Revision Lumbar Fusion Research Articles

The Effect of Community-Level Socioeconomic Status on Surgical Outcomes Following Revision Lumbar Fusion

The purpose of this study is to determine the impact of community-level socioeconomic status (SES) on surgical outcomes and patient reported outcome measures (PROMs) following revision lumbar fusion. Adult patients who underwent revision lumbar fusion surgery from 2011-2021 were grouped by Distressed Community Index (DCI) into Prosperous, Comfortable, Mid-tier, and At risk/Distressed cohorts. Demographics, surgical information, and PROMs were compared based on DCI community status. Outcome measures were collected preoperatively, three months postoperatively, and one year postoperatively. 853 patients were included in the final cohort. There was no difference in terms of surgical approach or utilization of a staged procedure between the patient groups. Readmission (p=0.752) and reoperation rates (p=0.467) were similar across all community groups. Furthermore, for patients who required reoperation, the incision and drainage or revision surgery rate in each cohort was not statistically different (p=0.902). Prosperous community patients reported significantly lower VAS Back pain preoperatively in comparison to patients from other DCI communities. All groups experienced a similar degree of postoperative improvement in VAS Back scores (p= 0.271). There were no other differences in pre- or postoperative PROMs analyzed. While there are socioeconomic differences based on DCI, community-level SES was not predictive of worse surgical outcomes following revision lumbar fusion. Patients from the most distressed communities were able to achieve similar improvement after revision surgery. This should encourage spine surgeons to feel comfortable discussing an indicated revision lumbar procedure with patients, and not view SES as a barrier to successful outcomes.

P286. Revision lumbar fusion in the elderly: How old is too old?

P286. Revision lumbar fusion in the elderly: How old is too old?

The attainment of a patient acceptable symptom state in patients undergoing revision spine fusion

IntroductionRevision lumbar fusion is most commonly due to nonunion, adjacent segment disease (ASD), or recurrent stenosis, but it is unclear if diagnosis affects patient outcomes. The primary aim of this study was to assess whether patients achieved the patient acceptable symptom state (PASS) or minimal clinically important difference (MCID) after revision lumbar fusion and assess whether this was influenced by the indication for revision.MethodsWe retrospectively identified all 1–3 level revision lumbar fusions at a single institution. Oswestry Disability Index (ODI) was collected at preoperative, three-month postoperative, and one-year postoperative time points. The MCID was calculated using a distribution-based method at each postoperative time point. PASS was set at the threshold of ≤ 22.ResultsWe identified 197 patients: 56% with ASD, 28% with recurrent stenosis, and 15% with pseudarthrosis. The MCID for ODI was 10.05 and 10.23 at three months and one year, respectively. In total, 61% of patients with ASD, 52% of patients with nonunion, and 65% of patients with recurrent stenosis achieved our cohort-specific MCID at one year postoperatively with ASD (p = 0.78). At one year postoperatively, 33.8% of ASD patients, 47.8% of nonunion patients, and 37% of patients with recurrent stenosis achieved PASS without any difference between indication (p = 0.47).ConclusionsThe majority of patients undergoing revision spine fusion experience significant postoperative improvements regardless of the indication for revision. However, a large proportion of these patients do not achieve the patient acceptable symptom state. While revision spine surgery may offer substantial benefits, these results underscore the need to manage patient expectations.

Sickle Cell Disease Has No Impact on 10-Year Cumulative Incidence and Indications for Revision Lumbar Fusion.

Retrospective Cohort Study. Patients with sickle cell disease (SCD) experience distinct physiological challenges that may alter surgical outcomes. There has been no research establishing 10-year lumbar fusion (LF) implant survivorship rates among individuals with SCD. This study aims to determine the 10-year cumulative incidence and indications for revision LF between patients with and without SCD. A national database was queried to identify patients with and without SCD who underwent primary LF. SCD patients undergoing LF were propensity-score matched in a 1:4 ratio by age, gender, and Charlson Comorbidity Index (CCI) to a matched LF control. In total, 246 SCD patients were included along with 981 and 100,000 individuals in the matched and unmatched control cohorts, respectively. Kaplan-Meier survival analysis was utilized to determine the 10-year cumulative incidence rates of revision LF. Furthermore, multivariable analysis using Cox proportional hazard modeling was performed to compare indications for revisions and surgical complications between cohorts including hardware removal, drainage and evacuation, pseudoarthrosis, and mechanical failure. No significant differences were found in the cumulative incidence of 10-year all-cause revision LF between patients in the SCD cohort and either of the control cohorts (P > .05 for each). Additionally, there were no significant differences between the SCD cohort and either of the control cohorts in regards to the indications for revision or surgical complications in LF (P > .05 for each). This study indicates that SCD patients do not have increased risk for revision LF, nor any of its indications.

