Sacroiliac Joint Fusion Research Articles

269. Two-year clinical and radiographic outcomes after minimally invasive sacroiliac joint fusion with decortication and none grafting utilizing a threaded implant

269. Two-year clinical and radiographic outcomes after minimally invasive sacroiliac joint fusion with decortication and none grafting utilizing a threaded implant

246. Is the implant in bone? The accuracy of CT and fluoroscopic imaging for detecting malpositioned pelvic screw and SI fusion implants

Spine fusions to the pelvis have been associated with increased strain to the sacroiliac joint (SI) and possibly continued postoperative low back pain. To minimize this, concomitant SI joint fusion at the time of lumbopelvic fixation has been advocated. This requires concomitant placement of sacral alar iliac screws (S2AI) for lumbopelvic fixation and triangular titanium rods (TTR) for the SI joint fusion. Traditionally, surgeons have mostly relied on fluoroscopic images to confirm final implant position and patient safety after pelvic instrumentation, although computer tomography (CT) has also been used.We wanted to know which imaging modality, if any, was superior in helping to identify malpositioned implants during concomitant lumbopelvic fixation and SI joint fusion. We instrumented pelvic sawbones models with S2AI screws, TTR's, or both in the correct anatomic positions or malpositioned variants that led to known cortical breaches. Pelvic models were then imaged with fluoroscopy and CT, and the images assessed by blinded reviewers (spine surgeons and a musculoskeletal radiologist) for the presence of cortical breaches, the identity of the breached implant, and its direction. The responses of the blinded reviewers were then compared to the known position of the implants and Kappa coefficient calculated to determine agreement.We found that thorough evaluation of implant position with multiple fluoroscopic views (kappa 0.641) or CT imaging (kappa 0.906) allowed reviewers to assess implant position, identity, and breach direction.These findings suggest that intraoperative CT imaging allows surgeons to make the best decision regarding implant position prior to leaving the operating room, thus potentially improving patient safety and unplanned returns to the operating room.Level of Evidence: V.

Quantitative gait analysis of patients with severe sacroiliac joint dysfunction: a prospective clinical study.

Sacroiliac joint (SIJ) dysfunction is a chronic painful condition responsible for up to 30% of back pain. Treatment modalities include physiotherapy, intraarticular analgesic injections, ablation techniques or SIJ fusion. The severity of SIJ dysfunction is commonly assessed via subjective pain or disability scales. Quantitative gait analysis offers an objective means of evaluating patients with SIJ dysfunction prior to its surgical treatment. Ten patients diagnosed with severe SIJ dysfunction were matched with 10 healthy controls. All individuals underwent quantitative 3D gait analysis using the Qualisys program and statistical analysis was performed to identify significant differences in gait parameters between the two groups. Two groups of data were obtained; angular parameters described by the Gait Profile Score (GPS) and spatiotemporal parameters described in standard SI units. Statistically significant differences were found between the patient and control group for parameters: overall GPS (p = 0,049), hip abduction/adduction (p = 0,017) and ankle plantar/dorsal flexion (p = 0,003), stride length (p = 0,002), step length (p = 0,001), swing time (p = 0,03) and initial double limb support (p = 0,02). This paper is the first to perform complex quantitative gait analysis of patients with SIJ dysfunction and to compare it with healthy individuals. These results can provide clinicians with baseline gait values for these patients in order to objectively quantify the extent of their disease.

