Objective To evaluate the incidence of heterotopic ossification (HO) after single-level Bryan cervical artificial disc replacement, and to identify the relationship between HO and the effectiveness. Methods The cl inical data of 48 patients undergoing single-level Bryan cervical artificial disc replacement between October 2005 and October 2007 were reviewedretrospectively. There were 27 males and 21 females with an average age of 40.5 years (range, 33-51 years), including 8 cases of cervical myelopathy, 27 cases of nerve root cervical spondylosis, and 13 cases of mixed cervical spondylosis with an average disease duration of 10.3 months (range, 2-14 months). The involved segments included C3, 4 in 3 cases, C4, 5 in 6 cases, C5, 6 in 30 cases, and C6, 7 in 9 cases. The outcomes were evaluated using Visual Analogue Scale (VAS) score, the neck disabil ity index (NDI), and cervical range of motion (ROM). According to patients with or without HO, 48 patients were divided into 2 groups (HO group and no HO group). VAS score, NDI, and cervical ROM were compared between 2 groups at 1, 2, 3, and 4 years after operation. Results No severe complication occurred during and after operation in all patients. Forty-eight patients were followed up 48-72 months (mean, 56.6 months). VAS score and NDI were significantly improved when compared with preoperative values at all time points (P lt; 0.05); except at 3 days after operation, no significant difference was found in cervical ROM at the other time points when compared with preoperation (P gt; 0.05). Thirteen patients (27.08%) had HO at 4 years after operation, including 8 cases of grade 1, 3 cases of grade 2, and 2 cases of grade 3. There was no significant difference in VAS score, NDI, and cervical ROM between 2 groups at 1, 2, 3, and 4 years (P gt; 0.05). Conclusion The incidence of HO after single-level Bryan cervical artificial disc replacement is relatively high. However, HO has no effect on the cervical ROM and the effectiveness.
Objective To investigate the cl inical effect of cervical artificial disc replacement (CADR) on twosegment cervical spondylosis and to research its influences on the range of motion (ROM) of the diseased segments and theadjacent superior and inferior segments. Methods From September 2004 to February 2007, 7 cases with cervical spondylosis at C4,5 and C5,6 were treated with CADR using Bryan artificial disc prosthesis, including 4 males and 3 females aged 30-45 years old (average 38.5 years old). All the patients had cervicodynia in various degrees, pain and numbness of l imbs and decreased muscle strength, including 3 cases of cervical spondylotic radiculopathy, 3 of cervical spondylotic myelopathy and 1 of mixed cervical spondylosis. The course of disease was 12-54 months (average 27 months). Preoperatively, X-ray films revealed the intervertebral space of C4, 5 and C5,6 was narrowed and the cervical curve became straight, CT or MRI showed the intervertebral disk hernia of C4, 5 and C5,6, and the hyperostosis of vertebral margin compressed nerve root or spinal cord. All the patients had no response to the preopratively conservative treatment. JOA score and ROM of the diseased segments and the adjacent superior and inferior segments were compared before and after operation. Results All the patients survived the perioperative period, without hoarse voice, muscle spasm, dysphagia and cervicodynia. X-ray films showed the implanted prosthesis was well located, the height of intervertebral space was normal, and no prosthesis loosening, prosthesis migration and infection occurred 12 months after operation. All the 7 cases were followed up for 12-41 months (average 26.7 months). Cervicodynia and l imbs’pain and numbness disappeared, and muscle strength was improved obviously. The JOA score before and during the followup period was (8.35 ± 1.27) and (14.65 ± 1.61) points, respectively, indicating there was a significant difference (P lt; 0.05). For the ROM of C4,5 and C5,6, it was (8.38 ± 0.48)° and (9.16 ± 0.54)° before operation, respectively, and it increased to (11.15 ± 0.65)° and (12.75 ± 0.73)° after operation, respectively, showing there was a significant difference (P lt; 0.05). The ROM at C3,4 and C6,7 before operation was (9.71 ± 0.76)° and (12.39 ± 0.58)°, espectively, while it was improved to (10.26 ± 0.47)° and (13.67 ± 0.71)° after operation, respectively, indicating there were no significant differences between before and after operation (P gt; 0.05). Conclusion The appl ication of Bryan Disc CADR for two-segment cervical spondylosis has satisfying therapeutic effects, can improve the ROM of diseased segments obviously, and has minor influences on the ROM of adjacent superior and inferior segment.
