Interbody Graft Research Articles

MRI Vertebral Bone Quality Correlates With Interbody Cage Subsidence After Anterior Cervical Discectomy and Fusion.

Retrospective observational study of consecutive patients. The purpose of the study was to evaluate VBQ as a predictor of interbody subsidence and to determine threshold values that portend increased risk of subsidence. Many risk factors have been reported for the subsidence of interbody cages in anterior cervical discectomy and fusion (ACDF). MRI Vertebral Bone Quality (VQB) is a relatively new radiographic parameter that can be easily obtained from preoperative MRI and has been shown to correlate with measurements of bone density such as DXA and CT Hounsfield Units. All patients who underwent 1- to 3-level ACDF using titanium interbodies with anterior plating between the years 2018 and 2020 at our tertiary referral center were included. Subsidence measurements were performed by 2 independent reviewers on CT scans obtained 6 months postoperatively. VBQ was measured on pre-operative sagittal T1 MRI by 2 independent reviewers, and values were averaged. Eight-five fusion levels in 44 patients were included in the study. There were 32 levels (38%) with moderate subsidence and 12 levels with severe subsidence (14%). The average VBQ score in those patients with severe subsidence was significantly higher than those without subsidence (3.80 vs. 2.40, P<0.01). A threshold value of 3.2 was determined to be optimal for predicting subsidence (AUC=0.99) and had a sensitivity of 100% and a specificity of 94.1% in predicting subsidence. VBQ strongly correlates with the subsidence of interbody grafts after ACDF. A threshold VBQ score value of 3.2 has excellent sensitivity and specificity for predicting subsidence. Spine surgeons can use VBQ as a readily available screening tool to identify patients at higher risk for subsidence. Level-IV.

Instrumented L5-S1 interbody graft with IFUSE implant using the reverse Bohlman technique

BackgroundIn case of high sacral slope, anterior lumbosacral fusions can be performed by retroperitoneal or transperitoneal approach using a reversed Bohlman technique with an autologous corticocancellous fibular graft. The use of a trans-lumbosacral implant can avoid the iatrogenic effects but currently, there is no implant specifically designed for this fusion technique. Could the IFUSE implant from SI BONE replace a fibular graft to avoiding the iatrogenic effect induced by sampling during a Reverse Bohlman technique? Patients and methodsWe present the case of a 38-year-old woman with L5S1 interbody pseudarthrosis after posterior fixation for grade 2 L5-S1 spondylolisthesis with isthmic lysis of L5, and that of a 69-year-old woman who underwent a posterior T4 fusion to the pelvis for degenerative scoliosis. Both required a trans-lumbosacral instrumented fusion via an anterior approach using the reverse Bohlman technique. Surgical technique was described. ResultsThere were no perioperative or postoperative complications. At 6 months, the patients reported a decrease in lumbar and radicular symptomatology. There were no infectious, neurological or vascular complications. CT-scans confirmed the good position and stability of the IFUSE implant. DiscussionWe present an innovative interbody grafting technique adapted to spines with high pelvic incidence. The surgical technique is safe, minimally invasive, and reduces surgical iatrogeny. The short and medium-term results are positive but require longer-term follow-up and a larger cohort.

288 Impact of Disc Degeneration on Clinical Outcomes After Fusion for Grade 1 Spondylolisthesis: A 5-year QOD Study

INTRODUCTION: Disc degeneration with loss of disc height can be an indication to fuse patients with lumbar spondylosis. However, its relevance for spondylolisthesis is unknown. METHODS: The Quality Outcomes Database was queried for adult patients who underwent fusion for single-level degenerative grade 1 lumbar spondylolisthesis. Pfirrmann grade at the level to be fused was assessed on preoperative sagittal T2-weighted MRI. VAS-back pain (BP-VAS), VAS-leg pain (LP-VAS), and ODI were collected preoperatively and at 3, 12, 24, 36, and 60 months postoperatively. RESULTS: The query returned 395 patients. Mean age (95% CI) was 60 (58.9-61.1) years; 39.5% were male. None had a Pfirrmann grade 1 disc. One (0.3%) had a grade 2 disc, 53 (13.4%) had a grade 3 disc, 245 (62%) had a grade 4 disc, and 96 (24.3%) had a grade 5 disc. Posterior-only approach was performed in 92.6%; interbody graft was placed in 92.7%. Mean BP-VAS (95% CI) at baseline, 3 months, 12 months, 24 months, 36 months, and 60 months were 7.1 (6.8-7.3) (n = 343), 3.1 (2.8-3.3) (n = 353), 2.9 (2.6-3.2) (n = 305), 3.2 (2.8-3.5) (n = 283), 3.5 (2.9-4.1) (n = 107), and 3.7 (3.3-4.0) (n = 324). Mean LP-VAS (95% CI) were 6.7 (6.4-7.0) (n = 392), 2.3 (2.0-2.6) (n = 353), 2.2 (1.9-2.6) (n = 306), 2.6 (2.2-2.9) (n = 284), 2.8 (2.2-3.4) (n = 107), and 2.8 (2.4-3.1) (n = 322). Mean ODI (95% CI) were 49.4 (47.8-51.1) (n = 392), 27.4 (25.3-29.5) (n = 347), 22.9 (20.6-25.2) (n = 313), 22.4 (20.1-24.8) (n = 291), 22.4 (18.3-26.4) (n = 97), and 25.9 (23.7-28.2) (n = 325). Utilizing linear regression, Pfirrmann grade was not associated with improvements in VAS-BP, VAS-LP, or ODI at any time point in unadjusted and adjusted analyses (p &gt; 0.05). CONCLUSIONS: Patients who undergo fusion for single-level grade 1 spondylolisthesis are likely to experience significant and sustained improvements in pain and function regardless of severity of disc degeneration.

