Etiopathogenesis of sacroiliitis: implications for assessment and management.

The sacroiliac joints connect the base of the sacrum to the ilium. When inflamed, they are suspected to cause low back pain. Inflammation of the sacroiliac joints is called sacroiliitis. The severity of the pain varies and depends on the degree of inflammation. Sacroiliitis is a hallmark of seronegative spondyloarthropathies. The presence or absence of chronic sacroiliitis is an important clue in the diagnosis of low back pain. This article aims to provide a concise overview of the anatomy, physiology, and molecular biology of sacroiliitis to aid clinicians in the assessment and management of sacroiliitis. For this narrative review, we evaluated articles in English published before August 2019 in PubMed. Then, we selected articles related to the painful manifestations of the sacroiliac joint. From the retrieved articles, we found that chronic sacroiliitis may be caused by various forms of spondyloarthritis, such as ankylosing spondyloarthritis. Sacroiliitis can also be associated with inflammatory bowel disease, Crohn's disease, gout, tuberculosis, brucellosis, and osteoarthritis, indicating common underlying etiological factors. The pathophysiology of sacroiliitis is complex and may involve internal, environmental, immunological, and genetic factors. Finally, genetic factors may also play a central role in progression of the disease. Knowing the genetic pre-disposition for sacroiliitis can be useful for diagnosis and for formulating treatment regimens, and may lead to a substantial reduction in disease severity and duration and to improved patient performance.

Molecular Aspects of Regional Pain Syndrome.

The purpose of this review is to summarize the pathophysiology of complex regional pain syndrome (CRPS), the underlying molecular mechanisms, and potential treatment options for its management. CRPS is a multifactorial pain condition. CRPS is characterized by prolonged or excessive pain and changes in skin color and temperature, and/or swelling in the affected area, and is generally caused by stimuli that lead to tissue damage. An inflammatory response involving various cytokines and autoantibodies is generated in response to acute trauma/stress. Chronic phase pathophysiology is more complex, involving the central and peripheral nervous systems. Various genetic factors involved in the chronicity of pain have been identified in CRPS patients. As with other diseases of complex pathology, CRPS is difficult to treat and no single treatment regimen is the same for two patients. Stimulation of the vagus nerve is a promising technique being tested for different gastrointestinal and inflammatory diseases. CRPS is more frequent in individuals of 61-70 years of age with a female to male ratio of 3 : 1. Menopause, migraine, osteoporosis, and asthma all represent risk factors for CRPS and in smokers the prognosis appears to be more severe. The pathophysiological mechanisms underlying CRPS involve both inflammatory and neurological pathways. Understanding the molecular basis of CRPS is important for its diagnosis, management, and treatment. For instance, vagal nerve stimulation might have the potential for treating CRPS through the cholinergic anti-inflammatory pathway.

Randomized Trial of Sacroiliac Joint Arthrodesis Compared with Conservative Management for Chronic Low Back Pain Attributed to the Sacroiliac Joint.

BACKGROUND: Sacroiliac joint pain is increasingly recognized as a cause of low back pain. We compared the safety and effectiveness of minimally invasive sacroiliac joint arthrodesis using triangular titanium implants and conservative management in patients with chronic sacroiliac joint pain. METHODS: This study was a prospective, multicenter randomized controlled trial of adults with chronic sacroiliac joint pain assigned to either conservative management or sacroiliac joint arthrodesis with triangular titanium implants. The study end points included self-rated low back pain (visual analog scale [VAS]), back dysfunction (Oswestry Disability Index [ODI]), and quality of life. Ninety percent of subjects in both groups completed the study. RESULTS: Between June 6, 2013, and May 15, 2015, 103 subjects were randomly assigned to conservative management (n = 51) or sacroiliac joint arthrodesis (n = 52). At 2 years, the mean low back pain improved by 45 points (95% confidence interval [CI], 37 to 54 points) after sacroiliac joint arthrodesis and 11 points (95% CI, 2 to 20 points) after conservative management, with a mean difference between groups of 34 points (p < 0.0001). The mean ODI improved by 26 points (95% CI, 21 to 32 points) after sacroiliac joint arthrodesis and 8 points (95% CI, 2 to 14 points) after conservative management, with a mean difference between groups of 18 points (p < 0.0001). Parallel improvements were seen in quality of life. In the sacroiliac joint arthrodesis group, the prevalence of opioid use decreased from 56% at baseline to 33% at 2 years (p = 0.009), and no significant change was observed in the conservative management group (47.1% at baseline and 45.7% at 2 years). Subjects in the conservative management group, after crossover to the surgical procedure, showed improvements in all measures similar to those originally assigned to sacroiliac joint arthrodesis. In the first 6 months, the frequency of adverse events did not differ between groups (p = 0.664). By month 24, we observed 39 severe adverse events after sacroiliac joint arthrodesis, including 2 cases of sacroiliac joint pain, 1 case of a postoperative gluteal hematoma, and 1 case of postoperative nerve impingement. The analysis of computed tomographic (CT) imaging at 12 months after sacroiliac joint arthrodesis showed radiolucencies adjacent to 8 implants (4.0% of all implants). CONCLUSIONS: For patients with chronic sacroiliac joint pain due to joint degeneration or disruption, minimally invasive sacroiliac joint arthrodesis with triangular titanium implants was safe and more effective throughout 2 years in improving pain, disability, and quality of life compared with conservative management. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Risk Factors for Continued Opioid Use in Conservative Versus Surgical Management of Low Back Pain Originating From the Sacroiliac Joint.

