Kunihiko Sasai

Preventing C5 Palsy After Laminoplasty

Study Design. The incidences of postoperative C5 palsy between a group treated by a standardized diagnostic and surgical treatment and a control group treated by a different cervical laminoplastic technique were prospectively compared. Objective. To investigate the cause, risk factors, and prevention of C5 palsy after laminoplasty for cervical myelopathy. Summary of Background Data No one factor could predict postoperative C5 palsy, although postoperative C5 palsy is a clinically significant complication of cervical laminoplasty. Methods. One hundred eleven patients who underwent laminoplasty for cervical myelopathy were studied. Seventy-four patients who consulted two spinal surgeons (two of the authors) were placed into Group A. Thirty-seven patients who consulted the other two spinal surgeons (the other two authors) were placed into Group B. There were no statistical differences between the two groups for age at operation, gender, spinal disorders, preoperative neurologic severity, and length of the follow-up period. All patients in Group A underwent preoperative electromyographic testing. Patients with no electromyographic abnormalities underwent a standard midsagittal laminoplasty. Those with preoperative electromyographic abnormalities, reflecting a subclinical radiculopathy, underwent a modified en bloc laminoplasty with microcervical foraminotomy done at each level of the EMG abnormality. All Group B patients underwent midsagittal laminoplasty without preoperative electromyographic testing. Microcervical foraminotomy was performed for C5 root in 11 patients (14.9%) of Group A. Results. No patients in Group A and three patients (8.1%) in Group B experienced postoperative C5 palsy. This difference was statistically significant (P = 0.035, Fisher’s exact method). Conclusions. Electromyography is a sensitive predictor of postoperative C5 palsy after laminoplasty. This complication may be avoided by performing selective foraminotomy in addition to posterior central canal decompression. Preexisting subclinical C5 root compression is a cause of C5 palsy after posterior cervical decompression for myelopathy.

Cervical curvature after laminoplasty for spondylotic myelopathy-involvement of yellow ligament, semispinalis cervicis muscle, and nuchal ligament

To assess the consequences of cervical laminoplasty on postoperative lordosis, a retrospective radiographic analysis of 31 patients undergoing laminoplasty for spondylotic myelopathy was completed. Special attention was paid to lordotic changes occurring at each level over more than 2 years. Preoperative lordosis remained unchanged with the patients wearing a cervical orthosis 1 week postoperatively. However the lordosis subsequently demonstrated a significant decrease in 87% of patients over an average of 3.1 years. Lordotic alignment at C2-C3 and C6-C7 before surgery significantly decreased in 81% and 58% of patients 1 week postoperatively, and 84% and 81% at last follow up, respectively, while lordotic alignment at other levels pre- and postoperatively did not significantly change. Loss of lordotic alignment was largely attributed to detachment of semispinalis cervicis muscle on C2 and nuchal ligament on C6/C7 with a posterior approach and/or section of yellow ligament at C2-C3.

Microsurgical bilateral decompression via a unilateral approach for lumbar spinal canal stenosis including degenerative spondylolisthesis

OBJECT Surgical outcome and radiographic changes after microsurgical bilateral decompression via a unilateral approach (MBDU) for lumbar spinal canal stenosis during midterm follow-up periods (> 2 years) have not been reported. The authors retrospectively investigated surgical outcomes after MBDU in patients with lumbar degenerative spondylolisthesis with stenosis in comparison with patients with degenerative stenosis during a minimum follow-up period of 2 years. Radiographic changes at the affected intervertebral level were analyzed during that follow-up period. METHODS Forty-eight patients (23 in the spondylolisthesis group, 25 in the degenerative stenosis group) were included in the study. The average follow-up period was 46 months (range 24-71 months). Surgical outcome was evaluated using the Neurogenic Claudication Outcome Score (NCOS) and the Oswestry Disability Index (ODI). Additionally, the back pain score within the NCOS was also compared. There were no statistically significant differences between the spondylolisthesis group and the degenerative stenosis group with regard to sex, age, follow-up period, operating time, blood loss, surgical sites, approach side, preoperative NCOS, preoperative back pain score, and preoperative ODI. Comparisons were also made between groups using 2 satisfaction measurements at the last follow-up visit. Radiographically, intervertebral angles of 80 sites and slip percentages of 24 sites were measured preoperatively and at the last follow-up. RESULTS No patient in either group had additional surgery in the lumbar spine, including fusion procedures. The NCOS, back pain score, and ODI had significantly improved at the last follow-up in both groups. There were no significant differences between the 2 groups in these 3 parameters and the 2 satisfaction measurements at the last follow-up, although those for the spondylolisthesis group indicated a somewhat worse outcome. Intervertebral angles, dynamic intervertebral angles, and dynamic slip percentage did not significantly change after surgery, whereas only slip percentage significantly increased postoperatively (p = 0.0319). CONCLUSIONS A satisfactory outcome of MBDU persisted for a period longer than 2 years for patients with degenerative spondylolisthesis with stenosis as well as for those with degenerative stenosis. Radiographically in both groups this less invasive procedure was not likely to result in postoperative dynamic instability at the affected level, although the slippage progressed in the spondylolisthesis group.

