With this issue of the newsletter, I would like to bring our attention to sacroiliac joint problems and the interrelationship between such as Fascia, Osseous structures, Ligaments, Muscles, Tendons, Neuro-Vascular structures, and Visceral structures.
There are different degrees of sacroiliac joint pathologies-from SIJ dysfunction to SIJ dislocation. What units them is the common element of instability of the supportive structures and a resulting lack of tensegrity. I will focus on the mechanical aspect of SIJ pathology. We will discuss other SIJ problems such as Infectious, Rheumatologic and Malignancy in the future newsletters.
Realizing the difference between dysfunction and dislocation I see similarities between them as well. Different factors and combinations of factors cause Sacroiliac Joint Dysfunction: Connective tissue insufficiency, Ligament laxity, and Muscular imbalance. All of these factors lead to abnormal Sacroiliac movement (hyper or hypo-mobility), joint locking and muscular imbalance.
There are many of variations of SIJ mechanical problems: Up-slip and down-slip are good examples. They develop as a result of acute or chronic injury. They are extreme manifestations of the Sacroiliac Joint instability. Very often underlying mechanism of these injuries are connective tissue insufficiency and ligamental laxity involving multiple ligamentous and musculotendinous structures.
Fryette originally described up-slip in 1914. This lesion (up-slip) is essentially a vertical shear between the sacrum and ilium and most commonly occurs on the left side. This injury shortens the distance between the sacroccygeal attachments of the Sacrotuberous ligament to the ischial tuberosity attachment. Control of Nutation (forward flexion of the base of the sacrum) becomes insufficient. Secondary stabilizers, such as the Piriformis, Gemellus Superior & Inferior, Quadratus femoris , and Obturator internus muscles are activated to mainatain stability. Significant effort is required on the part of the muscles involved to keep the SI joint stable. Due to this extreme exertion and unnatural forces neuro-muscular pathology eventually evolves such as Piriformis syndrome, Posterior hip pain, buttocks pain, sciatica, peripheral nerve entrapment syndromes and so on.
What happens to the posterior Long and Short Sacroiliac Ligaments? Their orientation and tension will change in response to the structural and functional tensions present, this is turn will affect their control over Counter-nutation (backward movement of the base of the sacrum). Losing control over nutation and counter-nutation will bring into action Gluteal muscles, Thoracodorsal Fascia, Quadratus Lumborum, the Hamstrings in the immediate area and have far reaching consequences through fascial planes and connections.
Superior displacement of the ilium (up-slip) will shorten the Ligaments running from the transverse processes of L4 and L5 to anterior ilium – the Ilio-Lumbar ligaments. Instability of these ligaments will increase shearing forces on L4-L5-S1 discs and lead to annulus tears, disc protrusion and eventually disc herniation. These forces will also activate contraction of the Quadratus Lumborum, Multifidus muscles, Psoas, Latissimus Dorsi muscles.
Inferior displacement of the ilium (down-slip)- is a rare condition. To differentiate between the up-slip and the down-slip the physician utilizes thorough clinical examination and Standing x-rays. Sometimes the Iliac crest on the side of the down-slip can be perceived as superior due to activation of the Ipsilateral Quadratus lumborum, which pulls pelvis up and tilts the pelvis to the opposite side.
The pubic symphysis has no strong intrinsic stabilizing structures. Without the stabilizing actions of these muscles: transverse abd. m, oblique abd. m., rectus abdominis m. and adductor longus m., the pubic symphysis would permit 5-10mm of vertical shear.
Any discussion of Sacrum and pelvis would not be complete without mention of the role of the Psoas muscle. This muscle is always involved in lumbo-pelvic instability. Having arisen from the sides of the lumbar vertebrae and anterior aspects of the transverse processes, it connects to the respiratory and pelvic diaphragms. It plays an important role in general body support, maintaining body structure and the body’s functional relationships through it’s support of the autonomic lumbar plexus. It exerts it’s major impact through the viscera innervated by this plexus, it can well exert a vital influence on visceral function and bodily well-being.
Therefore, treatment of Sacroiliac Joint Mechanical Pathology should include many of the following treatment options: Osteopathic Manipulative Therapy-to restore normal structural relationships; Regenerative therapy utilizing Prolotherapy, Platelet-Rich Plasma, Stem Cell therapy-to restore structural integrity; Neural therapy, Neuro-fascial injection therapy-to restore neurologic and autonomic function; Physical therapy-to restore proper biomechanics and neuromuscular re-education; Nutritional and Hormonal treatment-to provide critical elements for healing and repair.
The following structures should be considered for treatments: Sacroiliac Joint(s), Sacroiliac Ligaments, Sacrotuberous Ligaments, Ilio-Lumbar ligaments, Thoracodorsal Fascia, Thoraco-Lumbar junction, Facets joints, Inter- and Supra-spinous ligaments, Multifidus, Quadratus Lumborum, Piriformis, Psoas muscles and in some cases distal attachments of the hamstrings.
Most cases will require diagnostic imaging studies, such as X-Ray , Ultrasound or MRI.
All of these modalities require a intensive study, reading, and education. Skill does not come after one or two conferences or workshops. The learning of Orthopaedic Medicine is a lifetime affair.
Be patient and persistent. Success will come.
Jon Trister MD