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Background Lumbar disc herniation (LDH) is a common problem. When surgical treatment is required, the intervention is typically decompression without fusion. Successful return-to-work (RTW) is a standard expectation with these limited procedures. Occasionally, the size or location of the disc herniation suggests the need for fusion, but the inability to RTW is a significant concern in these cases. The purpose of this study is to determine if the addition of lumbar fusion, as compared to decompression alone, will substantially diminish RTW in patients with lumbar disc herniation. Methods This is a longitudinal cohort study using prospectively collected data from the Quality and Outcomes Database (QOD). Patients with LDH, eligible to RTW (not retired, a student, or on disability) with complete 12-month follow-up data, were identified. Standard demographic and surgical variables, patient-reported outcomes (PROs), and RTW status at 3 and 12 months were collected. Results Of the 5062 patients identified, 4560 (90%) had decompression alone and 502 (10%) had a concurrent fusion. Age and gender were similar in the two groups. The fusion group had worse back pain (NRS 6.52 vs. 5.96) and less leg pain (6.31 vs. 7.01) at baseline compared to the no fusion group. Statistically significant improvement in all PROs was seen in both groups. RTW at 3 months post-op was seen in 85% of decompression cases and 66% of cases with supplemental fusion. At 12 months post-op, RTW increased to 93% and 82%, respectively. Conclusion The need for fusion in LDH cases is unusual, seen in only 10% of cases in this series. The addition of fusion decreased the RTW rate from 85 to 66% at 3 months and from 93 to 82% at 12 months post-op. While the difference is significant, the ultimate deterioration in RTW may be less than anticipated. A reasonable RTW rate can still be expected in the rare patient who requires fusion as part of their treatment for LDH.

Background In 2011, studies suggested that complications and cancer rates associated with bone morphogenetic protein (BMP) were greater than previously reported. However, later studies reported complication rates similar to prior literature and no increased cancer rate. We evaluated the pattern of clinical utilization of BMP in posteriorly based lumbar fusion by comparing two periods: 2002-2004 and 2017-2019. Methods Patients who received BMP from 2002-2004 (Early) and 2017-2019 (Late) from a single multi-surgeon institution who had a lumbar fusion were identified. One hundred patients from each cohort were randomly selected. Mean total BMP used at each level and the proportion of BMP placed in the interbody space versus posterolateral gutters were evaluated. Results In the transforaminal lumbar intebody fusion (TLIF) cohort, the total BMP dose in the Late group (6.15 mg) was nearly half of that used in the Early group (12.04 mg, p

BACKGROUND CONTEXT Previous studies suggest that a postoperative symptom state with Oswestry Disability Index (ODI)≤20 and pain Numeric Rating Scales (NRS)≤2 following surgery for lumbar degenerative conditions are reasonable thresholds for best outcomes in which patients will be unlikely to seek additional medical care or require additional health-care resources. PURPOSE To identify prognostic factors that predict a “best outcome,” defined as postoperative ODI≤20 and pain NRS≤2 following fusion for lumbar degenerative conditions. STUDY DESIGN Longitudinal observational cohort. PATIENT SAMPLE A total of 396 patients from a single site enrolled in the Quality Outcomes Database who underwent fusion for lumbar degenerative conditions. Outcome Measures Oswestry Disability Index, Back and Leg Pain NRS (0–10). METHODS Collected and analyzed variables included age, sex, body mass index, American Society of Anesthesia grade, number of surgical levels, surgical time, preoperative ODI, preoperative back pain, preoperative leg pain, workmen compensation status, surgical approach, smoking status, and principal diagnosis. RESULTS A total of 74 patients (19%) reported a minimal symptom state at 1-year postoperative (ODI≤20, back pain NRS≤2, and leg pain NRS≤2) and were included in the best outcomes group. Patients in the best outcomes group were older (62 vs. 57 years, p=.001), had lower preoperative ODI (43 vs. 56, p=.000), lower preoperative back pain (6.5 vs. 7.5, p=.000). They had fewer surgical levels (1.25 vs. 1.47, p=.005) and shorter operative times [OR] times (208 vs. 241 minutes, p=.002). They were more likely to have a preoperative diagnosis of spondylolisthesis or disc herniation and less likely to have a diagnosis of adjacent segment disease or mechanical disc collapse (p=.001). Stepwise forward regression analysis revealed diagnosis (p=.023, OR=0.75), age (p=.000, OR=1.04), baseline ODI (p=.000, OR=0.96), and number of levels (p=.019, OR=0.53) as predictive variables. CONCLUSION Achieving a minimal symptom state, defined here as a postoperative ODI≤20 and pain NRS≤2, following fusion for lumbar degenerative conditions is more likely in an older patient with a lower baseline ODI undergoing a single level lumbar fusion for spondylolisthesis.

OBJECTIVEThe goal of this study was to determine efficacy and cost-effectiveness of Cell Saver in 2- and 3-level lumbar decompression and fusion.METHODSPatients seen at a tertiary care spine center who were undergoing a posterior 2- or 3-level lumbar decompression and fusion were randomized to have Cell Saver used during their surgery (CS group, n = 48) or not used (No Cell Saver [NCS] group, n = 47). Data regarding preoperative and postoperative hemoglobin and hematocrit, estimated blood loss, volume of Cell Saver blood reinfused, number of units and volume of allogeneic blood transfused intraoperatively and postoperatively, complications, and costs were collected. Costs associated with Cell Saver use were calculated based on units of allogeneic blood transfusions averted.RESULTSDemographics and surgical parameters were similar in both groups. The mean estimated blood loss was similar in both groups: 612 ml in the CS group and 742 ml in the NCS group. There were 53 U of allogeneic blood transfused in 29 patients in the NCS group at a total blood product cost of $67,688; and 38 U of allogeneic blood transfused in 16 patients in the CS group at a total blood cost of $113,162, resulting in a cost of $3031 per allogeneic blood transfusion averted using Cell Saver.CONCLUSIONSCell Saver use produced lower rates of allogeneic transfusion but was found to be more expensive than using only allogeneic blood for 2- and 3-level lumbar degenerative fusions. This increased cost may be reasonable to patients who perceive that the risks associated with allogeneic transfusions are unacceptable.■ CLASSIFICATION OF EVIDENCE Type of question: therapeutic; study design: randomized controlled trial; evidence: class III.

Background Context Transforaminal lumbar interbody fusion (TLIF) and dual-approach anteroposterior (AP) are common techniques to achieve circumferential fusion for lumbar spondylolisthesis. It is unclear which approach is more cost-effective. Purpose Our goal was to determine the incremental cost-effectiveness ratio (ICER) by calculating the cost per quality-adjusted life year (QALY) for each approach. Study Design/Setting This study is a propensity-matched cost-effectiveness comparison. Patient Sample Patients with lumbar spondylolisthesis undergoing single-level AP fusion or TLIF and enrolled in a prospective observational surgical database were included in this study. Outcome Measures The outcome measures in this study were the Oswestry Disability Index (ODI) and the Short Form-6D (SF-6D). Methods From a prospective surgical database, patients with lumbar spondylolisthesis undergoing single-level AP fusion were propensity matched to a TLIF cohort based on age, gender, body mass index, smoking status, workers compensation, preoperative ODI, and back and leg pain numeric scores. Quality-adjusted life years gained were determined using baseline and 1- and 2-yearpostoperative SF-6D scores. Cost was calculated from actual, direct hospital costs and included subsequent postsurgical costs (epidural spinal injections, spine-related emergency department visits, readmissions, and revision surgery). Results Thirty-one cases of AP fusions were identified and propensity matched to 31 TLIF patients. Patients undergoing TLIF had a shorter mean operative time (270 vs. 328 minutes, p=.039) but no difference in estimated blood loss (526 vs. 548 cc, p=.804) or hospital length of stay (4.5 vs. 6.1 days, p=.146). Quality-adjusted life years gained at 2 years were also similar (0.140 vs. 0.130, p=.672). The mean index surgery and the total 2-year costs were lower for TLIF compared with AP (index: $29,428 vs. $31,466; final: $30,684 vs. $331,880). As overall costs were lower and QALYs gained were similar for TLIF compared with AP fusion, TLIF was the dominant intervention with an ICER of $116,327. Conclusions Under our study parameters, surgical treatment of lumbar spondylolisthesis with TLIF is more cost-effective compared with AP fusion. Because of the short-term follow-up, the longevity of this should be further investigated.

