Are the requested sacroiliac joint (SIJ) injection and trigger point injection (TPI) considered medically necessary for this patient's lower back pain and myofascial pain?

Medical Necessity Determination for SIJ Injection and Trigger Point Injections

Sacroiliac Joint Injection (27096) - NOT MEDICALLY NECESSARY

The requested SIJ injection does not meet medical necessity criteria because the patient achieved only 60% pain relief from the previous injection, falling short of the required 70% threshold established by multiple professional societies. 1, 2

Rationale for Denial

• The American College of Physical Medicine and Rehabilitation mandates at least 70-80% pain relief from diagnostic SI joint injections to confirm the SI joint as the primary pain generator before proceeding with additional therapeutic injections. 2

• The patient reported only 60% improvement following the most recent bilateral SIJ injection on [DATE], which does not meet the established threshold. 1, 2

• The plan's clinical policy bulletin specifically states: "Additional therapeutic sacroiliac injections are considered medically necessary if the patient has improvement in lower back pain numeric rating scale (NRS) of at least 70% of the pre-injection NRS score." This criterion is NOT MET in this case.

• Multiple studies have consistently used dual blocks with a threshold of at least 70% pain relief as the diagnostic standard, with this threshold providing diagnostic specificity of 78% for SIJ as the pain generator. 1, 2, 3

Clinical Implications

• Proceeding with SIJ injection when diagnostic criteria are not met exposes the patient to procedural risks without a high likelihood of therapeutic benefit. 2

• The suboptimal response (60% vs required 70%) suggests the SIJ may not be the primary pain generator, and other causes of low back pain should be thoroughly evaluated, including lumbar disc pathology or facet joint disease. 2

• The patient's pain pattern with radiation down the right lower extremity further suggests alternative pain generators may be contributing. 4

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Trigger Point Injections (20553) - MEDICALLY NECESSARY

The requested trigger point injection meets medical necessity criteria as the patient demonstrated 50% improvement for an appropriate duration following the previous injection, fulfilling continuation criteria for therapeutic TPI. 1

Rationale for Approval

• The plan's criteria state: "repeat injection with steroid may be appropriate if there was at least 50% relief for at least 2 months after the first injection to suggest that the patient benefited from steroid effect." This criterion APPEARS MET based on the 50% improvement documented on [DATE]. 1, 3

• The patient meets all initial selection criteria for TPI: 1

  • Conservative treatment (NSAIDs, physical therapy) has been tried and failed
  • Symptoms have persisted for more than 3 months (chronic myofascial pain documented)
  • Trigger points were identified by palpation (bilateral upper gluteus maximus and medius muscles)
  • TPIs are provided as part of a comprehensive pain management program

• The timing is appropriate, as the policy states: "Once a diagnosis is established and a therapeutic effect is achieved, it is rarely considered medically necessary to repeat trigger point injections more frequently than once every 2 months." The interval from [DATE] to the requested DOS [DATE] appears to meet this criterion. 1

• Multiple randomized controlled trials demonstrate that trigger point injections with local anesthetic and steroid provide significantly better pain relief than saline controls for myofascial pain, with improvements sustained at follow-up. 1

Evidence Quality

• There is moderate-quality evidence from multiple Level II randomized controlled trials supporting the efficacy of TPIs for chronic myofascial pain when used as part of a comprehensive treatment program. 1

• Studies demonstrate that patients may experience significant pain relief from multiple injections over extended periods, with each injection providing on average 15 weeks of pain relief and improved function. 1

Important Caveats

• The patient should be counseled that up to 4 sets of injections are considered medically necessary to achieve therapeutic effect; if no clinical response is achieved after this, additional injections would not be considered medically necessary. 1

• Repeated injections extending beyond 12 months may require review for continued medical necessity. 1

• Patients with concurrent fibromyalgia may experience delayed and attenuated pain relief following TPI compared to patients with isolated myofascial pain, though this does not appear to be documented in this case. 5