A psoas injection involves delivering medication directly into the deep psoas muscle, its surrounding sheath, or the adjacent bursa. This targeted approach typically uses a combination of a potent anti-inflammatory corticosteroid and a short-acting local anesthetic. Because the psoas muscle is located deep within the body, near the lower lumbar spine and pelvis, patients often wonder about the physical sensation of the procedure. The treatment addresses pain and inflammation originating from this anatomical area.
Purpose of the Psoas Injection
The psoas muscle joins the iliacus muscle to form the iliopsoas, the body’s strongest hip flexor, which plays a large role in walking and core stabilization. When this muscle, its tendon, or the adjacent fluid-filled sac known as the bursa becomes inflamed, it can cause significant pain deep in the groin or hip. This condition is formally known as iliopsoas tendinopathy or bursitis.
The injection serves two primary functions: diagnostic and therapeutic. Diagnostically, placing an anesthetic onto the irritated structure helps physicians confirm if the psoas is the source of the patient’s pain. Therapeutically, the corticosteroid component works to reduce inflammation and swelling around the affected muscle, tendon, or bursa.
This procedure is commonly used to treat chronic groin pain, particularly in athletes who perform repetitive hip flexion movements or in patients who have developed irritation following a total hip replacement. The medication is delivered to the site of irritation to calm the inflammatory response. Reducing this inflammation helps to relieve the irritation of nearby nerves and structures, providing symptomatic relief.
Patient Experience During the Procedure
The most common concern patients have is whether the needle insertion will be painful, but the process is carefully managed to minimize discomfort. Before the main injection, the skin and the underlying tissue are thoroughly numbed with a local anesthetic, which feels like a small pinch and burning sensation. This initial step significantly dulls the feeling of the subsequent, deeper needle insertion.
The entire procedure is performed with continuous imaging guidance, typically using fluoroscopy (live X-ray) or ultrasound. This guidance allows the physician to visualize the needle’s path, ensuring it reaches the deep psoas compartment accurately. Using imaging makes the procedure faster, safer, and more precise than unguided injections.
Once the deep needle is positioned correctly, the medication is slowly injected. Patients usually do not report a sharp pain at this stage; instead, they often feel a sensation of deep pressure or fullness in the hip or groin area as the fluid enters the muscle sheath or bursa. In some cases, if the local anesthetic spreads to nearby nerves, a temporary feeling of heaviness or a warm tingling sensation may be felt down the leg. The actual injection component of the treatment is very quick, generally lasting only a few minutes.
Immediate Post-Injection Experience and Recovery
Immediately following the procedure, the local anesthetic will likely provide instant or near-instant pain relief. This rapid initial relief is temporary and should not be mistaken for the long-term effect of the steroid. As the anesthetic begins to wear off, usually within 12 to 18 hours, the original pain may return, or the patient may experience a temporary period of increased soreness.
This post-procedure pain, often referred to as a “steroid flare,” is a common reaction to the injected corticosteroid and can be managed with over-the-counter pain relievers. During the first 24 hours, gentle activity and rest are recommended. Patients are advised to have someone drive them home, as temporary leg weakness or numbness may occur if the anesthetic spreads to the nerves that control leg movement.
The full therapeutic effect of the corticosteroid medication generally takes 48 to 72 hours to start working effectively. Patients should monitor their symptoms during this initial period, recognizing that the immediate post-injection flare-up is a normal part of the healing process. The goal is a sustained reduction in pain and inflammation that allows for improved function in the weeks following the injection.