ObjectiveTo investigate the effect of modified lateral mass screws implantation strategy on axial symptoms in cervical expansive open-door laminoplasty. MethodsA clinical data of 166 patients, who underwent cervical expansive open-door laminoplasty between August 2011 and July 2016 and met the selection criteria, was retrospective analyzed. Among them, 81 patients were admitted before August 2014 using the traditional mini-plate placement and lateral mass screws implantation strategy (control group), and 85 patients were admitted after August 2014 using modified lateral mass screws implantation strategy (modified group). There was no significant difference in the gender composition, age, clinical diagnosis, disease duration, diseased segment, and preoperative Japanese Orthopaedic Association (JOA) score, pain visual analogue scale (VAS) score, Neck Disability Index (NDI), cervical curvature and range of motion, spinal canal diameter and cross-sectional areas, and Pavlov’s value between the two groups (P>0.05). The operation time, intraoperative blood loss, the number of facet joints penetrated by lateral mass screws, effectiveness evaluation indexes (JOA score and improvement rate, VAS score, NDI), imaging evaluation indexes (cervical curvature and range of motion, spinal canal diameter and cross-sectional areas, Pavlov’s value, and lamina open angle), and complications were recorded and compared between the two groups.ResultsThe modified group had shorter operation time and lower intraoperative blood loss than the control group (P<0.05). There were 121 (29.9%, 121/405) and 10 (2.4%, 10/417) facet joints penetrated by lateral mass screws in control and modified groups, respectively; and the difference in incidence was significant (χ2=115.797, P=0.000). Eighteen patients in control group had 3 or more facet joints penetrated while no patients in modified group suffered 3 or more facet joint penetrated. The difference between the two groups was significant (P=0.000). All patients were followed up, the follow-up time was (28.7±4.9) months in modified group and (42.4±10.7) months in control group, showing significant difference (t=10.718, P=0.000). The JOA score, VAS score, and NDI at last follow-up of the two groups were significantly improved compared with preoperative (P<0.05); there was no significant difference in JOA score and improvement rate and VAS score between the two groups (P>0.05), but the NDI was significantly lower in modified group than in control group (P<0.05). There were significant differences in cervical curvature and range of motion, spinal canal diameter, Pavlov’s value, and cross-sectional areas at last follow-up when compared with those before operation in both groups (P<0.05). There was no significant difference in the above indicators and lamina open angle between the two groups (P>0.05). The modified group has a relative lower axial symptom rate (23/85, 27.1%) than the control group (27/81, 33.3%), but the difference was not significant (Z=−1.446, P=0.148). There was no significant differences between the two groups in the incidences of C5 nerve root palsy, cerebrospinal fluid leakage, wound infection, and lung or urinary tract infection (P>0.05). ConclusionIn the cervical expansive open-door laminoplasty, the modified lateral mass screws implantation strategy can effectively reduce the risk of lateral mass screw penetrated to the cervical facet joints, and thus has a positive significance in avoiding the axial symptoms caused by facet joint destruction.
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 explore if the modified unilaterally-open expansive laminoplasty using bridge grafting and reconstructing posterior ligamentous complex methods is effective in preventing persisting axial symptoms, restriction of neck motion, and loss of cervical curvature. Methods From June 2000 to October 2005, 138 patients with cervical spondylotic myelopathy underwent this procedure. Of them, 78 who were followed for more than 2 years (group A) were included in this study. Another 69 patients who underwent conventional unilaterally opendoor laminoplasty served as controls(groupB). The JOA scores and the incidence of newly developed or deteriorated axial symptoms were recorded. Preoperative and postoperative ranges of neck motion were measured on lateral flexion and extension radiographs. Preoperative and postoperative cervical curvature indices were calculated according to Ishihara’s method. Results The patients of group A were followed 24-44 months (mean 33 months), and the patients of group B were followed 2453 months(mean 35 months). The operative time was 114±20 min in group A and 70±25 min in group B,showing statistically significant difference(P＜0.05). The operative blood loss was 280±72 ml in group A and 210±80 ml in group B(P＞0.05). Accordingto JOA scoring, the average recovery rates were 67.0%±17.3% in group A and 65.0%±21.4% in group B(P＞0.05). Postoperative development or deterioration of axial symptoms occurred in 12% of patients in group A and 51% of patients in group B, showing statistically significant difference(P＜0.05). Postoperative range of neck motion was 88.0%±10.1% of the preoperative one in group A and 64.0%±16.3% in group B(P＜0.05). There was no significant difference between preoperative(15.3±8.2) and postoperative(13.5±9.3) cervical curvature index in group A, whereas the mean value of postoperative index (11.1±5.7) was significantly smaller than that of preoperative one (17.2±13.5) in group B (Plt;0.05). Conclusion This new procedure was less invasive to the posterior extensor mechanism than the conventional unilaterally-open laminoplasty and was effective in preventing postoperative morbidities.
