Review of Current Evidence for Minimally Invasive Posterior Sacroiliac Joint Fusion

Salvage of failed direct lateral sacroiliac joint fixation using a new percutaneous lateral-oblique transfixation technique with two variable-threaded screws: a multicenter case report of three cases

Background

The direct lateral trans-gluteal muscle splitting transiliac approach was popularized to fixate the sacroiliac joint (SIJ) using three cannulated triangular titanium implants (TTIs) wedges. Publications support efficacy of the direct lateral approach but a paucity of literature to help surgeons revise these implants when they fail. Intuitively the implants can be removed but require an open incision and dissection through the gluteal muscles and scar tissue which can lead to muscle and neurovascular injuries. Our objective was to evaluate the clinical outcome, measured by patient-reported Visual Analog Score (VAS), of three patients who had failed direct lateral SIJ fusions each using three implants and describe a revision technique using a new percutaneous lateral-oblique transfixation technique with two variable-threaded screws while preserving the original implants.

Case Description

Two separate orthopedic spine surgeons at different hospitals performed the technique using two SacroFuse® screws for SIJ revision fusion in three patients who had clinical symptoms and radiographic findings of SIJ pseudoarthrosis after direct lateral approach. One 61 years old male patient had a previous surgery with three lateral threaded screw implants. Two females with ages 47 and 40 years old had three TTI wedges. Follow-up from 10 to 26 months. Patients discharged home the same day. Mean procedure time of 20 minutes with blood loss less than five cc. Incision size was approximately 1 inch. Each patient had a 12 mm × 60 mm and a 12 mm × 50 mm screw filled with NanoFuse Biologics synthetic bioactive glass and demineralized bone matrix. Prior implants were left in place. There was an 89% decrease in mean VAS score of 9.5 to 1.

Conclusions

This is a clinically valuable report because until now there was no reconstructive surgery to revise direct lateral implants other than removal with potential neurovascular risks. This is the first article to demonstrate a lateral-oblique transfixation technique with two variable-threaded screws for successful salvage of SIJ pseudoarthrosis after direct lateral fixation without implant removal. The Sacrix technique achieved immediate stability and long-term fusion documented on computed tomography (CT) scan as early as 6 months.

Posterior oblique technique for sacroiliac joint fusion leads to greater pain relief and similar improvement in function compared to the lateral technique: A retrospective, comparative study

Background

Management of chronic sacroiliac joint (SIJ) pain among patients who do not respond to nonsurgical treatment is increasingly turning toward minimally invasive SIJ fusion. There are different techniques available to perform this procedure, with the lateral technique being more commonly studied than the posterior oblique technique. This study examined the effects of these techniques on pain relief and functional improvement, both preoperatively and at a 12-month follow-up.

Methods

This retrospective cohort study analyzed data from 45 patients who underwent SIJ fusion. Included patients were ≥50 years old, nonresponsive to conservative treatment. Subjects were divided into 2 cohorts based on the SIJ fusion technique. Primary outcomes were pain relief, measured by Visual Analog Scale (VAS), and functional improvement, determined by the Oswestry Disability Index (ODI); both were recorded and assessed at baseline, postoperative, and the change from pre- to postoperative. Additionally, data regarding patient demographics, previous lumbar fusion, operative time, and duration of hospital stay were collected and analyzed.

Results

Baseline demographic and clinical variables exhibited no significant differences in distribution between groups. The posterior oblique cohort demonstrated a substantial reduction in operative time (over 50%) and duration of hospital stay compared to lateral cohort. Pain relief (postoperative VAS: lateral 3.5±1.7 vs. posterior oblique 2.4±1.5 [p=.02]) and functional improvement (postoperative ODI: lateral 29.6±7.3 vs. posterior oblique 21±5.7 [p≤.001]) were significantly better in the posterior oblique group. Pre- to postoperative improvement analysis indicated greater reduction in pain (VAS: lateral -4.4±1.9 vs. posterior oblique -6.1±1.5 [p=.002]) in the posterior oblique group.

