Sacroiliac joint pain can last anywhere from a few days to many years, depending on the cause, how quickly it is identified, and how it is treated. Mild, mechanically triggered flare-ups often settle within a few weeks with rest and physical therapy, while untreated or inflammatory cases can persist for months or become a permanent source of discomfort. The SI joint sits at the junction between your spine and pelvis, bearing a large share of your upper-body weight, so the forces that irritate it rarely go away on their own unless you actively address them.
The Typical Recovery Window
For a straightforward SI joint flare triggered by an awkward lift, a fall, or an unusually long run, the pain often improves within days to a few weeks once the aggravating activity stops. More stubborn cases that need structured physical therapy or injections tend to see meaningful relief within one to three months. Estimates suggest that up to 95 percent of people with SI joint pain respond well to nonsurgical treatment when it is applied early, with significant pain reduction in that one-to-three-month window.1Spine-health. How Long Does SI Joint Pain Last? The trouble starts when the pain is ignored, misdiagnosed, or driven by an underlying condition that simple rest cannot fix. In those scenarios, SI joint pain can settle in for the long haul.
Why Some Cases Become Chronic
The SI joint is responsible for transferring load between your torso and legs every time you walk, stand, or sit. In humans, who walk upright on two legs, the joint is constantly subjected to shearing forces during every stride.2Medical Hypotheses. Optimal screw insertion trajectory for sacroiliac joint fusion surgery: An evolutionary and growth process perspective on the sacroiliac joint That relentless mechanical stress means any structural imbalance or tissue injury is re-aggravated with routine movement. Repeated micro-trauma from activities like distance running, heavy lifting, or prolonged sitting can transition an acute injury into a chronic problem if the underlying mechanics are not corrected.3Orthopaedics & Traumatology: Surgery & Research. The sacro-iliac joint: A potentially painful enigma. Update on the diagnosis and treatment of pain from micro-trauma
Several structural and medical factors predispose people to chronic SI joint pain:
- Leg length discrepancy: Even a modest difference in leg length increases the load and peak stress across the SI joint surfaces on the longer side. Correcting the discrepancy with a shoe lift or surgical intervention can reduce that excess load.4PubMed. Relationship between limb length discrepancy and load distribution across the sacroiliac joint–a finite element study
- Hypermobility or hypomobility: Too much or too little motion in the joint can both produce pain. Pregnancy-related ligament laxity is a classic example of hypermobility, while degenerative changes in older adults tend to stiffen the joint unevenly.
- Prior lumbar fusion: Surgery that fuses one or more segments of the lower spine shifts extra mechanical demand to the SI joint. About 12 percent of lumbar fusion patients develop new SI joint pain, with symptoms appearing on average around 22 months after surgery.5PubMed Central. The incidence of new onset sacroiliac joint pain following lumbar fusion
- Inflammatory disease: Conditions like ankylosing spondylitis and psoriatic arthritis target the SI joint directly. Inflammatory back pain typically starts before age 40, comes on gradually, improves with exercise, does not improve with rest, and often wakes you at night.6PubMed Central. Evaluating Inflammatory Versus Mechanical Back Pain in Individuals with Psoriatic Arthritis: A Review of the Literature If an inflammatory condition is the driver, SI joint pain can persist indefinitely unless the disease itself is controlled.
The SI joint is also an underappreciated source of low back pain in general. Among people with chronic, non-radiating low back pain, between 15 and 30 percent turn out to have the SI joint as the primary source.7PubMed Central. Sacroiliac joint pain: a comprehensive review of epidemiology, diagnosis and treatment Many of these individuals spend months or years being treated for a disc problem or muscular strain before the SI joint is even examined, and that diagnostic delay itself contributes to the pain becoming entrenched.
