Percutaneous Posterior Fixation Research Articles

Typical air kerma area product values for trauma orthopaedic surgical procedures.

BackgroundThe aim of study was to establish the typical radiation quantity values for the most common trauma orthopaedic surgical procedures and to compare them with reference values of equivalent procedures performed in other institutions. In addition, we assess the impact of image intensifier and flat panel detector technology used for fluoroscopically guidance on patient exposure.Materials and methodsFive most frequently performed fluoroscopically guided trauma orthopaedic procedures in University Medical Centre Ljubljana were analysed. Data on 199 cases over a 6 months period from December 2016 to June 2017 were gathered retrospectively. Study covered 40 dynamic hip screw fixations (DHS), 23 proximal femoral nail insertions (PFN), 20 proximal humeral nail insertions (PHN), 77 partial hip endoprosthesis implantations (PEP) and 39 percutaneous posterior spine fixations (PPS). The median and average along with the first and third quartile values of air kerma area product (KAP) for each procedure type were calculated as well as median and average value of fluoroscopy screening time.ResultsTypical KAP value for dynamic hip screw fixation was set at 0.52 Gycm2; for proximal femoral nail insertion at 0.53 Gycm2 and for proximal humeral nail insertion at 0.26 Gycm2. For implantation of partial endoprosthesis typical KAP value utilizing flat panel technology was set at 0.08 Gycm2 and at 0.21 Gycm2 when the image intensifier technology was used. Typical KAP value for percutaneous posterior spine fixation was set at 1.26 Gycm2, using flat panel technology and at 3.98 Gycm2 using image intensifier technology.ConclusionsEstablished typical KAP levels of surgical orthopaedic procedures in traumatology will serve as a valuable tool for further radiation exposure optimization.

Current concepts in management for fractures of thoracolumbar spine

Thoracolumbar fractures are common in high energy trauma patients and could be divided into compression fractures, burst fractures, flexion-distraction injury, and fracture dislocations. A comprehensive evaluation of the patient is crucial including end-to-end motor and sensation examination and possible associated injuries. The current treatment methods are still controversial. The goal of treatment is to restore proper alignment and mechanical stability, to induce neurological recovery, and to achieve early mobilization and rehabilitation. The stability of the spine, the neurological status, and the integrity of the posterior ligament complex (PLC) are the keys to determine the treatment policy. The role of percutaneous posterior fixation without arthrodesis increased in recent years. But it is still controversial for the use of these treatments and there is no verified evidence for long-term results yet. The necessity of decompression and the treatment methods in regards to the degree of neurologic injury is discussed as well. Generally, early decompression within 24 hours over incomplete spinal cord injury is recommended.

Single-level controlled comparison of OLIF51 and percutaneous screw in lateral position versus MIS-TLIF for lumbosacral degenerative disorders: Clinical and radiologic study

BackgroundWe have performed minimally invasive Oblique Lateral Interbody Fusion at L5/S1 (OLIF51) and simultaneous posterior screwing in lateral position for lumbosacral disorders. This study compared the clinical and radiologic results between OLIF51 versus Minimally Invasive Transforaminal Lumbar Interbody Fusion (MIS-TLIF) in single-level fusion for lumbosacral degenerative disorders. MethodsA total of 71 patients underwent either OLIF51 (33 cases) or MIS-TLIF (38 cases) at L5/S1 spinal segment. The average age was 64 yrs (27–88). The disorders were L5 isthmic or degenerative spondylolisthesis, foraminal stenosis, pseudarthrosis and adjacent segment degeneration, and others. Using 35 mm oblique incision, OLIF51 was performed followed by posterior percutaneous fixation in same lateral position. MIS-TLIF was performed with midline 40 mm incision and modified cortical bone trajectory (CBT) screws. The operation time, estimated blood loss, JOABPEQ effectiveness rate (%), Visual Analogue Scale (VAS), fusion rate, radiologic alignment, and complications were evaluated. ResultsAverage follow-up period was 25 and 31 months (12–45) in OLIF51 and MIS-TLIF, respectively. The average operation time and estimated blood loss were 165min, 62 ml and 163 min and 68 ml, respectively. The JOABPEQ effectiveness rate in OLIF51 demonstrated higher value in low back function (44% vs 17%, P < 0.02). The fusion rate was 97% and 92% in OLIF51 and MIS-TLIF, respectively. The segmental lordosis was significantly larger in OLIF51 (17 vs 11 deg, P < 0.01). There were no vascular or neural complications. ConclusionsAlthough two groups demonstrated the equivalent surgical invasiveness, there was the significant superiority of OLIF51 in terms of low back function over MIS-TLIF. The segmental lordosis creation was also better in OLIF51. Even in the single-level lumbosacral fusion, OLIF51 serves as the safe and viable surgical procedure with use of lateral position surgery, minimizing the residual low back dysfunction.

