Sacroiliac joint dysfunction
Encyclopedia
Sacroiliac Joint Dysfunction or SI Joint Dysfunction is a condition in which the joint
is locked, partially dislocated or "subluxated
" in a non-anatomically
correct position due to hypermobility
(too much movement) or hypomobility (too little movement) within the joint. Sacroiliac joint dysfunction is commonly characterized by low back and gluteal
pain and may be accompanied with referred groin, hip, and sciatic leg pain (see "sciatica
"). The condition can affect one sacroiliac joint
(left or right), or both joints. The degree of pain and disability due to the condition can vary widely, from an occasional discomfort that limits certain activities to severely debilitating and a constant source of pain. It is reported to affect between 15% and 38% of the general population, with women being 3 or 4 times more likely to be affected than men. In spite of these statistics, many patients with sacroiliac joint dysfunction go years without a correct diagnosis. The sacroiliac joints are often overlooked as a causative role in lower back pain.
joint that joins the sacrum to the pelvis. The sacrum
(tailbone) connects on the right and left sides of the ilia
(pelvic bones) to form the sacroiliac joints. The pelvic girdle is made up of two innominate bones
(the iliac bones) and the sacrum. The innominate bones join in the front of the pelvis to form the pubic symphysis
, and at back of the sacrum to form the sacroiliac (SI) joints. Each innominate bone (ilium) joins the femur
(thigh bone) to form the hip joint; thus the sacroiliac joint moves with walking and movement of the torso.
In this joint, hyaline cartilage
on the sacral side moves against fibrocartilage
on the iliac side. The sacroiliac joint contains numerous ridges and depressions that function in stability. Studies have documented that motion does occur at the joint; therefore, slightly subluxed and even locked positions can occur.
Muscles and ligaments surround and attach to the SI joint in the front and back, primarily on the ilial or sacral surfaces. These can all be a source of pain and inflammation if the SI joint is dysfunctional. The sacroiliac joint is highly dependent on its strong ligamentous structure for support and stability. The most commonly disrupted and/or torn ligaments are the iliolumbar ligament and the posterior sacroiliac ligament
. The ligamentous structures offer resistance to shear and loading. The deep anterior
, posterior, and interosseous
ligaments resist the load of the sacrum relative to the ilium. More superficial ligaments (e.g., the sacrotuberous ligament
) react to dynamic motions (such as straight-leg raising during physical motion). The long dorsal sacroiliac ligament can become stretched in periods of reduced lumbar lordosis
(e.g., during pregnancy
).
), urinary frequency, and "transient numbness, prickling, or tingling". Pain can range from dull aching to sharp and stabbing and increases with physical activity. Symptoms also worsen with prolonged or sustained positions (i.e., sitting, standing, lying). Bending forward, stair climbing, hill climbing, and rising from a seated position can also provoke pain. Pain is reported to increase during sexual intercourse and menstruation in women. Like with other chronic pain conditions, patients with severe and disabling sacroiliac joint dysfunction can suffer from insomnia
and depression.
(see “piriformis syndrome
”, a condition often related with sacroiliac joint dysfunction), biceps femoris
, gluteus maximus and minimus, erector spinae, latissimus dorsi
, thoracolumbar fascia
, and iliacus
. Any of these muscles can be involved or spasm
with a painful and dysfunctional sacroiliac joint. The SI joint is a pain-sensitive structure richly innervated by a combination of unmyelinated
free nerve endings and the posterior primary rami of spinal segments L2-S3. The wide possibility of innervation may explain why pain originating from the joint can manifest in so many various ways, with different and unique referral patterns (see “referred pain
”) for individual patients. Patients with sacroiliac joint dysfunction can also develop tightness and dysfunction in the hamstring
, quadriceps, iliotibial tract
(see “iliotibial band syndrome
”) and hip flexors
, including the psoas muscle
. Individuals with severe and long-standing sacroiliac joint dysfunction can develop muscle deconditioning
and atrophy throughout the body due to limitation of activities and exercise that bring about pain in the low back.
ed ligaments, while the joint itself is structurally normal and healthy. The sacroiliac joint itself often will not show degenerative
changes, such as arthritis
, until many years of the dysfunction being allowed to continue. Injury to the ligaments that hold the sacroiliac joints in proper support is thought to be caused by a torsion or high impact injury (such as an automobile accident) or a hard fall, resulting in the hypermobility. As many as 58% of patients diagnosed with sacroiliac joint pain had some inciting traumatic injury based on clinical examination findings. The joint that was once stabilized by strong ligaments, now overly stretched, sprained, or torn, will move beyond its normal range. This is thought to result in the ilium and sacral surfaces "locking" in an incongruent or asymmetrical fashion (one innominate bone is tilted anteriorly; the other innominate bone is tilted posteriorly) causing pain that can be debilitating.
Hormone imbalances, particularly those associated with pregnancy and the hormone relaxin
, can also cause a ligamentous laxity
resulting in the weakening of the sacroiliac structure.
