Minimally Invasive Lumbar Transfacet Screw Fixation in the Lateral Decubitus Position After Extreme Lateral Interbody Fusion: A Technique and Feasibility Study

Single-position circumferential lumbar spinal fusion: an overview of terminology, concepts, rationale and the current evidence base

PURPOSE

To provide definitions and a conceptual framework for single position surgery (SPS) applied to circumferential fusion of the lumbar spine.

METHODS

Narrative literature review and experts' opinion.

RESULTS

Two major limitations of lateral lumbar interbody fusion (LLIF) have been (a) a perceived need to reposition the patient to the prone position for posterior fixation, and (b) the lack of a robust solution for fusion at the L5/S1 level. Recently, two strategies for performing single-position circumferential lumbar spinal fusion have been described. The combination of anterior lumbar interbody fusion (ALIF) in the lateral decubitus position (LALIF), LLIF and percutaneous pedicle screw fixation (pPSF) in the lateral decubitus position is known as lateral single-position surgery (LSPS). Prone LLIF (PLLIF) involves transpsoas LLIF done in the prone position that is more familiar for surgeons to then implant pedicle screw fixation. This can be referred to as prone single-position surgery (PSPS). In this review, we describe the evolution of and rationale for single-position spinal surgery. Pertinent studies validating LSPS and PSPS are reviewed and future questions regarding the future of these techniques are posed. Lastly, we present an algorithm for single-position surgery that describes the utility of LALIF, LLIF and PLLIF in the treatment of patients requiring AP lumbar fusions.

CONCLUSIONS

Single position surgery in circumferential fusion of the lumbar spine includes posterior fixation in association with any of the following: lateral position LLIF, prone position LLIF, lateral position ALIF, and their combination (lateral position LLIF+ALIF). Preliminary studies have validated these methods.

Lateral versus prone robot-assisted percutaneous pedicle screw placement: a CT-based comparative assessment of accuracy

OBJECTIVE

Single-position lateral lumbar interbody fusion (SP-LLIF) has recently gained significant popularity due to increased operative efficiency, but it remains technically challenging. Robot-assisted percutaneous pedicle screw (RA-PPS) placement can facilitate screw placement in the lateral position. The authors have reported their initial experience with SP-LLIF with RA-PPS placement in the lateral position, and they have compared this accuracy with that of RA-PPS placement in the prone position.

METHODS

The authors reviewed prospectively collected data from their first 100 lateral-position RA-PPSs. The authors graded screw accuracy on CT and compared it to the accuracy of all prone-position RA-PPS procedures during the same time period. The authors analyzed the effect of several demographic and perioperative metrics, as a whole and specifically for lateral-position RA-PPS placement.

RESULTS

The authors placed 99 lateral-position RA-PPSs by using the ExcelsiusGPS robotic platform in the first 18 consecutive patients who underwent SP-LLIF with postoperative CT imaging; these patients were compared with 346 prone-position RA-PPSs that were placed in the first consecutive 64 patients during the same time period. All screws were placed at L1 to S1. Overall, the lateral group had 14 breaches (14.1%) and the prone group had 25 breaches (7.2%) (p = 0.032). The lateral group had 5 breaches (5.1%) greater than 2 mm (grade C or worse), and the prone group had 4 (1.2%) (p = 0.015). The operative level had an effect on the breach rate, with breach rates (grade C or worse) of 7.1% at L3 and 2.8% at L4. Most breaches were grade B (< 2 mm) and lateral, and no breach had clinical sequelae or required revision. Within the lateral group, multivariate regression analysis demonstrated that BMI and number of levels affected accuracy, but the side that was positioned up or down did not.

CONCLUSIONS

RA-PPSs can improve the feasibility of SP-LLIF. Spine surgeons should be cautious and selective with this technique owing to decreased accuracy in the lateral position, particularly in obese patients. Further studies should compare SP-LLIF techniques performed while the patient is in the prone and lateral positions.

Single position lumbar fusion: a systematic review and meta-analysis

BACKGROUND CONTEXT

Recently, a single position lumbar fusion has been described in which both the anterior or lateral interbody fusion as well as posterior percutaneous pedicle screw fixation are performed in a single position.

PURPOSE

The purpose of this study was to present and analyze the current evidence for single position lumbar fusion.

