Henry H. Bohlman

Radiculopathy and Myelopathy at Segments Adjacent to the Site of a Previous Anterior Cervical Arthrodesis

BACKGROUND We studied the incidence, prevalence, and radiographic progression of symptomatic adjacent-segment disease, which we defined as the development of new radiculopathy or myelopathy referable to a motion segment adjacent to the site of a previous anterior arthrodesis of the cervical spine. METHODS A consecutive series of 374 patients who had a total of 409 anterior cervical arthrodeses for the treatment of cervical spondylosis with radiculopathy or myelopathy, or both, were followed for a maximum of twenty-one years after the operation. The annual incidence of symptomatic adjacent-segment disease was defined as the percentage of patients who had been disease-free at the start of a given year of follow-up in whom new disease developed during that year. The prevalence was defined as the percentage of all patients in whom symptomatic adjacent-segment disease developed within a given period of follow-up. The natural history of the disease was predicted with use of a Kaplan-Meier survivorship analysis. The hypothesis that new disease at an adjacent level is more likely to develop following a multilevel arthrodesis than it is following a single-level arthrodesis was tested with logistic regression. RESULTS Symptomatic adjacent-segment disease occurred at a relatively constant incidence of 2.9 percent per year (range, 0.0 to 4.8 percent per year) during the ten years after the operation. Survivorship analysis predicted that 25.6 percent of the patients (95 percent confidence interval, 20 to 32 percent) who had an anterior cervical arthrodesis would have new disease at an adjacent level within ten years after the operation. There were highly significant differences among the motion segments with regard to the likelihood of symptomatic adjacent-segment disease (p<0.0001); the greatest risk was at the interspaces between the fifth and sixth and between the sixth and seventh cervical vertebrae. Contrary to our hypothesis, we found that the risk of new disease at an adjacent level was significantly lower following a multilevel arthrodesis than it was following a single-level arthrodesis (p<0.001). More than two-thirds of all patients in whom the new disease developed had failure of nonoperative management and needed additional operative procedures. CONCLUSIONS Symptomatic adjacent-segment disease may affect more than one-fourth of all patients within ten years after an anterior cervical arthrodesis. A single-level arthrodesis involving the fifth or sixth cervical vertebra and preexisting radiographic evidence of degeneration at adjacent levels appear to be the greatest risk factors for new disease. Therefore, we believe that all degenerated segments causing radiculopathy or myelopathy should be included in an anterior cervical arthrodesis. Although our findings suggest that symptomatic adjacent-segment disease is the result of progressive spondylosis, patients should be informed of the substantial possibility that new disease will develop at an adjacent level over the long term.

Robinson anterior cervical discectomy and arthrodesis for cervical radiculopathy. Long-term follow-up of one hundred and twenty-two patients.

We evaluated the results of the Robinson method of anterior cervical discectomy and arthrodesis with use of autogenous iliac-crest bone graft, at one to four levels, in 122 patients who had cervical radiculopathy. A one-level procedure was done in sixty-two of the 122 patients; a two-level procedure, in forty-eight; a three-level procedure, in eleven; and a four-level procedure, in one. The average duration of clinical and roentgenographic follow-up was six years (range, two to fifteen years). The average age was fifty years (range, twenty-five to seventy-eight years). Preoperatively, 118 patients had pain in the arm, fifty-five had weakness of one or more motor roots, and seventy-seven had sensory loss. At the time of follow-up, eighty-one patients had no pain in the neck, twenty-six had mild pain in the neck, nine had moderate pain in the neck, four had mild radicular pain, and two had a combination of mild radicular pain and moderate pain in the neck. One hundred and eight patients had no functional impairment, and fourteen had a slight limitation of function during the activities of daily living. Nine of eleven patients who had symptoms related to a change at one level cephalad or caudad to the site of a previous arthrodesis had another operative procedure. Lateral roentgenograms of the cervical spine, made in flexion and extension, showed a pseudarthrosis at twenty-four of 195 operatively treated segments. Sixteen of the patients who had a pseudarthrosis were symptomatic, but only four had sufficient pain to warrant revision. The risk of pseudarthrosis was significantly greater after a multiple-level arthrodesis than after a single-level arthrodesis (p < 0.01). At the time of the most recent follow-up, fifty-three of the fifty-five patients who had had a motor deficit had had a complete recovery, and the two remaining patients had had a partial recovery. Seventy-one of the seventy-seven patients who had had a sensory loss had regained sensation. None of the patients had an increased neurological deficit postoperatively. Our results suggest that the Robinson anterior cervical discectomy and arthrodesis with an autogenous iliac-crest bone graft for cervical radiculopathy is a safe procedure that can relieve pain and lead to resolution of neurological deficits in a high percentage of patients.