During pregnancy, relaxin serves as nature's way of allowing the female pelvis to achieve distention of the birthing canal. Pelvic joint pain in post pregnancy women is thought to be derived from the inability of the stretched out ligaments to return to normal tautness. Women who have delivered large babies or who have had extended labors also are prone to developing chronic sacroiliac joint pain and instability.
In some people, the sacroiliac joints reverse the normal concave-convex 'locking' relationship, which can lead to rotational misalignment. The variation in joint configuration results in some sacroiliac joints being inherently weaker or more prone to misalignment. Certain biomechanical or muscle length imbalances may ultimately predispose a person to sacroiliac dysfunction and pain. Likely, this is a result of altered gait patterns and repetitive stress to the SI joint and related structures. These conditions exist in persons with leg-length inequality, scoliosis, a history of polio, poor-quality footwear, and hip osteoarthritis. There is also a notable incidence of lumbar spinal fusion patients that present with sacroiliac pain and hypermobility, potentially due to the adjacent lumbar joints being fixed and unable to move. Clinical studies have found up to 75% of post-lumbar fusion patients develop SI joint degeneration within five years of surgery.
, rheumatoid arthritis
, or an infection.
imaging to discern the disorder. Diagnostic testing, such as X-ray
, CT scan, or MRI, do not usually reveal abnormalities; therefore, they cannot reliably be used for diagnosis of sacroiliac joint dysfunction. If the joint has been in dysfunction for many years it may be possible to detect “reactive spurring” or preliminary arthritis due to prolonged abnormal motion within the joint on a computed tomography (CT) scan.
A clinician well-trained in manual medicine (i.e., a spine surgeon, orthopedic surgeon, sports medicine
doctor, physical therapist
, physiatrist
, osteopath or chiropractor
) can diagnose the disorder using a hands on approach by palpating
the painful areas as well as administering one or more of the following tests:
In all tests, pain in the typical area raises suspicion for a sacroiliac joint lesion. Upon neurologic
examination, motor strength, sensory examination, and reflex
es in the lower extremities should all prove normal. Strength examination can prove challenging to a patient with SI joint dysfunction and they may exhibit weaknesses due to pain inhibition or muscle imbalance that has developed during episodes of pain and relative inactivity (deconditioning or atrophy). True neurogenic weakness, numbness, or loss of reflex should alert the clinician to consider nerve root injury or pathology other than a mechanical dysfunction.
The current gold standard for diagnosis of sacroiliac joint dysfunction is a local anesthetic block performed under fluoroscopy
or CT-guidance. The test is administered by injecting an anesthetic, such as Lidocaine
hydrochloride, into the painful area of the sacroiliac joint. The diagnosis is confirmed when the patient reports relief from pain. The patient/doctor may decide to administer a corticosteroid
at the same time the anesthetic is injected into the painful sacroiliac joint for prolonged pain relief since the numbing agent provides only temporary relief.
(see “piriformis syndrome
”), and the sciatic nerve
had not yet been discovered.
In 1934, the work of Mixter and Barr shifted all emphasis in research and treatment from the sacroiliac to the herniated intervertebral disc
, namely lumbar discs. Medical focus on herniated discs was further forwarded by the invention of the MRI in 1977. Recent medical research has revealed that patients with degenerating or herniated discs shown on MRI can frequently complain of little to no pain symptoms, while patients with an unremarkable MRI and no disc pathology can have severe back or sciatic pain. Over-diagnosis and attention on herniated discs has led to the SI joint becoming an underappreciated pain generator in an estimated 15% to 25% of patients with axial low back pain.
The ligaments in the sacroiliac are among the strongest in the body and are not suspected by many clinicians to ever be susceptible to spraining or tearing. Skepticism of the existence of sacroiliac joint dysfunction within the medical community is furthered by the debate on how little or much the sacroiliac joint moves. A discrepancy as large as 2-17 degrees has been reported in clinical findings. The normal range of motion within the joint is small often considered being only a few degrees or millimeters, hence it is seldom considered as a source of pain in spite of being a load-bearing synovial joint
.
medicine. If the pain does not resolve in this time frame, then the patient may benefit from a steroid and anesthetic mixture fluoroscopically injected into the joint (this also serves in confirming diagnosis), as well as manipulative or manual therapy that does not include aggressive spinal adjustments. For the most severe and chronic forms of sacroiliac dysfunction, treatment should proceed with the support of a sacroiliac belt, a series of prolotherapy
injections to aid in regeneration and healing of the surrounding injured ligaments, injection therapy, and finally, surgery. The anti-inflammatory effect of injection therapy is not permanent, and the injections do not offer an opportunity to stabilize an incompetent joint. Surgery is often considered a last resort, but for some patients, it is the only method of effectively stabilizing the loose joint. A fixation of the joint (screws or similar hardware only, without the use of bone grafting
) is more common than a spinal fusion
, as it is much less invasive, surgically straightforward, and results in a quicker recovery time for the patient. Some experts in the field believe that it is important to make sure the sacroiliac joint is in an anatomically correct position prior to fixation or fusion, but published research contradicts this belief.
