Posterior cervical fusion with local anesthesia. The awake patient as the ultimate spinal cord monitor

A technique is described for posterior cervical stabilization with wire and fusion using iliac crest bone graft, performed under local anesthesia. Thirty-four consecutive cases performed at Rancho Los Amigos Medical Center are reviewed. In patients with unstable cervical spines and variable degrees of neurologic injury, posterior stabilization and fusion using local anesthesia allows the patient to interact with the surgeon during crucial moments of spinal manipulation. The technique is well tolerated by patients, and no untoward complications have occurred with use of this technique.     

Increased fusion rates with cervical plating for three-level anterior cervical discectomy and fusion

STUDY DESIGN: A retrospective review of all patients surgically treated by a single surgeon with a three-level anterior cervical discectomy and fusion with and without anterior plate fixation. OBJECTIVES: To compare the clinical and radiographic success of anterior three-level discectomy and fusion performed with and without anterior cervical plate fixation. SUMMARY OF BACKGROUND DATA: Previous studies of multilevel cervical discectomies and fusions have shown fusion rates to decrease as the number of surgical levels increases. Anterior cervical plate stabilization can provide more stability and may increase fusion rates for multilevel fusions. METHODS: Over a 7-year period, 59 patients were treated surgically with a three-level anterior cervical discectomy and fusion by the senior author. Forty patients had cervical plates, whereas 19 had fusions with no plates. These patients were observed for an average of 3.2 years. Clinical and radiographic follow-up data were obtained. RESULTS: Of the 59 patients, 14 had a pseudarthrosis (7 in each group). The pseudarthrosis rates were 18% (7 of 40) for patients with plating and 37% (7 of 19) for patients with no plating. Although the nonunion rate for unplated fusions was double that of plated fusions, this difference was not statistically significant. There was no statistically significant correlation between pseudarthrosis and gender, age, level of surgery, history of tobacco use, or previous anterior surgery. The fusion rates were improved with the use of a cervical plate. Inferior clinical results were demonstrated in patients with a pseudarthrosis, regardless of the use of a cervical plate. CONCLUSIONS: The addition of plate fixation for three-level anterior cervical discectomy and fusion is a safe procedure and does not result in higher complication rates. In this study, the pseudarthrosis rate was lower for patients with a cervical plate. However, this difference was not statistically significant. Patients treated with cervical plating had overall better results when compared with those of patients treated without cervical plates. Although the use of cervical plates decreased the pseudarthrosis rate, a three-level procedure is still associated with a high nonunion rate, and other strategies to increase fusion rates should be explored.     

Dorsal atlanto-axial screw fixation. A stability test in vitro and in vivo

Clinical and biomechanical testing of the stability of atlantoaxial fusions was studied. For biomechanical testing, four different techniques for posterior atlantoaxial fusion were tested: (1) wire fixation with one median graft; (2) wire fixation with two bilateral grafts; (3) transarticular screw fixation and two bilateral posterior clamps. Ten fresh human cadaveric specimens were tested. The loads applied were 6 pure moments. The motion of C1 relative to C2 in the intact, injured and mechanically fixed spine were measured and compared. In flexion/extension the difference between Brooks, Magerl and Halifax were not significant, but each was significantly less than the Gallie-system. For the anterioposterior translation the stabilization of all fixation techniques was about equal. In axial rotation measuring the translations between C1 and C2, the screw-fixation technique proved to be the most stable. For lateral bending, there was no significant difference between the different techniques, except for Galliefixation, but the screw-fixation technique allowed the least motion. In additional in vivo tests ten patients with posterior atlantoaxial fusion by the transarticular screw-fixation technique underwent bending X-rays of the upper cervical spine as well as computertomograms. Solid fusion was achieved in all patients. Both investigations proved the reliability of the multidirectional stability of the atlantoaxial screw fixation technique.     

