Does Bone Morphogenetic Protein Use Reduce Pseudarthrosis Rates in Single-Level Transforaminal Lumbar Interbody Fusion Surgeries?

BACKGROUND: Recombinant human bone morphogenetic protein 2 (rhBMP-2, or BMP for short) is a popular biological product used in spine surgeries to promote fusion and avoid the morbidity associated with iliac crest autograft. BMP's effect on pseudarthrosis in transforaminal lumbar interbody fusion (TLIF) remains unknown. OBJECTIVE: To assess the rates of pseudarthrosis in single-level TLIF with and without concurrent use of BMP. METHODS: This was a retrospective cohort study conducted at a single academic institution. Adults undergoing primary single-level TLIF with a minimum of 1 year of clinical and radiographic follow-up were included. BMP use was determined by operative notes at index surgery. Non-BMP cases with iliac crest bone graft were excluded. Pseudarthrosis was determined using radiographic and clinical evaluation. Bivariate differences between groups were assessed by independent t test and χ 2 analyses, and perioperative characteristics were analyzed by multiple logistic regression. RESULTS: One hundred forty-eight single-level TLIF patients were included. The mean age was 59.3 years, and 52.0% were women. There were no demographic differences between patients who received BMP and those who did not. Pseudarthrosis rates in patients treated with BMP were 6.2% vs 7.5% in the no BMP group (P = 0.756). There was no difference in reoperation for pseudarthrosis between patients who received BMP (3.7%) vs those who did not receive BMP (7.5%, P = 0.314). Patients who underwent revision surgery for pseudarthrosis more commonly had diabetes with end-organ damage (revised 37.5% vs not revised 1.4%, P < 0.001). Multiple logistic regression analysis demonstrated no reduction in reoperation for pseudarthrosis related to BMP use (OR 0.2, 95% CI 0.1-3.7, P = 0.269). Diabetes with end-organ damage (OR 112.6,95% CI 5.7-2225.8, P = 0.002) increased the risk of reoperation for pseudarthrosis. CONCLUSIONS: BMP use did not reduce the rate of pseudarthrosis or the number of reoperations for pseudarthrosis in single-level TLIFs. Diabetes with end-organ damage was a significant risk factor for pseudarthrosis. CLINICAL RELEVANCE: BMP is frequently used "off-label" in transforaminal lumbar interbody fusion; however, little data exists to demonstrate its safety and efficacy in this procedure.

Lateral decubitus single position anterior posterior surgery improves operative efficiency, improves perioperative outcomes, and maintains radiological outcomes comparable with traditional anterior posterior fusion at minimum 2-year follow-up.

BACKGROUND CONTEXT: The advantages of lateral single position surgery (LSPS) in the perioperative period has previously been demonstrated, however 2-year postoperative outcomes of this novel technique have not yet been compared to circumferential anterior-posterior fusion (FLIP) at 2-years postoperatively. PURPOSE: Evaluate the safety and efficacy of LSPS versus gold-standard FLIP STUDY DESIGN/SETTING: Multicenter retrospective cohort review. PATIENT SAMPLE: Four hundred forty-two patients undergoing lumbar fusion via LSPS or FLIP OUTCOME MEASURES: Levels fused, operative time, estimated blood loss, perioperative complications, and reasons for reoperation at 30-days, 90-days, 1-year, and 2-years. Radiographic outcomes included lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), PI-LL mismatch, and segmental lumbar lordosis. METHODS: Patients were grouped as LSPS if anterior and posterior portions of the procedure were performed in the lateral decubitus position, and FLIP if patients were repositioned from supine or lateral to prone position for the posterior portion of the procedure under the same anesthetic. Groups were compared in terms of demographics, intraoperative, perioperative and radiological outcomes, complications and reoperations up to 2-years follow-up. Measures were compared using independent samples or paired t-tests and chi-squared analyses with significance set at p<.05. RESULTS: Four hundred forty-two patients met inclusion, including 352 LSPS and 90 FLIP patients. Significant differences were noted in age (62.4 vs 56.9; p≤.001) and smoking status (7% vs 16%; p=.023) between the LSPS and FLIP groups. LSPS demonstrated significantly lower Op time (97.7min vs 297.0 min; p<.001), fluoro dose (36.5mGy vs 78.8mGy; p<.001), EBL (88.8mL vs 270.0mL; p<.001), and LOS (1.91 days vs 3.61 days; p<.001) compared to FLIP. LSPS also demonstrated significantly fewer post-op complications than FLIP (21.9% vs 34.4%; p=.013), specifically regarding rates of ileus (0.0% vs 5.6%; p<.001). No differences in reoperation were noted at 30-day (1.7%LSPS vs 4.4%FLIP, p=.125), 90-day (5.1%LSPS vs 5.6%FLIP, p=.795) or 2-year follow-up (9.7%LSPS vs 12.2% FLIP; p=.441). LSPS group had a significantly lower preoperative PI-LL (4.1° LSPS vs 8.6°FLIP, p=.018), and a significantly greater postoperative LL (56.6° vs 51.8°, p = .006). No significant differences were noted in rates of fusion (94.3% LSPS vs 97.8% FLIP; p=.266) or subsidence (6.9% LSPS vs 12.2% FLIP; p=.260). CONCLUSIONS: LSPS and circumferential fusions have similar outcomes at 2-years post-operatively, while reducing perioperative complications, improving perioperative efficiency and safety.