Joint
A joint is the location at which two or more bones make contact. They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally.-Classification:...
is locked, partially dislocated or "subluxated
Subluxation
A subluxation may have different meanings, depending on the medical specialty involved. It implies the presence of an incomplete or partial dislocation of a joint or organ. The World Health Organization defines both the medical subluxation and the chiropractic subluxation...
" in a non-anatomically
Anatomical terms of location
Standard anatomical terms of location are designations employed in science that deal with the anatomy of animals to avoid ambiguities that might otherwise arise. They are not language-specific, and thus require no translation...
correct position due to hypermobility
Hypermobility
Hypermobility describes joints that stretch farther than is normal. For example, some hypermobile people can bend their thumbs backwards to their wrists, bend their knee joints backwards, put their leg behind the head or other contortionist performances...
(too much movement) or hypomobility (too little movement) within the joint. Sacroiliac joint dysfunction is commonly characterized by low back and gluteal
Gluteal muscles
The gluteal muscles are the three muscles that make up the buttocks: the gluteus maximus muscle, gluteus medius muscle and gluteus minimus muscle.-The gluteal muscles:...
pain and may be accompanied with referred groin, hip, and sciatic leg pain (see "sciatica
Sciatica
Sciatica is a set of symptoms including pain that may be caused by general compression or irritation of one of five spinal nerve roots that give rise to each sciatic nerve, or by compression or irritation of the left or right or both sciatic nerves. The pain is felt in the lower back, buttock, or...
"). The condition can affect one sacroiliac joint
Sacroiliac joint
The sacroiliac joint or SI joint is the joint in the bony pelvis between the sacrum and the ilium of the pelvis, which are joined together by strong ligaments. In humans, the sacrum supports the spine and is supported in turn by an ilium on each side...
(left or right), or both joints. The degree of pain and disability due to the condition can vary widely, from an occasional discomfort that limits certain activities to severely debilitating and a constant source of pain. It is reported to affect between 15% and 38% of the general population, with women being 3 or 4 times more likely to be affected than men. In spite of these statistics, many patients with sacroiliac joint dysfunction go years without a correct diagnosis. The sacroiliac joints are often overlooked as a causative role in lower back pain.
Anatomy and Physiology of the Sacroiliac Joints
The sacroiliac joint is a true diarthrodialDiarthrodial
Diarthrodial joints are freely moveable joints held together by a joint capsule, such as the knee and shoulder, as opposed to slightly moveable or immoveable joints, such as the spinal and sutural joints, respectively. They are the type of joint most commonly involved in rheumatological disease...
joint that joins the sacrum to the pelvis. The sacrum
Sacrum
In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...
(tailbone) connects on the right and left sides of the ilia
Ilium (bone)
The ilium is the uppermost and largest bone of the pelvis, and appears in most vertebrates including mammals and birds, but not bony fish. All reptiles have an ilium except snakes, although some snake species have a tiny bone which is considered to be an ilium.The name comes from the Latin ,...
(pelvic bones) to form the sacroiliac joints. The pelvic girdle is made up of two innominate bones
Hip bone
The hip bone, innominate bone or coxal bone is a large, flattened, irregularly shaped bone, constricted in the center and expanded above and below...
(the iliac bones) and the sacrum. The innominate bones join in the front of the pelvis to form the pubic symphysis
Pubic symphysis
The pubic symphysis or symphysis pubis is the midline cartilaginous joint uniting the superior rami of the left and right pubic bones. It is located anterior to the urinary bladder and superior to the external genitalia; for females it is above the vulva and for males it is above the penis...
, and at back of the sacrum to form the sacroiliac (SI) joints. Each innominate bone (ilium) joins the femur
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
(thigh bone) to form the hip joint; thus the sacroiliac joint moves with walking and movement of the torso.
In this joint, hyaline cartilage
Hyaline cartilage
Hyaline cartilage consists of a slimy mass, pearly bluish in colour with firm consistency and considerable collagen. It contains no nerves or blood vessels, and its structure is relatively simple....
on the sacral side moves against fibrocartilage
Fibrocartilage
White fibrocartilage consists of a mixture of white fibrous tissue and cartilaginous tissue in various proportions. It owes its flexibility and toughness to the former of these constituents, and its elasticity to the latter...
on the iliac side. The sacroiliac joint contains numerous ridges and depressions that function in stability. Studies have documented that motion does occur at the joint; therefore, slightly subluxed and even locked positions can occur.