STUDY DESIGN/SETTING

This is a systematic review and meta-analysis.

PATIENT SAMPLE

Prospective or retrospective studies published in English that assessed outcomes of single position lumbar fusion surgery for patients with lumbar degenerative disease, spondylolisthesis, or radiculopathy were included.

OUTCOME MEASURES

Outcome measures included operative time, estimated blood loss, hospital length of stay, X-Ray exposure time, and postoperative outcomes including leg numbness or pain, leg weakness, lumbar lordosis, and segmental lordosis.

METHODS

This systematic review was performed in accordance with PRISMA guidelines. Two separate meta-analyses were performed. The first compared single position (SP) surgery, both lateral and prone, to dual position or flipped (F) surgery. The second meta-analysis compared lateral single position (LSP) surgery to prone single position (PSP) surgery. Variables were included if (1) they were a mean with a reported standard deviation or (2) if they were a categorical variable. For calculating standard error of the mean, we used sample size, mean, and standard deviation. A random effects model was used. The heterogeneity among studies was assessed with a significance level of <0.05.

RESULTS

Twenty-one articles were included for analysis. Three studies were prospective nonrandomized studies, while 18 were retrospective. Seven articles studied lateral single position only, 10 articles compared lateral single position to traditional repositioning surgery, three articles studied prone single position surgery, and one article compared prone single position surgery to traditional repositioning surgery. A detailed review is provided for all 21 articles. Seventeen studies were included for meta-analysis comparing the SP versus F groups, for a total of 942 patients in the SP group and 254 in the F group. Mean operative time was significantly less for the SP group compared with the F group (SP: 127.5±7.9, F: 188.7±15.5, p<.001). Average hospital length of stay was 2.87±0.3 days in the SP group and 6.63±0.6 days in the F group (p<.001). Complication rates did not significantly differ between groups. Pedicle screws placed in the lateral position had a higher rate of complication as compared with those placed in a prone position (L: 10.2±2%, P: 1.6±1%, p=.015). Seventeen studies were included in the LSP versus PSP analysis, including 13 in the LSP group and four in the PSP group, with a total of 785 patients in the LSP group and 85 patients in the PSP group. Operative time and X-Ray exposure was significantly less in the LSP compared with the PSP group (117.1±5.5 minutes vs. 166.9±21.9 minutes, p<.001; 43.7±15.5 minutes vs. 171.0±25.8 minutes, p<.001). Postoperative segmental lordosis was greater in the prone single position group (p<.001).

CONCLUSIONS

Single position surgery decreases operative times and hospital length of stay, while maintaining similar complication rates and radiographic outcomes. PSP surgery was found to be longer in duration and have increased radiation exposure time compared with LSP, while increasing postoperative segmental lordosis.

Alternatives to Traditional Pedicle Screws for Posterior Fixation of the Degenerative Lumbar Spine

BACKGROUND

Traditional pedicle screws are currently the gold standard to achieve stable 3-column fixation of the degenerative lumbar spine. However, there are cases in which pedicle screw fixation may not be ideal. Due to their starting point lateral to the pars interarticularis, pedicle screws require a relatively wide dissection along with a medialized trajectory directed toward the centrally located neural elements and prevertebral vasculature. In addition, low bone mineral density remains a major risk factor for pedicle screw loosening, pullout, and pseudarthrosis. The purpose of this article is to review the indications, advantages, disadvantages, and complications associated with posterior fixation techniques of the degenerative lumbar spine beyond the traditional pedicle screws.

METHODS

Comprehensive literature searches of the PubMed, Scopus, and Web of Science databases were performed for 5 methods of posterior spinal fixation, including (1) cortical bone trajectory (CBT) screws, (2) transfacet screws, (3) translaminar screws, (4) spinous process plates, and (5) fusion mass screws and hooks. Articles that had been published between January 1, 1990, and January 1, 2020, were considered. Non-English-language articles and studies involving fixation of the cervical or thoracic spine were excluded from our review.

RESULTS

After reviewing over 1,700 articles pertaining to CBT and non-pedicular fixation techniques, a total of 284 articles met our inclusion criteria. CBT and transfacet screws require less-extensive exposure and paraspinal muscle dissection compared with traditional pedicle screws and may therefore reduce blood loss, postoperative pain, and length of hospital stay. In addition, several methods of non-pedicular fixation such as translaminar and fusion mass screws have trajectories that are directed away from or posterior to the spinal canal, potentially decreasing the risk of neurologic injury. CBT, transfacet, and fusion mass screws can also be used as salvage techniques when traditional pedicle screw constructs fail.

