Bilateral sacroiliac degenerative joint disease is a progressive wearing-down of the cartilage in both sacroiliac joints, the pair of joints that sit at the base of your spine where the sacrum meets the left and right hip bones. The cartilage on the iliac (hip-bone) side tends to deteriorate faster than the sacral side, and the changes closely resemble osteoarthritis seen elsewhere in the body. Because most people have two functioning sacroiliac joints that share the same mechanical loads, degeneration often shows up on both sides, though not always at the same pace or severity.
What the Sacroiliac Joint Actually Does
Your sacroiliac joints (often shortened to “SIJ”) sit deep in the pelvis, one on each side. Their primary job is transferring the weight of your upper body down through your pelvis and into your legs. They handle large compressive forces and bending loads every time you walk, run, stand, or lift something. The joint itself is not especially stable on its own against shearing forces; it relies on the tight wedge shape of the sacrum between the two hip bones and a dense network of surrounding ligaments for reinforcement.1PubMed Central. Biomechanics of the Sacroiliac Joint: Anatomy, Function, Biomechanics, Sexual Dimorphism, and Causes of Pain
The front portion of the sacroiliac joint is a true synovial joint, meaning it has a fluid-filled capsule and cartilage-covered surfaces that allow small amounts of gliding and rotational movement during walking.2Medical Engineering & Physics. 3-D finite element analysis of the influence of synovial condition in sacroiliac joint on the load transmission in human pelvic system The back portion is more of a fibrous connection held together by some of the strongest ligaments in the body. This combination of synovial and fibrous anatomy makes the joint unusual and partly explains why it can degenerate in ways that overlap with, but are not identical to, a typical arthritic knee or hip.
How the Cartilage Breaks Down
As you age, the cartilage lining both sides of the sacroiliac joint undergoes changes that mirror what happens in osteoarthritis. The smooth surface develops irregularities and fissures, the cells that maintain cartilage start clustering in abnormal patterns, and the supportive matrix becomes uneven. Research on human tissue specimens shows that these changes are consistently more pronounced on the iliac side of the joint. The collagen that normally keeps cartilage resilient shifts in type, with type I collagen (a marker of degeneration) appearing where type II collagen (the healthy cartilage variety) used to dominate.3PubMed. Age-related changes in the articular cartilage of human sacroiliac joint
These changes do not happen overnight. They accumulate over years, and many people develop some degree of sacroiliac cartilage wear without ever experiencing symptoms. The progression from normal aging changes to a clinically meaningful “degenerative joint disease” diagnosis typically involves a combination of enough cartilage loss to narrow the joint space, subchondral sclerosis (thickening of the bone beneath the cartilage), and the formation of osteophytes, or bone spurs, around the joint margins.
Why Both Sides Tend to Be Affected
Because the two sacroiliac joints share the same postural loads and the same aging body, bilateral involvement is common. If the underlying cause is systemic, like general age-related wear, obesity, or hormonal changes, there is no reason degeneration would spare one side. That said, bilateral disease does not mean symmetrical disease. One side can be significantly worse than the other, depending on habitual posture, leg-length differences, prior injury, or whether you tend to bear more weight on one leg.
Bilateral degeneration is especially common after lumbar spinal fusion surgery. When the spine is fused across multiple vertebral segments, the sacroiliac joints absorb a greater share of the motion and force that the fused segments can no longer handle. A prospective study following patients for five years after instrumented lumbar fusion found that bilateral sacroiliac joint degeneration was significantly more common when the fusion extended to the sacrum.4Spine. Degeneration of Sacroiliac Joint After Instrumented Lumbar or Lumbosacral Fusion: A Prospective Cohort Study Over Five-Year Follow-up Another study found that roughly 44% of patients whose fusion was fixed to the sacrum developed sacroiliac joint degeneration, compared to about 34% whose fusion stopped short of it.5Journal of Advanced Spine Surgery. Sacroiliac Joint Degeneration Following Lumbar Fusion: What are the Risk Factors?
