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.
ObjectiveTo explore early clinical effects of Centerpiece-based unilateral open-door cervical expansive laminoplasty plus centerpiece titanium minitype plate fixation, to research the data of the best slotting in the CT-based open-door cervical operation and to provide the reference for accurate operation. MethodsA retrospective analysis of the patients who had received Centerpiece-based unilateral open-door cervical expansive laminoplasty plus centerpiece titanium plate fixation from West China Hospital of Sichuan University from February 2013 to November 2013 were performed. The neurological function assessment results (JOA score), cervical curvature indexhave, Pavlov value, spinal canal cross-sectional area and different position, angle and depth of C7 lamina slotting data of all patients before and after the operation were all analyzed and compared. ResultsA total of 58 patients were included. The postoperative JOA score was significantly higher than that of the preoperative (9.4±2.9 vs. 14.7±2.6, t=11.417, P=0.000). The sagittal diameter of vertebral canal (21.3±2.1 mm vs. 9.7±2.1 mm, t=27.737, P=0.000), Pavlov value (0.92±0.13 vs. 0.44±0.12, t=30.621, P=0.000), and spinal canal cross-sectional area (276±37 mm2 vs. 129±25 mm2, t=32.104, P=0.000) at the end of the last follow-up were significantly greater than those of preoperative. When comparing the last follow-up with preoperative, cervical curvature index showed significant difference (11.2±11.5 vs. 9.3±11.7, t=-1.713, P=0.000). Significant differences were found in the comparison of the ideal position and angle of the open door of the C7 lamina and the angle and position of the operation (all P values >0.05); when comparing the position and angle of the ideal position and angle of the C7 lamina hinge with that of the actual operation, no significant differences were found (all P values >0.05); but when comparing the ideal depth with the actual depth of the operation, a significant difference was found (P<0.05). ConclusionCenterpiece micro plate used in posterior cervical expansive open-door laminoplasty forming operation of laminectomy fixed screw loosening and plate breakage, can effectively maintain the lamina in the open state, and prevent it to be closed. The patients have good recovery of nerve function after operation and the clinical efficacy is good.