The sacroiliac joint: a critical review

Non-invasive assessment of sacroiliac joint and lumbar spine positioning in different unilateral sitting postures

BACKGROUND

Sacroiliac joint (SIJ) motion has been documented using invasive and noninvasive kinematic techniques. No study has explored SIJ angular positions in functional postures using noninvasive techniques. The purpose of this study was to quantify SIJ positioning among different seated postures in a healthy population.

METHODS

Twelve female and 11 male healthy young participants participated. Left and right anterior and posterior superior iliac spines were manually digitized during standing, neutral sitting and four different seated postures. Rigid bodies recorded the kinematics of the lumbar spine. Angles calculated included transverse sacroiliac angle, innominate sagittal angle, sacral tilt, lumbar flexion-extension, lumbar lateral bend and lumbar axial twist.

FINDINGS

The observed range of angular positions was approximately 3 to 4 degrees across the SIJ-related angles. The main effect of seated posture was observed for all angles measured. The main effect of sex was observed for all angles except lumbar lateral bending. Females consistently experienced more posterior sacral tilt than males. Interaction effects between sex and posture were only observed at the right-transverse sacroiliac angle and sacral tilt. Previous sitting posture affected the subsequent neutral sitting posture for the right-transverse sacroiliac angle and lumbar spine angle.

INTERPRETATION

SIJ angular position differences among the seated postures were similar in magnitude to motions previously reported in participants undergoing prone passive hip abduction and external rotation. Sex differences, including greater sacral posterior tilt observed in females, likely reflect underlying morphological and physiological differences. Future studies should explore SIJ positioning during functional tasks in pathological populations to help elucidate the underlying causes of SIJ pain and inform treatment strategies.

Manipulations of Oblique Pulling Affect Sacroiliac Joint Displacements and Ligament Strains: A Finite Element Analysis

Objective

Clinical studies have found that manipulation of oblique pulling has a good clinical effect on sacroiliac joint pain. However, there is no uniform standard for manipulation of oblique pulling at present. The purpose of this study was to investigate the effects of four manipulations of oblique pulling on sacroiliac joint and surrounding ligaments.

Methods

A three-dimensional finite element model of the pelvis was established. Four manipulations of oblique pulling were simulated. The stresses and displacements of sacroiliac joint and the strains of surrounding ligaments were analyzed under four manipulations of oblique pulling.

Results

Manipulation of oblique pulling F2 and F3 caused the highest and lowest stress on the pelvis, at 85.0 and 52.6 MPa, respectively. Manipulation of oblique pulling F3 and F1 produced the highest and lowest stress on the left sacroiliac joint, at 6.6 and 5.6 MPa, respectively. The four manipulations of oblique pulling mainly produced anterior-posterior displacement. The maximum value was 1.21 mm, produced by manipulation of oblique pulling F2, while the minimal value was 0.96 mm, produced by manipulation of oblique pulling F3. The four manipulations of oblique pulling could all cause different degrees of ligament strain, and manipulation of oblique pulling F2 produced the greatest ligament strain.

Conclusions

The four manipulations of oblique pulling all produced small displacements of sacroiliac joint. However, they produced different degrees of ligament strain. Manipulation of oblique pulling F2 produced the largest displacement of sacroiliac joint and the greatest ligament strain, which could provide a certain reference for physiotherapists.

Biomechanical analysis of sacroiliac joint motion following oblique-pulling manipulation with or without pubic symphysis injury

Background: Oblique-pulling manipulation has been widely applied in treating sacroiliac joint (SIJ) dysfunction. However, little is known about the biomechanical mechanism of the manipulation. This study aims to analyze the SIJ motion under oblique-pulling manipulation, in comparison with compression and traction loads.

Methods/Study Design: A total of six specimens of embalmed human pelvis cadavers were dissected to expose the SIJ and surrounding ligaments. Through a servo-hydraulic testing system, biomechanical tests were performed on the stable pelvis and the unstable pelvis with pubic symphysis injury (PSI). A three-dimensional (3D) photogrammetry system was employed to determine the separation and nutation in three tests: axial compression (test A), axial traction (test B), and oblique-pulling manipulation (test C).

Results: After applying the testing loads, the range of nutation was no more than 0.3° (without PSI) and 0.5°(with PSI), separately. Except for test B, a greater nutation was found with PSI (p < 0.05). Under both conditions, nutation following test A was significantly greater than that of other tests (p < 0.05). SIJ narrowed in test A and separated in tests B and C, where the range of motion did not exceed 0.1 mm (without PSI) or 0.3 mm (with PSI) separately. Under both conditions, the separation of SIJ in test C was not as apparent as the narrowness of SIJ in test A (p < 0.05). Compared to SIJ, a more significant increasing displacement was found at the site of the iliolumbar ligament (p < 0.05). Nevertheless, when the force was withdrawn in all tests, the range of nutation and separation of SIJ nearly decreased to the origin.

Conclusion: Pubic symphysis is essential to restrict SIJ motion, and the oblique-pulling manipulation could cause a weak nutation and separation of SIJ. However, the resulting SIJ motion might be neutralized by regular standing and weight-bearing load. Also, the effect on SIJ seems to disappear at the end of manipulation. Therefore, the stretching and loosening of surrounding ligaments need to be paid more attention to.

Comparison of pelvic rotation angle in the transverse plane in the supine position and during active straight leg raise between people with and without nonspecific low back pain

BACKGROUND

Faults in postural alignment and movement of the pelvis are associated with non-specific low back pain. However, limited studies have investigated the differences in pelvic rotation angle in the transverse plane in the supine position and during active straight leg raise between subjects with and without non-specific low back pain.

METHODS

Thirty-one subjects with non-specific low back pain and 31 subjects without non-specific low back pain were examined. Angular measures of the pelvic rotation angle in the transverse plane were obtained in the supine position and during active straight leg raise using a Smart KEMA measurement system.