STUDY DESIGN: Case-matched retrospective. OBJECTIVES: The purpose of this study is to compare 2-year health-related quality of life (HRQOL) outcomes of patients who underwent 1-level or 2-level posterolateral spine fusion (PSF) versus transforaminal interbody fusion (TLIF) for degenerative spondylolisthesis, disk pathology, and postdecompression instability. SUMMARY OF BACKGROUND DATA: The optimal surgical technique for patients with spondylolisthesis or other degenerative conditions has not been defined. Historically, PSF was the most common procedure, whereas in recent years TLIF has gained popularity. Although theoretical advantages for TLIF have been outlined, evidence for improved outcomes with the addition of interbody support is limited. METHODS: Patients with degenerative spondylolisthesis, with disk pathology and or postdecompression instability who underwent 1-level or 2-level TLIF and completed 2 years postoperative HRQOL measures were identified from a prospective database. These patients were then propensity-matched to a cohort of PSF patients based on age, number of surgical levels, body mass index, sex, smoking status, workers' compensation status, and preoperative outcome measures including the Oswestry Disability Index, SF-36 Physical Component Summary score, SF-36 Mental Composite Summary score, and back and leg pain scores. This produced 63 matched pairs with degenerative spondylolisthesis, 46 with disk pathology and 32 with postdecompression instability. RESULTS: All patients in both groups for each cohort reported statistically significant improvement in HRQOL scores at 2 years postoperatively compared with baseline. Improvements in the Oswestry Disability Index, SF-36 Physical Component Summary score, and back and leg pain scores within the spondylolisthesis and disk pathology subgroups were similar between patients who had a TLIF compared with those who had a PSF. The postdecompression instability subgroup was the only subgroup in which TLIF outperformed PSF for every outcome measure. CONCLUSIONS: Clinical outcome was not significantly altered with TLIF as compared with PSF in patients with spondylolisthesis or disk pathology. However, TLIF resulted in better outcomes at 2 years postoperatively in patients with postdecompression instability.

Study design: Retrospective review. Objective: To identify risk factors for cell saver transfusion in lumbar spinal surgery and determine if cell saver transfusions affected intraoperative or postoperative transfusion rates. Summary of background data: Cell saver has been used to minimize allogeneic blood transfusion in lumbar spinal surgery. Conflicting reports exist, which call into question the efficacy of cell saver use. Methods: We reviewed medical records of randomly selected patients who underwent posterolateral fusion with or without transforaminal interbody fusion from July 2010 to June 2011. Transfusion rates and transfusion-related complications were determined. Binary logistic regression was performed to identify risk factors for use of autologous cell saver transfusion. Results: There were 178 females and 107 males, with a mean age of 57.2 years. Of the 285 cases, 39 had no cell saver available, 147 had cell saver available but no autologous blood was recovered or transfused and 99 had an autologous cell saver transfusion. Patients who had cell saver transfusion had a higher rate of intraoperative allogeneic blood transfusion (52%) compared with those who did not (22%). There was no significant difference in the rate of postoperative transfusions or transfusion-related reactions between patients who did and did not have cell saver transfusion. Patient's age, smoking status, American Society of Anesthesiologists grade, use of anticoagulants preoperatively, primary or revision surgery, iliac crest bone graft harvest, anesthesiologist, or surgeon had no significant effect on cell saver infusion. Body mass index (odds ratio [OR] = 1.06), number of posterolateral fusion levels fused (OR = 2.50), and number of transforaminal interbody fusions performed (OR = 2.41) were independent risk factors for the use of autologous cell saver transfusion. Conclusion: Body mass index, multi-level fusion and transforaminal interbody fusion result in increased use of autologous cell saver transfusion in lumbar spinal surgery. Use of autologous cell saver transfusion did not reduce the requirement for intraoperative or postoperative allogeneic blood transfusion. Level of evidence: 2.

Object Previous studies have reported on the minimum clinically important difference (MCID), a threshold of improvement that is clinically relevant for lumbar degenerative disorders. Recent studies have shown that pre- and postoperative health-related quality of life (HRQOL) measures vary among patients with different diagnostic etiologies. There is also concern that a patient's previous care experience may affect his or her perception of clinical improvement. This study determined if MCID values for the Oswestry Disability Index (ODI), 36-Item Short-Form Health Survey (SF-36), and back and leg pain are different between patients undergoing primary or revision lumbar fusion. Methods Prospectively collected preoperative and 1-year postoperative patient-reported HRQOLs, including the ODI, SF-36 physical component summary (PCS), and numeric rating scales (0–10) for back and leg pain, in patients undergoing lumbar spine fusion were analyzed. Patients were grouped into either the primary surgery or revision group. As the most widely accepted MCID values were calculated from the minimum detectable change, this method was used to determine the MCID. Results A total of 722 patients underwent primary procedures and 333 patients underwent revisions. There was no statistically significant difference in demographics between the groups. Each group had a statistically significant improvement at 1 year postoperatively compared with baseline. The minimum detectable change–derived MCID values for the primary group were 1.16 for back pain, 1.36 for leg pain, 12.40 for ODI, and 5.21 for SF-36 PCS. The MCID values for the revision group were 1.21 for back pain, 1.28 for leg pain, 11.79 for ODI, and 4.90 for SF-36 PCS. These values are very similar to those previously reported in the literature. Conclusions The MCID values were similar for the revision and primary lumbar fusion groups, even when subgroup analysis was done for different diagnostic etiologies, simplifying interpretation of clinical improvement. The results of this study further validate the use of patient-reported HRQOLs to measure clinical effectiveness, as a patient's previous experience with care does not seem to substantially alter an individual's perception of clinical improvement.

In this study, we compare intermediate-term outcomes in minimally invasive surgical transforaminal lumbar interbody fusion (MIS TLIF) to open TLIF. Sixty-four patients who underwent 1- to 2-level MIS TLIF with baseline, 1-, and 2-year outcome measures were identified. These were propensity-matched to a cohort of open TLIF patients based on age, body mass index, sex, smoking status, workers' compensation status, and preoperative outcome measures. At 1 year, both groups had similar improvements in pain and Short-Form 36 (SF-36) Physical Composite Summary (PCS), but the MIS TLIF group had a statistically significantly greater improvement in Oswestry Disability Index (ODI) compared with the open TLIF group. At 2 years, the MIS TLIF group had a statistically significantly greater improvement in pain and ODI compared with the open TLIF group, but no statistically significant difference in SF-36 PCS. Both MIS TLIF and open TLIF lead to significant improvements in clinical outcomes. At 1 year after surgery, MIS TLIF patients had greater improvements in ODI, and at 2 years after surgery, they had greater improvements in pain and ODI. This study showed that the perioperative advantages of MIS TLIF, such as less muscle dissection and faster recovery, continue to be beneficial 1 to 2 years after surgery.