Muscles and ligaments surround and attach to the SI joint in the front and back, primarily on the ilial or sacral surfaces. These can all be a source of pain and inflammation if the SI joint is dysfunctional. The sacroiliac joint is highly dependent on its strong ligamentous structure for support and stability. The most commonly disrupted and/or torn ligaments are the iliolumbar ligament and the posterior sacroiliac ligament
Posterior sacroiliac ligament
The posterior sacroiliac ligament is situated in a deep depression between the sacrum and ilium behind; it is strong and forms the chief bond of union between the bones.It consists of numerous fasciculi, which pass between the bones in various directions....
. The ligamentous structures offer resistance to shear and loading. The deep anterior
Anterior sacroiliac ligament
The anterior sacroiliac ligament consists of numerous thin bands, which connect the anterior surface of the lateral part of the sacrum to the margin of the auricular surface of the ilium and to the preauricular sulcus....
, posterior, and interosseous
Interosseous sacroiliac ligament
The Interosseous Sacroiliac Ligament lies deep to the posterior ligament, and consists of a series of short, strong fibers connecting the tuberosities of the sacrum and ilium. The major function of the interosseous sacroiliac ligament is to keep the sacrum and ilium together and therefore prevent...
ligaments resist the load of the sacrum relative to the ilium. More superficial ligaments (e.g., the sacrotuberous ligament
Sacrotuberous ligament
The sacrotuberous ligament is situated at the lower and back part of the pelvis. It is flat, and triangular in form; narrower in the middle than at the ends....
) react to dynamic motions (such as straight-leg raising during physical motion). The long dorsal sacroiliac ligament can become stretched in periods of reduced lumbar lordosis
Lordosis
Lordosis is a medical term used to describe an inward curvature of a portion of the lumbar and cervical vertebral column. Two segments of the vertebral column, namely cervical and lumbar, are normally lordotic, that is, they are set in a curve that has its convexity anteriorly and concavity...
(e.g., during pregnancy
Pregnancy
Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...
).
Common Symptoms
Common symptoms include lower back pain, buttock pain, sciatic leg pain, groin pain, hip pain (for explanation of leg, groin, and hip pain, see referred painReferred pain
Referred pain is pain perceived at a location other than the site of the painful stimulus. An example is the case of ischemia brought on by a myocardial infarction , where pain is often felt in the neck, shoulders, and back rather than in the chest, the site of the injury...
), urinary frequency, and "transient numbness, prickling, or tingling". Pain can range from dull aching to sharp and stabbing and increases with physical activity. Symptoms also worsen with prolonged or sustained positions (i.e., sitting, standing, lying). Bending forward, stair climbing, hill climbing, and rising from a seated position can also provoke pain. Pain is reported to increase during sexual intercourse and menstruation in women. Like with other chronic pain conditions, patients with severe and disabling sacroiliac joint dysfunction can suffer from insomnia
Insomnia
Insomnia is most often defined by an individual's report of sleeping difficulties. While the term is sometimes used in sleep literature to describe a disorder demonstrated by polysomnographic evidence of disturbed sleep, insomnia is often defined as a positive response to either of two questions:...
and depression.
Affected Muscle Groups
Many large and small muscles have relationships with the ligaments of the sacroiliac joint including the piriformisPiriformis muscle
The piriformis is a muscle in the gluteal region of the lower limb. It was first named by Spigelius, a professor from the University of Padua in the 16th century.- Origin and insertion :...
(see “piriformis syndrome
Piriformis syndrome
Piriformis syndrome is a neuromuscular disorder that occurs when the sciatic nerve is compressed or otherwise irritated by the piriformis muscle causing pain, tingling and numbness in the buttocks and along the path of the sciatic nerve descending down the lower thigh and into the leg...
”, a condition often related with sacroiliac joint dysfunction), biceps femoris
Biceps femoris muscle
The biceps femoris is a muscle of the posterior thigh. As its name implies, it has two parts, one of which forms part of the hamstrings muscle group.-Origin and insertion:It has two heads of origin;...
, gluteus maximus and minimus, erector spinae, latissimus dorsi
Latissimus dorsi muscle
The latissimus dorsi , meaning 'broadest muscle of the back' , is the larger, flat, dorso-lateral muscle on the trunk, posterior to the arm, and partly covered by the trapezius on its median dorsal region.The latissimus dorsi is responsible for extension,...
, thoracolumbar fascia
Thoracolumbar fascia
The thoracolumbar fascia is a deep investing membrane which covers the deep muscles of the back of the trunk. It is made up of three layers, anterior, middle, and posterior. The anterior layer is the thinnest and the posterior layer is the thickest. Two spaces are formed between these three...
, and iliacus
Iliacus muscle
The iliacus is a flat, triangular muscle which fills the iliac fossa.- Course :The iliacus arises from the iliac fossa on the interior side of the hip bone, and also from the region of the anterior inferior iliac spine...
