Prevalence and distribution of thoracic and lumbar compressive lesions in cervical spondylotic myelopathy.

STUDY DESIGN: Retrospective cross-sectional study. PURPOSE: This study analyzed the prevalence and distribution of horacic and lumbar compressive lesions in cervical spondylotic myelopathy as well as their relationships with cervical developmental spinal canal stenosis (DCS) by using whole-spine postmyelographic computed tomography. OVERVIEW OF LITERATURE: There are few studies on missed compressive lesions of the spinal cord or cauda equina at the thoracolumbar level in cervical spondylotic myelopathy. Furthermore, the relationships between DCS, and the prevalence and distribution of thoracic and lumbar compressive lesions are unknown. METHODS: Eighty patients with symptomatic cervical spondylotic myelopathy were evaluated. Preoperative image data were obtained. Patients were classified as DCS or non-DCS (n=40 each) if their spinal canal longitudinal diameter was <12 mm at any level or ≥12 mm at all levels, respectively. Compressive lesions in the anterior and anteroposterior parts, ligamentum flavum ossification, posterior longitudinal ligament ossification, and spinal cord tumors at the thoracolumbar levels were analyzed. RESULTS: Compressive lesions in the anterior and anteroposterior parts were observed in 13 (16.3%) and 45 (56.3%) patients, respectively. Ligamentum flavum and posterior longitudinal ligament ossification were observed in 19 (23.8%) and 3 (3.8%) patients, respectively. No spinal cord tumors were observed. Thoracic and lumbar compressive lesions of various causes tended to be more common in DCS patients than non-DCS patients, although the difference was statistically insignificant. CONCLUSIONS: Surveying compressive lesions and considering the thoracic and lumbar level in cervical spondylotic myelopathy in DCS patients are important for preventing unexpected neurological deterioration and predicting accurate neurological condition after cervical surgery.

Predictable imaging signs of cauda equina entrapment in thoracolumbar and lumbar burst fractures with greenstick lamina fractures.

STUDY DESIGN: A retrospective study. PURPOSE: The aim of present study was to investigate imaging findings suggestive of cauda equina entrapment in thoracolumbar and lumbar burst fractures. OVERVIEW OF LITERATURE: Burst fractures with cauda equina entrapment can cause neurologic deterioration during surgery. However, dural tears and cauda equina entrapment are very difficult to diagnose clinically or radiographically before surgery. METHODS: Twenty-three patients who underwent spinal surgery for thoracolumbar or lumbar burst fractures were enrolled in this study. In magnetic resonance imaging T2-weighted images of the transverse plane, we defined cauda equina notch sign (CENS) as a v-shaped image that entrapped cauda equina gathers between lamina fractures. We evaluated the fractured spine by using CENS and lamina fractures and the rate of available space for the spinal canal at the narrowest portion of the burst fracture level. We classified patients into entrapment group or non-entrapment group, based on whether cauda equina entrapment existed. RESULTS: Lamina fractures were detected in 18 (78.3%) and CENS were detected in 6 (26.1%) of 23 burst-fracture patients. Cauda equina entrapment existed in all the patients with CENS. In addition, the rate of available space for the spinal canal increased according to logistic regression. The size of the retropulsed fragment in the spinal canal was the most reliable of all the factors, suggesting cauda equina entrapment. CONCLUSIONS: CENS was the most predictable sign of cauda equina entrapment associated with burst fractures.

Analysis of the prevalence and distribution of cervical and thoracic compressive lesions of the spinal cord in lumbar degenerative disease.

STUDY DESIGN: Retrospective study. PURPOSE: The aim of the present study is to analyze the prevalence and distribution of cervical and thoracic compressive lesions of the spinal cord in lumbar degenerative disease, using whole-spine postmyelographic computed tomography. OVERVIEW OF LITERATURE: Of the various complications resulting from spinal surgery, unexpected neurological deterioration is the most undesired. There are reports of missed compressive lesions of the spinal cord at the cervical or thoracic level in lumbar degenerative disease. METHODS: There were 145 consecutive patients with symptomatic lumbar degenerative disease evaluated. Before the lumbar surgery, image data were obtained. The following parameters at the cervical and thoracic levels were analyzed: compressive lesions from the anterior parts; compressive lesions from the anterior and posterior parts; ossification of the ligamentum flavum; ossification of the posterior longitudinal ligament; and spinal cord tumor. RESULTS: Compressive lesions from the anterior parts were observed in 34 cases (23.4%). Compressive lesions from the anterior and posterior parts were observed in 34 cases (23.4%). Lesions of ossification of the ligamentum flavum were observed in 45 cases (31.0%). Lesions of ossification of the posterior longitudinal ligament were observed in 15 cases (10.3%). Spinal cord tumor was not observed. CONCLUSIONS: A survey of compressive lesions at the cervical or thoracic level in lumbar degenerative disease is important in preventing unexpected neurological deterioration after the lumbar surgery.