Study design Randomized clinical trial. Objective To perform a cost-utility analysis using actual cost data from a randomized clinical trial of patients over 60 years old who underwent posterolateral fusion using either rhBMP-2/ACS or iliac crest bone graft (ICBG). Summary background data Bone morphogenetic protein has been shown to be an effective bone graft substitute for spine fusion. However, a clinical trial-based economic analysis of rhBMP-2/ACS compared with iliac crest bone graft has not been done. Methods Patients over 60 years old requiring decompression and posterolateral fusion were randomized to rhBMP-2/ACS (n = 50) or ICBG (n = 52). A dedicated hospital coder and research nurse tracked each patient to determine direct costs of inpatient care and all postoperative healthcare encounters up to 2 years after surgery. Preoperative and 2-year-postoperative SF-6D utility scores for each patient were determined. A decision tree was created, which included the probability of complications, need for additional treatments and revision surgery; and the costs associated with initial surgery and treatment for complications and additional treatment for continued spine symptoms; and utility scores. Results The mean total 2-year cost for care (excluding complication and additional spine treatment costs) was $34,235 in the ICBG group and $36,530 in the rhBMP-2/ACS group. For the entire group, the mean cost to treat a major complication was $10,888, the cost of revision surgery for nonunion was $46,852, and additional treatment for spine-related events was $5892. In the ICBG group, 8 patients had complications; 20 had additional interventions, 5 of whom required revision for nonunion. In the rhBMP-2/ACS group, 6 patients had complications, 10 had additional interventions, and 1 required revision for nonunion. The cost of using rhBMP-2/ACS was $39,967 with a 0.11 mean improvement in SF-6D; and for ICBG the cost was $42,286 with a mean improvement of 0.10 in SF-6D. Conclusion There are more complications, increased need for additional treatment and revision surgery in patients over 60 years old receiving ICBG compared with rhBMP-2/ACS. This may account for higher costs and lower improvements in utility seen in patients receiving ICBG compared with rhBMP-2/ACS in this study population.

Background One of the primary difficulties in evaluating the effectiveness of lumbar fusion is that, with the exception of spondylolisthesis, specific diagnostic indications for surgery are poorly defined. Diagnostic specificity beyond the symptom of low back pain or the presence of lumbar degeneration needs to be delineated such that outcomes data can be effectively translated into clinical decision making or evidence-based guidelines. Purpose The purpose of this study was to report on prospectively collected clinical outcome measures, stratified by diagnosis, among a series of patients with lumbar degenerative disease whose treatment included lumbar spine fusion. Study design Demographics, diagnostic categorization, and clinical outcome measures were prospectively collected by six spine surgeons at a single tertiary spine center, as part of the surgeons' standard clinical practice. Patient sample Four hundred and twenty-eight patients were enrolled in the study and complete 1- and 2-year Health-Related Quality of Life (HRQOL) data were available in 327 patients whose treatment included decompression and posterolateral lumbar fusion. Outcome measures The Oswestry Disability Index (ODI), Short Form-36 (SF-36), numeric rating scales for back pain and leg pain. Methods Preoperative diagnosis was classified, in the primary surgical cases, as disc pathology, spondylolisthesis, instability, stenosis, or scoliosis. In revision cases, the diagnosis was classified as nonunion, adjacent level degeneration, or postdiscectomy revision. Patient-reported outcomes at 1 and 2 years post-op were assessed based on diagnostic stratification. Statistical evaluation of clinical outcome was performed for both mean net change in outcome scores and the percentage of patients reaching a minimum clinically important difference (MCID) threshold for each outcome measure. Results Preoperative diagnosis was spondylolisthesis (n=80), scoliosis (n=17), disc pathology (n=33), instability (n=21), stenosis (n=46), postdiscectomy revision (n=67), adjacent level degeneration (n=40), or nonunion (n=23). Evaluation of 2-year post-op HRQOL measures by diagnostic subgroup revealed the most substantial improvement in ODI score for patients with spondylolisthesis (22.7 points) and scoliosis (21.2 points). Patients with the diagnosis of disc pathology (16.2 points), postdiscectomy revision (14.0 points), instability (12.7 points), stenosis (10.6 points), and adjacent level degeneration (9.5 points) demonstrated a progressively smaller magnitude of ODI improvement. The least ODI improvement at 2 years after surgery was seen in patients with nonunion of a prior fusion (5.5 points). The percentage of patients reaching MCID for ODI at 2 years post-op ranged from 71.0% in the spondylolisthesis subgroup to 34.8% in the nonunion subgroup. The greatest SF-36 physical component score improvement at 2-year follow-up was seen in patients with disc pathology (7.9 points) and spondylolisthesis (7.7 points), followed by scoliosis (6.6 points) and stenosis (6.5 points), instability (5.6 points), postdiscectomy revision (5.3 points) nonunion (3.1 points) and adjacent level degeneration (2.5 points). No significant changes from Year 1 to Year 2 were noted in any of the subgroups. For SF-36 physical component score, percentage of patients reaching MCID ranged from 63.6% in the disc pathology subgroup to 25% in the nonunion subgroup. Conclusions This study supports the concept that added diagnostic specificity is a critical component in building an improved evidence base for lumbar fusion surgery. The magnitude of HRQOL improvement was not equal among diagnostic subgroups. The percentage of patients reaching an MCID level of improvement was also significantly influenced by diagnostic stratification. Without diagnostic specificity for entities beyond spondylolisthesis, the absence of well-defined study populations will continue to limit our ability to move toward evidence-based decision making.

STUDY DESIGN Retrospective cohort analysis. OBJECTIVE To investigate and compare back and leg pain, and health-related quality of life measures in obese patients undergoing lumbar spine fusion, and to compare the results to nonobese patients. SUMMARY OF BACKGROUND DATA Obesity is a growing healthcare crisis in the United States and an increasing number of patients undergoing spinal surgery are obese. Obesity is also associated with low back pain. Some obese patients with significant structural spine problems may be dismissed as having their pain only coming from their weight. We compared patient outcomes in obese and nonobese patients undergoing lumbar fusion surgery. METHODS We retrospectively reviewed a single-center patient database of patients undergoing lumbar fusion and identified 270 patients with greater than 2-year outcome data. Body mass index (BMI) was calculated and patients were classified as obese (BMI >or= 30) or nonobese (BMI < 30). All patients completed Oswestry Disability Index (ODI), Short Form (SF)-36 questionnaires, and back and leg pain numerical rating scores before surgery and at 2 years. We compared clinical outcomes and complication rates in the 2 groups. RESULTS The overall study group consisted of 109 obese patients and 161 nonobese patients. Both the obese and nonobese patients demonstrated significant improvements in back pain, leg pain, SF-36 physical composite summary (PCS), and ODI scores (P < 0.001) at 2-year follow-up compared with baseline. There was no significant difference in the mean improvements seen in obese patients compared with nonobese patients with respect to back pain, leg pain, or SF-36 PCS or ODI scores. Both SF-36 PCS (P = 0.037) and ODI score (P = 0.028) at 2-year follow-up were better in the nonobese patients compared with the obese patients. Overall complication rates were slightly higher in the obese group (P = 0.045), predominantly because of wound-related complications. CONCLUSION Obese patients undergoing lumbar fusion achieve similar benefits to nonobese patients. Wound-related complications are more common in obese patients. Obese patients with otherwise good indications for lumbar fusion should not be denied this procedure because of their weight.

Background context There is mounting evidence supporting the efficacy of bone morphogenetic protein (BMP) for both anterior interbody and posterolateral lumbar fusion. However, the relative cost of BMP remains an important concern for physicians, hospitals, and payers. Purpose The purpose of this study is to report on the perioperative costs for patients treated with rhBMP-2 as compared with an iliac crest bone graft (ICBG) supplemented with graft extenders. Study design/setting A prospective randomized controlled trial of rhBMP-2/ACS (Infuse Bone Graft; Medtronic Sofamor Danek, Memphis, TN) versus ICBG±graft extender for lumbar spine fusion in patients over 60 years old. Patient sample One hundred two patients over 60 years old who required a posterolateral lumbar spine fusion randomized between receiving rhBMP-2/ACS or ICBG. Outcome measures All health-care costs over the first 3 months after surgery. Methods As part of a prospective randomized trial of rhBMP-2/ACS versus ICBG±graft extender for lumbar spine fusion, all costs over the first 3 months after surgery were directly recorded by a dedicated coder funded by Norton Healthcare, Louisville, KY. A dedicated research nurse also followed all patients throughout their hospital stay and posthospitalization recovery to identify any adverse events or additional outpatient medical care. Results Fifty patients received rhBMP-2/ACS and 52 underwent ICBG harvest. The mean hospital cost for the index admission was $24,736 for the rhBMP-2/ACS group and $21,138 for the ICBG group. Mean inpatient physician costs were $5,082 in the rhBMP-2/ACS group and $5,316 in the ICBG group. Costs associated with posthospital rehabilitation averaged $4,906 in the rhBMP-2/ACS group versus $6,820 in the ICBG group. Total payer expenditure for the 3-month perioperative period averaged $33,860 in the rhBMP-2/ACS group and $37,227 in the ICBG group. Conclusions The hospital carries the cost burden associated with the utilization of rhBMP-2/ACS. In contrast, the payer in a Diagnosis-Related Group (DRG) model achieves a net savings, based primarily on the decreased payment for inpatient rehabilitation, but also on decreased hospital reimbursement, physician costs, and other outpatient services.