The Diagnostic Delay Problem
One of the biggest reasons SI joint pain drags on is that it gets misidentified. The pain pattern overlaps heavily with lumbar disc issues, hip bursitis, and piriformis syndrome. There is no single imaging test that reliably confirms SI joint dysfunction; diagnosis often hinges on a combination of specific physical exam maneuvers and a diagnostic injection that temporarily numbs the joint. When the underlying cause is an inflammatory spondyloarthritis, the average delay between symptom onset and correct diagnosis can stretch for years. Systematic reviews have found that people who wait longer for a correct diagnosis end up with worse disease activity, poorer physical function, and more structural damage than those diagnosed earlier.8PubMed Central. Clinical, Economic, and Humanistic Burden Associated With Delayed Diagnosis of Axial Spondyloarthritis: A Systematic Review Delayed diagnosis is also linked to less favorable responses to treatment once it finally begins.9PubMed. Delayed diagnosis is linked to worse outcomes and unfavourable treatment responses in patients with axial spondyloarthritis
The practical takeaway is that the clock matters. If your lower back or buttock pain has persisted for more than a few weeks and is not responding to the usual treatments for a pulled muscle, asking your provider to specifically evaluate the SI joint can shorten the road to relief considerably. This is especially true if the pain is one-sided, centered over the dimple area of your lower back, and aggravated by standing from a seated position or climbing stairs.
SI Joint Pain During and After Pregnancy
Pregnancy is one of the most common triggers for SI joint pain. Hormonal changes loosen the ligaments around the pelvis to prepare for delivery, and the growing belly shifts your center of gravity forward, increasing shear stress on both SI joints. For the majority of women, this pain resolves within weeks to several months after giving birth as hormones normalize and ligaments tighten back up.10PubMed. Peripartum changes of the sacroiliac joints on MRI: increasing mechanical load correlating with signs of edema and inflammation kindling spondyloarthropathy in the genetically prone
A minority of women are not so lucky. Roughly 8 to 10 percent of those with pregnancy-related pelvic girdle pain continue to have pain for one to two years postpartum.11PubMed Central. Sacroiliac Joint and Pelvic Dysfunction Due to Symphysiolysis in Postpartum Women And about 4 percent go on to develop a form of spondyloarthritis, an inflammatory joint disease, possibly triggered by the mechanical and hormonal stresses of pregnancy in someone who was genetically predisposed.10PubMed. Peripartum changes of the sacroiliac joints on MRI: increasing mechanical load correlating with signs of edema and inflammation kindling spondyloarthropathy in the genetically prone If your postpartum SI joint pain has not improved after several months of physical therapy and pelvic stabilization exercises, it is worth getting evaluated for an inflammatory cause rather than assuming the pain will eventually fade.
How Long Do Conservative Treatments Take to Work?
Physical therapy is the first-line treatment for most mechanical SI joint pain, and the timeline for improvement is weeks, not days. A systematic review of physiotherapy interventions for SI joint dysfunction found that manipulation and exercise therapy both reduce pain and disability, with manipulation producing the strongest short-term results.12Journal of Physical Therapy Science. The effectiveness of physiotherapy interventions for sacroiliac joint dysfunction: a systematic review A separate review noted that both exercise and manipulation therapy can improve pain outcomes for up to 24 weeks compared to baseline.13PubMed Central. Minimally Invasive and Conservative Interventions for the Treatment of Sacroiliac Joint Pain: A Review of Recent Literature
The exercise programs that work best for SI joint pain are not generic core routines. They typically focus on strengthening the gluteal muscles, hamstrings, and the latissimus dorsi, the muscles that help stabilize and compress the SI joint in the right direction.3Orthopaedics & Traumatology: Surgery & Research. The sacro-iliac joint: A potentially painful enigma. Update on the diagnosis and treatment of pain from micro-trauma If you have been given a general low-back exercise sheet and seen no improvement after a month or two, a therapist who specifically assesses the SI joint may make a meaningful difference. SI joint belts, which compress the pelvis externally, can also help during the rehabilitation period by reducing the shearing forces across the joint while you build strength.
