It is often assumed that an analgesic response to a properly performed diagnostic block is the most reliable method to diagnose SI joint pain. Although this may seem to be self-evident, the validity of intraarticular SI joint blocks remains unproven.
SI joint block can be one of the most challenging spinal injection procedures. Extravasation of LA to surrounding pain-generating structures such as muscles, ligaments, and lumbosacral nerve roots can lead to false-positive blocks. Conversely, failure to obtain adequate LA spread to the anterior and cephalad portions of the SI joint can result in false-negative blocks.
Regardless of the imaging modality used to confirm intra articular injection, SI joint injections should never be performed blindly because of a high failure rate. It is also accepted that diagnostic injections can frequently be therapeutic as well. In effect there is no infallible, universally accepted method for diagnosing pain originating in the SI joint.
Treatment of SI joint pain
Treatment of SI joint pain can be challenging.
As with any pain condition psychosocial factors can influence both the development of chronic pain conditions and the response to treatment. To optimize outcomes, the identification and treatment of concomitant psychosocial issues is of paramount importance. This is best accomplished via a multidisciplinary approach.
This includes controlling the pain with non-pharmacological option (TENS, acupuncture), oral analgesics and exercise regimes to strengthen the core muscles in the back.
Intra articular injections
Intra articular injections with local anaesthetic and steroid often serve the dual function of being diagnostic and therapeutic. Most investigators have found radiologically guided SI joint injections to provide good to excellent pain relief lasting from 6 months to 1 year. Various studies have also shown a beneficial effect for peri articular corticosteroid treatment as well.
Botulinum toxin injection
Botulinum toxin injections have been used in management of SI joint pain. Both peri articular and intra articular botox injections have been reported.
Cooled radiofrequency treatment for SI joint pain
Cooled radiofrequency is a relatively new concept developed for conditions that are difficult to treat effectively using conventional radiofrequency treatment. Cooled radiofrequency utilises a special radiofrequency probe designed to produce a larger lesion size and therefore treat a larger area than is possible with conventional radiofrequency treatment.
There is some evidence that suggests that cooled RF treatment may be more efficacious in management of SI joint pain, compared to standard RF and intra articular injections, though more robust studies are needed to confirm this.