Trends, major medical complications, and charges associated with surgery for lumbar spinal stenosis in older adults

CONTEXT

In recent decades, the fastest growth in lumbar surgery occurred in older patients with spinal stenosis. Trials indicate that for selected patients, decompressive surgery offers an advantage over nonoperative treatment, but surgeons often recommend more invasive fusion procedures. Comorbidity is common in older patients, so benefits and risks must be carefully weighed in the choice of surgical procedure.

OBJECTIVE

To examine trends in use of different types of stenosis operations and the association of complications and resource use with surgical complexity.

DESIGN, SETTING, AND PATIENTS

Retrospective cohort analysis of Medicare claims for 2002-2007, focusing on 2007 to assess complications and resource use in US hospitals. Operations for Medicare recipients undergoing surgery for lumbar stenosis (n = 32,152 in the first 11 months of 2007) were grouped into 3 gradations of invasiveness: decompression alone, simple fusion (1 or 2 disk levels, single surgical approach), or complex fusion (more than 2 disk levels or combined anterior and posterior approach).

MAIN OUTCOME MEASURES

Rates of the 3 types of surgery, major complications, postoperative mortality, and resource use.

RESULTS

Overall, surgical rates declined slightly from 2002-2007, but the rate of complex fusion procedures increased 15-fold, from 1.3 to 19.9 per 100,000 beneficiaries. Life-threatening complications increased with increasing surgical invasiveness, from 2.3% among patients having decompression alone to 5.6% among those having complex fusions. After adjustment for age, comorbidity, previous spine surgery, and other features, the odds ratio (OR) of life-threatening complications for complex fusion compared with decompression alone was 2.95 (95% confidence interval [CI], 2.50-3.49). A similar pattern was observed for rehospitalization within 30 days, which occurred for 7.8% of patients undergoing decompression and 13.0% having a complex fusion (adjusted OR, 1.94; 95% CI, 1.74-2.17). Adjusted mean hospital charges for complex fusion procedures were US $80,888 compared with US $23,724 for decompression alone.

CONCLUSIONS

Among Medicare recipients, between 2002 and 2007, the frequency of complex fusion procedures for spinal stenosis increased while the frequency of decompression surgery and simple fusions decreased. In 2007, compared with decompression, simple fusion and complex fusion were associated with increased risk of major complications, 30-day mortality, and resource use.

Anterior cervical discectomy and fusion associated complications

STUDY DESIGN

Retrospective review study with literature review.

OBJECTIVE

The goal of our current study is to raise awareness on complications associated with anterior cervical discectomy and fusion (ACDF) and their early detection and proper management.

SUMMARY OF BACKGROUND DATA

It is known that ACDF constitutes one of the most commonly performed spinal procedures. Its outcome is quite satisfactory in the majority of cases. However, occasional complications can become troublesome, and in rare circumstances, catastrophic. Although there are several case reports describing such complications, their rate of occurrence is generally underreported, and data regarding their exact incidence in large clinical series are lacking. Meticulous knowledge of potential intraoperative and postoperative ACDF-related complications is of paramount importance so as to avoid them whenever possible, as well as to successfully and safely manage them when they are inevitable.

METHODS

In a retrospective study, 1015 patients undergoing first-time ACDF for cervical radiculopathy and/or myelopathy due to degenerative disc disease and/or cervical spondylosis were evaluated. A standard Smith-Robinson approach was used in all our patients, while an autologous or allograft was used, with or without a plate. Operative reports, hospital and outpatient clinic charts, and radiographic studies were reviewed for procedure-related complications. Mean follow-up time was 26.4 months.

RESULTS

The mortality rate in our current series was 0.1% (1 of 1015 patients, death occurred secondary to an esophageal perforation). Our overall morbidity rate was 19.3% (196 of 1015 patients). The most common complication was the development of isolated postoperative dysphagia, which observed in 9.5% of our patients. Postoperative hematoma occurred in 5.6%, but required surgical intervention in only 2.4% of our cases. Symptomatic recurrent laryngeal nerve palsy occurred in 3.1% of our cases. Dural penetration occurred in 0.5%, esophageal perforation in 0.3%, worsening of preexisting myelopathy in 0.2%, Horner's syndrome in 0.1%, instrumentation backout in 0.1%, and superficial wound infection in 0.1% of our cases.

CONCLUSION

Meticulous knowledge of the ACDF-associated complications allows for their proper management. Postoperative dysphagia, hematoma, and recurrent laryngeal nerve palsy were the most common complications in our series. Management of complications was successful in the vast majority of our cases.

Donor site morbidity after anterior iliac crest bone harvest for single-level anterior cervical discectomy and fusion

STUDY DESIGN

This retrospective, questionnaire-based investigation evaluated iliac crest bone graft (ICBG) site morbidity in patients having undergone a single-level anterior cervical discectomy and fusion (ACDF) procedure performed by a single surgeon (T.J.A.).

OBJECTIVE

To evaluate acute and chronic problems associated with anterior ICBG donation, particularly long-term functional outcomes and impairments caused by graft donation.

SUMMARY OF BACKGROUND DATA

Anterior cervical discectomy and fusion procedures frequently use autologous anterior ICBG to facilitate osseous union. Although autologous ICBG offers several advantages over alternative grafting materials, donor site morbidity can be significant. Acute and chronic complications of donor sites have been reported, yet there are currently no reports of long-term functional outcomes after autologous anterior ICBG donation after single-level ACDF.

METHODS

A questionnaire was mailed to 187 consecutive patients who were retrospectively identified to have undergone autologous anterior ICBG harvest for single-level ACDF between 1994 and 1998. The questionnaire divided items into symptomatic (acute and chronic) and functional assessments. Patients answered yes, no, or not applicable; pain was assessed with a Visual Analogue Scale (VAS).