CONCLUSIONS

CBT and non-pedicular fixation may be preferred in certain lumbar degenerative cases, particularly among patients with osteoporosis. Limitations of non-pedicular techniques include their reliance on intact posterior elements and the lack of 3-column fixation of the spine. As a result, transfacet and translaminar screws are infrequently used as the primary method of fixation. CBT, transfacet, and translaminar screws are effective in augmenting interbody fixation and have been shown to significantly improve fusion rates and clinical outcomes compared with stand-alone anterior lumbar interbody fusion.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Single position circumferential fusion improves operative efficiency, reduces complications and length of stay compared with traditional circumferential fusion

BACKGROUND CONTEXT

Anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF) with percutaneous posterior screw fixation are two techniques used to address degenerative lumbar pathologies. Traditionally, these anterior-posterior (AP) surgeries involve repositioning the patient from the supine or lateral decubitus position to prone for posterior fixation. To reduce operative time (OpTime) and subsequent complications of prolonged anesthesia, single-position lumbar surgery (SPLS) is a novel, minimally invasive alternative performed entirely from the lateral decubitus position.

PURPOSE

Assess the perioperative safety and efficacy of single position AP lumbar fusion surgery (SPLS).

STUDY DESIGN

Multicenter retrospective cohort study.

PATIENT SAMPLE

Three hundred and ninety patients undergoing AP surgery were included, of which 237 underwent SPLS and 153 were in the Flip group.

OUTCOME MEASURES

Outcome measures included levels fused, percentage of cases including L5-S1 fusion, fluoroscopy radiation dosage, OpTime, estimated blood loss (EBL), length of stay (LOS), and perioperative complications. Radiographic analysis included lumbar lordosis (LL), pelvic incidence, pelvic tilt, and segmental LL.

METHODS

Patients undergoing primary ALIF and/or LLIF surgery with bilateral percutaneous pedicle screw fixation between L2-S1 were included over a 4-year period. Patients were classified as either traditional repositioned "Flip" surgery or SPLS. Outcome measures included levels fused, percentage of cases including L5-S1 fusion, fluoroscopy radiation dosage, OpTime, EBL, LOS, perioperative complications. Radiographic analysis included LL, pelvic incidence, pelvic tilt, and segmental LL. All measures were compared using independent samples t-tests and chi-squared analyses as appropriate with significance set at p < .05. Propensity matching was completed where demographic differences were found.

RESULTS

Three hundred and ninety patients undergoing AP surgery were included, of which 237 underwent SPLS and 153 were in the Flip group. Age, gender, BMI, and CCI were similar between groups. Levels fused (1.47 SPLS vs 1.52 Flip, p = .468) and percent cases including L5-S1 (31% SPLS, 35% Flip, p = .405) were similar between cohorts. SPLS significantly reduced OpTime (103 min vs 306 min, p < .001), EBL (97 vs 313 mL, p < .001), LOS (1.71 vs 4.12 days, p < .001), and fluoroscopy radiation dosage (32 vs 88 mGy, p < .001) compared to Flip. Perioperative complications were similar between cohorts with the exception of postoperative ileus, which was significantly lower in the SPLS group (0% vs 5%, p < .001). There was no significant difference in wound, vascular injury, neurological complications, or Venous Thrombotic Event. There was no significant difference found in 90-day return to operating room (OR).

CONCLUSIONS

SPLS improves operative efficiency in addition to reducing blood loss, LOS and ileus in this large cohort study, while maintaining safety.

Percutaneous CT-guided lumbar trans-facet pedicle screw fixation in lumbar microinstability syndrome: feasibility of a novel approach

STUDY DESIGN

Prospective experimental uncontrolled trial.

BACKGROUND

Lumbar microinstability (MI) is a common cause of lower back pain (LBP) and is related to intervertebral disc degeneration that leads to inability to adequately absorb applied loads. The term "microinstability" has recently been introduced to denote a specific syndrome of biomechanical dysfunction with minimal anatomical change. Trans-facet fixation (TFF) is a minimally invasive technique that involves the placement of screws across the facet joint and into the pedicle, to attain improved stability in the spine.