ObjectiveTo investigate the risk factors of axial symptoms after single door laminoplasty for cervical myelopathy. MethodsA retrospective analysis was made on the clinical data of 102 patients with cervical myelopathy who underwent single door laminoplasty and were accorded with selective standard between February 2009 and October 2011. There were 59 males and 43 females, aged 35 to 72 years (mean, 58 years). The disease duration was 1-70 months (mean, 18 months). The operated segments included C3-7 in 58 cases, C3-6 in 23 cases, C4-7 in 15 cases, and C3-5 in 6 cases. The visual analogue scale (VAS) was used to determine whether the patient had axial symptoms (group A) or not (group B). The logistic regression analysis was used to analyze the risk factors of postoperative axial symptoms by assessing the following indexes:preoperative VAS score, preoperative Japanese Orthopaedic Association (JOA) score, gender, age, disease duration, operated segment, operation time, intraoperative blood loss, wearing collar time, preoperative encroachment rate of anterior spinal canal, preoperative cervical curvature, and preoperative cervical range of motion. ResultsA total of 102 cases were followed up 18-26 months (mean, 24 months). And no postoperative spinal cord injury, cerebrospinal fluid leakage, or infection occurred. Of 102 cases, 50 had axial symptoms (group A) and 52 had no axial symptoms (group B). There were significant differences in age, wearing collar time, preoperative cervical range of motion, preoperative cervical curvature, and preoperative encroachment rate of anterior spinal canal between 2 groups (P<0.05), but no significant difference was found in preoperative JOA score and VAS score, blood loss, gender, disease duration, operated segment, and operation time (P>0.05). The logistic regression analysis showed that the increased preoperative encroachment rate of anterior spinal canal, reduced preoperative cervical curvature, and preoperative cervical range of motion loss were the risk factors for cervical axial symptoms. ConclusionAge, wearing collar time, preoperative cervical range of motion, preoperative encroachment rate of anterior spinal canal, and preoperative cervical curvature are relevant factors of axial symptoms; increased preoperative encroachment rate of anterior spinal canal, reduced preoperative cervical curvature, and preoperative cervical range of motion loss are risk factors for cervical axial symptoms.
Objective To evaluate the effectiveness of combined posterior decompression with laminoplasty and anterior decompression with fusion for the treatment of cervical spinal canal stenosis with reverse arch. Methods Between May 2009 and February 2012, 13 cases of cervical spinal canal stenosis with reverse arch underwent posterior decompression with laminoplasty surgery in prone position and then anterior decompression with fusion surgery in supine position. There were 7 males and 6 females with an average age of 43.5 years (range, 38-62 years) and an average disease duration of 25 months (range, 18-60 months). All the patients had neck axial symptoms and spinal cord compressed symptoms, and lateral computer radiology (CR) of the neck showed reverse arch of cervical vertebrae. Segments of intervertebral disc protrusion included C3-6 in 4 cases, C4-7 in 4 cases, and C3-7 in 5 cases. After operation, anteroposterior and lateral CR was used to observe the cervical curvature change and fixation loosening, MRI to observe the change of the compression on spinal cord, visual analogue scale (VAS) score to evaluate the improvement of axial symptom, and Japanese Orthopaedic Association (JOA) score to assess the nerve function improvement. Results All incisions healed by first intention. All patients were followed up 9-32 months (mean, 15.4 months). Internal fixator had good position without loosening or breaking and the compression on spinal cord improved significantly after operation. All the patients obtained bony fusion at 6 months after operation. The axial symptoms and the nerve function at last follow-up were improved. VAS score at last follow-up (3.25 ± 1.54) was significantly lower than that at preoperation (6.55 ± 1.52) (P lt; 0.05); JOA score at last follow-up (10.45 ± 4.23) was significantly higher than that at preoperation (7.05 ± 1.32) (P lt; 0.05); and cervical curvature value at last follow-up [(6.53 ± 3.12) mm] was significantly higher than that at preoperation [(3.22 ± 5.15) mm] (P lt; 0.05). Conclusion Combined posterior decompression with laminoplasty and anterior decompression with fusion for the treatment of cervical spinal canal stenosis with reverse arch is a safe and effective surgical method.
