Does the Direction of Kirschner Wire Fixation in Pediatric Supracondylar Humerus Fractures Really Matter?

Supracondylar humerus fracture (SCHF) is the most common elbow fracture in children. For displaced fractures, percutaneous Kirschner wire (K-wire) fixation is the preferred treatment. Although standard wire placement is traditionally recommended, clinical constraints-such as soft tissue swelling, limited surgical access, and variable anatomy-may necessitate deviations from standard configurations. This study aimed to evaluate the clinical efficacy and safety of nonstandard K-wire placement in pediatric SCHF, providing evidence to support practical surgical decision-making.

A retrospective analysis was conducted on pediatric patients treated for supracondylar humerus fractures between January 2022 and December 2023. A total of 526 patients met the inclusion criteria. On the basis of the fixation method, patients were categorized into a lateral K-wire fixation group (including a standard placement subgroup with 164 cases and a nonstandard placement subgroup with 124 cases) and a crossed medial-lateral K-wire fixation group (including a standard placement subgroup with 134 cases and a nonstandard placement subgroup with 104 cases). Various clinical and radiographic parameters were compared, including baseline data, surgical time, intraoperative fluoroscopy times, pin separation ratio (PSR), pin crossing angle (PCA), radiographic alignment, and functional outcomes at follow-up.

Baseline characteristics were comparable across all 4 groups (P>0.05). Among Gartland type II patients, the nonstandard subgroup in the lateral fixation group showed shorter surgical time (36.10±14.48 vs. 43.90±11.71 min), fewer fluoroscopy exposures (8.46±2.60 vs. 10.58±2.71), and a larger PCA (8.00 to 14.00 vs. 3.00 to 5.00 degrees) compared with the standard group (P<0.05). Similar trends were observed in the medial-lateral fixation group, with shorter surgical time (27.52±11.41 vs. 34.80±14.05 min), fewer fluoroscopies (8.99±2.75 vs. 10.31±3.17), smaller PSR (0.39±0.16 vs. 0.48±0.17), and larger PCA (82.00-92.00 vs. 63.00-80.00 degrees) in the nonstandard subgroup (P<0.05). Within 24 hours and last follow-up postoperatively, all groups showed comparable reduction quality based on radiographic parameters. No significant differences were observed in Baumann angle, humeral anteversion angle, lateral condylar angle, fracture gap, or alignment with the anterior humeral line (P>0.05), except for a slightly larger Baumann angle in the nonstandard medial-lateral subgroup of Gartland type III patients (77.25±5.20 vs. 74.85±5.78 degrees, P<0.05). At a mean follow-up of 72.07±43.14 days, all fractures achieved bony union without complications. Radiographic alignment and Flynn elbow function scores were comparable between groups, with excellent-good rates ranging from 95.74% to 98.67%.

Nonstandard K-wire placement offers clinical outcomes equivalent to standard configurations in pediatric supracondylar humerus fractures. It significantly reduces surgical time and fluoroscopy exposure without compromising fracture stability or functional recovery. When anatomic or intraoperative constraints prevent ideal pin placement, a more flexible strategy is justified, provided that appropriate postoperative splinting and activity restriction are implemented.

Level III-retrospective cohort study.