RESULTS

Surveys were completed either by mail or follow-up telephone interview by 134 patients (71.6%). Average follow-up was 48 months (range, 24-72 months). Acute symptoms were reported at the following rates: ambulation difficulty, 50.7%; extended antibiotic usage, 7.5%; persistent drainage, 3.7%; wound dehiscence, 2.2%; and incision and drainage, 1.5%. The chronic symptom questionnaire demonstrated a high degree of satisfaction with the cosmetic result (92.5%). Pain at the donor site was reported by 26.1% of patients with a mean VAS score of 3.8 in 10, and 11.2% chronically use pain medication. Twenty-one patients (15.7%) reported abnormal sensations at the donor site, but only 5.2% reported discomfort with clothing. A unique functional assessment revealed current impairments at the following rates: ambulation, 12.7%; recreational activities, 11.9%; work activities, 9.7%; activities of daily living, 8.2%; sexual activity, 7.5%; and household chores, 6.7%.

CONCLUSIONS

A large percentage of patients report chronic donor site pain after anterior ICBG donation, even when only a single-level ACDF procedure is performed. Moreover, long-term functional impairment can also be significant. Patients should be counseled regarding these potential problems, and alternative sources of graft material should be considered.

Adjacent segment degeneration and adjacent segment disease: the consequences of spinal fusion?

Given the number of spinal fusions performed annually, concerns have mounted over the potential for adjacent segment degeneration (radiographic changes of degeneration at levels adjacent to a spinal fusion) and adjacent segment disease (development of new symptoms correlating with adjacent segment degeneration). This article reviews documented evidence on adjacent segment degeneration and disease as it relates to cervical and lumbar arthrodesis. There appears to be an incidence of adjacent segment degeneration and disease after arthrodesis that may be related to natural degeneration or the adjacent fusion. It remains to be seen whether restoration of motion with disc arthroplasty will alter the rate of adjacent segment degeneration or disease.

2001 Volvo Award Winner in Clinical Studies: Lumbar fusion versus nonsurgical treatment for chronic low back pain: a multicenter randomized controlled trial from the Swedish Lumbar Spine Study Group

STUDY DESIGN

A randomized controlled multicenter study with a 2-year follow-up by an independent observer.

OBJECTIVES

To determine whether fusion of the lower lumbar spine could reduce pain and diminish disability more effectively when compared with nonsurgical treatment in patients with severe chronic low back pain (CLBP).

SUMMARY OF BACKGROUND DATA

The reported results after fusion surgery on patients with CLBP vary considerably, and the evidence of treatment efficacy is weak in the absence of randomized controlled studies.

PATIENTS AND METHODS

A total of 294 patients referred to 19 spinal centers from 1992 through 1998 were randomized blindly into four treatment groups. Patients aged 25-65 years with CLBP for at least 2 years and with radiologic evidence of disc degeneration at L4-L5, L5-S1, or both were eligible to participate in the study. The surgical group (n=222) included three different fusion techniques, not analyzed separately in this study. Patients in the nonsurgical group (n=72) were treated with different kinds of physical therapy. The surgical group comprised 49.5% men, and the mean age was 43 years. The corresponding figures for the nonsurgical group were 48.6% and 44 years. The patients had suffered from low back pain for a mean of 7.8 and 8.5 years and been on sick leave due to back pain for a mean of 3.2 and 2.9 years, respectively. The Visual Analogue Scale (VAS) was used to measure pain. The Oswestry Low Back Pain Questionnaire, the Million Score and the General Function Score (GFS) were used to measure disability. The Zung Depression Scale was used to measure depressive symptoms. The overall result was assessed by the patient and by an independent observer. Records from the Swedish Social Insurance were used to evaluate work disability. Patients who changed groups were included in the analyses of significance according to the intention-to-treat principle.

RESULTS

At the 2-year follow-up 289 of 294 (98%) patients, including 25 who had changed groups, were examined. Back pain was reduced in the surgical group by 33% (64 to 43), compared with 7% (63 to 58) in the nonsurgical group (P=0.0002). Pain improved most during the first 6 months and then gradually deteriorated. Disability according to Oswestry was reduced by 25% (47 to 36) compared with 6% (48 to 46) among nonsurgical patients (P=0.015), according to Million by 28% (64 to 46) compared with 8% (66 to 60) (P=0.004), and accordingtoGFS by 31% (49 to 34) compared with 4% (48 to 46) (P=0.005). The depressive symptoms, according to Zung, were reduced by 20% (39 to 31) in the surgical group compared with 7% (39 to 36) in the nonsurgical group (P=0.123). In the surgical group 63% (122/195) rated themselves as "much better" or "better" compared with 29% (18/62) in the nonsurgical group (P<0.0001). The "net back to work rate" was significantly in favor of surgical treatment, or 36% vs. 13% (P=0.002). The early complication rate in the surgical group was 17%.

CONCLUSION

Lumbar fusion in a well-informed and selected group of patients with severe CLBP can diminish pain and decrease disability more efficiently than commonly used nonsurgical treatment.

Adverse effects associated with high-dose recombinant human bone morphogenetic protein-2 use in anterior cervical spine fusion

STUDY DESIGN

A retrospective review of patients who underwent an anterior cervical fusion using recombinant human bone morphogenetic protein (rhBMP)-2 with an absorbable collagen sponge (INFUSE; Medtronic Sofamor Danek, Minneapolis, MN).

OBJECTIVE

To ascertain the complication rate after the use of high-dose INFUSE in anterior cervical fusions.

SUMMARY OF BACKGROUND DATA

The rhBMP-2 has been primarily investigated in lumbar spine fusions, where it has significantly enhanced the fusion rate and decreased the length of surgery, blood loss, and hospital stay.

METHODS

We present 151 patients who underwent either an anterior cervical discectomy and fusion (n = 138) or anterior cervical vertebrectomy and fusion (n = 13) augmented with high-dose INFUSE between July 2003 and March 2004. The rhBMP-2 (up to 2.1 mg/level) was used in the anterior cervical discectomy and fusions.

RESULTS

A total of 35 (23.2%) patients had complications after the use of high-dose INFUSE in the cervical spine. There were 15 patients diagnosed with a hematoma, including 11 on postoperative day 4 or 5, of whom 8 were surgically evacuated. Thirteen individuals had either a prolonged hospital stay (> 48 hours) or hospital readmission because of swallowing/breathing difficulties or dramatic swelling without hematoma.