Who Is Most at Risk
Several factors raise your chances of developing sacroiliac degeneration on one or both sides. A large analysis of patients who had undergone instrumented spinal fusion identified female sex, obesity, fibromyalgia, diabetes, and tobacco use as risk factors for progressive sacroiliac joint problems severe enough to eventually require further intervention. Longer fusion constructs, those spanning three or more vertebral segments, also increased the risk substantially.6PubMed Central. Risk Factors for Sacroiliac Joint Fusion after Instrumented Spinal Fusion
Women face additional risk because of pregnancy-related changes. Increased body weight, altered posture, and hormones like relaxin that loosen pelvic ligaments all place extra stress on the sacroiliac joints. Compared to men, women also have a wider pubic angle and less sacroiliac joint curvature, which increases mobility at the joint and may predispose it to accelerated wear over a lifetime.7PubMed Central. Sacroiliac Joint and Pelvic Dysfunction Due to Symphysiolysis in Postpartum Women Interestingly, skeletal research on sacroiliac joint fusion (the natural, age-related ankylosis of the joint, not the surgical procedure) shows very different rates by sex and childbearing history: roughly 13% of male specimens showed natural fusion, compared to about 7% of females who had never given birth and less than 1% of females who had.
What the Pain Feels Like
Sacroiliac pain has a reputation for being hard to pin down, and bilateral disease makes this even trickier because the discomfort can spread across both sides of the low back and buttocks. In a study using diagnostic injections to confirm sacroiliac-origin pain, 94% of patients reported buttock pain, 72% had lower lumbar pain, and half described pain radiating into a leg. About 14% felt groin pain, and some experienced pain as far down as the foot.8PubMed. Sacroiliac joint pain referral zones When both joints are involved, you might feel pain alternating sides or aching across the entire low back and both buttocks simultaneously, which can easily be mistaken for a lumbar spine problem.
Common aggravating activities include prolonged sitting, standing from a seated position, climbing stairs, rolling over in bed, and transitional movements where the pelvis shifts load from one side to the other. If the degeneration is more advanced on one side, you might notice that certain movements bother you only in one direction, like pain when stepping up with a specific leg.
How It Is Diagnosed
Diagnosing sacroiliac degenerative joint disease involves a combination of physical examination, imaging, and, in many cases, a confirmatory injection.
On physical exam, clinicians use a battery of provocation tests designed to stress the sacroiliac joint and reproduce your pain. No single test is reliable enough on its own, but combining several improves accuracy. A systematic review found that five tests had acceptable sensitivity and specificity when at least a few were positive together: the distraction test, compression test, thigh thrust, sacral thrust, and resisted hip abduction.9PubMed Central. Specificity, sensitivity, and predictive values of clinical tests of the sacroiliac joint: a systematic review of the literature The FABER test (flexion, abduction, and external rotation of the hip) has been found to have particularly high specificity, and combining it with the thigh thrust test improved diagnostic accuracy more than other pairings.10PubMed Central. Accuracy of the Diagnostic Tests of Sacroiliac Joint Dysfunction
Imaging helps confirm structural changes. Standard X-rays can show joint space narrowing, sclerosis, and osteophytes, and they are a reasonable first step. MRI, however, has proven substantially better at detecting erosions and joint space changes. In one head-to-head comparison using CT as the reference standard, MRI detected erosions with about 79% sensitivity versus 42% for plain radiographs, and picked up joint space changes at 75% versus 41%.11Annals of the Rheumatic Diseases. Comparison of MRI with radiography for detecting structural lesions of the sacroiliac joint using CT as standard of reference: results from the SIMACT study One exception: X-rays remain better at spotting sclerosis, where MRI’s sensitivity drops considerably. CT itself, when available, also shows excellent specificity for structural sacroiliitis.12PubMed. Radiography, abdominal CT and MRI compared with sacroiliac joint CT in diagnosis of structural sacroiliitis
