Arg (odds ratio = 0.57, P = 0.041) and Arg/Arg (odds ratio = 0.41, P = 0.18) than His/His. Conclusions. Patients with osteophyte formation preceding intervertebral disc narrowing had a lower risk of low back pain compared with those without osteophytes. The 47Arg polymorphism in the ADH2 may act to suppress osteophyte formation unaffected by disc degeneration.

Long-term results of occipitothoracic fusion surgery in RA patients with destruction of the cervical spine.

Objective: This is a retrospective study of the outcome of occipitothoracic fusion surgery in rheumatoid arthritis (RA) patients with destruction of the cervical spine, designed to assess the efficacy of halo vest before surgery, the postoperative outcome, and the activities-of-daily living (ADL) problems associated with surgical management. There have been no reports regarding these issues, including surgical effect on subjacent vertebrae. Methods: This study included 20 RA patients with destruction of the cervical spine. All patients underwent preoperative halo vest followed by occipitothoracic fusion with an average follow-up of 5 years. The long-term clinical outcomes were analyzed using a modified Ranawat classification. Results: Before halo application, the neurologic status was assessed as IIIC in 15 patients and IIIB in 5 patients. After halo application, the neurologic status improved in all patients: IIIA in 12 patients and IIIB in 8 patients. After surgery, the neurologic status did not improve in six of the eight IIIB patients but improved to IIIA in two patients. Of the 12 IIIA patients, the neurologic status improved to II in 6 patients but did not improve in the other 6 patients. Patient satisfaction was excellent for 14 patients, good for 3 patients, and fair for only 3 patients (1 had difficulty drinking, another had back pain, and the last had low back pain associated with a compression fracture of the lumbar spine). Conclusions: We have performed occipitothoracic fusion surgery in RA patients with destruction of the cervical spine. Preoperative halo vest was very effective for improving the neurologic status, for the general condition, and for an optimal sagittal alignment. Occipitothoracic fusion using unit rods gave satisfactory long-term clinical results compared with the prognosis of patients in whom the disease follows its natural course.