CONCLUSIONS

A significant rate of complications resulted after the use of a high dose of INFUSE in anterior cervical fusions. We hypothesize that in the cervical area, the putative inflammatory effect that contributes to the effectiveness of INFUSE in inducing fusion may spread to adjacent critical structures and lead to increased postoperative morbidity. A thorough investigation is warranted to determine the optimal dose of rhBMP-2 that will promote cervical fusion and minimize complications.

Adjacent segment degeneration in the lumbar spine

BACKGROUND

A primary concern after posterior lumbar spine arthrodesis is the potential for adjacent segment degeneration cephalad or caudad to the fusion segment. There is controversy regarding the subsequent degeneration of adjacent segments, and we are aware of no long-term studies that have analyzed both cephalad and caudad degeneration following posterior arthrodesis. A retrospective investigation was performed to determine the rates of degeneration and survival of the motion segments adjacent to the site of a posterior lumbar fusion.

METHODS

Two hundred and fifteen patients who had undergone posterior lumbar arthrodesis were included in this study. The study group included 126 female patients and eighty-nine male patients. The average duration of follow-up was 6.7 years. Radiographs were analyzed with regard to arthritic degeneration at the adjacent levels both preoperatively and at the time of the last follow-up visit. Disc spaces were graded on a 4-point arthritic degeneration scale. Correlation analysis was used to determine the contribution of independent variables to the rate of degeneration. Survivorship analysis was performed to describe the degeneration of the adjacent motion segments.

RESULTS

Fifty-nine (27.4%) of the 215 patients had evidence of degeneration at the adjacent levels and elected to have an additional decompression (fifteen patients) or arthrodesis (forty-four patients). Kaplan-Meier analysis predicted a disease-free survival rate of 83.5% (95% confidence interval, 77.5% to 89.5%) at five years and of 63.9% (95% confidence interval, 54.0% to 73.8%) at ten years after the index operation. Although there was a trend toward progression of the arthritic grade at the adjacent disc levels, there was no significant correlation, with the numbers available, between the preoperative arthritic grade and the need for additional surgery.

CONCLUSIONS

The rate of symptomatic degeneration at an adjacent segment warranting either decompression or arthrodesis was predicted to be 16.5% at five years and 36.1% at ten years. There appeared to be no correlation with the length of fusion or the preoperative arthritic degeneration of the adjacent segment.

Use of recombinant human bone morphogenetic protein-2 to achieve posterolateral lumbar spine fusion in humans: a prospective, randomized clinical pilot trial: 2002 Volvo Award in clinical studies

STUDY DESIGN

A prospective randomized clinical study was conducted.

OBJECTIVE

To determine whether the dose and carrier that were successful in rhesus monkeys could induce consistent radiographic spine fusion in humans.

SUMMARY OF BACKGROUND DATA

Preclinical studies have demonstrated that recombinant human bone morphogenetic protein-2 (rhBMP-2), an osteoinductive bone morphogenetic protein, is successful at generating spine fusion in rabbits and rhesus monkeys.

METHODS

For this study, 25 patients undergoing lumbar arthrodesis were randomized (1:2:2 ratio) based on the arthrodesis technique: autograft/Texas Scottish Rite Hospital (TSRH) pedicle screw instrumentation (n = 5), rhBMP-2/TSRH (n = 11), and rhBMP-2 only without internal fixation (n = 9). On each side, 20 mg of rhBMP-2 were delivered on a carrier consisting of 60% hydroxyapatite and 40% tricalcium phosphate granules (10 cm /side). The patients had single-level disc degeneration, Grade 1 or less spondylolisthesis, mechanical low back pain with or without leg pain, and at least 6 months failure of nonoperative treatment.

RESULTS

All 25 patients were available for follow-up evaluation (mean, 17 months; range 12-27 months). The radiographic fusion rate was 40% (2/5) in the autograft/TSRH group and 100% (20/20) with rhBMP-2 group with or without TSRH internal fixation ( = 0.004). A statistically significant improvement in Oswestry score was seen at 6 weeks in the rhBMP-2 only group (-17.6; = 0.009), and at 3 months in the rhBMP-2/TSRH group (-17.0; = 0.003), but not until 6 months in the autograft/TSRH group (-17.3; = 0.041). At the final follow-up assessment, Oswestry improvement was greatest in the rhBMP-2 only group (-28.7, < 0.001). The SF-36 Pain Index and PCS subscales showed similar changes.

DISCUSSION

This pilot study is the first with at least 1 year of follow-up evaluation to demonstrate successful posterolateral spine fusion using a BMP-based bone graft substitute, with radiographs and CT scans as the determinant. Consistently, rhBMP-2 was able to induce bone in the posterolateral lumbar spine when delivered at a dose of 20 mg per side with or without the use of internal fixation. Patients with spondylolisthesis classified higher than Meyerding Grade 1 or with more than 5 mm of translational motion may still require internal fixation. Some patients did smoke during the postoperative period, and all in the rhBMP-2 groups still obtained solid fusions.

CONCLUSIONS

Consistently, rhBMP-2 with the biphasic calcium phosphate granules induced radiographic posterolateral lumbar spine fusion with or without internal fixation in patients whose spondylolisthesis did not exceed Grade 1. Statistically greater and quicker improvement in patient-derived clinical outcome was measured in the rhBMP-2 groups.

Incidence of dysphagia after anterior cervical spine surgery: a prospective study

STUDY DESIGN

A prospective longitudinal study was conducted to evaluate dysphagia after anterior cervical spine surgery.

OBJECTIVES

To evaluate the incidence and natural history of dysphagia after anterior cervical spine surgery, and to identify risk factors for the development of postoperative dysphagia.

SUMMARY OF BACKGROUND DATA

The literature contains only retrospective evaluations of postoperative dysphagia. A wide range of incidence has been reported in these studies.

METHODS

Altogether, 249 consecutive patients undergoing anterior cervical spine surgery were eligible for the study. These patients were contacted 1, 2, 6, and 12 months after the procedure to evaluate swallowing. Risk factors such as age, gender, procedure type, hardware use, and number and location of surgical levels addressed were assessed.