Anterior Cervical Decompression and Arthrodesis for the Treatment of Cervical Spondylotic Myelopathy. Two to Seventeen-Year Follow-up*

We reviewed the cases of 108 patients with cervical spondylotic myelopathy who had been managed with anterior decompression and arthrodesis at our institution. Operative treatment consisted of anterior discectomy, partial corpectomy, or subtotal corpectomy at one level or more, followed by placement of autogenous bone graft from the iliac crest or the fibula. At the latest follow-up examination, thirty-eight of the eighty-two patients who had had a preoperative gait abnormality had a normal gait, thirty-three had an improvement in gait, six had no change, four had improvement and later deterioration, and one had a worse gait abnormality. Of the eighty-seven patients who had had a preoperative motor deficit, fifty-four had complete recovery; twenty-six, partial recovery; six, no change; and one had a worse deficit. The average grade according to the system of Nurick improved from 2.4 preoperatively to 1.2 (range, 0.0 to 5.0) postoperatively. A pseudarthrosis developed in sixteen patients, thirteen of whom had had a multilevel discectomy. Only one of thirty-eight arthrodeses that had been performed with use of a fibular strut graft was followed by a non-union. An unsatisfactory outcome with respect to pain was significantly associated with pseudarthrosis (p < 0.001). The development of complications other than non-union was associated with a history of one previous operative procedure or more (p = 0.005). Recurrent myelopathy was rare, but when it occurred it was associated with a pseudarthrosis or stenosis at a new level. The strongest predictive factor for recovery from myelopathy was the severity of the myelopathy before the operative intervention—that is, better preoperative neurological function was associated with a better neurological outcome. Anterior decompression and arthrodesis with autogenous bone-grafting can be performed safely, and is associated with a high rate of neurological recovery, functional improvement, and pain relief, in patients who have cervical spondylotic myelopathy.

Rheumatoid arthritis of the cervical spine. A long-term analysis with predictors of paralysis and recovery.

We analyzed the cases of seventy-three patients who were managed over a twenty-year period for rheumatoid involvement of the cervical spine and were followed for a minimum of two years, with an average follow-up of seven years. A neurological deficit did not develop in thirty-one patients (Ranawat et al. Class I) and paralysis developed in the remaining forty-two patients: Class II in eleven and Class III in thirty-one. Of the forty-two patients in whom paralysis developed, thirty-five had operative stabilization. Seven patients were managed with a soft cervical collar because they refused or were medically unable to have the operation; all of the had an increase in the severity of the paralysis. The posterior atlanto-odontoid interval and the diameter of the subaxial sagittal canal measured on the cervical radiographs demonstrated statistically significant correlations with the presence and severity of paralysis. All of the patients who had a Class-III neurological deficit had a posterior atlanto-odontoid interval or diameter of the subaxial canal that was less than fourteen millimeters. In contrast, the anterior atlanto-odontoid interval, which has traditionally been reported, did not correlate with paralysis. The prognosis for neurological recovery following the operation was not affected by the duration of the paralysis but was influenced by the severity of the paralysis at the time of the operation. The most important predictor of the potential for neurological recovery after the operation was the preoperative posterior atlanto-odontoid interval. In patients who had paralysis due to atlanto-axial subluxation, no recovery occurred if the posterior atlanto-odontoid interval was less than ten millimeters, whereas recovery of at least one neurological class always occurred when the posterior atlanto-odontoid interval was at least ten millimeters. If basilar invagination was superimposed, clinically important neurological recovery occurred only when the posterior atlanto-odontoid interval was at least thirteen millimeters. All patients who had paralysis and a posterior atlanto-odontoid interval or diameter of the subaxial canal of fourteen millimeters had complete motor recovery after the operation. In this series, although only patients who had a neurological deficit were operated on, we observed the range of the posterior atlanto-odontoid interval that was associated with poor or no recovery after the operation, and we identified the safe range on the basis of the patients in whom paralysis did not develop.(ABSTRACT TRUNCATED AT 400 WORDS)

Pyogenic and fungal vertebral osteomyelitis with paralysis.