STUDY DESIGN: Secondary analysis of data from a randomized controlled trial. OBJECTIVES: To identify risk factors for continued opioid use after conservative management (CM) or minimally invasive surgical management (MISM) of low back pain (LBP) originating from the sacroiliac joint. METHODS: Patients were randomized either to CM (n = 49) or MISM (n = 52). We documented opioid use, pain intensity (visual analogue scale [VAS]), Oswestry Disability Index (ODI), and the Zung depression score (Zung Self-Rating Depression Scale) at baseline and at months 3 and 6 after treatment initiation. RESULTS: Compared with opioid nonusers, opioid users at baseline had higher mean levels of disability (ODI 61.5, standard deviation [SD] 13.3 vs ODI 51.5, SD 12.8; P < .01) and higher depression scores (Zung 48.5, SD 8.5, vs Zung 42.2, SD 7.2; P < .01). At 6 months, opioid users had higher 6-month pain levels (VAS 60.4, SD 24.0, vs VAS 42.4, SD 28.2; P < .01), higher disability scores (ODI 50.5, SD 16.2, vs ODI 32.7, SD 19.3; P < .01) and higher depression scores (Zung 47.6, SD 8.0, vs Zung 38.8, SD 8.9; P < .01). Risk factors for continued opioid use at 6 months were patient age (odds ratio [OR] for age = 0.91; P = .02) and an increase in LBP (OR 1.08; P = .02) in the CM group and a lack of improvement in depression scores (OR 1.12; P = .03) in the MISM group. CONCLUSIONS: In our patient cohort, the risk of continued opioid use in the treatment of LBP increased not only with pain intensity but also with levels of depression during the course of treatment.

1-Year Results of a Randomized Controlled Trial of Conservative Management vs. Minimally Invasive Surgical Treatment for Sacroiliac Joint Pain.

BACKGROUND: Low back pain (LBP) emanating from the sacroiliac joint (SIJ) is a common finding. Devices to fuse the SIJ are now commercially available, but high-quality evidence supporting their effectiveness is limited. OBJECTIVES: To compare the safety and effectiveness of conservative management (CM) to minimally invasive sacroiliac joint fusion (SIJF) in patients with chronic LBP originating from the SIJ. STUDY DESIGN: Prospective, multicenter randomized controlled trial. SETTING: One hundred three adults in spine clinics with chronic LBP originating from the SIJ. METHODS: Patients were randomly assigned to CM (n = 51) or SIJF using triangular titanium implants (n = 52). CM consisted of optimization of medical therapy, individualized physiotherapy, and adequate information and reassurance as part of a multifactorial treatment. The primary outcome was the difference in change in self-rated LBP at 6 months using a 0 - 100 visual analog scale (VAS). Other effectiveness and safety endpoints, including leg pain, disability using Oswestry Disability Index (ODI), quality of life using EQ-5D, and SIJ function using active straight leg raise test (ASLR), were assessed up to 12 months. RESULTS: At 12 months, mean LBP improved by 41.6 VAS points in the SIJF group vs. 14.0 points in the CM group (treatment difference of 27.6 points, P < 0.0001). Mean ODI improved by 25.0 points in the SIJF group vs. 8.7 points in the CM group (P < 0.0001). Mean improvements in leg pain and EQ-5D scores were large after SIJF and superior to those after CM. CM patients were allowed to crossover to SIJF after 6 months. Patients who crossed to surgical treatment had no pre-crossover improvement in pain and ODI scores; after crossover, improvements were as large as those originally assigned to SIJF. One case of postoperative nerve impingement occurred in the surgical group. Two SIJF patients had recurrent pain attributed to possible device loosening and one had postoperative hematoma. In the CM group, one crossover surgery patient had recurrent pain requiring a revision surgery. LIMITATIONS: The primary limitation was lack of blinding and the subjective nature of self-assessed outcomes. CONCLUSIONS: For patients with chronic LBP originating from the SIJ, minimally invasive SIJF with triangular titanium implants was safe and more effective than CM in relieving pain, reducing disability, and improving patient function and quality of life. Our findings will help to inform decisions regarding its use as a treatment option in this patient population.Key words: Sacroiliac joint dysfunction, pelvic girdle pain, randomized controlled trial, quality of life, spine implants.