. Any of these muscles can be involved or spasm
Spasm
In medicine a spasm is a sudden, involuntary contraction of a muscle, a group of muscles, or a hollow organ, or a similarly sudden contraction of an orifice. It is sometimes accompanied by a sudden burst of pain, but is usually harmless and ceases after a few minutes...
with a painful and dysfunctional sacroiliac joint. The SI joint is a pain-sensitive structure richly innervated by a combination of unmyelinated
Myelin
Myelin is a dielectric material that forms a layer, the myelin sheath, usually around only the axon of a neuron. It is essential for the proper functioning of the nervous system. Myelin is an outgrowth of a type of glial cell. The production of the myelin sheath is called myelination...
free nerve endings and the posterior primary rami of spinal segments L2-S3. The wide possibility of innervation may explain why pain originating from the joint can manifest in so many various ways, with different and unique referral patterns (see “referred pain
Referred pain
Referred pain is pain perceived at a location other than the site of the painful stimulus. An example is the case of ischemia brought on by a myocardial infarction , where pain is often felt in the neck, shoulders, and back rather than in the chest, the site of the injury...
”) for individual patients. Patients with sacroiliac joint dysfunction can also develop tightness and dysfunction in the hamstring
Hamstring
In human anatomy, the hamstring refers to any one of the three posterior thigh muscles, or to the tendons that make up the borders of the space behind the knee. In modern anatomical contexts, however, they usually refer to the posterior thigh muscles, or the tendons of the semitendinosus, the...
, quadriceps, iliotibial tract
Iliotibial tract
The iliotibial tract or iliotibial band is a longitudinal fibrous reinforcement of the fascia lata. It is attached to the anterolateral iliac tubercle portion of the external lip of the iliac crest and to the lateral condyle of the tibia...
(see “iliotibial band syndrome
Iliotibial band syndrome
Iliotibial band syndrome is a common injury to the thigh, generally associated with running, cycling, hiking or weight-lifting .- Definition :...
”) and hip flexors
Hip flexors
In human anatomy, the hip flexors are a group of skeletal muscles that act to flex the femur onto the lumbo-pelvic complex, i.e., pull the knee upward....
, including the psoas muscle
Psoas major muscle
-External links: - "Posterior Abdominal Wall: Muscles of the Posterior Abdominal Wall"* *...
. Individuals with severe and long-standing sacroiliac joint dysfunction can develop muscle deconditioning
Deconditioning
Deconditioning is adaptation of an organism to less demanding environment, or, alternatively, the decrease of physiological adaptation to normal conditions...
and atrophy throughout the body due to limitation of activities and exercise that bring about pain in the low back.
Hypermobility
SI joint dysfunction is sometimes referred to as "sacroiliac joint instability" or "sacroiliac joint insufficiency" due to the lack of support the once strong and taut ligaments can no longer sustain. When the joint is hypermobile or loose, it is classified as an extra-articular dysfunction because abnormal joint movement and alignment is a consequence of weakened, injured, or sprainSprain
A sprain is an injury in a joint, caused by the ligament being stretched beyond its capacity. A muscular tear caused in the same manner is referred to as a strain. In cases where either ligament or muscle tissue is torn, immobilization and surgical repair may be necessary...
ed ligaments, while the joint itself is structurally normal and healthy. The sacroiliac joint itself often will not show degenerative
Degenerative disease
A degenerative disease, also called neurodegenerative disease, is a disease in which the function or structure of the affected tissues or organs will progressively deteriorate over time, whether due to normal bodily wear or lifestyle choices such as exercise or eating habits...
changes, such as arthritis
Arthritis
Arthritis is a form of joint disorder that involves inflammation of one or more joints....
, until many years of the dysfunction being allowed to continue. Injury to the ligaments that hold the sacroiliac joints in proper support is thought to be caused by a torsion or high impact injury (such as an automobile accident) or a hard fall, resulting in the hypermobility. As many as 58% of patients diagnosed with sacroiliac joint pain had some inciting traumatic injury based on clinical examination findings. The joint that was once stabilized by strong ligaments, now overly stretched, sprained, or torn, will move beyond its normal range. This is thought to result in the ilium and sacral surfaces "locking" in an incongruent or asymmetrical fashion (one innominate bone is tilted anteriorly; the other innominate bone is tilted posteriorly) causing pain that can be debilitating.
Hormone imbalances, particularly those associated with pregnancy and the hormone relaxin
Relaxin
Relaxin is a protein hormone first described in 1926 by Frederick Hisaw.The relaxin-like peptide family belongs in the insulin superfamily and consists of 7 peptides of high structural but low sequence similarity; relaxin-1 , 2 and 3 , and the insulin-like peptides, INSL3, INSL4, INSL5 and INSL6...
, can also cause a ligamentous laxity
Ligamentous Laxity
Ligamentous laxity is a term given to describe "loose ligaments."In a 'normal' body, ligaments are naturally tight in such a way that the joints are restricted to 'normal' ranges of motion. This creates normal joint stability...
resulting in the weakening of the sacroiliac structure.
During pregnancy, relaxin serves as nature's way of allowing the female pelvis to achieve distention of the birthing canal. Pelvic joint pain in post pregnancy women is thought to be derived from the inability of the stretched out ligaments to return to normal tautness. Women who have delivered large babies or who have had extended labors also are prone to developing chronic sacroiliac joint pain and instability.