Risks associated with chronic cannabis use on opioid use, length of stay, and revision rate for patients undergoing posterior lumbar interbody fusion

BACKGROUND CONTEXTOpioids are commonly prescribed to treat spinal pain, especially those undergoing surgery. Cannabis has been suggested as an agent that can modulate opioid needs in these patients. PURPOSETo investigate the effect of cannabis use on perioperative opioid requirement and revision surgery rate in patients undergoing lumbar fusion. STUDY DESIGNRetrospective cross-sectional study. PATIENT SAMPLEA total of 48,499 patients from PearlDiver national database who underwent posterior lumbar interbody fusion. OUTCOME MEASURESOpioid-use rates, MME, length of stay, and revision rates. METHODSUsing PearlDiver, we identified patients for posterior lumbar interbody fusion (PLIF), cannabis use disorder, revision lumbar fusion, demographics, and comorbidities. Cannabis users and non-users were propensity matched for age, sex, and tobacco use. Pre and postoperative cumulative morphine milli equivalence (MME) were calculated. Opioid-use rates, MME, length of stay (LOS), and revision rates were compared using univariate analysis. Revision rates were compared using Kaplan-Meyer log-rank analysis, and logistic and cox regression. RESULTSOf 48,499 patients undergoing PLIF, 3.4% were identified as chronic cannabis users. They were younger, and more likely to be male and use tobacco. They had a higher rate and amount of opioid use within 90-days preoperatively, and 90- and 365-days postoperatively, after controlling for age, sex, and tobacco use. Cannabis users had longer LOS (4.4 vs 4.0 days), and a higher rate of revision surgery (6.9% vs 3.2%). Log-rank analysis, as well as logistic and cox regression confirmed an increased revision rate. Concurrent tobacco and cannabis use also had an additive effect on revision rate to 8.1%, compared with those who used only cannabis (5.4%) or tobacco (4.5%). CONCLUSIONSChronic cannabis use is associated with an increased preoperative and long-term postoperative opioid use, a longer length of stay, and an increased revision rate.

Prior Fragility Fractures are Associated With a Higher Risk of Bone Health-Related Complications Within Eight Years Following Lumbar Fusion.

Retrospective study. To determine the 8-year risk of revision lumbar fusion, pseudoarthrosis, mechanical failure, fragility fracture, and vertebral compression fracture in patients with a prior fragility fracture compared with those without. Osteoporosis is a known modifiable risk factor for revision following lumbar fusion due to inadequate fixation. Patients with prior fragility fractures have been shown to have increased bone health-related complications following various orthopedic surgeries; however, there is a paucity of literature that identifies these complications in patients undergoing lumbar fusion. Patients aged 50 years and older who underwent elective lumbar fusion were identified in a large national database and stratified based on whether they sustained a fragility fracture within three years prior to fusion. These patients were propensity-score matched to a control based on age, gender, and Charlson the comorbidity index using a 1:1 ratio. Kaplan-Meier and Cox proportional hazards analyses were used to observe the cumulative incidences and risk of complications within eight years of index surgery. After matching, 8805 patients were included in both cohorts. Patients who sustained a prior fragility fracture had a higher risk of revision [hazard ratio (HR): 1.46; 95% CI: 1.26-1.69; P <0.001), pseudoarthrosis (HR: 1.31; 95% CI: 1.17-1.48; P <0.001), mechanical failure (HR: 2.08; 95% CI: 1.78-2.45; P <0.001), secondary fragility fracture (HR: 6.36; 95% CI: 5.86-6.90; P <0.001), and vertebral compression fracture (HR: 7.47; 95% CI: 7.68-8.21; P <0.001) when compared with the control cohort. Patients who sustain a fragility fracture prior to lumbar fusion have an increased risk of revision, pseudoarthrosis, and mechanical failure within eight years. Surgeons should be aware of this high-risk patient population and consider bone health screening and treatment to reduce these preventable complications.

Surgical outcomes of anterior lumbar interbody fusion in revision lumbar interbody fusion surgery

BackgroundsAnterior lumbar interbody fusion (ALIF) is an attractive option for revision lumbar interbody fusion as it provides wide access for implant removal and accommodation of large interbody grafts for fusion. However, revision lumbar interbody fusion surgery has not been found to result in significantly better functional outcomes compared with other approaches. To date, no prognostic factors of anterior lumbar interbody fusion in revision lumbar interbody fusion have been reported. In this study, we investigated the surgical results and possible prognostic factors of anterior lumbar interbody fusion in revision lumbar interbody fusion.MethodsPatients who received revision interbody fusion surgery between January 2010 and May 2018 in our hospital were reviewed. Clinical outcomes were determined according to whether the VAS score improvement in back pain and leg pain reached the minimum clinically important difference (MCID) and Macnab criteria. Radiographic outcomes were assessed with fusion rate, preoperative, and postoperative lumbar lordosis. Operative-relative factors that may affect clinical outcomes, such as BMI, existence of cage migration, cage subsidence, pseudarthrosis, previous procedure, and number of fusion segments, were collected and analyzed.ResultsA total of 22 consecutive patients who received ALIF for revision interbody fusion surgery were included and analyzed. There were 9 men and 13 women with a mean age at operation of 56 years (26–78). The mean follow-up was 73 months (20–121). The minimal clinically important difference (MCID) was reached in 11 (50%) of the patients for back pain and 14 (64%) for leg pain. According to the modified Macnab criteria, 73% of the patients in this study had successful outcomes (excellent or good). The pain and lumbar lordosis had significant improvement (P < 0.05). Preoperative fusion segment ≥ 2 was shown to be a poor prognostic factor for back pain improvement reaching MCID (P = 0.043).ConclusionsALIF has proven effective for revision lumbar fusion surgery, yielding positive clinical and radiographic results. However, having two or more preoperative fusion segments can negatively impact back pain improvement.Level of evidence: IV.