When physical exam and imaging point toward the sacroiliac joint but you and your clinician want more certainty, a diagnostic injection is often the next step. A small amount of local anesthetic is injected directly into the joint under imaging guidance. If your pain drops substantially, it confirms the sacroiliac joint as the source. This is the closest thing to a gold standard in sacroiliac diagnostics.13PubMed Central. Use of Diagnostic Injections to Evaluate Sacroiliac Joint Pain
Telling It Apart from Other Conditions
Sacroiliac degeneration can look a lot like other low back conditions, and the overlap with lumbar disc disease, hip arthritis, and inflammatory sacroiliitis (as seen in ankylosing spondylitis) trips up clinicians regularly. One helpful imaging distinction: the sclerosis and bone spurs in degenerative disease tend to cluster along the upper and lower edges of the sacroiliac joint, and true bony fusion of the joint cavity is generally absent. Sometimes anterior bridging osteophytes can mimic fusion on a standard frontal X-ray, but the pattern differs from the continuous bridging seen in ankylosing spondylitis.14PubMed. Comparison of radiographic abnormalities of the sacroiliac joint in degenerative disease and ankylosing spondylitis
Lumbar disc herniations can coexist with, and mask, sacroiliac problems. Research has shown that sacroiliac dysfunction is surprisingly common in patients with confirmed disc herniations on imaging, and missing the sacroiliac component can lead to unnecessary spinal surgery that doesn’t resolve the patient’s pain.15PubMed Central. Sacroiliac joint dysfunction in patients with imaging-proven lumbar disc herniation This is worth keeping in mind if you have been told your pain is from a disc but your symptoms include prominent buttock pain on both sides that does not match a typical nerve-root pattern.
Conservative Treatment
First-line treatment for bilateral sacroiliac degenerative joint disease usually starts with physical therapy focused on stabilizing the pelvis, strengthening the muscles around the hip and core, and improving mobility. Pelvic compression belts are sometimes recommended alongside exercise, and there is evidence that they can provide immediate pain relief and improve quality of life in patients with sacroiliac dysfunction.16PubMed Central. Pelvic Belt Effects on Health Outcomes and Functional Parameters of Patients with Sacroiliac Joint Pain However, a small randomized trial found no clear benefit of adding a belt to a stabilization exercise program, suggesting that the exercises themselves may be doing most of the heavy lifting.17Journal of Women’s Health Physical Therapy. Effectiveness of Adding a Pelvic Compression Belt to Lumbopelvic Stabilization Exercises for Women With Sacroiliac Joint Pain: A Feasibility Randomized Clinical Trial
Anti-inflammatory medications, activity modification, and sometimes manual therapy round out the conservative toolkit. For bilateral disease, the challenge is that both joints need attention and the exercises must address symmetry and balanced load distribution, not just one painful side.
Injections and Radiofrequency Ablation
When conservative care is not enough, steroid injections into the sacroiliac joint can reduce inflammation and temporarily relieve pain. These are sometimes combined with a local anesthetic and performed under fluoroscopic or ultrasound guidance. For many patients they provide weeks to months of relief, though the effect tends to wear off.
Radiofrequency ablation (RFA), which uses heat to disable the small nerve branches that carry pain signals from the joint, offers a longer-lasting option. A systematic review and meta-analysis comparing the two approaches found that patients treated with steroid injections had significantly higher pain scores at both three and six months compared to those who received radiofrequency ablation.18PubMed Central. Radiofrequency vs Steroid Injections for Spinal Facet and Sacroiliac Joint Pain: A Systematic Review and Meta-Analysis RFA does not fix the degeneration itself, but it can meaningfully reduce how much pain you feel from it, and the effect typically lasts several months to over a year before the nerves regenerate.