PURPOSE

In this study, we aimed to evaluate the effectiveness, in terms of pain and disability reduction, of a stand-alone TFF in treatment of patients with chronic low back pain (LBP) due to MI. Moreover, as a secondary endpoint, the purpose was to assess the feasibility and safety of a novel percutaneous CT-guided technique.

METHODS

We performed percutaneous CT-guided TFF in 84 consecutive patients presenting with chronic LBP attributable to MI at a single lumbar level without spondylolysis. Pre- and post-procedure pain and disability levels were measured using the visual analogue scale (VAS) and Oswestry Disability Index (ODI).

RESULTS

At 2 years, TFF resulted in significant reductions in both VAS and ODI scores. CT-guided procedures were tolerated well by all patients under light sedation with a mean procedural time of 45 min, and there were no reported immediate or delayed procedural complications.

CONCLUSION

TFF seems to be a powerful technique for lumbar spine stabilization in patients with chronic mechanical LBP related to lumbar MI. CT-guided technique is fast, precise, and safe and can be performed in simple analgo-sedation.

Robot-assisted Percutaneous Transfacet Screw Fixation Supplementing Oblique Lateral Interbody Fusion Procedure: Accuracy and Safety Evaluation of This Novel Minimally Invasive Technique

Objectives

Percutaneous transfacet screw fixation (pTSF) is a minimally invasive posterior fixation technique supplementing oblique lateral interbody fusion (OLIF) for lumbar spinal disorders. Accurate screw insertion is difficult to achieve and technically demanding under 2‐D fluoroscopy. Recently developed robot‐assisted spinal surgery demonstrated a high level of accuracy of pedicle screw insertion and a low complication rate. No published study has reported this combination technique. The aim of our study was to evaluate the accuracy and safety properties of the combination of both minimally invasive techniques: robot‐assisted pTSF supplementing the OLIF procedure.

Methods

This was an experimental and prospective study. Selected consecutive patients with lumbar degenerative disorders received robot‐assisted pTSF supplementing the OLIF procedure using the TianJi Robot system operated by one senior surgeon from March to October 2018. The accuracy of screw insertion and perioperative screw‐related complications were evaluated. Assessment of the accuracy of screw insertion included intraoperative robotic guidance accuracy and incidence of screw encroachments. Intraoperative robotic guidance accuracy referred to translational and angular deviations of screws, which were assessed by comparing the planned and actual screw trajectories guided by the robot on reconstructed images using TianJi Robot Planning Software. Screw encroachments were evaluated on postoperative CT images and classified by a grading system (A, excellent; B, good; C, poor). Screw‐related complications including intraoperative pin skidding, screw malposition and adjustment, together with postoperative neurological symptoms that correlated with screw malposition were recorded.

Results

Ten patients, with an average age of 60.2 years, were selected and recruited in this study. All cases were degenerative lumbar spinal disorders, out of which there were 6 cases of Meyerding Grade I degenerative spondylolisthesis. Twenty‐four transfacet screws were inserted by robotic assistance. Instrumented levels included nine segments at L_4–5 level and three segments at L_3–4 level. Two patients had both L_4–5 and L_3–4 level fixation. The average surgical time was 3.3 h (SD, 0.8 h). The mean blood loss was 90 mL (SD, 32 mL). Intraoperative guidance accuracy showed 1.09 ± 0.17 mm (ranging from 0.75 to 1.22 mm) translational deviation and 2.17° ± 0.39° (ranging from 1.47° to 2.54°) angular deviation. The gradings of screw encroachment were: 17 screws (71%) with Grade A, 6 screws (25%) with Grade B, and 1 screw (4%) with Grade C. Only one pin skidding occurred intraoperatively and revised subsequently. No postoperative neurological complications were found.

Conclusion

Our preliminary study of robot‐assisted pTSF supplementing the OLIF procedure showed a high level of accuracy for screw insertion and this minimally invasive combination technique was found to be a feasible and safe procedure.

MIS Single-position Lateral and Oblique Lateral Lumbar Interbody Fusion and Bilateral Pedicle Screw Fixation: Feasibility and Perioperative Results

STUDY DESIGN

Retrospective review of prospectively collected data of the first 72 consecutive patients treated with single-position one- or two-level lateral (LLIF) or oblique lateral interbody fusion (OLLIF) with bilateral percutaneous pedicle screw and rod fixation by a single spine surgeon.