56. Minimally invasive pedicle screws provide similar clinical outcomes to open posterior fusion in the management of adult isthmic spondylolisthesis

BACKGROUND CONTEXT In adult patients undergoing anterior lumbar interbody fusion (ALIF) for the treatment of isthmic spondylolisthesis, the literature shows that posterior percutaneous pedicle screw fixation leads to shorter hospital stays, less time under anesthesia, and less intraoperative blood loss compared to open posterior fusion. However, there is conflicting evidence on whether patients undergoing posterior percutaneous fixation experience similar clinical outcomes as those undergoing open posterior fusion. PURPOSE The purpose of this study was to determine the impact of minimally invasive posterior surgery on clinical outcomes following lumbar spinal fusion for isthmic spondylolisthesis. STUDY DESIGN/SETTING This study was a retrospective analysis of prospectively collected data from a single, high-volume academic medical center. PATIENT SAMPLE Analysis of patients who underwent lumbar fusion for isthmic spondylolisthesis from 2014 to 2019 was conducted. Surgery was indicated after failure of conservative treatment to address lumbar radiculopathy and/or neurogenic claudication. OUTCOME MEASURES Patient-reported outcome measures (PROMs) were recorded at preoperative and postoperative clinical visits, and included the Visual Analog Scale back pain (VAS back) and leg pain (VAS leg), the Short-Form 12 Mental Component Score (MCS-12) and Physical Component Score (PCS-12), and the Oswestry Disability Index (ODI). Secondary measures included estimated blood loss (EBL) and length of stay (LOS). METHODS Patient and surgical characteristics including age, gender, body mass index (BMI), Charlson Comorbidity Index (CCI), number of levels decompressed and number of levels fused were recorded. Preoperative and final PROMs were obtained from an institutional query. For analysis, patients were divided into two groups based on surgical approach: ALIF with percutaneous pedicle screws (Percutaneous) and ALIF with open posterior fusion (Open). Multivariate linear regression was performed to correlate surgical approach and outcomes. RESULTS A total of 61 patients were included, with 20 patients in the Percutaneous group and 41 patients in the Open group. Patients undergoing open surgery had greater intraoperative EBL (p=0.013) and longer LOS (p=0.034). Otherwise, there were no significant differences in patient characteristics. Patients in both the Percutaneous and the Open groups had significant improvement in VAS back scores (p=0.001, p CONCLUSIONS Our results suggest that patients undergoing minimally invasive posterior fusion and patients undergoing open posterior fusion for adult isthmic spondylolisthesis have similar improvement of PROMs from preoperative to final assessment. Additionally, open surgery is significantly correlated with less improvement in VAS leg scores than minimally invasive approaches and was associated with significantly higher intraoperative blood loss and hospital length of stay. This study underscores the importance of considering surgical approach as a prognostic factor. Furthermore, the results provide additional information that can be used by physicians in preoperative discussions with patients regarding expectations of postoperative improvements in pain. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

176. Thoracolumbar interfascial plane (TLIP) block and intrathecal fentanyl injection results in an opioid-free peri- and postoperative recovery and early ambulation after percutaneous lumbar spine surgery