RESULTS

Dysphagia incidences of 50.2%, 32.2%, 17.8%, and 12.5% were found at 1, 2, 6, and 12 months, respectively. At 6 months after the procedure, only 4.8% of the patients were experiencing moderate or severe dysphagia. Patient age, type of procedure (corpectomy vs. discectomy or primary vs. revision), hardware presence, and location of surgical levels were not statistically significant risk factors for the development of postoperative dysphagia. Female gender was significant for increased risk of dysphagia at 6 months. Surgery at multiple disc levels increased the risk of postoperative dysphagia at 1 and 2 months. The etiology of the dysphagia in most of the patients was unknown. However, vocal cord paresis was identified in 1.3% of the patients at 12 months.

CONCLUSIONS

Dysphagia after anterior cervical spine surgery is a common early finding. However, it decreases significantly by 6 months. The minority of patients experience moderate or severe symptoms by 6 months after the procedure. Female gender and multiple surgical levels could be identified as risk factors for the development of postoperative dysphagia.

Perioperative complications of posterior lumbar decompression and arthrodesis in older adults

BACKGROUND

Lumbar arthrodesis is commonly done in elderly patients to treat degenerative spine problems. These patients may be at increased risk for complications because of their age and associated medical conditions. In this study, we examined the rates of perioperative complications associated with posterior lumbar decompression and arthrodesis in patients sixty-five years of age or older.

METHODS

We reviewed the hospital records of ninety-eight patients who were sixty-five years of age or older when they had a posterior decompression and lumbar arthrodesis with instrumentation, between 1993 and 1995, to treat degenerative disease of the spine. The average age was seventy-two years (range, sixty-five to eighty-four years).

RESULTS

Perioperative complications occurred in seventy-eight patients. Twenty-one patients had at least one major complication, and sixty-nine had at least one minor complication. Forty-nine patients had more than one complication. The most common major complication was wound infection (prevalence, 10%), and the most common minor complication was urinary tract infection (prevalence, 34%). The complication rate increased with older age, increased blood loss, longer operative time, and the number of levels of the arthrodesis.

CONCLUSIONS

Surgeons should be vigilant about perioperative complications in elderly patients treated with multi-level lumbar decompression and arthrodesis with instrumentation. Elderly patients should be made aware that they are at increased risk for surgical complications because of their age. Attention should be paid to controlling blood loss and limiting operative time.

Accelerated degeneration of the segment adjacent to a lumbar fusion

Previously reported biomechanical studies on the effects of various types of spinal fusion procedures upon the adjacent segment indicate a significant degree of increased stress at that segment. This study presents 18 patients in whom new symptoms developed from the segment adjacent to a fusion after an average symptom-free interval of 8.5 years (1-38 years). The most common pathologic condition at the adjacent segment was hypertrophic degenerative arthritis of the facet joints. Spinal stenosis was found there in eight cases; severe disc degeneration in five; degenerative spondylolisthesis in two; and spondylolysis acquisita in one.

Donor site pain from the ilium. A complication of lumbar spine fusion

Chronic pain at the donor site was reported by 25% of 290 patients who had undergone anterior lumbar spine fusion for low back pain. Donor site pain has characteristic clinical features, may be severely disabling and is stubbornly resistant to treatment. The highest prevalence was in patients who had a tricortical full thickness graft taken through a separate incision overlying the iliac crest. Patients with a clinically unsatisfactory result from the spine fusion also had a significantly higher prevalence of donor site pain.

Results of the prospective, randomized, controlled multicenter Food and Drug Administration investigational device exemption study of the ProDisc-C total disc replacement versus anterior discectomy and fusion for the treatment of 1-level symptomatic cervical disc disease

BACKGROUND CONTEXT

Cervical total disc replacement (TDR) is intended to address radicular pain and preserve functional motion between two vertebral bodies in patients with symptomatic cervical disc disease (SCDD).

PURPOSE

The purpose of this trial is to compare the safety and efficacy of cervical TDR, ProDisc-C (Synthes Spine Company, L.P., West Chester, PA), to anterior cervical discectomy and fusion (ACDF) surgery for the treatment of one-level SCDD between C3 and C7.

STUDY DESIGN/SETTING

The study was conducted at 13 sites. A noninferiority design with a 1:1 randomization was used.

PATIENT SAMPLE

Two hundred nine patients were randomized and treated (106 ACDF; 103 ProDisc-C).

OUTCOME MEASURES

Visual analog scale (VAS) pain and intensity (neck and arm), VAS satisfaction, neck disability index (NDI), neurological exam, device success, adverse event occurrence, and short form-36 (SF-36) standardized questionnaires.

METHODS

A prospective, randomized, controlled clinical trial was performed. Patients were enrolled and treated in accordance with the US Food and Drug Administration (FDA)-approved protocol. Patients were assessed pre- and postoperatively at six weeks, 3, 6, 12, 18, and 24 months.

RESULTS

Demographics were similar between the two patient groups (ProDisc-C: 42.1+/-8.4 years, 44.7% males; Fusion: 43.5 +/- 7.1 years, 46.2% males). The most commonly treated level was C5-C6 (ProDisc-C: 56.3%; Fusion=57.5%). NDI and SF-36 scores were significantly less compared with presurgery scores at all follow-up visits for both the treatment groups (p<.0001). VAS neck pain intensity and frequency as well as VAS arm pain intensity and frequency were statistically lower at all follow-up timepoints compared with preoperative levels (p<.0001) but were not different between treatments. Neurologic success (improvement or maintenance) was achieved at 24 months in 90.9% of ProDisc-C and 88.0% of Fusion patients (p=.638). Results show that at 24 months postoperatively, 84.4% of ProDisc-C patients achieved a more than or equal to 4 degrees of motion or maintained motion relative to preoperative baseline at the operated level. There was a statistically significant difference in the number of secondary surgeries with 8.5% of Fusion patients needing a re-operation, revision, or supplemental fixation within the 24 month postoperative period compared with 1.8% of ProDisc-C patients (p=.033). At 24 months, there was a statistically significant difference in medication usage with 89.9% of ProDisc-C patients not on strong narcotics or muscle relaxants, compared with 81.5% of Fusion patients.