When Surgery Becomes the Discussion
Surgery for sacroiliac joint disease is reserved for cases where conservative measures and injection-based therapies have failed to provide adequate relief. The most common procedure today is minimally invasive sacroiliac joint fusion, in which small implants are placed across the joint to stabilize it and encourage bone growth that locks it in place. Multicenter data on one such approach using triangular titanium implants showed an average pain improvement of about 6 points on a 10-point scale, with over 90% of patients achieving what the researchers defined as a substantial clinical benefit at one year.19PubMed Central. One-year outcomes after minimally invasive sacroiliac joint fusion with a series of triangular implants: a multicenter, patient-level analysis
A randomized controlled trial comparing minimally invasive fusion to continued nonsurgical management found that about 81% of surgical patients met the study’s success criteria at six months, compared to 26% in the nonsurgical group. Pain and disability improvements held at 12 months, and patients who initially received conservative care and then crossed over to surgery saw similar gains to those who had surgery from the start.20PubMed Central. Randomized Controlled Trial of Minimally Invasive Sacroiliac Joint Fusion Using Triangular Titanium Implants vs Nonsurgical Management for Sacroiliac Joint Dysfunction: 12-Month Outcomes A posterior-approach technique using allograft bone showed similarly large drops in pain scores, from about 8.3 out of 10 down to roughly 2.6, sustained through 12 months, with an average operating time of around 40 minutes and no reported adverse events.21PubMed. Clinical outcomes for minimally invasive sacroiliac joint fusion with allograft using a posterior approach
For bilateral disease, the question of whether to fuse both sides at once or in staged procedures is decided case by case, depending on symptom severity, overall health, and surgeon preference. Fusing a joint eliminates its already-limited motion, and the long-term consequences of bilateral fusion on pelvic mechanics and gait are still being studied.
The Impact on Daily Life
The burden of sacroiliac joint disease is easy to underestimate because the joint sits out of sight and the pain often gets lumped in with generic “low back pain.” But research directly comparing quality-of-life scores in patients with sacroiliac dysfunction to those with other common spinal conditions found that the sacroiliac group scored at least as poorly, and often worse, than patients with degenerative spondylolisthesis, spinal stenosis, or disc herniation.22PubMed Central. Quality of life in preoperative patients with sacroiliac joint dysfunction is at least as depressed as in other lumbar spinal conditions This is worth knowing if you feel your condition is being minimized. Sacroiliac pain, especially when bilateral, interferes with sitting, sleeping, walking, and working.
The economic toll is substantial as well. Chronic low back pain in the United States carries direct healthcare costs estimated in the range of $12 billion to $90 billion per year, with total costs exceeding $100 billion when indirect costs like lost productivity and caregiver burden are included. Patients with chronic low back pain have roughly double the yearly healthcare expenditures of those without pain, and since sacroiliac problems often begin during working years, the financial impact accumulates over decades.23PubMed Central. Sacroiliac joint pain: burden of disease
Platelet-Rich Plasma and Other Emerging Options
Platelet-rich plasma (PRP) injections, which concentrate healing factors from your own blood and deliver them into the joint, have generated interest as an alternative to steroids for sacroiliac pain. A case series reported marked improvement in joint stability and pain that persisted at both one and four years after treatment.24PubMed. Case series of ultrasound-guided platelet-rich plasma injections for sacroiliac joint dysfunction Another preliminary study found that all treated patients had greater than 50% reduction in pain scores over 12 months with no adverse reactions.25Techniques in Regional Anesthesia and Pain Management. Role of intra-articular platelet-rich plasma in sacroiliac joint pain
The reality check: a systematic review with pooled analysis concluded that while PRP injections do appear beneficial, the evidence is not strong enough to support using them over standard steroid injections. The improvements were more modest than initial small studies suggested, and well-designed randomized trials are still needed before PRP can be recommended as a go-to treatment.26PubMed. Efficacy of platelet-rich plasma for sacroiliac joint dysfunction: a qualitative systematic review with pooled analysis PRP remains a reasonable option to discuss with your clinician if steroids have worn off quickly or you want to avoid repeated steroid exposure, but don’t expect miracles based on current data.