Long-term incidence of subaxial cervical spine instability following cervical arthrodesis surgery in patients with rheumatoid arthritis

OBJECTIVE: Cervical spine deformities are well-known complications of RA. A 5- to 20-year follow-up of 51 consecutive rheumatoid patients who underwent posterior cervical arthrodesis is presented to evaluate the recurrence of instability and need for further surgery. METHODS: We conducted a retrospective review of the clinical features of 11 men and 40 women with an established diagnosis of RA and associated cervical deformities who underwent cervical spine surgery at the Mayo Clinic (Rochester, MN) between 1979 and 1990. Their mean age was 61 +/- 10 years (SD), and their duration of RA averaged 21 +/- 8.9 years (SD). There were 22 patients who presented with myelopathy, 7 with radiculopathy, and 22 with instability/neck pain. There were 33 patients with AAS, 2 with SMO process into the foramen magnum, 8 with SAS, and 8 with combinations of these. Preoperative reduction was followed by decompression and fusion using wiring techniques and autologous bone graft. Postoperative halo orthosis was provided for at least 3 months. The mean follow-up was 8.3 +/- 6 years (SD). RESULTS: There were 31 patients (61%) who underwent atlantoaxial arthrodesis, 17 patients (33%) who underwent subaxial, and 3 patients (6%) who underwent occipitocervical arthrodesis. During follow-up, 39% (13/33) of patients with AAS developed nonsymptomatic (6) or symptomatic/unstable (7) SASs subsequent to C1-C2 fusion. The latter 7 patients (21%) subsequently required extension of their arthrodesis. Adjacent segment disease was most common at the C3-C4 interspace after atlantoaxial fusion in 62% (8/13). Among the 8 patients who underwent isolated cervical fusion for SAS, 1 patient (1/8, 12%) developed adjacent instability after a fall and required extension of the previous fusion. No secondary procedure was required for the 6 patients initially stabilized by C1-(C6-T1) fusions for combinations of AAS + SAS. None of the patients initially treated by C1-C2 arthrodesis for AAS progressed to SMO. CONCLUSIONS: The incidence of subaxial instability in patients with rheumatoid disease who underwent cervical arthrodesis may be higher than previously reported, indicating the need for continued follow-up in these patients. Adjacent segment disease may be most common at the C3-C4 level following atlantoaxial fusion. Early stabilization of the C1-C2 complex in the patients with AAS may potentially prevent progression of SMO.     

Fusion of the cervical spine for instability

The orthopedic and neurosurgical literature is neither clear nor consistent in describing an unstable cervical spine. In a series of 25 patients treated by arthrodesis of the cervical spine for instability, 12 had Gallie fusions at the atlantoaxial level. Eight of those fusions were performed for rheumatoid arthritis. In three patients persistent subluxation of the atlas on the axis occurred because the wires were not fully tightened in areas of poor-quality bone. Stable fixation with relief of symptoms was achieved in all patients who had fusions at the subaxial level. Several of these patients had had prolonged nonsurgical treatment. With rheumatoid bone of poor quality, the surgeon must be very careful to tighten the wires only enough to secure a stable reduction for treatment of subaxial cervical instability. Since stability achieved by healing of soft tissue is generally unreliable, prolonged periods of nonsurgical treatment are not justified for traumatic instability.     

Increased fusion rates with cervical plating for two-level anterior cervical discectomy and fusion

STUDY DESIGN: A retrospective review of all patients surgically treated with a two-level anterior cervical discectomy and fusion with and without anterior plate fixation by a single surgeon. OBJECTIVES: To compare the clinical and radiographic success of two-level discectomy and the effect of anterior cervical plate fixation. SUMMARY OF BACKGROUND DATA: Prior studies of multisegment fusions have shown decreased fusion rates correlating with the number of increased levels. The use of anterior plates for single-level cervical fusions is controversial. However, their use in multilevel fusions may be warranted because of the increased pseudarthrosis rates. METHODS: Over a 6-year period, 60 patients were treated surgically with a two-level anterior cervical discectomy and fusion by the senior author. Thirty-two patients had cervical plates, and 28 underwent fusions without plates. These patients were followed for an average of 2.7 years. Clinical and radiographic follow-up evaluations were performed. RESULTS: Of the 60 patients, 7 had a pseudarthrosis. The pseudarthrosis rates were 0% for patients with plating and 25% for those with no plating. This difference was statistically significant (P = 0.003). No correlation of pseudarthrosis with gender, age, level of surgery, history of tobacco use, or the presence of prior anterior surgery was found. There was significantly less graft collapse (P = 0.0001) in the patients without plates in whom pseudarthrosis developed (1.4 mm) than in those who had fusions with plates (0.3 mm). The amount of kyphotic deformity of the fused segment was 0.4 degree in patients with plating compared with 4.9 degrees in those without plating who developed a pseudarthrosis (P = 0.0001). CONCLUSIONS: The addition of plate fixation for two-level anterior cervical discectomy and fusion is a safe procedure with no significant increase in complication rates. The pseudarthrosis rates are significantly higher in patients treated without plate fixation. No nonunions occurred in the patients treated with plate fixation. There was significantly less disc space collapse and kyphotic deformity with the plated fusions than with the nonplated fusions, in which a pseudarthrosis developed. The complication rates for plated fusions are extremely low and do not differ from those for nonplated fusions.     