Novel Interventional Techniques for Chronic Pain with Minimally Invasive Arthrodesis of the Sacroiliac Joint: (INSITE, iFuse, Tricor, Rialto, and others)

Acute and chronic pain are public health issues that clinicians have been battling for years. Opioid medications have been a treatment option for both chronic and acute pain; however, they can cause unwanted complications and are a major contributor to our present opioid epidemic. The sacroiliac (SI) joint is a common cause of both acute and chronic low back pain. It affects about 15–25% of patients with axial low back pain, and up to 40% of patients with ongoing pain following lumbar fusion. Recent advances in the treatment of SI joint pain have led to the development of a wide variety of SI joint fusion devices. These fusion devices seek to stabilize the joints themselves in order that they become immobile and, in theory, can no longer be a source for pain. This is a minimally invasive procedure aimed to address chronic pain without subjecting patients to lengthy surgery or medications, including opioids with the potential for addiction and abuse. Minimally invasive SI fusion can be performed by a lateral approach (i.e., iFuse, Tricor) or posterior approach (i.e., CornerLoc, LinQ, Rialto). The posterior approach requires the patient to be in the prone position but allows for less disruption of muscles with entry. More data are necessary to determine which fusion system may be best for a particular patient. SI fusion devices are a promising way of treating chronic lower back pain related to the SI joint. This narrative review will discuss various types of SI fusion devices, and their potential use in terms of their safety and efficacy.

Propensity-matched Analysis of 1062 Patients Following Minimally Invasive Versus Open Sacroiliac Joint Fusion.

This was a retrospective cohort study. The aim of this study was to compare the hospital charges and postoperative complications of minimally invasive surgery (MIS) and open approaches to sacroiliac joint (SIJ) fusion. The data source utilized in this study is the Healthcare Cost and Utilization Project National Readmission Database (NRD) from 2016 and 2017. The NRD is a yearly nationally representative inpatient database from the Agency for Healthcare Research and Quality with information regarding patient demographics, diagnoses, procedures, and readmissions. The 2016-2017 NRD was used to identify 2521 patients receiving SIJ fusion with open (n=1990) or MIS approaches (n=531) for diagnosed sacrum pain, sacroiliitis, sacral instability, or spondylosis after excluding for those who received prior SIJ fusion, those diagnosed with neoplasms or trauma of the pelvis or sacrum, and nonelective procedures. We then one-to-one propensity-matched the open (n=531) to the MIS approach (n=531) for age, sex, and Charlson Comorbidity Index. Statistical analysis was performed to compare total hospital charges, immediate surgical complications, nonelective readmission rate, and 30-, 90-, and 180-day postoperative complications between the 2 approaches. The mean total hospital charge was the only significant difference between 2 group. Open SIJ fusion had significantly higher charge compared with the MIS approach (open $101,061.90±$81,136.67; MIS $83,594.78±$49,086.00, P<0.0001). The open approach was associated with nonsignificant higher rates of novel lumbar pathology at 30-, 90-, and 180-day readmissions and revision surgeries at 30 and 180 days. MIS approach had higher rates nervous system complications at 30-, 90-, and 180-day readmission, as well as infection and urinary tract infection within 30 days, none being significant. Novel postprocedural pain was similar between the 2 groups at 90 and 180 days. The current study found that open SIJ fusion was associated with significantly higher hospital charges. Although no significant differences in postoperative complications were found, there were several notable trends specific to each surgical approach.

Perioperative Outcomes of Minimally Invasive Sacroilliac Joint Fusion Using Hollow Screws Through a Lateral Approach: A Single Surgeon Retrospective Cohort Study

Sacroiliac joint (SIJ) pain is a common cause of lower back pain and a significant source of disability in the United States. There is no consensus on the best surgical treatment for SIJ pain that is not responsive to conservative therapy. Minimally invasive fusion of the SIJ using hollow fenestrated screws from a lateral trajectory is a newer technique for SIJ fusion. This study presents perioperative and patient-reported outcomes amongst 62 patients who underwent SIJ fixation with hollow fenestrated screws. We find that mean disability on the Oswestry disability index improved from 52.2% to 34.9% at one-year post-op. Mean operative time was 34±9 minutes and blood loss was 22±35ml. Only six patients required overnight hospitalization. There were two cases of complications requiring operative intervention. We conclude that SIJ fixation using hollow fenestrated screws is a safe and effective procedure for the fixation of the SIJ. Further investigation is warranted to determine the best surgical treatment for SIJ pain.