Anterior lumbar interbody fusion (ALIF): a review of the procedure and associated complications

Degenerative disc disease and facet joint disease involving the lumbar spine are common in the aging population and are the most frequent causes of disability. Surgical interbody fusion of degenerative levels is the most common management technique. This is an effective treatment option to stabilize the spine and reduce mechanical pain and provides indirect decompression of the neural elements while restoring lordosis and correcting the deformity. Depending on the direction of the approach to the vertebral column, various techniques have been described. Anterior lumbar interbody fusion (ALIF) offers clear and wide visualization of the disc allowing the use of large interbody grafts, which provide a significant biomechanical advantage over other types of fusion. The transperitoneal approach is a much older technique and it is not commonly performed unless in isolated cases with extensive retroperitoneal scaring following multiple abdominal surgeries. The transperitoneal approach has been associated with higher rates of bowel injury, ileus, and retrograde ejaculation, and is limited at the L5–S1 segment, hence many spine surgeons favor a retroperitoneal approach. The major setback of ALIF is the need for great vessel mobilization. This manipulation of the vessels may lead to deep vein thrombosis and a direct vascular injury. This makes vascular anatomy studies in the preoperative stage invaluable in avoiding vascular injury. Other complications include possible injury to intraperitoneal and retroperitoneal organs, especially in patients with previous surgery and adhesions. Manipulation of the intestines causes postoperative ileus which lasts a few days. Sexual dysfunction in form of retrograde ejaculation is another complication seen in patients following ALIF and this has been attributed to injury to the superior hypogastric sympathetic nerves in the lower lumbar region.This article reviews the ALIF procedure i. e., transperitoneal and retroperitoneal approaches, and the associated intraoperative, early, and late 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.

122 Prospective, Randomized, Blinded Clinical Trial Comparing PEEK and Allograft Spacers in Patients Undergoing ACDF Surgeries

INTRODUCTION: The biomechanical qualities as well as osteoconductive, osteogenic, and osteoinductive properties of various graft materials have been previously evaluated. There remain questions, however as to whether there are any clinical and/or radiographic outcome differences in the selection of interbody graft types for ACDF. METHODS: Patients undergoing one- to three-level ACDF with single anterior plate fixation were randomized (1:1 ratio) to receive either cortical allograft or PEEK interbody spacers. Radiographic and clinical outcomes were assessed at 3, 6, 12 and 24 months with an additional postoperative radiographic assessment. RESULTS: A total of 120 patients were enrolled and randomized. Comparing clinical outcomes, no differences in arm or neck pain scores were noted, however, there was a statistically significant (&lt;0.041) improvement in SF-36 PCS scores for the allograft group at all follow-up time points and a tendency towards lower disability scores. Overall, evidence of radiographic fusion was achieved in 87 (91.6%) patients: five (10.2%) and three (6.5%) patients had pseudoarthrosis (p=0.72) in the PEEK and allograft groups, respectively. At the 24-month follow-up, any cervical or segmental alignment restoration achieved with surgery was lost and no statistically significant changes were detected when all levels of surgery were included. Likewise, there were no statistically significant differences between the groups for anterior or posterior body height measurements at the 24-month follow-up. Approximately 20% of patients had anterior and posterior subsidence, all grade 0 regardless of the group assignment. CONCLUSIONS: Comparable radiographic outcomes were observed for patients undergoing one- to three-level PEEK vs. allograft-assisted ACDF surgeries.