Injections and How Long the Relief Lasts
When physical therapy alone is not enough, a corticosteroid injection directly into the SI joint is the standard next step. These injections can provide substantial pain relief relatively quickly. One study using CT-guided steroid injections found that pain scores dropped from an average of about 7 out of 10 to about 4 within the first week. That improvement held at the one-month and three-month marks but started creeping back up toward 5 by six months.14PubMed. CT-guided corticosteroid injection of the sacroiliac joints: quality assurance and standardized prospective evaluation of long-term effectiveness over six months In other words, a steroid injection buys you a window, typically three to six months of meaningful relief, rather than a permanent fix. That window can be extremely valuable if you use it to pursue physical therapy and address contributing factors like muscle weakness or movement habits.
Platelet-rich plasma (PRP) injections have also been studied as an alternative. In one trial, PRP reduced pain scores significantly at one month and maintained improvement at three months, though the effect was slightly less pronounced than steroids at the one-month mark.15Pain Medicine. Intra-Articular Platelet Rich Plasma vs Corticosteroid Injections for Sacroiliac Joint Pain: A Double-Blinded, Randomized Clinical Trial Another small study reported that PRP kept pain levels low without additional treatments for up to six months after injection.16Techniques in Regional Anesthesia and Pain Management. Role of intra-articular platelet-rich plasma in sacroiliac joint pain The hope with PRP is that it promotes tissue healing rather than just suppressing inflammation, but the evidence remains mixed. At this point, PRP is not clearly better than steroids for SI joint pain, and the research is still early.
Radiofrequency Ablation and Its Duration of Effect
For people whose pain returns after injections wear off, radiofrequency ablation is the next rung on the treatment ladder. The procedure uses heat to disrupt the small sensory nerves that carry pain signals from the SI joint. It does not fix the joint itself; it interrupts the pain transmission. The relief is temporary because nerves regenerate, but it lasts considerably longer than an injection.
Studies of radiofrequency ablation for SI joint pain report that the majority of patients achieve at least 50 percent pain reduction for three to six months.17The Clinical Journal of Pain. Comparative Outcomes of Cooled Versus Traditional Radiofrequency Ablation of the Lateral Branches for Sacroiliac Joint Pain A newer technique, cooled radiofrequency ablation, creates a larger treatment zone around each nerve and appears to extend these results. In one multicenter study, about 57 percent of patients still had clinically meaningful pain relief 12 months after the procedure, with average pain scores dropping from roughly 6.4 to 3.5 out of 10.18Regional Anesthesia & Pain Medicine. Cooled radiofrequency ablation provides extended clinical utility in the management of chronic sacroiliac joint pain: 12-month follow-up results from the observational phase of a randomized, multicenter, comparative-effectiveness crossover study The benefit does tend to fade as the nerves grow back, but many patients choose to repeat the procedure every one to two years with good results. One head-to-head comparison of ablation techniques found that multi-lesion approaches provided a clear advantage, with 36 percent of patients maintaining at least 50 percent pain relief at six months and 27 percent at 12 months, versus 16 percent and 11 percent for a single-lesion technique.19PubMed. Radiofrequency denervation for treatment of sacroiliac joint pain-comparison of two different ablation techniques
When Surgery Becomes the Answer
SI joint fusion is reserved for people who have failed conservative treatment, injections, and ablation, or whose joint instability is severe enough that nerve procedures alone cannot address the problem. The surgery involves placing implants across the joint to eliminate its motion entirely. Because the SI joint only moves a few degrees under normal conditions, fusing it does not dramatically change how you walk or sit.