Although outcomes after cervical fusion in rheumatoid arthritis (RA) patients are widely published, outcomes of lumbar fusion in RA patients has not been reported. Nineteen patients with RA, identified using ICD-9 and CPT codes, who underwent instrumented posterolateral lumbar fusion were matched for age, gender, smoking status, date, and level of surgery to a contemporaneous non-RA group. Medical records and radiographs were reviewed by the primary author who had no role in the treatment of these patients. The average age was 64 years in the RA group and 65 years in the non-RA group. The male to female ratio was 2:17 and 1:18, respectively. There were three smokers and two diabetics in each group. An average of 1.5 levels was fused in each group. Average follow-up was 24 and 27 months, respectively. In the RA group, 15 patients were taking DMARDs with 7 of those also taking oral steroids; 4 patients were taking NSAIDs only. There were seven complications (37%) in the RA group versus four (21%) in the non-RA group; wound infections in three patients (16%) in the RA group versus one (5%) in the non-RA group; and non-union in two patients (11%) in the RA group versus three (16%) in the non-RA group. Clinical outcomes were similar between the two groups with 74% of patients achieving good to excellent results in the RA group compared to 63% in the non-RA group (p = 0.692). Surgeons and their RA patients who undergo an instrumented lumbar fusion can expect a slightly higher complication rate than patients without RA which may be related to osteopenia and immunosuppression.

Background Context Obesity is a growing problem in health care. Studies have demonstrated similar functional outcomes but higher complication rates after spine surgery in obese patients. Purpose This study aimed to compare patient-reported outcomes and revision rates 5 years after instrumented posterior lumbar fusion between normal, overweight, and obese patients. Study design Propensity matched case control. Patient sample Patients who had posterior instrumented lumbar spinal fusion from 2001 to 2008 from a single spine specialty center with complete preoperative and 5-year postoperative outcome measures were identified. Outcome measures Oswestry Disability Index (ODI), Back Pain (0–10) and Leg Pain (0–10) Numeric Rating Scales, and Short Form-36 Physical Composite Summary Scores (SF-36 PCS). Methods Three comparison groups, one with body mass index (BMI) ≥20–25 kg/m 2 (normal), another with ≥25– 2 (overweight), and another with ≥30–40 kg/m 2 (obese) were created using propensity matching techniques based on demographics, baseline clinical outcome measures, and surgical characteristics. Five-year postoperative outcome measures and revision rates in the three groups were compared. One-way analysis of variance was used to compare continuous variables, and Fisher exact test was used to compare categorical variables between the groups. Significance was set at p Results There were 82 cases matched in each cohort. Estimated blood loss (440 cc vs. 702 cc vs. 798 cc, p=.000) and operative time (234 minutes vs. 263 minutes vs. 275 minutes, p=.003) were significantly greater in the overweight and obese patients. Improvements in ODI (14.2 vs. 9.6 vs. 10.4, p=.226), SF-36 PCS (5.9 vs. 2.9 vs. 3.5, p=.361), back pain (3.0 vs. 2.0 vs. 2.1, p=.028), and leg pain (3.0 vs. 2.3 vs. 2.3, p=.311) scores were similar among the groups. Revision rates (14 vs. 15 vs. 13, p=.917), and time between index and revision surgery (p=.990) were similar among the three groups as well. Conclusion When considering a subset of patient-reported outcomes and revision surgery after 5 years, patients with an elevated BMI >25 at baseline did not appear to have worse outcomes than those with a normal BMI of 20–25 when undergoing posterior lumbar fusion surgery. Obesity should not be considered a contraindication to surgery in patients with appropriate surgical indications.

This is a prospective study of 26 patients undergoing posterior cervical spine instrumentation with lateral mass or pedicle screws to determine the correlation between intraoperative screw stimulation thresholds and the position of posterior cervical lateral mass and pedicle screws.One hundred forty-seven posterior cervical screws (122 lateral mass screws and 25 C7 pedicle screws) in 26 patients were electrically stimulated intraoperatively and stimulation thresholds recorded. Computed tomography (CT) scans were taken postoperatively and were evaluated independently to assess screw position. Electromyographic (EMG) thresholds and CT data were compared to assess the accuracy of the EMG screw stimulation technique in detecting screw malposition.Intraoperative electrical stimulation was accurate in verifying screw position. A stimulation threshold of 15 mA provided a 99% positive predictive value (89% sensitivity, 87% specificity) that the screw was within the lateral mass or pedicle. Stimulation values of 10-15 mA provided a 13% predictive value (66% sensitivity, 90% specificity) that the screw was within the lateral mass or pedicle. A stimulation value of10 mA provided a 100% predictive value that the screw was malpositioned (70% sensitivity, 100% specificity).Intraoperative evoked EMG monitoring is a valuable tool in posterior cervical instrumentation using lateral mass and pedicle screws. Stimulation thresholds in this study correlated with screw position. Stimulation values of15 mA reliably predict acceptable screw position. Values between 10 and 15 mA are generally associated with acceptable screw position, although exploration is recommended. Values below 10 mA are associated with screw malposition and warrant exploration, repositioning, and possible removal.

STUDY DESIGN This report describes a case of vertebral body osteonecrosis associated with the use of intradiscal electrothermal therapy. OBJECTIVES To alert clinicians to a previously unreported complication, vertebral body osteonecrosis, after an intradiscal electrothermal therapy procedure. SUMMARY OF BACKGROUND DATA The intradiscal electrothermal therapy procedure is a new treatment that has been advocated in the management of chronic low back pain of discogenic origin. The intradiscal electrothermal therapy procedure uses a fluoroscopically guided thermal catheter to heat the intervertebral disc. A review of the literature regarding this procedure has not revealed osteonecrosis as a complication. METHODS The patient's work-up and postoperative course are documented, and all medical records were reviewed retrospectively. RESULTS The patient's pain had improved only minimally at initial follow-up after L5-S1 combined anterior and posterior spinal fusion, undertaken after intradiscal electrothermal therapy failure. CONCLUSIONS Intradiscal electrothermal therapy has gained increasing popularity in the treatment of discogenic low back pain, in large part because of its minimally invasive nature and perceived low risk for major complications. Previous reports in the literature have not noted any major complications associated with the proper use of this device. Clinicians should be advised that intradiscal electrothermal therapy can be associated with complications, which in the current case, led to osteonecrosis of the vertebral body.