Single Posterior Surgery Versus Combined Posterior–Anterior Surgery for Lumbar Tuberculosis Patients

Posterior approach of debridement, interbody graft, and instrumentation, and combined posterior-anterior approach of posterior instrumentation and anterior debridement and interbody graft are two essential surgeries for the surgical treatment of spinal tuberculosis (TB), and, until now, which one should be chosen is still controversial. This study aimed to compare the therapeutic efficacy between the single posterior surgery and combined posterior-anterior surgery for lumbar tuberculosis (LTB) patients to elucidate the role of debridement and the effects that result from posterior structure resection. One hundred and nineteen LTB patients managed with single posterior debridement, interbody graft, and instrumentation surgery (Group P, 73 cases), or combined posterior-anterior surgery of posterior instrumentation and anterior debridement and interbody graft (Group P-A, 46 cases) from January 2008 to December 2016 were retrospectively analyzed. Different indexes were compared between the two groups to evaluate the curative effect and explore the role of debridement and the effects that result from posterior structure resection: operation time, blood loss, visual analog scale (VAS), Japanese Orthopaedic Association (JOA), Erythrocyte Sedimentation Rate (ESR), C-reactive Protein (CRP), surgical complication type and rate, spinopelvic sagittal parameters (local kyphosis [LK], pelvic incidence [PI] and pelvic tilt [PT], lumbar lordosis [LL], and sacral slope [SS]), drainage retention duration, hospital stay, time of abscess disappearance, time of activity recovery, and time of bone graft fusion by t-test or χ2 test. The follow-up period ranged from 24 to 60months. No significant variations were detected between the two groups for age, sex ratio, BMI, disease duration, indication, and the preoperative values of VAS, JOA, ESR, CRP, and LK (p > 0.05). The VAS, JOA, ESR, and CRP significantly improved in both groups after the operation (p < 0.05), along with the LK and LL (p < 0.05). Meanwhile, the SS, PI, and PT showed minor improvement after the operation (p > 0.05). Compared to the P-A group, the P group had shorter operation time and less blood loss and hospital stay (p < 0.05). However, both groups presented similar VAS, JOA, ESR, CRP, and LK improvements (p > 0.05). Additionally, the surgical complication type and rate, postoperative spinopelvic sagittal parameters, and bone graft fusion time did not differ between the two groups (p > 0.05). On the other hand, the patients in the P-A group had a shorter time of abscess disappearance and activity recovery (p < 0.05) but a similar time of drainage retention (p > 0.05) compared to the P group. Both single posterior and combined posterior-anterior surgeries presented a good therapeutic effect for LTB patients with a low surgical complication rate and good quality of LK correction and LL reconstruction and maintenance. Moreover, single posterior surgery was less traumatic than combined posterior-anterior surgery but with slower TB lesion healing and activity recovery. Compared to debridement, stability seems to be more vital for STB healing, posterior structure resection does not affect the effect of spinopelvic realignment.

Proximal and distal mechanical repercussions of instrumentation by double rods and interbody grafts in adult scoliosis

IntroductionCorrection of adult scoliosis by instrumentation with double rods and interbody grafts aims to reduce the risk of pseudarthrosis with rod fracture. An increase in instrumentation rigidity can lead to an increase in stresses at the proximal and distal ends of the construct. The aim of this study was to analyze the incidence and clinical repercussions of proximal junctional kyphosis (PJK), proximal junctional failure (PJF) and iliac screw loosening. Materiel and methodsAn analysis of patients operated on for adult scoliosis with instrumentation to the pelvis using 4 rods and interbody cages was carried out from a prospective register. The Visual Analog Scale (VAS), Oswestry Disability Index (ODI), Scoliosis Research Society 22 (SRS-22) clinical scores and radiological parameters were collected preoperatively, postoperatively at 3 months, 1 year and 2 years. The appearance of PJK, PJF or distal screw loosening was sought; the clinical impact and the risk factors were analyzed by Bayesian inference. ResultsFifty-one patients with a mean age of 64.5 years were included. The clinical scores improved significantly (Pr>0.95) at 2 years: VAS back 6.9 versus 2.6, VAS leg 4.9 versus 2.5, ODI 48.2 versus 25.4, SRS-22 2.4 versus 3.5. The radiological parameters were corrected (Pr>0.95): Cobb angle 63.9° versus 22.8°, spinosacral angle (SSA) 112.4° versus 118.8°, T1-pelvic angle (TPA) 24, 8° versus 20.8°, lumbar lordosis 43.8° versus 51.0°, thoracic kyphosis 45.2° versus 53.6°. Thirteen patients (25.5%) presented with PJK and 11 (21.6%) with PJF. Seven patients (13.7%) presented with iliac screw loosening. None of these complications was associated with a significant deterioration in clinical scores. Cranial migration of the lumbar apex increased the risk of distal screw loosening: Odds-Ratio 10.31 (Pr>0.999). Two patients were re-operated on for PJF and one patient for iliac screw loosening (5.9%). No rod fracture with pseudarthrosis was found. ConclusionInstrumentation with double rods and interbody grafts was associated with a rate of 47.1% of mechanical repercussions at the extremity of the construct. However, these complications were not associated with a significant deterioration in clinical scores. Level of evidenceIII.