Long-term data on minimally invasive SI joint fusion are encouraging. A five-year follow-up study found that improvements in pain seen at 12 months were maintained through five years, with no evidence of implant loosening or migration.20PubMed Central. Five-year clinical and radiographic outcomes after minimally invasive sacroiliac joint fusion using triangular implants The percentage of patients who achieved a clinically meaningful improvement actually increased over time, reaching 88 percent at the five-year mark, and 82 percent said they would have the same surgery again for the same result.21The Open Orthopaedics Journal. Five-Year Clinical and Radiographic Outcomes After Minimally Invasive Sacroiliac Joint Fusion Using Triangular Implants Another multi-site study with an average follow-up of nearly four years found that pain scores dropped from about 7.5 preoperatively to about 2.6, a roughly five-point improvement on a ten-point scale.22PubMed Central. Durable intermediate-to long-term outcomes after minimally invasive transiliac sacroiliac joint fusion using triangular titanium implants
These numbers are promising, but they come with context. Surgery carries inherent risks, and success depends heavily on confirming that the SI joint is actually the pain source beforehand. People whose pain is partly coming from the lumbar spine, the hip, or soft tissues around the pelvis may not get the same degree of relief from fusion alone.
SI Joint Pain After Lumbar Fusion
This is a scenario that deserves its own attention because of how common and frustrating it is. When one or more levels of the lumbar spine are fused, the segments that remain mobile have to absorb the motion and stress that the fused levels can no longer handle. The SI joint, which sits immediately below the lumbar spine, is a frequent casualty. The joint was never designed to compensate for a rigid spine segment above it, and the extra load can produce pain that mimics the original back problem.23PubMed Central. Sacroiliac joint pain after lumbar/lumbosacral fusion: current knowledge
If you had lumbar fusion surgery and develop new low back or buttock pain months afterward, the SI joint should be on the list of possible culprits. The average onset is around 22 months after fusion, and the incidence is roughly 12 percent.5PubMed Central. The incidence of new onset sacroiliac joint pain following lumbar fusion This type of SI joint pain can become chronic if it is attributed to a failed spine surgery and treated with more lumbar interventions rather than being evaluated at the correct joint.
How to Tell if Your SI Joint Pain Is Becoming Chronic
There is no universally agreed-upon threshold for when SI joint pain crosses from “acute” to “chronic,” but in musculoskeletal medicine, pain lasting more than three months is generally considered chronic. A few signals suggest your SI joint pain may not resolve on its own:
- Worsening with rest: Mechanical pain usually feels better with rest. If your pain is worse in the morning or after sitting for long periods and improves with movement, an inflammatory process may be driving it.
- Night pain: Waking up from SI joint pain, especially in the second half of the night, is a hallmark of inflammatory sacroiliitis.
- No response to therapy: If six to eight weeks of targeted physical therapy has not produced any change, the diagnosis itself may need revisiting.
- Bilateral symptoms: Mechanical SI joint pain tends to be one-sided. Pain that alternates between sides or affects both is more typical of an inflammatory condition.
The distinction between mechanical and inflammatory causes has direct implications for how long the pain lasts. Mechanical causes are often self-limiting or responsive to physical interventions. Inflammatory causes like spondyloarthritis are systemic diseases that can produce chronic, fluctuating SI joint pain for years unless controlled with medications that target the immune system.
Biomarkers and Predicting Outcomes
Researchers have begun looking at blood markers that might predict whose SI joint pain will persist or progress. In patients with spondyloarthritis, certain proteins involved in bone remodeling, including sclerostin and a molecule called Dkk-1, were found at lower levels compared to healthy individuals. Lower Dkk-1 levels correlated with more chronic structural changes on MRI.24PubMed Central. Bone turnover biomarkers, disease activity, and MRI changes of sacroiliac joints in patients with spondyloarthritis These findings are not yet useful in everyday clinical decisions, and your doctor is unlikely to order these tests for routine SI joint pain. But they point toward a future in which a blood draw could help predict whether someone’s SI joint inflammation is going to self-limit or progressively damage the joint over years. For now, the best practical predictors remain the clinical red flags for inflammatory disease: young age at onset, gradual onset, morning stiffness lasting more than 30 minutes, improvement with exercise, and an elevated C-reactive protein on standard blood work.