Prevention of corticosteroid-induced osteonecrosis in rabbits by intra-bone marrow injection of autologous bone marrow cells.

OBJECTIVES Femoral head osteonecrosis (ON) is a serious complication of steroid administration. We evaluated bone marrow transplantation (BMT) for preventing corticosteroid-induced ON. METHODS Rabbits, injected with methylprednisolone (MPSL; 20 mg/kg), were divided into four groups: (i) MPSL alone; MPSL injection only, (ii) MPSL+needling; 2 days after MPSL injection, a hole (1.2 mm diameter) was drilled from the outer cortex 2.5 cm distal to the proximal end of the greater trochanter, (iii) MPSL+saline; 2 days after MPSL injection, 2 ml saline was injected directly into the bone marrow cavity, and (iv) MPSL+BMT; 2 days after MPSL injection, 1 x 10(7)/2 ml bone marrow cells (BMCs) were injected directly into the bone marrow cavity. Platelets, fibrinogen, prothrombin time and total cholesterol in peripheral blood were measured before and after treatment. Tissues were stained with haematoxylin and eosion and terminal deoxynucleotidyl-mediated deoxyuridine triphosphate nick-end labelling stain and immunostained for VEGF, while cell proliferation and viability of whole BMCs in the femur were analysed by cell cycle analysis and [(3)H]-thymidine uptake. RESULTS The ON incidence in rabbits treated with MPSL alone, MPSL+needling and MPSL+saline was 72.7, 70.0 and 66.7%, respectively, while in the MPSL+BMT group, the incidence was 0%. Serological findings in the MPSL+BMT group were almost normalized. VEGF and TUNEL staining were reduced in the MPSL+BMT group compared with all other groups. There were significantly fewer BMCs in G1 phase from the MPSL+BMT group than the other groups, while uptake of [(3)H]-thymidine was significantly increased. CONCLUSION Direct injection of autologous BMCs into femurs prevents corticosteroid-induced ON following treatment with high-dose, short-term steroids.

External iliac artery occlusion in posterior spinal surgery.

STUDY DESIGN Report of a case of external iliac artery occlusion occurring as a rare complication of lumbar posterior spinal surgery. OBJECTIVE To clarify the cause of this rare complication and recommend methods for preventing its recurrence. SUMMARY OF BACKGROUND DATA Several cases of central retinal artery occlusion after posterior spinal surgery have been reported, but there has been no reported case of external iliac artery occlusion after posterior spinal surgery. METHODS A 65-year-old woman who had a 32-year history of systemic lupus erythematosus underwent posterior decompression and spinal fusion for degenerative scoliosis. She was supported on a Hall frame during the operation. Three hours after surgery, paralysis and sensory impairment of the left leg and cyanosis of the toes of the left foot were noted. The popliteal, dorsalis pedis, and posterior tibial pulses were not palpable. Angiography showed complete occlusion of the external iliac artery, and emergency removal of the thrombus was performed. RESULTS One year later, neurologic symptoms were absent, and the leg vessels were normal. CONCLUSIONS Prolonged direct pressure on the inguinal region during posterior spinal surgery on a Hall frame may cause external iliac artery occlusion. Early recognition and adequate treatment can prevent serious sequelae.