BACKGROUND CONTEXT Open lumbar spine fusion surgery usually requires opioid analgesia for several weeks during the postoperative recovery period. Recently, a facet-sparing, full percutaneous transforaminal lumbar interbody fusion (TLIF) has been introduced that uses an endoscopic cannula for placement of an interbody cage in combination with percutaneous transpedicular screws and rods. The Thoraco-Lumbar Interfascial Plain (TLIP) block is a novel, ultrasound-guided local anesthesia technique that targets the sensory component of the dorsal rami of the thoracolumbar nerves. PURPOSE We aim to evaluate the efficacy in avoiding post-operative opioid analgesics and allowing early patient ambulation of a novel inter-disciplinary, spine surgery protocol that combines a perioperative TLIP block, intrathecal fentanyl injection and percutaneous TLIF spine surgery. STUDY DESIGN/SETTING Prospective, nonrandomized sequential case series study. PATIENT SAMPLE A total of 15 consecutive patients underwent TLIP combined with percutaneous TLIF spine surgery between 2018 and 2019. Indication for spine surgery was degenerative disk disease of the lumbar spine with or without spondylolisthesis up to grade 2 and foraminal stenosis. OUTCOME MEASURES Pre- and postoperative visual analogic scale (VAS) for lumbar back and leg pain were quantitatively assessed (range 0 to 10) immediately, at 6 and at 12 hours after surgery and at time of hospital discharge. Oswestry Disability Index (ODI) scores (range 0 to 50) were assessed preoperatively and at time of hospital discharge. The time of first post-operative patient ambulation was registered. Significance between pre- and postoperative scores were analyzed with student's paired t-test. METHODS Intrathecal fentanyl 25 mcgr was administered to the patient in sitting position and ultrasound-guided bilateral TLIP was performed in prone position with bupivacaine 0.25% and dexamethasone 8mgrs (20ml each side) by the anesthesia team. All patients were operated on under general anesthesia (protocol: propofol 2.0-3.0 mcg/ml (TCI) following BIS, ketamine 0.15 mg/Kg/h, rocuronium 0.4 mg/Kg). Percutaneous TLIF was performed by inserting an expandable interbody implant using the facet-sparing, trans-Kambin approach with an endoscopic cannula and complemented with a percutaneous posterior fixation consisting of transpedicular screws and rods. Postoperative analgesia included NSAIDs, acetaminophen and a manually patient-controlled oral sublingual 15 mcgr sufentanil microtablet analgesic system (Zalviso®), while its use was monitored. RESULTS Fifteen patients with a mean age of 64.1 years (range, 34 to 82 years) were evaluated. A median of two levels (range, 1 to 4 levels) per patient were instrumented and a median of one interbody cage (range, 1 to 2 cages) was placed in the lumbar spine. No intravenous fentanyl administration was necessary during surgery. The median time of surgery was 3.5 hours. Mean preoperative VAS scores for lumbar back and leg pain were 6.3 and 5.8, respectively. Mean postoperative VAS back scores at 0h, 6h, 12h and at discharge improved to 1.2, 1.8, 2.4 and 2.7 (P CONCLUSIONS The combination of perioperative TLIP, intrathecal fentanyl injection and percutaneous TLIF surgery prevents peri- and postoperative opioid administration and improves the quality of peri- and postoperative analgesia, allowing early patient ambulation and fast hospital discharge. This interdisciplinary analgesia protocol is a promising solution to avoid opioid analgesia in spine surgery and could be particularly interesting in the context of an outpatient spine surgery setting. FDA DEVICE/DRUG STATUS Fentanyl (Approved for this indication), Zalviso (Approved for this indication), Bupivacaine (Approved for this indication), Globus RISE (Approved for this indication)

Surgical Wound Complications After Percutaneous Posterior Pelvic Ring Fixation in Patients Who Undergo Pelvic Arterial Embolization.

To report on the incidence of surgical wound complications after percutaneous posterior pelvic ring fixation in patients who have also undergone pelvic arterial embolization (PAE) and determine whether the risks outweigh the benefits. Retrospective cohort study. Academic level 1 trauma center. Two hundred one consecutive patients who underwent percutaneous posterior pelvic fixation at our institution were included in this study. Of these, 27 patients underwent pelvic arterial embolization. Percutaneous posterior pelvic fixation and pelvic arterial embolization. Charts were reviewed for posterior percutaneous surgical wound complications including infection, dehiscence, seroma, tissue necrosis, and return to OR for debridement in all patients. Of the 27 patients who received PAE, none developed posterior surgical wound complications. Of those who did not receive PAE, there was one posterior surgical wound complication documented. There were no cases of wound infection in either group. Pelvic arterial embolization can be a valuable intervention in treating hemodynamically unstable patients with pelvic ring injuries. Although even selective pelvic arterial embolization is not entirely benign, there seems to be minimal risk of wound complications when percutaneous posterior pelvic ring fixation is performed. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Comparison of Outcomes of Oblique Lateral Interbody Fusion with Percutaneous Posterior Fixation in Lateral Position and Minimally Invasive Transforaminal Lumbar Interbody Fusion for Degenerative Spondylolisthesis.

Study DesignSingle-center retrospective study.PurposeTo compare the physical function and quality of life (QOL) parameters of two minimally invasive surgical (MIS) procedures: oblique lateral interbody fusion with percutaneous posterior fixation in lateral position (OLIF-LPF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for single-level degenerative spondylolisthesis (DS). Overview of LiteratureTo date, many options for the surgical treatment of lumbar DS and reports have described the effectiveness of minimally invasive lateral access surgery and MIS-TLIF. However, there is still a paucity of comparative data regarding the physical function and QOL outcomes of OLIF and MIS-TLIF.MethodsEighty-six patients were enrolled in this study (group O: OLIF-LPF, n=38; group T: MIS-TLIF, n=48). We evaluated the operation time, estimated blood loss (EBL), postoperative laboratory data, preoperative and postoperative radiographic parameters, overall functional outcome with the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) effectiveness rate, and Visual Analog Scale (VAS) score for low back pain, leg pain, and leg numbness.ResultsNo statistical differences in operation time, EBL, and C-reactive protein level, 5 days postoperatively, between groups O and T. With respect to radiological outcome, preoperative and postoperative disc height change was significantly greater in group O than in group T (3.8 vs. 1.8 mm, p<0.05). Both groups showed postoperative improvements in the clinical outcome scores of all JOABPEQ domains, but the effectiveness rate increase in the psychological domain was significantly higher in group O than in group T (47.1% vs. 14.6%, p<0.05). No differences in the preoperative and postoperative VAS score change were noted between the two groups in any of the items.ConclusionsThe changes in physical function and QOL parameters after OLIF-LPF and MIS-TLIF were almost equivalent; however, OLIF-LPF had significant superiority in the psychological domain.