Lateral decubitus single position anterior-posterior (AP) fusion shows equivalent results to minimally invasive transforaminal lumbar interbody fusion at one-year follow-up.

PURPOSE: This study compares perioperative and 1-year outcomes of lateral decubitus single position circumferential fusion (L-SPS) versus minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) for degenerative pathologies. METHODS: Multicenter retrospective chart review of patients undergoing AP fusion with L-SPS or MIS TLIF. Demographics and clinical and radiographic outcomes were compared using independent samples t tests and chi-squared analyses with significance set at p < 0.05. RESULTS: A total of 445 patients were included: 353 L-SPS, 92 MIS TLIF. The L-SPS cohort was significantly older with fewer diabetics and more levels fused. The L-SPS cohort had significantly shorter operative time, blood loss, radiation dosage, and length of stay compared to MIS TLIF. 1-year follow-up showed that the L-SPS cohort had higher rates of fusion (97.87% vs. 81.11%; p = 0.006) and lower rates of subsidence (6.38% vs. 38.46%; p < 0.001) compared with MIS TLIF. There were significantly fewer returns to the OR within 1 year for early mechanical failures with L-SPS (0.0% vs. 5.4%; p < 0.001). 1-year radiographic outcomes revealed that the L-SPS cohort had a greater LL (56.6 ± 12.5 vs. 51.1 ± 15.9; p = 0.004), smaller PI-LL mismatch (0.2 ± 13.0 vs. 5.5 ± 10.5; p = 0.004). There were no significant differences in amount of change in VAS scores between cohorts. Similar results were seen after propensity-matched analysis and sub-analysis of cases including L5-S1. CONCLUSIONS: L-SPS improves perioperative outcomes and does not compromise clinical or radiographic results at 1-year follow-up compared with MIS TLIF. There may be decreased rates of early mechanical failure with L-SPS.

Comparison of Plastic Surgeon and Spine Surgeon Closure in Revision Short Segment Thoracolumbar Spinal Fusions.

STUDY DESIGN: Retrospective cohort analysis. OBJECTIVE: To compare outcomes of plastic versus spine surgeon wound closure in revision 1 to 4 level thoracolumbar fusions. SUMMARY OF BACKGROUND DATA: Plastic surgeons perform layered musculocutaneous flap closures in high-risk spine patients such as revision posterior spinal fusion and complex deformity correction surgeries. Few studies have assessed outcomes of revision fusion performed with plastic surgical closures, particularly in nondeformity thoracolumbar spinal surgery. METHODS: A retrospective review of 1 to 4 level revision thoracolumbar fusion performed by Orthopedic or Neurosurgical spine surgeons. Patient charts were reviewed for demographics and perioperative outcomes. Patients were divided into two cohorts: wound closures performed by spine surgeons and those closed by plastic surgeons. Outcomes were analyzed before and after propensity score match for prior levels fused, iliac fixation, and levels fused at index surgery. Significance was set at P < 0.05. RESULTS: Three hundred fifty-seven (87.3%) spine surgeon (SS) and 52 (12.7%) plastic surgeon (PS) closures were identified. PS group had significantly higher number of levels fused at index (PS 2.7 ±â€Š1.0 vs. SS 1.8 ±â€Š0.9, P < 0.001) and at prior surgeries (PS 1.8 ±â€Š1.2 vs. SS 1.0 ±â€Š0.9, P < 0.001), and rate of iliac instrumentation (PS 17.3% vs. SS 2.8%, P < 0.001). Plastics closure was an independent risk factor for length of stay  > 5 days (odds ratio 2.3) and postoperative seroma formation (odds ratio 7.8). After propensity score match, PS had higher rates of seromas (PS 36.5% vs. SS 3.8%, P < 0.001). There were no differences between PS and SS groups in surgical outcomes, perioperative complication, surgical site infection, seroma requiring aspiration, or return to operating room at all time points until follow-up (P > 0.05 for all). CONCLUSION: Plastic spinal closure for 1 to 4 level revision posterior thoracolumbar fusions had no advantage in reducing wound complications over spine surgeon closure but increased postoperative seroma formation.Level of Evidence: 4.