CONCLUSIONS

The results of this clinical trial demonstrate that ProDisc-C is a safe and effective surgical treatment for patients with disabling cervical radiculopathy because of single-level disease. By all primary and secondary measures evaluated, clinical outcomes after ProDisc-C implantation were either equivalent or superior to those same clinical outcomes after Fusion.

Adult spinal deformity surgery: complications and outcomes in patients over age 60

STUDY DESIGN

A retrospective analysis, including prospectively collected patient outcomes data.

OBJECTIVE

To determine the rate of complications and outcomes in patients >or=60 years of age who underwent major spinal deformity surgery requiring a minimum 5-level arthrodesis procedure.

SUMMARY OF BACKGROUND DATA

As the population ages, an increasing number of older patients are presenting with spinal deformity disorders that may require major reconstructive procedures. Previous studies have reported complication rates as high as 80% in this age group for 1- and 2-level fusion procedures. The prevalence of complications was found to increase with the greater number of levels fused.

METHODS

Forty-six patients who were 60 years of age or older underwent a thoracic or lumbar arthrodesis procedure consisting of 5 levels or greater. Diagnosis, comorbidities, operative data, hospital data, major and minor complications, and deaths were recorded. Oswestry Disability Index (ODI) Scores were used to evaluate clinical outcomes.

RESULTS

Thirty-eight females and 8 males with a mean age of 67 years (range, 60-85 years) and a mean follow-up of 4.2 years (range, 2-11 years) had complete records. Thirty-six (78%) patients had at least 1 comorbidity. Twenty-nine (63%) patients had at least 1 prior spinal surgery. A mean of 9 levels (range, 5-16 levels) were fused in each patient. The overall complication rate was 37%. The major complication rate was 20%. ODI improved from 49 to 25 for a mean improvement of 24 (49%) (P < 0.0001).

CONCLUSION

The overall complication rate was 37% and the major complication rate was 20%. Increasing age was a significant factor (P < 0.05) in predicting the presence of a complication. Patients older than 69 years had more complications. The presence of a comorbidity had no association with complication rates and neither had an effect on final patient reported outcomes, which showed significant improvement (ODI preoperative, 49; postoperative, 25) (P < 0.0001).

Prevalence, complications, and hospital charges associated with use of bone-morphogenetic proteins in spinal fusion procedures

CONTEXT

No national data exist to examine use of bone-morphogenetic proteins (BMPs) in spinal fusion surgery.

OBJECTIVE

To determine the patterns of use and rates of complications and financial charges associated with BMP use in spinal fusion nationally.

DESIGN, SETTING, AND PATIENTS

Retrospective cohort study of 328,468 patients undergoing spinal fusion procedures from 2002-2006 identified from the Nationwide Inpatient Sample database, a 20% sample of US community hospitals.

MAIN OUTCOME MEASURES

The rates of use of BMP among patients undergoing spinal fusion procedures are examined along with complications, length of stay, and hospital charges associated with use of this fusion adjunct.

RESULTS

The nationwide usage of BMP has increased from 0.69% of all fusions in 2002 to 24.89% of all fusions in 2006. Use of BMP varied by patient sex, race, and primary payer with increased use seen in women (56.26% with BMP vs 53.35% without BMP; odds ratio [OR], 1.12; 95% confidence interval, [CI], 1.09-1.16) and Medicare patients (29.62% with BMP vs 27.16% without BMP; OR, 1.43; 95% CI, 1.31-1.56) and decreased use in nonwhite patients (8.69% with BMP vs 10.23% without BMP; OR, 0.80; 95% CI, 0.75-0.85). When comparing immediate postoperative, in-hospital rates of complications for the year 2006 among patients undergoing spinal fusion by BMP use status, no differences were seen for lumbar, thoracic, or posterior cervical procedures. On univariate analysis and after multivariable adjustment, the use of BMP in anterior cervical fusion procedures was associated with a higher rate of complication occurrence (7.09% with BMP vs 4.68% without BMP; adjusted OR, 1.43; 95% CI, 1.12-1.70) with the primary increases seen in wound-related complications (1.22% with BMP vs 0.65% without BMP; adjusted OR, 1.67; 95% CI, 1.10- 2.53) and dysphagia or hoarseness (4.35% with BMP vs 2.45% without BMP; adjusted OR, 1.63; 95% CI, 1.30-2.05). Bone-morphogenetic protein use was associated with greater inpatient hospital charges across all categories of fusion. Increases between 11% and 41% of total hospital charges were reported, with the greatest percentage increase seen for anterior cervical fusion.

CONCLUSION

Bone-morphogenetic protein was used in approximately 25% of all spinal fusions nationally in 2006, with use associated with more frequent complications for anterior cervical fusions and with greater hospital charges for all categories of fusions.

Complications associated with pedicle screws

BACKGROUND

The safety and the effectiveness of pedicle-screw instrumentation in the spine have been questioned despite its use worldwide to enhance stabilization of the spine. This review was performed to answer questions about the technique of insertion and the nature and etiology of complications directly attributable to the screws.

METHODS

We performed a retrospective review of all of the pedicle-screw procedures that were done by us from January 1, 1984, to December 31, 1993. We inserted 4790 screws during 915 operative procedures on 875 patients; 668 (76.3 percent) of the patients had a lumbosacral arthrodesis. The mean duration of follow-up was three years (range, two to five years). The accuracy of screw placement was assessed on intraoperative, immediate postoperative, and follow-up radiographs with use of a technique that was developed by one of us (F. D.); this technique has yet to be validated to determine the prevalence of various types of error.