Objective To investigate the operational method of cervical vertebral flavectomy and its cl inical appl ication in the management of cervical canal stenosis. Methods From June 1997 to June 2007, 25 patients suffering from cervical spinal canal stenosis caused by obvious flaval l igament hypertrophy were given flavectomy. There were 22 males and 3 females, with an age range of 32 to 68 years (average 54 years). The course of disease was from 3 weeks to 7 years, with an average of 3 years and 7 months. All patients had degenerative cervical canal stenosis; of them, 5 cases had a history of cervical injury 2 to 3 weeks before operation (3 cases of fall ing injury and 2 cases of traffic accident injury). The X-ray film, CT, and MRI examinations showed that the compression locations were C4-7 in 12 cases, C3-7 in 9 cases, C5-7 in 3 cases, and C6,7 in 1 case. Spinous process and vertebral lamella were exposed by central posterior approach. The insertions of flaval l igaments were cut off at the superior vertebral lamella border, then the starting points of which were cut down from the anterior side of the upper vertebral lamella at their inferior border after l ifting up the flaval l igaments. The residual flaval l igaments in front of the vertebral lamella were scraped off by slope rongeur, the dura mater then could be seen to inflate from the intervertebral lamella space, showing the compression having been rel ieved. Twenty-five cases were all given posterior flavectomy. At 1 week to 3 months after operation, 12 patients received anterior cervical discectomy or vertebral gaining decompression with fusion by bone graft. Results The time for flavectomy was from 60 to 180 minutes, with an average of 95 minutes. The blood loss during operation was from 90 to 360 mL, with an average of 210 mL. The dura maters were lacerated by knife tips during operation with the cervical vertebrae in hyperflexion in 2 cases. Immediate suture and repair were performed and there were no postoperative cerebrospinal fluid leakage. All the incisions healed by first intension after operation. All of the 25 cases were followed up from 2 to 10 years, with an average of 3 years and 9 months. All patients had no compl ication of axial symptoms, and no restenosis at their operation site of cervical canal stenosis. The section area ratios of functional spinal canal to spinal cord were 1.12 ± 0.07 before operation and 2.11 ± 0.19 at 24 months after operation, showing significant difference (P lt; 0.05). The range of motion of cervical vertebrae was (39.4 ± 3.2)º befeore operation and (42.1 ± 2.9)° at 24 months after operation in 13 cases without anterior cervical discectomy fusion, showing no significant difference (P gt; 0.05); was (34.3 ± 3.4)° before operation and (29.2 ± 3.6)° at 24 months after operation in 12 cases with anterior cervical discectomy fusion, showing significant difference (P lt; 0.05). The bone graft achieved bony union 3-5 months after operation (average 3.8 months). The Japanese Orthopaedic Association (JOA) scores were 7.9 ± 2.2 before operation and 15.6 ± 1.4 at 24 months after operation, showing significant difference (P lt; 0.05), with an average improvement rate of 86.3%. Conclusion Cervical flavectomy could rel ieve compression to spinal cord and nerves caused by the flaval l igament hypertrophy without damaging the normal integral ity of bony canal, thus avoiding the compl ication of axial symptoms and so on which are encountered in open-door expansile cervical laminoplasty.
