Localizing retrograde K-wire insertion points in distal phalanges using the nail plate: a clinical controlled study.

Objective: Distal phalangeal fractures are the most common hand injuries, and K-wire fixation is the most frequently used surgical treatment. This study aims to utilize the nail plate shadow on preoperative X-ray images to locate the insertion point for retrograde(from the distal to the proximal direction of the distal phalanx) K-wire fixation of distal phalanges, thereby improving the accuracy of K-wire placement.

Methods: A case-control study was conducted on 60 patients with distal phalangeal fractures from November 2020 to May 2024. Patients in Group A underwent retrograde longitudinal implantation of a single K-wire based on the surgeon's experience. In Group B, preoperative standard anteroposterior and lateral X-rays were used to outline the nail plate shadow, the central axis between the middle and distal phalanges, and measure the distance between the central axis and the nail plate shadow. Intraoperatively, the measured values were used to mark the skin insertion point, through which a single K-wire was inserted retrogradely. The distal interphalangeal (DIP) joint range of motion (ROM), DASH score, VAS score, operation time, intraoperative times of fluoroscopy, and postoperative complications were compared between the two groups.

Results: All cases achieved healing without clinical deformity, and all fractures showed radiological union. In Group A, 2 cases developed superficial infections; in Group B, 1 case had a superficial infection. All 3 infected cases healed after debridement, dressing changes, and oral antibiotic therapy. There were no significant differences in demographic characteristics between the two groups. No statistically significant differences were observed in DASH scores or DIP ROM (P > 0.05). However, significant differences were found in VAS scores, operation time, and times of fluoroscopy (P < 0.05), with Group B performing better than Group A.

Conclusion: Compared with empirically placed retrograde K-wires, using the nail plate shadow on preoperative X-rays to locate the insertion point for distal phalangeal retrograde K-wire fixation improves the accuracy of K-wire placement, avoids repeated insertion, shortens operation time, and reduces radiation exposure for both surgeons and patients.