Imaging of sharp foreign body closer to the ulnar nerve using ultrasonography.

We report here the management of glass fragment buried in the soft tissue close to the ulnar nerve. Also discuss how ultrasound provides real-time guidance without radiation exposure and emphasize the importance of this evolving and exciting imaging field.

INTRODUCTION

Soft tissue foreign bodies are commonly encountered in daily orthopedic practice. Traditionally, plain X-ray films have been used for detection of foreign bodies, whereas localization and removal is accomplished with fluoroscopy aid; an imaging modality needs radiation exposure and does not provide a real-time guidance.[1]

Recently, ultrasound (US) has emerged as an imaging study of choice for detection and localization of soft tissue foreign bodies, especially the radiolucent one along with the evaluation of the surrounding adjacent structures.[23] We reported the use of real-time intraoperative US guidance to localize and removal of buried foreign body in the soft tissue of the upper extremity.

CASE REPORT

A 30-year-old American Society of Anesthesiologists (ASA) Saudi man involved in road traffic accident 2 years earlier, presented with a painful swelling in the posterior elbow region. Plain X-ray film showed a peak-shaped fragment, and a decision was made to retrieve the fragment under general anesthesia. The orthopedic surgeon requested assistance from anesthesia team because of the experience and familiarity of the anesthesia staff in our hospital with musculoskeletal sonography and readily available US machine in the operating room. The patient was given general anesthesia, after aseptic preparation, including sterile US probe sheath and US gel, 6–13 MHz linear probe was used to scan the area between the olecranon and the medial head of the humeral epicondyle. Short axis view showed peak-shaped 1.2 cm echogenic fragment with an associated inflammatory edema. The sharp edge of the fragment was 2 mm close to the ulnar nerve [Figure 1]. The surgeon made a small skin incision, under real-time guidance surgical forceps introduced; the positional relation between the foreign body, instrument, and the ulnar nerve was under US control. The foreign body retrieved and was a glass fragment. Surgical procedure took 10 min without any complication.

Figure 1

A cross-section view at the level of the posterior elbow between the olecranon and medial humeral epicondyle showed a glass fragment with its sharp edge close to the ulnar nerve (Un)

DISCUSSION

This report showed the importance of US in the detection, localization, and removal of foreign bodies. All intraoperative surgical steps were accomplished under real-time sonography guidance without radiation exposure. The accuracy and availability of US machine make it an excellent imaging modality for detection of foreign bodies,[45] along with evaluation of their associated complications.[68] In the present case, the sharp edge of the glass fragment was 2 mm close to the ulnar nerve. Knowledge of the exact location of the fragment relative to the skin surface and adjacent neurovascular bundles allows more controlled surgical dissection, and this should be translated into reducing skin incision size, depth of dissection, less surgical maneuvers, minimize complication, and reduce the operating time.