Not Frail and Elderly: How Invasive Can We Go in This Different Type of Adult Spinal Deformity Patient?

STUDY DESIGN: Retrospective review of a single-center spine database. OBJECTIVE: Investigate the intersections of chronological age and physiological age via frailty to determine the influence of surgical invasiveness on patient outcomes. SUMMARY OF BACKGROUND DATA: Frailty is a well-established factor in preoperative risk stratification and prediction of postoperative outcomes. The surgical profile of operative patients with adult spinal deformity (ASD) who present as elderly and not frail (NF) has yet to be investigated. Our aim was to examine the surgical profile and outcomes of patients with ASD who were NF and elderly. METHODS: Patients with ASD 18 years or older, four or greater levels fused, with baseline (BL) and follow-up data were included. Patients were categorized by ASD frailty index: NF, Frail (F), severely frail (SF]. An elderly patient was defined as 70 years or older. Patients were grouped into NF/elderly and F/elderly. SRS-Schwab modifiers were assessed at BL and 1 year (0, +, ++). Logistic regression analysis assessed the relationship between increasing invasiveness, no reoperations, or major complications, and improvement in SRS-Schwab modifiers [Good Outcome]. Decision tree analysis assessed thresholds for an invasiveness risk/benefit cutoff point. RESULTS: A total of 598 patients with ASD included (55.3 yr, 59.7% F, 28.3 kg/m2). 29.8% of patients were older than 70 years. At BL, 51.3% of patients were NF, 37.5% F, and 11.2% SF. Sixty-sis (11%) patients were NF and elderly. About 24.2% of NF-elderly patients improved in SRS-Schwab by 1 year and had no reoperation or complication postoperatively. Binary regression analysis found a relationship between worsening SRS-Schwab, postop complication, and reoperation with invasiveness score (odds ratio: 1.056 [1.01-1.102], P = 0.011). Risk/benefit cut-off was 10 (P = 0.004). Patients below this threshold were 7.9 (2.2-28.4) times more likely to have a Good Outcome. 156 patients were elderly and F/SF with 16.7% having good outcome, with a risk/benefit cut-off point of less than 8 (4.4 [2.2-9.0], P < 0.001). CONCLUSION: Frailty status impacted the balance of surgical invasiveness relative to operative risk in an inverse manner, whereas the opposite was seen amongst elderly patients with a frailty status less than their chronologic age. Surgeons should perhaps consider incorporation of frailty status over age status when determining realignment plans in patients of advanced age.Level of Evidence: 3.

Patient Outcomes After Single-level Coflex Interspinous Implants Versus Single-level Laminectomy.

STUDY DESIGN: Retrospective cohort analysis. OBJECTIVE: The aim of this study was to compare postoperative outcomes of Coflex interspinous device versus laminectomy. SUMMARY OF BACKGROUND DATA: Coflex Interlaminar Stabilization device (CID) is indicated for one- or two-level lumbar stenosis with grade 1 stable spondylolisthesis in adult patients, as an alternative to laminectomy, or laminectomy and fusion. CID provides stability against progressive spondylolisthesis, retains motion, and prevents further disc space collapse. METHODS: Patients ≥18 years' old with lumbar stenosis and grade 1 stable spondylolisthesis who underwent either primary single-level decompression and implantation of CID, or single-level laminectomy alone were included with a minimum 90-day follow-up at a single academic institution. Clinical characteristics, perioperative outcomes, and postoperative complications were reviewed until the latest follow-up. χ2 and independent samples t tests were used for analysis. RESULTS: Eighty-three patients (2007-2019) were included: 37 cases of single-level laminectomy (48.6% female) were compared to 46 single-level CID (50% female). CID cohort was older (CID 69.0 ±â€Š9.4 vs. laminectomy 64.2 ±â€Š11.0, P = 0.042) and had higher American Society of Anesthesiologists (ASA) grade (CID 2.59 ±â€Š0.73 vs. laminectomy 2.17 ±â€Š0.48, P = 0.020). CID patients had higher estimated blood loss (EBL) (97.50 ±â€Š77.76 vs. 52.84 ±â€Š50.63 mL, P = 0.004), longer operative time (141.91 ±â€Š47.88 vs. 106.81 ±â€Š41.30 minutes, P = 0.001), and longer length of stay (2.0 ±â€Š1.5 vs. 1.1 ±â€Š1.0 days, P = 0.001). Total perioperative complications (21.7% vs. 5.4%, P = 0.035) and instrumentation-related complication was higher in CID (10.9% vs. 0% laminectomy group, P = 0.039). There were no other significant differences between the groups in demographics or outcomes. CONCLUSION: Single-level CID devices had higher perioperative 90-day complications, longer operative time, length of stay, higher EBL compared to laminectomies alone. Similar overall revision and neurologic complication rates were noted compared to laminectomy at last follow-up.Level of Evidence: 3.

