Comparative Outcome Data Using Different Techniques for Posterior Lumbar Fusion: A Large Single-Center Study.

STUDY DESIGN: Retrospective single-center study. PURPOSE: This study aims to evaluate perioperative and intermediate-term clinical outcomes of patients undergoing different lumbar fusion techniques. OVERVIEW OF LITERATURE: Various open and minimally invasive techniques for lumbar fusion are available, but previous studies comparing lumbar fusion techniques have heterogeneous data, making interpretation challenging. METHODS: Between 2011 and 2018, data from 447 consecutive patients undergoing one/two-level lumbar fusion were analyzed. Posterior lumbar interbody fusion (PLIF) with bilateral muscle strip or Wiltse approach, open transforaminal lumbar interbody fusion (TLIF) and minimally invasive TLIF, and posterolateral fusion only were among the surgical techniques used. Core outcomes measure index (COMI) questionnaires were distributed before surgery and at 3 months, 1 year, and 2 years postoperatively to establish patient selfreported outcome measures. Demographic data (age, gender, and body mass index [BMI]) for each patient were also collected in addition to surgical indication, previous operative history, perioperative outcomes, and complications, and whether later revision surgery was required. Pearson's chi-square test, Kruskal-Wallis test, repeated measure mixed-effects models, and ordinal logistic regression were used for statistical analysis. RESULTS: Postoperative COMI scores improved across all procedures compared with pre-surgery (p<0.001). There was no significant difference between different postoperative COMI scores. Significant predictors of higher postoperative COMI score included higher pretreatment COMI score (p≤0.001), previous surgery (p≤0.04), younger age (p≤0.05), higher BMI (p≤0.005), and the indications of lytic spondylolisthesis (p=0.02) and degenerative disc disease (p<0.001). Patients undergoing minimally invasive TLIF had a significantly shorter post-surgery stay than patients undergoing open PLIF (Kruskal-Wallis test, p=0.03). CONCLUSIONS: At 2 years postoperatively, there was no significant difference in clinical outcomes between open and minimally invasive techniques. These findings suggest that the main determinant of surgical approach should be surgeon preference and training.

Revision pedicle screws with impaction bone grafting: a case series.

BACKGROUND: Pedicle screw fixation in spinal constructs can be subject to failure requiring revision surgery. In cases of aseptic loosening various salvage techniques have been described. Revision screws augmented with cement have become popular but are not without risks. Larger diameter screws are often used but result in reducing bone stock or expanding the pedicles. We present a novel technique of pedicle screw revision by impaction bone allografting and a case series. METHODS: The failed screws are removed. The screw track is probed to check its integrity. Milled bone allograft is funneled into the screw hole and sequentially impacted, before insertion of a replacement screw. We report a case series and describe a single case where this method has been used. Information was gathered from the electronic patient record in our hospital. RESULTS: Ten screws were revised in 7 patients. Mean age at first surgery was 60.86 (48-76) years. Average time between first surgery and revision was 12.6 (4.7-49.9) months. Average follow-up was 26.2 (5.7-62.2) months and no screws showed any signs of loosening. CONCLUSIONS: Impaction grafting with bone allograft is a technique for pedicle screw salvage that can be used safely and effectively as an alternative to cemented screws, when pedicle screws have failed by aseptic loosening. It avoids the risks associated with cemented screws and in our series was successful.

Clinical outcomes of sacroplasty for metastatic sacral tumours: a systematic review and meta-analysis.

