New approach to the distal radius: Single incision and double window, strong fixation of complex double-column fractures!

Distal radius fractures Volar locking plates can provide stable anatomical reduction in the distal radius, but comminuted fractures of the exposed volar-ulnar joint remain a challenge when using the classic volar flexor carpi radialis (FCR) approach. challenge. A direct volar-ulnar extension approach is currently available that provides easy access to the volar-ulnar angle (VUC) of the distal radius, but limited access to the fracture of the radial styloid process.

Therefore, this study proposes a new approach to expose the two posts of the distal radius through a single incision, thereby providing a dual window for adequate exposure of the intra-articular fragments involving the radial VUC, DRUJ, and radial styloid process (Figure 1). The radial column interval (RCI) is created through the classic volar flexor carpi radialis approach, while the ulnar column interval (UCI) consists of subcutaneous anatomy on the ulnar side of the wrist, where the septum between the ulnar neurovascular bundle and the carpal tunnel is routed. shape.

Insets illustrate radial and ulnar column spacing created using the single-incision, double-window technique. The ulnar septum is between the ulnar nerve (UN) and artery (UA) and the carpal tunnel contents; the radial septum is between the radial artery (RA) and the flexor carpi radialis (FCR). MN, median nerve; PCBMN, palmar cutaneous branch of median nerve; PL, palmar longus muscle.

This approach improves visualization of the distal radioulnar joint (DRUJ), radial VUC, and radial styloid process, while avoiding undue stress on the median nerve and its branches from excessive retraction. Complex double-column fractures of the distal radius can be effectively approached and fixed with a single-incision, double-window approach. This is an effective technique if the initial Henry approach has been performed and a small metacarpophalnar fragment is encountered that cannot be effectively stabilized by the radial approach alone.

Surgical methods

With the patient supine, the tourniquet is attached to the upper arm. The initial approach is the volar flexor carpi radialis (FCR) approach, utilizing an incision centered on the FCR tendon. The distal portion of the standard Henry's approach is extended through a zigzag incision through the wrist crease to the base of the thenar eminence to expose and gain access to both columns and avoid excessive tension on the median nerve. The FCR tendon sheath was incised on the radial side of the FCR, and the tendon was folded on the ulnar side. The flexor pollicis longus tendon and muscle belly are retracted ulnar, and the pronator anterior (PQ) is reflected from the radial side of the distal radius and away from the fracture site. This provides exposure of the radial column.

To create the UCI, a subcutaneous anatomical extension is made between the skin and the superficial forearm fascia. The soft tissue flap is above the palmar longus muscle (Figure 2). The forearm aponeurosis was preserved to protect the median nerve and palmar cutaneous branch. Continue the ulnar dissection until the flexor carpi ulnaris is reached. Next, the space between the carpal tunnel contents and the ulnar nerve vasculature is used for dissection to the deep radius. The flexor tendons and median nerve are moved radially, and the PQ is reflexed further ulnar through the window to expose the VUC and DRUJ.

Single incision, double window access to the radius. The subcutaneous dissection of the ulnar side of the wrist is shown.

Direct access to the VUC is now possible without excessive traction on the median nerve. This direct spacing is very helpful in reducing and immobilizing small and critical metacarpophalnar fragments. Use either window for temporary repositioning and fixation as needed (Figure 3A,B). VUC fractures can be reduced with Kirschner wires through UCI and then plates can be applied through RCI. Alternatively, a plate can be placed through the UCI followed by a distal ulnar screw. Complete exposure to the VUC allows the surgeon to easily place distal ulnar screws, which typically need to be placed in a proximal and slightly radial orientation.

A) The pronator muscle and radial axis are seen through the radial column septum. (B) The metacarpal-ulnar fragment of the distal radius is directly visible and fixed with two Kirschner wires.

Fracture reduction is verified by viewing the ulnar and radial column septa. UCI provides direct exposure to the volar DRUJ and ulnar head. Direct exposure (Figure 4) and final fluoroscopic images were used to verify reduction therapy and plate placement. The stability of the DRUJ was assessed by the shelling test prior to closure, followed by deflation of the tourniquet and hemostasis. Through direct exposure and fluoroscopic images, we ensured that the distal radius fragment was stable and that the carpal was not subluxed.

(A) The entire plate and radial styloid process are exposed through the radial column septum. (B) The ulnar portion of the plate and the distal radioulnar joint are directly visible through the ulnar column septum. The carpal tunnel contents are retracted radially.

case

A 59-year-old right-handed woman fell from a height with her hands in an outstretched position. Her career is a dressmaker and costume maker for theatrical performances. The initial treatment was closed reduction by the emergency physician. Subsequently, a post-reduction radiograph was taken and she was referred to our clinic for further evaluation. Radiographically unstable distal radius fracture (AO C1) involving volar ulna and radial styloid fragments

Anterior and posterior preoperative radiographs showed an unstable distal radius fracture involving the radial styloid process, volar-ulnar angle, and dorsal cortex.

Initially, a volar flexor carpi radialis approach, Kirschner wires and a volar plate were used for reduction and temporary fixation. However, complete exposure and fixation of the volar-ulnar fragment was not possible. At that time, a subcutaneous dissection was performed and the UCI was opened.

Under direct exposure and fluoroscopic guidance, the volar fragment of the ulna was identified and adequately reduced. Using the volar locking plate for fixation, the ulnar fragments were too small for stable fixation with screws alone, so two K-wires were placed from volar to dorsal and left in place. The Kirschner wire is pulled to the back and left over the skin on the back of the wrist. A radial styloid K-wire is left for additional fixation. All fragments were securely fixed and the carpal bones were well aligned. Sew the capsule to the plate and fix the PQ on the plate. The wound is sutured, then bandaged and placed in a volar splint.

Postoperative results

Postoperative radiographs are shown in Figure 6, and the postoperative course was smooth. The incision healed well, with adequate radial length and alignment. Complete union of the fracture was observed on imaging at 8 weeks postoperatively. Clinical examination revealed 65 degrees of wrist extension, 70 degrees of flexion, 80 degrees of pronation, and 85 degrees of supination (Figure 7). The patient's finger movements showed full compound flexion into the palm and full extension. Patients were able to return to work 2 months postoperatively without any problems or limitations.

Postoperative anterior and posterior X-rays. Fixation was performed using the volar locking plate, radial styloid pin, and two Kirschner wires in the volar ulnar fragment.

At postoperative follow-up, the range of motion of the upper extremity was measured. The patient has a good range of motion in pronation (A), supination (B), extension (C) and flexion (D).