Epidemiologic and Economic Burden Attributable to First Spinal Fusion Surgery: Analysis From an Italian Administrative Database.

STUDY DESIGN: Retrospective large population based-study. OBJECTIVE: Assessment of the epidemiologic trends and economic burden of first spinal fusions. SUMMARY OF BACKGROUND DATA: No adequate data are available regarding the epidemiology of spinal fusion surgery and its economic impact in Europe. METHODS: The study population was identified through a data warehouse (DENALI), which matches clinical and economic data of different Healthcare Administrative databases of the Italian Lombardy Region. The study population consisted of all subjects, resident in Lombardy, who, during the period January 2001 to December 2010, underwent spinal fusion surgery (ICD-9-CM codes: 81.04, 81.05, 81.06, 81.07, and 81.08). The first procedure was used as the index event. We estimated the incidence of first spinal fusion surgery, the population and surgery characteristics and the healthcare costs from the National Health Service's perspective. The analysis was performed for the entire population and divided into the main groups of diagnosis. RESULTS: The analysis identified 17,772 [mean age (SD): 54.6 (14.5) years, 55.3% females] spinal fusion surgeries. Almost 67% of the patients suffered from a lumbar degenerative disease. The incidence rate of interventions increased from 11.5 to 18.5 per 100,000 person-year between 2001 and 2006, and was above 20.0 per 100,000 person-year in the last 4 years. The patients' mean age increased during the observational time period from 48.1 to 55.9 years; whereas the median hospital length of stay reported for the index event decreased. The average cost of the spinal fusion surgery increased during the observational period, from &OV0556; 4726 up to &OV0556; 9388. CONCLUSION: The study showed an increasing incidence of spinal fusion surgery and costs from 2001 to 2010. These results can be used to better understand the epidemiological and economic burden of these interventions, and help to optimize the resources available considering the different clinical approaches accessible today. LEVEL OF EVIDENCE: 4.

Six-month outcomes from a randomized controlled trial of minimally invasive SI joint fusion with triangular titanium implants vs conservative management.

PURPOSE: To compare the safety and effectiveness of minimally invasive sacroiliac joint fusion (SIJF) using triangular titanium implants vs conservative management (CM) in patients with chronic sacroiliac joint (SIJ) pain. METHODS: 103 adults with chronic SIJ pain at nine sites in four European countries were randomly assigned to and underwent either minimally invasive SIJF using triangular titanium implants (N = 52) or CM (N = 51). CM was performed according to the European guidelines for the diagnosis and management of pelvic girdle pain and consisted of optimization of medical therapy, individualized physical therapy (PT) and adequate information and reassurance as part of a multifactorial treatment. The primary outcome was the difference in change in self-rated low back pain (LBP) at 6 months. Additional endpoints included quality of life using EQ-5D-3L, disability using Oswestry Disability Index (ODI), SIJ function using active straight leg raise (ASLR) test and adverse events. NCT01741025. RESULTS: At 6 months, mean LBP improved by 43.3 points in the SIJF group and 5.7 points in the CM group (difference of 38.1 points, p < 0.0001). Mean ODI improved by 26 points in the SIJF group and 6 points in the CM group (p < 0.0001). ASLR, EQ-5D-3L, walking distance and satisfaction were statistically superior in the SIJF group. The frequency of adverse events did not differ between groups. One case of postoperative nerve impingement occurred in the surgical group. CONCLUSIONS: In patients with chronic SIJ pain, minimally invasive SIJF using triangular titanium implants was safe and more effective than CM in relieving pain, reducing disability, improving patient function and quality of life.