Microsurgical posterior herniotomy with en bloc laminoplasty: alternative method for treating cervical disc herniation.

Objective: At the present time, the anterior cervical discectomy and fusion procedure is widely accepted for treating cervical disc herniation. Recently, however, several authors have reported new disease due to degeneration of an adjacent segment. On the other hand, posterior discectomy, which can preserve mobility at the affected disc level, has been considered risky and technically difficult, especially for central or paracentral disc herniation. We are performing a new surgical technique, microsurgical posterior herniotomy with en bloc laminoplasty, for patients with myelopathy and radiculomyelopathy caused by cervical disc herniation. Methods: Here, the surgical outcomes and radiographic changes were retrospectively investigated. Thirty patients (13 patients with myelopathy, 13 patients with radiculomyelopathy, and 4 patients with C5 dissociated motor loss) who underwent this procedure were reviewed. The average age was 50 years (range 31-70 years), and the average follow-up period was 28 months (range 12-76 months). Neurologic improvements were evaluated using the Japanese Orthopaedic Association (JOA) Scoring System as well as radicular pain and deltoid muscle power. Postoperative axial symptoms were scored, and radiographic changes were noted. Results: The mean JOA score improvement was 74.2% (range 27.3-100%). In all 13 patients, preoperative radicular pain completely resolved after surgery. Deltoid power (in cases of C5 dissociated motor loss) markedly increased postoperatively. Cervical lordosis significantly increased at the time of the last follow-up (P = 0.01). The postoperative axial symptom score significantly correlated with the numbers of opened laminae (P = 0.03). Conclusions: This technique was safe and effective. Radiographically, the range of motion in the cervical spine and at the affected disc levels was preserved. In the future, this surgical procedure can become an alternative method for cervical disc herniation treatment.

A less-invasive cervical laminoplasty for spondylotic myelopathy that preserves the semispinalis cervicis muscles and nuchal ligament

OBJECT Modified cervical laminoplasty techniques have been developed to reduce postoperative axial neck pain and preserve function in patients with cervical spondylotic myelopathy (CSM). However, the previous studies demonstrating satisfactory surgical outcomes had a retrospective design. Here, the authors aimed to prospectively evaluate the 2-year outcomes of a modified cervical laminoplasty technique for CSM that preserves the paravertebral muscles. METHODS Outcomes were analyzed for 40 patients (22 men and 18 women; mean age, 66.6 years; age range 44-92 years) with CSM who underwent C4-6 laminoplasty with C-3 and C-7 partial laminectomies or C-3 total and C-7 partial laminectomies and received hydroxyapatite spacers. Neurological, pain severity, and spinal radiographic evaluations were performed preoperatively and at 3, 6, 12, 18, and 24 months postoperatively. Plain radiography and MRI of the cervical spine were performed to evaluate the range of motion (ROM), sagittal alignment, and cross-sectional areas of the deep extensor muscles. The extent of bone-spacer bonding and bony union at the gutter was assessed by CT. RESULTS The mean preoperative Japanese Orthopaedic Association CSM score was 10.2, but it increased to 14.4 by 24 months after surgery. Eleven patients had axial neck pain preoperatively, but only 3 reported mild pain at 24 months, and in all 3 cases the pain was mild. The mean angle of lordosis was 11.7° preoperatively and 12.0° 2 years postoperatively. Although the ROM at the C2-7 levels was significantly reduced 3 months postoperatively, an increasing trend was observed up to 12 months, and 86% of the preoperative ROM was achieved by 2 years postoperatively. The mean paravertebral muscle cross-sectional areas were 833 ± 215 mm(2) preoperatively and 763 ± 197 mm(2) 24 months postoperatively, but the difference was not statistically significant. The rates of bone-spacer bonding and bony union at the gutter were low during the early stages but increased to 90% and 93%, respectively, by 2 years after surgery. CONCLUSIONS The modified laminoplasty technique used in this study ensured very good neurological status and ROM after 2 years and was associated with low incidences of axial neck pain and serious complications. This simple and easy operative method could benefit future laminoplasty protocols.

