Shunsuke Kanbara

Cervical alignment and range of motion after laminoplasty: radiographical data from more than 500 cases with cervical spondylotic myelopathy and a review of the literature.

Study Design. A large-scale analysis of radiographical results of patients with cervical spondylotic myelopathy and a review of the literature. Objective. To identify changes in sagittal alignment and range of motion (ROM) after cervical laminoplasty. Summary of Background Data. Cervical laminoplasty is an effective procedure for decompressing multilevel spinal cord compression. It often induces postoperative complications such as loss of lordotic alignment and restriction of neck motion. Although numerous studies have reported the loss of flexion-extension ROM after laminoplasty, no large-scale study has been reported. Methods. Five hundred twenty consecutive patients with cervical spondylotic myelopathy (331 male and 189 female; mean age, 62.2 yr) who underwent modified double-door laminoplasty were enrolled. The average follow-up period was 33.3 months. All patients were allowed to sit up and walk on the first postoperative day using an orthosis, which could be removed within the first 2 weeks, even if long. Early cervical ROM exercises were performed as a part of the rehabilitation schedule. Radiography was performed before surgery and at the final follow-up. Cervical alignment in the neutral and flexion-extension view were measured by the Cobb method at C2–C7. The ROM was assessed by measuring the difference in alignment between flexion and extension. Results. The mean C2–C7 alignment in the neutral position was 11.9° lordotic preoperatively and 13.6° lordotic postoperatively; the alignment increased by 1.8° in lordosis. The mean total ROM decreased from a preoperative value of 40.1° to 33.5° at the final follow-up, showing a significant difference of 6.6°. The mean total ROM preservation after laminoplasty was 87.9%. Conclusion. Sagittal alignment was slightly changed, with only a 1.8° increase in lordosis. The ROM of the cervical spine was preserved by 87.9%. This preservation of alignment and ROM might be attributable to improvements including early removal of the cervical orthosis, postoperative neck exercises, and some surgical modifications.

Can magnetic resonance imaging reflect the prognosis in patients of cervical spinal cord injury without radiographic abnormality

Study Design. This is a prospective imaging study of adult patients with cervical spinal cord injury without radiographic abnormality (SCIWORA). Objective. The purpose of this study was to investigate the occurrence rate of intramedullary high-signal intensity (increased signal intensity [ISI]) and prevertebral hyperintensity (PVH) in patients with SCIWORA, and examine their relationship to symptom severity and surgical outcome. Summary of Background Data. SCIWORA is accompanied by the presence of neurologic symptoms in the absence of positive radiographic findings before the emergence of magnetic resonance imaging (MRI). There are few reports regarding the image features on MRI in these patients. Methods. One-hundred consecutive patients with SCIWORA who had undergone expansive laminoplasty were enrolled. There were 79 men and 21 women; the mean age was 55 years (range, 16–87 years). All patients underwent functional x-ray and MRI in the acute phase. On MR T2-weighted imaging sagittal view, occurrence of ISI and PVH was evaluated. Range of ISI and PVH was measured relative to C3 vertebral height. Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy (JOA score), its recovery rate, and ASIA impairment scale were used to evaluate neurological status. Results. ISI was observed in 92 patients and PVH in 90 patients on MRI preoperatively. The range of ISI and PVH tended to increase with scores on the preoperative ASIA scale. ISI and PVH were seen in all patients with ASIA A and B. There was a significant negative correlation between the range of ISI and preoperative JOA score. A significant negative correlation between the range of ISI and recovery rate of JOA score was also seen. Conclusion. ISI and PVH occurred in more than 90% of patients with SCIWORA. The range of ISI significantly reflected symptom severity and prognosis for neurologic outcome.

Can Elderly Patients Recover Adequately After Laminoplasty? : A Comparative Study of 520 Patients With Cervical Spondylotic Myelopathy