Referred leg pain originating from the sacroiliac joint: 6-month outcomes from the prospective randomized controlled iMIA trial.

BACKGROUND: The first results from the randomized, controlled iFuse Implant System Minimally Invasive Arthrodesis (iMIA) trial showed that minimally invasive surgical management (MISM) of low back pain originating from the sacroiliac joint (SIJ) by placing transarticular triangular titanium implants reduced pain more effectively than conservative management (CM). We now conducted a separate analysis of the iMIA data to assess whether the referred leg pain (RLP) component of SIJ-associated pain may also be affected by MISM or CM. METHODS: Data from 101 patients, recruited between June 2013 and May 2015 at nine European spine care centers, were included. Forty-nine patients were randomized to CM and 51 patients to MISM. RLP was defined as pain below the gluteal fold and assessed using the visual analogue scale (VAS). Changes in RLP over 6 months were the primary endpoint. RESULTS: The prevalence of clinically significant RLP was 76.2 %. Over 6 months of follow-up, CM produced no significant change in RLP, which was 51.0 VAS points (interquartile range (IQR) 17.0-75.0) at baseline. In contrast, in the MISM cohort, we found a significant decrease in RLP from VAS 58.0 (IQR 24.5-80.0) at baseline to VAS 13.5 (IQR 0.0-39.3) after 6 months (p < 0.01). Improvement of RLP was associated only with the type of treatment (OR 5.04, p < 0.01), but not with patient age, sex, or different patterns of pain referral. CONCLUSIONS: Our analysis shows that RLP is a frequent phenomenon in patients with SIJ-associated pain. At 6 months of follow-up, MISM helped relieve RLP more effectively than CM. Clinical Trial Registration-URL: http://www.clinicaltrials.gov . Unique identifier: NCT01741025.

OP-1 Compared with Iliac Crest Autograft in Instrumented Posterolateral Fusion: A Randomized, Multicenter Non-Inferiority Trial.

BACKGROUND: Spinal fusion with the use of autograft is a commonly performed procedure. However, harvesting of bone from the iliac crest is associated with complications. Bone morphogenetic proteins (BMPs) are extensively used as alternatives, often without sufficient evidence of safety and efficacy. The purpose of this study was to investigate non-inferiority of osteogenic protein-1 (OP-1, also known as BMP-7) in comparison with iliac crest bone graft in posterolateral fusions. METHODS: This study was a randomized, controlled multicenter trial. Patients who underwent a single-level instrumented posterolateral fusion of the lumbar spine for degenerative or isthmic spondylolisthesis with symptoms of neurological compression were randomized to receive OP-1 combined with local bone (OP-1 group) or autologous bone graft from the iliac crest combined with local bone (autograft group). The primary outcome was overall success, defined as a combination of clinical success and evidence of fusion on computed tomography (CT) scans, at one year postoperatively. RESULTS: One hundred and nineteen patients were included in the study, and analysis of the overall outcome was performed for 113. Non-inferiority of OP-1 compared with iliac crest autograft was not found at one year, with a success rate of 40% in the OP-1 group versus 54% in the autograft group (risk difference = -13.3%, 90% confidence interval [CI] = -28.6% to +2.10%). This was due to the lower rate of fusion (the primary aim of OP-1 application) seen on the CT scans in the OP-1 group (54% versus 74% in the autograft group, p = 0.03). There were no adverse events that could be directly related to the use of OP-1. CONCLUSIONS: OP-1 with a collagen carrier was not as effective as autologous iliac crest bone for achieving fusion and cannot be recommended in instrumented posterolateral lumbar fusion procedures. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Profunda femoris artery pseudoaneurysm following revision for femoral shaft fracture nonunion.

Femoral artery pseudoaneurysms (FAPs) have been described following internal fixation of intertrocantheric, subtrocantheric and intracapsular femoral neck fractures as well as core decompression of the femoral head. The diagnosis of FAP is usually delayed because of non-specific clinical features like pain, haematoma, swelling, occasional fever and unexplained anaemia. Because of the insidious onset and of the possible delayed presentation of pseudoaneurysms, orthopaedic and trauma surgeons should be aware of this complication. We report a case of Profunda Femoris arterial branch pseudoaneurysm, diagnosed in a 40-year-old male 4 wk after revision with Kuntscher intramedullary nail of a femoral shaft nonunion. The diagnosis was achieved by computed tomography angiography and the lesion was effectively managed by endovascular repair. The specific literature and suggestions for treatment are discussed in the paper.