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

PurposeThe 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).MethodsThree 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.ResultsOur 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.ConclusionThis 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.

Trends in Diagnosis and Treatment of Sacroiliac Joint Pathology Over the Past 10 Years: Review of Scientific Evidence for New Devices for Sacroiliac Joint Fusion

Sacroiliac (SI) joint pathology is a newly appreciated contributor to lower back pain. Sacroiliac joint fusion (SIJF) has grown rapidly in popularity in association with the advent of minimally-invasive surgical techniques. This has led to an explosion of new medical devices used for SIJF. The objective of this article is to outline clinical trends, summarize the current data, and categorize novel devices for SIJF. Trends in SI joint pathology and fusion were obtained via the Healthcare Cost and Utilization Project’s (HCUP) National Inpatient Sample (NIS) database and Web of Science. To review literature on devices for SIJF, PubMed was searched using the Boolean phrase “sacroiliac joint AND (fusion OR arthrodesis)” since 2010. To establish a list of SIJF devices not represented in the literature, searches were performed on the FDA 510(k), premarket approval, and de novo databases, as well as Google and LinkedIn. Literature review yielded 11 FDA-approved devices for minimally invasive SIJF. Database query yielded an additional 22 devices for a total of 33 devices. Twenty-one devices used the lateral transiliac approach, six posterior allograft approach, three posterolateral approach, and three combined the lateral transiliac and posterolateral approaches. The evidence for the lateral transiliac approach is the most robust. Many novel devices have been developed for minimally invasive SIJF over the past 10 years. Further randomized comparative trials are warranted to evaluate different surgical approaches and novel devices at this time.

Robotic navigation system utilization for percutaneous sacroiliac screw placement: surgical setup and technique.

Sacroiliac joint (SIJ) pathology is a common cause of significant pain and disability, and operative treatment consisting of SIJ fusion can be performed in cases where non-operative measures fail to provide sustained relief. Through the years, SIJ fusion has evolved from an open invasive procedure, to more recently, being performed through minimally invasive techniques. Intraoperative navigation systems and robotic guidance are becoming popularized for SIJ fusion, as well as other routine and complex spinal cases. The utility of navigation and robotics is the enhanced ability of the surgeon to place instrumentation more accurately, with less dissection, blood less, and overall operative time. We present a technique guide for robotic instrumented SIJ fusion with intraoperative navigation that we have put into practice at our institution and found to be very beneficial to patients for the above reasons. We describe the setup and utilization of these technologies intraoperatively, and provide specific case examples to highlight our technique. The described methods have been found to be effective and reproducible, allowing for minimally invasive SIJ screw placement with high accuracy and safety. We emphasize that utilizing intraoperative navigation and robotics is not meant to substitute for surgeon knowledge of case steps or anatomy, but rather to enhance safety and efficacy. To our knowledge, robotic SIJ fusion has not been previously described in the literature.

Minimally invasive sacroiliac joint fusion using a novel hydroxyapatite-coated screw: final 2-year clinical and radiographic results.

The proper diagnosis and treatment of sacroiliac joint (SIJ) pain remains a clinical challenge. Dysfunction of the SIJ can produce pain in the lower back, buttocks, and extremities. The present prospective clinical study is a follow-up report on a previous 1-year report on the use of a novel hydroxyapatite (HA)-coated titanium screw for the surgical treatment of SIJ dysfunction. Data were prospectively collected on 32 consecutive patients who underwent minimally invasive SIJ fusion with a novel HA-coated screw. Clinical assessments and radiographs were collected and evaluated at 24 months postoperatively. Mean preoperative visual analog scale (VAS) back, left, and right leg pain scores decreased significantly to 20.0 (±18.4), 5.8 (±8.1), and 11.5 (±20.1) at 24-month follow-up, respectively. Oswestry Disability Index (ODI) scores significantly decreased to 27.5 (±18.8) points at 24 months (P<0.01). Two patients who required revision surgery reported improvement of their symptoms within 3 weeks and did not require subsequent surgery to be performed. This study shows positive clinical and functional outcomes for patients who have undergone fusion using HA-coated screws for SIJ dysfunction. SIJ fusion using a HA-coated screw to treat SIJ dysfunction significantly decreased VAS back and leg pain and ODI scores at 2-year follow-up.