Correction of marked sagittal deformity with circumferential minimally invasive surgery using oblique lateral interbody fusion in adult spinal deformity

BackgroundSpinal surgery performed entirely with minimally invasive surgery is referred to as circumferential MIS (cMIS). However, cMIS still has a limited sagittal correction capability for adult spinal deformity (ASD) with a marked sagittal deformity. We investigated the effectiveness of cMIS using oblique lateral interbody fusion (OLIF) and percutaneous posterior spine fixation in correcting marked sagittal deformity.MethodsThis study retrospectively evaluated 23 patients with ASD with marked sagittal deformity who underwent cMIS using OLIF without osteotomy and were followed-up for at least 24 months (whole group). The whole group was divided into the following two groups according to the type of interbody fusion at L5–S1: the OLIF51 group (n = 13) underwent OLIF at L1–L5 and L5–S1 and the TLIF51 group (n = 10) underwent OLIF at L1–L5 and transforaminal lumbar interbody fusion (TLIF) at L5–S1.ResultsSagittal vertebral axis (SVA; 125.7 vs. 29.5 mm, p < 0.001), lumbar lordosis (LL; 18.2° vs. 51.7°, p < 0.001), and pelvic incidence-LL mismatch (PI-LL, 35.5° vs. 5.3°) significantly improved postoperatively in the whole group. The OLIF51 group showed significantly higher postoperative LL than the TLIF51 group (55.5° vs. 46.9°, p < 0.001). OLIF yielded a significantly greater disc angle at L5–S1 than did TLIF (18.4° vs. 6.9°, p < 0.001). Proximal junctional kyphosis occurred significantly earlier in the OLIF51 group than in the TLIF51 group (8.6 vs. 26.3 months, p < 0.001).ConclusionSuccessful sagittal correction in ASD patients with marked sagittal deformity was achieved with cMIS using OLIF. OLIF at L5–S1 showed a synergistic effect in sagittal deformity correction by cMIS.

Minimally Invasive Versus Open TLIF in the Management of Lumbar Spondylolisthesis

This study aims to assess the difference between minimal invasive TLIF surgery and conventional TLIF surgery in cases of lytic spondylolisthesis, as regards pain, disability, hospital stay and complications. Lytic Spondylolisthesis patients may require fusion of one or more spinal segments to treat their condition adequately. The chances of achieving a successful lumbar spinal fusion has increased. TLIF technique is gradually being accepted in these cases and widely used by most spine surgeons. Minimal invasive TLIF is a recent trend for spinal fusion. This is a prospective randomized comparative study conducted from March 2016 to December 2018 included forty patients with low grade lytic spondylolisthesis that underwent surgeries. Twenty patients underwent MI-TLIF through percutaneous posterior lumbar pedicular screw fixation, microscopic minimally invasive transformational discectomy and interbody cage fusion (patients group “A”) and another twenty patients underwent traditional open posterior lumbar pedicular screw fixation and TLIF (control group “B”). In our results, both surgical techniques showed improvement in pain and function within 12 months (follow up period), but group A showed statistically significant improvement in pain and function in the 1^st three months. Regarding blood loss, need for transfusion and hospital stay, group A showed statistically significant better results. As a conclusion, minimally invasive TLIF is a better option in surgical management of spondylolisthesis especially in the early postoperative period.

