Effect of decompression range on decompression limit of cervical laminoplasty / 中华医学杂志(英文版)

BACKGROUNDS@#Cervical posterior decompression surgery is used to relieve ventral compression indirectly by incorporating a backward shift of the spinal cord, and this indirect decompression is bound to be limited. This study aimed to determine the decompression limit of posterior surgery and the effect of the decompression range.@*METHODS@#We retrospectively reviewed the data of 129 patients who underwent cervical open-door laminoplasty through 2008 to 2012 and were grouped as follows: C4-C7 (n = 11), C3-C6 (n = 61), C3-C7 (n = 32), and C2-C7 (n = 25). According to the relative location of spinal levels within a decompression range, the type of decompression at a given level was categorized as external decompression (ED; achieved at the levels located immediately external to the decompression range margin), internal decompression (ID; achieved at the levels located immediately internal to the decompression range margin), and central decompression (CD; achieved at the levels located in the center, far from the decompression range margin). The vertebral-cord distance (VCD) was used to evaluate the decompression limit. The C2-C7 angle and VCD on post-operative magnetic resonance images were analyzed and compared between groups. The relationship between VCD and decompression type was analyzed. Moreover, the relationship between the magnitude of the ventral compressive factor and the probability of post-operative residual compression at each level for different decompression ranges was studied.@*RESULTS@#There was no significant kyphosis in cervical curvature (> -5°), and there was no significant difference among the groups (F = 2.091, P = 0.105). The VCD of a specific level depended on the decompression type of the level and followed this pattern: ED < ID < CD (P < 0.05). The decompression type of a level was sometimes affected by the decompression range. For a given magnitude of the ventral compressive factor, the probability of residual compression was lower for the group with the larger VCD at this level.@*CONCLUSIONS@#Our study suggests that the decompression range affected the decompression limit by changing the decompression type of a particular level. For a given cervical spinal level, the decompression limit significantly varied with decompression type as follows: ED < ID < CD. CD provided maximal decompression limit for a given level. A reasonable range of decompression could be determined based on the relationship between the magnitude of the ventral compressive factor and the decompression limits achieved by different decompression ranges.

Comparison of adjacent segment degeneration five years after single level cervical fusion and cervical arthroplasty: a retrospective controlled study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cervical arthroplasty is indicated to preserve cervical motion and prevent accelerated adjacent segment degeneration. Whether accelerated adjacent segment degeneration is prevented in the long term is unclear. This trial compared adjacent segment degeneration in Bryan disc arthroplasty with that in anterior cervical decompression and fusion five years after the surgery.</p><p><b>METHODS</b>We studied patients with single level degenerative cervical disc disease. The extent of adjacent segment degeneration was estimated from lateral X-rays.</p><p><b>RESULTS</b>Twenty-six patients underwent single level Bryan disc arthroplasty and twenty-four patients underwent single level anterior cervical decompression and fusion. All patients were followed up for an average of sixty months. In the Bryan arthroplasty group, nine (17.6%) segments developed adjacent segment degeneration, which was significantly lower than that (60.4%) in the anterior cervical decompression and fusion group. Eleven segments in the Bryan arthroplasty group developed heterotopic ossification according to McAfee's classification and two segments had range of motion less than 2°. In the heterotopic ossification group, four (19.5%) segments developed adjacent segment degeneration, similar to the number in the non-heterotopic ossification group (16.7%). Adjacent segment degeneration rate was 50% in grade IV group but 11.8% in grade II to III.</p><p><b>CONCLUSIONS</b>Adjacent segment degeneration was accelerated after anterior cervical decompression and fusion. However, Bryan disc arthroplasty avoided accelerated adjacent segment degeneration by preserving motion. Patients with grade IV heterotopic ossification lost motion, and the rate of adjacent segment degeneration was higher than that in patients without heterotopic ossification.</p>

Reoperation to the ossification of the posterior longitudinal ligament / 中华外科杂志

<p><b>OBJECTIVE</b>To discuss surgical approaches of ossification of the posterior longitudinal ligament (OPLL) of cervical spine.</p><p><b>METHODS</b>Between June 2005 to July 2010, 36 patients with OPLL of cervical spine were reoperated. There were 23 male, 13 female, age from 39 to 72 years (mean 57 years). The time of the first operation to the reoperation were 4 months to 24 years, an average of 3.9 years. Among 20 patients underwent anterior corpectomy and fusion (ACD) at first operation, 14 cases combined stenosis of cervical spinal canal, 10 cases were insufficient decompression of OPLL, 5 cases injured of cervical spinal cord during the first operation, 1 case was adjacent disc herniation. Among 14 cases underwent expensive open-door laminoplasty (ELAP) at first operation, 6 cases were insufficient decompression of OPLL, 4 cases were inadequate decompressed segment, 2 cases were cervical segmental kyphosis, 2 cases were progression of OPLL combined with disc herniation. Among 2 cases underwent combined approach at first operation, 1 case was insufficient decompression of OPLL, the other was adjacent disc herniation. Their pre- and post-operative X-ray, CT and MRI were analyzed. The complications of reoperation were recorded.</p><p><b>RESULT</b>There were 30 patients followed-up, with a period of 1.5 - 4.0 years, average 1.8 years. With 36 patients, none had deterioration, 2 patients had no recovery post-reoperation, 34 patients had 31.2% Japanese Orthopedic Association score improve rate. Among 22 cases underwent ELAP at second operation, 3 cases had postoperative segmental palsy. Among 14 cases underwent ACD at second operation, 3 cases had intraoperative dural defects.</p><p><b>CONCLUSION</b>Surgical strategy for OPLL of cervical spine should consider the type of OPLL and stenosis of cervical spinal canal.</p>

The application and early result of rectangle titanium cage in the anterior cervical spine fusion / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the value of rectangle titanium cage (SynCage-C) in the anterior cervical spine fusion.</p><p><b>METHODS</b>Nineteen patients underwent anterior cervical discectomy and interbody fusion using SynCage-C with average follow-up of 9 months.</p><p><b>RESULTS</b>All cases had cervical spondylosis with 13 cases of myelopathy and 6 cases of radiculopathy. One level fusion were 16 cases and two levels were 3 cases. The mean operation time was 40 minutes per level with average bleeding 60 ml. Patients were asked to wear a hard collar for average 8.5 weeks after the operation. The fusion was solid on lateral view X-ray films three months post-operation. Only 1 case had neck stiffness due to prolonged collar protection and another case had short term pain on bone dorner site. There were no other complications such as cage subsidence, displacement, milaligment and kyphosis of cervical spine.</p><p><b>CONCLUSION</b>The SynCage-C can resort and maintain the intervertebral space effectively with the advantage of immediate stability, satisfactory fusion and easy to use.</p>