Anesthesiology | Interventional Pain Medicine
Assistant Professor — University of Toronto
Interventional Pain Physician — Afiya Spine & Pain Institute
Staff Anesthesiologist — Scarborough Health Network
Hip articular branch blocks are injections used to test whether pain from the hip joint is being carried by small sensory nerve branches around the hip capsule.
The front part of the hip joint is commonly supplied by articular branches from the femoral nerve and obturator nerve. Some patients also have contribution from an accessory obturator nerve. The back part of the hip capsule can receive branches from other nerves, including the nerve to quadratus femoris, superior gluteal nerve, and sciatic nerve.
Most hip radiofrequency ablation procedures focus on the more accessible articular branches from the femoral and obturator nerves. These branches carry pain signals from the hip region, but they are not the main nerves responsible for moving the leg.
The block uses local anesthetic to temporarily numb selected articular branches. If your usual hip pain improves during the numbing window, that suggests you may be a candidate for hip radiofrequency ablation.
An intra-articular hip injection may be performed at the same appointment to provide temporary pain relief while the response to the nerve blocks is assessed and, if appropriate, while hip radiofrequency ablation is being considered or scheduled.
The hip joint injection usually contains local anesthetic and corticosteroid medication. The local anesthetic may help briefly. The steroid is intended to reduce inflammation inside the hip joint and may take several days to work.
Steroid injections may reduce hip osteoarthritis pain for several weeks to a few months, but the benefit varies. They do not rebuild cartilage, reverse arthritis, or replace the role of hip replacement surgery when surgery is otherwise appropriate.
In our clinic, we usually start with femoral articular branch blocks first. These targets are commonly involved in anterior hip joint pain and are generally more straightforward to tolerate.
If the response is incomplete, or if pain remains refractory, we may add obturator articular branch blocks at a later visit. The obturator target can be more uncomfortable, so we usually reserve it for situations where it is likely to add useful information or improve treatment planning.
This staged approach is meant to keep the first diagnostic step as tolerable as possible while still collecting useful information about whether hip radiofrequency ablation may help.
This procedure is most commonly considered for chronic hip joint pain from osteoarthritis when pain remains significant despite medication, physiotherapy, exercise, walking aids, weight management, or previous injections.
Hip joint pain is often felt in the groin, front of the hip, thigh, buttock, or sometimes toward the knee. Pain may be worse with walking, standing, stairs, getting in and out of a car, putting on socks or shoes, or rotating the hip.
The articular branch block portion is a test. The goal is not long-term relief from the block itself, but to determine whether the targeted articular branches are carrying a meaningful part of your hip pain.
Hip radiofrequency ablation may be considered for patients who are not candidates for hip replacement surgery, are trying to delay surgery, are using it as a bridge while waiting for surgery, or have persistent hip-region pain after hip replacement once surgical causes have been assessed.
Tell us if you have a hip replacement booked within the next 6 months. We generally do not want to inject steroid into the hip joint if this could delay your surgery.
Tell us if you already have a hip replacement, have had recent hip surgery, have an active infection, are taking antibiotics, or have had a recent major change in your health.
If you already have a hip replacement and have persistent pain, your surgeon should assess the hip replacement before nerve procedures are considered. Problems such as infection, loosening, fracture, instability, or other surgical complications need to be ruled out first.
You usually do not need to fast for this procedure unless you are specifically told otherwise.
The injections are quick, but the full visit includes check-in, assessment, preparation, and recovery.
Most patients should expect the full appointment to take approximately 60 to 90 minutes, although this can vary depending on clinic flow that day.
Obturator articular branch blocks are not always done at the first visit. If they are added later, the needle target is deeper and more medial, which is one reason that portion can be more uncomfortable.
Most patients describe:
Local anesthetic is used to reduce discomfort. We usually start with the femoral articular branch targets first partly because this is usually better tolerated.
The numbing medication from the articular branch blocks usually lasts for several hours. This is the most important part of the test.