Single-Position Prone Lateral Lumbar Interbody Fusion Increases Operative Efficiency and Maintains Safety in Revision Lumbar Spinal Fusion.

Multi-centre retrospective cohort study. To evaluate the feasibility and safety of the single-position prone lateral lumbar interbody fusion (LLIF) technique for revision lumbar fusion surgery. Prone LLIF (P-LLIF) is a novel technique allowing for placement of a lateral interbody in the prone position and allowing posterior decompression and revision of posterior instrumentation without patient repositioning. This study examines perioperative outcomes and complications of single position P-LLIF against traditional Lateral LLIF (L-LLIF) technique with patient repositioning. A multi-centre retrospective cohort study involving patients undergoing 1 to 4 level LLIF surgery was performed at 4 institutions in the US and Australia. Patients were included if their surgery was performed via either: P-LLIF with revision posterior fusion; or L-LLIF with repositioning to prone. Demographics, perioperative outcomes, complications, and radiological outcomes were compared using independent samples t-tests and chi-squared analyses as appropriate with significance set at P <0.05. 101 patients undergoing revision LLIF surgery were included, of which 43 had P-LLIF and 58 had L-LLIF. Age, BMI and CCI were similar between groups. The number of posterior levels fused (2.21 P-LLIF vs. 2.66 L-LLIF, P =0.469) and number of LLIF levels (1.35 vs. 1.39, P =0.668) was similar between groups.Operative time was significantly less in the P-LLIF group (151 vs. 206 min, P =0.004). EBL was similar between groups (150mL P-LLIF vs. 182mL L-LLIF, P =0.31) and there was a trend toward reduced length of stay in the P-LLIF group (2.7 vs. 3.3d, P =0.09). No significant difference was demonstrated in complications between groups. Radiographic analysis demonstrated no significant differences in preoperative or postoperative sagittal alignment measurements. P-LLIF significantly improves operative efficiency when compared to L-LLIF for revision lumbar fusion. No increase in complications was demonstrated by P-LLIF or trade-offs in sagittal alignment restoration. Level 4.

Revision lumbar fusions have higher rates of reoperation and result in worse clinical outcomes compared to primary lumbar fusions