Fusion and clinical outcomes of lumbar interbody fusion for low-grade isthmic spondylolisthesis

IntroductionLow-grade isthmic spondylolisthesis (ISPL) is generally treated by circumferential fusion with interbody graft, although there is no consensus on technique. HypothesisThe various interbody fusion strategies provide satisfactory fusion rates and clinical results. MethodsA multicenter retrospective study analyzed lumbar interbody fusion for low-grade ISPL performed between March 2016 and March 2019. Techniques comprised: circumferential fusion on a posterior or a transforaminal approach (PLIF, TLIF: n=57), combined anterior (ALIF)+posterolateral fusion (ALIF+PLF: n=60), and ALIF+percutaneous posterior fixation (ALIF+PPF: n=55). Function was assessed on a lumbar and a radicular visual analog scale (AVS-L, VAS-R), Oswestry Disability Index (ODI) and Short Form 12 (SF12). ResultsAmong the 129 patients, 85.3% showed fusion (Lenke 1 or 2), with no significant differences between the ALIF-PLF or ALIF-PPF groups and the PLIF or TLIF groups (p=0.3). Likewise, there was no difference in fusion rates between the ALIF-PPF and ALIF-PLF subgroups (p=0.28). VAS-L (p<0.001) and VAS-R (p<0.0001), ODI (p<0.001) and SF12 physical (PCS) (p<0.01) and mental component sores (MCS) (p<0.001) all showed significant improvement at 12months. Combined approaches provided greater clinical efficacy than TLIF or PLIF for lumbar (p<0.0001) and radicular pain (p<0.05), ODI (p<0.0001) and SF12 PCS (p<0.01). At 12months, there was no clinical difference between the ALIF-PPF and ALIF-PLF subgroups. However, patents with interbody non-union (Lenke 3 or 4) had lower SF12 PCS scores (p<0.004) and VAS-L ratings (p<0.001) than Lenke 1-2 patients. ConclusionLow-grade ISPL treated by circumferential arthrodesis and interbody graft showed 85.3% consolidation at 2years, with equivalent outcomes between anterior and posterior techniques. Successful fusion was associated with better clinical results. Level of evidenceIV.

Analysis of Nanohydroxyapatite/Polyamide-66 Cage, Titanium Mesh, and Iliac Crest in Spinal Reconstruction of the Patients with Thoracic and Lumbar Tuberculosis

The standard recommended and common reconstruction method for spinal tuberculosis is titanium mesh bone graft and autogenous iliac crest. However, these methods have their own disadvantages. To evaluate the clinical efficacy of one-stage posterior debridement with iliac bone graft, titanium mesh bone graft, or nanohydroxyapatite/polyamide-66 cage in thoracic and lumbar tuberculosis. Between January 2013 and December 2018, 57 patients with thoracic or lumbar tuberculosis were treated by interbody bone graft combined with posterior internal fixation after debridement. Thirteen patients were treated with iliac bone graft to construct the stability of the vertebral body, 26 patients were treated with titanium mesh bone graft, and 18 patients were treated with nanohydroxyapatite/polyamide-66 cage bone graft. The main clinical results were evaluated by intervertebral height, cage subsidence, operation time, operative blood loss, postoperative hospitalization, postoperative complications, visual analog scale (VAS) score, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), American Spinal Injury Association (ASIA) grade, and bone graft fusion time. All the outcomes were recorded and analyzed by statistical methods. The mean follow-up time was 24.5 months. Neurologic function was improved in most patients at the last follow-up. There were significant differences in ESR, CRP, and VAS score between preoperative and postoperative values; however, there were no significant differences in ESR, CRP, and VAS score among the three groups. There were no significant differences in operation time, blood loss, postoperative hospitalization, and postoperative complications among the three groups at discharge. There was no significant difference in ASIA grade among the three groups at the last follow-up. Nanohydroxyapatite/polyamide-66 cage group had a lower cage subsidence (P = 0.013). The bone graft fusion time of the nanohydroxyapatite/polyamide-66 cage group was significantly shorter than the iliac bone graft group and the titanium mesh bone graft (P < 0.05). The follow-up outcomes showed that the method involving one-stage posterior debridement and internal fixation, interbody graft, and fusion is an effective and safe surgical method for patients with thoracic and lumbar tuberculosis. The incidence rate of cage subsidence was less and the bone graft fusion time was shorter with nanohydroxyap atite/polyamide 66 cage when compared with iliac bone graft and titanium mesh bone graft in the surgical treatment of thoracic and lumbar tuberculosis. Nanohydroxyapatite/polyamide-66 cage has a promising application prospect to be a new bone graft material.