Conclusions

Compared to the lateral technique group, patients undergoing minimally invasive SIJ fusion through the posterior oblique technique experienced greater pain relief and demonstrated a trend toward better functional improvement, with shorter operative times and duration of hospital stay. The posterior oblique technique may be more efficient and beneficial to manage patients suffering from chronic SIJ pain through joint fusion.

Minimally Invasive Postero-Inferior Sacroiliac Joint Fusion: Surgical Technique and Procedural Details

(1) Background: Minimally invasive sacroiliac joint (SIJ) fusion is the preferred surgical intervention to treat chronically severe pain associated with SIJ degeneration and dysfunction. (2) Methods: This paper details the ten-step surgical procedure associated with the postero-inferior approach using the PsiF™ DNA Sacroiliac Joint Fusion System. (3) Results: The posterior surgical approach with an inferior operative trajectory (postero-inferior) utilizes easily identifiable landmarks to provide the safest, most direct access to the articular joint space for transfixing device placement. Implanting the device through the subchondral bone provides maximum fixation and stabilization of the joint by utilizing an optimal amount of cortical bone-implant interface. Approaching the joint from the inferior trajectory also places the implant perpendicular to the S1 endplate at a "pivot point" near the sacral axis of rotation, which addresses the most significant motion of the joint. (4) Conclusions: Further observational data from real-world clinical use are encouraged to further validate this procedure as the surgical preference for minimally invasive SIJ fusion.

Posterior intra-articular fixation stabilizes both primary and secondary sacroiliac joints: a cadaveric study and comparison to lateral trans-articular fixation literature

BACKGROUND

Posterior and lateral techniques have been described as approaches to sacroiliac joint arthrodesis. The purpose of this study was to compare the stabilizing effects of a novel posterior stabilization implant and technique to a previously published lateral approach in a cadaveric multidirectional bending model. We hypothesized that both approaches would have an equivalent stabilizing effect in flexion-extension and that the posterior approach would exhibit better performance in lateral bending and axial rotation. We further hypothesized that unilateral and bilateral posterior fixation would stabilize both the primary and secondary joints.

METHODS

Ranges of motion (RoMs) of six cadaveric sacroiliac joints were evaluated by an optical tracking system, in a multidirectional flexibility pure moment model, between ± 7.5 N-m applied moment in flexion-extension, lateral bending, and axial rotation under intact, unilateral fixation, and bilateral fixation conditions.

RESULTS

Intact RoMs were equivalent between both samples. For the posterior intra-articular technique, unilateral fixation reduced the RoMs of both primary and secondary joints in all loading planes (flexion-extension RoM by 45%, lateral bending RoM by 47%, and axial RoM by 33%), and bilateral fixation maintained this stabilizing effect in both joints (flexion-extension at 48%, lateral bending at 53%, and axial rotation at 42%). For the lateral trans-articular technique, only bilateral fixation reduced mean RoM of both primary and secondary sacroiliac joints, and only under flexion-extension loads (60%).

CONCLUSION

During flexion-extension, the posterior approach is equivalent to the lateral approach, while producing superior stabilization during lateral bend and axial rotation.

Posterior Oblique Approach for Sacroiliac Joint Fusion

Introduction Sacroiliac joint (SIJ) pain is a common source of low back pain. Though this condition can be treated with conservative measures, there is a subset of patients who fail to respond to conservative treatment. For them, surgical treatment using minimally invasive techniques could be considered. There are currently a number of SIJ fixation methods described. However, there is no case series reported on posterior oblique approach. Therefore, in this paper, the authors report their experience with the Sacrix system via the posterior oblique approach. Method In this series, 19 patients aged 44-84 years, with a median of 58 years, underwent SIJ fusion using this technique. This is a posterior oblique approach in which two screws are inserted into the ilium through the posterior part of the iliac crest and then advanced into the sacrum through the SIJ. Results The follow-up is between 7 and 30 months, with a median of 12 months. Eighteen patients had excellent pain relief. There was no complication from the procedure, and the blood loss was minimal. All eight patients who had follow-up radiographs showed solid fusion. Conclusion Posterior oblique approach for SIJ fusion is a minimally invasive procedure that proved to be effective and safe in this series. It also resulted in solid radiographic fusion, decreased pain, and improved function.

