Platelet-rich plasma for the treatment of lateral epicondylitis: sonographic assessment of tendon morphology and vascularity (pilot study).

OBJECTIVE: To investigate the efficacy of using contrast-enhanced ultrasound to assess the relationship of altered vascularity and tendon morphology following injection of platelet-rich plasma (PRP) for lateral epicondylitis. MATERIALS AND METHODS: This study prospectively evaluated six patients who had a baseline ultrasound confirming tendinosis of the common extensor tendon. Patients received a single 3-ml PRP injection under ultrasound guidance. Grayscale images of the injected elbow were obtained at baseline and were repeated at 1 and 6 months after injection. DEFINITY® contrast was also injected after by 2 sets of wrist-extension exercises in order to obtain contrast-enhanced images of the elbow. Qualitative and quantitative analyses of the level of enhancement to the regions of interest were performed using off-line quantitative analysis software. RESULTS: All patients had either moderate or severe common extensor tendinosis as determined on clinical examination and baseline imaging. Five patients demonstrated improved tendon morphology using ultrasound imaging 6 months after PRP injection (one patient was lost to follow-up). At baseline, there was evidence of increased vascularity at the myotendinous junction (MT) of the common extensor tendon when compared to its footprint (FP). There was a trend towards no change in FP vascularity between baseline and 6 months (p = 0.062) and between 1 and 6 months (p = 0.288). There was a trend for increased vascularity to the MT region from baseline to 6 months (p = 0.433) and from 1 to 6 months (p = 0.783). CONCLUSIONS: Contrast-enhanced ultrasound provides a sensitive method the display alterations in vascularity in the common extensor tendon of the elbow. PRP therapy for lateral epicondylitis can improve extensor tendon morphology. Corresponding increased extensor tendon FP vascularity, however, was not seen. There is a trend for increased vascularity at the MT up to 6 months following PRP injection, based on limited pilot data.

High-frequency sonography of the volar digital nerves of the hand.

INTRODUCTION: The purpose of this study is to describe our technique for high-frequency sonography of the volar digital nerves and to define the course, caliber, and morphology of normal volar digital nerves. METHODS: The volar digital nerves of 10 volunteers were imaged in the long axis using a linear ultrasound transducer. Height, weight, glove size, and hand dominance were recorded. Each radial and ulnar nerve was divided into four segments. Segment thickness and depth were measured. A mixed model analysis for repeated measures was utilized (α = 0.05). RESULTS: The average nerve thickness (NT) was 1.1 mm (± 0.01 SE), and the average nerve depth (ND) was 2.8 mm (± 0.04 SE). Neither NT nor ND demonstrated any significant correlation with height, age, weight, body mass index, or glove size. Nerves ranged in thickness from 0.7 to 1.5 mm and in depth from 0.7 to 6.8 mm. CONCLUSION: High-frequency sonography permits high-resolution imaging of the volar digital nerves.

Sonographic assessment of suture artifact obscuring visualization of the digital nerve.

INTRODUCTION: The purpose of this study was to grade the severity of sonographic artifact produced by four suture materials and to determine whether these artifacts affect visualization of a digital nerve. METHODS: A needle was placed into a pig foot to mimic a normal volar digital nerve. Incisions superficial to the needle were closed with different suture types, specifically nylon (N), chromic (C), vicryl (V), and prolene (P). Sonographic images were obtained using a high-frequency transducer. Twenty radiology residents and attending physicians graded the severity of artifact and nerve obscuration. Two image types were shown: one suture type per image and a composite image of each suture type, adjacent to one another. RESULTS: Severity of nerve obscuration was as follows: composite image: P = N = V > C; individual images: P > N > V > C. Severity of artifact was: composite image: V = N > P > C; individual image: P > N > V > C. CONCLUSION: Although all sutures produced artifact, only C produced mild artifact, which did not significantly obscure visualization of the nerve model.

Sonographic assessment of volar digital nerve injury in the context of penetrating trauma.

OBJECTIVE: The purpose of this article was to report our experience using ultrasound to assess digital nerve integrity after penetrating hand trauma with sensory deficit. Ultrasound was performed in the long axis on 22 digital nerves in 11 patients using a 12-14-MHz linear array hockey stick transducer. CONCLUSION: Of 22 volar digital nerves evaluated by sonography, six were transected. All imaging findings were confirmed surgically. High-frequency ultrasound permits accurate imaging of intact and transected volar digital nerves.