Accuracy of Palpation-Guided and Ultrasound-Guided Needle Tip Placement Into the Deep and Superficial Posterior Leg Compartments

Abstract

Background: Invasive leg compartment testing may be performed to diagnose chronic exertional compartment syndrome. No prior study has assessed the accuracy of leg compartment needle tip access. Purpose: This study was undertaken to describe and determine the accuracy of palpation-guided and ultrasound-guided techniques for needle tip placement into the deep and superficial posterior leg compartments by a less experienced clinician and a more experienced clinician using a cadaveric model. Study Design: Controlled laboratory study. Methods: Twenty unembalmed adult lower limb cadaveric specimens were used for the study. Two investigators, a sports medicine fellow with 10 months of musculoskeletal ultrasound experience and a staff physiatrist with 3 years of musculoskeletal ultrasound experience, each performed 1 palpation-guided and 1 ultrasound-guided colored latex dye injection into the deep and superficial posterior leg compartments of each cadaveric specimen. A blinded investigator dissected the specimens and graded them for accuracy. Results: The accuracy rates of palpation-guided (accuracy rate, 90%; 95% confidence interval [CI], 76%-97%) and ultrasound-guided (accuracy rate, 88%; 95% CI, 73%-95%) deep posterior compartment injections were statistically equivalent (P = 1.000). All 80 injections performed into the superficial posterior compartment were accurate (accuracy rate, 100%; 95% CI, 89%-100%). The accuracy of the less experienced investigator (total injection accuracy rate, 88%; 95% CI, 73%-95%) and the more experienced investigator (total injection accuracy rate, 90%; 95% CI, 76%-97%) were not significantly different (P = 1.000). Conclusion: Needle tip placement into the deep and superficial posterior leg compartments is relatively accurate with palpation guidance regardless of level of experience, and does not improve with the use of ultrasound guidance. Clinical Relevance: Ultrasound guidance does not appear to be indicated for routine deep or superficial posterior leg compartment pressure testing. However, this does not preclude the need for ultrasound guidance in selected clinical scenarios.