A radiographic evaluation of facet sagittal angle in cervical spinal cord injury without major fracture or dislocation.

STUDY DESIGN: A retrospective radiographic study with a minimum 2-year follow-up. OBJECTIVE: To evaluate the relationships between the cervical articular facets' morphology and the incidence of traumatic cervical spinal cord injury (CSCI) without major fracture or dislocation. SETTING: Spinal Injuries Center, Japan. METHODS: This study included 113 patients with traumatic CSCI without major fracture or dislocation. Eighty-four healthy volunteers without neurological deficits or cervical cord pathology on magnetic resonance imaging (MRI) were defined as control subjects. We used a plain sagittal radiograph to measure the facet sagittal angles (FSA) at four cervical segments in all the CSCI patients and controls. We defined the FSA as the angle between the inferior margin of the superior cervical spinal body and the inferior articular process of the superior vertebra. RESULTS: Most frequent incidence of CSCI was seen at C3-4 segment (54%). With respect to CSCI at C3-4 segment, 55.7% of the subjects showed smallest FSA at C3-4 segment. CONCLUSION: Most of the traumatic CSCI at C3-4 segment showed raised cervical articular facets at C3-4 segment. On the basis of our results, we hypothesized that the raised cervical articular facets might have an important role in the etiology of traumatic CSCI. The cervical spinal cord at the C3-4 segment might receive the highest load during acute hyperextension of the cervical spine because of the C3-4 articular facets' morphology.

Subacute T1-low intensity area reflects neurological prognosis for patients with cervical spinal cord injury without major bone injury.

STUDY DESIGN: A retrospective imaging and clinical study. OBJECTIVES: To evaluate the relationship between magnetic resonance imaging (MRI) features and neurological prognosis in patients with traumatic cervical spinal cord injury (CSCI) without major bone injury. METHODS: A total of 72 patients with CSCI without major bone injury were treated conservatively in our hospital. MRI was performed for all patients at admission and 1 month following injury. We measured the antero-posterior and cranio-caudal diameter of intramedullary intensity changed area with T1-weighted images at the injured segment. Neurological evaluations were performed using the American Spinal Injury Association (ASIA) motor score and the modified Frankel grade at the time of admission and discharge. RESULTS: There was a significant relationship between the antero-posterior diameter ratio of the T1-weighted low-intensity area on MRI at the subacute stage and the ASIA motor score. The optimal threshold of the T1-weighted low-intensity diameter ratio for predicting the patient's ability to walk with or without assistance at discharge was determined to be 46%. Moreover, 96.8% of the patients with <50% T1-weighted low-intensity area recovered to walk with or without a cane at discharge. CONCLUSION: The T1-low intensity area may be an important predictive factor for the neurological recovery of CSCI without major bone injury.

The potential for functional recovery of upper extremity function following cervical spinal cord injury without major bone injury.

STUDY DESIGN: This was a retrospective observational study. OBJECTIVES: The objectives were to describe the prognosis of upper extremity function following cervical spinal cord injury (CSCI), and to identify prognostic factors for functional recovery. SETTING: Spinal Injuries Center, Japan. METHODS: Sixty patients with C3-4 CSCI without major bone injury participated in the study. Patients were treated nonsurgically and evaluated using the American Spinal Injury Association (ASIA) scales for the upper and lower extremities, their residual cervical motor functions, the modified Frankel grade and an upper extremity function scale. We compared the findings for the upper extremity function scale at 6 months with those for the residual cervical motor functions and modified Frankel grade obtained 3 days after injury. RESULTS: Most patients with CSCI who could flex their hip and knee from a supine position (95%) or who showed some active elbow extension (86%) 3 days after their injury could use a spoon at 6 months. We compared patients who used their fingers at 6 months to those who could not, and observed significant differences in age and ASIA scores for the upper and lower extremities obtained 3 days after injury. A strong correlation was observed between the initial motor scores and the extent of functional recovery at 6 months. CONCLUSION: Hip and knee flexion from the supine position and elbow extension 3 days after injury significantly predicted a positive prognosis for upper extremity function. Younger age and higher ASIA motor scores obtained 3 days after injury were factors associated with neurological recovery.

[Static and dynamic modifications of the cervical spine after laminoplasty for cervical spondylotic myelopathy]. / Modifications statiques et dynamiques du rachis cervical après laminoplastie cervicale dans le traitement de la myélopathie cervicarthrosique: à propos de 30 cas avec un recul moyen de 3,7 ans.

PURPOSE OF THE STUDY: Cervical laminoplasty has been widely used in Japan as the treatment of progressive cervical myelopathy. However, in 1993, Guigui reported that extensive cervical laminectomy was enough for the treatment of cervical myelopathy secondary to stenotic conditions. The purpose of this report was to compare the results of extensive laminectomy as reported by Guigui in 1998 with those of laminoplasty in our series using exactly the same criteria for anatomic analysis. MATERIAL AND METHODS: Thirty patients aged over 40 years who underwent a spinous process splitting laminoplasty using a threadwire saw from C3 to C7 without fusion for cervical spondylotic myelopathy were reviewed retrospectively with an average follow-up of 3.7 years. Functional results were evaluated according to the Japanese Orthopedic Association scoring system for cervical myelopathy. Lateral views in the neutral position, in flexion, and in extension of the preoperative cervical roentgenograms were analyzed in comparison with the last follow-up films in order to identify the change in the curvature of the cervical alignment, in the range of neck motion, in the intervertebral angular mobility, and in the anteroposterior displacement of the vertebral bodies, and finally to identify the incidence of spinal instability. These data were compared with those of extensive laminectomy published by Guigui. RESULTS: Seven patients (23%) developed postoperative changes in cervical spine curvature. Only one patient had a new destabilized level postoperatively. No patient required new surgery. Compared with the results obtained after extensive cervical laminectomy, incidence of new destabilized level or aggravated level was statistically lower after laminoplasty than after laminectomy. CONCLUSION: Spinous process splitting laminoplasty causes an ossification between the remaining spinous process and an unexpected fusion of the lateral mass. These results may prevent postoperative segmental destabilization.

Preliminary results of partial surface replacement of the femoral head in osteonecrosis.

We report our initial results using a partial surface replacement for osteonecrosis of the femoral head. We believe the prosthesis has the most minimalist design that has been reported either in Europe or North America. The surgical technique, implant design, and instrumentation cause minor soft tissue disruption and require little bony resection. We report the results of our first 25 prostheses performed over the past 5 years in 19 patients. The mean age was 42.5 years, (range, 24-59 years), with a preoperative Ficat classification of 15 hips, stage III; 9 hips, stage IV; and I hip, stage II. For the surviving prostheses, mean follow-up was 43 months, (range, 20-60 months). Of these 19 surviving implants, 15 continue to function well with excellent or good hip scores according to the Merle d'Aubigne system. We have had 6 failures: 1 owing to technical error, 4 owing to local tissue factors, and 1 owing to a progression of the osteonecrosis. The parameters for the use of this prosthesis are defined with our increasing experience, and the prosthesis is compared with other prosthetic implants available. In comparison with alternative techniques, the operative surgery is straightforward requiring little preoperative planning; immediate weight bearing is allowed postoperatively. Should failure occur, little bone stock loss is incurred, and revision to a total hip replacement is as simple as primary hip arthroplasty.