What Are The Risks Of These Procedures?
With any operation or injection procedure there are risks. In the case of these procedures, the risks are small. These procedures are performed on the posterior spine and are thus away from the neuroaxis (spinal cord, etc). This dramatically reduces the risk of serious problems. With 7-joint injections, the most common problems side-effect is a temporary increase in pain. It occurs in about less than one per cent of patient’s undergoing this procedure and appears to be related to the volume of substance injected into the joint. On occasion, the joint can be over-filled and this can cause a rupture of the joint capsule. This will normally heal with time. Your physician will take care to inject the appropriate amount of solution.
With medial branch blocks there are no specific side-effects or complications, only the general ones listed below.
With radiofrequency ablation, there are inherently more risks because your physician is creating permanent tissue damage. It is theoretically possible to have the needle too close to the spinal nerve. If the probe ablated the spinal nerve could result in weakness and numbness in the arm or leg. If at any point during the procedure you feel pain shooting into your arm or leg, please notify the doctor. This is a very rare complication and can usually be avoided with proper technique. Also on very rare occasions, the nerve that has been burned responds poorly to the procedure, becomes inflamed (neuritis) and produces increased pain. As mentioned above, your physician may inject corticosteroid following the ablation to help reduce the risk of this.
If you are allergic to one of the additives in the steroid solution you may experience a hot flush or develop a rash. However, this should get better within a few hours or days.
As with any injection through the skin, it is possible for bacteria to gain entry causing an infection. Your physician will use sterile technique and the risk of infection with these procedures is very small.
Sometimes a patient’s blood pressure falls at the time of the injection. If so, the doctor will use the venous canula inserted before the epidural procedure commenced so that intravenous fluids or medication, if necessary, can rapidly control the blood pressure.
Some side-effects may occur as a result of the corticosteroid administered. If you have diabetes, you may notice that your blood sugars are elevated for 2-3 days following the procedure. If they are, usually only monitoring is required. However, if you are concerned, call your physician. Corticosteroids may also cause fluid retention, weight gain, alterations in skin pigmentation at the site of injection, fluid and electrolyte alterations andfor gastrointestinal upset. These side-effects are usually not serious.
How Long Does It Take?
These procedures take 20 minutes to one hour depending on the number of levels involved. On occasion radiofrequency ablation can take longer if the nerves are difficult to localize. The patient will usually be in the recovery room for 30 minutes to one hour after the procedure.
Any of these procedures may be repeated. In general however, if the effect of a Z-joint injection wears off and the patient has adequately participated in a physical therapyprogram after the procedure, it is more reasonable to proceed with medial branch blocks and ultimately radiofrequency ablation.
Medial branch blocks may be repeated with a different local anesthetic to absolutely confirm that blocking the medial branch nerves will be effective. Repeating this procedure is at the doctor’s discretion.
Radiofrequency ablation is frequently permanent and does not need to be repeated. On rare occasions, the medial branch nerves will regenerate and the procedure will have to be repeated. Your doctor will usually not do this until 6 months have passed.