FINDING

The pelvic rotation angle in the transverse plane during active straight leg raise was significantly greater in subjects with non-specific low back pain than in healthy subjects (p < 0.05). However, the pelvic rotation angle in the transverse plane in the supine position and asymmetry index of the pelvic rotation angle during active straight leg raise were not significantly different between subjects with and those without non-specific low back pain.

INTERPRETATION

This indicates that a greater pelvic rotation angle in the transverse plane during active straight leg raise could be contributing factors to the development of a non-specific low back pain related to lumbopelvic instability.

A finite element analysis of sacroiliac joint displacements and ligament strains in response to three manipulations

BACKGROUND

Clinical studies have found that manipulations have a good clinical effect on sacroiliac joint (SIJ) pain without specific causes. However, the specific mechanisms underlying the effect of manipulations are still unclear. The purpose of this study was to investigate the effects of three common manipulations on the stresses and displacements of the normal SIJ and the strains of the surrounding ligaments.

METHODS

A three-dimensional finite element model of the pelvis-femur was developed. The manipulations of hip and knee flexion (MHKF), oblique pulling (MOP), and lower limb hyperextension (MLLH) were simulated. The stresses and displacements of the SIJ and the strains of the surrounding ligaments were analyzed during the three manipulations.

RESULTS

MOP produced the highest stress on the left SIJ, at 6.6 MPa, while MHKF produced the lowest stress on the right SIJ, at 1.5 MPa. The displacements of the SIJ were all less than 1 mm during the three manipulations. The three manipulations caused different degrees of ligament strain around the SIJ, and MOP produced the greatest straining of the ligaments.

CONCLUSION

The three manipulations all produced small displacements of the SIJ and different degrees of ligament strains, which might be the mechanism through which they relieve SIJ pain. MOP produced the largest displacement and the greatest ligament strains.

Clinimetric properties of sacroiliac joint mobility tests: A systematic review

BACKGROUND

Previous systematic reviews revealed poor reliability and validity for sacroiliac joint (SIJ) mobility tests. However, these reviews were published nearly 20 years ago and recent evidence has not yet been summarised.

OBJECTIVES

To conduct an up-to-date systematic review to verify whether recommendations regarding the clinical use of SIJ mobility tests should be revised.

STUDY DESIGN

Systematic review.

METHOD

The literature was searched for relevant articles via 5 electronic databases. The review was conducted according to the PRISMA guidelines. COSMIN checklists were used to appraise the methodological quality. Studies were included if they had at least fair methodology and reported clinimetric properties of SIJ mobility tests performed in adult patients with non-specific low back pain, pelvic (girdle) pain and/or SIJ pain. Only tests that can be performed in a clinical setting were considered.

RESULTS

Twelve relevant articles were identified, of which three were of sufficient methodological quality. These three studies evaluated the reliability of eight SIJ mobility tests and one test cluster. For the majority of individual tests, the intertester reliability showed slight to fair agreement. Although some tests and one test cluster had higher reliability, the confidence intervals around most reliability estimates were large. Furthermore, there were no validity studies of sufficient methodological quality.

CONCLUSION

Considering the low and/or imprecise reliability estimates, the absence of high-quality diagnostic accuracy studies, and the uncertainty regarding the construct these tests aim to measure, this review supports the previous recommendations that the use of SIJ mobility tests in clinical practice is problematic.

Biomechanics of the Sacroiliac Joint: Anatomy, Function, Biomechanics, Sexual Dimorphism, and Causes of Pain

BACKGROUND

The sacroiliac joints (SIJs), the largest axial joints in the body, sit in between the sacrum and pelvic bones on either side. They connect the spine to the pelvis and thus facilitate load transfer from the lumbar spine to the lower extremities. The majority of low back pain (LBP) is perceived to originate from the lumbar spine; however, another likely source of LBP that is mostly overlooked is the SIJ. This study (Parts I and II) aims to evaluate the clinical and biomechanical literature to understand the anatomy, biomechanics, sexual dimorphism, and causes and mechanics of pain of the SIJ leading to conservative and surgical treatment options using instrumentation. Part II concludes with the mechanics of the devices used in minimal surgical procedures for the SIJ.

METHODS

A thorough review of the literature was performed to analyze studies related to normal SIJ mechanics, as well as the effects of sex and pain on SIJ mechanics.

RESULTS

A total of 65 studies were selected related to anatomy, biomechanical function of the SIJ, and structures that surround the joints. These studies discussed the effects of various parameters, gender, and existence of common physiological disorders on the biomechanics of the SIJ.

CONCLUSIONS

The SIJ lies between the sacrum and the ilium and connects the spine to the pelvic bones. The SIJ transfers large bending moments and compression loads to lower extremities. However, the joint does not have as much stability of its own against the shear loads but resists shear due the tight wedging of the sacrum between hip bones on either side and the band of ligaments spanning the sacrum and the hip bones. Due to these, sacrum does not exhibit much motion with respect to the ilium. The SIJ range of motion in flexion-extension is about 3°, followed by axial rotation (about 1.5°), and lateral bending (about 0.8°). The sacrum of the female pelvis is wider, more uneven, less curved, and more backward tilted, compared to the male sacrum. Moreover, women exhibit higher mobility, stresses/loads, and pelvis ligament strains compared to male SIJs. Sacroiliac pain can be due to, but not limited to, hypo- or hypermobility, extraneous compression or shearing forces, micro- or macro-fractures, soft tissue injury, inflammation, pregnancy, adjacent segment disease, leg length discrepancy, and prior lumbar fusion. These effects are well discussed in this review. This review leads to Part II, in which the literature on mechanics of the treatment options is reviewed and synthesized.

Biomechanical analysis of motion following sacroiliac joint fusion using lateral sacroiliac screws with or without lumbosacral instrumented fusion

BACKGROUND

Sacroiliac joint hypermobility or aberrant mechanics may be a source of pain. The purpose of this study was to assess sacroiliac joint range of motion after simulated adjacent lumbosacral instrumented fusion, with or without sacroiliac joint fusion, with lateral sacroiliac screws.