Objective To evaluate and compare the relation of the cl inical results of expansion of open-door cervical laminoplasty (EOLP), C5 nerve root palsy in hinge side, and reclose of the opened laminae with different angles in lamina opendoor.Methods Between July 2006 and January 2009, 198 patients with cervical myelopathy were treated by EOLP. Accordingto different opening angles which were measured by CT scan after operation, the patients were divided into group A (gt; 30°, 76 patients including 44 males and 32 females) and group B (15-30°, 122 patients including 71 males and 51 females). There was no significant difference in gender, age, disease duration, and segmental lesions between 2 groups (P gt; 0.05). The Japanese Orthopaedic Association (JOA) score before and after operation was used for neurological assessment and improvement rate, and the postoperative C5 nerve root palsy and reclose of the opened laminae were recorded. Results There was no significant difference in operation time, bleeding volume, and hospital ization days between 2 groups (P gt; 0.05). After 3 weeks of operation, C5 nerve root palsy in the hinge side occurred in 7 patients (9.2%) of group A, and in 2 patients (1.6%) of group B, were restored after symptomatic treatment, showing significant difference between 2 groups (χ2= 4.568, P= 0.033). All patients were followed up 24 to 48 months. Between group A and group B, no significant difference was found in JOA improvement rate at 24 months after operation (P gt; 0.05), and in JOA score at preoperation and at 24 months after operation (P gt; 0.05), but JOA score was significantly improved at 24 months after operation when compared with preoperative score in the same group (P lt; 0.05). The function of l imb l ifting restored in 9 cases of C5 nerve root palsy at 24 months after operation; CT examination revealed that no reclose occured in group A and reclose occurred in 4 cases (3.3%) of group B, but no persistent symptoms or worsen situationwere found during follow-up. Conclusion Different angles in lamina open-door have the same cl inical result; C5 nerve palsy has good prognosis. The opening angle between 15° and 30° will reduce the incidence of C5 nerve root palsy in the hinge side, but the open side should be firmly fixed to prevent further reclose of the opened laminae.
Objective To evaluate the cl inical appl ication value and short-term results of Vertex rod-screw system in cervical expansive open-door laminoplasty. Methods Between February 2008 and January 2010, 28 patients underwent Vertex rod-screw system fixation in cervical expansive open-door laminoplasty, including 15 cases of cervical spondylotic myelopathy, 5 cases of ossification of posterior longitudinal l igament，and 8 cases of cervical spondylosis with spinal stenosis. There were 16 males and 12 females, aged 42-77 years (mean, 61.3 years). The disease duration was 2 months to 11 years. The decompression range of cervical spine was from C3 to C7. The operation time, blood loss, Japanese Orthopedic Association (JOA) scores, and incidence of axial symptom were recorded. Pre- and postoperative curvature angles were demonstrated by the cross angle between posterior vertebral body margins of C2 and C7 on cervical X-ray films. The angle of the opened laminae was measured on CT scan at last follow-up. Results The operation time was (142.5 ± 22.8) minutes, and the blood loss was (288.2 ± 55.1) mL. All incisions healed by first intention. All patients were followed up 14-25 months (mean, 22 months). CT showed that no reclosed open-laminae or loosening and breakage of rod-screw system occurred at 1 week and 1 year after operation. The axial bony fusion rate was 89.3% (25/28). The improvement rate of JOA scores at 1 week after operation (29.5% ± 15.0%) was significantly smaller than that at 1 year after operation (64.9% ± 28.1%) (t=0.810, P=0.000). No case presented with C5 nerve root palsy. The cervical curvature angle was (24.29 ± 5.04)° before operation, was (23.89 ± 3.57)° at 1 week, and was (23.41 ± 3.35)° at 1 year after operation, showing no significant difference between pre- and postoperative angles (P gt;0.05). The angle of the opened laminae was (27.90 ± 4.74)° at 1 week after operation, and was (28.07 ± 4.21)° at 1 year after operation, showing no significant difference (P gt; 0.05). Conclusion Vertex rod-screw system in cervical expansive opendoor laminoplasty is effective in preventing reclosed open-laminae, which can reduce the loss of cervical curvature angle.