Objective To observe the clinical outcomes of Hangman fracture treated by anterior cervical discectomy and fusion. Methods A total of 41 patients with Hangman fracture were retrospectively analyzed, who underwent anterior cervical discectomy and fusion from May 2010 to May 2016. Intervertebral bone graft fusion was observed through postoperative radiographic images, and improvement of symptoms was evaluated by Visual Analogue Scale (VAS), Neck Disability Index (NDI) and Modified Japanese Orthopaedic Association Scale (m-JOA). Surgical complications were evaluated as well. Results No severe complications occurred after surgery, but 5 patients had a transient dysphagia, which relieved spontaneously. Thirty-five patients had a fusion of intervertebral bone graft 3 months after surgery, and the remaining 6 patients did at the last follow-up. The VAS score was improved from 4.5±1.6 pre-operatively to 2.4±1.7 immediately post-operatively (P>0.05), and was further improved to 0.7±0.9 at the last follow-up (P<0.05). The NDI score was improved from 29.3±10.9 pre-operatively to 13.2±5.4 immediately post-operatively (P<0.05), and was further improved to 4.6±3.1 at the last follow-up (P<0.05). The m-JOA score was improved from 8.4±2.3 pre-operatively to 11.6±3.5 immediately post-operatively (P<0.05), and was further improved to 14.3±2.0 at the last follow-up (P<0.05). Conclusion Anterior cervical discectomy and fusion can be used in Hangman fracture, which is safe and reliable.
ObjectiveTo quantitatively determine the levels of type Ⅰ and type Ⅱ collagen mRNA in the intervertebral disc cartilage endplate of injured animal model, and to clarify the cytological function of intervertebral disc chondrocytes during fibrosis repair after intervertebral disc injury.MethodsForty healthy New Zealand rabbits were randomly divided into fibrosus puncture group, upper cartilage endplate single puncture group, upper and lower cartilage endplate multiple puncture group, and sham group. Two experimental animals were randomly selected from each group on the 2nd day, and the 2nd, 8th, 12th, and 24th week after the animal modeling operation to obtain intervertebral disc specimens. The levels of type Ⅰ collagen and type Ⅱ collagen in cartilage endplate cells of the intervertebral disc were determined by reverse transcriptase polymerase chain reaction (PCR). RNA was extracted from the endplate of the intervertebral disc, and the RNA concentration and the ratio of RNA concentration to protein concentration were determined by nucleic acid analyzer. Reverse transcription was performed by Revertaid M-Mulv reverse transcriptase, type Ⅰ and type Ⅱ collagen primers were designed to establish a PCR reaction system, 2% agarose gel electrophoresis (120 V, 40 min) was prepared by using 0.5×TBE electrophoresis buffer. The amplification results were observed under ultraviolet light, and the gray values of different electrophoresis bands were determined.ResultsThe level of type Ⅰ collagen mRNA in each operation group showed a progressive increase after 8 weeks, and the magnitude of the increase was related to the degree of injury. The level of type Ⅱ collagen mRNA showed a transient increase in the fibrosis puncture group and the upper endplate single-puncture group in the first two weeks after the endplate punctures were completed, and then began to decline progressively; in the multiple puncture group, it showed a downward trend from the beginning of the operation. ConclusionsThe synthesis of type Ⅰ collagen in chondrocytes of the injured nucleus pulposus tissue continues to increase with time, while the synthesis of type Ⅱ collagen begin to decrease progressively after a small increase. The formation and change of type Ⅰ and type Ⅱ collagen in injured intervertebral disc chondrocytes are different from natural degeneration.
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 study the correlation between the cervical posture in the cervical disc replacement (CDR) and the cervical curve restoration in neutral position after surgery. Methods Between January 2008 and August 2010, 51 patients underwent single segmental PRESTIGE LP replacement, and the clinical data were retrospectively analyzed. During the surgery, the patient was supinely placed and the lordosis of the cervical spine was mantained with a pillow placed beneath the neck. Of them, 28 were male and 23 were female, aged 30-64 years (mean, 45 years); 32 were diagnosed as having cervical spondylotic myelopathy, 7 having radiculopathy, and 12 having myelopathy and radiculopathy. The disease duration was 3-48 months (mean, 15 months). CDR was performed at C4, 5 in 5 cases, at C5, 6 in 42 cases, and at C6, 7 in 4 cases. The Cobb angles of the cervical alignment, targeted functional spinal unit (FSU), and targeted disc were measured by sagittal X-ray film of the cervical spine in neutral position before and after surgery, as well as the intraoperative C-arm fluroscopy of the cervical spine. Linear correlation and regression were performed to analyze the relation between cervical Cobb angle difference at intraoperation and improvement of the Cobb angles at 3 months after operation. Results The cervical Cobb angles at intraoperation and 3 months after operation were larger than those at preoperation (P lt; 0.05). The difference of the Cobb angle between intra- and pre-operation was (6.72 ± 9.13)° on cervical alignment, (2.10 ± 5.12)° on targeted FSU, and (3.33 ± 3.75)° on targeted disc. At 3 months after operation, the Cobb angle improvement of the cervical alignment, targeted FSU, and targeted disc was (6.30 ± 7.28), (3.99 ± 5.37), and (4.29 ± 5.36)°, respectively. There was no significant difference in the Cobb angle improvement between the targeted FSU and the targeted disc (t= — 0.391, P=0.698), and between the targeted disc and the cervical alignment (t= — 1.917, P=0.061), but significant difference was found between the targeted FSU and the cervical alignment (t= — 2.623, P=0.012). The linear correlation between the Cobb angle difference and the Cobb angle improvement of the cervical spine was observed (P lt; 0.05). Conclusion A slightly lordotic cervical posture during CDR is an important factor to maintaining normal physiological lordosis of the cervical spine after surgery.
Objective To observe the early effectiveness of cervical disc replacement with Pretic-I, a new type artificial disc. Methods A retrospective analysis was made on the clinical data of 10 patients who underwent single segmental cervical disc replacement with Pretic-I from June to December 2014. Among 10 patients, 4 were male and 6 were female, with an average age of 40 years (range, 27-51 years). The mean disease duration was 15.4 months (range, 4-36 months). Affected segments located at C4, 5 level in 1 case, at C5, 6 level in 8 cases, and at C6, 7 level in 1 case. The visual analogue scale (VAS), Japanese Orthopaedic Association (JOA) score, and neck disability index (NDI) were used to evaluate the clinical outcomes. Besides, the disc height and the range of motion (ROM) at operated level, and ROM of upper and lower adjacent level were measured to assess the function. Results The operation was successfully completed in all patients who were followed up for 12 months. No complications of aggravated nerve symptoms, vertebral artery injury, esophagotracheal fistula, cerebrospinal fluid leakage, incision infection, hematoma and prosthetic loosening were observed during follow-up. The VAS score, JOA score, and NDI significantly improved at each time point after operation when compared with preoperative scores (P<0.05). The height of intervertebral disc at operated level was significantly increased at immediate and 3 months after operation when compared with preoperative one (P<0.05), but no significant difference was found between at 6 months or 12 months after operation and at pre-operation (P>0.05). No significant difference was shown in the ROM at operated level, and ROM of upper and lower adjacent level between at pre-operation and at each time point after operation (P>0.05). Conclusion The early effctiveness of cervical disc replacement using Pretic-I is satisfactory. The symptoms can be relieved significantly and the dynamic features of the operated level, as well as the upper and lower adjacent levels, are well preserved.