OBJECTIVE

To evaluate the clinical feasibility, accuracy, and efficiency of a single-position technique for LLIF and OLLIF with bilateral pedicle screw and rod fixation.

SUMMARY OF BACKGROUND DATA

Minimally-invasive lateral interbody approaches are performed in the lateral decubitus position. Subsequent repositioning prone for bilateral pedicle screw and rod fixation requires significant time and resources and does not facilitate increased lumbar lordosis.

METHODS

The first 72 consecutive patients (300 screws) treated with single-position LLIF or OLLIF and bilateral pedicle screws by a single surgeon between December 2013 and August 2016 were included in the study. Screw accuracy and fusion were graded using computed tomography and several timing parameters were recorded including retractor, fluoroscopy, and screw placement time. Complications including reoperation, infection, and postoperative radicular pain and weakness were recorded.

RESULTS

Average screw placement time was 5.9 min/screw (standard deviation, SD: 1.5 min; range: 3-9.5 min). Average total operative time (interbody cage and pedicle screw placement) was 87.9 minutes (SD: 25.1 min; range: 49-195 min). Average fluoroscopy time was 15.0 s/screw (SD: 4.7 s; range: 6-25 s). The pedicle screw breach rate was 5.1% with 10/13 breaches measured as < 2 mm in magnitude. Fusion rate at 6-months postoperative was 87.5%. Two (2.8%) patients underwent reoperation for malpositioned pedicle screws with subsequent resolution of symptoms.

CONCLUSION

The single-position, all-lateral technique was found to be feasible with accuracy, fluoroscopy usage, and complication rates comparable with the published literature. This technique eliminates the time and staffing associated with intraoperative repositioning and may lead to significant improvements in operative efficiency and cost savings.

LEVEL OF EVIDENCE

4.

Percutaneous Lumbar Transfacet Screw Fixation: A Technique Analysis of 176 Screws in 83 Patients With Assessment of Radiographic Accuracy, Hardware Failure, and Complications

Supplemental Digital Content Is Available in the Text.

Emerging Techniques for Posterior Fixation of the Lumbar Spine

Pedicle screw fixation is the preferred method of posterior fusion in lumbar spinal surgery. The technique provides three-column support of the vertebrae, contributing to the biomechanical strength of the construct. However, open pedicle screw fixation often necessitates wide posterior exposure and dissection with soft-tissue disruption of the facet joint. Alternative posterior fixation techniques have been developed to reduce surgical time, soft-tissue dissection, disruption of the adjacent facet joint capsule, neurologic risk, and implant cost. Results of these techniques are comparable to those of standard pedicle screw fixation systems. Certain patients, especially those at a lower risk of nonunion or those who require posterior fixation only as an adjunct to anterior column support, may benefit from the shorter surgical time and limited posterior exposure of the alternative techniques. However, the decreased rigidity of these alternative constructs can result in excessive motion, which can lead to nonunion and early hardware failure.

[Facet Fixation Combined with Lumbar Interbody Fusion: Comparative Analysis of Clinical Experience and A New Method of Surgical Treatment of Patients with Lumbar Degenerative Diseases]

Background

For the treatment of patients with degenerative diseases of the lumbar spine the technique of pedicle fixation is widespread, when after open decompression channel structure locking screws are introduced into the vertebral body through the back vertebra legs. We first used a fundamentally new way of fixing the rear using the facet-boards Cage «Facet Wedge», when posterior fixation is done by closing the facet joints with minimally invasive, percutaneous method. We have not found data on the clinical efficacy of facet fixation in scientific literature.

Aims

To compare the clinical efficacy of facet fixation combined with interbody fusion in the treatment of patients with degenerative lumbar spine disease.

Materials and Methods

The study included 145 patients who were divided into 2 groups. The study group with long-term observation included patients (n=100) who underwent a new method for lumbar fixation; the method comprises unilateral or bilateral implantation of titanium Cage «facet Wedge» in the joint space facet joint in combination with the anterior, lateral, and transforaminal interbody fusion. Clinical comparison group (n=45) included retrospectively recruited patients who were performed titanium pedicle screw installation after open decompression and interbody fusion posterior lumbar fixation. Dynamic observation and comprehensive evaluation of the treatment clinical results was carried out for 18 months after surgery.

