Apical hemifacetectomy of the first sacral vertebra in the treatment of an osteoid osteoma

We present the surgical technique of apical hemifacetectomy, which is useful for performing selective resection of lesions located in the upper articular processes avoiding facet joint inestabiliy. This surgical technique was used in a 20-year-old patient to remove an osteoid osteoma deeply located in the S1 articular process.