Introduction
Central cord syndrome (CCS) frequently happens with cervical hyperextension injury without radiographic spinal fracture-dislocation. Expectant treatment was usually applied in CCS in the past, and some doctors considered anterior cervical surgery methods were not appropriate in treating CCS. We treated patients with central cord syndrome without radiographic spinal fracture-dislocation (CCSWORFD) by an anterior operation with titanium mesh bone grafting or iliac bone grafting, and achieved satisfactory curative effect [
1,
2]. The clinical features, principles of the anterior surgery and curative effect of CCSWORFD are summarized in this paper.
Methods
Patient information
All of the 24 cases (19 males, 5 females) were with cervical hyperextension injury and were 45-68 (average 59) years old. The time length from being injured to admission was 6 hours to 10 days. The causes of injury included: automobile accidents (3 cases), falling from riding bicycles (9 cases), forehead impact injury (2 cases), tumble-fall injury (5 cases) and others (5 cases). Three cases of the total had cervical spondylotic radiculopathy before and 3 cases did not obtain satisfactory curative effects from expectant treatment for 7-10 days in other hospitals. Clinical manifestations were as follows: spinal shock after injury in two cases, hand grip of grade 0-3, leg-raising myodynamia of grade 3-5; 18 cases with pricking pain and fine touch impairment (more obvious in upper limbs than in lower limbs); patellar reflex: hyporeflexia (18 cases), reinforcement (1 case), normal (5 cases); 1 case with Hoffmann’s sign (+) and Babinski sign (+); 3 cases with dysuria, and none of the cases had urinary or fecal incontinence. Magnetic resonance imaging (MRI) shows cervical vertebras with retrogression and dural sacs being oppressed in 17 cases, spinal cord being oppressed in 2 cases and anterior ligaments being broken with anterior hematoma in 8 cases. A spinal cord high signal appeared in 1 case in T2 of MRI 12 days after injury, and MRI of the other cases did not have obvious spinal cord signal change. During surgery, anterior ligaments were found broken in 12 cases.
Surgical technique
Under general anaesthesia, the anterior approach through a cross neck incision was performed. The vertebral body between the collilongus of both sides was ectomized; herniated disc, terminal plate of the upper and inferior vertebral body, osteophyma of posterior border and part of posterior longitudinal ligament were ablated. A titanium mesh filled with ectomized vertebral body was planted into the front 2/3 of the groove of the vertebral body. If 3 segments or more were involved in the case, the herniated disc was ablated and the inferior border of the upper vertebral body and the upper border of inferior vertebral body were cut. Then, the titanium mesh filled with ectomized vertebral body was planted between vertebras (Fig. 1). Iliac bone grafting was performed through which an appropriate three-sided osintegumentale strip was planted into the front 2/3 groove of vertebral body. Finally, the anterior plate was planted. Mannitol and MP-urbason were used for venous transfusion 3-6 days after operation.
Results
Eighteen cases were followed up for 6–24 (average 15) months, 10 cases with titanium mesh bone grafting and 8 cases with iliac bone grafting. Three months after the operation, bone grafting fusion was evaluated by X-ray. The two groups both achieved reliable grafting fusion, without cervical body collapse or fixation loosening. The stitches were removed 5 days after the operation in cases with titanium mesh bone grafting. The cases with iliac bone grafting were discharged from the hospital after the stitches were removed in the bone supply region 14 days after operation. By use of the Japanese Orthopedics Association (JOA) evaluation pre-operatively and post-operatively, a significant difference was found in cases with titanium mesh bone grafting before and after operation (t = 2.800, P <0.05, Table 1), as well as in cases with iliac bone grafting (t = 3.270, P <0.05, Table 2). Comparison of the two groups by t test (test of homogeneity of variance, F = 1.18, P >0.05, two variances were at the same level) show that the two groups had the same curative effect (t = 0.470, P >0.05). None of the cases had pneumonia or urinary system infection, or aggravation after nerve injury recovery.