METHODS

In this in vitro biomechanical study, seven cadaveric specimens were tested on a six-degrees-of-freedom machine under load control. Left posterior sacroiliac joint ligaments were severed to maximize joint range of motion. Influence of lumbosacral instrumentation on sacroiliac joint motion, with or without fixation, was studied.

FINDINGS

During flexion-extension in the setting of posterior sacroiliac joint injury and L5-S1 fixation, sacroiliac joint range of motion increased to 195% of intact. After fixation with lateral sacroiliac screws, average range of motion reduced to 144% of intact motion. Sacroiliac joint screws thus partially stabilized the joint and reduced motion. Use of 6 bilateral sacroiliac joint screws with L5-S1 screw and rod fixation in lateral bending and axial rotation yielded the greatest reduction in range of motion. Without lumbosacral fixation, baseline motion of the sacroiliac joint was reduced, and sacroiliac joint screw alone, using either 2, 3, or 6 screws, was able to restore motion at or below the level of an intact joint.

INTERPRETATION

Sacroiliac joint ligament injury with existing lumbosacral fixation doubled sacroiliac joint range of motion, but thereafter, fixation with lateral sacroiliac screws decreased range of motion of the injured sacroiliac joint. Screw configuration played a minor role, but generally, 6 sacroiliac joint screws had the greatest motion reduction.

Diagnosing Sacroiliac Joint Pain

The sacroiliac joint (SIJ) is a diarthrodial joint that has been implicated as a pain generator in approximately 10% to 25% of patients with mechanical low back or leg symptoms. Unique anatomic and physiologic characteristics of SIJ make it susceptible to mechanical stress and also create challenges in the diagnosis of SIJ pain. A variety of inciting causes for SIJ pain may exist, ranging from repetitive low-impact activities such as jogging to increased stress after multilevel spine fusion surgery to high-energy trauma such as in motor vehicle accidents. Similarly, wide variability exists in the clinical presentation of SIJ pain from localized pain or tenderness around the SIJ to radiating pain into the groin or even the entire lower extremity. No pathognomonic clinical history, physical examination finding, or imaging study exists that aids clinicians in making a reliable diagnosis. However, imaging combined with clinical provocative tests might help to identify patients for further investigation. Although provocative physical examination tests have not received reliable consensus, if three or more provocative tests are positive, pursuing a diagnostic SIJ injection is considered reasonable. Notable pain relief with intra-articular anesthetic injection under radiographic guidance has been shown to provide reliable evidence in the diagnosis of SIJ pain.

Image Guidance Technologies for Interventional Pain Procedures: Ultrasound, Fluoroscopy, and CT

Chronic pain is a common medical condition. Patients who suffer uncontrolled chronic pain may require interventions including spinal injections and various nerve blocks. Interventional procedures have evolved and improved over time since epidural injection was first introduced for low back pain and sciatica in 1901. One of the major contributors in the improvement of these interventions is the advancement of imaging guidance technologies. The utilization of image guidance has dramatically improved the accuracy and safety of these interventions. The first image guidance technology adopted by pain specialists was fluoroscopy. This was followed by CT and ultrasound. Fluoroscopy can be used to visualize bony structures of the spine. It is still the most commonly used guidance technology in spinal injections. In the recent years, ultrasound guidance has been increasingly adopted by interventionists to perform various injections. Because its ability to visualize soft tissue, vessels, and nerves, this guidance technology appears to be a better option than fluoroscopy for interventions including SGB and celiac plexus blocks, when visualization of the vessels may prevent intravascular injection. The current evidence indicates the efficacies of these interventions are similar between ultrasound guidance and fluoroscopy guidance for SGB and celiac plexus blocks. For facet injections and interlaminar epidural steroid injections, it is important to visualize bony structures in order to perform these procedures accurately and safely. It is worth noting that facet joint injections can be done under ultrasound guidance with equivalent efficacy to fluoroscopic guidance. However, obese patients may present challenge for ultrasound guidance due to its poor visualization of deep anatomical structures. Regarding transforaminal epidural steroid injections, there are limited evidence to support that ultrasound guidance technology has equivalent efficacy and less complications comparing to fluoroscopy. However, further studies are required to prove the efficacy of ultrasound-guided transforaminal epidural injections. SI joint is unique due to its multiplanar orientation, irregular joint gap, partial ankylosis, and thick dorsal and interosseous ligament. Therefore, it can be difficult to access the joint space with fluoroscopic guidance and ultrasound guidance. CT scan, with its cross-sectional images, can identify posterior joint gap, is most likely the best guidance technology for this intervention. Intercostal nerves lie in the subcostal grove close to the plural space. Significant risk of pneumothorax is associated with intercostal blocks. Ultrasound can provide visualization of ribs and pleura. Therefore, it may improve the accuracy of the injection and reduce the risk of pneumothorax. At present time, most pain specialists are familiar with fluoroscopic guidance techniques, and fluoroscopic machines are readily available in the pain clinics. In the contrast, CT guidance can only be performed in specially equipped facilities. Ultrasound machine is generally portable and inexpensive in comparison to CT scanner and fluoroscopic machine. As pain specialists continue to improve their patient care, ultrasound and CT guidance will undoubtedly be incorporated more into the pain management practice. This review is based on a paucity of clinical evidence to compare these guidance technologies; clearly, more clinical studies is needed to further elucidate the pro and cons of each guidance method for various pain management interventions.

A computed tomographic anatomical study of the upper sacrum. Application for a user guide of pelvic fixation with iliosacral screws in adult spinal deformity

PURPOSE

Widely used in traumatic pelvic ring fractures, the iliosacral (IS) screw technique for spino-pelvic fixation remains anecdotal in adult spinal deformity. The objective of this study was to assess anatomical variability of the adult upper sacrum and to provide a user guide of spino-pelvic fixation with IS screws in adult spinal deformity.