Results

Cage facet installation technology is quite simple, universal for the stabilization of the rear of the complex after interbody fusion from the front, side, and rear access; and does not require the intraoperative application of expensive high-tech equipment. Comparative analysis of the main group showed significantly better results in terms of the duration of the operation [CG 125 (90; 140) min, the CCG 205 (160; 220) min; p=0.01], the volume of blood loss [CG 80 (70; 120) ml, CCG 350 (300; 550) ml; p=0.008], activation time [CG 2 (1; 2) days, 4 CCG (3; 5) days; p=0.02], length of hospitalization [CG 9 (10; 11) days, the CCG 13 (12; 15) days; p=0.03], the level of pain on a visual analog scale [CG 3 (2; 4) mm, CCG 15 (12; 18) mm; p=0.001], quality of life (by index Oswestry) [CG 8 (6; 8) points, the CCG 23 (20; 28) points, p=0.003], and labor rehabilitation [CG 3 (2; 6) months, CCG 9 (6; 12) months; p=0.0001]. The number of postoperative complications in group 1 was 13%, in the 2nd ― 31,1% (p=0,0012). The new method involves fixing the back with considerably less surgical trauma of paravertebral soft tissue that results in early activation of patients, reduction of stay in hospital period, and better functional recovery of patients.

Conclusions

The application of facet fixation combined with interbody fusion in the treatment of patients with degenerative diseases of the lumbar spine allows achieving the best clinical outcomes and fewer postoperative complications during the short and long-term follow-up if compared with the traditional method of transpedicular stabilization. The combination of low-impact and reliability facet fixation techniques for posterior stabilization of the operated segment creates favorable conditions for the restoration of a functional condition of patients, full social and physical rehabilitation.

Prospective evaluation of 1-year outcomes in single-level percutaneous lumbar transfacet screw fixation in the lateral decubitus position following lateral transpsoas interbody fusion

PURPOSE

Lateral transpsoas lumbar interbody fusion (LTIF) is an accepted treatment for degenerative lumbar disc disease. Bilateral percutaneous transfacet (TF) fixation is a promising option for stabilization following LTIF. Here, we describe our experience with this technique and assess the clinical outcomes and efficacy.

METHODS

Thirty-eight consecutive patients were identified who underwent LTIF followed by bilateral percutaneous transfacet fixation in the lateral position. Preoperative and 1-year postoperative VAS scores, and operative data were prospectively recorded. One-year outcomes were also assessed according to the MacNab criteria. Fusion was assessed at 1 year via computed tomography and dynamic radiography. Two-tailed Student's t test was used to compare VAS scores.

RESULTS

Twenty-six patients underwent fusion at L4-5, 11 at L3-4, and one at L2-3; two patients were lost to follow-up. Mean operative time was 148.0 ± 47.9 min; mean blood loss was 33.0 ± 26.1 ml; mean hospital stay was 53.5 ± 51.2 h. Mean preoperative VAS scores for back and leg pain were 7.4 ± 3.0 and 7.0 ± 2.9, respectively; mean postoperative VAS scores for back and leg pain were 1.9 ± 2.4 (p < 0.0001) and 2.0 ± 3.0 (p < 0.0001), respectively. Most (89 %) patients had some relief, 72 % good to excellent and 17 % fair outcomes; eleven percent had little to no relief. There was one postoperative complication (pulmonary embolus). All patients had evidence of solid bony fusion.

CONCLUSIONS

Percutaneous transfacet fixation in the lateral position is a safe and effective alternative for fixation after LTIF and may be associated with shorter operative time and less blood loss than other posterior fixation techniques.

CT-Guided Transfacet Pedicle Screw Fixation in Facet Joint Syndrome: A Novel Approach

Axial microinstability secondary to disc degeneration and consequent chronic facet joint syndrome (CFJS) is a well-known pathological entity, usually responsible for low back pain (LBP). Although posterior lumbar fixation (PIF) has been widely used for lumbar spine instability and LBP, complications related to wrong screw introduction, perineural scars and extensive muscle dissection leading to muscle dysfunction have been described. Radiofrequency ablation (RFA) of facet joints zygapophyseal nerves conventionally used for pain treatment fails in approximately 21% of patients. We investigated a "covert-surgery" minimal invasive technique to treat local spinal instability and LBP, using a novel fully CT-guided approach in patients with axial instability complicated by CFJS resistant to radioablation, by introducing direct fully or partially threaded transfacet screws (transfacet fixation - TFF), to acquire solid arthrodesis, reducing instability and LBP. The CT-guided procedure was well tolerated by all patients in simple analogue sedation, and mean operative time was approximately 45 minutes. All eight patients treated underwent clinical and CT study follow-up at two months, revealing LBP disappearance in six patients, and a significant reduction of lumbar pain in two. In conclusion, CT-guided TFF is a fast and safe technique when facet posterior fixation is needed.