During this time, pay attention to whether your usual hip pain is better when you do the activities that normally bring it on. This may include walking, standing, stairs, getting into or out of a car, putting on socks or shoes, or rotating the hip.
Do not simply go home and rest for the full numbing period. The test is most useful when you gently test your usual painful activities in a safe and controlled way.
You may walk and do normal light activity after the procedure. Avoid unusually strenuous activity for the rest of the day.
Do not drive until any numbness, weakness, heaviness, or altered sensation has fully resolved. If you feel lightheaded or weak after the procedure, do not drive.
Log your pain level out of 10 every hour for 6 hours after the injection.
Also write down:
Bring your pain log to your follow-up appointment. Your pain log helps determine whether hip radiofrequency ablation is appropriate and whether obturator articular branch blocks should be added.
The articular branch block is expected to work only during the numbing window. If the hip joint injection included steroid, relief may take a few days.
It is common to have temporary soreness or a pain flare before the benefit from the joint injection becomes clear.
The amount and duration of relief from the hip joint injection varies. Some patients have meaningful relief for weeks to a few months, some have partial relief, and some do not improve.
The next step depends on how much relief you had during the numbing window.
If your usual hip pain clearly improves after femoral articular branch blocks, this suggests those branches are carrying a meaningful part of your hip pain. In that case, hip radiofrequency ablation may be discussed.
If the response is incomplete, or if pain remains refractory, we may consider adding obturator articular branch blocks at a later visit. This can help determine whether adding the obturator target is likely to improve the result of hip radiofrequency ablation.
If your pain does not improve, that is still useful information. It suggests that hip radiofrequency ablation may be less likely to help, or that the pain source may not be primarily carried by the targeted articular branches.
Some patients have more than one source of hip or leg pain. Hip articular branch blocks may help identify hip joint pain, but they may not explain all of your symptoms.
Keep the injection sites dry for 24 hours. Remove bandages after 24 hours.
Hip articular branch blocks and intra-articular hip injections are deeper procedures performed near important nerves and blood vessels.
The most common issues are mild soreness, bruising, temporary lightheadedness, temporary increase in pain, or temporary irritation after the injection.
Uncommon risks include bleeding, infection, allergic reaction, medication entering a blood vessel, temporary numbness or weakness, temporary hip or leg heaviness, or irritation of nearby nerves.
The femoral artery and vein are near the front of the hip region. X-ray guidance, careful positioning, and sterile technique are used to reduce risk.
Steroid injection into the hip before hip replacement surgery may delay surgery because of infection-risk concerns. Tell us if you have a hip replacement booked within the next 6 months.
Seek medical attention if you develop fever, worsening redness or swelling at the injection site, drainage from the injection site, severe worsening pain, new leg weakness, or a hot swollen hip that does not settle.
The procedure itself, including the clinic visit and use of X-ray guidance, is covered by OHIP.
OHIP does not cover the cost of medications used or prescribed, such as local anesthetic, steroid medication, contrast dye, or other medications. These costs may be covered by private insurance.
The medication cost is usually in the range of $25 to $100, depending on the extensiveness of the procedure, but this may vary.
Unless you are told otherwise, you may usually take your regular medications. Blood thinners require separate review.
Tell us before the procedure if you take blood thinners or antiplatelet medications. Do not stop them on your own. We will give you specific instructions based on the medication and your medical history.
Tell us before the procedure if you have ever had an allergy or serious reaction to contrast dye, local anesthetic, steroid medication, or antiseptic skin-cleaning solution.
Tell us if you have diabetes, an active infection, are taking antibiotics, are pregnant or may be pregnant, have a hip replacement booked within the next 6 months, or have had a recent major change in your health.
Afiya Spine & Pain Institute
301 - 15 Wellesley St W, Toronto, ON M4Y 1G1
Phone: 416-413-7999 | E-Fax: 416-641-4520
For questions or concerns after your procedure, contact the clinic.