Symptomatic Iliosacral Screw Removal After Pelvic Trauma—Incidence and Clinical Impact

To calculate the incidence of symptomatic iliosacral (SI) screw removal following pelvic trauma and to determine the clinical impact of the secondary intervention. Retrospective chart review. Level 1 and Level 2 trauma centers. Four hundred seventy-one consecutive patients undergoing percutaneous posterior pelvic fixation over 10 years, with 7 excluded for spinopelvic fixation,and 7 excluded due to age <16 year old. Implant removal. Secondary intervention. A total of 25/457 patients underwent screw removal (5.4%). Two patients were lost to follow-up, leaving 23 for analysis. There were 13 male patients and 10 female patients. There were 13 SI and 10 trans-sacral screws removed. Four screws were loose before removal (17%). Average time to screw removal was 10.7 months (4-26 minutes). Fifteen (83.3%) patients had subjective improvement, and 3 (16.7%) had no notable improvement. The incidence of symptomatic SI screws necessitating removal is low (5.4%). When removed, there is a high likelihood (83%) that the secondary intervention will result in subjective symptomatic improvement. Routine screw removal is unnecessary because most patients tolerate the implants without symptoms necessitating subsequent surgery. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Percutaneous posterior short-segment pedicle screw fixation combined with vertebroplasty for stage III Kümmell's disease without neurological deficit

Objective To investigate the clinical efficacy of percutaneous posterior short-segment pedicle screw fixation combined with vertebroplasty for stage III Kummell's disease without neurological deficit. Methods A retrospective case series study was conducted to analyze the clinical data of 36 patients with stage III Kummell's disease without nerve injury admitted to Xiaoshan Hospital of Traditional Chinese Medicine from January 2012 to January 2017. There were 10 males and 26 females, aged 55-75 years, with an average of 67.5 years. The injuried vertebrae were located at T11 in 9 patients, at T12 in 12, at L1 in 10 and at L2 in 5. The course of disease ranged from 6 to 48 months, with an average of 28.5 months. X-ray, CT and MRI were performed before operation. All patients underwent percutaneous posterior short-segment pedicle screw fixation combined with vertebroplasty. The operation time, intraoperative bleeding volume, complications, visual analogue scale (VAS), Oswestry dysfunction index (ODI) and sagittal Cobb angle of the injured vertebrae were recorded before operation, 1 week after operation and at the last follow-up. Results All patients were followed up for an average of 32.5 months (range, 12-48 months). Operation time ranged from 0.6 to 1.5 hours[(1.1±0.4)hours]. The intraoperative blood loss was 50-90 ml [(62.5±17.5)ml]. There was no internal fixation failure or fracture of adjacent vertebra. The VAS was improved from preoperative (8.6±0.4)points to (2.5±0.7)points one week after operation and (2.9±0.7)points at the last follow-up (P<0.05). The ODI was improved from preoperative 68.2±3.9 to 22.7±4.3 one week after operation and 25.3±4.8 at the last follow-up (P<0.05). The Cobb angle was improved from preoperative (24.3±9.3)° to (8.6±3.2)° 1 week after operation and (10.5±4.1)° at the last follow-up (P<0.05). Conclusion For stage III Kummell's disease without neurological deficit, percutaneous posterior short-segment pedicle screw fixation combined with vertebroplasty can significantly relieve pain, improve spinal function and maintain spinal stability. Key words: Spinal fractures; Internal fixators; Vertebroplasty; Kummell's disease

Minimally invasive treatment of thoracolumbar flexion-distraction fracture

IntroductionFlexion-distraction fractures represent around 15% of all thoracolumbar fractures, with neurological deficit in 25% of cases. Optimal surgical strategy remains controversial. In neurologically intact patients, percutaneous fixation can offer quick stabilization with good deformity correction. If necessary, an additional minimally invasive anterior approach can complete the surgical strategy. We report results in a series of 28 thoracolumbar flexion-distraction fractures without neurologic deficit, treated using a minimally invasive approach. MethodA single-center retrospective study was conducted for the period 2008–2015. Patients over 16 years of age with a flexion-distraction fracture without neurologic deficit were included. Analysis was based on preoperative CT-scan and measurement of post-traumatic kyphotic deformity. Surgery comprised posterior percutaneous fixation, alone or associated to an anterior step in case of discal lesion on preoperative MRI or of severe vertebral comminution. Operative time, blood loss and postoperative complications were recorded. Residual segmental kyphosis and bone healing were evaluated on CT at 1 year. ResultsSeventeen males and 11 females were included (mean age, 29.2 years). An anterior approach was performed in 11 cases (39%): 5 for B1 fractures due to severe comminution (corpectomy and expandable vertebral cage with bone and BMP-2) and 6 for B2 fractures due to discal involvement on MRI (discectomy and iliac graft fusion). Regional kyphosis was significantly reduced (17.3° vs. 5.7°; p<0.05) and bone healing was obtained in all cases. There were no cases of postoperative infection. ConclusionPatients with flexion-distraction fractures without neurologic deficit can be eligible for minimally invasive percutaneous posterior fixation, associated if necessary to a minimally invasive anterior approach. This technique provides excellent bone healing with low surgical trauma and bleeding. Level of evidenceIV.

Long-Term Patient-Reported Functional Outcome of Polytraumatized Patients With Operatively Treated Pelvic Fractures.