227. Prospective, randomized, blinded clinical trial comparing PEEK and allograft spacers in patients undergoing ACDF surgeries

BACKGROUND CONTEXT The biomechanical qualities as well as osteoconductive, osteogenic and osteoinductive properties of various graft materials have been previously evaluated. There remain questions, however as to whether there are any clinical and/or radiographic outcome differences in the selection of interbody graft types for ACDF. PURPOSE The main objective of the study was to examine clinical and radiological outcomes in patients undergoing ACDF surgeries randomized to receive either PEEK or structural bone allografts. STUDY DESIGN/SETTING A prospective, randomized, blinded clinical trial was initiated at a single center. PATIENT SAMPLE A total of 120 patients were enrolled and randomized. OUTCOME MEASURES All patients were followed for 2 years ± 2 months; radiographic and clinical outcomes were assessed at 3, 6, 12 and 24 months with an additional follow-up at 3 weeks for radiographic assessment. METHODS Patients undergoing one- to three-level ACDF with single anterior plate fixation were randomized (1:1 ratio) to receive either cortical allograft or PEEK interbody spacers. RESULTS Comparing clinical outcomes, no differences in arm or neck pain scores were noted, however there was a statistically significant (< 0.041) improvement in SF-36 PCS scores for the allograft group at all follow-up time points and a tendency towards lower disability scores. Overall, evidence of radiographic fusion was achieved in 87 (91.6%) patients: five (10.2%) and three (6.5%) patients had pseudoarthrosis (p=0.72) in the PEEK and allograft groups, respectively. At 24 months follow-up time, any cervical or segmental alignment restoration achieved with surgery was lost and no statistically significant changes were detected when all levels of surgery were included. Likewise, there were no statistically significant differences between the groups for anterior or posterior body height measurements at the 24 months follow-up. Approximately 20% of patients had anterior and posterior subsidence, all grade 0 regardless of the group assignment. CONCLUSIONS Comparable radiographic outcomes were observed for patients undergoing one- to three-level PEEK vs allograft-assisted ACDF surgeries. There was a tendency for improved clinical outcomes in the allograft patient group. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. The biomechanical qualities as well as osteoconductive, osteogenic and osteoinductive properties of various graft materials have been previously evaluated. There remain questions, however as to whether there are any clinical and/or radiographic outcome differences in the selection of interbody graft types for ACDF. The main objective of the study was to examine clinical and radiological outcomes in patients undergoing ACDF surgeries randomized to receive either PEEK or structural bone allografts. A prospective, randomized, blinded clinical trial was initiated at a single center. A total of 120 patients were enrolled and randomized. All patients were followed for 2 years ± 2 months; radiographic and clinical outcomes were assessed at 3, 6, 12 and 24 months with an additional follow-up at 3 weeks for radiographic assessment. Patients undergoing one- to three-level ACDF with single anterior plate fixation were randomized (1:1 ratio) to receive either cortical allograft or PEEK interbody spacers. Comparing clinical outcomes, no differences in arm or neck pain scores were noted, however there was a statistically significant (< 0.041) improvement in SF-36 PCS scores for the allograft group at all follow-up time points and a tendency towards lower disability scores. Overall, evidence of radiographic fusion was achieved in 87 (91.6%) patients: five (10.2%) and three (6.5%) patients had pseudoarthrosis (p=0.72) in the PEEK and allograft groups, respectively. At 24 months follow-up time, any cervical or segmental alignment restoration achieved with surgery was lost and no statistically significant changes were detected when all levels of surgery were included. Likewise, there were no statistically significant differences between the groups for anterior or posterior body height measurements at the 24 months follow-up. Approximately 20% of patients had anterior and posterior subsidence, all grade 0 regardless of the group assignment. Comparable radiographic outcomes were observed for patients undergoing one- to three-level PEEK vs allograft-assisted ACDF surgeries. There was a tendency for improved clinical outcomes in the allograft patient group.

Posterior-only debridement, bone fusion, single-segment versus short-segment instrumentation for mono-segmental lumbar or lumbosacral pyogenic vertebral osteomyelitis: minimum five year follow-up outcomes

BackgroundPyogenic vertebral osteomyelitis (PVO), which is a potentially life-threatening condition and is associated with significant morbidity and mortality, is a cause of back pain that can lead to neurologic deficits if not diagnosed in time and effectively treated. The objective of this study is to compare the efficacy of posterior single-segment and short-segment fixation combined with one-stage posterior debridement and fusion for the treatment of mono-segmental lumbar or lumbosacral PVO.MethodsCharts of all patients with mono-segmental lumbar or lumbosacral PVO were treated by single-stage posterior debridement, bone graft fusion, and pedicle screw fixation from April 2012 to January 2016. All patients were divided into two groups: sinlge-segment fixation (Group A, n = 31) and short-segment fixation (Group B, n = 36). These patients were followed up for a minimum of five years. The clinical efficacy was evaluated and compared on average operation time, blood loss, visual analog scale (VAS), erythrocyte sedimentation rate (ESR), C-Reactive protein (CRP), neurological function recovery and local lordotic angle.ResultsAll 67 patients were completely cured during the follow-up. All patients had significant improvement of neurological condition and pain relief at the final follow-up. The VAS was 7.1 ± 0.7 in group A and 7.2 ± 0.6 in group B pre-operatively, which decreased to 2.1 ± 0.6 and 2.0 ± 0.7, respectively, at three months after surgery, then reduced to 0.4 ± 0.5 and 0.5 ± 0.5, respectively, at the final follow-up. ESR, CRP returned to normal limits in all patients 3 months after surgery. The mean blood loss and operation time in group A were less than that in group B (P < 0.05). The local lordotic angle in group A was increased from preoperative − 1.7 ± 7.9° to postoperative 5.8 ± 7.1°, with angle loss of 1.5 ± 0.8° at the final follow-up, respectively (P < 0.05). The local lordotic angle in group B was increased from preoperative − 1.6 ± 7.8° to postoperative 13.5 ± 6.2°, with angle loss of 1.3 ± 0.8° at the final follow-up, respectively (P < 0.05). In the mean postoperative local lordotic angle, there was significant difference between the two groups at the time of immediate postoperative period or the final follow-up (P < 0.05).ConclusionPosterior-only debridement, interbody graft using titanium mesh cage, posterior single-segment instrumentation and fusion represent a safe and effective treatment option for selected patients with mono-segmental lumbar and lumbosacral PVO. This approach may preserve more lumbar normal motor units with less blood loss and operation time when compared with that of short-segment fixation. But short-segment fixation was superior to the single-segment fixation in the correction of kyphosis.

