Minimally invasive transforaminal lumbar interbody fusion with unilateral pedicle screw fixation (UNILF): outcomes at 7 years.

PURPOSE: To assess clinical, functional and radiographical results of one-level minimally invasive transforaminal interbody fusion with unilateral pedicle screw fixation (UNILIF) in the treatment of stable lumbar degenerative diseases with a minimum of 5 years of follow-up. MATERIAL AND METHOD: From January 2012 to December 2016, clinical and radiological data of patients with degenerative lumbar disease managed by UNILIF were prospectively collected. Patients with a follow-up that ended before 5 years were excluded. SF-12, Oswestry disability index (ODI) and visual analog scale (VAS) were collected preoperatively, at 2 years and at the last follow-up. A full-spine standing radiograph was performed at each follow-up appointment. RESULTS: Mean operative time was 74.7 (± 19) minutes, mean blood loss was 131.1 (± 207) ml and mean follow-up was 7.5 (± 1.7) years. All functional scores and VAS were significantly improved between the preoperative and the 2 years postoperative. Between the 2 years postoperative and the last follow-up ODI and VAS continued to significantly improved. Fusion rate was 98.6% on radiographic analysis at follow-up. CONCLUSION: UNILIF method is a safe and effective surgical strategy. It provides a durable improvement in functional score over 7 years of follow-up with a stable radiological correction over time.

Intraoperative neurophysiological monitoring in scoliosis surgery: literature review of the last 10 years.

INTRODUCTION: Patients with spinal deformities undergoing corrective surgery are at risk for iatrogenic spinal cord injury (SCI) and subsequent neurological deficit. Intraoperative neurophysiological monitoring (IONM) allows early detection of SCI which enables early intervention resulting in a better prognosis. The primary aim of this literature review was to search if there are threshold values of TcMEP and SSEP in the literature that are widely accepted as alert during IONM. The secondary aim was to update knowledge concerning IONM during scoliosis surgery. METHOD: PubMed/MEDLINE and Cochrane library electronic databases were used to search publication from 2012 to 2022. The following keywords were used: evoked potential, scoliosis, surgery, intraoperative monitoring and neurophysiological. We included all studies dealing with SSEP and TcMEP monitoring during scoliosis surgery. Two authors reviewed all titles and abstracts to identify studies that met the inclusion criteria. RESULTS: We included 43 papers. Rates of IONM alert and neurological deficit varied from 0.56 to 64% and from 0.15 to 8.3%, respectively. Threshold values varied from a loss of 50 to 90% for TcMEP amplitude, whereas it seems that a loss of 50% in amplitude and/or an increase of 10% of latency is widely accepted for SSEP. Causes of IONM changes most frequently reported were surgical maneuver. CONCLUSION: Concerning SSEP, a loss of 50% in amplitude and/or an increase of 10% of latency is widely accepted as an alert. For TcMEP, it seems that the use of highest threshold values can avoid unnecessary surgical procedure for the patient without increasing risk of neurological deficit.

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

INTRODUCTION: Low-grade isthmic spondylolisthesis (ISPL) is generally treated by circumferential fusion with interbody graft, although there is no consensus on technique. HYPOTHESIS: The various interbody fusion strategies provide satisfactory fusion rates and clinical results. METHODS: A 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). RESULTS: Among 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. CONCLUSION: Low-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 EVIDENCE: IV.

Minimally invasive unilateral lumbar interbody fusion (UNILIF) in over-80-year-olds. Continuous series of 42 patients at 1.4 years' follow-up.

INTRODUCTION: In lumbar stenosis, surgery aims to improve quality of life in increasingly elderly patients. Minimally invasive techniques better suit the requirements of elderly patients with increasing functional demand. HYPOTHESIS: The UNILIF unilateral lumbar interbody fusion technique improves functional scores at 1 year in over-80 year-olds, with low morbidity. METHOD: Patients undergoing minimally invasive decompression with transforaminal lumbar interbody fusion (TLIF) associated to unilateral pedicle screwing for degenerative lumbar stenosis were analyzed at a minimum 1 year's follow-up. SF12, Oswestry Disability Index (ODI) and Quebec scores and sagittal spinopelvic radiographic parameters were assessed at follow-up. Surgical and general complications were also collated. RESULTS: In all, 42 patients (64.3% female; mean age, 83.7±2.9 years) were treated by UNILIF at levels L2-L3 (3.8%), L3-L4 (15.4%), L4-L5 (71.2%) and L5-S1 (9.6%). Mean follow-up was 520±226 days (range, 340-1166 days). Mean preoperative SF12 score was 77.5±10.9, with significant improvement at last follow-up: 81.9±138 (p<0.05). Mean preoperative ODI was 44.4%±14.0, with significant improvement at last follow-up: 32.4%±13.3 (p<0.001). Mean preoperative Quebec score was 42.9±19.9, with significant improvement at last follow-up: 28.5±21.9 (p<0.001). Spinopelvic sagittal balance was not affected by the UNILIF procedure. There were no cases of infection or severe general complications during follow-up, although 2 cases of non-union required revision surgery. CONCLUSION: Lumbar stenosis surgery by UNILIF improved functional scores at 1 year, with low morbidity. It is a suitable strategy for degenerative lumbar stenosis in elderly patients. LEVEL OF EVIDENCE: IV, non-comparative cohort study.