BACKGROUND CONTEXTIndications for revision lumbar fusion are variable, but include recurrent stenosis (RS), adjacent segment disease (ASD), and pseudarthrosis. The efficacy of revision lumbar fusion has been well established, but their outcomes compared to primary procedures is not well documented. PURPOSEThe purpose of this study was to compares surgical and clinical outcomes between (1) revision and primary lumbar fusion, (2) revision lumbar fusion based on indication (ASD, pseudarthrosis, or RS), and (3) revision lumbar fusion based on whether the index procedure included an isolated decompression or decompression with fusion. STUDY DESIGN/SETTINGRetrospective single-institution cohort study. PATIENT SAMPLEFour thousand six hundred seventy-one consecutive lumbar fusions from 2011 to 2021, of which 892 (23.6%) were revision procedures. The indication for revision procedures included 502 (56.3%) for ASD, 153 (17.2%) for pseudarthrosis, and 237 (26.6%) for RS. Of the 892 revision procedures, 694 (77.8%) underwent an index fusion while 198 (22.2%) underwent an index decompression without fusion. OUTCOME MEASURESHospital readmissions, all-cause reoperation, need for subsequent revision and patient reported outcome measures (PROMs) at baseline, 3-months postoperatively, and 1-year postoperatively, including the Mental Health Component score (MCS-12) and Physical Health Component score (PCS-12) of the Short Form 12 survey, the Oswestry Disability Index (ODI), and the Visual Analog Scale (VAS) for Back and Leg pain. METHODSPatient demographics, comorbidities, surgical characteristics, and outcomes were collected from electronic medical records. Twenty-eight percent of patients had preoperative and postoperative PROMs. A delta PROM score was calculated for the 3-month and 1-year postoperative timepoints, which was the change from the preoperative to postoperative value. Univariate comparisons were performed to compare revision fusions to primary fusions. Multivariate logistic regression was performed for all-cause reoperation and subsequent revision surgery, while multivariate linear regression was performed for ∆PROMs at 3-months and 1-year. Revision procedures were then separately regrouped based on indication for revision fusion and whether they underwent a fusion for their index procedure. Univariate comparisons and multivariate linear regressions for ∆PROMs were then repeated based on the new groupings. RESULTSThere was no difference in hospital readmission rate (5.38% vs. 4.60%, p=.372) or length of stay (4.10 days vs. 3.94 days, p=.129) between revision and primary lumbar fusion, but revision fusions had a higher rate of all-cause reoperation (16.1% vs. 11.2%, p<.001) and subsequent revision (13.7% vs. 9.71%, p=.001), which was confirmed on multivariate logistic regression (Odds Ratio (OR): 1.42, p=.001 and OR: 1.37, p=.007, respectively). On multivariate analysis, a revision procedure was an independent risk factor for worse improvement ∆ODI, ∆VAS Back, ∆VAS Leg, and ∆PCS-12 and 1-year postoperatively. Regardless of the indication for revision lumbar fusion, patients significantly improved in the 3-month and 1-year postoperative PCS-12, ODI, VAS Back, and VAS Leg, with the exception of the 3-month PCS-12 for pseudarthrosis (p=.620). Patients undergoing revision for ASD had significantly worse 1-year postoperative PCS-12 (32.3 vs. Pseudarthrosis: 35.6 and RS: 37.0, p=.026), but there were no differences in ∆PROMs. There was no difference in hospital readmission, all-cause reoperation, or subsequent revision based on whether a patient had an index lumbar fusion or isolated decompression. Multivariate linear regression analysis found that a surgical indication of pseudarthrosis was a significant predictor of decreased improvement in 3-month ∆VAS Leg (ref: ASD, β=2.26, p=.036), but having an index fusion did not significantly predict worse improvement in ∆PROMs when compared to isolated decompressions. CONCLUSIONSRevision lumbar fusions had a higher rate of reoperation and subsequent revision surgery when compared to primary lumbar fusions, but there were no difference in hospital readmission rates. Patients undergoing revision lumbar fusion experience improvements in all patient reported outcome measures, but their baseline, postoperative, and magnitude of improvement are worse than primary procedures. Regardless of whether the lumbar fusion is a primary or revision procedure, all patients have significant improvements in pain, disability and physical function. Further, the indication for the revision procedure is not correlated with the expected magnitude of improvement in patient reported outcomes. Finally, no differences in baseline, postoperative, and ∆PROMs for revision fusions were identified when stratifying by whether the patient had an index decompression or fusion.

225. Comparison of single position prone lateral lumbar interbody fusion and lateral lumbar interbody fusion with repositioning in revision lumbar spinal fusion

<h3>BACKGROUND CONTEXT</h3> Prone LLIF (P-LLIF) is a novel technique allowing for placement of a lateral interbody in the prone position and allowing posterior decompression and revision of posterior instrumentation without repositioning. To date, studies evaluating the P-LLIF have been small single surgeon series. This multicentre retrospective cohort examines perioperative outcomes and complications of single position P-LLIF againsttraditional Lateral LLIF (L-LLIF) technique with patient repositioning in patients undergoing revision lumbar fusion surgery. <h3>PURPOSE</h3> To evaluate the feasibility and safety of the single-position P-LLIF technique for revision lumbar fusion surgery. <h3>STUDY DESIGN/SETTING</h3> Multicenter retrospective cohort study. <h3>PATIENT SAMPLE</h3> A total of 101 patients undergoing revision circumferential fusion with lateral lumbar interbody fusion (LLIF) were included, of which 43 had P-LLIF and 58 had L-LLIF. <h3>OUTCOME MEASURES</h3> Outcome measures included levels fused, operative time, estimated blood loss and perioperative complications. Radiographic analysis included lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), PI-LL mismatch and segmental lumbar lordosis. <h3>METHODS</h3> A multicenter retrospective cohort study was performed from 4 institutions from the USA and Australia of patients undergoing revision anterior-posterior lumbar fusion via either: 1) single-position prone LLIF (P-LLIF); or 2) lateral decubitus LLIF with repositioning to prone (L-LLIF) between January 2015 and November 2021. Patients with greater than 4 levels fused were excluded. Demographics, perioperative outcomes, complications and radiological outcomes were compared using independent samples t-tests and chi-squared analyses as appropriate with significance set at p<0.05. <h3>RESULTS</h3> A total of 101 patients undergoing revision lateral lumbar interbody fusion surgery were included, of which 43 had P-LLIF and 58 had L-LLIF. Age, BMI and CCI were similar between groups. The number of posterior levels fused (2.21 P-LLIF vs 2.66 L-LLIF, p=0.469) and interbody levels fused (1.23 P-LLIF vs 1.25 L-LLIF, p=0.838) were similar between groups. Levels decompressed, posterior column osteotomy and anterior column release were similar between groups. Operative time was significantly less in the P-LLIF group compared to the L-LLIF group (151 vs 206 min, p=0.004). EBL was similar between groups (150 mL P-LLIF vs 182 mL L-LLIF, p=0.31) and there was a trend toward reduced length of stay (2.7 vs 3.3 days, p=0.09). No significant difference was demonstrated in perioperative or postoperative complications between P-LLIF and L-LLIF groups. Radiographic analysis demonstrated no significant differences in preoperative or postoperative sagittal alignment as measured by lumbar lordosis, PI-LL mismatch, or segmental lumbar lordosis between groups. <h3>CONCLUSIONS</h3> P-LLIF significantly improves operative efficiency and may reduce length of stay when compared to L-LLIF and repositioning for revision lumbar fusion. No increase in complications was demonstrated by P-LLIF or trade-offs in sagittal alignment restoration. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Evaluation of bone mineral density after instrumented lumbar fusion with computed tomography