Revision of Failed Sacroiliac Joint Posterior Interpositional Structural Allograft Stabilization with Lateral Porous Titanium Implants: A Multicenter Case Series

Background

Distraction arthrodesis (DA) and stabilization of the sacroiliac (SI) joint by placing standalone structural allograft (SA) into the joint from a posterior trajectory has recently been introduced as a surgical procedure for chronic SI joint pain refractory to non-operative care.

Methods

Retrospective case series of patients with recurrent and/or persistent pain after placement of one or more interpositional/intraarticular standalone SAs between the ilium and sacrum using a posterior procedure to treat SI joint pain/dysfunction. Patients subsequently underwent surgical revision with porous titanium fusion implants using a lateral transfixing procedure. The demographic, clinical, and radiographic features of these cases are described.

Results

Data were available for 37 patients. The average (SD) age was 57 (13) years, 62% were female, and the average BMI was 31 (5.4). On average, two SA implants were placed per joint; 46% of cases were bilateral. At follow-up, two common themes were identified: lucencies around the implants and suboptimal implant position. None of the cases showed radiographic fusion of the SI joint prior to revision. One patient had an inflammatory reaction to the SA. All patients presented for revision due to either continued (49%) or recurrence (51%) of pain. In one revision case, the SA was forced ventrally, resulting in a sacral fracture, which was treated conservatively without sequelae.

Conclusions

The popularity of standalone SA for SI joint stabilization/fusion with a posterior procedure is increasing. This case series demonstrates that clinical failures from this procedure may require surgical revision. The proposed fusion strategy (DA) for these products is unproven in the SI joint, and, therefore, properly conducted prospective randomized clinical trials with long-term clinical and radiographic follow-up are important to establish the safety and efficacy of this approach. In the meantime, the placement of lateral titanium implants appears to be an effective revision strategy.

Sacroiliac Joint Fusion Using Robotic Navigation: Technical Note and Case Series

BACKGROUND

Patients undergoing sacroiliac (SI) fusion can oftentimes experience significant improvements in pain and quality of life.

OBJECTIVE

To describe a novel application of robotic navigation to assist with minimally invasive SI joint fusion.

METHODS

Patients undergoing stand-alone SI joint fusion with ExcelsiusGPS robotic navigation from July 2020 through June 2021 were retrospectively enrolled. Baseline demographic and perioperative variables including radiation exposure, postoperative pain scores, and narcotic requirements in the postanesthesia care unit (PACU) were recorded. Length of stay and any postoperative complications were also noted.

RESULTS

A total of 10 patients (64.4 ± 8.2 years, body mass index 28.7 ± 4.8 kg/m2) met inclusion criteria. Seven patients (70.0%) were female, and there was a 6:4 split between left-sided and right-sided SI joint fusion. The total operative time was 54 ± 9 minutes, and the estimated blood loss was 21.0 ± 16.7 mL. The intraoperative radiation exposure was 13.7 ± 6.2 mGy, and there were no complications. The average pain score in PACU was 5.2 ± 1.0, and the average opioid administration in PACU was 27.6 ± 10.3 morphine equivalents. Length of stay was 0.4 ± 0.7 days, with 7 of 10 patients discharged on the same day as surgery. There were no readmissions. The average length of follow-up was 4.3 ± 2.5 months. At the last follow-up, patients reported an average of 73.1% ± 30.1% improvement in their preoperative pain.