METHODS

Anatomical variability of the upper sacrum according to age, gender, height and weight was sought on 30 consecutive pelvic CT-scans. Thus, a user guide of spino-pelvic fixation with IS screws was modeled and assessed on ten CT-scans as described below. Two invariable landmarks usable during the surgical procedure were defined: point A (corresponding to the connector binding the IS screw to the spinal rod), equidistant from the first posterior sacral hole and the base of the S1 articular facet and 10 mm-embedded into the sacrum; point B (corresponding to the tip of the IS screw) located at the junction of the anterior third and middle third of the sacral endplate in the sagittal plane and at the middle of the endplate in the coronal plane. Point C corresponded to the intersection between the A-B direction and the external facet of the iliac wing. Three-dimensional reconstructions modeling the IS screw optimal direction according to the A-B-C straight line were assessed.

RESULTS

Age had no effect on the anatomy of the upper sacrum. The distance between the base of the S1 superior articular facet and the top of the first posterior sacral hole was correlated with weight (r = 0.6; 95% CI [0.6-0.9]); p < 0.001). Sacral end-plate thickness increased for male patients (p < 0.001) and was strongly correlated with height (r = 0.6; 95% CI [0.29-0.75]); p < 0.001) and weight (r = 0.8; 95% CI [0.6-0.9]); p < 0.001). The thickness of the inferior part of the S1 vertebral body increased in male patients (p < 0.001). Other measured parameters slightly varied according to gender, height and weight. Simulating the described technique of pelvic fixation, no misplaced IS screw was found whatever the age, gender and morphologic parameters.

CONCLUSION

This user guide of spinopelvic fixation with IS screws seems to be reliable and reproducible independently of age, gender and morphologic characteristics but needs clinical assessment.

LEVEL OF EVIDENCE

Level IV.

Malalignment Syndrome in Runners

More than 80% of runners are out of alignment. The standard back examination should include assessment of pelvic alignment. An awareness of pelvic malalignment and the the malalignment syndrome is essential to allow one to provide proper care of a runner. The 3 most common presentations usually respond to a supervised, progressive treatment program. The validity of any research into the biomechanics of running should be questioned if the study has failed to look at whether pelvic malalignment was present and whether the altered, asymmetrical biomechanical changes attributable to the malalignment itself could have affected the results of the study.

Radiosteriometric analysis of movement in the sacroiliac joint during a single-leg stance in patients with long-lasting pelvic girdle pain

BACKGROUND

Chamberlain's projections (anterior-posterior X-ray of the pubic symphysis) have been used to diagnose sacroiliac joint mobility during the single-leg stance test. This study examined the movement in the sacroiliac joint during the single-leg stance test with precise radiostereometric analysis.

METHODS

Under general anesthesia, tantalum markers were inserted into the dorsal sacrum and the ilium of 11 patients with long-lasting and severe pelvic girdle pain. After two to three weeks, a radiostereometric analysis was conducted while the subjects performed a single-leg stance.

FINDINGS

Small movements were detected in the sacroiliac joint during the single-leg stance. In both the standing- and hanging-leg sacroiliac join, a total of 0.5 degree rotation was observed; however, no translations were detected. There were no differences in total movement between the standing- and hanging-leg sacroiliac joint.

INTERPRETATION

The movement in the sacroiliac joint during the single-leg stance is small and almost undetectable by the precise radiostereometric analysis. A complex movement pattern was seen during the test, with a combination of movements in the two joints. The interpretation of the results of this study is that, the Chamberlain examination likely is inadequate in the examination of sacroiliac joint movement in patients with pelvic girdle pain.

3-D finite element analysis of the influence of synovial condition in sacroiliac joint on the load transmission in human pelvic system

The anterior part of the sacroiliac joint (SIJ) is a synovial joint, with little gliding and rotary movement between the contact surfaces of SIJ during locomotion. Due to its complex structure, especially when considering the surrounding ligaments, it is difficult to construct an accurate three-dimensional (3-D) finite element model for the human pelvis. Most of the pelvic models in the previous studies were simplified with either SIJ fusing together or without the sacral bone. However, the influence of those simplifications on the load transmission in human pelvis has not been studied, so the reliability of those studies remains unclear. In this study, two 3-D pelvic models were constructed: an SIJ fusing model and an SIJ contacting model. In the SIJ fusing model, the SIJ interfaces were fused together. In the SIJ contacting model, the SIJ interfaces were just in contact with each other without fusion. Compared with the SIJ contacting model, the SIJ fusing model have smaller movements in the SIJ. The stress distribution area in the SIJ fusing model on sacroiliac cartilages was also different. Those differences contributed to the decline of tensile force in the SIJ surrounding ligaments and the re-distribution of stress in the pelvic bones. In addition, the SIJ fusing model was far less sensitive to the increase in modulus of the sacroiliac cartilages, and decrease in stiffness of the ligaments surrounding the SIJ. The presence of synovia in the SIJ had greater influence on the load transmission in the human pelvic system. Therefore, the effect of the presence of synovia should not be neglected when the biomechanical behavior of human pelvis is being studied, especially for those studies related to clinical applications.

Sacroiliac joint pain: a comprehensive review of epidemiology, diagnosis and treatment

Sacroiliac joint (SIJ) pain is an underappreciated source of mechanical low back pain, affecting between 15 and 30% of individuals with chronic, nonradicular pain. Predisposing factors for SIJ pain include true and apparent leg length discrepancy, older age, inflammatory arthritis, previous spine surgery, pregnancy and trauma. Compared with facet-mediated and discogenic low back pain, individuals with SIJ pain are more likely to report a specific inciting event, and experience unilateral pain below L5. Owing in part to its size and heterogeneity, the pain referral patterns of the SIJ are extremely variable. Although no single physical examination or historical feature can reliably identify a painful SIJ, studies suggest that a battery of three or more provocation tests can predict response to diagnostic blocks. Evidence supports both intra- and extra-articular causes for SIJ pain, with clinical studies demonstrating intermediate-term benefit for both intra- and extra-articular steroid injections. In those who fail to experience sustained relief from SIJ injections, radiofrequency denervation may provide significant relief lasting up to 1 year. This review covers all aspects of SIJ pain, with the treatment section being primarily focused on procedural interventions.