Surgical stabilization of the cervical spine. A comparative analysis of anterior and posterior spine fusions

Two hundred twenty-two cervical spine stabilization procedures in 212 patients are reviewed. In 114 posterior cervical fusions, 88 anterior fusions, and ten combined procedures, no deaths occurred. Surgical complication rates were similar, but more severe complications were noted with anterior cervical fusions, including tracheoesophageal problems and transient neurologic loss. Six cases of graft dislodgement requiring reoperation also occurred. In long-term follow-up evaluations, 36 anterior fusion patients developed progressive kyphotic deformity averaging 22 degrees between surgery and the time solid fusion was obtained. Degenerative changes above and below the fusion mass were detected in 36 of 59 patients treated by anterior surgery. Posterior cervical fusion patients were noted to have no significant late change in alignment, and degenerative changes were infrequent. However, 73 of 98 patients had significant extension of fusion mass beyond the originally intended levels of stabilization. Because anterior cervical spine fusion was associated with significant complications of graft dislodgement and tracheoesophageal trauma, as well as postsurgical progressive deformity, the authors recommend posterior wiring and fusion as the procedure of choice to treat cervical spine instability and permit halo-free postsurgical rehabilitation. When anterior neural decompression and fusion is necessary, concomitant posterior wiring and fusion or halo vest immobilization may be necessary to maintain reduction and prevent kyphotic angulation, because posterior ligamentous disruption is not always grossly evident on radiographic examination.     

Posterior upper cervical fusion in rheumatoid arthritis.

The purpose of this study was to determine fusion rates in patients who underwent posterior cervical fusion for instability of the upper cervical spine secondary to rheumatoid arthritis. A retrospective review of clinical and radiographic data was conducted. Nineteen patients underwent posterior cervical fusions limited to the upper cervical spine. There were 11 C1-C2 fusions and 8 occiput-C2 fusions. Instability with pain or neurologic deficits were the main indications. A uniform technique was used in all cases. Preoperative reduction in halo vest or cast was followed by a Gallie type fusion using autogenous iliac bone graft and wire, and postoperative halo vest or cast immobilization for 3 months. A fusion rate of 94% was achieved. The average follow-up was 5 years. Complete or partial relief of pain was obtained in all patients; 30% of those with preoperative deficits improved after surgery. A high fusion rate may be achieved with C1-C2 and occiput-C2 fusions in rheumatoid arthritis, with relief of pain and prevention of neurologic deterioration.     

Occipitocervical stabilization for myelopathy in patients with rheumatoid arthritis. Implications of not bone-grafting