Prospective Trial of Sacroiliac Joint Fusion Using 3D-Printed Triangular Titanium Implants: 24-Month Follow-Up.

BackgroundStrong evidence supports minimally invasive sacroiliac joint (SIJ) fusion using triangular titanium implants (TTI) for chronic SIJ dysfunction.ObjectiveTo report safety and effectiveness of SIJF using a 3D-printed TTI at 24 months.MethodsSIJF with TTI was performed in 51 subjects. Structured follow-up occurred at 3, 6, 12 and 24 months. Both quality of life questionnaires and functional tests were performed at all study visits.Results84% of subjects were available for 24-month follow-up. Observed were rapid and persistent improvements in dysfunction due to pain (Oswestry Disability Index [ODI], mean 52.8 at baseline and 28.3 at 24 months, p<0.0001) and SIJ pain ratings (mean 78.5 at baseline [0–100 scale] to 21.5 at 24 months). Opioid use for SIJ pain decreased markedly from baseline. Physical function tests impaired by SIJ pain showed persistent improvements compared to baseline. There was no evidence of device breakage, migration or subsidence and few late adverse events occurred attributable to the device.ConclusionIn this prospective study, SIJF using 3D-printed TTI resulted in immediate, marked and persistent improvements in pain and quality of life, with improved physical function, reduced opioid use and a low rate of late device-related adverse events.Level of EvidenceLevel II.

Review of Current Evidence for Minimally Invasive Posterior Sacroiliac Joint Fusion.

The sacroiliac joint (SIJ) is a large, irregularly shaped, serpentine joint structure bordered anteriorly and posteriorly by the sacroiliac ligaments. With increased recognition of the SIJ as a pain source, treatments have been historically nonsurgical in nature. Common treatments include bracing, medications, activity modification, manual therapy, chiropractic manipulation, physical therapy, and intra-articular SIJ injections. Surgical stabilization and/or fusion of the SIJ may be considered when a patient has persistent moderate to severe pain, functional impairment, and failed conservative management. Surgical stabilization and fusion has traditionally been by way of the transiliac approach. More recent SIJ fusion systems have proposed not only a posterior approach but one that stabilizes the joint space by placing an allograft within the SIJ. Anatomically, a posterior approach is able to avoid neurovascular structures that otherwise are encountered with the transiliac approach and may be performed percutaneously. Preliminary evidence reports consistent pain reduction with minimal complications. This paper is purposed to detail the present evidence of minimally invasive posterior SIJ fusion, as well as highlight the need for further research moving forward.

Subchondral Bone Changes Following Sacroiliac Joint Arthrodesis – A Morpho-mechanical Assessment of Surgical Treatment of the Painful Joint