Spine osteoarthritis

Osteoarthritis of the spine develops as a consequence of the natural aging process and is associated with significant morbidity and health care expenditures. Effective diagnosis and treatment of the resultant pathologic conditions can be clinically challenging. Recent evidence has emerged to aid the investigating clinician in formulating an accurate diagnosis and in implementing a successful treatment algorithm. This article details the degenerative cascade that results in the osteoarthritic spine, reviews prevalence data for common painful spinal disorders, and discusses evidence-based treatment options for management of zygapophysial and sacroiliac joint arthrosis.

Radiation dose reduction in CT-guided sacroiliac joint injections to levels of pulsed fluoroscopy: a comparative study with technical considerations

Background

The sacroiliac (SI) joint is frequently the primary source of low back pain. Over the past decades, a number of different SI injection techniques have been used in its diagnosis and therapy. Despite the concerns regarding exposure to radiation, image-guided injection techniques are the preferred method to achieve safe and precise intra-articular needle placement. The following study presents a comparison of radiation doses, calculated for fluoroscopy and CT-guided SI joint injections in standard and low-dose protocol and presents the technical possibility of CT-guidance with maximum radiation dose reduction to levels of fluoroscopic-guidance for a precise intra-articular injection technique.

Objective

To evaluate the possibility of dose reduction in CT-guided sacroiliac joint injections to pulsed-fluoroscopy-guidance levels and to compare the doses of pulsed-fluoroscopy-, CT-guidance, and low-dose CT-guidance for intra-articular SI joint injections.

Study design

Comparative study with technical considerations.

Methods

A total of 30 CT-guided intra-articular SI joint injections were performed in January 2012 in a developed low-dose mode and the radiation doses were calculated. They were compared to 30 pulsed-fluoroscopy-guided SI joint injections, which were performed in the month before, and to five injections, performed in standard CT-guided biopsy mode for spinal interventions. The statistical significance was calculated with the SPSS software using the Mann–Whitney U-Test. Technical details and anatomical considerations were provided.

Results

A significant dose reduction of average 94.01% was achieved using the low-dose protocol for CT-guided SI joint injections. The radiation dose could be approximated to pulsed-fluoroscopy- guidance levels.

Conclusion

Radiation dose of CT-guided SI joint injections can be decreased to levels of pulsed fluoroscopy with a precise intra-articular needle placement using the low-dose protocol. The technique is simple to perform, fast, and reproducible.

The predictive value of the sacral base pressure test in detecting specific types of sacroiliac dysfunction

OBJECTIVE

This study aimed to evaluate the validity of the sacral base pressure test in diagnosing sacroiliac joint dysfunction. It also determined the predictive powers of the test in determining which type of sacroiliac joint dysfunction was present.

METHODS

This was a double-blind experimental study with 62 participants. The results from the sacral base pressure test were compared against a cluster of previously validated tests of sacroiliac joint dysfunction to determine its validity and predictive powers. The external rotation of the feet, occurring during the sacral base pressure test, was measured using a digital inclinometer.

RESULTS

There was no statistically significant difference in the results of the sacral base pressure test between the types of sacroiliac joint dysfunction. In terms of the results of validity, the sacral base pressure test was useful in identifying positive values of sacroiliac joint dysfunction. It was fairly helpful in correctly diagnosing patients with negative test results; however, it had only a "slight" agreement with the diagnosis for kappa interpretation.

CONCLUSIONS

In this study, the sacral base pressure test was not a valid test for determining the presence of sacroiliac joint dysfunction or the type of dysfunction present. Further research comparing the agreement of the sacral base pressure test or other sacroiliac joint dysfunction tests with a criterion standard of diagnosis is necessary.

Effective treatments for pain in the older patient

By 2050, the number of older persons across the globe will exceed the number of younger people for the first time in history. Chronic conditions, especially pain, will rise in prevalence as the population ages. Controlling pain in this unique subset of the population demands careful attention to pharmacokinetic and pharmacodynamic factors and their specific impact on pharmacotherapies, relevant complementary and alternative medicine therapies, and interventional strategies.

Disfunção da articulação sacro-ilíaca em jovens com dor lombar

INTRODUÇÃO: A dor lombar representa um problema de saúde pública. Estima-se que uma elevada porcentagem de casos de dor lombar (85-90%) não tem uma causa conhecida. Acredita-se que a disfunção da articulação sacro-ilíaca possa explicar, em parte, essa alta porcentagem. OBJETIVO: Determinar a frequência da disfunção da articulação sacro-ilíaca em jovens com dor lombar e descrever possíveis associações com características sócio-demográficas, clínicas e antropométricas da população estudada. METODOLOGIA: A amostra foi selecionada por meio de entrevista direta. Sessenta e sete sujeitos (92,5% mulheres) com idade média de 21 ± 2,1 participaram do estudo. Foi realizado exame físico que incluiu a avaliação da dor à palpação, amplitude de movimento da flexão do quadril, funcionalidade avaliada por meio do Oswestry Disability Index, e realização de quatro provas de provocação de dor da articulação sacro-ilíaca (Gaenslen, thigh thrust, compressão ilíaca e compressão sacra). O diagnóstico para disfunção da articulação sacro-ilíaca foi considerado positivo se pelo menos três das provas foram positivas. RESULTADOS: A frequência de disfunção da articulação sacro-ilíaca foi de 35,8% IC 95% (24,0-47,6). Foi observada associação da disfunção da articulação com diminuição de flexibilidade dos isquiotibiais, pontuação do Oswestry Disability Index e dor à palpação. Não foram encontradas associações estatisticamente significativas com as variáveis sócio-demográficas. CONCLUSÃO: A alta frequência de disfunção da articulação sacro-ilíaca encontrada sugere a possibilidade de detectar e intervir precocemente uma possível causa de dor lombar, evitando alterações funcionais de maior severidade.

