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Masayuki Ohashi, Takui Ito, Toru Hirano, and Naoto Endo

An aneurysmal bone cyst (ABC) is a rare skeletal tumor that accounts for ~ 1% of all bone tumors. A spinal location for an ABC is very rare. Methods for treatment of an ABC include resection, curettage, embolization, and intralesional injection of a variety of agents. The patient in this case was a 9-year-old girl presenting with neck pain who was diagnosed with an ABC involving the C-2 spinal level. Percutaneous intralesional injections of calcitonin and methylprednisolone were performed. Two years and 7 months after the initial injection, a CT scan showed massive bone formation and cortical thickening without a change in the size of the lesion. To the authors' knowledge, this is the third reported case of intralesional injection of calcitonin and methylprednisolone for treatment of an ABC. This method is safe and effective, and is an important alternative to surgery, especially when a surgical procedure is technically difficult or unsafe in high-risk patients.

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Kei Watanabe, Kazuhiro Hasegawa, Toru Hirano, Naoto Endo, Akiyoshi Yamazaki, and Takao Homma

Object

The mechanism underlying cervical flexion myelopathy (CFM) is unclear. The authors report the results of anterior decompression and fusion (ADF) in terms of neurological status and radiographically documented status in young patients and discuss the pathophysiological mechanism of the entity.

Methods

Twelve patients underwent ADF in which autogenous iliac bone graft was placed. The fusion area was one segment in four cases, two segments in seven, and three segments in one. Neurological status, as determined by the Japanese Orthopaedic Association (JOA) score, radiographic findings, and intraoperative findings were evaluated. The mean follow-up period was 63.3 months (range 20–180 months).

Grip strength was significantly improved and sensory disturbances resolved completely. Intrinsic muscle atrophy, however, persisted in all patients at the final follow-up examination. Local kyphosis in the flexed-neck position at the fusion levels was corrected by surgery. Preoperative computerized tomography myelography revealed that the cord compression index, which was calculated by anteroposterior and transverse diameters of the spinal cord, decreased to 33 ± 6.2% in the flexed-neck position from 39.7 ± 9.9% in the extended-neck position. The anterior dura mater—spinal cord distance decreased to 1.9 ± 0.7 mm in the flexed-neck position from 4 ± 1.2 mm in extended-neck position. The posterior dura mater—spinal cord distance increased to 2.5 ± 1.1 mm in the flexed-neck position from 1.3 ± 0.5 mm in the extended-neck position.

Conclusions

Postoperative neurological status was improved in terms of grip strength, sensory disturbance, and JOA score, and local kyphosis in the flexed-neck position at the fusion levels was reduced and stabilized by ADF.

In most cases local kyphosis in the flexed-neck position was demonstrated at the corresponding disc level, as were cervical cord compression and decrease of the anterior wall of the dura mater—spinal cord distance in the flexed-neck position. Therefore, the contact pressure between the spinal cord and anterior structures (intact vertebral bodies and intervertebral discs) in the mobile and kyphotic segments was considered to contribute to the onset of CFM. The ADF-related improvement of the clinical symptoms, preventing kyphotic alignment in flexion and decreasing movement of the cervical spine, supports the idea of a contact pressure mechanism. Furthermore, short ADF performed only at the corresponding segments can preserve more mobile segments compared with posterior fusion. Thus, ADF should be the first choice in the treatment of CFM.

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Keiichi Katsumi, Akiyoshi Yamazaki, Kei Watanabe, Toru Hirano, Masayuki Ohashi, and Naoto Endo

Cervical radiculopathy of the C2–4 spinal nerves is a rare condition and is poorly documented in terms of clinical symptoms, hindering its detection during initial patient screening based on imaging diagnostics. The authors describe in detail the clinical symptoms and successful surgical treatment of a patient diagnosed with isolated C-4 radiculopathy. This 41-year-old man suffered from sleep disturbance because of pain behind the right ear, along the right clavicle, and at the back of his neck on the right side. The Jackson and Spurling tests were positive, with pain radiating to the area behind the patient's ear. Unlike in cases of radiculopathy involving the C5–8 spinal nerves, no loss of upper-extremity motor function was seen. Magnetic resonance imaging showed foraminal stenosis at the C3–4 level on the right side, and multiplanar reconstruction CT revealed a beak-type ossification of the posterior longitudinal ligament in the foraminal region at the same level. In the absence of intracranial lesions or spinal cord compressive lesions, the positive Jackson and Spurling tests and the C3–4 foraminal stenosis were indicative of isolated C-4 radiculopathy. Microscopic foraminotomy was performed at the C3–4 vertebral level and the ossified lesion was resected. The patient's symptoms completely resolved immediately after surgery. To the authors' knowledge, this report is the first to describe the symptomatic features of isolated C-4 radiculopathy, in a case in which the diagnosis has been confirmed by both radiological findings and surgical outcome. Based on this case study, the authors conclude that the characteristic symptoms of C-4 radiculopathy are the presence of pain behind the ear and in the clavicular region in the absence of upper-limb involvement.