Previous studies have reported on the minimum clinically important difference (MCID), a threshold of improvement that is clinically relevant for lumbar degenerative disorders. Recent studies have shown that pre- and postoperative health-related quality of life (HRQOL) measures vary among patients with different diagnostic etiologies. There is also concern that a patient's previous care experience may affect his or her perception of clinical improvement. This study determined if MCID values for the Oswestry Disability Index (ODI), 36-Item Short-Form Health Survey (SF-36), and back and leg pain are different between patients undergoing primary or revision lumbar fusion.Prospectively collected preoperative and 1-year postoperative patient-reported HRQOLs, including the ODI, SF-36 physical component summary (PCS), and numeric rating scales (0-10) for back and leg pain, in patients undergoing lumbar spine fusion were analyzed. Patients were grouped into either the primary surgery or revision group. As the most widely accepted MCID values were calculated from the minimum detectable change, this method was used to determine the MCID.A total of 722 patients underwent primary procedures and 333 patients underwent revisions. There was no statistically significant difference in demographics between the groups. Each group had a statistically significant improvement at 1 year postoperatively compared with baseline. The minimum detectable change-derived MCID values for the primary group were 1.16 for back pain, 1.36 for leg pain, 12.40 for ODI, and 5.21 for SF-36 PCS. The MCID values for the revision group were 1.21 for back pain, 1.28 for leg pain, 11.79 for ODI, and 4.90 for SF-36 PCS. These values are very similar to those previously reported in the literature.The MCID values were similar for the revision and primary lumbar fusion groups, even when subgroup analysis was done for different diagnostic etiologies, simplifying interpretation of clinical improvement. The results of this study further validate the use of patient-reported HRQOLs to measure clinical effectiveness, as a patient's previous experience with care does not seem to substantially alter an individual's perception of clinical improvement.

Study design Retrospective review. Objective To determine the incremental cost-effectiveness of cell saver for single-level posterior lumbar decompression and fusion (PLDF). Summary of background data Intraoperative cell salvage is used during surgery to reduce the need for perioperative allogeneic blood transfusion. Although the use of cell saver may be beneficial in certain circumstances, its utility has not been clearly established for the common procedure of an adult single-level PLDF. Methods Randomly selected adult patients treated with a single-level PLDF between July 2010 and June 2011 at a single institution were identified. Patients who had a combined anterior and posterior approach were excluded. The final study sample for analysis consisted of 180 patients. Hospital records were reviewed to determine whether: (1) cell saver was available during surgery, (2) recovered autologous blood was infused, and (3) the patient received intra- or postoperative allogeneic transfusions. Estimated blood loss, levels fused, volume(s) transfused, and all related complications were recorded. Costs included the cost of allogeneic blood transfusion, setting up the cell saver recovery system, and infusing autologous blood from cell saver, whereas effectiveness measures were allogeneic blood transfusions averted and quality adjusted life years. Results The incremental cost-effectiveness ratio was $55,538 per allogeneic transfusion averted, with a decrease in the transfusion rate from 40.0% to 38.7% associated with the cell saver approach. This translated into an incremental cost-effectiveness ratio of $5,555,380 per quality adjusted life years gained, which is well above the threshold for an intervention to be considered cost-effective ($100,000 per quality adjusted life years gained). Conclusion The use of cell saver during a single-level PLDF does not significantly reduce the need for allogeneic blood transfusion and is not cost-effective. The high cost of cell saver in combination with the low complication rate of allogeneic blood transfusion, suggest that cell saver should not be used for single-level PLDF. Further studies are needed to evaluate the necessity for cell saver among other types of spinal surgery.

Clinical studies use both disease-specific and generic health outcomes measures. Disease-specific measures focus on health domains most relevant to the clinical population, while generic measures assess overall health-related quality of life. There is little information about which domains of the Oswestry Disability Index (ODI) are most important in determining improvement in overall health-related quality of life, as measured by the 36-Item Short Form Health Survey (SF-36), after lumbar spinal fusion. The objective of the study is to determine which clinical elements assessed by the ODI most influence improvement of overall health-related quality of life.A single tertiary spine center database was used to identify patients undergoing lumbar fusion for standard degenerative indications. Patients with complete preoperative and 2-year outcomes measures were included. Pearson correlation was used to assess the relationship between improvement in each item of the ODI with improvement in the SF-36 physical component summary (PCS) score, as well as achievement of the SF-36 PCS minimum clinically important difference (MCID). Multivariate regression modeling was used to examine which items of the ODI best predicted achievement for the SF-36 PCS MCID. The effect size and standardized response mean were calculated for each of the items of the ODI.A total of 1104 patients met inclusion criteria (674 female and 430 male patients). The mean age at surgery was 57 years. All items of the ODI showed significant correlations with the change in SF-36 PCS score and achievement of MCID for the SF-36 PCS, but only pain intensity, walking, and social life had r values0.4 reflecting moderate correlation. These 3 variables were also the dimensions that were independent predictors of the SF-36 PCS, and they were the only dimensions that had effect sizes and standardized response means that were moderate to large.Of the health dimensions measured by the ODI, pain intensity, walking, and social life best predicted improvement in overall health-related quality of life, as measured using the SF-36 PCS.

STUDY DESIGN Longitudinal cohort. OBJECTIVE To present Oswestry Disability Index scores and SF-6D utility values among patients with different diagnostic etiologies who underwent fusion surgery. SUMMARY OF BACKGROUND DATA Several studies have increased our understanding of health-related quality-of-life measures in patients with low back pain. With rising health care costs, cost-utility analysis is increasingly used by decision makers. Thus, clinicians and researchers need to understand the psychometrics and clinical importance of health state utility values in patients with spine disorders. METHODS A total of 1104 patients who had decompression and lumbar fusion with complete data to compute the SF-6D score at baseline and 2-year follow-up were identified. Primary surgical cases were classified as disc pathology (n = 200), spondylolisthesis (n = 288), instability (n = 43), stenosis (n = 134), or scoliosis (n = 44). Revision cases were classified as nonunion (n = 94), adjacent-level degeneration (n = 98), or postdiscectomy revision (n = 203). Baseline SF-6D and change in SF-6D scores at 2 years were compared among the groups as well as primary versus revision cases. RESULTS There were 674 women and 430 men. The mean age at surgery was 56.65 ± 12.7 years. There were 220 (19.9%) smokers. The worst mean baseline SF-6D score was in patients with nonunion (0.492), followed by disc pathology (0.493), adjacent-level degeneration (0.494), postdiscectomy revision (0.499), stenosis (0.504), instability (0.512), spondylolisthesis (0.520), and scoliosis (0.530). There was a statistically significant difference in baseline SF-6D score among the different groups (P = 0.002). The mean change in SF-6D score was greatest in patients with stenosis (0.088), followed by spondylolisthesis (0.085), scoliosis (0.076), disc pathology (0.076), instability (0.073), postdiscectomy revision (0.070), adjacent-level degeneration (0.066), and nonunion (0.050). There was no statistically significant difference in change in SF-6D score among the different groups (P = 0.096). However, revision cases had statistically significantly smaller gains in SF-6D score (0.064) than primary cases (0.082, P = 0.012). CONCLUSION Patients with lumbar degenerative disorders have health state values similar to patients with chronic renal disease, Crohn's disease, or coronary artery disease. Health state values of patients with different indications for surgery differ at baseline and after surgery. Revision cases have worse baseline SF-6D scores and less improvement in scores at 2 years after surgery than primary cases. Further studies are needed to gain a greater understanding of health state utility values in patients with lumbar degenerative disorders.

Spinal fusion as a treatment for degenerative disc disease is controversial. Prior authors have identified various MRI findings as being pain generators, which might help guide patient selection for lumbar fusion procedures. These findings have included disc desiccation, disc contour, high-intensity zone annular disruption, the presence of Modic endplate changes, and disc space collapse. The purpose of this study is to investigate which MRI findings in patients with degenerative disc disease predict clinical improvement with lumbar fusion.A single-center surgical database of patients undergoing lumbar fusion was reviewed for patients whose indication for fusion surgery was primary disc pathology. We identified 51 patients (71 disc levels) who had completed 2-year prospectively collected outcomes questionnaires and had preoperative MRIs available for review. NRS (0-10) back and leg pain, Oswestry Disability Index (ODI) and SF-36 Physical Composite Summary scores were obtained preoperatively and at 1- and 2-year follow-up. MRIs were reviewed by three fellowship-trained spine surgeons who were asked to grade them for the following five characteristics: (a) disc desiccation, (b) disc contour, (c) presence of a high-intensity zone (HIZ) annular tear, (d) presence of Modic endplate changes and (e) disc height. Two-year outcome measures were compared to MRI findings to identify which findings correlated with improvement in outcome scores.Statistically significant improvements were noted in back pain, leg pain, SF-36 PCS and ODI in the group overall. Disc desiccation, disc contour, presence of an HIZ lesion, and the presence of Modic endplate changes did not correlate with 2-year outcomes. Disc height was correlated with 2-year change in outcome measures. Discs with preoperative height less than 5 mm demonstrated a 23.4 point ODI improvement compared to 9.2 points for discs7 mm. Similarly, SF-36 PCS improved 9.5 points in discs5 mm compared to 0.7 in discs greater than 7 mm. Discs between 5 and 7 mm demonstrated intermediate levels of improvement.Several commonly utilized MRI criteria proposed as indications for lumbar fusion do not seem to correlate with 2-year improvement in clinical outcomes. Discs which are narrowed and collapsed, preoperatively, demonstrate better improvement at 2 years postoperatively as compared to discs which have maintained disc height. Significant disc space collapse may represent a subset of "degenerative disc disease" which responds more favorably to treatment with fusion.