Inter-examiner reliability of four static palpation tests used for assessing pelvic dysfunction

In muscle energy technique (MET), palpation is an important tool aimed at detecting asymmetry and selecting interventions. The aim of this study was to test the inter-examiner reliability of static palpation of the transverse processes of L5 (L5), sacral sulci (SS), inferior lateral angles of the sacrum (ILA), and the medial malleoli (MM) in a clinical setting. Twenty-five participants, aged 18-78 years, with low back pain and/or sacroiliac pain with or without radiating pain to the knee, were independently examined by two experienced physiotherapists. For L5, SS, ILA, the proportion of observed agreement was 40-44% and the kappa coefficient 0.11 (SE=0.12) to 0.17 (SE=0.10). For MM, the observed agreement was 52% and the kappa coefficient 0.28 (SE=0.15). Differences in palpation technique seem to be the most likely source of the low inter-examiner reliability in this study. For clinical practise, continued use of these tests as methods for detecting asymmetry and selecting interventions is of doubtful utility.

Three dimensional evaluation of posture in standing with the PosturePrint: an intra- and inter-examiner reliability study

Background

Few digitizers can measure the complexity of upright human postural displacements in six degrees of freedom of the head, rib cage, and pelvis.

Methods

In a University laboratory, three examiners performed delayed repeated postural measurements on forty subjects over two days. Three digital photographs (left lateral, AP, right lateral) of each of 40 volunteer participants were obtained, twice, by three examiners. Examiners placed 13 markers on the subjects before photography and chose 16 points on the photographic images. Using the PosturePrint^® internet computer system, head, rib cage, and pelvic postures were calculated as rotations (Rx, Ry, Rz) in degrees and translations (Tx, Tz) in millimeters. For reliability, two different types (liberal = ICC_3,1 & conservative = ICC_2,1) of inter- and intra-examiner correlation coefficients (ICC) were calculated. Standard error of measurements (SEM) and mean absolute differences within and between observers' measurements were also determined.

Results

All of the "liberal" ICCs were in the excellent range (> 0.84). For the more "conservative" type ICCs, four Inter-examiner ICCs were in the interval (0.5–0.6), 10 ICCs were in the interval (0.61–0.74), and the remainder were greater than 0.75. SEMs were 2.7° or less for all rotations and 5.9 mm or less for all translations. Mean absolute differences within examiners and between examiners were 3.5° or less for all rotations and 8.4 mm or less for all translations.

Conclusion

For the PosturePrint^® system, the combined inter-examiner and intra-examiner correlation coefficients were in the good (14/44) and excellent (30/44) ranges. SEMs and mean absolute differences within and between examiners' measurements were small. Thus, this posture digitizer is reliable for clinical use.

CT-Guided Stabilization for Chronic Sacroiliac Pain: A Preliminary Report

BACKGROUND

We evaluated a percutaneous, computed tomographic, stabilization from S1 to S2, for chronic painful sacroiliac disease. Our hypothesis was that this technique carries low morbidity, and may provide substantial relief of recalcitrant sacroiliac pain.

METHODS

17 patients had CT guided injection with local anesthesia and steroid to confirm the diagnosis. If symptoms recurred, they had a CT guided stabilization using only local anesthesia and conscious sedation. Outcome was evaluated with a visual analog scale. Univariate analysis and Spearman correlations used for analysis.

RESULTS

Pain improved from a mean of 8.3 pre-injection to 3.5 post-injection and remained at 3.3 at final follow up. Four patients had complete relief, 11 patients had significant pain relief, and two patients experienced little to no pain relief. There was a statistically significant difference between pre-injection and post injection pain scores (p < 0.0001), final and pre injection pain scores (p < 0.0001), but not between the post injection and final pain scores (p = 0.8906). A statistically significant correlation (p < 0.02) was found between final pain score and the difference between pre and post injection scores. There were no infections, hardware or technical complications.

CONCLUSIONS

This technique appeared effective in relieving the majority of confirmed sacroiliac pain and appeared to be lasting with few complications. While we did not confirm nor deny an arthrodesis with this technique, it appears that stabilization of the sacroiliac joint may have resulted in enough stability (e.g. alkalosis, mechanical restriction) that it relieved symptoms.

Sacroiliac joint fusion and the implications for manual therapy diagnosis and treatment

The present paper examines gender differences and changes in prevalence of ankylosed sacroiliac joint (SIJ) with age. SIJs of 287 patients (159 males and 128 females), aged 22-93 years, were examined for fusion, using 3-D CT images. Presence, side and location of the fusion along the joint borders were recorded. Fusion of the SIJ was found to be gender and age dependent; present in 27.7% of all males in contrast to only 3.0% in females (p<0.001). The phenomenon increased with age in the male population from 5.8% in the 20-39 age cohorts to 46.7% in the 80+ cohort. As mobilization and/or manipulation of a dysfunctional SIJ are common procedures used by manual therapists, the effect that aging has on SIJ mobility requires therapists to alter or change their method with advancing age.