Computed tomography (CT) measurement of Hounsfield Units (HU) has been described as a tool for assessing BMD. For surgeons considering a revision lumbar fusion, knowledge of the BMD of the UIV is of value for surgical planning. However, the presence of metal artifact from instrumentation presents a potential confounder, and prior studies have not validated measurements of HU in this setting. To determine if HU can be measured reliably at the supra-adjacent and upper instrumented levels of a lumbar fusion. Retrospective observational cohort PATIENT SAMPLE: Consecutive series of patients who had lumbar CT scans after an instrumented posterior lumbar fusion. Hounsfield Units at the upper instrumented vertebra and levels proximal. We analysed pre- and postoperative CT scans of 50 patients who underwent L2 and distal instrumented lumbar fusion whose scans were no greater than 1 year apart, obtaining HU measurements of analogous axial cuts at the upper instrumented level (immediately caudal to the halo of the pedicle screw), as well as additional control levels above the construct. The HU at the pre-and postoperative UIV exhibited a strong correlation (r=0.917, p<.001), as did one (r=0.887, p<.001) and two (r=0.853, p<.001) levels above the UIV. There were significant but predictable reductions in the postoperative HU compared to preoperative at one (-9.0±26.2) and two (-12.2±30.2) levels above the UIV, as well as T12 (-13.9±42.2). There was no significant difference in HU at the UIV (4.6±34.1). Postoperative HU at the UIV was strongly correlated with and not significantly different from the preoperative HU. Although the HU in the vertebrae proximal to the UIV were slightly lower postoperatively, this change was predictable using a correction factor.

Independent Predictors of Revision Lumbar Fusion Outcomes and the Impact of Spine Surgeon Variability: Does It Matter Whether the Primary Surgeon Revises?

There is a paucity of information regarding treatment strategies and variables affecting outcomes of revision lumbar fusions. To evaluate the influence of primary vs different surgeon on functional outcomes of revisions. All elective lumbar fusion revisions, March 2018 to August 2019, were retrospectively categorized as performed by the same or different surgeon who performed the primary surgery. Oswestry Disability Index (ODI) and clinical variables were collected. Multiple logistic regression identified multivariable-adjusted odds ratio (OR) of independent variables analyzed. Of the 130 cases, 117 (90%) had complete data. There was a slight difference in age in the same (median: 59; interquartile range [IQR], 54-66) and different surgeon (median: 67; IQR, 56-72) groups (P=.02); all other demographic variables were not significantly different (P >.05). Revision surgery with a different surgeon had an ODI improvement (median: 8; IQR, 2-14) greater than revisions performed by the same surgeon (median: 1.5; IQR, -3 to 10) (P <.01). Revisions who achieved minimum clinically important difference (MCID) performed by different surgeon (59.7%) were also significantly greater than the ones performed by the same surgeon (40%) (P=.042). Multivariate analysis demonstrated that a different surgeon revising (OR, 2.37; [CI]: 1.007-5.575, P=.04) was an independent predictor of MCID achievement, each additional 2 years beyond the last surgery conferred a 2.38 ([CI]: 1.36-4.14, P <.01) times greater odds of MCID achievement, and the anterior lumbar interbody fusion approach decreased the chance of achieving MCID (OR, 0.19; [CI]: 0.04-0.861, P=.03). All revision lumbar spinal fusion approaches may not achieve the same outcomes. This analysis suggests that revision surgeries may have better outcomes when performed by a different surgeon.

