Systematic review and meta-analyses of the difference between the spinal level of the palpated and imaged iliac crests.

OBJECTIVE: The purpose of this study was to undertake a systematic review of the literature to determine and compare, for patient sub-groups, the spinal level of the iliac crests as commonly measured through manual palpation and radiographic imaging procedures.

METHODS: Relevant citations were retrieved by searching the PubMed, ICL, CINAHL, AMED, Osteopathic Research Web, OstMed, and MANTIS biomedical databases, and included articles were rated for quality. Search terms included Tuffier*, intercristal line, intercrestal line, Jacoby's line, lumbar spine, lumbar landmark, pelvic landmark, palpation, and TL (Tuffier's Line). Meta-analyses were performed on the full datasets as well as subsets based on various patient demographics.

RESULTS: Original search strategies retrieved 1301 citations; 47 articles were used for qualitative synthesis and 31 for meta-analyses. Across these studies imaged crests were found to be most consistent with and closest to the L4-5 interspace in females and L4 spinous process in males. In comparison, the spinal level for the palpated crests was nearest to the L3-4 interspace in males and females. The palpated crest line was 0.7 levels cephalad to the imaged crest line in males, and 1.0 levels cephalad to the imaged line in females.

DISCUSSION AND CONCLUSIONS: During manual palpation, the examiner's fingers contact soft tissue overlying the iliac crests, thereby usually identifying the L3-4 spinal level rather than the assumed L4-5 level. Palpating iliac crests to guide anesthetic injections or manual therapy without appreciating these findings can be hazardous or lead to suboptimal patient care.