In some people, the sacroiliac joints reverse the normal concave-convex 'locking' relationship, which can lead to rotational misalignment. The variation in joint configuration results in some sacroiliac joints being inherently weaker or more prone to misalignment. Certain biomechanical or muscle length imbalances may ultimately predispose a person to sacroiliac dysfunction and pain. Likely, this is a result of altered gait patterns and repetitive stress to the SI joint and related structures. These conditions exist in persons with leg-length inequality, scoliosis, a history of polio, poor-quality footwear, and hip osteoarthritis. There is also a notable incidence of lumbar spinal fusion patients that present with sacroiliac pain and hypermobility, potentially due to the adjacent lumbar joints being fixed and unable to move. Clinical studies have found up to 75% of post-lumbar fusion patients develop SI joint degeneration within five years of surgery.
Hypomobility
Hypomobility (too little movement) of the sacroiliac joint is an intra-articular disorder in which the joint locks due to wearing down with age or degenerative joint disease. Hypomobility of this kind can also occur with an inflammatory disease such as ankylosing spondylitisAnkylosing spondylitis
Ankylosing spondylitis , previously known as Bekhterev's disease, Bekhterev syndrome, and Marie-Strümpell disease is a chronic inflammatory disease of the axial skeleton with variable involvement of peripheral joints and nonarticular structures...
, rheumatoid arthritis
Rheumatoid arthritis
Rheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
, or an infection.
Diagnosis and Testing
Perhaps the biggest reason for misdiagnosis or lack of diagnosis of sacroiliac joint dysfunction is based on the inability of common radiologicalRadiology
Radiology is a medical specialty that employs the use of imaging to both diagnose and treat disease visualized within the human body. Radiologists use an array of imaging technologies to diagnose or treat diseases...
imaging to discern the disorder. Diagnostic testing, such as X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
, CT scan, or MRI, do not usually reveal abnormalities; therefore, they cannot reliably be used for diagnosis of sacroiliac joint dysfunction. If the joint has been in dysfunction for many years it may be possible to detect “reactive spurring” or preliminary arthritis due to prolonged abnormal motion within the joint on a computed tomography (CT) scan.
A clinician well-trained in manual medicine (i.e., a spine surgeon, orthopedic surgeon, sports medicine
Sports medicine
Sports medicine is a branch of medicine that deals with physical fitness, treatment and prevention of injuries related to sports and exercise...
doctor, physical therapist
Physical therapy
Physical therapy , often abbreviated PT, is a health care profession. Physical therapy is concerned with identifying and maximizing quality of life and movement potential within the spheres of promotion, prevention, diagnosis, treatment/intervention,and rehabilitation...
, physiatrist
Physical medicine and rehabilitation
Physical medicine and rehabilitation , physiatry or rehabilitation medicine, is a branch of medicine that aims to enhance and restore functional ability and quality of life to those with physical impairments or disabilities. A physician having completed training in this field is referred to as a...
, osteopath or chiropractor
Chiropractor
A Chiropractor, according to the Association of Chiropractic Colleges , "focuses on the relationship between the body's main structures – the skeleton, the muscles and the nerves – and the patient's health. Chiropractors believe that health can be improved and preserved by making adjustments to...
) can diagnose the disorder using a hands on approach by palpating
Palpation
Palpation is used as part of a physical examination in which an object is felt to determine its size, shape, firmness, or location...
the painful areas as well as administering one or more of the following tests:
- Fortin Finger Test - Palpation may be the most reliable indication of SI joint pain. The clinician will also ask the patient to point directly to the painful area. If the patient points to one particular spot in the dimple of the posterior superior iliac spinePosterior superior iliac spineThe posterior border of the ala, shorter than the anterior, also presents two projections separated by a notch, the posterior superior iliac spine and the posterior inferior iliac spine. The posterior superior iliac spine serves for the attachment of the oblique portion of the posterior sacroiliac...
(PSIS), the patient can usually precisely reproduce the pain over that one spot. More diffuse back or buttock and leg pain could prompt the clinician to look for a differential diagnosisDifferential diagnosisA differential diagnosis is a systematic diagnostic method used to identify the presence of an entity where multiple alternatives are possible , and may also refer to any of the included candidate alternatives A differential diagnosis (sometimes abbreviated DDx, ddx, DD, D/Dx, or ΔΔ) is a...
. - Gillet Test - Standing flexionFlexionIn anatomy, flexion is a position that is made possible by the joint angle decreasing. The skeletal and muscular systems work together to move the joint into a "flexed" position. For example the elbow is flexed when the hand is brought closer to the shoulder...
testing involves the comparison of the symmetrySymmetrySymmetry generally conveys two primary meanings. The first is an imprecise sense of harmonious or aesthetically pleasing proportionality and balance; such that it reflects beauty or perfection...
of motion between the PSIS on the tested side and the S2 spinous processSpinous processThe spinous process of a vertebra is directed backward and downward from the junction of the laminae , and serves for the attachment of muscles and ligaments. In animals without an erect stance, the process points upward and may slant forward or backward...