Study Design. This was a prospective clinical comparative study of surgical outcomes for patients with cervical spondylotic myelopathy (CSM). Objective. The purpose of this study was to compare the surgical outcomes between nonelderly and elderly patients with CSM who underwent laminoplasty. Summary of Background Data. Age at the time of surgery influences the surgical outcome. We designed a large-scale study of the surgical outcome for CSM from a single operative procedure used exclusively in elderly patients. Methods. A total of 520 consecutive patients with CSM (331 men; 189 women) who underwent double-door laminoplasty were included. Mean age was 62 years (range, 23–93), and mean duration of disease was 20.1 ± 32.0 months. Average postoperative follow-up period was 33.3 ± 15.7 months. Patients were divided into 3 groups by age: nonelderly (<65 years), young-old (65–74 years), and old-old (≥75 years). The number of patients in each group was 287, 143, and 90. Pre- and postoperative neurological status was evaluated using the Japanese Orthopaedic Association scoring system for cervical myelopathy (JOA score). Results. Mean pre- and postoperative JOA scores in nonelderly, young-old, and old-old groups were 11.0 and 14.4, 10.2 and 13.2, and 8.7 and 11.8 points, respectively. The elderly group showed significantly low recovery rates of JOA scores compared with the nonelderly group (P < 0.0001). However, mean achieved JOA scores (postoperative JOA score − preoperative JOA score) were 3.4, 3.0, and 3.1 in nonelderly, young-old, and old-old groups, respectively, with no significant difference among these groups (P = 0.17). Conclusion. Pre- and postoperative JOA scores were low in elderly patients. However, the achieved JOA score was almost similar among the 3 groups. Thus, elderly patients could obtain reasonable recovery after cervical laminoplasty.

Modified double-door laminoplasty in managing multilevel cervical spondylotic myelopathy: surgical outcome in 520 patients and technique description.

Study Design: This is a prospective study on surgical outcomes of double-door laminoplasty in patients with cervical spondylotic myelopathy (CSM). Objective: The purpose of this study was to report the efficacy and safety of modified double-door laminoplasty in a large series of patients with CSM. Summary of Background Data: Laminoplasty is an established procedure for the decompression of multisegmental CSM. However, no report has described the clinical outcomes of laminoplasty for a large number of patients with CSM (>500 patients). Methods: Between April 1995 and December 2006, 520 consecutive patients (331 male and 189 female) with CSM who underwent double-door laminoplasty and were followed-up for more than 1 year were enrolled in this study. The mean age was 62.2 years (23 to 93 y), and the mean duration of disease was 20.1±32.0 months. The severity of myelopathy before and after surgery was evaluated according to a scoring system proposed by the Japanese Orthopedic Association for cervical myelopathy (JOA score). Functional improvement was expressed by the recovery rate (RR) of the JOA score. Results: The average surgery time for laminoplasty was 75.2±23.3 minutes, and the average blood loss was 72.6±84.6 mL. The average follow-up period was 33.3±15.7 months. The mean JOA score was 10.4±2.8 points preoperatively and 13.6±2.5 points at final follow-up. The mean RR was 51.2±29.0%. On the basis of RR, we found that the conditions of 493 patients (94.8%) improved (RR, >1%), 20 patients (3.8%) showed no change (RR, 0%), and 7 patients (1.3%) in worse condition (RR, <0%). The 7 patients deteriorated for reasons (lumbar spinal canal stenosis and cerebral infarction) that were unrelated to CSM. Conclusions: Modified double-door laminoplasty is a safe, reliable, and effective procedure for patients with CSM.

The prevalence of pre- and postoperative symptoms in patients with cervical spondylotic myelopathy treated by cervical laminoplasty.

Study Design. A retrospective single-center study. Objective. To investigate the prevalence of symptoms before and after surgery in a large series of patients with cervical spondylotic myelopathy (CSM). Summary of Background Data. No study has elucidated the epidemiological data regarding the prevalence of pre- and postoperative symptoms in patients with CSM. Methods. Five hundred twenty consecutive patients with CSM (331 male and 189 female; mean age, 62.2 yr) treated by laminoplasty were enrolled. The average follow-up period was 33.3 months. Severity of myelopathy was evaluated according to a scoring system proposed by the Japanese Orthopedic Association for CSM, and prevalence was determined by the presence or absence of a full Japanese Orthopedic Association score for each function. The persistence rate (%) (postoperative prevalence/preoperative prevalence × 100) of each function impairment was also assessed after surgery. Results. The preoperative prevalence of motor function impairment in the upper and lower extremities was 77.7% and 80.4%, respectively, whereas that of sensory function impairment in the upper and lower extremities and trunk was 88.6%, 56.5%, and 48.3%, respectively. The preoperative prevalence of urinary bladder function impairment was 41.2%. The persistence rate of motor function impairment in the upper and lower extremities was 52.7% and 71.5%, respectively, whereas that of sensory function impairment in the upper and lower extremities and trunk was 72.0%, 56.8%, and 61.4%, respectively. The persistence rate of urinary bladder function impairment was 49.1%. Conclusion. The preoperative prevalence of motor function impairment in the upper and lower extremities and that of sensory function impairment in the upper extremity is higher than that of other function impairments, and impairments in lower extremity motor function and upper extremity sensory function often persist after surgery. These findings provide baseline data that may allow clinicians to accurately assess preoperative impairment and postoperative outcomes in patients with CSM.

