Functional and radiological outcomes of 360 degrees fusion of three or more motion levels in the lumbar spine for degenerative disc disease.

STUDY DESIGN: This is a single-center, multisurgeon, retrospective study of radiologic and functional outcome measures at a minimum 2-year follow-up. OBJECTIVE: We studied the radiologic and functional outcomes following 3 or more motion segment fusions of the lumbar spine for low back pain due to multilevel degenerative disc disease. SUMMARY OF BACKGROUND DATA: Good functional outcomes have been reported for 1 or 2-level fusions, but there are no reports dealing specifically with 3 or more level fusions. METHODS: A total of 80 adult patients met the inclusion/exclusion criteria of multilevel (3 or more motion segments) 360 degrees fusion for lumbar degenerative disc disease, failed nonoperative treatment for at least 1 year, no previous lumbar fusion, no fracture, tumor or infection of the spine, completed preoperative and postoperative functional questionnaires including SF-36 (n = 80), Oswestry (n = 69), Roland Morris (n = 68), and radiologic evaluation of fusion solidity with a minimum follow-up of 2 years. RESULTS: The average patient age was 57 years (range, 27-81). The mean follow-up was 4 years (2-7). On average, patients had fusion of 4 motion segments (range, 3-8 levels). Solid arthrodesis at the first surgery was achieved in 65/80 (81%). Adjacent segment degeneration was noted in 11 patients. Of these, 5 had undergone an extension of their fusion within the study period. There were no deaths or neurologic complications. Deep wound infection occurred in 2 patients, neither requiring implant removal. The Oswestry Disability Index scores improved from 49.8 to 35.1 (29.5%) (P < 0.001). The Roland Morris scores improved from 17.6 to 12.2 (30.7%) (P < 0.001). For the SF-36 scales, significant (P < 0.001) improvement was seen in all scales except Role Emotional scores and Mental Composite Scales. CONCLUSION: The surgical treatment of lumbar degenerative disc disease by 360 degrees fusion should be considered for properly selected patients. The goal of surgery is reduction, not elimination of disability.

A concomitant posterior approach improves fusion rates but not overall reoperation rates in multilevel cervical fusion for spondylosis.

STUDY DESIGN: Retrospective comparative study of 2 approaches to multilevel fusion for cervical spondylosis in consecutive patients at a single institution. OBJECTIVE: To provide justification for a concomitant posterior approach in multilevel cervical fusion for spondylosis by demonstrating decreased pseudarthrosis and reoperation rates. SUMMARY OF BACKGROUND DATA: Among the factors that affect cervical rates is the number of levels, such that increasing the number of levels leads to lower fusion rates. Because of this, modifications have been sought to improve union in multilevel procedures. One option is an antero-posterior (AP) approach or circumferential arthrodesis. METHODS: Seventy-eight consecutive patients who underwent multilevel cervical fusion at a single institution and with minimum 2-year follow-up data were divided into an anterior-only group (anterior: n=55), and an AP group (AP: n=23). Union was assessed by surgical exploration, computerized tomography scan, and flexion-extension radiographs. The groups were compared in terms of pseudarthrosis rates and reoperation rates. RESULTS: Using chi(2) analysis, there was a significant difference in pseudarthrosis rates (anterior 38% vs. AP 0%; P<0.001), and reoperation rate for pseudarthrosis (anterior 22% vs. AP 0%; P=0.01). There were no differences in overall (anterior 36% vs. AP 30%; P=0.62) and early (anterior 15% vs. AP 26%; P=0.13) reoperation rates, but late reoperations were increased in the anterior group (24% vs. AP 4%; P=0.043). CONCLUSIONS: A concomitant posterior fusion significantly reduced the incidence of pseudarthrosis (0% vs. 38%) and pseudarthrosis-related reoperations (0% vs. 22%) compared with traditional anterior-only fusion. However, this did not translate to a difference in overall reoperation rates. The majority of reoperations in the AP group (86%) were performed within 6 months, whereas those in the anterior-only group (65%) were performed later, which was generally when a pseudarthrosis became evident.

