Sonoelastographic Findings of Carpal Tunnel Injection

Abstract

Purpose: The objectives of this study were to compare sonoelastographic color findings of the perineural area between carpal tunnel syndrome patients and healthy volunteers, and to analyze elastographic findings in that area before and immediately after intracarpal tunnel injection in carpal tunnel syndrome patients.

Materials and Methods: We studied both hands of 15 healthy volunteers (7 men, 8 women; mean age: 60.1 years, range: 41 – 88 years) and 72 hands from 70 patients with symptomatic carpal tunnel syndrome (24 men, 46 women; mean age: 54.2 years, range: 24 – 83 years). Sonoelastographic color distribution was assessed in the perineural area between the median nerve and adjacent flexor tendons. The color elastograms were graded using the following system: Grade 1 as red (softest), grade 2 as yellow (soft), grade 3 as green (hard), grade 4 as blue (hardest). The patients were treated with corticosteroid injection and were reassessed with sonoelastography immediately after the injection.

Results: The median color grading in the perineural area of carpal tunnel syndrome patients was grade 3 (3.1 ± 0.3, mean ± 95 % Cl), which was stiffer than that of healthy volunteers (grade 1, 1.9 ± 0.4) (p < 0.0001). Immediately after injection, the diffusion of the injected fluid was observed as having a softer appearance (grade 1, 1.4 ± 0.2) (p < 0.0001).

Conclusion: The perineural area surrounding the median nerve in carpal tunnel syndrome patients was stiffer than that in healthy volunteers. Diffusion of the injected fluid in the carpal tunnel was seen as a softer finding after injection in real time using sonoelastography.

Zusammenfassung

Ziel: Das Ziel der Studie ist ein Vergleich von sonoelastografischen Befunden des perineuralen Gewebes in Patienten mit Karpaltunnel Syndrom und Normalprobanden, und weiter die Analyse sonoelastografischer Veränderungen unmittelbar nach Infiltration des Karpaltunnels.

Material und Methoden: Es wurden beide Hände von 15 Normalprobanden (sieben Männer, acht Frauen; im Mittel 60,1 Jahre, im Alter von 41 – 88) und 72 Hände von 70 Patienten mit Karpaltunnel Syndrom (24 Männer, 46 Frauen; im Mittel 54,2 Jahre, im Alter von 24 – 83) mittels Sonoelastografie untersucht. Das perineurale Gewebe zwischen Nervus medianus und Fingerflexorensehnen wurde folgend beurteilt; Grad 1 als rot (weich), Grad 2 als gelb (mittelweich), Grad 3 als grün (mittelhart), Grad 4 als blau (hart). Die Patienten wurden sonografisch gezielt mit Korikosteroid infiltriert und infolge darauf unmittelbar wieder mittels Sonoelastografie untersucht.

Ergebnisse: Das Grading mittels Sonoelastografie in Patienten mit Karpaltunnel Syndrom ergab 3; 3,1 ± 0,3 (medianer Mittelwert ± 95 % Cl), deutlich härter als das der Normalprobanden (Grad 1; 1,9 ± 0,4) (p < 0,0001). Unmittelbar nach Infiltration zeigte sich eine Verteilung der infiltrierten Medikamentation, was zu einem deutlich weicherem Erscheinungsbild führte (Grad 1; 1,4 ± 0,2) (p < 0,0001).

Schlussfolgerung: Das perineurale Gewebe um den Nervus medianus zeigte sich deutlich härter in Patienten mit Karpaltunnel Syndrom als in Normalprobanden. Nach Infiltration zeigte sich eine weichere Darstellung des Karpaltunnels in der sonoelastografischen Untersuchung.

Key words

sonoelastography - carpal tunnel syndrome - steroid injection - ultrasound - nervous-peripheral - hand

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