Combining double antegrade intramedullary pinning with proximal interphalangeal joint transfixation in a bicondylar proximal phalangeal fracture

Unstable proximal phalangeal bicondylar fractures have been recognized as difficult to manage (Satake et al., 2020). Their aetiology is typically the consequence of high-energy axial loading at the fingertips and surgery is generally indicated to restore articular congruency. Restoration of movement is unpredictable in such cases due to their inherent instability. The difficulty of reduction and fixation may be daunting due to the small condylar fragments.

Meticulous surgical technique promotes anatomical reduction and stable fixation (Heifner and Rubio, 2023). Nevertheless, there is still no consensus on the most ideal modality for fixation of bicondylar proximal phalangeal fractures. Multiple techniques, including Kirschner (K)-wire fixation, lag screws (Shewring et al., 2015), plates (Heifner and Rubio, 2023), dynamic external fixation (Kamnerdnakta et al., 2018) and autograft reconstruction (Satake et al., 2020) have been reported for their common goal of initiating early mobility and restoring maximal painless range of motion (ROM).

Loss of flexion or extension are frequent with screw fixation, with mean loss of 19° and 21°, respectively (Shewring et al., 2015), while joint stiffness is generally seen after plate fixation (Heifner and Rubio, 2023). Joint stiffness and flexion contracture are the most common complications, which can be reduced by achieving concentric reduction and facilitating early active ROM exercises (Kamnerdnakta et al., 2018). An effective and minimally invasive technique utilizing double antegrade intramedullary pinning was proposed for our patient.

The surgical procedure was carried out with the patient in a supine position, under regional block, without tourniquet. Under fluoroscopy, the two 1.0 mm K-wires were inserted percutaneously from the radial and ulnar base of the proximal phalanx, respectively (Figure 1(a) and 1(b)). The first K-wire was inserted into the medullary canal until it reached but did not cross the fracture site. The second K-wire was inserted similarly from the opposite side of the proximal phalangeal base.

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Figure 1.

(a) The radiograph of a 38-year-old man with a comminuted bicondylar proximal phalangeal fracture of the left small finger. (b) Fracture fixation was achieved through the double antegrade intramedullary pinning technique with the proximal interphalangeal joint transfixed in extension. (c) Radiographs at 4 weeks postoperatively after K-wire retraction. (d) Good recovery of range of digital motion at 16 weeks postoperatively and (e) radiographs at 24 weeks postoperatively, showing fracture union.

To reduce the volar or dorsal displacement of fragments, traction was applied and palmar or dorsal pressure was exerted on the proximal phalangeal head before advancing the K-wires through the fracture site and into the proximal interphalangeal joint (PIPJ). Rotational malreduction should be avoided. Once reduction was achieved, the K-wires were driven forward through the PIPJ and into the medullary canal of the middle phalanx, transfixing the PIPJ in extension (Figure 1(b)).

After 4 weeks, partial union was visible and the tips of the K-wires were withdrawn precisely to the subchondral space of the proximal phalanx under fluoroscopy (Figure 1(c)). Manipulation of the PIPJ was carried out achieving 90° of flexion and active mobilization of PIPJ was started. The two K-wires were removed 6 weeks postoperatively and a good recovery of ROM achieved (Figure 1(d)). Union was demonstrated at 24 weeks postoperatively (Figure 1(e)). No complications such as infection, nonunion or pin migration were reported.

Transfixing the PIPJ in extension for 4 weeks may result in complications, such as pin tract infection (Satake et al., 2020), postoperative joint stiffness, loss of reduction, pin loosening and migration (Kamnerdnakta et al., 2018). Withdrawing the K-wires proximally to the subchondral space of the proximal phalanx allowed early motion exercises, promoting remodelling of the damaged articular surface (Kamnerdnakta et al., 2018).

Insertion of the K-wires from the bilateral edges of the proximal phalangeal base not only avoids tethering the soft tissues around the affected joint but also leaves the metacarpophalangeal (MCP) joint free, allowing early, active MCP joint motion. This technique using double antegrade intramedullary pinning with temporary PIPJ transfixation for bicondylar proximal phalangeal fractures not only provides a minimally invasive and effective approach but also exhibits satisfactory anatomical reduction and functional recovery.