Sacroiliac joint arthrodesis is an ultima ratio treatment option for sacroiliac joint dysfunction. Fusion drastically reduces sacroiliac joint movement providing long-lasting pain-relief associated with tension-relief to the innervated sacroiliac joint structures involved in force closure. To display the bone mineralization distribution patterns of the subchondral bone plate in 3 distinct regions (superior, anterior, and inferior) of the sacral and iliac counterparts of the sacroiliac joint pre- and post-sacroiliac joint arthrodesis and compare patterns of sacroiliac joint dysfunction post-sacroiliac joint fusion with sacroiliac joint dysfunction pre- arthrodesis patterns and those from healthy controls. An observational study. The research took place at the University of Basel, Switzerland, where the specific image analysis program (Analyze, v7.4, Biomedical Imaging Resources, Mayo Foundation, Rochester, NY, USA) was made available. Mineralization densitograms of 18 sacroiliac joint dysfunction patients pre- and post-sacroiliac joint arthrodesis (>= 6, >= 12, and >= 24 months post-surgery) were obtained using computed tomography osteoabsorptiometry. For each patient, pre- vs. post-surgery statistical comparisons were undertaken, using the Hounsfield unit values derived from the subchondral mineralization of superior, anterior, and inferior regions on the iliac and sacral auricular surfaces. Post-operative values were also compared to those from a healthy control cohort (n = 39). In the pre-operative cohort at all 3 follow-up times, the superior iliac region showed significantly higher Hounsfield unit values than the corresponding sacral region (P < 0.01). Mineralization comparisons were similar for the sacrum and ilium in the anterior and inferior regions at all follow-up points (P > 0.5) with no surgery-related changes. Sacral density increased significantly in the post-operative state; not observed on the ilium. Post-operative sacroiliac joints showed a significantly increased mineralization in the superior sacrum after >= 6 months (P < 0.05), not replicated after >= 12 nor >= 24 months. Further comparison of post-operative scans versus healthy controls revealed significantly increased mineralization in the superior sacral region at (>=) 6, 12, and 24 months (P < 0.01), likely related to bone grafting, and in the anterior and inferior regions in post-operative scans at >= 12 and >= 24 months follow-up (P < 0.05). The given study is limited in sample size. Post-operative computed tomography scans had screws which may have left artifacts or partial volume effects on the surfaces. Healthy controls were different patients to the sacroiliac joint dysfunction and post-operative cohorts. Both cohorts were age-matched but this comparison did not take into account potential population differences. Size differences in the regions may have also been an influencing factor of the results as the regions were based on the size and shape of the articular surface. Sacroiliac joint arthrodesis results in an increased morpho-mechanical conformity in the anterior and inferior sacrum and reflects variable morpho-mechanical density patterns compared to the healthy state due to permanent alterations in the kinematics of the posterior pelvis.

Sacroiliac joint fusion: a systematic review

Background Sacroiliac joint (SIJ) fusion represents a unique area of orthopedic surgery with procedural literature dating to the early 1920s, showing limited innovation in either technique or hardware over the past 90 years. Recent improvements in the diagnosis and treatment of SIJ dysfunction warrant comparisons with older surgical techniques. Aim and objectives This systematic review aimed to evaluate the efficacy and safety of SIJ fusion, whether open or minimally invasive, for the management of chronic low back pain. Materials and methods This was a systematic review and metaanalysis. The electronic databases up to June 2019 of ‘Pub med Medline,’ ‘EMbase,’ and ‘Google Scholar’ were explored using the combination of the following search terms: sacroiliac joint, fusion, arthrodesis, and back pain. We used different combinations of the following queries: sacroiliac joint AND (fusion OR arthrodesis) and back pain. A primary search of databases yielded 420 records. After duplicates removal, 228 potentially eligible articles were identified. A total of 21 studies fulfilled the inclusion criteria and were included in the final systematic review. Results Assessments of outcome were done by pain score, Oswestry Disability Index, Majeed score, and SF-36 Physical (PCS) and Mental (MCS) component scores changes before operation and after operation. Visual analog scale score was used by nine studies with mean pre operation value of 7.3, which decreased after operation to 2.8, and regarding Oswestry Disability Index score, it used by 12 studies, with mean preoperative score of 40.45, which improved postoperatively to 22.89. Conclusion SIJ fusion appears to be a satisfactory procedure for alleviating low back pain.

Minimally Invasive Sacroiliac Fusion Revision: A Technique Guide.