Cervical degenerative index: a new quantitative radiographic scoring system for cervical spondylosis with interobserver and intraobserver reliability testing.

BACKGROUND: The lack of a widely available scoring system for cervical degenerative spondylosis encouraged the authors to establish and validate a systematic quantitative radiographic index. MATERIALS AND METHODS: This study included intraobserver and interobserver reliability testing among three reviewers with different years of experience. Each observer independently scored four cervical radiographs of 48 patients at separate intervals, and statistical analysis of the grading was performed. RESULTS: There was high intraobserver and interobserver reliability between the two experienced observers. There was fair reliability between the less experienced observer and the more experienced observers. CONCLUSIONS: The cervical degenerative index appears to be a reliable and reproducible radiographic assessment of cervical spondylosis. The index will have direct applicability for longitudinal study of cervical spondylosis and may be clinically relevant as well.

Cervical degenerative changes in idiopathic scoliosis patients who underwent long fusion to the sacrum as adults: incidence, severity, and evolution.

BACKGROUND: To date, there have been no published studies of the degenerative changes in the cervical spine in adult idiopathic scoliosis patients with thoracic and lumbar curves severe enough to require major reconstructive surgery. MATERIALS AND METHODS: The primary study group was 48 adult patients who had previously undergone a fusion from T10 or higher to the sacrum as an adult for idiopathic scoliosis. These were compared to 38 adults with unfused idiopathic scoliosis of 30 degrees -50 degrees and to 42 symptomatic adults presenting with cervical pain. Cervical degeneration was assessed using a new cervical degenerative index (CDI). RESULTS: The amount of degenerative change seen in the cervical spine in the long-fusion group was significantly higher at baseline (just prior to the fusion) than the two control populations and became much higher at a mean follow-up of 8.5 years. CONCLUSIONS: This unique subgroup of patients, those having fusion from the thoracic spine to the sacrum as adults for adolescent idiopathic scoliosis, had a high incidence and severity of degenerative changes in their cervical spine. Due to the presence of advanced cervical degenerative changes prior to the fusion, it is not possible to blame the fusion as the main cause for these findings. These changes are either related to the thoracic and lumbar deformities or are more likely due to this subgroup having a higher natural propensity for degenerative changes.

Clinical and radiological outcome of anterior-posterior fusion versus transforaminal lumbar interbody fusion for symptomatic disc degeneration: a retrospective comparative study of 133 patients.

Abundant data are available for direct anterior/posterior spine fusion (APF) and some for transforaminal lumbar interbody fusion (TLIF), but only few studies from one institution compares the two techniques. One-hundred and thirty-three patients were retrospectively analyzed, 68 having APF and 65 having TLIF. All patients had symptomatic disc degeneration of the lumbar spine. Only those with one or two-level surgeries were included. Clinical chart and radiologic reviews were done, fusion solidity assessed, and functional outcomes determined by pre- and postoperative SF-36 and postoperative Oswestry Disability Index (ODI), and a satisfaction questionnaire. The minimum follow-up was 24 months. The mean operating room time and hospital length of stay were less in the TLIF group. The blood loss was slightly less in the TLIF group (409 vs. 480 cc.). Intra-operative complications were higher in the APF group, mostly due to vein lacerations in the anterior retroperitoneal approach. Postoperative complications were higher in the TLIF group due to graft material extruding against the nerve root or wound drainage. The pseudarthrosis rate was statistically equal (APF 17.6% and TLIF 23.1%) and was higher than most published reports. Significant improvements were noted in both groups for the SF-36 questionnaires. The mean ODI scores at follow-up were 33.5 for the APF and 39.5 for the TLIF group. The patient satisfaction rate was equal for the two groups.

Perioperative complications in revision anterior lumbar spine surgery: incidence and risk factors.

