Introduction

Distal radial physeal fractures represent approximately 20% of all growth plate fractures in children, second in frequency only to those of the phalanges [1]. Fractures with less than 15° of angulation and up to 1 cm of shortening will demonstrate complete remodeling without functional impairment in skeletally immature patients [2].

Most of the cases are the result of a fall on a hyperextended wrist, resulting in displacement of the fracture dorsally. A rare type of injury in which the fracture displaces vollarly (Fig. 1) occurs in less than 5% of distal radius physeal fractures [3, 4]. Tredwell et al. described only six cases of 72 (8%) distal radius physeal fractures [5], while Cannata et al. described only five cases of 157 (3%) distal radius physeal fractures [6].

Fig. 1
figure 1

Preoperative radiographs of a distal radius fracture

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The fracture can be treated operatively by several methods. Seriat-Gautier and Jouve used a plate without inserting the distal screws [7]. Hoël and Kapandji described a percutaneous technique using two anterior skin incisions, 5 mm medial to the radial artery and lateral to the ulnar artery, to pass Kirschner wires into the fracture site before reducing the fracture (Fig. 2). The wires were then advanced into the posterior cortex at an angle of 45° [8]. Guichet et al. described a reversed Kapandji technique with the pins introduced through a posterior approach and locked at the anterior cortex at the fracture site after reduction (Fig. 3) [9].

Fig. 2
figure 2

Hoël and Kapandji described a percutaneous technique using two anterior skin incisions, 5 mm medial to the radial artery and lateral to the ulnar artery, to pass Kirschner wires into the fracture site

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Fig. 3
figure 3

Guichet et al. described reversed Kapandji technique with the pins introduced through a posterior approach and locked at the anterior cortex at the fracture site after reduction

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We describe a surgical technique termed “Volar Kapandji” that we previously described for intra-articular distal radius fractures in adults [10].

Patients and methods

Subjects

Three patients with distal radial physeal fractures with anterior displacement were treated with the “Volar Kapandji technique”. The follow-up evaluations, which were conducted for three months from the injury, included assessments of wrist motion, standard wrist radiographs and visual analog scores (VAS).

Surgical technique

Surgery was performed with the patient under general anesthetic. We inserted smooth K-wires [1.4/1.6 mm (0.054/0.062 in.) diameter] into the fracture site of the radius with fracture reduction according to the fracture pattern. The K-wires were well padded, and a below-elbow plaster cast was applied for 4 weeks following surgery. The K-wires were removed 4 weeks’ post-surgery. Active finger motion was encouraged early after surgery. Active and active-assisted motion of the wrist joint was started according to patient tolerance, following removal of the plaster cast.

Volar K-wire insertion technique

We used a technique similar to volar radial arthroscopic portal placement [11]. Under a fluoroscopic intensifier of the fracture site, the joint line and the flexor carpi radialis tendon (FCR) were marked on the skin (Fig. 4a). A 1 cm longitudinal incision was made over the FCR. The tendon sheath was divided (Fig. 4b) and the FCR tendon retracted ulnarly with a K-wire being introduced through a mosquito point into the fracture site, with the drill at oscillating mode to avoid any unnecessary damage (Fig. 4c–e). Additional K-wires were added from the radial styloid (Fig. 4f).

Fig. 4
figure 4

a Under fluoroscopic intensifier, the fracture site, joint line and flexor carpi radialis tendon are marked on the skin. b A 1 cm longitudinal incision was made over the FCR and the tendon sheath is divided. c The FCR tendon retracted ulnarly and a mosquito point into the fracture site. d K-wire being introduced into the fracture site with the drill at oscillating mode. e Inserting the K-wire into the fracture site, levering to restore anatomy and driving the wire into the distal cortex. f Additional K-wire added from the radial styloid

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Anatomy

The volar radial arthroscopic portal was studied in several articles, regarding its safety and proximity to the radial artery and the palmar cutaneous branch. Rees et al. performed arterial injection studies to investigate the vascular anatomy surrounding the volar radial portal, using a gelatin and lead oxide mixture or India ink in five fresh frozen cadaver arms. Measurements taken from the area surrounding the volar radial portal showed a “safe zone”, free of any neurovascular structures, that consisted of the width of the FCR tendon plus at least 3 mm or more in all directions [12]. The palmar cutaneous branch is closest in proximity but always lies to the ulnar side of the FCR [13, 14].

The portal for the entry of the K-wire is proximal to the volar radial arthroscopic portal which can be even safer regarding the palmar cutaneous branch.

Results

Three patients (Table 1) completed follow-up of three months. All patients had reduction and casting on the day of arrival and a loss of reduction in the next follow-up appointment. All patients had anatomic reduction at the last follow-up radiography (Fig. 5), and all patients had a full range of motion and VAS 0 at the last follow-up (Fig. 6). No complications were recorded.

Table 1 Demographic radiographic and clinical variables of patients
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Fig. 5
figure 5

One month postoperative radiographs of the distal radius fracture

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Fig. 6
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Three-month postoperative wrist ranges of motion of patient number 1 involving the right hand

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Discussion

Surgical treatment for the rare cases of volar displaced physeal distal radius fractures is described in very few articles so far. Plate fixation was described in seven patients [7]. When considering this technique, we should keep in mind the high complication rate of this procedure [15, 16] and the need for another operation to remove the pates.

Guichet et al. described a technique of inserting K-wires from the posterior approach to avoid neurovascular damage. They treated six patients with good results [9]. The disadvantage of the technique is the difficulty in buttressing the fracture from the dorsal approach.

Hoël and Kapandji described volar insertion of two pins and found it to be safe and effective [8]. The disadvantage of the technique is the risk to neurovascular structures with the use of two K-wires. We used only one volar K-wire. The major concern in this minimally invasive technique concerns safety while inserting a K-wire in the volar aspect of the wrist. The anatomy of this region can jeopardize the median nerve and its palmar cutaneous branch and the radial artery; however, several investigations addressing the volar radial arthroscopic portal found it to be safe [12–14].

Slutsky et al. [11, 17] described their results with the volar radial portal in cadavers and patients. They found a safe zone greater than 3 mm surrounding the portal that was free of any neurovascular structures, with no complications being recorded from the use of the portal in 30 patients. We also used the drill in an oscillating mode when inserting the K-wire to ensure no possibility of damaging a neurovascular structure.

The limitations of this study are the small group of patients and its retrospective nature. Nevertheless, this case study presents the minimally invasive option for treating rare cases of physeal distal radius fractures with volar displacement.