Prospective, Randomized, Blinded Clinical Trial Comparing PEEK and Allograft Spacers in Patients Undergoing Anterior Cervical Discectomy and Fusion Surgeries.

Prospective, randomized, blinded clinical trial. To examine clinical and radiological outcomes in patients undergoing anterior cervical discectomy and fusion (ACDF) surgeries randomized to receive either polyether-ether-ketone (PEEK) or structural bone allografts. The biomechanical qualities as well as osteoconductive, osteogenic, and osteoinductive properties of various graft materials have been previously evaluated. There remain questions, however, as to whether there are any clinical and/or radiographic outcome differences in the selection of interbody graft types for ACDF. Patients undergoing one- to three-level ACDF with single anterior plate fixation were randomized (1:1 ratio) to receive either cortical allograft or PEEK interbody spacers. Radiographic and clinical outcomes were assessed at 3, 6, 12, and 24 months with an additional postoperative radiographic assessment. A total of 120 patients were enrolled and randomized. Comparing clinical outcomes, no differences in arm or neck pain scores were noted; however, there was a statistically significant (≤0.041) improvement in SF-36 PCS scores for the allograft group at all follow-up time points and a tendency toward lower disability scores. Overall, evidence of radiographic fusion was achieved in 87 (91.6%) patients: five (10.2%) and three (6.5%) patients had pseudoarthrosis (P = 0.72) in the PEEK and allograft groups, respectively. At 24 months' follow-up time, any cervical or segmental alignment restoration achieved with surgery was lost and no statistically significant changes were detected when all levels of surgery were included. Likewise, there were no statistically significant differences between the groups for anterior or posterior body height measurements at the 24 months' follow-up. Approximately 20% of patients had anterior and posterior subsidence, all grade 0 regardless of the group assignment. Comparable radiographic outcomes were observed for patients undergoing one- to three-level PEEK versus allograft-assisted ACDF surgeries. Although MCID comparisons suggest that allograft and PEEK-treated patients have similar clinical outcomes, testing that incorporates the magnitude of the change suggests that there may be a statistically significant greater magnitude of improvement for the allograft group patients, but further studies with a larger sample size would be helpful to determine if a true effect exists.

Is L5/S1 interbody fusion necessary in long-segment surgery for adult degenerative scoliosis? A systematic review and meta-analysis.

There is no consensus regarding the best surgical strategy at the lumbosacral junction (LSJ) in long constructs for adult spinal deformity (ASD). The use of interbody fusion (IF) has been advocated to increase fusion rates, with additional pelvic fixation (PF) typically recommended. The actual benefit of IF even when extending to the pelvis, however, has not been vigorously analyzed. The goal of this work was to better understand the role of IF, specifically with respect to arthrodesis, when extending long constructs to the ilium. A systematic review of the PubMed and Cochrane databases was performed to identify the relevant studies in English, addressing the management of LSJ in long constructs (defined as ≥ 5 levels) in ASD. The search terms used were as follows: "Lumbosacral Junction," "Long Constructs," "Long Fusion to the Sacrum," "Sacropelvic Fixation," "Interbody Fusion," and "Iliac Screw." The authors excluded technical notes, case reports, literature reviews, and cadaveric studies; pediatric populations; pathologies different from ASD; studies not using conventional techniques; and studies focused only on alignment of different levels. The PRISMA protocol was used. The authors found 12 retrospective clinical studies with a total of 1216 patients who were sorted into 3 different categories: group 1, using PF or not (n = 6); group 2, using PF with or without IF (n = 5); and group 3, from 1 study comparing anterior lumbar interbody fusion versus transforaminal lumbar interbody fusion. Five studies in group 1 and 4 in group 2 had pseudarthrosis rate as primary outcome and were selected for a quantitative analysis. Forest plots were used to display the risk ratio, and funnel plots were used to look at the risk of publication bias. The summary risk ratios were 0.36 (0.23-0.57, p < 0.001) and 1.03 (0.54-1.96, p = 0.94) for the PF and IF, respectively; there is a protective effect of overall pseudarthrosis for using PF in long constructs for ASD surgeries, but not for using IF. The long-held contention that L5/S1 IF is always advantageous in long-construct deformity surgery is not supported by the current literature. Based on the findings from this systematic review and meta-analysis, PF with or without additional L5/S1 interbody grafting demonstrates similar overall construct pseudarthrosis rates. The added risk and costs associated with IF, therefore, should be more closely considered on a case-by-case basis.