RESULTS

Of the 4790 screws, 4548 (94.9 percent) had been inserted within the pedicle and the vertebral body. One hundred and thirty-four (2.8 percent) of the screws had perforated the anterior cortex, and this was the most common type of perforation. One hundred and fifteen (2.4 percent) of the screws were associated with complications that could be ascribed to the use of pedicle screws. The most common problem was late-onset discomfort or pain related to a pseudarthrosis or perhaps to the screws; this problem was associated with 1102 (23.0 percent) of the screws, used in 222 (24.3 percent) of the procedures. The symptoms necessitated removal of the instrumentation with or without repair of the pseudarthrosis. A pseudarthrosis was found during forty-six (20.7 percent) of the 222 procedures. Irritation of a nerve root occurred after nine procedures (1.0 percent) and was caused by eleven screws (0.2 percent); it was more commonly caused by medially placed screws. Three patients had residual neurological weakness despite removal of the screws. Twenty-five screws (0.5 percent), used in twenty procedures (2.2 percent), broke. The screws that broke were of an early design. A pseudarthrosis was found in thirteen of twenty patients who had broken screws. Sixteen of the twenty patients had an exploration; three of them were found to have a solid fusion, and thirteen were found to have a pseudarthrosis. The remaining four patients had evidence of a solid fusion on radiographs and had no pain.

CONCLUSIONS

There are few problems associated with the insertion of screws, provided that the surgeon is experienced and adheres to the principles and details of the operative technique. Our review revealed a low rate of postoperative complications related to pedicle screws. The problem of late-onset pain may be related to the implants or to the stiffness of the construct; however, it is difficult to accurately identify its exact etiology.

Chronic low back pain and fusion: a comparison of three surgical techniques: a prospective multicenter randomized study from the Swedish lumbar spine study group

STUDY DESIGN

A multicenter randomized study with a 2-year follow-up period and an independent observer was conducted.

OBJECTIVE

To compare three commonly used surgical techniques to achieve lumbar fusion primarily in terms of their ability to reduce pain and decrease disability in patients with severe chronic low back pain.

SUMMARY OF BACKGROUND DATA

Lumbar fusion can be used to reduce pain and decrease disability in patients with chronic low back pain, and different surgical techniques are available. The reported results after fusion surgery vary considerably, but most studies are retrospective and/or performed on heterogeneous patient groups. Spine surgeons commonly use the techniques presented in this report. However, in the absence of randomized trials it is difficult to know whether any one of them is better than the others for these patients.

METHODS

From 1992 through 1998, 294 patients referred to 19 spinal centers were blindly randomized into four treatment groups: three surgical groups (n = 222) and one nonsurgical group (n = 72). The sociodemographic and clinical characteristics did not differ among the groups. Eligibility included patients 25 to 65 years of age with therapy-resistant chronic low back pain that had persisted for at least 2 years and radiologic evidence of disc degeneration (spondylosis) at L4-L5, L5-S1, or both. Only patients randomized to one of three surgical groups were analyzed in the current study: Group 1 (posterolateral fusion; n = 73), Group 2 (posterolateral fusion combined with variable screw placement, an internal fixation device; n = 74), and Group 3 (posterolateral fusion combined with variable screw placement and interbody fusion; n = 75). The "circumferential fusion" in Group 3 was performed either as an anterior lumbar interbody fusion (n = 56) or as a biomechanically similar posterior lumbar interbody fusion (n = 19). The groups were composed of 51%, 58%, and 40% men respectively, and the respective mean ages were 44, 43, and 42 years. The patients had experienced low back pain for at least 2 years (mean, approximately 8 years). They had been on sick leave for approximately 3 years. Pain was measured by a visual analog scale, and disability was assessed by the Oswestry Low Back Pain Questionnaire, the Million Visual Analogue Score, and the General Function Score. Depressive symptoms were measured by the Zung Depression Scale. The global overall rating of the result was assessed by the patient and an independent observer after 2 years. Hospitalization data including operation time, blood loss, blood transfusion, and days of hospitalization in connection with surgery were reported, along with complications and the fusion rate. Records from the Swedish Social Insurance Board providing information on sick leave and economic compensation for Swedish residents were used to evaluate the patients' work status.

RESULTS

An independent observer examined 201 (91%) of 222 patients after 2 years, after 18 "group changers" and 3 dropouts had been excluded from the analyses. All surgical techniques were found to reduce pain and decrease disability substantially, but no significant differences were found among the groups. In all three groups, the patients rated the overall outcome similarly, as did the independent observer. The more demanding techniques in Groups 2 and 3 consumed significantly more resources in terms of operation time, blood transfusions, and days in hospital after surgery. The early complication rate was 6% in Group 1, 16% in Group 2, and 31% in Group 3. The fusion rate, as evaluated by plain radiograph, was 72% in Group 1, 87% in Group 2, and 91% in Group 3.

CONCLUSIONS

All the fusion techniques used in the study could reduce pain and improve function in this selected group of patients with severe chronic low back pain. There was no obvious disadvantage in using the least demanding surgical technique of posterolateral fusion without internal fixation.

The surgical and medical perioperative complications of anterior spinal fusion surgery in the thoracic and lumbar spine in adults. A review of 1223 procedures

STUDY DESIGN

A retrospective review of 1223 thoracic and lumbar anterior spinal fusions was performed from 1969 through 1992.

OBJECTIVES

To document the incidence and specific types of perspective complications related to anterior spinal fusions.

SUMMARY OF BACKGROUND DATA

Despite the increased use of anterior spinal surgery, there has been little documentation of the specific types and frequencies of the complications associated with its use.

METHODS

All Minnesota Spine Center patients age 18 years or older who had anterior spinal fusions between the levels of T1 and S1 from August 1969 to June 1992 were reviewed for the occurrence of perioperative complications. Surgical approach and technique and associated comorbidity was recorded.

RESULTS

The risk of a complication was increased for patients over age 60 years, for women, and for patients with multiple preexisting health problems. Serious complications, such as death (0.3%), paraplegia (0.2%), and deep wound infection (0.6%) were rare. The complication rate for complications that were directly attributed to the anterior spinal surgery was 11.5%.

CONCLUSIONS

Anterior spinal fusion surgery is a safe procedure and can be used with confidence when the nature of a patient's spinal disorder dictates its use. Complications are often approach specific.