BACKGROUND: Approximately 0.9 percent of the white adult population of the United States and 1.1 percent of the adult population in Europe are affected by seropositive rheumatoid arthritis. As many as 10 percent of those patients may need an operation for atlantoaxial subluxation. Severe instability, especially when associated with vertical subluxation of the odontoid process, can result in progressive cervical myelopathy. Typically, occipitocervical fixation has been performed for these patients with use of autograft bone to achieve long-term stability through a solid fusion. Harvesting the bone graft increases the operative risk to the patient and may result in increased morbidity. In our experience, patients who have had no clear radiographic evidence of fusion following use of occipitocervical instrumentation seemed to have done as well as those who have had obvious fusion. One assumption is that the clinical improvement might be attributable simply to stabilization of the joint rather than to osseous fusion. A longitudinal study was performed on patients with rheumatoid arthritis who required an operation because of craniocervical or upper cervical instability. METHODS: The results of clinical, radiographic, functional, and self-evaluations were studied to determine the efficacy of treatment and to compare the outcomes of bone-grafting with those of procedures done without bone-grafting in a group of 150 patients who underwent posterior occipitocervical stabilization with use of a contoured metal implant (a Ransford loop) that was affixed by sublaminar wires. Internal fixation was performed in 120 patients without bone-grafting and in thirty patients with use of autogenous bone-grafting. Preoperatively, 23 percent (thirty-five) of the 150 patients had mild neurological involvement (class II, according to the system of Ranawat et al.), 45 percent (sixty-eight) had objective findings of weakness and long-tract signs but were able to walk (class III-A), and 29 percent (forty-three) were quadriparetic and unable to walk (class III-B). The age of the patients at the time of the operation ranged from twelve to eighty-three years (mean, sixty-two years). RESULTS: There were significant improvements in postoperative Ranawat classes at all time-periods (range, p < 0.00005 to p = 0.0066) and in patient ratings of neck pain (range, p < 0.00005 to p = 0.0044) compared with preoperative scores. With the numbers available, there were no significant differences between the patients managed with a graft and those managed without grafting with respect to survival after the operation, Ranawat class, head or neck-pain rating, presence of subaxial abnormalities, radiographic craniovertebral motion, or vertical subluxation. Overall mortality at one month was 10 percent (fifteen of 150), although this value varied directly with the degree of preoperative disability. A second cervical spine operation was required in 11 percent (sixteen) of the 150 patients. CONCLUSIONS: While patients who have rheumatoid disease with anterior atlantoaxial subluxation should be treated with posterior atlantoaxial arthrodesis with use of bone-grafting and internal fixation, we believe that those who present with vertical instability and multi-level involvement can be treated with posterior occipitocervical stabilization with use of a contoured occipitocervical loop and sublaminar wire fixation without bone-grafting. Furthermore, we believe that the use of preoperative traction, bone cement, or a postoperative halo vest is unnecessary. Avoiding the harvesting of autogenous bone for grafting reduced the morbidity of this operation without compromising the outcome in these already sick patients.     

Acrylic spinal fusion. A 20-year clinical series and technical note

Methyl methacrylate (acrylic) was used in fusion techniques in 82 patients, most of whom had metastatic disease, between 1959 and 1979. In all cases the acrylic was used to supplement stabilization with Meurig-Williams stainless steel plates or with wire. In cases involving a decompressive laminectomy and excisional biopsy (radical resection of a tumor mass) that required posterior stabilization, acrylic helped to achieve rapid fusion with excellent results. The series included one anterior fusion with acrylic and nine atlantoaxial fusions in patients without tumors. Strict guidelines for selection of patients are outlined. The advantage of acrylic over bone fusion in selected patients is discussed. Careful follow-up studies including autopsy examinations are included. The technique of the use of acrylic is outlined. There was no case of late instability. There was one instance of infection in a patient who was immunodeficient and in whom a combination acrylic and bone fusion was performed. Tissue reaction to the acrylic in autopsy specimens is discussed.     

Risks and cost-effectiveness of sublaminar wiring in posterior fusion of cervical spine trauma

A report on the use of sublaminar wiring in the fusions of 34 patients with cervical spine injuries is given. No neurologic deficits were incurred in the use of this technique. There were no wire failures nor clinically significant complications. When compared with other forms of instrumentation to achieve similar results, the use of sublaminar wire is the most cost-effective.     

Laminar screw fixation in the subaxial cervical spine: A report on three cases

Although laminar screw fixation is often used at the C2 and C7 levels, only few previous case reports have presented the use of laminar screws at the C3-C6 levels. Here, we report a novel fixation method involving the use of practical laminar screws in the subaxial spine. We used laminar screws in the subaxial cervical spine in two cases to prevent vertebral artery injury and in one case to minimize exposure of the lamina. This laminar screw technique was successful in all three cases with adequate spinal rigidity, which was achieved without complications. The use of laminar screws in the subaxial cervical spine is a useful option for posterior fusion of the cervical spine.     

Fusion or stabilization alone for acute distractive flexion injuries in the mid to lower cervical spine?