Innovations in Spinal Endoscopy

Innovations in spinal endoscopy technology and technique have broadened their applications during the past 10 years. Smaller outer-diameter working-channel endoscopes have permitted safe usage in the cervical spine for full endoscopic decompressions. Endoscopic fusions have now been widely reported, leveraging compatible instrumentation for disc preparation and expandable interbody grafts. This ultra-minimally invasive technique has also enabled the performance of fusion procedures in awake patients under monitored anesthesia care, affording speedier recovery and treatment options for those unable to undergo general anesthesia. Revision surgery after open or minimally invasive posterior discectomy or instrumentation can now be performed with endoscopic techniques, which often leverage the transforaminal approach to avoid scar tissue and adhesions. These procedures, among other endoscopic surgeries, are now being increasingly performed in ambulatory surgery centers, as safe outcomes, economic benefits to the healthcare system, and patients' desire to recover at home are becoming more apparent. Finally, the standardization of endoscopic terminology, which has long been a confounder to proper communication and education in this field, has recently been addressed by leading experts in a consensus document, which will serve as the foundation for future collaborative advancements.

Radiographic analysis of neuroforaminal and central canal decompression following lateral lumbar interbody fusion

BackgroundLateral lumbar interbody fusion (LLIF) is a minimally invasive surgical option for treating symptomatic degenerative lumbar spinal stenosis (DLSS) in select patients. However, the efficacy of LLIF for indirectly decompressing the lumbar spine in DLSS, as well as the best radiographic metrics for evaluating such changes, are incompletely understood. MethodsA single-institutional cohort of patients who underwent LLIF for DLSS between 5/2015 – 12/2019 was retrospectively reviewed. Diameter, area, and stenosis grades were measured for the central canal (CC) and neural foramina (NF) at each LLIF level based on preoperative and postoperative T2-weighted MRI. Baseline facet joint (FJ) space, degree of FJ osteoarthritis, presence of spondylolisthesis, interbody graft position, and posterior disc height were analyzed as potential predictors of radiographic outcomes. Changes to all metrics after LLIF were analyzed and compared across lumbar levels. Preoperative and intraoperative predictors of decompression were then assessed using multivariate linear regression. ResultsA total of 102 patients comprising 153 fused levels were analyzed. Pairwise linear regression of stenosis grade to diameter and area revealed significant correlations for both the CC and NF. All metrics except CC area were significantly improved after LLIF (p < 0.05, 2-tailed t-test). Worse FJ osteoarthritis ipsilateral to the surgical approach was predictive of greater post-operative CC and NF stenosis grade (p < 0.05, univariate and multivariate ordinary least squares linear regression). Lumbar levels L3-5 had significantly higher absolute postoperative CC stenosis grades while relative change in CC stenosis at the L2-3 was significantly greater than other lumbar levels (p < 0.05, one-way ANOVA). There were no baseline or postoperative differences in NF stenosis grade across lumbar levels. ConclusionsRadiographically, LLIF is effective at indirect compression of the CC and NF at all lumbar levels, though worse FJ osteoarthritis predicted higher degrees of post-operative stenosis.

Analysis of the clinical effect of posterior focus debridement and interbody bone grafting in the treatment of spinal tuberculosis.

Analysis of the clinical effect of posterior focus debridement and interbody bone grafting in the treatment of spinal tuberculosis.

Efficacy and radiographic analysis of oblique lumbar interbody fusion in treating adult spinal deformity.

Adult spinal deformity (ASD) is usually rigid and requires a combined anterior–posterior approach for deformity correction. Anterior lumbar interbody fusion (ALIF) allows direct access to the disc space and placement of a large interbody graft. A larger interbody graft facilitates correction of ASD. However, an anterior approach carries significant risks. Lateral lumbar interbody fusion (LLIF) through a minimally invasive approach has recently been used for ASD. The present study was performed to evaluate the effectiveness of oblique lumbar interbody fusion (OLIF) in the treatment of ASD. We performed a retrospective study utilizing the data of 74 patients with ASD. The inclusion criteria were lumbar coronal Cobb angle > 20°, pelvic incidence (PI)–lumbar lordosis (LL) mismatch > 10°, and minimum follow–up of 2 years. Patients were divided into two groups: ALIF combined with posterior spinal fixation (ALIF+PSF) (n = 38) and OLIF combined with posterior spinal fixation (OLIF+PSF) (n = 36). The perioperative spinal deformity radiographic parameters, complications, and health-related quality of life (HRQoL) outcomes were assessed and compared between the two groups. The preoperative sagittal vertical axis (SVA), LL, PI–LL mismatch, and lumbar Cobb angles were similar between the two groups. Patients in the OLIF+PSF group had a slightly higher mean number of interbody fusion levels than those in the ALIF+PSF group. At the final follow–up, all radiographic parameters and HRQoL scores were similar between the two groups. However, the rates of perioperative complications were higher in the ALIF+PSF than OLIF+PSF group. The ALIF+PSF and OLIF+PSF groups showed similar radiographic and HRQoL outcomes. These observations suggest that OLIF is a safe and reliable surgical treatment option for ASD.