Accuracy of pedicle screw insertion with and without computer assistance: a randomised controlled clinical study in 100 consecutive patients

We performed a randomised controlled study to assess the accuracy of computer-assisted pedicle screw insertion versus conventional screw placement under clinical conditions. One hundred patients scheduled for posterior thoracolumbar or lumbosacral pedicle screw instrumentation were randomised into two groups, either for conventional pedicle screw placement or computer-assisted screw application using an optoelectronic navigation system. From the computer-assisted group, nine patients were excluded: one because of an inadequate preoperative computed tomography study, seven because of problems with the specific instruments or the computer system, and one because of an intraoperative anesthesiological complication. Thus, there were 50 patients in the conventional group and 41 in the computer-assisted group, and the number of screws inserted was 277 and 219, respectively. There was no statistical difference between the groups concerning age, gender, diagnosis, type of operation performed, mean operating time, blood loss, or number of screws inserted. The time taken for screw insertion was significantly longer in the computer-assisted group. Postoperatively, screw positions were assessed by an independent radiologist using a sophisticated CT imaging protocol. The pedicle perforation rate was 13.4% in the conventional group and 4.6% in the computer-assisted group (P = 0.006). Pedicle perforations of more than 4 mm were found in 1.4% (4/277) of the screw insertions in the conventional group, and none in the computer-assisted group. Complications not related to pedicle screws were two L5 nerve root lesions, one end plate fracture, one major intraoperative bleeding and one postoperative death in the conventional group, and one deep infection in the computer-assisted group. In conclusion, pedicular screws were inserted more accurately with image-guided computer navigation than with conventional methods.

Minimally invasive lumbar fusion

STUDY DESIGN

Review article.

OBJECTIVES

To provide an overview of current techniques for minimally invasive lumbar fusion.

SUMMARY OF BACKGROUND DATA

Minimally invasive techniques have revolutionized the management of pathologic conditions in various surgical disciplines. Although these same principles have been used in the treatment of lumbar disc disease for many years, minimally invasive lumbar fusion procedures have only recently been developed. The goals of these procedures are to reduce the approach-related morbidity associated with traditional lumbar fusion, yet allow the surgery to be performed in an effective and safe manner.

METHODS

The authors' clinical experience with minimally invasive lumbar fusion was reviewed, and the pertinent literature was surveyed.

RESULTS

Minimally invasive approaches have been developed for common lumbar procedures such as anterior and posterior interbody fusion, posterolateral onlay fusion, and internal fixation. As with all new surgical techniques, minimally invasive lumbar fusion has a learning curve. As well, there are benefits and disadvantages associated with each technique. However, because these techniques are new and evolving, evidence to support their potential benefits is largely anecdotal. Additionally, there are few long-term studies to document clinical outcomes.

CONCLUSIONS

Preliminary clinical results suggest that minimally invasive lumbar fusion will have a beneficial impact on the care of patients with spinal disorders. Outcome studies with long-term follow-up will be necessary to validate its success and allow minimally invasive lumbar fusion to become more widely accepted.

Clinical and radiographic outcomes of anterior lumbar interbody fusion using recombinant human bone morphogenetic protein-2

STUDY DESIGN

A prospective, nonblinded, multicenter study of outcomes in patients undergoing single-level anterior lumbar discectomy and interbody fusion with InFUSE Bone Graft.

OBJECTIVE

To determine the safety and effectiveness of InFUSE Bone Graft applied to an absorbable collagen sponge in anterior lumbar interbody fusion with threaded cortical allografts.

SUMMARY OF BACKGROUND DATA

In primates, InFUSE Bone Graft used with allograft dowels was shown to increase rates of interbody fusion by promoting osteoinduction and enhancing incorporation of the allograft. Recently, in a small series of human patients undergoing anterior lumbar interbody fusion with a tapered cylindrical metal fusion cage, InFUSE Bone Graft has been shown to promote osteoinduction and fusion.

METHODS

Forty-six patients underwent a single-level anterior lumbar discectomy and interbody fusion at five investigational sites. They were randomly assigned to one of two groups, and the results in the investigational patients who received threaded cortical allograft dowels with InFUSE Bone Graft were compared with those in the control patients who received threaded allograft dowels with autogenous iliac crest bone graft. Patients' clinical outcomes were assessed using neurologic status, work status, and Oswestry Low Back Pain Disability, Short Form-36, and back and leg pain questionnaires. Anteroposterior, lateral, flexion-extension radiographs, and computed tomography scans were used to evaluate the progression of fusion at 6, 12, and 24 months after surgery.

RESULTS

All patients who received InFUSE Bone Graft showed radiographic evidence of bony induction and early incorporation of the cortical allografts. All patients in this group had fusions at 12 months that remained fused at 24 months. At 12 and 24 months, the investigational group showed higher rates of fusion and improved neurologic status and back and leg pain when compared with the control group. There were no unanticipated adverse events related to the use of InFUSE Bone Graft.

CONCLUSION

The use of InFUSE Bone Graft is a promising method of facilitating anterior intervertebral spinal fusion, decreasing pain, and improving clinical outcomes in patients who have undergone anterior lumbar fusion surgery with structural threaded cortical allograft bone dowels.

