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Objective: To compare differences in the maintenance of cervical curvature after anterior cervical surgery between zero-profile and self-locking intervertebral cage and plate-cage construct (PCC). Methods: A clinical data of 100 patients with single-segment cervical disc herniation who were treated with anterior cervical discectomy and fusion were retrospectively analyzed between January 2015 and January 2016. Among them, 50 patients were treated with the zero-profile and self-locking intervertebral cage (group A) and 50 patients with the PCC (group B). There was no significant difference between the two groups in age, gender, bone mineral density, disease duration, operative segment, and preoperative visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height ( P>0.05). The operation time and intraoperative blood loss were recorded. The postoperative VAS and JOA scores were used to evaluate the clinical efficacy. The C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height were measured on lateral X-ray films, and the interbody fusion was evaluated according to Pitzen's criteria. Results: The operation time in group A was significantly shorter than that in group B ( t=2.442, P=0.021), but there was no significant difference in the intraoperative blood loss between the two groups ( t=0.812, P=0.403). All patients were followed up 24-36 months, with an average of 28.5 months. According to Pitzen's criteria for cervical interbody fusion, bone fusion achieved in both groups. The VAS score, JOA score, C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height of the two groups at 1 and 24 months after operation were significantly improved when compared with those before operation ( P0.05). There were significant differences in C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height between the two groups at 24 months after operation ( P0.05). Conclusion: Compared with the PCC, the zero-profile and self-locking intervertebral cage can significantly shorten the operation time and obtain the same clinical efficacy, but the intervertebral height loss and secondary cervical curvature change after operation is more serious.
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Objective To compare biomechanical effects of Zero-Profile anterior cervical intervertebral fusion system and Cage-Plate fusion system on the adjacent segments, so as to provide references for the long-term clinical efficacy of single segment cervical spondylosis. Methods The finite element model of cervical spine C1-7 was established based on CT scan data of normal people. After the validity of the model was validated, two finite element models of C5-6 segment implanted with Zero-P fusion system and Cage-Plate fusion system were built. The physiological torque 1.5 N·m was loaded respectively on the normal model, Zero-P implanted model and Cage-Plate implanted model to simulate cervical flexion, extension, lateral bending and rotation. Changes in the ranges of motion (ROMs) of adjacent segments and stresses on nucleus pulposus, endplate and annulus, facet joints of intervertebral disc were compared for the three models. Results After the two kinds of anterior cervical intervertebral fusion systems were implanted, ROMs of C4-5 segments increased by 20%, but ROMs of C6-7 segments increased up to 120%. The stresses on C4-5 nucleus increased by 78%, while the stresses on C6-7 nucleus increased up to 110%. The stresses on the adjacent endplates and the fiber ring also increased. Conclusions The implantation of Cage-Plate and Zero-P fusion system both increased the ROMs of the adjacent segments, and the stresses on annulus, fiber rings and facet joints of the adjacent discs increased as well, which would cause lesions of the adjacent segments in the long run. However, there was no essential difference in biomechanical effects of the Cage-Plate and Zero-P cage fusion system on the adjacent segments.
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STUDY DESIGN: Prospective cohort study. PURPOSE: To study clinicoradiological parameters of zero-profile cage screw used for anterior cervical discectomy and fusion (ACDF). OVERVIEW OF LITERATURE: Radiological parameters of various implants used for ACDF are available, but those for zero-profile cage are sparse. METHODS: Patients with unilateral intractable brachialgia due to single-level cervical disc prolapse between April 1, 2011 and March 31, 2014 were included. Clinical assessment included arm and neck pain using visual analogue score (VAS) and neck disability index (NDI) scores. Radiological assessment included motion segment height, adjacent disc height (upper and lower), segmental and cervical lordosis, implant subsidence, and pseudoarthrosis. Follow-ups were scheduled at 1, 3, 6, 12, and 24 months. RESULTS: Thirty-four patients (26 males, 8 females) aged 30–50 years (mean, 42.2) showed excellent clinical improvement based on VAS scores (7.4–0 for arm and 2.0–0.6 for neck pains). Postoperative disc height improved by 11.33% (p<0.001), but at 2 years, the score deteriorated by 7.03% (p<0.001). Difference in the adjacent segment disc height at 2 years was 0.08% (p=0.8) in upper and 0.16% (p<0.001) in lower disc spaces. Average segmental lordosis achieved was 5.59° (p<0.001) from a preoperative kyphosis of 0.88°; at 2 years, an average loss of 7.05° (p<0.001) occurred, resulting in an average segmental kyphosis of 1.38°. Cervical lordosis improved from 11.59° to 14.88° (p=0.164), and at 2 years, it progressively improved to 22.59° (p<0.001). Three patients showed bone formation and two mild protrusion of the implant at 2 years without pseudoarthrosis/implant failure. CONCLUSIONS: The zero-profile cage screw device provides good fusion and cervical lordosis but is incapable of maintaining the segmental lordosis achieved up to a 2-year follow-up. We also recommend caution when using it in patients with small vertebrae.