STUDY DESIGN: This is a retrospective review of 129 consecutive anterior lumbar revision surgeries in 108 patients. It is a single-center, multi-surgeon study. OBJECTIVE: To determine occurrence rates and risk factors for perioperative complications in revision anterior lumbar fusion surgery. SUMMARY OF BACKGROUND DATA: Although complication rates from large series of primary anterior fusion procedures have been reported, reports of complication rates for revision anterior fusion procedures are relatively rare. Concern exists chiefly about the risk to vascular and visceral structures because of scar tissue formation from the original anterior exposure. METHODS: This was a retrospective review of 129 consecutive anterior revision lumbar surgeries in 108 patients operated between 1998 and 2003. There were 40 men and 68 women. The age of patients ranged from 25 to 83 (average 50.6 years). Patients were excluded if surgery was for tumor or infection. Patients were divided into 2 groups; those with revision surgery at the same level and those with revision surgery at an adjacent level. Outcome measures included all perioperative complications. Statistical analysis included Student t test and nonparametric sign-rank. RESULTS: The number of surgical levels treated for revision was similar between the 2 groups (1 level 69%; 2 levels 19%; 3 or more levels 12%). Revision cases at the same operative level had a higher overall complication rate (42%) compared with extensions (20%; P = 0.007). This difference was primarily because of vein lacerations (23.7% vs. 3.6%, P = 0.002). There were 2 ureteral problems, both successfully salvaged. There were no arterial injuries or deaths. CONCLUSION: Complication rates for revision lumbar surgery in this series were 3 to 5 times higher than reported for primary lumbar exposures. Complication rates were significantly higher for revision anterior lumbar fusions at the same segment, which were typically in the lower lumbar spine, compared with cases involving extensions, which were typically in the upper lumbar spine.

A biomechanical evaluation of three revision screw strategies for failed lateral mass fixation.

STUDY DESIGN: This is a biomechanical study evaluating 3 revision strategies for failed cervical lateral mass screw fixation. OBJECTIVE: Our primary objective was to compare, following a Magerl trajectory screw failure in the subaxial cervical spine, the pullout strength of (1) a revision screw in the same trajectory, (2) a Roy-Camille trajectory, and (3) pedicle screw fixation. We additionally analyzed the contributions of bone mineral density (BMD) and peak insertional torque to pullout strength. SUMMARY OF BACKGROUND DATA: Biomechanical studies that have examined revision screw strategies for lateral mass fixation have found either unsatisfactory or highly variable performance. METHODS: Fresh frozen cervical spinal segments were harvested and BMD testing performed. Bicortical (3.5-mm Vertex) lateral mass screws were placed in a Magerl trajectory in 57 fresh frozen human subaxial cervical vertebrae. All screws were then stripped and revision screws (4.0-mm Vertex) placed using either the same screw path or conversion to a Roy-Camille trajectory. In line pullout testing was performed on each of the revision screws (57 in Magerl revision group, 55 in Roy-Camille). Specimens that had not fractured during testing then had cervical pedicle screws (3.5-mm Vertex) placed and in-line pullout testing repeated (64 pedicles were instrumented) The pullout failure results of the Magerl revision, Roy-Camille revision, and pedicle screw revision groups were compared. RESULTS: No significant difference was noted in insertional torque (0.28-Nm Magerl, 0.35 Nm Roy-Camille, P > 0.05) or pullout (382-N Magerl, 351 N Roy-Camille, P > 0.05) between the Magerl and Roy-Camille revision groups. Pedicle screw revision had greater pullout strength (566 N) when compared with either the Magerl (382 N) or Roy-Camille (351 N) revision groups (P < 0.01) but also had a 20% pedicle wall breech rate by visual inspection. Insertional torque and pullout strength increased with increased BMD and were significantly correlated in all 3 revision groups (P < 0.05). Similarly, increased BMD was associated with increased pullout strength as demonstrated by the significant positive correlation (P < 0.05). CONCLUSION: Conversion of a stripped lateral mass screw to an alternate trajectory appears to offer no biomechanical advantage over placement of an increased diameter salvage screw using the same trajectory. Pedicle screw fixation provides superior biomechanical fixation but was associated with a significant breech rate.