Postoperative spinal wound infection: a review of 2,391 consecutive index procedures

Postoperative infection remains a troublesome but not uncommon complication after spinal surgery. Most previous reports, however, are small or involve cases with more than one surgeon often at different institutions. This study represents a single surgeon's 9-year experience with postoperative infection at one institution. The authors describe the features of wound infection after spinal surgery with reference to diagnosis, microbiology, and treatment and they describe a protocol for effective management of postoperative spinal wound infection. The records of the senior author (F.P.C.) during a 9-year period for cases of postoperative wound infection were reviewed. Of 2,391 operative procedures, 46 cases of wound infection were identified, yielding an overall infection rate of 1.9%. Patients' preoperative risk factors, original diagnosis prompting the surgery, onset of infection, presentation, treatment, and outcome were analyzed. The mean age of the 23 men and 23 women was 57.2 years. The preoperative diagnoses included lumbar degenerative scoliosis or spinal stenosis in 28 cases, disk prolapse in 8 cases, metastatic disease in 4 cases, degenerative disk disease in 1 case, and a group of 5 miscellaneous cases. Seventeen (37%) of the patients underwent at least one previous spinal surgery at the same site. Twenty-three patients had a fusion, of whom 22 also had instrumentation. Forty-three (93%) of the patients had significant wound drainage after an average of 15 days (range, 5-80 days). The other three patients were examined approximately 2 years after the surgery. Fourteen of the patients also had pyrexia (temperature >37.5 degrees C) at presentation. Staphylococcus aureus alone was cultured in 29 patients, whereas another six patients had a different single organism. In nine patients, more than one organism was cultured during their hospital stay. Surgical treatment included primary closure in only seven patients, with most undergoing wound drainage and debridement followed by delayed closure. Instruments were removed in the three patients with late presentation who had solid fusion at operation. Viable bone graft and instrumentation were left in situ in all patients who were seen before fusion. All wounds healed without sequelae, except for three that required flap closure. Pseudarthrosis was noted in three patients after more than 1 year of follow-up in this series. Postoperative spinal wound infection is a potentially devastating problem. In this series, infection was more common in patients undergoing fusion with instrumentation and in patients with cancer metastatic to the spine. An aggressive surgical approach, including repeated debridement followed by delayed closure, is justified. Instrumentation may be safely left in situ to provide stability for fusion.

Outcome and complications of long fusions to the sacrum in adult spine deformity: luque-galveston, combined iliac and sacral screws, and sacral fixation

STUDY DESIGN

A retrospective study of adults with long fusion to the sacrum using three different fixations was performed.

OBJECTIVE

To compare the long-term clinical results and complications associated with three methods of lumbosacral fixation for adult spine deformities: Luque-Galveston, combined iliac and sacral screws, and sacral screws.

SUMMARY OF BACKGROUND DATA

The preferred technique for long fusion to the sacrum is controversial, and surgery for adult deformity is fraught with significant technical difficulties and high complication rates. No clinical study compares the long-term outcome of long fusion to the sacrum using these different methods of lumbosacral fixation.

METHODS

This study included 54 consecutive patients who underwent elective combined anterior and posterior surgical reconstruction for adult spine deformity with a minimum follow-up period of 2 years. The patients were divided into three groups on the basis of the surgical method used for the posterior spine instrumentation. Group 1 consisted of 11 patients with smooth L-rod and segmental sublaminar wire instrumentation (Luque-Galveston technique). Group 2 consisted of 36 patients with posterior Isola segmental instrumentation and combined iliac and sacral screws. Group 3 consisted of 12 patients with Isola segmental instrumentation using bicortical sacral screws. Five patients were revised to another fixation group, giving a total of 59 cases. Radiographic, clinical results, and long-term outcome data were obtained using the modified Scoliosis Research Society (SRS) outcome instrument.

RESULTS

There were 26 late complications. Pseudarthrosis developed in 10 patients, requiring revision surgery: 4 (36%) in the Group 1, 5 (14%) in Group 2, and 1 (8.5%) in Group 3. Comparison of the modified SRS outcomes showed no difference among the groups. The average SRS grand total score was 73.4% for Group 1, 70.9% for Group 2, and 62.6% for Group 3. Overall, 76% of the patients were satisfied with their outcome. The presence of perioperative complications or pseudarthrosis significantly correlated with a lower satisfaction score (P = 0.012 and P = 0.048, respectively). Sagittal plane decompensation significantly correlated with a higher pain score (P = 0.035). Patients with prior surgeries scored lower on the self-image questions than patients with no prior surgery (P = 0.007).

CONCLUSIONS

Attention to sagittal balance is critical in these patients. Revision surgery is as safe and effective as primary surgery. According to the current findings, the Luque-Galveston fixation technique has an unacceptably high rate of pseudarthrosis, and this method is not recommended for adult deformities. Currently, the authors are using bicortical and triangulated sacral screws with an anterior interbody support in patients with good bone stock, but only when the spine balance is restored. Otherwise, they recommend using iliac fixation, although there is a higher rate of painful hardware, requiring removal.

Primary posterior fusion C1/2 in odontoid fractures: indications, technique, and results of transarticular screw fixation

Odontoid fractures, especially unstable type II fractures have a poor prognosis in respect to healing. Therefore, operative stabilization (posterior fusion C1/2 or anterior screw fixation) has been suggested for the treatment of unstable type II and for some unstable type III fractures. Compared to posterior fusion C1/2, anterior screw fixation has proven to be effective; it has the advantage of leaving the motion segment C1/2 intact, therefore preserving at least some C1/2 rotation. However, in some instances, this method of stabilization is not indicated. In these cases, posterior fusion C1/2 is the treatment of choice. Primary posterior fusion C1/2 is indicated in (a) odontoid fracture associated with comminution of one or both atlanto-axial joints; (b) fracture of the odontoid associated with an unstable Jefferson fracture; (c) unstable type III odontoid fracture, when immobilization in a halo jacket or plaster cast is not suitable, as in elderly people or polytraumatized patients; (d) atypical type II fractures (comminuted or with oblique fracture in the frontal plane); (e) irreducible fracture dislocation C1/2, e.g., several-weeks-old fracture; (f) unstable type II or shallow and unstable type III odontoid fracture, when marked thoracic kyphosis is associated with limited extension of the cervical spine; (g) unstable type II or shallow type III odontoid fracture in elderly people with degenerative narrow spinal canal; (h) pathologic fracture of the odontoid. In all these instances, posterior fusion C1/2 is the treatment of choice. We prefer the transarticular screw fixation technique. Compared to other posterior fusion techniques, it has the advantage of increased stability and allows effective stabilization of C1/2 in a reduced position as well as immediate ambulation with minimal head support. This technique can also be performed when the posterior arch of the atlas is fractured or absent. Our experience of 12 acute odontoid fractures, managed by this technique, is presented. At follow-up, all C1/2 fusions were united in reduced position.