Objective To investigate the effect of the penetration of mini-plate mass screws into facet joint on axial symptoms in cervical laminoplasty. Methods A retrospective analysis was made on the clinical data of 52 patients who underwent unilateral open-door cervical expansive laminoplasty fixed with Centerpiece mini-plate between September 2009 and December 2011. There were 42 males and 10 females, with a mean age of 61.2 years (range, 34-83 years). Seventeen patients exhibited simple degeneration cervical canal stenosis, 25 patients had multilevel cervical disc protrusion, and 10 patients had ossification of posterior longitudinal ligaments. Disease duration ranged 1-120 months (median, 11 months). The Japanese Orthopedic Association (JOA) score was used to assess neurological function, and JOA recovery rates were calculated. The visual analogue score (VAS) and the neck disability index (NDI) were used to evaluate the axial pain and neck daily activities. The axial symptoms and other complications were recorded. The cervical canal diameter, cervical curvature, cervical canal cross area, and open angle were measured according to the X-ray films, CT scans, and MRI scans. The postoperative CT three dimensional (3-D) reconstruction images were used to identify whether the screws penetrated into the facet joints. All the patients were divided into 3 groups according to involved facet joints: no joint penetrating group (no penetrated facet joint), oligo-joint penetrating group (one or two penetrated facet joints), and multi-joint penetrating group (three or more penetrated facet joints). Results Five patients suffered from C5 nerve palsy, and 2 patients had cerebrospinal fluid leakage. The follow-up time ranged 3-35 months (mean, 15.7 months). At the final follow-up, the JOA scores, NDI, cervical canal diameter, and cervical canal cross area were significantly improved when compared with preoperative ones (P lt; 0.05). At 1 week after operation, CT 3-D reconstruction showed that 16 patients had no penetrated facet joint, 23 patients had one or two penetrated facet joints, and 13 patients had three or more penetrated facet joints. There was no significant difference in age, gender, disease duration, operation time, intraoperative blood loss, and follow-up time among 3 groups (P gt; 0.05). And at the final follow-up, there was no significant difference in JOA score, VAS score, cervical curvature, cervical canal diameter, cervical canal cross area, the JOA recovery rates, and lamiae open angle among 3 groups (P gt; 0.05). The NDI of the multi-joint penetrated group was significantly higher than that of other 2 groups (P lt; 0.05). Axial pain occurred in 1 case of no penetrating group, in 4 cases of oligo-joint penetrating group, and in 5 cases of multi-joint penetrating group, showing no significant difference among 3 groups (χ2=4.881, P=0.087). Conclusion The penetrations of lateral mass screws into articular surface of facet joint may contribute to the axial symptoms after cervical laminoplasty. The risk of axial symptom raises accompany with increased penetrated facet joints.
Objective To evaluate the fixation technique of using the cervical lateral mass plate in the cervical posterior approach operation. Methods Eight patients in this group were admitted from September 2001 to November 2006. Among the 8 patients, there were 6 males and 2 females, with their ages ranging from 28 to 78 years. Cervical vertebral fracture with dislocation was found in 4 patients, C2 spinal cord injury in 1, C1 fracture in 1, cervical spinal stenosis in 1, and C2-5 spinal cord neurofibroma in 1. Muscle strength 3-4. TheFrankel grading system was usedin 6 patients with traumatic injury. Before operation, Grade C was observed in 2patients，Grade D in 3，and Grade E in 1. All the operations were performed according to requirements of the Margel’s method. We positioned 40 screws in all the patients, including 4 screws at C2，6 screws at C3，12 screws at C4，4 screws at C5，4 screws at C6，2 screws at C7，and 6 screws at T1. Results The followingup for an average of 14.1 months (range,645 months) revealed that there was no malposition of the screws in the patients. One of the 8 patients developed spinal instability in the fixed segment at 3 months after operation. The headchestbrace was applied to the patient for 3 months, and the spinal fusion was achieved. The further followingup to 45 months indicated that there was no instability occurring. The remaining patients recovered to their spinal stability by the spinal fusion. The patients also recovered in their neurological function after operation. The Frankel assessment showed that 1 patient had Grade E, 3 from Grade D to Grade E, 1 from Grade C to Grade D, and 1 from Grade C to Grade E. Conclusion The cervical lateral mass plate fixation can provide the immediate and b segmental immobilization for the good cervical spine stability.
ObjectiveTo investigate the classification and clinical value of unilateral cervical lateral mass fracture (C3-7).MethodsFrom January 2008 to December 2017, 68 patients with unilateral cervical lateral mass fracture who had received treatment in Affiliated Hospital of Southwest Medical University, were included. According to the position of fracture, the fractures were classified into three types: articular process fractures (type A), isthmus fracture (type B), and comminution (type C). Two subtypes of articular process fractures were type A1 and type A2. Type A1 refered to articular process fracture with no or slight displacement. Type A2 refered to articular process fractures result in foraminal stenosis and nerve root compression. Single-level anterior cervical disectomy and fusion (ACDF) or anterior cervical corpectomy and fusion (ACCF) or conservative treatment was used in type A1. Posterior decompression, fixation and fusion or the method of posterior decompression associated with ACDF were suited to A2. Single-level ACDF was used in type B as well. Type C underwent two-level ACDF or ACCF or posterior procedure.ResultsThere were 35 cases of Type A1, of which 31 patients underwent single-level ACDF, 2 patients underwent ACCF, and 2 patients received conservative treatment, but one of the two underwent ACDF due to delayed cervical instability. Among the 7 cases of type A2, 4 underwent posterior foraminal decompression and posterior fusion with pedicure screw fixation, 2 underwent single-level ACDF and posterior decompression, and 1 underwent single section ACDF and posterior decompression combined with pedical screw fixation. Type C accounted for 21 cases of all targets. Fourteen performed two-level ACDF, 6 performed ACCF, and 1 performed posterior fixation with pedicure screw and expansive open-door laminoplasty. Six patients showed postoperative complications, including C5 root palsy in one case, incision hematoma in two and pulmonary infection in three. There were no case with incision infection or aggravating nervous injury. Sixty-two patients (91.2%) were followed up with a mean duration of 14 months. All the patients obtained bony fusion and no internal fixation failure or kyphosis was found.ConclusionsAccording to fracture position and CT, the unilateral cervical lateral mass fracture can be classified as type A1, type A2, type B, and type C. A satisfied clinical result can be obtained when choosing an appropriate treatment in accordance with different fracture types.