Modified Medial Para-Olecranon Pinning Versus Conventional Crossed Pinning for Displaced Pediatric Supracondylar Humerus Fractures: A Retrospective Comparative Cohort Study

Background/Objectives: Closed reduction and percutaneous pinning is the standard surgical treatment for displaced pediatric supracondylar humerus fractures. Although crossed-pin fixation provides excellent biomechanical stability, medial pin insertion remains associated with the risk of iatrogenic ulnar nerve injury. The modified medial para-olecranon technique has been introduced as an alternative medial wire insertion strategy while preserving the principles of crossed-pin fixation. This study compared its clinical performance with conventional crossed pinning. Methods: A retrospective comparative cohort study was conducted at a tertiary referral trauma center between January 2017 and December 2024. Seventy children younger than 14 years with Gartland type II–IV supracondylar humerus fractures met the inclusion criteria. All patients treated with the modified medial para-olecranon technique (n = 35) were included. A comparison cohort of 35 patients treated with conventional crossed pinning was selected from 68 eligible conventionally treated patients by computer-generated random sampling stratified by Gartland type (frequency matching), after application of identical eligibility criteria. The primary outcome was functional outcome assessed using the Flynn criteria. Secondary outcomes included operative time, radiographic alignment, fracture union, and postoperative complications. Results: Baseline demographic and fracture characteristics were comparable between groups. Mean age was 6.7 ± 2.8 years in the modified medial para-olecranon group and 6.9 ± 2.6 years in the conventional crossed-pin group. The modified medial para-olecranon group had a lower mean Flynn score (6.80 ± 3.31 vs. 10.74 ± 3.70; mean difference, −3.94; 95% CI, −5.61 to −2.27; p < 0.001) and a higher proportion of excellent Flynn outcomes (77.1% vs. 28.6%). Operative time was shorter in the modified medial para-olecranon group (47.49 ± 7.50 vs. 66.00 ± 8.19 min; mean difference, −18.51 min; 95% CI, −22.26 to −14.76; p < 0.001). Fracture union occurred at a comparable time in both groups (27.71 ± 3.94 vs. 28.34 ± 4.12 days; mean difference, −0.63 days; 95% CI, −2.55 to 1.29), and postoperative Baumann angles were similar. No postoperative iatrogenic ulnar nerve injuries occurred in the modified medial para-olecranon group, whereas two occurred in the conventional crossed-pin group; both were transient sensory paraesthesia that resolved without exploration within six months. Overall complications occurred in 1 patient (2.9%) and 7 patients (20.0%), respectively (odds ratio, 0.17; 95% CI, 0.03 to 1.02; Fisher exact p = 0.055). Conclusions: In this retrospective comparative cohort, the modified medial para-olecranon technique was associated with favorable functional outcomes, shorter operative time, and fewer observed postoperative ulnar nerve injuries, although the difference in complications did not reach statistical significance, while maintaining comparable radiographic alignment and fracture healing. Because treatment was not randomized and potential confounders could not be adjusted for, these between-group differences should be interpreted as associations rather than as evidence of a causal treatment effect. Further prospective multicenter studies and dedicated anatomical investigations are required before broader recommendations can be made.