STUDY DESIGN: A systematic review and meta-analysis. OBJECTIVE: The purpose of this study was to evaluate the clinical outcome and safety of sacroplasty for patients with secondary metastatic lesions to the sacrum. METHODS: Several databases, including the Cochrane library, PubMed and EMBASE, were systematically searched to identify potentially eligible articles in English language. All the above databases were searched until December 2019. The search strategy was based on the combination of the following keywords: sacroplasty AND secondary tumours OR metastasis OR metastases. The reference list of the selected literature was also reviewed and a standard PRISMA template utilised. RESULTS: From a total of 102 articles initially identified, a final seven studies were identified as meeting the inclusion criteria. A total of 107 patients from these studies were included. The follow-up ranged from immediate post-operatively to 30.5 months. The mean preoperative VAS was 8.38 (range 6.9-9.3), which improved significantly to 3.01 (range 1.12-4.7) post-operatively (p < 0.001). The most frequent complication reported was cement leakage, which occurred in 26 patients (25.4%), but without any neurological or other adverse sequelae. CONCLUSIONS: Sacroplasty in the management of secondary sacral tumours is a safe procedure that can achieve a significant reduction in pain, as quantified by VAS scores, and low complication rate.

Concomitant back and leg pain as predictors for trajectories of poor outcome after single level lumbar micro-decompression alone and with micro-discectomy: a study of 3,308 patients.

BACKGROUND: Lumbar decompression is the commonest spinal intervention. One in four patients have suboptimal outcome postoperatively, however no large studies identified clear poor outcome predictors. The aim of this study was to study low back pain (LBP) as a predictor of poor outcome following lumbar micro-decompression. METHODS: Prospectively collected spinal registry data was analysed for patients who underwent primary, single-level, decompression with or without discectomy at single spinal centre (2011-2017). Based on the response to the Likert global outcome question, we had two outcome groups (good & poor). Percentage of achievement of minimum clinically relevant change (MCRC) for Core Outcome Measures Index (COMI) score, LBP and leg pain (LP) was examined. A two-step approach was adopted. First, COMI score, LBP and LP visual analogue scales (VAS) trajectories were modelled using a discrete mixture model. Second, multinomial logistic regression was used to determine the association between variables and trajectories. RESULTS: We included 3,308 patients with mean follow up (1.4 y). MCRC was achieved in COMI score in 63% of cases, 42% in LBP and 62% in LP. A three-group trajectory model was identified: large-improvement (LI) (n=980), moderate-improvement (MI) (n=1,364) and no-improvement (NI) (n=966) with 99.5%, 84.5% and 31.5% of patients presenting good outcome, respectively. Higher pre-operative LBP and COMI score and smoking were strongly associated with MI and NI. In addition, higher LP, post-operative surgical complications, previous surgery at same level, conservative treatment >6 months and anxiety/depression were associated with NI. CONCLUSIONS: This is the first large-scale study reporting preoperative LBP severity, spinal stenosis and smoking as predictors for poor functional outcomes post lumbar decompression with or without discectomy. This is very useful while counselling patients for surgery to meet realistic expectations.

Comparative study of multilevel posterior interbody fusion plus anterior longitudinal ligament release versus classic multilevel posterior interbody fusion in the treatment of adult spinal deformities.

OBJECTIVE: Sagittal imbalance and loss of lumbar lordosis are the main drivers of functional disability in adult degenerative scoliosis. The main limitations of the classic posterior lumbar interbody fusion technique are increased risk of neurological injury and suboptimal correction of the segmental lordosis. Here, the authors describe the radiological results of a modified posterior lumbar interbody fusion and compare the results with a historical cohort of patients. METHODS: Eighty-two consecutive patients underwent surgical treatment for degenerative scoliosis/kyphosis in a single tertiary referral center for complex spinal surgery. Fifty-five patients were treated using the classic multilevel posterior lumbar interbody fusion (MPLIF) technique and 27 were treated using the modified MPLIF technique to include a release of the anterior longitudinal ligament (ALL) and the annulus. A radiographic review of both series of patients was performed by two independent observers. Functional outcomes were obtained, and patients were registered in the European Spine Tango registry. RESULTS: The mean L4-5 disc angle increased by 3.14° in the classic MPLIF group and by 12.83° in MPLIF plus ALL and annulus release group. The mean lumbar lordosis increased by 15.23° in the first group and by 25.17° in the second group. The L4-S1 lordosis increased on average by 4.92° in the classic MPLIF group and increased by a mean of 23.7° in the MPLIF plus ALL release group when both L4-5 and L5-S1 segments were addressed. There were significant improvements in the Core Outcome Measures Index and EQ-5D score in both groups (p < 0.001). There were no vascular or neurological injuries observed in either group. CONCLUSIONS: The authors' preliminary results suggest that more correction can be achieved at the disc level using posterior-based ALL and annulus release in conjunction with posterior lumbar interbody fusion. They demonstrate that ALL and annulus release can be performed safely using a posterior-only approach with minimal risk of vascular injury. However, the authors recommend that this approach should only be used by surgeons with considerable experience in anterior and posterior spinal surgery.