A retrospective case-series of revision sacroiliac joint (SIJ) fusions. To provide a technique guide for revision minimally invasive SIJ fusion. SIJ dysfunction is a prevalent, yet underdiagnosed condition. This disparity exists as a result of diagnostic complexity and lack of a viable surgical treatment option. However, the advent of minimally invasive SIJ fusion has created a resurgence of interest in this debilitating condition. Multiple studies have reported on the increased use of minimally invasive SIJ fusion in recent years, but there is a paucity of literature on management in a revision setting. A case series of 5 patients from a single academic tertiary referral center over a 3-year period will serve to highlight technical pearls and considerations in SIJ fusion revision. Revision SIJ fusions were identified through a retrospective review of a surgical database and demographic, surgical, and radiographic data were obtained through review of the electronic medical record. Five patients underwent SIJ fusion revision from 2015 to 2018. There were 3 main modes of failure, with indications for revision including nerve root irritation and SIJ pain recurrence. The mean age at time of revision was 48.8 ± 14.3 years, and the mean follow-up after revision was 2.0 + 0.9 years. Familiarity with SIJ anatomy and use of stereotactic navigation can improve implant position and purchase. Additionally, bone graft and bone morphogenetic protein can be used to fill in old implant tracks and to augment bony ingrowth and ongrowth of new implants. Increased use of SIJ fusion creates a demand for comprehensive revision strategies and necessitates familiarity with SIJ anatomy. Preoperative planning to determine causes of failure and use of intraoperative navigation are essential to help surgeons better understand the preferential trajectory for each implant. 4.

Sacroiliac joint arthropathy in adult spinal deformity patients with long constructs to the pelvis

ObjectiveSacroiliac joint (SIJ) arthropathy is an increasingly recognized problem in adult spinal deformity patients undergoing long construct surgery. S2-alar-iliac (S2AI) screw instrumentation is thought to reduce morbidity from pelvic fixation in these patients. The goal of this study is to assess the overall incidence of SIJ arthropathy in patients with long constructs to the pelvis as well as compare SIJ outcomes of partially threaded (PT) versus fully threaded (FT) S2AI screws. MethodsData of eligible patients were collected from a prospectively maintained database with retrospective review of electronic records at an academic institution between 2016 and 2019. Results65 consecutive patients who underwent S2AI screw instrumentation (40 in PT group, 25 in FT group) were enrolled. The rate of postoperative SIJ pain was higher in the PT (52.5 %) compared to FT (32 %) group. There was a significantly shorter time-to-pain development in the PT compared to FT group (11.8 versus 20.1 months, respectively). Of those who developed SIJ pain in the PT group, the pain worsened in 80.9 % versus only 25 % of those in the FT group despite conservative treatment. Cox regression found the PT group more likely to develop SIJ pain at any point during follow-up compared to the FT group (Hazard Ratio = 7.308). SIJ fusion was not detected on imaging of any patient during follow-up. ConclusionFT S2AI screws are associated with better SIJ outcomes compared to PT screws. However, our data suggest that S2AI screw instrumentation is not sufficient to achieve fusion or prevent development of SIJ pain. Concurrent SIJ fusion may be necessary in patients with long constructs to prevent SIJ arthropathy.

The Effect of Sacroiliac Fusion and Pelvic Fixation on Rod Strain in Thoracolumbar Fusion Constructs

Study Design. In vitro biomechanical study. Objective. Investigate effects of sacroiliac joint (SIJ) fusion and iliac fixation on distal rod strain in thoracolumbar fusions. Summary of Background Data. Instrument failure is a multifactorial, challenging problem frequently encountered by spinal surgeons. Increased rod strain may lead to instrumentation failure and rod fracture. Methods. Seven fresh frozen human cadaveric specimens (T9–pelvis) used. Six operative constructs tested to investigate changes in rod strain at L5–S1 and S1–Ilium rods, posterior pedicle screws/rods from T10–S1 (PS), PS + bilateral iliac screw fixation, PS + unilateral iliac screw fixation (UIS), PS+UIS+3 unilateral SIJ screws, PS + 3 unilateral SIJ screws, and PS +6 bilateral SIJ screws. Uniaxial strain gauges were used to measure surface strain of rods during flexion-extension. Results. In flexion-extension, bilateral iliac screws added significant strain to L5–S1 compared with long fusion constructs ending at S1 (PS) (P &lt; 0.05). Unilateral iliac fixation exhibited highest strain to L5–S1 ipsilateral rod, was significantly higher compared with bilateral iliac fixation and PS construct. Unilateral and bilateral SIJ fusion did not significantly change L5–S1 rod strain compared with PS. When measuring S1–Ilium rod strain, unilateral pelvic fixation had highest reported rod strain, approached significance compared with bilateral iliac screws (P = 0.054). Addition of contralateral SIJ fusion did not affect rod strain at S1–ilium on side with unilateral fixation. Conclusion. Results showed additional fixation below S1 to pelvis added significant rod strain. Unilateral pelvic screws had highest rod strain; SIJ fusion did not affect rod strain. Findings can help guide surgeons when associated risk of rod failure is a consideration. Level of Evidence: N/A