To report the long-term functional outcome of a cohort of patients with operatively treated unstable pelvic fractures using validated patient-reported outcome measures. Long-term observational study using prospective and retrospective data. Tertiary referral pelvic trauma center, Bristol, United Kingdom. Seventy-four polytraumatized patients with operatively treated unstable pelvic ring injuries (50 OTA/AO type B and 24 OTA/AO type C, mean Injury Severity Score 17) treated between 1994 and 2005. Sixty-four (86%) patients were treated with internal fixation. The remaining 10 patients (14%) were treated with either combined percutaneous posterior fixation and anterior external fixation or external fixation in isolation. Patient-reported functional outcome. Short Form-36, with UK norm-based comparator scores and EQ-5D-3L. Patients were between 11 and 22 years after injury (mean 15 years). We found no significant association between fracture classification and outcome score, but compared with age- and sex-matched scores for a UK population, differences were statistically significant in 3 of the 8 domains of health: physical function (P = 0.04), bodily pain (P = 0.001), and vitality (P = 0.001). The level of disability remained constant for these patients compared with their patient-reported outcome measure scores reported 8 years previously. Patients who sustain an unstable pelvic fracture continue to have significant functional limitations compared with an uninjured population. These changes were not found to be related to age, injury pattern, genitourinary injury, or neurological injury. Functional outcome scores did not change over the 2 long-term time points. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Neuro-navigation assisted pre-psoas minimally invasive oblique lumbar interbody fusion (MI-OLIF): New roads and impediments.

Minimally invasive spine-oblique lumbar interbody fusion (MIS-OLIF) has emerged as a novel anterolateral, retroperitoneal, "pre-psoas" approach for lumbar interbody fusion for degenerative spinal instability, as well as for correction of deformity in patients without severe canal stenosis. In the last decade, the technique has gained popularity owing to several advantages like the minimal blood loss, minimal tissue dissection, preservation of posterior tension bands, better biomechanical strength, provision of mechanical stability to the lumbar spine, and a larger footprint of the implant, associated with it. It, thus, maximises load bearing on the cortical bone, and provides a better lordotic correction of the lumbar spine. The armamentarium is further boosted by the use of neuro-navigation and neuro-monitoring tools, thereby improving the surgical outcome. The clinical indications of MIS-OLIF and various fixation methods [lateral lumbar fixation (LLF) and percutaneous posterior pedicle fixation (PPF)] are discussed. The summary of the 15 patients on whom the technique was utilized, are discussed. The patients' demographics, clinical history and neurological examination data, pre- operative Oswestry disability index (ODI) and visual analogue scale (VAS) score, intraoperative surgical details and postoperative follow up clinical as well as radiological data were assessed. Complications, readmissions, length of stay, estimated blood loss, surgical time and surgical outcome were also recorded. 11 cases had grade 1 spondylolisthesis and 4 had grade 2 spondylolisthesis. One patient had both grade I and II spondylolisthesis at different levels. 13 patients had improvement in mechanical back pain and neurogenic claudication. Two patients had improvement in back pain but one-sided limb radiculopathy persisted, which was treated conservatively. The mean pre-operative ODI score was 35 ± 6.1, which improved to 14.6 ± 4.1 at follow-up (range of follow-up: 1 to 10 months; mean 5.7 ± 3.3 months]. The mean pre-operative VAS score was 7 ± 0.7, which improved to 3.3 ± 0.4 at follow-up. The MIS-OLIF technique at the L2-L5 levels has shown encouraging early surgical outcomes with a good fusion rate and rapid recovery. While utilizing the unfamiliar oblique trajectory, the use of navigation can guide the surgeon in real time and also help in reducing the radiation exposure.

Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P129. True percutaneous transforaminal lumbar interbody fusion (pTLIF) with an expandable interbody cage using the endoscopic posterolateral approach: a long-term follow-up report of 50 cases