CONCLUSION

Robot-navigated SI joint fusion is a feasible and reproducible method for addressing refractory SI joint disease. Further investigation on clinical outcomes and long-term fusion rates is needed, as are studies comparing robot-navigated SI joint fusion with more traditional techniques.

Six Month Interim Outcomes from SECURE: A Single arm, Multicenter, Prospective, Clinical Study on a Novel Minimally Invasive Posterior Sacroiliac Fusion Device

INTRODUCTION

Sacroiliac joint disease is a prominent diagnosis across the world. A novel fixation technique employing a posterior approach, single point, bone allograft tranfixation has proven to be helpful anecdotally. The purpose of this is study is to investigate prospectively the safety and efficacy of this approach.

METHODS

A multicenter, prospective, single arm study was performed after patient identification and treatment with the novel posterior fusion, single-point transfixation system and followed for 24 months. Target enrollment is 100 patients. Interim results on the first 69 consecutive patients at 6 months is presented. Primary endpoint at 6-month analysis was Pain Intensity reduction by visual analogue scale and functional improvement by Oswestry Disability Index. Adverse events were assessed for safety analysis.

RESULTS

: 69 patients were identified for this analysis. At 6 months, a mean improvement of 34.9 was identified by a reduction in VAS and functional improvement was demonstrated by a mean reduction in ODI of 17.7. There were three adverse events, all unrelated to the device.

CONCLUSION

The posterior single point transfixation is safe and efficacious for the treatment of sacroiliac joint dysfunction with statistical improvements in pain and function.

Salvage of Failed Lateral Sacroiliac Joint Fusion with a Novel Posterior Sacroiliac Fusion Device: Diagnostic Approach, Surgical Technique, and Multicenter Case Series

Background

Studies have found that up to one-third of patients with LBP have sacroiliac joint (SIJ) dysfunction as a contributing cause. Historically, the management of SIJ dysfunction has been plagued by ineffectiveness or significant morbidity. In 2008, minimally invasive lateral SIJ fusion was developed. While this procedure is a safe and effective treatment, there is still a significant proportion of patients who will not experience therapeutic success. There is a paucity of data in the literature regarding the management of these patients. Recently, a novel posterior sacroiliac joint fusion device has been developed which minimizes complications compared to lateral approaches and may serve to salvage therapeutic failures in this patient population.

Objective

Determine the efficacy and feasibility of a posterior SIJ fusion device as a salvage technique in patients who have not experienced therapeutic success following lateral SIJ fusion.

Design

Multi-center retrospective observational study.

Methods

Patients who had previously undergone lateral SIJ fusion and had persistent LBP were evaluated and diagnosed to have persistent primary SIJ pathology. All patients underwent posterior SIJ fusion utilizing a machined allograft transfixing sacroiliac fusion device. Demographic data and patient reported pain scores were collected.

Results

A total of 7 patients who had undergone lateral SIJ fusion were included in the study and underwent posterior SIJ fusion. The mean patient reported pain improvement following posterior fusion was 80% with an average follow-up time of 10 months. Median morphine milliequivalents were 20 pre-procedure and 0 post-procedure.

Conclusion

We were able to show significant reductions in pain scores and opioid consumption, which suggests that minimally invasive posterior SIJ utilizing a novel implant and technique may be a viable treatment option to salvage pain relief in this patient population. Further, the favorable safety profile of this posterior technique uniquely positions it to be an appropriate first-line surgical therapy.

A Multicenter Retrospective Analysis of the Long-Term Efficacy and Safety of a Novel Posterior Sacroiliac Fusion Device

Background

Sacroiliac joint (SIJ) pathology is a cause of low back pain that may be difficult to diagnose and challenging to treat. Open and minimally invasive (MI) lateral approach fusions have been used to treat sacroiliitis over the past two decades. A novel MI posterior approach SIJ fusion technique utilizes a posteriorly placed transfixing device with single point S1/S2 level or mid-segment SIJ fixation (LinQ procedure). Current efficacy and safety data for this novel procedure are lacking.