Long-term pain problems and residual restricted mobility were evaluated for patients sustaining acute distractive flexion injuries to the cervical spine. To assess which of two alternative surgical approaches gives better long-term outcomes, 58 patients were studied, 29 in each group. The results of posterior wire stabilization without fusion according to Brandt were contrasted with those of the Cloward technique. We found significantly more late pain problems and restricted neck mobility in the group treated with wiring without fusion than in those managed with anterior fusion. We conclude that this continuing pain may be due to residual mobility in the damaged degenerated non-fused motion segment, and that the difference between the two groups may reflect the difference in the quality and rate of fusion achieved by the two surgical approaches.     

Mid- to long-term outcome of instrumented anterior cervical fusion for subaxial injuries

The management of patients with subaxial cervical injuries lacks consensus, particularly in regard to the decision which surgical approach or combination of approaches to use and which approach yields the best clinical outcome in the distinct injury. The trauma literature is replete with reports of surgical techniques, complications and gross outcome assessment in heterogeneous samples. However, data on functional and clinical outcome using validated outcome measures are scanty. Therefore, the authors performed a study on plated anterior cervical decompression and fusion for unstable subaxial injuries with focus on clinical outcome. For the purpose of a strongly homogenous subgroup of patients with subaxial injuries without spinal cord injuries, robust criteria were applied that were fulfilled by 28 patients out of an original series of 131 subaxial injuries. Twenty-six patients subjected to 1- and 2-level fusions without having spinal cord injury could be surveyed after a mean of 5.5 years (range 16–128 months). The cervical spine injury severity score averaged 9.6. Cross-sectional outcome assessment included validated outcome measures (Neck pain disability index, Cervical Spine Outcome Questionnaire, SF-36), the investigation of construct failure and successful surgical outcome were defined by strict criteria, the reconstruction and maintenance of local and total cervical lordosis, adjacent-segment degeneration and intervertebral motion, and the fusion-rate using an interobserver assessment. Self-rated clinical outcome was excellent or good in 81% of patients and moderate or poor in 19% that corresponded to the results of the validated outcome measures. Results of the NPDI averaged 12.4 ± 12.7% (0–40). With the SF-36 mean physical and mental component summary scores were 47.0 ± 9.8 (18.2–59.3) and 52.2 ± 12.4 (14.6–75.3), respectively. Using merely non-constrained plates, construct failure was observed in 31% of cases and loss of local lordosis, expressed as a mean injury angle of 14°, postoperative angle of −5.5° and follow-up angle of −1°, was significant. However, total cervical lordosis was within the limits of normalcy (−24.3° ± 13.3) and fusion-rate was 88.5%. The progression of adjacent-level degeneration was shown to be significantly influenced by a decreased plate-to-disc-distance. Adjacent-level intervertebral motion was not altered due to the adjacent fusion, but reduced in the presence of advanced adjacent-level degeneration. Patients were more likely to maintain a high satisfaction level if they succeeded to maintain segmental lordosis (<0°), had a solid fusion, an increased plate-to-disc distance, and if they were judged to have a successful surgical outcome that included the absence of construct failure and reconstruction of lordosis within ±1 SD of normalcy. Using validated outcome vehicles the interdependencies between radiographical, functional and clinical outcome parameters could be substantiated with statistically significant correlations. The use of validated outcome vehicles in a subgroup of patients with plated anterior cervical fusions for subaxial injuries is recommended. With future studies, it enables objective comparison of surgical techniques and related radiographical, functional and clinical outcome. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Plate augmentation in anterior cervical discectomy and fusion with cage for degenerative cervical spinal disorders