The active straight leg raising test (ASLR) in pregnant women: differences in muscle activity and force between patients and healthy subjects

Pregnancy-related low back and pelvic pain (PLBP) is a frequent complication of pregnancy. Although pathological mechanisms underlying PLBP are obscure, dysfunction of the sacroiliac joints (SI-joints) seems to play an important role. A cross-sectional study was performed on 24 pregnant women with and without PLBP. The objective was to determine muscle activation patterns of trunk and leg muscles during the active straight leg raising test (ASLR) and static hip flexion, and to determine maximal hip flexion force at 0 and 20 cm leg raise height. Moreover, the effort to raise the leg was scored. The measurements resulted in several significant differences between the patients and healthy controls; among others (a) patients scored subjectively more effort during ASLR, (b) at both 0 and 20 cm leg raise height patients had less hip flexion force, and (c) patients developed more muscle activity during ASLR. Since pregnant women with PLBP developed a higher muscle activity during ASLR with a significantly lower output at 0 and 20 cm than healthy pregnant women, it could be proposed that the ASLR demonstrates a disturbed load transfer across the SI-joints in this population.

Mechanical Diagnosis and Therapy approach to assessment and treatment of derangement of the sacro-iliac joint

This case report describes the clinical reasoning and management of the sacroiliac joint, utilising the McKenzie Method of Mechanical Diagnosis and Therapy (MDT). A patient with a 2 year history of buttock and thigh pain demonstrates a directional preference for repeated anterior SIJ rotation. The MDT approach is discussed and is an ideal method for emphasising the patients involvement in managing their own back problem.

Anatomy of the interosseous region of the sacroiliac joint

STUDY DESIGN

Anatomical study of the interosseous region of the sacroiliac joint (SIJ) complex.

OBJECTIVES

To document and quantify the surface topography of the interosseous region of the SIJ.

BACKGROUND

A review of the literature reveals that little consideration has been given to the interosseous region of the SIJ anatomically, biomechanically, and clinically.

METHODS AND MEASURES

The interosseous region of 11 cadaveric specimens (9 formalin embalmed and 2 fresh frozen) were studied. Ten specimens were 55 years of age or older and 1 was 20 years old. To view the interosseous surfaces of the sacrum and ilium the specimens were either axially sectioned (1-cm slices) or disarticulated. One fresh-frozen and 6 embalmed specimens were disarticulated and the remainder axially sectioned. The topography (surface ridging and areas of ossification) of the interosseous region was documented in all specimens and in 2 specimens the surfaces were 3-dimensionally reconstructed using modeling and animation software (MAYA; Autodesk, Inc, San Rafael, CA).

RESULTS

Surface characteristics of the SIJ complex observed in specimens 55 years of age or older included moderate to extensive ridging of the interosseous region of the sacrum and ilium in 100% of specimens and ossification of the central interosseous region of the sacroiliac (SI) ligament in 60% of specimens.

CONCLUSIONS

Central region ossification of the interosseous SI ligament and the presence of ridges and depressions over the opposing interosseous surfaces of the sacrum and ilium are features common to specimens that are in or beyond their sixth decade. These findings further support the contention that there is little to no movement available at this joint in older individuals.

Sacroiliac Joint Pain: A Comprehensive Review of Anatomy, Diagnosis, and Treatment

Sacroiliac (SI) joint pain is a challenging condition affecting 15% to 25% of patients with axial low back pain, for which there is no standard long-term treatment. Recent studies have demonstrated that historical and physical examination findings and radiological imaging are insufficient to diagnose SI joint pain. The most commonly used method to diagnose the SI joint as a pain generator is with small-volume local anesthetic blocks, although the validity of this practice remains unproven. In the present review I provide a comprehensive review of the anatomy, function, and mechanisms of injury of the SI joint, along with a systematic assessment of its diagnosis and treatment.

What diagnostic tests are useful for low back pain?

Low back pain (LBP) is a common problem that poses some interesting and difficult diagnostic problems. It is typically benign and self-limited, but it is occasionally the presenting symptom of serious systemic disease. The general diagnostic approach to low back pain is to check for 'red flags' in the history and physical that suggest the presence of malignancy, infection or spondyloarthridites, and for neurological compromise that could indicate that surgery is required (cauda equina syndrome) or may be beneficial (such as herniated discs or spinal stenosis that have not improved with conservative care). In the absence of these features, imaging is of limited value. Recent research has begun to evaluate subgroups with 'non-specific' low back pain that seem to benefit from specific interventions such as median branch or sacroiliac joint injections, manipulation, or specific exercises, but these require further investigation and validation.

Sagittal Skin Contour of the Cervical Spine: Interexaminer and Intraexaminer Reliability of the Flexicurve Instrument

OBJECTIVES

To evaluate reliability of a simple instrument, the flexicurve, in determining cervical sagittal skin contour.

METHODS

This study obtained repeated random measurements involving 3 investigators and 30 subjects once per day over a 2-day trial period. Thirty normal subjects were examined for cervical spine skin contour twice by 3 separate investigators with a 1-day delay. With subjects in a neutral standing position, investigators placed the flexicurve on the posterior portion of the subject's neck from the external occipital protuberance to the vertebral prominens and traced the flexicurve shape onto paper. The tracings were divided into 6 equal arcs and digitized. Statistical computation was performed on the depth at 5 points, arc angle, and arc radius of curvature. Interexaminer and intraexaminer correlation coefficients (ICCs) were calculated to determine reliability.

RESULTS

All interexaminer correlation coefficients were in the poor range (<0.40). For the arc radius, arc angle, depth at top one third, and depth at bottom two thirds, the intraexaminer correlation coefficients were in the poor range. For the 3 deepest depths, the intraexaminer correlation coefficients were in the fair range (0.4-0.50).

CONCLUSION

The flexicurve showed marginal reliability with most (12/16) ICCs in the poor range (ICC <0.40) and 4 values in the fair range (0.4 < ICC < 0.5).

Influence of Axial Rotation on Chiropractic Pelvic Radiographic Analysis

OBJECTIVE

The aim of the study is to explore associations between axial (y-axis) rotation of the pelvis and pelvic radiographic measurements.

STUDY DESIGN

Descriptive film statistics of an incrementally rotated pelvis and linear regression analysis were performed.