Discussion
The Central gray area in spinal cord injuries involves the fibers of the corticospinal tract. The fibers controlling the muscles of the upper extremities are near the center of the spinal cord, and fibers that control muscles of lower extremities are relatively located in the periphery. But, Quencer considered that there were no obvious gradations in the fibers of the corticospinal tract which control muscles of the upper extremities and lower extremities. The reason that the symptoms of the upper extremities in CCS patients are more conspicuous than that of the lower extremities is that fine activities of the upper extremity rely on the integrality of fibers of corticospinal tract more [
3]. Some patients did not even have nerve injury symptoms of the lower extremity. Moreover, the lower limb functions revive first in the restoration process, and hand functional recoveries are the last and the worst. Most patients who developed CCSWORFD were associated with the degeneration of cervical vertebra, which could decrease the compensatory space that contained the spinal cord. And then, spinal cord injury may happen [
4,
5] under a strength that can cause cervical vertebra hyperextension injury but cannot cause spinal fracture-disolation when the cervical vertebral canal was severely stenosed. Hyperextension injury can also lead to disc herniation or aggravation of disc herniation and flaval ligament folding, which is the cause of spinal cord injury. Some hyperextension injuries caused by powerful strength are associated with cervical vertebra dislocation-replacement immediately. So, CCSWORFD can be classified into three types: (1) with cervical vertebra degeneration (most cases with cervical disc herniation, or hypertrophic ligamentum flavum, cervical spinal stenosis, ankylosing spondylitis, etc. CCSWORFD can be caused by a small force based on a cervical instability; (2) with ruptured disc (the cervical disk is ruptured and the anterior ligament is broken with anterior hematoma and cervical vertebra is severely instable, which are injured by high-energy) (Fig. 2); (3) without cervical vertebra degeneration or ruptured disc (mostly in children without abnormality of radioactive ray or MRI).
These cases mostly had degeneration of the cervical vertebra, for example, cervical disc herniation (79.26% of these cases), cervical spinal stenosis, etc. Twenty four cases of CCSWORFD without successional ossification of the posterior longitudinal ligament or hypertrophic ligamentum flavum were treated with anterior surgery. Both cervical vertebra degeneration and hyperextension injury lead to the instability of the cervical vertebra, which happens in most adult cases of CCSWORFD. The two factors can contribute to each other. Some cases had been improved through expectant treatment for one or two weeks, but then the improvement stopped, and the patients even became worse again. This is because that the syndrome of spinal cord injury was improved after the edema of the spinal cord, which was temporary and declined gradually. The instability of the cervical vertebra still existed which resulted in the slowness of the recovery process, or even worsening. These cases could get better recovery through surgery with anterior decompression and fixation for spinal stability. If the operation is performed early, the decompression which can relieve oppression to spinal cord will help lessen the edema of the spinal cord, and the early fixation for the stability of the cervical vertebra is beneficial for the recovery of spinal cord injury. Instability of cervical vertebra is usually evaluated by x-ray of the cervical vertebra in hyperextension and hyper-flexion, but because of spinal cord injury, this kind of x-ray is not easily performed for the patients of CCSWORFD. So, the following factors are important to evaluate the instability of cervical vertebra: (1) anterior ligament is broken with anterior hematoma; (2) disk is ruptured; (3) severity of spinal cord injury.
Compared with iliac bone grafting, the titanium mesh bone grafting is more advantageous in keeping the height of vertebral body, and can avoid the secondary injury of supplying grafting bone. The titanium mesh bone grafting can re-establish the stability of cervical vertebra more firmly [
6], achieving good grafting fusion [
6], and is beneficial for permanent stability. Titanium mesh in proper lengths cut with serrated extremity and intervertebral pressurization formed by planting titanium mesh with proper cervical traction are essential, which can help keep stability of the titanium mesh grafting. The titanium mesh to be planted should not be too long [
7,
8], since it is not helpful for grafting fusion. To ectomize three discs or more, one long titanium mesh should be avoided, and a short titanium mesh graft in the intervertebral area is better for fusion (Fig. 1). Three cases of the iliac bone grafting group (37.5%) had persistent pain. One hundred and twenty six patients with iliac bone grafting were followed up two years later: 1 case (0.79%) had regional supply graft infection, with incision healing beyond six months; 1 case (0.79%) with avulsion fracture of the anterior superior iliac spine; and 27 cases (21.4%) had persistent pain in the supplying region.
In most patients of CCSWORFD, the disease arises from background disease or degeneration and the instability of the cervical vertebra. Therefore, these cases need decompression for the spinal cord and reestablishment of cervical vertebra stability. Anterior operation for suitable patients with titanium mesh bone grafting or iliac bone grafting and plate fixation are reliable curative methods for CCSWORFD.
Higher Education Press and Springer-Verlag Berlin Heidelberg
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