Anterior cervical discectomy and fusion (ACDF) with cage alone (ACDF-C) is associated with a significant incidence of subsidence, local kyphosis, and migration. The use of concurrent plate augmentation may decrease the incidence of these complications while improving the fusion rate. The purpose of the study is to present our results with ACDF with cage and plate augmentation (ACDF-CPA) and to compare these results to previous reports of outcomes following ACDF-C. We evaluated the radiologic and clinical parameters of 83 patients (266 fusion sites) who had an ACDF-CPA between March 2002 and May 2006. Radiologic parameters included fusion rate, fusion time, fusion type, site of pseudoarthrosis and rate and degree of subsidence. Clinical parameters included complications and overall outcomes assessed with Robinson’s criteria; 79 of 83 patients showed bony fusion (95.1%) at last follow-up postoperatively, and there was no significant difference in fusion rate between the number of fusion levels. Type I (pseudoarthrosis) was noticed in 9 patients (12 fusion sites), type II in 14 (19 fusion sites), and type III in 60 (235 fusion sites). Five type I and all type II fusions converged into type III by the last follow-up; 76 of 83 patients (91.6%) experienced good clinical outcomes. Pseudoarthrosis occurred more commonly in more proximal locations, and the subsidence rate was significantly greater in two-level fusions when compared with single-level fusions (P = 0.046). There were four metal-related complications. Plate augmentation in one- or two-level anterior cervical fusions for degenerative cervical spine disorders may improve fusion rates and reduce subsidence and complication rates, resulting in improved clinical outcomes.     

Treatment of tumors of the cervical spine

In 34 patients with primary or metastatic tumors of the cervical spine over a ten-year period, the presenting symptom was neck pain. Eleven patients demonstrated evidence of radiculopathy, one a myelopathy, and three a combined myeloradiculopathy. Surgical stabilization, combined in eight cases with cord decompression, successfully relieved pain and prevented further neurologic deterioration in 17 of 18 patients with radioresistant tumors. Complications included two patients who were treated with short posterior fusions displacing as a result of tumors progressing above and below the fusion, and one patient in whom an anterior methacrylate mass became dislodged and appeared to jeopardize the esophagus. Methacrylate was used to augment the grafts posteriorly to facilitate early mobilization without the need for a halo splint. Mean patient survival was not significantly increased by surgical intervention (26 weeks vs. 20 weeks). While most lesions of the cervical spine can best be managed by nonoperative methods, in selected patients long posterior fusion with wires and methacrylate appears successful in relieving pain, halting progress of neurologic deficits, and facilitating early mobilization.     

枕颈融合与寰枢椎融合治疗上颈椎失稳症的疗效比较

目的探讨枕颈融合与寰枢椎融合治疗上颈椎失稳的疗效及对颈椎退变的影响。方法 2004年6月～2008年6月收治且获得2年以上随访的上颈椎失稳患者共33例,根据融合节段不同,分为A(枕颈融合)组和B(寰枢椎融合)组。按照JOA法评估神经功能,应用X线片评价两组患者植骨融合情况及颈椎退变情况;比较两组患者的临床疗效和颈椎活动度等方面的差异。两组病例年龄、术前JOA评分、术前颈椎活动度和术前牵引时间无统计学差异。结果 A、B两组均顺利完成手术,术中、术后未出现并发症。两组病例的植骨融合情况及术后JOA评分差异无统计学意义(P>0.05)。术后颈椎的屈伸活动度、颈椎曲度两组之间差异有统计学意义(P<0.05)。结论颈枕融合及寰枢椎融合均能取得满意的植骨融合和神经症状缓解,但相比枕颈融合,寰枢椎融合对颈椎的屈伸活动度、颈椎曲度影响较小,应为上颈椎失稳的首选手术方式。     

Significance of occipitoaxial angle in subaxial lesion after occipitocervical fusion

STUDY DESIGN: The significance of occipitoaxial angle in the development of subaxial subluxation after occipitocervical fusion was determined in a minimum 5-year follow-up study performed retrospectively. OBJECTIVE: To clarify the association between the position of the fixed occipital bone and axis and the development of subaxial subluxation. SUMMARY OF BACKGROUND DATA: There have been few reports describing the association between the position of fixation of the occipital bone and axis and subaxial lesion in occipitocervical fusion. MATERIALS AND METHODS: Thirty-eight patients with rheumatoid arthritis who underwent occipitocervical fusion for irreducible atlantoaxial dislocation were reviewed. The angle between the McGregor line and the inferior surface of the axis (O-C2) was measured in healthy volunteers and patients who had undergone occipitocervical fusion. The association between any changes in the alignment of the cervical vertebrae and the development of subaxial subluxation during follow-up periods was studied. RESULTS: The number of the patients in whom postoperative kyphosis and swan neck deformity developed was only five, but in four (80%) of them, retroversion of the occipital bone was used to increase the O-C2 angle. In 14 patients, in whom anteversion of the occipital bone against the axis was excessive, 12 (86%) patients experienced subaxial subluxation after surgery. In the patients in whom fixed O-C2 angles were in normal range, only one patient developed such abnormal changes in the middle and lower cervical vertebrae. CONCLUSION: It is necessary to give attention to the position of the fixed occipital bone and axis during procedures of occipitoaxial fusion for patients with rheumatoid arthritis.     