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Animals , Humans , Male , Arm , Cohort Studies , Diskectomy , Follow-Up Studies , Kyphosis , Lordosis , Neck , Neck Pain , Osteogenesis , Prolapse , Prospective Studies , Pseudarthrosis , SpineABSTRACT
<p><b>OBJECTIVE</b>To compare the short-term efficacy of anterior cervical discectomy and fusion(ACDF) with traditional nail plate system and Zero-profile device in the treatment of cervical spondylotic myelopathy(CSM).</p><p><b>METHODS</b>The clinical data of 45 patients with CSM treated from July 2014 to August 2015 was retrospectively analyzed. There were 23 males and 22 females with an average age of 53.7 years old(range, 32 to 71 years old). The course of disease was 5 months to 2 years. All the patients were treated with ACDF with 24 cases by traditional nail plate system fixation(group A) and 21 cases by Zero-P system fixation(group B). Operation time and intraoperative bleeding were compared between two groups. Neurological function and cervical pain were evaluated by Japanese Orthopaedic Association scores (JOA) and visual analogue scale (VAS), respectively. Cervical curvature(Cobb angle) change and intervertebral fusion were evaluated by X-rays and CT. And associated complications were analyzed in two groups.</p><p><b>RESULTS</b>All the patients were followed up for 12 to 16 months with an average of 14 months. Operation time of group A and B was(87.6±23.2) min and (62.7±17.3) min respectively, and the difference was significant between two groups; and intraoperative bleeding was (80.2±36.8) ml and (78.4±29.6) ml respectively, and the difference was not significant. At final follow-up, JOA and VAS of all patients were obvious improved, but there was no significant difference between two groups. Preoperative Cobb angle in group A and B was (8.7±4.3) ° and (8.6±4.2) ° respectively, and the difference was significant. The Cobb angle at final follow-up was (14.5±6.4) ° and (17.4±8.6) ° respectively, and the difference between two groups was significant. The incidence of dysphagia in group A and B were 29.17% and 9.52% respectively, and there was significant difference between two groups. All intervertebral spaces got fusion at final follow-up. No tracheo-asophageal injury and recurrent laryngeal nerve damage or other complications were found. No fusional migration, subsidence, loosening, breakage, etc. were found.</p><p><b>CONCLUSIONS</b>The clinical comparison of Zero-P interbody fixation system and cervical plate internal fixation for the treatment of cervical spondylosis was quite fair, but Zero-P showed a better therapeutic effect with improvement of life quality.</p>
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OBJECTIVE: We compared the clinical and radiographic outcomes of stand-alone polyetheretherketone (PEEK) cage and Zero-Profile anchored spacer (Zero-P) for single level anterior cervical discectomy and fusion (ACDF). METHODS: We retrospectively reviewed 121 patients who underwent single level ACDF within 2 years (Jan 2011-Jan 2013) in a single institute. Total 50 patients were included for the analysis who were evaluated more than 2-year follow-up. Twenty-nine patients were allocated to the cage group (m : f=19 : 10) and 21 for Zero-P group (m : f=12 : 9). Clinical (neck disability index, visual analogue scale arm and neck) and radiographic (Cobb angle-segmental and global cervical, disc height, vertebral height) assessments were followed at pre-operative, immediate post-operative, post-3, 6, 12, and 24 month periods. RESULTS: Demographic features and the clinical outcome showed no difference between two groups. The change between final follow-up (24 months) and immediate post-op of Cobb-segmental angle (p=0.027), disc height (p=0.002), vertebral body height (p=0.033) showed statistically better outcome for the Zero-P group than the cage group, respectively. CONCLUSION: The Zero-Profile anchored spacer has some advantage after cage for maintaining segmental lordosis and lowering subsidence rate after single level anterior cervical discectomy and fusion.