263. Evaluation of bone mineral density after instrumented lumbar fusion using computed tomography

<h3>BACKGROUND CONTEXT</h3> Computed tomography (CT) measurement of Hounsfield Units (HU) has been described as a tool for assessing bone mineral density (BMD). For surgeons considering a revision lumbar fusion, knowledge of the BMD of the upper instrumented verterbra (UIV) is of value for surgical planning. However, the presence of metal artifact from instrumentation presents a potential confounder and prior studies have not validated measurements of HU in this setting. <h3>PURPOSE</h3> The purpose of this study is to determine if HU can be measured reliably at instrumented levels after a lumbar fusion. <h3>STUDY DESIGN/SETTING</h3> Retrospective observational cohort at a single multisurgeon spine center. <h3>PATIENT SAMPLE</h3> Consecutive series of patients who had lumbar CT Scans after an instrumented posterior lumbar fusion. <h3>OUTCOME MEASURES</h3> Hounsfield Units at the upper instrumented vertebra and levels proximal. <h3>METHODS</h3> We analyzed pre- and postoperative CT scans of 50 patients who underwent L2 and distal instrumented lumbar fusion whose scans were no greater than 1 year apart, obtaining HU measurements of analogous axial cuts at the upper instrumented level (immediately caudal to the halo of the pedicle screw), as well as additional control levels above the construct. <h3>RESULTS</h3> The HU at the pre-and postoperative UIV exhibited a strong correlation (r=0.917, p <0.001), as did one (r=0.887, p <0.001) and two (r=0.853, p <0.001) levels above the UIV. There were significant but predictable reductions in the postoperative HU compared to preoperative at one (-9.0 ± 26.2) and two (-12.2 ± 30.2] levels above the UIV, as well as T12 (-13.9 ± 42.2). There was no significant difference in HU at the UIV (4.6 ± 34.1). <h3>CONCLUSIONS</h3> Postoperative HU at the UIV was strongly correlated with and not significantly different from the preoperative HU. Although the HU in the vertebrae proximal to the UIV were slightly lower postoperatively, this change was predictable using a correction factor. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Radiographic evaluation of low back pain after lumbar fusion using Technetium-99 single-photon emission computed tomography: Impact on clinical decision-making and outcome

Accurate identification of spinal pain generators is critical to selecting the optimal treatment strategy for patients with persistent low back pain following instrumented lumbar fusion. Conventional diagnostic imaging modalities such as CT and MRI often yield equivocal results in this patient population. The purpose of this study is to assess the utility of Tc-99 SPECT/CT as an adjunct to conventional imaging modalities in the identification of spinal pain generators in patients with persistent low back pain after a lumbar fusion. A retrospective cohort review of 18 patients with a history of at least 1-year of persistent low back pain following a lumbar fusion surgery was conducted. All patients had MRI and/or CT scans that did not definitively identify a spinal pain generator. Tc-99 SPECT/CT imaging was subsequently performed in this cohort and treatment was determined according to imaging results. For patients undergoing revision fusion, pre- and post-operative visual analogue scores (VAS) at last follow-up were analyzed. All pain sites not clearly visualized on CT or MRI were identified by increased uptake of Tc-99 on SPECT/CT. According to anatomic location of uptake, six patients in this cohort underwent revision lumbar fusion. For patients undergoing revision lumbar fusion, preoperative VAS score averaged 8.5 ± 0.29 and declined after surgery to 4.75 ± 0.95. Patients in our series who suffered from failed lumbar spinal surgery syndrome, and subsequently underwent SPECT/CT imaging leading to the identification of pain generators amenable to surgical treatment experienced significant reduction in VAS scores after revision surgery.

Sagittal imbalance, muscle atrophy, and osteoporosis: risk factors for revision posterior lumbar fusion surgery in patients with Parkinson's disease.

The aim of our study was to evaluate features and complications of patients with Parkinson's disease (PD) who underwent posterior lumbar fusion surgery for lumbar degenerative diseases (LDD), as well as the risk factors for revision. Between January 2010 and December 2016, 132 patients were retrospectively identified for inclusion. Patients were divided into a 29 revision PD group and a 103 non-revision PD group. Patient factors included bone mineral density (BMD) and severity of PD using the Hoehn and Yahr staging system. Surgical factors included surgical levels and fusion methods. Radiographic measurements included pre-operative spinopelvic parameters, paraspinal muscle atrophy, and fatty infiltration. Logistic regression analysis was used to determine independent predictors for revision posterior lumbar fusion. The average age of the PD patients was 67.96years, and the follow-up time was 49.01months. R-PD patients accounted for 21.97% of all PD patients who underwent lumbar fusion surgery. Multivariable analysis indicated that low BMD (p = 0.012), fatty infiltration (p = 0.038), a smaller relative cross-sectional area (rCSA) of the paraspinal muscle (p = 0.008), larger pelvic incidence-lumbar lordosis (PI-LL) (p = 0.01), and sagittal vertical axis (SVA) (p = 0.004) were significant independent risk factors for revision posterior lumbar fusion in PD patients. PD patients with low pre-operative BMD, fatty infiltration, a smaller rCSA of the paraspinal muscle, and larger PI-LL and SVA had a higher rate of revision lumbar fusion. Maintaining sagittal balance, functional exercises, and anti-osteoporosis treatment were important in preventing complications in PD patients.

Ninety-Day Readmission in Elective Revision Lumbar Fusion Surgery in the Inpatient Setting.