Indirect foraminal decompression is independent of metabolically active facet arthropathy in extreme lateral interbody fusion

STUDY DESIGN

Retrospective analysis of prospectively collected, nonrandomized radiographical data.

OBJECTIVE

To examine the relationship between the presence of preoperative metabolically active facet arthropathy (FA) and the amount of indirect foraminal decompression gained after extreme lateral interbody fusion (XLIF).

SUMMARY OF BACKGROUND DATA

Although evidence of significant radiographical indirect decompression after XLIF has been shown, the relationship between the extent of indirect decompression and the presence of potentially attenuating, FA is yet to be studied.

METHODS

A prospective database of consecutive patients undergoing XLIF was retrospectively analyzed. Posterior disc height, foraminal height, and cross-sectional foraminal area were measured on computed tomographic scans obtained preoperatively and 2 days postoperatively. The selected radiographical parameters were examined with respect to the presence of FA based on preoperative computed tomographic and bone scans.

RESULTS

Fifty-two consecutive patients underwent 79 levels of XLIF without direct decompression. Average age was 66.4 years and 34 (65.4%) were females. Surgery resulted in significant increases in posterior disc height 3.0 to 5.7 mm (89.0% increase), P<0.0001; foraminal height 1.4 to 1.7 cm (38.0% increase), P<0.0001; and foraminal area 1.1 to 1.4 cm (45.1% increase), P<0.0001. These increases were independent of the presence of metabolically active arthropathy.

CONCLUSION

Significant indirect neural decompression is possible in XLIF, regardless of the presence of metabolically active FA.

LEVEL OF EVIDENCE

3.

Adult degenerative scoliosis treated with XLIF: clinical and radiographical results of a prospective multicenter study with 24-month follow-up

STUDY DESIGN

Prospective, multicenter, single-arm study.

OBJECTIVE

The objective of this study was to evaluate the clinical and radiographical results of patients undergoing extreme lateral interbody fusion (XLIF), a minimally disruptive lateral transpsoas retroperitoneal surgical approach for the treatment of degenerative scoliosis (DS).

SUMMARY OF BACKGROUND DATA

Surgery for the treatment of DS has been reported to have acceptable results but is traditionally associated with high morbidity and complication rates. A minimally disruptive lateral transpsoas retroperitoneal surgical approach (XLIF) has become popular for the treatment of DS. This is the first prospective, multicenter study to quantify outcomes after XLIF in this patient population.

METHODS

A total of 107 patients with DS who underwent the XLIF procedure with or without supplemental posterior fixation at one or more intervertebral levels were enrolled in this study. Clinical and radiographical results were evaluated up to 24 months after surgery.

RESULTS

Mean patient age was 68 years; 73% of patients were female. A mean of 3.0 (range, 1-6) levels were treated with XLIF per patient. Overall complication rate was low compared with traditional surgical treatment of DS. Significant improvement was seen in all clinical outcome measures at 24 months: Oswestry Disability Index, visual analogue scale for back pain and leg pain, and 36-Item Short Form Health Survey mental and physical component summaries (P < 0.001). Eighty-five percent of patients were satisfied with their outcome and would undergo the procedure again. In patients with hypolordosis, lumbar lordosis was corrected from a mean of 27.7° to 33.6° at 24 months (P < 0.001). Overall Cobb angle was corrected from 20.9° to 15.2°, with the greatest correction observed in patients supplemented with bilateral pedicle screws.

CONCLUSION

This study demonstrates the use of the XLIF procedure in the treatment of DS. XLIF is associated with good clinical and radiographical outcomes, with a substantially lower complication rate than has been reported with traditional surgical procedures.

LEVEL OF EVIDENCE

3.