Dynamic changes in the dural sac of patients with lumbar canal stenosis evaluated by multidetector-row computed tomography after myelography

PurposeSome reported studies have evaluated the dural sac in patients with lumbar spinal stenosis (LSS) by computed tomography (CT) after conventional myelography or magnetic resonance imaging (MRI). But they have been only able to evaluate static factors. No reports have described detailed dynamic changes in the dural sac during flexion and extension observed by multidetector-row computed tomography (MDCT). The aim of this study was to elucidate or demonstrate, in detail, the influence of dynamic factors on the severity of stenosis.MethodsOne hundred patients with LSS were enrolled in this study. All underwent MDCT in both flexion and extension positions after myelography, in addition to undergoing MRI. The anteroposterior diameter (AP-distance) and cross-sectional area of the dural sac (D-area) were measured at each disc level between L1–2 and L5–S1. The dynamic change in the D-area was defined as the absolute value of the difference between flexion and extension. The rate of dynamic change (dynamic change in D-area/D-area at flexion) in the dural sac at each disc level was also calculated.ResultsThe average AP-distance in flexion/extension (mm) was 9.2/7.4 at L3–4 and 8.3/7.4 at L4–5. The average D-area in flexion/extension (mm2) was 96.3/73.6 at L3–4 and 72.3/61.0 at L4–5. The values were significantly lower in extension than in flexion at all disc levels from L1–2 to L5–S1. AP-distance was narrowest and D-area smallest at L4–5 during extension. The rates of dynamic changes at L2–3 and L3–4 were higher than those at L4–5.ConclusionsMDCT clearly elucidated the dynamic changes in the lumbar dural sac. Before surgery, MDCT after myelography should be used to evaluate the dynamic change during flexion and extension, especially at L2–3, L3–4, and L4–5.

Persistent physical symptoms after laminoplasty: analysis of postoperative residual symptoms in 520 patients with cervical spondylotic myelopathy.

Study Design. A large-scale retrospective study of analysis of postoperative residual symptom in patients with cervical spondylotic myelopathy (CSM). Objective. The purpose of this study was to investigate which symptom remains postoperatively in a large series of patients with CSM. Summary of Background Data. CSM is an increasingly common neurological disorder of the geriatric population. Cervical laminoplasty is an established procedure for the decompression of multisegmental CSM, and numerous studies have documented satisfactory surgical results. However, no report has yet elucidated the postoperative residual symptoms in patients with CSM. Methods. Between April 1995 and December 2006, 520 consecutive patients with CSM who underwent laminoplasty were enrolled in this study. They were 331 males and 189 females, and mean age was 62.2 years. Severity of myelopathy was evaluated according to a scoring system proposed by the Japanese Orthopedic Association for cervical myelopathy. Each functional improvement was expressed by the recovery rate (RR) of the Japanese Orthopedic Association score. Results. The average follow-up period was 33.3 months. The mean recovery rates of motor function of the upper and lower extremities were 59.6% and 44.9%, respectively. The mean recovery rates of sensory function of the upper extremity, lower extremity, and trunk were 48.1%, 56.6%, and 54.6%, respectively, and that of urinary bladder function was 59.6%. Conclusion. Motor function impairments of the lower extremities and sensory function impairments of the upper extremities persist more than other symptoms after surgery. Such findings should be incorporated within treatment-planning discussions.

Surgical outcomes of modified lumbar spinous process–splitting laminectomy for lumbar spinal stenosis