The clinical and radiological outcomes of multilevel posterior lumbar interbody fusion in the treatment of degenerative scoliosis: a consecutive case series with minimum 2 years follow up.

BACKGROUND: Surgical treatment for adult degenerative scoliosis (ADS) is a complex undertaking and is associated with a high complication rate. Our aim was to evaluate the clinical and radiological outcomes, mortality and morbidity of multilevel posterior lumbar interbody fusion (MPLIF) in the treatment in ADS based on the experience of a single tertiary referral center for spinal surgery. METHODS: We performed a retrospective analysis of prospectively collected data of consecutive patients who had undergone multi-level posterior interbody fusion for degenerative scoliosis. We prospectively recorded patients' demographics, co-morbidities; coronal and sagittal plane deformity assessment and surgical details: number of instrumented levels, and intra-operative and postoperative complications. Functional outcomes and patient-reported complications were entered in our local spine surgery database (part of the Eurospine Spine Tango Registry) and used to collect data on functional scores and patient-reported complications preoperatively and at 6, 12 and 24 months' follow-up. RESULTS: Our study involved 13 males and 51 females with a mean age of 70.26 (range 49-90, SD 8.9). MPLIF was performed at five levels in one patient, four levels in 29 patients, three levels in 20 patients, and two levels in 14 patients. There were a total of 14 (21.87%) major, minor and mechanical complications. There were no procedure-related mortalities. The average COMI and Eq5d scores improved significantly post-surgery, and this improvement was maintained at a mean follow-up of up to two years. CONCLUSIONS: Multilevel posterior interbody fusion is a safe procedure, and in selected cases can result in good clinical and radiological outcomes with improvement in patient quality of life.

Health-related quality of life in patients undergoing cervico-thoracic osteotomies for fixed cervico-thoracic kyphosis in patients with ankylosing spondylitis.

PURPOSE: Ankylosing spondylitis (AS) can result in severe cervico-thoracic kyphotic deformity (CTKD). Few studies have addressed the relationship between cervico-thoracic osteotomies in AS and health-related quality of life scores. The aim of this study is to evaluate the impact of cervico-thoracic osteotomy (CTO) on improving quality of life for patients with fixed CTKD. METHODS: A database of all patients who underwent a CTO for CTKD in patients with AS was created. Data entered into the database consisted of patients' demographics and comorbidities, as well as surgical, clinical and radiological data. The outcome measures used in our study were Neck Disability Index (NDI), EuroQol 5D-5L (EQ-5D-5L) and Visual Analogue Scale. We also measured the following radiological parameters: chin-brow to vertical angle (CBVA), C7-Slope, C2-7 angle, Regional Kyphosis Angle, C2-C7 sagittal vertical axis (SVA) and C7-S1 SVA. RESULTS: A total of 13 male patients with AS were included in our study. The mean age was 57.5 years (40-74); and mean follow-up was 37.6 months (12-78). Following the C7-T1 osteotomy (10 Smith Peterson Osteotomies and 3 Pedicle Subtraction Osteotomies), NDI improved from a mean of 65.54 (SD 8.95) to a mean of 22.09 (SD 6.99). The EQ-5D-5L improved from a mean of 0.41 (SD 0.16) to 0.86 (SD 0.088). Pre-operative CBVA was on average 54° (40°-75°) and post-operative was 7° (2°-12°). There were no major complications, 1 superficial infection and 5 minor nerve root irritations. CONCLUSIONS: Cervical osteotomy for the management of fixed flexion deformity of cervical spine in ankylosing spondylitis is a safe procedure and can result in restoration of horizontal gaze and sagittal balance with significant improvement of the patient's health-related quality of life. These slides can be retrieved under Electronic Supplementary Material.

