[A comparative study between on-endcaps and non-endcaps titanium mesh cage for the treatment of elderly cervical spondylotic myelopathy complicated with osteoporosis approach for anterior cervical spine surgery].

OBJECTIVE: To compare radiographic results and clinical effects of titanium mesh cage with two endcaps(on-endcaps titanium mesh cage) and without endcaps(non-endcaps titanium mesh cage) in anterior cervical corpectomy and fusion(ACCF) for elderly cervical spondylotic myelopathy. METHODS: The clinical data of 60 patients with cervical spondylotic myelopathy underwent ACCF from January 2011 to January 2016 were retrospectively analyzed. There were 26 males and 34 females, aged from 68 to 79 years old with a mean 75.8 years old. The patients were divided into two groups according to the different titanium mesh cage, using on-endcaps titanium mesh cage(group A, 32 cases) or non-endcaps titanium mesh cage (group B, 28 cases). The nerve function was evaluated by JOA score system; the height of intervertebral fusion segments and fusion segmental lordosis angle (Cobb angle) were measured by cervical lateral X-ray films, the bone graft fusion rate of titanium mesh was evaluated by CT. RESULTS: All the patients were followed up from 1 to 2 years with an average of 1.5 years. The preoperative JOA scores of group A were 9.3±1.7, postoperative at 1 week, 3 months, 1 year were 14.2±1.8, 15.7±1.2, 15.4±1.5, respectively; and the preoperative JOA scores of group B were 9.1±1.8, postoperative at 1 week, 3 months, 1 year were 14.5±1.3, 14.9±1.7, 15.2±1.6, respectively. The postoperative JOA scores between two groups were obviously improved than that of preoperative (P<0.05). There was no significant difference in JOA scores of 3 time-point after operation between two groups (P>0.05). In the group A, preoperative intervertebral height were(42.1±2.4) mm, postoperative at 1 week, 3 months, 1 year were (45.3±3.2) mm, (44.7±2.9) mm, (44.5±3.0) mm, respectively; preoperative Cobb angle of fusion segments were (5.3±1.2)°, postoperative at 1 week, 3 months, 1 year were (10.3±1.9) °, (10.1±1.7) °, (9.9±1.3) °, respectively. And in group B, preoperative intervertebral height were (43.4±2.3)mm, postoperative at 1 week, 3 months, 1 year were (45.7±2.8) mm, (44.2±2.7) mm, (41.5±2.1) mm, respectively; preoperative Cobb angle of fusion segments were (5.4±1.0) °, postoperative at 1 week, 3 months, 1 year were (11.2±1.8)°, (10.8±1.6)°, (7.2±1.4) °, respectively. The postoperative intervertebral height, Cobb angle of fusion segments between two groups were obviously improved than that of preoperative (P<0.05). There was no significant difference in intervertebral height and Cobb angle at 1 week, 3 months after operation between two groups(P>0.05). One year after operation, intervertebral height and Cobb angle in group A was better than that of group B(P<0.05). CONCLUSIONS: On-endcaps titanium mesh cage is superior to non-endcaps titanium mesh cage in the maintenance of cervical intervebral height and segmental lordosis angle postoperatively at elderly spondylotic myelopathy complicated with osteoporosis. The usage of on-endcaps titanium mesh cage can effectively reduce postoperative subsidence rate.