METHODS

A phantom pelvic model was incrementally imaged (1 degrees increments) at 40-in source-to-image distance through 10 degrees of axial rotation. Chiropractic line drawing analysis was performed. The chiropractic examiner was blinded to the degree of rotation during the film analysis. Regression analysis was performed between axial rotation and pubic symphysis deviation, sacral width, and innominate and femur head heights. Each measurement corresponds to a chiropractic listing within the Gonstead system.

RESULTS

Regression analysis revealed a strong association between the degree of axial rotation and each response variable: pubic symphysis deviation, sacral width, innominate height, and femur head height. The strongest relationship existed between y-axis rotation and pubic symphysis deviation.

CONCLUSIONS

Chiropractic pelvic listings are strongly influenced by positioning of the subject. A few degrees of axial rotation may create apparent misalignments of several millimeters.

Inciting Events Initiating Injection-Proven Sacroiliac Joint Syndrome

OBJECTIVE

To determine the inciting events leading to the development of sacroiliac joint syndrome (SIJS).

METHODS

This was a retrospective descriptive cohort series from an academic interdisciplinary spine center. Consecutive patients presenting with low back or buttock pain with or without leg symptoms who met specific inclusion and exclusion criteria for the diagnosis of SIJS were included in the study. Inciting events leading to the development of SIJS in these patients were categorized into traumatic, cumulative, and idiopathic events.

RESULTS

Of 194 patients who were included in the study, 54 patients had symptom resolution with one or more therapeutic intraarticular sacroiliac joint injections, following a positive diagnostic injection. Those patients were given the diagnosis of SIJS. Of these, 24 (44%) had had a traumatic event (13 motor vehicle accidents, six falls onto the buttock, three immediately postpartum, one severe football tackle, and one pelvis fracture). Eleven (21%) patients were considered to have a cumulative injury (four lifting, two running, three altered gait due to lower extremity disorder, one crew training injury, and one forceful hip extension injury). Nineteen (35%) patients had spontaneous or idiopathic onset of sacroiliac joint pain.

CONCLUSION

SIJS can occur following a traumatic event or cumulative shear events, or can occur spontaneously.

Functional deficits in athletes with a history of low back pain: a pilot study

OBJECTIVE

To evaluate whether athletes with a history of low back pain (LBP) would, on average, perform slower on a timed 20-m shuttle run as compared with a normal athletic population.

DESIGN

A timed shuttle run to evaluate residual functional limitations in college athletes with resolved LBP.

SETTING

National College Athletic Association (NCAA) division I college.

PARTICIPANTS

NCAA division I athletes (161 men, 50 women).

INTERVENTION

A timed 20-m shuttle run.

MAIN OUTCOME MEASURE

Each athlete was timed in a divided 20 m (66 ft) run in which 2 taped lines were positioned 6.7 m (22 ft) apart.

RESULTS

Of 211 athletes evaluated, 27 had been treated for LBP during the previous year. Currently asymptomatic athletes with a recent history of LBP were slower (6.3s vs 5.8s) during performance of the timed 20-m shuttle run than athletes without LBP (P=.0002).

CONCLUSIONS

Athletes with resolved LBP were slower than a matched group of normal athletes without LBP in the timed 20-m shuttle run. Further research is needed to support these findings and to understand fully the influence of the kinetic chain and the effects of both gender and sport on the observed findings.

Sacroiliac joint pain referral zones

OBJECTIVE

To determine the patterns of pain referral from the sacroiliac joint.

STUDY DESIGN

Retrospective.

PARTICIPANTS/METHODS

Fifty consecutive patients who satisfied clinical criteria and demonstrated a positive diagnostic response to a fluoroscopically guided sacroiliac joint injection were included. Each patient's preinjection pain description was used to determine areas of pain referral, and 18 potential pain-referral zones were established.

OUTCOME MEASURES

Observed areas of pain referral.

RESULTS

Eighteen men (36.0%) and 32 women (64.0%) were included with a mean age of 42.5 years (range, 20 to 75 yrs) and a mean symptom duration of 18.2 months (range, 1 to 72 mo). Forty-seven patients (94.0%) described buttock pain, and 36 patients (72.0%) described lower lumbar pain. Groin pain was described in 7 patients (14.0%). Twenty-five patients (50.0%) described associated lower-extremity pain. Fourteen patients (28.0%) described leg pain distal to the knee, and 6 patients (14.0%) reported foot pain. Eighteen patterns of pain referral were observed. A statistically significant relationship was identified between pain location and age, with younger patients more likely to describe pain distal to the knee.

CONCLUSIONS

Pain referral from the sacroiliac joint does not appear to be limited to the lumbar region and buttock. The variable patterns of pain referral observed may arise for several reasons, including the joint's complex innervation, sclerotomal pain referral, irritation of adjacent structures, and varying locations of injury with the sacroiliac joint.

Clinical tests of the sacroiliac joint. A systematic methodological review. Part 1: Reliability

In the literature concerning the sacroiliac joint (SIJ) there are numerous specific tests used to detect joint mobility or pain provocation. In this article the authors have reviewed 11 studies which investigated the reliability of these tests. The methodological quality of the studies was tested by a list of criteria developed by the authors. This list consisted of three categories: (1) study population, (2) test procedures and (3) test results. To each criterion a weighting was attached. The methodological score for nine out of the 11 studies was found to be acceptable. The results of this review, however, could not demonstrate reliable outcomes and therefore no evidence on which to base acceptance of mobility tests of the SIJ into daily clinical practice. There are no indications that 'upgrading' of methodological quality would have improved the final conclusions. With respect to pain provocation tests, the findings did not show the same trend. Two studies demonstrated reliable results using the Gaenslen test and the Thigh thrust test. One study showed acceptable reliability for five other pain provocation tests; however, since other authors have described contradictory results, there is a necessity for further research in this area with an emphasis on multiple test scores and pain provocation tests of the SIJ.