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Animals , Humans , Arm , Body Height , Diskectomy , Follow-Up Studies , Kyphosis , Lordosis , Retrospective StudiesABSTRACT
Objective To observe the difference of efficacy of three different treatment of internal fixation of intervetebral crasis on cervical spondylosis (spinal cord) .Methods From January 2009 to January 2013 ,There are 167 cases of patients admitted to hospital from cervical spondylosis (spinal cord ) ,randomly selected different fusion fixation methods are divided into three groups :in the first group ,there were 55 patients treated with autologous iliac bone graft fusion plate fixation ;in the second group , there were 60 patients treated with zero profile material PEEK interbody fusion with autologous bone graft ;in the third group ,the 52 patients were treated with the PEEK material MC + self‐locking cervical interbody fusion with autologous bone graft .Observa‐tion and comparison indicators include :spinal cord function JOA scores before and after surgery ,surgical segment intervertebral height and cervical curvature condition .Results Follow‐up lasted from 13 to 50 months ,the average length was 26 months .The difference in operation time ,blood loss during surgery analysis ,wherein the first group and the second or third group of three groups was statistically significant (P0 .05) .In the first group ,there were 17 patients had transient throat discomfort and symptom disappeared 48 hours later ;dysphagia relieved or disappeared in one week ;there were two cases of screws and titanium loosen one week after operation , and were treated with immediate revision surgery .In the second ,third group ,there were 19 cases and 13 cases showed temporary throat discomfort disappeared within 48 hours after surgery respectively ,there was no dysphagia .No patient experienced cerebrospi‐nal fluid leakage ,hematoma and wound infection .The postoperative JOA scores spinal cord function (17 points France) ,surgical segmental cervical intervertebral height and curvature of three groups improved significantly compared with preoperative evaluation index ,and there was no significant difference among three groups (P>0 .05) .In the last follow‐up ,the interbody fusion rates of the first ,second and third groups were 67 .1% ,66 .3% and 65 .9% ,the difference between groups was not statistically significant (P>0 .05) .Conclusion Anterior decompression and interbody fusion locking device applications showed good performance in maintai‐ning the intervertebral height segment surgery ,rehabilitation cervical curvature ,and promote bone fusion with autogenous titanium plate fixation comparison .Patients can get a good surgery ,and the former has a simpler surgical fixation method ,shorter time ,less bleeding and less complications .
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OBJECTIVE: This study analyzed clinical and radiological outcomes of a zero-profile anchored spacer (Zero-P) and conventional cage-plate (CCP) for single level anterior cervical discectomy and fusion (ACDF) to compare the incidence and difference of postoperative dysphagia with both devices. METHODS: We retrospectively reviewed our experiences of single level ACDF with the CCP and Zero-P. From January 2011 to December 2013, 48 patients who had single level herniated intervertebral disc were operated on using ACDF, with CCP in 27 patients and Zero-P in 21 patients. Patients who received more than double-level ACDF or combined circumferential fusion were excluded. Age, operation time, estimated blood loss (EBL), pre-operative modified Japanese Orthopaedic Association (mJOA) scores, post-operative mJOA scores, achieved mJOA scores and recovery rate of mJOA scores were assessed. Prevertebral soft tissue thickness and postoperative dysphagia were analyzed on the day of surgery, and 2 weeks and 6 months postoperatively. RESULTS: The Zero-P group showed same or favorable clinical and radiological outcomes compared with the CCP group. Postoperative dysphagia was significantly low in the Zero-P group. CONCLUSIONS: Application of Zero-P may achieve favorable outcomes and reduce postoperative dysphagia in single level ACDF.