A multicenter cohort study of spinal osteoid osteomas: results of surgical treatment and analysis of local recurrence.

BACKGROUND CONTEXT: Spinal osteoid osteomas are benign primary tumors arising predominantly from the posterior column of the spine. These "osteoblastic" lesions have traditionally been treated with intralesional excision. PURPOSE: The purpose of the present study was to review the treatment and local recurrence rates for symptomatic spinal osteoid osteomas. STUDY DESIGN/SETTING: Multicenter ambispective cross-sectional observational cohort study. PATIENT SAMPLE: During the study period, a total of 84 patients (65 males, 19 females) were diagnosed with a spinal osteoid osteoma and received surgical treatment. The mean age at surgery was 21.8 ± 9.0 years (range: 6.7-52.4 years) and the mean follow-up was 2.7 years (13 days-14.5 years). OUTCOME MEASURES: Local recurrence, perioperative morbidity, and cross-sectional survival. METHODS: Using the AOSpine Knowledge Forum Tumor multicenter ambispective database, surgically treated osteoid osteoma cases were identified. Patient demographic, clinical and diagnostic, treatment, local recurrence, perioperative morbidity, and cross-sectional survival data were collected and retrieved. Descriptive statistics were summarized using mean/standard deviation or frequency/percentage. RESULTS: In our study, most of the tumors were localized in the mobile spine (81 of 84 [96%]); all patients reported pain as a symptom. According to the postoperative assessment, 10 (12%) patients received an en bloc resection with marginal or wide margins, whereas two (2%) patients received en bloc resections with intralesional margins, 69 (82%) patients were treated by piecemeal "intralesional" resection, and three (4%) patients were not assessed. A total of six patients (7%) experienced a local recurrence, all of which occurred in patients who had received an intralesional resection. CONCLUSIONS: Benign bone-forming tumors of the spine are uncommon. Most patients in our series underwent a piecemeal resection with intralesional margins. This remains safe with a low local recurrence rate. En bloc excision may provide more chance of complete excision of the nidus but is not mandatory. The importance of complete excision of the nidus cannot be overemphasized.

Correction of sagittal plane deformity and predictive factors for a favourable radiological outcome following multilevel posterior lumbar interbody fusion for mild degenerative scoliosis.

PURPOSE: Limited data is available in the literature on the radiographic results of multilevel posterior lumbar interbody fusion (MPLIF) in the treatment of degenerative scoliosis. The objective of our study was to evaluate the segmental and global correction achieved with MPLIF in the treatment of degenerative scoliosis. METHODS: Between 2009 and 2014, 42 patients underwent correction of degenerative scoliosis with MPLIF. Several radiological parameters were measured pre- and post-operatively by two independent observers. A statistical analysis was performed to assess the inter-observer reliability of the measurements and to determine the degree of segmental correction achieved at each intervertebral disc. Using sagittal vertical axis (SVA) less than 47 mm; lumbar lordosis (LL) within 11° of pelvic incidence (PI); and pelvic tilt (PT) no more than 22° as radiological criteria for procedural acceptability, we determined predictive factors for a favourable radiological outcome. RESULTS: Forty-two patients (34 female) were included in our study. The average amount of correction per segment was 6.2°. The overall correction achieved with MPLIF was 16.6°. Twenty-six of the 42 patients (61.9 %) had post-operative SVA values less than 47 mm. Nineteen of the 42 patients (45.2 %) had average post-operative LL within 11° of the PI. Sixteen of the 42 patients (38.1 %) had PT less than 22°. Younger age, female gender and a low pre-operative PT were significantly associated with the attainment of a satisfactory sagittal alignment. CONCLUSION: Our results demonstrate that a satisfactory correction can be achieved in degenerative scoliosis with MPLIF. In addition, our results show that it is significantly more likely to achieve a satisfactory radiological outcome in younger, female patients with low pre-operative PT.