Expandable cages increase the risk of intraoperative subsidence but do not improve perioperative outcomes in single level transforaminal lumbar interbody fusion.

BACKGROUND CONTEXT: Expandable cages (EXP) are being more frequently utilized in transforaminal lumbar interbody fusions (TLIF). EXP were designed to reduce complications related to neurological retraction, enable better lordosis restoration, and improve ease of insertion, particularly in the advent of minimally invasive surgical (MIS) techniques, however they are exponentially more expensive than the nonexpandable (NE) alternative. PURPOSE: To investigate the clinical results of expandable cages in single level TLIF. STUDY DESIGN/SETTING: Retrospective review at a single institution. PATIENT SAMPLE: Two hundred and fifty-two single level TLIFs from 2012 to 2018 were included. OUTCOME MEASURES: Clinical characteristics, perioperative and neurologic complication rates, and radiographic measures. METHODS: Patients ≥18 years of age who underwent single level TLIF with minimum 1 year follow-up were included. OUTCOME MEASURES: clinical characteristics, perioperative and neurologic complications. Radiographic analysis included pelvic incidence-lumbar lordosis (PI-LL) mismatch, segmental lumbar lordosis (LL) mismatch, disc height restoration, and subsidence ≥2 mm. Statistical analysis included independent t tests and chi-square analysis. For nonparametric variables, Mann-Whitney U test and Spearman partial correlation were utilized. Multivariate regression was performed to assess relationships between surgical variables and recorded outcomes. For univariate analysis significance was set at p<.05. Due to the multiple comparisons being made, significance for regressions was set at p<.025 utilizing Bonferroni correction. RESULTS: Two hundred and fifty-two TLIFs between 2012 and 2018 were included, with 152 NE (54.6% female, mean age 59.28±14.19, mean body mass index (BMI) 28.65±5.38, mean Charlson Comorbidity Index (CCI) 2.20±1.89) and 100 EXP (48% female, mean age 58.81±11.70, mean BMI 28.68±6.06, mean CCI 1.99±1.66) with no significant differences in demographics. Patients instrumented with EXP cages had a shorter length of stay (3.11±2.06 days EXP vs. 4.01±2.64 days NE; Z=-4.189, p<.001) and a lower estimated blood loss (201.31±189.41 mL EXP vs. 377.82±364.06 mL NE; Z=-6.449, p<.001). There were significantly more MIS-TLIF cases and bone morphogenic protein (BMP) use in the EXP group (88% MIS, p<.001 and 60% BMP, p<.001) as illustrated in Table 1. There were no significant differences between the EXP and NE groups in rates of radiculitis and neuropraxia. In multivariate regression analysis, EXP were not associated with a difference in perioperative outcomes or complications. Radiographic analyses demonstrated that the EXP group had a lower PI-LL mismatch than the NE cage group at baseline (3.75±13.81° EXP vs. 12.75±15.81° NE; p=.001) and at 1 year follow-up (3.81±12.84° EXP vs. 8.23±12.73° NE; p=.046), but change in regional and segmental alignment was not significantly different between groups. Multivariate regression demonstrated that EXP use was a risk factor for intraoperative subsidence (2.729[1.185-6.281]; p=.018). CONCLUSIONS: Once technique was controlled for, TLIFs utilizing EXP do not have significantly improved neurologic or radiographic outcomes compared with NE. EXP increase risk of intraoperative subsidence. These results question the value of the EXP given the higher cost.