Study Design:Retrospective review.Objectives:(1) Identify the 90-day rate of readmission following revision lumbar fusion, (2) identify independent risk factors associated with increased rates of readmission within 90 days, (3) and identify the hospital costs associated with revision lumbar fusion and subsequent readmission within 90 days.Methods:Utilizing 2014 data from the Nationwide Readmissions Database, patients undergoing elective revision lumbar fusion were identified. With this sample, multivariate logistic regression was utilized to identify independent predictors of readmission within 90 days. An analysis of total hospital costs was also conducted.Results:In 2014, an estimated 14 378 patients underwent elective revision lumbar fusion. The readmission rate at 90 days was 3.1% (n = 446). Diabetes with chronic complications was the only comorbidity found to carry significantly increased odds of readmission. Surgical complications such as deep venous thrombosis, surgical wound disruption, hematoma, and pneumonia (experienced during the index admission) were also independent predictors of readmission. Anterior approaches were associated with increased odds of readmission. The most common related diagnoses on readmission were hardware issues, postoperative infection, and disc herniation. Readmissions were associated with an average of $96 152 in increased hospital costs per patient compared with those not readmitted.Conclusion:Relevant patient comorbidities and surgical complications were associated with increased readmission within 90 days. Readmission within 90 days was associated with significant increases in hospital costs.

Impact of lumbar arthrodesis on outcomes after elective total hip arthroplasty

BackgroundAcetabular component malpositioning has been associated with major complications including dislocation, edge-loading, stripe wear and squeaking. Anteversion is determined by pelvic orientation; flexion of the pelvis increases and extension decreases acetabular anteversion. The degree of pelvic movement is determined by lumbar spine sagittal balance and it is well established that lumbar arthrodesis procedures influence spinal and pelvic parameters including sagittal balance. The purpose of this study is to determine the impact of prior lumbar arthrodesis and revision lumbar arthrodesis on complications after primary elective THA. MethodsA database review using the entire Medicare sample within the PearlDiver database was performed using International Classification of Diseases, 9th Edition codes. The search identified 14,439 patients who underwent primary THA after prior lumbar arthrodesis and 1,157 patients who underwent primary THA after prior revision lumbar arthrodesis. A search for patients who underwent primary THA without prior history of lumbar or revision lumbar fusion yielded 749,403 patients who served as a control. Incidence (IN), odds ratios (ORs) and their respective 95% confidence intervals (CIs) for 30-day, 90-day and overall complications were calculated. ResultsThe following complications reached statistical significance (p < 0.001) for THA after primary lumbar arthrodesis: bleeding (IN:9.7%, OR:2.33, CI:2.21–2.47), dislocation (IN:5.6%, OR:1.95, CI:1.81–2.09), infection (IN:3.6%, OR:1.99, CI:1.85–2.12), mechanical complication (IN:0.7%, OR:1.42, CI:1.16–1.73), mechanical loosening (IN:2.3%, OR:1.74, CI:1.56–1.94), other mechanical complication (IN:2.1%, OR:2.13, CI:1.90–2.39), DVT/PE (IN:8.4%, OR:1.50, CI:1.42–1.60), acute renal failure (IN:22%, OR:1.20, CI:1.15–1.25), periprosthetic fracture (IN:1.6%, OR:1.45, CI:1.27–1.65), and prosthetic-related complication (IN:30%, OR:1.85, CI:1.78–1.91). Higher complications rates were observed in patients who had revision lumbar arthrodesis: bleeding (IN:12.4%, OR:3.06, CI:2.57–3.65), dislocation (IN:9.7%, OR:3.54, CI:2.92–4.31), infection (IN:5%, OR:3.32, CI:2.71–4.06), mechanical complication (IN:6.9%, OR:14.94, CI:11.88–18.79), mechanical loosening (IN:3.2%, OR:2.41, CI:1.74–3.35), other mechanical complication (IN:3.5%, OR:3.56, CI:2.61–4.87), DVT/PE (IN:10.7%, OR:1.96, CI:1.63–2.36), acute renal failure (IN:25.5%, OR:1.46, CI:1.28–1.66), periprosthetic fracture (IN:2.7%, OR:2.47, CI:1.72–3.52), and prosthetic-related complication (IN:40%, OR:2.88, CI:2.56–3.24). ConclusionsLumbar arthrodesis and revision lumbar arthrodesis significantly negatively impact postoperative complication rates after THA. Level of Evidence: Therapeutic Level III

Revision lumbar surgery in elderly patients with symptomatic pseudarthrosis, adjacent-segment disease, or same-level recurrent stenosis. Part 1. Two-year outcomes and clinical efficacy