ObjectiveTo evaluate the long-term efficacy and influencing factors of cervical artificial disc replacement (CADR) for patients with cervical spondylotic radiculopathy (CSR).MethodsThe data of 29 CSR patients who underwent Bryan artificial disc replacement between December 2003 and December 2007 and followed up more than 10 years were retrospectively analysed. There were 16 males and 13 females with an average age of 54.1 years (range, 40-70 years). The disease duration was 2-144 months (mean, 19.2 months). CT and MRI were performed before operation to identify the compression segments (C3, 4 in 2 cases, C4, 5 in 6 cases, C5, 6 in 18 cases, C6, 7 in 3 cases) and the compression factors. According to the compression factor, the patients were divided into 2 groups: 14 patients with cervical disc herniation were in the group A and 15 patients combined with osteophyte were in the group B. There was no significant difference in gender, age, disease duration, and compressed level between 2 groups (P>0.05). The radiographic and clinical evaluation indexes were recorded before operation and at last follow-up. The radiographic evaluation indexes included the global cervical and segmental range of motion (ROM), loss of ROM (ROM<3°) at last follow-up, Cobb angle and incidence of local kyphosis, paravertebral ossification (PO) grading. The clinical evaluation indexes included neck disability index (NDI) and overall efficacy (Odom’s score).ResultsAll patients were followed up 121-153 months (mean, 130 months). The results of radiographic evaluation indexes showed that within group comparison, except that the Cobb angle of the operated level was significantly decreased (P<0.05) in both 2 groups, there was no significant difference in global cervical ROM and segmental ROM between preoperation and last follow-up (P>0.05). Except that the loss of ROM (ROM<3°) at last follow-up and high-grade PO at last follow-up in group B were significantly higher than those in group A (P<0.05), there was no significant difference in other radiographic evaluation indexes between 2 groups (P>0.05). The results of clinical evaluation indexes showed that the NDI was significantly improved in both groups (P<0.05) at last follow-up. There was no significant difference in the NDI at preoperation and at last follow-up, the decline of NDI at last follow-up, and the overall efficacy evaluated by Odom’s score between 2 groups (P>0.05). The excellent and good rate of overall efficacy reached 100% in both groups.ConclusionCADR has satisfied long-term efficacy in treating CSR. The maintenance of segmental mobility was better in patients with disc herniation than in patients with disc herniation and osteophyte.
Anterior cervical decompression and fusion (ACDF) treatment for cervical spondylosis has been more than half a century, and achieved good clinical results. However, with the continuous extension of follow-up time, the fusion segment-associated postoperative complications emerged gradually. Reserved cervical stability and activity, the concept of non-fusion was born. As a non-fusion technique, cervical artificial disc replacement (CADR) developed rapidly. With the continuous development of artificial prosthesis materials and design concepts, and specification and proficiency of surgical procedures, CADR has achieved better short- and mid-term clinical efficacy than ACDF. Compared with ACDF, the main advantages of CADR are that the postoperative recovery is quick, the activity and stability of cervical vertebra are maintained, the height of cervical intervertebral space is restored, and the stress of adjacent segments and the rate of surgical renovation are reduced. In clinical work, as an emerging technology, CADR requires spine surgeons to control the surgical indications, contraindications, and patients’ conditions strictly. This article reviews the research progress of CADR in order to provide new ideas for clinical treatment of cervical spondylosis.