Clinicians use descriptive classification systems when treating patients with low back pain as an adjunct to surgical decision making. Magnetic resonance imaging (MRI) changes, including Modic changes, the presence of a high-intensity zone, and internal disk desiccation, are commonly used descriptors. The question remains whether different clinicians interpret these terms similarly. This study evaluated the inter- and intraobserver reliability of commonly used MRI classifications in patients presenting with low back pain. Sixty-six patients who underwent lumbar spine fusion surgery at a single multiphysician spine specialty practice for degenerative disk disease were identified. For each surgical level, the following MRI variables were determined independently by 3 fellowship-trained spine surgeons: presence or absence of high-intensity zone and/or internal disk desiccation, presence and classification of disk herniation, Modic grade, and disk height. Each surgeon reviewed the same set of MRI studies a second time at least 2 weeks from the first reading. Inter- and intraobserver reliability was determined using multiobserver Kappa coefficients. Intraobserver reliability ranged from 0.563 to 0.988, with greatest agreement in determining disk height. The greatest interobserver agreement was for determining Modic changes (0.819). Controversy remains on the criteria for diagnosing degenerative disk disease. In patients presenting with low back pain diagnosed with degenerative disk disease, the inter- and intraobserver reliability with use of several common MRI diagnostic tools was substantial. These data imply that clinicians interpret these findings in a reproducible fashion and interpret these terms similarly.

Study Design. Prospective cohort. Objectives. The purpose of this study is to examine the relationship between radiographic fusion and patient-reported health-related quality of life (HRQOL) measures in patients undergoing instrumented posterolateral lumbar fusion. Summary of Background Data. Previous studies have shown that a solid fusion does not always produce clinical success. However, these studies did not use validated patient-reported HRQOL measures. Methods. One hundred ninety-three patients who underwent instrumented posterolateral fusion with complete preoperative and 2-year HRQOL measures and a fine-cut computed tomographic (CT) scan with reconstructions done at 2 years after surgery specifically done to assess fusion status were identified. HRQOL measures included the Oswestry Disability Index (ODI), the Short Form-36 and back and leg pain numerical rating scales. The percentage of patients reaching the minimum clinically important difference and substantial clinical benefit for ODI and Short Form-36 were also calculated. CT scans were graded as fused or not by three independent reviewers. Comparisons were made in outcomes measures between the patients with solid fusions and those judged not to have a solid radiographic fusion. Results. There were 124 women and 69 men with an average age of 63 years. Patients judged to have a solid fusion demonstrated a better ODI score at 2 years than those who were not solidly fused (P = 0.023). There was a trend toward greater improvement in mean ODI score in those with a solid fusion (P = 0.074). A statistically greater number of patients who had a solid fusion (111 of 171, 65%) achieved the minimum clinically important difference for ODI than those who did not achieve a solid fusion (7 of 22, 32%) (P = 0.004). Conclusion. A greater proportion of patients achieved clinically relevant improvements in low back specific quality-of-life measures when they had achieved a solid fusion than patients who did not have a solid fusion. Although radiographic fusion may not be the true measure of clinical success, this study suggests that solid arthrodesis contributes to clinical outcome and is an important goal of fusion surgery.

Study Design. Cross-sectional cohort. Objective. This study aims to provide an algorithm to estimate Short Form-6D (SF-6D) utilities using data from the Neck Disability Index (NDI), neck pain, and arm pain scores. Summary of Background Data. Although cost-utility analysis is increasingly used to provide information about the relative value of alternative interventions, health state values or utilities are rarely available from clinical trial data. The Neck Disability Index (NDI) and numerical rating scales for neck and arm pain are widely used diseasespecific measures in patients with cervical degenerative disorders. The purpose of this study is to provide an algorithm to allow estimation of SF-6D utilities using data from the NDI, and numerical rating scales for neck and arm pain. Methods. SF-36, NDI, neck and arm pain rating scale scores were prospectively collected before surgery, at 12 and 24 months after surgery in 2080 patients undergoing cervical fusion for degenerative disorders. SF-6D utilities were computed, and Spearman correlation coefficients were calculated for paired observations from multiple time points between NDI, neck and arm pain scores, and SF-6D utility scores. SF-6D scores were estimated from the NDI, neck and arm pain scores were estimated using a linear regression model. Using a separate, independent dataset of 396 patients in which NDI scores were available, SF-6D was estimated for each subject and compared to their actual SF-6D. Results.The mean age for those in the development sample was 50.4 ± 11.0 years and 33% were male. In the validation sample, the mean age was 53.1 ± 9.9 years and 35% were male. Correlations between the SF-6D and the NDI, neck and arm pain scores were statistically significant (P < 0.0001) with correlation coefficients of 0.82, 0.62, and 0.50, respectively. The regression equation using NDI aloneto predict SF-6D had an R 2 of 0.66 and a root mean square error of 0.056. In the validation analysis, there was no statistically significant difference (P = 0.961) between actual mean SF-6D (0.49 ± 0.08) and the estimated mean SF-6D score (0.49 ± 0.08), using the NDI regression model. Conclusion.This regression-based algorithm may be a useful tool to predict SF-6D scores in studies of cervical degenerative disease that have collected NDI but not utility scores.

Study design Retrospective cohort analysis. Objective To investigate health-related quality of life improvements in patients undergoing lumbar fusion to revise a previous lumbar spine surgery. Summary of background data Spinal fusion is often used as a surgical intervention in patients who have previously undergone lumbar surgery. Prior studies suggest results that are inferiorto primary fusions. However, most of these studies are based on subjective surgeon evaluations, lack patient-reported outcomes, and include various diagnoses such as prior discectomy, adjacent level degeneration, and nonunion. Methods From a single-center database, we identified 171 patients who underwent lumbar fusion to revise a previous lumbar spine surgery. All had prospectively collected outcome measures at a minimum 2-year follow-up. The study group included 91 patients who had previous discectomy or laminectomy, 42 patients undergoing revision for adjacent segment degeneration (ASD) and 38 patients undergoing revision for nonunion. All patients completed the Oswestry Disability Index (ODI), MOS Short Form 36 (SF-36), and back and leg pain numerical rating scores before surgery and at 1 and 2 years after surgery. We compared mean changes in outcome measures and percentage of patients reaching the minimum clinically important difference (MCID) threshold in the 3 groups. Logistic regression analysis was performed to identify preoperative factors which could predict significant improvement. Results Statistically significant improvements were noted in back pain, leg pain, and ODI in all 3 groups. Postdecompression and ASD patients demonstrated significant improvements in SF-36 PCS at 2 years, while nonunion patients did not. A total of 49% of postdecompression patients, 38% of ASD patients, and 29% of nonunion patients reached the MCID for ODI. About 46% of postdecompression patients, 40% of ASD patients, and 24% of nonunion patients reached the MCID for SF-36 PCS. Significant improvement from index surgery was the only factor which able to predict reaching the MCID for ODI, while worker's compensation and narcotic use predicted failure to reach the MCID for SF-36 PCS. Conclusion The current study demonstrates that patients undergoing lumbar fusion as a revision of a prior lumbar surgery can expect only modest improvements in health-related quality of life. Postdecompression patients achieved moderate improvements in clinical outcome measures, whereas ASD and nonunion patients showed only modest improvements. Further investigation is needed to identify preoperative predictors that will assist the selection of patients who will benefit from revision lumbar fusion.

