Functional outcome from sacroiliac joint prolotherapy in patients with sacroiliac joint instability.

OBJECTIVES: Examine the effectiveness of sacroiliac (SI) joint prolotherapy for SI joint instability, and characterize the patients most likely to benefit from this treatment.

DESIGN: Retrospective cohort study.

SETTING: Department of Veterans Affairs outpatient physical medicine clinic.

INTERVENTIONS: Patients referred for low back pain and diagnosed with SI joint instability received a series of three SI joint prolotherapy injections (15% dextrose in lidocaine) at approximately a one-month interval. The outcome of those completing treatment was retrospectively examined, and characteristics were compared between those with at least a minimum clinically important improvement and those without improvement.

MAIN OUTCOME MEASURES: Patients completed the Oswestry Disability Index (ODI) before treatment was initiated, immediately preceding each prolotherapy injection, and at 3-4 month follow-up.

RESULTS: Of 103 treated patients returning for post-treatment follow-up at a median of 117 days, 24 (23%) showed a minimum clinically important improvement despite a median of 2 years with low back pain and a mean (±SD) pre-intervention ODI of 54 ± 15 points. Much of the improvement was evident after the initial prolotherapy injection, and a 15-point improvement in ODI prior to the second prolotherapy injection had a sensitivity of 92% and specificity of 80% for determining which patients would improve.

CONCLUSIONS: A satisfactory proportion of patients with symptomatic SI joint instability as an etiology of low back pain can have clinically meaningful functional gains with prolotherapy treatment. The patients who are not likely to improve with prolotherapy are generally evident by lack of improvement following the initial prolotherapy injection.