The lumbar spinous process-splitting laminectomy (LSPSL) procedure was developed as an alternative to lumbar laminectomy. In the LSPSL procedure, the spinous process is evenly split longitudinally and then divided at its base from the posterior arch, leaving the bilateral paravertebral muscle attached to the lateral aspects. This procedure allows for better exposure of intraspinal nerve tissues, comparable to that achieved by conventional laminectomy while minimizing damage to posterior supporting structures. In this study, the authors make some modifications to the original LSPSL procedure (modified LSPSL), in which laminoplasty is performed instead of laminectomy. The purpose of this study was to compare postoperative outcomes in modified LSPSL with those in conventional laminectomy (CL) and to evaluate bone unions between the split spinous process and residual laminae following modified LSPSL. Forty-seven patients with lumbar spinal stenosis were enrolled in this study. Twenty-six patients underwent modified LSPSL and 21 patients underwent CL. Intraoperative blood loss and surgical duration were evaluated. The Japanese Orthopaedic Association (JOA) scale scores were used to assess parameters before surgery and 12 months after surgery. The recovery rates were also evaluated. Postoperative paravertebral muscle atrophy was assessed using MRI. Bone union rates between the split spinous process and residual laminae were also examined. The mean surgical time and intraoperative blood loss were 25.7 minutes and 42.4 ml per 1 level in modified LSPSL, respectively, and 22.7 minutes and 29.5 ml in CL, respectively. The recovery rate of the JOA score was 64.2% in modified LSPSL and 68.7% in CL. The degree of paravertebral muscle atrophy was 7.8% in modified LSPSL and 22.2% in CL at 12 months after surgery (p < 0.05). The fusion rates of the spinous process with the arcus vertebrae at 6 and 12 months in modified LSPSL were 56.3% and 81.3%, respectively. The modified LSPSL procedure was less invasive to the paravertebral muscles and could be a laminoplasty; therefore, the modified LSPSL procedure presents an effective alternative to lumbar laminectomy.

Posterior ligamentous complex injuries are related to fracture severity and neurological damage in patients with acute thoracic and lumbar burst fractures.

Purpose The proposed the thoracolumbar injury classification system (TLICS) for thoracolumbar injury cites the integrity of the posterior ligamentous complex (PLC). However, no report has elucidated the severity of damage in thoracic and lumbar injury with classification schemes by presence of the PLC injury. The purpose of this study was to accurately assess the severity of damage in thoracic and lumbar burst fractures with the PLC injuries. Materials and Methods One hundred consecutive patients treated surgically for thoracic and lumbar burst fractures were enrolled in this study. There were 71 men and 29 women whose mean age was 36 years. Clinical and radiologic data were investigated, and the thoracolumbar injury classification schemes were also evaluated. All patients were divided into two groups (the P group with PLC injuries and the C group without PLC injuries) for comparative examination. Results Fourth-one of 100 cases showed PLC injuries in MRI study. The load sharing classification score was significantly higher in the P group [7.8±0.2 points for the P group and 6.9±1.1 points for the C group (p<0.001)]. The TLICS (excluded PLC score) score was also significantly higher in the P group [6.2±1.1 points for the P group and 4.0±1.4 points for the C group (p<0.001)]. Conclusion The presence of PLC injury significantly influenced the severity of damage. In management of thoracic lumbar burst fractures, evaluation of PLC injury is important to accurately assess the severity of damage.

Transforaminal thoracic interbody fusion in the management of lower thoracic spine fracture dislocations: technical note.

Study Design: A case-control clinical study. Objectives: To assess the usefulness and safety of a novel reconstructive procedure known as transforaminal thoracic interbody fusion (TTIF) in the treatment of lower thoracic spine fracture dislocations, and to compare its efficacy with posterior/anterior combined surgery (PACS). Summary of Background Data: We developed a TTIF procedure for thoracic spine lesions, and obtained good clinical outcomes for degenerative disorders of the thoracic spine. However, the technique of TTIF in the lower thoracic spine fracture dislocation has never been reported. Methods: Seven consecutive patients with lower thoracic spine fracture dislocations underwent TTIF (6 males, 1 female; mean age, 32 y), and 16 consecutive patients with lower thoracic spine fracture dislocations underwent PACS (14 males, 2 females; mean age, 37 y). Surgical complications, clinical outcomes, and sagittal alignment were investigated. Bony fusion was assessed using plain and functional x-rays and computed tomography scans. Results: In the TTIF group and the PACS group, the mean operative times were 153 and 224 minutes, respectively, and the mean operative bleeding was 421 and 698 mL, respectively. All patients in the TTIF group were ambulatory within 2 days after surgery. Preoperative local sagittal alignments (kyphotic angles) were 22.9 and 22.5 degrees, respectively. Postoperative local sagittal alignments were 9.9 and 7.2 degrees, respectively. There were no instances of instrumentation failure or nonunion, and there were no serious complications such as neurological deficits in either group. In addition, a chest tube was necessary in 11 cases (69%) of PACS after thoracotomy, but was not required in any TTIF cases. Conclusions: TTIF achieves posterior rigid fixation with instrumentation, and anterior column reconstruction by interbody fusion. This procedure also enables early postoperative ambulation without respiratory problems. TTIF can be a useful option for reconstructive surgery of the lower thoracic spine after fracture dislocations.