[Long-term outcome of 57 patients after ventral interbody spondylodesis of the lower cervical spine].

In this retrospective study we present the long-term results in 89 patients who underwent anterior interbody fusion of acute cervical spine injuries in our institution between 1972 and 1983. There were 23 dislocations, 50 fracture-dislocations and 16 burst fractures without significant posterior lesions. Only 20 patients showed no neurologic symptoms. In all 79 patients who were treated initially in our trauma department, closed reduction was performed as soon as possible. No aggravation of the neurologic conditions by this manoeuvre was observed. The mean time between injury and operation was 7 days (range 0-110 days). In 79 patients an H-plate or one-third-tubular plate was used, and in 10 patients fusion was performed only by bone grafting according to the technique of Robinson [40]. Severe complications, i.e. persistent instability with kyphosis or sagittal dislocation, were found in only 2 of these 10 patients secondary to technical problems. The radiologic results demonstrated a high fusion rate, with fusion in 78 out of the 79 patients. Of the 79 patients treated with plate spondylodeses, 7 devices had to be removed without loss of correction: 6 owing to loosening and 1 to breakage of the plate. Only in one additional case after early hardware removal because of loosening was a loss of correction detected. Of the original 89 patients, 17 had died of causes unrelated to the operation. The mean age of the surviving 72 patients at the time of injury was 36 years (14-83 years). A further 15 patients were lost during follow-up, so that 57 (79%) could be included in the study with a mean follow-up of 11 years, 9 months (10-19 years). The functional results were as follows: Active range of motion was limited between 25 and 50%. 40 patients had no pain at rest, 38 only during motion without need for treatment. A significant correlation between pain and fused segments could not be found. Spontaneous fusion and spondylophytes in adjacent motion segments were seen in 27 patients, again without significant correlation to residual pain. No hypermobility of adjacent motion segments in functional X-rays was seen. 46 patients returned to their former work, 7 were not able to work again secondary to the injury, 4 patients received old-age pension. Improvement of the neurologic deficits in the 37 symptomatic patients was observed in 30 cases (81.1%) according to the "Sunnybrook Cord Injury Scale" [49]; according to the ASIA Neurological Impairment Scale [5] 25 (67.6%) of them improved of at least 1 degree. No correlation could be found between the interval injury to operation and neurologic improvement. With regard to the early stage of the procedure of anterior interbody fusion for traumatic lesions this study shows promising data with high fusion rates and low morbidity, especially for the combination with plate fixation. Further improved within the last 12 years this method offers an excellent alternative for operative treatment of most acute lower cervical spine injuries. Using devices which are not angle stable, special attention should be given to precise bicortical screw fixation.