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Takaaki Urakawa, Hitoshi Matsuzawa, Yuji Suzuki, Naoto Endo, Ingrid L. Kwee, and Tsutomu Nakada

Object

The authors assessed the role of 3D anisotropy contrast (3DAC) in evaluating specific ascending tract degeneration in patients with cervical spondylotic myelopathy (CSM).

Methods

The authors studied 10 patients (2 women, 8 men; mean age 59.8 ± 14.6 years) with CSM and spinal cord compression below the C2–3 disc level, as well as 10 healthy control individuals (3 women, 7 men; mean age 42.0 ± 24.1 years). Images of the cervical cord at the C2–3 level were obtained using a 3.0-T MR imaging system.

Results

Three-dimensional anisotropy contrast imaging clearly made possible tract-by-tract analysis of the fasciculus cuneatus, fasciculus gracilis, and spinocerebellar tract. Tract degeneration identified using 3DAC showed good correlation with a decline in fractional anisotropy. Degeneration of the fasciculus gracilis detected by “vector contrast” demonstrated a good correlation with Nurick grades.

Conclusions

The study unambiguously demonstrated that 3DAC imaging is capable of assessing ascending tract degeneration in patients with CSM. Degeneration of an individual tract can be easily identified as a vector contrast change on the 3DAC image, a reflection of quantitative changes in anisotropism, similar to fractional anisotropy. Excellent correlation between Nurick grades and fasciculus gracilis degeneration suggests potential application of 3DAC imaging for tract-by-tract clinical correlation.

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Kimihiko Sawakami, Kei Watanabe, Kazuhiro Hasegawa, Noriaki Yamamoto, Taketoshi Shimakura, Masayuki Ohashi, Hirokazu Shoji, Tatsuki Mizouchi, Yuki Tanaka, Hiroyuki Segawa, Seiichi Ishikawa, Toru Hirano, Hiroyuki Kawashima, Naoto Endo, and Hideaki E. Takahashi

OBJECTIVE

Teriparatide (TPTD) is a potent promoter of early-stage osteogenesis and may be a useful adjuvant therapy to reduce complications related to bone fragility in spinal surgery patients with osteoporosis. However, effective neoadjuvant TPTD therapy regimens remain poorly understood. This study aimed to examine the effect of preoperative TPTD administration on cancellous bone with bone histomorphometry and to clarify the timing of preoperative TPTD administration for patients with spinal fusion and osteoporosis.

METHODS

In this longitudinal multicenter study, 57 patients with spinal fusion and osteoporosis, who consented to undergo iliac biopsy, were allocated to the following treatment groups: neoadjuvant TPTD therapy group (n = 42) and no neoadjuvant therapy (NTC) group (n = 15). Patients in the TPTD group were categorized into subgroups on the basis of duration of preoperative TPTD administration, as follows: 1 month (n = 9), 2 months (n = 8), 3 months (n = 9), 4 months (n = 7), and 6 months (n = 9). All patient samples were preoperatively double labeled with tetracycline, and iliac biopsies were performed during spinal fusion surgery. Histomorphometric analyses were performed on nondecalcified, thin-sliced specimens. Specimens were classified on the basis of TPTD administration duration and subsequently compared with those of the NTC group. Postoperative complications and Oswestry Disability Index scores were evaluated at 1 and 2 years after surgery.

RESULTS

There were no demographic differences between groups. Mineralizing surface/bone surface, a key parameter of dynamic bone formation, started to increase after 1 month of TPTD administration; this increase became significant after 3 months of administration and peaked at 4 months, with a 6-fold increase relative to that of the NTC group. The patients who received preoperative TPTD for 3 months or more had superior clinical results in terms of the osteoporotic complication rate and Oswestry Disability Index scores, except for bisphosphonate-pretreated patients.

CONCLUSIONS

When considering neoadjuvant TPTD therapy, the authors recommend at least 3 months of preoperative administration to provide a more substantial anabolic effect from the early postoperative stage.