BACKGROUND CONTEXT Interbody fusion by open discectomy is the usual treatment for degenerative disc disease but requires a relatively long recovery period. The transforaminal posterolateral approach is a well-known standard in endoscopic spine surgery that allows direct access to the disk with progressive tissue dilation, avoiding tissue and bone dissection. PURPOSE The aim of this study was to assess the efficacy and safety of percutaneous transforaminal interbody fusion (pTLIF) for lumbar spinal fusion. pTLIF consists of percutaneous insertion of an expandable implant with the endoscopic posterolateral approach through an endoscopic cannula with progressive tissue dilatation. The anterior cage placement is complemented with a percutaneous posterior fixation. STUDY DESIGN/SETTING Prospective, nonrandomized, single-arm, single-center, single surgeon sequential case series study. PATIENT SAMPLE Between 2009 and 2017, the pTLIF procedure was performed in one center for 50 patients with an expandable interbody cage. OUTCOME MEASURES Patient outcome was scored pre- and post-operatively with visual analogic scale (VAS), Oswestry disability index (ODI) and modified Macnab criteria. Scores were performed preoperatively and at 1 month, 3 months, 6 months, 1 year and at least 2yearspost-operatively. A CT scan was performed immediately after surgery. Conventional X-ray controls were performed at 1 month and 1 year post-operatively. METHODS Indication for surgery was degenerative disc disease of the lumbar spine with or without spondylolisthesis up to grade 2, and for revision surgery. Percutaneous transforaminal interbody fusion was performed by inserting an expandable implant with the endoscopic posterolateral approach through an endoscopic cannula with progressive tissue dilatation. Percutaneous posterior fixation comprised transpedicular screws and rods, interspinous spacer and transfacet screws depending on each case. Significance between pre- and postoperative scores was analyzed with Student's paired t-test. RESULTS The mean follow-up period was 33.1 (SD 20.4) months. The outcome was excellent in 28 (56%), good in 17 (34%), fair in 3 (6%) and poor in 2 (4%) cases according to Macnab criteria. The latter two cases were lost before 6 months of follow-up and consequently classified as poor. Significant differences (p CONCLUSIONS The pTLIF technique shows 90% of Excellent and Good postoperative results and no major complications for a long-term mean follow-up of 33 months, proving the efficacy and safety of the pTLIF procedure for primary and revision surgery cases. Percutaneous transforaminal interbody fusion allows bypassing posterior scar tissue from previous operations in revision surgery cases hereby reducing the risk of dural tear and nerve injury. Postoperative median time until walking (6 hours) and until hospital discharge was faster compared to standard open TLIF (25hours vs. 5 days), probably due to the less invasive handling of the soft and bony tissues with the endoscopic posterolateral approach. The pTLIF technique has disruptive potential as it opens the way to ambulatory fusion surgery in an outpatient clinical setting.

Comparison of lateral lumbar interbody fusion (LLIF) with open versus percutaneous screw fixation for adult degenerative scoliosis

Study designRetrospective Review ObjectivesCompare clinical outcomes and radiographic correction of adult degenerative scoliosis (ADS) patients treated with lateral lumbar interbody fusion (LLIF), combined either with percutaneous (no laminectomy) versus open laminectomy/pedicle screw instrumentation. MethodsTwenty-two ADS patients undergoing combined LLIF and posterior instrumentation were divided into two groups: thirteen patients underwent LLIF with open laminectomy and posterior pedicle instrumentation (Group-1, six revision); nine patients underwent LLIF with percutaneous pedicle instrumentation (no decompression) (Group-2). Radiographs, CT/MRI, peri-operative complications, VAS, SF-12, and ODI were measured. ResultsAverage follow up was 22 months. In Group-1 and Group-2, respectively: Mean coronal Cobb angle corrected 12.6° and 5.8°; Mean regional lumbar lordosis improved 11.1° and 3.8°; Pelvic incidence minus lumbar lordosis mismatch corrected to within +/−9° in 46% and 0% of patients; Mean VAS improved from 5.4 to 2.8 and 6.3 to 1; Mean ODI improved 19% and 22%. Improvements were found in SF-12 PCS and MCS scores. ConclusionsBoth open and percutaneous posterior techniques following LLIF significantly improved clinical outcomes. Open procedures resulted in significantly better radiographic improvements but also higher complication rates. LLIF with percutaneous posterior fixation, without decompression, should be considered part of the algorithm in select ADS patients with remaining compensatory mechanisms and understanding that greater degrees of correction may require an open, more extensive approach.

Impact of case type, length of stay, institution type, and comorbidities on Medicare diagnosis-related group reimbursement for adult spinal deformity surgery.

OBJECTIVE The aim of this study was to educate medical professionals about potential financial impacts of improper diagnosis-related group (DRG) coding in adult spinal deformity (ASD) surgery. METHODS Medicare's Inpatient Prospective Payment System PC Pricer database was used to collect 2015 reimbursement data for ASD procedures from 12 hospitals. Case type, hospital type/location, number of operative levels, proper coding, length of stay, and complications/comorbidities (CCs) were analyzed for effects on reimbursement. DRGs were used to categorize cases into 3 types: 1) anterior or posterior only fusion, 2) anterior fusion with posterior percutaneous fixation with no dorsal fusion, and 3) combined anterior and posterior fixation and fusion. RESULTS Pooling institutions, cases were reimbursed the same for single-level and multilevel ASD surgery. Longer stay, from 3 to 8 days, resulted in an additional $1400 per stay. Posterior fusion was an additional $6588, while CCs increased reimbursement by approximately $13,000. Academic institutions received higher reimbursement than private institutions, i.e., approximately $14,000 (Case Types 1 and 2) and approximately $16,000 (Case Type 3). Urban institutions received higher reimbursement than suburban institutions, i.e., approximately $3000 (Case Types 1 and 2) and approximately $3500 (Case Type 3). Longer stay, from 3 to 8 days, increased reimbursement between $208 and $494 for private institutions and between $1397 and $1879 for academic institutions per stay. CONCLUSIONS Reimbursement is based on many factors not controlled by surgeons or hospitals, but proper DRG coding can significantly impact the financial health of hospitals and availability of quality patient care.

