ABSTRACT
Titanium mesh cage is one of the fusion devices used in anterior cervical corpectomy and fusion (ACCF). It can not only immediately rebuild the stability of cervical spine during the operation, maintain the height and physiological curvature of intervertebral vertebrae, but also avoid the complications of bone donor area caused by autologous bone extraction. Therefore, titanium mesh cage has become the most commonly used internal plant in ACCF. However, there exist many problems in traditional titanium cage, such as stress shielding and titanium cage sinking, which will affect the surgical effect to a certain extent, and even lead to serious postoperative complications requiring revision surgery. At present, a variety of new titanium cages have been invented, which can solve the problems caused by traditional titanium cage to a certain extent. Biomechanical evaluation and its testing methods are an indispensable process for judging whether a new type of spinal fusion cage can be used in clinical practice. This article reviews the biomechanical studies related to cervical spine anatomy, the biomechanical properties of traditional titanium cages and new titanium cages, so as to provide new ideas for the improvement of traditional titanium cages and the development of new titanium cages.
ABSTRACT
<p><b>OBJECTIVE</b>To study the change trend of cervical range of motion(ROM) after single-level anterior cervical corpectomy and fusion(ACCF) in treating cervical spondylotic myelopathy.</p><p><b>METHODS</b>The clinical data of 23 patients with cervical spondylotic myelopathy was retrospectively analyzed from February 2015 to April 2016. There were 11 males and 12 females, with an average age of (54.6±13.3) years. All the patients were diagnosed as cervical spondylotic myelopathy by interrogation, physical examination and radiology, and were treated by ACCF. The Coda motion system was applied to assess the cervical range of motion pre-and post-operation. JOA and VAS scores were used to evaluate the clinical outcomes.</p><p><b>RESULTS</b>The mean follow-up time was (9.4±1.6) months. Cervical ROM in all directions at 3 months postoperatively were significantly lower except for the left rotation(<0.05). There was significant difference of cervical ROM in all directions between preoperative and 6 months postoperatively(>0.05). The right lateral bending and the left rotation at 9 months postoperatively increased significantly(<0.05). Postoperative extension at 6 months was significantly better than that of 3 months postoperatively(<0.05). The extension, left and right lateral bending and left rotation at 9 months postoperatively were significantly better than of 6 months postoperatively(<0.05). Postoperative JOA scores at each time points were significantly higher than that of preoperative(<0.05) and VAS scores at each time points were significantly lower than that of preoperative(<0.05).</p><p><b>CONCLUSIONS</b>The change trend of three-dimensional cervical ROM after single-level ACCF revealed that the ROM decreased in short term, and later increased and was better than the preoperative level. Meanwhile, the neurological function improved significantly. But the short-term and long-term change trend of ROM postoperatively and the change trend of ROM after multi-level ACCF need to be further studied.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To compare the clinical effects between anterior cervical discectomy and fusion(ACDF) combined with anterior cervical corpectomy and fusion(ACCF) and cervical posterior single open-door laminoplasty with mini-titanium plate fixation in treating three-segment cervical spondylotic myelopathy.</p><p><b>METHODS</b>The clinical data of 63 patients (39 males and 24 females) with three-segment cervical spondylotic myelopathy underwent surgical treatment from March 2014 to March 2016 were retrospectively analyzed. Among them, 43 cases were treated by ACDF combined with ACCF(anterior group), and 20 cases were treated by cervical posterior single open-door laminoplasty with mini-titanium plate fixation(posterior group). Operative time, intraoperative blood loss, postoperative complications were compared between two groups. And according to JOA score to evaluate the clinical effect.</p><p><b>RESULTS</b>All the patients were follow-up from 16 to 40 months with an average of 25.8 months. Operative time of anterior group and posterior group were (123.70±6.21) min and(118.70±5.41) min, respectively, there was no significant difference between two groups(>0.05). Intraoperative blood loss of anterior group and posterior group were (85.23±7.51) ml and (107.18±9.41) ml, respectively, there was significant difference between two groups(<0.05). In anterior group, axial symptoms occurred in 6 cases, dysphagia in 1 case, and no C₅ nerve root palsy, hoarseness and choking cough were found, the incidence rate of complication was 16.3%(7/43); and in posterior group, axial symptoms occurred in 5 cases, C5 nerve root palsy in 1 case, and no dysphagia, hoarseness and choking cough were found, the incidence rate of complication was 30.0%(6/20); there was significant defference in incidence rate of complication between two group(<0.05). At 1 week after operation and final follow-up, the JOA scores of anterior group were obviously better than that of posterior group(<0.05).</p><p><b>CONCLUSIONS</b>Above-mintioned two surgical treatment for cervical spondylotic myelopathy can provide instantly stability, the method of ACDF combined with ACCF was obviously better that of the method of cervical posterior single open-door laminoplasty in intraoperative blood loss, the incidence rate of complications, clinical effect.Thus, for the treatment of three-segment cervical spondylotic myelopathy, the method of ACDF combined with ACCF would be firstly chosen.</p>