Manipulation of anabolic and catabolic responses with bone morphogenetic protein and zoledronic acid in a rat spinal fusion model.

Bone fusion involves a complex set of regulated signaling pathways that control the formation of new bone matrix and the resorption of damaged bone matrix at the surgical site. It has been reported that systemically administering a single dose of zoledronic acid (ZA) at the optimal time increases the strength of the bone morphogenetic protein (BMP)-mediated callus. In the present study, we aimed to investigate the effect of BMP-2 and ZA in a rat spinal model. Sixty-seven rats were divided into 6 groups: group I (n=11) animals were implanted with a carrier alone, group II (n=12) animals were implanted with a carrier and a subcutaneous injection of ZA was administered 2weeks after surgery, group III (n=12) animals were implanted with a carrier containing 1µg of rhBMP-2, group IV (n=12) animals were implanted with a carrier containing 1µg of rhBMP-2 and a subcutaneous injection of ZA was administered 2weeks after surgery, group V (n=10) animals were implanted with a carrier containing 3µg of rhBMP-2, and group VI (n=10) animals were implanted with a carrier containing 3µg of rhBMP-2 and a subcutaneous injection of ZA was administered 2weeks after surgery. The rats were euthanized after 6weeks, and their spines were explanted and assessed by manual palpation, radiography, high-resolution micro-computerized tomography (micro-CT), and histologic analysis. The fusion rates in group VI (60%) were considerably higher than those in the groups I (0%), II (0%), III (12.5%), IV (20.8%), and V (35%), (P<0.05). Additionally, the radiographic scores of group VI were higher than those in the other groups, (P<0.05). In micro-CT analysis, the tissue and bone volumes of the callus were significantly higher in group VI than those in the other groups, (P<0.05). The trabecular number was significantly higher and the trabecular spacing was significantly lower in group VI than those in the other groups, (P<0.05). The combination of rhBMP-2 and ZA administered systemically as a single dose at the optimal time was efficacious in our rat spinal fusion model. Our results suggest that this combination facilitates spinal fusion and has potential clinical application.

Clinical features of cervical pyogenic spondylitis and intraspinal abscess.

STUDY DESIGN: Retrospective study. OBJECTIVES: The purpose of the present study was to elucidate the clinical features of cervical pyogenic spondylitis and intraspinal abscess and to use this knowledge for early diagnosis and treatment. SUMMARY OF BACKGROUND DATA: Cervical pyogenic spondylitis and intraspinal abscess are relatively rare diseases in which accurate diagnosis is difficult at early stage. However, because both diseases can cause severe paralysis and vital crisis at advanced stages, early diagnosis and treatment are very important. METHODS: Fourteen patients (men: 9, women: 5; average age at treatment: 65.4 y; age range: 49-89 y) with cervical pyogenic spondylitis and/or intraspinal abscess were treated in our hospital. We analyzed their initial symptoms, initial diagnosis, duration between the appearance of initial symptoms and final diagnosis, symptoms at final diagnosis, level of the affected cervical spine, predisposing factors, organisms, and treatments. RESULTS: Initial symptoms included neck pain with fever (n=7), neck pain without fever (n=3), pharyngeal pain with fever (n=1), muscle weakness in both the upper and lower extremities (n=1), gait disturbance (n=1), and numbness of the lower extremities (n=1). Patients were initially diagnosed with meningitis (n=4), fever of unknown origin (n=2), cervical spondylosis (n=2), polymyalgia rheumatica (n=1), upper respiratory tract inflammation (n=1), metastatic spinal tumor (n=1), cervical spondylotic myelopathy (n=1), and cervical disc herniation (n=1). Of the 14 patients, 1 was correctly diagnosed with cervical pyogenic spondylitis. CONCLUSIONS: The initial symptoms of cervical pyogenic spondylitis and intraspinal abscess varied and neck pain with fever was not essential. Therefore, doctors should consider the possibility of cervical pyogenic spondylitis and repeat the assessments of the clinical examination for early diagnosis of this disease.