Bone morphogenetic protein (BMP) is commonly used as an ICBG substitute for transforaminal lumbar interbody spine fusion (TLIF). However, multiple recent reports have raised concerns regarding a substantial incidence of perioperative radiculopathy. Also, given the serious complications reported with anterior cervical BMP use, risks related to swelling and edema with TLIF need to be clarified. As TLIF related complications with rhBMP-2 have generally been reported in small series or isolated cases, without a clear denominator, actual complication rates are largely unknown. The purpose this study is to characterize perioperative complications and complication rates in a large consecutive series of TLIF procedures with rhBMP-2. We reviewed inpatient and outpatient medical records for a consecutive series of 204 patients [113 females, 91 males, mean age 49.3 (22–79) years] who underwent TLIF using rhBMP-2 between 2003 and 2007. Complications observed within a 3-month perioperative interval were categorized as to etiology and severity. Wound problems were delineated as wound infection, hematoma/seroma or persistent drainage/superficial dehiscence. Neurologic deficits and radiculopathies were analyzed to determine the presence of a clear etiology (screw misplacement) and identify any potential relationship to rhBMP-2 usage. Complications were observed in 47 of 204 patients (21.6%) during the 3-month perioperative period. Major complications occurred in 13 patients (6.4%) and minor complications in 34 patients (16.7%). New or more severe postoperative neurologic complaints were noted in 13 patients (6.4%), 6 of whom required additional surgery. These cases included one malpositioned pedicle screw and one epidural hematoma. In four patients (2.0%), localized seroma/hematoma in the area of the foramen caused neural compression, and required revision. In one additional patient, vertebral osteolysis caused foraminal narrowing and radiculopathy, but resolved without further surgery. Persistent radiculopathy without clear etiology on imaging studies was seen in six patients. Wound related problems were seen in six patients (2.9%), distributed as wound infection (3), hematoma/seroma (1) and persistent drainage/dehiscence (2). Overall, this study demonstrates a modest complication rate for TLIF using rhBMP-2. While perioperative complications which appeared specific to BMP usage were noted, they occurred infrequently. It will be necessary to weigh this incidence of complications against the complication rate associated with ICBG harvest and any differential benefit in obtaining a solid arthrodesis.

Study Design. Case-control propensity matched. Objective. To compare clinical outcomes after lumbar fusion in patients receiving workers' compensation with a case-matched control group who are not on workers' compensation. Summary of Background Data. Previous studies have demonstrated poor outcomes in patients receiving workers' compensation after lumbar fusion. However, a case-control study where patients are matched for covariates known to affect outcomes after lumbar fusion, including baseline clinical outcome measures, has not been done. Methods. From 783 patients who underwent posterolateral fusion with complete preoperative and 2-year postoperative outcome measures, 60 patients who were receiving workers' compensation were identified. Outcome measures included the Oswestry Disability Index (ODI), Short Form-36 (SF-36), and back and leg pain numerical rating scales. Propensity scoring technique was used to match these patients with a control group not receiving workers' compensation using sex, age, smoking status, body mass index, diagnosis, number of levels fused, preoperative ODI, SF-36 Physical Component Summary (PCS), SF-36 Mental Component Summary, and back and leg pain scores, producing 58 matched pairs. Results. There were no significant differences between the demographics, job classification, and preoperative outcome scores in the two groups. At 2 years after operation, patients not receiving workers' compensation had a significantly greater improvement in ODI (P = 0.009) and SF-36 PCS (P = 0.007) compared with those receiving workers' compensation. Although patients not receiving workers' compensation had greater improvements in back and leg pain compared with those receiving workers' compensation, this did not reach statistical significance (P = 0.079). The mean 2-year ODI, SF-36 PCS, and back pain raw scores of patients receiving workers' compensation were significantly lower than those not receiving workers' compensation. Only 19% of workers' compensation patients achieved minimum clinically important difference in terms of ODI compared with 36% of those not receiving workers' compensation (P= 0.061). Only 16% of workers' compensation patients achieved SF-36 PCS minimum clinically important difference compared with 40% of those not receiving workers' compensation (P = 0.006). Conclusion. After controlling for covariates known to affect outcomes after lumbar fusion, patients on workers' compensation have significantly less improvement of clinical outcomes in both mean change in ODI and SF-36 PCS, as well as the number of patients achieving substantial clinical benefit. The improvement in back pain was similar between the two groups, but patients on workers' compensation remained more disabled after lumbar fusion. Differences in outcomes may be related to unidentified covariates associated with workers' compensation status.

Lumbar spinal stenosis is a common cause of impaired quality of life and diminished functional capacity in the elderly. Due to the advance of noninvasive imaging modalities, spinal stenosis is becoming more frequently identified, and has become the most frequent cause for spinal surgery in patients older than 65 years. Despite the ubiquitous nature of this condition, considerable controversy exists regarding the preferred treatment. Level I evidence that compares the effectiveness of surgical and nonsurgical treatment is lacking. The Spine Patient Outcomes Research Trial, a study that evaluates the common surgical treatments for the lumbar spine, has addressed this deficiency and is discussed in this article.

STUDY DESIGN: Prospective longitudinal cohort. OBJECTIVE: This study evaluated the effect of preoperative Mental Component Summary (MCS), preoperative Physical Component Summary (PCS), preoperative Oswestry Disability Index (ODI), back pain predominance, body mass index (BMI), age, smoking status, and workers' compensation on health-related quality of life after lumbar fusion. These factors were selected as they are readily available and may influence a surgeon's decision-making process. SUMMARY OF BACKGROUND DATA: Measures of health-related quality of life are increasingly used to evaluate treatment effectiveness. However, their use as a predictive tool to determine which patients will improve has been limited. METHODS: The Short Form 36 (SF-36) and ODI were collected before surgery and two years after surgery in 489 patients undergoing lumbar fusion for degenerative disorders. Linear regression modeling was used to determine the effect of preoperative MCS, preoperative PCS, preoperative ODI, back pain predominance, BMI, age, smoking status, and workers' compensation on the change in ODI and change in SF-36 PCS two years after lumbar fusion. RESULTS: Patients with better preoperative MCS (P = 0.008) and worse preoperative ODI scores (P < 0.0001) achieved greater ODI improvement. Workers' compensation patients did significantly worse (P = 0.03). Patients with better preoperative MCS (P = 0.0004), better preoperative PCS (P = 0.0155), and worse preoperative ODI scores (P = 0.0210) achieved greater PCS improvement. Those on workers' compensation had lower changes in PCS, an effect that was nearly significant (P = 0.0644). There were no significant correlations between PCS and ODI improvement and back pain predominance, BMI, age, and smoking status. Attempts at determining threshold values for MCS, PCS, and ODI that are predictive of a patient achieving minimum clinically important difference for PCS and ODI were unsuccessful. CONCLUSION: Patients with good preoperative MCS and poor preoperative ODI scores who are not on workers' compensation are more likely to improve after lumbar fusion. Threshold values for MCS, PCS, and ODI predictive of a patient achieving minimum clinically important difference for PCS and ODI could not be determined.