Same-level recurrent lumbar stenosis, pseudarthrosis, and adjacent-segment disease (ASD) are potential complications that can occur after index lumbar spine surgery, leading to significant discomfort and radicular pain. While numerous studies have demonstrated excellent results following index lumbar spine surgery in elderly patients (age > 65 years), the effectiveness of revision lumbar surgery in this cohort remains unclear. The aim of this study was to assess the long-term effectiveness of revision lumbar decompression and fusion in the treatment of symptomatic pseudarthrosis, ASD, and same-level recurrent stenosis, using validated patient-reported outcomes. After a review of the institutional database, 69 patients who had undergone revision neural decompression and instrumented fusion for ASD (28 patients), pseudarthrosis (17 patients), or same-level recurrent stenosis (24 patients) were included in this study. Baseline and 2-year scores on the visual analog scale for leg pain (VAS-LP), VAS for back pain (VAS-BP), Oswestry Disability Index (ODI), and Zung Self-Rating Depression Scale (SDS) as well as the time to narcotic independence, time to return to baseline activity level, health state utility (EQ-5D, the EuroQol-5D health survey), and physical and mental component summary scores of the 12-Item Short-Form Health Survey (SF-12 PCS and MCS) were assessed. Compared with the preoperative status, VAS-BP was significantly improved 2 years after surgery for ASD (mean ± standard deviation 9 ± 2 vs 4.01 ± 2.56, p = 0.001), pseudarthrosis (7.41 ± 1 vs 5.52 ± 3.08, p = 0.02), and same-level recurrent stenosis (7 ± 2.00 vs 5.00 ± 2.34, p = 0.003). The 2-year ODI was also significantly improved after surgery for ASD (29 ± 9 vs 23.10 ± 10.18, p = 0.001), pseudarthrosis (28.47 ± 5.85 vs 24.41 ± 7.75, p = 0.001), and same-level recurrent stenosis (30.83 ± 5.28 vs 26.29 ± 4.10, p = 0.003). The Zung SDS score and SF-12 MCS did not change appreciably after surgery in any of the cohorts, with an overall mean 2-year change of 1.01 ± 5.32 (p = 0.46) and 2.02 ± 9.25 (p = 0.22), respectively. Data in this study suggest that revision lumbar decompression and extension of fusion for symptomatic pseudarthrosis, ASD, and same-level recurrent stenosis provides improvement in low-back pain, disability, and quality of life and should be considered a viable treatment option for elderly patients with persistent or recurrent back and radicular pain. Mental health symptoms may be more refractory to revision surgery.

Differentiating minimum clinically important difference for primary and revision lumbar fusion surgeries

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.

Determination of minimum clinically important difference (MCID) in pain, disability, and quality of life after revision fusion for symptomatic pseudoarthrosis

Spinal surgical outcome studies rely on patient reported outcome (PRO) measurements to assess the effect of treatment. A shortcoming of these questionnaires is that the extent of improvement in their numerical scores lacks a direct clinical meaning. As a result, the concept of minimum clinically important difference (MCID) has been used to measure the critical threshold needed to achieve clinically relevant treatment effectiveness. Post hoc anchor-based MCID methods have not been applied to the surgical treatment for pseudoarthrosis. To determine the most appropriate MCID values for visual analog scale (VAS), Oswestry Disability Index (ODI), Short Form (SF)-12 physical component score (PCS), and European Quality of Life 5-Dimensions (EQ-5D) in patients undergoing revision lumbar arthrodesis for symptomatic pseudoarthrosis. STUDY DESIGN/ SETTING: Retrospective cohort study. In 47 patients undergoing revision fusion for pseudoarthrosis-associated back pain, PRO measures of back pain (BP-VAS), ODI, physical quality of life (SF-12 PCS), and general health utility (EQ-5D) were assessed preoperatively and 2 years postoperatively. Four subjective post hoc anchor-based MCID calculation methods were used to calculate MCID (average change; minimum detectable change; change difference; and receiver operating characteristic curve analysis) for two separate anchors (health transition index (HTI) of SF-36 and satisfaction index). All patients were available for a 2-year PRO assessment. Two years after surgery, a significant improvement was observed for all PROs; Mean change score: BP-VAS (2.3±2.6; p<.001), ODI (8.6%±13.2%; p<.001), SF-12 PCS (4.0±6.1; p=.01), and EQ-5D (0.18±0.19; p<.001). The four MCID calculation methods generated a wide range of MCID values for each of the PROs (BP-VAS: 2.0-3.2; ODI: 4.0%-16.6%; SF-12 PCS: 3.2-6.1; and EQ-5D: 0.14-0.24). There was no difference in response between anchors for any patient, suggesting that HTI and satisfaction anchors are equivalent in this patient population. The wide variations in calculated MCID values between methods precluded any ability to reliably determine what the true value is for meaningful change in this disease state. Using subjective post hoc anchor-based methods of MCID calculation, MCID after revision fusion for pseudoarthrosis varies by as much as 400% per PRO based on the calculation technique. MCID was suggested to be as low as 2 points for ODI and 3 points for SF-12. These wide variations and low values of MCID question the face validity of such calculation techniques, especially when applied to heterogeneous disease and patient groups with a multitude of psychosocial confounders such as failed back syndromes. The variability of MCID thresholds observed in our study of patients undergoing revision lumbar fusion for pseudoarthrosis raises further questions to whether ante hoc or Delphi methods may be a more valid and consistent technique to define clinically meaningful, patient-centered changes in PRO measurements.