Open vs. Percutaneous Pedicle Screw Insertion for Thoracolumbar Traumatic A3 and A4 AO Fractures - 18-Months Follow-Up

Purpose To compare the efficacy and safety of the percutaneous screw fixation (PSF) and the open pedicle screw fixation (OPSF) on thoracolumbar (TL) fracture. Methods Sixty-four adult patients with TL vertebral fractures who underwent open or percutaneous posterior short-segment transpedicular screw fixation between January of 2013 and September of 2015 were retrospectively reviewed. All patients underwent clinical, radiological and quality of life follow-up for at least 18 months. Results There was no significant difference in age, gender, time between injury and surgery, and preoperative percentage of anterior column height, preoperative sagittal regional Cobb angle, or kyphotic angle of fractured vertebra between these two groups (p &gt; 0.05). There was significantly less intraoperative blood loss in the PSF (87.6 ± 24.6 mL) than in the OPSF group (271.4 ± 142.6 mL) (p &lt; 0.05). The mean surgery time was 62 minutes (range 42–130 minutes) for open and 58 minutes (range 35 to 128 minutes) for percutaneous screw fixation. The surgery time was shorter in the PSF group, but with no statistical significance (p &gt; 0.05). The mean Oswestry disability index (ODI) scores after 18-months were 23.12 ± 8.2 for the PSF and 24.12 ± 9.2 for the OPSF group, without any statistical significance (p &gt; 0.05). Conclusion Both open and percutaneous screw fixations are safe and effective. The percutaneous techniques significantly reduced the intraoperative blood loss compared with the open techniques.

Percutaneous posterior fixation for unstable pelvic ring fractures

Several posterior fixation techniques for unstable pelvic ring fractures have been described. Here, we present a minimally invasive, percutaneous technique to fix the two posterior iliac crests using spinal instrumentation. Between September 2008 and March 2012, 11 patients with a mean age of 36.4 years were operated because of a vertically unstable Tile C pelvic ring fracture. Posterior fixation was performed using two polyaxial screws in each iliac crest with two subfascial connector rods. At the final follow-up, all patients were evaluated clinically and radiologically. The mean surgery time was 45 minutes; there were no intraoperative complications. At a mean follow-up of four years, the functional Majeed score was excellent in eight patients and good in three patients. The radiological results were excellent in eight patients and good in three patients. Percutaneous posterior fixation of vertically unstable pelvic fractures leads to good functional and radiological outcomes. Type of studyTechnical note, retrospective. Level of evidenceIV.

Indirect decompression and reduction of lumbar spondylolisthesis does not result in higher rates of immediate and long term complications

Nerve root decompression and spondylolisthesis reduction is typically reserved for open surgery. MIS techniques have been thought to be associated with higher rates of neurological complications. This study aims to report acute and chronic neurologic complications encountered with MIS surgery for spondylolisthesis, specifically, the incidence of nerve root injury and clinical and radiographic outcomes. A retrospective review of 269 patients who underwent MIS LIF or ALIF treatment for lumbar degenerative or isthmic grade 1 or 2 spondylolisthesis was conducted. Immediate and long-term complication rates were the primary outcome. Only patients who had symptomatic anterolisthesis and 2-year outcome data were included in the study. 52 patients met inclusion criteria with 54 lumbar spondylolisthesis levels treated. Five patients (9.6%) experienced postoperative anterior thigh numbness, which completely resolved within 3months. There were no permanent neurologic deficits; however, 2 patients (3.8%) suffered a transient foot weakness that resolved with physical therapy by 3months follow-up. There was one incidence of wound breakdown that required revision and one incidence of L5/S1 endplate/sacral promontory fracture and relisthesis 3months postoperatively. Overall fusion rate was 98% at 6months. Indirect decompression and closed anatomical reduction for treatment of low-grade spondylolisthesis using ALIF and LIF with posterior percutaneous fixation was not associated with an increased risk of neurologic deficit. This study suggests that this technique is safe, reproducible, durable, and provides adequate fusion rates.