Anterior C2-3 fusion surgery alone for highly displaced Hangman’s fracture with severe angulation of C2-3 of more than 30°

BackgroundHighly displaced Hangman’s fracture is a very rare and extremely unstable fracture of the C2 axis. Combined anteroposterior or posterior long-segment fusion surgery is typically performed for the treatment of highly displaced Hangman’s fracture. However, these kinds of surgeries increase the risk of complications, loss of motion, and hospital costs. ObjectiveWe sought to investigate the surgical outcomes of anterior C2-3 fusion surgery alone for highly displaced Hangman’s fractures with severe angulation of C2-3 by more than 30° and discoligamentous injury. MethodsA total of five patients (four men and one woman) were included in this study with a mean age of 40.4 years (range, 26–70 years). The mean follow-up period after surgery was 37.2 months (range, 12–96 months). The fracture characteristics, treatment methods, and outcomes were retrospectively analyzed. ResultsAll five patients had type II Hangman’s fractures (according to the Levine and Edwards classification scheme). None of the included patients had neurologic deficit or other spine injury but all patients had complete C2-3 discoligamentous injury. Before surgery, all patients successfully achieved closed reduction by skull traction, followed by C2-3 anterior decompression and fusion (ACDF) with plating. For interbody grafting, three patients received a polyetheretherketone (PEEK) cage filled with an autogenous cancellous iliac bone graft and two received autogenous tricortical iliac bone grafts. Severe angulation (39.2° vs. 3.0°, P < 0.001) and severe displacement (76.1% vs. 4.0%, P < 0.001) of C2-3 were both significantly corrected after surgery. All patients had achieved solid fusion at last follow-up. In terms of clinical outcomes, the mean neck pain visual analog scale score was significantly improved (8.6 points vs. 1.8 points, P < 0.001). The mean neck disability index value was also significantly improved (45.4 points vs. 13.0 points, P < 0.01). According to Odom’s criteria, all patients achieved satisfactory outcomes. No major complications occurred. One patient complained of dysphagia, but recovered after three months with conservative treatment. ConclusionsPreoperative closed reduction and anterior C2-3 fusion surgery alone should be considered as a less-invasive and useful surgical option for highly displaced Hangman’s fracture with severe angulation of C2-3, which is an extremely unstable fracture of the C2 axis.

Hybrid Anterior Column Realignment—Pedicle Subtraction Osteotomy for Severe Rigid Sagittal Deformity

Recently, a hybrid anterior column realignment-pedicle subtraction osteotomy (ACR-PSO) approach has been conceived for patients with severe rigid sagittal deformity, the clinical and radiographic outcomes of which require further investigation compared with ACR only. A single-center, retrospective chart review identified patients undergoing a combination of hyperlordotic lateral lumbar interbody grafting (ACR) and concurrent Schwab grade 3 three-column osteotomy and propensity-matched patients undergoing ACR only in the same time frame. Anterior longitudinal ligament was directly released or partially sectioned in all patients. Chart data included demographics, Oswestry Disability Index scores, ACR and osteotomy locations, cage dimensions, fusion length, and complications. Radiographic measurements included lumbar lordosis, sagittal vertical axis, pelvic tilt (PT), and proximal junctional kyphosis. Fourteen patients were enrolled in the ACR+ PSO group and 36 in the ACR-only group. Mean ages were 68.5 and 63.9 years, 64% and 67% were female, average body mass index was 27.9 and 29.2, and cardiopulmonary comorbidities were 21% and 17%, respectively. There was no difference in complications (P= 0.347). The average follow-up for the ACR+ PSO and ACR-only groups were 22 and 18 months, respectively. Excluding 2 mortalities, fusion occurred in all patients. Average change in lumbar lordosis measured-40.8 ± 9.2 degrees and-19.1 ± 15.7 degrees (P= 0.0006), and PT correction measured 10.5 ± 3.4 degrees and 27.3 ± 1.6 degrees (P < 0.0001), respectively. For patients with severe rigid sagittal deformity, the hybrid ACR-PSO approach offers significant restoration of lumbar lordosis compared with ACR only, with similar complications but reduced PT correction.