Study Design. Prospective randomized controlled trial of rhBMP-2/ACS (Infuse bone graft) versus iliac crest bone graft (ICBG) for lumbar spine fusion in patients over 60 years of age. Objective. To report on clinical, radiographic, and economic outcomes, at 2-year follow-up, in patients treated by posterolateral lumbar fusion with rhBMP-2/ACS versus ICBG. Summary of Background Data. RhBMP-2/ACS is widely used "off-label" for posterolateral spinal fusion. Despite encouraging initial reports, outstanding issues include the need for evidence regarding safety and efficacy in an older population; and an assessment of cost-effectiveness. Methods. Patients over 60 years old were randomized to rhBMP-2/ACS (n = 50) or ICBG (n = 52). Oswestry Disability Index, Short Form-36, and numerical rating scales for back and leg pain were determined preoperatively and at 6, 12, and 24 months postoperatively. Fusion was evaluated by fine-cut computed tomography scan 2 years postoperatively by 3 reviewers. All in-patient and subsequent out-patient event costs were recorded by a dedicated hospital coder. Results. Two-year postoperative improvement in Oswestry Disability Index averaged 15.8 in the rhBMP-2/ACS group and 13.0 in the ICBG group. Mean improvement in Short Form-36 physical component score was 6.6 in the rhBMP-2/ACS group and 7.5 in the ICBG group. There were 20 complications in the ICBG group and 8 complications in the rhBMP-2/ACS group (P = 0.014). Sixteen ICBG and 10 rhBMP-2/ACS patients required additional treatment for persistent back or leg symptoms. Two rh-BMP-2/ACS patients had revision procedures, 1 for nonunion. Eight patients in the ICBG group had revision procedures, 5 for nonunion. Mean fusion grade on computed tomography scan was significantly (P = 0.030) better in the rhBMP-2/ACS (4.3) compared with the ICBG group (3.8). Mean cost of the initial admission was $36,530 in the rhBMP-2/ACS group and $34,235 in the iliac crest bone graft (ICBG) group. Total cost of care over 2 years was $42,574 for the ICBG group and $40,131 for the rhBMP-2/ ACS group. Conclusion. RhBMP-2/ACS is a viable ICBG replacement in older patients in terms of safety, clinical efficacy, and cost-effectiveness.

This study examined whether sagittal alignment, preexisting adjacent level degeneration, and smoking predispose patients to adjacent segment degeneration following lumbar fusion. Fifty-one patients with adjacent segment degeneration were identified and matched with control patients based on age, sex, level, and date of index surgery. Preexisting adjacent level degeneration and sagittal alignment through the fusion and from L1-S1 were determined before and after initial surgery. Patients with adjacent segment degeneration had significantly less lordosis through the fusion and lumbar spine following their initial surgery. There was no significant difference in the amount of preexisting adjacent level degeneration and smoking between the adjacent segment degeneration and control groups. Fusion of the lumbar spine in abnormal sagittal alignment, with loss of lumbar lordosis, predisposes patients to the development of adjacent segment degeneration. Adjacent segment degeneration does not appear to be just a progression of preexisting degenerative changes at the adjacent level.

Background context INFUSE has been proven effective in conjunction with threaded cages and bone dowels for single-level anterior lumbar interbody fusion (ALIF). The published experience with posterolateral fusion, although encouraging, utilizes a significantly higher dose and concentration of recombinant human bone morphogenic protein-2 (rhBMP-2) and a different carrier than the commercially available INFUSE. Purpose To present an assessment of fusion rate for posterolateral spine fusion with INFUSE Bone Graft. Study design/setting Retrospective review of patients treated using INFUSE in posterolateral spine fusion in a single institution. Patient sample 91 patients with minimum 2-year follow-up who underwent posterolateral spine fusion using INFUSE as an iliac crest bone graft (ICBG) substitute. Outcome measures Fusion rate based on fine-cut computed tomographic (CT) scans with sagittal and coronal reconstructions. Methods Fusion was performed using one large INFUSE kit (12 mg rhBMP-2, 1.5 mg/mL), which was prepared according to the manufacturer's instructions. The INFUSE sponge was wrapped around the local bone or graft extender and placed over the decorticated surfaces in the lateral gutters. Postoperative CT scans with reconstructions were reviewed by two independent orthopedic spine surgeons. CT scans of a comparison group of 35 patients who underwent primary single-level posterolateral fusion with ICBG were also reviewed. Results The overall group had a mean 4.38 CT fusion grade and a 6.6% nonunion rate. Primary one-level fusion cases (n=48) had a mean 4.42 fusion grade a 4.2% nonunion rate. Primary multilevel fusions (n=27) had a mean 4.65 CT grade and no nonunions detected. Assessment of the 35 primary one-level ICBG control cases demonstrated a mean CT grade of 4.35 and a nonunion rate of 11.4%. In the 16 cases of revision for prior nonunion, mean CT grade was 3.81 and 4 subjects had nonunions. Additional subgroup analysis showed that smokers (n=14) had a mean 4.32 CT grade with no nonunions. Men had a mean 4.04 CT grade and an 11.1% nonunion rate compared with a mean 4.61 CT grade and 3.6% nonunion rate in women. This difference was statistically significant (p=.036). No significant differences in fusion rate were observed based upon the specific graft extender used (p=.200). Conclusions Posterolateral spine fusion involves a more difficult healing environment with a limited surface for healing, a gap between transverse processes and the milieu of distractive forces. Historically, only ICBG has been able to overcome these challenges and reliably generate a successful posterolateral lumbar spine fusion. In contrast to prior studies, clinically available INFUSE delivers only 12 mg rhBMP-2 at a concentration of 1.5 mg/mL. Despite the lower dose and concentration of rhBMP-2, this study suggests that fusion success with INFUSE is equivalent to ICBG for posterolateral spine fusion. As with ICBG, development of solid fusion or nonunion is a multifactorial process. The use of INFUSE is not a substitute for proper surgical technique or optimization of patient-related risk factors. Additional studies are needed to determine the incremental benefit of a greater rhBMP-2 dose or use of alternative carriers for posterolateral fusion. Finally, correlation between radiographic findings and clinical outcomes, and a cost-benefit analysis are needed. Despite these issues, this study presents compelling evidence that commercially available INFUSE is an effective ICBG substitute for one- and two-level posterolateral instrumented spine fusion.

Background context Current imaging techniques used to evaluate fusion status after a posterolateral fusion such as radiographs, computed axial tomography (CT) scans, and tomograms are known to be inaccurate, with error rates estimated from 20% to 40%. Previous studies evaluated CT scans using 2–4-mm thick slices with limited reconstructions. Purpose The purpose of this study is to determine the intraobserver and interobserver agreement of plain radiographs and fine-cut (1-mm) CT scans with sagittal and coronal reconstructions in evaluating fusion status after instrumented posterolateral fusions. The correlation between radiographic evaluations and CT scan evaluations was also analyzed. Study design/setting Cross-sectional, blinded. Patient sample One-year radiographs and CT scans of 86 patients who had single-level instrumented posterolateral fusions. Outcome measures Fusion grades based on previously published criteria were determined. Methods Three spine surgeons graded the fusions of 86 patients who had single-level instrumented posterolateral fusions using 1-year postoperative flexion/extension lateral and anteroposterior radiographs, and fine-cut CT scans with sagittal and coronal reconstructions. The technique used to obtain the radiographs and the CT scans was the same in all cases. Two separate readings, 2 weeks apart, were done on each patient by each surgeon. The kappa coefficients for interobserver and intraobserver variability were determined. Results The intraobserver agreement using CT scans to assess fusion status was moderate for both classification systems (Molinari=0.48, Glassman 0.47). The intraobserver agreement using X-rays to assess fusion status was fair for the Molinari classification (kappa=0.37) and moderate for the Glassman classification (kappa=0.43). The interobserver agreement using CT scans to assess fusion status was moderate for both classification systems (Molinari=0.48, Glassman 0.48). The interobserver agreement using X-rays to assess fusion status was fair for both classification systems (Molinari=0.24, Glassman 0.26). Observers agreed most often when the fusion was assessed as solid (Molinari k=0.61, Glassman k=0.63). The rating on the radiographs and CT scans agreed only 46% to 59% of the time. Conclusions Fine-cut CT scans with reconstructions have a considerably greater degree of interobserver and intraobserver agreement compared with flexion/extension and anteroposterior radiographs. Observers agree most often when the fusion is assessed as solid. Fusion evaluation based on radiographs agrees with CT scans only half the time. Future studies are needed to correlate the findings on fine-cut CT scans with surgical exploration.