A retrospective review of the cases of sixty-one patients with vertebral osteomyelitis revealed that the associated diseases of diabetes mellitus and rheumatoid arthritis as well as increased age and a more cephalad level of infection predisposed to paralysis. For patients with paralysis and a long-term follow-up, the prognosis for isolated nerve-root deficits is good with or without surgery. For patients with spinal cord compression, the results generally are better with anterior decompression and stabilization than with laminectomy. Early treatment should be directed at prevention of intrinsic spinal-cord damage, which is irreversible.

Dural tears secondary to operations on the lumbar spine : Management and results after a two-year-minimum follow-up of eighty-eight patients

We reviewed the results of acute management of patients who had sustained a dural tear during an operation on the lumbar spine, and we attempted to determine the long-term sequelae of this complication. In the five years from July 1989 to July 1994, 641 consecutive patients had a decompression of the lumbar spine, performed by the senior one of us; of these patients, eighty-eight (14 percent) sustained a dural tear, which was repaired during the operation. The duration of follow-up ranged from two to eight years (average, 4.3 years). Postoperative management consisted of closed suction wound drainage for an average of 2.1 days and bed rest for an average of 2.9 days. Of the eighty-eight procedures that resulted in a dural tear, forty-five were revisions; these revisions were performed after an average of 2.2 previous operations on the lumbar spine, all of which resulted in a scar adherent to the dura. Only eight patients had headaches related to the spinal procedure and photophobia in the postoperative period; these symptoms resolved in all but two patients, both of whom had had a revision operation. Each of the two patients had symptoms of a persistent leak of spinal fluid and needed a reoperation for repair. Overall, seventy-six patients had a good or excellent result and twelve had a poor or satisfactory result with some residual back pain. One patient had arachnoiditis, and another had symptoms of viral meningitis one month postoperatively. A dural tear that occurs during an operation on the lumbar spine can be treated successfully with primary repair followed by bed rest. Such a tear does not appear to have any long-term deleterious effects or to increase the risk of postoperative infection, neural damage, or arachnoiditis. Closed suction wound drainage does not seem to aggravate the leak and can be used safely in the presence of a dural repair.

The success of anterior cervical arthrodesis adjacent to a previous fusion.

Study Design. A retrospective review of all patients surgically treated for adjacent segment disease of the cervical spine over a 20‐year period. Objectives. To determine the clinical and radiographic success of discectomy with interbody grafting and corpectomy with strut grafting in the treatment of adjacent segment disease of the cervical spine. Summary of Background Data. Up to 25% of all patients undergoing anterior cervical fusion have new disease due to degeneration of an adjacent segment within 10 years. The success of surgical treatment in these patients with adjacent segment disease has not been reported. Methods. Thirty‐eight patients were surgically treated for adjacent segment disease by discectomy with interbody grafting or corpectomy with strut grafting. Arthrodesis was evaluated by flexion‐extension lateral radiographs and clinical outcomes were assessed using Robinsons criteria at least 2 years after surgery. Fusion rates were compared by Fishers exact test, and outcomes were compared by rank‐sum analysis. Results. The rate of arthrodesis was significantly lower in the 24 patients treated by discectomy with interbody grafting at one or more levels (63%) than in the 14 patients treated by corpectomy with strut grafting (100%; P = 0.01). Clinical outcomes were similar for the corpectomy and discectomy groups (P = 0.55). There was a trend toward better outcomes in patients who achieved a solid arthrodesis (P = 0.13). Conclusions. Achieving fusion is more difficult when anterior cervical arthrodesis is performed adjacent to a prior fusion. Strut grafting resulted in a significantly higher rate of arthrodesis than interbody grafting.