Complications in long fusions to the sacrum for adult scoliosis: minimum five-year analysis of fifty patients.

STUDY DESIGN: A retrospective study of complications with minimal 5-year follow-up of 50 adults with scoliosis with fusion from T10 or higher to S1. OBJECTIVES: To document the perioperative and long-term complications and instrumentation problems, and to attempt to determine variables which may influence these problems. It is not a study of curve correction, balance, or functional outcome. SUMMARY OF BACKGROUND DATA: Several previous studies from this and other centers have shown a relatively high complication rate for this select group of patients. Various fusion techniques (anterior, posterior, autograft, allograft), various instrumentation techniques, and various immobilization techniques have created confusion as to the best methodology to employ. Minimal 2-year follow-ups have been standard, but longer follow-ups have shown additional problems. METHODS: The study cohort consisted of 50 adult patients from a single center who had undergone corrective scoliosis surgery from T10 or higher to the sacrum and who had at least a 5-year minimum follow-up. The mean age was 54 years (range, 18-72), and the mean follow-up was 9.7 years (range, 5-26). All radiographs, office charts, and hospital charts were combed by an independent investigator for complications, which were divided into major and minor, as well as early, intermediate and late. The curvature values and corrections were the subject of a different article, and were not included in this study. RESULTS: There were no deaths or spinal cord injuries. Six patients had nerve root complications, 4 of which totally recovered. Pseudarthrosis was seen in 24% of the patients, only 25% of which were detected within the 2-year follow-up period. Pseudarthrosis was most common at the lumbosacral level. There was no statistical difference in the pseudarthrosis rate between patients with sacral-only fixation versus iliac fixation. Painful implants requiring removal were noted in 11 of the 50 patients. CONCLUSION: Long fusions to the sacrum in adults with scoliosis continue to have a high complication rate. As compared to the original publications in the 1980s (Kostuik and Hall, Spine 1983;8:489-500; Balderston et al, Spine 1986;11:824-9) the more recent articles have shown a reduction, but not elimination of the pseudarthrosis problem using segmental instrumentation and anterior fusion of the lumbar spine coupled with structural interbody grafting at L4-L5 and L5-S1. Two-year follow-up is inadequate as pseudarthrosis and painful implants often are detected later. Only 3 of the 12 patients with pseudarthrosis were detected within the first 2 years after surgery.

Removal of lumbar instrumentation for the treatment of recurrent low back pain in the absence of pseudarthrosis.

INTRODUCTION: Removal of spine instrumentation for the treatment of recurrent low back pain remains controversial in the absence of pseudarthrosis and when no obvious pain generators are present. It is our practice to offer these patients surgical exploration and removal of instrumentation. MATERIALS AND METHODS: Forty-five patients underwent an anterior and posterior lumbar spinal fusion. The removal of instrumentation was performed by the same surgeon and senior author of this paper (MRP). The reason for the revision surgery was recurrent low back and leg pain. All patients had a solid fusion based on a thorough surgical exploration of the fusion mass. Instrumentation was deemed either solid or loose at time of removal based on the purchase at the screw-bone interface. Final outcomes were determined using a functional and satisfactory questionnaire and compared between the two groups (Loose Instrumentation versus Solid Instrumentation). RESULTS: The majority of the patients in both groups would recommend the surgery to a family member (79% overall), would have the surgery again themselves (82%) and consider the surgery a success (77%). Pain was significantly decreased from pre-operatively to post-operatively and from pre-operative to final follow-up in both groups. The group of patients with loose instrumentation were significantly more likely to have a successful outcome than the group without loose instrumentation. CONCLUSIONS: This study indicates that the removal of instrumentation in the absence of pseudarthrosis is beneficial in the relief of low back pain and leg pain symptoms. Increased success rates were noted in patients with loose instrumentation. However, this classification was based on inter-operative inspection. Further studies of the ability to diagnose and predict success prior to surgery needs to be done.