Ultrasound-guided injection for De Quervain's disease: Accuracy and its influenceable anatomical variances in first extensor compartment of fresh cadaver wrists.

BACKGROUND: This study was designed to evaluate the accuracy of ultrasound-guided injection targeting EPB tendon sheath and influenceable anatomical variances to the accuracy in the first extensor compartment of fresh cadaver wrists.

METHODS: Thirty wrists of 15 cadavers were used. The wrists were divided into right-sided wrists (control group) and left-sided wrists (group A) to compare the accuracy of the manual injection technique (control group) and ultrasound-guided injection technique (group A) targeting EPB tendon sheath. To estimate the influence of anatomical variances within first extensor compartment to the accuracy of each injection techniques, control group (manual injection group) was divided into Control group I (right-sided wrists without septum) and II (right-sided wrists with septum) and group A (ultrasound-guided injection group) was also divided into group AI (left-sided wrists without septum) and group AII (left-sided wrists with septum), respectively. After the methylene blue dye injection, the location of methylene blue dye and anatomical variances in the first extensor compartment was identified by dissection.

RESULTS: The accuracy was higher in the group A (93.3%) than in control group (40.0%, p < 0.05). The accuracy in control group I (55.6%) was higher than in control group II (16.7%, p < 0.05). The accuracy between group AI (100%) and group AII (85.7%) was not significantly different (p > 0.05). Wrists with more EPB or APL tendon slips showed a tendency not to have septum and all intratendinous injections was occurred in the wrist with 1 EPB tendon slip or 1 or 2 APL tendon slip.

CONCLUSIONS: Ultrasound-guided injection targeting EPB tendon ensures correct needle placement through the visualization of compartmental anatomy and improves accuracy of injection though the septum in first extensor compartment encourage inaccurate injections.