Surgery of the lumbar spine for spinal stenosis in 118 patients 70 years of age or older.

Study Design. A consecutive case retrospective chart review and an outcome satisfaction questionnaire were used in this study. Objective. To provide a surgical reference for surgeons and elderly patients who may have concerns regarding the safety and outcome of lumbar spine surgery in their age population. Summary of Background Data. Elderly patients scheduled for spine surgery have a major concern about the safety and outcome of the procedure in light of their advanced age. A review of the literature demonstrated conflicting results regarding the outcome of lumbar spine surgery for spinal stenosis in the elderly. Methods. A retrospective review evaluated 118 consecutive patients ages 70 to 101 years who were managed surgically for lumbar spinal stenosis. This patient population was analyzed for the operative procedure, postoperative morbidity and mortality, and long-term clinical outcome and satisfaction. All 118 patients had at least a 2-year follow-up evaluation, and 21 of these patients were older than 80 years. Clinical parameters were compiled and analyzed on the basis of chart review. Results. Overall morbidity occurred in 24 patients (20%). During the study period, the average length of hospitalization declined an average of 2 days. Of the 118 patients, 109 expressed satisfaction with the operation and resumed daily activities, whereas 9 had fair or poor results. Conclusions. Advanced age did not increase the morbidity associated with this operation because the results reported in this study are comparable with those from other studies of a younger population, nor did advanced age decrease patient satisfaction or return to activities.

Anterior excision of herniated thoracic discs.

Twenty-two herniations of a thoracic disc in nineteen patients were surgically excised between 1972 and 1984. An anterior transthoracic decompression or a costotransversectomy was used for all discectomies. Pain and paraparesis were the most common symptoms preoperatively. The average length of follow-up was forty-eight months. Sixteen patients had an excellent or a good result, one had a fair result, and two had a poor result. Twelve of the fourteen patients who had had motor weakness preoperatively had varying degrees of improvement in motor function postoperatively. Pain was relieved in ten patients, reduced in eight, and unchanged in one. Anterior decompression of herniated thoracic discs yielded gratifying results, but the procedure is associated with some risk of damage to the spinal cord. It therefore requires meticulous preoperative planning and careful surgical technique.

Risk factors for the development of perioperative complications in elderly patients undergoing lumbar decompression and arthrodesis for spinal stenosis : an analysis of 166 patients

Study Design. Retrospective review. Objective. To quantify and describe perioperative complication rates in a large series of well-matched elderly patients who underwent lumbar decompression and arthrodesis. Summary of Background Data. Posterior lumbar decompression and fusion is frequently performed to treat lumbar stenosis with instability. An increasing number of elderly patients are undergoing operative treatment for degenerative lumbar disease. The reported morbidity of performing decompression and arthrodesis in this population varies widely in the literature, with recent reports showing a high rate of major complications. Methods. A total of 166 patients age 65 or older that underwent primary posterior lumbar decompression and fusion with (group 1; n = 75) or without (group 2; n = 91) instrumentation were included. Hospital records were reviewed for the occurrence of any complications (major and minor), the need for transfusion, estimated length of stay, and disposition at discharge. Logistic regression (with the presence/absence of major complications as the dependent variable) was used to identify risk factors for the occurrence of a complication. Results. Five major complications (3%) occurred (group 1, 1; group 2, 4). Minor complications developed in 30.7% of group 1 and 31.9% of group 2. There were no deaths, and only one perioperative complication was attributable to the use of instrumentation. Decompression/fusion of 4 or more segments was significantly associated with the occurrence of a major complication. Advanced age, the presence of medical comorbidities, or the use of instrumentation did not increase the rate of major or minor complications. The occurrence of either a major or minor complication prolonged hospital stay. Conclusions. Posterior lumbar decompression and fusion can be safely performed in elderly patients, with a low rate of major complications. The addition of instrumentation does not increase the complication rate. These results differ from those previously reported in the literature, which describe a significantly higher rate of complications in this age group, with a prolonged rate of hospitalization.