Objective

To review multicenter retrospective 12 months or greater outcomes data in patients receiving the LinQ procedure, with sub-analysis of patients with prior lumbar fusions.

Methods

Patients with sacroiliitis refractory to conservative care with short-term benefit from diagnostic local anesthetic SIJ injections receiving MI posterior approach SIJ fusion with allograft were included from different centers including both academic and private practice. Numeric rating scale (NRS) scores at baseline (pre-procedural) and most recent follow-up were reviewed across three institutions.

Results

Of 110 patients who received MI SIJ fusion, 50 patients had sufficient data for evaluation of outcomes at least 12 months post-implant. The average time out from implant at follow-up was 612.2 days for all unique patients. The average NRS was 6.98 pre-fusion and 3.06 at last follow-up. Twenty-four patients had prior lumbar surgery of which 17 had prior lumbar fusions. Average NRS for this subset was 6.85 at baseline and 2.86 at last follow-up with an average follow-up of 613.2 days out from implant. No major adverse events or complications were associated with any of the 50 implants.

Conclusion

Real-world evidence suggests that MI posterior SIJ fusion with the LinQ procedure is a viable approach for medically refractory sacroiliitis management with long-term efficacy and safety. Further prospective studies are needed to fully evaluate this technique.

CT Scan and Clinical Outcomes of Novel Lateral-Oblique Percutaneous Sacroiliac Joint (SIJ) Fixation: Technique and Literature Review

Purpose The sacroiliac joint (SIJ) is estimated to be a source of pain in 15%-30% of patients presenting for the evaluation of low back pain. The SIJ may develop symptoms in an estimated 43% of patients who have had previous lumbar fusion surgeries. With increased awareness of SIJ as a pain source and for those patients who have intractable pain and who fail nonoperative treatment, surgery to stabilize the SIJ is becoming more common. Thus multiple different technologies and techniques need to be evaluated. The purpose of this study is to report on the clinical and radiographic follow-up of percutaneous lateral-oblique sacroiliac joint fusion with a threaded compression screw performed in an outpatient ambulatory surgery center (ASC). Methods Three consecutive patients were chosen for this technique, and after completion, were followed for at least 24 months as part of a pilot study to see how they responded to the treatment. The medical charts of these patients were reviewed along with follow-up radiographs and computed tomography (CT) scans to assess for radiographic fusion designated as bridging bone across the SIJ with no signs of implant loosening such as haloes around the screws, change in position, or screw breakage. The SacroFuse (Sacrix LLC, Boston, MA) SIJ screws were 12 mm x 60 mm at S1 and 12 mm x 50 mm at S2 with threads for compressive fixation and cannulated for percutaneous placement over a guidewire. We evaluated patients' demographics, the pain visual analog scale (VAS) score, and the Oswestry Disability Index (ODI) preoperatively and postoperatively. Results Our first patient was a 51-year-old male body mass index (BMI) 33.3 kg/m² with a previous lumbar fusion. He underwent a two-staged SIJ fusion. The first surgery was done as an open direct lateral surgery, and the second stage was performed three months later using a direct percutaneous lateral-oblique technique for three months. The second and third patients, respectively, were 22-year-old female status prior L5-S1 anterior lumbar interbody fusion (ALIF) plus right posterior unilateral pedicle screws. She had a BMI of 38.3 kg/m². The third patient was a 41-year-old male with a BMI of 29.5 kg/m² who underwent lateral-oblique bilateral percutaneous SIJ fixation. The latest CT imaging of each patient demonstrated increased bone density adjacent and within implants with intra-articular osseous bridging. There were no implant failures or complications. Conclusion This pilot study demonstrated the feasibility and effectiveness of a new percutaneous lateral-oblique SIJ fusion technique with a threaded compression screw done safely in an ASC. Patients demonstrated early pain relief and long-term fusion of their SIJ. We introduced the Sacrix line as a key fluoroscopic landmark for the success of this percutaneous technique.