Activation of rat nucleus pulposus cells by coculture with whole bone marrow cells collected by the perfusion method.

Cell proliferation and matrix synthesis were compared for rat nucleus pulposus cells cocultured with mesenchymal stem cells (MSCs) or fresh whole bone marrow cells (BMCs), harvested by the perfusion or aspiration methods. Nucleus pulposus cells were isolated from tail intervertebral discs of F344/slc rats, and BMCs were obtained from femora. Proteoglycan synthesis, DNA synthesis, and aggrecan mRNA expression were measured. The level of transforming growth factor‐β in supernatants from the culture system was also measured. Cell number, aggrecan mRNA expression, and uptake of [35S]‐sulfate and [3H]‐thymidine by nucleus pulposus cells cocultured with fresh whole BMCs all increased significantly compared with nucleus pulposus cells cocultured with MSCs. TGF‐β secreted by nucleus pulposus cells cocultured with fresh whole BMCs also significantly increased when compared with cocultures with MSCs. The perfusion method was superior to the aspiration method for preventing contamination of BMCs with peripheral red blood cells and lymphocytes, which may cause an autoimmune response in the disc. In conclusion, we suggest that fresh whole BMCs harvested by the perfusion method are more effective for increasing the proliferative and matrix synthesis capacity of nucleus pulposus cells.

Atlantoaxial arthrodesis for vertebrobasilar insufficiency due to rheumatoid arthritis: A case report

Patients with rheumatoid arthritis often have involvement of the cervical spine, which may lead not only to impairment of activities of daily living but also to sudden death 1. Cervical instability secondary to rheumatoid arthritis is associated with compression myelopathy in many patients and with vertebrobasilar insufficiency in some patients. To our knowledge, this is the first report of the surgical treatment of vertebrobasilar insufficiency in a patient with rheumatoid atlantoaxial subluxation without evidence of a compression myelopathy. The subject of this case report was informed that data concerning the case would be submitted for publication. A woman was diagnosed with rheumatoid arthritis in 1982, at the age of forty-five years, and hemodialysis was begun in 1997 to treat chronic renal insufficiency. She was hospitalized repeatedly since 1998 because of difficulty walking due to arthritis of both hips and knees and, in 1998, she underwent a right total hip arthroplasty. Cervical pain developed in the spring of 1999. A diagnosis of atlantoaxial subluxation was made, and the patient wore a cervical collar to help control the pain. In the fall of 1999, she began experiencing neuralgia of the left greater occipital nerve when she extended the neck. At the same time, she had vertigo, a feeling of faintness, and slurred speech. These symptoms were transient and resolved shortly after their onset. In December 1999, the patient had a spontaneous seizure and was unconscious for approximately five minutes. After that episode, she could not speak clearly for several hours. She was examined for signs of cerebral infarction and underwent electroencephalography, the findings of which were reported to be normal. In June 2000, she lost consciousness again and had difficulty with her speech immediately thereafter; she …

Clinical and pathologic characteristics of lumbar disk herniation in the elderly.

The clinical and pathologic characteristics of lumbar disk herniation in 23 elderly patients (15 men and 8 women) who required surgical treatment were investigated. Average age at surgery was 67.3 years, and average follow-up was 23 months. Preoperatively, the predominant symptom was severe unilateral leg pain, and 13 patients were nonambulatory because of leg pain. Operative treatment included wide laminectomy in 8, hemilaminectomy in 3, fenestration in 10, and osteoplastic laminectomy in 2 patients. Four (17%) patients had disk herniation at the L2-L3 or L3-L4 level. Sequestered herniation with or without migration was observed in 15 (65%) patients. Of 14 sequestered disk fragments examined histologically, 8 (57%) specimens contained cartilaginous or bony end plate with anulus fibrosus or nucleus pulposus. Postoperatively, results were rated as excellent in 11 patients and good in 12; no patient was rated as fair or poor. Severe leg pain affecting activities of daily life is a predominant symptom of disk herniation in the elderly. For patients in whom conservative treatment has failed, operative treatment should be considered. In lumbar disk herniation in the elderly, the incidence of cephalad and lateral herniation is higher than in younger patients. In addition, sequestered and migrated herniations including end plate are frequent.