. Inspection often reveals a pelvis with asymmetricAsymmetryAsymmetry is the absence of, or a violation of, symmetry.-In organisms:Due to how cells divide in organisms, asymmetry in organisms is fairly usual in at least one dimension, with biological symmetry also being common in at least one dimension....
height. This finding can be an indication of unilateral restriction in motion of one or both SI joints. While performing this test the clinician should also measure the leg lengths to look for inequality (in patient sitting with legs extended as well as supineSupine positionThe supine position is a position of the body: lying down with the face up, as opposed to the prone position, which is face down, sometimes with the hands behind the head or neck. When used in surgical procedures, it allows access to the peritoneal, thoracic and pericardial regions; as well as the...
) and inspect the lumbarLumbarIn tetrapod anatomy, lumbar is an adjective that means of or pertaining to the abdominal segment of the torso, between the diaphragm and the sacrum ...
spine to look for scoliosisScoliosisScoliosis is a medical condition in which a person's spine is curved from side to side. Although it is a complex three-dimensional deformity, on an X-ray, viewed from the rear, the spine of an individual with scoliosis may look more like an "S" or a "C" than a straight line...
. - Gaenslen test - This pain provocation test applies torsion to the joint. With one hip flexed onto the abdomen, the other leg is allowed to dangle off the edge of the table. Pressure should then be directed downward on the leg in order to achieve hip extension and stress the sacroiliac joint.
- Iliac Gapping Test - Distraction can be performed to the anterior sacroiliac ligaments by applying pressure to the anterior superior iliac spine.
- Iliac Compression Test - Apply compression to the joint with the patient lying on his or her side. Pressure is applied downward to the uppermost iliac crestIliac crest-External links: - "Superficial muscles of the gluteal region and posterior thigh." - "Anterior Abdominal Wall: Osteology and Surface Anatomy " - "The Back, Posterior View" * *...
. - FABER or Patrick test - To identify if pain may come from the sacroiliac joint during flexion, abductionAbduction (kinesiology)Abduction, in functional anatomy, is a movement which draws a limb away from the median plane of the body. It is thus opposed to adduction.-Upper limb:* of arm at shoulder ** Supraspinatus** Deltoid* of hand at wrist...
, and external rotation, the clinician externally rotates the hip while the patient lies supine. Then, downward pressure is applied to the medial knee stressing both the hip and sacroiliac joint. - Thigh Thrust - This test applies anteroposterior shear stress on the SI joint. The patient lies supine with one hip flexed to 90 degrees. The examiner stands on the same side as the flexed leg. The examiner provides either a quick thrust or steadily increasing pressure through the line of the femur. The pelvis is stabilized at the sacrum or at the opposite ASIS with the hand of the examiner
In all tests, pain in the typical area raises suspicion for a sacroiliac joint lesion. Upon neurologic
Neurology
Neurology is a medical specialty dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue,...
examination, motor strength, sensory examination, and reflex
Reflex
A reflex action, also known as a reflex, is an involuntary and nearly instantaneous movement in response to a stimulus. A true reflex is a behavior which is mediated via the reflex arc; this does not apply to casual uses of the term 'reflex'.-See also:...
es in the lower extremities should all prove normal. Strength examination can prove challenging to a patient with SI joint dysfunction and they may exhibit weaknesses due to pain inhibition or muscle imbalance that has developed during episodes of pain and relative inactivity (deconditioning or atrophy). True neurogenic weakness, numbness, or loss of reflex should alert the clinician to consider nerve root injury or pathology other than a mechanical dysfunction.
The current gold standard for diagnosis of sacroiliac joint dysfunction is a local anesthetic block performed under fluoroscopy
Fluoroscopy
Fluoroscopy is an imaging technique commonly used by physicians to obtain real-time moving images of the internal structures of a patient through the use of a fluoroscope. In its simplest form, a fluoroscope consists of an X-ray source and fluorescent screen between which a patient is placed...
or CT-guidance. The test is administered by injecting an anesthetic, such as Lidocaine
Lidocaine
Lidocaine , Xylocaine, or lignocaine is a common local anesthetic and antiarrhythmic drug. Lidocaine is used topically to relieve itching, burning and pain from skin inflammations, injected as a dental anesthetic or as a local anesthetic for minor surgery.- History :Lidocaine, the first amino...
hydrochloride, into the painful area of the sacroiliac joint. The diagnosis is confirmed when the patient reports relief from pain. The patient/doctor may decide to administer a corticosteroid
Corticosteroid
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte...
at the same time the anesthetic is injected into the painful sacroiliac joint for prolonged pain relief since the numbing agent provides only temporary relief.