Solid fusion vs. non-union in long-term follow-up of in situ fusion without internal fixation in symptomatic spondylolisthesis in young patients

Summary A clinical and radiological long-term follow-up study is presented of 175 patients under the age of 20 years operated on for symptomatic isthmic spondylolisthesis of L5. The mean observation time was 15 years (range 5–30 years). There were 89 female and 86 male patients; mean age at operation was 14.8 years. Posterior fusion was carried out in 112 cases, posterolateral fusion in 60 and anterior fusion in 3; a concomitant laminectomy was performed in 34 cases. One segment (L5-S1) was fused in 54 patients, two segments (L4-S1) in 104, and three segments (L3-S1) in 17. Autogenous cortico-spongeous bone was used in 119 cases and free periosteal grafts in 56. At follow-up, solid bony fusion was found in 145 patients; 30 patients (17.1%) had non-union. The data for these two groups were compared statistically. The frequency of non-union was significantly higher after posterior than after posterolateral fusion (P<0.05), in two-level fusions than in one-level fusions (P=0.003), and in cases where periosteal rather than cortico-spongeous bone grafts had been used (P<0.01). The posterior fusion technique using periosteal grafts gave the highest rate of non-unions, whereas the posterolateral technique with cortico-spongeous grafts gave the highest rate of successful fusions (P<0.001). Non-union occurred significantly more often in cases of grade I slip (36%) than in cases of grade II (7%), III (8%) or IV slip (0%). The higher frequency of non-unions in grade I slips was associated with more frequent use of the posterior fusion technique in cases of minor or moderate grades of slip. The duration of postoperative bed rest or duration of immobilization in a corset had no statistically significant influence on fusion rate. The rate of non-union had no statistically significant association with the long-term clinical result. Postoperative pain symptoms, however, lasted longer in non-union patients (mean 14.2 months) than in successfully fused patients (mean 4.5 months; P<0.01). The results show the benign nature of the condition, which seems to be a self-limiting process leading to stabilization of the affected segment. The posterolateral fusion technique using autogenous cortico-spongeous bone grafts is recommended as the method of choice for most cases.     

寰枢椎后路融合角度与下位颈椎曲度的相关性研究

目的 评价寰枢椎后路融合角度与术后下位颈椎矢状面曲度之间的联系并确定最佳的寰枢椎固定角度以保护颈椎生理曲度.方法 对1995年2月至2005年6月因寰枢椎脱位而行后路C1,C2融合术的92例患者进行术后随访.术前测量颈椎侧位片C1-C2,C2-C7夹角,并且进行术后长期随访,以观察术后随访C1-C2,C2-C7夹角之间的相关性. 结果所有患者均获得随访,时间2.0～10.3年,平均5.2年.术前及术后随访时C1-C2夹角平均值分别为18.4°±9.3°、26.0°±6.8°,差异有统计学意义(t=10.4,P<0.05);术前及术后随访时C2-C7夹角平均值分别为14.5°±10.1°、5.6°±12.0°,差异有统计学意义(t=6.0,P<0.05);其中术后随访C1-C2固定角度<20°(10°～20°)共计30例,≥20°(20.0°～43.6°)共计62例.C1-C2固定角度<20°者,术后随访C1-C2角度与C2-C7夹角之间无明确的相关性;C1-C2固定角度≥20°者,术后随访C1-C2角度与C2-C7夹角之间存在线性负相关;C1-C2术前、术后随访夹角的变化值与C2-C7术前、术后随访夹角的变化值之间也存在线性负相关. 结论寰枢关节行后路手术固定于高度前凸位时将导致术后下位颈椎的脊柱后凸,并且固定角度越大,下位颈椎的后凸程度就越大;为了保持下位颈椎的生理性曲度,手术中应尽量将C1-C2固定的角度控制在10°～20吨围内.