Enhancing perioperative landmark detection during sacroiliac joint fusion in patients suffering from low back pain

Over the past decade, minimally invasive sacroiliac joint (SIJ) fusion has become an effective treatment for patients suffering from low back pain (LBP) originating from the SIJ. Perioperative C-arm fluoroscopy-assisted surgical navigation during SIJ fusion remains challenging due to the lack of 3D spatial information. This study developed and assessed a 3D CT/2D fluoroscopy integration approach based on digitally reconstructed radiographs (DRRs) obtained from pre-operative CT scans. Development of this approach proved feasible and landmarks were successfully translated, in retrospect, to perioperatively acquired fluoroscopies. Further expansion of and research into the proposed approach to increase perioperative navigation is indicated and additional validation should be performed.

Minimally Invasive Endoscopic Spine Surgical Techniques for Treating Radiculopathy Secondary to Sacroiliac Joint Fusion Complications: Case Series

Background: Minimally invasive SI joint fusion has increased in popularity. A possible complication that can result from the procedure is a radiculopathy (sacral or lumbar) that is caused by placement of the SI joint fusion implant. Case Report: Two cases are presented: A 60-year-old woman with a S1 radiculopathy secondary to a cortical bone fragment contacting the S1 nerve, and a 62-year-old man with a L5 radiculopathy and the anteriorly directed SI joint fusion implant positioned anteriorly and compressing on the L5 nerve. Both patients had resolution of their symptoms with endoscopic treatment. Conclusion: An endoscopic treatment is suggested here for radiculopathy secondary to minimally invasive SI joint fusion. Key words: Endoscopic spine surgery, lumbar radiculopathy, minimally invasive spine, SI joint fusion

Wireless Peripheral Nerve Stimulation for the Treatment of Chronic Shoulder Pain

Background: Shoulder pain is a common condition, often refractory to treatment. Peripheral nerve stimulation (PNS) of the suprascapular nerve (SSN) can be efficacious in providing relief of shoulder pain while improving pain-related quality of life (QOL). The objective of this case report is to demonstrate the effectiveness of a minimally invasive wireless PNS in the treatment of chronic shoulder pain. Case Report: This 94-year old man presented with severe shoulder pain. He suffered from poliomyelitis as a child affecting his left leg, forcing him to use crutches to be ambulatory. He developed progressive right shoulder pain and was subsequently diagnosed with right glenohumeral osteoarthritis. The patient was treated semiannually for 4 years with corticosteroids injections and pain medication with minimal relief (7 out of 10 on the Visual Analog Scale [VAS]). A suprascapular block with lidocaine 2% resulted in significant pain reduction (1 out of 10 on the VAS). As a result, the patient opted for wireless PNS of the SSN via a minimally invasive procedure. Two weeks post implant, the patient reported no postoperative pain, and his chronic pain was rated 0 out of 10 even during movement. Reports of reduced pain were sustained throughout the 6 months of observation with subsequent improvements in QOL and functionality. Conclusion: Wireless neurostimulation of the SSN can be a very effective therapy option for the treatment of refractory, chronic shoulder pain as a result of glenohumeral osteoarthritis. Key words: Endoscopic spine surgery, lumbar radiculopathy, minimally invasive spine, SI joint fusion