Misdiagnosis and Controversy within Medical Community
In the early 1900s, dysfunction of the sacroiliac joint was a common diagnosis associated with low back and sciatic nerve pain. However, research by Danforth and Wilson in 1925 concluded that the sacroiliac joint could not cause sciatic nerve pain because the joint does not have a canal in which the nerves can be entrapped against the joint. The biomechanical relationship between the sacroiliac joint, the piriformis musclePiriformis muscle
The piriformis is a muscle in the gluteal region of the lower limb. It was first named by Spigelius, a professor from the University of Padua in the 16th century.- Origin and insertion :...
(see “piriformis syndrome
Piriformis syndrome
Piriformis syndrome is a neuromuscular disorder that occurs when the sciatic nerve is compressed or otherwise irritated by the piriformis muscle causing pain, tingling and numbness in the buttocks and along the path of the sciatic nerve descending down the lower thigh and into the leg...
”), and the sciatic nerve
Sciatic nerve
The sciatic nerve is a large nerve fiber in humans and other animals. It begins in the lower back and runs through the buttock and down the lower limb...
had not yet been discovered.
In 1934, the work of Mixter and Barr shifted all emphasis in research and treatment from the sacroiliac to the herniated intervertebral disc
Spinal disc herniation
A spinal disc herniation , informally and misleadingly called a "slipped disc", is a medical condition affecting the spine due to trauma, lifting injuries, or idiopathic, in which a tear in the outer, fibrous ring of an intervertebral disc allows the soft, central portion A spinal disc herniation...
, namely lumbar discs. Medical focus on herniated discs was further forwarded by the invention of the MRI in 1977. Recent medical research has revealed that patients with degenerating or herniated discs shown on MRI can frequently complain of little to no pain symptoms, while patients with an unremarkable MRI and no disc pathology can have severe back or sciatic pain. Over-diagnosis and attention on herniated discs has led to the SI joint becoming an underappreciated pain generator in an estimated 15% to 25% of patients with axial low back pain.
The ligaments in the sacroiliac are among the strongest in the body and are not suspected by many clinicians to ever be susceptible to spraining or tearing. Skepticism of the existence of sacroiliac joint dysfunction within the medical community is furthered by the debate on how little or much the sacroiliac joint moves. A discrepancy as large as 2-17 degrees has been reported in clinical findings. The normal range of motion within the joint is small often considered being only a few degrees or millimeters, hence it is seldom considered as a source of pain in spite of being a load-bearing synovial joint
Synovial joint
A Synovial joint, also known as a diarthrosis, is the most common and most movable type of joint in the body of a mammal. As with most other joints, synovial joints achieve movement at the point of contact of the articulating bones....
.
Current Treatments
Treatment is often dependent on the duration and severity of the pain and dysfunction. In the acute phase (first 1–2 weeks) for a mild sprain of the sacroiliac, it is typical for the patient to be prescribed rest, ice/heat, physical therapy, and anti-inflammatoryAnti-inflammatory
Anti-inflammatory refers to the property of a substance or treatment that reduces inflammation. Anti-inflammatory drugs make up about half of analgesics, remedying pain by reducing inflammation as opposed to opioids, which affect the central nervous system....
medicine. If the pain does not resolve in this time frame, then the patient may benefit from a steroid and anesthetic mixture fluoroscopically injected into the joint (this also serves in confirming diagnosis), as well as manipulative or manual therapy that does not include aggressive spinal adjustments. For the most severe and chronic forms of sacroiliac dysfunction, treatment should proceed with the support of a sacroiliac belt, a series of prolotherapy
Prolotherapy
Prolotherapy is also known as "proliferation therapy" or "regenerative injection therapy." involves injecting an otherwise non-pharmacological and non-active irritant solution into the body, generally in the region of tendons or ligaments for the purpose of strengthening weakened connective tissue...
injections to aid in regeneration and healing of the surrounding injured ligaments, injection therapy, and finally, surgery. The anti-inflammatory effect of injection therapy is not permanent, and the injections do not offer an opportunity to stabilize an incompetent joint. Surgery is often considered a last resort, but for some patients, it is the only method of effectively stabilizing the loose joint. A fixation of the joint (screws or similar hardware only, without the use of bone grafting
Bone grafting
Bone grafting is a surgical procedure that replaces missing bone in order to repair bone fractures that are extremely complex, pose a significant health risk to the patient, or fail to heal properly....
) is more common than a spinal fusion
Spinal fusion
Spinal fusion, also known as spondylodesis or spondylosyndesis, is a surgical technique used to join two or more vertebrae. Supplementary bone tissue, either from the patient or a donor , is used in conjunction with the body's natural bone growth processes to fuse the vertebrae.Fusing of the...
, as it is much less invasive, surgically straightforward, and results in a quicker recovery time for the patient. Some experts in the field believe that it is important to make sure the sacroiliac joint is in an anatomically correct position prior to fixation or fusion, but published research contradicts this belief.